ppxscal/embedding_network huggingface dataset:
Model Composition Using Filter Spaces
Authors: Kaushal Chari
Venue: Information Systems Research (2002)

Decision support systems (DSS) typically contain data and models to facilitate decision making. DSS users, in response to a particular decision-making situation, often execute a sequence of models, in which inputs to a model in the sequence are obtained from outputs of other models upstream in the sequence and from database retrievals. The problem of generating a sequence of models from the set of available models is known as the model composition problem. In this paper, we propose a new construct called filter spaces to support model composition. We show how filter spaces can significantly facilitate automation of model composition and execution process, and provide effective means to integrate partial solutions from multiple composite models and databases.
Properties of Batched Quadratic-Form Variance Parameter Estimators for Simulations
Authors: Christos Alexopoulos, David Goldsman, Gamze Tokol
Venue: INFORMS Journal on Computing (2001)

We examine the practice of batching of certain quadratic-form estimators for the variance parameter of a stochastic process. The class of batched quadratic-form estimators includes, among others, the standardized time series (STS) weighted area and weighted CramÃ©r-von Mises estimators. We give results on the expected value and variance of such estimators as the batch size and/or the number of batches increase. In particular, we show that the above STS estimators are consistent for the variance parameter in terms of mean squared error. An analytical example involving a first-order autoregressive process illustrates our findings.
Optimality of Myopic Ordering Policies for Inventory Model with Stochastic Supply
Authors: Do Ba Khang, Okitsugu Fujiwara
Venue: Operations Research (2000)

This paper addresses a discrete time inventory model where the maximum amount of supply from which instantaneous replenishment orders can be made is a random variable. Optimal ordering policies are characterized as critical number policies with monotone increasing optimal critical values. A sufficient condition is then presented for myopic ordering policies to be optimal.
Modeling software maintenance requests: a case study
Authors: E. Burch, Hsiang-Jui Kungs
Venue: Proceedings of the International Conference on Software Maintenance (1997)

Software maintenance costs often total twice the original development cost in the lifetime of application software. Modeling the changes of software maintenance activities might improve software maintenance planning. Current studies model software activities only covering a portion of software lifetimes. This study investigates the changes of maintenance requests during the lifetime of large application software. It discusses the modeling of different software maintenance requests such as: user support, repair and enhancement. We found four distinct stages. User support reaches its peak in the first stage, repair inundates in the second stage. In the third stage, enhancement is the dominant factor. The frequencies of all three different maintenance requests are small in the last stage, when the IS department is looking for new software to replace the existing one.
Development reuse and the logic program derivation of two string-matching algorithms
Authors: Manuel Hernández, David A. Rosenblueth
Venue: Proceedings of the 3rd ACM SIGPLAN international conference on Principles and practice of declarative programming (2001)

Program transformation advocates the development of programs by applying a sequence of meaning-preserving rules to a specification, thereby obtaining an implementation. The cost of program development and maintenance decreases if previous, similar derivations can be reused conveniently Through the string-matching problem, we study the reuse of complete parts of the derivation of an algorithm, in the deriv ation of another, "similar" algorithm. In particular, we first derive the search stage of a variant of the Boyer--Moore algorithm, and then reuse some "dev elopments" in a derivation of the search stage of the Knuth-Morris-Pratt algorithm. Several advantages result from employing logic programming. First, we get the semantic benefit of having a logical basis. Second, we can easily exploit nondeterminism. Third, we link both deriv ations by observing that repetitive "deterministic" unfolding (i.e. sequences of unfolding steps that halt when more than one clause would be inferred) is closely related to the preprocessing stage of both algorithms.
A student project in 3D graphics
Authors: Troy Kammerdiener
Venue: Journal of Computing Sciences in Colleges (2003)

