멜라토닌의 효율적인 합성

최동균,이학준 한양대학교 이학기술연구소 2002 이학기술연구지 Vol.4 No.-

아릴하이드진 8을 4-아미노부틸알데히드 디에틸아세탈 (3) 또는 피롤린 (6)과 one-pot 반응으로 손쉽고 효율적으로 멜라토닌 (1)을 합성하였다. The facile synthesis of Melatonin (1) was achieved by the one-pot reaction of arylhydrazine 8 with 4-aminobutyraldehyde diethyldacetal (3) or pyrroline (6).

유도전동기 드라이브의 고성능 제어를 위한 새로운 퍼지제어기

정동화,이정철,이홍균 한국산업안전학회 2002 한국안전학회지 Vol.17 No.4

This paper is presented new fuzzy controller for high performance of induction motor drive. New fuzzy controller took out appropriate amounts of accumulated control input according to fuzzily described situations in addition to the incremental control input calculated by conventional direct fuzzy controller. The structures of the proposed controller was motivated by the problems of direct fuzzy controller. The direct controller was given generally inevitable overshoot when one tries to reduce rise time of response. The undesirable characteristics of the direct fuzzy controller are caused by integrating operation of the controller, even though the integrator itself is introduced to overcome steady state error in response. The proposed controller clear out fuzzily integrated quantities according to the situation. This paper attempts to provide a thorough comparative insight into the behavior of induction motor drive with direct and new fuzzy speed controller. The validity of the comparative results is confirmed by the simulation results for induction motor drive system.

커패시터 공진전압을 이용한 하프 브릿지 고주파 인버터의 특성해석에 관한 연구

김동희,김도선,김종해,노채균 嶺南大學校 工業技術硏究所 1997 工業技術硏究所論文集 Vol.25 No.2

This paper presents operating characteristics of the main conversion considering half-bridge high frequency resonant inverter using capacitor Resonant voltage to the object of research. The analysis of the proposed circuit describes generally by using normalized parameter, and basic operating principle and driving characteristics have been evaluated as to switching frequency and load parameter. Several features are considered, this paper suggests some fundamental data for designing the main power conversion circuit. To prove rightfulness for characteristics analysis of proposed inverter, it is confirmed that this paper are nearly, equal to circuit analysis by comparison theoretical and experimental waveforms results of proposal inverter using Power-MOSFET of switching devices. In the future, design technique proposed in this paper can be applied to several areas such as induction heating, power supply of DC-DC converter, UPS etc.

작업의 특성에 종속되는 병렬기계의 일정계획을 위한 발견적 기법

이동현,이경근,김재균,박창권,장길상 한국경영과학회 2000 經營 科學 Vol.17 No.1

In the real world, situations that some jobs need be processed only on certain limited machines frequently occur due to the capacity restrictions of machines such as tools, fixtures, or material handing equipment in this paper, we consider n-job, non-preemptive and m parallel machines scheduling problem having two machines group The objective function is to minimize the sum of earliness and tardiness with different release times and due dates The problems is formulated as a mixed integer programming problem The problem is proved to be NP-complete Thus, a heuristic is developed to solve this problem To illustrate its suitability and efficiency, a proposed heuristic is compared with a genetic algorithm and tabu search for a large number of randomly generated test problems in ship engine assembly shop Through the experimental results, it is showed that the proposed algorithm yields good solutions efficiently

약계자 영역에서 SynRM의 MTPA를 위한 속도 센서리스 제어

정동화,이정철,이홍균 국립7개대학공동논문집간행위원회 2001 공업기술연구 Vol.1 No.-

In this paper, a new approach for the SynRM(Synchronous Reluctance Motor) control which ensures producing MTPA (Maximum Torque per Ampere) over the entire field weakening region is presented. In addition, This paper presents a speed sensorless control scheme of SynRM using flux observer. Also, by adjusting the base speed for the field weakening operation according to the flux level, the current and voltage limit, the smooth and precise transition into the field weakening operation can be achieved. The proposed scheme is verified validity through simulation.

