text: Nise in a magnetic field. Java Project Tutorial - Make Login and Register Form Step by Step Using NetBeans And MySQL Database - Duration: 3:43:32. The solenoid force and back emf characteristics are defined by the FEM-Parameterized Linear Actuator block. We use a Kalman filter to do this. The electrical equations and the expression for mechanical force on the coil are realized via an Embedded Matlab block (shown below), but the mechanical system is realized using regular Simulink blocks. are not explicitly shown. A voice coil (consisting of a former, collar, and winding) is the coil of wire attached to the apex of a loudspeaker cone. In any electric motor, operation is based on simple electromagnetism. Capacitance. The bacl emf, e is proportional to angular velocity of the shaft by a constant factor Ke. Magnetic Field in Two-Pole Electric Motor. This example shows how to use blocks from the Simulink Support Package for Android Devices to create a Simulink® model and run it on an Android device. By means of a 3-axis Hall Probe, it generates a 3D map of the magnetic field, measures the dipole moment, counts number of poles, calculates pole width and pole distribution for multipole magnets and rotors, measures magnetic angle, angle. when the magnetic field is reduced the magnetization starts to randomize and also tends to go to zero but do not go to zero exactly for which probability is also used. The data of 2D magnetic field distribution and magnetic field density distribution along the air gap are analyzed and the evaluation is presented. It has the same unit as the magnetic field intensity, amperes per meter. However, since the forces arise from the interaction between magneto-static fields these bearings have a destabilizing stiffness contribution in at least one degree of freedom. This example shows how to use stream lines, slice planes, and contour lines in one graph. The high frequency signal is. The International Geomagnetic Reference Field 12 block calculates the Earth magnetic field and secular variation using the 12th generation International Geomagnetic Reference Field. The magnetic field produced by an inductive coil. The magnetization M is the magnetic moment per unit volume at a given point in a medium. See the complete profile on LinkedIn and discover Mingzhou’s connections and jobs at similar companies. On the other hand, Psiaki. Solve second-order PDEs that model static electrical and magnetic fields, harmonic electrical fields in conductors, and direct current electrical conduction. This example shows how to use blocks from the Simulink Support Package for Android Devices to create a Simulink® model and run it on an Android device. $\begingroup$ Thank you very much. A reluctance force is produced which drives the plunger to close the air gap, initially 5mm in length. The block outputs acceleration, angular rate, and strength of the magnetic field along the axes of the sensor in Random and DMP mode. Field-Oriented Control of Permanent Magnet Synchronous Machine - Example Xilinx Zynq Intelligent Drives Support from Simulink - Hardware Support Motor Drives Migrate to Zynq SoC with Help from MATLAB - Article Prototyping SoC-based Motor Controllers with MATLAB and Simulink (19:41) - Video. DC Motor Speed: Simulink Modeling. The LIS3MDL has user-selectable full scales of ±4/ 8/ 12/ 16 gauss. The direction and magnitude of magnetic and electric field can be changed along with other attributes of motion. Magnetic fields can be very precisely measured by measuring the cyclotron frequency of protons. Using this model, a nonlinear control law based on dif-ferential geometry is firstly synthesized. platforms including xPC Target Box and Motorola ColdFire microcontroller using Simulink and real-time workshop. The inductor that creates the magnetic field is called the primary coil, and the inductor that picks up the magnetic field is called the secondary coil. As a non-profit organization, it is dedicated to the promotion of science in the field of "medical physics" including medical technology and sees itself here in particular as a focal point to initiate the research, development and application of physical and technical methods in medicine and related fields shape. Okay in class we performed a lab consisting of a Helmholtz pair and we need (to compare to experimental values) to model the magnetic field through a computer simulation. It helps in attracting the space debris and junk towards it. Magnetic field. Field-Oriented Control of Permanent Magnet Synchronous Machine - Example Xilinx Zynq Intelligent Drives Support from Simulink - Hardware Support Motor Drives Migrate to Zynq SoC with Help from MATLAB - Article Prototyping SoC-based Motor Controllers with MATLAB and Simulink (19:41) - Video. Okan University. After the implementation of machine model, a sensorless control of induction motor using Direct Synthesis from State Equations have been carried out by using Matlab /Simulink for the evaluation of dynamic performance of induction motor. This is modeled by the Power amplifier and coil block in the Simulink® model. example fieldsCustom( fields , points , scalefield ) scales the field arrows by a scalar value, scalefield. ELMER (Elmer finite element software) 3. [L-MU-93] JMAG/Adams/Simulink Coupled Vehicle Drive Simulation. Air gap flux plot due to three-phase excitation 5. Effect of Magnetic Field on I-V Characteristics. A reduced model has been built and tested. a magnetic field, about 10mm above the guideway. Nise in a magnetic field. The differences between Voltages connected to the three stator windings terminals cause current flow which forms rotating magnetic field. Magnetic Torque Modeling 4/28/2010 CubeSat Summer Workshop 18. Quanser is joining engineering education experts from universities, research institutes, industry, governmental and non-governmental organizations at the IX World Engineering Educ. The International Geomagnetic Reference Field 12 block calculates the Earth magnetic field and secular variation using the 12th generation International Geomagnetic Reference Field. The magnetic moment of a single-domain nanoparticle can be effectively switched on an ultrashort time scale by means of oscillating (microwave) magnetic fields. The block has one output port, Magnet. I am completely new to simulink and don't know where to start. Considering the very costly price ranges of such hardware, this project's original objective was to implement multiple controllers for the magnetic suspension system using a low-cost Field Programmable Gate Array board. ppt), PDF File (. ObhájenoThe purpose of this thesis is to control the motion of the permanent magnet using the currents in four coils placed in plain. This MATLAB function returns one sample of the magnetic field data on x, y, and z axes read from the sensor in units of µT (microtesla). For these properties of the Magnetic levitation system, modeling and mainly control design is very difficult. HeliMag3 is a magnetic based robotic system with applications towards targeted therapy and clearing of clogged blood vessels. However, Magnetic levitation system has wide application in various industries than high-speed trains, frictionless bearing, etc and therefore this field of research is devoted significant effort in recent years. Simulation of a Permanent Magnet Synchronous Motor using Matlab-Simulink Aishwarya Apte l, Rahee Walambe 2, Vrunda Joshi 3, Kirti Rathod 4 and Jaywant Kolhe 5 Abstract-In the recent past, use of permanent magnet synchronous motors (PMSMs) has increased considerably ow ing to their inherent advantages. Magnetic Field Strength designated by H at any point is defined as the force experienced by a u it north pole when placed at that point. Ducharne, J. The International Geomagnetic Reference Field 12 block calculates the Earth magnetic field and secular variation using the 12th generation International Geomagnetic Reference Field. According to Lorentz’s law, the electric force of moving charges equals the magnetic Lorentz force exerted on the particles in question: (2) The induced electric field is therefore perpendicular to both the velocity and the magnetic field strength. It is used to determine individual resistance values for the field and armature windings so that the thermal heat generated by the two resistors can be apportioned correctly. MATLAB/Simulink for position control of the motor, and verify its operation. In this paper a coupled simulation program of a modular hybrid linear stepper motor is presented. The input to the inductor is a voltage signal and the output a current. The nature of magnetism. The magnetic field of this satellite can be varied with accordance to the requirement. Masson, and G. In induction motors the 'environmental' field is supplied by one or more. ∗ Sidney Osses Nunes∗ ∗ Systems and Energy Control Department - Computer and Electrical Engineering School - Campinas University,. Scope Block with Android Devices. Electromagnetic Field matlab code and research calculate the electric or magnetic field level in the vicinity of a transmission or distribution line. The path of this magnetic field line has been calculated by means of Biot-Savart, and is only affected by the current through the solenoid and the frame. An axially symmetric electric or magnetic field can be used to focus a beam of electrons much as a light lens focuses visible rays. Since ∇ ⋅ B = 0, there exists a magnetic vector potential A such that B = ∇ × A and ∇ × (1 μ ∇ × A) = J. The geometry consists of three regions:. Abstract—In this study, modeling and simulation of a speed sensored field-oriented control (FOC) of a. However, since the forces arise from the interaction between magneto-static fields these bearings have a destabilizing stiffness contribution in at least one degree of freedom. Field Oriented Control of Permanent Magnet Synchronous Motors User's Guide Revision 0 9 Figure 1-3 shows the transformations done for decoupling the stator currents into the torque producing (Iq) and flux producing (Id) components. methods for the speed control of the motor. Skilled in GT-Power, Simscape/Simulink, AMESim, Autodesk CFD, Ansys Fluent, AVL FIRE, Powertrain, Aerodynamics, Fluid Mechanics, Thermodynamics, Acoustics, and Internal Combustion Engines. Simulation of a Permanent Magnet Synchronous Motor using Matlab-Simulink Aishwarya Apte l, Rahee Walambe 2, Vrunda Joshi 3, Kirti Rathod 4 and Jaywant Kolhe 5 Abstract-In the recent past, use of permanent magnet synchronous motors (PMSMs) has increased considerably ow ing to their inherent advantages. (DGMP) was founded in 1969 in Stuttgart. Electromagnetic Field matlab code and research calculate the electric or magnetic field level in the vicinity of a transmission or distribution line. See the complete profile on LinkedIn and discover Ashutosh’s connections and jobs at similar companies. Jan Stouthuysen’s Activity. Simulink are the tools used in order to find the responses of plant. Equations and boundary conditions for these applications must be specified in a particular divergence form required by the toolbox. MATLAB/SIMULINK is used to simulate the power pad of transmitter and receiver with proper calculation of inductance in each pad and mutual inductance between pads. McIlwain) is a parameter describing a particular set of planetary magnetic field lines. MATLAB/Simulink for position control of the motor, and verify its operation. The Magnetometer block reads the strength of the magnetic field from the built-in magnetometer sensor on your Android device. The magnetic field intensity at the exit middle channel cross-section ranges in Brmax=30,35,40,45,50. • Performed electromagnetic simulation of large hydro-generators using ANSYS Electromagnetics (Maxwell) and MATLAB Simulink, ANSYS mechanical and Workbench • Developed new concepts in R&D. SYNCHRONOUS MACHINE FIELD CURRENT CALCULATION TAKING INTO ACCOUNT THE MAGNETIC SATURATION Ernesto Ruppert Filho∗ ruppert@fee. The correct SIMULINK implementation of the magnetic control algorithm will be verified with an ACS air bearing SIMULINK model and a hardware-embedded ACS control algorithm SIMULINK model that controls the test platform on a spherical air bearing table. The example is based on a Field-Oriented Controller (FOC) for a Permanent Magnet Synchronous Machine (PMSM), but you can apply these techniques to the development of most controller algorithms. When the field flux is decreased, the armature will be rotate faster, due to reduced magnetic field interaction. The International Geomagnetic Reference Field 12 block calculates the Earth magnetic field and secular variation using the 12th generation International Geomagnetic Reference Field. pdf), Text File (. From that, the torque is simply $\boldsymbol{\mu}\times \boldsymbol{B}$ for my Simulink simulation (I already have the World Magnetic Map in Simulink which gives me the local magnetic field vector for any point in the orbit). Inside the shell, a coil is connected to DC voltage source. Swing equation simulink model for analysis of swing equation. txt) or read online for free. A reduced model has been built and tested. The 6-wind-turbine farm is simulated by a single Fig. Electric