ppxscal/embedding_network huggingface dataset:
A simple weighting scheme for classification in two-group discriminant problems
Authors: Kim Fung Lam, Jane W. Moy
Venue: Computers and Operations Research (2003)

This paper introduces a new weighted linear programming model, which is simple and has strong intuitive appeal for two-group classifications. Generally, in applying weights to solve a classification problem in discriminant analysis where the relative importance of every observation is known, larger weights (penalties) will be assigned to those more important observations. The perceived importance of an observation is measured here as the willingness of the decision-maker to misclassify this observation. For instance, a decision-maker is least willing to see a classification rule that misclassifies a top financially strong firm to the group that contains bankrupt firms. Our weighted-linear programming model provides an objective-weighting scheme whereby observations can be weighted according to their perceived importance. The more important this observation, the heavier its assigned weight. Results of a simulation experiment that uses contaminated data show that the weighted linear programming model consistently and significantly outperforms existing linear programming and standard statistical approaches in attaining higher average hit-ratios in the 100 replications for each of the 27 cases tested.
A Framework for Adaptive Cluster Computing Using JavaSpaces
Authors: Jyoti Batheja, Manish Parashar
Venue: Cluster Computing (2003)

Heterogeneous networked clusters are being increasingly used as platforms for resource-intensive parallel and distributed applications. The fundamental underlying idea is to provide large amounts of processing capacity over extended periods of time by harnessing the idle and available resources on the network in an opportunistic manner. In this paper we present the design, implementation and evaluation of a framework that uses JavaSpaces to support this type of opportunistic adaptive parallel/distributed computing over networked clusters in a non-intrusive manner. The framework targets applications exhibiting coarse grained parallelism and has three key features: (1) portability across heterogeneous platforms, (2) minimal configuration overheads for participating nodes, and (3) automated system state monitoring (using SNMP) to ensure non-intrusive behavior. Experimental results presented in this paper demonstrate that for applications that can be broken into coarse-grained, relatively independent tasks, the opportunistic adaptive parallel computing framework can provide performance gains. Furthermore, the results indicate that monitoring and reacting to the current system state minimizes the intrusiveness of the framework.
The Impact of Cell Dropping Policies in Atm Nodes
Authors: Zhen Liu, Rhonda Righter
Venue: Operations Research (2001)

We consider policies for deciding which cells will be lost or dropped when losses occur at a finite buffer asynchronous transfer mode (ATM) node. The performance criteria of interest are the delay of transmitted (nonlost) cells, the jitter (or variability in the delay of transmitted cells), and the burstiness of lost cells. We analyze the performance trade-offs for various cell dropping policies. We show that "rear dropping," in which cells that arrive to a full buffer are lost, stochastically maximizes delay, whereas "front dropping," in which cells at the front of the buffer are lost, stochastically minimizes delay. On the other hand, rear dropping stochastically minimizes the jitter. We also propose policies that have both stochastically smaller delay and less lost cell burstiness in a stochastic majorization sense than the rear dropping policy.
Maximum mean weight cycle in a digraph and minimizing cycle time of a logic chip
Authors: Christoph Albrecht, Bernhard Korte, Jürgen Schietke, Jens Vygen
Venue: Discrete Applied Mathematics (2002)

