...Topology-Transparent Duty Cycling for Wireless Sensor Networks Computer Science& Engineering Arizona State University syrotiuk@asu.edu Abstract Our goal is to save energy in wireless sensor networks (WSNs) by periodic duty-cycling of sensor nodes. We schedule sensor nodes between active (transmit or receive) and sleep modes while bounding packet latency in the presence of collisions. In order to support a dynamic WSN topology, we focus on topology-transparent approaches to scheduling; these are independent of detailed topology information. Much work has been done on topology-transparent scheduling in which all nodes are active. In this work, we examine the connection between topology-transparent dutycycling and such non-sleeping schedules. This suggests a way to construct topology-transparent duty-cycling schedules. We analyse the performance of topology-transparent schedules with a focus on throughput in the worst case. A construction of topology-transparent duty-cycling schedules based on a topology-transparent non-sleeping schedule is proposed. The constructed schedule achieves the maximum average throughput in the worst case if the given nonsleeping schedule satisfies certain properties. 1 Introduction Wireless sensor networking has been a growing research area for the last years. It has a wide range of potential applications, such as environment monitoring, smart spaces, medical systems and robotic exploration. In sensor networks, sensor nodes are normally...
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...infrastructure, have already been showed effective ways to increase it. In this work, we jointly consider the impact of the above three factors on network capacity. We assume that m static base stations and n mobile users are placed in an ad hoc network. A general mobility model is adopted, such that each user moves within a bounded distance from its home-point with an arbitrary pattern. In addition, each mobile node serves as a source of multicast transmission, which results in a total number of n multicast transmissions. We focus on the situations in which base stations actually benefit the capacity improvement, and find that multicast capacity in a mobile hybrid network falls into several regimes. For each regime, reachable upper and lower bounds are derived. Our work contains theoretical analysis of multicast capacity in hybrid networks and provides guidelines for the design of real hybrid system combing cellular and ad hoc networks. 1 Index Terms—Wireless ad hoc network; multicast capacity; mobility; infrastructure; hybrid network; scaling law; that each moving node is located within a circle of radius 1/f (n) [3]. By mapping the network to a generalized random geometric graph, they have proven that Θ(1/f (n)) per-node capacity is achievable. Infrastructure in an ad hoc network provides a more straightforward increase to the capacity. In [4], Liu et al. claim that infrastructure...
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...Name Boyu xia Collins on Chaos INTRODUCTION In this article, it use an example from Climbers, which is “20 miles goals.” A team who has clearly goals and plan, it could be success than others. Statement one You need both parts of a 20-Mile March: a lower bound and an upper bound, a hurdle that you jump over and a ceiling that you will not rise above, the ambition to achieve and the self-control to hold back. Comment I like this sentence because I strongly agree with its idea. First, we need set a goal that should be done after we efforts. This is important, people always need goals to motivate us to get things done. Setting goals is a good habit for us. For the second one, I think it brings new idea to me. Its said, we need set a upper bound that we will not rise above. Its means if we required we do fitness two hours a day, at the begging, we may have more passion to do this, but we could not do more than two hours in one day, because it will drain your stamina, you may not have stamina for tomorrow’s goal. Same idea in other’s area, we setting a good goals, and strict the plan carefully. We should always put our views on a long term. Statement two (bold face) 20-Mile Marching reduces the likelihood of catastrophe when you're hit by turbulent disruption. In a setting characterized by unpredictability, full of immense threat and opportunity...
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...interest rate has fallen as far as it can? In the recession of 2008 and 2009, the federal funds rate fell to about zero. What, if anything, can monetary policy do then to stimulate the economy? Some economists describe this situation as a liquidity trap. According to the theory of liquidity preference, expansionary monetary policy works by reducing interest rates and stimulating investment spending. But if interest rates have already fallen almost to zero, then perhaps monetary policy is no longer effective. Nominal interest rates cannot fall below zero: Rather than making a loan at a negative nominal interest rate, a person would just hold cash. In this environment, expansionary monetary policy raises the supply of money, making the public’s asset portfolio more liquid, but because interest rates can't fall any further, the extra liquidity might not have any effect. Aggregate demand, production, and employment may be "trapped" at low levels. Other economists are skeptical about the relevance of liquidity traps and believe that a central bank continues to have tools to expand the economy, even after its interest rate target hits its lower bound of zero. One possibility is that the central bank could raise inflation expectations by committing itself to future monetary expansion. Even if nominal interest rates cannot fall any further, higher expected inflation can lower real interest rates by making them negative, which would stimulate investment spending. A second possibility...
