ppxscal/embedding_network huggingface dataset:
A Stochastic Optimal Control Approach to Real-time, Incident-Responsive Traffic Signal Control at Isolated Intersections
Authors: Jiuh-Biing Sheu
Venue: Transportation Science (2002)

Real-time, incident-responsive traffic control and management is vital to development of advanced incident management systems in ITS. More importantly, it provides, from an academic point of view, the linkages between incident detection, incident management, and traffic signal control. This study explores the application of a stochastic optimal control approach to real-time, incident-responsive traffic control at isolated intersections. In the methodology development, time-varying lane traffic state variables and control variables are specified to characterize sectionwide interlane and intralane traffic states under conditions of lane-blocking incidents. Following specification of system states, we formulated a discrete-time nonlinear stochastic model that comprises four types of equations, namely (1) recursive equations, (2) measurement equations, (3) incident-induced delay equations, and (4) boundary constraints. From the proposed stochastic model we then developed a stochastic optimal control algorithm to update the time-varying control variables and lane traffic state variables in real-time with lane-blocking incidents at isolated intersections. To generate traffic data used in model tests efficiently, we employed an advanced microscopic traffic simulator, Paramics, Version 3.0, which is developed to model and analyze ITS traffic flow conditions. The preliminary test results indicate that the proposed method can accomplish the goal of real-time, incident-responsive traffic signal control. In addition to proposing a new methodology, we hope that this study can initiate investigation into real-time, incident-responsive traffic control and management to achieve the final goal of networkwide incident-responsive, traffic-optimal control for incident management.
A position paper on the agenda for soft decision analysis
Authors: Christer Carlsson, Robert Fullér
Venue: Fuzzy Sets and Systems (2002)

In this position paper, we shall undertake a critical scrutiny of the decision analysis (DA) paradigm on the basis of experience we gained from working on the bullwhip effect. We had some success with sorting out the complexities of the bullwhip by using fuzzy numbers in the bullwhip models, and we found out that this points the way to a more viable approach to sort out complex decision problems. As a positive criticism of the DA paradigm we have collected the insights we have gained in an agenda for soft decision analysis (SDA), which we hasten to add is not complete but--hopefully--an opening for focused research and continuing development.
Sorting Permutations by Reversals Through Branch-and-Price
Authors: Alberto Caprara, Giuseppe Lancia, See-Kiong Ng
Venue: INFORMS Journal on Computing (2001)

We describe an exact algorithm for the problem of sorting a permutation by the minimum number of reversals, originating from evolutionary studies in molecular biology. Our approach is based on an integer linear programming formulation of a graph-theoretic relaxation of the problem, calling for a decomposition of the edge set of a bicolored graph into the maximum number of alternating cycles. The formulation has one variable for each alternating cycle, and the associated linear programming relaxation is solved by column generation.A major advantage with respect to previous approaches is that the subproblem to face in the column-generation phase no longer requires the solution of min-cost general matching problems, but of min-cost bipartite matching problems. Experiments show that there is a tremendous speed-up in going from general matching to bipartite matching, although the best-known algorithms for the two problems have the same theoretical worst-case complexity. We also show the worst-case ratio between the lower bound value obtained by our new method and previous ones.We illustrate the effectiveness of our approach through extensive computational experiments. In particular, we can solve to proven optimality the largest real-world instances from the literature in a few seconds, and the other (smaller) real-world instances within a few milliseconds on a workstation. Moreover, we can solve to optimality random instances with n = 100 within 3 seconds, and with n = 200 within 15 minutes, where n is the size of the permutation, whereas the size of the instances solvable by previous approaches was at most 100. We also describe a polynomial-time heuristic algorithm that consistently finds solutions within 2% of the optimum for random instances with n up to 1000.
A dynamic lab approach to reinforcing computing concepts
Authors: Dana E. Madison
Venue: Journal of Computing Sciences in Colleges (2002)

The cost of providing hands-on environments for reinforcing Computer Science concepts forces many educational institutions to prioritize the courses and topics that get specialized computer lab support in light of funding and facility constraints. A modular solution to this problem provides a dynamic environment that can be used for a multitude of purposes and evolves over time, as funding is made available.
Adding Value to Innovation: Impressionism and the Transformation of the Selection System in Visual Arts
Authors: Nachoem M. Wijnberg, Gerda Gemser
Venue: Organization Science (2000)

