The north-west sea area of Cheju Island is where originate two layer current in the summer season. The case of the fishing operations in this sea area is almost impossible for normal expansion of the net gear for shooting net, and is happened to be frequent occasions for rise of tension suddenly in purseline by changes of the net shapes in the operation. Therefore, the safety of the operations is often obstructed by the above mentioned. In connection with the above, model experiments on the purse seine in the circulating water tank was carried out in comparison and analysis on the changes of tension in the pruseline by deformation of purse seine in the sea area of two layer current. THe results obtained are as follows;In the case of the required time for pursing of 20 minutes in the no current set, the increasing curve for tension of purseline can be expressed as:Y=0.0004x3+0.0098x2+0.3000x(r=0.9989)where Y is tension(metric tons) of a purseline, x is required time(minutes) for pursing. And, the maximum value of tension in this time was an increase of 31.3 percent at 15 minutes, and was a decrease of 30.3 percent at 30 minutes than that of 20 minutes.When the bottom margin of net is held on the position in velocity of 0.5 knot at three-eighths of net in the bottom current to the net height, the maximum tension of the required time for pursing of 30 minutes in tight set and loose set were decrease of 29.5 percent and 28.7 percent respectively than that of 20 minutes.The work load during the required time for pursing of 20 minutes were calculated 5.79×106 kgf·m in no current set, 7.89×106 kgf·m in tight set and 5.15×106 kgf·m in loose set, therefore it was an increase of 22.3 percent in tight set, and was a decrease of 11.1 percent in loose set than that of the no current set. Where tight set and loose set is a range of the bottom current with velocity of 0.5 knot at three-eighths of net to the net height.

서 언 저자들은 1995년 12월부터 2개년간에 걸쳐 농림수산부가 지원하는 농수산 첨단 연구 과제로서 “안강망 어로 시스템 자동화에 관한 연구 개발을 수행하였다. 이 해설에서는 상기 연구의 초기 단계에 저자들의 조사한 안강망 어선 어로 시스템의 현황과 개선점에 대하여 기술함으로써 향후 안강망어업 관련 연구의 기초자료를 제공하고자 한다.

The purpose of this study is analyzing the performance of sea water cooling system under various refrigerant pipe length. In sea water cooling system, the increase of refrigerant pipe length cause increases of pressure drops. These pressure drops cause fresh gas in liquid pipe and increase specific volume in gas pipe outlet, so sea water cooling system capacity is decreased by decrease of refrigerant mass flow rate. Sea water cooling system capacity in refrigerant pipe length 70m is decreased more than 30% when compared with pipe length 10m and the decrease of the coefficient of performance is nearly 20%.

The purpose of this paper is to investigate the effect of the specimen geometries on the pin bearing strength of the angle ply carbon fiber reinforced composites. The effect of the edge distance and the specimen width on the pin bearing strength of angle ply CFRP composites are experimentally investigated in this paper. As results, the failure mode and pin bearing strength of mechanical joints turned out to depends on the stacking sequence and specimen geometries such as the edge distance and the specimen width. The higher pin bearing strength obtained for the angle ply CFRP composites is attributed to a combination of debonding, pull out, buckling and breakage of fiber and also the matrix cracking.

It is main objective of this approach to present a method to analyse stochastic design sensitivity for problems of structural dynamics with randomness in design parameters. A combination of the adjoint variable approach and the second oder perturbation method is used in the finite element approach. An alternative form of the constant functional that holds for all times is introduced to consider the time response of dynamic sensitivity. The terminal problem of the adjoint system is solved using equivalent homogeneous equations excited by initial velocities. The numerical procedures are shown to be much more efficient when based on the fold superposition method : the generalized co-ordinates are normalized and the correlated random variables are transformed to uncorrelated variables, where as the secularities are eliminated by the fast Fourier transform of complex valued sequences. Numerical algorithms have been worked out and proved to be accurate and efficient : they codes whose element derivative matrices can be explicitly generated. The numerical results of two cases - 2-dimensional portal frame and 3/4-cylindrical shell structure - for the deterministic and stochastic sensitivity analysis illustrates in this paper.

1987년 2월부터 1988년 1월까지 낙동강 하구해역에서 채집된 전갱이(체장 4~15cm)의 식성을 조사하였다. 전갱이의 주요 먹이생물은 요각류(Copepoda), 단각류(Amphipods), 공쟁이류(Mysidacea)등의 갑각류였다. 특히 요각류가 위 내용물 중 차지하는 비율이 매우 높았다. 그 외에 십각류(Decapoda), 난바다공쟁이류(eEuphausiacea), 모악류(Chaetognatha), 갯지렁이류(Polycheata), 어란 및 자어 등이 위내용물 중 소량 발견되었다. 요각류 중에서는 Paracalanus parvus, Acartia clausi 그리고 Calanus sinicus 가 많이 섭이되었는데, 특히 C. sinicus에 대한 선호도가 높았다. 전갱이가 성장함에 따라 먹이생물의 조성이 점차 변하였다. 작은 전갱이들은 그들의 먹이를 요각류에 거의 전적으로 의존하였으나, 체장이 증가하면서 위내용물 중 요각류가 차지하는 비율은 점차 감소하였으며, 그 대신 비교적 큰 먹이생물인 단각류 및 곤쟁이류의 점유율은 점차 증가하였다.