text:
## LilVeroDez13 Group Title Ugh another story problem. Hate these! one year ago one year ago

1. LilVeroDez13 Group Title

At a pet show the ratio of dogs to cats is 4:3 if the number of cats is 45 find the number of dogs at the show?

2. shubham.bagrecha Group Title

story problems are generally more easier.

3. LilVeroDez13 Group Title

:/ not for me

4. shubham.bagrecha Group Title

its on you how you interpret.

5. Shane_B Group Title

dogs to cats is 4:3 so cats to dogs is 3:4 Knowing that you can just relate the ratios:$\frac{3}{4}=\frac{45}{x}$

6. shubham.bagrecha Group Title

let the common ratio be x. so no. of dogs = 4x no. of cats = 3x now , it is given that no. of cats = 45 = 3x find x. find no. of dogs.

7. LilVeroDez13 Group Title

would it b 60?

8. shubham.bagrecha Group Title

yes

9. Shane_B Group Title

I guess you could skip the first step to get the same answer:$\frac{4}{3}=\frac{x}{45}$

10. Shane_B Group Title

Yes. 60.

11. LilVeroDez13 Group Title

thanks!


text:
1

### IIT-JEE 2000

Subjective
For any positive integer $$m$$, $$n$$ (with $$n \ge m$$), let $$\left( {\matrix{ n \cr m \cr } } \right) = {}^n{C_m}$$
Prove that $$\left( {\matrix{ n \cr m \cr } } \right) + \left( {\matrix{ {n - 1} \cr m \cr } } \right) + \left( {\matrix{ {n - 2} \cr m \cr } } \right) + ........ + \left( {\matrix{ m \cr m \cr } } \right) = \left( {\matrix{ {n + 1} \cr {m + 2} \cr } } \right)$$

Hence or otherwise, prove that $$\left( {\matrix{ n \cr m \cr } } \right) + 2\left( {\matrix{ {n - 1} \cr m \cr } } \right) + 3\left( {\matrix{ {n - 2} \cr m \cr } } \right) + ........ + \left( {n - m + 1} \right)\left( {\matrix{ m \cr m \cr } } \right) = \left( {\matrix{ {n + 2} \cr {m + 2} \cr } } \right).$$.

Solve it.
2

Subjective
Let $$n$$ be any positive integer. Prove that $$\sum\limits_{k = 0}^m {{{\left( {\matrix{ {2n - k} \cr k \cr } } \right)} \over {\left( {\matrix{ {2n - k} \cr n \cr } } \right)}}.{{\left( {2n - 4k + 1} \right)} \over {\left( {2n - 2k + 1} \right)}}{2^{n - 2k}} = {{\left( {\matrix{ n \cr m \cr } } \right)} \over {\left( {\matrix{ {2n - 2m} \cr {n - m} \cr } } \right)}}{2^{n - 2m}}}$$$for each non-be gatuve integer $$m \le n.$$ $$\,\left( {Here\left( {\matrix{ p \cr q \cr } } \right) = {}^p{C_q}} \right).$$ ## Answer Solve it. 3 ### IIT-JEE 1998 Subjective Let $$p$$ be a prime and $$m$$ a positive integer. By mathematical induction on $$m$$, or otherwise, prove that whenever $$r$$ is an integer such that $$p$$ does not divide $$r$$, $$p$$ divides $${}^{np}{C_r},$$ [Hint: You may use the fact that $${\left( {1 + x} \right)^{\left( {m + 1} \right)p}} = {\left( {1 + x} \right)^p}{\left( {1 + x} \right)^{mp}}$$] ## Answer Solve it. 4 ### IIT-JEE 1997 Subjective Let $$0 < {A_i} < n$$ for $$i = 1,\,2....,\,n.$$ Use mathematical induction to prove that $$\sin {A_1} + \sin {A_2}....... + \sin {A_n} \le n\,\sin \,\,\left( {{{{A_1} + {A_2} + ...... + {A_n}} \over n}} \right)$$$

where $$\ge 1$$ is a natural number. {You may use the fact that $$p\sin x + \left( {1 - p} \right)\sin y \le \sin \left[ {px + \left( {1 - p} \right)y} \right],$$ where $$0 \le p \le 1$$ and $$0 \le x,y \le \pi .$$}

Solve it.

### Joint Entrance Examination

JEE Main JEE Advanced WB JEE

### Graduate Aptitude Test in Engineering

GATE CSE GATE ECE GATE EE GATE ME GATE CE GATE PI GATE IN

NEET

Class 12

format: plain


text:
# Operations on Formulas

## Checking Satisfiability

The standard way of checking whether formulas are satisfiable involves the following four steps:

1. Construct a context for the relevant logic
2. Assert the formulas in this context
3. Call check_context
4. Optionally, get a model from the context

Since Yices 2.6.2, the API includes functions that implement these four steps seamlessly. The new functions also gives access to a new feature of Yices 2.6.2, namely, the use of third-party Boolean satisfiability solvers for bit-vector problems.

smt_status_t yices_check_formula(term_t f, const char *logic, model_t **model, const char *delegate)

Check satisfiability of formula f

This returns STATUS_SAT if f is satisfiable, STATUS_UNSAT if f is not satisfiable, or STATUS_ERROR if there is an error.

Parameters

• f must be a Boolean term
• logic must be either NULL or be the name of an SMT logic (like “QF_UFIDL”)
• model must be either NULL or be a pointer to a variable in which to store a model
• delegate mut be either NULL or the name of a delegate, that is, an external SAT solver

The function first checks whether f is trivially satisifiable or unsatisfiable. If that fails, the function performs the four steps listed previously:

1. Construct a context specialized for the given logic.

If logic is NULL, a generic context is used instead with default configuration. This context supports linear arithmetic, bit-vectors, uninterpreted functions, and arrays (see _context_operations).

2. Assert f in this context.

3. Check whether the context is satisfiable.

4. If the context is satisfiable and model is not NULL, the function returns a model of f in the model variable.

This model must be deleted when no-longer needed by calling yices_free_model.

Delegates

A delegate is a SAT solver to use as backend when checking satisfiability of a bit-vector formula. The delegate parameter is ignored and has no effect unless the logic is “QF_BV”. In the latter case, three different delegates can be used:

These three delegates are known to Yices but support for CaDiCaL and CryptoMiniSat is optional. They may or may not be available depending on how the Yices library was configured and compiled. The “y2sat” delegate is always available.

If delegate is NULL, the default SAT solver internal to Yices is used (which can be much slower than state-of-the-art solvers such as CaDiCaL).

