원형제트출구 전단류 조절에 따른 제트충돌면에서의 열전달 특성

이창호,김영석,조형희,Lee, Chang-Ho,Kim, Yeong-Seok,Jo, Hyeong-Hui 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.3

The present experiment is conducted to investigate heat transfer characteristics on the impinging surface with secondary flows around circular nozzle jets. The changed vortex pattern around jet affects significantly the flow characteristics and heat transfer coefficients on the impinging surface. The effects of the jet vortex control are also considered with jet nozzle-to-plate distances and main jet velocities. The vortex pattern around a jet is changed from a convective instability to an absolute instability with a velocity suction ratio of the main jet and the secondary counterflow. With the absolute instability condition, the jet potential core length increases and the heat transfer on the impinging surface is increased by small scale eddies. The region of high heat transfer coefficients is enlarged with the high Reynolds number due to increasing secondary peak values. The effect of suction flows is influenced largely with collars attached the exit of the jet nozzle because the attached collar guides well the counterflow around the main jet.

웹 서비스 애플리케이션의 동적 성장을 위한 ESB와 에이전트 기반 프레임워크

이창호,김진한,이재정,이병정,Lee, Chang-Ho,Kim, Jin-Han,Lee, Jae-Jeong,Lee, Byung-Jeong 한국정보처리학회 2007 정보처리학회논문지 A Vol.14 No.7

유비쿼터스 컴퓨팅 환경에서는 이기종 플랫폼간의 상호작용과 빠른 환경의 변화에 대처할 수 있는 능력이 필요하다. 웹 서비스는 이러한 문제를 위해 이종의 분산 서비스 또는 자원들을 활용하고 조직하기 위한 방법을 제공한다. 그렇지만 서비스 요청 시, 의미 정보의 부족으로 원하는 서비스를 찾기가 어렵다. 시맨틱 웹 서비스는 의미 정보는 제공하지만 다양한 매칭에 대한 방법은 지원하지 않고 있다. 또한 웹 서비스를 이용해서 소프트웨어에 적응과 확장 능력을 제공할 순 있지만, 서비스들을 관리하고 운영하는 방법이 필요하다. 따라서 본 논문에서는 웹 서비스 애플리케이션의 동적 성장을 위해 ESB(Enterprise Service Bus)와 에이전트 기반의 프레임워크를 제안하고 유용성을 보이기 위한 프로토타입을 제시한다. Software adaptation may be required to interact between heterogeneous platforms and to react to rapid change of environment in ubiquitous computing. Web service provides a way to use heterogeneous and distributed services or resources to utilize and organize them. But it is not easy to retrieve appropriate services when we search services because web service lacks of semantic information. Semantic web service provides additional information of services, but it does not support a method to match them in various ways. We can adapt and extend web applications by using web service, but a method for management and administration is still needed. Therefore in this paper, we propose a framework for dynamic growing of web service applications based on ESB(Enterprise Service Bus) and agent and provide a prototype to show its usefulness.

주민자력의 주택개량을 위한 주거모델 선정 시스템 구축 및 시뮬레이션에 관한 연구

이창호(Lee, Chang-Ho),백혜선(Parik, Hae-Sun) 한국도시설계학회 2009 도시설계 : 한국도시설계학회지 Vol.10 No.4

본 연구는 주민들이 자신들의 의지에 따라 손쉽게 주택개량을 추진할 수 있도록 주거모델 선정 시스템을 구축하고, 실제의 대상지에 주거모델을 적용하여 그 변화상을 시뮬레이션 하였다. 연구방법으로서는 첫째, 박스형, 필로티형, 테라스형, 굴곡형, 응용형의 5가지 유형별로 필지단위 주거모델을 제시하였다. 다음으로 과거 15년간의 선행연구로부터 7가지 평가지표를 도출하여 각각의 주거모델에 대한 주거환경을 상대평가 방식으로 평가하였다. 둘째, 주민들이 자력으로 주택개량을 할 때 사업비 및 대지폭, 가구구성으로부터 주거모델의 후보군을 선정한 후, 주거환경을 평가하여 주민들이 자신에게 맞는 최적의 모델을 선정할 수 있는 시스템을 구축하였다. 마지막으로 셋째로는, 충남 서천군사지구의 주민들을 대상으로 설문조사를 실시하여 이를 바탕으로 시뮬레이션의 기본구상을 설정하고, 주거모델을 실제로 적용하여 지구의 변화상을 시뮬레이션 하였다. 도출된 연구성과는 정비지구 주민들이 자신들의 의지에 따라 손쉽게 주택개량을 추진할 수 있도록 해주는 가이드라인의 역할과, 담당공무원 및 사업시행자 등이 주택개량을 원활히 유도할 수 있도록 하는 매뉴얼의 역할을 담당할 수 있다. This study set up a selection system of housing models with self-evaluation results that induce the residents to self-improvement and simulated the changes of the test site with applying the new housing models. The research process and conclusions of this study are as follows. First, it proposes five types of housing models for a lot - Box type, Piloti type, Terrace type, Folded type and Complex type - for residents’ self-improvement, and they are evaluated by the 7 evaluation index based on the literature review over the past 15 years. Second, it suggests the selection system from which residents can judge each housing type with its factors - cost, width of each lot and household feature and select several alternations of housing model, and then select their own housing model with self-evaluation results by the 7 evaluation index, if they improve their housing environment. Third, it suggests the master plan for a test site - Chungnam Seochoen Gunsa area- based on the results of the residents’ survey, designs the site plan with the devised housing types and simulates the changes.

