• Journal of Advanced Marine Engineering and Technology
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• 제22권1호
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• pp.108-116
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• 1998

In this paper it is investigated the roles of key elementary reactions for NO formation in methane-air one-dimensional premixed flame and counterflow diffusion flame, which were studied numerically by using NO kinetics and $C_{2}$ -chemistry complied by Miller and Bowman. The spatial distributions of the reaction rates of 9 main elementary reactions directly related to NO formation and destruction were calculated. Integration of the rates of all reactions in the NO formation across the flame yields the quantitative reaction path diagram, which shows clearly relative importance of each reaction path in NO formation and how it changes with the type and parameters of the flame. The results show that the thermal and Fenimore mechanisms are dominant respectively for learn and rich premixed flames, and the latter is dominant for diffusion flames. In addition, it was found that the HCN recycle route is important for diffusion flame, and that the routes of mutual transformation between NO and NO$^{2}$, and between NO and HNO do not contribute to the net NO formation.

• 대한산업공학회지
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• 제35권2호
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• pp.150-159
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• 2009

The heterogeneous fleet vehicle routing problem(HVRP) is a variant of the classical vehicle routing problem in which customers are served by a heterogeneous fleet of vehicles with various capacities, fixed costs and variable costs. We propose a new conceptual HVRPCR(HVRP with customer restriction) model including additional customer restrictions in HVRP. In this paper, we develop hybrid particle swarm optimization(HPSO) algorithm with 2-opt and node exchange technique for HVRP. The solution representation is a n-dimensional particle for HVRP with N customers. The decoding method for this representation starts with the transformation of particle into a priority list of customer to enter route and limit of vehicle to serve each customer. The vehicle routes are then constructed based on the customer priority list and limit of vehicle to serve. The proposed algorithm is tested using 8 benchmark problems and it consistently produces high-quality solutions, including new best solutions. The numerical results show that the proposed algorithm is robust and efficient.

• 수산해양기술연구
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• 제32권3호
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• pp.273-285
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• 1996

Generally, the flow around the ship's hull often appear 3-dimensional separation at the bow and stem, and the vortex by this flow affects greatly the resistance propulsive efficiency and maneuverability of the ship. This study is compared the calculated result based on the streamlines calculation method with the experimental result by oil fIlm method to analyze the patterns and characteristics of the flows around the ship's hull of chine form. DTMB Series 62, 4667-1 vessel was selected as a sample ship of chine form and model ship was painted with the mixture of oil-color, paint, and poly wax at the surface of the vessel and tested in the model towing tank of Inha University. The results obtained in this study are listed briefly as follows ; 1. For the single chine form, after $4\frac{1}{2}$ station the streamlines are crossed at the chine line and the streamlines are converted to the vortex follow the chine line. 2. For the single chine form, the vortex appered increases and severely in and arround the stern. 3. The approximate streamlines for the ship's hull of chine form can be assigned by the use of the Watanabe's basic transformation formular.

• 정보저장시스템학회논문집
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• 제2권2호
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• pp.138-143
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• 2006

We developed a numerical simulator in order to study the Super-RENS/ROM (Super REsolution Near-Field Structure, Read Only Memory) using 3-dimensional FDTD (finite difference time domain) method. The simulation can be performed by three steps. In the first step, we utilized the vector-diffraction theory to calculate the characteristics of incident laser beam from the object-lens to the surface of the disk. At the second step, we fed the calculated result as an input for the main FDTD simulations on the optical layers in the disk structure. After performed the FDTD simulations, we took near-to-far field transformation for the reflected signal, from the surface of the disk to the detector. Finally, we can get reflected signal at the photo-diode. Using this developed simulator, we were able to study about the reading signal from various disk structures as a function of a laser beam position. We calculated reading signals for various pit sizes for Super-ROM structure, and it is found that the simple optical diffraction theory can not explain the reading mechanism of Super-ROM, and more complicated temperature dependent physics must be involved.

