ppxscal/embedding_network huggingface dataset:
On the transport capacity of Gaussian multiple access and broadcast channels
Authors: G. A. Gupta, S. Toumpis, J. Sayir, R. R. Müller
Venue: Wireless Networks (2008)

We study the transport capacity of the Gaussian multiple access channel (MAC), which consists of multiple transmitters and a single receiver, and the Gaussian broadcast channel (BC), which consists of a single transmitter and multiple receivers. The transport capacity is defined as the sum, over all transmitters (for the MAC) or receivers (for the BC), of the product of the data rate with a reward r (x) which is a function of the distance x that the data travels. In the case of the MAC, assuming that the sum of the transmit powers is upper bounded, we calculate in closed form the optimal power allocation among the transmitters, that maximizes the transport capacity, using Karush-Kuhn-Tucker (KKT) conditions. We also derive asymptotic expressions for the optimal power allocation, that hold as the number of transmitters approaches infinity, using the most-rapid-approach method of the calculus of variations. In the case of the BC, we calculate in closed form the optimal allocation of the transmit power among the signals to the different receivers, both for a finite number of receivers and for the case of asymptotically many receivers, using our results for the MAC together with duality arguments. Our results can be used to gain intuition and develop good design principles in a variety of settings. For example, they apply to the uplink and downlink channel of cellular networks, and also to sensor networks which consist of multiple sensors that communicate with a single central station.
Document History System and its Application to Abnormal Document Access Pattern Detection with a Probabilistic Model
Authors: Wenxing Peng, Taro Terao, Yoshihiro Masuda, Naofumi Yoshida, Jun Miyazaki
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications (2008)

We present a design and implementation of tracing document history and its application to detecting abnormal document access patterns. We have been working on Document History System, which enables us to trace complete access history of operations for both electronic and paper documents. Document History System organizes access pattern trees based on dependency of user operations on documents. We also present a new probabilistic model, Multi-layered Tree Markov Model (MTMM), in order to analyze access pattern trees of documents. The main feature of MTMM is to conduct tree pattern summarization and multi-level structural abstraction for trees. Our contribution is multi-level structural abstraction by incorporating hierarchical inner-state structure of Markov Model. Abnormal patterns, such as sending documents to unexpected users, can be detected by applying MTMM to access pattern trees of Document History System. We clarify the feasibility and effectiveness of our MTMM by several experiments for synthetic trees and real document access pattern trees.
New asymptotic estimates for spherical designs
Authors: Andriy V. Bondarenko, Maryna S. Viazovska
Venue: Journal of Approximation Theory (2008)

Let N(n,t) be the minimal number of points in a spherical t-design on the unit sphere S^n in R^n^+^1. For each n>=3, we prove a new asymptotic upper boundN(n,t)=10.
Computer-based dietary menu planning
Authors: Barbara Koroušic Seljak
Venue: Proceedings of the 7th WSEAS International Conference on Evolutionary Computing (2006)

Nutrition is one of many disciplines, where intractable optimization problems naturally arise and require special attention of meta-heuristic methods. The problem of generating an optimal dietary menu that considers nutrient and non-nutrient requirements can be solved by evolutionary algorithms in an efficient and effective way. The menu optimality may be defined by several factors, such as cost, food functionality and season, as well as aesthetic standards for taste, consistency, color, temperature, shape, and method of preparation. In this paper, we present a multi-objective and multi-constrained evolutionary algorithm for planning and optimization of daily menus. It is based on the Elitist Non-Dominated Sorting Genetic Algorithm [2] and the Baldwinian repair algorithm [6]. The paper also presents an example of planning a daily menu by this method to demonstrate the approach.
DEM-optical-radar data integration for palaeohydrological mapping in the northern Darfur, Sudan: implication for groundwater exploration
Authors: E. Ghoneim, F. El-Baz
Venue: International Journal of Remote Sensing (2007)

