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2022 | Buch

# ISUW 2021

## Proceedings of the 7th International Conference and Exhibition on Smart Energy and Smart Mobility for Smart Cities

herausgegeben von: Reji Kumar Pillai, B. P. Singh, N. Murugesan

Verlag: Springer Nature Singapore

Buchreihe: Lecture Notes in Electrical Engineering

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### Über dieses Buch

This book presents selected articles from INDIA SMART UTILTY WEEK (ISUW 2021), which is the seventh edition of the Conference cum Exhibition on Smart Grids and Smart Cities, organized by India Smart Grid Forum from 02-05 March 2021, in New Delhi, India. ISGF is a public private partnership initiative of the Ministry of Power, Govt. of India with the mandate of accelerating smart grid deployments across the country. This book gives current scenario updates of Indian power sector business. It also highlights various disruptive technologies for power sector business.

### Inhaltsverzeichnis

##### Legal Framework for Protection of Critical Information Infrastructure

Many utilities have adopted digital technologies to bring the required efficiency in their operations and meet the stakeholder requirements. As part of these digitization initiatives, the organizations have implemented multiple state of the art technologies which have helped them to improve and deliver quality services. Although implementation of latest technologies have brought numerous advantages to the utilities but it has also brought a unique challenge in the form of Cybersecurity. As power distribution utilities host nation’s Critical Information Infrastructure, it becomes imperative for utilities to ensure all required measures are in place to protect them from any kind of misadventure from Cyber adversaries. In view of above, many utilities have implemented various controls covering all aspects of People, Process and Technology. But it seems that a gap still exists which is not covered by standard approach. A survey of recent cyber-attacks on CII has revealed that a lot of advance and modern utilities have been a successful target of such malicious campaigns. The reason for utilities to become victim of such campaigns seems to be due to lack of legal framework for protection of Critical Information Infrastructure. It is also required that accountability for protection of CII at multiple stages should be recognized along with stringent review mechanisms. This paper shall focus on approaches adopted by various cyber instruments to curb crimes and what strategy needs to be adopted by nations to protect CII from falling victim to malicious campaigns by cyber adversaries who are based out of different geopolitical location.

Tarun Batra, Aamir Hussain Khan, S. Samanta
##### Real Time Monitoring of OT Devices Through INMS

Tata Power-DDL is a front-runner utility in implementing new technologies in order to improve quality of service to its consumers and enhance consumer delight from time to time. Tata Power-DDL has been successfully managing its power grids remotely. As we are aware that technology plays an important role in increasing the efficiency of our electrical network system, hence to increase the reliability and efficiency of our electrical network system we have automate our network along with real time control on OT devices. In view of this we need a system by which can enable us to monitor the real time availability of the Operational devices like RTUs, FRTUs IEDs etc. which are used to operate the electrical network remotely. To achieve this we propose to implement an integrated system called INMS (Integrated Network Management System) which will enable the utilities to monitor the real time availability and performance of all OT devices. In this paper we are focusing on mainly two issues that is (A.) How we will monitor OT devices on real time basis (B.) What would be the benefits of implementing INMS in a Power Utility? With the help of INMS we are able to monitor the availability and performance of our large electrical network devices on real time basis. It automatically detects faults of electrical network devices through periodic polling of each devices and generate alerts if it is unable to communicate with that device. INMS gives us a complete monitoring solution with following capabilities: (a) Fault monitoring, (b) Alerting, (c) Topology discovery, (d) Performance monitoring.

Aamir Hussain Khan, Tarun Batra, Kundan Kumar
##### Combined Billing and Customer Care Systems for All Utilities in a Smart City

Smart city is a structural, predominantly composed of Information and Communication Technologies (ICT) and several physical devices, to optimize the system efficiency and improvement in various services including utilities (Electricity, Water, Gas, etc.). ICT assist to enhance service quality, system performance and collaboration between numerous departments to deliver services in a time bound manner. Utilities supply electricity, gas, water, sewer etc. to consumer’s premise and charge fee against the services provided as per regulatory guidelines. These services might be provided by a single entity or multiple entities as per structure of urban local body. In major cases, utility services are provided by distinct entities and charges from the consumers are collected independently. In such a scenario, each entity must visit consumer premises and generate reports for billing, payments, collections, customer notices and customer base, which consume a lot of time, effort and impose huge costs. Consumers pay all utilities bills separately, which billing cycle, cash collection counter and customer care systems are working independently. Combined billing and customer care systems will help utilities to overcome aforementioned problems and visiting of consumer premises is required only once a month to collect consumption data and bill distribution for all utility services. In such scenarios all utilities will work in an efficient manner with a smaller number of employees, which leads to cost savings to them. The combined CC&B enables utilities to manage payments, deposits, consumer accounts, tax and meters through a single interface. Consumers will be empowered to make payment for all utility services at the same counter in one go and their service problem will be resolved in an efficient manner.

Amit Jindal
##### Effective OT Cyber Security for Modern Grid Operations and Asset Management

Historically, Substation automation system were based on local connections and proprietary applications. Systems were designed for safety, reliability and ease of use, and security was not traditionally a concern of power system managers or implementers. But this approach is no longer valid. As power system grid has evolved significantly over the past decade in terms of technological advancement and breakthroughs. At the heart of these intelligent advancements are specialized IT systems—various control and automation solutions such as SCADA/AMI/substation automation systems etc. The new generation of automation systems uses open standards such as IEC 60870-5-104, DNP 3.0, Modbus and IEC 61850 and commercial technologies, in particular Ethernet- and TCP/IP-based communication protocols. They also enable connectivity to external networks, such as office intranet systems and the Internet. These changes in technology, including the adoption of open IT standards, have brought huge benefits from an operational perspective, but they have also introduced cyber security concerns previously known only to office or enterprise IT systems. Cyber security is often used to describe protection against online attacks, but a more holistic view of cyber security involves a collection of measures adopted to prevent unauthorized use, malicious use, denial of use, or modification of information, facts, data or resources. Cyber security not only refers to intentional attacks from outside the network, but also internal issues and unintentional modifications of information. Many automation and modernization programs are now employing intranet/internet technologies in industrial control strategies. The ensuring systems are a mixture of state-of-the-art and legacy installations and create challenges in the implementation and enforcement of security measures. Control system intrusions can cause environmental damage, safety risks, poor quality and lost operations. This paper give glimpses of the methodologies involved for IT-OT convergence along with the Cyber security, asset management, information security implementation on the OT (Power system) networks and components. This will presents methods to determine and reduce the vulnerability of networked control systems to unintended and malicious intrusions. The procedure for conducting a thorough assessment of the process control networks to evaluate these risks is presented. Security issues are identified, as are technical and procedural countermeasures to mitigate these risks. It also includes hindrance/obstacle occur during the implementation approach where OT system run far behind from the IT systems in any organization.

Anil Kumar Ojha, Yogesh Gupta, Amit Mazumdar, Aakash Verma
##### IIOT in Utility Operations Paper

In this paper, we have explicitly described about the needs, implementation methodologies, and challenges being faced in Internet of Things (IOT) solutions adoption in Tata Power-DDL operations. Utilities have been trying hard to optimize Operational and Capital expenditures to achieve higher operational efficiencies and improved performance indices. A Smart grid roadmap was adopted by TPDDL and technologies like Substation and Distribution Automation, SCADA/ADMS, GIS, AMI, DSM, Smart Meters, Communication Infrastructure and RF Canopy have been successfully implemented. Early technologies in TPDDL different verticals have dedicated centralized smart systems with field devices are often appeared to be locked into purpose built, non-interoperable solutions. As uses and requirements multiplied, the complexities and obstacles to integrate these SILOS of technologies are becoming more and more challenging. The Internet of Things (IoT) is creating huge opportunities in Power Utilities, adding value to both the Utility and the Consumer. IOT or Cloud based solutions which utilizes all three technology verticals i.e. IT, OT and Communication infrastructure break open the new era of “Digitalization and Data Analytics” in Power Industry. In TPDDL, we have implemented IOT innovations which are helping us to drive down the cost in Operations and Maintenance and Project Execution. Case I—IOT based communication system to conduct an Integrated-Factory Acceptance Test. I-FAT plays an important role to ensure timely completion and quality execution of a project. However, OEMs are still reluctant to conduct the IFAT because most of their equipment’s are being manufactured at different geographical locations. An IOT/Cloud based wireless communication was established between two OEMs locations and complete integration and protection testing was carried out using a pair of 4G enabled Modems. Site commissioning of project carried out effortlessly with record time. Case II—Remote secure access of SCADA network for Work from Home. During the tested times of Covid-19, an IOT based cyber secure wireless connectivity was established by which Automation and Protection maintenance teams could able to connect with Grid Automation devices to perform critical activities like Fault Data recorders downloading during faults, IED breakdowns rectification, RTU and relays configurations. Case III—IOT cloud based Power Transformer Residual Life Assessment system. This system is being used to fetch critical performance parameters of transformer like DGA, Oil and winding temperatures, Moisture content and further data analytics. Smart Grid may be viewed as IoT for electric power 1.0. Critical processes and Assets health can now be monitored more accurately using IOT enabled digital data collection and analytics. Connected technologies and operations can reshape the way Utilities operate, allowing them to make smarter and more informed decisions.

