Effects of a respite from work on burnout: Vacation relief and fade-out.

In a quasi-experiment designed to examine the relief from job stress and burnout afforded by a vacation respite, 76 clerks completed measures of job stress and burnout twice before a vacation, once during vacation, and twice after vacation. There was a decline in burnout during the vacation and a return to prevacation levels by the time of the second postvacation measure. Comparing the two prevacation measures indicated no anticipation effects. However the return to work showed gradual fade-out, as burnout returned part way toward its prevacation level by 3 days after the vacation and all the way by 3 weeks after the vacation. Women and those satisfied with their vacations experienced greater relief; however, both subsamples also experienced the quickest fade-out. The respite effect and its complete fade-out were detected among all subgroups analyzed. Burnout, relief, interpersonal stress crossover, and burnout climate at work are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Personal efficacy, external locus of control, and perceived contingency of parental reinforcement among depressed, paranoid, and normal subjects.

Hypothesized that different combinations of personal efficacy and outcome expectancies (i.e., locus of control) would characterize the thought structures of normal Ss and of psychiatric patients suffering from distinctly different disorders. 26 normal (mean age 30.1 yrs), 15 depressed, and 22 paranoid Ss (mean age of patients 34.5 yrs) completed scales that measured beliefs in personal efficacy, beliefs that outcomes are controlled either by chance or by powerful others, and perceived contingency of parental reinforcement. Findings show that normals judged themselves to be more efficacious than did psychiatric Ss, depressives expected outcomes to be controlled by chance, and paranoids expected outcomes to be under the control of powerful others. Among the normals, outcome expectancies were strongly associated with personal efficacy, but among the patients, these beliefs were unrelated. Depressives and paranoids equally reported more noncontingent parental reinforcement than did normals. Perceived contingency of parental reinforcement was predictive of outcome expectancies but not of personal efficacy. Data suggest that low personal efficacy may be a distinguishing characteristic of all psychiatric patients, whereas outcome expectancies may determine the specific nature of the psychiatric disorder. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sequential Dynamic Logic

We introduce a substructural propositional calculus of Sequential Dynamic Logic that subsumes a propositional part of dynamic predicate logic, and is shown to be expressively equivalent to propositional dynamic logic. Completeness of the calculus with respect to the intended relational semantics is established.     

Fuzzy Control of a Helio-Crane

In this paper we present a comparison of two fuzzy-control approaches that were developed for use on a non-linear single-input single-output (SISO) system. The first method is Fuzzy Model Reference Learning Control (FMRLC) with a modified adaptation mechanism that tunes the fuzzy inverse model. The basic idea of this method is based on shifting the output membership functions in the fuzzy controller and in the fuzzy inverse model. The second approach is a 2 degrees-of-freedom (2 DOF) control that is based on the Takagi-Sugeno fuzzy model. The T-S fuzzy model is obtained by identification of evolving fuzzy model and then used in the feed-forward and feedback parts of the controller. An error-model predictive-control approach is used for the design of the feedback loop. The controllers were compared on a non-linear second-order SISO system named the helio-crane. We compared the performance of the reference tracking in a simulation environment and on a real system. Both methods provided acceptable tracking performance during the simulation, but on the real system the 2 DOF FMPC gave better results than the FMRLC.     

Reactive automata

A reactive automaton has extra links whose role is to change the behaviour of the automaton. We show that these links do not increase the expressiveness of finite automata but that they can be used to reduce dramatically their state number both in the deterministic case and the non-deterministic case.Typical examples of regular expressions associated with deterministic automata of exponential size according to the length of the expression show that reactive links provide an alternative representation of total linear size for the language.     

Two-terminal routing games with unknown active players

We analyze 2-terminal routing games with linear cost functions and with unknown number of active players. We deal with both splittable and unsplittable models. We prove the existence and uniqueness of a symmetric safety-level equilibrium in such games and show that in many cases every player benefits from the common ignorance about the number of players. Furthermore, we prove new theorems on existence and uniqueness of equilibrium in 2-terminal convex routing games with complete information.     

