중생대 백악기 함평분지의 고퇴적환경과 지질연대를 지화학, 암상 분포, 퇴적암석학 그리고 고식물학 측면에서 재고찰을 시도하였다. 연구 결과는 함평분지가 하성과 호성층으로 구성된 구조적으로 활동적인 분지였음을 시사한다. 이 분지에서는 주변 지형과 관련되어 분명한 환경 변화를 시사하는 산성응회암류, 흑색 셰일/사암상, 적색층, 응회암질 역암을 포함하는 중성응회암류 등 4가지 암상이 인지되었다. 구조적 운동에 수반하여 일어난 화산활동이 이들 퇴적층을 형성시킨 퇴적물을 주로 제공하였을 것이다. 이들 퇴적층들은 인접한 해남분지와 잘 대비된다. 그리고 화산성 기원의 퇴적물들은 유천층군에 해당하는 능주층의 경우와 유사하다. 분지 내에서 흑색 셰일의 광역적인 분포는 혐기성 환경 하에서 퇴적이 이루어졌음을 지시한다. 이들 암층에 있어서의 유기탄소의 함량(0.81%에서 1.75%)은 석유근원 셰일의 평균치 정도로 나타났다. 식물화석은 흑색셰일과 사암에서 산출된다. Platanoid류 잎 화석의 산출은 이들 퇴적층이 Oishi의 피자식물 계열 지층에 해당하며 시대상 Aptian/Albian 또는 보다 신기 지층임을 시사한다.

Nowadays, every kind of system is changed so complex and enormous, it is necessary to assure system reliability, product liability and safety. Fault tree analysis(FTA) is a reliability/safety design analysis technique which starts from consideration of system failure effect, referred to as “top event”, and proceeds by determining how these can be caused by single or combined lower level failures or events. So in fault tree analysis, it is important to find the combination of events which affect system failure. Minimal cut sets(MCS) and minimal path sets(MPS) are used in this process. FTA-I computer program is developed which calculates MCS and MPS in terms of Gw-Basic computer language considering Fussell's algorithm. FTA-II computer program which analyzes importance and function cost of VE consists. of five programs as follows : (l) Structural importance of basic event, (2) Structural probability importance of basic event, (3) Structural criticality importance of basic event, (4) Cost-Failure importance of basic event, (5) VE function cost analysis for importance of basic event. In this study, a method of initiation such as failure, function and cost in FTA is suggested, and especially the priority rank which is calculated by computer-aided decision analysis program developed in this study can be used in decision making determining the most important basic event under various conditions. Also the priority rank can be available for the case which selects system component in FMEA analysis.

Physical properties of artificial graphite electrodes were evaluated along three different directions; circumferential (X), radial (Y), and axial (Z) directions. Four kinds of commercial electrode products were used in this study for the evaluation; pole (AP) and nipple (AN) of manufacturer A, pole (BP) and nipple (BN) of manufacturer B. The mechanical, electrical, and thermal properties in X and Y directions were very similar to each other. In Z direction, however, the mechanical properties, including flexural strength and compressive strength, were higher, and electric resistance and thermal expansion were much lower than those in the other directions. The microstructures observed by optical microscope and scanning electron microscope revealed that the differences in properties by the measuring direction were caused by the preferential alignment of needle cokes along the Z direction. When comparing the properties of the electrode samples in the same direction, the mechanical properties mainly depended on the bulk density or porosity of the samples as well as preferential alignment of needle cokes.

This paper describes the mechanical properties and oxidation resistance of carbon fibers with and without additions of boron oxide additives, and describes the changes in the properties resulting from increased heat treatment temperature (HTT) of the fibers. Carbon fibers in this experiment were heat treated up to 2800℃ each with and without boron oxide treated on the surface of fibers. In the case of boron oxide added carbon fibers, they do not show the improvement of tensile strength and modulus compared to those of no treated carbon fibers below 2200℃ since they are doped substitutionally with boron above 2600℃, which accelerate the graphitization of carbon fibers. Boron oxide implanted carbon fibers showed high resistance to oxidation, however, when carbon fibers were heat treated below 2200℃, they showed almost the same trend of air oxidation.

이 연구의 목적은 만성요통 여성 환자들에서 나타나는 자세 이상을 평가하고 방사선적 변수들과 임상적인 변수들과의 상관성을 알아보는 것이다. 이 연구의 대상자는 만성요통 여성 환자 38명과 대조군 32명이었다. 변수의 측정은 모든 대상자들이 이완된 자세로 기립한 상태에서 방사선 검사를 실시한 후 경추전만각, 흉추후만각, 요추전만각, 그리고 요추경사각을 측정하였다. 대상자들의 연령과 통증기간은 의무기록지를 참고하였다. 자료분석은 요통군과 대조군의 방사선적 변

As an efficient method to detect blending of general gravitational microlensing events, it is proposed to measure the shift of source star image centroid caused by microlensing. The conventional method to detect blending by this method is measuring the difference between the positions of the source star image point spread function measured on the images taken before and during the event (the PSF centroid shift, δθc,PSF). In this paper, we investigate the difference between the centroid positions measured on the reference and the subtracted images obtained by using the difference image analysis method (DIA centroid shift, δθc.DIA), and evaluate its relative usefulness in detecting blending over the conventional method based on δθc,PSF measurements. From this investigation, we find that the DIA centroid shift of an event is always larger than the PSF centroid shift. We also find that while δθc,PSF becomes smaller as the event amplification decreases, δθc.DIA remains constant regardless of the amplification. In addition, while δθc,DIA linearly increases with the increasing value of the blended light fraction, δθc,PSF peaks at a certain value of the blended light fraction and then eventually decreases as the fraction further increases. Therefore, measurements of δθc,DIA instead of δθc,PSF will be an even more efficient method to detect the blending effect of especially of highly blended events, for which the uncertainties in the determined time scales are high, as well as of low amplification events, for which the current method is highly inefficient.