Multidisciplinary Design Optimization with Quasiseparable Subsystems

Numerous hierarchical and nonhierarchical decomposition strategies for the optimization of large scale systems, comprised of interacting subsystems, have been proposed. With a few exceptions, all of these strategies lack a rigorous theoretical justification. This paper focuses on a class of quasiseparable optimization problems narrow enough for a rigorous decomposition theory, yet general enough to encompass many large scale engineering design problems. The subsystems for these problems involve local design variables and global system variables, but no variables from other subsystems. The objective function is a sum of a global system criterion and the subsystems' criteria. The essential idea is to give each subsystem a budget and global system variable values, and then ask the subsystems to independently maximize their constraint margins. Using these constraint margins, a system optimization then adjusts the values of the system variables and subsystem budgets. The subsystem margin problems are totally independent, always feasible, and could even be done asynchronously in a parallel computing context. An important detail is that the subsystem tasks, in practice, would be to construct response surface approximations to the constraint margin functions, and the system level optimization would use these margin surrogate functions. The purpose of the present paper is to present a decomposition strategy in a general context, provide rigorous theory justifying the decomposition, and give some simple illustrative examples.     

Posture, locomotion, spatial orientation, and motion sickness as a function of space flight

This article summarizes a variety of newly published findings obtained by the Neuroscience Laboratory, Johnson Space Center, and attempts to place this work within a historical framework of previous results on posture, locomotion, motion sickness, and perceptual responses that have been observed in conjunction with space flight. In this context, we have taken the view that correct transduction and integration of signals from all sensory systems is essential to maintaining stable vision, postural and locomotor control, and eye-hand coordination as components of spatial orientation. The plasticity of the human central nervous system allows individuals to adapt to altered stimulus conditions encountered in a microgravity environment. However, until some level of adaptation is achieved, astronauts and cosmonauts often experience space motion sickness, disturbances in motion control and eye-hand coordination, unstable vision, and illusory motion of the self, the visual scene, or both. Many of the same types of disturbances encountered in space flight reappear immediately after crew members return to earth. The magnitude of these neurosensory, sensory-motor and perceptual disturbances, and the time needed to recover from them, tend to vary as a function of mission duration and the space travelers prior experience with the stimulus rearrangement of space flight. To adequately chart the development of neurosensory changes associated with space flight, we recommend development of enhanced eye movement systems and body position measurement. We also advocate the use of a human small radius centrifuge as both a research tool and as a means of providing on-orbit countermeasures that will lessen the impact of living for long periods of time with out exposure to altering gravito-inertial forces.     

Innovations in disaster mental health: Psychological first aid.

Professional psychologists are called upon to deal with a broad array of crises and traumatic events. However, training and expertise in crisis response varies widely among practitioners, and there has been considerable controversy about the value of widely disseminated mental health crisis intervention protocols that include "debriefing" as an essential feature. This article gives an overview of the developmental process, guiding principles, and core actions of the Psychological First Aid Field Operations Guide (PFA Guide), which provides guidance for practitioners in responding to immediate mental health needs of children, adults, and families who have recently experienced a disaster or terrorist event. Issues in training, provider self-care, and evaluation research are also presented. The PFA Guide presents approaches thought to be most consistently supported by current research and practice so that they can be taught, used, and evaluated in field settings. Although we expect further refinement as more systematic research becomes available, the PFA Guide represents a sustained collaborative effort to define current evidence-informed best practices that can be utilized now by practitioners involved in disaster mental health responses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender and conflict structure in marital interaction: A replication and extension.

29 married couples engaged in 2 videotaped discussions: 1 in which the husband requested a change in the wife and 1 in which the wife requested a change in the husband. Conflict behavior was assessed by self-report and observer ratings. Neither conflict structure (who requested the change) nor gender was associated with the positivity or negativity of spouses' behavior. During discussions of husbands' issues, wives and husbands did not differ in demand/withdraw behavior, whereas when discussing wives' issues, wives were more demanding and husbands were more withdrawing. Husband-demand/wife-withdraw interaction predicted an increase in wives' satisfaction 1 yr later, whereas wife-demand/husband-withdraw interaction predicted a decline in wives' satisfaction 1 yr later. These results replicate and extend those of an earlier study (A. Christensen and C. L. Heavey; see record 1991-01045-001). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long term preservation of scientific data: Lessons from jet and other domains

All fusion devices generate large amounts of data, which must remain accessible throughout and beyond the lifetime of the device. This need for long-term data preservation creates major software and hardware challenges. Issues surrounding long-term data preservation will be discussed, and the main challenges in data curation will be outlined. The paper will then review the approaches taken at JET to ensure accessibility of all of JET's data over almost three decades. Using the JET experience and the wider context, the paper will then suggest how new experiments should plan for the long-term preservation of their data.     

Mass customized testing and manufacturing via the Internet

This paper sets forth a global scheme for creating Internet-accessible machines that perform a variety of digital-physical operations in a highly flexible manner. The scheme integrates existing capabilities and technologies from a number of areas - laboratory science, automation and robotics, interconnect standards, object-oriented languages, relational databases, shipping services, and Internet providers. For scientific and medical research applications, the batch science machines described herein would serve as programmable laboratory technicians, perform the work of hundreds of humans, and help investigators tackle “big” problems. For consumer-related applications, the batch manufacturing machines described herein would allow individuals to design, order, and purchase many types of customized product at the touch of a button.     

Multiobjective optimization using an adaptive weighting scheme

A new Pareto front approximation method is proposed for multiobjective optimization problems (MOPs) with bound constraints. The method employs a hybrid optimization approach using two derivative-free direct search techniques, and intends to solve black box simulation-based MOPs where the analytical form of the objectives is not known and/or the evaluation of the objective function(s) is very expensive. A new adaptive weighting scheme is proposed to convert a multiobjective optimization problem to a single objective optimization problem. Another contribution of this paper is the generalization of the star discrepancy-based performance measure for problems with more than two objectives. The method is evaluated using five test problems from the literature, and a realistic engineering problem. Results show that the method achieves an arbitrarily close approximation to the Pareto front with a good collection of well-distributed nondominated points for all six test problems.     

Parallel algorithms and architectures report of a workshop

This is an unreviewed contribution. It is a report of the workshop conducted for the Supercomputing Research Center by the University of Maryland Institute for Advanced Computer Studies during July and August 1985. The advice in this report was originally directed specifically at the SRC. Changes have been made to the original report to rephrase this advice, where appropriate, so that it is generic. Despite the passage of time, it is our judgment that the contents of this report remain timely.     

Relationship of self-management to personality types and indices

This study addressed the relationship between self-management (as measured by the Lifestyle Approaches Inventory, Williams, Moore, Pettibone, & Thomas, 1992) and personality types and indexes (as measured by the Myers-Briggs Type Indicator, Myers & McCaulley, 1985) in a sample of 347 university students. Correlational analyses indicated that the self-management factor most consistently linked to the Myers-Briggs indices was Organization of Physical Space. The Myers-Briggs index most consistently correlated with the self-management factors was Judgment-Perception. Overall, male and female subjects showed similar patterns of relationships between the self-management and personality indices. When the self-management scores were compared for the various Myers-Briggs types, the analysis indicated that types having a J (planful and organized) or S (precise and practical) in the typology tended to score higher than those having a P (spontaneous and flexible) or N (imaginative and insightful).