ppxscal/embedding_network huggingface dataset:
Probabilistic Analyses and Practical Algorithms for Inventory-Routing Models
Authors: Lap Mui Ann Chan, Awi Federgruen, David Simchi-Levi
Venue: Operations Research (1998)

We consider a distribution system consisting of a single warehouse and many geographically dispersed retailers. Each retailer faces demands for a single item which arise at a deterministic, retailer specific rate. The retailers? stock is replenished by a fleet of vehicles of limited capacity, departing and returning to the warehouse and combining deliveries into efficient routes. The cost of any given route consists of a fixed component and a component which is proportional with the total distance driven. Inventory costs are proportional with the stock levels. The objective is to identify a combined inventory policy and a routing strategy minimizing system-wide infinite horizon costs. We characterize the asymptotic effectiveness of the class of so-called Fixed Partition policies and those employing Zero Inventory Ordering. We provide worst case as well as probabilistic bounds under a variety of probabilistic assumptions. This insight is used to construct a very effective algorithm resulting in a Fixed Partition policy which is asymptotically optimal within its class. Computational results show that the algorithm is very effective on a set of randomly generated problems.
Using confluence to generate rule-based constraint solvers
Authors: Slim Abdennadher, Christophe Rigotti
Venue: Proceedings of the 3rd ACM SIGPLAN international conference on Principles and practice of declarative programming (2001)

A general approach to implement propagation and simplification of constraints consists of applying rules over these constraints. Recently, several proposals have been made to solve finite constraint satisfaction problems by means of automatically generated propagation rules [4, 9, 3]. Since propagation rules do not rewrite constraints but add new ones, the constraint store may contain superfluous constraints. Removing these constraints not only allows saving of space but also decreases the cost of constraint solving. Constraints can be removed using simplification rules. In this paper, we present a method to transform propagation rules into simplification rules using the concept of confluence. The generated rules are implemented in the language Constraint Handling Rules (CHR). An example tak en from the field of digital circuit design shows that our approach is of practical use.
Cognitive style may mitigate the impact of communication mode
Authors: Reza Barkhi
Venue: Information and Management (2002)

With the proliferation of Internet-based applications for collaborative work such as group decision support system (GDSS), traditional face-to-face (FTF) interactions are being augmented or replaced by screen-to-face (STF) technology. Extant research results find that some individuals prefer FTF mode for interaction and would feel frustrated under an STF mode, but others may feel very comfortable using electronic STF applications. This paper evaluates the influence of cognitive style on the perception of individuals negotiating over FTF or STF communication modes. Cognitive style explains how individuals prefer to receive information and what methods they use to process that information. The results suggest that when individuals are faced with a mixed-motive negotiation task, some cognitive styles mitigate the effects of communication modes while other cognitive styles are not sensitive to it. Hence, cognitive style and communication modes have interaction effects.
The Production of Information Services: A Firm-Level Analysis of Information Systems Budgets
Authors: Vijay Gurbaxani, Nigel Melville, Kenneth Kraemer
Venue: Information Systems Research (2000)

Previous research has demonstrated that the production of information services can be characterized at the aggregate economy-wide level by the Cobb-Douglas production function. However, the underlying production process at the firm level has not yet been ascertained. The objective of this paper is to determine the form of the production process for information systems services at the firm level by conducting an empirical analysis of IS budget data. The production of information services is modeled using a production function with two inputs, hardware and personnel. We estimate various econometric specifications to determine several characteristics of the provision of information services, including the allocation of the information systems budget to its two largest components--hardware and personnel--and its implications for the form of the production function. After controlling for industry sector, we find that the ratio of personnel to hardware is independent of scale, which indicates a homothetic production function. We also find that the ratio of factor shares is constant with time, consistent with the Cobb-Douglas production function.We conclude that the underlying form of the production function is the same at the level of both the firm and the economy. Our analysis demonstrates how the application of production theory to the production of information services can yield useful insights from both a theoretical and managerial perspective.
The semicircle law for semiregular bipartite graphs
Authors: Hirobumi Mizuno, Iwao Sato
Venue: Journal of Combinatorial Theory Series A (2003)

We give the (Ahumada type) Selberg trace formula for a semiregular bipartite graph G. Furthermore, we discuss the distribution on arguments of poles of zeta functions of semiregular bipartite graphs. As an application, we present two analogs of the semicircle law for the distribution of eigenvalues of specified regular subgraphs of semiregular bipartite graphs.
The Dynamic and Stochastic Knapsack Problem with Random Sized Items
Authors: Anton J. Kleywegt, Jason D. Papastavrou
Venue: Operations Research (2001)

