• Journal of KSNVE
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• v.6 no.5
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• pp.575-585
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• 1996

In order to build a quiet and comfortable ship, the noise levels on board ship must be predicted at early design stage. Statistical Energy Analysis (SEA) developed by R. H. Lyon has been well known to be the most useful frame work to study the energy flow of noise and vibration in structure. This paper applied this theory to predict the transmission loss of structure-borne noise of model structure and has developed computer program. Components constructions model structure have been all considered as SEA elements. And we also estimated the SEA parameters from the model structure. Using SEA and a new conception of STL, we found the transimission character of structure-borne noise theoretically by the idealized ship model, and then compared the results with three cases.

• Korean journal of applied entomology
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• v.19 no.1 s.42
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• pp.1-4
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• 1980

Quantitative differences in pathogenicity of monoconidial subcultures of Pyricularia oryzae Cav. were examined. The subcultures had been isolated from a susceptible-(STL) and an intermediate type lesion (ITL), which originated from a single culture. The majority of the STL monoconidial subcultures produced more susceptible type lesions than did the ITL subcultures. The production of intermediate type lesions was similar in both groups of subcultures, whereas the ITL subcultures produced a high number of resistant type lesions. Within both groups, there was also some variation in numbers of lesions produced.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.321-326
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• 1997

This paper present how VRML file format can be used for RP Technology. VRML standards provids compact and powerful interface between remote RP manufacturer in network independent environment. We have constructed integrated and network-connected server system which can share the CAD data and varios process which is STL-to-VRML translater,slicing process,slice anchor process etc. This Server system consisted in file converter between STL and VRML,CGI system which sends a generated data to VRML client or browser, slice-generator which can re-slice at varied thickness and simulator which can show and check simultaneously status between near slices with support. This system aims to the integrated simulator which supports graphic animator and FEA analysis system.

• Journal of Positioning, Navigation, and Timing
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• v.7 no.3
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• pp.113-125
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• 2018

Since the global positioning system receivers on the surface of the Earth use satellite signals sent from a remote distance and the intensity of received signals is weak, they are vulnerable to jamming. This paper implements a vector-tracking loop (VTL)-based global navigation satellite system (GNSS) receiver algorithm as an anti-jamming technique and compares the performance of VTL-based receivers with that of scalar-tracking loop (STL) that is used in general GNSS receivers at various jamming environments and a vehicle's dynamics. The simulation results shows that VTL is more robust against jamming than STL in all operating environments.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.592-596
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• 1996

The CAD/CAM System oriented to StereoLithographic Rapid Prototyping was constructed and developed. The software architecture uses a 586PC running the windows NT operating system. An .STL file brought into the software program can be verified in divers view points and focused for a detail of concern. A variety of Entity was applied to define an array of triangular facets and sliced loops. The system provides Edit, Scale, Orient, Copy and Divide commands to modify .STL model. The NC codes are created according to various laser beam scan pattern and the software show the parts on the platform before they are constructed. This system is written in Visual C and has been proved as a powerful tool for producing solid parts directly from a CAD modelling, using actual applications.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.441-447
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• 2003

In the study, we described on the 3D solid model be made on the AutoCAD haved an effect on the deviation of form as RP manufactures the facetres. The STL file improved the deviation of form as the facetres value but the deviation of form have the difference a little as the RP system. In result, we ruled the correlation with the 3D solid model and the RP sample manufacturing, with manufacture RP sample according to facetres value in complex shape. And we developed the program which recombination the STL file that we make use of the AutoLISP.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.849-854
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• 2001

Cabin noise reduction in maglev trains developed by KIMM is studied. Based on the measurements of cabin noise and acceleration levels during running and zero speed conditions, dominant noise sources are identified. After spectra characteristics of noise sources is investigated, efficient noise reducing methods are studied such as STL increasement of floor panels, sealing, and absorption treatment. It is found that the most important noise sources are VVVF inverter and SLIM in running condition. Since the noise sources are under the cabin floor, complete sealing and high STL of the floor panel are shown to be the most crucial factors in noise reduction. After polyurethan form (50t) is added for more sound absorption and sealing treatment, the cabin noise is reduced by 3-4 ㏈.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.51-58
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• 2006

In rapid prototyping, the optimal part orientation during fabrication is critical as it can improve part accuracy, minimize the requirement for supports and reduce the production time. Through investigating the geometric issues of STL model and process planning of RPM, This paper establishes optimizing model based on the considerations of staircase effect, support area and production time. The general satisfactory degree function is constructed employing the multi-objective optimization theory based on the general satisfactory degree principle. The best part-building orientation is obtained by solving the function employing generic algorithm. Experiment shows that the methods can effective resolve the part-building orientation in RP.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.180-183
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• 2006

엔진 밸브와 밸브시트의 마모는 엔진 성능에 영향을 미치는 가장 중요한 요소 중에 하나이다. 엔진 밸브와 밸브시트는 엔진 구동 과정에서 발생하는 고온의 배기가스, 밸브 스프링의 빠른 움직임, 엔진 폭발 과정의 고압, 균일하지 못한 냉각시스템으로 발생하는 실린더 헤드의 뒤틀림이 만들어 내는 극한 환경을 이겨내야 한다. 본 연구에서는 밸브 및 밸브시트의 마모율과 마모 메카니즘을 명확하게 규명하기 위해서 실제 자동차 엔진 내부의 조건인 온도, 밸브와 밸브시트간의 충돌, 스라이딩 등에 관한 것들을 고려하여 밸브 및 밸브시트가 충돌 시험할 수 있는 전용마모 시험기를 사용하였다. 본 연구에 사용된 시편은 현재 실차에 사용되고 있는 밸브와 밸브시트를 사용하였다. 그 종류는 STR35 밸브, STL #6 및 STL #32이다. 밸브시트는 HVS1-2 재질을 사용하였다.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.403-405
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• 2003

본 논문에서는 대전류 표준측정에 대한 STL TC의 Ad-Hoc Working Group의 최종방안에 대해 자세히 소개하여 이를 계기로 국내에서도 필요한 사전준비에 만전을 기하고자 한다. 향후 연속적으로 해야 할 업무, Shunt의 소유, 경비 지불방법 등에 대한 사항과 함께 우리나라 대전류 표준측정시스템의 구축절차를 제안하였으며, 이를 통해 대전류 측정에 있어서 국제표준과의 소급성을 확보할 수 있기 때문에 국내에서 시행하는 각종 시험에서 대전류 측정이 국제적으로 유효하게 될 것이다.