We describe a project in 3D perspective graphics, which was implemented by the students in our computer graphics class. We explain our objectives and the basic concept behind the project, as well as the components used to construct it. We also describe how the students divided the work among themselves. Finally, we explain how the final presentation worked, and how the results satisfied our initial objectives.
Toward a social cognitive basis for the IT professional's person-organization fit research-in-progress
Authors: Stephen C. Wingreen, J. Ellis Blanton, Marcy L. Kittner, Richard A. Fentriss
Venue: Proceedings of the 2003 SIGMIS conference on Computer personnel research: Freedom in Philadelphia--leveraging differences and diversity in the IT workforce (2003)

Development and maintenance of the corporate IT skill portfolio through the in-house development of IT talent demands that managers have a strategy for implementing the proper incentives for the IT workforce to pursue the appropriate training and skill acquisition programs. Social-cognitive theory is used as a foundation for proposing a process-oriented model and the development of instrumentation to measure the IT professional's person-organization fitting processes. The instrumentation was successfully pilot tested with respect to the initial estimates of its reliability and validity.
A robust level-set algorithm for centerline extraction
Authors: Alexandru Telea, Anna Vilanova
Venue: Proceedings of the symposium on Data visualisation 2003 (2003)

We present a robust method for extracting 3D centerlines from volumetric datasets. We start from a 2D skeletonization method to locate voxels centered with respect to three orthogonal slicing directions. Next, we introduce a new detection criterion to extract the centerline voxels from the above skeletons, followed by a thinning, reconnection, and a ranking step. Overall, the proposed method produces centerlines that are object-centered, connected, one voxel thick, robust with respect to object noisiness, handles arbitrary object topologies, comes with a simple pruning threshold, and is fast to compute. We compare our results with two other methods on a variety of real-world datasets.
Genetic algorithm with fuzzy logic controller for preemptive and non-preemptive job-shop scheduling problems
Authors: Young Su Yun
Venue: Computers and Industrial Engineering (2002)

In this paper, we propose a new genetic algorithm (GA) with fuzzy logic controller (FLC) for dealing with preemptive job-shop scheduling problems (p-JSP) and non-preemptive job-shop scheduling problems (np-JSP). The proposed algorithm considers the preemptive cases of activities among jobs under single machine scheduling problems. For these preemptive cases, we first use constraint programming and secondly develop a new gene representation method, a new crossover and mutation operators in the proposed algorithm.However, the proposed algorithm, as conventional GA, also has a weakness that takes so much time for the fine-tuning of genetic parameters. FLC can be used for regulating these parameters.In this paper, FLC is used to adaptively regulate the crossover ratio and the mutation ratio of the proposed algorithm. To prove the performance of the proposed FLC, we divide the proposed algorithm into two cases: the GA with the FLC (pro-fGA) and the GA without the FLC (pro-GA).In numerical examples, we apply the proposed algorithms to several job-shop scheduling problems and the results applied are analyzed and compared. Various experiments show that the results of pro-fGA outperform those of pro-GA.
Measuring Switching Costs and the Determinants of Customer Retention in Internet-Enabled Businesses: A Study of the Online Brokerage Industry
Authors: Pei-Yu (Sharon) Chen, Lorin M. Hitt
Venue: Information Systems Research (2002)

The ability to retain and lock in customers in the face of competition is a major concern for online businesses, especially those that invest heavily in advertising and customer acquisition. In this paper, we develop and implement an approach for measuring the magnitudes of switching costs and brand loyalty for online service providers based on the random utility modeling framework. We then examine how systems usage, service design, and other firm and individual-level factors affect switching and retention. Using data on the online brokerage industry, we find significant variation (as much as a factor of two) in measured switching costs. We find that customer demographic characteristics have little effect on switching, but that systems usage measures and systems quality are associated with reduced switching. We also find that firm characteristics such as product line breadth and quality reduce switching and may also reduce customer attrition. Overall, we conclude that online brokerage firms appear to have different abilities in retaining customers and have considerable control over their switching costs.
Cherry: checkpointed early resource recycling in out-of-order microprocessors
Authors: José F. Martínez, Jose Renau, Michael C. Huang, Milos Prvulovic, Josep Torrellas
Venue: Proceedings of the 35th annual ACM/IEEE international symposium on Microarchitecture (2002)