Examples

The following code fragment shows how to check satisfiability of a formula f in the QF_LRA theory and obtain a model:

model_t *result;
smt_status_t status = yices_check_formula(f, "QF_LRA", &result, NULL);
if (status == STATUS_SAT) {
// a model is returned in result
yices_pp_model(stdout, result, 100, 100, 0);
...
// delete the model when we don't need it
yices_free_model(result);
}

If the model is not needed, call the function as follows:

smt_status_t status = yices_check_formula(f, "QF_LRA", NULL, NULL);

For a bitvector formula f, we can pass a delegate as follows:

smt_status_t status = yices_check_formula(f, "QF_BV", &result, "cadical");

Error report

smt_status_t yices_check_formulas(const term_t f[], uint32_t n, const char *logic, model_t **model, const char *delegate)

Check satisfiability of an array formula f

This is similar to yices_check_formula except that it checks satisfiability of a conjunction of n formulas.

Parameters

• f must be an array of Boolean term
• n is the size of array f
• logic must be either NULL or be the name of an SMT logic (like “QF_UFIDL”)
• model must be either NULL or be a pointer to a variable in which to store a model
• delegate mut be either NULL or the name of a delegate, that is, an external SAT solver

The last three parameters have the same meaning as in yices_check_formula. The returned value and error codes are as in this function too.

int32_t yices_has_delegate(const char *delegate)

Check whether the given delegate is supported.

Return 0 if delegate is not the name of a known delegate, or if it’s known but not available in this version of the Yices library.

Return 1 if delegate is NULL or if it’s the name of a delegate that’s available in this version of the Yices library.

## Export to DIMACS

It is possible to use Yices to export the results of bit-blasting. Input to this process is a formula or array of formulas in the QF_BV logic. Bit-blasting converts this input into a equisatifiable Boolean formula in Conjunctive Normal Form (CNF). The CNF is exported in the DIMACS format, which is used by all modern SAT solvers.

Bit-blasting starts by applying simplifications and rewriting rules to the input problem. This preprocessing may be sufficient to determnine whether the input is satisfiable or not. In such cases, exporting to DIMACS cannot be performed as no CNF is constructed.

The following two functions process formulas in the QF_BV logic. They first perform preprocessing and simplification. If the formulas are solved by this preprocessing, the functions return the status (either STATUS_SAT or STATUS_UNSAT). Otherwise, the functions construct a CNF formula and write it to a file. Optionally, the functions can perform an extra round of simplification to the CNF formula before exporting it.

int32_t yices_export_formula_to_dimacs(term_t f, const char *filename, int32_t simplify_cnf, smt_status_t *status)

Export a bit-vector formula to CNF

Parameters

• f must be a Boolean term in the QF_BV theory
• filename is the name of a file in which to store the CNF
• simplify_cnf enables CNF simplification using the “y2sat” SAT solver
• staus is a pointer to a variable that will store the formula’s status if no DIMACS file is produced.

Returned Value

The function returns an integer code that indicates whether a DIMACS file was produced, or the formula was solved by preprocessing, or an error occurred:

• a negative code (-1) indicates an error while processing the formula or while writing the DIMACS file.

• the value 0 means that the formula was solved by preprocessing and that no file was created.

In this case, the formula’s status is returned in variable status.

• the value 1 means that a DIMACS file was successfully generated.

Error Reports

Other error codes are possible if f is not in the QF_BV theory

If the error code is OUTPUT_ERROR, it is possible to get more information on the error by using standard functions such as perror and strerror.

int32_t yices_export_formulas_to_dimacs(const term_t f[], uint32_t n, const char *filename, int32_t simplify_cnf, smt_status_t *status)

Export an array of bit-vector formulas to CNF

This is similar to yices_export_formula_to_dimacs except that it processes an array of n bit-vector formulas.

Parameters
• f must be an array of Boolean terms in the QF_BV theory
• n is the size of array f
• filename is the name of a file in which to store the CNF
• simplify_cnf enables CNF simplification using the “y2sat” SAT solver
• staus is a pointer to a variable that will store the formula’s status if no DIMACS file is produced.

The returned code and error reports are the same as yices_export_formula_to_dimacs.


text:
## Applied Math Seminar: A Scalable Matrix-Free Eigensolver for Studying Many-Body Localization

Seminar | February 19 | 4-5 p.m. | 939 Evans Hall

Roel Van Beeumen, LBNL

Department of Mathematics

We present a scalable and matrix-free eigensolver for studying nearest-neighbor Heisenberg spin chain plus random on-site disorder models that undergo a many-body localization (MBL) transition. This type of problem is computationally challenging because its dimension grows exponentially with the physical system size, and the solve must be iterated many times to average over different configurations of the random disorder. For each eigenvalue problem, eigenvalues from different regions of the spectrum and their corresponding eigenvectors need to be computed. Traditionally, the interior eigenstates for a single eigenvalue problem are computed via the shift-and-invert Lanczos algorithm. Due to the extremely high memory footprint of the LU factorizations, this technique is not well suited for large number of spins $L$, e.g., one needs thousands of compute nodes on modern high performance computing infrastructures to go beyond $L = 24$. We propose a new matrix-free approach that does not suffer from this memory bottleneck and even allows for simulating spin chains up to $L = 24$ spins on a single compute node. We discuss the OpenMP and hybrid MPI–OpenMP implementations of matrix-free block matrix-vector operations that are the key components of the new approach. The efficiency and effectiveness of the proposed algorithm is demonstrated by computing eigenstates in a massively parallel fashion, and analyzing their entanglement entropy to gain insight into the MBL transition.

linlin@berkeley.edu


text:
Posted on Categories:Corporate Finance, 企业融资, 金融代写

# 金融代写|企业融资代写Corporate Finance代考|LRS28/TKMS13 Short-Term Solvency

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## 金融代写|企业融资代写Corporate Finance代考|Short-Term Solvency

Ratios of short-term solvency measure the ability of the firm to meet recurring financial obligations (that is, to pay its bills). To the extent a firm has sufficient cash flow, it will be able to avoid defaulting on its financial obligations and, thus, avoid experiencing financial distress. Accounting liquidity measures short-term solvency and is often associated with net working capital, the difference between current assets and current liabilities. Recall that current liabilities are debts that are due within one year from the date of the balance sheet. The basic source from which to pay these debts is current assets.

The most widely used measures of accounting liquidity are the current ratio and the quick ratio.

Current Ratio To find the current ratio, divide current assets by current liabilities. For the U.S. Composite Corporation, the figure for $20 \mathrm{X} 2$ is
$$\text { Current ratio }=\frac{\text { Total current assets }}{\text { Total current liabilities }}=\frac{761}{486}=1.57$$
If a firm is having financial difficulty, it may not be able to pay its bills (accounts payable) on time or it may need to extend its bank credit (notes payable). As a consequence, current liabilities may rise faster than current assets and the current ratio may fall. This may be the first sign of financial trouble. Of course, a firm’s current ratio should be calculated over several years for historical perspective, and it should be compared to the current ratios of other firms with similar operating activities.

