A new algorithm for the extraction of the surface waves for the Green''''s function in layered dielectrics

There exist the complicated waveguide modes as well as the surface waves in the electromagnetic field induced by a horizontal electric dipole in layered lossless dielectrics between two ground planes. In spectral domain, all these modes can be characterized by the rational parts with the real poles of the vector and scalar potentials. The accurate extraction of these modes plays an important role in the evaluation of the Green's function in spatial domain. In this paper, a new algorithm based on rational approximation is presented, which can accurately extract all the real poles and the residues of each pole simultaneously. Thus, we can get all the surface wave modes and waveguide modes, which is of great help to the calculation of the spatial domain Green's function. The numerical results demonstrated the accuracy and efficiency of the proposed method.     

Hybrid Broadcast for the Video-on-Demand Service

Multicast offers an efficient means of distributing video contents/programs to multiple clients by batching their requests and then having them share a server‘s video stream.Batching customers‘ requests is either client-initiated or server-initiated.Most anvanced client-initiated video multicasts are implemented by patching.Periodic broadcast,a typical server-initiated approach,can be entirety-based or segment-based.This paper focuses on the performance of the VoD service for popular videos.First,we analyze the limitation of conventional patching when the customer request rate is high.Then,By combining the advantages of each of the two broadcast schemes,we propose a hybrid broadcast scheme for popular videos ,which not only lowers the serviec latency but also improves clients‘ interactivity by using an active buffering technique ,This is shown to be a good compromise for both lowering service latency and improving the VCR-like interactivity.     

Application Research for the Grid Technology

1 Preface Since 1990' s, combing with the high performance count technology, internet work technology and mutual medium technolo- gy the third- high wave is forming after internet and Web- - - that is Grid. Grid is a resource pond of count, and grid techn…     

A new algorithm for the extraction of the surface waves for the Green’s function in layered dielectrics

There exist the complicated waveguide modes as well as the surface waves in the electromagnetic field induced by a horizontal electric dipole in layered lossless dielectrics between two ground planes. In spectral domain, all these modes can be characterized by the rational parts with the real poles of the vector and scalar potentials. The accurate extraction of these modes plays an important role in the evaluation of the Green’s function in spatial domain. In this paper, a new algorithm based on rational approximation is presented, which can accurately extract all the real poles and the residues of each pole simultaneously. Thus, we can get all the surface wave modes and waveguide modes, which is of great help to the calculation of the spatial domain Green’s function. The numerical results demonstrated the accuracy and efficiency of the proposed method.     

After the Anthropocene: the photographic for earthly survival?

ABSTRACT

This essay explores the relation between photography and future environments in the context of the Anthropocene. It is particularly concerned with the way in which Anthropocene debates highlight the following: climate change as a matter of human extinction and survival; agency as anthropos or Man and technology as problem and solution, cause and consequence of climate change (noting of course Heidegger’s critical reading of technology as the tool of man; its reduction to instrumental and anthropological uses). The essay contends that the Anthropocene, as the performatively named era of Man and his tools, is humanistic (with all of the normativity that this implies) and also that it frames the relation between photography and future environments in predictable cycles of extinction and survival, ends and beginnings that limit its potential for imagination and intervention. To what extent then, might a critical engagement with the Anthropocene help to liberate this potential and begin to outline a photographics for earthly survival?     

Some Hard Examples for the Resolution Method

Given n propositional variables,let Kn(i,j),0≤i≤j≤n,be the set(or disjunction)of all conjunctions of i literals of which exactly j literals are negative.Dunham and Wang conjectured that it may require exponential time to decide that every disjunction Kn(i,j)is not valid by the resolution metho.This paper gives a proof of the conjecture and then exhibits a new counterexample to the feasibility of the resolution or consensus method.     

Algorithms for the Gauss–Manin Connection

We give an introduction to the theory of the Gauss–Manin connection of an isolated hypersurface singularity and describe an algorithm to compute the V-filtration on the Brieskorn lattice. We use an implementation in the computer algebra system Singular to prove C. Hertling’s conjecture about the variance of the spectrum for Milnor numberμ ≤  16.     

