• Architectural research
• /
• 제7권1호
• /
• pp.27-38
• /
• 2005

No specific guidelines are available for computing the bearing strength of connection between steel coupling beam and reinforced concrete shear wall in a hybrid wall system. There were carried out analytical and experimental studies on connection between steel coupling beam and concrete shear wall in a hybrid wall system. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the bearing strength of the connection between steel coupling beam and reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behavior in connection between steel coupling beam and shear wall, i.e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between steel coupling beam and reinforced concrete shear wall. The proposed equations in this study were in good agreement with both our test results and other test data from the literature.

• 국제지역연구
• /
• 제15권3호
• /
• pp.393-405
• /
• 2011

미국의 장단기 국채 수익률 스프레드와 한국 거래소시장의 종합주가지수 변화를 통해 한국경제와 미국경제에 동조화가 존재하는지, 또 동조화가 존재한다면 어느 정도의 시차로 동조화가 진행되고 있는지, 그리고 미국의 금융위기로 동조화의 내용에 사실상 어떤 변화가 발생했는지를 분석하였다. 본 연구는 먼저 한국의 대표적 자산시장인 거래소시장이 미국의 장단기 국채금리 스프레드와 동조화를 보이고 있는 사실을 발견하였다. 또 동조화의 방향도 미국 국채의 장단기 금리차가 벌어지면, 즉 세계경제의 견인차 역할을 하고 있는 미국경제의 전망이 밝아지는 경우 자산시장에서 안전자산보다는 위험자산을 선호하는 분위기가 조성되어 국제적으로 자금이 고수익을 기대할 수 있는 한국과 같은 신흥시장으로 흘러들어오면서 신흥시장의 주가를 끌어올리게 될 것이라는 일반적인 예상과 일치하였다. 본 연구에서는 또 다양한 시차를 대상으로 하여 동조화가 극대화되는 시점을 조사했는데 양국 시장의 동조화가 불과 1주일 만에 극대화되는 사실도 발견하였다. 또 가변수를 이용하여 미국에서 시작된 금융위기가 동조화에 어떤 변화를 주었는지에 대한 분석에서는 금융위기 후 동조화의 강도가 현저하게 낮아진 사실도 발견하였다.

• 콘크리트학회논문집
• /
• 제18권1호
• /
• pp.135-145
• /
• 2006

In high multistory reinforced concrete buildings, coupled shear walls can provide an efficient structural system to resist horizontal force due to wind and seismic effects. Coupled shear walls are usually built over the whole height of the building and re laid out either as a series of walls coupled by beams and/or slabs or a central core structure with openings to accommodate doors, elevators walls, windows and corridors. A number of recent studies have focused on examining the seismic response of concrete, steel, and composite coupling beams. However, since no specific equations are available for computing the bearing strength of steel coupling beam-wall connections, it is necessary to develop such strength equations. There were carried out analytical and experimental studies to develop the strength equations of steel coupling beam-connections. Experiments were conducted to determine the factors influencing the bearing strength of the steel coupling beam-wall connection. The results of the proposed equations were in good agreement with both test results and other test data from the literature. Finally, this paper provides background for design guidelines that include a design model to calculate the bearing strength of steel coupling beam-wall connections.

• 콘크리트학회논문집
• /
• 제17권6호
• /
• pp.1065-1074
• /
• 2005

Due to lack of information, current design methods to calculate bearing strength of connections are tacit about cases in which hybrid coupled walls have connection details of stud bolts and horizontal ties. In this study, analytical study was carried out to develop model for calculating the connections strength of embedded steel section. The bearing stress at failure in the concrete below the embedded steel coupling beam section is related to the concrete compressive strength and the ratio of the width of the embedded steel coupling beam section to the thickness of the shear walls. Experiments were carried out to determine the factors influencing the bearing strength of the connection between steel coupling beam and reinforced concrete shear wall. The test variables included the reinforcement details that confer a ductile behavior in connection between steel coupling beam and shear wall, i. e., the auxiliary stud bolts attached to the steel beam flanges and the transverse ties at the top and the bottom steel beam flanges. In addition, additional test were conducted to verify the strength equations of the connection between steel coupling beam and reinforced concrete shear wall. The results of the proposed equations in this study are in good agreement with both our test results and other test data from the literature.