Quick Ratio The quick ratio is computed by subtracting inventories from current assets and dividing the difference (called quick assets) by current liabilities:
$$\text { Quick ratio }=\frac{\text { Quick assets }}{\text { Total current liabilities }}=\frac{492}{486}=1.01$$
Quick assets are those current assets that are quickly convertible into cash. Inventories are the least liquid current assets. Many financial analysts believe it is important to determine a firm’s ability to pay off current liabilities without relying on the sale of inventories.

## 金融代写|企业融资代写Corporate Finance代考|Activity

Ratios of activity are constructed to measure how effectively the firm’s assets are being managed. The level of a firm’s investment in assets depends on many factors. For example, Toys ” Us might have a large stock of toys at the peak of the Christmas season; yet that same inventory in January would be undesirable. How can the appropriate level of investment in assets be measured? One logical starting point is to compare assets with sales for the year to arrive at turnover. The idea is to find out how effectively assets are used to generate sales.

Total Asset Turnover The total asset turnover ratio is determined by dividing total operating revenues for the accounting period by the average of total assets. The total asset turnover ratio for the U.S. Composite Corporation for $20 \mathrm{X} 2$ is
$$\text { Total asset turnover }^8=\frac{\text { Total operating revenues }}{\text { Total assets (average) }}=\frac{2,262}{1,810.5}=1.25$$
Average total assets $=\frac{1,879+1,742}{2}=1,810.5$
This ratio is intended to indicate how effectively a firm is using all of its assets. If the asset turnover ratio is high, the firm is presumably using its assets effectively in generating sales. If the ratio is low, the firm is not using its assets to their capacity and must either increase sales or dispose of some of the assets. One problem in interpreting this ratio is that it is maximized by using older assets because their accounting value is lower than newer assets. Also, firms with relatively small investments in fixed assets, such as retail and wholesale trade firms, tend to have high ratios of total asset turnover when compared with firms that require a large investment in fixed assets, such as manufacturing firms.

## 金融代写|企业融资代写Corporate Finance代考|Short-Term Solvency

$$\text { Current ratio }=\frac{\text { Total current assets }}{\text { Total current liabilities }}=\frac{761}{486}=1.57$$

$$\text { Quick ratio }=\frac{\text { Quick assets }}{\text { Total current liabilities }}=\frac{492}{486}=1.01$$

## 金融代写|企业融资代写Corporate Finance代考|Activity

$$\text { Total asset turnover }{ }^8=\frac{\text { Total operating revenues }}{\text { Total assets (average) }}=\frac{2,262}{1,810.5}=1.25$$

## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。


text:
# Heat in an Engine

1. Jul 30, 2006

### KingTutATL

The hot reservoir for a Carnot engine has a temperature of 890K, while the cold reservoir has a temperature of 670K. The heat input for this engine is 4800J. The 670K reservoir also serves as the hot reservoir for a second Carnot engine. This second engine uses the rejected heat of the first engine as input and extracts additional work from it. The rejected heat of the first engine as input and extrats additional work from it. The rejected heat from the second engine goes into a reservoir that has a temperature of 420K. Find the total work delivered by the 2 engines?

I'm lost

2. Jul 30, 2006

### Andrew Mason

What is the efficiency of a Carnot engine? Remember:

$$\eta = \frac{W_{output}}{Q_H}$$

AM

3. Aug 1, 2006

### Mute

Also useful will be the fact that the efficiency is also

$$\eta = 1 - \frac{T_C}{T_H}$$

So, calculate the work output from the first engine, from that calculate the heat transfered to the first cold resevior... Wash, rinse, repeat to find the work output of the second engine, and you're pretty much in the clear.


text:
# The Odious – Combaticus (playthrough)

Want to see something cool as fuck?

Of course you do.

Here it is.

On January 7 2013, this entry was posted and


text:
# Small confusion regarding logarithmic formula

Tags:
1. Jan 29, 2015

### 22990atinesh

I've a small confusion about formula
$\log^3 n = \log \log \log n$
or $\log^3 n = (\log n)^3$

2. Jan 29, 2015

### Staff: Mentor

That's the one you want.

3. Jan 29, 2015

### Staff: Mentor

In exactly the same way, cos2(x) does not mean cos(cos(x)), but rather it means cos(x) * cos(x) = (cos(x))2. The exponent indicates repeated multiplication, not repeated function composition.

4. Jan 29, 2015

### HallsofIvy

It is not uncommon to put a an exponent in parentheses to indicate a repeated composition.
That is, $(log(x))^{(3)}$ or $log^{(3)}(x)$ is "log(log(log(x)))".

Unfortunately, that is also often used to indicate the third derivative so you must be careful to state which!

Last edited by a moderator: Jan 30, 2015
5. Jan 31, 2015

### 22990atinesh

You mean $\log^{(3)} n = (\log n)^{(3)} = \log (\log(\log n))$
$\log^3 n = (\log n)^3$

6. Jan 31, 2015

### Staff: Mentor

The above is what HallsOfIvy said. I haven't seen it, myself, but I have seen f(3), with parentheses around the exponent, to indicate the third derivative.
This is what I said.

7. Jan 31, 2015

### 22990atinesh

I know, I was just rechecking from you. :)


text:
# If GRB 080319B happened next to nearest star: Proxima Centauri, what effect would that have had on us?

From a Reddit post

GRB 080319B was a gamma-ray burst (GRB) detected by the Swift satellite at 06:12 UTC on March 19, 2008. The burst set a new record for the farthest object that was observable with the naked eye: it had a peak visual apparent magnitude of 5.7 and remained visible to human eyes for approximately 30 seconds. The magnitude was brighter than 9.0 for approximately 60 seconds. If viewed from 1 AU away, it would have had a peak apparent magnitude of −67.57 (21 quadrillion times brighter than the Sun seen from Earth). Wiki

Someone asked what would happen if that GRB happened from the distance of Proxima Centauri, what effect would that have had on us?

• Question is fine and well-received, two well-received answers support this as well. The vote to close is unproductive, clutters the review queue and makes unnecessary work for others
– uhoh
Mar 21, 2021 at 23:19
• Comments are not for extended discussion; this conversation has been moved to chat. Mar 24, 2021 at 12:58

Faster than light's answer is fine if the gamma ray burst is "pointing" towards us. The emission from rapidly moving material in a GRB is thought to be beamed in the direction of that motion, along the rotation axis of the progenitor object in fact.

The opening angle of the beam may only be a few degrees (e.g. Frail et al. 2001), which would mean that for random orientations of the GRB source there would only be about a 1 in 500 chance of the solar system being "in the beam". Thus the highly destructive conclusion of Faster than Light's answer is a remote possibility.

