• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.208-212
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• 2011

In this work, the calculated nuclear quadrupole coupling constants of $^{17}O$ in some styrylquinoline conformers were presented. The calculations were carried out to find the relationships between the charge distribution of styrylquinolines and their pharmaceutical behavior and to explore the differences among the electronic structures of some conformers of these potent HIV IN inhibitors. Furthermore, the HIV IN inhibitory of R1 and R2 rotamers was compared. On the basis of our results: - Charge density on oxygen atoms of carboxyl moiety has a dominant role in the drug activity. - The a conformer in which a divalent hydrogen atom is a link, has more capability in antiviral drug treatment. - The R1 conformer, as a $Mg^{+2}$ chelating agent, is better than R2 conformer and thus it is more inhibitor of HIV IN.

• 전기학회논문지
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• 제64권3호
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• pp.438-444
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• 2015

A new approach to the active phased arrays for the second harmonic generation is presented. Phase variation between the second harmonic oscillators by the mutual synchronization is analyzed theoretically. In this coupling, the active antenna consists of the FET oscillator which plays two roles in fundamental oscillation and frequency multiplying, and the patch antenna resonated at the second harmonic frequency. The radiated second harmonic wave was scanned by varying the free-running oscillation frequencies of the active antennas. In the experiment using the 2-elements array and the 4-elements array, the radiated beam of the second harmonic wave was scanned more widely compared with the case of the fundamental wave radiation.

• Structural Engineering and Mechanics
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• 제38권5호
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• pp.573-592
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• 2011

Comprehensive and accurate analysis of a finite foundation beam is a challenging engineering problem and an important subject in foundation design. One of the limitation of the traditional Winkler elastic foundation model is that the model neglects the effect of the interface resistance between the beam and the underneath foundation soil. By taking the beam-soil interface resistance into account, a deformation governing differential equation for a finite beam resting on the Winkler elastic foundation is developed. The coupling effect between vertical and horizontal displacements is also considered in the presented method. Using Galerkin method, semi-analytical solutions for vertical and horizontal displacements, axial force, shear force and bending moment of the beam under symmetric loads are presented. The influences of the interface resistance on the behavior of foundation beam are also investigated.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 춘계 학술발표회 논문집 Proceedings of EESK Conference-Spring
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• pp.275-283
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• 1999

To predict the dynamic behavior of the cylindrical liquid storage tank subjected to seismic ground motion three dimesional analysis with liquid-structure interaction must be performed, In this study a three dimensional dynamic analysis method over the frequency domain using FE-BE coupling technique which combines the efficiency of the boundary elements for liquid with the versatility of the finite shell elements for tank. The liquid region is modeled using boundary elements which can counter the sloshing effect at free surface and the structure region the tank itself is modeled using the degenerated finite shell elements. At the beginning of the procedure the equivalent mass matrix of the liquid is generated by boundary elements procedure. Then this equivalent mass matrix is combined with the mass matrix of the structure to produce the global mass matrix in the equation of the motion of fluid-structure interaction problem In order to demonstrate the accuracy and validity of the developed method the numerical results re compared with the previous studies. Finally the effects of the fluid-structure interaction on the natural frequency and dynamic response of the system are analyzed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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• pp.133-136
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• 1992

Electrical resistivity and piezoelectric properties were investigated in Lead Zirconate-Titante(PZT) with Nb$_2$O$\sub$5/dopant, fabricated from conventional mixed-oxide powders and molten salt synthesis. The resistivity and electromechanical coupling factor(K$\sub$p/) were increased with increasing Nb content. The reason for increasing of the electrical resistivity below the Curie Temperature(TC). It is believed that the Curie Temperature(Tc). It is believed that the p-type electrical conduction in PZT is due to lead vacancies. The electromechanical coupling factor(K$\sub$p/) and piezoelectric constant d$\sub$33/ were improved. This behavior can be explained as a compensation effect and Nb$\^$5+/ can serve as a donar and contribute electrons to the conduction process. As a result, the optimized Nb$_2$O$\sub$5/ dopants on the PZT specimens were 0.75 wt%.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.404-408
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• 2005