• 한국BIM학회 논문집
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• 제14권2호
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• pp.1-12
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• 2024

The paper proposes a methodology that combines the Random Sample Consensus (RANSAC) algorithm and the Point Cloud Encoder-Decoder Network (PCEDNet) algorithm to automatically extract the length of infrastructure elements from point cloud data acquired through 3D LiDAR scans of retaining walls. This methodology is expected to significantly improve time and cost efficiency compared to traditional manual measurement techniques, which are crucial for the data-driven analysis required in the precision-demanding construction sector. Additionally, the extracted positional and dimensional data can contribute to enhanced accuracy and reliability in Scan-to-BIM processes. The results of this study are anticipated to provide important insights that could accelerate the digital transformation of the construction industry. This paper provides empirical data on how the integration of digital technologies can enhance efficiency and accuracy in the construction industry, and offers directions for future research and application.

• 한국운동역학회지
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• 제19권4호
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• pp.671-680
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• 2009

본 연구는 실제 경기에서 프로 배구선수 스파이크 서브의 성공과 실패 동작을 3차원 영상분석을 통해 비교 분석하여 과학적인 자료를 현장에 제공하고, 기술의 향상에 기여하고자 실시하였다. 스파이크서브를 수행하는 3명을 대상으로 카메라 4대를 이용하여 60 fields/s의 속도로 촬영하였다. 3차원좌표의 계산은 DLT(Direct Linear Transformation)방법을 사용하였으며, Kwon3D(v.3.1) 프로그램을 이용하여 분석하였으며, 그 결과 다음과 같은 결론을 얻었다. 총 소요시간은 구간별 차이가 나타나지 않았다. 신체중심 수직위치는 성공 시 1.87 m로 실패 시의 1.91 m 보다 낮게 나타났고, 최대 볼 높이는 성공 시 6.31m로 실패 시의 6.42m 보다 낮은 볼 위치를 나타냈다. 임팩트 시점의 손 높이는 성공과 실패 시기에서 차이가 나타나지 않았다. 점프하기 직전까지 신체중심의 전후속도를 높였다가 점프하는 시점에서 수직속도로 빠르게 이동시키는 것으로 나타났고, 임팩트 시 손 속도(17.11m/s)와 임팩트 직후 볼 속도(23.74m/s)는 성공 시기에서 빠르게 나타났다. 성공 시기에서 견관절을 신전시키면서 타점을 놀게 하고, 주관절은 적절한 각도를 유지시키면서 빠르고 정확한 임팩트를 하는 것으로 나타났다. 또한, 동체를 전후로 크게 움직이지 않고 어깨의 회전을 원활하게 하는 것이 중요한 것으로 나타났다.

• 한국임상수의학회지
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• 제19권1호
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• pp.49-54
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• 2002

Korean safflower (Carthami Flos) seed has been known to have healing effects on both bone fracture and osteoporosis. On the base of such a notice, this experiment was carried out to explore the effects of safflower seed on bone formation and bone repair. In addition, the healing mechanism was evaluated by analysing serum after feeding the seed to experimental. animals. The effect of Korean safflower seed were evaluated with 40 rats,3-month old. Forty Sprague-Dawley rats composed of 20 male and 20 female were underwent unilateral tibial defect and then fastened with unilateral fixators. The operated rats were divided into two groups depending on the composition of diet, such as positive control group fed normal diet (C-OP group) and safflower seed group fed 30% of safflower seed diet and 70% of normal diet (S-OP group). Postoperative radiographys were taken once in 2 weeks to evaluate callus formation for operated groups. In addition, a possible protein spots involved in bone recovery were examined using 2-Dimensional Gel Electrophoresis (2-DE). The comparison of the radiography between C-OP and S-OP group were showed that the safflower seed diet appeared to stimulate the formation of callus in the rat. On the images of 2-BE, it was able to identify possible five protein spots, having pl from 4 to 5 and molecular weight range from 24 to 26 kDa, involved in bone formation and repair, since no differing protein spots were found the two between groups except the five spots. No differences were observed between two groups before operation, but clear and bigger protein spots were observed from the S-OP group compared with C-OP group on 6 and 9 weeks post operation. These protein spots were, however, showed similar sizes and densities between two groups in 12 weeks later. The transformation of protein spots was suggested that these protein spots were involved in bone formation and recovery, in addition safflower seed might induce the formation of factors and activate these factors. In conclusion, this study suggest that safflower seed influence a variety of factors in the course of bone formation or the periods of remedy.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.561-565
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• 1994