and Magnetic Field Simulation EMS is an electric and magnetic field simulation software. Measure the linear acceleration, angular rate, and magnetic field using the 9-DoF IMU (Inertial Measurement Unit) sensor on board Raspberry Pi™ SenseHAT. A metal ring at the ends resulting in a short circuit connects the wires along the rotor axis. The MPU9250 block reads data from the MPU-9250 sensor that is connected to the hardware. approximate circular rotary magnetic field is obtained. E-mail: baris. In Eddy current braking system, a conducting disc is rotated in the air gap of the magnetic field produced by a permanent magnet or an electromagnet. The experiment itself is performed with a metal ball floating in the magnetic field. If you place the device face-up on a table, the positive X-axis extends out of the right side of the device, positive Y-axis extends out of the top side, and the positive Z-axis extends out of the front face of. Dielectric constant. The vibration / noise caused by large power transformers were greatly reduced with the adoption of the step lap structure with regards to the iron core. Here, B = μ H, where B is the magnetic flux density, H is the magnetic field intensity, J is the current density, and µ is the material's magnetic permeability. Assuming that the motor is long and end effects are negligible, you can use a 2-D model. The debris is docked to this satellite. • Explain the differences and similarities between magnetic fields and electric fields. The WMM2015 block calculates the Earth's magnetic field vector, horizontal intensity, declination, inclination, and total intensity at a specified location and time. The reference frame is north-east-down. Preprints is a multidisciplinary preprint platform that accepts articles from all fields of science and technology, given that the preprint is scientifically sound and can be considered part of academic literature. magnetic field, the Earth's atmosphere, the motion of Moon and Sun and the interplanetary environment Equations of motion, focusing on both translational and rotational motion, and the numerical aspects due to the integration of the differential equations Perturbations, of gravitational origin, due to third-bodies (Sun. Using the parameters of this block, you can select the Output Data Rates (ODR) for the magnetometer. Masson, Houston University). This can be achieved by either exerting a time varying magnetic field over a static conductor or a static magnetic field over a moving conductor. The RMF that is generated through the stator windings produces a magnetic field that rotates throughout the air gap. Naveen Kumar hat Informationen zur Ausbildung im Profil angegeben. It is equally true for the computation of magnetic field distribution of electromagnet. ROTATING MAGNETIC FIELDS. The Earth's magnetic field model in this simulator is used as a model of magnetometer in the satellite, this value of the magnetic field is used as reference to consider how much current must be flowing through the coil to gain a torque (result of the interaction between Earth's magnetic field and. 5 magnetic shape memory alloy. The Mag field port outputs the strength of the magnetic field along the x-, y-, and z-axes of the sensor as a 3-by-1 vector. It provides an easier path for the calculation of field in the electric motor. The blocks of the simulation programs were implemented in several different simulation platforms (SIMULINK, SIMPLORER and MagNet); each one of them widely used in its field. %magnetometer noise gain without motor magnetic field. The magnetic levitation system is available as a kit or fully assembled unit. of energizing coil, the electric energy will be transferred to magnetic field energy. a time varying magnetic field over a static conductor or a static magnetic field over a moving conductor. Also, the substantial fluctuations of the geomagnetic field, which occur constantly during magnetic storms and almost constantly in the disturbance field (auroral zones), are not included. Magnetic Levitation System in Control Engineering Education 155 The steps necessary to obtain the executable file from a controller model are shown in Fig. Power angle or torque angle are the angle between the two. Keywords: Magnetic levitation, mathematical modeling, Sigmoidal function (Nonlinear), Controller Design 1. A 4x4 array of coils with iron cores, each with a controllable current, creates a magnetic field. When a stator winding is energized, producing a single magnetic field, reluctance torque. This switching technique can be. My UDP block sends data to localhost over remote port 25000 and local. The relative position of the resultant magnetic field axis and rotor axis is fixed under normal conditions. Petersburg Polytechnic University. Magnetic Levitation Controller Tuning. A New Modeling of the Non-Linear Inductances in MATLAB 307 An integrator to derive the flux from the voltage. ACCURATE MODELLING AND POSITIONING OF A MAGNETICALLY-CONTROLLED CATHETER TIP. See the complete profile on LinkedIn and discover Rohit’s connections and jobs at similar companies. The magnetic field is established by using a magnet. Ψ 90 Ψ 180 ψ A ψ B ψ C A B C 90 180 C A B. Lectured courses-Electrical machines - Laboratory and Calculation exercises (in Czech)-Electrical machines - Lectures for Erasmus students (in English) Teaching, research and publications activities in field of electrical machines. Biomedical Signal & Medical Image Processing. the synchronous speed is related to the electrical speed by: 2 ωsm = ωe P If the rotor is rotating at an angular speed ωrm the slip speed is. Magnetic Field in Two-Pole Electric Motor: PDE Modeler App. Proceedings of SPIE - The International Society for Optical Engineering. The objectives of this project are to model and control a. Proposed system This is well explained by Figures 6 and 7. pdf), Text File (. Stator and rotor currents necessary for the magnetic field model are obtained from the simulation model using MATLAB-Simulink. The magnetic coupling is expressed in terms of an inductance matrix which is a function of position θ. “The magnetic field we need for NMR must usually be as strong as possible, but even more importantly, it must be as. The multi-pole series expansion and magnetic field simulation are performed by a MATLABTM based. magnetic field density in the rotor, the proper magnetic material is chosen to make the rotor. This will helps us to build a magnetic salient tracking observer to estimate the rotor position and to eliminate the need for having a position sensor mounted on the motor shaft. A current-carrying conductor generates a magnetic field; when this is then placed in an external magnetic field, it will experience a force proportional to the current in the conductor, and to the strength of the external magnetic field. when the magnetic field is reduced the magnetization starts to randomize and also tends to go to zero but do not go to zero exactly for which probability is also used. Simulink power electronics models for better accu-racy and higher simulation efficiency. The YETI-2019 Conference gave an opportunity to young. • Describe the pattern of magnetic fields near various sources, such as permanent "bar" magnets, straight current-carrying wires, and coils of wire. txt) or read online for free. Biomedical Signal & Medical Image Processing. By controlling currents. MagNet 2D/3D is a powerful simulation software which engineers and scientists worldwide use for the design of motors, sensors, transformers, actuators, solenoids or any component with permanent magnets or coils. Scope Block with Android Devices. has enough acquisitive power, they might prefer to avoid dealing with Octave drawbacks. Use Simulink® Design Optimization™ to track a reference signal and optimize the response with uncertainties in the plant model. Magnetic Field in Two-Pole Electric Motor: PDE Modeler App. The magnetic field of this satellite can be varied with accordance to the requirement. / Electromotive force generation using the dynamic response of Ni 50 Mn 28. In Eddy current braking system, a conducting disc is rotated in the air gap of the magnetic field produced by a permanent magnet or an electromagnet. Simulink simulation of the CUGravity CubeSat System. The electromagnetic force will move plunger in a positive direction of coordinate (x) and decrease the reluctance of the magnetic circuit (increase inductance). Solve second-order PDEs that model static electrical and magnetic fields, harmonic electrical fields in conductors, and direct current electrical conduction. The blocks of the simulation programs were implemented in several different simulation platforms (SIMULINK, SIMPLORER and MagNet); each one of them widely used in its field. Find the static magnetic field induced by the stator windings in a two-pole electric motor. If you could correct me or give me suggestions, that would be great. See the complete profile on LinkedIn and discover Simon’s connections and jobs at similar companies. Scope Block with Android Devices. reaction magnetic field is zero and therefore: (5) The previously presented leads to the conclusion that the internal angle of the machine can be determined by measuring the phase difference between idling voltage U0 and load operating voltage U. This article provides a baseline of information. pptx), PDF File (. In this example you will review common tasks to design a control algorithm and implement it on a Zynq processor. A high-fidelity simulation model developed in Simulink that compatible with different types of multicopters. The main difference is the alternator spins the field coil, the brushes don't need to carry so much current and slip rings instead of segments for almost no electrical noise - later designs had the field coil stationary as well, coaxial pole pieces coupled the flux to the rotor. The combined representation of the quantities in the entire reference frames is shown in Figure 1-4. 6 Jobs sind im Profil von Hapa Hassan, MSc aufgelistet. How can I use hall effect sensors in MATLAB Simulink? Current flow in each winding produces a magnetic field vector, which sums with the fields from the other windings. I would like to send the Simulink values to the Analog discovery to alter the voltage output of the Analog Discovery accordingly so that the current in the coil setup can vary in real time, thus spoofing the magnetic field for the magnetometer. For these properties of the Magnetic levitation system, modeling and mainly control design is very difficult. Using the parameters of this block, you can select the Output Data Rates (ODR) for the magnetometer. INTRODUCTION The conception of magnetic forces is the basis of all magnetic levitation. Electric Arc model for High Voltage Circuit Breakers Based on MATLAB/SIMULINK 1N. It helps in attracting the space debris and junk towards it. by a DC motor is proportional to the armature current and the strength of the magnetic field. A high-fidelity simulation model developed in Simulink that compatible with different types of multicopters. In induction motors the 'environmental' field is supplied by one or more. The blockset includes validated environment models for atmosphere, gravity, wind, geoid height, and magnetic field to represent flight conditions and increase simulation fidelity. This article presents the process of designing a robot with a magnetic pressure pad for inspections of ferromagnetic ventilation ducts. The Magnetometer block reads the sensor_mag uORB topic and outputs the magnetic field of the PX4 Autopilot board along the x, y and z axis. Abdulkadir Department of Energy Conversion, Faculty of Electrical Engineering, Universiti Teknologi Malaysia (UTM). I am completely new to simulink and don't know where to start. The first stage involved mathematical modeling of the system while the second stage centered on the simulation of an armature controlled direct current motor using Simulink environment in MATLAB. Experienced Project Engineer with a demonstrated history of working in the mechanical or industrial engineering industry. Fleming's left-hand rule gives the direction of force. View Avdit Kohli’s profile on LinkedIn, the world's largest professional community. The idea is to control the motion and position of the ball by dynamically shaping the magnetic field over the surface which will result in controlled motion of the ball. In compliance with the assumption. Experience. Quanser is joining engineering education experts from universities, research institutes, industry, governmental and non-governmental organizations at the IX World Engineering Educ. A Lookup Table function, which contains a big number of N points (N=100 points) relating to flux and currents deduced from the code previously quoted. DC Motor Speed: Simulink Modeling. It generates a magnetic dipole field with both a variable dipole-moment magnitude and orientation with no moving parts. Mahajan, 2 K. Lubna Moin Dr. The Magnetometer block reads the strength of the magnetic field from the built-in magnetometer sensor on your Android device. Our results show that by this combination, the magnitude as well as the sign of the force on a magnetic particle can be controlled. the