ppxscal/embedding_network huggingface dataset:
A cost-efficient scheduling algorithm of on-demand broadcasts
Authors: Weiwei Sun, Weibin Shi, Bole Shi, Yijun Yu
Venue: Wireless Networks (2003)

In mobile wireless systems data on air can be accessed by a large number of mobile users. Many of these applications including wireless internets and traffic information systems are pull-based, that is, they respond to on-demand user requests. In this paper, we study the scheduling problems of on-demand broadcast environments. Traditionally, the response time of the requests has been used as a performance measure. In this paper we consider the performance as the average cost of request composed of three kinds of costs - access time cost, tuning time cost, and cost of handling failure request. Our main contribution is a self-adaptive scheduling algorithm named LDFC, which computes the delay cost of data item as the priority of broadcast. It costs less compared with some previous algorithms in this context, and shows good adaptability as well even in pure push-based broadcasts.
Experience teaching hands-on parallel computing at a small college
Authors: David A. Hastings
Venue: Journal of Computing Sciences in Colleges (2003)

Parallel computing can be taught at a small college given a well-planned approach and utilizing easily obtained tools. Parallel computing is defined as a combination of parallel architecture and parallel programming and is one of the few hardware/software continuums. The course hardware is a cluster of workstations that can be adapted for use from most CS labs. Most of the software used in the course is based in cooperative learning, group activities which lend themselves to the experimental nature of the topic.
Approximation of membership functions and aggregation operators using splines
Authors: Gleb Beliakov
Venue: Technologies for constructing intelligent systems: tools (2002)

A good choice of membership functions and aggregation operators is crucial to the behavior fuzzy systems. In many cases there are no theoretical criteria that would justify the use of one or another function, and they are selected based on their goodness of fit to empirical data. This paper discusses a general non-parametric approach to construction of membership functions and aggregation operators based on empirical data. This method is computer oriented: it does not produce operators in closed algebraic form, but the quality of fit and flexibility are superior to other methods. The method is also general, since it can produce membership functions and operators from any class. Restrictions to a particular class can be easily introduced. Examples based on published empirical data are provided.
Multiperiod Airline Overbooking with a Single Fare Class
Authors: Suman Basuroy, Dung Nguyen, Richard E. Chatwin
Venue: Operations Research (1998)

Consider a multiperiod airline overbooking problem that relates to a single-leg flight and a single service class. Passengers may cancel their reservations at any time, including being no-shows at flight-time. At that time, the airline bumps passengers in excess of flight capacity and pays a penalty for so doing. We give conditions on the fares, refunds, and distributions of passenger demand for reservations and cancellations in each period, and on the bumping penalty function, that ensure that a booking-limit policy is optimal, i.e., in each period the airline accepts reservation requests up to a booking limit if the number of initial reservations is less than that booking limit, and declines reservation requests otherwise. The optimal booking limits are easily computed. We give conditions under which the optimal booking limits are monotone in the time to flight departure. The model is applied to the discount allocation problem in which lower fare classes book prior to higher fare classes.
Optimizing database architecture for the new bottleneck: memory access
Authors: Stefan Manegold, Peter A. Boncz, Martin L. Kersten
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2000)

In the past decade, advances in the speed of commodity CPUs have far out-paced advances in memory latency. Main-memory access is therefore increasingly a performance bottleneck for many computer applications, including database systems. In this article, we use a simple scan test to show the severe impact of this bottleneck. The insights gained are translated into guidelines for database architecture, in terms of both data structures and algorithms. We discuss how vertically fragmented data structures optimize cache performance on sequential data access. We then focus on equi-join, typically a random-access operation, and introduce radix algorithms for partitioned hash-join. The performance of these algorithms is quantified using a detailed analytical model that incorporates memory access cost. Experiments that validate this model were performed on the Monet database system. We obtained exact statistics on events such as TLB misses and L1 and L2 cache misses by using hardware performance counters found in modern CPUs. Using our cost model, we show how the carefully tuned memory access pattern of our radix algorithms makes them perform well, which is confirmed by experimental results.
A practical fuzzy ISODATA method
Authors: Cao Xiedong, Zhao Jinzhou, Huang Guangyan
Venue: Second international workshop on Intelligent systems design and application (2002)

This paper describes a fuzzy ISODATA clustering method adopted in the project of oil and gas exploration and exploitation information synthesis integrate intelligence application system, discusses the characteristics of fuzzy ISODATA clustering, adopts relation degree as indexes of the sample characteristics and the sample distance function, and briefly describes the characteristics selection in the classification problem of the sidewall stability.
Stdsim: a Microsimulation Model for Decision Support in STD Control
Authors: Catharina P. B. Van Der Ploeg, Carina Van Vliet, Sake J. De Vlas, Jeckoniah O. Ndinya-Achola, Lieve Fransen, Gerrit J. Van Oortmarssen, J. Dik F. Habbema
Venue: Interfaces (1998)

