• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.327-332
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• 1993

One maglev vehicle is composed of 6 r 8 modules. Each module is composed of 4 staggered magnets attached to an aluminum bogie. In the view point of levitation control except propulsion by LIM, 5 is the maximum degrees of freedo to be controlled. But rolling control of the vehicle depends on the bogie structure. We describe just anti-roll type out of bogie structures and 4 degrees of freedom control is sufficient for levitation quality improvement. Multivariable pole-placement concept and the decentralized control concept are used for controller design. Computer simulation and control experiment are performed on a specially designed test module.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.430-432
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• 2004

Tele-operation and remote monitoring techniques are essential and important technologies for the inspection and maintenance of the radioactive waste. A mobile robot has been developed for the application of remote monitoring and inspection of nuclear facilities, where human access is limited because of the high-level radioactive environments, The mobile robot was designed with reconfigurable crawler type of wheels attached on the front and rear side in order to pass through the ditch, The extendable mast, mounted on the mobile robot, car be extended up to 8 m vertically. The robust controller for radiation is designed in focus on electric components to prevent abnormal operation in a highly radioactivated area during reactor operation, This robot system will enhance the reliability of nuclear power facilities, and cope with the unexpected radiation accident.

• Journal of Advanced Marine Engineering and Technology
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• 제20권1호
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• pp.31-36
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• 1996

In recent years, as the electonic industry has become more advanced, the LPM(Linear Pulse Motor) has appeared in a wide range of applications because of easier control, operation by open-loop control, high positioning accuracy, and retrieval of position or velocity data by the input pulses. In this study, we deal with the development of a position detection device attached to a hybrid LPM in our laboratory. Precise position detection signals could be sensed by the synchronous rectifier method from the LPM stator scale. In addition, we can keep the amplitude constant by using an AGC(Automatic Gain Control) circuit. Experimental results show that the position data is good enough to perform the LPM position control.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2003년도 ISIS 2003
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• pp.252-255
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• 2003

In this paper, we suggest the method for a service robot to move safely from an initial position to n goal position in the wide environment like a building. There is a problem using odometry encoder sensor to estimate the position of n mobile robot in the wide environment like a building. Because of the phenomenon of wheel's slipping, a encoder sensor has the accumulated error of n sensor measurement as time. Therefore the error must be compensated with using other sensor. A vision sensor is used to compensate the position of a mobile robot as using the regularly attached light's panel on a building's ceiling. The method to create global path planning for a mobile robot model a building's map as a graph data type. Consequently, we can apply floyd's shortest path algorithm to find the path planning. The effectiveness of the method is verified through simulations and experiments.

• 한국항공운항학회지
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• 제12권3호
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• pp.25-39
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• 2004

An experimental study was quantitatively carried out in order to investigate the influence of flow conditions on a boundary layer in the near-wake of a flat plate. Tripping wires attached at various positions were selected to change flow conditions of a boundary layer in the vicinity of trailing edge. The flows such as laminar, transitional, and turbulent boundary layer at 0.98C from the leading edge are imposed to investigate the evolution of symmetric and asymmetric wake. Measurements were made at freestream velocity of 6.0m/s, and the corresponding Reynolds number is $2.8{\times}10^5$. An x-type hot-wire probe(55P61) was employed to measure at 8 stations in the near-wake region. Test results show that the near-wake of the flat plate for the case of a laminar and transitional boundary layer is sensitive to mean flow shear generated after separation but for the case of turbulent boundary layer is insensitive.

• 한국소음진동공학회논문집
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• 제22권4호
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• pp.372-376
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• 2012

The most common type of the piezoelectric energy harvester is the cantilevered beam since it is attached to the host structure and tuned to the frequency of the base excitation easily. However, the excessive strain at the fixed end of cantilevered beam causes some problems such as fatigue and durability. The use of higher vibration modes of the cantilevered beam may reduce the concentration of the strain at the fixed end since the strains of higher modes are distributed along the span. The results show that the use of high vibration mode is not efficient for power generation, but it reduces the excessive strain lever at typical region to prevent the failure by fatigue.

• 소음진동
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• 제7권1호
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• pp.153-159
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• 1997

In a stiffened plate reinforced on one of its sides by beam type stiffeners, the asymmetry about the plate mid-plane induces coupling between flexural wave and longitudinal wave. In this research interactions between flexural and longitudinal wave motion are analyzed in a stiffened plate which is reinforced only in one direction. The plate is modelled as a beam to which offset spring-mounted masses are attached at regular intervals. Propagation constants of the coupled waves and corresponding characteristic waves are derived by using periodic structure theory, and a computer code is developed. Also, sample calculations are carried out and the results are discussed.

• 한국가시화정보학회지
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• 제8권3호
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• pp.22-28
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• 2010

In the present study, we performed the velocity field measurement in a microchannel using a focal length variable micro liquid lens. The liquid lens is used as a beam expander in a micro-PIV system to acquire the scatter image of the seeded particle. A thin film-type micro liquid lens was made of PDMS material and it was attached on top of the 700-micron-wide working fluid supply channel trench. As a result, the focal length and contact angle of the liquid lens changed with variations in applied pressure.

• Journal of Chest Surgery
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• 제11권3호
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• pp.239-245
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• 1978

Recently, we experienced a case of rare neurilemmoma originated from intercostal nerve [9th] in the right chest wall in a 25 year old male officer. The tumor was incidentally found in the routine chest X ray, where the round well circumscribed mass tumor the ninth rib with notching and sclerotic margin, suggesting slowly growing benign benign of chest wall was revealed and the tumor mass was easily extirpated in the exploratory thoracotomy, with uneventful recovery. Grossly, the tumor was firm, partly soft and well circumscribed, measuring 4.5X3.0X 3.0 cm with yellowish smooth outer surface, attached with intercostal nerve trunk. Cut surface exhibits partly grayish white and largely hemorrhagic areas. Microscopically, the characteristic palisading arrangement of schwann cells and Verocay bodies are seen but dominant features are cystic degeneration and hemorrhage with organization and fibrosis. The sheath of intercostal nerve and capsule of neurilemmoma were con joined. There is no evidence of malignancy. The tumor was confirmed as neurilemmoma of intercostal nerve, Antony type B.

• 전기학회논문지P
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• 제56권2호
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• pp.104-108
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• 2007

This paper deals with an approach to the reduction of potential rise according to the buried depth of structure. In order to analyze the surface potential rise of structure, an electrolytic tank which simulates the semi-infinite earth has been used. The potential rise has been measured and analyzed for types of structure using an electrolytic tank experimental apparatus in real time. The structure models were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. When a test current flowed through structure models, potential gradient was the highest value in case of the outline frame type(structure model A). The distributions of surface potential rise are dependent on the resistivity and absorption percentage in concrete attached to structure model.