As the fireball phase of the GRB develops then it is thought that the beam opening angle will widen over days and weeks, but of course the source brightness also fades drastically on these timescales too. It should also be noted that most of the highly destructive X-ray and Gamma ray emission arises during the tightly beamed phase within minutes or hours of the burst.

Thus although I'm not saying we're not "screwed", I am saying that the issue is more complex than scaling the apparent magnitude of a GRB and comparing it to the Sun. I suspect that in most cases the effects would be similar to the explosion of a supernova at the distance of Proxima Cen.

The conclusions I can garner from such as https://physics.stackexchange.com/questions/26578/near-earth-supernova?rq=1 , suggest that would still likely remove the ozone layer for some time and therefore could have serious and deadly consequences for life on Earth.

• 'The opening angle of the beam may only be a few tenths of a degree (e.g. Frail et al. 2001), which would mean that for random orientations of the GRB source there would only be about a 1 in 500 chance of the solar system being "in the beam".' I find the number 1/500 in the paper, but wouldn't the corresponding angle be $\arccos(1-1/500) \approx 3.6^\circ$?
– JiK
Mar 20, 2021 at 21:54
• @JiK I misread the x-axis of the plot. Mar 20, 2021 at 22:42


text:
# Math Help - asymptote

1. ## asymptote

What is the asymptote for g(x)=log(5)2x
What exactly is an asymptote?

2. Originally Posted by nellabrown
What is the asymptote for g(x) ??
well, we would need to know what g(x) is to help you with that...

What exactly is an asymptote?
asymptotes are lines that our function gets close to as we approach particular value(s) in the domain. there are three types: vertical, horizontal and oblique. you should look these up in a google search or something. you need to know what asymptotes are and how to find them if you are to answer problems of this nature.

3. Hello,

To look out asymptotes, you have to study limits at infinites and at particular points, such as points where the function is not defined.

4. Originally Posted by nellabrown
What is the asymptote for g(x)=log(5)2x? I cannot get this to sink in.


text:
## contrapositive in a sentence

The contrapositive of "p implies q" is "not q implies not p". Now he wants to prove it using the contrapositive, just as we saw last week. The fact that this little bit of the sentence can be pulled out into a sentence of its own means that grammatically it is called a “relative clause”. If 2 + 3 5, then today is not Friday. The negation of S is A, and A is false. One definition of contrapositive is: "The contrapositive of a conditional statement is formed by negating both the hypothesis and the conclusion, and then interchanging the resulting negations." That's a reasonable definition, but if your logic course isn't fresh in your mind, it might not mean much. The law of contrapositive states that, in a conditional, if the conclusion is false, then the hypothesis must be false also. 1 Never begin a sentence with a mathematical symbol. It does BOTH the jobs of the INVERSE and the CONVERSE. Contrapositive. Example sentences with "contrapositive", translation memory. Complete the sentences below, filling in A-G from the following list, and T … In sentence 1 the reporters ascribe a mental state--surprise--to the Bushies. Mouths open, not yet inured to the sight, many adopt the famous sculpture's contrapposto. The Contrapositive of a Conditional Statement. What does contraposition mean? Agreed? This is … Let S be the statement: All women are humans. 6 Use the rst person plural. The contrapositive statement is that a graph with a cycle does not have treewidth 1 . If today is Friday, then 2 + 3 = 5. This in fact is the basic approach of contrapositive proof, summarized as follows. View Answer. Here, your statement is "if c and d are integers then cd is an integer" so the contrapositive is "if cd is not an integer then c and d are not both integers". View Answer. Now we introduce the notion of a contrapositive of a conditional. Contrastive Lin So the setup for contrapositive proof is very simple. ‘The contrapositive of the inference is logically equivalent - X simulates Y, X does not have P therefore Y does not - where P is understands Chinese.’ More example sentences ‘And you know also the contrapositive, that your being at place X entails that you are not then in a tank on Alpha Centauri.’ A contrapositive statement is when we interchange the hypothesis and conclusion of the sentence and negate both of them. So what does “contrapositive” mean? 7 Use the active voice. Contrapositive The contrapositive of a conditional statement is formed by negating both the hypothesis and the conclusion, and then interchanging the resulting negations. 3. a contrastive analysis of British and Australian English. The "contrapositive" of "if A then B" is "if not B then not A". This packet will cover "if-then" statements, p and q notation, and conditional statements including contrapositive, inverse, converse, and biconditional. Hi there! Converse, Contrapositive, Negation? Contraposition definition is - the relationship between two propositions when the subject and predicate of one are respectively the negation of the predicate and the negation of the subject of the other. So, the symbolic form is p → q where-p : … See more. [The contrapositive of a statement always has the same truth-value as the original statement, because they are equivalent.] Contrapositive of a conditional statement • The contrapositive of the conditional statement p q is ~ q ~ p • A conditional and its contrapositive are equivalent. Suppose $$\sim Q$$. The first line of the proof is the sentence "Suppose Q is not true." I will not ski tomorrow only if it does not snow today. Or, in symbols: The contrapositive … (noun) To form the contrapositive of the conditional statement, interchange the hypothesis and the conclusion of the inverse statement. 2 Use correct punctuation. 3 Separate mathematical symbols and expressions with words. And here’s where the grammar gets particularly tricky. An opposite position; antithesis. The outline should include phonemic contrastive charts of the consonants and vowels. In the language system, they are contrastive yet unified. Proposition If P, then Q. In fact, the contrapositive is true because the original statement is true: if a part of BC were not in Canada, then both the original statement and the contrapositive would be false. Answered By . Proof. Contrapositive Statement-If I will not go, then he does not stay. Doctor Fenton replied: Hi Rahul, I think this is primarily a matter of interpretation. Just like twins. Example sentences with "contrapositive", translation memory KFTT Under such circumstances , it is thought that railway relevant people and railway maniacs at the time began to use this name , in contraposition to Express , as the one that means ' trains that stop at every station . There are 130 contrapositive-related words in total, with the top 5 most semantically related being inverse, antecedent, consequent, biconditional and logically equivalent.You can get the definition(s) of a word in the list below by tapping the question-mark icon next to it. If it snows today, I will ski tomorrow. : The preferred figure type was more mature and monumental, with contrapposto being used to give movement to the large, solid figures. Upvote(4) How satisfied are … We just studied conditionals, sentences that either have the form “If A, then B”, or could be rephrased in terms of such a form. Then that lead-in sentence isn’t an if-then construction, so it isn’t part of the contrapositive. Contrapositive definition, of or relating to contraposition. For example instead of showing directly p › q, one proves its contrapositive ~q › ~p (one assumes ~q and shows that it leads to ~p). [The negation of a true statement is, of course, always false.] ( open , save , copy ) en.wikipedia.org The contrapositive is certainly true because the entire province of BC is a part of Canada. 2. Sentence 2: Democrats have charged that the mass firing is a political purge, intended to squelch corruption investigations or install less independent-minded successors. In logic and mathematics, contraposition refers to the inference of going from a conditional statement into its logically equivalent contrapositive, and an associated proof method known as proof by contraposition. contractor in a sentence.. conversion in a sentence The word contrapositive 4 Avoid misuse of symbols. It is in the form of - if not q then not p. Given statement here is - A converse statement is formed by exchanging the hypothesis and conclusion of the conditional. 3. Outline for Contrapositive Proof. First, let’s agree that these sentences say the exact same thing. ... A proposition, or statement, is a sentence that is either true or false. Below is a massive list of contrapositive words - that is, words related to contrapositive. WikiMatrix. They’re contrapositives of each other. Show that the following statement is true by the method of contrapositive MEDIUM. Then, the sentence is- “We leave if he comes.” This sentence is of the form- “q if p”. More Sentences： 1 2 3 Neighbors "contrapositions" in a sentence , "contrapositive" in a sentence , "contrapositives" in a sentence , "contraposto" in a sentence , "contrappasso" in a sentence , "contrappunti" in a sentence , "contraption" in a sentence , "contraption maker" in a sentence , "contraptions" in a sentence , fr Malheureusement, au temps de Buridan, le principe de contraposition avait été préconisée par un certain nombre d'auteurs. toppr. $$\cdots$$ Therefore $$\sim P$$. Contrapositive definition is - a proposition or theorem formed by contradicting both the subject and predicate or both the hypothesis and conclusion of a given proposition or theorem and interchanging them. The logical steps in the proof are essentially the same for the argument by contradiction and the contrapositive. choose this method if from assuming ~Q more usefull things are provable than from assuming P. The contrapositive of S is E, and E is true. Suppose you have the conditional statement {\color{blue}p} \to {\color{red}q}, we compose the contrapositive statement by interchanging the hypothesis and conclusion of the inverse of the same conditional statement.. For math.. What would be the converse inverse and contrapositive of this sentence; If you want to win grand champion, then feed your pig with Purina Thanks! In other words, the contrapositive negates and switches the parts of the sentence. 48 sentence examples: 1. 4. The contrapositive of the statement "If you believe in yourself and are honest then you will get sucess" is. p → q and its contrapositive statement (∼q → ∼p) are equivalent to each other. Good. Example: Conditional: “If 9 is an odd number, […] 5 Avoid using unnecessary symbols. EASY. For example, end each sentence with a period, even if it ends with a stand-alone equation. Part-06: We have-The given sentence is- “We leave whenever he comes.” We can replace “whenever” with “if”. The contrapositive of "if x has courage then x will win", is. 4) Contrapositive Indirect proof This is a variation of conditional indirect proof method (no 3) the assumptions are reshuffeled. 2. That can be written more simply by using the fact that "not A and B" is the same as "not A or not B". The contrapositive of “If A, then B” is “If not-B, then not-A”. en Unfortunately, by Buridan's time the principle of contraposition had been advocated by a number of authors. The contrapositive of the sentence ... Its converse statement (q → p) and inverse statement (∼p → ∼q) are equivalent to each other. Converse, inverse, and contrapositive Now we can review the meanings of all three terms, in this 1999 question, which again uses an example from basic number theory: Contrapositive, Converse, Inverse Let m and n be whole numbers, and consider the statement p implies q given by " … Hi Rahul, I think this is … First, let ’ S agree that these say. 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E, and then interchanging the resulting negations course, always false. q and its contrapositive is... In sentence 1 the reporters ascribe a mental state -- surprise -- to the large, solid..

