摘要:

AbstractThis article is a study of problems of contraction and cohesion in the Order of the Servants of Mary. Focusing on the history of the Order since the Second Vatican Council (1962‐1965), it seeks to uncover the dynamics that underlie these problems and to recommend broad directions for future policy. The logical level of the policy recommendations conforms with that of the analysis, which concentrates on a few highly aggregated driving force

ISSN:0883-7066    

DOI:10.1002/sdr.4260070102

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractA model of safety and of the impact of the Occupational Safety and Health Administration (OSHA) on safety in industrial firms is described in this article. The model incorporates safety feedback processes in U.S. manufacturing firms, including the relations between safety programs, safety equipment, and accidents. Monte Carlo‐like simulations were produced, with 1,000 firms simulated sequentially. The firms were distributed among the 20 standard industrial sectors and the five size categories that comprise the manufacturing industry. Each firm's safety behavior was simulated for a four‐year period, and each firm was inspected once by OSHA. Injury rates across all firms were measured to determine if OSHA's actions had a measurable effect upon safety in firms. The model captures important underlying assumptions regarding safety regulation that have typically been excluded from evaluations of the impact of safety regulation in the United States. These assumptions may in fact be central to understanding the relations between intervent

ISSN:0883-7066    

DOI:10.1002/sdr.4260070103

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractCombining mathematical analysis with simulations, we obtain a bifurcation diagram for a simple (two state variables) system dynamics model of the economic long wave. Previous linear analysis of the onset of oscillatory behavior (Hopf bifurcation) is extended to include nonlinear effects. It is shown that both sub‐ and supercritical Hopf bifurcation can occur. In the case of subcritical Hopf bifurcation, the system has two coexisting stable solutions, one stationary and one periodic, in a parameter interval below the bifurcation point. The importance of distinguishing between the two types of Hopf bifurcation is discussed. The model also exhibits homoclinic bifurcation to infinity for some parameter combinations: a limit cycle explodes and disappears. Finally, we discuss how the results may apply to other system dynamics model

ISSN:0883-7066    

DOI:10.1002/sdr.4260070104

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractNotes and Insightsis a forum for discussion and debate about current issues in the philosophy and application of the system dynamics approach, and a marketplace for the exchange of information about current research, policy issues, and teaching experiences. Manuscripts treating material particularly suited to presentation in short form (less than 2,000 words) should be sent to Erich Zahn, Betriebswirtschaft‐liches Institut, Abt. IV, Universität Stuttgart, Keplerstr. 17, D‐7000 Stuttgart 1, Ger

ISSN:0883-7066    

DOI:10.1002/sdr.4260070105

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

摘要:

AbstractFounded in the mid‐1950s, the field of system dynamics has intellectual roots reaching much further into the past. The Archives section of theReviewseeks to publish material from that past which can contribute to current theory and practice. The section welcomes previously unpublished but deserving system dynamics work, classics from past system dynamics literature that should receive renewed attention, and previously published articles from other disciplines of particular significance to current system dynamicists. Contributions emphasizing the philosophy and theory of model building, validation, implementation, education, and generic structures are particularly encouraged. Submissions may range in length from notes to main articles but may be edited. Send suggested material, together with a brief introduction placing it in historical and current contexts, to John D. Sterman, System Dynamics Group. MIT E40‐294, Cambridge, MA 02139, U.

ISSN:0883-7066    

DOI:10.1002/sdr.4260070106

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0883-7066    

DOI:10.1002/sdr.4260070108

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0883-7066    

DOI:10.1002/sdr.4260070109

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY

ISSN:0883-7066    

DOI:10.1002/sdr.4260070101

出版商:John Wiley&Sons, Ltd.    

年代:1991

数据来源: WILEY