High level methods for scene exploration

Virtual worlds exploration techniques are used in a wide variety of domains — from graph drawing to robot motion. This paper is dedicated to virtual world exploration techniques which have to help a human being to understand a 3D scene. An improved method of viewpoint quality estimation is presented in the paper, together with a new off-line method for automatic 3D scene exploration, based on a virtual camera. The automatic exploration method is working in two steps. In the first step, a set of “good” viewpoints is computed. The second step uses this set of points of view to compute a camera path around the scene. Finally, we define a notion of semantic distance between objects of the scene to improve the approach.

Lag Camera: A Moving Multi-Camera Array for Scene-Acquisition

Many applications, such as telepresence, virtual reality, and interactive walkthroughs, require a three-dimensional(3D)model of real-world environments. Methods, such as lightfields, geometric reconstruction and computer vision use cameras to acquire visual samples of the environment and construct a model. Unfortunately, obtaining models of real-world locations is a challenging task. In particular, important environments are often actively in use, containing moving objects, such as people entering and leaving the scene. The methods previously listed have difficulty in capturing the color and structure of the environment while in the presence of moving and temporary occluders. We describe a class of cameras called lag cameras. The main concept is to generalize a camera to take samples over space and time. Such a camera, can easily and interactively detect moving objects while continuously moving through the environment. Moreover, since both the lag camera and occluder are moving, the scene behind the occluder is captured by the lag camera even from viewpoints where the occluder lies in between the lag camera and the hidden scene. We demonstrate an implementation of a lag camera, complete with analysis and captured environments.

Explaining the Long-Term Trend in Violent Crime: A Heuristic Scheme and Some Methodological Considerations

There has been a discontinuous but fairly persistent long-term decline in homicide rates in core European countries since about 1500. Since the 1950s, however, we observe an upward trend in violent crime not only in Europe but in almost all of the economically advanced nations that combine democratic political structures with free-market economies. The paper presents an explanatory scheme designed to account for both, the long decline and its apparent reversal. The theoretical model draws heavily upon ideas taken from the sociological work of Emile Durkheim and Norbert Elias—with some modifications and extensions. It seeks to integrate sociological and historical perspectives and to give due weight to both, structural and developmental forces. A key hypothesis is that the pacifying effects of the erosion of traditional collectivism can only be maintained to the extent by which “cooperative individualism” dominates over against the forces of “disintegrative individualism.” Some suggestions are made concerning the selection of appropriate indicators and the handling of methodological problems related to causal attribution.

Hating the neighbors: The role of hate crime in the perpetuation of black residential segregation

Grounded in group conflict theory and the defended neighborhoods thesis, this nationwide empirical study of cities and their residential segregation levels, examines the occurrence of hate crime using data on for all U.S. cities with populations over 95,000, and data compiled from the Uniform Crime Report for hate crime, in conjunction with 2000 census data. Hate crime is any illegal act motivated by pre-formed bias against, in this case, a person’s real or perceived race. This research asks: Do hate crime levels predict white/black segregation levels? How does hate crime predict different measures of white/black segregation? I use the dissimilarity index measure of segregation operationalized as a continuous, binary and ordinal variable, to explore whether hate crime predicts segregation of blacks from whites. In cities with higher rates of hate crime there was higher dissimilarity between whites and blacks, controlling for other factors. The segregation level was more likely to be “high” in a city where hate crime occurred. Blacks are continually multiply disadvantaged and distinctly affected by hate crime and residential segregation. Prior studies of residential segregation have focused almost exclusively on individual choice, residents’ lack of finances, or discriminatory actions that prevent racial minorities from moving, to explore the correlates of segregation. Notably absent from these studies are measures reflecting the level of hate crime occurring in cities. This study demonstrates the importance of considering hate crime and neighborhood conflict when contemplating the causes of residential segregation.

Anomic Crime in Post-Welfarist Societies. Cult of the Individual, Integration Patterns and Delinquency

Post-Fordist economies come along with post-welfarist societies marked by intensified cultural individualism and increased structural inequalities. These conditions are commonly held to be conducive to relative deprivation and, thereby, anomic crime. At the same time, post-welfarist societies develop a new ‘balance of power’ between institutions providing for welfare regulation, such as the family, the state and the (labour) market – and also the penal system. These institutions are generally expected to improve social integration, ensure conformity and thus reduce anomic crime. Combining both perspectives, we analyse the effects of moral individualism, social inequality, and different integration strategies on crime rates in contemporary societies through the lenses of anomie theory. To test our hypotheses, we draw on time-series cross-section data compiled from different data sources (OECD, UN, WHO, WDI) for twenty developed countries in the period 1970-2004, and run multiple regressions that control for country-specific effects. Although we find some evidence that the mismatch between cultural ideal (individual inclusion) and structural reality (stratified exclusion) increases the anomic pressure, whereas conservative (i. e. family-based), social-democratic (i. e. state-based) and liberal (i. e. market-based) integration strategies to a certain extent prove effective in controlling the incidence of crime, the results are not very robust. Moreover, reservations have to be made regarding the effects of “market” income inequality as well as familialist, unionist and liberalist employment policies that are shown to have reversed effects in our sample: the former reducing, the latter occasionally increasing anomic crime. As expected, the mismatch between cultural ideal (individual inclusion) and structural reality (stratified exclusion) increases the anomic pressure, whereas conservative (i. e. family-based), social-democratic (i. e. state-based) and liberal (i. e. market-based) integration strategies generally prove effective in controlling the incidence of crime. Nevertheless, we conclude that the new cult of the individual undermines the effectiveness of conservative and social-democratic integration strategies and drives societies towards more “liberal” regimes that build on incentive as well as punitive elements.

Institutions, Anomie, and Violent Crime: Clarifying and Elaborating Institutional-Anomie Theory

A limited but accumulating body of research and theoretical commentary offers support for core claims of the “institutional-anomie theory” of crime (IAT) and points to areas needing further development. In this paper, which focuses on violent crime, we clarify the concept of social institutions, elaborate the cultural component of IAT, derive implications for individual behavior, summarize empirical applications, and propose directions for future research. Drawing on Talcott Parsons, we distinguish the “subjective” and “objective” dimensions of institutional dynamics and discuss their interrelationship. We elaborate on the theory’s cultural component with reference to Durkheim’s distinction between “moral” and “egoistic” individualism and propose that a version of the egoistic type characterizes societies in which the economy dominates the institutional structure, anomie is rampant, and levels of violent crime are high. We also offer a heuristic model of IAT that integrates macro- and individual levels of analysis. Finally, we discuss briefly issues for the further theoretical elaboration of this macro-social perspective on violent crime. Specifically, we call attention to the important tasks of explaining the emergence of economic dominance in the institutional balance of power and of formulating an institutional account for distinctive punishment practices, such as the advent of mass incarceration in the United States.

Violence, Crime, and Violent Crime

I propose a dual conceptualization of violent crime. Since violent crime is both violence and crime, theories of aggression and deviance are required to understand it. I argue that both harm-doing and rule breaking are instrumental behaviors and that a bounded rational choice approach can account for both behaviors. However, while some of the causes of harm-doing and deviance (and violent and nonviolent crime) are the same, some are different. Theories of crime and deviance cannot explain why one only observes individual and group differences in violent crime and theories of aggression and violence cannot explain why one observes differences in all types of crimes. Such theories are “barking up the wrong tree.”