• 한국소음진동공학회논문집
• /
• 제15권4호
• /
• pp.445-451
• /
• 2005

This paper is the result of a experimental study about non-linear one to one modal coupling of a flexible circular cantilever beam which was transversely excited with harmonic excitation. It was proved that 2 order jumping in out of plane was caused by jump phenomenon in in-plane of flexible circular cantilever beam, because of non-linear coupling. In addition, cantilever beam showed hardening spring characteristics in in-plane and softening spring characteristics in out-of-plane.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2004년도 추계학술대회논문집
• /
• pp.129-133
• /
• 2004

This paper is the result of a experimental study about non-linear one to one modal coupling of a flexible circular cantilever beam which was transversely excited with harmonic excitation. It was proved that 2 order jumping in out of plane was caused by jump phenomenon in in-plane of flexible circular cantilever beam, because of non-linear coupling. In addition, cantilever beam showed hardening spring characteristics in in-plane and softening spring characteristics in out-of-plane.

• 한국정밀공학회지
• /
• 제17권5호
• /
• pp.100-107
• /
• 2000

The hydraulic couplings have been widely used in industries, automobile, and power-station drives including ships. A mathematical analysis by which the design and application of hydraulic couplings are made is used in conventional design formulae and general roto-dynamic theories. The fluid flow of hydraulic couplings can be considered to have two component, one circumferentially about the coupling axis, and the other passing fluid from the pump to the turbine in the plane of the coupling axis. Tests have been carried out on the full-scale production coupling. The performance test consists of taking measurement of torque of the fluid coupling for three different amount of working fluid inside with various loads to the output shaft. The purpose of this research is to construct the experimental test equipments and to establish a series of performance test for the domestically developed hydraulic couplings, and to obtain experimental results which can be used to improve the performance of the hydraulic coupling and to solve the practical problems confronted in operation.

• Journal of Magnetics
• /
• 제20권1호
• /
• pp.57-61
• /
• 2015

In this paper wireless power transmission system based on magnetic resonance coupling circuit was carried out. With the research objectives based on the mutual coupling model, mathematical expressions of optimal coupling coefficients are examined. Equivalent circuit parameters are calculated by Maxwell software, and the equivalent circuit was solved by Matlab software. The power transfer efficiency of the system was derived by using the electrical parameters of the equivalent circuit. System efficiency was analyzed depending on the different air gap values for various characteristic impedances. Hence, magnetic resonance coupling involves creating a resonance and transferring the power without radiating electromagnetic waves. As the air gap between the coils increased the coupling between the coils were weakened. The impedance of circuit varied as the air gap changed, affecting the power transfer efficiency.

• 제어로봇시스템학회논문지
• /
• 제6권9호
• /
• pp.777-785
• /
• 2000

This paper provides a guideline for the determination of compliance characteristics and the proper location of the compliance center in typical peg-in-hole and peg-out-hole tasks using hands. We first observe the fact that some of coupling stiffness elements cannot be planned arbitrarily. The given peg-in/out-hole tasks are classified into two contact styles. Then, we analyze concluded of the operational siffness matrix, which achieve the give peg-in/out-hole tasks effectively for each case. It is concluded that the location of the compliance center on the peg and the coupling stiffness element existing between the translational and the rotational direction play ompliance on the peg and the coupling siffness element existing between the translational and the rotational direction play important roles for successful peg-in/out-hole tasks. The analytic results verified through simulations.

• 한국정밀공학회지
• /
• 제30권11호
• /
• pp.1171-1177
• /
• 2013

In this study, the torque transmitting capability of a flexible disk coupling was investigated. Flexible disc coupling is used to transmit power between two axes, and there exist mis-alignments such as angle of deviation and end play between two shafts. A disk is an important part in the flexible disk coupling because the disk has to transmit power between two mis-aligned shafts. To investigate the effect of mis-alignment on load carrying capacity, finite element analyses were carried out. Analyses were carried out for two types of disk; i.e., circular and square disks. The rotational and bending stiffness of disk plates was predicted to investigate the effect of mis-alignment on stress. As a result, it was shown that the mis-alignment can cause severe decrease in load-carrying capacity. And, the square disk showed better performance than the circular disk.