A timber lattice roof, which has around 30m span, was constructed. In order to figure out the realistic buckling load level, the structural analysis of this roof structure was performed especially by stiffness of connection with various asymmetric snow load. Due to the characteristics of application of snow load, the load combinations of snow should be considered not only global area but also local part so that the critical buckling load could be observed as easy as possible. Geometrical imperfection was simulated to consider inaccurate shape of structure. And then nonlinear analysis were performed. Finally, this paper could investigate that the asymmetric snow load with the lower level stiffness of connection decreased the level of buckling load significantly.

Middle size of membrane retractable roof is under 25m span which consists of various moving systems. Sliding carriage is the system that leads the membrane to parking place, transferring the load from the membrane to structural cable. When membrane moves roof, thus, structural behavior of sliding carriage, which may contain various shapes with friction coefficients, should be investigated by vertical load as well as horizontal load. Nummerical simulation of sliding carriage prototypes, in this research, were performed by incrementation of vertical load and horizontal load as well. Consequently, this paper evaluated proper shapes of inner holder of Sliding carriage and evaluated the effective contact area of inner hold.

The governing equation for a dome-type shallow spatial truss subjected to a transverse load is expressed in the form of the Duffing equation, and it can be derived by considering geometrical non-linearity. When this model under constant load exceeds the critical level, unstable behavior is appeared. This phenomenon changes sensitively as the number of free-nodes increases or depends on the imperfection of the system. When the load is a periodic function, more complex behavior and low critical levels can be expected. Thus, the dynamic unstable behavior and the change in the critical point of the 3-free-nodes space truss system were analyzed in this work. The 4-th order Runge-Kutta method was used in the system analysis, while the change in the frequency domain was analyzed through FFT. The sinusoidal wave and the beating wave were utilized as the periodic load function. This unstable situation was observed by the case when all nodes had same load vector as well as by the case that the load vector had slight difference. The results showed the critical buckling level of the periodic load was lower than that of the constant load. The value is greatly influenced by the period of the load, while a lower critical point was observed when it was closer to the natural frequency in the case of a linear system. The beating wave, which is attributed to the interference of the two frequencies, exhibits slightly more behavior than the sinusoidal wave. And the changing of critical level could be observed even with slight changes in the load vector.

Single-layered grid space steel roof structure is an architectural system in which the structural ability of the nodal connection system greatly influences the stability of the entire structure. Many bolt connection systems have been suggested to enhance for better construct ability, but the structural behavior and maximum resistance of the connection system according to the size of bolt clearance play were difficult to identify. In particular, the identification of bending stiffness of the connection system is very important due to the characteristics of shell structures in which membrane stresses based on bending force effect significantly. To identify effective structural behavior and maximum bearing force, four representative nodal connection systems were selected and nonlinear numerical analysis were performed. The numerical analysis considering the size of the bolt clearance were performed to investigate structural behavior and maximum values of the bending force. In addition, the type of effective nodal connection system were evaluated. As a result, the connection system, which has two shear plane, represented high bending stiffness.

In this paper, the dynamic snapping of the 3-free-nodes spatial truss model was studied. A governing equation was derived considering geometric nonlinearity, and a model with various conditions was analyzed using the fourth order Runge-Kutta method. The dynamic buckling phenomenon was observed in consideration of sensitive changes to the force mode and the initial condition. In addition, the critical load level was analyzed. According to the results of the study, the level of critical buckling load elevated when the shape parameter was high. Parallelly, the same result was caused by the damping term. The sensitive asymmetrical changes showed complex orbits in the phase space, and the critical load level was also becoming lowly. In addition, as the value of damping constant was high, the level of critical load also increases. In particular, the larger the damping constant, the faster it converges to the equilibrium point, and the occurrence of snapping was suppressed.

A stadium roof that uses the pin-jointed spatial truss system has to be designed by taking into account the unstable phenomenon due to the geometrical non-linearity of the long span. This phenomenon is mainly studied in the single-free-node model (SFN) or double-free-node model (DFN). Unlike the simple SFN model, the more complex DFN model has a higher order of characteristic equations, making analysis of the system’s stability complicated. However, various symmetric conditions can allow limited analysis of these problems. Thus, this research looks at the stability of the DFN model which is assumed to be symmetric in shape, and its load and equilibrium state. Its governing system is expressed by nonlinear differential equations to show the double Duffing effect. To investigate the dynamic behavior and characteristics, we normalize the system of the model in terms of space and time. The equilibrium points of the system unloaded or symmetrically loaded are calculated exactly. Furthermore, the stability of these points via the roots of the characteristic equation of a Jacobian matrix are classified.

