Showing papers by "University of Maryland, College Park published in 1995"

The Stakeholder Theory of the Corporation: Concepts, Evidence, and Implications

Abstract: ?The stakeholder theory has been advanced and justified in the management literature on the basis of its descriptive accuracy, instrumental power, and normative validity. These three aspects of the theory, although interrelated, are quite distinct; they involve different types of evidence and argument and have different implications. In this article, we examine these three aspects of the theory and critique and integrate important contributions to the literature related to each. We conclude that the three aspects of stakeholder theory are mutually supportive and that the normative base of the theory-which includes the modern theory of property rights-is fundamental. If the unity of the corporate body is real, then there is reality and not simply legal fiction in the proposition that the managers of the unit are fiduciaries for it and not merely for its individual members, that they are . . . trustees for an institution [with multiple constituents] rather than attorneys for the stockholders.

Human and machine recognition of faces: a survey

Abstract: The goal of this paper is to present a critical survey of existing literature on human and machine recognition of faces. Machine recognition of faces has several applications, ranging from static matching of controlled photographs as in mug shots matching and credit card verification to surveillance video images. Such applications have different constraints in terms of complexity of processing requirements and thus present a wide range of different technical challenges. Over the last 20 years researchers in psychophysics, neural sciences and engineering, image processing analysis and computer vision have investigated a number of issues related to face recognition by humans and machines. Ongoing research activities have been given a renewed emphasis over the last five years. Existing techniques and systems have been tested on different sets of images of varying complexities. But very little synergism exists between studies in psychophysics and the engineering literature. Most importantly, there exists no evaluation or benchmarking studies using large databases with the image quality that arises in commercial and law enforcement applications In this paper, we first present different applications of face recognition in commercial and law enforcement sectors. This is followed by a brief overview of the literature on face recognition in the psychophysics community. We then present a detailed overview of move than 20 years of research done in the engineering community. Techniques for segmentation/location of the face, feature extraction and recognition are reviewed. Global transform and feature based methods using statistical, structural and neural classifiers are summarized. >

Thermodynamics of spacetime: The Einstein equation of state.

Abstract: The Einstein equation is derived from the proportionality of entropy and the horizon area together with the fundamental relation $\ensuremath{\delta}Q\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}T\mathrm{dS}$. The key idea is to demand that this relation hold for all the local Rindler causal horizons through each spacetime point, with $\ensuremath{\delta}Q$ and $T$ interpreted as the energy flux and Unruh temperature seen by an accelerated observer just inside the horizon. This requires that gravitational lensing by matter energy distorts the causal structure of spacetime so that the Einstein equation holds. Viewed in this way, the Einstein equation is an equation of state.

Information Seeking in Electronic Environments

Abstract: Information and information seeking 2. Information seekers and electronic environments 3. Information-seeking perspective and framework 4. Foundations for personal information infrastructures: 5. Information-seeking knowledge, skills, and attitudes 6. Analytical search strategies 7. Browsing strategies 8. Designing support for Browsing: 9. A research and development perspective 10. The continuing evolution of information seeking 11. Future directions and conclusion.

Nearest neighbor queries

Abstract: A frequently encountered type of query in Geographic Information Systems is to find the k nearest neighbor objects to a given point in space. Processing such queries requires substantially different search algorithms than those for location or range queries. In this paper we present an efficient branch-and-bound R-tree traversal algorithm to find the nearest neighbor object to a point, and then generalize it to finding the k nearest neighbors. We also discuss metrics for an optimistic and a pessimistic search ordering strategy as well as for pruning. Finally, we present the results of several experiments obtained using the implementation of our algorithm and examine the behavior of the metrics and the scalability of the algorithm.

Economic growth, carrying capacity, and the environment.

Abstract: National and international economic policy has usually ignored the environment. In areas where the environment is beginning to impinge on policy, as in the General Agreement on Tariffs and Trade (GATT) and the North American Free Trade Agreement (NAFTA), it remains a tangential concern, and the presumption is often made that economic growth and economic liberalization (including the liberalization of international trade) are, in some sense, good for the environment. This notion has meant that economy-wide policy reforms designed to promote growth and liberalization have been encouraged with little regard to their environmental consequences, presumably on the assumption that these consequences would either take care of themselves or could be dealt with separately. In this article, we discuss the relation between economic growth and environmental quality, and the link between economic activity and the carrying capacity and resilience of the environment.

