ppxscal/embedding_network huggingface dataset:
EVolve: an open extensible software visualization framework
Authors: Qin Wang, Wei Wang, Rhodes Brown, Karel Driesen, Bruno Dufour, Laurie Hendren, Clark Verbrugge
Venue: Proceedings of the 2003 ACM symposium on Software visualization (2003)

Existing visualization tools typically do not allow easy extension by new visualization techniques, and are often coupled with inflexible data input mechanisms. This paper presents EVolve, a flexible and extensible framework for visualizing program characteristics and behaviour. The framework is flexible in the sense that it can visualize many kinds of data, and it is extensible in the sense that it is quite straightforward to add new kinds of visualizations.The overall architecture of the framework consists of the core EVolve platform that communicates with data sources via a well defined data protocol and which communicates with visualization methods via a visualization protocol.Given a data source, an end-user can use EVolve as a stand-alone tool by interactively creating, configuring and modifying visualizations. A variety of visualizations are provided in the current EVolve library, with features that facilitate the comparison of multiple views on the same execution data. We demonstrate EVolve in the context of visualizing execution behaviour of Java programs.
Semantic Structuring in Analyst Acquisition and Representation of Facts in Requirements Analysis
Authors: George M. Marakas, Joyce J. Elam
Venue: Information Systems Research (1998)

The determination of information requirements is one of the most crucial stages in the software design and development process (Montezemi 1988). It is during this stage that the greatest degree of interaction occurs between the analyst and the user (Lauer et al. 1992). Despite the system development method employed, the functional success of many aspects of requirements determination ultimately rests on how well the user(s) and analyst(s) communicate (Holtzblatt and Beyer 1995). The purpose of this paper is to report the results obtain from a laboratory experiment that investigated the effects of a semantic structuring process of inquiry on the process of interview-derived information acquisition and the subsequent overall correctness of the logical representation of the facts obtained. The study focused on the specific question types used by systems analysts and the role their semantic construction pla yed in representing the information flows in a business system. Three underlying semantic patterns of questions emerged from the analysis. The results showed that certain question types were associated with increased accuracy of logical representations re gardless of analyst experience level. Further, the semantic and process patterns that emerged were also directly related to accurate representation of facts and demonstrated an experience-level independence. The results indicate that disciplined questioning strategies are not necessarily learned from practice and they can be improved via structured training. Each of the patterns provide insight into the questioning process employed and the effectiveness of different strategies of inquiry. Implications for both the practitioner and the academic research communities with regard to analyst interview behavior are discussed.
The true lift model: a novel data mining approach to response modeling in database marketing
Authors: Victor S. Y. Lo
Venue: ACM SIGKDD Explorations Newsletter (2002)

In database marketing, data mining has been used extensively to find the optimal customer targets so as to maximize return on investment. In particular, using marketing campaign data, models are typically developed to identify characteristics of customers who are most likely to respond. While these models are helpful in identifying the likely responders, they may be targeting customers who have decided to take the desirable action or not regardless of whether they receive the campaign contact (e.g. mail, call). Based on many years of business experience, we identify the appropriate business objective and its associated mathematical objective function. We point out that the current approach is not directly designed to solve the appropriate business objective. We then propose a new methodology to identify the customers whose decisions will be positively influenced by campaigns. The proposed methodology is easy to implement and can be used in conjunction with most commonly used supervised learning algorithms. An example using simulated data is used to illustrate the proposed methodology. This paper may provide the database marketing industry with a simple but significant methodological improvement and open a new area for further research and development.
Random dyadic tilings of the unit square
Authors: Svante Janson, Dana Randall, Joel Spencer
Venue: Random Structures Algorithms (2002)

A "dyadic rectangle" is a set of the form R = [a2-s,(a + 1)2-s] × [b2-t,(b + 1)2-t], where s and t are nonnegative integers. A dyadic tiling is a tiling of the unit square with dyadic rectangles. In this paper we study n-tilings, which consist of 2n nonoverlapping dyadic rectangles, each of area 2-n, whose union is the unit square. We discuss some of the underlying combinatorial structures, provide some efficient methods for uniformly sampling from the set of n-tilings, and study some limiting properties of random tilings.
Random Queues in Signalized Road Networks
Authors: Andrzej P. Tarko
Venue: Transportation Science (2000)