An automatic measuring system of three dimensional shape by a projection method with grating pattern from in optical spatial modulator has been developed. The characteristics of the system were studied. This system is composed of a projector, an optical spatial modulator, a CCD camera, and computer. A liquid crystal is used as the optical spatial modulator. The grating patterns that ire projected on the surface of the object are controlled by the computer connected with the optical spatial modulator. The projector patterns are measured by the CCD camera. The data are transferred to the computer. After a transformation into line data, the data are analyzed to obtain the coordinate of the surface of the object. This system has advantages as follows. (1) It is possible to capture the surface topography without any contact. (2) The time required for the measurements is shorter than the light-section method. (3) An optical spatial modulator using a liquid crystal is possible to control the grating patterns accurately by a computer. Surfaces of a plate and a cylinder were measured. The threshold level had an influence on the measurement. It was shown that this system has adequae accuracy in the measurements.

• 대한토목학회논문집
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• 제3권3호
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• pp.95-106
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• 1983

사면(斜面)의 3차원(次元) 파괴(破壞)의 신뢰성(信賴性) 해석(解析)에 안전율(安全率)대신 파괴확률(破壞確率)이 사용(使用)되었다. 강도정수(强度定數)는 정규분포(正規分布)와 베타분포(分布)(beta distribution)로 가정하였고 특별(特別)한 신뢰도(信賴度)와 최우추정법(最尤推定法)에 의하여 구간추정(區間推定)을 하였다. 정규분포(正規分布)와 베타분포(分布)의 의사무작위변수(擬似無作爲變數)는 중심극한정리(中心極限定理)와 Rejection방법(方法)에 따라 일양분포변환방법(一樣分布變換方法)을 사용(使用)하여 발생(發生)시켰고 몬테칼로방법 (Monte-Carlo Method)에 의한 파괴확률(破壞確率)은 다음과 같이 정의(定義)된다. $$P_f$$=M/N M: 파괴회수(破壞回數) N: 시행회수(施行回數) 본(本) 연구(硏究)의 결론(結論)은 강도정수(强度定數)를 정규분포(正規分布)로 가정한 경우에는 주어진 파괴표면(破壞表面)에 대하여 어떤 해석방법(解析方法)과 차원(次元)에 대해서도 안전율(安全率)과 파괴확률(破壞確率)과의 관계는 일정(一定)하였으나 베타분포(分布)로 가정 한 경우에는 일정(一定)한 관계가 나타나지 않았다.

• 감성과학
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• 제5권1호
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• pp.25-32
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• 2002

본 연구에서는 7가지 실크직물의 스치는 소리를 녹음한 후, 색채로 변환시켜 변환색채에 대한 감각과 감성을 평가하고, 2차원 모형을 제시하여 감각/감성과 직물의 관계를 시각화하였다. 피험자 30명을 대상으로 변환색채에 대한 감각과 감성을 평가하도록 하였으며 색채의 물리량은 홍색비율(RP), 녹색비율(GP), 청색비율(BP)과 색채 빈도수(CC)를 계산하였다. 감성차원에 대하여 활동감, 우아함, 터프함의 세 요인이 도출되었다. 활동감 차원은 GP, CC와는 정적인 상관을 보였으며 능직물과 견방사의 교직물을 가장 활동적이라고 평가하였다 우아함 차원은 RP와는 정적상관을, CC와는 부적상관을 보였으며 수자직물과 평직물이 가장 우아하다고 평가되었다. 터프함 차원은 RP와 높은 정적상관을 가졌다. 능직물과 같이 색채 빈도수가 많고 홍색비율과 녹색비율이 많은 변환색채를 선호하였다.