• 한국컴퓨터정보학회논문지
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• 제23권4호
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• pp.57-64
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• 2018

In this paper, we propose the automatic detection method for individual region separation using panorama image. Finding areas that contain individual teeth is one of the most important tasks in automating 3D models through individual tooth separation. In the conventional method, the maxillary and mandibular teeth regions are separated using a straight line or a specific CT slide, and the tooth regions are separated using a straight line in the vertical direction. In the conventional method, since the teeth are arranged in a curved shape, there is a problem that each tooth region is incorrectly detected in order to generate an accurate tooth region. This is a major obstacle to automating the creation of individual tooth models. In this study, we propose a method to find the correct tooth curve by using the jawbone curve which is very similar to the tooth curve in order to overcome the problem of finding the area containing the existing tooth. We have proposed a new method to accurately set individual tooth regions using the feature that individual teeth are arranged in a direction similar to the normal direction of the tooth alignment curve. In the proposed method, the maxillary and mandibular teeth can be more precisely separated than the conventional method, and the area including the individual teeth can be accurately set. Experiments using real dental CT images demonstrate the superiority of the proposed method.

• 한국해양공학회지
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• 제21권4호
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• pp.15-20
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• 2007

The harbor siltation by longshore sediment transports has become a serious problem on the East Coast of Korea. A reasonable prediction of the longshore sediment rate is important to approach the siltation problem effectively. In the recently developed 1-line model, the empirical constants of the sediment transport formula, which include the absolute quantity of sediment transport rate and the spatial distribution of breaking wave height by wave deformation, are treated as calibration parameters. Since these constants should be determined by the very long-term shoreline data, the longshore sediment rates are much more reasonable values. The method was applied to Hupo Beach, which has experienced heavy siltation. The authors also discuss long-term shoreline change using aerial photos and the observed wave-induced current patterns. According to the result, the SW-direction sediment transport rate was $146,892m^3/year$, and the NE direction was $2,694,450m^3/year$ at Hupo Beach for the last 11 years. The siltation in Hupo Harbor might be affected by the NE-direction sediment transport from Hupo Beach.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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• pp.283-292
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• 1999

Temperature prediction model was developed for on-line application to plate rolling mills of POSCO. The adequate boundary conditions of heat transfer coefficients were obtained by comparing the predicted temperature with the measured temperatures taken by measuring system in plate rolling mill of POSCO. In obtaining the boundary condition which minimize the mean and standard deviation of the difference between prediction and measurement, orthogonal array for experimental design was used to reduce the calculation time of large data set. To predict the temperature drop at four edge of plate in one dimensional model, the energy change by heat transfer though directions perpendicular to thickness direction was treated like that by deformation. And the heat transfer through four edge directions was inferred from that through thickness direction with two coefficients of depth and severity of temperature drop at the edge. The boundary condition for the depth and severity of temperature drop were also determined using the measured temperature.

• 국제학술발표논문집
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• The 2th International Conference on Construction Engineering and Project Management
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• pp.573-582
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• 2007

Working spaces in the construction site are much more complicated than completed spaces in the building. There are many researches focus on partition of building spaces. However, few discussed partition sequencing in building construction sites. Space syntax is a set of techniques for analyzing spatial configurations. It has become a useful tool in a variety of researches. Partition sequencing of working spaces should be related to the working direction. However, with convex space and axial line, the partition sequencing became unrelated to the working direction. When critical space is blocked, the partition sequencing with axial line will be changed. It is significant to reveal the impact of the entire spatial structure when some of the working spaces are blocked. This paper discussed the improved partition sequencing theory and highlighted the importance of critical space and analyzed the spatial structure of working space. A real case project was demonstrated in this paper.

• 한국국방경영분석학회지
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• 제12권1호
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• pp.87-105
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• 1986

Among the various types of waiting line systems, the elevator servicing system is quite different from the usual queueing system in view of the service characteristics. For example, the FIFO discipline is not always valid depending upon the situation when the direction of first-come customer's is opposite of the operating elevator direction and at that time a later-arrived one has a luck to be served first. In this paper, a simulation model is constructed and tested by the sample data and the results have turned out to be fairly adequate. This model, therefore, will provide a good guide to anyone who is interested in the decision of optimal location selection of no-passenger elevator in high buildings whatsoever. This model is also available, with slight modification, to the problem of city bus dispatching or any other waiting line problems where the servicing equipments are moving.

