• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.147-152
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• 2014

A longitudinal modal transmission-line theory(L-MTLT) to analyze the static and dynamic behavior of two-section distributed feedback (DFB) lasers is used. The characteristic impedance and equivalent propagation constant of DFB structure with active layer are derived from L-MTLT. A two-section DFB laser is analogous to a transmission-line network, in which each section is described by transmission-line block corresponding to the equivalent factors. The longitudinal resonant condition of DFB laser based on equivalent transmission-line network is used to reformulate the rate equations so that static and dynamic behavior of two-section DFB lasers with active layer is demonstrated and analyzed accurately.

• Structural Engineering and Mechanics
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• v.58 no.6
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• pp.967-988
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• 2016

Due to the significant aerodynamic interference from sub-towers and surrounding tall buildings, the wind loads and dynamic responses on main tower of three-tower connected tall building typically change especially compared with those on the isolated single tall building. This paper addresses the wind load effects and equivalent static wind loads (ESWLs) of three-tower connected tall building based on measured synchronous surface pressures in a wind tunnel. The variations of the global shape coefficients and extremum wind loads of main tower structure with or without interference effect under different wind directions are studied, pointing out the deficiency of the traditional wind loads based on the load codes for the three-tower connected tall building. The ESWLs calculation method based on elastic restoring forces is proposed, which completely contains the quasi-static item, inertia item and the coupled effect between them. Then the wind-induced displacement and acceleration responses for main tower of three-tower connected tall building in the horizontal and torsional directions are investigated, subsequently the structural basal and floor ESWLs under different return periods, wind directions and damping ratios are studied. Finally, the action mechanism of interference effect on structural wind effects is investigated. Main conclusions can provide a sientific basis for the wind-resistant design of such three-tower connected tall building.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.717-724
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• 2006

The major objective of this study is to investigate the effects and application of improvement for railway steel plate girder bridge by resilient panel track system. It analyzed the mechanical behaviors of steel plate girder bridge with applying resilient panel track system on the finite element analysis and laboratory test for static & dynamic characteristics. As a result, the improvement of steel plate girder bridge with resilient panel track systems are obviously effective for the static & dynamic response which is non-ballast steel plate girder bridge. The analytical and experimental study are carried out to investigate resilient panel track system decrease vertical acceleration and deflection on steel plate girder bridge for serviceability. And the resilient panel track system reduced dynamic maximum displacements (about 59%) and stresses (about 82%), the increase of dynamic safety is predicted by adopting resilient panel track system. From the dynamic test results of steel plate girder bridge, it is investigated that vertical acceleration and deflection is very low with applying resilient panel track system. The servicing steel plate girder bridge with resilient panel track system has need of the reasonable improvement measures which could be reducing the effect of static and dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.1
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• pp.73-83
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• 2016

PURPOSE : The purpose of this study to suggest the exercise programs for improving the function and structure by applying the Masan university scoliosis program exercise method and electrical therapy method to the scoliosis patient. METHODS : The subjects were 18 patients who were diagnosed with scoliosis. They were randomly assigned either to a Masan university scoliosis program exercise group (n=11) that received Masan university scoliosis program exercise program or to a electrical therapy group (n=7). Flexibility, static balance, dynamic balance, and spinal angles were measured by using one leg standing with closed eyes, functional reach test, and Cobb's angle, respectively. The chest expansion were calculated using differences of chest circumference between maximum inspiration and maximum expiration. RESULT : Masan university scoliosis program group before and after the intervention there was a difference in the static balance, spine angle(p<.05). Masan university scoliosis program group before and after the intervention there was a difference in the flexibility, static balance, spine angle, chest expansion (p<.05). CONCLUSION : These results revealed that Masan university scoliosis program exercise program improved flexibility, static standing balance, spine angle, used as scoliosis management and intervention. Therefore, it is expected to be used as a method for the treatment and prevention in the process of rehabilitation of patients with scoliosis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.3
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• pp.31-36
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• 2006

In this study, nonlinear static aeroelastic analysis system for a high-aspect-ratio wing are developed using the transonic small disturbance (TSD) and large deflection beam theory and validated. For the coupling between fluid and structure, the transformation of displacement from the structural mesh to aerodynamic one is performed by the shape function of the beam finite element and the inverse transformation of force by work equivalent load concept. Also, for the static aeroelastic analysis of the wing the use of TSD aerodynamics are justified. The validation of the system includes one of the efficient transformation methods of force and displacement.

• Journal of the Earthquake Engineering Society of Korea
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• v.6 no.2
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• pp.21-28
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• 2002

Ductile behavior and strength of concrete-filled steel(CFS) piers was supported by many quasi-static cyclic loading tests. This test method, however, only estimates the member′s deformation capacity under escalating and repetitive displacement and ignores dynamic and random aspects of an earthquake load. Therefore, to understand complete seismic behavior of the structure against an earthquake, dynamic tests such as shaking table test and pseudo-dynamic tests are required as well as quasi-static tests. In this paper, following "Seismic Performance of Concrete-Filled Steel Piers Part I : Quasi-Static Cyclic Loadint Test", the seismic behavior of CFS and steel piers designed for I-Soo overpass in Seoul in investigated by the pseudo-dynamic test. In addition, the residual strength of both piers after an earthquake is estimated by the quasi-static test. The results show that both piers have satisfactory ductility and strength against well-known EI Centro earthquake although the CFS pier has better strength and energy dissipation than the steel pier.