Valuation of cultural products tends to be problematic. In this paper, we provide insight into how valuation of cultural products takes place by describing the changing role and significance of different types of selection systems. Three basic types of selection systems are distinguished: market selection, peer selection, and expert selection. We show that the rise of a group of painters known as the Impressionists was facilitated by a change in the selection system of the visual arts industry from one dominated by peers into one dominated by experts. In the new selection system, innovativeness has become the most highly prized product characteristic, while a range of experts have begun to play an essential role, certifying the innovativeness of either individual artists or groups of artists.
Efficient Multiplication Beyond Optimal Normal Bases
Authors: Arash Reyhani-Masoleh, M. Anwar Hasan
Venue: IEEE Transactions on Computers (2003)

In cryptographic applications, the use of normal bases to represent elements of the finite field {\rm GF}( 2^{m}) is quite advantageous, especially for hardware implementation. In this article, we consider an important field operation, namely, multiplication which is used in many cryptographic functions. We present a class of algorithms for normal basis multiplication in {\rm GF}( 2^{m}). Our proposed multiplication algorithm for composite finite fields requires a significantly lower number of bit level operations and, hence, can reduce the space complexity of cryptographic systems.
Critical trigger mechanism: a modeling paradigm for cognitive science application in the design of artificial learning systems
Authors: Jack Allen, Sukanto Bhattacharya
Venue: Smarandache Notions Journal (2002)

In our present short paper we introduce a rather promising modeling paradigm for the design of artificial learning systems, incorporating critical trigger mechanism (CTM). We contend that at various stages of the learning process, such trigger mechanism may be activated when certain 'critical' points in the learning curve are attained. Such points are marked by fuzzification of the learner's decision set. At all other 'non-critical' points where the decision set is crisp, this trigger mechanism lies dormant. We proceed to show that identification and subsequent incorporation of such trigger mechanisms will be of substantial help in modeling learning systems that closely emulate cognitive learning pattern of the human mind. This is not a complete work in any sense but just an indication of what is to come - a mere map of the long and challenging road ahead.
Congestion and Complexity Costs in a Plant with Fixed Resources that Strives to Make Schedule
Authors: William S. Lovejoy, Kannan Sethuraman
Venue: Manufacturing Service Operations Management (2000)

In a firm that makes schedule, orders are always processed within a fixed time frame. In a congested facility, such a situation would be impossible using conventional queuing logic. We propose a conceptual model of a firm in which workers make schedule by rushing jobs, if necessary, with potential quality consequences. Hence, time and quality are substitutes, a feature that we recognize explicitly in our definition of the firm's capacity. Production yields are not exogenous parameters but endogenously determined by workers responding to schedule pressures. The plant manager can authorize overtime to relieve this pressure or live with the quality consequences of rushing. The model reveals the close relationships among the firm's workforce policies, the integrity of the inspection system, and the cost performance of the firmas its volume and/or product line expands. We consider pure congestion (driven by volume) and pure complexity (driven by product line breadth) effects in the context of our plant performance model. We consider two root causes of complexity costs: time and quality. The time effects of complexity will only have cost consequences in congested facilities, but quality effects are always present. Also in contrast to time effects, quality effects of complexity can be present in nonbottleneck workstations. Hence, the quality consequences of complexity can be as, or more important than the time consequences.
Parametric real-time model checking using splitting trees
Authors: R. F. Lutje Spelberg, W. J. Toetenel
Venue: Nordic Journal of Computing (2001)

This article discusses a new approach to model checking of real-time systems. One of the novel aspects of our approach is the fact that an unconventional approach is chosen to deal with representing symbolic state spaces. Its key feature is that it does not use a canonical representation for representing symbolic nodes, but an alternative representation based on splitting trees. We describe this approach in terms of the verification problem of parametric reacheability of systems described in an extension of timed automata. Additionally, we describe how we extended this approach to deal With more complex verification problems, namely the parametric verification of an extension of the real-time temporal logic TCTL. This resulted in a model checking tool called PMC. The practical application of our approach is addressed through the analysis and verification of the root contention protocol of the IEEE1394 (FireWire) standard using this tool.
An approximation result for the interval coloring problem on claw-free chordal graphs
Authors: Giuseppe Confessore, Paolo Dell'Olmo, Stefano Giordani
Venue: Discrete Applied Mathematics (2002)

We study the problem of finding an acyclic orientation of an undirected graph, such that each (oriented) path is covered by a limited number k of maximal cliques. This is equivalent to finding a k-approximate solution for the interval coloring problem on a graph. We focus our attention on claw-free chordal graphs, and show how to find an orientation of such a graph in linear time, which guarantees that each path is covered by at most two maximal cliques. This extends previous published results on other graph classes where stronger assumptions were made.
The simulation of a SVC and a parallel active filter by means of transfer function concept of VSI
Authors: M. Tarafdar Haque, S. H. Hosseini
Venue: Iranian Journal of Science and Technology (2002)

