• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.7
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• pp.674-681
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• 2011

In the early phase of vehicle development, CAE is conducted as tool for vehicle performance assessment. To maintain acceptable road noise performance, solution for reduced vehicle sensitivity is required. Chassis interface dynamic stiffness characteristics are key component to isolating vibration and noise of road from the vehicle interior. This research provide how to set up the optimized dynamic characteristics under noise effect through DFSS study. CAE-based DOE is performed to build prediction math model, CMS process involves DOE to achieve very fast run times while giving results very comparable. Minimized 95th percentile of performance distribution is applied to minimize vehicle sensitivity and road noise levels variation during the optimization process. Finally, the results of optimization were reviewed for performance and robustness.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.253-259
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• 2019

The wedding seating problem(WSP) is to finding a minimum loss of guest relations(sit together preference) with restricted seats of a table for complex guest relation network. The WSP is NP-hard because of the algorithm that can be find the optimal solution within polynomial-time is unknown yet. Therefore we can't solve the WSP not computer-assisted programming but by hand. This paper suggests min-cut rule theory that the two guests with maximum preference can't separate in other two tables because this is not obtains minimum loss of preference. As a result of various experimental, this algorithm obtains proper seating chart meet to the seats of a table constraints.

• Journal of the Korean Society for Railway
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• v.14 no.2
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• pp.167-173
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• 2011

This paper considers the problem of revising train departure time to reduce electric power consumption of mass rapid transit (MRT) railways. The motion of a train running between stations is divided into three phases: traction, coasting, and deceleration phases. The traction phase requires high electric power to operate MRT railways. In the coasting phase, the train moves stably by consuming little or no power. The deceleration phase is a braking mode and produces some electric power called regenerated brake power owing to inertia force for the train generated In the traction and coasting phases. The regenerative energy can be used by other accelerating trains within a specific range from the train and thereby the power consumptions of train can be reduced. We developed a mixed integer programming model to solve the problem. To validate the suggested model, a computational experiment was conducted using real data from Korea Metropolitan Subway.

• Journal of Radiation Protection and Research
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• v.20 no.1
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• pp.45-52
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• 1995

This study is to compare A point doses in human pelvic phantom by film dosimetry, computer planning and manual calculation by using of along-away table. We developed tissue equivalent human pelvic phantom composed of four pieces of cylindrical acryl tubes with water, to simulate intracavitary radiation (ICR) in patients with cervix cancer. When the phantom assembled from 4 pieces, it has a small space for inserting Fletcher-Suit-Delclos applicator like a human vagina. Fletcher-Suit-Delclos applicator inserted into the space was packed tightly with furacin gauzes, and three $^{137}Cs$ sources with radioactivity of $15.7mg\;Ra-eq$ were inserted into the tandem. For the film dosimetry, two pieces of X-OMAT V film (Kodak Co.) of which planes include point A, were arranged orthogonally in the slits between phantoms. A point dose and iso-dose curves were measured by means of optical densitometer. A point doses by film dosimetry, RTP system and manual calculation by using of along-away table were compared, and iso-dose curves by film dosimetry and computer planning were also compared. The dose of A point was 51.2cGy/hr by film dosimetry, 46.7cGy/hr by RTP system and 47.9 cGy/hr by along-away table. A point dose by computer planning was similar to the dose by calculation using of along-away table with acceptable accuracy $({\pm}3%)$, however, the dose by film dosimetry was different from two others with about 10% error. Since most clinical beams contains a scatter component of low energy photons, the correlation between optical density and dose becomes tenuous. In addition, film suffers from several potential errors such as changes in processing conditions, interfilm emulsion differences, and artifacts caused by air pockets adjacent to the film. For these reasons, absolute dosimetry with film is impractical, however, it is very useful for checking qualitative patterns of a radiation distribution. In future, solid state dosimeter such as TLD must be used for the dosimetry of ionizing radiation. When considerable care is used, precision of approximately 3% may be obtained using TLD.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.253-261
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• 2006