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...buy the call and immediately exercise it. This would cost $3 for the call and $40 for the stock. Then the stock would be immediately sold for $44, netting a risk-free profit of $1. In other words, the investor could obtain a $44 stock for $43. Since everyone would do this, it would drive the price of the call up to at least $4. If the call were European, however, immediate exercise would not be possible (unless, of course, it was the expiration day), so the European call could technically sell for less than the intrinsic value of the American call. We saw, though, that the European call has a lower bound of the stock price minus the present value of the exercise price (assuming no dividends). Since this is greater than the intrinsic value, the European call would sell for more than the intrinsic value. Then at expiration, it would sell for the intrinsic value. 3. (Lower Bound of a European Call) The call is underpriced, so buy the call, sell short the stock, and buy risk-free bonds with face value of X. The cash received from the stock is greater than the cost of the call and bonds. Thus, there is a positive cash flow up front. The payoffs from the portfolio at expiration are as follows: |...
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...necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peerreviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications. © 2009 by Volker Wieland. All rights reserved. Short sections of text, not to exceed two paragraphs, may be quoted without explicit permission provided that full credit, including © notice, is given to the source. Quantitative Easing: A Rationale and Some Evidence from Japan Volker Wieland NBER Working Paper No. 15565 December 2009 JEL No. E31,E52,E58,E61 ABSTRACT This paper reviews the rationale for quantitative easing when central bank policy rates reach near zero levels in light of recent announcements regarding direct asset purchases by the Bank of England, the Bank of Japan, the U.S. Federal Reserve and the European Central Bank. Empirical evidence from the previous period of quantitative easing in Japan between 2001 and 2006 is presented. During this earlier period the Bank of Japan was able to expand the monetary base very quickly and significantly. Quantitative easing...
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...option prices. The six factors affecting stock option prices are the stock price, strike price, risk-free interest rate, volatility, time to maturity, and dividends. Problem 10.2. What is a lower bound for the price of a four-month call option on a non-dividend-paying stock when the stock price is $28, the strike price is $25, and the risk-free interest rate is 8% per annum? The lower bound is [pic] Problem 10.3. What is a lower bound for the price of a one-month European put option on a non-dividend-paying stock when the stock price is $12, the strike price is $15, and the risk-free interest rate is 6% per annum? The lower bound is [pic] Problem 10.4. Give two reasons that the early exercise of an American call option on a non-dividend-paying stock is not optimal. The first reason should involve the time value of money. The second reason should apply even if interest rates are zero. Delaying exercise delays the payment of the strike price. This means that the option holder is able to earn interest on the strike price for a longer period of time. Delaying exercise also provides insurance against the stock price falling below the strike price by the expiration date. Assume that the option holder has an amount of cash [pic] and that interest rates are zero. When the option is exercised early it is worth [pic] at expiration. Delaying exercise means that it will be worth [pic] at expiration. Problem 10.5. “The early exercise of an American put is a...
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...Monetary Policy in the United States: A Brave New World? Stephen D. Williamson This article is a reflection on monetary policy in the United States during Ben Bernanke’s two terms as Chairman of the Federal Open Market Committee, from 2006 to 2014. Inflation targeting, policy during the financial crisis, and post-crisis monetary policy (forward guidance and quantitative easing) are discussed and evaluated. (JEL E52, N12) Federal Reserve Bank of St. Louis Review, Second Quarter 2014, 96(2), pp. 111-21. en Bernanke chaired his last Federal Open Market Committee (FOMC) meeting in January 2014 and departed from the Board of Governors on February 3 after eight years as the head of the Federal Reserve System. So, the time is right to look back on the Bernanke era and ask how central banking has and has not changed since 2006. There is plenty in the macroeconomic record from 2006 to 2014 to keep economists and policy analysts busy for many years, so in this short piece we can only scratch the surface of what is interesting about the Bernanke era. I will focus on three issues: (i) inflation targeting, (ii) Fed lending and other interventions during the financial crisis, and (iii) post-crisis Fed policy, in particular experiments with forward guidance and quantitative easing (QE). B INFLATION TARGETING When Bernanke began his first term in 2006, I think the big change people expected was an inflation-targeting regime for U.S. monetary policy, similar to what exists in New...