This paper presents CHeckpointed Early Resource RecYcling (Cherry), a hybrid mode of execution based on ROB and checkpointing that decouples resource recycling and instruction retirement. Resources are recycled early, resulting in a more efficient utilization. Cherry relies on state checkpointing and rollback to service exceptions for instructions whose resources have been recycled. Cherry leverages the ROB to (1) not require in-order execution as a fallback mechanism, (2) allow memory replay traps and branch mispredictions without rolling back to the Cherry checkpoint, and (3) quickly fall back to conventional out-of-order execution without rolling back to the checkpoint or flushing the pipeline.We present a Cherry implementation with early recycling at three different points of the execution engine: the load queue, the store queue, and the register file. We report average speedups of 1.06 and 1.26 in SPECint and SPECfp applications, respectively, relative to an aggressive conventional architecture. We also describe how Cherry and speculative multithreading can be combined and complement each other.
Abstraction the key to CS1
Authors: Peter Sprague, Celia Schahczenski
Venue: Journal of Computing Sciences in Colleges (2002)

It is commonly agreed that a first-year programming class should not so much be a class in programming as a class in problem solving. In this paper we argue that problem solving is better taught using the object-oriented paradigm than the traditional procedural programming paradigm. We argue that abstraction is key to problem solving and that object-orientation facilitates, and even forces, a higher level of abstraction than does procedural programming. We discuss the benefits of abstraction and those topics that should be presented in a first year "objects-first" programming course.
LVMSR: an efficient algorithm to multicast layered video
Authors: Wushao Wen, Biswanath Mukherjee, S.-H. Gary Chan, Dipak Ghosal
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2003)

Layered video is a video-compression technique to encode video data in multiple layers. It typically consists of a base layer and some additional layers that provide enhanced video quality. The multicasting operation of layered video consists of many receivers dynamically joining and leaving different multicast sessions of different layers depending on their network condition. A layered video multicasting system needs to satisfy: (i) bounded end-to-end delay from the video source to each receiver; (ii) minimum total cost; and (iii) minimum delay jitter between the various video streams received by each receiver. The problem of computing such data distribution paths is NP-complete. This paper presents a new heuristic algorithm, called layered video multicast super-tree routing algorithm, with O(Rn2) time complexity and O(R2) message complexity, where n is the number of nodes in the network and R is the receiver group size. Our investigation shows that the multicast data paths computed by our algorithm can always satisfy the delay constraint with reasonably low total cost.
A new lower bound on the number of edges in colour-critical graphs and hypergraphs
Authors: Alexandr V. Kostochka, Michael Stiebitz
Venue: Journal of Combinatorial Theory Series B (2003)

A graph G is called k-critical if it has chromatic number k, but every proper subgraph of G is (k- 1)-colourable. We prove that every k-critical graph (k≥ 6) on n ≥ k + 2 vertices has at least 1/2(k- 1 + (k-3)/(k-c)(k-1)+k-3) n edges where c = (k - 5)(1/2- 1/ (k-1)(k-2)). This improves earlier bounds established by Gallai (Acad. Sci. 8 (1963) 165) and by Krivelevich (Combinatorica 17 (1999) 401).
A Similarity Graph-Based Approach to Declustering Problems and Its Application towards Paralleling Grid Files
Authors: Duen-Ren Liu, Shashi Shekhar
Venue: Proceedings of the Eleventh International Conference on Data Engineering (1995)