Varun Thakur, Abhinav Mogha
##### Demystifying Digitally Empowered Prosumer—Transformation Opportunities for Utilities in Energy Value Ecosystem

Utilities business is getting more and more attractive and interesting, thanks to consumer empowerment, blurring of industry boundaries, fusion of energy and exponentially emerging technologies and transition towards the new business models. Consumers, who are already donning the hats of ‘prosumers’ are opinionated when it comes to exercising their choices, control, and comfort from the utilities. The two-fold democratization of consumers and energy are empowering the prosumers to partner with the utilities in grid management. Paradoxically, consumer perception about the utility is still evolving and according to IDC Utilities Consumer Survey 2020; the Net Promoter Score (NPS) for Utilities Customers are still negative. That propels the Utilities to pay heed to the digitally empowered prosumer voices and cater accordingly. The paper will start with understanding the need of digitally empowered customers across the value chain starting from Aware, Join, Use, Analyze, Pay, Served etc. A design thinking led approach will be taken to understand the consumer empathy in the journey. Then the paper look how COVID is playing the role of an accelerator for utilities to understand and getting more closure of the customer through new roles like ‘partner in crisis’. Next, we will see how global utilities today are leveraging the ‘energy value ecosystem’ to collaborate and co-create value around the lifestyle of the empowered consumer through fusion of commodity and services. In conclusion, the paper will emphasize the importance of technology and ecosystem to make the voice of customer an integral part of the utility’s DNA.

##### Smart Solutions Based on Smart Metering Data to Improve Distribution Network Operations and Customer Management in France

Energy transition, with the integration of distributed energy resources, and digitalization are new challenges that transform distribution networks management in depth. Those challenges lead to a new role for the Smart Distribution System Operator in a growing digital environment: the DSO as a Data Manager. The Smart Metering infrastructure, with all the data it generates, is the game changer for Grid Operations and Customer Management that allows the DSO to embody this new role. In France, the DSO Enedis has developed Smart Solutions for Grid Operations and Client Satisfaction based on its homemade Smart Metering System Linky: Solutions for Grid Operations MV Network Dispatching LV Network Operations Quality of Supply Monitoring Network Model Improvement Big Data for Predictive Maintenance Solutions for Client Satisfaction Collective Self-Consumption Open Data Public Lighting Management Customers Emergency Management. Those solutions are also proposed worldwide by EDF International Networks—the subsidiary that promotes Enedis expertise abroad. In this paper, we will detail those Smart Solutions and emphasize their benefits from a DSO’s point of view. Moreover, we will focus on the main milestones of the process for a DSO from customized solutions development towards industrial rollout.

Antoine Trobois, Sébastien Brun, Victoria Tan, Laurent Karsenti
##### Electric Vehicle Charging Infrastructure Planning and Security Measures in Indian Urban Centres

Electric Vehicle penetration in India could reach 30% by 2030 and this will generate an estimated savings of about 474 Million tons of oil import and 846 Million tons of CO2 according to a study by NITI Aayog and Rocky Mountain Institute. Research shows that 83% of the consumers globally are hesitant to adopt EVs because of the battery life and range anxiety. The extreme price sensitive Indian customers are skeptical about siting charging infrastructure in the road network. In the past few years, researchers worked on the optimal deployment and sizing of charging stations using objective functions and different optimization algorithms. But most of the works have taken the European and other Western cities into consideration. This paper proposes a methodology to calculate the number of charging stations for EVs considering extensive environmental elements in designing the charging infrastructure in Indian Cities. Though there is a strong push for EVs, currently we are in the nascent stage of market development in India and thus it will be difficult to lay down a detailed plan. In this paper, the security factors that are to be prioritized for the installation of EV charging infrastructure in Indian Urban areas are also identified. Finally, the feasibility and viability of the methodology are applied in an Indian City as a business case.

Premachandran Aravind, Abinash Dash, Abhijeet Ray
##### A Sustainable Power Distribution Model

Distribution is the weakest link of the Indian power sector. The last electricity reforms has ampullated the distribution from generation and transmission, but the problem is not evaded. Privatization of Distribution company is being recommended but failures of past cannot be repeated. Majority of the distribution companies has an amalgamation of urban and rural consumers. While urban consumers may find many suitors among private bidders because of better density and better returns, rural consumers may find it difficult to be managed by profit seeking entities. A more “atmanirbhar” or a self-dependent path may suit the rural consumers, for a sustainable power growth. This paper presents an electricity distribution model in which electricity supply is treated as a catalyst of development in rural areas and is treated as a market commodity in urban. It is proposed to separate urban and rural grids. While urban grid be licensed to lowest bidder, rural grid be managed by rural electricity cooperative society (RECS). Each RECS, to source its power from grid as well as from solar plants installed under PM-KUSUM scheme. The power produced to be utilized in battery swapping stations (BSS), for electric vehicles, in such a manner that power flow from grid remains unaffected and commercial transaction compensates for AT&C losses. Urban DISCOM shall bill for the net energy transacted, to RECS at the DTR level through pre-paid meter. The regulatory, technical aspect and financial modelling is dealt in this paper supported by experience in different countries. It also focuses on synergizing of various Government schemes implemented or under implementation.

Aurabind Pal
##### Energy Storage System—Application in Green City Transport

Keeping view of the NDC target for reducing CO2 emission and facilitating the inrush mix of green energy into the main stream of power generation and footing further for a green city, a proposal of creating a central hub of energy storage which is interlinked with road side small packets of energy fuel banks meant for EV and HEV is analyzed along with the V2G concept. Stringent Govt. policy toward the mandatory run of only EV and HEV in the city road, facilitating the opening of battery fuel centers by the road-side, subsidizing the EV sector and providing loan facility with attractive subsidies for the general people may evolve the new world of clean city.

B. B. Mehta
##### Access to Standardised, Transparent, and Granular Electricity Consumption Data: A Novel Engagement Model for the Indian Consumer

Electricity consumers in India receive their energy consumption information through monthly bills with limited data (such as per-unit rate, units consumed). Application of advancement in digitisation of metering data limited to improving the billing and collection efficiency. Post the COVID-19 lockdown, consumers in different parts of India complained about inflated electricity bills. The bills in lockdown were generated based on past data and no opportunity for consumers to monitor their real-time consumption. This strengthens the need to provide consumers with easy access to transparent and granular electricity consumption data. The growing penetration of technology has evolved consumers into digitally-enabled consumers, and their requirements have changed significantly. One prominent example is telecom consumers who can track their real-time usage (internet data usage, calls, bill dues, economical plans as per usage). However, such flexibility is not available with electricity consumers to track their consumption to manage bills, evaluate the benefit to opt for ToD rate plans, etc. With this backdrop, this paper attempts to answer two key questions: Does the consumer have sufficient, straightforward and standardised electricity consumption data to make informed decisions? What are the potential value propositions for different consumer types? This paper will develop a standardised end-use (In the paper, end-use refers to the data of electricity consumers. Data access refers to consumer access to energy usage data.) data-sharing framework. It will also draw inferences from how end-use energy data is shared with consumers in other countries and with consumers in India’s different sectors. The findings will help develop better energy efficiency interventions such as effective demand response programmes and customer engagement strategies.

Bhawna Tyagi, Akash Goenka, Sangeeta Mathew
##### Pioneering Data Quality and Security in Smart Grid

The essence of a data lies in the hidden information inside it. If the data is not of good quality or not sufficiently protected, the outcome will undoubtedly be harmful. Quality and Security are two essential aspects that add value and meaning to the data and their implementation has become a real need and must be adopted before any data exploitation. Due to the high volume of data generated every day, the effective implementation of such systems requires well thought out mechanisms and strategies. This paper provides a detailed analysis and solutioning of Data Quality and Data Security in the context of Smart Grid. Through this paper we want to highlight the proposed solution and challenges that may exist during the implementation of data security and data quality management systems.

Bright Roy, Prashant Tripathi, Rahul Goel
##### Vehicle to Grid Integration and Strategies for Managed EV Charging in India

Electrification of vehicles has its share of benefits and risks to the power distribution companies (DISCOMs). While EV adoption can potentially result in a substantial increase in revenue for DISCOMs from additional electricity sales due to EV charging, charging demand may increase the peak load in the DISCOM's service area. Unmanaged EV charging at the charging stations can hamper smooth power system operations by causing voltage instability, harmonic distortion, power losses, and degradation of reliability indices. To manage or avoid these impacts on the power system, there are both passive and active solutions. The passive solutions include specially designed electricity tariffs or incentives. The active management of charging is either unidirectional active management of charging referred to as V1G, or bidirectional active management of electricity referred to as V2G. Vehicle-Grid Integration (VGI) refers to this entire gamut of EV charging management solutions to mitigate the negative impacts of uncontrolled EV charging on the power system. The benefits of VGI extend beyond EV charging load, as it can provide useful services to the grid. The present paper is a discussion of VGI strategies for India for managing EV charging. The paper presents recommendations for VGI implementation in India.