Estimating the size of unerupted teeth is an essential aspect of orthodontic diagnosis and treatment planning in the mixed dentition. Several methods were introduced and used for the prediction. The most common methods among these would be Moyers probability chart and Tanaka and Johnston equations. These are currently used widely, but they were developed for Caucasians. Because there are clear racial differences in teeth size, the objectives of this study were to produce correlation coefficients between the combined mesiodistal widths of the permanent mandibular incisors and those of the canines and premolars for each quadrant, and prediction tables with regression equations, specifically for Korean. 178 young adults (70 women, 108 men, mean age 21.63 years) were selected from the College of Dentistry, Yonsei University, Seoul, Korea. The mesiodistal crown diameters of the permanent teeth were measured with calipers. Significant sexual dimorphism was found in tooth sizes. The correlation coefficients between the total mesiodistal width of the mandibular permanent incisors and those of the maxillary and mandibular canines and premolars were found to be between 0.52 and 0.64. The standard error of the estimatation was better (0.60) for women and the ${\gamma}^2$ values ranged from 0.27 to 0.41 for both sexes Prediction tables were prepared for Korean. This study showed larger canine and premolar diameters than Tanaka and Johnston's and Moyers' studies which might be due to the racial differences. Further investigations with a larger sample size will be needed for more representative data on the Korean population.

• Journal of Sericultural and Entomological Science
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• v.3
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• pp.61-67
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• 1963

This report is prepared to find how the filament of cocoon bave size deviation relates with the raw silk made by them which are intensively cultured in this country. Three recommended hybrid varieties and two varieties under working at Suwon Sericultural Experiment Station were selected as specimens. The cocoons were reeled as an individual filament of every fifty meters long skein with a wrap reel to weigh the denier and to investigate the relationship of the above statement so that it may be used for the quality estimation before processing it into raw silk. The conclusions obtained are as follows. (1) The variation of Pk${\times}$Sn was found as best cocoon for 21 denier raw silk use, but the number of cocoon to make the denier has to be eight which might cause more labor cost. (2) Baektoo-Kumkang and Myohiang-Chongchon were found as economical varieties for 21 denier use. (3) Seulak-Soyang is a proper variety for the use of 14 or 28 denier silk use. (4) Myohiang-Chongchon did not confirm a good property from the aspect of denier deviation. (5) It was found that there was a fairly strong corelationship between the mean cocoon bave size deviation as indicated by Ono's report. (6) Three graphs were prepared to estimate the cocoon quality before processing into various sizes of raw silk using the mean cocoon bave size and the raw silk size to be prepared. (7) Mean time, the graph which is able to estimate the expectable grade of the raw silk size deviation was designed for the practical use. (8) The expectable grade of the varieties used in this report were found as following data. Notice (A......cocoon number to make raw silk (B......total cocoon bave size deviation (C......expectable silk grade (9) The result of the work concerning the expectable denier deviation on 21 denier silk was the same with the statistical actual testing result as 1.25 D while the distribution showed farther necessity of improvement in technically.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.683-688
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• 2018

Recently, the demand for electric energy has been increasing due to the spread of hybrid electric vehicles. In this study, to meet this demand, the ANSYS MAXWELL electromagnetic simulation system was used to compare the power generation characteristics of three types of suspension system that can generate electricity using energy harvesting technology. Next, the optimal design was determined for each model by using the commercial PIDO (Process Integration and Design Optimization) tool, PIANO (Process Integration, Automation and Optimization). We selected three design variables and constructed an approximate model based on the experimental design method through electromagnetic analysis for 18 experimental points derived from Orthogonal Arrays among the experimental design methods. Then, we determined the optimal design by applying the Evolutionary Algorithm. Finally, the optimal design results were verified by electromagnetic simulation of the optimum design result model using the same analysis conditions as those of the initial model. After comparing the power generation characteristics for the optimal structure for each linear generator model, the maximum power generation amounts in the 8pole-8slot, 12pole-12slot, and 16pole-16slot structures were 366.5W, 466.7W and 579.7W, respectively, and it was found that as the number of slots and poles increases, the power generation increases.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.475-482
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• 2014

This paper presents the results of an experimental feasibility study on low-temperature differential Stirling engines with water spray heat transfer. The water spray enhances the efficiency of the heat transfer from heat sources to the engine and reduces the performance degeneration due to the dead volumes of conventional heat exchangers. A test Stirling engine was developed and an experiment was conducted to determine the characteristics for the initial start-up, steady-state operation, and power output for various flow rates and temperatures of hot supply water. The test results showed that larger flow rates led to reductions in the minimum working temperature of the hot water at start-up. During a series of steady-state operations, higher flow rates and temperatures increased the working speed. Furthermore, the work per cycle and power output were also increased. Eventually, the test Stirling engine had a power level of 0.05 W. Based on this, further research will be conducted to obtain a higher power output and investigate various applications.

