멜트블로운 부직포를 이용한 전열교환소자의 특성 연구 (II) -폴리프로필렌과 나일론 멜트블로운 부직포 특성 고찰-

이창환,이종현,권은희,이경주,손은종,김성훈,Lee, Chang-Hwan,Lee, Jong-Hyun,Kwon, Eun-Hee,Lee, Kyung-Ju,Son, Eun-Jong,Kim, Seong-Hun 한국섬유공학회 2010 한국섬유공학회지 Vol.47 No.6

An enthalpy exchanger made from meltblown was prepared by a range of physical treatments to identify the production potential, and its characteristics were compared with an enthalpy exchanger based on polypropylene (PP). SEM revealed excellent compatibility between nylon and PVA. Various measurements were carried out as a function of the calendering temperature and speed, content of moisture absorbent, and concentration of water soluble polymer. The optimum conditions for the enthalpy exchanger made from nylon meltblown were as follows: a calendering temperature of $124^{\circ}C$, calendering speed of 2 m/min, and pick-up of 8~10%. The tensile strength of nylon was higher than that of the PP materials. In conclusion, nylon melt-blown nonwoven has greater potential than PP melt-blown nonwoven and can be used as a substitute in commercial paper type heat exchangers.

고밀도 극세사 닦음포의 고기능화

이창환,이준희,이경주,박근후,김성훈,Lee, Chang-Hwan,Lee, Jun-Hee,Lee, Kyung-Ju,Park, Keun-Hoo,Kim, Seong-Hun 한국섬유공학회 2010 한국섬유공학회지 Vol.47 No.2

To obtain high performance microfiber knit wiping cloth used for manufacturing electronic devices benzyl alcohol pretreatment method was optimized. WAXD patterns of the PET, nylon and nylon/polyester filament fibers pretreated with benzyl alcohol showed stronger crystalline peak than 50d/14f fibers. Some properties including wiping efficiency of the wiping cloths made of 75d/36f filament fibers of nylon/PET(N/P) and the ones made of 50d/14f fibers were tested and compared. Results showed that water absorption rate of the former was higher than that of the latter. The former showed excellent removing efficiency of approximately 90% compared to 60% for the latter. Air particle counter analysis revealed that the former has less residue content than the latter.

포속된 민족의술

이창환,Lee, Chang-Hwan 대한한약협회 2000 大韓漢藥 Vol.4 No.-

이산화탄소 포집 시스템 개념설계 개발을 위한 시스템 엔지니어링 기반 접근방법

이창환,홍대근,윤수철,서석환,서활원,Lee, Chang Hwan,Hong, Dae Geun,Yoon, Su Chul,Suh, Suk-Hwna,Sur, Hwal Won 한국시스템엔지니어링학회 2013 시스템엔지니어링학술지 Vol.9 No.2

Plant industry is one of technology-intensive and most prosperous industries in Korea because of its recent prosperity and promising outlook in export. However, no Korean EPC company has yet been well prepared in lifting their capacity sufficient enough to get the upstream conceptual or basic design and engineering orders for sizable plant projects which are known as the more value-added. If systems engineering, a methodology which developed complex systems such as airplanes and has been justified its effectiveness in Defense and NASA projects, can be integrated with plant engineering which should be developed and applied based on the requirements of so many stakeholders, conditions, lifecycle concepts, and constraints of the projects, huge synergic effect is expected particularly in developing a specific upstream design, which is a conceptual or basic design. The notion of integration with each other between systems engineering and plant engineering can be really the crux of EPC's success in any plant projects. This paper suggests an approach showing a methodology how to dig out, analyze, evaluate, verify and implement the stakeholders' requirements into a plant design in conceptual phase using the theory and skills of systems engineering. ISO/IEC 15288 well known systems engineering standards is used. Carbon capture system is used for a case study, for it is an emerging technology in reducing emissions of carbon dioxide causing global warming from flue gas after combustion. Here systems engineering was proven to play a substantial role in enhancing the capability of designers in developing a conceptual design of whole plant or certain part of crucial plant systems.

한국인에서 가변각막보정 주사레이저편광측정계의 진단적 유용성

이창환,권용혁,최재완,국문석,Chang Hwan Lee,Yong Hyuk Kwon,Jae Wan Choi,Michael S,Kook 대한안과학회 2007 대한안과학회지 Vol.48 No.3

Purpose: To investigate the relationship between the SLP-VCC parameters and the SLP-ECC parameters in the eyes with typical retardation pattern (TRP) and atypical retardation pattern (ARP), and the sensitivities and specificities of the SLP-VCC parameters and the SLP-ECC parameters in the eye with TRP and ARP. Methods: In this prospective study, 72 eyes with TRP images (30 glaucomatous and 42 normal eyes) and 53 eyes with ARP images (28 glaucomatous and 25 normal eyes) were recruited. For each group, we analyzed relationship between each parameters of GDx-VCC and GDx-ECC and the diagnostic ability of GDx-ECC by using the ROC curve. Results: In the eyes with TRP, TSNIT average was significantly lower by GDx-ECC than GDx-VCC in the control group. Inferior average was significantly higher by GDx-ECC than GDx-VCC in both glaucomatous and normal group. TSNIT standard deviation was significantly higher by GDx-ECC than GDx-VCC in both groups. NFI was significantly lower by GDx-ECC than GDx-VCC in both groups. TSS (typical scan score) was significantly higher by GDx-ECC than GDx-VCC in both groups. In the eyes with ARP, TSNIT average was significantly lower by GDx-ECC than GDx-VCC in both groups. Superior and Inferior average was not different between GDx-ECC and GDx-VCC. TSNIT standard deviation was significantly higher by GDx-ECC than GDx-VCC in both groups. NFI was not different between groups. TSS was significantly higher by GDx-ECC than GDx-VCC in both groups. Comparison of ROC curve for the SLP parameters revealed no difference between VCC and ECC. TSNIT standard deviation, however, showed relatively high value in GDx-ECC compared with GDx-VCC. Conclusions: GDx-ECC has comparable diagnostic ability in discriminating glaucomatous and normal eyes with GDx-VCC and TSNIT standard deviation by the GDx-ECC algorithm could be a useful parameter in discriminating glaucomatous and normal eyes.