STDSIM is a dynamic stochastic simulation model for decision support in attempts to control sexually transmitted diseases (STDs). It describes the mechanisms responsible for the transmission of five STDs, including HIV/AIDS, at the level of individuals. A large variety of outcome measures (for example, STD prevalence, incidence, and mortality) can be calculated for different groups of the population (for example, adolescents, prostitutes, pregnant women, and migrants) to evaluate the effects of alternative STD control interventions. We designed the model to support decision making for different settings in developing countries, with Nairobi (Kenya) as its first application area. The model adequately describes STD prevalences and the time-trend of HIV prevalence measured in Nairobi. As an illustration of the possibilities of the model, we show model predictions of the effects of improved STD care and increased condom use on the prevalence and incidence of HIV.
Power analysis: attacks and countermeasures
Authors: Suresh Chari, Charanjit S. Jutla, Josyula R. Rao, Pankaj Rohatgi
Venue: Programming methodology (2003)

Side channel cryptanalytic techniques, such as the analysis of instantaneous power consumption, have been extremely effective in attacking cryptographic implementations on simple hardware platforms. The significant economic ramifications of such attacks, especially on the smart card market, have spurred a scramble for countermeasures. Unfortunately, most of the proposed countermeasures are ad hoc and ineffective. This is largely due to the absence of a sound scientific basis for understanding side channel information leakage resulting in the lack of a methodology for designing and validating proposed countermeasures.A more scientific approach to the problem is to create a model for the power consumption characteristics of the device, and then design implementations that are provably secure in that model, i.e. they resist generic attacks with an a priori bound on the number of experiments. We propose such a model for power consumption and a generic programming technique to create provably secure implementations. We expect that this formal model will become the basis for further work in this area.
An Equalizer and Memory Mapping Predistorter for Nonlinearly Amplified Signals Transmitted by Coded OFDM Systems in Multipath Fading Channel
Authors: Y. Kim, R. M. Braun
Venue: Wireless Personal Communications: An International Journal (2003)

We present an improved channel equalizing scheme to be used in Coded OFDM systems over an ISI channel. The scheme uses Turbo Trellis Coded Modulation (TTCM) which retains a powerful error correction capability while elegantly incorporating turbo coding into the Trellis Coded Modulation (TCM). In OFDM over wireless communications, M-ary Quadrature Amplitude Modulation (M-QAM) schemes have been widely used to achieve high bandwidth efficiency. However, M-QAM signals require linear amplification to avoid spectral regrowth and severe performance degradation due to their large envelope fluctuations. Moreover, the OFDM transmitter shapes the signal with a linear pulse shaping filter. The combination of a linear filter with a High Power Amplifier (HPA) forms a nonlinear system with memory, which severely degrades performance. We propose an efficient one-tap-equalizer using a modified LMS algorithm and a novel adaptive predistortion technique to compensate for the nonlinear distortion caused by the high power amplifier cascaded with a linear filter in TTCM-OFDM systems. The performance of this method is compared with methods that have been used previously with OFDM. A computer simulation confirms that the proposed approach is superior to the conventional methods.
On the uncontrollable damped triple inverted pendulum
Authors: H. Su, C. A. Woodham
Venue: Journal of Computational and Applied Mathematics (2003)

In this paper, the controllability of the damped triple inverted pendulum is investigated. The work is concerned with the form of the cancelling pole and zero which appear in the transfer functions of an uncontrollable system, and follows on from earlier work on the damped double inverted pendulum. The investigation considers first the cases where only one of the three arm frictions is non-zero, and then explores the cases when two of the three arm frictions are non-zero. Due to the complexity of this problem, and the difficulties with the symbolic manipulation software, exploratory numerical investigations have been carried out to facilitate the symbolic investigations, all of which are reported here.
Oblique fuzzy vectors and their use in possibilistic linear programming
Authors: Masahiro Inuiguchi, Jaroslav Ramik, Tetsuzo Tanino, Milan Vlach
Venue: Fuzzy Sets and Systems (2003)

In this paper, we propose oblique fuzzy vectors to treat the interactivity among fuzzy numbers. Oblique fuzzy vectors are extensions of fuzzy numbers and vectors of non-interactive fuzzy numbers. The interactivity among fuzzy numbers can be treated by a non-singular matrix in an oblique fuzzy vector. We discuss characterization of an oblique fuzzy vector and the tractability of manipulation of oblique fuzzy vectors in fuzzy linear functions. Moreover, we discuss possibilistic linear programming problems with oblique fuzzy vectors. It is shown that the possibilistic linear programming problems are reduced to linear programming problems with a special structure.
Scheduling in Robotic Cells: Heuristics and Cell Design
Authors: Hichem Kamoun, Nicholas G. Hall, Chelliah Sriskandarajah
Venue: Operations Research (1999)