A resource allocation problem, called the dynamic and stochastic knapsack problem (DSKP), is studied. A known quantity of resource is available, and demands for the resource arrive randomly over time. Each demand requires an amount of resource and has an associated reward. The resource requirements and rewards are unknown before arrival and become known at the time of the demand's arrival. Demands can be either accepted or rejected. If a demand is accepted, the associated reward is received; if a demand is rejected, a penalty is incurred. The problem can be stopped at any time, at which time a terminal value is received that depends on the quantity of resource remaining. A holding cost that depends on the amount of resource allocated is incurred until the process is stopped. The objective is to determine an optimal policy for accepting demands and for stopping that maximizes the expected value (rewards minus costs) accumulated. The DSKP is analyzed for both the infinite horizon and the finite horizon cases. It is shown that the DSKP has an optimal policy that consists of an easily computed threshold acceptance rule and an optimal stopping rule. A number of monotonicity and convexity properties are studied. This problem is motivated by the issues facing a manager of an LTL transportation operation regarding the acceptance of loads and the dispatching of a vehicle. It also has applications in many other areas, such as the scheduling of batch processors, the selling of assets, the selection of investment projects, and yield management.
The Rutgers Computational Grid: A Distributed Linux PC Cluster
Authors: B. Chernyavsky, E. Gallicchio, D. Knight, R. Levy, A. Page
Venue: Cluster Computing (2003)

The Rutgers Computational Grid (RCG) project is aimed at providing high throughput performance to Rutgers university faculty and students. The RCG employs dual processor PCs, with Pentium II and III processors, as computational nodes, running the Linux RedHat operating system. The Load Sharing Facility (LSF) scheduling system from Platform Computing is used for job control and monitoring. The nodes are grouped into subclusters physically located in several departments and controlled by a single master node through LSF. The hardware and software used in RCG are described. Utilization and performance issues, including parallel performance, are discussed based on the experience of the first two years of RCG operation.
Indirect VLIW memory allocation for the ManArray multiprocessor DSP
Authors: Nikos P. Pitsianis, Gerald G. Pechanek
Venue: ACM SIGARCH Computer Architecture News (2003)

The indirect very long instruction word (iVLIW) architecture and its implementation on the BOPS ManArray family of multiprocessor digital signal processors (DSP) provides a scalable alternative to the wide instruction busses usually required in a multiprocessor VLIW DSP. The ManArray processors indirectly access VLIWs from small caches of VLIWs localized in each processing element. With this work, we present an algorithm to perform 1) iVLIW instruction memory allocation on multiple processing elements to minimize instruction memory requirements and 2) scheduling of the iVLIW setup instructions to minimize execution overhead. We present preliminary experimental results that demonstrate the effectiveness of our approach.
Extracting Logical Schema from the Web
Authors: Vincenza Carchiolo, Alessandro Longheu, Michele Malgeri
Venue: Applied Intelligence (2003)

One of the main limitations when accessing the web is the lack of explicit structure, whose presence may help in understanding data semantics. Schema for web data can be constructed at different levels, structuring a single pages or a whole site or group of sites. Here we present an approach to give a logical schema to a web-site, first defining a model for a single page, where its contents is divided into &ldquo;logical&rdquo; sections, i.e. parts of a page each collecting related information. Then, we introduce a site model in which both physical and logical links among different page sections are represented: physical are existing hyperlinks, while logical links are links between sections containing semantically related information. We show how such links can be found and classified according to their relevance, also showing how schema is used in a structure-aware browser to improve both browsing and searching.
Measures of Perceived Risk
Authors: Jianmin Jia, James S. Dyer, John C. Butler
Venue: Management Science (1999)

Based on our previous work on the standard measure of risk, this paper presents two classes of measures for perceived risk by decomposing a lottery into its mean and standard risk. One of the classes of our risk measures presumes that there is no risk when there is no uncertainty involved, and the other allows different degenerate lotteries to be evaluated with different values of "risk." The former has more prescriptive appeal in risky decision making, but the latter may have more descriptive power for subjective risk judgments. Our risk measures can also take into account the asymmetric effects of losses and gains on perceived risk based on an appropriate choice of the standard measure of risk. The perceived risk models we propose unify a large body of empirical evidence regarding risk judgments, and provide sufficient flexibility to better capture people's perceptions of risk than previously developed risk models. In particular, our risk measures provide clear ways to accommodate financial measures of risk and psychological measures of risk, and they can be incorporated into preference models in an appealing form based on mean-risk tradeoffs.
Performance-Based Incentives in a Dynamic Principal-Agent Model
Authors: Erica L. Plambeck, Stefanos A. Zenios
Venue: Manufacturing Service Operations Management (2000)

