• 전기의세계
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• v.24 no.5
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• pp.107-110
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• 1975

This paper describes computational algorithms and a computer program for optimum determinations of wire conductor sizes of radial or tree-type distibution lones with given constraints. Here, The objective function is defined as the total summation of the volume or weight of respective conductor materials required for buildingup the entire distributing system. Four categories of constraints are applied to the obiective function. That is, on the respective load points constraint is imposed by a specified voltage drop limit, and the respective line elements are capable of carrying the current safely(safety current) and also must maintain the minimum thickness in viewpoint of mechanical strength and legal requirements. And finally, the conductor sizes have to be selected among the standardized size levels of the products. These kinds of optimization problems cannot be solved by the ordinary optimization tediniques such as the Linear Programming Method, SUMT Technique, etc. This paper, therefore, successfully devised the powerful alorithms to solve the problem, using the particular properties or characteristics ingerent to the radial or tree-type distribution system. The computer program developed from the algorithms was applied to several sample systems and shown to be exact and very efficient.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3145-3150
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• 2010

Ruthenium catalysts modified by selenium have been introduced as alternative materials to Pt in Direct methanol fuel cells (DMFCs). RuSe nano-particles were synthesized on the Vulcan XC72R carbon supports via polyol method. The prepared catalysts were electrochemically and physically characterized by cyclic voltammetry (CV,) linear sweep voltammetry, methanol tolerance test, X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energydispersive Spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). Increasing the Se concentration up to 20 at % increased the electro-catalytic activity for the oxygen reduction. By increasing Se amount, Ru metallic form on the surface was increased. The $Ru_{80}Se_{20}$/C catalysts showed the highest oxygen reduction reaction (ORR) activity and outstanding methanol tolerant property in half cell tests as well as single cell test.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.34-40
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• 2006

Many producers put sampling inspection policy into the way of their convenience. Examples of the convenience are irregular lot size and too small sample size. Because they don't use a standard sampling inspection policy, they can not guarantee the quality level of their products. In this study, we developed a user-centered design program which can calculate the AOQL of their products to their buyers in the case of irregular lot size and too small sample size. Also this program propose a linear inspection cost by Hald's model.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1928-1931
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• 2002

Orthogonal Frequency Division Multiplexing or OFDM is a form of multi-carrier modulation technique. High spectral efficiency, robustness to channel fading, immunity to impulse interference, uniform average spectral density, capability of handling very strong echoes and less on linear distortion are among the favorite properties of OFDM. Even though there are many advantages of OFDM, t has two main drawbacks: high Peak to Average Power Ratio (PAPR) and frequency of offset. In this paper, the issue of PAPR in OFDM is discussed. A new algorithm is proposed to reduce PAPR by selecting the input sequences property using a lookup table.

• Journal of the Korean Institute of Telematics and Electronics
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• v.16 no.2
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• pp.24-34
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• 1979

In this paper characteristics of the Ebers-Mull , charge control and Linvill iumped models are reviewed. A 1%eery for systematically modeling solid state device by F.A Lind helm and D. J. Hamilton is discussed in detail. Nonlinear and linear modeds for the junction field effect transistor are derived from the systematic modeling theory. Computer program for the transient analysis is develooped and application of the program to the RC amplifler shows guod results.

• Journal of Ocean Engineering and Technology
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• v.10 no.2
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• pp.13-19
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• 1996

For fatigue analsis of offshore structures, existing methods have been reviewed and a computer code has been developed on PC. As methods to estimate the probabillity distribution of the fatigue stress, three methods(the deterministic method, the stochastic method, and the simplified method) are used in this code, to choose the appropriate method according to the situations. This code estimates damage ratios, fatigue lives, and probabilities of fatigue failure considering scatterness of SN-data, based on linear damage rule and SN-curves. Also, allowable stress for the design extreme wave can calculated by the simplified method.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2000.10a
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• pp.361-368
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• 2000

This paper demonstrates how nonlinear soil behavior in a soil-structure interaction system can be realistically incorporated by using a hybrid method in a nonlinear time-domain analysis. The hybrid method employs a general-purpose nonlinear finite element program coupled with a linear SSI program for the unbounded layered soil medium In order to verify the validity and applicability of the hybrid method, nonlinear earthquake response analyses are carried out for the Hualien free-field problem, in which the ground and underground accelerations were measured during several earthquake events, and for a 2-D subway station. It is found that the nonlinear earthquake responses predicted for the Hualien free-field using the hybrid method compare very well with the observed responses whereas the subway station example gives reasonable results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.2
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• pp.1-14
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• 1991

A computer program for the linear elastic buckling anlalysis of thin walled members is developed using a 3-node triangular shell element. The element has real stiffness value for a kinematic degree of freedom associated with rotation about the surface normal at each node. The validity of the present computer program is demonstrated through the plate buckling analysis and the lateral-torsional buckling analysis of a straight beam. Then, simply supported circular arches subjected to uniform bending are analyzed and the results are compared with existing solutions.

• Structural Engineering and Mechanics
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• v.53 no.1
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• pp.131-146
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• 2015

In the present paper a three-dimensional non-linear truss element and a short computer program for the modeling and predicting approximate lateral deflections in thin glass plates by the method of incremental loading are proposed. Due to the out-of-plane large deflections of thin glass plates compared to the plate thickness within each loading increment, the equilibrium and stiffness conditions are written with respect to the deformed structure. An application is presented on a thin fully tempered monolithic rectangular glass plate, laterally supported around its perimeter subjected to uniform wind pressure. The results of the analysis are compared with published experimental results and found to have satisfactory approximation. It is also observed that the large deflections of a glass plate lead to a part substitution of the bending plate behavior by a tensioned membrane behavior which is favorable.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.04a
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• pp.284-291
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• 1999

The reliability analysis is of great importance in their design since offshore towers are high-cost and high-risk structures. The design of platforms in the marine environment depends on results of the dynamic behavior of the structure during earthquakes and storm wave conditions. this paper presents results of an analytical study on evaluating dynamic response of steel jacket modelled by space frame elements. program $\boxDr$OFSPC$\boxUl$for the linear and nonlinear dynamic analysis of steel jacket platform has been developed using FORTRAN 90 programing language through the present study. Free vibration and dynamic behavior of steel jackets under regular and irregular wave and earthquake force are investigated using this program