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.

고속역류크로마토그래프의 분리효율에 미치는 작동조건의 영향

이창호,이부용,이철호 ( Chang Ho Lee,Boo Yong Lee,Cherl Ho Lee ) 한국산업식품공학회 1997 산업 식품공학 Vol.1 No.3

PET/CT 검사에서 환자체형에 따른 적정검사 프로토콜에 관한 고찰

조석원,함준철,강천구,반영각,이승재,임한상,이창호,박훈희,Cho, Seok Won,Ham, Joon-Chul,Kang, Chun Goo,Bahn, Young Kag,Lee, Seung Jae,Lim, Han Sang,Lee, Chang-Ho,Park, Hoon-Hee 대한핵의학기술학회 2013 핵의학 기술 Vol.17 No.2

Purpose: Whole-body PET using radiopharmaceutical is one of the imaging study methods for physiological changes of body. High specificity of the PET-CT examination is used to detect an early stages of cancer and metastatic cancer by imaging a physiological changes. During the imaging process, PET image has been characterized by a relatively low image quality due to its low sensitivity and the acquisition of random and scatter coincidences as well as patients figure. Therefore, the image quality as the changes of the acquisition times of patient weight was evaluated in this study. Materials and Methods: Thirty patients who presented to our hospital were enrolled. They were divided to normal, overweight, and obese group using BMI index, respectively. The patients with a liver disease and diabetes were excluded. $^{18}F-FDG$ was administered to the patients as 5.2 MBq per kg. After an hour from an injection, image acquisition was obtained as List mode in a part of liver in 1 bed. SNR (signal-to-noise ratio) of each groups acquisition times were confirmed from the calculated radiation counts and random fractions. The statistical significance of three groups was confirmed through one-way ANOVA test. On the basis of the counts of 2 minutes on normal group, the SNR of overweight group and obese group were compared. Results: The SNR were increased with loger aquisition time in 3 groups. In the condition of same acquisition time, the SNR had a statistical significance (P<0.05). The SNR were decreased to the normal, overweight, and obese, respectively. Liver activity had no significance difference on each group and RF had the significance differences (P<0.05). On the basis of the counts of 2 minutes on normal group, there were no statistical significance in a three minute acquisitions of overweight group and two minute acquisitions of obese group (P=0.150). Conclusion: In this study, the administrated amount of radiation dose did not adjust as the change of the patients weight. Increasing the acquisition time when the administration of the same amount of dose was able to get a good result of SNR. When the Based 2 minute on normal group, if overweight and obese case the increased acquisition time of 3 minute was able to obtain a similar SNR. On the basis of the normal group, the acquisition times of overweight and obese group were increased to 3 minutes per bed and the SNR were similar to the normal group.

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.

구조실험정보를 위한 데이터 모델의 구성 및 사용성 평가

이창호,Lee, Chang-Ho 한국전산구조공학회 2015 한국전산구조공학회논문집 Vol.28 No.6

구조실험을 위한 데이터 모델은 구조실험에 관련된 실험정보를 정형화하여 표현하므로 데이터 저장소를 개발하는데 이용할 수 있다. 데이터 모델은 특히 대규모의 구조실험정보 또는 일반적인 다양한 실험정보를 위한 데이터 저장소에 효과적인데 예를 들면 NEES에서 개발한 NEEShub Project Warehouse가 있다. 본 논문은 데이터 모델의 구성과 사용을 평가하기 위한 평가요소를 제안하고 있다. 클래스의 속성이 값을 갖는지를 의미하는 AVE(attribute value existence)란 용어를 도입하여 속성의 사용성에 대한 Attribute AVE, 클래스의 사용성에 대한 Class AVE, 하위레벨에 있는 클래스를 포함하는 Class Level AVE, 하나의 프로젝트의 모든 클래스를 포함하는 Project AVE, 모든 프로젝트를 포함하는 데이터 모델에 대한 Data Model AVE를 정의하였다. 이러한 평가요소들을 NEES 데이터 모델의 프로젝트들에 적용하였는데 데이터 모델내의 클래스와 객체에 대한 사용성을 수치적으로 기술하여 평가하는 것이 가능하였다. The data model for structural experiment information formally organizes the information involved in the structural experiments before the data repository using the data model is implemented. The data model is particularly required for the data repositories for the large-scale structural experiment information and the general information for various types of experiments, such as the NEEShub Project Warehouse developed by NEES. This paper proposes criteria for evaluating the organization and the use of design model for structural experiment information. The term of AVE(attribute value existence) indicates the ratio of attributes who values exist in objects, and then used for defining the Attribute AVE for the use of an attribute, the Class AVE for a class, the Class Level AVE for a class including its lower-level classes, the Project AVE for a project including all classes at class levels, and the Data Model AVE for a data model including projects. These criteria are applied to the projects in the NEES data model, and it is successively possible to numerically describe the evaluation of the use of classes and attributes in the data model.

현미의 기능성

이창호,Lee, Chang-Ho 한국식품연구원 1998 食品技術 Vol.11 No.1

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.