• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.9
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• pp.1972-1978
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• 2010

AAM(Active Appearance Model) is one of the most effective ways to detect deformable 2D objects and is a kind of mathematical optimization methods. The cost function is a convex function because it is a least-square function, but the search space is not convex space so it is not guaranteed that a local minimum is the optimal solution. That is, if the initial value does not depart from around the global minimum, it converges to a local minimum, so it is difficult to detect face contour correctly. In this study, an AAM-based face tracking algorithm is proposed, which is robust to various lighting conditions and backgrounds. Eye detection is performed using SIFT and Genetic algorithm, the information of eye are used for AAM's initial matching information. Through experiments, it is verified that the proposed AAM-based face tracking method is more robust with respect to pose and background of face than the conventional basic AAM-based face tracking method.

• Membrane Journal
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• v.13 no.4
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• pp.239-245
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• 2003

The origin of large difference of selectivity of $C_3H_6$ over $C_3H_8$ between pure gas and mixed gas through silver polymer electrolyte membranes is investigated. Firstly, the effect of feed condition on the permeance of mixture gas ($C_3H_6/C_3H^8$) and the separation performance is examined. Upon decrease of the $C_3\;H_6$ concentration, the $C_3H_6$ permeance decreased whereas the permeance of $C_3H_8$ increased, resulting in the decrease of the selectivity of $C_3H_6/C_3H_8/.$ This result is ascribed to the $C_3H_6$-induced plasticization of membranes. Experimental results were validated by means of mathematical modeling, where pressure independent permeabilities were used.

• Journal of the Korean Electrochemical Society
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• v.4 no.2
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• pp.70-76
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• 2001

The present work describes the capabilities of laser beam deflection (LBD) technique for the analysis of the stresses developed during hydrogen diffusion through Pd foil electrode. First, we explain briefly the elasto-diffusive (Gorsky effect) and diffusion-elastic phenomena. A model for the diffusion-elastic phenomenon is theoretically derived from the solution of the Fick's equation for given initial and boundary conditions, Vegard's second law and Hooke's law. Second, we introduce how to apply the principle of LBD technique to the study on the stresses generated during hydrogen diffusion. From the comparison of the deflection transients numerically calculated with those experimentally measured, we finally discuss the change in the tensile deflection with time in terms of hydrogen concentration profile transient and hydrogen diffusivity.

• Journal of the Korean Institute of Educational Facilities
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• v.3 no.3
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• pp.41-57
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• 1996

본 연구는 광희중학교 학구내에서 재개발로 인하여 증가되는 인구수을 예측하여 장래 중학교 학생수를 예측하였다. 2016까지 학급당 학생수를 37명으로 하고 36학급 규모의 학교를 추구한다면 중학교는 적어도 1개 더 건축하여야만 재개발로 늘어나는 제1학군의 학생수를 수용할 수있을 것음을 분석하였다. 또, 교과과정을 분석한 결과 도덕 2.5교실, 국어 6교실, 사회 5교실, 수학 5교실, 과학 5교실, 체육 4교실, 음악 2교실, 미술 2교실, 가정 1.5교실, 기술 3교실, 영어 5.5교실, 한문 1교실, 컴퓨터 1교실로 분석되어 이용율이 88%가 되었다. 본 연구는 광희중학교 구체적 건축계획에 앞서 계획의 모델을 설정하여 이를 토대로 계획에 임하였다. 광희중학교 주변의 접근성, 교통 조건, 소음 상태, 지역사회인의 이용, 전망 등의 환경 분석을 토대로 4개의 죠닝(Zonning)안을 제시하여 평가한 후 가장 바람직한 안을 선정하였다. 이를 토대로 브록(Block)프랜을 5개 작성하여 평가후 1개 안을 채택하여 구체적 평면 계획안을 작성하였다. 36학급 37명 학생수를 기준으로 교과교실형으로 계획하였으며 특별 교실형의 학습도 가능하게 계획하였다. 교수, 학습의 복합화에 대처하여 칸막이를 이동 가능한 형태로 계획하였으며, 일반 교과도 컴퓨터를 이용한 수업이 가능하게 정보 코너를 설치하였다. 지역사회인에게 열린 교실이 되게 계획하였고 개별 학습이 가능한 구조로 계획하교 기자재의 선진화를 대비한 학습 환경의 제고도 고려하였다. 본 연구의 입면 형상은 주변 건물과 조화되게 수평적 요소가 강조되는 형상이 되도록 계획하며 고층의 아파트의 위협을 상쇄시키기 위하여 지붕이 있는 구조로 계획하여 지역사회에서 중심임을 강조하도록 계획하였다.