rotor is generally different from the speed of the revolving magnetic field. The magnetic. MATLAB/SIMULINK S. 1 Fields of application S imulation is very versatile and suitable for applications in the field of engineering, physics, astrophysics, chemistry, biology, economics, social science, training, education, video games, and more. Masson, Houston University). Whenever the conductor of length l is made to move in the magnetic field of flux density B with the velocity v, then e. The direction and magnitude of magnetic and electric field can be changed along with other attributes of motion. This MATLAB function calculates the Earth magnetic field at a specific location and time using World Magnetic Model (WMM) model WMM2015v2, which is valid from January 1, 2015 to December 31, 2019. This is modeled by the Power amplifier and coil block in the Simulink® model. The vibration / noise caused by large power transformers were greatly reduced with the adoption of the step lap structure with regards to the iron core. The direction and magnitude of the magnetic field produced by the coil can be changed with the direction and magnitude of the current flowing through it. 2 FUTURE SCOPE This project has demonstrated the starting of Synchronous Motor in MATLAB /SIMULINK, both in basic and extended mode. In this work, the position control of permanent magnetic and electromagnetic / hybrid magnetic actuators are studied. txt) or read online for free. The geometry consists of three regions:. Accounts for tether dynamics, Earth's magnetic field environment, three body-3D rigid body dynamics, simulated on board sensors, ground commands, ACS state machine, ACS estimator, ACS controller, 3D animation - CUGravity/ACS-Full-System-Simulation. Magnetic Levitation System in Control Engineering Education 155 The steps necessary to obtain the executable file from a controller model are shown in Fig. The Newton’s law and Kirchhoff’s law was applied to motor system to generate the. Even the magnetic fields due to onboard electronics leads to residual magnetic fields which adds as bias in the measured magnetic field data. Coupled Magnetic Field and Vibration Analysis for Power Transformer 1. Transformers are designed to have the greatest mutual inductance possible by winding both coils on the same core. But would like to know if it is ok, and how can I make it better with bigger dimension. Thus, when the density of magnetic field flow on the device increases or decreases the metal ball can be moved up and down. This MATLAB function calculates the Earth magnetic field at a specific location and time using World Magnetic Model (WMM) model WMM2015v2, which is valid from January 1, 2015 to December 31, 2019. Skills: Electrical Engineering , Engineering , Mathematics , Matlab and Mathematica , Mechanical Engineering. MATLAB/SIMULINK S. The trajectory is calculated by computationally solving differential equations. Simulink are the tools used in order to find the responses of plant. The first is the principle of electromagnetic induction discovered by the British scientist Michael Faraday in 1831. The characteristic analysis investigates the function of voltage as well as current over all magnetic field parameters of harmonics. Guarda il profilo completo su LinkedIn e scopri i collegamenti di Ruggero e le offerte di lavoro presso aziende simili. Modern theories of magnetism maintain that a magnetic field is produced by an electric charge in motion, and thus it is theorized that the magnetic field of a so-called "permanent" magnets such as lodestone is the result of electrons within the atoms of iron spinning uniformly in the same direction. The model also does not include the time lag due to energy storage in the rotor inertia. This example shows how to plot real-time data on an Android device by using the Simulink® Scope block with Simulink Support Package for Android Devices. The International Youth Conference on Electronics, Telecommunications and Information Technologies (YETI-2019) was held in Saint Petersburg on July 11 – 22, 2019. Vali Uddin Abstract:This paper investigates the issue of real time simulations using MATLAB as a tool. I have trying to plot magnetic field potential, and been partially successful for a point source, I believe. ozturk@okan. See the complete profile on LinkedIn and discover Ashutosh’s connections and jobs at similar companies. Objective Europa – A fluxgate magnetometer and an EMIS algorithm to study Europa’s subsurface – Elias Solorzano to simulate the VIP4 magnetic field data at any given location in space with respect to Jupiter’s reference frame. Colloquially, L-value often describes the set of magnetic field lines which cross the Earth's magnetic equator at a number of Earth-radii equal to the L-value. The magnetic field produced by an inductive coil. Jan Stouthuysen’s Activity. Simulink power electronics models for better accu-racy and higher simulation efficiency. Some of them recommend s-functions for accessing the model variable but they are not use the full power of simulink. Low Frequency Electromagnetic Field Simulation. When compared to induction motors, a PMSM is powerful for its size. The solenoid force and back emf characteristics are defined by the FEM-Parameterized Linear Actuator block. (1) E is the electric field, B is the magnetic flux density, H is the magnetic field, J is the current density, ϟ v is the volume charge density and D is the electric flux density. The Magnet port outputs the magnetic field as a [1x3] vector in uT. We use Simulink to calculate the orbit, rotation, magnetic field values, and sun and earth vectors. I know what I'm trying to do can be achieved since I've done it manually, but I need to achieve this programatically to create large models. View Rohit Babbar’s profile on LinkedIn, the world's largest professional community. Comparison of magnitude of magnetic field among equation 6 and equation 8 along z axis only. The bacl emf, e is proportional to angular velocity of the shaft by a constant factor Ke. The first is the principle of electromagnetic induction discovered by the British scientist Michael Faraday in 1831. pdf), Text File (. (d) Coil voltage vs time. Swing equation simulink model. The electromagnetic force will move plunger in a positive direction of coordinate (x) and decrease the reluctance of the magnetic circuit (increase inductance). Rohit has 5 jobs listed on their profile. I am completely new to simulink and don't know where to start. It is important to notice that in electromagnetic problems the fourth Maxwell's law, that concerning to the electrostatic Gauss's law, is not considered. I have to measure the temperature of the chassis of a device with magnetic fields in it. Time to practice your calculus chops. This example shows you how to use Simulink Coder Support Package for NXP FRDM-K64F for code verification and validation using External mode. Magnetic Actuator Design What you’ll do: Like in many branches of applied sciences, remote manipulation of objects is a desired feature, which is enabled by magnetic field originating forces. Also, the substantial fluctuations of the geomagnetic field, which occur constantly during magnetic storms and almost constantly in the disturbance field (auroral zones), are not included. Magnetic Field in Two-Pole Electric Motor. Regarding your question about trigger, the big picture is: Default model base time step is triggered by a timer. I have trying to plot magnetic field potential, and been partially successful for a point source, I believe. View Rohit Babbar’s profile on LinkedIn, the world's largest professional community. 1, there is no torque because field lines are orthogonal to the surfaces (considering a small gap). I've created some basic Simulink models in the past using the add_block and add_line functions, but it seems Matlab Function blocks work differently. Guarda il profilo completo su LinkedIn e scopri i collegamenti di Ruggero e le offerte di lavoro presso aziende simili. In this position,. The model does not include power loss due to friction and other rotational losses of hysteresis, eddy current, and windage. Thereby the currents turn out to be on parallel axes of the system of reference. The electrical equations and the expression for mechanical force on the coil are realized via an Embedded Matlab block (shown below), but the mechanical system is realized using regular Simulink blocks. Wye-connected current transformers mathematical model implementation in Simulink-SimPowerSystems. 6 Jobs sind im Profil von Hapa Hassan, MSc aufgelistet. a time varying magnetic field over a static conductor or a static magnetic field over a moving conductor. It is also electrically less noisy than a DC motor,. It's not for 3D field modeling, but it is very useful for modeling and simulating magnetic elements with electrical and electro-mechanical elements. View Sina Haji Alizad’s profile on LinkedIn, the world's largest professional community. X axis is X direction from -1 to 1 and Y axis is Y from -1 to 1 GSM. The dual cone speaker features coated internal wiring for long life. There are two control loops, one for controlling current and another for speed. Hall effect sensors measure magnetic fields, and their datasheet parameters can initially be difficult to understand and apply toward system design. The magnetic field produced by an inductive coil. If disruptions are detected, officials dismantle the bike to inspect it. I am completely new to simulink and don't know where to start. The force from the coil depends on the square of the current, the air-gap between the coil and the ball, and the physical properties of the ball. The behaviour of motor under load and no load characteristics have been studied with the help of virtual instrumentation. Modeling and simulation of nonlinear magnetic hysteresis Internal magnetic fields are present in all materials but with different intensity. The example uses the PDE Modeler app. But would like to know if it is ok, and how can I make it better with bigger dimension. The conductor moves at an angle q with the direction of the lines of force then the induced e. Magnetic Fields and Magnetic Field Lines; Magnetic Field Strength: Force on a Moving Charge in a Magnetic Field; Force on a Moving Charge in a Magnetic Field: Examples and Applications; The Hall Effect; Magnetic Force on a Current-Carrying Conductor; Torque on a Current Loop: Motors and Meters; Magnetic Fields Produced by Currents: Ampere’s. Obviously, as opposed to the DC motor, the flux and torque depend on each other. View Rob Forrester’s profile on LinkedIn, the world's largest professional community. Lovera [2] showed that the average Earth’s magnetic field for the dipole model is defined as a closed-form solution. The Earth's magnetic field model in this simulator is used as a model of magnetometer in the satellite, this value of the magnetic field is used as reference to consider how much current must be flowing through the coil to gain a torque (result of the interaction between Earth's magnetic field and. 1, there is no torque because field lines are orthogonal to the surfaces (considering a small gap). The model also does not include the time lag due to energy storage in the rotor inertia. modular hybrid linear stepper motor coupled simulink-simplorer model simulation program power electronics look-up table static characteristic good accordance linear motor analytical computation converter unit electrical machine sim2sim link fem-based magnetic field analysis program novel construction time step coupled simulation program single. symmetric magnetic field produced by current-carrying coils with or without ferromagnetic materials or by permanent magnets is known as a charged particle lens (magnetic lens) [2]. “soft” material of low coercivity can be magnetized by the Earth’s magnetic field and follows hysteresis patterns as it cycles in a magnetic field. Charges and Fields: Balloons and Static Electricity: Capacitor Lab: Circuit Construction Kit (AC+DC) About PhET Our Team Sponsors. The high performance speed. Department of Transportation to develop a new. Jan Stouthuysen’s Activity. Figure 6: Complete loudspeaker model in Simulink. Code Verification and Validation with External Mode. 2a) rotates with the stator current frequency and crosses the air-gap radially. (EPS) II year Government College of Engineering, Aurangabad (MS), India. Plus, the Low Magnetic Field will not interfere with your compass or autopilot. of energizing coil, the electric energy will be transferred to magnetic field energy. But would like to know if it is ok, and how can I make it better with bigger dimension. Magnetic Fields and Magnetic Field Lines; Magnetic Field Strength: Force on a Moving Charge in a Magnetic Field; Force on a Moving Charge in a Magnetic Field: Examples and Applications; The Hall Effect; Magnetic Force on a Current-Carrying Conductor; Torque on a Current Loop: Motors and Meters; Magnetic Fields Produced by Currents: Ampere’s. A detailed example of this approach is given in a later section. ∗ Sidney Osses Nunes∗ ∗ Systems and Energy Control Department - Computer and Electrical Engineering School - Campinas University,.