Having flexibility in a manipulator will degrade trajectory tracking control and manipulator tip positioning. In practice, however, constraints imposed by various operating requirements, will render the presence of such flexibility unavoidable. The dynamic analysis of the flexible manipulator is essential in designing proper control systems. A flexible manipulator consists of infinite number of elastic modes and the modes are usually coupled to each other. For the practicality, however, it is usually assumed that the flexible system consists of finite number of elastic modes and the modes are decoupled. These assumptions result in a linear and decoupled mathematical model of the flexible manipulator and simplify the analysis of the dynamic behavior and the design of the control system. The decoupling and linearization of the flexible link, however, has been assumed without in depth analysis. This paper focuses on the analysis of the significance of the non-linear coupling factors.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 춘계학술발표회 논문집
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• pp.280-280
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• 2012

Mg의 첨가한 Zn-Mg-Al 합금도금강판에 형성된 $Zn-MgZn_2$ 공정조직의 부식거동을 이해하고자 진공 고주파 용해로 $MgZn_2$ 제작한 후 Zn와 galvanic coupling하여 $MgZn_2$합금과 Zn간의 galvanic corrosion 거동을 알아보았다. $MgZn_2-Zn$ galvanic coupling의 SVET 결과에서 $MgZn_2$가 anode, Zn가 cathode가 됨을 확인되었다. $MgZn_2$의 Zn와의 galvanic corrosion 평가에서 galvanic current는 Zn 보다 낮은 potential에서 anodic current density를 나타내었으며, galvanic potential은 $MgZn_2$전위로부터 두 합금의 혼합전위를 향해 증가함을 알 수 있었다. Zn-Mg-Al 합금도금강판의 염수분무 평가에서도 초기 $Zn-MgZn_2$ 공정조직에서 $MgZn_2$가 용출되는 것이 관찰되었다.

• Steel and Composite Structures
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• 제25권2호
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• pp.187-196
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• 2017

In this work, transient thermo-piezo-elastic responses of an infinite functionally graded piezoelectric (FGPE) plate whose upper surface suffers time-dependent thermal shock are investigated in the context of different thermo-piezo-elastic theories. The thermal and mechanical properties of functionally graded piezoelectric plate under consideration are expressed as power functions of plate thickness variable. The solution of problem is obtained by solving the corresponding finite element governing equations in time domain directly. Transient thermo-piezo-elastic responses of the FGPE plate, including temperature, stress, displacement, electric intensity and electric potential are presented graphically and analyzed carefully to show multi-field coupling behaviors between them. In addition, the effects of functionally graded parameters on transient thermo-piezo-elastic responses are also investigated to provide a theoretical basis for the application of the FGPE materials.

• 국제초고층학회논문집
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• 제10권3호
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• pp.211-218
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• 2021

A new type of earthquake resilient reinforced concrete (RC) shear wall structure, installed with replaceable coupling beams and replaceable corner components at the bottom of wall piers, is proposed in this study. At first, the mechanical behavior of replaceable components, such as combined dampers and replaceable corner component, is studied by cyclic loading tests on them. Then, cycling loading tests are conducted on one conventional coupled shear wall and one new type of coupled shear wall with replaceable components. The test results indicate that the damage of the new type of coupled shear wall concentrates on replaceable components and the left parts are well protected. Finally, a case study is introduced. The responses of one conventional frame-tube structure and one new type of structure installed with replaceable components under the wind and the earthquake are compared, which verify that the performance of new type of structure is much better than the conventional structure.

• 한국지진공학회논문집
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• 제14권6호
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• pp.1-9
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• 2010

대부분의 전단벽 구조물은 통로의 목적으로 개구부를 필요로 하게 되고 전단벽들 사이가 슬래브나 연결보로 연결된 병렬 전단벽의 형태를 띠게 된다. 이러한 구조물에 지진하중이 작용할 때 연결보에 과도한 전단력이 작용하여 연결보가 취성적으로 파괴되거나 전단벽이 먼저 항복하는 문제점이 발생할 수 있다. 이를 방지하기 위하여 연결보에 감쇠장치를 설치하게 되면 구조물의 진동제어효과와 더불어 연결보의 응력집중 및 취성적 파괴를 막을 수 있어서 내진성능 향상을 기대할 수 있다. 본 논문에서는 병렬전단벽 연결보 중앙부에 LRB (Lead Rubber Bearing)가 설치된 구조물의 지진응답제어효과 및 응력의 분포를 평가하여 구조적 효율성을 확인하고자 한다. 이를 위하여 병렬전단벽의 거동을 비교적 정확하게 모사할 수 있는 모형화 방법을 제안하였고, 제안된 모형화 방법을 통하여 지진하중을 받는 예제 병렬구조물에 대한 시간이력해석을 수행한 후 지진응답제어성능을 검토하였다.