Global self-esteem and specific self-esteem : Different concepts different outcomes

Abstract: Les AA. eclairent la relation entre estime de soi globale (Rosenberg 1979) et estime de soi specifique (academique). Ils montrent que ces deux types d'evaluation ne sont pas equivalent. L'estime de soi globale etant plus adequate en ce qui concerne la perception psychosociologique du bien-etre et l'estime de soi specifique (academique) plus pertinente en ce qui concerne le comportement et constituant plus particulierement un indicateur de performance scolaire. Les resultats d'un modele causal d'equation structurale lineaire indique que le degre selon lequel l'estime de soi specifique affecte l'estime de soi globale, particulierement les aspects positif de l'estime de soi globale, est fonction de la valeur attribuee individuellement a la performance academique superieure

Orienting in a defensive world: Mammalian modifications of our evolutionary heritage. A Polyvagal Theory

Abstract: The vagus, the 10th cranial nerve, contains pathways that contribute to the regulation of the internal viscera, including the heart. Vagal efferent fibers do not originate in a common brainstem structure. The Polyvagal Theory is introduced to explain the different functions of the two primary medullary source nuclei of the vagus: the nucleus ambiguus (NA) and the dorsal motor nucleus (DMNX). Although vagal pathways from both nuclei terminate on the sinoatrial node, it is argued that the fibers originating in NA are uniquely responsible for respiratory sinus arrhythmia (RSA). Divergent shifts in RSA and heart rate are explained by independent actions of DMNX and NA. The theory emphasizes a phylogenetic perspective and speculates that mammalian, but not reptilian, brainstem organization is characterized by a ventral vagal complex (including NA) related to processes associated with attention, motion, emotion, and communication. Various clinical disorders, such as sudden infant death syndrome and asthma, may be related to the competition between DMNX and NA.

Tracking Democracy's Third Wave with the Polity III Data

Abstract: This article reports and analyzes an updated version of the widely-used Polity II dataset, consisting of annual indicators of institutional democracy and autocracy for 161 states spanning the years from 1946 through 1994. The validity of the Polity III indicators of regime type is supported by their strong correlations (.85 to .92) with seven conceptually and operationally different indicators of democracy developed by other researchers. Comparative analysis of global and regional trends in democracy shows the extent to which the Middle East and Africa lag behind other world regions in the transition to democracy. A series of challenges to the `third wave' of democratization are identified, with particular attention paid to the large numbers of institutionally unconsolidated, or `incoherent', polities that have recently emerged, mainly due to attempts by autocratic elites to contain domestic and international pressures to liberalize their regimes.

The ASA framework: An update.

Abstract: In 1987, B. Schneider proposed a person-oriented model of organizational behavior based on the proposition that it is the collective characteristics of people who define an organization. He further proposed that, over time, organizations become defined by the persons in them as a natural outcome of an attraction-selection-attrition (ASA) cycle. We provide a brief overview of the ASA cycle and review literature relevant to two facets of the theory. The literature reviewed provides some indirect support for the proposal that founders and the members of top management have long-term effects on organizations through the ASA cycle. The literature reviewed provides both indirect and direct evidence supporting a central proposition of ASA theory–that organizations over time become relatively homogeneous with regard to the kinds of people in them. Suggestions for future research on ASA are presented.

Observation of the top quark

Abstract: The D0 collaboration reports on a search for the Standard Model top quark in p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron, with an integrated luminosity of approximately 50 pb{sup {minus}1}. We have searched for t{bar t} production in the dilepton and single lepton decay channels, with and without tagging of b quark jets. We observe 17 events with an expected background of 3.8 {plus_minus} 0.6 events. The probability for an upward fluctuation of the background to produce the observed signal is 2 {times} 10{sup {minus}6} (equivalent to 4.6 standard deviations). The kinematic properties of the excess events are consistent with top quark decay. We conclude that we have observed the top quark and measure its mass to be 199{sub {minus}21}{sup +19} (stat.) {plus_minus}22 (syst.) GeV/c{sup 2} and its production cross section to be 6.4 {plus_minus} 2.2 pb.