In this paper the idea of transfer function of a voltage source inverter (VSI) is used for simulation of a static var compensator (SVC) and a parallel active filter (PAF). This concept makes simulation possible for the above-mentioned converters by generally available simulation software such as student version of Pspice. The idea of transfer function (TF) makes it possible simulation of VSI as a macro-model. In this way, it is not necessary to use semi-conductor switches of VSI or their control circuits. This subject decreases the node number of the circuits, the problem of convergence, the excessive run time and the large memory requirement for output file. The PSCAD/EMTDC simulation package is used as a professional simulation package to satisfy the results. In addition, a new control method for switches of PSCAD/EMTDC simulated converters is presented.
The Online TSP Against Fair Adversaries
Authors: Michiel Blom, Sven O. Krumke, Willem E. de Paepe, Leen Stougie
Venue: INFORMS Journal on Computing (2001)

In the online traveling salesman problem, requests for visits to cities (points in a metric space) arrive online while the salesman is traveling. The salesman moves at no more than unit speed and starts and ends his work at a designated origin. The objective is to find a routing for the salesman that finishes as early as possible.Performance of algorithms is measured through their competitive ratio, comparing the outcome of the algorithms with that of an adversary who provides the problem instance and therefore is able to achieve the optimal offline solution. Objections against such omnipotent adversaries have lead us to devise an adversary that is in a natural way, in the context of routing problems, more restricted in power.For the exposition we consider the online traveling salesman problem on the metric space given by , the non-negative part of the real line. We show that a very natural strategy is 3/2-competitive against the conventional adversary, which matches the lower-bound on competitive ratios achievable for algorithms for this problem.Against the more"fair adversary", that we propose, we show that there exists an algorithm with competitive ratioand provide a matching lower bound.We also show competitiveness results for a special class of algorithms (calledzealous algorithms) that do not allow waiting time for the server as long as there are requests unserved.
Managing dynamic virtual enterprises using FIPA agents
Authors: Vaggelis Ouzounis
Venue: Managing virtual web organizations in the 21st century: issues and challenges (2002)

Virtual enterprises (VEs) enable the deployment of distributed business processes among different partners in order to shorten development and manufacturing cycles, reduce time to market and operational costs, increase customer satisfaction, and operate on global scale and reach. Dynamic virtual enterprises are an emerging category of VE where the different partners are being selected dynamically during business process execution based on market-driven criteria and negotiation. In this chapter, we present an agent-based platform for the management of dynamic VEs. The main contributions of this approach are the distributed, autonomous agent-based business process management, the XML-based business process definition language, the flexible ontologies, and the dynamic negotiation and selection of partners based on virtual marketplaces. The presented platform has been fully developed using emerging agent and Internet standards like FIPA, MASIF, and XML.
DNA computing by blocking
Authors: G. Rozenberg, H. Spaink
Venue: Theoretical Computer Science (2003)

We present a method for molecular computing which relies on blocking (inactivating) this part of the total library of molecules that does not contribute to (finding) a solution--this happens essentially in one biostep (after the input has been read). The method is explained by presenting a DNA based algorithm for solving (albeit in the theoretical sense only!) the satisfiability problem.
A blueprint for introducing disruptive technology into the Internet
Authors: Larry Peterson, Tom Anderson, David Culler, Timothy Roscoe
Venue: ACM SIGCOMM Computer Communication Review (2003)

This paper argues that a new class of geographically distributed network services is emerging, and that the most effective way to design, evaluate, and deploy these services is by using an overlay-based testbed. Unlike conventional network testbeds, however, we advocate an approach that supports both researchers that want to develop new services, and clients that want to use them. This dual use, in turn, suggests four design principles that are not widely supported in existing testbeds: services should be able to run continuously and access a slice of the overlay's resources, control over resources should be distributed, overlay management services should be unbundled and run in their own slices, and APIs should be designed to promote application development. We believe a testbed that supports these design principles will facilitate the emergence of a new service-oriented network architecture. Towards this end, the paper also briefly describes PlanetLab, an overlay network being designed with these four principles in mind.
The delta operation: from strings to trees to strings
Authors: Joost Engelfriet
Venue: Formal and natural computing (2002)