• 한국인터넷방송통신학회논문지
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• 제11권6호
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• pp.87-91
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• 2011

본 논문에서는 하나의 필드만을 사용하여 비월 주사 영상을 순차 주사 영상으로 변환하는 디인터레이싱 방법을 제안한다. 먼저, ELA 기법을 이용하여 에지의 방향성을 예측한다. 에지의 방향성을 정확히 예측하였을 경우에는 ELA(Edge-based Line Average) 기법에 의한 화소를 보간하고 에지의 방향을 잘못 예측하였을 경우에는 다시 새로운 에지의 방향을 결정한다. 결정된 방향에 대하여 화소를 본 논문에서 제안한 중간값 필터(median filter)를 이용하여 보간한다. 모의실험 결과 기존의 비인터레이싱 방법에 비해 주관적 및 객관적 화질이 개선됨을 보인다.

• The Journal of the Acoustical Society of Korea
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• 제21권3E호
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• pp.105-111
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• 2002

The parabolic equation technique provides an excellent model to describe the wave phenomena when there exists a predominant direction of propagation. The model handles the square root wave number operator in paraxial direction. Realization of the pseudo-differential square root operator is the essential part of the parabolic equation method for its numerical accuracy. The wide-angled approximation of the operator is made based on the Pade series expansion, where the branch line rotation scheme can be combined with the original Pade approximation to stabilize its computational performance for complex modes. The Galerkin integration has been employed to discretize the depth-dependent operator. The benchmark tests involving the half-infinite space, the range independent and dependent environment will validate the implemented numerical model.

• 한국지하수토양환경학회지:지하수토양환경
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• 제19권3호
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• pp.111-122
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• 2014

Partitioning interwell tracer test (PITT) is a method to quantify and qualify a site contaminated with NAPLs (Non-Aqueous Phase Liquids). Analytical description of PITT assumes that the injection-pumping well pair is on the line of the ambient groundwater flow direction, but the test-well pair could frequently be off the line in a real field site, which could be an erroneous factor in analyzing PITT data. The purpose of this work is to study the influence of the angle of the test-well pair on the ambient groundwater flow direction based on the result from PITT. From the experiments, it was found that the obliqueness of the test-well pair to the ambient groundwater flow direction could affect the tracer test resulting in a decreased NAPL estimation efficiency. In case of an oblique arrangement of the test-well pair to the ambient flow direction, it was found that the injection of a chase fluid could enhance the estimation efficiency. An increase of the pumping rate could enhance the recovery rate but it cannot be said that a high pumping rate can increase the test efficiency because a high pumping rate cannot give partitioning tracers enough time to partition into NAPLs. The results have a implication that because the arrangement of the test-well pair is a controlling factor in performing and interpreting PITT in the field in addition to the known factors such as heterogeneity and the source zone architecture, flow direction should be seriously considered in arranging test-well pair.

• 대한의용생체공학회:의공학회지
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• 제17권4호
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• pp.545-552
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• 1996

Researches on chromosome are very significant in cytogenetics since a gene of the chromosome controls revelation of the inheritance plasma The human chromosome analysis is widely used to diagnose genetic disease and various congenital anomalies. Many researches on automated chromosome karyotype analysis has been carried out, some of which produced commercial systems. However, there still remains much room for improving the accuracy of chromosome classification. In this paper, we propose an algorithm for reconstruction of the chromosDme image to improve the chromosome classification accuracy. Morphological feature parameters are extracted from the reconstructed chromosome images. The reconstruction method from chromosome image is the 32 direction line algorithm. We extract three morphological feature parameters, centromeric index(C.I.), relative length ratio(R.L.), and relative area ratio(R.A.), by preprocessing ten human chromosDme images. The experimental results show that proposed algorithm is better than that of other researchers'comparing by feature parameter errors.

• 디지털융복합연구
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• 제12권11호
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• pp.373-378
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• 2014

방위탐지기술은 위치표정 정확도를 높이기 위해서 매우 중요하다. 도착시간차(TDOA) 방위탐지 방식은 정확도가 매우 높은 기술이며 1990년대부터 고주파신호 방위탐지에 사용되었다. TDOA 방식은 송신기에서 송신된 신호가 거리가 다른 위치에 있는 두 개의 수신기에 도착하는 시간차를 이용하여 송신기의 방위를 측정하는 방식으로서 수신신호의 신호대잡음비(SNR)와 안테나 기준선이 방위탐지 정확도에 매우 큰 영향을 미치며, 본 논문에서는 SNR과 안테나 기준선에 대한 방위각 정확도와 위치표정 정확도를 모사하였다. 기준선의 길이가 50m이고 SNR이 40dB 이상이면, 입사방위각 $0^{\circ}$에서 약 $0.51^{\circ}$의 방위탐지 정확도를 얻었다.