• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.4
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• pp.499-507
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• 2018

Autonomous Underwater Vehicle (AUV), which are becoming more and more important in ocean exploitation tasks, needs energy conservation urgently when sailing the complex mission path in long time cruise. As hull lines optimization design becomes the key factor, which closely related with resistance, in AUV preliminary design stage, uncertainty parameters need to be considered seriously. In this research, Myring axial symmetry revolution body with parameterized expression is assumed as AUV hull lines, and its travelling resistance is obtained via modified DATCOM formula. The problems of AUV hull lines design for the minimum travelling resistance with uncertain parameters are studied. Based on reliability-based optimization design technology, Design For Six Sigma (DFSS) for high quality level is conducted, and is proved more reliability for the actual environment disturbance.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.12
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• pp.1183-1189
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• 2010

Shock-resistance test for a real equipment for a normal vessel is one of the difficult problem in many cases because of terrible cost and weight. An analysis technique to evaluate the shock resistance in a design stage is necessary, instead In this paper, the process to evaluate the shock resistance of a propulsion motor for naval vessels was presented based on German navy's BV043 regulation. The shock signal to impose the equipment under the test was first evaluated, and was then applied to the structural FE model of the equipment. From the transient FEA, the time history of von-Mises stress was obtained by the mode superposition method. The shock resistance was evaluated using the peak value of the von-Mises stress.

• Journal of the Korean Society of Systems Engineering
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• v.1 no.2
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• pp.34-42
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• 2005

Logistic Support Analysis(LSA) and Logistic Supportability Review must be carried out as soon as possible in development stage in order to minimize operation/maintenance cost that head the list of weapon cost and improve logistic supportability of the weapon system. And the result must be used for hardware designs to set up to be able to input to the system design and logistic support elements. Therefore Logistic Support Elements must be planed/developed/supplied with the main combat system concurrently and performance and logistic supportability of the comabat system had better be improved mutually. This report describes maintenance concept changes of weapon systems, fault diagnosis function and test equipment state on the domestic MBT(main battle tank). And then it presents application and intensification of itself fault diagnosis system for a domestic future MBT considering connection with IETM(Interactive Electronic Technical Manual) and TE(Test Equipment).

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.1
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• pp.22-29
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• 2010

In this study, computational multi-body dynamics and structural vibration analyses including some impact condition have been conducted for the ground flight test system of the developed smart UAV model. Designed ground test system has four degree-of-freedom motions with limited motion control mechanism. Design safety margin designs for several structural components are tested and verified considering expected critical motions (pitching and rolling) of the test smart UAV model. Computational results for various analysis conditions are practically presented in detail. Futhermore, proper design modifications of the initially designed test equipment in order to guarantee or increase structural safety have been successfully conducted in the design stage.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.14-15
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• 2019

In this paper, it was tried to prove the possibility and effect of coordinate measurement by using MEP layout equipment at the construction stage, and to propose a method to improve measurement accuracy during construction. For this study, the passenger terminal site, which is a long span structure, was selected and compared with three dimensional CAD drawings and construction measurement results using MEP layout equipment for the precise construction of long-span irregular curved roof layers. As a result, it was found that it is possible to construct three-dimensional curved roof layers using MEP layout equipment through measurement and analysis.

• Journal of Drive and Control
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• v.13 no.4
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• pp.74-81
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• 2016

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.458-463
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• 1998

The paper describes the methods and means of measurement and study of vibrations, stresses and shocks affecting electronic equipment during its use and in the testing stage as well as original units to determine shapes and frequencies of vibrations of functional boards. Particular attention has been given to the development of methods and means to protect sturctures against vibrations and shocks.

• Korean Institute of Interior Design Journal
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• v.25 no.4
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• pp.68-79
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• 2016

The purpose of this study is to provide a reference for stage space planning in modern theaters by analyzing and understanding stage components in terms of spatial composition, purposes, and correlation between them, and collecting various opinions from stage managers an directors. The findings are as follow: the determination of the size of proscenium arch is crucial, and it needs to be considered not only with the genre of the performance and the number of seats, but also with the size of the stage facility. The two-dimensional size of proscenium arch affects the scale of stage area in three-dimensional way; the size of main stage comes from the width of the arch, and the length of set battens comes from the stage width, and so on. The height of the arch affects the elevation of gridiron, and the height of the building itself ultimately. The number and length of the set battens are directly linked to the size of the winch room, and so is the number of the winches to the Mcc panel room. The 1st level gallery supplying power to lighting equipment needs to be wide enough for staffs to work with various equipments effectively and safely. Degree of practical usage of under-stage machinery turned out to be very low. In order to cut unnecessary waste and cost, the characteristics of the theater must get set first, and experts who know how stage works need to get involved in planning stage.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.347-356
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• 2020

Mechanization and automation constitute an essential stage in the production and operation of any company, as one of the determinants of increase in labor productivity and decrease in product price, while significantly contributing to shortening of the lead time. Businesses are, therefore, able to quickly put projects into operation, improving economic efficiency, quality, and aesthetics, which speeds up the national economic growth. For the construction industry to be the most effective, modern construction equipment is a necessity. It is one of the five main resources of a construction project. Thus, effective construction equipment management contributes to the success of a project and benefits the relevant construction companies economically. This paper presents the critical risk factors affecting equipment management and proposes suitable solutions. The questionnaire-based survey with experienced experts in the construction sector on the management of the likelihood and consequence of risk factors revealed thirty-two risks for equipment management in construction companies. These factors fell into six groups: (i) site organization-related risks; (ii) management-related risks; (iii) owner-related risks; (iv) supplier-related risks; (v) legal risks, and (vi) site condition-related and external risks. The results showed that management-related factors contributed to the most significant risks and problems for equipment management in construction companies.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2199-2201
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• 2008

Sulfur hexafluoride($SF_6$) is a gaseous dielectric used in high voltage electrical equipment such as an insultor or arc quenching medium in the transmission and distribution of electricity. however, $SF_6$ is one of the greenhouse gases(GHG) with a global warming potential that is 23,900 times greater than that of carbon dioxide($CO_2$). for this reason, $SF_6$ emissions in electric equipment shall be controlled to reduce GHG and improve cost-effective use of $SF_6$ for economical benefits. Until recently there has not been any investigation on $SF_6$ emission characteristics and inventory in Korea. To understand emission characteristics during the use-phase, the scope of this study was limited to the following closed pressure system equipment from 10 substations in Korea. This study highlights (1) the investigation of sampling/analysis methodology for $SF_6$ emissions in high voltage equipment, (2) the estimation of $SF_6$ emissions in the use-phase, and (3) the comparison between the emission ratio and the mass-balance applied to inventory study. According to this study, the majority of emissions were related to electric equipment nameplates and the rest of the emissions were related to the handling of $SF_6$ during operations. from this result, emission ratios estimated from this study were similar; GIS was 14% and GCB was 13%, as maintenance process conditions were the same as manual process conditions for both equipment.