TL;DR: The develop-ment of a metric that predicts controller workload as afunction of air traffic characteristics in a volume of airspace is essential to the development of both air traffic management automation and air traffic procedures.
Abstract: The definition of a metric of air traffic controller workload based on air traffic characteristics is essential to the development of both air traffic management automation and air traffic procedures. Dynamic density is a proposed concept for a metric that includes both traffic density (a count of aircraft in a volume of airspace) and traffic complexity (a measure of the complexity of the air traffic in a volume of airspace). It was hypothesized that a metric that includes terms that capture air traffic complexity will be a better measure of air traffic controller workload than current measures based only on traffic density. A weighted linear dynamic density function was developed and validated operationally. The proposed dynamic density function includes a traffic density term and eight traffic complexity terms. A unit-weighted dynamic density function was able to account for an average of 22% of the variance in observed controller activity not accounted for by traffic density alone. A comparative analysis of unit weights, subjective weights, and regression weights for the terms in the dynamic density equation was conducted. The best predictor of controller activity was the dynamic density equation with regression-weighted complexity terms.
TL;DR: DurDurkheim as discussed by the authors argued that crime is necessary, it is bound up with the fundamental conditions of all social life, and that it is no longer possible to dispute the fact that law and morality vary from one social type to the next, nor that they change within the same type if the conditions of life are modified.
Abstract: For Smile Durkheim, crime and punishment were integral features of organized social life. He considered the study of crime and punishment essential to the sociological enterprise precisely because these "social facts" revealed the inner workings of society and the mechanism through which societies change. In The Rules of Sociological Method Durkheim argues (1938:70) that "crime is ... necessary, it is bound up with the fundamental conditions of all social life," and that "it is no longer possible . . to dispute the fact that law and morality vary from one social type to the next, nor that they change within the same type if the conditions of life are modified." Because he viewed law as a reflection of basic social arrangements, Durkheim grounded his theory of social change in an analysis of comparative legal types. He assumed (1933:68) that "since law reproduces the principal forms of social solidarity, we have only to classify the different types of law to find therefrom the different types of social solidarity which correspond to it." In his central theoretical work, The Division of Labor in Society (1933), Durkheim linked the changing nature of legal controls (repressive to restitutive) to transformations in the nature of social solidarity (mechanical to organic). Durkheim's assertion that repressive controls were dominant in simple societies and restitutive controls in complex societies has been criticized by sociologists and anthropologists alike (cf. Merton, 1934; Schwartz and Miller, 1964; Barnes, 1966; Diamond, 1971; Lukes, 1972; Dubow, 1974). Restitution clearly represents an important principle in many undifferentiated (mechanical) societies (cf. Malinowski, 1926; Kuper, 1965), and the decline of repressive sanctions has not been as general or systematic as Durkheim (1933: 152-168) implied. Although many questions
TL;DR: Kymlicka as mentioned in this paper has joined the ranks of those who perpetuate the Westphalian fantasy of a world of separate and politically equal nation-states and embrace nationalism as a progressive force at this moment of history.
TL;DR: The impact of population size, physical density, social density, and age of 600 communities on the extent of their industrial diversification was analyzed in this paper, and it was found that the combined influence of the independent variables fails to account for the bulk of the variation in industrial diversifications.
Abstract: The impact of population size, physical density, social density, and age of 600 communities upon the extent of their industrial diversification was analyzed. Hypotheses concerning each independent variable were generated from the theory of the development of the division of labor proposed by Durkheim and subsequently adopted by human ecologists. Regression analysis was employed to test the hypotheses. The standardized partial regression coefficients indicated that only social density exerts a significant impact upon industrial diversification. In addition, it was discovered that the combined influence of the independent variables fails to account for the bulk of the variation in industrial diversification. Factors which may be responsible for these results, as well as directions for future research, are presented and discussed. One of the areas in human ecology where the gap between theory and research is most apparent is in the study of the division of labor. Although the concept itself has received relatively extensive treatment at the theoretical level (Durkheim, 1933; Hawley, 1950; Simmel, 1959:52-62; Smith, 1963:3-17; Spencer, 1921; Stigler, 1951), attempts at operationalization have been rare (Gibbs and Martin, 1962:669). The few studies which have attempted to delineate empirical components of the "division of labor" (e.g., Olsen, 1968:703) generally employ ad hoc operational definitions whose utility is limited to the specific research problem under consideration. One exception to this trend is a series of studies by Gibbs and Martin (1962), Labovitz and Gibbs (1964), Gibbs and Browning (1966), and Browning and Gibbs (1971), endeavoring to measure the division of labor at the national or international level. Unfortunately, beyond these efforts virtually no work has been done to formulate an empirically based theory of functional differentiation. This article attempts to further the development of a grounded theory of the division of labor by testing a series of hypotheses derived from the conceptual scheme proposed by Durkheim (1933) and subsequently adopted by human ecologists. We are cognizant of the many difficulties involved in attempting to provide empirical linkage to the theoretical