The maximum mean weight cycle problem is well-known: given a digraph G with weights c:E(G) → R, find a directed circuit in G whose mean weight is maximum. Closely related is the minimum balance problem: Find a potential π: V(G) → R such that the numbers slack(e):=π(w)-π(v)-c((v, w))(e=(v, w)∈E(G)) are optimally balanced: for any subset of vertices, the minimum slack on an entering edge should equal the minimum slack on a leaving edge. Both problems can be solved by a parametric shortest path algorithm.We describe an application of these problems to the design of logic chips. In the simplest model, optimizing the clock schedule of a chip to minimize the cycle time is equivalent to a maximum mean weight cycle problem. It is very important to find a solution with well-balanced slacks; this problem, in the simple model, is a minimum balance problem.However, in practical situations many constraints have to be taken into account. Therefore minimizing the cycle time and finding the optimum slack distribution are more general problems. We show how a parametric shortest path algorithm can be extended to solve these problems efficiently.Computational results with recent IBM processor chips show that the cycle time reduces considerably. Moreover, the number of critical paths (with small slack) decreases dramatically. As a result we obtain significantly faster chips. The running time of our algorithm is reasonable even for very large designs.
Modeling of Transport Risk for Hazardous Materials
Authors: Erhan Erkut, Vedat Verter
Venue: Operations Research (1998)

The transport of hazardous materials is an important strategic and tactical decision problem. Risks associated with this activity make transport planning difficult. Although most existing analytical approaches for hazardous materials transport account for risk, there is no agreement among researchers on how to model the associated risks. This paper provides an overview of the prevailing models, and addresses the question "Does it matter how we quantify transport risk?" Our empirical analysis on the U.S. road network suggests that different risk models usually select different "optimal" paths for a hazmat shipment between a given origin-destination pair. Furthermore, the optimal path for one model could perform very poorly under another model. This suggests that researchers and practitioners must pay considerable attention to the modeling of risks in hazardous materials transport.
Controlling Web Query Execution in a Web Warehouse
Authors: Sourav S. Bhowmick, Sanjay Kumar Madria
Venue: Proceedings of the 13th International Workshop on Database and Expert Systems Applications (2002)

Most of the contemporary web query systems have limited capabilities in controlling web query execution. Such query facility is important as it gives us an opportunity to optimize the evaluation of a web query. In this paper, we address this issue in the context of our web warehousing system called WHOWEDA (Warehouse Of Web Data). Specifically, we investigate different types of constraints (related to query execution) which may be imposed on a web query such as number of query results, time of execution, restrict the evaluation of a query to specified set of web sites, etc.. An important feature of our approach is that it attempts to address the query evaluation issues which may arise due to the existence of broken links and forms in the Web.
The human side of information systems development: a case of an intervention at a British visitor attraction
Authors: Brian Lehaney, Steve Clarke, Sarah Spencer-Matthews, Vikki Kimberlee
Venue: Advanced topics in end user computing (2002)

Information systems (IS) are growing in importance within the tourism industry, where one key application is database marketing. Evidence from the IS domain suggests systems failure may be due, at least in part, to concentration on technical rather than human issues in the development process. Through an empirical study of visitor attractions in the United Kingdom, the need for a more human-centered approach to IS development is supported, and an example of such an approach is outlined. Both in-depth focus group analysis and a broader questionnaire survey are used and lend weight to the human-centered arguments.From the analysis of a failed tourism database marketing information system, and from evidence of similar successful systems, the value of technology-enabled database marketing within the sector is demonstrated, but its success is seen to rest on participative, human-centered approaches to development.
Back to Pascal: retro but not backwards
Authors: Katrin Becker
Venue: Journal of Computing Sciences in Colleges (2002)

The debate over which language to use when teaching beginning programming has persisted for decades. One institution has elected to give Pascal a second chance. The rationale for this change and some early experiences are outlined. The difficulties experienced when this institution used C++ are described and the requirements for a first language are listed. Pascal satisfies most of the requirements as specified. Opposition to the change was noted and countered. Now, after the first semester of use, some clear advantages as well as disadvantages are evident.
Social Structure of "Coopetition" Within a Multiunit Organization: Coordination, Competition, and Intraorganizational Knowledge Sharing
Authors: Wenpin Tsai
Venue: Organization Science (2002)

