Wide Range Of Viewpoints Research Articles

A Theory of Shape by Space Carving

In this paper we consider the problem of computing the 3D shape of an unknown, arbitrarily-shaped scene from multiple photographs taken at known but arbitrarily-distributed viewpoints. By studying the equivalence class of all 3D shapes that reproduce the input photographs, we prove the existence of a special member of this class, the photo hull, that (1) can be computed directly from photographs of the scene, and (2) subsumes all other members of this class. We then give a provably-correct algorithm, called Space Carving, for computing this shape and present experimental results on complex real-world scenes. The approach is designed to (1) capture photorealistic shapes that accurately model scene appearance from a wide range of viewpoints, and (2) account for the complex interactions between occlusion, parallax, shading, and their view-dependent effects on scene-appearance.

An introduction to object recognition.

In this report we present a general introduction to object recognition. We begin with brief discussions of the terminology used in the object recognition literature and the psychophysical tasks that are used to investigate object recognition. We then discuss models of shape representation. We dispense with the idea that shape representations are like the 3-D models used in computer aided design and explore instead models of shape representation that are based on future descriptions. As these descriptions encode only the features that are visible from a particular viewpoint, they are generally viewpoint-specific. We discuss various means of achieving viewpoint-invariant recognition using such descriptions, including reliance on diagnostic features visible from a wide range of viewpoints, storage of multiple descriptions for each object, and the use of transformation mechanisms. Finally, we discuss how differences in viewpoint dependence that are often observed for within-category and between-category recognition tasks could be due to differences in the types of features that are naturally available to distinguish among different objects in these tasks.

Serials spoken here: Reports on conferences, institutes and seminars

We have one report this issue which is, not surprisingly, on the topic of electronic serials. This institute, which reached full capacity, covered both theoretical and practical considerations for dealing with the influx of electronic serials. Many of us are barely coping with the need to plan and implement access to the vast amount of electronic information publishers have now mounted. We are faced with many new decisions about cataloging, vendor selection, license agreements, and consortial arrangements. The institute was planned as a basic course on electronic serials and addressed many of these topics froma wide range of viewpoints. Due to the popularity and success of this institute it will be repeated in April, 1998, in St. Louis.

A reappraisal of the concept of ‘culture’

Abstract This investigation considers a number of approaches to the definition and analysis of ‘culture’. It shows that although approaches to culture span a wide range of viewpoints, there are gems that can be distilled and developed. To that end, a definition of ‘culture’ is proposed that it is contended captures much of the positive character in what has preceded it and hopefully avoids the negative. This is followed by a discussion of some of the most important studies concerned with the evolution of culture and the notions of culture that constitute the fulcrum of these investigations. Here we find almost as many approaches as there are proponents. However one stands out, of those surveyed here, as being of potentially greatest value to social scientists, the dual inheritance theory of Boyd and Richerson (1985).

