Evaluating holonic control systems: A case study

in the last 10 years many designs and trial implementations of holonic manufacturing systems have been reported in the literature. Few of these have resulted in any industrial take up of the approach and part of this lack of adoption might be attributed to a shortage of evaluations of the resulting designs and implementations and their comparison with more conventional approaches. This paper proposes a simple approach for evaluating the effectiveness of a holonic system design, with particular focus on the ability of the system to support reconfiguration (in the face of change). A case study relating to a laboratory assembly system is provided to demonstrate the evaluation approach. Copyright © 2005 IFAC.

Auto ID based control systems - An overview

This paper will provide a rationale for developing control systems based on the availability of automated identification (Auto ID) information provision. Much of the Auto-ID research has to date focussed on developing the essential infrastructure for dynamically extracting, networking and storing product data. These developments will help to revolutionise the accuracy, quality and timeliness of data acquired by Business Information Systems and should lead to major cost savings and performance improvements as a result. This paper introduces an additional phase of Auto ID research and development in which the nature of control system decisions is reconsidered in the light of the availability of ubiquitous, unique, item-level information. The paper will: (i) Indicate why the availability of ubiquitous, unique, item-level data can enable enhanced and fundamentally different control approaches and highlight potential benefits from control systems incorporating this Auto ID data (ii) Demonstrate what is required to develop control systems based around the availability of Auto ID data. (iii) Outline the research challenges in determining how such systems will be developed.

MULTIPLE PERIODIC SOLUTIONS OF ASYMPTOTICALLY LINEAR HAMILTONIAN SYSTEMS VIA CONLEY INDEX THEORY

In this paper we study the existence of periodic solutions of asymptotically linear Hamiltonian systems which may not satisfy the Palais-Smale condition. By using the Conley index theory and the Galerkin approximation methods, we establish the existence of at least two nontrivial periodic solutions for the corresponding systems.

The meaning of environmental control systems (ECS) for people with spinal cord injury: An occupational therapist explores an intervention

Environmental Control Systems (ECS), enable people with high cervical Spinal Cord Injury (high SCI) to control and access everyday electronic devices. In Ireland, however, access for those who might benefit from ECS is limited. This study used a qualitative approach to explore the insider experience of an ECS starter-pack developed by the author, an occupational therapist. The primary research questions: what is it really like to live with ECS, and what does it mean to live with ECS, were explored using a phenomenological methodology conducted in three phases. In Phase 1 fifteen people with high SCI met twice in four focus groups to discuss experiences and expectations of ECS. Thematic analysis (Krueger & Casey, 2000), influenced by the psychological phenomenological approach (Creswell, 1998), yielded three categories of rich, practical, phenomenological findings: ECS Usage and utility; ECS Expectations and The meaning of living with ECS. Phase 1 findings informed Phase 2 which consisted of the development of a generic electronic assistive technology pack (GrEAT) that included commercially available constituents as well as short instructional videos and an information booklet. This second phase culminated in a one-person, three-week pilot trial. Phase 3 involved a six person, 8-week trial of the GrEAT, followed by individual in-depth interviews. Interpretative Phenomenological Analysis IPA (Smith, Larkin & Flowers, 2009), aided by computer software ATLAS.ti and iMindmap, guided data analysis and identification of themes. Getting used to ECS, experienced as both a hassle and engaging, resulted in participants being able to Take back a little of what you have lost, which involved both feeling enabled and reclaiming a little doing. The findings of this study provide substantial insights into what it is like to live with ECS and the meanings attributed to that experience. Several practical, real world implications are discussed.

Sequentially continuous non-linear fundamental systems of solutions of affine equations in locally convex spaces

According to the Mickael's selection theorem any surjective continuous linear operator from one Fr\'echet space onto another has a continuous (not necessarily linear) right inverse. Using this theorem Herzog and Lemmert proved that if $E$ is a Fr\'echet space and $T:E\to E$ is a continuous linear operator such that the Cauchy problem $\dot x=Tx$, $x(0)=x_0$ is solvable in $[0,1]$ for any $x_0\in E$, then for any $f\in C([0,1],E)$, there exists a continuos map $S:[0,1]\times E\to E$, $(t,x)\mapsto S_tx$ such that for any $x_0\in E$, the function $x(t)=S_tx_0$ is a solution of the Cauchy problem $\dot x(t)=Tx(t)+f(t)$, $x(0)=x_0$ (they call $S$ a fundamental system of solutions of the equation $\dot x=Tx+f$). We prove the same theorem, replacing "continuous" by "sequentially continuous" for locally convex spaces from a class which contains strict inductive limits of Fr\'echet spaces and strong duals of Fr\'echet--Schwarz spaces and is closed with respect to finite products and sequentially closed subspaces. The key-point of the proof is an extension of the theorem on existence of a sequentially continuous right inverse of any surjective sequentially continuous linear operator to some class of non-metrizable locally convex spaces.