North-western Sudan, as a part of the eastern Sahara, is among the driest places on earth. However, the region underwent drastic climatic changes through the alternation of dry and wet conditions in the past. During humid phases, when the rain was plentiful over a prolonged time period, the surface was veined by rivers and dotted by large lakes. The new Shuttle Radar Topography Mission data (SRTM ∼90 m) revealed a large endorheic drainage basin, which is centred by a large terminal palaeolake, in the northern Darfur State. The use of GIS methods allowed the delineation of the drainage basin and its associated palaeorivers. The SRTM data along with the Landsat (ETM+) and Radarsat-1 images corroborate the presence of segments of palaeoshorelines associated with the palaeolake highstands. These constitute a convincing argument of the long-term existence of a possible pre-Holocene large water body in the region in the past. The remains of the highest palaeoshoreline have a constant altitude of 573±3 m asl. At its maximum extent, the mega Lake occupied an area of about 30 750 km2 (the same size as the Great Bear Lake, Canada's largest lake), which would have contained approximately 2530 km3 of water. This, ancestral lake, which we named the Northern Darfur Megalake (ND Megalake), represents indisputable evidence of the past pluvial conditions in the eastern Sahara. The discovered palaeoshorelines will have significant consequences for improving our knowledge of continental climate change and regional palaeohydorology, and should be taken into consideration in studies of past human habitation in the region. Much of the water carried by the Northern Darfur palaeorivers and the ND Megalake would have percolated into the underlying rocks feeding the Nubian Sandston aquifer. These findings show that the used approach of space-data integration can help significantly in the groundwater exploration efforts in the Darfur region, where freshwater access is essential for refugee survival, and can be successfully adopted in other parts of Sudan and arid lands in general.
NetSim: a Simulation and Visualization Software for Information Network Modeling
Authors: Mélanie Lord, Daniel Memmi
Venue: Proceedings of the 2008 International MCETECH Conference on e-Technologies (2008)

For social and technical reasons, various information networks have become an important phenomenon, which it is useful to study and formalize. For this purpose we have developed NetSim, a generic software tool for modeling and simulating diverse network structures. We will see how to use this system to simulate and visualize two quite different network types: a preferential attachment model, and a typical social network. We will also present a modeling language we designed to express different network models to be interpreted by the NetSim system. We will show graphical simulation results that demonstrate the operation of the software.
Computing irreducible representations of finite groups
Authors: L. Babai
Venue: Proceedings of the 30th Annual Symposium on Foundations of Computer Science (1989)

The bit complexity of computing irreducible representations of finite groups is considered. Exact computations in algebraic number fields are performed symbolically. A polynomial-time algorithm for finding a complete set of inequivalent irreducible representations over the field of complex numbers of a finite group given by its multiplication table is presented. It follows that some representative of each equivalence class of irreducible representations admits a polynomial-size description. The problem of decomposing a given representation V of the finite group G over an algebraic number field F into absolutely irreducible constituents is considered. It is shown that this can be done in deterministic polynomial time if V is given by the list of matrices (V(g); g in G) and in randomized (Las Vegas) polynomial time under the more concise input (V(g); g in S), where S is a set of generators of G.
The real value of testing
Authors: Jim Larus
Venue: Proceedings of the 2008 international symposium on Software testing and analysis (2008)

A decade ago, Tony Hoare noted that "The real value of tests is not that they detect bugs in the code but that they detect inadequacies in the methods, concentration, and skills of those who design and produce the code." As usual, Tony saw far ahead of the current reality. At that time, Microsoft Research was very focused on a specific aspect of software development (finding code defects). Over the intervening years, Microsoft Research's efforts in this area grew greatly and our research agenda broadened considerably. This talk will trace the evolution of Microsoft Research's efforts to improve software development and explore how testing fits into the more people-centric approach that we have reached.
Zone state revocation for DNSSEC
Authors: Eric Osterweil, Vasileios Pappas, Dan Massey, Lixia Zhang
Venue: Proceedings of the 2007 workshop on Large scale attack defense (2007)

