ppxscal/embedding_network huggingface dataset:
A hybrid fuzzy-neural network for modeling short-term demand forecasting in Czech Republic
Authors: Muhammad Riaz Khan, Ajith Abraham
Venue: Second international workshop on Intelligent systems design and application (2002)

This paper focuses on the methodologies into which the fuzzy expert system is embedded into well-developed neural network based algorithm to achieve improved performance for Short-Term electric Load Forecasting (STLF). Its performance is then contrasted with an Artificial Neural Network (ANN) and a Fuzzy Inference System (FIS). These models have been developed to produce a short-term forecast of the electrical load demand on an hourly basis. These techniques have been tested on actual load and weather data for the year 2000 provided by the Czech Electric Power Company (CEZ), Czech Republic. The illustrative results obtained through the application of soft computing approach show the adequacy of the adopted approach. FNN shows better convergence speed than a pure ANN and FIS approach, which confirms its applicability in the real life applications.
A result on braids via the investigation of a rewriting system
Authors: Serge Burckel
Venue: Journal of Symbolic Computation (2003)

The study of a rewriting system gives a very simple characterization of a canonical form of positive braids on three strands which had previously been defined with a well-ordering structure.
System Optimum, Stochastic User Equilibrium, and Optimal Link Tolls
Authors: F. Fumero, C. Vercellis, Hai Yang
Venue: Transportation Science (1999)

Previous studies have shown that the Wardropian system optimum may not necessarily be supported as a (logit-based) stochastic user equilibrium (SUE) by finite and meaningful link tolls. This paper demonstrates that the classical principle of marginal-cost pricing is still applicable in a network under SUE from the standpoint of economic benefit maximization within the context of the classical consumer behavior theory. The marginal-cost link tolls areshown to be meaningful from both economic and behavioral viewpoints, and therefore proposed to be a good alternative to drive a SUE flow pattern toward system optimum.
Precise goal-independent abstract interpretation of constraint logic programs
Authors: Peter Schachte
Venue: Theoretical Computer Science (2003)

We present a goal-independent abstract interpretation framework for constraint logic programs, and prove the sufficiency of a set of conditions for abstract domains to ensure that the analysis will never lose precision. Along the way, we formally define constraint logic programming systems, give a formal semantics that is independent of the actual constraint domain and the details of the proof algorithm, and formally define the maximally precise abstraction of a constraint logic program.
An object pattern for computer user interface systems
Authors: Stanley Y. P. Chien
Venue: Information processing and technology (2001)

As the real-time embedded systems become more complex, the advantages of using object-oriented analysis (OOA) in software development becomes more apparent. Since the learning curve of OOA is relatively long and OOA is still more a creative work than an engineering routine, it is desirable to capture the common features of a set of problems in such away that they can be reused as is or easily replaced as necessary. In this paper, a message pattern, which is applicable to many computer user interface systems, is proposed. The process of using the message pattern to model the system is also described. The message pattern and the associated development process have four advantages. (1) It separates the system requirement into passive data objects and the active program control objects. This separation enables the quick development and easy modification of OOA model according to the given specification. (2) The approach is systematic and can be scaled up to large systems. (3) It represents the information explicitly so that it is easier for the OOA model compiler to generate efficient code. (4) It is easy to learn and apply since it provides detailed steps for model development. The application of the message pattern is demonstrated through a voice-controlled telephone dialing system.
Optimal Policies for Multiechelon Inventory Problems with Markov-Modulated Demand
Authors: Fangruo Chen, Jing-Sheng Song
Venue: Operations Research (2001)

This paper considers a multistage serial inventory system with Markov-modulated demand. Random demand arises at Stage 1, Stage 1 orders from Stage 2, etc., and StageN orders from an outside supplier with unlimited stock. The demand distribution in each period is determined by the current state of an exogenous Markov chain. Excess demand is backlogged. Linear holding costs are incurred at every stage, and linear backorder costs are incurred at Stage 1. The ordering costs are also linear. The objective is to minimize the long-run average costs in the system. The paper shows that the optimal policy is an echelon base-stock policy with state-dependent order-up-to levels. An efficient algorithm is also provided for determining the optimal base-stock levels. The results can be extended to serial systems in which there is a fixed ordering cost at stageN and to assembly systems with linear ordering costs.
Bounded size dictionary compression: SCk -completeness and NC algorithms
Authors: Sergio De Agostino, Riccardo Silvestri
Venue: Information and Computation (2003)