긴급제안 - 민간에 의한 공공부문 정보자원 상업화 추구

이창환,Lee, Chang-Hwan 한국데이터베이스진흥원 1998 디지털콘텐츠 Vol.9 No.-

정보의 산업화란 산업 경제 활동, 교육 문화 활동, 국가 운영을 비롯한 공익 활동 등 인류제반 활동의 결과를 정보화하고 이를 외부에 제공하여 또 하나의 전문 산업 분야로 창출하는 것을 의미한다. 산업의 정보화와 산업화는 상호 균형있게 발전되어야 진정한 정보화 사회로 다가갈 것이다. 지금까지 국내 정보화 정책은 산업의 정보화에 치중되었다. 공공부문 정보자원의 민간에 의한 상업화는 전형적인 정보의 산업화 정책이 될 것이다.

JPP(JNI 전처리기)의 설계 및 구현

이창환,오세만,Lee, Chang-Hwan,O, Se-Man 한국정보처리학회 2002 정보처리학회논문지 A Vol.9 No.1

JNI는 자바가 플랫폼 의존적인 특수한 기능을 이용할 수 있게 하고, 기존의 라이브러리와 프로그램을 재사용할 수 있게 하기 위해 C/C++와 같은 다른 프로그래밍 언어와 연결되는 방법이다. 그러나 JNI를 사용하기 위해서는 복잡하고 어려운 과정을 거쳐야 하며 자바 소스와 C/C++ 소스를 따로 다루어 불편하였다. 본 논문에서는 JNI를 쉽게 사용하기 위해서 동일한 파일에 자바 소스와 C/C++ 소스를 함께 작성할 수 있게 하고 JNI 사용에 필요한 단계들을 줄인 JPP(Java PreProcessor)를 설계하고 구현하였다. JNI is a linkage method to other languages such as C/C++ which enables the Java to do the platform-dependent specific tasks and also, it can be used to reuse the existing libraries and programs. However, the complex and difficult steps are required to use JNI and it is Inconvenient to manipulate Java source and C/C++ source separately. We design and implement the JPP (Java Preprocessor) that enables the Java source and C/C++ source to handle in a same source file and reduces the required steps so as to use JNI easily.

결합적 방법에 의한 귀납법칙 집합의 생성

이창환,Lee, Chang-Hwan 한국정보처리학회 2003 정보처리학회논문지B Vol.10 No.1

귀납법칙 생성 시스템은 데이터에서부터 법칙을 자동으로 발견하는 시스템으로서 현재 많은 연구가 진행되고 있다. 본 논문은 정보이론을 이용하여 데이터로부터 귀납법칙을 자동으로 생성하는 시스템을 제시하고 또한 귀납법칙 생성 시스템에 의하여 생성되는 규칙들 중에서 가장 좋은 성능을 보이는 규칙 집합을 구하기 위하여 이를 유전자 알고리즘과 결합시켜 최적화된 귀납법칙 집합을 탐색하는 방법을 제시하였다. 제안된 시스템의 성능을 평가하기 위하여 다수의 기계학습 데이터를 사용하여 기존의 다른 방법들과 비교하였으며, 제안된 시스템은 대부분의 경우에 좋은 정확도를 제공하였다. The rule induction system generates a set of inductive rules, and the task of selecting an optimal rule subset is one of the important problem in the area of rule induction. This paper proposes a new learning method which combines rule induction system with the paradigm of genetic algorithm. This paper shows that genetic algorithm can be effectively applied to optimal rule selection problem. The proposed system was evaluated using a set of different machine learning data sets and, showed better performance in all cases than other traditional methods.

이창환의 임상이제

이창환,Lee, Chang-Hwan 대한한약협회 2003 大韓漢藥 Vol.7 No.-

모듈러 건축물의 수평력 저항 구조시스템

이창환,정광량,Lee, Chang-Hwan,Chung, Kwang-Ryang 한국공간구조학회 2016 한국공간구조학회지 Vol.16 No.2

Modular buildings are constructed by assembling modular units which are prefabricated in a factory and delivered to the site. However, due to a problem of noise between floors, concrete slab is usually poured at the top or bottom level of a modular unit in Korea. This greatly increases the weight of buildings, but designing vertical members of modular units to resist overall gravity loads is very inefficient. In this study, considering domestic building construction practices, feasible structural systems for tall modular buildings are proposed in which separate steel frames and reinforced concrete core walls are designed to resist gravity and lateral loads. To verify performance, a three-dimensional structural analysis has been performed with two types of prototype buildings, i.e., a residential building and a hotel. From the results, wind-induced lateral displacements and seismic story drifts are examined and compared with their limit values. Between the two kinds of buildings, the efficiency of the proposed system is also evaluated through a comparison of the weight of structural components. Finally, the effect of a floor diaphragm on the overall behavior is analyzed and discussed.