The Effects of Team-Member Attributes on Team Performance: a Model of Individual Contribution to Team Performance.

Although team composition is one of the most frequently studied topics in team research, much remains unknown regarding what attributes to look for when selecting team-members and how these attributes affect team performance. The purpose of this study was to present and to test a theoretical model that depicts how individual attributes affect team-member performance and how team-member performance ultimately affects team performance. The proposed model is based on the integration of research on team and individual performance. From a practical standpoint, understanding the relationships among the variables in the proposed model may be important for the selection of employees in team-based organizations. In general, the results did not support the proposed model. However, further examination of the data showed that task knowledge and skills is a separate construct from teamwork knowledge and skills, task motivation is a separate construct from teamwork motivation, and task experience is a separate construct from teamwork experience. One implication of these findings is that assessing knowledge, skills, motivation, and experience for several appropriate job performance dimensions may be useful for selecting employees who may perform well on their job specific tasks and work well with others in a team environment. Furthermore, the data suggest that the use of peer ratings in a team setting may be problematic due to the close personal relationships among team-members. These results seem to be consistent with various studies that found that ratings in a team setting may be affected by contextual factors (e.g., Grey & Kipnis, 1976; Liden & Mitchell, 1983; Mitchell & Liden, 1982). In addition, the problems encountered with peer ratings seem to have been magnified by the political context of the organization examined in the present study. Implications of these results are discussed

Sound Radiation Modes of a Tire on a Reflecting Surface

Wave number decomposition of a tire\u27s radial vibration can be used to reveal the wave propagation characteristics of tires. In this paper, the relationship between the structural wave propagation characteristics of a tire excited at one point and its sound radiation is considered. The sound radiation resulting from structural vibration of a tire in contact with the ground was investigated by using boundary element analysis. In particular, the orthogonal radiation modes of a tire in the presence of a reflecting surface, along with their radiation efficiency characteristics, were calculated by applying an eigenvector analysis to the tire\u27s radiation resistance matrix. The latter analysis made use of acoustic transfer vectors and a recovery surface appropriate for a pass‐by noise test. The radiation mode results reveal that it is the vibration in the region close to the contact patch that primarily controls sound radiation. In particular, to reduce pass‐by noise levels, it is necessary to mismatch the tire\u27s structural ring mode and the radiation modes with high radiation efficiencies. It has also been found that the radiation from a tire is controlled by a relatively small number of radiation modes (although the number of contributing modes increases with frequency)

Influence of Tire Size and Shape on Sound Radiation from a Tire in the Mid-Frequency Region

In this research, the influence of tire size and shape on sound radiation in the mid-frequency region was studied. First, the relationship between the structural wave propagation characteristics of a tire excited at one point and its sound radiation was identified by using FE and BE analyses. Then, by using that relationship, the effect of modifying a tire’s aspect ratio, width and wheel diameter on its sound radiation between 300 Hz and 800 Hz was investigated. Finally, an optimization of the sound radiation was performed by modification of the tire structure and shape. It was found that most of a tire’s structural vibration does not contribute to sound radiation. In particular, the effective radiation was found to occur at the frequencies where low wave number components of the longitudinal wave and the flexural wave first appear. In addition, when the tire size and shape were modified, it was found that the flexural wave motion was controlled primarily by the tire cross-sectional length while the longitudinal wave motion was mainly affected by the treadband overall diameter

Sound Radiation Control Resulting from Tire Structural Vibration

The objective here was to study the control of sound radiation resulting from the structural vibration of a tire excited at one point. First, the tire was modeled as an orthotropic shell by using finite elements and the effect of various tire material parameters on structural wave propagation and the associated sound radiation was estimated. The parameters that were effective at controlling structural wave propagation were then identified. In addition, the radiation field characteristics in the space surrounding a tire placed on a rigid ground were analyzed by using radiation mode analysis. Based on these analyses, a strategy for reducing the radiated sound levels by modifying the tire parameters from a base set was determined. An improved set of material parameters was identified that resulted in reduced sound radiation within a specified target frequency region. That reduction was achieved by an increase of treadband circumferential stiffness that was found to move the onset of longitudinal wave motion within the treadband into a higher frequency region. Secondly, flexural wave propagation was found to be mainly controlled by inflation pressure and cross-sectional treadband stiffness. By appropriate adjustment of these three parameters, it was found possible to substantially reduce sound radiation in a mid-frequency region

A visibility-based lower bound for android unlock patterns

The Android pattern unlock is a widely adopted graphical password system that requires a user to draw a secret pattern connecting points arranged in a grid. The theoretical security of pattern unlock can be defined by the number of possible patterns. However, only upper bounds of the number of patterns have been known except for 3��3 and 4��4 grids for which the exact number of patterns was found by brute-force enumeration. In this letter, we present the first lower bound by computing the minimum number of visible points from each point in various subgrids. ? 2017 The Institute of Electronics, Information and Communication Engineers.11Ysciescopu

Physical Electronics and Surface Physics

Contains reports on one research project.Joint Services Electronics Program (Contract DAAB07-74-C-0630

Inelastic J/ΨJ/\Psi Photoproduction off Nuclei: Gluon Enhancement or Double Color Exchange?

The nuclear enhancement observed in inelastic photoproduction of $J/\Psi$ should not be interpreted as evidence for an increased gluon density in nuclei. The nuclear suppression of the production rate due to initial and final state interactions is calculated and a novel two-step color exchange process is proposed, which is able to explain the data.Comment: Latex file, 23 pages including 5 Postscript figure