• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.261-264
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• 2000

Two hull forms of 2, 500 TEU Container Vessel, designed by Daedong Shipbuilding CO., LTD. were tested at the Circulating Water Channel of Chosun University for the evaluation of resistance performance. The test results of resistance, wave profile measurement and trim-sinkage measurement are compared in the form of diagrams and figures, and the results are discussed. A conclusion is drawn that the performance of modified form (model number : CU-201F2A2) is improved about 8% resistance performance at the design speed compare with original form (model number : CU-201F1A1).

• 한국경영과학회지
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• 제30권1호
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• pp.55-74
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• 2005

Bankruptcy prediction has drawn a lot of research interests in previous literature, and recent studies have shown that machine learning techniques achieved better performance than traditional statistical ones. This paper employs a relatively new machine learning technique, support vector machines (SVMs). to bankruptcy prediction problem in an attempt to suggest a new model with better explanatory power and stability. To serve this purpose, we use grid search technique using 5-fold cross-validation to find out the optimal values of the parameters of kernel function of SVM. In addition, to evaluate the prediction accuracy of SVM. we compare its performance with multiple discriminant analysis (MDA), logistic regression analysis (Logit), and three-layer fully connected back-propagation neural networks (BPNs). The experiment results show that SVM outperforms the other methods.

• 동력기계공학회지
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• 제9권4호
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• pp.24-30
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• 2005

For a reciprocating compressor of household refrigerators, a direct analogy between the pipe flow network and the electric circuit network has been utilized to set up a mathematical model for oil supply system. Individual lubrication elements of the oil supply system, such as propeller- installed oil cap, oil galleries, radial oil feeding holes, spiral oil grooves, and various sliding surfaces have been analogized by equivalent electric elements, and these have been combined together to form an electric circuit corresponding to the whole oil supply system. By solving the closed network equations of the model, oil flow rates at various lubrication elements could be obtained. Total amount of the oil flow rate drawn into the shaft has been measured and compared reasonably well with the prediction of the numerical simulation.

• 소성∙가공
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• 제22권6호
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• pp.310-316
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• 2013

Recently, numerical predictions of surface deflection based on curvature analysis have been developed. In the current study, a measure of surface deflection is proposed as the maximum variation of curvature difference between the panel and the tool in order to account for surfaces that have high curvature. The current study focused on the assessment of accuracy for the surface deflection prediction with the consideration of planar anisotropy. As an example, a shallow rectangular drawn part with rectangular embossing was considered. In terms of the proposed surface deflection measure, the maximum variation of curvature difference, the prediction with a planar anisotropic model shows better correspondence with experiment than the one using a normal anisotropic model.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제22권3호
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• pp.179-199
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• 2018

The paper explores a tri-trophic food chain model with density dependent mortality of intermediate predator. To analyze this aspect, we have worked out the local stability of different equilibrium points. We have also derived the conditions for global stability of interior equilibrium point and conditions for persistence of model system. To observe the global behaviour of the system, we performed extensive numerical simulations. Our simulation results reveal that chaotic dynamics is produced for increasing value of half-saturation constant. We have also observed trajectory motions around different equilibrium points. It is noticed that chaotic dynamics has been controlled by increasing value of density dependent mortality parameter. So, we conclude that the density dependent mortality parameter can be used to control chaotic dynamics. We also applied basic tools of nonlinear dynamics such as Poincare section and Lyapunov exponent to investigate chaotic behaviour of the system.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.1-4
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• 2005

This research is to present experimental materials model of high strength concrete for prediction of fire safety of structural members based on physical properties of materials during heating up to 800$^{circ}C$. The following conclusions are drawn from this study. First of all, between 100 to 200 $^{circ}C$, the physical models of concrete such as specific heat and thermal conductivity, show visible degradation, regardless of concrete strength. Second, between 300 to 600$^{circ}C$, the physical models of the 29MPa and 49MPa concrete show degradation continually at these temperatures. Finally, beyond 600$^{circ}C$, the physical models of 49MPa strength concrete show larger degradation than 29MPa strength concrete due to rise of pore pressure and melting of the interface between aggregate and cement paste.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권2호
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• pp.188-195
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• 2005