Average delay is an important criterion of evaluating traffic signals. Traffic signals, stream merges, and stream splits influence vehicular delay in signalized networks through influencing random fluctuation of traffic. This paper proposes a method of estimating the random component of queues and delays at signalized intersections inside a network of urban streets. Equations describing the effect of signals and traffic merging and splitting are derived, as well as a comprehensive equation combining the considered effects. Fixed speeds and capacities are assumed. The derived comprehensive equation is used to discuss certain cases of signalized streets. The equation is evaluated using the Monte Carlo technique. The proposed method can be incorporated into existing procedures for evaluating and optimizing traffic signals.
Using Geographical Information Systems for Decision Making: Extending Cognitive Fit Theory to Map-Based Presentations
Authors: Alan R. Dennis, Traci A. Carte
Venue: Information Systems Research (1998)

As the use of Geographical Information Systems (GIS) by business becomes more common, we need to better understand when these systems are and are not useful. This research uses a laboratory experiment to extend cognitive fit theory (Vessey 1991) to geographic tasks performed using either map-based presentations or tabular presentations. The experiment found that decision makers using a map-based presentation made faster and more accurate decisions when working on a geographic task in which there were adjacency relationships among the geographic areas. Decision makers using a map-based presentation made faster but less accurate decisions when working on a geographic task in which there were no relationships among the geographic areas.
Guide to wireless LAN analysis
Venue: Wireless local area networks: the new wireless revolution (2002)

The world is going wireless. The prohibitive cost of building wired network infrastructures has paved the way for wireless networking on a global scale. Developing countries, with more sophisticated network and Internet access than ever before, have surged ahead in the utilization of wireless networks so that even the most remote parts of the globe have coverage undreamed of only a few years ago. Although deployment of wireless LANs in the United States has lagged behind the rest of the world, the domestic market is now quickly coming up to speed. It is therefore of critical importance for the corporate network manager to understand not only how the wireless revolution is taking place but how this technological paradigm shift will affect the day-to-day monitoring and management of network data. This chapter provides a brief overview of wireless networks and the 802.11b standard in particular, followed by a discussion of troubleshooting and network maintenance problems and the types of monitoring and analysis required to resolve them.
The $P_1^\protect\lowercasemod$ Element: A New Nonconforming Finite Element for Convection-Diffusion Problems
Authors: Petr Knobloch, Lutz Tobiska
Venue: SIAM Journal on Numerical Analysis (2003)

We consider a nonconforming streamline diffusion finite element method for solving convection-diffusion problems. The loss of the Galerkin orthogonality of the streamline diffusion method when applied to nonconforming finite element approximations results in an additional error term which cannot be estimated uniformly with respect to the perturbation parameter for the standard piecewise linear or rotated bilinear elements. Therefore, starting from the Crouzeix--Raviart element, we construct a modified nonconforming first order finite element space on shape regular triangular meshes satisfying a patch test of higher order. A rigorous error analysis of this $P_1^{\mbox{\scriptsize\it mod}}$ element applied to a streamline diffusion discretization is given. The numerical tests show the robustness and the high accuracy of the new method.
Semiparametric estimates of the relation between weather and electricity sales
Authors: Robert F. Engle, C. W. J. Granger, John Rice, Andrew Weiss
Venue: Essays in econometrics: Spectral analysis, seasonality, nonlinearity, methodology, and forecasting (2001)

A nonlinear relationship between electricity sales and temperature is estimated using a semiparametric regression procedure that easily allows linear transformations of the data. This accommodates introduction of covariates, timing adjustments due to the actual billing schedules, and serial correlation. The procedure is an extension of smoothing splines with the smoothness parameter estimated from minimization of the generalized cross-validation criterion introduced by Craven and Wahba (1979). Estimates are presented for residential sales for four electric utilities and are compared with models that represent the weather using only heating and cooling degree days or with piecewise linear splines.
Testing transition systems: an annotated bibliography
Authors: Ed Brinksma, Jan Tretmans
Venue: Modeling and verification of parallel processes (2001)

Labelled transition system based test theory has made remarkable progress over the past 15 years. From a theoretically interesting approach to the semantics of reactive systems it has developed into a field where testing theory is (slowly) narrowing the gap with testing practice. In particular, new test generation algorithms are being designed that can be used in realistic situations whilst maintaining a sound theoretical basis. In this paper we present an annotated bibliography of labelled transition system based test theory and its applications covering the main developments.
Taylor and Lyubeznik resolutions via Gröbner bases
Authors: Werner M. Seiler
Venue: Journal of Symbolic Computation (2002)