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# Energy & Grid

Xi Lu, Liang Cao, Haikun Wang, Wei Peng, Jia Xing, Shuxiao Wang, Siyi Cai, Bo Shen, Qing Yang, Chris P. Nielsen, and Michael B. McElroy. 2019. “Gasification of coal and biomass as a net carbon-negative power source for environment-friendly electricity generation in China.” Proceedings of the National Academy of Sciences, 116, 17, Pp. 8206-8213. Publisher's VersionAbstract

2019 Nov 14

# Driving and the Built Environment: Is Transit-Oriented Development Effective in Shanghai?

3:30pm to 4:45pm

## Location:

Pierce 100F, 29 Oxford Street, Cambridge

A Harvard-China Project Research Seminar with Faan Chen, Postdoctoral Fellow, Harvard-China Project, Paulson School of Engineering and Applied Sciences, Harvard University

Abstract: The rapid growth of cities such as Shanghai in China has presented many transportation, land use and climate change challenges for local government officials, planning and transit practitioners and property...

Read more about Driving and the Built Environment: Is Transit-Oriented Development Effective in Shanghai?
Jing Cao, Mun S Ho, and Wenhao Hu. 2019. “Energy consumption of urban households in China.” China Economic Review, 58, 101343. Publisher's VersionAbstract
We estimate China urban household energy demand as part of a complete system of consumption demand so that it can be used in economy-wide models. This allows us to derive cross-price elasticities unlike studies which focus on one type of energy. We implement a two-stage approach and explicitly account for electricity, domestic fuels and transportation demand in the first stage and gasoline, coal, LPG and gas demand in the second stage. We find income inelastic demand for electricity and home energy, but the elasticity is higher than estimates in the rich countries. Demand for total transportation is income elastic. The price elasticity for electricity is estimated to be −0.5 and in the range of other estimates for China, and similar to long-run elasticities estimated for the U.S.

# Solar Energy Could Turn the Belt and Road Initiative Green

June 27, 2019

Researchers quantify the region's renewable energy potential

The region covered by the Belt and Road Initiative (BRI) has significant potential to be powered by solar energy, researchers report June 27 in the journal Joule. Less than 4 percent of the maximum solar potential of the region could meet the BRI's electricity demand for 2030. The research suggests a possible solution to reduce BRI countries' need for fossil fuels as they develop. This is the first time the renewable energy potential of the region is quantified.

The Chinese...


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# 构造

## 例题¶

### 例题 1¶

Codeforces Round #384 (Div. 2) C.Vladik and fractions

### 例题 2¶

Luogu P3599 Koishi Loves Construction

Taks2：试判断能否构造并构造一个长度为的排列，满足其个前缀积在模的意义下互不相同

### 例题 3¶

AtCoder Grand Contest 032 B

You are given an integer . Build an undirected graph with vertices with indices to that satisfies the following two conditions:

• The graph is simple and connected.
• There exists an integer such that, for every vertex, the sum of the indices of the vertices adjacent to that vertex is .

It can be proved that at least one such graph exists under the constraints of this problem.

### 例题 4¶

BZOJ 4971「Lydsy1708 月赛」记忆中的背包


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# Calculate the arc length between two points over a hyper-sphere

1. ### 7toni7

7
Good morning,

I'm trying to compute the arclength (geodesic distance) between two n-dimensional points over a n-dimensional sphere (hypersphere). Do you know if it is possible? If yes, please, I'd be very pleased if you, as experts, provide me this knowledge.