비구조화 환경의 입력영상에 대한 영역기반의 추적 방법

오홍균,손용준,장동식 한국경영과학회 2001 한국경영과학회 학술대회논문집 Vol.- No.1(3)

The main problems of computational complexity in object tracking were object definition, identification and segmentation in non-structured environments with erratic movements and object collisions. Therefore, for efficiency, we considered the object information as a region that corresponds to objects without discriminating among objects in the same frame. This paper describes the algorithm that, automatically and efficiently, recognizes and keeps tracks of interest-regions selected by a user in video or camera image sequences. The block-based feature matching method was used for region tracking. This matching process considers only dominant feature points such as corners , edges, bright and dark spots without requiring a pre-defined model of object s . Experimental results showed that matching process captured correct region successfully even when the objects undergo scaling and 3-dimensional movements in successive image sequences.

생물막 공정에서 질소제거효율 향상을 위한 유기성담체의 효용성 검토

최동욱,최영균,김대영,김윤중,정태학 대한상하수도학회 2003 상하수도학회지 Vol.17 No.3

Availability of organic media for improving nitrogen removal efficiency in a biofilter process was studied. Although, aerobic and anoxic phase could be clearly divided during the operation of single-stage biofilter process and nitrification efficiency was about 80%, denitrification efficiency was very low due to depletion of organic substrate in anoxic phase. However, the deficiency could be improved by addition of organic media in anoxic phase from the simulated result. Nitrogen removal efficiency in a biofilter process packed with organic media in anoxic phase was predicted to be 29% higher than that packed with inorganic media. In addition, about 79% of nitrogen removal efficiency could be obtained from a column test using organic media innoculated by activated sludge. Improvement in nitrogen removal efficiency was responsible for organic leaching from the organic media and the leaching rate was 0.21㎎COD/g-org.media/day.

내부에 피라미드 구조를 가지는 ISB 판넬의 정적 특성 분석

안동규,이상훈,김민수,한길영,김진석,정창균,양동열 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

The objective of this research work is to investigate into static characteristics of ISB panels with the pyramidal structure as a internally structured material. In order to investigate the behavior of material deformation and frracture characteristics, several tensile tests have been carried out for the ISB panel and skin sheet. Through the results of the experiments, the mechanical properties of ISB panel and skin sheet and fracture characteristics have been obtained. In addition, the mechaical properties of the ISB panel have been compared with that of the skin sheet by the view point of a specific modulus, a specific yield strength and a specific strength. From the results of the comparision, it has been shown that the ISB panel has an excellent static characteristics.

Solid Modeling 기법을 응용한 복합곡면 가공에 있어서 공구간섭 제거

장동규,조시완,양균의 한국공작기계학회 1996 한국생산제조학회지 Vol.5 No.2

Compound surface modeling is widely used for die cavities and punches. A compound surface is defined in 3-D space by specifying the topological relationship of several analytic surface elements and a sculptured surface. A constructive solid geometry scheme is employed to model the analytic compound surface. the desired compound surface can be accomplished by specifying topological relationships in terms of boolean relations between primitives and the sculptured surfaces. Additionally, a method is presented for checking and avoiding the tool interference occurred in machining the compound surface. Using this method the interference of concave, convex, and side region can be checked easily and avoided rapidly.

Ku 대역 무선통신 시스템의 강우영향 분석

최동유,김재섭,박창균 조선대학교 에너지.자원신기술연구소 2004 에너지·자원신기술연구소 논문지 Vol.26 No.2

In this study selected Koreasat 3, which uses the Ku-band(14㎓/12㎓) frequency, and analyzed the beacon signal level data according to the rain rate from June to August in 2001. Then to provide analysis, the experimental data was compared with that obtained using typical rain attenuation models, such as the ITU-R model, the SAM model and the Global model, which have previously been used in satellite communication systems. Also, this study analyzed predicted area path diversity gain on the basis of the path of Daejeon-Koreasat 3 in order to compensate excess attenuation caused by rain, and estimated link budget by hour rate on the basis of the ITU-R model. Establishing the reliability of path diversity gain and link budget achieved by this study may be greatly used as a basic material to design satellite communication system in the future. Furthermore, according to methods to be applied, it could be utilized to construct microwave communication network or broadcasting network on the ground.