text:
# K&R 1-20 Solution

I'm currently reading the infamous K&R C book and trying to solve Exercise 1-20. My solution looks kind of too simple, but it works. I've searched the web for different solutions, but they all are much longer, although I didn't see any improvement compared to my code. Do you see anything which might compromise my approach? The exercise is as follows:

Write a program detab that replaces tabs in the input with the proper number of blanks to space to the next tab stop. Assume a fixed set of tab stops, say every n columns. Should n be a variable or a symbolic parameter?

And here's my solution:

#include <stdio.h>
#define COLS 8

int main (void)
{
int ch;
int charCounter = 0;

while ((ch = getchar()) != EOF) {
if (ch != '\t'){
putchar(ch);
charCounter++;
}

if (ch == '\t'){
for (int i = 0; i < (COLS - (charCounter % COLS)); ++i) {
putchar(' ');
}
charCounter = 0;
}

if (ch == '\n'){
charCounter = 0;
}
}
}

Do you see anything which might compromise my approach?

1. Good use of int ch; as the type returned by fgetc() is int and not char - avoided a rookie mistake.

2. The if() layout looks weak. Suggest using else

// current
if (condition) {
}
if (!condition) {
}

// Suggest
if (condition) {
}
else {
}

3. It is easier for people to understand == rather than !=. This is important for writing the correct code and maintaining it. So, when practical, avoid negation. Don't you think it is not a bit mis-understandable to negate the inverse of a sentence, No?

if (ch == '\t') {
for (int i = 0; i < (COLS - (charCounter % COLS)); ++i) {
putchar(' ');
}
charCounter = 0;
} else {
putchar(ch);
charCounter++;
}

4. The if (ch == '\n') is only possible when ch != '\t'. But this is minor. In a more complex code having this if() stand alone may be preferable.

...
} else {
putchar(ch);
charCounter++;
if (ch == '\n') {
charCounter = 0;
}
}

5. Then there is the missing return _something_;. With main(), lack of a return in the end will inject a return 0;. Should you do this or not is a coding style. One side says, no. Minimal code. The other side says - yes. Be explicit, it is poor practice to omit. The larger point here is that some "do/don't do" axioms are driven by your group's coding style. Following a consistent style is more important than being "right". If your group lacks a coding style, create one. This applies to all sorts of indentation, brackets or not, ++i or i++ issues.

6. Pedantic code would avoid integer overflow from pathological long lines. Example:

 // charCounter++;
charCounter = (charCounter + 1)%COLS;

// i < (COLS - (charCounter % COLS)_;
i < (COLS - charCounter);

7. Clerical: Since the design document is "K&R C, Exercise 1-20.", that information should have been in code. Name and date is nice. It is your work, proudly sign it,

/* K&R C,  Exercise 1-20. */
/* Saalim  2016 Apr 5 */

#include <stdio.h>
...

Should n be a variable or a symbolic parameter?

A more advance code would code some means to pass in a variable rather than a fixed tab stop of 8.

Very good initial post.

format: plain


text:
## derived kind of quantity

https://doi.org/10.1351/goldbook.D01612
A kind of quantity characterized by an equation between base kinds of quantities, e.g. $$\text{mass concentration} = \text{mass}\ \left(\text{length}\right)^{-3}$$.
Source:
PAC, 1979, 51, 2451. (Quantities and Units in Clinical Chemistry) on page 2460 [Terms] [Paper]


text:
# Environment which sends text conditionally to an appendix?

I am writing a paper and would like an environment that has the following property. If some flag is set to "true" in the preamble, all text wrapped in that environment is sent to the appendix. If the flag is "false", the text is placed inline. Ideally, it would also be possible to send the text to a specific subsection of the appendix (the specific subsection could be an argument to the environment?). Does something like this already exist? My ideal usage would look something like:

\documentclass{article}
\ifappendix[true]

\begin{document}

This text is always in the main body of the paper.

\begin{maybeappendix}[~\ref{sec:appendix-subsection}]
This text is produced inline if \ifappendix[false], thrown into the subsection ~\ref{sec:appendix-subsection} if \ifappendix[true].
\end{maybeappendix}

\appendix
\section{Section Name}\label{ref:appendix-subsection}
\end{document}

I've tried to define a new command that would do this, that looks like this:

\documentclass{article}
\usepackage{etoolbox}

\newif\iffull
\fulltrue

\begin{document}

\condloc{\where}{Text Should be inserted before app if full is true,
after app if full false.}

\section{app}
\where
\end{document}

which doesn't render anything if full is false, and places the text where I want for false when true, rather than placing the text in the intended places (before app if full is true and after app if full is false).

• I'm pretty sure this can be done with a layer on top of constructions using the answers package. If no one else provides a solution I may work on one tomorrow. – Ethan Bolker Nov 4 '14 at 14:55

This should do the trick.

\documentclass{article}

% Beginning of definitions
\usepackage{environ}

\newif\ifappendix
\NewEnviron{maybeappendix}[1]
{\ifappendix
\expandafter\global\expandafter\let\csname putmaybeappendix#1\endcsname\BODY%
\else
\expandafter\newcommand\csname putmaybeappendix#1\endcsname{}\BODY%
\fi}
\newcommand{\putmaybeappendix}[1]{\csname putmaybeappendix#1\endcsname}
% End of definitions

\appendixtrue

\begin{document}

Main body

\begin{maybeappendix}{label}
Movable text
\end{maybeappendix}

\appendix
\section{Section name}
\putmaybeappendix{label}

\end{document}

Change \appendixtrue to \appendixfalse to place the text where it is (or just delete it, as \appendixfalse is default (to change the default, add \appendixtrue after \newif\ifappendix)).

It seems to support several paragraphs and even figures in the movable text :)

If you want to collect several texts with the same label, use the following definition instead (the code above would discard an old text with that label):

\usepackage{environ,etoolbox}

\newif\ifappendix
\NewEnviron{maybeappendix}[1]
{\ifcsname putmaybeappendix#1\endcsname
\else
\expandafter\gdef\csname putmaybeappendix#1\endcsname{}
\fi
\ifappendix
\expandafter\xdef\csname putmaybeappendix#1\endcsname{\expandafter\expandonce\csname putmaybeappendix#1\endcsname\unexpanded{\par}\expandonce\BODY}
\else
\BODY%
\fi}
\newcommand{\putmaybeappendix}[1]{\csname putmaybeappendix#1\endcsname}

Then all texts are collected and separated with \par in the appendix (if the \par is undesired, just remove \unexpanded{\par} from the definition).

• How would I collect content in the same appendix? I've been having trouble working out how to stick more content on the end of the internal variable, rather than simply overwriting it as this solution would. – figlesquidge May 18 '15 at 17:31
• @figlesquidge see edit :) – Jonas Granholm May 18 '15 at 19:33
• Thanks very much. I think my error was forgetting to check it was defined first before using it in the same iterative manner you do. (Sorry can't give you another upvote for the updated version!) – figlesquidge May 18 '15 at 19:54

So this is a janky workaround, but the following has the intended consequences:

\documentclass{article}
\usepackage{etoolbox}

\newif\iffull
\fullfalse

\newcommand{\condloc}[2]{\newrobustcmd{#1} \protect{\iffull{#2}\else{\gpreto#1{#2}}\fi}}

\begin{document}
\condloc{\where}{Text Should be inserted before app if full is true, after app if full false.}

\section{App}
\where
\end{document}

I'm not sure how to do this with an environment, but it works for simple things, at least.


text:
Why doesn't Dijkstra's algorithm work for negative weight edges?

Can somebody tell me why Dijkstra's algorithm for single source shortest path assumes that the edges must be non-negative.

I am talking about only edges not the negative weight cycles.

Recall that in Dijkstra's algorithm, once a vertex is marked as "closed" (and out of the open set) - the algorithm found the shortest path to it, and will never have to develop this node again - it assumes the path developed to this path is the shortest.

But with negative weights - it might not be true. For example:

``````       A
/ \
/   \
/     \
5       2
/         \
B--(-10)-->C

V={A,B,C} ; E = {(A,C,2), (A,B,5), (B,C,-10)}
``````

Dijkstra from A will first develop C, and will later fail to find `A->B->C`

EDIT a bit deeper explanation:

Note that this is important, because in each relaxation step, the algorithm assumes the "cost" to the "closed" nodes is indeed minimal, and thus the node that will next be selected is also minimal.

The idea of it is: If we have a vertex in open such that its cost is minimal - by adding any positive number to any vertex - the minimality will never change.
Without the constraint on positive numbers - the above assumption is not true.

Since we do "know" each vertex which was "closed" is minimal - we can safely do the relaxation step - without "looking back". If we do need to "look back" - Bellman-Ford offers a recursive-like (DP) solution of doing so.

• Sorry but I'm not getting any error. First `A->B` will 5 and `A->C` will 2. Then `B->C` will `-5`. So the value of `C` will be `-5` same as bellman-ford. How is this not giving the right answer? – Anirban Nag 'tintinmj' May 23 '14 at 7:02
• @tintinmj first, Dijkstra will "close" node `A` with value of 0. Then, it will look on the minimal valued node, `B` is 5 and `C` is 2. The minimal is `C`, so it will close `C` with value 2 and will never look back, when later `B` is closed, it cannot modify the value of `C`, since it is already "closed". – amit May 23 '14 at 8:33
• @amit How Dijkstra's algorithm won't find the path `A -> B -> C`? It will first update `C`'s distance to 2, and then `B`'s distance to 5. Assuming that in your graph there are no outgoing edges from `C`, then we do nothing when visiting `C` (and its distance is still 2). Then we visit `D`'s adjacent nodes, and the only adjacent node is `C`, whose new distance is -5. Note that in the Dijkstra's algorithm, we also keep track of the parent from which we reach (and update) the node, and doing it from `C`, you will get the parent `B`, and then `A`, resulting in a correct result. What am I missing? – nbro Aug 15 '15 at 15:10
• @amit The problem with your reasoning (I think), and I have seen other people doing it (strangely), is that you think the algorithm will not reconsider nodes whose shortest distance has already been determined (and that we are done with), but this is not correct, and that's why we have the "relaxation" step...We iterate through all nodes of the graph, and, for each of them, we iterate through the adjacent nodes, even if any of the adjacent node might have already been removed from our min-priority queue, for example. – nbro Aug 15 '15 at 15:46
• @amit Check this answer to a similar question, where the example actually makes sense: stackoverflow.com/a/6799344/3924118 – nbro Aug 15 '15 at 15:51

Consider the graph shown below with the source as Vertex A. First try running Dijkstra’s algorithm yourself on it.