We study the parallel complexity of a bounded size dictionary version (LRU deletion heuristic) of the LZ2 compression algorithm. The unbounded version was shown to be P-complete. When the size of the dictionary is O(logk n), the problem of computing the LZ2 compression is shown to be hard for the class of problems solvable simultaneously in polynomial time and O(logk n) space (that is, SCk). We also introduce a variation of this heuristic that turns out to be an SCk-complete problem (the original heuristic belongs to SCk+1). In virtue of these results, we argue that there are no practical parallel algorithms for LZ2 compression with LRU deletion heuristic or any other heuristic deleting dictionary elements in a continuous way. For simpler heuristics (SWAP, RESTART, FREEZE), practical parallel algorithms are given.
Multiobjective Metaheuristics for the Bus Driver Scheduling Problem
Authors: Helena R. Lourenço, José P. Paixão, Rita Portugal
Venue: Transportation Science (2001)

We present new multiobjective metaheuristics for solving real-world crew scheduling problems in public bus transport companies. Since the crews of these companies are drivers, we will designate the problem as bus-driver scheduling. Crew scheduling problems are well known, and several mathematical programming-based techniques have been proposed to solve them, in particular, using the single-objective set-covering formulation. However, in practice, there exists the need to consider multiple objectives, some of them in conflict with each other; for example, the cost and service quality, implying also that alternative solution methods have to be developed. We propose multiobjective metaheuristics based on the tabu search and genetic algorithms. These metaheuristics also present some innovation features related with the structure of the crew scheduling problem that guide the search efficiently and enable them to find good solutions. Some of these new features can also be applied to the development of heuristics to other combinatorial optimization problems. A summary of computational results with real-data problems is presented. The methods have been successfully incorporated in the GIST Planning Transportation Systems and are actually used by several companies.
An effective query pruning technique for multiple regular path expressions
Authors: Chang-Won Park, Chin-Wan Chung
Venue: Journal of Systems and Software (2002)

Regular path expressions are essential for formulating queries over the semistructured data without specifying the exact structure. The query pruning is an important optimization technique to avoid useless traversals in evaluating regular path expressions. While the previous query pruning optimizes a single regular path expression well, it often fails to fully optimize multiple regular path expressions. Nevertheless, multiple regular path expressions are very frequently used in nontrivial queries, and so an effective optimization technique for them is required. In this paper, we present a new technique called the two-phase query pruning that consists of the preprocessing phase and the pruning phase. Our two-phase query pruning is effective in optimizing multiple regular path expressions, and is more scalable and efficient than the combination of the previous query pruning and post-processing in that it never deals with exponentially many combinations of sub-results produced from all the regular path expressions.
Uniformly hard languages
Authors: Rod Downey, Lance Fortnow
Venue: Theoretical Computer Science (2003)

Ladner (J. Assoc. Comput. Mach. 22 (1975) 155) showed that there are no minimal recursive sets under polynomial-time reductions. Given any recursive set A, Ladner constructs a set B such that B strictly reduces to A but B does not lie in P. The set B does have very long sequences of input lengths of easily computable instances.We examine whether Ladner's results hold if we restrict ourselves to "uniformly hard languages" which have no long sequences of easily computable instances. Under a hard to disprove assumption, we show that there exists a minimal recursive uniformly hard set under honest many-one polynomial-time reductions.
Bootstraps of sums of independent but not identically distributed stochastic processes
Authors: Michael R. Kosorok
Venue: Journal of Multivariate Analysis (2003)

A central limit theorem is developed for sums of independent but not identically distributed stochastic processes multiplied by independent real random variables with mean zero. Weak convergence of the Hoffmann-Jørgensen-Dudley type, as described in van der Vaart and Wellner (Weak Convergence and Empirical Processes, Springer, New York, 1996), is utilized. These results allow Monte Carlo estimation of limiting probability measures obtained from application of Pollard's (Empirical Processes. Theory and Applications, IMS, Hayward, CA, 1990) functional central limit theorem for empirical processes. An application of this theory to the two-parameter Cox score process with staggered entry data is given for illustration. For this process, the proposed multiplier bootstrap appears to be the first successful method for estimating the associated limiting distribution. The results of this paper compliment previous bootstrap and multiplier central limit theorems for independent and identically distributed empirical processes.
Exploiting Special Structures in Constructing a Hierarchy of Relaxations for 0-1 Mixed Integer Problems
Authors: Hanif D. Sherali, Warren P. Adams, Patrick J. Driscoll
Venue: Operations Research (1998)