Chandana Sasidharan, Ishan Bhand, Srijan Mukhopadhyay
##### Journey of Implementation of Line Differential Protection at Distribution Utility “Tata Power Delhi Distrbution Limited”

Protection Relays and the Communication Systems brain and heart of a power system network. Utilities in India have been using electro-mechanical and static protection relays since a very long time and have already adopted conventional protection schemes. With the advancement in Protection Relay technology, a shift is however imperative to achieve efficiency and cost optimization in an ever growing distribution network. Being a front-runner in the adoption of latest technologies in the utility space, TATA Power-DDL has successfully revamped its Protection and Communication Infrastructure by commissioning modern numerical relays having capability to integrate on IEC 61,850 communication protocol. A Smart grid roadmap has now been adopted by TPDDL and various technologies have already been successfully implemented like Grid Substation and Distribution Automation, SCADA/ADMS, GIS, AMI, DSM, Smart Meters, Communication Infrastructure and RF Canopy. Traditional protection schemes have worked successfully alongside all the recent advancements in technology as stated above. One of such schemes is Line Differential Protection wherein Line Differential Relays are installed at both ends of a transmission line and communicate with each other through a medium.In TATA Power-DDL network, there are around 200 sub-transmission line circuits, most of them being of short length (2–3 km). Initially, these lines were protected by Back-Up protection—Over Current and Earth Fault Relays. But difficulties started to be observed while doing relay coordination based on current and time margin. Some cases of cascaded tripping were also experienced, resulting in MU loss and customer dissatisfaction. However, Distance Protection scheme had already been implemented as Main Protection in Boundary Line Feeders. But, the reliability and selectivity of distance protection is lost in the following cases:- Shorter lengths of Line Circuits Inaccuracies in available Line Parameters. Taking the fact into consideration that TPDDL network is having significant Circuit-Kilometers as compound (Overhead and Underground Cable) sub-transmission lines, distance protection relay may operate inadvertently. Hence, the organization decided to shift to Line Differential Relays. Ever since, two major revamping projects have been implemented in TATA Power-DDL, based on the type of Communication technology adoption. The two technologies currently in service are:- Direct (Dark) Fibre Communication- Implemented on around 45 Circuits IP-MPLS (IEEE C37.94) based communication-Implemented on around 140 circuits Technological Upgradation in tele-protection systems got our attention and we decided to implement the IP-MPLS infrastructure. The IP-MPLS based Line Differential communication offered us following advantages:- Lower Latency time Ease in remote health monitoring of the communication ports. Moreover, all the IED project files of Line Differential Relays have been kept in a secured central server for easily accessing Fault Data Records and checking relay communication.This major advancement has improved our reliability indices and have played an important part in reducing Uncoordinated Trippings.

Himanshu Lalchandani, Deepak Agrawal, Lalit Kumar
##### Development of Smart Data Analytics Module Enabling Access to Electric Vehicle Usage in Smart City

The progressive acceptability of E-mobility is a key performance indicator for any City Authority. The trend of citizens towards acceptability for the personal and public E- transportation usage is increasing recently. Under the urban development, new initiatives towards Green Energy is socially welcomed such as increased use of Solar PV Renewable Energy Integration as well as Electric Vehicle. Both these green initiatives have opened up many business opportunities for participants under V to G and G to V integration and solar PV integration to grid due to restructured and deregulated power sector. The ‘Electric Vehicle’ is the source of innumerous diversified data useful for City Authorities to leverage, enabling insightful strategic planning for future growth, development and investments in the initiatives benefiting citizens and stakeholders of the city. This paper provides proof of concept of development of prototype hardware with the optimum cost along with applicability to maximize the visibility.

Surekha Deshmukh
##### Hosting Capacity Analysis and Managed Charging Solutions for Electric Vehicle Grid Integration

It is important for the DISCOMs to ascertain the location and time of charging in order to manage demand response. Electric Vehicles as additional load potentially run the risk of overloading local transformers especially during peak hours of the day. This paper includes a sample HV/LV N/W case study for E-mobility specific Studies in a Software Tool “NEPLAN” covering the typical Outputs of Load Profiling, Hosting Capacity Analysis (HCA) by Connection Point Power / Aggregated Power, Load Flow Time Simulation; and Sensitivity of Bottleneck Equipment wrt to Max ∆V. Charging of fleets would also require special attention from utilities for Depot and cluster charging since they would have strong geographically concentrated load with a distinctive charging profile depending upon the nature and use of an EV Fleet. All this increased load if unmanaged would have an impact on the distribution network leading to irregular load patterns. Additionally, since majority of EV charging is expected to be done at home, during nights the EV loads may also alter the daily load pattern for the DISCOMs. It also highlights the latest trend of Charging Management Systems focused on providing cheaper charging tariffs and the use of smart or managed charging solutions. Managed Charging could be divided into two major categories: Passive Managed Charging solutions that rely on customer behavior to affect charging patterns; Active Managed Charging that relies upon a bi-directional flow of information through multiple communications technologies. However, there is lack of industry protocols for the managed charging.

Shivani Sharma
##### CFIP—Water Inhibitor Cable Jointing Kit

The Objective of this paper is to work out and highlights the major causes of failure in Power Cables and further to propose solution to restrict cable faults. The average time to repair the fault is 2.0 days i.e. Utility has to sacrifice w.r.t its reliability parameters in case of Power cable failure. Nowadays, Joint box failure is contributing significantly w.r.t total numbers of cable failures and it is majorly due to ingress of water inside the cable and cable joint attributed to external damages. The inhibition of ingress of water is possible using well designed cable joints that would include components for inhibiting the water flow through the cable joints. We have developed an unique solution which is to be provided in the joints to prevent water ingress in the cable and cable joints. After installation of this unique design No such failure has been observed till date.

Sanjeev Atri, Vineet Tripathi, Gagandeep Kaur, Sanjana Rani
##### AI Based Alert Voice App for Customer

We want to discuss about AI based alert voice app for customer support. Our responsibility is to provide better services for the customers. Sometimes customers forget to submit their electricity bills before the last date. So, this app will send a voice alert message before customer last date to remind him to pay the bill. This app will also be useful for visually impaired customers as they can open this app and speak about their concern.

Gaurav Sharma, Shachi Jain, Srishti Prakash, Kumari Bharti
##### Assessing the Impact of Integrating Electric Vehicles and Solar Rooftop Photovoltaic System into the Power Distribution Network

This paper presents our analysis of the impact of integrating electric vehicles (EVs) and rooftop photovoltaic (RTPV) on the power system distribution feeders at the 11 kV level. For the assessment, we selected a sample urban feeder that served both domestic and commercial consumers within Bengaluru city limits. The EV-demand projection was considered on the basis of a report by Indian Institute of Technology, Kanpur, while the RTPV potential was estimated using CSTEP’s Rooftop Evaluation for Solar Tool (CREST). The feeder was modelled and simulated using the Electrical Transient Analyzer Program (ETAP) software tool. Various load-flow scenarios were run to analyze the feeder capability for integrating EVs and RTPVs for horizon year 2025. The simulation results reveal that the selected feeder will be critically loaded due to the EV-charging demand, during the evening peak hours. With optimal integration of RTPVs and daytime EV charging, the increased demand can be met without augmenting the feeder capacity.

G. V. Hanumanth Raju, E. V. Mallik, K. V. Harikrishna, P. Sagar Singh
##### Key Learnings from a Successful AMI Project in Indore (Learnings from Smart Grid Projects)

Advanced metering infrastructure (AMI) is one of the foundation pillar of Smart Grid. It is not only designed to collect, analyze live data and bring losses down on monthly basis but it has host of other benefits to consumers which leads to an adaptive, intelligent, smart and collaborative grid. Effective implementation of an AMI project encompasses much more than installing just the smart meters like any other conventional metering projects. An AMI project will succeed only when three pillars of the project viz. Technology Selection, Contracts and Execution and Operation—form an equilibrium. This is where the role of a Systems Integrator is so very important. Indore AMI project covering 120,000 Smart Metering nodes is well accepted as the most successful project in India so far in similar size. This paper brings out the Key Success factors of the project from an SI’s perspective. It deliberates on the possible challenges faced in all the three areas of Technology, Execution and Operation and how a deep-rooted Project execution methodology and customer collaboration helped to anticipate, handle and mitigate challenges. The paper also brings out clearly how the choice of SI is directly linked to the success of a project of this nature and how it tracks and helps to achieve an attractive Return on Investment (ROI). These learnings can be emulated to all other AMI projects to achieve a fast and successful rollout.

Hiranmoy Mukhopadhyay, Ajay Sinha, Navdeep Sharma
##### Implementation of Robotics and Drones in Power Distribution

Drones are considered as one of the aspects of energy industry. Under the Robotics heading, there are six categories which includes AI, automation and IOT. Drones are considered as a broad spectrum pertaining to emerging technology. Drones are very effective tool with the right sensors for data collection. Through the Drone Inspection process data collected through Drone inspection process can be protected and analyzed. Power sector is realizing that condition-based maintenance and running assets has consequences and will not be acceptable. Organizations can also use Drones effectively to enhance safety at project sites as one can constantly monitor real time data and notice the safety violations, if any which may have negative impact on the overall project execution. Considering the Serious injury and Fatality rate in Electricity as a utility, to tackle various high risk jobs, implementation of Robotics is the way forward across globe. This paper highlights the scope of drones, implementation of robotics and artificial intelligence in various dimensions on the power sector.

Kaushal Pandya, S. M. Javed, Abhishek Das
##### Two Capacity Transformer for Technical Loss Reduction

This paper proposes a modification in distribution transformer design to reduce losses occurring inside transformer during light loading conditions. Month wise Loading analysis of a particular financial year of all distribution transformers installed in network of TATA Power DDL was done to identify the light loading periods and under loaded transformers in the system. Further All day efficiency of transformers was calculated to establish their inefficiency during under loaded conditions. Further modifications in design of winding, their termination methodology inside tank and inside terminal box is discussed to operate transformers efficiently throughout the year. In the end analysis of efficiency with new design is done.

