Theory Of Active Systems Research Articles

Active RF pulse compression using an electrically controlled semiconductor switch

First we review the theory of active pulse compression systems using resonant delay lines. Then we describe the design of an electrically controlled semiconductor active switch. The switch comprises an active window and an overmoded waveguide three-port network. The active window is based on a four-inch silicon wafer which has 960 PIN diodes. These are spatially combined in an overmoded waveguide. We describe the philosophy and design methodology for the three-port network and the active window. We then present the results of using this device to compress 11.4 GHz RF signals with high compression ratios. We show how the system can be used with amplifier-like sources, in which one can change the phase of the source by manipulating the input to the source. We also show how the active switch can be used to compress a pulse from an oscillator-like source, which is not possible with passive pulse compression systems.

A sustainable platform for e-service system design

By integrating system thinking and social psychology, this paper presents an Activity System Theory (AST) approach to the platform design of e-service systems in general, and e-healthcare systems in specific. In the first part, some important principles of AST and a sustainable model of human activity system are introduced. Then a project ‘Integrated Mobile Information System for Healthcare (IMIS)’ is presented to demonstrate how to construct a comprehensive platform for various complex e-service systems based on the sustainable model of AST. Our research focused on the complex e-healthcare system in Sweden, and the results showed that the model of AST can provide the designers of e-service system with a comprehensive and sustainable platform for designing various kinds of e-service systems.

The Collaborative Construction of a Management Report in a Municipal Community of Practice

Drawing on rhetorical genre studies and recent work in activity system theory, this study focuses on the collaborative development of a new written form, a municipal plan for protecting and managing natural areas. The author advances a twofold claim: (a) that the written plan is developed in the absence of a stable textual model and (b) that the text, as part of the context, functions, in turn, as a mediational tool for solving the rhetorical problem of audience resistance. Findings show that as participants reconfigure the project into successive cycles of activity, they create corresponding zones of proximal development. This study contributes to our understanding of the dynamics of the text-context relationship and to recent elaborations of genre as an activity system that help explain the relationship between genre and learning.

Capturing dissonance in university teacher education environments

In response to policy developments in higher education in the UK, the Institute for Learning and Teaching in Higher Education (ILTHE—now merged in the Higher Education Academy) was established in 1999 to provide a national framework for teaching and learning at tertiary level. This article considers the training environment of novice lecturers within the ILTHE framework and identifies areas of tensions within it. Activity systems theory is used as a broad framework for apprehending this environment. Praxis‐related, epistemological, structural and ideological dissonances are identified. Suggestions to advance change in this area are formulated in the light of the main findings. The limitations afforded by the activity systems approach are also discussed.

Coming to Know in Higher Education: Theorising faculty entry to new work contexts

This research contributes to practice in the induction of faculty staff entering new work contexts and identifies theories that are worth further testing. Lightly structured interviews with 24 new entrants to the academic profession were complemented by re-analysis of transcripts from another interview study with 50 faculty members and by appraisal of data from three North American studies. The account of the processes of socialisation into academic life that was developed from repeated analysis of these data sets leads to some propositions about better induction. As the emerging account was repeatedly tested by appraising it for goodness of fit with the data, it was found that activity system theory and the idea of communities of practice contributed to a fuller and more coherent position. Consequently, it is argued that there is value in treating these two notions as heuristics that can evoke fresh understandings of higher education practices.

Statistical theory of active radar systems for remote probing of natural environment

Optimal algorithms for obtaining radar images of the Earth's surface by means of active remote probing are determined on the basis of the theory of statistical solutions.

Stimulation and decision-making in the active system theory: Review of problems and new results

The recent two decades witnessed intensive research in the area of organizational (socio-economic) mechanisms. Foreign researchers concentrated mostly on collective decision-making and contract theories. In the former USSR these problems were considered within the informational theory of hierarchical systems and the theory of active systems that are, basically, a unique area studying active human behavior in organizational systems. By activity we mean the human ability of choosing purposefully actions (states), manipulating data (conscientious representation of doubtful information for making preferential decisions) and, finally, foresight in decision-making.

Discrete problems of coordinating planning

The problem of control mechanism optimal synthesis in the theory of active systems consists in the choice of a stimulation system and planning procedure which provide maximum of the Centre goal function under the condition that active elements are maximizing their goal functions 1.The paper presents the obtained conditions and in the course of their fulfilment the optimal solution exists in the class of coordinated control mechanisms. Under these conditions fulfilment of the plans becomes profitable for the elements. The generalized notion of coordinated mechanisms is provided in the case of active elements probabilistic models.

Active Systems Theory and Organizational Mechanisms Design

The paper considers the problem of designing the organizationnal mechanisms. It has been proved that the theory of active systems can be the theoretical basis of developing the computer-aided systems of designing the organizational mechanisms. The main notions of the theory of well as base organizational mechanisms and their features are considered. The state-of-the-art of investigations in this field in the USSR is described.

Development of Expert-modelling System for Computer-aided Design of Organizational Mechanism

Organizational mechanisms analysis and synthesis methods, developed in the active systems theory, make it possible to form the organizational mechanisms with the assigned features. The paper consi-ders the approaches to construction of an organizational mechanisms computer-aided design system (OMCAD). It presents the description of the system components, and determines the ways of the system development. A special attention is paid to human participation in this system as well as to the role of expert in system design and possibility of using his knowledge.

Regular Functioning Mechanisms of Organizational Systems

The paper reports the findings of latest investigations in theory of active systems. It is concerned with design of optimal functioning mechanisms such as planning procedures and incentive systems for one of basic models in theory of organizational systems, a two level system where the Center is fully informed on models of elements. Extensions to the case of dependent elements are studied.