• Wind and Structures
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• 제30권5호
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• pp.485-497
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• 2020

A study, using potential water wave theory, is conducted on the oblique water wave motion over two fixed submerged rectangular blocks (breakwaters) placed over a finite step bottom. We have considered infinite and semi-infinite fluid domains. In both domains, the Fourier expansion method is employed to obtain the velocity potentials explicitly in terms of the infinite Fourier series. The unknown coefficients appearing in the velocity potentials are determined by the eigenfunction expansion matching method at the interfaces. The derived velocity potentials are used to compute the hydrodynamic horizontal and vertical forces acting on the submerged blocks for different values of block thickness, gap spacing between the two blocks, and submergence depth of the upper block from the mean free surface. In addition, the wave load on the vertical wall is computed in the case of the semi-infinite fluid domain for different values of blocks width and the incident wave angle. It is observed that the amplitudes of hydrodynamic forces are negligible for larger values of the wavenumber. Furthermore, the upper block experiences a higher hydrodynamic force than the lower block, regardless of the gap spacing, submergence depth, and block thickness.

• 대한산업공학회지
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• 제37권3호
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• pp.198-208
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• 2011

At a shipyard, the efficient handling of blocks is one of the most important factors in the shipbuilding process. We consider the problem of deployment planning of blocks from storage yards. As some information of block arrangement should be considered to handle the problem, we adopt the block arrangement based on the coordinates and sizes of each block at a storage yard. Deployment planning for a block involves deciding upon its transportation route from the storage yard and searching for blocks that would obstruct its transportation along this route. A tabu search algorithm for deploying several blocks is developed to minimize the number of obstructive blocks deployed together from the storage yards at a shipyard. The results of computational experiments show that the developed algorithm is very useful in the deployment planning of multiple blocks from the storage yards.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2292-2299
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• 2011

The CBTC(Communication Based Train Control) system, a recent train control system, is a wireless communication based train control system that is operated in the moving block system control by tracking trains in real time. In additioin, the system helps to increase the volume of traffic by shortening driving headways through controlling moving block system control. Furthermore, driverless modes are performed by controlling ATP(Automatic Train Protection)/ATO(Automatic Train Operation). In this paper, controllable elements in ATO driverless train control system, affecting comfortable ride, will be analysed and applied to CBTC train control system that developed by POSCO ICT. Finally, the test results of improved comfortable ride will be showed by appling the developed system to the Gyeong-san light rail transit test track.

• 대한기계학회논문집A
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• 제28권5호
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• pp.593-602
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• 2004

We have developed a digital control rod control system not only to improve its performance but also to improve its reliability and speed of response so that it can replace the old fashioned analog system. However, a new developed digital control system should be tested to prove the validity by using any prototype or mock-up before application. The reliability prediction and the reliability block diagram analysis methods were adopted to verify the reliability of the developed hardware. For the case of software, especially fur a new developed control algorithm it has been tested to prove performances and validation by using a dynamic simulator and mock-up of control rod drive mechanism altogether. Here we want to present some key factors regarding to the new developed digital system with some verification procedures.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 춘계학술대회논문집
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• pp.508-514
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• 2005

This paper is concerned with the active vibration control of a grid structure equipped with piezoceramic sensors and actuators. The grid structure is a replica of the solar panel commonly mounted on satellites, which contains complex natural mode shapes. The multi input and multi output positive position feedback controller is considered as an active vibration controller for the grid structure. A new concept, the block-inverse technique, is proposed to cope with more modes than the number of actuators and sensors. This study also deals with the stability and the spillover effect associated with the application of the multi-input multi-output positive position feedback controller based on the block inverse technique. It was found that the theories developed in this study are capable of predicting the control system characteristics and its performance. The new multi-input multi-output positive position feedback controller was applied to the test structure using a digital signal processor and its efficacy was verified by experiments..

• 한국소음진동공학회논문집
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• 제15권9호
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• pp.1037-1044
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• 2005

This paper is concerned with the active vibration control of a grid structure equipped with piezoceramic sensors and actuators. The grid structure is a replica of the solar panel commonly mounted on satellites, which contains complex natural mode shapes. The multi-input and multi-output positive position feedback controller is considered as an active vibration controller for the grid structure. A new concept, the block-inverse technique, is proposed to cope with more modes than the number of actuators and sensors. This study also deals with the stability and the spillover effect associated with the application of the multi-input multi-output positive position feedback controller based on the block-inverse technique. It was found that the theories developed in this study are capable of predicting the control system characteristics and its performance. The new multi-input multi-output positive position feedback controller was applied to the test structure using a digital signal processor and its efficacy was verified by experiments.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권7호
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• pp.286-293
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• 2002

This paper presents a new method for finding the Block Pulse series coefficients and deriving the Block Pulse integration operational matrices which are necessary for the control fields using the Block Pulse functions. In order to apply the Block Pulse function technique to the problems of continuous-time dynamic systems more efficiently, it is necessary to find the more exact value of the Block Pulse series coefficients and drives the related integration operational matrices by using the Lagrange second order interpolation polynomial.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.74-75
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• 2006

In organic opto-electronic applications, such as light emitting diodes (LEDs) and photovoltaic devices (PVDs), the morphology of the active layer is of crucial importance. To control the morphology of the active layer the self-assembling properties of block copolymers was used. Several rod-coil semiconducting diblock copolymers consisting of a conjugated block and a second coil block functionalized with electron transporting and/or accepting materials (such as $C_{60}$) were synthesized. The conjugated block acting as light absorbing, electron donating and hole transporting material. The donor/acceptor photovoltaic devices performance with active layer the above mentioned semiconducting block copolymers will be presented.

• Journal of Chest Surgery
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• 제26권10호
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• pp.781-786
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• 1993

Effrctive analgesia after elective thoracotomy can be provided by continuous extrapleural intercostal nerve block.This study was designed to prove the effectiveness of continuous extrapleural intercostal nerve block. Twenty patients undergoing elective thoracotomy were randomized into two groups. Group I received lumbar epidural block[N=10] and group II received continuous extrapleural intercostal nerve block[N=10]. Postoperative pain relief was assessed on Numeric Rating Scale[NRS] and recovery of pulmonary function was assessed by coparison of preoperatrive and postoperative FVC[Forced Vital Capacity], FEV1[Forced expiratory Volume in 1 second], VC[Vital Capacity]. Arterial blood gas analysis[ABGA], vital signs and amount of additive analgesics were compared also. No significant difference was observed between the groups concerning these parameters mentioned above. Systemic complications, such as urinary retention[2/10] and weakness of lower extremity[2/10], occurred in group I but no complication occurred in group II. We conclude that continuous extrapleural intercostal nerve block is as effective as epidural block in pain relief and restoration of pulmonary mechanics with fewer comlications. Also because of it`s ease and safetiness, this must be considered as a substitute of epidural block in routine use for thoracotomy pain relief.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.324-329
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• 1999

This paper proposes new torque control of an induction motor, which is robust against time verying parameters. The control is based on adaptive vector control with serial block adaptive algorithm. Motor parameters used to estimates slip frequency and torque. Frequency mismatch in the control system detrimentally affects slip frequency estimation and torque response. In order to compensate for degradation of the responses an adaptive identifier for the magnetizing inductance and the secondary time constand is introduced. adaptive vector control system consisted of two subsystems, a vector control system realized on synchronous frame and a parameter identification system on stationary frame. the effectiveness of the proposed method was verified by some digital simulations.