Modeling Scientists as Agents. How Scientists Cope with the Challenges of the New Public Management of Science

The paper at hand applies agent-based modeling and simulations (ABMS) as a tool to reconstruct and to analyze how the science system works. A Luhmannian systems perspective is combined with a model of decision making of individual actors. Additionally, changes in the socio-political context of science, such as the introduction of „new public management\", are considered as factors affecting the functionality of the system as well as the decisions of individual scientists (e.g. where to publish their papers). Computer simulation helps to understand the complex interplay of developments at the macro (system) and the micro (actor) level.Systems Theory, Theory of Action and Decision Making, Academic Publication System, Science System, New Public Management, Agent-Based Modeling and Simulation

Steuerung komplexer Systeme - Ein Mehrebenen-Modell von Governance

Die Frage, ob sich komplexe Systeme steuern lassen, beschäftigt die Sozialwissenschaften seit geraumer Zeit. Der folgende Beitrag greift die steuerungstheoretische Debatte der 1980er Jahre wie auch den seit den 1990er Jahre andauernden Governance- Diskurs auf und entwickelt auf dieser Grundlage ein Mehrebenen Modell von Governance, das drei Dimensionen umfasst: die Abstimmungsprozesse in Verhandlungssystemen, die Regulierung funktioneller Teilsysteme sowie die operative Steuerung dieser Teilsysteme. In diesem Sinne steht der Begriff „Governance“ für eine spezifische Kombination der basalen Mechanismen Koordination und Steuerung in einem sozialen bzw. sozio-technischen System. Das Mehrebenen-Modell ermöglicht es, die unterschiedlichen Dimensionen von Governance getrennt in den Blick zu nehmen, aber auch die Interdependenzen zwischen den Ebenen zu analysieren. Bezogen auf komplexe Systeme, so die steuerungstheoretische Implikation unseres Governance-Begriffs, hat Governance immer das Kernproblem zu bewältigen, durch die Koordination von Akteuren sicherzustellen, dass gesteuert werden kann

Steuerung komplexer Systeme – Ergebnisse einer soziologischen Simulationsstudie

Die Frage, ob sich komplexe Systeme steuern lassen, beschäftigt die Sozialwissenschaften seit geraumer Zeit. Der folgende Beitrag bearbeitet das Thema „Steuerung komplexer Systeme“ mit Mitteln der experimentellen Soziologie, um auf diese Weise die Wirkung und die Leistungsfähigkeit unterschiedlicher Governance-Modi empirisch zu überprüfen. Zu diesem Zwecke wurde das Simulationsframework SUMO-S entwickelt, dessen soziologische Grundlagen das Modell soziologischer Erklärung (Esser) und das Modell der Frame-Selektion (Kroneberg) bilden. Die Performance von Governance wurde mittels dreier Makro-Indikatoren und zweier Mikro-Indikatoren vermessen. Überraschenderweise erreicht die zentrale Steuerung in der Regel bessere Werte als die dezentrale Koordination. Aber offenbar kommt es nicht allein auf den Governance- Modus an; denn es gibt einen – bislang wenig erforschten – Zusammenhang zwischen der Leistungsfähigkeit der Governance-Modi und der Zusammensetzung der Agentenpopulation

Acceleration of Diffusional Jumps of Interstitial Fe with Increasing Ge Concentration in Si1 − x Ge x Alloys Observed by Mössbauer Spectroscopy

Radioactive 57Mn isotopes have been implanted into Si1 − x Ge x crystals (x ≤ 0.1) at elevated temperatures for Mössbauer studies of the diffusion of interstitial 57Fe daughter atoms. The atomic jump frequency is found to increase upon Ge alloying. This is attributed to a lowering of the activation energy, i.e. the saddle point energy at hexagonal interstitial sites with Ge neighbour atom

A Large Solid Angle Study of Pion Absorption on He3

Measurements have been made of pi+ absorption on He3 at T_pi+ = 118, 162, and 239 MeV using the Large Acceptance Detector System (LADS). The nearly 4pi solid angle coverage of this detector minimizes uncertainties associated with extrapolations over unmeasured regions of phase space. The total absorption cross section is reported. In addition, the total cross section is divided into components in which only two or all three nucleons play a significant role in the process. These are the first direct measurements of the total and three nucleon absorption cross sections.Comment: 8 pages, LaTeX. 3 figures, anonymous ftp MITLNS.MIT.EDU, cd LADS. Submitted to PRL. PSI-PR-94-11 (Paul Scherrer Institute) and LNS 94-56 (MIT Lab. for Nucl. Sci.

Biogenic non-crystalline U (IV) revealed as major component in uranium ore deposits

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U (VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U (IV) generated through biologically mediated U (VI) reduction is the predominant U (IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (-1/458-89%) of U is bound as U (IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U (VI) represent only minor components. The uranium deposit exhibited mostly 238 U-enriched isotope signatures, consistent with largely biotic reduction of U (VI) to U (IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U (IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.University of Wyomin

Hints of (trans-Planckian) asymptotic freedom in semiclassical cosmology

We employ the semiclassical approximation to the Wheeler-DeWitt equation in the spatially flat de Sitter Universe to investigate the dynamics of a minimally coupled scalar field near the Planck scale. We find that, contrary to naive intuition, the effects of quantum gravitational fluctuations become negligible and the scalar field states asymptotically approach plane-waves at very early times. These states can then be used as initial conditions for the quantum states of matter to show that each mode essentially originated in the minimum energy vacuum. Although the full quantum dynamics cannot be solved exactly for the case at hand, our results can be considered as supporting the general idea of asymptotic safety in quantum gravity.Comment: 11 pages, 2 figures; replaced to match content of published versio