DNS Security Extensions (DNSSEC) are designed to add cryptographic protection to the Internet's name resolution service. However the current design lacks a key revocation mechanism. In this paper we present Zone State Revocation (ZSR), a lightweight and backward compatible enhancement to DNSSEC. ZSR enables zones to explicitly revoke keys using self-certifying certificates, and enables DNS name-servers to opportunistically inform distributed caching resolvers of key revocations via lightweight control messages. Further, ZSR allows resolvers to distinguish between legitimate key changes and potential attacks when authentication chains are broken. ZSR is designed to work well with global-scale DNS operations, where millions of caches may need to be informed of a revocation, and where time is critical.
Fast Measurement of the "Non-Deterministic Zone" in Microprocessor Debug Using Maximum Likelihood Estimation
Authors: Desta Tadesse, Iris Bahar, Joel Grodstein
Venue: Proceedings of the 26th IEEE VLSI Test Symposium (2008)

Speed debug is a critical part of microprocessor diagnosis and debug. During this stage, the test engineer must determine and increase the maximum speed at which the processor can run reliably. One of the difficulties of this stage is that the pass-fail boundary, in practice, is not abrupt, but rather encompasses a non-deterministic region of behavior. Accurately modeling this non-deterministic region is particularly important since it directly influences the amount of time needed for speed debug.Current chip debug efforts often rely on the use of brute force techniques to deduce the shape of the pass-fail boundary region. More specifically, speed debug (i.e., the process of finding and fixing critical paths that prevent a chip from running at a higher frequency) requires a thorough understanding of the width and shape of the pass-fail boundary region where the chip’s behavior is nondeterministic. In this paper, we propose a statistical method based on Maximum Likelihood Estimation (MLE) techniques to infer the underlying shape of the non-deterministic region. Our method was tested on pre-production Intel microprocessors and was successful in modeling the shape of the fuzz-region in substantially feweriterations compared to a brute force approach.
A (de)constructive approach to program checking
Authors: Shafi Goldwasser, Dan Gutfreund, Alexander Healy, Tali Kaufman, Guy N. Rothblum
Venue: Proceedings of the 40th annual ACM symposium on Theory of computing (2008)

Program checking, program self-correcting and program self-testing were pioneered by [Blum and Kannan] and [Blum, Luby and Rubinfeld] in the mid eighties as a new way to gain confidence in software, by considering program correctness on an input by input basis rather than full program verification. Work in the field of program checking focused on designing, for specific functions, checkers, testers and correctors which are more efficient than the best program known for the function. These were designed utilizing specific algebraic, combinatorial or completeness properties of the function at hand. In this work we introduce a novel composition methodology for improving the efficiency of program checkers. We use this approach to design a variety of program checkers that are provably more efficient, in terms of circuit depth, than the optimal program for computing the function being checked. Extensions of this methodology for the cases of program testers and correctors are also presented. In particular, we show: For all i ≥ 1, every language in RNCi (that is NCO-hard under NCZ-reductions) has a program checker in RNCi-1. In addition, for all i ≥ 1, every language in RNCi (that is NCO-hard under ACZ-reductions) has a program corrector, tester and checker in RACi-1. This is the first time checkers are designed for a wide class of functions characterized only by its complexity, rather than by algebraic or combinatorial properties. This characterization immediately yields new and efficient checkers for languages such as graph connectivity, perfect matching and bounded-degree graph isomorphism. Constant-depth checkers, testers and correctors for matrix multiplication, inversion, determinant and rank. All previous program checkers, testers and correctors for these problems run in nearly logarithmic depth. Moreover, except for matrix multiplication, they all require the use of the library notion of [Blum-Luby-Rubinfeld], in which checkers have access to a library of programs for various matrix functions, rather than only having access to a program for the function being checked. Furthermore, we provide conditions under which program libraries can be eliminated. Important ingredients in these results are new and very efficient checkers for complete languages in low complexity classes (e.g. NCO). These constructions are based on techniques that were developed in the field of cryptography.
Enabling Self-Configuration in Autonomic Systems Using Case-Based Reasoning with Improved Efficiency
Authors: Malik Jahan Khan, Mian Muhammad Awais, Shafay Shamail
Venue: Proceedings of the Fourth International Conference on Autonomic and Autonomous Systems (2008)