Taylor presented an explicit resolution for arbitrary monomial ideals. Later, Lyubeznik found that a subcomplex already defines a resolution. We show that the Taylor resolution may be obtained by repeated application of the Schreyer Theorem from the theory of Gröbner bases, whereas the Lyubeznik resolution is a consequence of Buchberger's chain criterion. Finally, we relate Fröberg's contracting homotopy for the Taylor complex to normal forms with respect to our Gröbner bases and use it to derive a splitting homotopy that leads to the Lyubeznik complex.
Building knowledge base management systems
Authors: John Mylopoulos, Vinay Chaudhri, Dimitris Plexousakis, Adel Shrufi, Thodoros Topologlou
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (1996)

Advanced applications in fields such as CAD, software engineering, real-time process control, corporate repositories and digital libraries require the construction, efficient access and management of large, shared knowledge bases. Such knowledge bases cannot be built using existing tools such as expert system shells, because these do not scale up, nor can they be built in terms of existing database technology, because such technology does not support the rich representational structure and inference mechanisms required for knowledge-based systems. This paper proposes a generic architecture for a knowledge base management system intended for such applications. The architecture assumes an object-oriented knowledge representation language with an assertional sublanguage used to express constraints and rules. It also provides for general-purpose deductive inference and special-purpose temporal reasoning. Results reported in the paper address several knowledge base management issues. For storage management, a new method is proposed for generating a logical schema for a given knowledge base. Query processing algorithms are offered for semantic and physical query optimization, along with an enhanced cost model for query cost estimation. On concurrency control, the paper describes a novel concurrency control policy which takes advantage of knowledge base structure and is shown to outperform two-phase locking for highly structured knowledge bases and update-intensive transactions. Finally, algorithms for compilation and efficient processing of constraints and rules during knowledge base operations are described. The paper describes original results, including novel data structures and algorithms, as well as preliminary performance evaluation data. Based on these results, we conclude that knowledge base management systems which can accommodate large knowledge bases are feasible.
Routing and wavelength assignment in optical networks
Authors: Asuman E. Ozdaglar, Dimitri P. Bertsekas
Venue: IEEE/ACM Transactions on Networking (TON) (2003)

The problem of routing and wavelength assignment (RWA) is critically important for increasing the efficiency of wavelength-routed all-optical networks. Given the physical network structure and the required connections, the RWA problem is to select a suitable path and wavelength among the many possible choices for each connection so that no two paths sharing a link are assigned the same wavelength. In work to date, this problem has been formulated as a difficult integer programming problem that does not lend itself to efficient solution or insightful analysis. In this work, we propose several novel optimization problem formulations that offer the promise of radical improvements over the existing methods. We adopt a (quasi-)static view of the problem and propose new integer-linear programming formulations, which can be addressed with highly efficient linear (not integer) programming methods and yield optimal or near-optimal RWA policies. The fact that this is possible is surprising, and is the starting point for new and greatly improved methods for RWA. Aside from its intrinsic value, the quasi-static solution method can form the basis for suboptimal solution methods for the stochastic/dynamic settings.
Open learning objects for data structure course
Authors: Longzhuang Li, Hongchi Shi, Yi Shang, Su-Shing Chen
Venue: Journal of Computing Sciences in Colleges (2003)

The paper presents an approach to the design of Open Learning Objects (OLOs). The approach is based on open standards, mostly XML markup languages and their related tools. It enables learning-object-to-learner interaction and supports learning object adaptation to the learner. We use inner metadata to describe the OLOs with features of learner adaptation and interaction. OLOs designed using this approach can be used to organize learning materials of a wide range of courses, and better support learner-centered, self-paced, and highly interactive Web-based learning environment. To demonstrate the use of the innovative approach, we create the OLOs for a core computer science course, Data Structure.
Froissart doublets in Pad&#x00E9; approximation in the case of polynomial noise
Authors: Jacek Gilewicz, Yuri Kryakin
Venue: Journal of Computational and Applied Mathematics (2003)

First, we study the relation between the zeros of random polynomials Rn+1 and the zeros and poles of their Padé approximants [n/n]Rn+1. Next, we consider the distribution of zeros and poles of Padé approximants to the geometric series perturbed by a random polynomial noise. We observe numerically interesting connections between two above problems. Some numerical observations on the Froissart doublets have been also made.
Designing Workflow Coordination: Centralized Versus Market-Based Mechanisms
Authors: Jui Chiew Tan, Patrick T. Harker
Venue: Information Systems Research (1999)