This paper considers scheduling problems arising in robot-served manufacturing cells in which the machines are configured in a flowshop that repetitively produces a family of similar parts. We study the problem of determining the robot move cycle and the part sequence that jointly minimize the average steady-state cycle time required for the repetitive production of a minimal part set, or equivalently maximize the long-run throughput rate. Three earlier related papers provide algorithms, or proofs of intractability, for a variety of cell configurations. We use the intuition developed there to design and test simple heuristic procedures for the part sequencing problem under different robot move cycles in three-machine cells where that problem is intractable. This enables us to develop a heuristic procedure for a general three-machine cell. A methodology for extending this heuristic to four-machine cells is described and tested. Ideas for extension to even larger cells are also discussed. We also describe and test two heuristics for a cell design problem that involves partitioning machines into cells as well as determining the sequence of robot moves and parts. Finally, we provide a list of open research problems.
Real-time representation of complex lighting data in a nightdrive simulation
Authors: J. Berssenbrügge, J. Gausemeier, M. Grafe, C. Matysczok, K. Pöhland
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

For the development of new automobile lighting systems, special raytracing methods are used to completely simulate the illumination properties of the new product. For further evaluation, real test drives with real prototypes are still necessary. But changing weather and lighting conditions make the test drive results not fully comparable. Therefore, a high number of test drives have to be performed. This leads to a time-consuming and cost-intensive development process. Virtual test drives at night combined with a realistic simulation of a lighting system's illumination characteristics can minimize the number of real nightdrives and allow reproducible testing conditions as well as comparable results. A close-to-reality simulation poses high demands on the real-time method for calculating and displaying illumination data in a virtual scene. This paper introduces a real-time illumination method for use in a nightdrive simulation.
The Little Engines That Could: Modeling the Performance of World Wide Web Search Engines
Authors: Eric T. Bradlow, David C. Schmittlein
Venue: Marketing Science (2000)

This research examines the ability of six popular Web search engines, individually and collectively, to locate Web pages containing common marketing/management phrases. We propose and validate a model for search engine performance that is able to represent key patterns of coverage and overlap among the engines.The model enables us to estimate the typical additional benefit of using multiple search engines, depending on the particular set of engines being considered. It also provides an estimate of the number of relevant Web pagesnot found by any of the engines. For a typical marketing/management phrase we estimate that the "best" search engine locates about 50% of the pages, and all six engines together find about 90% of the total.The model is also used to examine how properties of a Web page and characteristics of a phrase affect the probability that a given search engine will find a given page. For example, we find that the number of Web page links increases the prospect that each of the six search engines will find it. Finally, we summarize the relationship between major structural characteristics of a search engine and its performance in locating relevant Web pages.
Mathematical, logical, and formal methods in information retrieval: an introduction to the special issue
Authors: Fabio Crestani, Sandor Dominich, Mounia Lalmas, Cornelis Joost van Rijsbergen
Venue: Journal of the American Society for Information Science and Technology (2003)

Research on the use of mathematical, logical, and formal methods, has been central to Information Retrieval research for a long time. Research in this area is important not only because it helps enhancing retrieval effectiveness, but also because it helps clarifying the underlying concepts of Information Retrieval. In this article we outline some of the major aspects of the subject, and summarize the papers of this special issue with respect to how they relate to these aspects. We conclude by highlighting some directions of future research, which are needed to better understand the formal characteristics of Information Retrieval.
Transmit Diversity Schemes for WCDMA
Authors: Américo Correia
Venue: Wireless Personal Communications: An International Journal (2003)

Previous work on transmitter antenna diversity has shown that the use of multiple transmitter antennas at the base station results in improved performance due to increase of diversity (path diversity). This happens with no bandwidth cost, even when the signal quality along several paths is poor, but the receiver estimates the channel with accuracy. This paper evaluates the effects of channel estimation errors in the performance of the schemes designated as Space-Time Transmitter Diversity (STTD) and Selective Transmitter Diversity (STD). We consider low to medium signal to noise ratios characteristic of Wideband Code Division Multiple Access (WCDMA) networks. Different fading channel models are considered for comparison between the two schemes. The improvement due to convolutional coding associated with these techniques is also evaluated.
A security model for distributed product data management system
Authors: K. K. Leong, K. M. Yu, W. B. Lee
Venue: Computers in Industry (2003)