Keshav Raghav, Sanatan Kumar, Krishna Porwal, Tarun Singh
##### Experimental Study on Improvement of Power Generation in Building Integrated PV

Building integrated Photovoltaic (BIPV) is emerging as a promising pathway for green zero energy buildings where it can replace traditional construction material and generate electricity at the same time. Though BIPV is at 1% of solar installations globally, with the right incentives and regulations in place it can quickly accelerate. We know that a solar panel is known to perform the best when it is south facing and is latitude tilted (it produces 1500 Kwh/Kwp). However, in a BIPV system an East or West facing building facade obtains sunshine for only one half of the day and gives a yield of only 800 Kwh/kwp (Won Jun Choi, Hong Jin Joo, Jae-Wan Park, Sang-kyun Kim, Jae-Bum Lee, Power Generation Performance of Building-Integrated Photovoltaic Systems in a Zero Energy Building, Energies 2019, 12, 2471; doi:10.3390/en12132471). The primary challenge in BIPV is that the panels have high capture losses due to the sub-optimal orientation of the panels and thermal related losses due to the lack of air spaces. At Renkube we intend to solve the challenge of improving the energy production in a vertically mounted panel. We have developed an innovative PV panel design that can increase the energy production of BIPV modules by upto 20% for different wall orientations. Our panel uses patented geometric patterns created on the top surface of the glass to better capture more sunlight coming at an oblique angle of incidence and redirect it to the solar cell. We provide detailed simulation studies conducted for different building wall orientations of our BIPV panels and for different locations from Singapore to Laddak. We also highlight the annual performance and seasonal gains of our panels. This technology has potential to further reduce the installation prices of the BIPV system.

Lakshmi Santhanam, Balaji Lakshmikanth Bangolae
##### Unconventional Operation of Power Transformer Through Reverse Feeding Process

In parlance of India’s electrical power sector, all general-purpose transformers are generally used for stepping down the voltage for furthering the flow of electrical power from generation to distribution till end consumers. Though, a transformer is electrically designed as a bidirectional device which translates to that same transformer may be operated for stepping-down or stepping-up the voltage however, practically operating a transformer for stepping-up the voltage is quite uncommon and unconventional as rarely any such need arises which would require attempting such ‘reverse’ operation. This report puts forth, at length, details of once such operation of a step-down transformer in step-up mode.

Lalit Wasan, Vishal Panchal, Nishant Singh
##### Cyber Physical Security of the Critical Infrastructure

Power Sector, a critical electrical infrastructure in India, is at risk due to increasing cyber incidences. The electrical infrastructure depends on electronic control systems for its operation which are Cyber physical IT systems. Cyber threats to system can take many forms e.g. failure of a system/element to act/react in designed way due to virus, software bugs, intrusion and congestion in the underlying/supervising system and it may lead the misguidance to the operating engineers and there by taking false decision in real time operation. Non availability of ICT systems is also a form of Cyber Security vulnerability. Cyber intrusions are costly to Power Sector and many are preventable following safe design and Cyber Security Standards. The effect of vulnerabilities in centralized systems e.g. SCADA/Automation etc. used in Transmission and Distribution sector is wider and has potential impact on the synchronous operation of entire Power System, leading to Grid collapse. As far as Distribution sector is concerned where bulk of Smart Grid activities are visible, the impact of compromise of a centralized SCADA/DMS can lead to disruption of services to critical customers like Hospitals, Metro Rail etc. which is critical for the units/Services involved but at the same time not global and widespread. The impact of cyber vulnerabilities is proportional to the criticality of the functions and systems being impacted. The paper details the Cyber threats and prevention techniques involving IoT sensors, communication protocols, cloud architecture and predictive data analytics.

N. S. Sodha, M. L. Sachdeva
##### Review of Charging Infrastructure Pilot Projects: Global Scenario and Lessons Learnt

With the tremendous advancement in technology we have vehicle running of electrical energy. For the success of this invention various other arrangements are made which includes the establishment of charging infrastructure. The establishment of charging infrastructure imposes great effects on grid stability, loading scenarios and economic conditions. To point out the various positive and negative aspects of charging infrastructure Pilot projects are run. Here various charging infrastructure pilot projects are reviewed and the lessons learnt from them are mentioned. The global scenario of Electric vehicle charging station optimization is also stated. Pilot projects are run to resolve real-world deployment issues and to run improvement programmes for charging stations. Areas of working of various pilot projects are cost management, grid reliability and load optimisation, solar power incorporation, etc. Mostly pilot projects aim the improvement of smart-charging infrastructure. The benefits of smart-charging includes: lower generation costs and carbon intensity, lower upgrade costs for grid infrastructure, increased grid reliability, etc. The further areas of research are also mentioned.

Mahena Mahmood, M. Saad Alam, Sanchari Deb, Yasser Rafat
##### Solar—Wind Hybrid System for Optimized Planning and Coordination of Hybrid Renewable Energy

It is well known fact that the rate of industrial growth of any country is a function of the amount of energy available in that country and the extent to which this energy is utilized. Energy plays an indispensable role in modern society. Besides energy independence the devasting impact of climate change has become an issue of critical consideration. The burning of fossil fuels to generate energy is a dirty process. Greenhouse gas (GHG) emissions result when fossil fuels are produced and consumed and these emissions contribute to climate change. Hence, transition towards a low carbon energy economy is the real solution for the mitigating the impact of climate change. Recommendations for the integration of renewable energy sources beyond other measures have been offered, especially with reference to the salient environmental benefits that accrue to it. A wind turbine upon which solar (PV) panels are placed supplementary which is ideal hybrid concept. Solar panels are attached to the structure of the turbine thus maximizing the power output of the device for its given size. Thus integration of the two renewable energy sources will help in maximizing the power output of a domestic-size, and improve the system’s economics. Installing a hybrid system, instead of a pure solar or wind device, could assist in maximizing energy output from a given area and hence improve the economics of renewable energy.

Manan Pathak, Rohan Gupta
##### Global Product in Local Need—Impact of Environment Over Smart Grid IED/Electronic Equipment

Intelligent electronic devices (IEDs)/Relays are considered as brain of any electrical networks or power system and its healthiness ensure protection of electrical equipment’s. Pre-mature failure of IEDs in Delhi’s polluted environment leading to disruption of major chunk of healthy network along with faulty section. Need for global IEDs in local condition is recognized after environmental gaseous analysis and corrosion study. Also, regulator is being pursued for review of IED’s life assessment. We would like to share our experience gained through the whole journey.

Deepak Kumar Agrawal, Mani Bhushan Prasad
##### A System Design Using IoT, IEC61508, IEC61850, and IEEE C37.X to Improve Reliability of Smart Grid

This paper presents a system design and protocol are presented in this paper for improving the reliability of the Smart Grid using IEC 61850, IEC C37.x, and IEC 61508-x protocols. It starts with a brief introduction of IEC 61850, IEC C37.x, and IEC 61508-x. Then, it gives the block diagram of the proposed system and the proposed protocol. The design incorporates redundancy to recover faster from failure. The protocol allows the transmission of data, alerts, or a combination of data and alerts over the network. It also allows substation or master station to explicitly request data from a sensor or any subsystem in the hierarchy. It defines time synchronization protocol across the system to help detect duplicate packets. It also adds a layer of authentication and optional encryption of data from the field. The paper concludes with the constraints of the proposed system and protocol and the scope for future work.

Moreshwar Salpekar

Generally, consumers get to know their electricity consumption & Bill amount only at the end of the month on receipt of bill. Consumption patterns of a consumer can fluctuate widely without explicit knowledge of the consumer. Monthly Electricity Bill can be much more than the consumer's expectations due to higher consumption, consumption crossing over to the next higher tariff slab for residential consumers or penalty imposed on Commercial & Industrial consumers due to poor pf, billing Demand exceeding Contract demand, etc. KYEC is a unique, digital, value added service provided to our consumers through which they get information about their Electricity consumption on daily basis. The in-house developed mobile based software has been enriched based on consumer inputs. The residential consumers can set monthly budget towards bill & monitor/ control their consumption, get slab change alert, consumption alert during non-occupancy, etc. Commercial and Industrial consumers can also receive alert whenever their PF falls below a set value or maximum demand crosses a set value .This service is currently provided to around 23000 consumers who are covered under Automatic Meter Reading system. This "On the Go" service, helps consumer know, monitor & manage consumption, Demand, power factor & eventually earn incentives/reduce penalties. TATA Power Consumers saved Rs.120 million annually under this Value Added Service.KYEC is a pioneering & unique service in Indian Power Sector. This service is highly appreciated by our consumers. It has also helped in improving consumer's consciousness to reduce power consumption and thereby contribute towards energy conservation.

Devanjan Dey, Suchit Yeragi, Ruman Maknojia, Laxmi Patel
##### Self Submission of Meter Readings(MR)

During the crisis of COVID-19, meter-reading services are suspended and all NON AMR consumers are Getting billed on estimation. Thus, a new option of self submission of meter reading(MR) is required that does not require registration and no boundation is imposed on the consumer. Consumers can self-submission reading in simple way and get their bills prepared on actual basis. Thus consumer grievances is reduced recovery of dues gets facilitated. We have implemented 3 different services to consumer to submit their Meter reading. Self-MR submission through SMS, Website and Mobile App.