Drawing on a social network perspective of organizational coordination, this paper investigates the effectiveness of coordination mechanisms on knowledge sharing in intraorganizational networks that consist of both collaborative and competitive ties among organizational units. Internal knowledge sharing within a multiunit organization requires formal hierarchical structure and informal lateral relations as coordination mechanisms. Using sociometric techniques, this paper analyzes how formal hierarchical structure and informal lateral relations influence knowledge sharing and how interunit competition moderates the association between such coordination mechanisms and knowledge sharing in a large, multiunit company. Results show that formal hierarchical structure, in the form of centralization, has a significant negative effect on knowledge sharing, and informal lateral relations, in the form of social interaction, have a significant positive effect on knowledge sharing among units that compete with each other for market share, but not among units that compete with each other for internal resources.
Stabilization of Motions of the Descent Vehicle in the Upper Atmosphere
Authors: V. I. Matyukhin
Venue: Automation and Remote Control (2003)

The paper was written in continuation of a series of papers on construction of a control law stabilizing a wide range of motions of the controlled plant. At that, the law in essence must be independent of the plant's dynamic characteristics and the environment. These multimodal (general-purpose) laws must generate the control signal with the minimum computational burden and in the minimum time. These laws have other important characteristics concerning stability of the closed-loop system, its robustness, and so on. The paper studied a controlled plant moving under the action of aerodynamic and other forces. The distinction of the formulated control problem is due to the deficiency of the control actions because it is assumed that the controlled plant has only two control engines. This is the case in the well-known problem of controlling the descent vehicle by stabilizing its lateral motion on the hypersonic leg of flight in the upper atmosphere.
To the uniqueness problem for nonlinear elliptic equations
Authors: H. Gajewski, I. V. Skrypnik
Venue: Nonlinear Analysis: Theory, Methods Applications (2003)

We prove existence and uniqueness of solutions u ∈ W1,2 (Ω) ∩ L∞ (Ω) to equations of the form -Σi=1n ∂/∂xi[ρ(u)bi (x,∂u/∂x)]+a (x,u, ∂u/∂x) =0, x ∈ Ω. Our nonstandard assumptions on the coefficients are such that log ρ(u) is concave and a(x, u, ξ)/ ρ(u), is increasing in u. Such assumptions are natural in view of drift diffusion processes for example in semiconductors and chemotaxis.
Cross-language information retrieval: experiments based on CLEF 2000 corpora
Authors: Jacques Savoy
Venue: Information Processing and Management: an International Journal (2003)

Search engines play an essential role in the usability of Internet-based information systems and without them the Web would be much less accessible, and at the very least would develop at a much slower rate. Given that non-English users now tend to make up the majority in this environment, our main objective is to analyze and evaluate the retrieval effectiveness of various indexing and search strategies based on test-collections written in four different languages: English, French, German, and Italian. Our second objective is to describe and evaluate various approaches that might be implemented in order to effectively access document collections written in another language. As a third objective, we will explore the underlying problems involved in searching document collections written in the four different languages, and we will suggest and evaluate different database merging strategies capable of providing the user with a single unique result list.
Parameter identification of an unconfined aquifer using extended Kalman filter
Authors: H. D. Yeh, C. H. Leng
Venue: Development and application of computer techniques to environmental studies (2002)

A method using extended Kalman filter (EKF) and cubic spline is proposed to identify the aquifer parameters of an unconfined aquifer system. Neuman's model combined with EKF, using the interpolated drawdown data produced by cubic spline, can optimally determine the parameters for unconfined aquifers through the recursive filtering process. The proposed method can quickly identify the parameters, using only part of observed drawdown data, and achieves good accuracy. Thus, the lengthy pumping test may be shortened. In addition, the comparisons of results among using conventional graphical methods, nonlinear least-squares combined with finite-difference Newton's method (NLN), and EKF are presented. The EKF is shown to allow a wider range of initial guess values, though the results are slightly less accurate than those by NLN, but much more accurate than those by graphical methods. Finally, the identification process of specific yield reflects the effect of gravity drainage on the drawdown curve and conforms to the physical nature of an unconfined aquifer, when determining the aquifer parameters.
The blue-c distributed scene graph
Authors: Martin Naef, Edouard Lamboray, Oliver Staadt, Markus Gross
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