Model-based object pose in 25 lines of code

Abstract: In this paper, we describe a method for finding the pose of an object from a single image. We assume that we can detect and match in the image four or more noncoplanar feature points of the object, and that we know their relative geometry on the object. The method combines two algorithms; the first algorithm,POS (Pose from Orthography and Scaling) approximates the perspective projection with a scaled orthographic projection and finds the rotation matrix and the translation vector of the object by solving a linear system; the second algorithm,POSIT (POS with ITerations), uses in its iteration loop the approximate pose found by POS in order to compute better scaled orthographic projections of the feature points, then applies POS to these projections instead of the original image projections. POSIT converges to accurate pose measurements in a few iterations. POSIT can be used with many feature points at once for added insensitivity to measurement errors and image noise. Compared to classic approaches making use of Newton's method, POSIT does not require starting from an initial guess, and computes the pose using an order of magnitude fewer floating point operations; it may therefore be a useful alternative for real-time operation. When speed is not an issue, POSIT can be written in 25 lines or less in Mathematica; the code is provided in an Appendix.

FastMap: a fast algorithm for indexing, data-mining and visualization of traditional and multimedia datasets

Abstract: A very promising idea for fast searching in traditional and multimedia databases is to map objects into points in k-d space, using k feature-extraction functions, provided by a domain expert [25]. Thus, we can subsequently use highly fine-tuned spatial access methods (SAMs), to answer several types of queries, including the 'Query By Example' type (which translates to a range query); the 'all pairs' query (which translates to a spatial join [8]); the nearest-neighbor or best-match query, etc.However, designing feature extraction functions can be hard. It is relatively easier for a domain expert to assess the similarity/distance of two objects. Given only the distance information though, it is not obvious how to map objects into points.This is exactly the topic of this paper. We describe a fast algorithm to map objects into points in some k-dimensional space (k is user-defined), such that the dis-similarities are preserved. There are two benefits from this mapping: (a) efficient retrieval, in conjunction with a SAM, as discussed before and (b) visualization and data-mining: the objects can now be plotted as points in 2-d or 3-d space, revealing potential clusters, correlations among attributes and other regularities that data-mining is looking for.We introduce an older method from pattern recognition, namely, Multi-Dimensional Scaling (MDS) [51]; although unsuitable for indexing, we use it as yardstick for our method. Then, we propose a much faster algorithm to solve the problem in hand, while in addition it allows for indexing. Experiments on real and synthetic data indeed show that the proposed algorithm is significantly faster than MDS, (being linear, as opposed to quadratic, on the database size N), while it manages to preserve distances and the overall structure of the data-set.

Winning the service game

Abstract: The chapter presents a summary and extension of our book, Winning the Service Game, published in 1995 by Harvard Business School Press (Schneider & Bowen , 1995). We summarize the “rules of the game” we had presented there concerning the production and delivery primarily of consumer services and note several advances in thinking since we wrote the book. We emphasize that people (customers, employees, and managers) still are a prominent key to success in service and that this should be fully recognized in the increasingly technical sophistication of service science . The foundation of this thesis is the idea that promoting service excellence and innovation requires an understanding of the co-creation of value by and for people. Further, that such co-creation is most likely to effectively occur when an appropriate psycho-social context is created for people as they produce, deliver and experience a service process. Such a context is the result of understanding the complexities of the people who are a central component of the service delivery system.

General deterrent effects of police patrol in crime “hot spots”: A randomized, controlled trial

Abstract: Many criminologists doubt that the dosage of uniformed police patrol causes any measurable difference in crime. This article reports a one-year randomized trial in Minneapolis of increases in patrol dosage at 55 of 110 crime “hot spots,” monitored by 7,542 hours of systematic observations. The experimental group received, on average, twice as much observed patrol presence, although the ratio displayed wide seasonal fluctuation. Reductions in total crime calls ranged from 6 percent to 13 percent. Observed disorder was only half as prevalent in experimental as in control hot spots. We conclude that substantial increases in police patrol presence can indeed cause modest reductions in crime and more impressive reductions in disorder within high crime locations.

Intra- and Interorganizational Cooperation: Toward a Research Agenda

Abstract: The 1994 Special Research Forum on Intra- and Interorganizational Cooperation is dedicated to the proposition that issues of cooperation are fundamental to management success and of increasing impo...

