복합재료 보에 삽입된 Ni-Ti 형상기억합금 선의 센서로의 응용을 위한 연구

이창호,이정주,허증수 ( Chang Ho Lee,Jung Ju Lee,Jeung Soo Huh ) 한국센서학회 1998 센서학회지 Vol.7 No.4

Shape Memory Alloy(SMA) has been used in many engineering fields because of its good characteristics of actuator. For example, SMA wire can be embedded easily in the polymer composite laminate and then be used as actuator for structural control. Since the strain have a significant influence on the electrical resistance of SMA wire, It is a possible to use the SMA wire as a sensor of such physical quantities. In this study, the possibility for the application of Ni-Ti SMA wire as a sensor embedded within a composite laminate is investigated.

소표본인 경우 비모수 순위척도를 이용한 정규성 검정

이창호,최성운,Lee, Chang-Ho,Choi, Sung-Woon 대한안전경영과학회 2008 대한안전경영과학회지 Vol.10 No.3

The present study proposes two normality tests using nonparametric rank measures for small sample such as modified normal probability paper(NPP) tests and modified Ryan-Joiner Test. This research also reviews various normality tests such as $X^2$ test, and Kullback-Leibler test. The proposed normality tests can be efficiently applied to the sparsity tests of factor effect or contrast using saturated design in $k^n$ factorial and fractional factorial design.

실시간 공력모델을 이용한 비행 시뮬레이션 연구

이창호,박영민,최형식,Lee, Chang Ho,Park, Young Min,Choi, Hyoung Sik 항공우주시스템공학회 2015 항공우주시스템공학회지 Vol.9 No.4

Accurate aerodynamic data is required for the flight simulation or control logic design of aircraft. The aerodynamic look-up table has been used widely to provide aerodynamic forces and moments for given flight conditions. In this paper, we replace the aerodynamic look-up table with real-time aerodynamic model which calculates aerodynamic forces and moments of quasi-steady flow directly for given flight conditions and control surface deflections. Flight simulations are conducted for the low-speed small UAV using real-time aerodynamic model, and responses of the UAV are predicted successfully for inputs of control surfaces.

수종 치과용 시메트에 의한 주조 포오스트의 유지력에 관한 연구

이창호,장익태,김광남,Lee, Chang-Ho,Chang, Ik-Tae,Kim, Kwang-Nam 대한치과보철학회 1988 대한치과보철학회지 Vol.26 No.1

An in vitro study was performed to compare the retentive value of cast post cemented with three commonly used cements and one composite resin. Twenty cast posts were made from twenty extracted lower premolars. The samples were randomly divided into four groups. The first group was cemented with zinc phosphate cement, the second group with polycarboxylate cement, the third group with glass-ionomer cement, and the fourth group with composite resin. The tensile load test was performed on an Instron testing machine with crosshead speed of 2 mm/min and the results were compared statistically. The results were as follows ; 1. The mean value of tensile break force of cemented cast post was 23.36Kg in case of zinc phosphate cement, 16.28Kg in case of polycarboxylate cement, 22.09Kg in case of glass-ionomer cement , and 26.88Kg in case of composite resin. 2. Retention was not significantly different among zinc phosphate cement, glass-ionomer cement and composite resin. 3. Polycarboxylate cement was found to be less retentive than zinc phosphate cement, glass-ionomer cement , and composite resin.

Improved Stability and Stabilization for Sampled-data Control System via Augmented Lyapunov-Krasovskii Functional

이창호,이승훈,박명진,권오민,Lee, Chang-Ho,Lee, Seung-Hoon,Park, Myeong-Jin,Kwon, Oh-Min The Korean Institute of Electrical Engineers 2017 전기학회논문지 Vol.66 No.1

This paper investigates improved stability and stabilization criteria for sampled-data control systems. By using a suitable and newly constructed augmented Lyapunov-Krasovskii functional and some recent mathematic techniques such as auxiliary function-based integral inequalities, sufficient conditions for stability and stabilization conditions are derived within the framework of linear matrix inequalities(LMI) form. The superiority and validity of the proposed results are illustrated by three numerical examples.

저궤도 상용위성 개발을 위한 시스템 신뢰성 엔지니어링 적용사례

이창호,Lee, Chang-Ho 한국시스템엔지니어링협회 2003 시스템엔지니어링워크숍 Vol.1 No.-

주민자력의 주택개량을 위한 가구단위 주거모델 선정에 관한 연구

이창호(Lee Chang-Ho),백혜선(Paik Hae-Sun) 대한건축학회 2009 대한건축학회논문집 Vol.25 No.10

Korean Government launched the local improvement project on May, 2007 that was a public-based model project for setting up the base for further renewal in terms of social renewal. This study researched 12 deteriorated residential area case for devicing housing types and a selection system with self-evaluation results that induce the residents to self-environment improvement and provides an easy reference. The study is concluded as follows. First, it proposes four types of block housing models for residents' self-environment improvement, and is evaluated by the evaluation index based on the literature review over the past 15 years. Second, it suggests the selecting system from which residents can judge each housing type by its factors-cost, the number of households and layers, and select their own model, if they improve their housing environment. Third, it suggests the master plan for a test site, designs the site plan with the devised housing types and simulates the changes. It can be used as a guideline for inducing the residents to self-environmental improvement and easy improvement in their own way, and also a manual for government officials and professionals to promote the local improvement project in actuality.