When I refer to Dijkstra’s algorithm in my explanation I will be talking about the Dijkstra's Algorithm as implemented below,

So starting out the values (the distance from the source to the vertex) initially assigned to each vertex are,

We first extract the vertex in Q = [A,B,C] which has smallest value, i.e. A, after which Q = [B, C]. Note A has a directed edge to B and C, also both of them are in Q, therefore we update both of those values,

Now we extract C as (2<5), now Q = [B]. Note that C is connected to nothing, so `line16` loop doesn't run.

Finally we extract B, after which . Note B has a directed edge to C but C isn't present in Q therefore we again don't enter the for loop in `line16`,

So we end up with the distances as

Note how this is wrong as the shortest distance from A to C is 5 + -10 = -5, when you go .

So for this graph Dijkstra's Algorithm wrongly computes the distance from A to C.

This happens because Dijkstra's Algorithm does not try to find a shorter path to vertices which are already extracted from Q.

What the `line16` loop is doing is taking the vertex u and saying "hey looks like we can go to v from source via u, is that (alt or alternative) distance any better than the current dist[v] we got? If so lets update dist[v]"

Note that in `line16` they check all neighbors v (i.e. a directed edge exists from u to v), of u which are still in Q. In `line14` they remove visited notes from Q. So if x is a visited neighbour of u, the path $source&space;\to&space;u&space;\to&space;x&space;\to&space;v$ is not even considered as a possible shorter way from source to v.

In our example above, C was a visited neighbour of B, thus the path $A&space;\to&space;B&space;\to&space;C$ was not considered, leaving the current shortest path $A&space;\to&space;C$ unchanged.

This is actually useful if the edge weights are all positive numbers, because then we wouldn't waste our time considering paths that can't be shorter.

So I say that when running this algorithm if x is extracted from Q before y, then its not possible to find a path - which is shorter. Let me explain this with an example,

As y has just been extracted and x had been extracted before itself, then dist[y] > dist[x] because otherwise y would have been extracted before x. (`line 13` min distance first)

And as we already assumed that the edge weights are positive, i.e. length(x,y)>0. So the alternative distance (alt) via y is always sure to be greater, i.e. dist[y] + length(x,y)> dist[x]. So the value of dist[x] would not have been updated even if y was considered as a path to x, thus we conclude that it makes sense to only consider neighbors of y which are still in Q (note comment in `line16`)

But this thing hinges on our assumption of positive edge length, if length(u,v)<0 then depending on how negative that edge is we might replace the dist[x] after the comparison in `line18`.

So any dist[x] calculation we make will be incorrect if x is removed before all vertices v - such that x is a neighbour of v with negative edge connecting them - is removed.

Because each of those v vertices is the second last vertex on a potential "better" path from source to x, which is discarded by Dijkstra’s algorithm.

So in the example I gave above, the mistake was because C was removed before B was removed. While that C was a neighbour of B with a negative edge!

Just to clarify, B and C are A's neighbours. B has a single neighbour C and C has no neighbours. length(a,b) is the edge length between the vertices a and b.

• Like you said, the better way to solve this is to use heapq.heappush method after each comparison. We push back the updated distance into the queue. Under this condition, the Dijkstra's can work on negative weights. I tried, and the result came out as 0,5,-5 – nosense Nov 25 '17 at 21:39
• "the path source to x to u is not even considered"; did you mean source to u to x? – slmatrix Nov 10 '18 at 22:09
• @slmatrix thanks for catching that, yes, I meant that the path from source to u to x, because x is a neighbor of u. – Aditya P Nov 11 '18 at 15:14

Dijkstra's algorithm assumes paths can only become 'heavier', so that if you have a path from A to B with a weight of 3, and a path from A to C with a weight of 3, there's no way you can add an edge and get from A to B through C with a weight of less than 3.

This assumption makes the algorithm faster than algorithms that have to take negative weights into account.

Correctness of Dijkstra's algorithm:

We have 2 sets of vertices at any step of the algorithm. Set A consists of the vertices to which we have computed the shortest paths. Set B consists of the remaining vertices.

Inductive Hypothesis: At each step we will assume that all previous iterations are correct.

Inductive Step: When we add a vertex V to the set A and set the distance to be dist[V], we must prove that this distance is optimal. If this is not optimal then there must be some other path to the vertex V that is of shorter length.

Suppose this some other path goes through some vertex X.

Now, since dist[V] <= dist[X] , therefore any other path to V will be atleast dist[V] length, unless the graph has negative edge lengths.

Thus for dijkstra's algorithm to work, the edge weights must be non negative.

Try Dijkstra's algorithm on the following graph, assuming `A` is the source node, to see what is happening:

• Sorry but I'm not getting any error. First `A->B` will `1` and `A->C` will `100`. Then `B->D` will `2`. Then `C->D` will `-4900`. So the value of `D` will be `-4900` same as bellman-ford. How is this not giving the right answer? – Anirban Nag 'tintinmj' May 22 '14 at 23:11
• @tintinmj If you have an outgoing edge from D, it will get visited before D's distance is decreased and hence not updated after it is. This will then result in an error for sure. If you consider D's 2 as the final distance already after scanning outgoing edges, even this graph results in an error. – Christian Schnorr Jul 16 '14 at 14:46
• @tb- Sorry for asking after such a long time but, am I on the right track here? First `A->B` will be `1` and `A->C` will be `100`. Then `B` is explored and sets `B->D` to `2`. Then D is explored because currently it has the shortest path back to the source? Would I be correct in saying that if `B->D` was `100`, `C` would've been explored first? I understand all other examples people give except yours. – Pejman Poh Feb 8 '17 at 0:40
• @PejmanPoh from my understanding, if B->D was 100, since A->C is higher in the HeapStructure which will be used, the extract min will return A->C first which means the next found shortest path will be the path to C, after that the path from C->D which is with weight -5000 will be the obvious choice, leading us to a conclusion that the shortest path would be from A->C->D and i am pretty sure this would be the normal behaviour. So sometimes when we have negative cycles we still might get the right value for the shortest path, but definitely not always, this is an example where we will not.. – T.Dimitrov Aug 17 '18 at 10:07

Recall that in Dijkstra's algorithm, once a vertex is marked as "closed" (and out of the open set) -it assumes that any node originating from it will lead to greater distance so, the algorithm found the shortest path to it, and will never have to develop this node again, but this doesn't hold true in case of negative weights.

The other answers so far demonstrate pretty well why Dijkstra's algorithm cannot handle negative weights on paths.

But the question itself is maybe based on a wrong understanding of the weight of paths. If negative weights on paths would be allowed in pathfinding algorithms in general, then you would get permanent loops that would not stop.

Consider this:

``````A  <- 5 ->  B  <- (-1) ->  C <- 5 -> D
``````

What is the optimal path between A and D?

Any pathfinding algorithm would have to continuously loop between B and C because doing so would reduce the weight of the total path. So allowing negative weights for a connection would render any pathfindig algorithm moot, maybe except if you limit each connection to be used only once.

You can use dijkstra's algorithm with negative edges not including negative cycle, but you must allow a vertex can be visited multiple times and that version will lose it's fast time complexity.

In that case practically I've seen it's better to use SPFA algorithm which have normal queue and can handle negative edges.

Dijkstra's Algorithm assumes that all edges are positive weighted and this assumption helps the algorithm run faster ( O(V^2) ) than others which take into account the possibility of negative edges (e.g bellman ford's algorithm with complexity of O(V^3)).

This algorithm wont give the correct result in the following case where A is the source vertex:

Also, Dijkstra's Algorithm may sometimes give correct solution even if there are negative edges. Following is an example of such a case:

It will never detect a negative cycle and always produce a result which will always be incorrect if a negative weight cycle is reachable from the source, as in such a case there exists no shortest path in the graph from the source vertex.


text:
# Thread: Solution for a particular column vector implies solution for all column vectors.

1. ## Solution for a particular column vector implies solution for all column vectors.

Let $A$ be a square matrix. Show that if the system $AX=B$ has a unique solution for some particular column vector $B$, then it has a unique solution for all $B$.

So I'm not really sure how to go about this since there's no assumption that $A$ is invertible, and I'm assuming I have to utilize row operations or the like, but I just can't make any connections. Any help would be appreciated, thanks.

2. Originally Posted by Pinkk
Let $A$ be a square matrix. Show that if the system $AX=B$ has a unique solution for some particular column vector $B$, then it has a unique solution for all $B$.

So I'm not really sure how to go about this since there's no assumption that $A$ is invertible, and I'm assuming I have to utilize row operations or the like, but I just can't make any connections. Any help would be appreciated, thanks.
Here is my thoughts on the question.

Every solution to a linear system can be decomposed into two separate pieces.

$X=X_c+X_p$ where $X_c$ is the complimentary solution (the solution to the homogeneous equation) and $X_p$ is a particular solution.

Since we know the solution is unique for some particular $b$

We have
$Ax=A(x_c+x_p)=b$ Since the solution is unique The complementary solution cannot have any free parameters.

e.g the kernel of this Matrix has only one vector in it and since $\vec{0} \in x_c$ the only solution to the system

$Av=0$ is $v=0$

This will give the desired conclusion.

3. I'm not sure I exactly follow (we haven't covered kernel, etc).

Are you saying that since the solution is unique, it must be the case that $x_{c}$ is the zero column vector?

And I'm not sure I make the connection to how it follows that there must be a unique solution for any $B$.

4. Originally Posted by Pinkk
So I'm not really sure how to go about this since there's no assumption that $A$ is invertible, and I'm assuming I have to utilize row operations or the like, but I just can't make any connections. Any help would be appreciated, thanks.

If $AX=B_0$ has unique solution, then

$E_n\cdot\ldots\cdot E_1AX=E_n\cdot\ldots\cdot E_1B_0\Leftrightarrow UX=E_n\cdot\ldots\cdot E_1B_0$

(where $U$ is a row echelon form) has unique solution. This implies that all leading coefficients of $U$ are different from $0$. Now, you can conclude.