work of someone like Durkheim (Land, 1970:262; Merton, 1934). Because of the level of generality of Durkheim's explanation it is impossible to give attention to all possible meanings of all constructs and all their implications. What must be done is to extract a logically consistent piece from the more global scheme and empirically examine that statement. Perhaps Land (1970:262) best states the nature of this epistemological problem as well as a possible resolution: "The modern social theorist... can rarely claim to have captured the 'complete' meaning of a classic in his more rigorous restatements of classical social theory. At best, he can choose the goals of his formalization and attempt to show how the classic implies his restatement...." THEORETICAL STATEMENT While a variety of theorists have attempted to delineate the factors involved in the development of the division of labor, the explanation that is most generally accepted today was first proposed by Durkheim (1933) in 1893. Ac[ 176 ] * Paper presented at the annual meeting of the Southern Sociological Society, New Orleans, 1972. We are indebted to John Stoeckel and two unidentified readers for their helpful comments on an earlier version. This content downloaded from 207.46.13.101 on Thu, 21 Apr 2016 05:49:15 UTC All use subject to http://about.jstor.org/terms Division of Labor / 177 cording to this approach, functional heterogeneity is the consequence of increased physical and social density. With an increase in population size and social interaction, the struggle for existence becomes acute. This intensification of competition stimulates the development of the division of labor. For, with the rise of functional differentiation, homogeneity of demands upon the sustenance supply is minimized and competition is more or less resolved (Lampard, 1955:91; see also Simmel, 1959:53). In explaining the role of competition in stimulating the development of the division of labor, Durkheim drew many of his ideas from the work of Darwin (1958:84-86). Consequently, much of his presentation is exemplified through organic analogies (e.g., 1933: 266). From Durkheim's discussion, however, Hawlcy (1950:202-203) has outlined four general stages that competition follows in the formation of community structure: (1) the demand for sustenance exceeds the supply, (2) there is an increasing degree of homogeneity among competitors, (3) the weakest competitors are eliminated, and (4) organization occurs since competition differentiates and multiplies functions. Hawley's statement lays the groundwork for referring to one of Durkheim's (1933:262) major propositions: The division of labor develops, as there are more individuals in contact to . . . act and react upon one another . . . the division of labor is in direct ratio to moral or dynamic density . . . and, if it progresses in a continuous manner in the course of social development, it is because societies regularly become denser and more voluminous. That the general constellation of variables within which Durkheim worked is essentially the same as that employed by human ecologists (e.g., Hawley, 1950: 192-203; Park, 1936) has been demonstrated by Schnore (1958). In addition, this overlap extends to the more specific conception of the development of the division of labor since Durkheim's propositions have, for the most part, found uncritical acceptance within the theory of ecological organization (Gibbs and Martin, 1962:669). Independent Variables In his discussion of the development of the division of labor Durkheim (1933:262) delineates three major determining factors-population size, physical density, and social density. Because he sets his argument in an evolutionary perspective, a fourth factor-time-can also be said to possess causal implications. While the impact of these four variables has been frequently discussed (Coste, 1899:95-103; McKenzie, 1933:316; Spencer, 1921:471; Stigler, 1951:185; Thompson, 1965:147), it has not been empirically verified although several studies (Keyes, 1958; Marden, 1966; Rogers, 1957) have found a direct association between size and the number of different services or industries extant in a population. And in regard to size, Clemente and Sturgis (1971) discovered a moderate correlation between city population size and one dimension of industrial diversification. Although there has been little other empirical research in the area, on the basis of the theoretical explanations proposed by Durkheim and subsequent human ecologists the following general conceptual hypothesis can
TL;DR: This letter presents a density filter which takes advantage of the system dynamics to gradually improve its estimation and is scalable to the agents’ population, and the notion of input-to-state stability is used to prove that the performance of the suboptimal density filter remains close to the optimal one.
Abstract: Large-scale agent systems have foreseeable applications in the near future. Estimating their macroscopic density is critical for many density-based optimization and control tasks, such as sensor deployment and city traffic scheduling. In this letter, we study the problem of estimating their dynamically varying probability density, given the agents’ individual dynamics (which can be nonlinear and time-varying) and their states observed in real-time. The density evolution is shown to satisfy a linear partial differential equation uniquely determined by the agents’ dynamics. We present a density filter which takes advantage of the system dynamics to gradually improve its estimation and is scalable to the agents’ population. Specifically, we use kernel density estimators (KDE) to construct a noisy measurement and show that, when the agents’ population is large, the measurement noise is approximately “Gaussian”. With this important property, infinite-dimensional Kalman filters are used to design density filters. It turns out that the covariance of measurement noise depends on the true density. This state-dependence makes it necessary to approximate the covariance in the associated operator Riccati equation, rendering the density filter suboptimal. The notion of input-to-state stability is used to prove that the performance of the suboptimal density filter remains close to the optimal one. Simulation results suggest that the proposed density filter is able to quickly recognize the underlying modes of the unknown density and automatically ignore outliers, and is robust to different choices of kernel bandwidth of KDE.