The principal-agent paradigm, in which a principal has a primary stake in the performance of some system but delegates operational control of that system to an agent, has many natural applications in operations management (OM). However, existing principal-agent models are of limited use to OM researchers because they cannot represent the rich dynamic structure required of OM models. This paper formulates a novel dynamic model that overcomes these limitations by combining the principal-agent framework with the physical structure of a Markov decision process. In this model one has a system moving from state to state as time passes, with transition probabilities depending on actions chosen by an agent, and a principal who pays the agent based on state transitions observed. The principal seeks an optimal payment scheme, striving to induce the actions that will maximize her expected discounted profits over a finite planning horizon. Although dynamic principal-agent models similar to the one proposed here are considered intractable, a set of assumptions are introduced that enable a systematic analysis. These assumptions involve the "economic structure" of the model but not its "physical structure." Under these assumptions, the paper establishes that one can use a dynamic-programming recursion to derive an optimal payment scheme. This scheme is memoryless and satisfies a generalization of Bellman's principle of optimality. Important managerial insights are highlighted in the context of a two-state example called "the maintenance problem".
Sticky Aspirations: Organizational Time Perspective and Competitiveness
Authors: Henrich R. Greve
Venue: Organization Science (2002)

Managers evaluate the organizational performance by comparing it with historical aspiration levels, and are more likely to make strategic changes when the performance falls below the aspiration level. Historical aspiration levels can be updated with different speed, because a focus on current performance will lead to quickly adjusting aspiration levels where historical performance has low weight, while a focus on past performance will lead to slowly adjusting performance levels where the current performance has low weight. A simulation model of aspiration-level learning and strategic change under uncertainty yields the following findings: (1) Slow adjustments of an aspiration level gives higher performance across different levels of environmental uncertainty, (2) slow adjustments of aspirations will dominate in populations with different adjustment levels if low-performing organizations are removed and replaced by organizations of the form currently performing best, and (3) stronger selection leads to faster domination by slow adjusters. Empirical analysis of format changes in radio stations finds slow adjustment of aspiration levels to be prevalent, and finds slower adjustment in competitive markets, as predicted.
On polynomial interpolation of two variables
Authors: Borislav Bojanov, Yuan Xu
Venue: Journal of Approximation Theory (2003)

Polynomial interpolation of two variables based on points that are located on multiple circles is studied. First, the poisedness of a Birkhoff interpolation on points that are located on several concentric circles is established. Second, using a factorization method, the poisedness of a Hermite interpolation based on points located on various circles, not necessarily concentric, is established. Even in the case of Lagrange interpolation, this gives many new sets of poised interpolation points.
Channel Assignment with Separation for Interference Avoidance in Wireless Networks
Authors: Alan A. Bertossi, Cristina M. Pinotti, Richard B. Tan
Venue: IEEE Transactions on Parallel and Distributed Systems (2003)

Given an integer\sigma > 1 , a vector(\delta_1, \delta_2, \ldots, \delta_{\sigma-1})of nonnegative integers, and an undirected graphG=(V,E) , anL(\delta_1, \delta_2, \ldots,\delta_{\sigma-1}){\hbox{-}}\rm coloringofGis a functionffrom the vertex setVto a set of nonnegative integers such that| f(u) -f(v) | \ge \delta_i , ifd(u,v) = i, \ 1 \le i \le \sigma-1 , whered(u,v)is the distance (i.e., the minimum number of edges) between the verticesuandv . An optimalL(\delta_1, \delta_2, \ldots,\delta_{\sigma-1}){\hbox{-}}\rm coloringforGis one using the smallest range\lambdaof integers over all such colorings. This problem has relevant application in channel assignment for interference avoidance in wireless networks, where channels (i.e., colors) assigned to interfering stations (i.e., vertices) at distanceimust be at least\delta_iapart, while the same channel can be reused in vertices whose distance is at least\sigma . In particular, two versions of the coloring problem¿ L(2,1,1)andL(\delta_1, 1, \ldots,1) ¿are considered. Since these versions of the problem areNP{\hbox{-}}\rm hardfor general graphs, efficient algorithms for finding optimal colorings are provided for specific graphs modeling realistic wireless networks, including rings, bidimensional grids, and cellular grids.
New linking theorem and elliptic systems with nonlinear boundary condition
Authors: Wenming Zou, Shujie Li
Venue: Nonlinear Analysis: Theory, Methods Applications (2003)

In this paper, we establish a new linking theorem without (PS)-type assumption. The new theorem produces bounded (PS) sequences. The abstract result will be used to study the existence of nontrivial (positive) solutions to the elliptic system Δu=u, Δv=v in Ω with nonlinear boundary condition ∂u/∂η= Gv, ∂u/∂η = Gu on ∂Ω, where Ω is a bounded domain of RN with smooth boundary, ∂/∂η is the outer normal derivative. We consider "weak" superlinear and asymptotically linear cases.
Exact Analysis of Continuous Review (R,Q) Policies in Two-Echelon Inventory Systems with Compound Poisson Demand
Authors: Sven Axsäter
Venue: Operations Research (2000)