Performance impacts of self-similarity in traffic

Recent measurement studies in Bellcore and elsewhere have convincingly established the presence of statistical self similarity in high-speed network traffic. What is less clear --- and as such the subject of intense current research --- is the impact of the self-similarity on network performance. Given that traditional queueing models of network performance do not model self-similarity, the validity of traditional models to predict network performance would be supported if it is shown that self-similarity does not have measurable impacts on performance. On the other hand, if the converse of this assertion were true, it would have significant impacts on the way networks are designed and analyzed, as well as open up new areas of research in mathematical modeling, queueing analysis, network design and control. The issues addressed in this session are therefore of fundamental importance in high-speed network research.Given that queueing behavior is dominated by traffic characteristics over the time scales of busy periods, it has been argued that phenomena that span many time scales, such as self-similarity, should not be relevant for queueing performance. However, the paper by Narayan, Erramilli and Willinger presents evidence that for data traffic, the long range dependence (which is related to the self-similarity in traffic) can dominate queueing behavior under a variety of conditions. Specifically, it is shown based on a series of carefully designed simulation experiments with actual traffic traces, that the queueing behavior with actual traces is considerably heavier than that predicted by traditional theory, and that these differences are attributable to long range dependence. The paper by Heyman and Lakshman investigates modeling of video traffic to predict cell loss performance with finite buffer systems, and they conclude that long-range dependence is not a crucial property in determining the finite buffer behavior of video conferences. In particular, a Markov chain model that does not model long-range dependence is nevertheless able to reproduce various operating characteristics over a wide range of loadings obtained with the actual video trace. Mukherjee, Adas, Klivansky and Song investigate the performance impacts of short-range and long-range correlation components using simulations with a fractional ARIMA model. They also discuss a strategy to provide quality of service guarantees with long range dependent traffic, as well as recent results on NSFNET traffic. Finally, the paper by Li describes a frequency-domain based analytical tool that matches a special class of Markov chains with traces exhibiting a variety of characteristics, including long-range dependence. Good agreement is reported between analytical queueing solutions of the matched Markov chains, and simulation results obtained video and data traffic traces.This session therefore brings together a wide range of viewpoints on this issue. Resolution of such seemingly conflicting conclusions lies in the fact that in performance analysis, answers sensitively depend on the specific details of a problem. Thus the proper question to ask is not whether or not self-similarity matters in queueing; but under what conditions it matters. Likewise, the question to ask is not whether a class of models is invalid; but to identify the conditions under which traditional Markov or self-similar traffic models are expected to be valid. Finally, given an understanding of statistical features that are relevant to a given problem, the challenge is to model these accurately and parsimoniously so that the model is useful in practical performance analysis. The work outlined in the abstracts below adds significantly to our understanding of these issues.

The Genetic revolution: scientific prospects and public perceptions

Remarkable advances in molecular genetics have brought benefits ranging from more flavorful tomatoes to inexpensive human insulin produced in bacteria. But not everyone welcomes the inevitable revolution. Perhaps because experts and the general public belatedly recognized that the benefits of other technologies have come at great cost--pollution of the environment, exhaustion of natural resources, even damage to the atmosphere--many assume that similarly unintended and unforeseen harmful consequences are inevitable for biotechnology. What monsters and disasters, they wonder, will accompany the miracles of this latest advance?In The Genetic Revolution Bernard D. Davis and other experts address such fears with clear explanations of molecular genetics, its practical applications in biotechnology, its legal implications, and its surprising historical context. In fact, biotechnology is as old as civilization itself--and was originally called domestication: the adaptation of initiallywild organisms, by empirical genetic selection, to meet human needs. And the scientific record shows that, unlike more recent technologies based on the physical sciences, the great benefits of domestication have been remarkably free of harmful side effects. Defenders argue that the new techniques of genetic engineering will simply increase the speed, precision, and range of domestication. However, the purpose will remain the same: to strengthen those traits, in animals, plants, or microbes, that make the organism more useful for humans.To ensure that all sides of the debate are heard, Davis has chosen outstanding contributors with a wide range of viewpoints--from apprehensive toenthusiastic--and a variety of backgrounds, including political science, law, and government regulation, as well as biology and medicine. With the latest information on the likely impact of genetic engineering in agriculture, animal husbandry, ecology, and medical research and practice, The Genetic Revolution introduces scientific facts and informed opinions to an emotional and often confusing public discussion.

Introduction

Abstract Soviet historiography has entered into a phase of revisionism and rediscovery. No topic or issue is sacrosanct, and a wide range of viewpoints can be discerned in the pages of the scholarly and popular periodical press. In both respects, historical revisionism under Gorbachev has advanced beyond the revisionism of the Khrushchev era. Although the range of topics and diversity of viewpoints distinguish the revisionism of today from that of the Khrushchev period, many of the major issues remain the same. And no issue is more important and controversial than that of Stalinism. Whereas the earlier revisionists never went beyond facile descriptive models centered around the cult of personality in their attempts to explain Stalinism, Soviet revisionists today have begun to approach the issue in a much more sophisticated and complex fashion.