We propose a new similarity-based technique for declustering data. The proposed method can adapt to available information about query distributions, data distributions, data sizes and partition-size constraints. The method is based on max-cut partitioning of a similarity graph defined over the given set of data, under constraints on the partition sizes. It maximizes the chances that a pair of data-items that are to be accessed together by queries are allocated to distinct disks. We show that the proposed method can achieve optimal speed-up for a query-set, if there exists any other declustering method which will achieve the optimal speed-up. Experiments in parallelizing grid files show that the proposed method outperforms mapping-function-based methods for interesting query distributions as well for non-uniform data distributions.
Linear Programming
Authors: George B. Dantzig
Venue: Operations Research (2002)

The Story About How It Began: Some legends, a little about its historical significance, and comments about where its many mathematical programming extensions may be headed.
Solution of the Multisource Weber and Conditional Weberproblems by D.-C. Programming
Authors: Pey-Chun Chen, Pierre Hansen, Brigitte Jaumard, Hoang Tuy
Venue: Operations Research (1998)

D.-c. programming is a recent technique of global optimization that allows the solution of problems whose objective function and constraints can be expressed as differences of convex (i.e., d.-c.) functions. Many such problems arise in continuous location theory. The problem first considered is to locate a known number of source facilities to minimize the sum of weighted Euclidean distances between a user's fixed location and the source facility closest to the location of each user. We also apply d.-c. programming to the solution of the conditional Weber problem, an extension of the multisource Weber Problem, in which some facilities are assumed to be already established. In addition, we consider a generalization of Weber's problem, the facility location problem with limited distances, where the effective service distance becomes a constant when the actual distance attains a given value. Computational results are reported for problems with up to 10,000 users and two new facilities, 50 users and three new facilities, 1,000 users, 20 existing facilities and one new facility or 200 users, 10 existing and two new facilities.
Statistical Composites: A Transformation-Bound Representation of Statistical Datasets
Authors: Michaela Denk, Karl Anton Froeschl, Wilfried Grossmann
Venue: Proceedings of the 14th International Conference on Scientific and Statistical Database Management (2002)

Statistical data processing makes use of data matrices and tables as primary structures for data representation. Embedding these structures into processing-relevant context information gives rise to enhanced data structures linking data and metadata. The paper describes a framework for statistical data processing utilising metadata computationally.
STEP-UP: A Decision-Support System for Transforming the Dislocated US Defense Workforce
Authors: Theresa M. Vitolo, Robert J. Vance
Venue: Interfaces (2002)

We developed STEP-UP, a database-intensive, decision-support system for dislocated workers. We modeled the work positions at a micro- and macro-level and created tailored profiles for individuals to reflect prior positions, training, certifications, and interests. With the profile, career counselors matched employees to labor-market positions or identified training programs in growth industries. Also, giving the prospective employers an indication of the wealth of skilled employees, STEP-UP could provide client matches for job openings. We have continued to extend the capabilities of STEP-UP and offer it as a Web-based system. We expect that more decision support systems like STEP-UP will be developed for use in human resource decision-making situations.
CAD/CAE visualization in virtual environment for automotive industry
Authors: D. Paillot, F. Merienne, S. Thivent
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

In this paper we propose a method to link CAD models to an immersive environment. Since CAD models can not be directly viewed in a real-time visualization environment, we present here a complete chain of adaptation steps to view adapted CAD models in an immersive environment with high quality rendering. Our method allows high quality visualization of complex scenes in an immersive environment such as design reviewing for example.
The Value of Internet Commerce to the Customer
Authors: James R. Marsden, Y. Alex Tung, Ralph L. Keeney
Venue: Management Science (1999)

Internet commerce has the potential to offer customers a better deal compared to purchases by conventional methods in many situations. To make this potential a reality, businesses must focus on the values of their customers. We interviewed over one-hundred individuals about all the pros and cons of using Internet commerce that they experienced or envisioned. The results were organized into twenty-five categories of objectives that were influenced by Internet purchases. These categories were separated into means objectives and fundamental objectives used to describe the bottom line consequences of concern to customers. These results are applicable to designing an Internet commerce system for a business, creating and redesigning products, and increasing value to customers. The set of fundamental objectives also provides the foundation for developing a quantitative model of customer values.
Comparing the similarity of time-series gene expression using signal processing metrics
Authors: Atul J. Butte, Ling Bao, Ben Y. Reis, Timothy W. Watkins, Isaac S. Kohane
Venue: Computers and Biomedical Research (2001)