Autonomic computing is an emerging philosophy which promises to enable self-management capabilities in software systems. These self-management properties include self-configuration, self-healing, self-protection, self-optimization, self-awareness and self-governance. Enabling any of these properties in software systems is an open challenge. Exhibiting such self-management behavior is a continuous process in the software life cycle. Case-based reasoning is a problem solving methodology which exploits past experience. Past experience is maintained in the form of problem-solution pairs, also called cases. On the arrival of new problem, solution of past similar problems is used after appropriate adaptation. This problem solving technique can be used to achieve some of the properties of autonomic systems based on experience. To find this solution, entire experience space is searched which reduces efficiency. To overcome this efficiency problem, we restrict the fast growth of case repository, so that every time we have to search a very limited number of cases. We applied the proposed approach on a simulation of Autonomic Forest Fire application for self-configuration capability. Our results show that the proposed approach is quite promising in terms of accuracy as well as efficiency.
Concurrent CS: preparing students for a multicore world
Authors: Daniel J. Ernst, Daniel E. Stevenson
Venue: Proceedings of the 13th annual conference on Innovation and technology in computer science education (2008)

Current trends in microprocessor design are fundamentally changing the way that performance is extracted from computer systems. The previous programming model of sequential uniprocessor execution is being replaced quickly with a need to write software for tightly-coupled shared memory multiprocessor systems. Academicians and business leaders have both challenged programmers to update their skill sets to effectively tackle software development for these newer platforms [2]. At the University of Wisconsin - Eau Claire, we have taken steps early in our curriculum to introduce our students to concurrent programming. Our approach is not to add parallel programming as a separate class, but to integrate concurrency concepts into traditional material throughout a student's coursework, beginning in CS1. Our goal is for students to gain both familiarity and confidence in using parallelism to their advantage. This paper describes the programming process we seek to introduce to our students and provides example assignments that illustrate the ease of integrating this process into a typical curriculum.
A new adaptive digital audio watermarking based on support vector machine
Authors: Xiang-Yang Wang, Pan-Pan Niu, Wei Qi
Venue: Journal of Network and Computer Applications (2008)

It is a challenging work to design a robust digital audio watermarking scheme against desynchronization attacks. On the basis of support vector machines (SVMs), a new robust digital audio watermarking algorithm against desynchronization attacks is proposed in this paper, and in this the audio statistics characteristics and synchronization code are utilized. Firstly, the optimal embedding positions are located adaptively by using the SVM theory. Secondly, the 16-bit Barker code is chosen as synchronization mark and embedded into the digital audio by modifying the statistics average value of several samples. Finally, the digital watermark are embedded into the statistics average value of low-frequency components in wavelet domain by making full use of auditory masking. Experimental results show that the proposed scheme is inaudible and robust against common signal processing such as MP3 compression, low-pass filtering, noise addition, equalization, etc., and is robust against desynchronization attacks such as random cropping, amplitude variation, pitch shifting, time-scale modification, jittering, etc.
A metric-based approach for reconstructing methods in object-oriented systems
Authors: Tatsuya Miyake, Yoshiki Higo, Katsuro Inoue
Venue: Proceedings of the 6th international workshop on Software quality (2008)

Refactoring is an important activity to improve software quality, which tends to become worse through repetitive bug fixes and function additions. Unfortunately, it is difficult to perform appropriate refactorings because a refactoring needs certain costs, and its effects should be greater than the costs. This paper describes an approach for appropriate refactorings. The approach identifies spots to be refactored and it suggests how they should be improved. Moreover, the approach estimates the effects of the refactorings. The approach requires a lightweight source code analysis for measuring several metrics, so that it can be applied to middle- or large-scale software system. The approach can make the refactoring process more effective and efficient one.
Induced embeddings in Steinhaus graphs
Authors: Franz A. Delahan
Venue: Journal of Graph Theory (1998)