A new hierarchy of relaxations is presented that provides a unifying framework for constructing a spectrum of continuous relaxations spanning from the linear programming relaxation to the convex hull representation for linear mixed integer 0-1 problems. This hierarchy is an extension of the Reformulation-Linearization Technique (RLT) of Sherali and Adams (1990, 1994a), and is particularly designed to exploit special structures. Specifically, inherent special structures are exploited by identifying particular classes of multiplicative factors that are applied to the original problem to reformulate it as an equivalent polynomial programming problem, and subsequently, this resulting problem is linearized to produce a tighter relaxation in a higher dimensional space. This general framework permits us to generate an explicit hierarchical sequence of tighter relaxations leading up to the convex hull representation. (A similar hierarchy can be constructed for polynomial mixed integer 0-1 problems.) Additional ideas for further strengthening RLT-based constraints by using conditional logical implications, as well as relationships with sequential lifting, are also explored. Several examples are presented to demonstrate how underlying special structures, including generalized and variable upper bounding, covering, partitioning, and packing constraints, as well as sparsity, can be exploited within this framework. For some types of structures, low level relaxations are exhibited to recover the convex hull of integer feasible solutions.
Strategic Valuation of Investment Under Competition
Authors: Patricio Del Sol, Pankaj Ghemawat
Venue: Interfaces (1999)

The most serious problem with the widely used discounted-cash-flow (DCF) methods of investment valuation is that they are commonly applied without explicit regard to competition. As a result, the prescriptions they afford are often inconsistent with those given by competitive strategy frameworks. To remedy this, we show how such frameworks can be integrated with DCF methods to value investments (and disinvestments)in competitive and uncertain contexts. We recommend that the DCF analysis be carried out within a framework that includes the following three analytical steps: positioning, which focuses on competitive advantages; sustainability, which focuses on competitive dynamics; and flexibility, which focuses on options to revise the initial investment plan in the face of uncertainty. Valuators using this framework will reduce the likelihood that the DCF analysis misses relevant competitive-strategy considerations. Firms that have used this framework for positioning, sustainability, and flexibility have shaped and clarified their choices, solving apparent inconsistencies between DCF results and the competitive-strategy argument.
Selection of secure hyperelliptic curves of g = 2 based on a subfield
Authors: Fangguo Zhang, Futai Zhang, Yumin Wang
Venue: Journal of Computer Science and Technology (2002)

In the implementation of hyperelliptic curve cryptosystems, a siginificant step is the selection of secure hyperelliptic curves on which the Jacobian is constructed. In this paper, we discuss the hyperelliptic curves of g = 2 such as v2 + uv = f and v2 + v = f(u) defined on GF(2r). The curves defined on GF(4) and GF(8) are expanded to the curves defined on GF(4)k and GF(8)t respectively, where 38 < k < 70, 25 < t < 50. We also find out all the secure curves of g = 2 that are suitable for establishing cryptosystems.
Application of soft landing to the process control of chemical mechanical polishing
Authors: Jian-Bin Chiu, Cheng-Ching Yu, Shih-Haur Shen
Venue: Microelectronic Engineering (2003)

In chemical mechanical polishing (CMP), a two-stage polishing strategy is often employed. A high removal rate (RR) is set at the initial stage, then a lower RR is employed to remove residual metal and extended to the over-polish stage. An analogy between the soft landing of a spacecraft and CMP operation is established and the CMP operation can be viewed as a minimum-time optimal control problem. Measurement uncertainties prevent direct implementation of bang-bang control law for the entire polishing process. Thus, a two-stage CMP operation procedure is devised to ensure robust operation while maintaining a high throughput.
Some equivalence results concerning multiplicative lattice decompositions of multivariate densities
Authors: Edward H. Ip, Yuchung J. Wang, Yeong-nan Yeh
Venue: Journal of Multivariate Analysis (2003)

This note provides some equivalence results across the partition lattice, the monotypic lattice, and the subset lattice, for decomposing a multivariate density.
Is seasonal adjustment a linear or nonlinear data-filtering process?
Authors: Eric Ghysels, Clive W. J. Granger, Pierre L. Siklos
Venue: Essays in econometrics: Spectral analysis, seasonality, nonlinearity, methodology, and forecasting (2001)

We investigate whether seasonal-adjustment procedures are, at least approximately, linear data transformations. This question was initially addressed by Young and is important with respect to many issues including estimation of regression models with seasonally adjusted data. We focus on the X-11 program and rely on simulation evidence, involving linear unobserved component autoregressive integrated moving average models. We define a set of properties for the adequacy of a linear approximation to a seasonal-adjustment filter. These properties are examined through statistical tests. Next, we study the effect of X-11 seasonal adjustment on regression statistics assessing the statistical significance of the relationship between economic variables. Several empirical results involving economic data are also reported.
Transforming backpropagation neural networks to decision trees using NN-DT cascade method
Authors: Milan Zorman, Peter Kokol, Bruno Stiglic
Venue: Second international workshop on Intelligent systems design and application (2002)