Study on the Noise Signal for the Volume Holographic Storage System

Volume Holographic Storage （VHS） is currently the subject of widespread interest as a fast-readout-rate, high-capacity digital data-storage technology. However, various noise cause high bit error rate （BER） in VHS high-speed channel. In the paper, we introduce the theory of VHS and analyze the characteristic of noise sources so that we can design the appropriate channel and error correction codes to decrease the BER.     

Occurrence Counting Analysis for the π-calculus

We propose an abstract interpretation-based analysis for automatically proving non-trivial properties of mobile systems of processes. We focus on properties relying on the number of occurrences of processes during computation sequences, such as mutual exclusion and non-exhaustion of resources.We design a non-standard semantics for the π-calculus in order to explicitly trace the origin of channels and to solve efficiently problems set by α-conversion and non-deterministic choices. We abstract this semantics into an approximate one. The use of a relational domain for counting the occurrences of processes allows us to prove quickly and efficiently properties such as mutual exclusion and non-exhaustion of resources. At last, dynamic partitioning allows us to detect some configurations by which no infinite computation sequences can pass.     

Using the Dempster–Shafer method for the fusion of LIDAR data and multi-spectral images for building detection

A method for the detection of buildings in densely built-up urban areas by the fusion of first and last pulse laser scanner data and multi-spectral images is presented. The method attempts to achieve a classification of land cover into the classes “building”, “tree”, “grassland”, and “bare soil”, the latter three being considered relevant for the subsequent generation of a high-quality digital terrain model (DTM). Building detection is accomplished by first applying a hierarchical rule-based technique for coarse DTM generation based on morphological filtering. After that, data fusion based on the theory of Dempster–Shafer is used at two different stages of the classification process. We describe the algorithms involved, giving examples for a test site in Fairfield (New South Wales).     

Analysis of the “Hiring Above the Median” Selection Strategy for the Hiring Problem

This paper gives a precise mathematical analysis of the behaviour of “hiring above the median” strategies for a problem in the context of “on-line selection under uncertainty” that is known (at least in computer science related literature) as the “hiring problem”. Here a sequence of candidates is interviewed sequentially and based on the “score” of the current candidate an immediate decision whether to hire him or not has to be made. For “hiring above the median” selection rules, a new candidate will be hired if he has a score better than the median score of the already recruited candidates. Under the natural probabilistic model assuming that the ranks of the first n candidates are forming a random permutation, we show exact and asymptotic results for various quantities of interest to describe the dynamics of the hiring process and the quality of the hired staff. In particular we can characterize the limiting distribution of the number of hired candidates of a sequence of n candidates, which reveals the somewhat surprising effect, that slight changes in the selection rule, i.e., assuming the “lower” or the “upper” median as the threshold, have a strong influence on the asymptotic behaviour. Thus we could extend considerably previous analyses (Krieger et al., Ann. Appl. Probab., 17:360–385, 2007; Broder et al., Proceedings of the 19th Annual ACM-SIAM Symposium on Discrete Algorithms (SODA), pp. 1184–1193, ACM/SIAM, New York/Philadelphia, 2008 and Archibald and Martinez, Proceedings of the 21st International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2009), Discrete Mathematics and Theoretical Computer Science, pp. 63–76, 2009) of such selection rules. Furthermore, we discuss connections between the hiring process and the Chinese restaurant process introduced by Pitman (Combinatorial Stochastic Processes, Springer, Berlin, 2006).     

Control design for the nonlinear benchmark problem via the output regulation method

The problem of designing a feedback controller to achieve asymptotic disturbance rejection / attenuation while maintaining good transient response in the RTAC system is known as a benchmark nonlinear control problem, which has been an intensive research subject since 1995. In this paper, we will further investigate the solvability of the robust disturbance rejection problem of the RTAC system by the measurement output feedback control based on the robust output regulation method. We have obtained a design by overcoming two major obstacles: find a closed-form solution of the regulator equations; and devise a nonlinear internal model to account for non-polynomial nonlinearities.     

