• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2001.04a
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• pp.49-53
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• 2001

터보프롭 엔진의 성능진단을 위한 선형 GPA(Gas Path Analysis) 및 비선형 GPA 프로그램을 개발하고 최적 계측 변수 선정을 위한 해석을 수행하였다. 압축기 오염과 압축기 터빈 및 동력터빈의 부식에 의한 손상을 가정하고 계측변수를 6개, 8개, 10개로 달리하여 각각 선형 GPA 기법과 비선형 GPA 기법을 이용하여 해석을 수행한 후 RMS 오차를 비교하였다. 해석 결과 비선형 GPA 기법을 이용한 경우의 RMS 오차가 선형 GPA 기법을 이용한 경우보다 적어 비선형 GPA 기법의 유용성을 확인할 수 있었다. 또한 적절한 계측변수의 선정을 통해 보다 적은 계측 장비로 더 신뢰성 있는 결과를 얻을 수 있음을 확인하였다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2003.11a
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• pp.105-111
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• 2003

The valve train system of engines has long been a sensitive area with respect to wear performance because of the high contact loads and surface sliding speeds encountered. In particular, wear problems of load-carrying components in relative motion, such as cam and tappet in valve train system have made troubles. To overcome these problems, combination of proper materials is important, as well as selecting of high wear performance materials. This paper presents the experimental result of friction and wear properties of ca/tappet materials. To investigate friction and wear properties for several combinations of materials, using commonplace tribometer(Plint 77, reciprocating type), we make a selection of a optimum material combination.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.692-694
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• 1995

Multi-channel adaptive algorithms have poor convergence behaviors because of difficulties in selection of convergence coefficients. In this paper, a MCFLMS(Multi-Channel Fuzzy LMS) algorithm, where the convergence coefficients are updated by a fuzzy inference engine, was proposed. A proposed algorithm showed better convergence characteristics than conventional MCLMS(Multi-Channel LMS) algorithms in computer simulations.

• International Journal of Automotive Technology
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• v.6 no.5
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• pp.513-517
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• 2005

A full-bead of multi-layer-steel engine head gasket, taking charge of the dynamic sealing of combustion chamber, is susceptible to fatigue failure. The fatigue durability of full-bead was assessed with the finite element analysis results and the high-cycle multi-axial fatigue theory. The assessment aimed to reveal the effects of the forming parameters and dimensions of full-bead. The results show that the selection of embossing parameters producing less deformation of bead plate is beneficial for the improvement of durability while the flatting has marginal influence. The fatigue durability also improves with the increase in the width of full-bead and the radial length of bore-side flat region. However, the dimensional effects are limited due to the occurrence of snap-through.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.17 no.4
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• pp.55-62
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• 2009

The Prime objectives of this study are to identify and analyze possible solutions and select a solution for the specification and operation plan of the meteorological purpose aircraft in Korea. Infrastructure like meteorological purpose aircraft and aircraft operating systems should be set up and their efficient plan must be established to improve meteorological technic in Korea. As a result of the study, we have found that the turboprop engine powered aircraft is the most suitable to initial model for the meteorological purpose aircraft. It was found that the indirect operation method might be the best solution, also. The results of this study may be useful to make decision for selecting specification and operation of the meteorological purpose aircraft.

• Proceedings of the Korea Information Processing Society Conference
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• 2018.10a
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• pp.896-899
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• 2018

고령사회에 대응하기 위한 휴먼케어 서비스 로봇은 다양한 동적 환경에서 사용자에게 최적의 서비스를 제공하기 위해 서비스 선택 엔진을 요구한다. 서비스 선택 엔진은 로봇이 수집한 각종 원시 데이터를 활용하여 계층적으로 상위 수준의 정보로 가공하고 최종 단계에서는 휴먼케어 전문가가 설계한 규칙에 의해 사용자에게 제공할 서비스를 선택한다. 본 논문에서는 휴먼케어 서비스 로봇을 위해 기계학습 기반의 지식 생성과 규칙 기반의 지식 생성을 함께 활용하여 하이브리드 형태로 계층적 지식을 생성하고, 생성된 지식을 바탕으로 서비스를 선택하는 메커니즘을 제공할 수 있는 서비스를 선택 엔진 내용을 설명한다.

• Journal of Industrial Convergence
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• v.13 no.2
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• pp.45-54
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• 2015

This Study aims to analyze the factors for the success of commercialization of the facial extraction and recognition image security information system of the domestic companies in Korea. As the results of the analysis, the internal factors for the success of commercialization of the facial extraction and recognition image security information system of the company were found to include (1) Holding of technology for close range facial recognition, (2) Holding of several facial recognition related patents, (3) Preference for the facial recognition security system over the fingerprint recognition and (4) strong volition of the CEO of the corresponding company. On the other hand, the external environmental factors for the success were found to include (1) Extensiveness of the market, (2) Rapid growth of the global facial recognition market, (3) Increased demand for the image security system, (4) Competition in securing of the engine for facial extraction and recognition and (5) Selection by the government as one of the 100 major strategic products.

• Journal of Industrial Convergence
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• v.12 no.2
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• pp.16-23
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• 2014

The aim of this study is to find the strategic industries that fulfills the on-site demands of the Gyeonggi province region related to the advancement and development of the local industries. As the results of the analysis, the 4 major strategic industries in the Gyeonggi province region were determined to be (1) electronic component, computer, visual, acoustic and telecommunication equipment manufacturing, (2) pulp, paper and paper product manufacturing, (3) medical substances and pharmaceutical product manufacturing, and (4) rubber and plastic product manufacturing. The industry of concordance between the 4 major strategic industry of the Gyeonggi province determined in this Study and the 13 future growth engine industry of Korea was the area of intelligent semiconductor. Accordingly, it was analyzed that there is a need to strategically cultivate the electrical and electronic telecommunication device industry, which is ranked the $1^{st}$among the strategic industries of Gyeonggi province by generating synergic effects with the policy of the government for nurturing of intelligent semiconductor industry.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.10
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• pp.806-813
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• 2018

The fracture of a turbine blade of aerospace engine is presented. Although there are a lot of causes and failure modes in blades, the main failure modes are two ways that fracture and fatigue. Degradation of blade material affects most failure modes. Total propagation of failure in this study specifies failure of fracture type. Some section appears fatigue mode. Especially since this study describes analysis of failure for blade in high temperature, it can be a case in point. Analysed blade is Ni super alloy. Investigations of blade are visual inspection, material, microstructure, high temperature stress rupture creep test, analysis and fracture surface, etc. The root cause for fracture was stress rupture due to abnormal thermal environment. Thermal property of Ni super alloy is excellent but if each chemical composition of alloys are different due to change mechanical properties, selection of material is very important.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.54-62
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• 2009

To avoid the redundant investment on the project selection process, it is necessary to check whether the submitted research topics have been proposed or carried out at other institutions before. This is possible through the search engines adopted by the keyword matching algorithm which is based on boolean techniques in national-sized research results database. Even though the accuracy and speed of information retrieval have been improved, they still have fundamental limits caused by keyword matching. This paper examines implemented TFIDF-based algorithm, and shows an experiment in search engine to retrieve and give the order of priority for similar and redundant documents compared with research proposals, In addition to generic TFIDF algorithm, feature weighting and K-Nearest Neighbors classification methods are implemented in this algorithm. The documents are extracted from NDSL(National Digital Science Library) web directory service to test the algorithm.