• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제43권3호
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• pp.204-211
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• 2017

In dentistry, elevator instruments are used to luxate teeth, and this technique imparts forces to tooth particles that sever the periodontal ligament around tooth roots inside the socket and expand alveolar bone around tooth particles. These effects can result in extraction of the tooth particles or facilitate systematic forceps extraction of the tooth particles. This article presents basic oral surgery techniques for applying elevators to luxate teeth. Determination of the optimal luxation technique requires understanding of the functions of the straight elevator and the Cryer elevator, the concept of purchase points, how the design elements of elevator working ends and tips influence the functionality of an elevator, application of forces to tooth particles, sectioning teeth at furcations, and bone removal to facilitate luxation. The effectiveness of tooth particle luxation is influenced by elevator tip shape and size, the magnitude and the vectors of forces applied to the tooth particle by the tip, and sectioning and bone removal within the operating field. Controlled extraction procedures are facilitated by a dental operating microscope or the magnification of binocular surgical loupes telescopes, combined with co-axial illumination.

• Tuberculosis and Respiratory Diseases
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• 제40권4호
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• pp.353-356
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• 1993

Advent of new imaging modalities such as computed tomography, magnetic resonance imaging and ultrasound contributed greately to the specific imaging diagnosis. However plain chest X-ray is still most prequently used for imaging diagnosis of respiratory disease in clinical pratic and it is important to make a good quality of X-ray film and good interpretation. The optimal chest X-ray should be taken with full inspiration without rotation and motion and the exposure is at the level of barely demonstrable thoracic vertebral disc space. It is recommended that higk KVP technique for detection of lesions which is overlaped by mediastinum, heart and rib cage. It is better to examine chest X-ray film start at some distance(6-8 feet) and closer to the film later on and the reader should not read a film in fatigue condition. The reading room should be quiet and relately dark illumination. It is important, to make a good X-ray film and good interpretation to reduce the observer error.

• 전기학회논문지
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• 제65권12호
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• pp.1965-1970
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• 2016

This paper studies generator rescheduling technique for congestion management in power system with wind farms. The proposed technique is formulated to minimize the rescheduling cost of conventional and wind generators to alleviate congestion subject to operational line overloading. The generator rescheduling method has been used with incorporation of wind farms in the power system. The locations of wind farms are selected based upon power transfer distribution factor (PTDF). Because all generators in the system do not need to participate in congestion management, the rescheduling has been done by generator selection based on the proposed generator sensitivity factor (GSF). The selected generators have been rescheduled using linear programming(LP) optimization techniques to alleviate transmission congestion. The effectiveness of the proposed methodology has been analyzed on IEEE 14-bus systems.

• 대한전기학회논문지:전력기술부문A
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• 제49권3호
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• pp.124-135
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• 2000

This paper presents reasonable evaluation technique to determine system configuration of underground distribution system. To set up reasonable evaluation for a certain object region, it is necessary for methodology to access accurately factors such as economics, reliability, customer interruption cost, implementation and flexibility about proposed various configuration of underground distribution system. But it is difficult to evaluate factors as above-mentioned since there is no criterion to assess them in our country. Accordingly, having completed the technical and economical analysis and customer interruption cost of various types of system, this paper presents the most reasonable results to get the optimal configuration of underground distribution system. Also, this paper presents possible methodology which can be applied other areas having a different load characteristics by application actually making a selection Myungdong as sample area.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.801-803
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• 1995

This paper presents the linearized fuzzy modeling technique of nonlinear dynamical system and the stability analysis of fuzzy control system. Firstly, the nonlinear system is partitionized by multiple linear fuzzy subcontrol systems based on fuzzy linguistic variables and fuzzy rules. Secondly, the disturbance adaptation controllers which guarrantee the global asymptotic stability of each fuzzy subsystem by an optimal feedback control law are designed and the stability analysis procedures of the total fuzzy control system using Lyapunov functions and eigenvalues are discussed in detail through a given illustrative example.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 B
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• pp.823-825
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• 1995

This paper presents an efficient and robust robot path planning technique that can always find a path, if one exists, in a densely cluttered, unknown and unstructured obstacle environment. The terrain in which the robot is expected to navigate is represented as a tesselated grid of square cells. The generated path is resolution complete and also resolution optimal once the terrain is fully explored by the robot or all the information about the terrain is given. The technique enables the accurate wave propagation to the diagonally adjacent cells and facilitates the implementations of various essential features for a real-time path planner such as partial updates and parallel computations.

• 전자공학회논문지A
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• 제30A권3호
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• pp.104-113
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• 1993

A new switchbox router, called CONQUEROR, is proposed in this paper. The proposed CONQUEROR efficiently routes large switchbox routing area using divide-and-conquer technique. The CONQUEROR consists of three phases` namely, partition of large routing area and assignment of optimal pins of sub-area, detailed routing of each sub-ared, reassignment of pins after rip-up. First, large switchbox routing area is partitioned into several sub-areas and each sub-area contains 4-6 detailed grids. Then pins are assigned on boundary of sub-area by the estimated weight. Secondly, when global pin assignment is completed on all sub-areas, each sub-area is routed using detailed router. Also, detailed routing consists of three pases` layerless maze routing, assignment of layer using coloring, and rip-up and reroute. Lastly, if detailed routing of any sub-area fails,reassignment of pins after rip-up is invoked. Detailed routing is performed for the failed sub-area again. Benchmark test cases have been run, and on all the benchmark data known in the literature CONQUEROR has performed as well as or better than existing switchbox routers.

• 대한전자공학회논문지TC
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• 제45권12호
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• pp.20-25
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• 2008

Codebook-based opportunistic beamforming (COBF) 기법은 파일럿을 적게 사용하면서 기존의 opportunistic beamforming 기법에 빔 선택 다이버시티를 추가한다. 본 논문에서는 채널의 상관도를 고려한 kappa-factor 채널 모델에 기반을 두어 COBF 기법에서 사용되는 랜덤 행렬과 코드북을 디자인한다. 디자인한 COBF를 적용하면 최적의 빔과 유사한 빔을 생성할 수 있고, 이에 따라 채널의 상관도가 높거나 낮음에 상관없이 항상 최적의 시스템 용량을 보인다.

• 대한안전경영과학회지
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• 제9권4호
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• pp.129-136
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• 2007

This paper considers the sequencing of products in mixed model assembly lines under Just-In-Time (JIT) systems. Under JIT systems, the most important goal for the sequencing problem is to keep a constant rate of usage every part used by the systems. The sequencing problem is solved using Genetic Algorithm Genetic Algorithm is a heuristic method which can provide a near optimal solution in real time. The performance of proposed technique is compared with existing heuristic methods in terms of solution quality. Various examples are presented and experimental results are reported to demonstrate the efficiency of the technique.

• Bulletin of the Korean Chemical Society
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• 제25권1호
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• pp.101-105
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• 2004

The laser ablation/ionization time-of-flight mass spectrometry is applied to the isotopic analysis of solid samples using a home-made instrument. The technique is convenient for solid sample analysis due to the onestep process of vaporization and ionization of the samples. The analyzed samples were lead, cadmium, molybdenum, and ytterbium. To optimize the analytical conditions of the technique, several parameters, such as laser energy, laser wavelength, size of the laser beam on the samples surface, and high voltages applied on the ion source electrodes were varied. Low energy of laser light was necessary to obtain the optimal mass resolution of spectra. The 532 nm light generated mass spectra with the higher signal-to-noise ratio compared with the 355 nm light. The best mass resolution obtained in the present study is ~1,500 for the ytterbium.