Hierarchical control by functional allotment

AbstractMost of the studies in the past on the hierarchical control have been concerned with the computational allotment between higher and lower levels, or among lower levels. In the actual system with a hierarchical structure, however, it often happens that the functional allotment is made between higher and lower levels. From such a viewpoint, the following scheme is considered in this paper. Consider a hierarchical control scheme with a functional allotment between higher and lower levels. The higher‐level controller views the whole system by a macroscopic view, and makes decisions so that the system is optimized from a wide range of viewpoints. Then the instruction is issued toward the lower‐level controller. The lower‐level controller views his own subsystem in detail and makes finer decisions so that the subsystem is optimized, while observing the instruction from the higher level as far as possible. The problem is formulated for the hierarchical control with functional allotment, considering the controllable linear discrete‐time stochastic system with a quadratic cost function. Then a situation is assumed where the information concerning the state estimation and the control input can be exchanged at each time between the higher and lower levels, and an algorithm is derived which can successively determine the control input at each time for the higher‐ and lower‐level controllers. Furthermore, it is shown by a numerical example that the intention of the higher‐level controller is reflected on the actual control by the lower level, by a suitable definition of the cost function of the higher‐level controller.

Lord Jim and the Consequences of Kantian Autonomy

Joanne Wood LORDJIM AND THE CONSEQUENCES OF KANTIAN AUTONOMY Autonomy IS the fundamental principle of Kantian ethics. This is so because his moral system is based on the crucial idea that nothing in the world can be called "good without qualification except a good will."1 Thus a good will is good in and of itself, without regard to any possible end. For such a will, morality is categorical, for only with such an imperative can moral laws be said to be laws ofcomplete freedom, and willed without regard to any other interest. Thus autonomy is a necessary condition for a good will, because any heteronomous worth a will could achieve would by definition be conditional, and would therefore violate Kant's notion of the unconditional worth of a good will. However, it is precisely this notion of the absolute worth a good will merits on its own that would seem to bear looking into: there is something intuitively wrong with Kant's assertion that even if"it should happen that, by a particularly unfortunate fate or by the niggardly provision of a stepmotherly nature, this will should be wholly lacking in power to accomplish its purpose," it would still "sparkle like a jewel in its own right, as something that had its full worth in itselP (p. 10). The idea implied in this passage, that a good will could exist somehow apart from the world and any effects achieved therein, is problematic to say the least. How could such a will be known? The metaphor ofa "sparklingjewel" is striking, but flawed: ajewel exists in the world, for all eyes to see if they know where to look, whereas a good will exists in the hearts of men. It is for this reason thatJoseph Conrad's LordJim is a fitting supplement to understanding the implications of a Kantian view of morality, for the central concern of the novel is the moral ambiguity that results from our common obscurity ofvision into ourselves and those around us. Given this 57 58Philosophy and Literature ambiguity, which Kant recognizes when he says, "even the strictest examination can never lead us entirely behind the secret incentives, for, when moral worth is in question, it is not a matter of actions which one sees but ofdieir inner principles which one does not see" (p. 23). It seems then irresponsible still to maintain that the worth ofa good will is independent of the way of the world. Since it is evident that if results or other empirical factors are invalid tojudge intentions, then the only judge capable of assessing in advance what maxim is being acted upon is the moral agent; morality becomes a matter of strictly individual conscience or reason. The moral agent thus becomes romanticized, a lone figure needing no other guidance than that which his or her own reason can provide in order to lead a truly good life. LordJim challenges just such a conception of individualist or self-sufficient morality. Due to the essential ambiguity ofwhatjim himselfis, the novel is an extremely difficult one to read. This is further complicated by the fact that, after the first four chapters, the reader is never given an impersonal view ofJim, but instead Marlow's painstaking efforts to fit together the puzzle ofJim's character: "I don't pretend I understood him. The views he let me have of himself were like those glimpses through the shifting rents in a thick fog— bits of vivid and vanishing detail, giving no connected idea of the general aspect of a country . . . they were no good for purposes of orientation."2 Given this cloud of uncertainty, Jim remains an enigma from beginning to end. The reader is treated to various judgments ofhim during this time from a wide range of viewpoints which Marlow perhaps pursues in an effort to shed some light on the subject, but which nonetheless leave us in darkness because they all omit one factor or another. There is no Authority in this book. The facts ofJim's case are relatively straightforward: it is the interpretation of what lies behind them, ofJim's "inner principles," which is extraordinarily complex. Jim is working as first mate on...