Thank you very much
Best,

2. ### tiny-tim

26,041
welcome to pf!

hi 7toni7! welcome to pf!

won't it just be the radius times the angle between them?

(which you can get from the dot-product)

3. ### 7toni7

7
Hello tiny-tim,

Thank you very much for your answer, and I'm pleased to be in this forum.
Yes, I think the same.
In 2D and 3D is just: (arclength = S, radius = R (in radians), angle between points= ω)

S = R*ω.

Then, I have 3 doubts:
1 - when dealing with dimensions greater than 3...the order of hundreds, could we do the same computation than 2 and 3 Dimensions? Could we extend this equation to higher dimensions?

2 - The dot product in N dimensions...is just the same than 2 and 3 dimensions?

3 - This formula is in an euclidean space, isn't it?

Thank you very much,
Best regards.

4. ### tiny-tim

26,041
hello 7toni7!
1. yes

2. yes: (a1,a2,…an).(b1,b2,…bn) = a1b1 + a2b2 + …anbn

(don't forget that the dot product gives you R2cosω, so you'll have to divide by R2, and then use the cos-1 button ! )

3. yes

5. ### 7toni7

7
Thank you.
Then, the arclength on a n-sphere can be computed as follows:

S = R*acos(a.b/R2).

I think it is correct. Isn't it?

A last question, do you know how to compute the intersection point between a n-vector and a n-sphere?

Thank you so much again.
Best

6. ### tiny-tim

26,041
yes
(this is from your other thread, isn't it?)

do you mean an n-vector starting from the origin (the centre of the n-sphere)?

if not, how are you defining the n-vector and the n-sphere?

7. ### 7toni7

7
Hello,

Yes, suppose that we have one n-sphere. Inside it, we have a n-point (this point different of the origin, it is another point named H).

So, I have to compute the intersection of the line (that goes from the origin of the n-sphere passing from H) with the n-sphere. do you understand? is it possible?

Thank you in advance again,
Best.

8. ### tiny-tim

26,041
ah, so the line is a diameter of the n-sphere?

then yes, it's easy …

the n-vector to the intersection will be a scalar multiple of the n-vector to H, such that the magnitude of the n-vector (ie, the square-root of the dot-product with itself) equals the radius

9. ### 7toni7

7
Well,
This is how I do it in 2 dimensions. See image.

Now, my question is: could this development be extended to N dimensions?

Thank you

10. ### tiny-tim

26,041
yes, the same formula (radius times the unit vector in the P direction) works in n dimensions …

Q = R*(P/|P|)

11. ### HallsofIvy

40,939
Staff Emeritus
In n-dimensional Euclidean space, the (hyper)sphere with radius R and center at $(a_1, a_2, ..., a_n)$ has equation $(x_1- a_1)^2+ (x_2- a_2)^2+\cdot\cdot\cdot+ (x_n- a_n)^2= R^2$. The line through the origin and point $(b_1, b_2, ..., b_n)$ is given by the parametric equations $x_1= b_1t$, $x_2= b_2t$, ..., $x_n= b_nt$. Replacing $x_1$, etc. in the equation of the sphere with those gives a single quadratic equation for t. Finding the two solutions to that equation gives the two points at which the line crosses the sphere.

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# How do you simplify (x ^ { 5} y ^ { - 9} ) ^ { 3}?

Mar 3, 2018

Since the expression is inside parenthesis, the exponent 3 will affect the entire expression

#### Explanation:

In this form, the laws of exponents tell us (a^xb^y)^n)=a^{nx}b^{ny}

So, in your case ${\left({x}^{5} {y}^{- 9}\right)}^{3} \to {x}^{5 \cdot 3} {y}^{- 9 \cdot 3} \to {x}^{15} {y}^{-} 27$

Mar 3, 2018

${x}^{15} \cdot {y}^{- 27}$
$\textcolor{red}{\left(1\right) {\left(M \cdot N\right)}^{Z} = {M}^{Z} \cdot {N}^{Z}}$
$\textcolor{red}{\left(2\right) {\left({A}^{M}\right)}^{N} = {A}^{M N}}$
${\left({x}^{5} \cdot {y}^{- 9}\right)}^{3} = {\left({x}^{5}\right)}^{3} \cdot {\left({y}^{- 9}\right)}^{3} ,$ [Applying (1)]
(x^5*y^(-9))^3=(x^((5)(3))*(y^((-9)(3))), [Applying (2)]
${\left({x}^{5} \cdot {y}^{- 9}\right)}^{3} = {x}^{15} \cdot {y}^{- 27}$


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Finding normal and tangent of a curve

• Oct 14th 2009, 03:38 PM
Finding normal and tangent of a curve
Ok, i generally know how to find a tangent and it's normal by applying the f(a+h)+f(a)/h formula, but this equation apparently has tan(trig) and I have no idea how to deal with it:
y=2tan(pix/4) at x =1
• Oct 14th 2009, 03:50 PM
skeeter
Quote:

Ok, i generally know how to find a tangent and it's normal by applying the f(a+h)+f(a)/h formula, but this equation apparently has tan(trig) and I have no idea how to deal with it:
y=2tan(pix/4) at x =1

are you aware of the general formula for the derivative of the tangent function ?

$\frac{d}{dx} \tan{u} = \sec^2{u} \cdot \frac{du}{dx}$

finding the value of the derivative using the limit definition is going to be a bit long and overwhelming algebra-wise.


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March 4, 2019

## Plan for Today:

### (1) Types of Causes

Review:

• "structural" causes
• "triggering" events
• types of conjunctural claims

### (1) Causal Theories

• Causal Logics

## Types of Causes

### structural causes

Those causes that are necessary in many sets of sufficient conditions

• thus, structural causes contribute to an effect/outcome under many different conditions

### triggering events

triggering events are those causes that are only necessary in one or a few sets of sufficient conditions - produce outcome only under specific conditions in combination with some structural causes - substitutable (some trigger, not this specific trigger needed

## Types of Causes: Example

Which are structural causes? Which are triggers?

### Global Financial Crisis of 2008

1. Growing Wealth Inequality (structural)

2. Weak Regulatory Structures (structural)

3. Slow Wage Growth (structural)

4. Collapse of Lehman Brothers investment bank (trigger)

## Types of Causes: Example

Which are structural causes? Which are triggers?

### Voting

1. Level of education

2. Competitiveness of election

3. Income

4. Raining on election day

## Types of Causes: Example

Which are structural causes? Which are triggers?