• Journal of Navigation and Port Research
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• v.26 no.4
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• pp.473-479
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• 2002

The estimation of the volume of a pit excavation is often required in many surveying, soil mechanics, highway applications and transportation engineering situations. The calculation of earthwork plays a major role in plan or design of many civil engineering projects such as seashore reclamation, and thus it has become very important to improve the accuracy of earthwork calculation. In this paper the spot height method, proposed formulas(A, B, C), and chen and Line method are compared with the volumes of the pits in these examples. And we proposed an algorithm of finding a terrain surface with the free boundary conditions and both direction spline method drawback, i.e., the modeling curves form peak points at the joints. To avoid this drawback, the cubic spline polynomial was chosen as the methematical model of the new method. From the characteristics of the cubic spline polynomial, the modeling curve of the new method was smooth and matched the ground profile well. As a result of this study, algorithm of proposed three methods to estimate pit excavation volume provided a better accuracy than spot height, chamber, chen and Lin method. And the mathematical model mentioned makes is thought to give a maximum acccuracy in estimating the volume of a pit excavation.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1079-1084
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• 1998

Reaction kinetics between 4,4'-dihexyl methane diisocyanate($H_{12}MDI$) and n-hexanol in toluene with dibutyltin dilaurate(DBTDL) as catalyst was studied by experimental measurements and mathematical modeling. Experiments were carried out at various temperatures, catalyst concentrations and [NCO]/[OH] ratios, and the reaction kinetics were described by two second-order reactions, the one between NCO and OH leading to urethane and the other between urethane and NCO leading to allophanate. The rate constants were estimated by the Runge-Kutta 4th-order method. Experiments and mathematical simulations showed a good agreement for various experimental conditions. The [allophanate]/[urethane] ratios at 90% conversion of initial NCO were estimated to be over 20% for most conditions employed in the present study, indicating that allophanate formation might significantly affect the properties of urethane polymers.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.385-394
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• 1994

Numerical solutions were obtained to the model equations for various of the parameters characterizing the pore structure, effective internal diffusion, and the chemical reaction constant. The conversion was decreased with the cause of pore closure at the surface of reacting particles, reduction of porosity, surface area of reaction and effective diffusion coefficient in the solid with the progress of reaction. Total conversion was strongly dependent on the local conversion at surface. According to the decreasing of impregnated concentration of the copper oxide and the increase of the flue gases concentration, total conversion was increased. The conversion was affected by gas flow rate and pore size distribution in the reacting solid.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.9
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• pp.19-28
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• 2010

The GTS(Guaranteed Time Slot) of the IEEE 802.15.4 standard, which is the contention free access mechanism, is used for low-latency applications or applications requiring specific data bandwidth. But it has some problems such as delay of service due to FIFS(First In First Service) scheduling. In this paper, we proposes a weight based GTS allocation scheme for fair queuing in IEEE 802.15.4 LR-WPAN. The proposed scheme uses a weight that formed by how much more weight we give to the recent history than to the older history for a new GTS allocation. This scheme reduces service delay time and also guarantees transmission simultaneously within a limited time. The results of the performance analysis shows that our approach improves the performance as compared to the native explicit allocation mechanism defined in the IEEE 802.15.4 standard.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.113-118
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• 2021

The guided weapon system should ensure economical operation and user safety. In particular, in the case of guided weapon systems developed in the form of a guaranteed bomb, the standards for maintaining reliability considering the long-term storage environment are presented during the development stage, and an optimized inspection cycle is required to maintain this. This study calculated the reliability through a trend test, fitness test, and distribution analysis using a mathematical model based on the maintenance status and shooting results during the inspection period for OO missiles currently in operation for a long time in the military. Through this, it was applied to the inspection period model (Martinez) set during the development stage to determine if the improved inspection period can be utilized. Finally, by synthesizing the data from these studies, a policy management plan was developed according to the extension of the inspection period. The One-Shot system was operated at the inspection period set when it was developed. The study analyzed the actual failure and maintenance data to reset the efficient inspection period.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.2
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• pp.161-172
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• 2024

A Copula approach has the advantage of providing structural dependencies for representing multivariate distributions for the hydrometeorological variable marginal distribution involved, however, copulas are inflexible for extending in high dimensions, and satisfy certain assumptions to make the dependency. In addition, since the process of estimating design rainfall under the future climate associated with durations given a return period is mainly analyzed by 24-hour annual maximum rainfalls, the dependency structure contains information only on the daily and sub-daily extreme precipitation. Methods based on bivariate copula do not provide information for other duration's dependencies, which causes the intensity to be reversed. The vine copula has been proposed to process the multivariate analysis as vines consisting of trees with nodes and edges connecting pair-copula construction. In this study, we aimed to downscale under climate change to produce sub-daily extreme precipitation data considering different durations based on vine copula.