Product data management (PDM) and distributed product data management (DPDM) systems have made product data a valuable and available commodity for many different kinds of computing applications in production. However, there are worries that this product data will lead to new security risks, and to the invasion of the DPDM system. It is because all people in a manufacturing enterprise will somehow get in touch with the DPDM system. Dealing with these tremendous amounts of interaction between the system and the various users, the utmost importance is to ensure that all data are secured and all users are under controlled and managed. Therefore, the security of DPDM system has been of great concern to individuals and corporations. The paper discusses the security requirements faced by a DPDM system in different organizational contexts. It is argued that access control requires a workspace stratified user management security model to specify. The prominent supporting features of the system including user organization, workspace and security are outlined. A new mixed approach access model for the system is proposed. In this model, user management and two main classical access control methods, the Lampson's access matrix and Bell and LaPadula (BLP) security labels, are analyzed and adapted to the application with multiple system user and product data in order to support a workspace-oriented DPDM system.
Beyond EDI: Impact of Continuous Replenishment Program (CRP) Between a Manufacturer and Its Retailers
Authors: Srinivasan Raghunathan, Arthur B. Yeh
Venue: Information Systems Research (2001)

Electronic data interchange (EDI), used traditionally to exchange business documents, has recently been extended to facilitate interorganizational collaborative processes such as the continuous replenishment program (CRP). The key characteristics of CRP are the sharing of real-time inventory data by retailers with manufacturers and continuous replenishment of retailer inventory by manufacturers. Prior research on EDI has focused on the transaction efficiency of EDI. We analyze the impact of information sharing and continuous replenishment in the CRP context and study the factors that affect the value of CRP. The study quantifies the value derived from CRP and the optimal number of retailers a manufacturer should partner with.
A coincidence degree for bifurcation problems
Authors: Cristinel Mortici, Silviu Sburlan
Venue: Nonlinear Analysis: Theory, Methods Applications (2003)

In this work we define a new type of coincidence degree for a pair of operators (L, A) with A compact and L a compact perturbation of the identity to establish some results for bifurcation problems. Similar results to Krasnoselski and Rabinowitz theorems are given. Finally, these results are extended for operators of monotone type defined from a Banach space into its dual, using the super-elliptic regularization theorem due to Browder-Ton.
Information technology: a degree in computing
Authors: William J. Taffe
Venue: Journal of Computing Sciences in Colleges (2002)

Three years ago, our department developed a new computing degree, a degree in Information Technology conceptually distinct from the standard Computer Science, Information Systems or Computer Engineering degrees. The focus of this degree is on current computing technology, its implementation and application. This paper presents a description of our program, the motivation and justification for its development, the curriculum design goals, current curriculum implementation, problems yet to be resolved and future plans.
Innovation and Control in Standards Architectures: The Rise and Fall of Japan's PC-98
Authors: Joel West, Jason Dedrick
Venue: Information Systems Research (2000)

For more than a decade NEC dominated the Japanese PC market with its PC-98 architecture, which was incompatible both with its major Japanese rivals and the global PC standard. However, NEC was powerless to prevent the introduction of Japanese versions of Windows 3.1 and 95 that ran on its competitors' architectures as well as on the PC-98, unifying the Japanese PC market and creating a common set of application programming interfaces for all Intel-based Japanese PCs. The introduction of Windows rendered obsolete the large DOS-based software library that had provided strong positive externalities for the NEC architecture. Absent those advantages, the market share of the PC-98 standard fell from 60% to 33% in five years, and NEC finally abandoned the PC-98 in favor of the global standard. An examination of the unusual rise and fall of the PC-98 shows how victory in a standards competition can be negated by the introduction of a new architectural layer that spans two or more previously incompatible architectures.
Case study: comparing two methods for filtering external motion in 4D confocal microscopy data
Authors: Wim de Leeuw, Robert van Liere
Venue: Proceedings of the symposium on Data visualisation 2003 (2003)

In this case study, we compare two methods for filtering external motion in time dependent volume data sets acquired from confocal microscopy. The pros and cons of a landmark based and a voxel based method are discussed. We show that filtering external motion is an essential first step for the visualization of confocal data.
Efficient Learning in Adaptive Processing of Data Structures
Authors: Siu-Yeung Cho, Zheru Chi, Zhiyong Wang, Wan-Chi Siu
Venue: Neural Processing Letters (2003)

Many researchers have explored the use of neural network models for the adaptive processing of data structures. The learning formulation for one of the models is known as the Backpropagation Through Structure (BPTS) algorithm. The main limitations of the BPTS algorithm are attributed to the problems of slow convergence speed and long-term dependency. In this Letter, a novel heuristic algorithm is proposed. The idea of this algorithm is to optimize the free parameters of the node representation in data structure by using a hybrid type of learning algorithm. Encouraging results achieved demonstrate that this proposed algorithm outperforms the BPTS algorithm.