### Voting / Not Voting

1. Level of education (structural)

2. Competitiveness of election (structural)

3. Income (structural)

4. Raining on election day (structural)

Sufficient Causes Effect
A & B & Z E
A & B & Y E
A & B & X E
B & C & W E
C & D & V E
A & C & U E
A & D & T E

## Preceding Table:

In this table, causality of $$E$$ is multiple (7 different sufficient conditions) and conjunctural (each sufficient condition has multiple necessary conditions)

$$A, B, C, D$$ are "structural causes" per our definition, because they are necessary for multiple sufficient conditions

• of, $$A$$ is a cause under the MOST conditions (5), $$D$$ is a cause in the FEWEST conditions (2).

$$T,U,V,W,X,Y,Z$$ are all triggers. They are causes under one specific set of conditions

## Which causes?

Social science generally interested in structural causes.

### We want prediction

• This requires finding patterns/regularities in different contexts
• triggering events may not be relevant across contexts
• structural causes are.

Want causal patterns/regularities

## Review:

Which type of conjunctural causes?

1. Education has a positive effect on future earnings that is smaller for people who come from wealthy familities and larger for people from families with low or middle incomes.

2. Without an elite that is divided over economic policy and a growing middle class, countries will not transition from dictatorship to democracy

## Review:

Which type of conjunctural causes?

1. Education has a positive effect on future earnings that is smaller for people who come from wealthy familities and larger for people from families with low or middle incomes. (Conditional Effect)

2. Without an elite that is divided over economic policy and a growing middle class, countries will not transition from dictatorship to democracy. (Multiple Necessary Conditions)

## Causal Theory

A causal theory identifies systematic/structural causes that operate across space and time

• It is a kind of general knowledge
• Patterns/regularities within complexity
• Helps to predict what will happen
• Helps explain specific event

## Example: Democracy and Health

Might lead us to a causal claim:

"Democratizing causes countries to have better health outcomes on average."

## Causal Logic says "why"

More democracy $$\xrightarrow{}$$

Voters can remove leaders $$\xrightarrow{}$$

Leaders try to make voters happy $$\xrightarrow{}$$

Governments spend more on improving citizen health $$\xrightarrow{}$$

Better health for citizens

## Causal Logic

### causal logic:

Is a set of statements about how and why a cause $$C$$ produces its (claimed) effect $$E$$.

• Causal logic gives a causal chain that logically connects cause $$C$$ to the effect $$E$$: $$C \xrightarrow{} e_1 \xrightarrow{} e_2 \xrightarrow{} e_3 \xrightarrow{} E$$
• Each step/mechanism is causal: $$e_1$$ is a cause of $$e_2$$

Assumptions/assertions

• Each step in the logic assumes a theory of how the world works/might work (why $$e_1 \to e_2$$)
• E.g.: do we believe this logic if we don't accept $$e_2 \xrightarrow{} e_3$$

## Making a causal logic

Causal logic for claim that $$C \xrightarrow{causes} E$$:

1. Must start with cause $$C$$, end with the effect $$E$$
2. Each step is related to the next through a causal relationship
3. Not a chronological list of specific events. It is a general sequence through which one things causes another (structural causes)

## Example: Democracy and Health

More democracy $$\xrightarrow{}$$

Voters can remove leaders $$\not\xrightarrow{??}$$

Leaders try to make voters happy $$\xrightarrow{}$$

Governments spend more on improving citizen health $$\xrightarrow{}$$

Better health for citizens

#### For "??" step to work, assume that:

• Politicians motivated to stay in office

## Example: Democracy and Health

More democracy $$\xrightarrow{}$$

Voters can remove leaders $$\xrightarrow{}$$

Leaders try to make voters happy $$\not\xrightarrow{??}$$

Governments spend more on improving citizen health $$\xrightarrow{}$$

Better health for citizens

#### For "??" step to work, assume that:

• Votes are cast based on health policy/outcomes

## Why causal logics?

### Tell us how and when cause creates effect

• this can help refine the scope (generality) of the causal claim
• link to structural causes and probabilistic causal claims

### Suggest other causes

• If $$C_1 \xrightarrow{} e_1 \xrightarrow{} e_2 \xrightarrow{} e_3 \xrightarrow{} E$$
• We can find a $$C_2$$ that causes $$\to e_2 \to e_3 \to E$$

### Improve prescriptive claims

• If we can't change $$C$$, can we change $$e_2$$?
• Policies require specifics: causal logics give us more specifics on how

## Competing Causal Logics

Wealthy countries are less likely to experience civil war. Why?

### Three different logics

1. Wealth $$\xrightarrow{}$$ Larger defense budget $$\xrightarrow{}$$ Rivals deterred $$\xrightarrow{}$$ Less civil war
2. Wealth $$\xrightarrow{}$$ Higher standard of living $$\xrightarrow{}$$ Fewer grievances $$\xrightarrow{}$$ Weak support for change $$\xrightarrow{}$$ Less civil war
3. Wealth $$\xrightarrow{}$$ Lots of job opportunities $$\xrightarrow{}$$ Fewer listless young men $$\xrightarrow{}$$ Fewer rebel recruits $$\xrightarrow{}$$ Less civil war

## Competing Causal Logics

If you were a rebel (trying to start a civil war), what would you do if 1 were true? 2? 3?

### Three different logics

1. Wealth $$\xrightarrow{}$$ Larger defense budget $$\xrightarrow{}$$ Rivals deterred $$\xrightarrow{}$$ Less civil war
2. Wealth $$\xrightarrow{}$$ Higher standard of living $$\xrightarrow{}$$ Fewer grievances $$\xrightarrow{}$$ Weak support for change $$\xrightarrow{}$$ Less civil war
3. Wealth $$\xrightarrow{}$$ Lots of job opportunities $$\xrightarrow{}$$ Fewer listless young men $$\xrightarrow{}$$ Fewer rebel recruits $$\xrightarrow{}$$ Less civil war

## Competing Causal Logics

If you were the ruler (trying to prevent a civil war), what would you do if 1 were true? 2? 3?

### Three different logics

1. Wealth $$\xrightarrow{}$$ Larger defense budget $$\xrightarrow{}$$ Rivals deterred $$\xrightarrow{}$$ Less civil war
2. Wealth $$\xrightarrow{}$$ Higher standard of living $$\xrightarrow{}$$ Fewer grievances $$\xrightarrow{}$$ Weak support for change $$\xrightarrow{}$$ Less civil war
3. Wealth $$\xrightarrow{}$$ Lots of job opportunities $$\xrightarrow{}$$ Fewer listless young men $$\xrightarrow{}$$ Fewer rebel recruits $$\xrightarrow{}$$ Less civil war

When will wealth cause lower chance of civil war?


text:
# zbMATH — the first resource for mathematics

##### Examples
 Geometry Search for the term Geometry in any field. Queries are case-independent. Funct* Wildcard queries are specified by * (e.g. functions, functorial, etc.). Otherwise the search is exact. "Topological group" Phrases (multi-words) should be set in "straight quotation marks". au: Bourbaki & ti: Algebra Search for author and title. The and-operator & is default and can be omitted. Chebyshev | Tschebyscheff The or-operator | allows to search for Chebyshev or Tschebyscheff. "Quasi* map*" py: 1989 The resulting documents have publication year 1989. so: Eur* J* Mat* Soc* cc: 14 Search for publications in a particular source with a Mathematics Subject Classification code (cc) in 14. "Partial diff* eq*" ! elliptic The not-operator ! eliminates all results containing the word elliptic. dt: b & au: Hilbert The document type is set to books; alternatively: j for journal articles, a for book articles. py: 2000-2015 cc: (94A | 11T) Number ranges are accepted. Terms can be grouped within (parentheses). la: chinese Find documents in a given language. ISO 639-1 language codes can also be used.