RealTracer—Tools for Measuring the Performance of RealVideo on the Internet

The increase in high-bandwidth connections and high-speed computers has spurred the growth of streaming media across the Internet. While there have been a number of studies measuring the performance of traditional Internet traffic, there have not been sufficient empirical measurements ofvideo performance especially for commercial videos across the Internet. The lack of empirical workthat measures streaming video traffic may arise from the lack of effective video performance measurement tools. In this paper, we present RealTracer, a set of tools for measuring the performance of RealNetworks Video. RealTracer includes RealTracker, a customized video playe that plays RealNetworks Video from pre-selected playlist and records user-centric video performance information. RealTracer also includes RealData, a data analysis tool that helps manage,parse and analyze data captured by RealTracker. We describe the software architecture and usage ofRealTracker and the usage of RealData, both publicly available for download. To illustrate the useof RealTracer, we present some results from a study that used RealTracker to measure RealVideo performance across the Internet. Using RealData, that study made several contributions to better understanding the performance of streaming video on the Internet. Typical RealVideos have high quality, achieving an average frame rate of 10 frames per second and very smooth playout, but very few videos achieve full-motion frame rates. Overall video performance is most influenced by the bandwidth of the end-user connection to the Internet, but high-bandwidth Internet connections are pushing the video performance bottleneck closer to the server. Yubing Wang earned M.S. in Electrical Engineering from University of Science and Technology of China in 1993 and M.S. in Computer Science from WPI in 2001. He is currently working in EMC Corp. as a principal software engineer, participating in the developments of several EMC NAS products. He is also a Ph.D. candidate in Computer Science of WPI. His primary research interests include multimedia networking and distributed file system. Mark Claypool earned M.S. and Ph.D. degrees from the University of Minnesota in 1993 and 1997, respectively. Dr. Claypool joined the Computer Science department of WPI in 1997, receiving tenure and promotion to Associate Professor in 2004. He is also the Director of the Interactive Media and Game Development major at WPI, a 4-year degree in the principles of interactive applications and computer-based game development. His primary research interests include multimedia networking, congestion control, and network games.     

Estimating burned area for Tropical Africa for the year 1990 with the NOAA-NASA Pathfinder AVHRR 8 km land dataset

The international scientific community recognizes the long-term monitoring of biomass burning as important for global climate change, vegetation disturbance and land cover change research on the Earth's surface. Although high spatial resolution satellite images may offer a more detailed view of land surfaces, their limited area coverage and temporal sampling have restricted their use to local research rather than global monitoring. Low spatial resolution images provide an invaluable source for the detection of burned areas in vegetation cover (scars) at global scale along time. However, the automated burned area mapping algorithm applicable at continental or global scale must be sufficiently robust to accommodate the global variation in burned scar signals. Here, the estimation of the percentage of a pixel area affected by a fire is crucial. In a first step, an empirical method is used which is based on a function between the change in Normalized Difference Vegetation Index (NDVI) and the surface area affected by fire. Next, a new statistical method, based on the Monte Carlo algorithm, is applied to compute probabilities of burned pixels percentages in different neighbourhood conditions.     

Which Measures Count for the Public Interest?

Abstract: The “measure” of this article is a bit different from most—there are almost as many words in the notes as in the body of the text. Notes are a significant part of my writing, both in terms of recognizing the connections and complexities among issues, trying to capture the richness of interdisciplinary teaching, and in terms of strengthening our struggles by (when relevant) referring to each other's work so that our individual work becomes understood as part of collective work to move mathematics education in the direction of the public interest. A quote I love that I often start my talks with, after saying how I talk in parentheses, although eventually closing most of them, is from a Hmong saying that translates “to speak of all kinds of things.” It is often used at the beginning of an oral narrative as a way of reminding listeners that the world is full of things that may not seem to be connected but actually are; that no event occurs in isolation; that you can miss a lot by sticking to the point; and that the storyteller is likely to be rather long-winded (Fadiman, 1998, pp. 12–13). Teaching in an interdisciplinary way means that there are a lot of endnotes and a lot of parentheses, not all of which get closed—that is how to do this kind of teaching, without having to know everything and without needing a zillion years to research and teach one lesson.