Fernando Revilla

5. Whew, I get it now. Thanks so much!


text:
# zbMATH — the first resource for mathematics

Boundary effect for an elliptic Neumann problem with critical nonlinearity. (English) Zbl 0891.35040
Consider the Neumann problem $-\Delta u+\mu u=u^p\quad\text{in }\Omega,\quad u>0\quad\text{in }\Omega,\quad {\partial u\over\partial\nu}= 0\quad\text{on }\partial\Omega,$ where $$\mu>0$$, $$\Omega$$ is smooth and bounded in $$\mathbb{R}^n$$, $$n\geq 3$$, and $$p=(n+2)/(n-2)$$ is the critical exponent. This paper describes some interactions between the boundary behavior of solutions to the Neumann problem and the mean curvature $$H$$ of $$\partial\Omega$$ [see also Adimurthi, F. Pacella, and S. L. Yadava, J. Funct. Anal. 113, No. 2, 318-350 (1993; Zbl 0793.35033)], adapting the methods developed by the author for similar Dirichlet problems [J. Funct. Anal. 89, No. 1, 1-52 (1990; Zbl 0786.35059)].
Denote by $$H^b$$ the level set of $$H$$ to the level $$b$$ and assume that the relative topology $$(H^{a+\delta},H^{a-\delta})$$ is non-trivial for a positive critical value $$a$$ of $$H$$ and for any $$\delta>0$$ sufficiently small. If $$n\geq 5$$, the author then proves the existence of a solution $$u_\mu$$ to the Neumann problem which concentrates, as $$\mu$$ tends to infinity, at some point $$y\in \partial\Omega$$ such that $$H(y)= a$$. Moreover, if $$n\geq 6$$ and $$y^1,\dots,y^k$$ are nondegenerate critical points of $$H$$ with $$H(y^j)>0$$, there exists, for $$\mu$$ large enough, a solution $$u_\mu$$ which concentrates at $$y^1,\dots, y^k$$ (in the sense $$|\nabla u_\mu|^2\rightharpoonup{1\over 2} S^{n/2} \sum^k_{i= 1}\delta_{y^i}$$, $$S$$ being the best Sobolev constant for the embedding $$H^1_0(\Omega)\hookrightarrow L^{2n/n- 2}(\Omega)$$). In this case, it is proved additionally that, for $$\mu$$ large enough, the Neumann problem admits at least $$2^k- 1$$ nonconstant solutions.

##### MSC:
 35J65 Nonlinear boundary value problems for linear elliptic equations 35J67 Boundary values of solutions to elliptic equations and elliptic systems 35B05 Oscillation, zeros of solutions, mean value theorems, etc. in context of PDEs
##### Keywords:
effect of boundary geometry; multiple solutions
Full Text:
##### References:
 [1] ”A tribute in honour of G. Prodi” pp 9– (1991) [2] in press.The role of the mean curvature in semilinear Neumann problem involving critical exponent,.Partial. Diff. Equ., · Zbl 0847.35047 [3] 182 (1989) [4] in press.On a variational problem with lack of compactness: the topological effect of the critical points at infinity,.Calculus of Variations and Partial Diff. Equ., [5] 1991. ”Asymptotic behaviour of solutions of elliptic equations with critical exponent and Neumann boundary conditions,”. Vol.117 A, 225–250. Edinburgh Proc. Roy. Soc. · Zbl 0733.35038 [6] 1986. ”On the Diffusion Coefficient of a Semilinear Neumann Problem,”. Vol.1340, New York, Berlin: Springer Lecture Notes. [7] 1982. ”Models of Biological Pattern Formation,”. New York, London: Academic Press.
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.


text:
# Can a group have two different subgroups of index $2$?

I know that subgroup of index $2$ is normal.

I am interested in knowing that is that subgroup is unique or there exist example of subgroup which can have two subgroup of index $2$?

If there is example exist , then what is condition on subgroup implies that subgroup of index $2$ is unique?

Any Help will be appreciated.

• A short addition to the answers: If $4$ does not divide the order of the group then the group has a unique subgroup of index $2$. More generally, if the Sylow $2$-subgroup is cyclic, then the same happens. – Tobias Kildetoft Sep 19 at 8:37

Unfortunately it is not even unique up to isomorphism! Take, for instance, $(\mathbb{Z}/2\mathbb{Z})\times (\mathbb{Z}/4\mathbb{Z})$.

• Good example. Another: the dihedral group $D_4$ of order $8$ has at least two subgroups of order $4$: the Klein $4$-group and the subgroup consisting of the rotations. They are also non-iso. – Randall Sep 19 at 5:04

No way is it unique (generally). The group $G=\mathbb{Z}_2 \times \mathbb{Z}_2$ has three subgroups of index $2$: $\mathbb{Z}_2 \times\{0\}$, the vice versa, and $\{(0,0), (1,1)\}$. You can use the same idea to cook up plenty of other examples.

It is maybe worth noticing the following. Let $G$ be a group and let $I_2(G)=\#\{H \lt G: |G:H|=2\}$, be the number of subgroups of index $2$.

Theorem (Crawford, Wallace, 1975) Let $G$ be a group and $n$ a non-negative integer. Then $I_2(G)=n$ if and only if $n=2^k-1$ for some non-negative integer $k$.

See On the Number of Subgroups of Index Two-An Application of Goursat's Theorem for Groups, R. R. Crawford and K. D. Wallace, Mathematics Magazine Vol. 48, No. 3 (May, 1975), pp. 172-174.

From this it follows that $I_2(G) \equiv 1$ or $3$ mod $6$, and in particular, $I_2(G) \neq 2$.

(a) A group $G$ has a unique subgroup of index $2$.
(b) $G$ cannot be expressed as the union of 3 different subgroups.
(c) $G$ does not have a quotient isomorphic to Klein's group $V_4$.
You can actually make arbitrarily large groups where every element has order 2: Given $X$, the power set of $X$, $\mathcal{P}(X)$, is a group under the operation $\Delta$, known as symmetric difference ie for $A, B \subseteq X$, $A \Delta B = (A \cup B) - (A \cap B)$, and you further have that $\emptyset$ is the identity, and $A \Delta A = \emptyset$.


text:
# The MESSAGEix framework¶

Key features of the ix modeling platform (source: [1])

## Overview and scope¶

MESSAGEix is a versatile, open-source, dynamic systems-optimization model. It was developed for strategic energy planning and integrated assessment of energy-engineering-economy-environment systems (E4). It can be applied to analyse scenarios of the energy system transformation under technical-engineering constraints and political-societal considerations. The optimization model can be linked to the general-economy MACRO model to incorporate feedback between prices and demand levels for energy and commodities. The equations are implemented in the mathematical programming system GAMS for numerical solution of a model instance.

The MESSAGEix framework is fully integrated with IIASA’s ix modeling platform (ixmp), a data warehouse for high-powered numerical scenario analysis. The platform supports an efficient workflow between original input data sources, the implementation of the mathematical model formulation, and the analysis of numerical results. The platform can be accessed via a web-based user interface and application programming interfaces (API) to the scientific programming languages Python and R. The platform also includes a generic data exchange API to GAMS for numerical computation.

This documentation provides an introduction and the mathematical formulation of the MESSAGEix equations and auxiliary functions. For the scientific reference of the framework, see Huppmann et al. (submitted) [1]. The formulation of MESSAGEix is a re-implementation and extension of ‘MESSAGE V’ (Messner and Strubegger, 1995 [5]), the Integrated Assessment model developed at IIASA since the 1980s. For an overview of the MESSAGEix model used at the IIASA Energy Program and a list of recent publications, please refer to the MESSAGE-GLOBIOM documentation website.

MESSAGEix and the ix modeling platform are licensed under an APACHE 2.0 open-source license. See the LICENSE file for the full text.

Please read the NOTICE included in this repository and other documents referenced below for the user guidelines and further information.

The community mailing list for questions and discussions on new features is hosted using Googlegroups. Please join at groups.google.com/d/forum/message_ix and use <message_ix@googlegroups.com> to send an email to the MESSAGEix user community.

## Features of the MESSAGEix model¶

The MESSAGEix implementation includes:

• A comprehensive implementation of ‘technologies’ to represent a reference energy system (i.e., the fuel supply chain, conversion technologies from primary to secondary energy forms, transmissions and distribution, and final demand for energy services)
• Vintaging of capacity and explicit possibility for early retirement/decommissioning of technologies
• Explicit formulations for the system integration of variable renewable energy sources based on Sullivan et al., 2013 [6] and Johnson et al., 2016 [2].
• A direct implementation of the ‘soft’ relaxations of dynamic constraints on new capacity and activity (see Keppo and Strubegger, 2010 [3])
• Implementation of perfect-foresight and dynamic-recursive (myopic) solution approaches

## Documentation¶

The mathematical model description and other documentation pages are built from the documentation comments in the GAMS code and the Python and R interface bindings. The documentation available on MESSAGEix.iiasa.ac.at is synchronized with the GitHub repository. It is built from the latest master branch at github.com/iiasa/message_ix upon every update.

## Getting started¶

### Installation¶

For new users, we recommend to install Anaconda (Python 3.6 or higher) and GAMS. Importantly, when installing GAMS, check the box labeled Use advanced installation mode select Add GAMS directory to PATH environment variable on the Advanced Options page.

Then, open a command prompt and type

 conda install -c conda-forge message-ix

### Tutorials¶

To get started with a stylized energy system model implemented in MESSAGEix, look at the tutorials included in this repository at tutorial/README.

### Running the MESSAGEix model¶

There are three methods to run the MESSAGEix model:

• Via the scientific programming APIs using the packages/libraries ixmp and message_ix, calling the method solve() of the ixmp.Scenario class (see the tutorials).

• Using the file MESSAGE_master.gms, where the scenario name (i.e., the gdx input file), the optimization horizon (perfect foresight or myopic/rolling-horizon version), and other options can be defined explicitly.

This approach is recommended for users who prefer to work via GAMS IDE or other text editors to set the model specifications.

• Directly from the command line calling the file MESSAGE_run.gms (see the auto-doc page). The scenario name and other options can be passed as command line parameters, e.g. gams MESSAGE_run.gms --in="<data-file>" --out="<output-file>".

## Overview of model structure and includes files¶

The pages listed below provide a comprehensive documentation of the equations and the workflow when solving a MESSAGEix model instance. The documentation is generated to a large extent from mark-up comments in the GAMS code.

## Scientific programming API documentation¶

For a comprehensive documentation of the scientific programming APIs, please see the documentation of the ixmp package at software.ene.iiasa.ac.at/ixmp.


text:
# Are GIT's good categorical quotients just locally ringed space coequalizers?

Introduction: The definition of "good categorical quotient" in geometric invariant theory (given below) seems fairly ad hoc to me, except that it looks very similar to the coequalizer of the action in the category of locally ringed spaces. I'm trying to understand this similarity.

Some background: Suppose we have a group action $G\times X \to X$ in the category $\bf Sch$ of schemes. The category $\bf LRS$ of locally ringed spaces is cocomplete (see propositiion 1.12 in A. Vezzani's thesis), so in particular, $G\times X \rightrightarrows X$ has a $\bf LRS$-coequalizer; call it $Q$. One can construct it as the coequalizer in the category of topological spaces equipped with the sheaf of $G$-invariant functions to make it a locally ringed space, as Vezzani's proposition explains more carefully.

If $G\times X \rightrightarrows X$ has a $\bf Sch$-coequalizer $Y$, then GIT calls $Y$ a "categorical quotient"; see, for example, R. Birkner's Introduction to GIT. Note that here we get a universal map $u: Q\to Y$ in $\bf LRS$.

