Single System Design Research Articles

Single-System Design Use of Behavior Therapists:

The feasibility of adopting the use of single-system designs for evaluating practice has become an important topic in the field of social work. This study addresses this issue by examining the extent to which behavior therapists, who espouse empirical methods as part of their practice, use various single-system designs in their practice. In addition, the study examined what practitioner characteristics influence single-system design use. Result revealed that practitioners are not making much use of inferential single-system designs but do use the more flexible evaluative designs (such as B only or AB). The results of this study suggest that social work educators should spend more time teaching evaluative designs and not overemphasize single-system designs that are unlikely to be used in practice.

The Use of Single-System Design with Systemic Brief Problem-Solving Therapy

The authors argue that there is a “goodness of fit” between brief problem-solving systemic therapy and the evaluation procedures of experimental single-system design. The model and the evaluation procedures are summarized. A case example illustrates the integration of single-system evaluation with the therapeutic process.

The Programmable Implantable Medication System (PIMS): Design Features and Pre-Clinical Trials

This report describes the clinically significant design features of a variable rate implantable insulin infusion pump, the Programmable Implantable Medication System (PIMS), and its function in pre-clinical trials. PIMS has a number of unique features, including a solenoid, pulsatile pump design requiring minimal power (less than 15 microwatts) and a less-than-atmospheric pressure reservoir. Two-way communication is accomplished by radiotelemetry. The implanted device stores programs, and records its own hourly history of insulin delivery. Limits are set on total insulin delivery over time. Basal rates are adjustable, and patterned prandial insulin delivery curves can be programmed. Initial trials (3.1 dog-years) identified four problems which were corrected prior to final pre-clinical trials: microcracks in the diaphragm, a valve-seating leak, electronic failure of prototype microchips, and insulin aggregation. Sixteen dog-years of final pre-clinical trials with a single system design demonstrated that 5 pumps were still working continuously after up to 3.75 years (mean 3.3 years) without mechanical or electronic pump failure. The longest interval between reservoir refills was 5 months. Remaining potential causes of flow stoppage, however, include blockage of the peritoneal catheter by omentum (which occurred once), and air lock (which occurred two times).

Clinical Evaluation and Research in Occupational Therapy: Single System Designs

In this paper the authors present single system designs as a framework for the collecting, organising and analysing of information to evaluate programme impact. The steps involved in evaluation and research using single system designs are discussed and advantages and disadvantages of the design for occupational therapists are briefly presented. The authors conclude that single system designs are suitable for occupational therapists to use in research and clinical evaluation because of their flexibility and their emphasis on clinical significance.

Integrating Research and Practice in Social Work with Groups

The gap between research and practice in social work with groups is currently large. Yet the call for account- ability and the requirements for curriculum content integrating research and practice has increased. This article promotes three avenues through which to build the bridge between prac- tice and research in social work with groups, especially among students. These are: 1 identifying the use of empirical pro- cess in all practice; ( 1 2 building instrumentation into group work practice; and (3) usin single system designs for evaluat- ing group work practice. W a en workers learn to operationalize infefventive hypotheses, measure the outcome, process, and leadership variables involved in these hv~otheses, and analyze data coniistent with single system desii4, a major step wilibe advanced toward integrating research and practice in social work with groups.

Improved Time Domain Robustness Criteria for Multivariable Control Systems

Abstract This paper considers the problem of time domain robust stability analysis of multivariable control systems. New tests for robust stability are developed which are applicable in multivariable as well as single input single output system designs. Bounds on nonlinear and linear perturbations in the system dynamics are established such that system stability is assured. An aircraft control example is presented which illustrate the usefulness of the proposed stability robustness criteria.

Nomothetic and Idiographic Strategies for Clinical Research: In Apposition or Opposition?

The use of large-N group comparison research strategies based on a nomothetic model is compared and contrasted with idiographic methods employing single-system designs and advocating the intensive study of the individual The limitations of research design and analysis based on a nomothetic model are reviewed, and some corresponding advantages of the idiographic approach are presented A bias has existed in the generation of empirical knowledge in the behavioral and social sciences which favored the use of large-N group comparison designs This bias may result in a research literature with limited clinical relevance for the individual client or consumer of occupational therapy services. The argument is made that both nomothetic and idiographic approaches represent valid methods of establishing the effectiveness of therapeutic interventions. The implications for occupational therapy practice and research are briefly discussed.

Single System Designs for Preventive Practitioners

This paper provides an introduction to the problems and potentials for using single system designs in preventive social work, which usually involves a longitudinal design and some special assumptions not found in the more common short-term uses of this design. Historical introductions and connections between social work practice and single system designs are provided.

On the modal control of distributed systems with distributed feedback

This paper presents a solution to the problem of the control of a class of linear distributed systems. The system is described by a linear operator acting on functions of time and distance. It is shown that if the operator separates in time and distance and the distance operator has a real discrete spectrum (self-adjoint and completely continuous), the operator can be represented by an infinite diagonal matrix in which the entries are functions of the Laplace transform variable <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</tex> . In particular, if the problem stems from separable partial differential equations, the entries are rational ratios of polynomials of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">s</tex> . The system can be compensated with a series of discrete conventional filters using techniques of conventional lumped, single loop control system design. To implement the control system, the assumption is made that the distance dependent part of the output and forcing functions have negligible eigenfunction content beyond the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</tex> th one. If this assumption holds, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</tex> sensors, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</tex> filters, and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</tex> manipulators, plus 2 matrix multipliers and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</tex> subtractors provide a synthesis of the feedback control system. An illustrative numerical example is given.