Information technology devices, such as cellular phones, MP3s and so on, due to restrictions of space, require thin and small micro-speakers to generate sound. The reduction of the size of micro-speakers has resulted in the decrease of sound quality, due to such factors as frequency range and sound pressure level. In this study, the acoustical properties of oval microspeakers has been studied as a function of pattern shape on the diaphragm. The other conditions of micro-speakers, except for the pattern, was not changed. When the pattern is present on the diaphragm and the shape of pattern was a whirlwind, the resonance frequency was reduced due to the decrease of tensile strength of diaphragm. The patterns presented in the semi-minor axis of diaphragm did not effect a change of resonance frequency. However, increasing the number of patterns in the semimajor axis of diaphragm became a reason for the decrease of resonance frequency on edge side. When the depth of pattern on edge side was increased, the resonance frequency was decreased due to reduction of geometrical stiffness. If the height of edge and dome were increased, the resonance frequency and geometrical stiffness rapidly increased. After reaching the maximum values, they began to decrease with the continuous increase of height.

This study examined the relative effects of weekly and daily group feedback on the customer service behaviors in a gas station. Participants were four employees providing full services to the customers. Four target service behaviors, which were identified from the job description for the employees, served as the dependent variables. The data were collected by a supervisor. The independent variable was the frequency of group feedback on the four service behaviors: weekly and daily group feedback. An ABC within group design was adopted. After baseline (A), the weekly group feedback condition (B) was introduced. In the next phase, the daily group feedback condition (C) was introduced. Both weekly and daily group feedback were presented in a graph form and posted at a conspicuous location. Results showed that both weekly feedback and daily feedback conditions were effective in increasing the target behaviors. And, there was difference in the effects between the two conditions.

The purpose of this study was to examine the effects of stress response on safety behavior and to explore moderating effect of safety climate between stress response and safety behavior. 224 workers were asked to respond to the questionnaires that measured various demographic variables, stress response, safety climates and safety behaviors. A hierarchical regression was conducted to identify variables that had significant relationships with safety behavior and to examine moderating effect of safety climate between stress response and safety behavior. Results indicated that the depression response significantly predicted safety behavior. It was found that the safety climate was also a significant predictor for safety behavior. In addition, safety climate had a moderating effect on the relation between depression and anger responses and safety behavior.

This study examined the relative effect of participative and assigned goal-setting on team performance quantity and trend. Participants were 30 college students. They were divided into 15 pairs considering individual typing speed. Members in each pair were randomly assigned to the two experimental conditions. Participants were asked to type materials for 19 days. The dependent variable was the number of words typed. The results indicated that there was no significant difference in performance quantity between the two conditions. However, the average percentage of goal accomplishment under participative goal-setting condition was higher than that under assigned goal-setting condition. Also, the results showed that the difference in trend between two conditions was statistically significant.

This study compared the effects of praise and punishment for improving safety behaviors. Participants were 30 volunteer undergraduate students and they were randomly assigned to one of two experimental conditions: (1) praise under which positive feedback was delivered for safe behaviors, (2) punishment under which negative feedback was delivered for unsafe behaviors. A simulated computerized work task was developed specifically for this study. Participants had to work on the work task and follow seven safety rules while working. When they follow all the seven safety rules, their behaviors were considered safe. If they did not follow any one of the rules, their behaviors were considered unsafe. Results showed that the percentage of safe behavior under group of praise feedback was significantly higher than under group of punish feedback.

This study examined the relative effect of participative and assigned goal setting on team performance. Participants were 30 college students and their typing speed was tested. They were ordered on the basis of the typing speed and were divided into 15 pairs, with the members of each pair having similar typing speed. Members in each pair were randomly assigned to the two experimental conditions. Participants were asked to type materials provided by the experimenter for 20 days. The dependent variable was the number of words typed. The results showed that there was no significant difference in performance between the two conditions. The results also showed that the difference in trend between two conditions was not statistically significant.

We present the performance test results of VLBI Correlation Subsystem (VCS) trial product which was being developed for 1 year from August 2007. It is a core component of Korea-Japan Joint VLBI Correlator (KJJVC). The aim for developing VCS trial product is to improve the performance of VCS main product to reduce the efforts and cost, and to solve the design problems by performing the preliminary test of the manufactured trial product. The function of VCS trial product is that it is able to process the 2 stations-1 baseline, 8 Gbps/station speed, 1.2 Gbps output speed with FX-type. VCS trial product consists of Read Data Control Board (RDC), Fourier Transform Board (FTB), and Correlation and Accumulation Board (CAB). Almost main functions are integrated in the FTB and CAB board. In order to confirm the performance of VCS trial product functions, the spectral analysis, delay compensation and correlation processing experiments were carried out by using simulation and real observation data. We found that the overflow problem of re-quantization after FFT processing was occurred in the delay compensation experiment. We confirmed that this problem was caused by valid bit-expression of the re-quantized data. To solve this problem, the novel method will be applied to VCS main product. The effectiveness of VCS trial product has been verified through the preliminary experimental results, but the overflow problem was occurred.

The purpose of this study was to examine the relative effectiveness of immediate feedback and informational prompt on safe sitting behaviors that may cause VDT syndromes. Participants were three white color workers and an ABCB within-subject design was adopted. Safety Posture System was developed specifically for the present study. The system could detect participants' unsafe sitting postures using sensors and provide feedback and prompt on the computer monitors. The results indicated that both immediate feedback and informational prompt considerably increased safe sitting behaviors. More importantly, the immediate feedback was more effective than the informational prompt in increasing safe sitting behaviors.