Broadcast disks: data management for asymmetric communication environments

Abstract: This paper proposes the use of repetitive broadcast as a way of augmenting the memory hierarchy of clients in an asymmetric communication environment. We describe a new technique called "Broadcast Disks" for structuring the broadcast in a way that provides improved performance for non-uniformly accessed data. The Broadcast Disk superimposes multiple disks spinning at different speeds on a single broadcast channel--in effect creating an arbitrarily fine-grained memory hierarchy. In addition to proposing and defining the mechanism, a main result of this work is that exploiting the potential of the broadcast structure requires a re-evaluation of basic cache management policies. We examine several "pure" cache management policies and develop and measure implementable approximations to these policies. These results and others are presented in a set of simulation studies that substantiates the basic idea and develops some of the intuitions required to design a particular broadcast program.

Finishing High School and Starting College: Do Catholic Schools Make a Difference?

Abstract: In this paper, we consider two measures of the relative effectiveness of public and Catholic schools: finishing high school and starting college. These measures are potentially more important indicators of school quality than standardized test scores in light of the economic consequences of obtaining more education. Single-equation estimates suggest that for the typical student, attending a Catholic high school raises the probability of finishing high school or entering a four-year college by thirteen percentage points. In bivariate probit models we find almost no evidence that our single-equation estimates are subject to selection bias.

Finite element solution of the Helmholtz equation with high wave number Part I: The h-version of the FEM☆

Abstract: The paper addresses the properties of finite element solutions for the Helmholtz equation. The h-version of the finite element method with piecewise linear approximation is applied to a one-dimensional model problem. New results are shown on stability and error estimation of the discrete model. In all propositions, assumptions are made on the magnitude of hk only, where k is the wavelength and h is the stepwidth of the FE-mesh. Previous analytical results had been shown with the assumption that k 2 h is small. For medium and high wavenumber, these results do not cover the meshsizes that are applied in practical applications. The main estimate reveals that the error in H 1 -norm of discrete solutions for the Helmholtz equation is polluted when k 2 h is not small. The error is then not quasioptimal; i.e., the relation of the FE-error to the error of best approximation generally depends on the wavenumber k . It is noted that the pollution term in the relative error is of the same order as the phase lead of the numerical solution. In the result of this analysis, thorough and rigorous understanding of error behavior throughout the range of convergence is gained. Numerical results are presented that show sharpness of the error estimates and highlight some phenomena of the discrete solution behavior. The h - p -version of the FEM is studied in Part II.

Finding and reminding: file organization from the desktop

Abstract: This paper summarizes and synthesizes two independent studies of the ways users organize and find files on their computers. The first study (Barreau 1995) investigated information organization practices among users of DOS, Windows and OS/2. The second study (Nardi, Anderson and Erickson 1995), examined the finding and filing practices of Macintosh users. There were more similarities in the two studies than differences. Users in both studies (1) preferred location-based finding because of its crucial reminding function; (2) avoided elaborate filing schemes; (3) archived relatively little information; and (4) worked with three types of information: ephemeral, working and archived. A main difference between the study populations was that the Macintosh users used subdirectories to organize information and the DOS users did not.

Tracking and recognizing rigid and non-rigid facial motions using local parametric models of image motion

Abstract: This paper explores the use of local parametrized models of image motion for recovering and recognizing the non-rigid and articulated motion of human faces. Parametric flow models (for example affine) are popular for estimating motion in rigid scenes. We observe that within local regions in space and time, such models not only accurately model non-rigid facial motions but also provide a concise description of the motion in terms of a small number of parameters. These parameters are intuitively related to the motion of facial features during facial expressions and we show how expressions such as anger, happiness, surprise, fear, disgust and sadness can be recognized from the local parametric motions in the presence of significant head motion. The motion tracking and expression recognition approach performs with high accuracy in extensive laboratory experiments involving 40 subjects as well as in television and movie sequences. >

The Academic Lives of Neglected, Rejected, Popular, and Controversial Children

Abstract: The purposes of this study were to examine academically relevant characteristics of different sociometric status groups and to learn about the academic orientations of behavioral subgroups of rejected children. Results from a sample of 423 sixth and seventh graders (ages 11-13) suggested that sociometrically neglected children have quite positive academic profiles. When compared with average status children, these students reported higher levels of motivation, were described by teachers as more self-regulated learners, as more prosocial and compliant, and as being better liked by teachers. Analyses of two behavioral subgroups of rejected children indicated that aggressive-rejected but not submissive-rejected children have problematic academic profiles. Relations of neglected and aggressive-rejected status to academic adjustment in young adolescents' lives is discussed.