Electronic structure and self-assembly of cross-linked semiconductor nanocrystal arrays

We studied the electronic level structure of assemblies of InAs quantum dots and CdSe nanorods cross-linked by 1,4-phenylenediamine molecules using scanning tunneling spectroscopy. We found that the bandgap in these arrays is reduced with respect to the corresponding ligand-capped nanocrystal arrays. In addition, a pronounced sub-gap spectral structure commonly appeared which can be attributed to unpassivated nanocrystal surface states or associated with linker-molecule-related levels. The exchange of the ligands by the linker molecules also affected the structural array properties. Most significantly, clusters of close-packed standing CdSe nanorods were formed.     

On the design of geosynthetic-reinforced walls

An important design aspect of a geosynthetic-reinforced wall is specifying the reinforcement length. A simple limit equilibrium analysis, which considers two possible extreme inclinations of a reinforcement's resistance force, shows that predictions based on the K_a-analysis may not be safe. Although rules of thumb to determine embedment length are sometimes superimposed on the K_a-analysis prediction in design, it is demonstrated that such ‘rules’ may not always be safe. Design charts for granular backfill illustrate the effects of the reinforcement's force inclination showing quantitatively that the horizontal inclination required slightly larger tensile resistance force, while underestimating the embedment length.     

From generative fit to generative capacity: exploring an emerging dimension of information systems design and task performance

Information systems (IS) research has been long concerned with improving task-related performance. The concept of fit is often used to explain how system design can improve performance and overall value. So far, the literature has focused mainly on performance evaluation criteria that are based on measures of task efficiency, accuracy, or productivity. However, nowadays, productivity gain is no longer the single evaluation criterion. In many instances, computer systems are expected to enhance our creativity, reveal opportunities and open new vistas of uncharted frontiers.
To address this void, we introduce the concept of generativity in the context of IS design and develop two corresponding design considerations –'generative capacity' that refers to one's ability to produce something ingenious or at least new in a particular context, and 'generative fit' that refers to the extent to which an IT artefact is conducive to evoking and enhancing that generative capacity. We offer an extended view of the concept of fit and realign the prevailing approaches to human–computer interaction design with current leading-edge applications and users' expectations. Our findings guide systems designers who aim to enhance creative work, unstructured syntheses, serendipitous discoveries, and any other form of computer-aided tasks that involve unexplored outcomes or aim to enhance our ability to go boldly where no one has gone before.
In this paper, we explore the underpinnings of 'generative capacity' and argue that it should be included in the evaluation of task-related performance. Then, we briefly explore the role of fit in IS research, position 'generative fit' in that context, explain its role and impact on performance, and provide key design considerations that enhance generative fit. Finally, we demonstrate our thesis with an illustrative vignette of good generative fit, and conclude with ideas for further research.     

Reusing semi-specified behavior models in systems analysis and design

As the structural and behavioral complexity of systems has increased, so has interest in reusing modules in early development phases. Developing reusable modules and then weaving them into specific systems has been addressed by many approaches, including plug-and-play software component technologies, aspect-oriented techniques, design patterns, superimposition, and product line techniques. Most of these ideas are expressed in an object-oriented framework, so they reuse behaviors after dividing them into methods that are owned by classes. In this paper, we present a crosscutting reuse approach that applies object-process methodology (OPM). OPM, which unifies system structure and behavior in a single view, supports the notion of a process class that does not belong to and is not encapsulated in an object class, but rather stands alone, capable of getting input objects and producing output objects. The approach features the ability to specify modules generically and concretize them in the target application. This is done in a three-step process: designing generic and target modules, weaving them into the system under development, and refining the combined specification in a way that enables the individual modules to be modified after their reuse. Rules for specifying and combining modules are defined and exemplified, showing the flexibility and benefits of this approach.