Middle size of membrane retractable roof is under 25m span which consists of various moving systems. Trolley is the system that leads the membrane to parking place, transferring the load from the membrane to structural cable. When membrane closes roof completely, thus, structural behavior of trolley, which may contain various material with different friction coefficients, should be investigated by vertical load. Nummerical simulation of trolley prototypes, in this research, was performed by incrementation of vertical load. Consequently, this paper studied proper friction characteristics and provided the effective inner materials of trolley.

A single-layerd steel lattice roof, which has 50m span, was constructed. In order to figure out the realistic buckling load level, the structural analysis of this roof structure was performed especially by local snow load. Due to the characteristics of application of snow load, the load combinations of snow should be considered not only global area but also local part so that the critical buckling load could be observed as easy as possible. Geometrical imperfection was simulated to consider inaccurate shape of structure. And then nonlinear analysis were performed. Finally, this paper could investigate that the local snow load with geometrical imperfection decreased the level of buckling load significantly.

For the artistic column used by Glass Fiber Reinforced Plastic(GFRP), the connection of steel with GFRP were needed. Due to the fabricating characteristics of hand laminating, GFRP surfaces had to be connected. Because there were no existed data of these connection, experimental study has to be followed so that the structural strength and buckling mode could be investigated. In this paper, therefore, the axial tests of steel with GFRP were performed. The connection of GFRP's surfaces could be also tested as well. As a result, it could be figured out that the strength of these connections were determined by the adhesive strength.

유리강회플라스틱(GRP)은 재료의 자중에 비해 아주 높은 강도를 가지고 있다. 또한 부재의 두께에 따라서 투명 혹은 반투명의 효과를 거둘 수 있다. 하지만 Hand laminating의 특성상 일률적인 재료의 강도를 선뢰하기 어렵기 때문에 구조 계산 혹은 설계 시 반드시 재료 실험을 수행하여야한다. 본 논문은 두께 4mm, 높이 30m의 의장적 기둥을 구조적으로 설계하기 위한 재료 실험을 수행하였다. 또한 실험 결과에 대한 평가를 통해 DIN에서 규정하는 재료적인 강도와 비교 분석하였다. 이를 통해 규준에서 제시하는 값과의 차이를 확인했으며 실제 설계에 반영하기 위해 반드시 재료실험이 수행되어야함을 알 수 있다.

The structural system that discreterized from continuous shells is frequently used to make a large space structures. As well these structures show the unstable phenomena when a load level over the limit load, and snap-through and bifurcation are most well known of it. For the collapse mechanism, rise-span ratio, element stiffness and load mode are main factor, which it give an effect to unstable behavior. In our real situation, most structures have semi-rigid joint that has middle characteristic between pin and rigid joint. So the knowledge of semi-rigid joint is very important problem of stable large space structure. And the instability phenemena of framed space structures show a strong non-linearity and very sensitive behavior according to the joint rigidity For this reason In this study, we are investigating to unstable problem of framed structure with semi-rigidity and to grasp the nonlinear instability behavior that make the fundamental collapse mechanism of the large space frame structures with semi-rigid joint, by proposed the numerical analysis method. Using the incremental stiffness matrix in chapter 2, we study instability of space structures.

높은 농도로 투여된 성선자극호르몬 분비호르몬 이성체(GnRH-Ag)는 성선자극호르몬의 분비를 억제시키고 난소의 기능을 억제하는 하는 것으로 보고되고 있다. 그러나 체외수정 및 배아이식 시술과정에서 과배란 유도를 위해 다량의 GnRH-Ag를 사용하고 있으며, 이는 progesterone을 보충해 주어야 하는 황체기 결함을 유발시킨다. 본 실험의 목적은 이러한 황체기 결함을 유발시키는 원인을 알아보고자 사람 과배란 유도 과정과 비슷하게 생쥐에 GnRH-Ag

비만유전자 산물인 leptin은 지방 조직에서 생성되어 혈액으로 분비되며, 신진대사, 식욕, 체열 등을 조절하여 비만의 억제 조절 물질로 작용하는 것으로 알려져 있다. 또한 leptin은 비만 뿐만 아니라 생식 생리와도 관련이 있는 것으로 보이며, 이러한 leptin의 작용이 난소에 직접적인지 혹은 시상하부나 뇌하수체를 매개로 하는지는 아직 정확하게 밝혀지지 않고 있으며, 난소에서의 leptin 및 leptin 수용체의 발현 양상에 대한 연구 또한 미진