A number of stores can save costs by forming a centralized inventory system. The number and location of centralized warehouses can be determined in minimizing total costs and then these cost reductions should be allocated fairly to each store. If no group of stores feel that they are paying to subsidize to the complementary set of stores, then that cost allocation is in core. That is, all stores become better off by forming a group. This study shows that there does not exist the core in some examples. Hence, we suggest a framework for the cost allocation both of the case in which the core exists and the core does not exist.

The purposes of this study were to investigate the median frequency (MDF) between initiation and termination of muscle contraction through surface electromyographic (sEMG) analysis and to propose the basis of clinical treatment for movement problems in early hemiparetic upper limbs. Thirteen patients who had stroke with onset less than 3 months prior to the study and seven control subjects participated in the study. The median frequency in initiation and termination of muscle contraction was recorded from wrist flexor and extensor muscles using the sEMG, with 3 second beeper signals, during maximal isometric wrist flexion and extension. Flexion and extension must be done as quickly and forcefully as possible. The results of the study were as follows: 1. The MDF of the onset and offset sections were significantly lower on the paretic than the nonparetic and control sides. 2. The MDF of the offset section significantly decreased on the paretic and nonparetic sides. Consequently, this study showed that the lowering of the MDF was due to the hemiparetic wrist motor impairment and muscle weakness. These results are also related to Fugl-Meyer motor assessment (FMA) scores in hemiparetic upper limbs. This study also suggests that since muscle weakness of early stroke patients affects the functional decrease of upper limbs, further studies must focus on the treatment to improve muscle agility and muscle fiber recruitment efficiency that can induce the functional recovery correlated to motor control.

A centralized inventory system provides a number of stores with cost reduction, information sharing. To build centralized warehouses, two things should be considered: how many warehouses are required and where these are located. The number and location of centralized warehouses can be determined in minimizing total costs and then these cost reductions should be allocated fairly to each store. Since it is too time-intensive to find an optimal solution of minimizing total costs, this paper presents heuristics and compares its results with an optimal solution.

A number of stores can save costs by forming central warehouses. In this paper, transportation cost is included in the inventory model with the continuous review policy, namely, (Q,R) policy. The objective of this paper is to develop an efficient simulated annealing algorithm and heuristic for large-scale problems of determining the location and the number of central warehouses by minimizing total costs. Some computational results and suggestions for future research are also discussed.

남해 중앙부해역의 해양환경특성을 파악하기 위해 표층 퇴적물중의 와편모. 조류 시스트와 유기물 분포에 대한 조사를 2002년 4월부터 2003년 1월가지 총 6회 실시하였다. 분석 항목 중 함수율, 강열감량, 화학적 산소요구량, 입자성 유기탄소, 입자성 유기질소, 식물색소량은 각각 38.7~68.9% 3.9~ 12.5%, 9.60~44.05 m9O2 gdry-1, 3.12~13.14mgC gdry-1, 0.49~

A centralized inventory system provides a number of stores with cost reduction, information sharing. To build centralized warehouses, two things should be considered: how many warehouses are required and where these are located. The number and location of centralized warehouses can be determined in minimizing total costs and then these cost reductions should be allocated fairly to each store. Since it is too time-intensive to find an optimal solution of minimizing total costs, this paper presents heuristics and compares its results with an optimal solution.

Median frequency can be regarded as a valid indicator of local muscle fatigue. As local muscle fatigue develops, the muscle fiber conduction velocity decreases, the fast twitch fibers are recruited less, and consequently the median frequency shifts toward the lower frequency area. The aim of this study was to test the characteristics of the median frequency according to exercise load (30% and 60% of MVC on the biceps brachii, 40% and 80% of MVC on the vastus lateralis) during the fatiguing isometric exercise. Thirteen healthy male volunteer students of Yonsei University were recruited. After the testing maximal voluntary isometric contraction, three variables (initial median frequency, regression slope, fatigue index) from the regression line of MDF data were measured in each exercise load. The results showed that the regression slope and fatigue index were significantly different for the biceps brachii, but not for the vastus lateralis initial MDF was not significant difference according to the exercise load on both muscles. The regression slope and fatigue index could monitor physiologic muscle change during fatiguing isometric exercise. The results showed that two MDF variables reflect the local muscle fatigue according to the exercise load.

본 연구에서는 단부 철근콘크리트와 중앙부 철골로 이루어진 혼합구조보의 비선형 이력거동에 대한 해석 모형을 제시하였다. 해석을 위하여 IDARC2D 프로그램을 사용하였으며, 기존의 실험결과를 대상으로 적절한 모형화 기법과 계수를 제시하였다. IDARC2D의 다각형 모형은 부재의 초기강성을 과대평가할 수 있기 때문에, 먼저 혼합구조보의 초기강성을 적절히 표현할 수 있는 새로운 혼합모형을 도입하였다. 그리고 혼합모형을 이용하여 혼합구조보의 이력거동을 적절히 표현할 수 있도록 이력거동 계수들을 제시하였다. 끝으로 해석한 결과를 실험결과와 비교평가하였으며, 초기강성은 5%이내, 강도는 10%이내의 우수한 결과를 보였다.