$Y$ is called a "good categorical quotient" if it satisfies 3 properties, also found in Birkner's notes, which I prefer to re-express here in terms of the universal map $u$:

i) $u^\sharp : {\cal O}_Y \to u _* {\cal O}_Q$ is an isomorphism.

ii) $u: Q\to Y$ is a closed map (at the level of topological spaces).

iii) $u$ takes disjoint closed sets to disjoint closed sets.

(These together imply that $X\to Y$ is a categorical quotient, i.e. $\bf Sch$-coequalizer; see Mumford's GIT I.2 remark 6.)

All of these properties are clearly satisfied if $u$ is an isomorphism. That is, if the $\bf LRS$-coequalizer is a scheme, that scheme is a good categorical quotient.

Towards a converse, (i) implies that $u$ must be dominant, and hence by (ii) it is surjective. And (iii) implies it is injective on closed points, so it's looking a lot like an isomorphism. Can anything more be said?

1) When is a good categorical quotient an $\bf LRS$-coequalizer of the group action? I.e., are there nice and general conditions where $u$ must be an isomorphism?

2) If the answer is not always, what's a counterexample? (Answered by Anton)

Thanks!

-
The cocompletness of LRS is not due to Vezzani, it's already contained in Groupes algebriques (Demazure, Gabriel), 1970. I don't know the answer to your problem, but usually the notions concerning colimits of schemes are motivated by explicit applications, and not by abstract nonsense. I doubt that there is any connection. –  Martin Brandenburg Mar 28 '11 at 10:19
I agree with Martin (and also don't know the answer). The goodness is a kind of wish list of properties that make the quotient useful in applications. Even if it (by chance) should be the same as the LRS quotient that would be more or less useless as there does not seem to be any way of really using that a scheme is the LRS quotient of a schematic equivalence relation. –  Torsten Ekedahl Mar 28 '11 at 10:56
@ Martin, I prefer to give links to online references when possible. Thanks for the book recommendation. –  Andrew Critch Mar 28 '11 at 16:56

The answer to the title question is NO. If $X\rightrightarrows Y\to Z$ is a coequalizer in $\bf LRS$, then the underlying topological space of $Z$ is the coequalizer of the underlying topological spaces (and the structure sheaf is the equalizer of pushforwards of the structure sheaves). On the other hand, good categorical quotients identify any two points whose orbit closures intersect. So one of my favorite good quotients, $\mathbb A^1/\mathbb G_m$, provides a counterexample. The good categorical quotient in schemes has a single point as its underlying topological space, but the quotient in $\bf LRS$ has two points.
I think the bad behavior on underlying topological spaces is probably the only problem. That is, a good categorical quotient is a coequalizer in $\bf LRS$ precisely when it is a geometric quotient (i.e. when we impose the additional condition that each fiber is a single orbit).
Your question is only about the second paragraph, right? Say $q\in Q$ is a point of the LRS coequalizer, and $F=X\times_Q Spec(k(q))$ is the fiber (note: I think this is the topological fiber ; does the proof of Hartshorne, Ex. II.3.10 work in LRS?). Saying that $F$ is a single $G$-orbit is the same as saying that the map $G\times F\to F\times F$ (given by $(g,f)\mapsto (g\cdot f,f)$) is surjective. Surjectivity of this map can be checked on geometric points, so the topological fibers of $X\to Q$ are single $G$-orbits if and only if the geometric fibers are single $G$-orbits. –  Anton Geraschenko Mar 28 '11 at 19:06
Whoops, I missed your second comment while composing the above. I think a geometric fiber over the generic point in your example only has 2 points, and that $G=\mathbb Z/2$ swaps them. –  Anton Geraschenko Mar 28 '11 at 19:13
Bleh ... it's not true that a fiber is a single $G$-orbit topologically iff $G\times F\to F\times F$ is surjective. In the example of the parabola mapping to the line, the trivial group $G$ acts on the fibers. Over the generic point, the fiber $F$ is one point topologically, but $G\times F\to F\times F$ is the inclusion of one point into two points. Nevertheless, the direction I actually used is true: if $G\times F\to F\times F$ is surjective (which it is for a good geometric quotient), then $F$ is topologically a single $G$-orbit. –  Anton Geraschenko Mar 28 '11 at 19:20


text:
# How should I typeset the physical dimensions of quantities?

As an example: The Newton's Law gives

F=ma      vs.      dim F=MLT^{-2}

My question is: Should I typeset the "MLT" in \mathit shape?

You can contrast

$\mathit{LT}\mathit{LT}\mathit{LT}\mathit{LT}$
$\mathit{L}\mathit{T}\mathit{L}\mathit{T}\mathit{L}\mathit{T}\mathit{L}\mathit{T}$

the latter is more close together. Is there some tricks on using \mathit shape?

Or I should choose the \mathrm family, or even just the default math font?

• If M, L and T are variables, treat them just like you would m and a; as-is. Jun 30 '13 at 6:23
• As far as I know, dimensional quantities (I don't know if this is the correct word in English) as M, L, T in physics have to be typeset in upright shape. So you'd better use \mathrm for them. Jun 30 '13 at 6:34
• And anyway \mathit is more or less the same font used by default in math mode. See this thread for more details: \mathit spacing with \mathnormal font Jun 30 '13 at 6:38
• "Quantity symbols are always written in an italic font, and symbols for dimensions in sans-serif roman capitals" ([page 105] (bipm.org/utils/common/pdf/si_brochure_8.pdf)). Sep 6 '13 at 11:25
• Use the siunitx package?
– user10274
Sep 9 '13 at 11:17

Both, the SI-Brochure nr. 8 (section 1.3, p. 105) and DIN EN ISO 80000-1:2012-10 (chapter 5, p. 19) use upright capital and sans-serif letters for this.

Quantity symbols are always written in an italic font, and symbols for dimensions in sans-serif roman capitals - SI-Brochure

Therefore you should write dimensions of quantities like this:

% arara: lualatex

\documentclass{article}
\usepackage{mathtools}
\usepackage[%
,math-style=ISO
,bold-style=ISO
,sans-style=italic
]{unicode-math}

\begin{document}
$\dim Q = \mathsfup{L}^\alpha \mathsfup{M}^\beta \mathsfup{T}^\gamma \mathsfup{I}^\delta \mathup{\Theta}^\varepsilon \mathsfup{N}^\zeta \mathsfup{J}^\eta$
\end{document}

This yields:

Unfortunately, there is no sans-serif font for medium-weight Greek letters in the range of uni-code characters. But if you normally use italic capital Greeks in your document (math-style=ISO), it will be distinguishable.

Three other remarks on your OP:

• Your two examples for $\mathit{LT}$ and $\mathit{L}\mathit{T}$ should (and do) look the same.
• The default math font normally yields the same as \mathit{...}.
• Before I edited your question, you wrote: "[F]=MLT^{-2}". Please note that [Q] means "the unit of Q". {Q} would signify "the value of Q" and for your case, it should be dim Q. $Q = \{Q\}\cdot[Q] \wedge \dim Q = \mathsfup{L}^\alpha \dots$.

• Shouldn't it be [X]=\mathsfup{L}? The operator \dim has a different meaning. Sep 9 '13 at 9:41
• You refer to the dimension of a vector space? I am not into that anymore, seems to be the same operator. But ISO and SI both use it in this place, too. [X] is the unit of X. Sep 9 '13 at 10:28
• @egreg any idea on how to get an \mathsfup{\Theta}? The more I look at it, the less I like the serifs here. Sep 9 '13 at 10:43
• For information on the different conventions for the symbol [X], see Square bracket notation for dimensions and units: usage and conventions at Physics.SE.
– E.P.
Sep 18 '13 at 10:07


text:
Example of article in TORI (replace to your title)

Dmitrii Kouznetsov (replace my name to your name)

Address: (type it here)

Data of submission: 2022.02.22.

The source of this example can be loaded as example.txt

Languages: English, Russian, Japanese (type that applies to your article)

Abstract. The title above should be replaced to the tentative title of your article. The figures should be either removed or replaced to something that in the best way characterize your article. The Abstract should indicate, why the things you present in this article are important, and why the Human civilization cannot advance will without publication of your manuscript. Try to be so pretentious as possible, while your pretensions are supported with the results you present below.
Abstract is important part of the article. Many readers read the only abstract. The title of an article and the Abstract should help the reader to understand, that the article is not that he or she is searching for. If no attempts to declare this is seen in the Abstract, then, perhaps, even those, who are interested in the topic, qualify the Abstract as not good, and miss the article.
Here, I assume, that the article is in English. If not, the Abstract should appear twice, in English and in the language used in your article.

1. Introduction

Describe, what backgorund is required to understand your results. Indicate, what is done and published before your article on the topic, and why you are not satisfied with the previous publications. If some publications are wrong, and your article corrects the errors, this also should be mentioned in the introduction. Try to use short sentences, that are easy to understand and easy to translate into other languages.

Especially good (for publication at this site), if your article follows the TORI axioms. [2,3]
The concept is called "scientific, if it has the following 6 properties [2,3]:
1. Applicability: The concept has some limited range of validity, distinguishable from the empty set.
2. Verifiability: In the terms of the already accepted concepts, some specific experiment with some specific result, that confirms the concept, can be described.
3. Refutability: In the terms of the concept, some specific experiment with some specific result, that negates the concept, can be described.
4. Self-consistency: No internal contradictions of the concept are known.
5. Principle of correspondence: If the range of validity of a new concept intersects the range of validity of another already accepted concept, then, the new concept either reproduces the results of the old concept, or indicates the way to refute it. (For example, the estimate of the range of validity of the old concept may be wrong.)
6. Pluralism: Mutually - contradicting concepts may coexist; if two concepts, satisfying the 1-5 above, have some common range of validity, then, in this range, the simplest of them has priority.

The revolutionary, extraordinary concepts are also allowed; even if they contradict the basic principles of physics or even mathematics. However, this contradiction should be explicitly mentioned by the authors, in such a way, that the editors, reviewers and colleagues have no need to reveal it by themselves.
If you describe advances of the financial pyramide, where all the participants get their bebefites, you shoud indicate, that your concept contradicts the axioms of Arithmetics, and so, with your discovery, even elementary mathematics should be revised.
If you describe some mechanism, that generate support-less force, then, you should indicate, that your concept contradicts the basic concepts of modern physics (conservation of energy-momentum) and, therefore, the basic mechanical concepts (energy, force, power, system of coordinates, etc) loss their common sense and should be revised and redefined.

The preferred style of the article is description of some term or some phenomenon, mentioned in the title. It is assumed that the description is based on your personal observations, calculus and the published results, and these publications are mentioned in the text and collected in the list of references.

2. Illustrations

Illustrations are assumed to be pictures, figures and/or tables.

