The purpose of this study is to draw employee support program at the company level through field survey of foreign laborers' satisfaction level of working life. To analyze the factors that determine working life satisfaction, regression analysis was conducted. Satisfaction level of working hours(t=2.469), living environment(t=2.140), post offices/banks (t=3.024) showed a statistically significant. Also these variables, working hours, living environment, post office/banks are verified to be very important for improving the level of their working life. Through these findings we can understand that employee support activities, providing user-guide of bank and post office, compliance with standards for working hours, improvement of the living conditions (accommodation, meals, etc.), the leisure time program support, the children care support and active utilization of foreign workers and strengthen the educational program, are necessary to improve the satisfaction level of foreign laborers' working life in Korea. It is recommended that managers need to recognize that careful consideration of living and working condition could contribute to stable settlement and increase working life satisfaction for the foreign workers at company level.

The aim of this study was to determine the muscle activity of the abdominalis and erector spinae during bridging and unilateral bridging exercises on the firm surface, the sir-fit, and the foam roll. Eighteen healthy young subjects were recruited for this study. Surface electromyographic (EMG) activities were recorded from the both sides of the rectus abdominalis, external obliques, internal obliques, and erector spinae muscles during bridging and unilateral bridging-exercises. A one-way repeated analysis of variance was used to compare the EMG activity of each muscle according to the support surface condition. Differences in the EMG activities between the bridging and unilateral bridging exercises, and between the right and left side were assessed using a paired t-test. The study showed that the EMG activities of all of the muscles were significantly higher when the bridging exercise was performed using the foam roll or sit-fit than on the firm surface. The EMG activities of the right rectus abdominis, right external obliques, the right internal oblique, and both erector spinae were significantly higher during unilateral bridging ex exercise using the foam roll or the sit-fit than on the firm surface. The EMG activities of all of the muscles were significantly higher during the unilateral bridging exercise than during the bridging exercise. Based on these finding, performing the unilateral bridging exercise using the sit-fit or the foam roll is a useful method for facilitating trunk muscle strength and lumbar stability.

The ground tracking support is a critical factor for the navigation performance of spacecraft orbiting around the Moon. Because of the tracking limit of antennas, only a small number of facilities can support lunar missions. Therefore, case studies for various ground tracking support conditions are needed for lunar missions on the stage of preliminary mission analysis. This study analyzes the ground supporting condition effect on orbit determination (OD) of Korea Pathfinder Lunar Orbiter (KPLO) in the lunar orbit. For the assumption of ground support conditions, daily tracking frequency, cut-off angle for low elevation, tracking measurement accuracy, and tracking failure situations were considered. Two antennas of deep space network (DSN) and Korea Deep Space Antenna (KDSA) are utilized for various tracking conditions configuration. For the investigation of the daily tracking frequency effect, three cases (full support, DSN 4 pass/day and KDSA 4 pass/day, and DSN 2 pass/day and KDSA 2 pass/day) are prepared. For the elevation cut-off angle effect, two situations, which are 5 deg and 10 deg, are assumed. Three cases (0%, 30%, and 50% of degradation) were considered for the tracking measurement accuracy effect. Three cases such as no missing, 1-day KDSA missing, and 2-day KDSA missing are assumed for tracking failure effect. For OD, a sequential estimation algorithm was used, and for the OD performance evaluation, position uncertainty, position differences between true and estimated orbits, and orbit overlap precision according to various ground supporting conditions were investigated. Orbit prediction accuracy variations due to ground tracking conditions were also demonstrated. This study provides a guideline for selecting ground tracking support levels and preparing a backup plan for the KPLO lunar mission phase.

A Finite-Element (FE) model updating method is widely used for identifying structural integrities such as support conditions and material properties. However, it is still difficult to properly estimate support conditions using limited number of data. This study proposed a novel FE model updating method, which can identify support conditions by adding artificial springs at the supports, and by measuring the rotational angles of the supports.