• ETRI Journal
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• v.11 no.2
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• pp.120-136
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• 1989

최근의 데이터 베이스 응용분야에 있어서 시간에 따른 정보의 변화를 유지관리할 필요성이 대두되고 대용량의 기억장치 가격의 급속한 감소와 함께 이의 이용 기술이 향상되면서 시간주기에 따라 실세계의 상태에 대한 변경과정을 표현하는 시간 즉, 데이터의 변경이력을 지원하는 데이터베이스(Terporal Database)에 관심이 집중되고 있으며, 이러한 요구를 만족시키기 위한 여러 방법들이 연구되고 있다. 일반적으로 시간 지원 데이터베이스 모델은 지원되는 시간의 형태에 따라 Static, Static Rollback, Historical, Temporal, Revision 데이터베이스 모델로 나뉘어진다. 본 논문에서는 시간 및 변경이력을 지원하기 위한 데이터베이스 모델과 이를 위한 데이터베이스 시스템의 주요 설계 Issue들에 관하여 조사분석한 다음, Static Rollback 데이터베이스 모델을 기본으로 하는 "$SR^2DBS$: 시간 지원 데이터베이스 시스팀"의 설계 및 구현에 관하여 기술하였다. $SR^2DBS$은 기존의 관계형 데이터 베이스 시스팀"의 모델을 시간 애트리뷰트를 추가시킴으로서 데이터 베이스의 변경이력관리를 가능케 한 Direct Manipulation Database Processing System으로 데이터베이스의 현상태 뿐만 아니라 시간에 따른 변경이력에 대해서 Screenoriented Relation Browsing & Editing 기능을 제공하며, 다음과 같은 특징을 갖는다. - Screen oriented Processing - Directi-Manipulation of Objects - Object & Revision History of Interest Visibility - Rapid Reversible Actions - Transaction Time & Revision Number Supporting - Roll-back Query Supporting - Han-gul Data Supporting - Two level Storage Structure(Current Version & History Versions)

• Steel and Composite Structures
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• v.24 no.4
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• pp.467-479
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• 2017

The stud is one of the most frequently used shear connectors which are important to the steel-concrete composite action. The static and fatigue behavior of stud in the steel fiber reinforced concrete (SFRC) were particularly concerned in this study through the push-out tests and analysis. It was for the purpose of investigating and explaining a tendency proposed by the current existing researches that the SFRC may ameliorate the shear connector's mechanical performance, and thus contributing to the corresponding design practice. There were 20 test specimens in the tests and 8 models in the analysis. According to the test and analysis results, the SFRC had an obvious effect of restraining the concrete damage and improving the stud static performance when the compressive strength of the host concrete was relatively low. As to the fatigue aspect, the steel fibers in concrete also tended to improve the stud fatigue life, and the favorable tensile performance of SFRC may be the main reason. But such effect was found to vary with the fatigue load range. Moreover, the static and fatigue test results were compared with several design codes. Particularly, the fatigue life estimation of Eurocode 4 appeared to be less conservative than that of AASHTO, and to have higher safety redundancy than that of JSCE hybrid structure guideline.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.437-446
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• 2006

The major objective of this study is to investigate the effects and application of improvement for railway steel plate girder bridge by resilient panel track system. It analyzed the mechanical behaviors of steel plate girder bridge with applying resilient panel track system on the finite element analysis and laboratory test for static & dynamic characteristics. As a result, the improvement of steel plate girder bridge with resilient panel track systems are obviously effective for the static & dynamic response which is non-ballast steel plate girder bridge. The analytical and experimental study are carried out to investigate resilient panel track system decrease vertical acceleration and deflection on steel plate girder bridge for serviceability. And the resilient panel track system reduced dynamic maximum displacements(about 59%) and stresses(about 82%), the increase of dynamic safety is predicted by adopting resilient panel track system. From the dynamic test results of steel plate girder bridge, it is investigated that vertical acceleration and deflection is very low with applying resilient panel track system. The servicing steel plate girder bridge with resilient panel track system has need of the reasonable improvement measures which could be reducing the effect of static and dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

• Journal of the Korean Society of Safety
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• v.13 no.3
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• pp.11-23
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• 1998

In this study, collapse test of thin-walled structure is performed under axially quasi-static and impact load in collapse characteristic to develop the optimum structural member for a light-oriented automobile. Furthermore, the energy-absorbing capacity is observed according to the variety of configuration(circular, square), aspect ratio in aluminum specimen to obtain basic data for the improved member of vehicle. In both quasi-static and impact collapse test, Al circular specimens collapse, in general, with axisymmetric mode in case of thin thickness while collapse with non-axisynmetric mode according to the thickness increase. For Al rectangular specimens, they collapse with axisymmetric mode in case of thin thickness, with mixed collapse mode according to the increase of thickness. In terms of initial max. load, Al square specimen turns out the best member among specimens, and then Al square, circular and circular with large scaling ratio, respectively. In case of quasi-static compression test, the absorbed energy per unit volume and mass shows higher in Al circular specimen, and then Al square, circular with large scaling ratio, respectively, according to shape ratio the absorbed energy per unit volume and mass in case of max. impact compression load is higher than that of static load. But the absorbed energy per unit volume and mass shows that Al circular specimen is the best member. Especially, unlike max. compression loan, the absorbed energy per unit volume and mass in impact test turns out the low value.