• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.04a
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• pp.130-135
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• 1995

Wind-induced vibration of buildings with viscoelastic dampers are studied analytically. The added viscoelastic dampers change the damping distribution and reduce the response of buildings. The distribution of damping resistance that results from these viscoelastic dampers is known as non-classical or non-proportional. Non-classically damped structures are analyzed by state-space approach. However, this approach is complex and time-consumming compared to classical approach. This paper is aimed at the analysis of wind-induced Vibration Of buildings With Viscoelastic dampers. The Process Of State-Space approach is studied and the approximate analysis is suggested to overcome the complex and time-consuming access. For numerical certification, PSDF(Power Spectral Density Function) is obtained. Autocorrelation function is obtained in time domain and PSDF is obtained by fourier transformation of this function in frequency domain. It is found that Approximate method can give close approximation to exact solution.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1548-1555
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• 2016

This paper presents an application of time series analysis in hourly wind speed simulation and forecast in Jeju Island, Korea. Autoregressive - moving average (ARMA) model, which is well in description of random data characteristics, is used to analyze historical wind speed data (from year of 2010 to 2012). The ARMA model requires stationary variables of data is satisfied by power law transformation and standardization. In this study, the autocorrelation analysis, Bayesian information criterion and general least squares algorithm is implemented to identify and estimate parameters of wind speed model. The ARMA (2,1) models, fitted to the wind speed data, simulate reference year and forecast hourly wind speed in Jeju Island.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.744-750
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• 2014

In this paper, I have measured NCO(Network Centric Operation) Effectiveness of Anti-piracy Operation at the Chunghae Unit. For quantitative analysis, Network Centric Operations Conceptual Framework(U.S Office of Force Transformation) is applied. In accordance with the framework, the Chunghae unit anti-piracy operation scenario is analysed. The scenario is devided with two case(only voice communication and networking). The element of analysis be composed of the organic information, networking, share-ability, and individual information. As a result of analysis, the individual information of first case(only voice) gets 0.59 points. The other side, second case (networking) gets 1 points. This means that NCO has effect on the Chunghae Unit's mission. In addition, I stated the tactics advantage of NCO related a fighting power.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.286-290
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• 2003

Accurate acquisition of surface geometries such as machined surfaces, biological surfaces, and deformed parts have been very important technique in scientific study and engineering, expecially for system design, manufacturing and inspection. Two camera method keeps accuracy more than double than mechanical method. In this paper, we describe the processes surface data of teeth for automatic processing, transformation that changes to coping data of possible numeric data form and processed inlay teeth. As the result of the Inlay manufacture, which can process with high resolution, therefore we construct the automatic processing system that depends on manual

• IEIE Transactions on Smart Processing and Computing
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• v.1 no.1
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• pp.50-64
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• 2012

Quality of Service (QoS) and fairness considerations are undoubtedly essential parameters that need to be considered in the design of next generation scheduling algorithms. This work presents a novel game theoretic cross-layer design that offers optimal allocation of wireless resources to heterogeneous services in Orthogonal Frequency Division Multiple Access (OFDMA) networks. The method is based on the Axioms of the Symmetric Nash Bargaining Solution (S-NBS) concept used in cooperative game theory that provides Pareto optimality and symmetrically fair resource distribution. The proposed strategies are determined via convex optimization based on a new solution methodology and by the transformation of the subcarrier indexes by means of time-sharing. Simulation comparisons to relevant schemes in the literature show that the proposed design can be successfully employed to typify ideal resource allocation for next-generation broadband wireless systems by providing enhanced performance in terms of queuing delay, fairness provisions, QoS support, and power consumption, as well as a comparable total throughput.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.2
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• pp.71-79
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• 2002

In this paper, an oil hydraulic pipeline is terminated by both rotary sinusoidal flow generator at upstream oriffice at down stream. The pulsating pressure wave from generated by the rotary sinusoidal flow generator, is measured by using sensor. In the analysis of this paper, a component of the fundamental frequency is obtained by using Laplace transformation.. The experimental and analytical results make clear that (1) viscosity is significant role in hydraulic pipe. (2) When pulsating frequency is matched with the natural frequency, resonance frequency occured periodically. According to the study proposed here, dynamic pressure in a circular oil pipe is expressed in propagation of pressure wave with respect to frequency and Bessel function. The resonance at oil temperature $20^{\circ}$$0^{\circ}C$ in this study. The abrupt change of gain value is due to effect of resonance frequency. The results of experiment are compared with the calculated results, and agreement of both results is fairly good.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.171-172
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• 2011

The paper proposes a close loop control algorithm for Z-source inverter. The algorithm is realized by PWM duty ratio control in order to improve the output voltage to it's desired level. The controller consist of the output voltage PID controller and DC input voltage P controller. Using the DQ coordinate transformation simplify the controller design. The PSIM simulation results verify the validity by means of comparing the system with or without compensation and estimating if the system has output consistency function when ZSI's load and input voltage value changing.

• Journal of Korean Society for Quality Management
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• v.32 no.4
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• pp.208-219
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• 2004

This paper considers a nonparametric estimation of lifetime distribution for ramp stress tests with stress bound under intermittent inspection. The test items are inspected only at specified time points an⊂1 so the collected observations are grouped data. Under the cumulative exposure model, two nonparametric estimation methods of estimating the lifetime distribution at use condition stress are proposed for the situation which the time transformation function relating stress to lifetime is a type of the inverse power law. Each of items is initially put on test under ramp stress and then survivors are put on test under constant stress, where all failures in the Inspection interval are assumed to occur at the midi)oint or the endpoint of that interval. Two proposed estimators of quantile from grouped data consisting of the number of items failed in each inspection interval are numerically compared with the maximum likelihood estimator(MLE) based on Weibull distribution.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.315_317
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• 2009

전력계통은 발전, 송전, 변전, 배전계통으로 구성되지만 정전을 수반하는 대형고장은 전력계통 구성의 특성상 대부분 변전분야에서 발생하게 된다. 이러한 고장의 원인은 여러 가지로 분류할 수 있겠으나 특히 Human Error에 의한 고장 발생시 그 파급영향은 막대하다. 하지만 지금까지 변전설비의 고장 원인을 Human Error 측면에서 연구한 논문은 국내에서는 찾아보기가 힘들다. "전력계통의 고신뢰성 유지를 위한 변전분야 Human Error 예방대책"이란 논문이 2008년 한국전력 사내에서 발표된 정도이다. 본 논문에서는 해마다 끊이지 않고 반복되어지는 변전분야의 Human Error에 의한 고장에 대한 발생원인을 분석하고 현장 실행 위주의 예방대책을 제시하고자 한다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.32 no.1
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• pp.70-77
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• 2008

A pre-processing program based on the OOP(object-oriented programming) concept has been developed. The program consists of the input of a 2D or 3D flow problem to a CFD program by means of an user-friendly interface and the subsequent transformation of this input into a form suitable for the solver(PowerCFD) using unstructured cell-centered method. User-friendly GUI(graphic user interface) has been built on the base of MFC(Microsoft Foundation Class). The program is organized as modules by classes based on VTK(Visualization ToolKit)-library, and these classes are made to function through inheritance and cooperation which is an important and valuable concept of object-oriented programming. The major functions of this program are introduced and demonstrated, which include mesh generation, boundary settings, solver settings, generation of grid connectivity and geometric data etc.