• Magazine of the Korean Society of Agricultural Engineers
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• v.18 no.1
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• pp.4011-4020
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• 1976

본논문은 북해도대학심사학위논문으로 총면수 143면인 영문으로 되어 있고 도 48, 표 7, 문묵 66부도, 부표 20면이있음. Plow는 옛부터 발달한 농구이기 때문에 많은 연구가 행하여졌지만 복잡한 물리성을 가준 토양을 대상으로 하는 기계이기 때문에 미해결의 문제도 적지않다. 이견인저항에 대하여 토양의 종류 및 조건을 변경하면서 실제의 포장에서 조직적으로 행한 실험은 극히 적고, 하물며 우리나라의 쟁기에 관한 연구는 거의없다. 본논문은 쟁기의 특징을 구명하고, 그의 개량, 발달에 기여하기 위한 기기자료를 획득코저 실시한 것이다. 1. 쟁기와 플라우의 구조 및 그의 차이 특징을 명백히하고 이체에 걸리는 각종의 저항의 내용 또는 그 비율등에 대하여 과거의 연구성과를 소개하였다. 2. 발달사 ; 플라우는 B.C. 2000년경에 녹각, 목지의 인력용의 경운용구에서 발달하고, 동양이도 기원은 대체로 같고 발달과정이 다를 뿐이다. 쟁기는 양자강연안에 기원을 가진 지나이가 신라와 백제에 도입되여 차차 발달하고, 지역적인 특징을 가지게 되었다. 3. 본장은 쟁기의 견인력에 관한 이론적해석을하고, 쟁기의 진행에 의해 층상으로 전단되는 전단저항을 구하고 쟁기의 표면 및 지측판과 토양과의 마찰력, 그리고 토양의 이동의 관성력을 쟁기의 견인저항에 관련되는 주요한 "힘"으로 생각하고 진행방면, 수직방면의 힘의 성분의 평형을 고려하여 식 10. 12를 유도 하였다. 4. 본장에서는 실험계획, 방법 공시기, 공시포장등을 기록하고, 축력용의 쟁기와 플라우를 사용하여 전지 4종 답 2종의 포장에서 실험하는데 견인력계와 자동경심측정기를 사용하였다. 5. 실험결과 및 고찰; 경심과 견인저항 Dp와의 관계는 식 10. 12와 갈이 표시되고, 실제의 제치를 대입하여 이론식을 유도하였으니 직선에 가까운 관계가 있고, 실험결과는 조금 곡선에 가까워졌다. 그리고, 토양의 물리성이 견인력Dp에의 영향을 세밀히 검토하였다. 쟁기의 견인비저항에 있어서도 식 12에서 {{{{K=AT+ { B} over {T } +C}}}}로 표시할수 있기 때문에 최소치를 표시하는 경심이 존재하고 이값은 쟁기나 플라우폭의{{{{ { 1} over {2 } }}}} 즉 10m정도이고 쟁기는 비저항이 0.llkg/$\textrm{cm}^2$에서 0.39kg/$\textrm{cm}^2$이였다. 그러나 이 비저항도 토양의 물리성이 많은 영향을 미치고 있다. 6. 요약 및 결론 ; 이상의 장에서 검토 고찰한 결과만을 기재하고 플라우는 쟁기에 비해 견인저항 및 비저항이 논에서나 밭에서 대로 나타난 것이 특이하다. 이상의 내용을 지면관계로 3회에 거쳐 요약 발표합니다.

• Journal of Korean Home Economics Education Association
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• v.20 no.3
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• pp.85-105
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• 2008

The purpose of this study was to develop a narrative analytic scoring rubric through teacher-students negotiations, as an assessment of tasks using methods of experiment and practice for home economic(HE) in the middle school. In this study. an analytic rubric had been developed in the following three stages: In the first stage, all the things for rubric development were defined and prepared, by selecting tasks used for rubric application through a questionnaire survey, providing detailed directions on methods and procedures and needed items, and selecting a class for rubric negotiation and setting the development schedule. In addition, the method suggested by Ainsworth and Christinson(1998) in Student Generated Rubrics was used. In the second stage, performance criteria for tasks in terms of knowledge, skills, and attitude were developed, setting scoring framework and scales depending on assessment areas. Referring to selected scoring framework and assessment criteria, observable and assessable behaviors were used to describe rubric based on A, B, and C scale. Then, a primary rubric was developed through teacher-students negotiations, using rubrics made by group. In the last stage, the developed primary rubric was reviewed by an expert of HE education to test the validity. Moreover, the analysis to test the suitability of the final rubric assessment tool employed 46 copies of questionnaire collected from incumbent home economics teachers selected by way of random sampling mainly focusing on those teachers who were in the Master's degree program or completed the program at one university. As a result, the average of suitability of aa the rubrics were over 4.0 in th 5-point scale.