In this paper we present a distributed scene graph architecture for use in the blue-c, a novel collaborative immersive virtual environment. We extend the widely used OpenGL Performer toolkit to provide a distributed scene graph maintaining full synchronization down to vertex and texel level. We propose a synchronization scheme including customizable, relaxed locking mechanisms. Our distributed scene graph includes both locally stored nodes for static scene data as well as nodes shared across multiple sites, thus minimizing synchronization overhead. We discuss the performance and demonstrate the functionality of our toolkit with two prototype applications in our high-performance virtual reality and visual simulation environment.
Combining data and text mining techniques for yeast gene regulation prediction: a case study
Authors: Mark-A. Krogel, Marcus Denecke, Marco Landwehr, Tobias Scheffer
Venue: ACM SIGKDD Explorations Newsletter (2002)

In order to solve task 2 of the KDD Cup 2002, we exploited various available information sources. In particular, use of relational information describing the interactions among genes and information automatically extracted from scientific abstracts improves the accuracy of our predictions.
The Critical Transmitting Range for Connectivity in Sparse Wireless Ad Hoc Networks
Authors: Paolo Santi, Douglas M. Blough
Venue: IEEE Transactions on Mobile Computing (2003)

In this paper, we analyze the critical transmitting range for connectivity in wireless ad hoc networks. More specifically, we consider the following problem: Assume n nodes, each capable of communicating with nodes within a radius of r, are randomly and uniformly distributed in a d-dimensional region with a side of length l; how large must the transmitting range r be to ensure that the resulting network is connected with high probability? First, we consider this problem for stationary networks, and we provide tight upper and lower bounds on the critical transmitting range for one-dimensional networks and nontight bounds for two and three-dimensional networks. Due to the presence of the geometric parameter l in the model, our results can be applied to dense as well as sparse ad hoc networks, contrary to existing theoretical results that apply only to dense networks. We also investigate several related questions through extensive simulations. First, we evaluate the relationship between the critical transmitting range and the minimum transmitting range that ensures formation of a connected component containing a large fraction (e.g., 90 percent) of the nodes. Then, we consider the mobile version of the problem, in which nodes are allowed to move during a time interval and the value of r ensuring connectedness for a given fraction of the interval must be determined. These results yield insight into how mobility affects connectivity and they also reveal useful trade offs between communication capability and energy consumption.
On Three Problems About Dynamical Systems Related to Lattices and Homogeneous Spaces
Authors: A. M. Stepin
Venue: Journal of Dynamical and Control Systems (2003)

This communication is a survey about the problems discussed recently in my seminar at Moscow State University. Precisely the topics are as follows: (1) the Veech dichotomy for rational plane billiards, (2) T-induced flows, and (3) integrability of G-invariant Hamiltonian systems with homogeneous configuration spaces.
Application of the Principle of Design of Adaptive Systems with a Reference Model to Problems of Monitoring of a Current State of Transmission Shafts
Authors: V. M. Glumov, S. D. Zemlyakov, V. Yu. Rutkovskii, V. M. Sukhanov
Venue: Automation and Remote Control (2003)

A possibility of monitoring a current state of transmission shafts on the basis of an adaptive system with a reference model is considered. Using a gas-turbine engine as an example, a problem is solved for the estimation of a torsion angle of the shaft that transmits the torque of a free turbine through the reduction gear to the propeller in the condition of a finite value of the torsion stiffness of the shaft. The torsion angle specifies the current state of the shaft and can be used for the advanced disengagement of the engine in the event of the breakup of the transmission. It is shown that the suggested adaptive system of estimating the torsion angle of the shaft ensures a high dynamic accuracy in the stationary and nonstationary modes of operation of the engine. The mathematical modeling confirmed the serviceability of the system under conditions that are close to actual ones, in particular, under the action of random noise of the measurement.
Properties of the Log-Barrier Function on Degenerate Nonlinear Programs
Authors: Stephen J. Wright, Dominique Orban
Venue: Mathematics of Operations Research (2002)