Rohit Shukla, Ankamma Marpu, Ajay Gulati
##### Experience of Battery Energy Storage System by TATA Power DDL

The electric grid is a complex machine that is constantly being balanced to account for varying consumer demand and generation supply. An inability to balance these leads to grid instability, brown-outs or even black-outs in extreme situations. These situations happens on account of increase in variability of both supply and demand. With increase in Renewable energy and expected rise in Penetration of EVs which are unpredictable and intermittent in nature can be accommodated easily at low penetration levels but greater Penetration makes increasingly it difficult to maintain grid stability. TATA Power DDL has two Battery energy storage system (BESS) one is Grid integrated 10 MWh system and 150 kWh Community Energy storage System. In this paper we would like to share the TATA Power DDL experience of Battery Energy storage system usage from Distribution Utility perspective where the System has been used extensively for Deviation Settlement Mechanism (DSM/ADSM), Sustained Deviation violation management, Reactive Power Management, Peak Load management, Frequency regulation, Capex deferral and Emergency services by developing various Automated logics to run the system with best of the business potential perspective. In addition to this the paper would describe about potential Battery Energy storage system required for TATA Power DDL to overcome Penalties on account of deviations with respect to various regulations and Power for Emergency services. Initiatives like Pole mounted battery Energy storage system (Zero Foot Print solution) under development to cater the needs of consumers in densely populated areas with space constraints for maintaining voltage regulation within specified limit.

Nilesh Kane, Lalit Wasan, B. Karunakaran
##### Paperless and Contactless Operations in Distribution Services

Tata Power Distribution Mumbai, License area of 484 km2, Serving 7.4 lakh customers, 4700 km of network, 36 Distribution substations, over 1000 Customer substations in the city of Mumbai. During COVID the paperless and contactless operations became a must for operations the various digitization projects has helped in these. Some of these are Dynamic forms (GIS), Digital Shift Handing Over Taking over (HOTO), UVC Sanitizer Box, Samarthya App, RCM—Reliability centered maintenance, CBM, Social Distancing alarm, Daily dashboard/complaint management, Mechanized, Remote site monitoring using camera, Unmanned operations, Automation Using LoRA have been explained in detail in the paper.

Parmanand P. Tendulkar, Devendra H. Santani, Nikhil H. Pujari, Pramod B. Jadhav, Amit C. Dalvi
##### Electric Vehicle Adoption and Penetration in India: Charging Infrastructure and Distribution Grid Upgrades as Vital Goals

India is actively implementing policies to roll out a massive electric vehicle (EV) segment. Government’s push for clean and renewable energy and incentives for investments offer it a unique opportunity. It, however, needs to put in place robust charging infrastructure, grid upgrade plans and consumer friendly prices for EV markets to expand and sustain.

Pooran Chandra Pandey
##### Disruptive Innovation in Utilities

The power utility business is constantly exposed to regulatory constraints, policy changes, varying economics, technology and customer preferences. In order to exist in this competitive market, utilities need to facilitate uninterrupted power supply with efficient load distribution and minimize downtime with timely maintenance. The rapid growth in IoT, robotics and connected technologies are forcing traditional power utilities and industry participants to adapt, or be outpaced by strong new entrants possessing the benefits by these technological advancements. This paper proposes solutions to utility applications using disruptive technologies by highlighting specific use cases such as transforming customer experience by leveraging power of edge computing, quantum computing, robotics, cost effective maintenance of assets using image analytics, enhancing workforce efficiency by using augmented reality and virtual reality etc.

Prakhar Chaudhary, Tanmay Dalal, Sanjay Singh Rawat
##### GeoUrja—An Innovative GIS Solutions for an Electrical Network

Adoption of the Digital Technologies increasingly allow devices across the Grid to communicate and provide the data useful for the customers and for the grid management and its complex operations. To develop Smart Electrical Grid, Digital information of Grid devices and their location with connectivity is a mandatory requirement. The State Power Utilities do not have accurate data of the Network at their disposal. The asset details whatever are available are a partially digitized information of the Electrical Network and same is not updated, as per the real time changes. To digitize fully the Electrical Network, we require specially designed GPS receivers (Rovers), a Base Station and a GIS software, which are proprietary products of the Venders. But obviously, due to its vulnerability, it cannot match or handle the requirements on a large data scale. Also, it is difficult to develop and manage large Electrical Network of the Government Utilities, with multiple integration, amendments and changes. An innovative platform of GeoUrja is a topology analysis method to establish for a Power Distribution Network model, the connection between electrical equipment can be generated automatically according to the terminal position of the equipment primitives. It is a cross platform and open-source desktop application framework, the topology data is organized and modelled. ‘GeoUrja’ will extend the range of asset information, data modelling, integration and make analytics for a better Management Decision Support System and the better customer services.

Rohit Patel
##### New Trends in Smart Billing and It’s Efficiency for Smart Cities

Smart energy billing system is a humble attempt to eliminate the waste of time in taking meter reading and also to reduce human efforts. Smart meters have brought big revolution in the fields of energy and power measurement. Worldwide at so many places smart meter billing system has been already deployed but in India like in Uttar Pradesh it’s just a beginning of smart meter billings deployment. This work describes the key elements in a Smart Meter Billing system and compiles the most employed technologies and standards as well as their main features.

Ram Avtar
##### Enabling Smart Energy Communities Through PEER Strategies

Developing a smart grid is all about leveraging information and communication technology to bring advancements in power system efficiency and reliability. Also, resilient enhancement is crucial for cities, communities, and campus buildings so as to provide a stable power supply for critical loads and essential services during natural disasters and major grid failures. Communities can emphasize the smart grid abilities which improves grid flexibility and provides resilient power options to the consumers. Smart grid enables greater penetration of customer’s local renewable and/or clean energy sources (Distributed Energy Resources (DERs)), coupled with energy storage helping in maximizing their electric grid reliability and resiliency. Also, DERs connected to the grid encourages the consumers’ participation in the grid services, enabling the role of prosumers. These greater abilities of smart grids will help in minimizing the transmission and distribution losses and the costs associated with it. Smart grids provide more insight into the electricity grid’s operational health with the advanced metering and cyber secure communication infrastructure, enabling automatic outage detection and service restoration, making the electric grid strong and smart. GBCI’s PEER (Performance Excellence in Electricity Renewal) is a comprehensive framework that assists any city or campus in evaluating their power system performance and encourages the adoption of new technologies that can strengthen a community’s access to reliable and resilient power. This paper talks on how PEER strategies provide a roadmap to enable smart energy communities and can facilitate the grid modernization efforts globally, through a case study.

S. R. Sanjay Kumar, Ishaq Sulthan
##### Distributed Ledger Technology Based Common GIS Map for All Domains in a Smart City

By allowing multiple departments within Smart City to work on a common GIS map brings lots of benefits on their plate along with few challenges. One of the major challenges is in exchanging and contributing information among various departments. Distributed Ledger Technology (DLT or Blockchain) permits multiple stakeholders (departments) to own, manage and share geospatial data with other stakeholders (departments) almost in real-time. Each stakeholder has their own copy of the data and all changes done with respect to data are recorded on blockchain along with a timestamp. Stakeholders can trace the history of the updated data. A holistic vision provided by DLT based common GIS map would help in planning & coordinating various activities of stakeholders. Various stakeholders within a smart city like Civil Department, Drainage Department, Water Department, Electricity and Public Lighting Department, Metro, Roads Departments, Education department can work together on DLT based common GIS map which would make existing processes fast, more effective and efficient. It would also help in disseminating information for benefit of the public at large and in making various reports like land plot report, zone confirmation report available to the public quickly and efficiently. This paper not only proposes DLT based system but also describes a prototype which was developed using Hyperledger Fabric.

Sanjay Dhonde, Inzamam Ansari
##### Developing a Regulatory Approach to Enable EV Application as a Virtual Power Plant

The present paper is concerned with shedding light on an effective regulatory approach to enable the application of electric vehicles (EVs) as a Virtual Power Plant (VPP). Appropriate regulations are critical to facilitate the use and deter misuse of this new solution. The study highlights the key regulatory instruments like price signals which are potential drivers for employing EVs as a flexible grid resource. In this regard, the assessment takes into account the experience of the advanced EV markets which have already made progress in implementing VPP. The study goes beyond delving into the regulatory instruments. It deals with crucial aspects such as defining EVs as a resource and realizing EV aggregation in order to participate in the power market, conflicts of competing needs, safety, interconnection requirements, and communication standards. Moreover, considering the existing electricity market structure in India where the power distribution utilities play a central role and much of the regulations are designed pivoting on power utility engagement, this investigation makes a conscious effort to debate the role of utilities in the resource aggregation. It proposes different implementation models for aggregation with varied levels of utility involvement, with the ultimate objective to establish a competitive and efficient mechanism to unlock the benefits of EV application as a VPP. It is strongly believed that this research would potentially help design an effective regulatory framework to implement EV-based VPP in the country. Electricity distribution utilities, regulatory commissions, fleet operators, charging service providers, and policymakers will immensely benefit from this study.

Shyamasis Das
##### Flexibility Operation of Hydro Power Station: A Case Study on 9PM9Minutes Event on 5th April 2020

Hydropower can play a crucial role in India’s sustainable development and energy security as it meets the criteria of sustainability, availability and reliability. Hydropower by virtue of its inherent characteristics has gained importance with large scale RE integration and the flexibility it provides has made it amongst best suited to match the rate of variability of RE. Hydro flexibility was successfully tested during the recent 9PM9M event on 5th April 2020. Though the drop in loads was anticipated up to 15 GW but in actual it plunged by 31 GW, nevertheless, it didn’t turn out to be difficult task to maintain grid stability given the robust infrastructure, planning and sizeable Hydropower and Gas based generation capacity which had come to the rescue. Hydro generation played vital role in balancing the grid and provided the much more than the envisaged flexibility and ramping rate. The event significantly assessed and marked flexibility in the grid and its manageability. Going forward, the results of the event has provided advocacy of the need of hydropower in the Indian grid as one of the best suited energy sources to meet the variability of increasing RE generation. The paper presents the experience during the event on the flexible operations of hydropower stations with focus on NHPC power stations and its contribution in grid stability and security and future ready.