##### Operators
 a & b logic and a | b logic or !ab logic not abc* right wildcard "ab c" phrase (ab c) parentheses
##### Fields
 any anywhere an internal document identifier au author, editor ai internal author identifier ti title la language so source ab review, abstract py publication year rv reviewer cc MSC code ut uncontrolled term dt document type (j: journal article; b: book; a: book article)
The hyperpower iteration revisited. (English) Zbl 0848.65021

This paper discusses an extension of the hyperpower method [cf. A. Ben-Israel, Math. Comput. 19, 452-455 (1965; Zbl 0136.12703)], which may be used for iterative computation of generalised inverses for example. The hyperpower method uses a basic iteration ${X}_{k+1}={X}_{k}\left(I+{R}_{k}+\cdots +{R}_{k}^{q-1}\right)$, $q\ge 2$, where $A$ and ${X}_{0}$ are arbitrary complex matrices and ${R}_{k}$ is the residual $I-A{X}_{k}$. The authors examine the method with residual modified to $P\left(I-A{X}_{k}\right)$, with $P$ idempotent.

The main thrust of the paper is analysis of the convergence of ${B}^{{q}^{k}}$ for some $B\in {ℂ}^{n×n}$, where $B$ will be related to the matrices defined previously. If the basic iteration converges, an appropriate $P$ and limit $L$ have to be found and the paper discusses such possibilities.

##### MSC:
 65F20 Overdetermined systems, pseudoinverses (numerical linear algebra) 65F10 Iterative methods for linear systems 15A09 Matrix inversion, generalized inverses


text:
Power cycle efficiency problem

1. Sep 7, 2009

brvfan20

1. The problem statement, all variables and given/known data
A power cycle has a thermal efficiency of 40% and generates electricity at a rate of 100 MW. The electricity is valued at $0.08 per kW * h. Based on the cost of fuel, the cost to supply Qin is$4.50 per GJ. For 8000 hours of operation annually, determine, in \$.
a. The value of electricity generated per year.
b. The annual fuel cost.
c. Does the difference between the results of parts (a) and (b) represent profit? Discuss.

2. Relevant equations
Thermal Efficiency = W cycle/ Q in

3. The attempt at a solution
I don't even know where to begin.
Can someone please get me on the right track.

2. Sep 7, 2009

CFDFEAGURU

First convert GJ to KW.

3. Oct 16, 2009

mangeshpjoshi

i would solve today night ,youwould have answer tomorrow ..
faithfully
mangesh joshi

4. Oct 16, 2009

brvfan20

I figured it out...thanks though!


text:
# What about the handler argument?

The second argument to the sgml subroutine is the actual code or data associated with each event. If it is a string, it will be printed literally using the output subroutine from the SGMLS::Output library; if it is a reference to a perl5 subroutine, the subroutine will be called whenever the event occurs. The following three sgml commands will have identical results:

# Example 1
sgml('<DOC>', "\\begin{document}\n");

# Example 2
sgml('<DOC>', sub {
output "\\begin{document}\n";
});

# Example 3
sub do_begin_document { output "\\begin{document}\n"; }
sgml('<DOC>', \&do_begin_document);

For simply printing a string, of course, it does not make sense to use a subroutine; however, the subroutines can be useful when you need to check the value of an attribute, perform different actions in different contexts, or perform other types of relatively more complicated post-processing.

If your handler is a subroutine, then it will receive two arguments: the SGMLS.pm event's data, and the SGMLS.pm event itself (see the SGMLS.pm documentation for a description of event and data types). The following example will print '\begin{enumerate}' if the value of the attribute TYPE is 'ORDERED', and '\begin{itemize}' if the value of the attribute TYPE is 'UNORDERED':

sgml('<LIST>', sub {
my ($element,$event) = @_;
my $type =$element->attribute('TYPE')->value;

if ($type eq 'ORDERED') { output "\\begin{enumerate}\n"; } elsif ($type eq 'UNORDERED') {
output "\\begin{itemize}\n";
} else {
die "Bad TYPE '$type' for element LIST at line " .$event->line . " in " . \$event->file . "\n";
}
});

You will not always need to use the event argument, but it can be useful if you want to report line numbers or file names for errors (presuming that you called sgmls or nsgmls with the -l option). If you have a new version of nsgmls which accepts the -h option, you can also use the event argument to look up arbitrary entities declared by the program. See the SGMLS_Event documentation for more information.


text:
### A New Model of Binary Elliptic Curves with Fast Arithmetic

Hongfeng Wu, Chunming Tang, and Rongquan Feng

##### Abstract

This paper presents a new model of ordinary elliptic curves with fast arithmetic over field of characteristic two. In addition, we propose two isomorphism maps between new curves and Weierstrass curves. This paper proposes new explicit addition law for new binary curves and prove the addition law corresponds to the usual addition law on Weierstrass curves. This paper also presents fast unified addition formulae and doubling formulae for these curves. The unified addition formulae cost $12M+2D$, where $M$ is the cost of a field multiplication, and $D$ is the cost of multiplying by a curve parameter. These formulae are more efficient than other formulae in literature. Finally, this paper presents explicit formulae for $w$-coordinates differential addition. In a basic step of Montgomery ladder, the cost of a projective differential addition and doubling are $5M$ and $1M+1D$ respectively, and the cost of mixed $w$-coordinates differential addition is $4M$.

Available format(s)
Publication info
Published elsewhere. Unknown where it was published
Keywords
Contact author(s)
whfmath @ gmail com
History
2010-12-07: last of 4 revisions
See all versions
Short URL
https://ia.cr/2010/608

CC BY

BibTeX

@misc{cryptoeprint:2010/608,
author = {Hongfeng Wu and Chunming Tang and Rongquan Feng},
title = {A New Model of Binary Elliptic Curves with Fast Arithmetic},
howpublished = {Cryptology ePrint Archive, Paper 2010/608},
year = {2010},
note = {\url{https://eprint.iacr.org/2010/608}},
url = {https://eprint.iacr.org/2010/608}
}

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