The delta of a language L consists of the yields of trees of which all paths are in L. The context-free languages are the deltas of the regular languages. The indexed languages are the deltas of the deterministic context-free languages. In general, the nondeterministic (n+1)-iterated pushdown languages are the deltas of the deterministic n- iterated pushdown languages. The recursively enumerable languages are the deltas of the context-free languages. The delta of a string relation R consists of the yields of trees of which all paths are in the R-image of one string. The ETOL languages are the deltas of the relations recognized by deterministic two-tape finite automata. The recursively enumerable languages are the deltas of the finite state transductions.
Extracting Interpretable Fuzzy Rules from RBF Networks
Authors: Yaochu Jin, Bernhard Sendhoff
Venue: Neural Processing Letters (2003)

Radial basis function networks and fuzzy rule systems are functionally equivalent under some mild conditions. Therefore, the learning algorithms developed in the field of artificial neural networks can be used to adapt the parameters of fuzzy systems. Unfortunately, after the neural network learning, the structure of the original fuzzy system is changed and interpretability, which is considered to be one of the most important features of fuzzy systems, is usually impaired. This Letter discusses the differences between RBF networks and interpretable fuzzy systems. Based on these discussions, a method for extracting interpretable fuzzy rules from RBF networks is suggested. Simulation examples are given to embody the idea of this paper.
The role of training in preparing end users to learn related software packages
Authors: Conrad Shayo, Lorne Olfman
Venue: Advanced topics in end user computing (2002)

The aim of this chapter is to determine what types of formal training methods can provide appropriate "mapping via training" of a new but related software application (in this case, a database management system [DBMS]), given that "mapping via analogy" is also taking place. To this end, trainees' existing mental models were measured, and then the trainees were exposed to one of the three training methods. Training methods were varied in an experimental setting across two dimensions: the training task context (generic versus relevant), and the number of DBMSs demonstrated (one versus two). Outcomes were measured in terms of learning performance and perceptions of ability to transfer skills to a new but related DBMS. The results indicate that both task context and the number of software packages learned are important training variables that influence trainees' mental models of the software, their transfer self-efficacy expectations, and their perceptions about the usefulness of the training.
Fast approximate visible set determination for point sample clouds
Authors: Stephan Mantler, Anton L. Fuhrmann
Venue: Proceedings of the workshop on Virtual environments 2003 (2003)

We present a fast, efficient method to determine approximate visible sets for vegetation rendered as point sample clouds. A hardware accelerated preprocessing step is used to determine exact visibility for a selected set of views; at runtime the current view is rendered using an approximate visible set constructed from the three closest precalculated views. We will further demonstrate how this method leads to a significant per-frame reduction of the original data size.
Constraint Aggregation in Infinite-Dimensional Spaces and Applications
Authors: Arkadii V. Kryazhimskii, Andrzej Ruszczynski
Venue: Mathematics of Operations Research (2001)

An aggregation technique for constraints with values in Hilbert spaces is suggested. The technique allows us to replace the original optimization problem by a sequence of subproblems having scalar or finite-dimensional constraints. Applications to optimal control, games, and stochastic programming are discussed in detail.
A comparative experimental evaluation study of intrusion detection system performance in a gigabit environment
Authors: Charles Iheagwara, Andrew Blyth, Mukesh Singhal
Venue: Journal of Computer Security (2003)

Intrusion detection systems' (IDS) effectiveness requires balancing characteristics and elements so they fit together in appropriate compromises to create good network security systems. One major gauge for IDS effectiveness is the ability to detect attacks within operational specifications. Gigabit IDS sensors as opposed to Megabit IDS sensors promise dramatic increase in component performance and functional opportunities, possibly leading to dramatically changed system balance and overall performance. The research described here examines the system benefits of using a single Gigabit IDS sensor instead of multiple Megabit sensors for a wide range of defined system attacks, network traffic characteristics, and for their contexts of operational concepts and deployment techniques. The experimental results are analyzed in the context of practical experiences in the operation of these IDS systems. The difference in architectural designs, deployment strategies and operational concepts that characterized their performance in exploiting the strengths of attack systems are discussed.
An (S - 1, S) Inventory System with Fixed Shelf Life and Constant Lead Times
Authors: David Perry, M. J. M. Posner
Venue: Operations Research (1998)

We consider an (S - 1, S) type perishable inventory system in which the maximum shelf life of each item is fixed. An order for an item is placed at each demand time as well as at each time that the maximum shelf life of an item is reached. The order lead times are constant, and the demand process for items is Poisson. Although the resulting process is ostensibly nonregenerative, we adapt level-crossing theory for the case of an S-dimensional Markov process to obtain its stationary law. Within this framework a number of model variants are solved.