Three-dimensional object recognition from single two-dimensional images

A computer vision system has been implemented that can recognize three-dimensional objects from unknown viewpoints in single gray-scale images. Unlike most other approaches, the recognition is accomplished without any attempt to reconstruct depth information bottom-up from the visual input. Instead, three other mechanisms are used that can bridge the gap between the two-dimensional image and knowledge of three-dimensional objects. First, a process of perceptual organization is used to form groupings and structures in the image that are likely to be invariant over a wide range of viewpoints. Second, a probabilistic ranking method is used to reduce the size of the search space during model-based matching. Finally, a process of spatial correspondence brings the projections of three-dimensional models into direct correspondence with the image by solving for unknown viewpoint and model parameters. A high level of robustness in the presence of occlusion and missing data can be achieved through full application of a viewpoint consistency constraint. It is argued that similar mechanisms and constraints form the basis for recognition in human vision.

Grading Handicapped Pupils: Review and Position Statement

A review of grading issues, philosophies, and recommendations is provided with implications and specific suggestions for grading mainstreamed handicapped pupils at the secondary level. A synthesis of available literature examines the wide range of viewpoints regarding optimal grading practices for general students and for remedial and handicapped pupils. A position statement related directly to grading secondary mainstreamed handicapped pupils concludes the paper.

Requirements for and Preparation of Human Factors Professionals: Three Perspectives

Representatives from government, industry, and academia present a wide range of viewpoints regarding the needs, training, and development of Human Factors Professionals in a session which combines formal presentations with spontaneous interaction. Perspectives from within the government relative to Human Factors personnel are presented both in terms of the special needs for managing Human Factors programs and in terms of skills and capabilities which facilitate the implementation of development and research activities. Insights regarding the philosophy underlying career tracks in Human Factors can be readily extracted from the presentations. Viewpoints from industry reveal substantial overlap in required skills despite dramatically diverse end products. Insights regarding the structure of corporate Human Factors activities are provided along with insights about expectations for new employees and on the job training as an augmentation of academic training. Also included are discussions of areas of divergence between the industrial practitioners’ needs and the data/research base from which they must draw. Academic viewpoints from both Psychology and Industrial Engineering are presented. An emphasis on the development of problem solving skills and knowledge of how to apply Human Factors tools is a recurring theme. Viewpoints on the Human Factors specialist performing both in a scientist and practitioner role are discussed, and strengths and weaknesses of existing programs are reviewed. The diversity of viewpoints represented in the session allows frank recognition of problems being faced by the profession as well as providing a vehicle for discussing solutions.

Political Theory and Political Action in Karl Mannheim's Thought: Reflections uponIdeology and Utopiaand Its Critics

As a work of political theory,Ideology and Utopiahas satisfied almost no one. Mannheim's critics extend across a wide range of viewpoints, from Parsons, Merton, Bendix, Popper, and Shils on one side to Marcuse, Hork-heimer, Lukacs, and Adorno on the other. Neither Marxists nor non-Marxists have found much to their liking in the book, and the rather easy dismissal of Mannheim's arguments by such influential thinkers on both sides of the political spectrum has certainly constituted a major obstacle to any serious consideration of the position he developed inIdeology and Utopia. For, I shall argue, the arguments contained in that work, when they have not been neglected altogether, have been poorly understood by those individuals whose writings exercise a dominant influence upon the thinking of contemporary social scientists.