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열저항과 K-factor를 이용한 LED 조명광원의 정션온도 예측기법에 관한 연구
이호운(Ho-Woon Lee),조영진(Young-Jin cho),곽계달(Kae-Dal Kwack) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11
It is difficult to determine the maximum and partial junction temperature simultaneously because LED lightings are manufactured using several chips with low power rather than single chip with high power. In this study, in case of the lighting source module of the MR16 assembled lots of the LED, the method determining the maximum and partial junction temperature simultaneously with LED and simply applying to the industrial site was deduced. At this end, by using the transient measuring technique, the thermal resistance of an one-chip was analyzed in detail and the thermal resistance of the whole module was calculated by applying to the K-factor calculation method. Comparing to these techniques, thermal network techniques, by using conduction and convection thermal resistance, which can estimate the maximum and partial junction temperature of the LED chip simultaneously in which it is adhered to a module by applying the MR16 optical source module to the thermal resistance was propose.
3-자유도 헬리콥터 시스템의 입자군집최적화 기법을 이용한 시스템 식별
이호운(Ho-Woon Lee),김태우(Tae-Woo Kim),김태형(Tae-Hyoung Kim) 한국지능시스템학회 2015 한국지능시스템학회논문지 Vol.25 No.2
본 연구는 Quanser사의 3-자유도 헬리콥터 시스템에 대한 종래의 선형 수리 모델을 개선한 수리 모델을 제안하고, 실험을 통해 제안된 수리 모델을 기반으로 설계된 제어기의 제어 성능을 종래의 수리 모델을 기반으로 설계된 제어기의 제어 성능과 비교함으로써 그 타당성을 검증한다. 이에 대한 연구 진행 과정은 다음과 같다. 첫째, 3-자유도 헬리콥터 시스템의 동특성을 분석하고, 종래의 선형 수리 모델을 구축한다. 둘째, 종래의 수리 모델의 구축을 위해 수행된 선형화 과정에서 제거된 비선형적 요소들을 파악한다. 그리고 이 제거된 비선형적 요소들에 대응하는 파라미터들을 추가하여 개선된 수리 모델을 구축한다. 이 때, 수리 모델을 구축하기 위해 메타 휴리스틱 전역 최적화 기법인 입자군집최적화 알고리즘을 이용한다. 마지막으로, 제안된 모델을 기반으로 제어기를 설계하고, 이를 종래의 수리 모델을 기반으로 설계된 제어기의 제어 성능을 비교하여 제안된 수리 모델의 타당성을 검증한다. This study proposes the more improved mathematical model than conventional that for the 3-DOF Helicopter System in Quanser Inc., and checks the validity about the proposed model by performance comparison between the controller based on the conventional model and that based on the proposed model. Research process is next : First, analyze the dynamics for the 3-DOF helicopter system and establish the linear mathematical model. Second, check the eliminated nonlinear-elements in linearization process for establishing the linear mathematical model. And establish the improved mathematical model including the parameters corresponding to the eliminated nonlinear-elements. At that time, it is used for modeling that Particle Swarm Optimization algorithm the meta-heuristic global optimization method. Finally, design the controller based on the proposed model, and verify the validity of the proposed model by comparison about the experimental results between the designed controller and the controller based on the conventional model.
FRP 박스부재의 결함평가를 위한 위상배열초음파 적용성 평가
곽계환,양동운,김호선,이호현,윤국현,Kwak, Kae-Hwan,Yang, Dong-Woon,Kim, Ho-Sun,Lee, Ho-Hyun,Yun, Kuk-Hyun 한국농공학회 2010 한국농공학회논문집 Vol.52 No.5
The structural material with the highest possibility of new materials that will be used in the future construction field is fiber reinforced polymer. The current studies on FRP members by using such excellent material characteristics mostly focused on stability, composite problem, and durability of FRP members. The initially constructed FRP members secure excellent stability and durability compared to reinforced concrete and steel materials, but measures for defections during the periodical inspection, methods for detecting breakages, and maintenance and reinforcement are not insufficient. Accordingly, this study proposed a measurement system using the FRP sensor to evaluate the safety of the FRP modular box member, and applied the phased array ultrasonic technique to detect the defects and damage likely to occur during the performance period.
남상운,허연정,심옥자,심상일,이호상 안성산업대학교 1998 論文集 Vol.30 No.-
This study was carried out to investigate energy saving effect and thermal insulation characteristics of double film water curtain system during the coldest season in greenhouse. A double film water curtain system is a ground water spraying system between double layered plastic film, and it is able to make uniform water curtain. The experimental greenhouses were plastic greenhouses of two types. A type-Ⅰ was a two-thirds arched shape and its area was 350㎡ . A type-Ⅱ was a triangle shape and its area was 190㎡. Both greenhouses were cultivated with cactus. The minimum outside air temperature ranged was -2.6 to -16.7℃ and nocturnal ambient mean temperature was -6.5℃. The experimental greenhouses have maintained the air temperature above 2℃ of type-Ⅰ and 8℃ of type-Ⅱ. The ground water spraying flow rates of these greenhouses were 7.0ℓ/㎡hr of type-Ⅰ and 4.3ℓ/㎡hr of type-Ⅱ. The overall heat transfer coefficient of type-Ⅰ greenhouse was calculated at 1.97 kcal//㎡hr℃ and type-Ⅱ was 1.44 kcal/㎡hr℃. The energy saving rate of type-Ⅰ greenhouse was estimated and 78.1% and type-Ⅱ was 98.9%.
톨루엔의 알킬화반응에서의 Y - 제올라이트 촉매의 활성에 관한 연구
곽종운,이화영,이호인,고성운,성벽파정 한국화학공학회 1986 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.24 No.5
메탄올에 의한 톨루엔의 알킬화반응으로 자일렌을 생성하는 과정에서 Y-제올라이트 촉매의 활성변화에 관한 연구를 하였다. 실험은 고정상 촉매를 사용하여 연속적으로 수행하였으며, 반응물은 마이크로펌프를 이용하여 주입하였다. 생성된 전체 자일렌의 양은 반응시간이 지남에 따라 감소하였으나 p-자일렌의 선택성은 증가하였다. 활성저하속도를 줄이기 위하여 사용촉매를 수증기 및 강산으로 처리하였다. 수증기 및 강산처리한 촉매의 활성은 처리를 하지 않은 촉매에 비해서 증가하였으며, 활성저하속도도 줄어들었다. 자일렌 이성질체의 구성분포는 사용촉매의 Bro¨nsted 산의 농도에 의존하였으며, 특히 강산으로 Y-제올라이트 촉매를 처리하였을 때, m-자일렌의 생성량이 증가하였다. The activities of Y-zeolite catalysts were studied in alkylation of toluene with methanol to produce xylene isomers. The experiments were carried out continuously over fixed bed catalysts and reactants were fed by a micropump. The amount of total xylene decreased with time-on-stream, while the selectivity of p-xylene increased. In order to reduce the deactivation rate, catalysts were treated with water vapor or strong acids. It has been found that the modified catalysts by treatment show higher activities and lower deactivation rate than the corresponding untreated caltalysts. It has also been shown that the distribution of xylene isomers is dependent on the concentration of Bro¨nsted acid of the catalysts employed. Moreover, the formation of m-xylene increased when the catalysts were treated with strong acids.