Surendra Kumar Mishra, Jaganath Pani
##### Artificial Intelligence (AI) Powered Customer Care

This paper provides details on how Utilities can ensure elevated customer experience by reinventing the customer care experience leveraging Artificial Intelligence (AI). The paper introduces AI Powered Care—which as a concept is not just limited to only chatbots but extends seamless customer interaction both internally in the organization and externally through different channels. AI can provide Utilities with avenues to service customers in their preferred channels. AI can predict customer behavior and identify and nurture the most valuable leads, through in image and voice recognition are driving the growth of the regional market. Artificial Intelligence market will surpass $100 billion by 2025 and expected to trim business cost by more than$8 billion per year by 2022.

Tanmay Dalal, Prakhar Chaudhary, Sanjay Singh Rawat, Yuti Metha
##### Strategy and Workplan for Rollout of Smart Meters in Prepaid Mode

The power utilities across India are looking at smart metering with AMI towards accurate energy meter reading collection without manual intervention, improving revenue performance, remote connection and disconnection of power, facilitating real time analysis of power consumption/power quality parameters by the consumers and use of analytics on the huge volume of data generated by the smart grid system for building an effective decision support system. However, use of smart meters in postpaid only mode may not overcome many of the issues associated with the conventional metering system. Postpaid smart metering cannot ensure 100% collection efficiency as the remote disconnection procedure is partially dependent upon human intervention and procedural bottlenecks. Also, although postpaid implementation of smart metering collects energy meter readings automatically, the implementation still requires preparation of revenue bills in the utility’s revenue billing system as well as printing and dispatching the same to consumers’ premises. This involves considerable operational cost as well as time. The objective of this technical paper is to formulate robust and workable strategy plus workplan for rolling out smart metering in prepaid mode. The strategy takes care of migration of non-smart to smart prepaid mode, migration of smart prepaid to smart postpaid mode, migration of standalone prepaid mode to smart prepaid mode, integration of utility’s billing engine with the MDMS system of the smart metering system, appropriate frequency of invoicing of consumers, automatic connection/disconnection of consumers based on their account balance and facilitating real time tracking of account balance by the consumers. The workplan suggests ways to minimize resistance from consumers, if any, during rollout of smart metering in prepaid mode.

Tanmoy Mitra
##### Optimizing Electric Vehicle Charging with Charging Data Analytics

Electric vehicles are considered as viable replacements to gasoline cars since they help in reducing harmful emissions and stimulate power generation through renewable energy sources, hence contributing to sustainability. However, one of the significant obstacles in the mass deployment of electric vehicles is the charging time anxiety among users and thus, the subsequent large waiting times for available chargers at charging stations. Data analytics, on the other hand, has revolutionized the decision-making tasks of management and operating systems since its arrival. In this paper, we attempt to optimize the choice of EV charging stations for users in their vicinity by minimizing the summation of time taken to reach the charging stations and the waiting times for available chargers. The proposed framework utilizes real-time data and historical data from all operating charging stations in the city to assist the user in finding the best suitable charging station for their current situation and can be implemented in a mobile phone application.

##### Towards Smart Utilization, Maintenance and Planning of Distribution Transformers Using Smart Meter Data

Karunakar Jha, Hariom Sharma, Tushar Sharma
##### Smart LT Network Equipment: Introduction of Smart, Compact & Aesthetic LT Feeder Pillar

This paper highlights applications and advantages of using Compact Hexagonal feeder pillar. In a metro city where space is a major constraint. In present distribution Networks, the conventional LT feeder pillars which are used in the system are associated with many challenges. The biggest being the footprint requirement in a metropolitan city where space availability is big concern. Some other challenges being the conventional feeder pillar doors are very easy to open and have exposed bare busbars which are vulnerable to theft by direct tapping which is the most common method of stealing electricity. Also these conventional feeder pillars act as visible and physical obstacle and if installed on footpaths and road sides, causes problems to pedestrians and residents living in narrow and congested lanes.

V. T. Naraynan, Ajay Potdar, Ramesh Kharat, Alapathi Bhanuji, Vikas Koul, Swapnil Rao
##### Asset Performance Management Using Machine Learning

Utilities have assets spread across diverse geographies which are very difficult to monitor and provide timely attention on daily basis. In addition, unplanned downtime often costs utilities 10× the cost of planned maintenance. Traditional approach for asset reliability leverages the first principles model. Artificial Intelligence (AI) and Machine learning (ML) techniques appear to solve the same problems but differ in areas of human intervention and accuracy of prediction. A widespread integration of machine learning in Asset Performance Management (APM) marks a transition from estimated engineering and statistical models towards measuring patterns of asset behavior. Utilities are adopting the proliferation of advanced technology where they can predict failures before they occur and build proactive maintenance plan, thereby improving reliability and expenditure. Asset Performance Management (APM), with the capability to analyses large data sets from both IT and OT systems from field assets, helps take 3R decisions (Repair Vs Replace Vs Refurbish). This paper presents a case study of an Indian utility on APM using Machine Learning techniques on Distribution Transformers wherein the failure rate was reduced from 8 to 9% by estimated 2–3% thereby providing system reliability and estimated savings of USD 1.31 million per annum (for 20,000 DTs) through a reduction in transformer repair charges. These ML techniques can also be used for cables, switchgears and other critical assets across the power generation, transmission, distribution and renewables value chain thereby transitioning from Time-Based maintenance (TBM) to Condition-Based Maintenance (CBM).

Somesh Kumar, Vinit Mishra, Abinash Singh, Amit Sharma, Vivek Singh, Hem Thukral
##### Electric Cooking—The Way Forward

About 4 million people die prematurely from diseases caused by household air pollution, primarily from cooking with firewood, charcoal and biomass. As of 2019, 63% rural and 18% urban households in India use firewood, dung cakes or biomass for cooking. In 2019, nearly 600,000 people died of household air pollution in India. Having electrified almost all households in the country and with surplus electricity generation capacity, India should actively promote electric cooking. Increasingly higher share of electricity is being produced from renewable resources and during many time slots during the day, cheap electricity is available on the grid. During 2018-19, 1500 million LPG cylinders were distributed in the country which is not sustainable from the perspective of cost and energy efficiency. New city gas distribution networks cost Rs. 25,000 per connection. In order to meet the NDC targets it is imperative that emissions from the kitchen must be reduced drastically. Electric cooking is the fastest and least cost route to achieve these multiple targets which will also reduce LPG imports saving billions of dollars leading towards Atmanirbhar Bharat.

Reji Kumar Pillai, Reena Suri, Suddhasatta Kundu, Balasubramanyam Karnam, Akshay Kumar, Shuvam Sarkar Roy
##### Sustainable Air Conditioing with District Cooling System (DCS)

The summer temperature been on the rise constantly all across India during the past 3 decades. Soon the maximum summer temperature will exceed 50 °C in Northern India making it extremely difficult for people without access to cooling. India Cooling Action Plan (ICAP) targets incremental improvements in efficiency of equipment to reduce cooling demand by 25–30% by 2037–38 which is likely to be defeated by sheer increase in the number of air conditioners. Radical approaches are required to address the cooling challenge. District Cooling System (DCS) is an alternative route to address the space cooling challenge effectively. This paper highlights the DCS technology, the technical and commercial benefits it can offer and business models for effective DCS implementation.

Reji Kumar Pillai, Reena Suri, Suddhasatta Kundu, Shuvam Sarkar Roy, Balasubramanyam Karnam, Akshay Kumar, Parul Sribatham
##### New Revenue Opportunities For Utilities

In 2020, India has moved up from 76 to 74th positions on a Global 'Energy Transition Index (ETI)' with improvements on all key parameters of economic growth, energy security and environmental sustainability. With solar panels getting cheaper and its efficiency getting higher, renewable energy is playing a major role in energy transition. Alongside renewable energy, battery technologies are showing tremendous growth in terms of higher efficiency, longer life and cheaper price with compact form factor. This would accelerate the transition and also opens a window for introduction of vehicle to grid technology to play a vital role, where electric vehicle’s batteries would act as virtual power plants. With constantly declining prices and increasing efficiencies of solar panels and batteries, a large section of customers could generate, store and consume their own electricity. Today, the primary revenue for electric utilities is from the sale of energy (kWh) to their customers which is going to be seriously impacted in the near future. Since these changes are already on the horizon, it is important for utilities to consider New Revenue Streams for growth and sustainability. This White Paper suggests various opportunities for revenue generation for utilities from the Digitalization of the Power Sector and Unlocking Existing Infrastructure and Services.