Fix any positive integer n. Let S be the set of all Steinhaus graphs of order n(n - 1)-2 + 1. The vertices for each graph in S are the first n(n - 1)-2 + 1 positive integers. Let I be the set of all labeled graphs of order n with vertices of the form i(i - 1)-2 + 1 for the first n positive integers i. This article shows that the function &phi; : S ➝ I that maps a Steinhaus graph to its induced subgraph is a bijection. Therefore, any graph of order n is isomorphic to an induced subgraph of a Steinhaus graph of order n(n - 1)-2 + 1. This considerably tightens a result of Brigham, Carrington, and Dutton in [Brigham, Carrington, Dutton, Combin. Inform. System Sci. 17 (1992)], which showed that this could be done with a Steinhaus graph of order 2n-1. &copy; 1998 John Wiley Sons, Inc. J. Graph Theory 29: 19, 1998
A Security Protocol Compiler Generating C Source Codes
Authors: Shinsaku Kiyomoto, Haruki Ota, Toshiaki Tanaka
Venue: Proceedings of the 2008 International Conference on Information Security and Assurance (isa 2008) (2008)

In this paper, we propose a security protocol compiler that automatically generates security protocol modules based on a security protocol definition. Our security compiler loads a security protocol definition file that can be defined as a high-level specification of the protocol written in XML and it generates a C source code from the specification. Our security protocol compiler realizes fast C source code generation under 30 msec from the high-level security protocol definition. To implement the security protocol compiler on terminals, a security protocol can be modified or replaced easily in accordance with situations. Thus, the terminal is able to use several services without implementation of all security protocols for the services, and a vulnerable security protocol is can be replaced quickly.
Partitioning for Selective Flip-Flop Redundancy in Sequential Circuits
Authors: Uthman Alsaiari, Resve Saleh
Venue: Proceedings of the 9th international symposium on Quality Electronic Design (2008)

As the number of transistors on a chip begins to exceed 1 billion and their sensitivity to defects begins to degrade overall yield, it will be mandatory to assign a portion of the transistors for the purposes of Built-in-Self-Test (BIST) and Built-in-Self-Repair (BISR) as part of the supporting circuitry. Here, we focus on the self-test and self-repair of flip-flops (FF’s), and their associated interconnect, using spare FF’s to replace faulty ones. We describe our method to determine the number of spares based on delay and yield analysis. Using these results, we partition the flip-flops in a sequential design to improve the yield while keeping the delay and area overhead low. Next, we apply this redundancy approach only to non-critical paths in the circuit so that no timing penalty is incurred, and find that it can still provide significant improvement in the overall yield. A number of sequential benchmark circuits from ITC’99 are compared with and without redundant flip-flops, and also with and without partitioning. The total area overhead of our method is 8% on average while improving the yield by 6-29% and incurring no timing penalty.
Directed vs. undirected monotone contact networks for threshold functions
Authors: M. M. Halldorsson, J. Radhakrishnan
Venue: Proceedings of the 1993 IEEE 34th Annual Foundations of Computer Science (1993)

We consider the problem of computing threshold functions using directed and undirected monotone contact networks. Our main results are the following. First, we show that there exist directed monotone contact networks that compute T/sub k//sup n/, 2/spl les/k/spl les/n-1, of size O(k(n-k+2)log(n-k+2)). This bound is almost optimal for small thresholds, since there exists an /spl Omega/(knlog (n/(k-1))) lower bound. Our networks are described explicitly; the previously best upper bound known, obtained from the undirected networks of Dubiner and Zwick, used non-constructive arguments and gave directed networks of size O(k/sup 3.99/nlog n). Second, we show a lower bound of O(nlogloglog n) on the size of undirected monotone contact networks computing T/sub n-1//sup n/, improving the 2(n-1) lower bound of Markov. Combined with our upper bound result, this shows that directed monotone contact networks compute some threshold functions more easily than undirected networks.