논토양에 3요소비료 시용시 이들 비료성분의 토양내 잔존 형태와 용탈에 의한 수질오염에 관한 연구

이창호,임수길 ( Chang Ho Lee,Soo Kil Lim ) 한국물환경학회 1995 한국물환경학회지 Vol.11 No.4

In order to investigate the behavior of N,P,K fertilizers applied in submerged paddy soils and the water pollution caused by these leachate, Ammonium sulfate(AS), Urea, Superphosphate(SP), Fused phosphate(FP), Potassium chloride(PC) were applied in three levels in the columns filled with silty clay loam(SiCL) and sandy loam(SL), respectively. Distributions of N,P,K in soil were detertmined, and concentrations of N,P,K in leachate were also analyzed, separately. The obtained results were summarized as follows. In terms of residual amounts in soils, AS induced decreasing amount NH₄-N from top to bottom whereas Urea revealed reverse phenomenon. SL soil rather than SiCL soil and AS rather than Urea had a much effect on the water pollution. Residual amount of NO₃-N showed higher amount in SL soil than in SiCL soil regardless of fertilizer and application rates. In SiCL soil, main source of soluble phosphorus was SP whereas FP was the one in SL soil. Conc. of phosphorus in leachate were very small due to high adsorption ability of soils for phosphorus, the soil pollution was more considered than the water pollution. Leaching conc. of K^+ was higher from SL soil than SiCL soil, leaching conc. of K^+ increased as fertilizer application rates increasing on both SiCL and SL soils. Leaching concentrations(Y) of K^+ decreased with increasing leaching frequency(X), fitting the equation of exponential function could be expressed as Y=aX^b egardless of soil textures and potassium fertilizer application rates. The value of b is in between 0.41 and 0.63.

구조실험 정보를 위한 데이터 저장소의 클래스와 객체의 속성구성 평가요소

이창호,Lee, Chang-Ho 한국전산구조공학회 2014 한국전산구조공학회논문집 Vol.27 No.6

The data repositories for structural experiment information needs to be efficient to use in order to allow structural engineers and researchers to store and retrieve easily the information involved in the structural experiments. The data repositories can be evaluated in terms of the organization of the data repositories themselves and of the organization of the actual experiment information in the data repositories, which can be represented using classes and objects with their attributes. This paper proposes the evaluation criteria of attributes of the classes and objects. The evaluation criteria of the attributes of the classes, such as the number of attributes in class and the numbers of the data-valued and object entity-valued attributes, are used for understanding the complexity of the organization of the data repositories. The evaluation criteria of the attributes of the objects, such as the number of valued attributes in object, are used for describing how the actual experiment information is stored through the levels in the data repositories for the structural experiment information. 구조실험을 위한 데이터 저장소는 구조실험에 관련된 실험정보를 구조공학자와 연구자들이 편리하게 저장하고 열람할 수 있도록 효율적인 구성을 가져야 한다. 데이터 저장소에 대한 평가는 데이터 저장소 자체적인 구성에 대한 평가와 데이터 저장소에 저장된 실제 정보의 구성에 대한 평가로 나눌 수 있다. 데이터 저장소의 자체적인 구성은 클래스로 나타낼 수 있고 데이터 저장소 내에 저장된 실제의 실험정보는 객체로 표현할 수 있는데 본 논문은 클래스와 객체가 가지고 있는 속성구성에 대한 평가요소를 제안한다. 클래스의 속성구성 평가요소로는 클래스내 속성수와 구체적인 값 또는 객체에 의해 구분한 속성의 종류별 수 등이 있는데 이러한 평가요소들을 이용하여 데이터 저장소가 정한 구성을 이해할 수 있다. 객체의 속성구성 평가요소로는 객체내 값있는 속성수 등이 있는데 데이터 저장소내의 실제 실험정보가 레벨별로 어떻게 저장되어 있는가를 파악할 수 있다.

직접유지장치 설계 변화에 따른 하악 후방연장 국소의치 지지조직의 광탄성 응력분석

이창호,김광남,장익태,Lee Chang-Ho,Kim Kwang-Nam,Chang Ik-Tae 대한치과보철학회 1992 대한치과보철학회지 Vol.30 No.2

The purpose of this study was to evaluate the stress distribution developed in supporting structures by distal extension removable partial denture with 4-types of direct retainer. The direct retainers examined were Akers clasp, RPI clasp, RPA clasp and RPL clasp in bilateral & unilateral free end case. 3-dimensional photoelastic stress analysis was used to record the isochromatic fringe patterns and to calculate the compressive stress at measuring points. The results were as follows. 1. In bilateral free end case, RPI clasp exhibited the similar stress distribution on distal and mesial alveolar crest but Akers clasp exhibited higher stress concentration on distal alveolar crest than mesial alveolar crest. 2. In bilateral free end case, RPA clasp and RPL clasp exhibited the similar stress distribution on distal and mesial alveolar crest and RPL clasp exhibited higher stress concentration on buccal alveolar crest than lingual alveolar crest. 3. Akers clasp produced high stress concentration on residual alveolar ridge distally, but RPI clasp, RPA clasp and RPL clasp produced even stress distribution on residual alveolar ridge. 4. Removable partial denture in unilateral free end case exerted higher stress on abutment tooth root apex than bilateral distal extension removable partial denture.