As - result of the increasing diffusion of decision-making within and between organiza- tions, distributed scheduling methods have been proposed as alternatives to centralized, hierarchical, top-down production control schemes. While distributed scheduling methodol- ogies are appealing, one must first address the fundamental questions of when and where such methods are appropriate. This paper seeks to provide answers to these questions. Using generalized workflow framework, this paper models and compares the total expected costs of using decentralized and centralized organizational designs to coordinate the flows of infor- mation and work. This comparison allows one to define the characteristics of work environ- ments where distributed scheduling methods are more suitable than hierarchical, top-down production approaches. Finally, from this analysis, one can conclude that distributed sched- uling methods work well for systems where information technology is inexpensive relative to production cost, processing times are relatively long, and where the number of agents in the system is not too large.
Gauge groups and data classification
Authors: N. Prabhu
Venue: Applied Mathematics and Computation (2003)

We present a new method for constructing nonlinear classifiers. Given any two distinct sets of points in Rn the new method can construct, using gauge group techniques, a closed form expression of a surface, Φ(x) = 0, which separates the two sets. We also show that any two distinct sets of points in Rn can be separated by a polynomial surface and present an algorithm for constructing such polynomial surfaces. Finally we present two numerical examples to illustrate the new method.
Sustainable Network Design: A Commercial Fabric Case Study
Authors: Matthew M. Mehalik
Venue: Interfaces (2000)

I use an actor-network perspective to analyze a case study of an environmentally sustainable, commercial textile fabric design. Susan Lyons of DesignTex, Inc., William McDonough of William McDonough and Partners, and Albin KÃ¤in of Rohner Textil AG constructed and maintained a network of people and objects with an environmental focus by anticipating contingencies that continually threatened their network, such as waste disposal, credibility, and financial problems. In response to these contingencies, they developed and implemented environmental tools, such as an environmental design protocol, a life-cycle development (LCD) methodology, environmental cost accounting procedures, product-evaluation metrics, and employee-management systems. The success of their efforts rests on their ability to recruit network allies by integrating these environmental tools.
Performance evaluation of continuous production lines with machines having different processing times and multiple failure modes
Authors: R. Levantesi, A. Matta, T. Tolio
Venue: Performance Evaluation (2003)

This paper presents an approximate analytical method for the performance evaluation of asynchronous production lines with deterministic processing times, multiple failure modes and finite buffer capacity. The discrete flow of parts is approximated by a continuous flow of material. The technique developed here is based on the approximate evaluation of a K machine line by the evaluation of K - 1 two-machine lines: unlike previous work on this subject, the multiple failure approach allows to consider real and virtual failure modes for each building block in which the original line is decomposed. Indeed, to reproduce in each two-machine lines the flow of material observed in the related buffer of the original line, real failures are used to take into account the reliability of the physical machines while virtual failures are introduced to model the different interruptions of flow that can arise inside the line thus preventing machines from working. To assess the accuracy of the proposed method, extensive simulation and numerical experiments have been carried out.
Sustained Competitive Advantage: Temporal Dynamics and the Incidence and Persistence of Superior Economic Performance
Authors: Robert R. Wiggins, Timothy W. Ruefli
Venue: Organization Science (2002)

Competitive advantage is a key concept in strategic management research for a number of reasons--not the least of which is that an avowed consequence of its attainment is held to be superior economic performance. However, few prior empirical studies have directly and systematically documented the incidence or prevalence of persistent superior economic performance. The research reported here is based on empirical studies of a large number of industry samples for which longitudinal data were stratified by levels of performance using a new methodology and then analyzed in terms of their dynamics. This new stratification technique was used in lieu of autoregressive methods employed in prior studies of performance persistence to allow for a true outlier analysis because persistent superior economic performance both has been argued theoretically, and found empirically, to be rare. Detailed results from a sample of 6,772 firms in 40 industries over 25 years are presented to illustrate the findings that: (1) while some firms do exhibit superior economic performance, (2) only a very small minority do so, and (3) the phenomenon very rarely persists for long time frames. These results, while not providing direct support for a particular extant strategic management or economic theory concerning firm performance, are most consonant with the resource-based view of the firm and have implications for significant aspects of other received strategic management and economic theories.
Drive: Dynamic Routing of Independent Vehicles
Authors: Martin Savelsbergh, Marc Sol
Venue: Operations Research (1998)

We present DRIVE (Dynamic Routing of Independent VEhicles), a planning module to be incorporated in a decision support system for the direct transportation at Van Gend and Loos BV. Van Gend and Loos BV is the largest company providing road transportation in the Benelux, with about 1400 vehicles transporting 160,000 packages from thousands of senders to tens of thousands of addressees per day. The heart of DRIVE is a branch-and-price algorithm. Approximation and incomplete optimization techniques as well as a sophisticated column management scheme have been employed to create the right balance between solution speed and solution quality. DRIVE has been tested by simulating a dynamic planning environment with real-life data and has produced very encouraging results.