Many algorithms have been used to cluster genes measured by microarray across a time series. Instead of clustering, our goal was to compare all pairs of genes to determine whether there was evidence of a phase shift between them. We describe a technique where gene expression is treated as a discrete time-invariant signal, allowing the use of digital signal-processing tools, including power spectral density, coherence, and transfer gain and phase shift. We used these on a public RNA expression set of 2467 genes measured every 7 min for 119 min and found 18 putative associations. Two of these were known in the biomedical literature and may have been missed using correlation coefficients. Digital signal processing tools can be embedded and enhance existing clustering algorithms.
Automatic generation of interprocedural data-flow analyzers and optimizers
Authors: Ruiqi Lian, Zhaoqing Zhang, Ruliang Qiao
Venue: Journal of Computer Science and Technology (2002)

Interprocedural analysis and optimization are very important for compilers to exploit parallelism of modern high-performance computer systems. But it is very complicated, easy to make mistakes and difficult to maintain and port. To solve the problem, we construct an automatic generator of interprocedural analyzers and optimizers -- IGEN. In IGEN, first a new model to describe the interprocedural data-flow problem is designed. It is fit for all traditional data-flow problems and can be used in context-sensitive algorithms. Then, the structure and the working environment of IGEN are described in detail. Finally, the implementation of IGEN and our experimental result are given.
NLPIR: a theoretical framework for applying natural language processing to information retrieval
Authors: Lina Zhou, Dongsong Zhang
Venue: Journal of the American Society for Information Science and Technology (2003)

The role of information retrieval (IR) in support of decision making and knowledge management has become increasingly significant. Confronted by various problems in traditional keyword-based IR, many researchers have been investigating the potential of natural language processing (NLP) technologies. Despite widespread application of NLP in IR and high expectations that NLP can address the problems of traditional IR, research and development of an NLP component for an IR system still lacks support and guidance from a cohesive framework. In this paper, we propose a theoretical framework called NLPIR that aims at integrating NLP into IR and at generalizing broad application of NLP in IR. Some existing NLP techniques are described to validate the framework, which not only can be applied to current research, but is also envisioned to support future research and development in IR that involve NLP.
Transient Analysis of Deterministic and Stochastic Petri Nets by the Method of Supplementary Variables
Authors: Reinhard German
Venue: Proceedings of the 3rd International Workshop on Modeling, Analysis, and Simulation of Computer and Telecommunication Systems (1995)

The paper addresses the transient analysis of stochastic Petri nets with deterministic and exponentially distributed firing times. Using the method of supplementary variables, general state equations are derived which are valid under certain structural conditions. A numerical technique for the iterative solution of the state equations is proposed. Furthermore, a special case is identified, for which an efficient and easy to implement solution is possible. This technique can be also used for the approximate solution in more general cases. Numerical examples demonstrate the use of the different algorithms.
A space-time state-space model of phytoplankton allelopathy
Authors: A. Mukhopadhyay, P. K. Tapaswi, J. Chattopadhyay
Venue: Nonlinear Analysis: Real World Applications (2003)

An integro-differential equation system with nonlocal effects of interspecific allelopathic interaction has been studied to investigate the formation of spatio-temporal structures in toxin producing phytoplankton population. The model is inherently more realistic than the usual kind of reaction-diffusion model. Bifurcation from uniform steady-state solution has been examined. Evolution of steady-state spatially periodic structure and periodic standing waves have been studied. The model helps to investigate the blooms, pulses and succession in different patches of phytoplankton population. Numerical simulations for a hypothetical set of parameter values and experimental observations have been presented to substantiate the analytical findings.