Akshay Kumar, Bindeshwary Rai, Reena Suri, Reji Kumar Pillai
Titel
ISUW 2021
herausgegeben von
Reji Kumar Pillai
B. P. Singh
N. Murugesan


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# Tag Info

1

See generated subframe: A frame $\mathbf G=\langle G,S,W\rangle$ is a generated subframe of a frame $\mathbf F=\langle F,R,V\rangle$, if the Kripke frame $\langle G,S\rangle$ is a generated subframe of the Kripke frame $\langle F,R\rangle$ (i.e., $G$ is a subset of $F$ closed upwards under $R$, and $S$ is the restriction of $R$ to $G$), and $W ... 1$p \land \lnot q$is$\lnot (p \to q)$. Thus, we can rewrite$\varphi := □(□p∧¬◊p)$as$◻¬(◻p \to ◊p)$. 1 Hint There is an algorithm described into: Patrick Blackburn & Maarten de Rijke & Yde Venema, Modal Logic (2001), Ch3.6 Sahlqvist Formulas; see Example 3.43, page 159. The formula:$St_x(\varphi) := ∀P∀x \ [∃y(R(x,y) ∧ ∃z(R(y,z) ∧ P(z))) → ∃w(R(x,w) ∧ P(w))]$must be converted by the algorithm, with the instantiation$\sigma(P) := \lambda ...

0

0

It is true more general fact. Proposition. If $U$ is open and $A$ an arbitrary subset of $X$, then $IC(U)\cap IC(A)\subseteq IC(U\cap A)$. Proof. Suppose $$x\in IC(U)\cap IC(A)$$. $x\in IC(U)\cap IC(A)$ iff there exists $U'$ an open neighborhood of $x$ such that $U'\subseteq C(U)\cap C(A)$. Let us denote $$U'\cap U=V_1$$ and $$U'\cap A=V_2.$$ ...

1

Let $(X,\tau)$ be a topological space with interior operator $I$ and closure operator $C$. Let $A$ be a subset of $X$. For convenience lets make the following notations: $C(A)=^{def}A^{-}$ and $X\backslash A=^{def}A'$ There is conjugation $I(A)=X\backslash (C(X\backslash A))=(( A') ^{-})'$. We will need two following lemas. Lemma 1: Let $A$ be a subset ...

2

No, not necessarily. When changing the connective, the modality has to interact with the negation ($p \wedge q \equiv \neg (\neg p \vee \neg q)$), so it may behave differently. The negation may change the modality, $L$ may be changed to a dual modality $K$, with each modality having its own syntactic rules. For example, the exponential in linear logic ...

Top 50 recent answers are included

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## Seminars and Colloquia by Series

### The Arc Complex and Open Book Decompositions

Series
Geometry Topology Student Seminar
Time
Wednesday, January 30, 2013 - 13:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Meredith CaseyGeorgia Tech
This is an expository talk on the arc complex and translation distance of open book decompositions. We will discuss curve complexes, arc complex, open books, and finally the application to contact manifolds.

### Knots and Dynamics II

Series
Geometry Topology Student Seminar
Time
Wednesday, January 23, 2013 - 13:05 for 1 hour (actually 50 minutes)
Location
Skiles 006.
Speaker
Amey KalotiGeorgia Tech
This is continuation of talk from last week. Periodic orbits of flows on $3$ manifolds show very rich structure. In this talk we will try to prove a theorem of Ghrist, which states that, there exists vector fields on $S^3$ whose set of periodic orbits contains every possible knot and link in $S^3$. The proof relies on template theory.

### Knots and Dynamics

Series
Geometry Topology Student Seminar
Time
Wednesday, January 16, 2013 - 13:00 for 1 hour (actually 50 minutes)
Location
Skiles 006.
Speaker
Amey KalotiGeorgia Tech

### Braid Groups and Hodge Theory

Series
Geometry Topology Student Seminar
Time
Wednesday, November 14, 2012 - 14:05 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Becca WinarskiGeorgia Tech
We look at a paper of McMullen "Braid Groups and Hodge Theory" exploring representations of braid groups and their connections to arithemetic lattices.

### Stein fillings of planar open books.

Series
Geometry Topology Student Seminar
Time
Wednesday, October 31, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006.
Speaker
Amey KalotiGeorgia Tech
The goal of this talk is to study geography and classification problem for Stein fillings of contact structures supported by planar open books. In the first part we will prove that for contact structures supported by planar open books Stein fillings have a finite geography. In the second part we will outline an approach to classify Stein fillings of manifolds supported by planar open books.

### Talk in Geometry-Topology Research Seminar Today

Series
Geometry Topology Student Seminar
Time
Wednesday, October 24, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
none
Speaker
nonenone

### Toric Manifolds - Four Dimensions from Two

Series
Geometry Topology Student Seminar
Time
Wednesday, September 12, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Jamie ConwayGeorgia Tech
We will investigate a method of "seeing" properties of four dimensional symplectic spaces by looking at two dimensional pictures. We will see how to calculate the Euler characteristic, identify embedded surfaces, see intersection numbers, and how to see induced contact structures on the boundary of these manifolds.

### Topological entropy of automorphisms of free groups

Series
Geometry Topology Student Seminar
Time
Wednesday, September 5, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Hyunshik ShinSchool of Mathematics
The main goal is to characterize the dilatation of an outer automorphisms of free groups. It is known that for any automorphism, its dilatation is a weak Perron number. The converse was recently shown by Thurston; for every weak Perron number, there is an automorphism represented by a train track map. We will discuss Thurston's theorem and its proof.

### Train track and automorphisms of free groups

Series
Geometry Topology Student Seminar
Time
Wednesday, August 29, 2012 - 14:00 for 1 hour (actually 50 minutes)
Location
Skiles 006
Speaker
Hyunshik ShinSchool of Mathematics, Georgia Tech
We will discuss the basics of automorphisms of free groups and train track structure. We will define the growth rate which is a topological entropy of the train track map.

### Gel'fand Duality

Series
Geometry Topology Student Seminar
Time
Wednesday, February 8, 2012 - 14:05 for 1 hour (actually 50 minutes)
Location
Skiles 169
Speaker
Jonathan PaprockiGeorgia Tech
We will prove a duality between locally compact Hausdorff spaces and the C*-algebra of continuous complex-valued functions on that space. Formally, this is the equivalence of the opposite category of commutative C*-algebras and the category of locally compact Hausdorff spaces.


text:
# Partial imputation of missing dates

I'm working with dataframes (one for each of 185 locations) that shows sums of occurrences for each calendar date. There are no 0 values for occurrences in the entire dataset. There are several missing dates.

Below is a dataframe I created which shows the mean daily occurrences for some example locations. CI = 95% confidence interval of expected occurrences of 0, N/A = number of missing entries, ENTRIES = number of actual entries + number of missing. My null hypothesis is that all the missing dates are actually 0 counts.

    MEAN VALUE  CI      N/A   ENTRIES   P-VALUE
0   10.306675   0-1     1       1589    1.000000
1   5.416826    1-14    20      1589    0.141214
2   8.081301    0-0     2       248     0.088841
3   9.044795    0-1     4       1589    0.077208
4   7.531390    0-0     3       449     0.062347
5   7.720607    0-3     7       1589    0.043126
6   10.056911   0-0     2       248     0.026038
7   8.661017    0-1     4       1066    0.023237
8   6.040712    0-9     17      1589    0.021933
9   6.546326    0-6     14      1579    0.007288
10  9.160428    0-0     3       377     0.006710
11  8.538219    0-1     6       1589    0.005819
12  4.893248    4-20    34      1589    0.005412
13  3.400536    34-71   96      1589    0.004372
14  29.995498   0-0     34      1589    0.000000

The issue I'm having is how to impute data for the missing dates. For very low p-value, I believe imputing an average or forward fill for these locations' data would be the correct choice. Locations with a high p-value, such as the first location, I would believe imputing the missing data as a 0 would be appropriate.

However, when it comes to locations as such 13, I'm stuck. Some 0 counts should be expected, as reported by the confidence interval, but there are several more actual N/A then should be expected, which makes me think imputing all missing dates as either an average, or all as 0 would be incorrect.

Would it make sense for this location, to impute some of the missing dates as 0, and the rest as an average? Sorry if this has been asked. I'm a novice and not sure on my wording, and choices. Thanks for any help!

Edit: The p-value is from a binomial test. I counted N/A as the number of 'successes', ENTRIES as number of trials, and p= success rate from 97.5th percentile of CI.

I got my confidence interval from 10,000 Bernoulli trials of drawing 1,000 samples from a Poisson distribution (using MEAN VALUE as the event rate,lambda). Would count each 0 as success. This confidence interval (expressed as success rates) would then be multiplied by ENTRIES for each location to give the range of expected 0 count days.

Unsure if I used a suitable model, still learning.

