Approximation technique

We prove the Minimum Vertex Cover problem to be NPhard to approximate to within a factor of 1.3606, extending on previous PCP and hardness of approximation technique. To that end, one needs to develop a new proof framework, and to borrow and extend ideas from several ﬁelds. 1. Introduction The basic purpose of computational complexity theory is to classify computational problems according to the amount of resources required to solve them. In particular, the most basic task is to classify computational problems to those that are eﬃciently solvable and those that are not. ...
48p noel_noel 17012013 32 5 Download

Forces are at work which may be changing the way the general public thinks about the autopsy. The past few decades have seen a consistent, almost depressing drop in autopsy rates across the world. Once considered the foundation of medical science, the autopsy has fallen into relative disfavor. As the authors of this book discuss, the overall autopsy rate in England has dropped to approximately 25%, with 22% representing coroner mandated cases and only 3% attributable to hospital/academic cases.
465p gian_anh 18102012 19 3 Download

We introduce cube summing, a technique that permits dynamic programming algorithms for summing over structures (like the forward and inside algorithms) to be extended with nonlocal features that violate the classical structural independence assumptions. It is inspired by cube pruning (Chiang, 2007; Huang and Chiang, 2007) in its computation of nonlocal features dynamically using scored kbest lists, but also maintains additional residual quantities used in calculating approximate marginals. ...
9p bunthai_1 06052013 17 1 Download

When you have completed this chapter, you will be able to: Explain how probabilities are assigned to a continuous random variable, explain the characteristics of a normal probability distribution, define and calculate z value corresponding to any observation on a normal distribution, determine the probability a random observation is in a given interval on a normal distribution using the standard normal distribution, use the normal probability distribution to approximate the binomial probability distribution.
75p tangtuy09 21042016 4 1 Download

Each year , approximately 71,500 women in the United States are diagnosed with a gynecologic cancer. While all women are at risk for developing gynecologic cancers, few will ever develop one. Still, it is important to know the signs because there is no way to know for sure who will get a gynecologic cancer. The information included in this booklet will help you recognize any warning signs, so you can ask your health care provider about them. These signs and symptoms often are related to something other than gynecologic cancer. But it is...
32p le_minh_nha 18122012 38 15 Download

Therefore, research has shifted to focus development of pseudopolynomial time algorithm, diagnosis, and approximately algorithms for QoS path limited. In this chapter we present an accurate description of current stateofart and provide a overview of our work in the use of the concept of learning to strengthen focus on wireless Sensor Networks. We focused our attention by developing systems based on this model called AMDR and EDAR.
320p samsungwifi 03042012 62 9 Download

This project explores the development of a multiple input multiple output (MIMO) simulator using ray tracing techniques. This project gives an overview of ray tracing techniques, beamforming, MIMO channel models and MIMO systems. It explains the ability of MIMO systems to offer significant capacity increases over traditional wireless systems, by exploiting the phenomenon of multipath. By modelling high frequency radio waves as travelling along localized linear trajectory paths, they can be approximated as rays, just as in optics....
73p vankent 19072010 41 7 Download

Learning how to draw a rhinoceros has never been easier. No need to head down to the zoo or go on a safari, you're going to make your very own rhino come alive right before your very eyes with just a few simple steps. Sharpen your pencil and follow along below. STEP1: Start with the Head and Body Shapes Make two ovals approximately the same size. The difference between them is that one will be vertical for the head while the other one will be horizontal for the body. These ovals will be overlapping each other. Then at the top...
4p gietnggiandoi 27092012 42 9 Download

Overview The use of function approximation actually has a long history in control systems. For instance, we use function approximation ideas in the development of models for control design and analysis, and conventional adaptive control generally involves the online tuning of linear functions (linear approximators) to match unknown linear functions (e.g., tuning a linear model to match a linear plant with constant but unknown parameters) as we discussed in Chapter 1.
27p tienvovan 16092010 38 6 Download

They clam approximately 500 species, widely distributed in coastal intertidal zone of tropical temperate countries. Our country has about 40 species of 7 breed groups, distributed along the coast from north to south. Northern coastal areas have clam oil (Meretrix lime), clam password (Meretrix llusoria Rumplius). Southern coastal areas have clam (Meretrix lyrata Sowerby). Clams are mollusks team has great potential in the tide country. Culture technique is not complicated, short cycle, investment less valuable export.
46p xinh_la 10022012 34 6 Download

The quality organization will provide CQAM, DQAM, Staff Inspectors, and sampling and testing staff to meet the project schedule. The staffing levels indicated in Staffing Exhibit are based on a preliminary construction schedule and represent an approximate number of personnel needed per month. The staffing levels will be adjusted on a monthly and weekly basis, depending on the work being accomplished on each day, so that all work will be inspected and tested according to the QMP.
128p tainhacmienphi 25022013 23 5 Download

