Is the List of Incomplete Open Cubes Complete?

Variations of Incomplete Open Cubes is the major project by the twentieth-century conceptual artist Sol LeWitt. In this paper we interpret the enumerative component of the project as embeddings of graphs. This formulation permits use of an algorithm to check the completeness of the list of the structures produced by the artist. Our conclusion is that the artist found the correct number of structures (that is, 122), but that his list contains a mistake in the presentation of a pair of incomplete cubes, a discovery that appears not to have been noted before.     

Evaluating dynamic performance: The influence of salient Gestalt characteristics on performance ratings.

It is well recognized that performance changes over time. However, the effect of these changes on overall assessments of performance is largely unknown. In a laboratory experiment, we examined the influence of salient Gestalt characteristics of a dynamic performance profile on supervisory ratings. We manipulated performance trend (flat, linear-improving, linear-deteriorating, U-shaped, and ∩-shaped), performance variation (small, large), and performance mean (negative, zero, positive) within subjects and display format (graphic, tabular) between subjects. Participants received and evaluated information about the weekly performance of different employees over a simulated 26-week period. Results showed strong main effects on performance ratings of both performance mean and performance trend, as well as interactions with display format. Theoretical and practical implications of the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing Parallel Functional Languages: Programming and Performance

This paper presents a practical evaluation and comparison of three state-of-the-art parallel functional languages. The evaluation is based on implementations of three typical symbolic computation programs, with performance measured on a Beowulf-class parallel architecture.We assess three mature parallel functional languages: PMLS, a system for implicitly parallel execution of ML programs; GPH, a mainly implicit parallel extension of Haskell; and Eden, a more explicit parallel extension of Haskell designed for both distributed and parallel execution. While all three languages employ a completely implicit approach to communication, each language takes a different approach to specifying and controlling parallelism, ranging from explicit identification of processes as language constructs (Eden) through annotation of potential parallelism (GPH) to automatic detection of parallel skeletons in sequential code (PMLS).We present detailed performance measurements of all three systems on a widely available parallel architecture: a Beowulf cluster of low-cost commodity workstations. We use three representative symbolic applications: a matrix multiplication algorithm, an exact linear system solver, and a simple ray-tracer. Our results show how moderate speedups can be achieved with little or no changes to the sequential code, and that parallel performance can be significantly improved even within our high-level model of parallel functional programming by controlling key aspects of the program such as load distribution and thread granularity.     

Self‐induced short chain branching in homopolymers and 1‐hexene copolymers of ethylene produced with amido functionalized ansa half‐sandwich complexes as catalysts

Amido ansa 3‐substituted indenyl complex precursors can be activated with methylaluminoxane and used for prepolymerization with ethylene to give a heterogeneous catalyst for olefin polymerization. Homo polymerization of ethylene with 1‐(3‐pent‐4‐enylindenylidene) dimethylsilyl'butylamidotitaniumdichloride (1), 1‐(3‐hex‐5‐enylindenylidene)dimethylsilyl'butylamidotitanium‐dichloride (2), and 1‐(3‐pent‐4‐enylindenylidene) (oct‐7‐enyl)methylsilyl'butylamidotitaniumdichloride (3) produces polyethylenes that contain ethyl branches. The ethyl branching in the polymers made with complexes 1 and 2 is barely above the ¹³C NMR detection limit, but the level observed in the polymer made with complex 3 is 17 times greater. Copolymerization of ethylene and 1‐hexene using prepolymerized 3 yields copolymers containing both ethyl and butyl branches. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 734–739, 2006     

Procedural fairness, outcome favorability, and judgments of an authority's responsibility.

Fairness theory (R. Folger & R. Cropanzano, 1998, 2001) postulates that, particularly in the face of unfavorable outcomes, employees judge an organizational authority to be more responsible for their outcomes when the authority exhibits lower procedural fairness. Three studies lent empirical support to this notion. Furthermore, 2 of the studies showed that attributions of responsibility to the authority mediated the relationship between the authority's procedural fairness and employees' reactions to unfavorable outcomes. The findings (a) provide support for a key assumption of fairness theory, (b) help to account for the pervasive interactive effect of procedural fairness and outcome favorability on employees' attitudes and behaviors, and (c) contribute to an emerging trend in justice research concerned with how people use procedural fairness information to make attributions of responsibility for their outcomes. Practical implications, limitations, and suggestions for future research also are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Understanding performance ratings: Dynamic performance, attributions, and rating purpose.

The present two studies integrate and extend the literatures on dynamic performance, performance attributions, and rating purpose, making several important contributions. First, examining attributions of dynamic performance, Study 1 predicted that performance mean and trend would affect judged ratee ability and effort and that performance variation would affect locus of causality; both predictions were supported by the results. Second, investigating the interaction between dynamic performance and rating purpose, Study 2 predicted that performance mean would have a stronger impact on administrative than on developmental ratings, whereas performance trend and variation would have a stronger impact on developmental than on administrative ratings; again, both predictions were borne out by the results. Third, both studies found that performance trend interacted with performance mean and variability to predict overall ratings. Fourth, both studies replicated main effects of dynamic performance characteristics on ratings in a different culture and, in Study 2, a sample of more experienced managers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)