Transforming knowledge between connectionist and symbolic machine learning approaches is not a uniform task and there is no general recipe for performing it. Irrespective of the way the transformation of knowledge, the developed methods usually fall into two classes: methods with high rate of transformed knowledge is done, but with a lot of restrictions concerning the type of data in the training sets, training methods, and the size of data sets; and methods with moderate rate of transformed knowledge, but with less restrictions. Our main interest was to find or develop a technique that would possess the knowledge acquisition power of neural networks and explanation power of decision trees. That is why we developed a NN-DT Cascade method, which is capable of transforming a part of knowledge from the neural network into a decision tree.
Key Message Approach to Optimize Communication of Parallel Applications on Clusters
Authors: Ming Zhu, Wentong Cai, Bu-Sung Lee
Venue: Cluster Computing (2003)

Over the past few years, cluster/distributed computing has been gaining popularity. The proliferation of the cluster/distributed computing is due to the improved performance and increased reliability of these systems. Many parallel programming languages and related parallel programming models have become widely accepted. However, one of the major shortcomings of running parallel applications on cluster/distributed computing environments is the high communication overhead incurred. To reduce the communication overhead, and thus the completion time of a parallel application, this paper describes a simple, efficient and portable Key Message (KM) approach to support parallel computing on cluster/distributed computing environments. To demonstrate the advantage of the KM approach, a prototype runtime system has been implemented and evaluated. Our preliminary experimental results show that the KM approach has better improvement on communication of a parallel application when network background load increases or the computation to communication ratio of the application decreases.
On the Genesis of Organizational Forms: Evidence from the Market for Disk Arrays
Authors: David G. McKendrick, Glenn R. Carroll
Venue: Organization Science (2001)

This article asks a basic question of organizational evolution: When and where will a new organizational form emerge? Using a definition of organizational forms as external identity codes, we focus on two answers drawn from contemporary organization theory. The first holds that formal institutions such as industry associations and standard-setting bodies will result in a taken-for-granted organizational form. The second answer contends that increasing organizational density (number of organizations) will generate a legitimated organizational form. As reported here, a historical case study of the disk array market and its associated technologies finds both arguments limited. Although significant collective activity in association building and standard setting occurs among disk array producers, these have not yet led to an organizational form. Similarly, an observed trajectory of organizational density showing rapid growth followed by stabilization has not yet generated an organizational form. In our view, the diversity of origins and other activities of those organizations operating in this market work against institutionalization of the disk array organizational form. We reason that if firms in the market derive their primary identities from other activities (implying that there are few highly focused firms deriving their primary identity from disk arrays), then the disk array producer identity cannot cohere into a code or form. This conclusion suggests a respecification of the legitimation component of the density-dependent model of organizational evolution.
Evolving hierarchical coordination in simulated annelid locomotion
Authors: Edgar E. Vallejo, Fernando Ramos
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

This article presents a model for the evolution of locomotion behavior in a simulated annelid. In our model, segmental muscular coordination is modeled using a two-level hierarchy of cellular automata. We use genetic algorithms to evolve the dynamical law of the controller. We demostrate that this model can be used to evolve patterns of locomotion similar to those observed in natural annelids.
Flexible digital library search
Authors: Menzo Windhouwer, Albrecht Schmidt, Roelof van Zwol, Milan Petkovic, Henk Ernst Blok
Venue: Web-enabled systems integration: practices and challenges (2003)

In this chapter the development of a specialised search engine for a digital library is described. The proposed system architecture consists of three levels: the conceptual, the logical and the physical level. The conceptual level schema enables by its exposure of a domain specific schema semantically rich conceptual search. The logical level provides a description language to achieve a high degree of flexibility for multimedia retrieval. The physical level takes care of scalable and efficient persistent data storage. The role, played by each level changes during the various stages of a search engine's lifecycle: (1) modeling the index, (2) populating and maintaining the index and (3) querying the index. The integration of all this functionality allows the combination of both conceptual and content-based querying in the query stage. A search engine for the Australian Open tennis tournament website is used as a running example, which shows the power of the complete architecture and its various components.
Shrouds: optimal separating surfaces for enumerated volumes
Authors: Gregory M. Nielson, Gary Graf, Ryan Holmes, Adam Huang, Mariano Phielipp
Venue: Proceedings of the symposium on Data visualisation 2003 (2003)

We describe new techniques for computing a smooth triangular mesh surface that surrounds an enumerated volume consisting of a collection of points from a 3D rectilinear grid. The surface has the topology of an isosurface computed by a marching cubes method applied to a field function that has the value one at the points in the volume and zero for points not in the volume. The vertices are confined to the edges of the grid that penetrate this separating surface and the precise positions are computed so as to optimize a certain energy functional applied to the surface. We use efficient iterative methods to compute the optimal separating surfaces. We lift the concept of energy functionals for planar curves to isosurfaces by means of the 4*-network which is a unique collection of orthogonal planar polygons lying on the isosurface. The general strategy that we describe here leads to methods that are simple, efficient, and effective.