We consider a two-level inventory system with one central warehouse andN retailers. All installations apply different continuous review installation stock ( R,Q) policies. The retailers face independent compound Poisson demand processes. Transportation times are constant. We present a method for exact evaluation of control policies that provides the complete probability distributions of the retailer inventory levels.
Web information visualization method employing immune network model for finding topic stream from document-set sequence
Authors: Yasufumi Takama, Kaoru Hirota
Venue: New Generation Computing (2003)

A Web information visualization method based on the document set-wise processing is proposed to find the topic stream from a sequence of document sets. Although the hugeness as well as its dynamic nature of the Web is burden for the users, it will also bring them a chance for business and research if they can notice the trends or movement of the real world from the Web. A sequence of document sets found on the Web, such as online news article sets is focused on in this paper. The proposed method employs the immune network model, in which the property of memory cell is used to find the topical relation among document sets. After several types of memory cell models are proposed and evaluated, the experimental results show that the proposed method with memory cell can find more topic streams than that without memory cell.
Bounds and Policies for Dynamic Routing in Loss Networks
Authors: Dimitris Bertsimas, Thalia Chryssikou
Venue: Operations Research (1999)

We consider the problem of maximizing a weighted sum of expected rewards in steady-state in multiclass loss networks under dynamic routing and admission control, with Poisson arrivals and exponentially distributed holding times. By aggregating the underlying Markov decision process, we derive linear programming relaxations that contain the achievable performance region under all admissible policies and lead to a series of progressively tighter upper bounds. These relaxations allow stronger bounds at the expense of higher computational times. We further propose a series of routing and admission control policies from the relaxations that outperform, in computational experiments, other heuristic policies, such as the dynamic alternative routing with trunk reservation and the least busy alternative routing, variations of which are used in practice. The suboptimality guarantees defined as best bound/best policy range from 0 to 2.5% under symmetry conditions (symmetric network topology, arrival rates, link capacities, rewards), and from 4% to 10% under asymmetry conditions. We discuss the qualitative behavior of these policies and obtain insights about their performance.
Information clustering based on fuzzy multisets
Authors: Sadaaki Miyamoto
Venue: Information Processing and Management: an International Journal (2003)

A fuzzy multiset model for information clustering is proposed with application to information retrieval on the World Wide Web. Noting that a search engine retrieves multiple occurrences of the same subjects with possibly different degrees of relevance, we observe that fuzzy multisets provide an appropriate model of information retrieval on the WWW. Information clustering which means both term clustering and document clustering is considered. Three methods of the hard c-means, fuzzy c-means, and an agglomerative method using cluster centers are proposed. Two distances between fuzzy multisets and algorithms for calculating cluster centers are defined. Theoretical properties concerning the clustering algorithms are studied. Illustrative examples are given to show how the algorithms work.
SpaMod: design of a spatial modeling tool
Authors: Eric Andres, Rodolphe Breton, Pascal Lienhardt
Venue: Digital and image geometry: advanced lectures (2001)

The aim of this paper is to present the design of a spatial modeling tool, called SpaMod, that is currently developed in Poitiers (France). SpaMod will allow users to represent and manipulate both discrete and continuous representations of geometrical objects. It is a topology based geometric modeling tool with three types of embeddings: the classical Euclidean embedding, the discrete matrix embedding (voxel or inter-pixel) and the discrete analytical embedding (discrete objects defined by inequations). In order for such a tool to htlfill its role, all three embeddings have to be available together. Conversions between embeddings is thus an important however, in 3D, still partially open question.
Compiler-directed customization of ASIP cores
Authors: T. Vinod Kumar Gupta, Roberto E. Ko, Rajeev Barua
Venue: Proceedings of the tenth international symposium on Hardware/software codesign (2002)

This paper presents an automatic method to customize embedded application-specific instruction processors (ASIPs) based on compiler analysis. ASIPs, also known as embedded soft cores, allow certain hardware parameters in the processor to be customized for a specific application domain. They offer low design cost as they use pre-designed and verified components. Our design goal is choosing parameter values for fastest runtime within a given silicon area budget for a particular application set. Present-day technologies for choosing parameter values rely on exhaustive simulation of the application set on all possible combinations of parameter values -- a time-consuming and non-scalable procedure. We propose a compiler-based method that automatically derives the optimal values of parameters without simulating any configuration. Further, we expand the space of parameters that can be changed from the limited set today, and evaluate the importance of each. Results show that for our benchmarks, the runtimes for different configurations are predicted with an average error of 2.5%. In the two area constrained customization problem we evaluate, our method is able to recommend the same configuration that is recommended by brute force exhaustive simulation.