The emission factors of the 14 most abundant VOCs on sequential cold weather sampling dates (January 17 and March 12, 2003) are compared in Table 4. Indoor and outdoor temperatures and percent RHs were approximately equivalent between these dates (Table 1). However, the January air change rate was 0.58 h1 versus 0.31 h1 in March, likely due to the difference in wind conditions. Within both the aldehyde and the terpene hydrocarbon chemical classes, the ratio of the emission factor at the lower air change rate to the emission factor at the higher air change rate was near...
168p ut_hai_can 29122012 25 4 Download

Next, we can modify our model to account for different ﬁrm sizes. For notational convenience and ease of exposition, we have used a continuum model. A ﬁrm hires a unit mass of consumers. The size of the ﬁrm then becomes a normalization and hence has no bearing on the dynamics and steadystate properties. In practice, ﬁrms hire a ﬁnite number of workers, and the law of large number becomes a poor approximation when the ﬁrm is small. Even when a small ﬁrm draws from the same work force as any other ﬁrm, the variance of workers’ healthcare cost may be larger.
6p quaivatxanh 29112012 26 4 Download

The first, most conventional way to characterize the global health picture is a description of health and disease. Today, the overall picture for child health and maternal health in poor countries is worrisome indeed. While child mortality has steadily declined in the last two decades, still approximately 10.8 million children under the age of five die each year. Progress on key indicators is slowing, and in parts of SubSaharan Africa, child mortality is on the rise. The great bulk of the mortality decline since the 1970s is attributable to reduction in deaths...
79p can_thai 12122012 26 3 Download

International migrants include rural and urban women and men with different socioeconomic profiles and ages. Some are highly educated and specialized people (whose migration is referred to as ‘brain drain’). Some are poor people for whom migration is a subsistence strategy. The United Nations Population Fund (UNFPA) estimates that the typical profile of migrants comprises young women and men from 15 to 35 years of age, 8 generally belonging to medium and low socio economic groups, but not to the poorest segments of society (Hatton and Williamson 2004, 130).
56p enterroi 02022013 17 3 Download

Analyzing future distributed realtime systems, automotive and avionic systems, is requiring compositional hard realtime analysis techniques. Well known established techniques as SymTA/S and the realtime calculus are candidates solving the mentioned problem. However both techniques use quite simple event models. SymTA/S is based on discrete events the realtime calculus on continuous functions. Such simple models has been choosen because of the computational complexity of the considered mathematical operations required for realtime analysis.
10p giamdocamnhac 06042013 22 3 Download

This paper presents a global review of the strain smoothing method to finite element analysis for twodimension elastostatics. The strain at each point is replaced by a non – local approximation over a smoothing function. With choosing a constant smoothed function and applying the divergence theorem, the stiffness matrix is calculated on boundaries of smoothing elements (smoothing cells) instead of their interior. The presented method gains a high accuracy compared with the standard FEM without increasing computational cost. 1....
9p phalinh19 20082011 19 2 Download

In Mekong delta, mangrove forest distributes along the coastline of 700 km and it is a homeland for mud crab in tropical areas. The mud crab becomes potential to be alternative species from failed shrimp farming. Particularly, mud crab hatchery has been introduced and operated recently at Bac lieu, Tra vinh, Soc Trang, Ben Tre, Kien giang and Ca mau provinces. However, the survival from zoea stage to crablet stage 1 is low at approximately 5%. In addition, like shrimp rearing, the mud crab hatchery is using antibiotic as major treatment to prevent bacteria and fungi.
8p tam_xuan 02032012 27 3 Download

The Proportions of a Head Although the proportions of a head will vary from person to person and change slightly with age, there are some basic principles you can follow to improve your drawing. You can use these to check the general size, shape and position of features in your drawings. If you view a head from the front, its width is approximately two thirds of its height. If you view a head from the side, its width is approximately seven eighths of its height. .The proportions of the head can be divided horizontally into four equal quarters. ...
3p moi_tim 02102012 20 2 Download

Nanotechnology is an often misunderstood term. Say the word, and you are likely to elicit various conceptions from complete ignorance of the term to the fear of a science fiction type mass assembler that threatens the world. 2 The term has come to mean different things to different people. “Nano” is a prefix meaning onebillionth. In distance, a nanometer is one billionth of a meter. As illustration, a human hair is 100,000 nanometers (nm) in width. A red blood cell measures approximately 5,000 nm across. Ten hydrogen atoms, lined up side by side, if...
23p quynho77 13112012 30 2 Download