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...1.3.3.14.6. | Histogram Interpretation: Skewed (Non-Normal) Right | | Right-Skewed Histogram | | Discussion of Skewness | A symmetric distribution is one in which the 2 "halves" of the histogram appear as mirror-images of one another. A skewed (non-symmetric) distribution is a distribution in which there is no such mirror-imaging.For skewed distributions, it is quite common to have one tail of the distribution considerably longer or drawn out relative to the other tail. A "skewed right" distribution is one in which the tail is on the right side. A "skewed left" distribution is one in which the tail is on the left side. The above histogram is for a distribution that is skewed right.Skewed distributions bring a certain philosophical complexity to the very process of estimating a "typical value" for the distribution. To be specific, suppose that the analyst has a collection of 100 values randomly drawn from a distribution, and wishes to summarize these 100 observations by a "typical value". What does typical value mean? If the distribution is symmetric, the typical value is unambiguous-- it is a well-defined center of the distribution. For example, for a bell-shaped symmetric distribution, a center point is identical to that value at the peak of the distribution.For a skewed distribution, however, there is no "center" in the usual sense of the word. Be that as it may, several "typical value" metrics are often used for skewed distributions. The first metric is the mode of the...
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...savings and incomes. Low, stable, and predictable inflation has encouraged more solid economic growth and a well-functioning and more stable labour market. 4. The inflation- targeting agreement is renewed with the federal government approximately every five years and was last renewed in 2011. 5. Inflation rates should be low enough to minimize the effects that high inflation rates can have such as; destroying purchasing power, creates uncertainty, distorts relative prices and investment decisions, and causes arbitrary redistributions of wealth between savers and borrowers. 6. The bank decided not to target an inflation rate lower than 2% because there are some risks in very low rates of inflation. One of the most important risks is the zero lower bound (ZLB) on interest rates. 7. In the Deputy Governor’s speech ZIB refers to zero lower bound on interest rates. 8. Four key properties that an effective core measure must have are; * it must be less volatile than total inflation * track long-run movements in the total CPI very closely * reliably predict future trend movements in the total CPI * be easy to understand and explain to the public 9. Ms. Cote states that the component of the CPI that has shown fairly high volatility in the recent years is electricity. 10. The Deputy Governor stated the most important contribution that a central bank can make to the economic...
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...All eyes are on the Fed as the members of its Federal Open Market Committee (FOMC) convene on the 16th of December. Most economists predict that the Fed will announce an uncharacteristic increase in interest rates- the first such increase since 2006. The Fed’s policies work to regulate the supply of money and credit in the economy. In other words, it is responsible for the implementation of ‘monetary policy’ guided by three key goals: maximizing employment, stabilizing prices, and moderating long-term interest rates. This tripartite objective is referred to as the Fed’s ‘dual mandate’. While setting monetary policy in order to accomplish its dual mandate, the Fed examines a wide gamut of economic data including measures of labor market conditions...