The empirical investigation of perspective-based reading

Abstract: We consider reading techniques a fundamental means of achieving high quality software. Due to the lack of research in this area, we are experimenting with the application and comparison of various reading techniques. This paper deals with our experiences with a family of reading techniques known as Perspective-Based Reading (PBR), and its application to requirements documents. The goal of PBR is to provide operational scenarios where members of a review team read a document from a particular perspective, e.g., tester, developer, user. Our assumption is that the combination of different perspectives provides better coverage of the document, i.e., uncovers a wider range of defects, than the same number of readers using their usual technique. To test the effectiveness of PBR, we conducted a controlled experiment with professional software developers from the National Aeronautics and Space Administration/Goddard Space Flight Center (NASA/GSFC) Software Engineering Laboratory (SEL). The subjects read two types of documents, one generic in nature and the other from the NASA domain, using two reading techniques, a PBR technique and their usual technique. The results from these experiments, as well as the experimental design, are presented and analyzed. Teams applying PBR are shown to achieve significantly better coverage of documents than teams that do not apply PBR. We thoroughly discuss the threats to validity so that external replications can benefit from the lessons learned and improve the experimental design if the constraints are different from those posed by subjects borrowed from a development organization.

Communication in the age of virtual reality

Abstract: Contents: Preface. Part I: Virtual Reality as Communication Medium. F. Biocca, T. Kim, M.R. Levy, The Vision of Virtual Reality. F. Biocca, M.R. Levy, Virtual Reality as a Communication System. J. Steuer, Defining Virtual Reality: Dimensions Determining Telepresence. F. Biocca, B. Delaney, Immersive Virtual Reality Technology. Part II: Designing Virtual Environments. F. Biocca, M.R. Levy, Communication Applications of Virtual Reality. D.G. Hawkins, Virtual Reality and Passive Simulators: The Future of Fun. C. Heeter, Communication Research on Consumer VR. K. Meyer, Dramatic Narrative in Virtual Reality. G. Kramer, Sound and Communication in Virtual Reality. M.T. Palmer, Interpersonal Communication and Virtual Reality: Mediating Interpersonal Relationships. Part III: The Social Reality of Virtual Reality. T.W. Valente, T. Bardini, Virtual Diffusion or an Uncertain Reality: Networks, Policy, and Models for the Diffusion of VR Technology. M.A. Shapiro, D.G. McDonald, I'm Not a Real Doctor, But I Play One in Virtual Reality: Implications of Virtual Reality for Judgments About Reality. A. Balsamo, Signal to Noise: On the Meaning of Cyberpunk Subculture. L. St. Clair Harvey, Communication Issues and Policy Implications.

Dependence of giant magnetoresistance on oxygen stoichiometry and magnetization in polycrystalline La0.67Ba0.33MnOz

Abstract: We have studied resistivity, magnetization, and magnetoresistance in polycrystalline La0.67Ba0.33MnOz by reducing the oxygen stoichiometry from z=2.99 to 2.80. As the oxygen content decreases, the resistivity of La0.67Ba0.33 MnOz increases and the magnetic transition temperature shifts to lower temperature. A large magnetoresistance effect was observed over a wide temperature range for all samples except the insulating z=2.80 sample. The similarity between our results on oxygen-deficient polycrystalline La0.67 Ba0.33MnOz and films previously reported to have a very large intrinsic magnetoresistance is discussed. At low temperature the magnetoresistance was observed to be strongly dependent on the magnetization. A possible mechanism for this effect is discussed.

Designing and reporting on computational experiments with heuristic methods

Abstract: This article discusses the design of computational experiments to test heuristic methods and provides reporting guidelines for such experimentation. The goal is to promote thoughtful, well-planned, and extensive testing of heuristics, full disclosure of experimental conditions, and integrity in and reproducibility of the reported results.