The illustration should be supplied with the references: where did it come from. Even if it is appears not in Phys.Rev.Letters, but in some less famous blog, this should be explicitly indicated; See, for example, ref. [1] for Fig.1.

Usually, the readers like pictures rather than formulas. Try to put figure early, before it is first time mentioned in the text; however, it is desirable, that the figure and its description are placed close to each other and are seen at the same screen.

By default, the figures should be floated to right, as it does Fig.1. Then, the left margin remains free for numeration of formulas.
However, if necessary, figures can occupy all the width of the screen, or be floated to the left. The Japanese sites [4,5] provide tools for this.

3. Formulas

In TORI, formulas follow the standard Latex notations. Serious researchers write in Latex, so, there is no need to indicate, how to type

(1)$~ ~$ $a+b^2=c$

Hint: the code for equation (1) looks like this:

$a+b^2=c$

Таким образом, достаточно одного доллара, $\$\$, чтобы включить математическую моду и писать в ней математические символы, и ещё одного такого же доллара, чтобы её выключить. В отличие от многих случаев (когда бесплатный сыр только в мышеловке), тут халява настоящая: для того, чтобы включить или выключить математическую моду, доллар платить не надо; достаточно нажать на клавишу с изображением доллара, и должно получиться. Если обнаружится какой подвох (см., напр. MathJax), то укажите, чтобы исправить.

4. Languages

Sometimes it is necessary to change the language. The place of this change can be indicated as new paragraph or, at least, a new line.

にほんご　も　だいじょうぶ　でしょう。

Among various languages, English is preferred. 日本語, русский, etc. will be also considered.

The English characters, id est, ascii, are the same in all systems of encoding. So, with English, no abrakadabra
(for ex., Ð¢Ð¾Ð»ÑŒÐºÐ¾ ÐµÑÐ»Ð¸ Ð½Ð°Ð´Ð¾, Ð¿Ð¾ ÐºÐ°ÐºÐ¸Ð¼-Ñ‚Ð¾ Ð¿Ñ€Ð¸Ñ‡Ð¸Ð½Ð°Ð¼, ‚ã€€ã ã„ã˜ã‚‡ã†ã¶ã€€ã§ã—ã‚‡ã†ã€‚ )
appear. (Even at wrong setting at the brouser and/or the document head.)

Each English character is encoded with single byte. This greatly simplifies the treatment of the text. In addition, the English text happen to be much shorter, than its translation, for example, into Russian.

Capacities of the modern computers allow to deal even with Russian texts; especially, if the short sentences are used. So, articles in various languages are allowed.
Редактор знает русского языка и старается привнести в русские тексты даже правильную грамматику. Но английский лучше ещё и потому, что многие отдельные коллеги русского языка не понимают; а английский знают все.

5. Discussion

Discussion is good place to indicate the place of your result (presumably, described above) in the bunch of the Global Human Knowledge. Or, at least, in the topic of your article.

Discussion is good place to mention some wrong public opinion, some wrong publications, that are negated and corrected in your article.

Discussion is good place to refresh questions, that are formulated in the cited literature and answered in your manusctypt.

Discussion is good place to formulate new questions, new important hypothesis, that arise with your article and that can be answered, confirmed or negated in future. You may specify the methods, that, from your point of view, can be efficient in the proposed future research.

6. Conclusion

Conclusion should not be mixed, confused with the Discussion above. In the similar way, ability to confirm, to verify a concept should not be confused with the ability to reject, to negate, to refute it. Conclusion should be separated from Discussion.

Conclusion summarizes your results, described in the previous sections.
Every statement of the Conclusion should be supported with analyses supplied above.

Every deduction, cites, calculus of the previous sections should have the same goal, to support statements of the conclusion. If some part of your article does not serve this goal, consider to omit this part or to modify the Conclusion to mention the result of this part.

Refrences

0. http://mizugadro.mydns.jp/w/Submit submission form
http://mizugadro.mydns.jp/example.txt load this example. I provide the text version to simplify downloading of the source. Some brousers do not provide the special button to see the source of the page.
1. https://m.facebook.com/story.php?story_fbid=1975141659225976&id=100001904827825 Vika Michailovski. У нас дома. (TORI). 2018.03.31.

2. http://www.scirp.org/journal/PaperInformation.aspx?PaperID=36560 D.Kouznetsov. TORI axioms and the applications in physics. Journal of Modern Physics, 2013, v.4, p.1151-1156.

3. http://ufn.ru/tribune/trib120111
http://www.ils.uec.ac.jp/~dima/PAPERS/2010mestor.pdf
http://www.ils.uec.ac.jp/~dima/PAPERS/2010mestoe.pdf"
D.Kouznetsov. Place of science and physics in the human knowledge. Physics-Uspekhi, v.181, Trubune, p.1-9 (2010-2011)

4. https://gray-code.com/html_css/wrap-text-around-image/ レシピレイアウト. 画像に対してテキストを回り込ませる. 2019.06.10

5. https://cc.musabi.ac.jp/kenkyu/cl1/html5/css_lay01.html HTML+CSSまとめページ / レイアウト. 横並び. 2019.

Appendix A. Notes about references

The references should begin with its number and link. Please, check, that the link works, well before the submission.
Please, indicate the authors of the publication (id possible),
the name of the article,
Title of Journal, volume, pages (if possible)
and year of publication (or, at least, the year, when you looked at the page). Sometimes, the url repeats the title of the cited article; then, the title can be omitted.

Some Acknolegements, appendices, etc. may be added, if you think that they help the reader to understand your message.

It may have sense to indicate the End of your article:
The Manuscript ends here


text:
# Where does the indicated negative voltage terminal lie on this circuit?

Does the negative voltage terminal lie after the 150v source ?

• what does this mean? after the 150v source Oct 7 '18 at 3:52


text:
Definitions

# Trip generation

Trip generation is the first step in the conventional four-step transportation forecasting process (followed by trip distribution, mode choice, and route assignment), widely used for forecasting travel demands. It predicts the number of trips originating in or destined for a particular traffic analysis zone.

In the main trip generation analysis is focused on residences, and that trip generation is thought of as a function of the social and economic attributes of households. At the level of the traffic analysis zone, the language is that of land uses "producing" or generating trips. Zones are also destinations of trips, trip attractors. The analysis of attractors focuses on nonresidential land uses.

## Input data

A forecasting activity, such as one based on the concept of economic base analysis, provides aggregate measures of population and activity growth. Land use forecasting distributes forecast changes in activities in a disaggregate-spatial manner among zones. The next step in the transportation planning process addresses the question of the frequency of origins and destinations of trips in each zone: for short, trip generation.

## Early Analysis

The first zonal trip generation (and its inverse, attraction) analysis in the Chicago Area Transportation Study (CATS) followed the “decay of activity intensity with distance from the central business district (CBD)” thinking current at the time. Data from extensive surveys were arrayed and interpreted on a-distance-from-CBD scale. For example, a commercial land use in ring 0 (the CBD and vicinity) was found to generate 728 vehicle trips per day in 1956. That same land use in ring 5 (about 17 km (11 miles) from the CBD) generated about 150 trips per day.

The case of trip destinations will illustrate use of the concept of activity decline with intensity (as measured by distance from CBD) worked. Destination data are arrayed:

Table: Trip Destinations per unit (Acre) of Land
Ring Manufacturing Commercial Open Space etc
0 X1m X1c etc
. . . .
. . . .
7 x7m x7c etc.

The land use analysis provides information on how land uses will change from an initial year (say t = 0) to some forecast year (say t = 20). Suppose we are examining a zone. We take the mix of land uses projected, say, for year t = 20 and apply the trip destination rates for the ring in which the zone is located. That is, there will this many acres of commercial land use, that many acres of public open space, etc., in the zone. The acres of each use type are multiplied by the ring specific destination rates. The result is summed to yield the zone’s trip destinations. It is to be noted that the CATS assumed that trip destination rates would not change over time.

## Later Analysis

As was true for land use analysis, the approach developed at CATS was considerably modified in later studies. The conventional four-step paradigm evolved as follows: Types of trips are considered. Home-based (residential) trips are divided into work and other, with major attention given to work trips. Movement associated with the home end of a trip is called trip production, whether the trip is leaving or coming to the home. Non-home-based or non-residential trips are those a home base is not involved. In this case, the term production is given to the origin of a trip and the term attraction refers to the destination of the trip.

Residential trip generation analysis is often undertaken using statistical regression. Person, transit, walking, and auto trips per unit of time are regressed on variables thought to be explanatory, such as: household size, number of workers in the household, persons in an age group, type of residence (single family, apartment, etc.), and so on. Usually, measures on five to seven independent variables are available; additive causality is assumed.

Usually also, regressions are made at the aggregate/zone level. Variability among households within a zone isn’t measured when data are aggregated. High correlation coefficients are found when regressions are run on aggregate data, say, about 0.90, but lower coefficients, say, about 0.25, are found when regressions are made on observation units such as households. In short, there is much variability that is hidden by aggregation.

Sometimes cross-classification techniques are applied to residential trip generation problems. The CATS procedure described above is a cross-classification procedure.

Classification techniques are often used for non-residential trip generation. First, the type of land use is a factor influencing travel, it is regarded as a causal factor. A list of land uses and associated trip rates illustrated a simple version of the use of this technique:

Table: Trips per day
Land Use Type Trips
Department Store X
Grocery Store Y
etc.

Such a list can be improved by adding information. Large, medium, and small might be defined for each activity and rates given by size. Number of employees might be used: for example, <10, 10-20, etc. Also, floor space is used to refine estimates.

In other cases, regressions, usually of the form trip rate = f(number of employees, floor area of establishment), are made for land use types.

Special treatment is often given major trip generators: large shopping centers, airports, large manufacturing plants, and recreation facilities.

The theoretical work related to trip generation analysis is grouped under the rubric travel demand theory, which treats trip generation-attraction, as well as mode choice, route selection, and other topics.

## ITE Trip Generation procedures

The Institute of Transportation Engineers's Trip Generation informational report provides trip generation rates for numerous land use and building types. The planner can add local adjustment factors and treat mixes of uses with ease. Ongoing work is adding to the stockpile of numbers; over 4000 studies were aggregated for the current edition.

ITE Procedures estimate the number of trips entering or exiting a site at a given time (sometimes the number entering and exiting combined is estimated). ITE Rates are functions of type of development, and square footage, number of gas pumps, number of dwelling units, or other standard measurable things, usually produced in site plans. They are typically of the form $Trips = a + b * Area$ OR $Trips = a + b ln \left(Area\right)$. They do not consider location, competitors, complements, the cost of transportation, or many other obviously likely important factors. They are often estimated based on very few observations (a non-statistically significant sample). Many localities require their use to ensure adequate public facilities for growth management and subdivision approval.

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### Home > CAAC > Chapter 5 > Lesson 5.1.6 > Problem5-62

5-62.

Set up a proportion to solve this problem.

Solve the proportion for x.