We examine the sequence of local minimizers of the log-barrier function for a nonlinear program near a solution at which second-order sufficient conditions and the Mangasarian-Fromovitz constraint qualification are satisfied, but the active constraint gradients are not necessarily linearly independent. When a strict complementarity condition is satisfied, we show uniqueness of the local minimizer of the barrier function in the vicinity of the nonlinear program solution, and we obtain a semiexplicit characterization of this point. When strict complementarity does not hold, we obtain several other interesting characterizations, in particular, an estimate of the distance between the minimizers of the barrier function and the nonlinear program in terms of the barrier parameter, and a result about the direction of approach of the sequence of minimizers of the barrier function to the nonlinear programming solution.
Evaluating Financial Risk in the Medicare Prospective Payment System
Authors: Maqbool Dada, William D. White
Venue: Management Science (1999)

The Medicare Prospective Payment System (PPS) is analogous to an insurance scheme in which financial risk is mitigated through experience rating. In addition, risk is also mitigated through reinsurance provisions. Although a provider may not want this reinsurance, participation is mandatory. We develop a framework for evaluating financial risk under the PPS. We use this framework to examine optional reinsurance as an alternative risk mitigation mechanism. We illustrate an application of optional reinsurance using data for Medicare psychiatric inpatient services. Our analysis indicates that viable schemes exist for implementing optional reinsurance as a prospective payment option.
Stagnation flows with slip: exact solutions of the Navier-Stokes equations
Authors: C. Y. Wang
Venue: Zeitschrift f&uuml;r Angewandte Mathematik und Physik (ZAMP) (2003)

Exact similarity solutions of the Navier-Stokes equations are found for stagnation flows towards a plate with slip. The solutions are applicable to the slip regime of rarefied gases.
A machine learning approach for the curation of biomedical literature: KDD Cup 2002 (task 1)
Authors: S. Sathiya Keerthi, Chong Jin Ong, Keng Boon Siah, David B. L. Lim, Wei Chu, Min Shi, David S. Edwin, Rakesh Menon, Lixiang Shen, Jonathan Y. K. Lim, Han Tong Loh
Venue: ACM SIGKDD Explorations Newsletter (2002)

In this paper, we present an automated text classification system for the classification of biomedical papers. This classification is based on whether there is experimental evidence for the expression of molecular gene products for specified genes within a given paper. The system performs pre-processing and data cleaning, followed by feature extraction from the raw text. It subsequently classifies the paper using the extracted features with a Na&iuml;ve Bayes Classifier. Our approach has made it possible to classify (and curate) biomedical papers automatically, thus potentially saving considerable time and resources.
Finding Perceptually Closed Paths in Sketches and Drawings
Authors: Eric Saund
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (2003)

Closed or nearly closed regions are an important form of perceptual structure arising both in natural imagery and in many forms of human-created imagery including sketches, line art, graphics, and formal drawings. This paper presents an effective algorithm especially suited for finding perceptually salient, compact closed region structure in hand-drawn sketches and line art. We start with a graph of curvilinear fragments whose proximal endpoints form junctions. The key problem is to manage the search of possible path continuations through junctions in an effort to find paths satisfying global criteria for closure and figural salience. We identify constraints particular to this domain for ranking path continuations through junctions, based on observations of the ways that junctions arise in line drawings. In particular, we delineate the roles of the principle of good continuation versus maximally turning paths. Best-first bidirectional search checks for the cleanest, most obvious paths first, then reverts to more exhaustive search to find paths cluttered by blind alleys. Results are demonstrated on line drawings from several sources including line art, engineering drawings, sketches on whiteboards, as well as contours from photographic imagery.