• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.79-84
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• 2015

Transformer is widely used element on power system and industrial area. Especially the transformers installed at power system are exposed to an environment of arbitrary changed. Thus the prediction of degradation and the analysis of response to impulse are important. To conduct those works, the electrical characteristics of system should be analyzed, effectively. But the analysis of electrical characteristic in electric machine level such as pole and pad-mounted transformer is almost no, thus commercial VNA (Vector Network Analyzer) is used to getting the response in wide frequency range. However, the output power of VNA is usually under 10mW, so verification for effectiveness of measuring electrically large component should be conducted, firstly. Next, after getting total S-parameter of transformer, predicting impulse response can be performed in time-domain with circuit simulator. In this paper, it is introduced that verification effectiveness of VNA using transfer function from SFRA (Sweep Frequency Response Analyzer), firstly. Next, total S-parameter, six by six matix form, was built using measured 2 port S-parameter from vector network analyzer. To get the response to impulse which is defined by IEC 60060-1, time-domain simulation is conducted to ADS (Advenced Design System) circuit simulator.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.416-418
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• 1997

Stable power source and fast control response are important for the generator excitation system. To stabilize the control of excitation circuit the PI controller for excitation current has been used. But the response of the system with this conventional control technique is very poor, especially in transient response with a predictive current control, the response of the excitation system can be improved. In this study, it is verified by the PSIM simulation.

• Structural Engineering and Mechanics
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• v.60 no.4
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• pp.595-614
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• 2016

By taking the Runyang Highway Bridge over the Yangtze River with 1490 m main span as example, structural response of the bridge under the horizontal and vertical seismic excitations is investigated by the response spectrum and time-history analysis of MIDAS/Civil software respectively, the seismic behavior and the influence of structural nonlinearity on the seismic response of the bridge are revealed. Considering the aspect of seismic performance, the suitability of employing the suspension bridge in super long-span bridges is investigated as compared to the cable-stayed bridge and cable-stayed-suspension hybrid bridge with the similar main span. Furthermore, the effects of structural parameters including the span arrangement, the cable sag to span ratio, the side to main span ratio, the girder height, the central buckle and the girder support system etc on the seismic performance of the bridge are investigated by the seismic response spectrum analysis, and the favorable earthquake-resistant structural system of suspension bridges is also discussed.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.637-642
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• 2000

This paper suggests new analysis algorithm for tile dynamic response of three dimensional structure which is frequently found in pipe line system of plant by the combination of the transfer stiffness coefficient method(TSCM) and Newmark method. Presented analysis algorithm for dynamic response can improve the computational accuracy remarkably owing to advantages of tile TSCM in comparison of transfer matrix method(TMM). Analysis system was modeled as a lumped mass system in this mettled. The analysis algorithm for dynamic response was formulated for the three dimensional structure. The validity of the this method is demonstrated through the results of numerical experiment for simple computational model by the TSCM and TMM.

• Journal of Power System Engineering
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• v.19 no.6
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• pp.33-38
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• 2015

In this study new CVT(Continuously Variable Transmission) system which is adaptable to a small size electric vehicle is proposed available to gradient response CVT. New pulleys consist of springs adapted driving pulley and driven pulley. At the moment a small electric vehicle drive a slope, new system respond to a gradient as overcoming tensional force of springs. We made prototype of gradient response CVT to test parts performance and travelling performance test. As a result of test, belt pitch diameter varied for high torque direction at the gradient. In the flat travelling, acceleration travelling and gradient travelling performance test, the small electric vehicle with gradient response CVT get improved perfomance than the small electric vehicle with reduction gear.

• Journal of the Society of Disaster Information
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• v.6 no.2
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• pp.21-44
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• 2010

Today, in response to chemical, biological and radiological terrorism has been active for the study. However, if chemical, biological and radiological attack has occurred to respond to the agency has not conducted the research. The purpose of this study are as follows. First, South Korea and the United States 'CBR terrorism' comparative analysis of the response system. Second, South Korea 'CBR terrorism' measures to improve the system response is presented. To achieve the purpose of this study, the following research is carried out. First, determine the status of the case of CBR incident. Second, the United States 'CBR terrorism' response systems and organizational approaches. Third, Korea's 'CBR terrorism' response system and the problem is derived.

• Journal of Power System Engineering
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• v.3 no.1
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• pp.74-79
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• 1999

This paper describes formulation for algorithm of time historical response analysis of vibration for straight-line structure. This method is derived from a combination of the transfer stiffness coefficient method and the Newmark method. And this present method improves the computational accuracy of the transient vibration response analysis remarkably owing to several advantages of the transfer stiffness coefficient method. We regarded the structure as a lumped mass system here. The analysis algorithm for the time historical response was formulated for the straight-line structure containing crooked, tree type system. The validity of the present method compared with the transfer matrix method and the Finite Element Method for transient vibration analysis is demonstrated through the numerical computations.

• International Journal of Control, Automation, and Systems
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• v.2 no.3
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• pp.384-389
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• 2004

Recently a method of model reduction for discrete systems has been proposed in the literature based on a new impulse response Gramian. In this method, the system matrix$A_r$ of a reduced model is computed by approximating the reduced-order impulse response Gramian. The remaining matrices $b_r$ and $c_r$ are obtained so that various initial Markov parameters and time-moments of the original system are preserved in the reduced model. In this paper a different approach is presented based on the recursive relationship among the impulse response Gramians.

• Earthquakes and Structures
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• v.2 no.4
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• pp.323-336
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• 2011

The problem of reconstruction of complete building response from a limited number of response measurements is considered. The response at the intermediate degrees of freedom is reconstructed by using piecewise cubic Hermite polynomial interpolation in time domain. The piecewise cubic Hermite polynomial interpolation is preferred over the spline interpolation due to its trend preserving character. It has been shown that factorization of response data in variable separable form via singular value decomposition can be used to derive the complete set of normal modes of the structural system. The time domain principal components can be used to derive empirical transfer functions from which the natural frequencies of the structural system can be identified by peak-picking technique. A reduced-rank approximation for the system flexibility matrix can be readily constructed from the identified mass-orthonormal mode shapes and natural frequencies.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.625-628
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• 2007

갈수록 복잡화, 대량화되고 있는 시스템의 성능은 유지하면서 User Response Time 을 단축시키는 Tuning 은 투자 대비 이익률(ROI : Return On Investment)에 탁월한 효과를 가져온다는 점에서 중요시 되고 있다. 본 연구는 SAP R/3 System 환경에서 Tuning 통한 User Response Time 감소를 위하여 Query 분석 및 Table Index 생성, Program Logic 수정, Parallel Processing, SAP R/3 System 의 고유 기능인 Notes 적용을 통한 User Response Time 감소 기법을 제시한다.