• Could you please tell us how the values in the "P-VALUE" column are determined? What is your model and what test are you applying? – whuber Nov 25 '18 at 21:52


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Question

# Area under velocity-time graph depicts a physical quantity that has the unit _____.

A
m
B
ms1
C
ms2
D
s

Solution

## The correct option is A mWe know, velocity=displacement of the bodytime taken i.e, v=dt, where v is the velocity in ms−1 and t is the time taken in s. ⟹d=v×t Hence, the area under a velocity-time graph gives the displacement of the body. The S.I. unit of displacement is m.Physics

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Double/Debiased Machine Learning for Dynamic Treatment Effects via $g$-Estimation
Greg Lewis · Vasilis Syrgkanis
We consider the estimation of treatment effects in settings when multiple treatments are assigned over time and treatments can have a causal effect on future outcomes or the state of the treated unit. We propose an extension of the double/debiased machine learning framework to estimate the dynamic effects of treatments, which can be viewed as a Neyman orthogonal (locally robust) cross-fitted version of $g$-estimation in the dynamic treatment regime. Our method applies to a general class of non-linear dynamic treatment models known as Structural Nested Mean Models and allows the use of machine learning methods to control for potentially high dimensional state variables, subject to a mean square error guarantee, while still allowing parametric estimation and construction of confidence intervals for the structural parameters of interest. These structural parameters can be used for off-policy evaluation of any target dynamic policy at parametric rates, subject to semi-parametric restrictions on the data generating process. Our work is based on a recursive peeling process, typical in $g$-estimation, and formulates a strongly convex objective at each stage, which allows us to extend the $g$-estimation framework in multiple directions: i) to provide finite sample guarantees, ii) to estimate non-linear effect heterogeneity with respect to fixed unit characteristics, within arbitrary function spaces, enabling a dynamic analogue of the RLearner algorithm for heterogeneous effects, iii) to allow for high-dimensional sparse parameterizations of the target structural functions, enabling automated model selection via a recursive lasso algorithm. We also provide guarantees for data stemming from a single treated unit over a long horizon and under stationarity conditions.


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# Tissue to Air Ratio

Tissue-Air Ratio (TAR) is a term used in radiotherapy treatment planning to help calculate absorbed dose to water in conditions other than those directly measured.

## Definition

The TAR at a point in a water phantom irradiated by a photon beam is taken to be the ratio of the total absorbed dose at that point to the absorbed dose at the same point in a minimal-scatter phantom with just-sufficient build-up.[1][2]

Tissue-air ratio is defined as the ratio of the dose to water at a given depth to the dose in air measured with a buildup cap:

[TEX] TAR=\frac{D(f,z)}{D(f,0)} [/TEX]

where D(f,z) is the dose at a given depth z and distance focus-detector f; and D(f,0) is the dose in air (z=0).

Measurements for each are taken using an ion chamber for identical source to detector distances and field sizes.[3]


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# Can anyone identify these plots? [duplicate]

I need to produce some plots that look like these but I'm not sure what they are called in mathematica, can anyone identify them ?

Update: I want to plot triples of the form (xvalue, yvalue, intensity) in a graph like that

-

## marked as duplicate by Jens, Simon Woods, whuber, Oleksandr R., Yves KlettMar 27 '13 at 19:35

Try DensityPlot! –  PlatoManiac Mar 27 '13 at 15:17
DensityPlot appears to be for plotting functions, I have triples that I want to plot corresponding to (xvalue, yvalue, intensity) Is there a function for doing this ? –  Aaron Kalair Mar 27 '13 at 15:24
It's probably ArrayPlot. There's also MatrixPlot, Image, Graphics[Raster[...]], and ListDensityPlot (which can interpolate). For triples you need ListDensityPlot or see this –  Szabolcs Mar 27 '13 at 15:26

It might be ListDensityPlot with an InterpolationOrder of 0 and a black/white ColorFunction

http://imgur.com/DPCa78q

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# Quake 2 PVS, Realigned Lightmaps and Colour Lightmaps

932 views

Quake 2 stores its visibility lists differently to Quake 1 - as close leaves on the BSP tree will usually share the same visibility information, the lists are grouped into clusters (Quake 1 stored a visibility list for every leaf). Rather than go from the camera's leaf to find all of the other visible leaves directly, you need to use the leaf's cluster index to look up which other clusters are visible, then search through the other leaves to find out which reference that cluster too.

In a nutshell, I now use the visibility cluster information in the BSP to cull large quantities of hidden geometry, which has raised the framerate from 18FPS (base1.bsp) to about 90FPS.

I had a look at the lightmap code again. Some of the lightmaps appeared to be off-centre (most clearly visible when there's a small light bracket on a wall casting a sharp inverted V shadow on the wall underneath it, as the tip of the V drifted to one side). On a whim, I decided that if the size of the lightmap was rounded to the nearest 16 diffuse texture pixels, one could assume that the top-left corner was not at (0,0) but offset by 8 pixels to centre the texture. This is probably utter nonsense, but plugging in the offset results in almost completely smooth lightmaps, like the screenshot above.

Before and after - coloured lightmaps.

I quite like Quake 2's colour lightmaps, and I also quite like the chunky look of the software renderer. I've modified the pixel shader for the best of both worlds. I calculate the three components of the final colour individually, taking the brightness value for the colourmap from one of the three channels in the lightmap.

float4 Result = 1;ColourMapIndex.y = 1 - tex2D(LightMapTextureSampler, vsout.LightMapTextureCoordinate).r;Result.r = tex2D(ColourMapSampler, ColourMapIndex).r;ColourMapIndex.y = 1 - tex2D(LightMapTextureSampler, vsout.LightMapTextureCoordinate).g;Result.g = tex2D(ColourMapSampler, ColourMapIndex).g;ColourMapIndex.y = 1 - tex2D(LightMapTextureSampler, vsout.LightMapTextureCoordinate).b;Result.b = tex2D(ColourMapSampler, ColourMapIndex).b;return Result;
There is no impact on framerate at this stage (the rest of the code is the problem - I'm not even batching by texture at the moment).

There are no comments to display.


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File Storage and the Editor Pane

When a new file is created (using either the File —> Add New Data File… menu command, the New Data File button ( ) on the toolbar, or the keyboard command Ctrl + N), a dialog is provided to name the new file and choose the folder where it should be stored. The initial folder location provided in the dialog will be that containing the current project file. Once a data file has been created, a user may rename it using the File —> [file name] —> Rename [file name] menu command. Renaming this way also renames the file on the hard drive.

Users who are accustomed to working with data files in other text editors will want to be mindful of the project system in PFC, as described in the “Projects: Further Description” topic. The main thing to bear in mind is that while a data file is simultaneously open in PFC and in another editor, changes made on either side will not be reflected on the other. In addition, the “Save” command in PFC and that of an outside editor are independent of each other; either will overwrite the last saved version of the file regardless of which program previously saved it. This should be kept in mind when saving projects, since doing so automatically saves all open project items.


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Q

# By repeated subtraction of odd numbers starting from 1,find whether the following numbers are perfect squares or not? If the number is a perfect square then find its square root.(iv) 49

By repeated subtraction of odd numbers starting from 1, find whether the following numbers are perfect squares or not? If the number is a perfect square then find its square root.

(iv) 49

Views

We have $\sqrt{49}$ . Then

49 - 1 =  48

48 - 3 = 45

45 - 5 = 40

40 - 7 = 33

33 - 9 = 24

24 - 11 = 13

13 - 13 = 0 .

We get zero on the 7th step so $\sqrt{49} = 7$

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Inter-integrated Circuit (I2C) is a communication protocol that is used to connect many embedded devices. In our case, we are going to use it to connect an Organic LED (OLED), a tiny screen for more display goodness.

Assuming that you ordered your chip from someplace else (Aliexpress/Ebay), you might not be able to find documentation for this module. Alongside serving as a tutorial for the ULCK kit, this also serves as a guide to getting most OLED modules to work with other platforms.

#### Programming

Your OLED module other than the VCC/VDD and GND, has two other lines, SDA and SCL/SCK. These you'll have to connect to the respective SDA and SCL/SCK output pins on your device.

For the ESP8266 module, we will be using Adafruit's I2C Library and Adafruit's GFX Library to display images. But we have to make a few changes in order to get our screen to work.

Find where your Libraries folder is (usually in ~/Arduino/Libraries) and open the Adafruit_SSD1306.h file that you have just downloaded. Assuming that your OLED screen is 128 x 64, find the line #define SSD1306_128_64 and uncomment it. If this is not done the images on the OLED module might appear to be stretched. If there any other uncommented lines, comment them. Make sure only one of those four lines are defined.

Now going to the code, to start quickly, we'll be using Adafruit's I2C 128 x 64 example. In the code, instead of using display.begin(SSD1306_SWITCHCAPVCC, 0x3D), and change 0x3D to 0x3C.

Also note that if you are using a WeMos Mini, you will have to change the line #define OLED_RESET 4 to #define OLED_RESET 0 in the example sketch for your OLED to work because pin 4 is used for SDA communications on the WeMos board.

For the ATTINY85 module, Digispark's OLED example works without additional editing. You should be able to upload your code and get your OLED screen working immediately.

Both the ESP8266 and the ATTINY85 are compatible, however, while the ATTINY85 might be running up to its limit at 80% of memory used with the Digispark OLED sketch, for the ESP8266, the Adafruit example sketch takes up about 20% of its total memory.


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# XAT 2014

Instructions

For the following questions answer them individually

Question 71

Question 72

Question 73

Question 74

# Aditya has a total of 18 red and blue marbles in two bags (each bag has marbles of both colors). Amarble is randomly drawn from the first bag followed by another randomly drawn from thesecond bag, the probability of both being red is 5/16. What is the probability of both marbles being blue?

Instructions

Answer the questions based on the given data on the tourism sector in India.

Question 75

Question 76

Question 77

# Let ‘R’ be the ratio of Foreign Exchange Earnings from Tourism in India (in US \$ million) to Foreign Tourist Arrivals in India (in million). Assume that R increases linearly over the years. If we draw a pie chart of R for all the years, the angle subtended by the biggest sector in the pie chart would be approximately:

Instructions

Answer the questions based on the following information given below.
The exhibit given below compares the countries (first column) on different economic indicators (first row), from 2000-2010. A bar represents data for one year and a missing bar indicates missing data. Within an indicator, all countries have same scale.

Question 78

Question 79

Question 80

OR