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...seemingly suggested: a negative interest rate. The Fed's closely watched "dot plot" revealed that at least one committee member floated the idea that a fed funds rate below zero might be an appropriate target for the remainder of this year and next. The forecast is widely thought to be the work of Minneapolis Fed President Narayana Kocherlakota, a non-voting member of the committee who is known for his dovish views. In her press conference last week, Fed Chair Janet Yellen made clear that a negative federal funds rate "was not something that we considered very seriously at all today." Read MoreThe Fed has to deal with its own zombie apocalypse However, in an environment where prices are persistently low, negative rates mean that businesses and consumers are essentially paid to borrow money, which could serve as an important stimulative tool in times of crisis. The idea has been floated in the U.K., and tried in the euro zone and Switzerland. Suffice to say, the fact that the concept is being floated in the U.S. is striking to some. After all, the Fed has spent years noting that its benchmark rate is at the "zero lower bound," which forces it to take other actions in order to stimulate the economy, (i.e. purchase bonds) since rates can't be lowered any further. Yet what if that bound is not a bound at all, but a Rubicon waiting to be crossed? From...
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...WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2004; 4:247–249 (DOI: 10.1002/wcm.220) Guest Editorial Special Issue: Scalability Issues in Wireless Networks— Architectures, Protocols and Services By Amitabh Mishra, Guest Editor Scalability of computer-communication networks has been an important topic for quite some time. Internet community examined the services and protocols for scalability, and switching and routing researchers looked at the scalability of the switches and routers. Service providers studied the application architectures of the services for the scalable performance that they need to provide to subscribers and, the maintenance folks paid attention to scalability of service provisioning algorithms, protocols and software. Similarly, the wireless networking community has also started to look at the scalability issues that are relevant to wireless cellular, wireless local, as well as wireless personal area networks besides the emerging area of infrastructure-less networks such as ad-hoc and sensor networks. Surprisingly there is significant scope for research in the wireless scalability area as it relates to the ad hoc and sensor networks and this is one of the reasons why this topic was chosen for a special issue. A wireless sensor network is likely to have a large number of nodes perhaps in thousands to millions and that may create, potentially, numerous scaling problems in the networking protocols, addressing schemes, hardware architectures...
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...Economics for Business IMT Dubai The USA Economy Project Report submitted to Dr. Sujit Prepared by group 6: Abhinav Mohan Babbar - 14004 Ashish Sopori -14018 Manoj K. Sundaram – 14078 Abhishek Tomar - 14005 Introduction of the country The United States of America (USA or U.S), commonly referred to as the United States is a federal republic [1][2] consisting of 50 states and a federal district. The 48 contiguous states and Washington, D.C., are in central North America between Canada and Mexico. The United States is a developed country and has the world's largest national economy.3 The economy is fueled by an abundance of natural resources and high worker productivity.4 While the U.S. economy is considered post-industrial, it continues to be one of the world's largest manufacturers.5 The country accounts for 37% of global military spending,6 being the world's foremost economic and military power, a prominent political and cultural force, and a leader in scientific research and technological innovations.7 Economy The United States has a capitalist mixed economy which is fueled by abundant natural resources and high productivity.8 According to the International Monetary Fund, the U.S. GDP of $16.8 trillion constitutes 24% of the gross world product at market exchange rates and over 19% of the gross world product at purchasing power parity (PPP).9Its national GDP was about 5% larger at PPP in 2014 than the European Union's, whose population...
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...INFLATION TARGETS A radical central banking policy adopted by New Zealand initially in 1989 that revolves around meeting preset, publicly displayed targets for the annual rate of inflation, is more commonly known as inflation targeting. This policy was adopted later on most notably by countries like Chile, Canada, Israel, Sweden, Finland (Pre- Eurozone), Spain (Pre-Eurozone), Australia, Brazil, Mexico, England and South Africa. The benchmark used for inflation targeting is typically a price index of a basket of consumer goods, such as the Consumer Price Index (CPI) in the United States. Along with inflation target rates and calendar dates to be used as performance measures, an inflation targeting policy may also have established steps that are to be taken depending on how much the actual inflation rate varies from the targeted level, such as cutting lending rates or adding liquidity to the economy. It is arguable that the Federal Reserve is not explicitly following inflation targeting. After all, the Fed stated it was serious about its new 2% inflation target when announced in January 2012: “The inflation rate over the longer run is primarily determined by monetary policy, and hence the Committee has the ability to specify a longer-run goal for inflation. The Committee judges that inflation at the rate of 2 percent, as measured by the annual change in the price index for personal consumption expenditures, is most consistent over the longer run with the Federal Reserve's...
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