본 논문에서는 고차미분 연속성을 가지는 형상함수에 기초하여 오일러-베르누이 보 유한요소모델을 정식화하였으며, 다 양한 경계조건들에 대하여 그 성능을 평가하였다. 이러한 유한요소 모델들은 새로이 개발되는 고차 보 이론들과 논로컬 탄 성이론에 기초한 보 이론들의 유한요소해석에 필요하다. 그러나 고차 연속성을 가지는 유한요소에 대한 성능평가는 문헌에 서 찾아보기 어렵다. 따라서 본 연구에서는 C2 및 C3 두 종류의 고차 유한요소들을 정식화하여 외팔보, 단순지지, 고정-힌 지 등의 경계조건들을 적용하고 정적해석을 수행하였다. 고전적인 경계조건들 이외에도 고차 경계조건들이 보의 거동에 미 치는 영향을 비교분석하였다. 경계조건에 따라서는 처짐의 미분 값들이 경계주변에서 진동하는 현상이 관찰되었으며, 이는 기하학적 경계조건들에 대하여 뚜렷이 나타난다. 특히 고정단과 같은 경계에서의 변위의 고차미분 조건은 이러한 불안정한 현상을 유발한다. 본 연구에서 얻어진 결과들은 고차 미분 연속성을 가지는 유한요소 이용에 가이드라인으로서 역할을 할 수 있을 것으로 기대된다.

In this paper, a local deformation effect in thin-walled box beams is investigated via a finite element modal analysis. The analysis is carried out for single-cell and multi-cell box beam configurations. The single-cell box beam with and without a neck, which mimics a simple wind-turbine blade, is analyzed first. The results obtained by shell elements are compared to those of one-dimensional(1D) beam elements. It is observed that the wall thickness plays a crucial role in the natural frequencies of the beam. The 1D beam analysis deviates from the shell analysis when the wall thickness is either thin or thick. The shell modes(local deformations) are dominant as it becomes thin, whereas the shear deformation effects are significant as it does thick. The analysis is extended to the single-cell box beam with a neck, in which the shell modes are confined to near the neck. Finally the multi-cell box beam with a taper, which is quite similar to real wind-turbine blade configuration, is considered to investigate the local deformation effect. The results reveal that the 1D beam analysis cannot match with the shell analysis due to the local deformation, especially for the lagwise frequencies. There are approximately 5∼7% errors even if the number of segments is increased.

One of The standard issue in riding on the wave of the information system(IS) is records of performance, grow unprecedently fast, and has highly uncertain future. Within the framework of IS Evaluation, The main purpose of this study is to suggest performance quality evaluation system as follows, The Integrated Quality Evaluation Model Design(IQEMD) of Information System helps corporations to improve productivity, customer service and corporate competitive power. To respond flexibly this trend, we have to realize that the information system has to keep the most effective optimal information network at the proper time. The existing evaluation method has been concentrated on the evaluation of a degree of the information system maturity focused on static viewpoints. The evaluation of potential factors to affect the future-oriented performance, that can analyze both unit business being able to apply an information system base was used efficiently well and what performance evaluation item was obtained actually, was insufficient relatively. In this paper, An integrated quality evaluation method will analyze a degree of information system maturity in dynamic evaluation viewpoints rather than in static evaluation viewpoints. finally we estimated the relative degree of importance of each determinant using the AHP methodology The validity of the proposed model was also partially proved using two different methods, holistic and historical approach.