After making the surgical treatment plan, the surgical movements are duplicated in the model surgery. During this procedure, reference points and lines are drawn on the base of the models over the dental arch, and sawcuts are made according to these marked osteotomy lines. This method requires more accuracy for better postsurgical results in that the surgical splint which enables the surgeon to position the jaws intraoperatively is made from the casts as repositioned by the model surgery, and finally it will define the postsurgical results. This technique, however, has been found to be inexact, especially when the jaws are moved in several dimensions simultaneously. To overcome this, different methods have been developed for an accurate repositioning of the jaws as planned. A new appliance, Surgical Jaw Relator, was devised by the author for the simple 3-dimensional relocation of the upper and lower models, resulting in the easy construction of the splints such as centric relation splint, intermediate and final splint. This article describes an introduction and a clinical application of this appliance.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2006년도 추계학술대회 논문집
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• pp.86-91
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• 2006

In this parer, we present the bubble forming and motion in the micro channel by using the two-dimensional numerical computation and experiment. In the numerical computation, The Lattice Boltzmann method(LBM) and free-energy model is used to treat the interfacial force and deformation of binary fluid system, drawn in to a micro channel and a numerical simulation is carried out by using the parallel computation method. The urn in this investigation is to examine the applicability of LBM to numerical analysis and experimental method of binary fluid separation and motion in the micro channel.

• Geomechanics and Engineering
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• 제13권6호
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• pp.963-975
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• 2017

Improvement of soft clay deposit by preloading with vertical drains is one of the most popular techniques followed worldwide. These drains accelerate the rate of consolidation by shortening the drainage path. Although the analytical and numerical solutions available are mostly based on equal strain hypothesis, the adoption of free strain analysis is more realistic because of the flexible nature of the imposed surcharge loading, especially for the embankment loading used for transport infrastructure. In this paper, a numerical model has been developed based on free strain hypothesis for understanding the behaviour of soft ground improvement by vertical drain with preloading. The unit cell analogy is used and the effect of smear has been incorporated. The model has been validated by comparing with available field test results and thereafter, a hypothetical case study is done using the available field data for soft clay deposit existing in the eastern part of Australia and important conclusions are drawn therefrom.

• 감성과학
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• 제13권3호
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• pp.573-580
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• 2010

기존의 감성평가방법은 대립하는 뜻의 단어를 중복되지 않게 선택하거나, 단계별로 제시된 수치를 선택해야 하는 등, 미리 준비된 것 중에서 골라야만 했다. 하지만, 본 연구에서는 평가대상항목에 대해 미리 준비된 수치에서 고르지 않고, 인간의 애매한 평가를 시각화하는 방법을 개발했다. 본 프로그램은, 제시된 평가항목에 대한 주관적인 느낌을 피험자가 마우스나 펜타블렛을 이용해 손으로 그려서 입력하는 방식이다. 그리는 방법이 자유롭고, 평가에 대한 애매한 표현이 가능하다. 정해진 기준이나 제한이 적고, 생각대로 그려서 표현한다. 연이어 그려진 원은 면적이 자동으로 계산됨과 동시에 각 원의 면적비율이 원 그래프로 표시된다. 그려진 원은 크기, 색, 선의 굵기, 투명도 등의 수정이 가능하고, 평가 후에는 원의 비교, 조정이 가능하도록 되어 있다. 개념모델을 손으로 그린 원으로 표현하여 시각화 하는 것으로 인사평가, 고통평가, 제품평가 등의 응용범위가 넓다. 성 마리안나 이과대학병원 간호지원센터 직원들에 의해 그 가능성을 평가 받아, 현재 간호사자신의 인사평가 툴로써의 효과를 검증 중에 있다. 이와 함께 환자의 고통의 종류와 그 레벨을 표현하는 프로그램과 KJ법을 응용하여 다이내믹한 인터페이스로 개념모델을 효과적으로 시각화할 수 있도록 개발을 진행하고 있다.