• 천문학논총
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• 제11권1호
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• pp.1-26
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• 1996

We have built a near-infrared imaging camera with a PtSi array detector manufactured by the Mitsubishi Company. The PtSi detector is sensitive in the wavelength range 1 to $5{\mu}m$. Quantum efficiency of PtSi is much lower than that of InSb and HgCdTe types. However, the PtSi array has advantages over the latter ones: (i)The read-out noise is very low; (ii)the characteristics of the array elements arc uniform and stable; (iii)it is not difficult to make a large PtSi array; and (iv) consequently the price is affordably low. The array used consists of $512{\times}512$ pixels and its size is $10.2\;mm{\times}13.3\;mm$. The filter wheel of the camera is equipped with J, H, K filters, and an aluminum plate for measuring the dark noise. The dewar is cooled with liquid nitrogen. We have adopted a method of installing the clock pattern and the observing softwares in the RAM, which Gill he easily used for other systems. We have developed a software with a pull-down menu for operating the camera and data acquisition. The camera has been tested by observing $\delta$ Orionis.

• Journal of Korean Biological Nursing Science
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• 제17권1호
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• pp.37-43
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• 2015

Purpose: Stress, depending on its intensity and duration, results in either adaptive or maladaptive physiological and psychological changes in humans. Also, it was found that stressful experiences increase the signs of behavioral despair in rodents. On the other hand, exercise and melatonin treatment is believed to have many beneficial effects on health. Thus, this study was designed to evaluate the anti-depressant effects of physical activity and melatonin against chronic stress-induced depression in rats. Methods: Adult male Sprague-Dawley(SD) rats(200-250g, 7 weeks of age) were subjected to depression induced by chronic stress. Chronic depression was induced with forced-swim stress (FSS) and repeated change of light-dark cycle for 4 weeks. In the last 2 weeks, some rats were confined in a cage enriched with a running wheel, seesaw and chewed a ball from 19:00 to 07:00 every day. Melatonin was injected intra-peritoneally (I.P), and the rats received intraperitoneal injections of melatonin (15 mg/kg). The Forced Swim Test (FST) was performed to evaluate the immobility behaviors of rats for a 5 min test. Results: It was found that, the immobility time in FST was significantly (p<.05) lower in physical exercise ($M=58.83{\pm}22.73$) and melatonin ($M=67.33{\pm}37.73$) than in depressive rats ($M=145.93{\pm}63.16$) without physical activity. Also, TPH positive cell in dorsal raphe was significantly (p<.05) higher in exercise ($M=457.38{\pm}103.21$) and melatonin ($M=425.38{\pm}111.56$) than in depressive rats ($M=258.25{\pm}89.13$). Conclusion: This study suggests that physical activity and melatonin produces antidepressant-like effect on stress-induced depression in rats. So, physical exercise and melatonin may be a good intervention in depression patients.

• 교육시설 논문지
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• 제21권3호
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• pp.19-28
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• 2014

Student halls and their convenient facilities have been a focal point for various student activities at university campus. It has been for most of the student a place of unique memories and of attachment often associated with those good and bad school days. However, it is questionable whether these facilities are supportive and accessible for all of the students and other users including the handicapped. Therefore, based on the concept of UD(universal design) which was widely applied to U.S. institutions, this study intended to evaluate student hall facilities in U.S. and to provide an improvement direction for Korean UD application. For that purpose, four universities were selected for an in-depth analysis and 76 survey indices were utilized based on previous research. It was found that (1) design consideration without braille sign for VIP(visually impaired person) in student buildings can be differently approached with electronic devices; (2) the best demonstration of UD in student buildings can be seen in spacious flat pathway, easy access through ramp and wide entry area, necessary for people in wheel-chairs, but used by all, implying an increase of the ratio of public space; (3) one of the good UD features is an attractive physical environment rather than institutional appearance, in which they ultimately will support and completely adaptable at optimal levels by everyone; (4) consistent maintenance and management maximize the potential of UD principles and minimize physical limitations.

• 한국구조물진단유지관리공학회 논문집
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• 제10권6호
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• pp.87-94
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• 2006

교량의 설계 및 시공에 있어 적절한 설계하중을 산정하기 위해 차량의 하중을 측정하는 것은 매우 중요하다. 본 논문에서는 이동하중에 대해 다축의 모멘트 영향선을 이용하여 시간에 따라 하중을 식별하는 알고리듬을 제안하였다. 또한 2개 이상의 하중을 식별하는 경우, 시간에 따른 하중 식별 결과가 심한 진동을 하기 때문에 밀도추정함수를 통해 최종 식별하중을 구하는 방법을 제안하였다. 단경간 판형교에 대한 수치예제를 수행하여 제안한 알고리듬 및 방법들을 검증하였다. 수치예제에서는 계측오차와 속도오차에 대한 오차분석을 수행하였다. 또한 제안된 알고리듬을 6m 길이의 강재 모형교량을 이용한 실내실험을 통해 재검증하였다. 속도와 하중의 종류에 따라 하중식별 능력이 달랐으나 개발한 알고리듬이 최대 10% 수준의 오차 내에서 하중을 식별할 수 있음을 확인하였다.

• 한국자동차공학회논문집
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• 제8권2호
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• pp.120-128
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• 2000

At the initial design stage of a new vehicle, the chassis layout has the most important influence on the overall vehicle performance. Most chassis designers have achieved the target performances by trial and error method as well as individual knowhow. Accordingly, a general procedure for determining the optimum location of suspension hard points with respect to the kinematic characteristics needs to be developed. In this paper, a method to optimize the toe angle in the double wishbone type front suspension of the four-wheel-drive vehicle is presented using the design of experiment, multibody dynamic simulation, and optimum design program. The handling performances of two full vehicle models having the initial and optimized toe angle are compared through the single lane change simulation. The sensitive design variables with respect to the kinematic characteristics are selected through the experimental design sensitivity analysis using the perturbation method. An object function is defined in terms of the toe angle among those kinematic characteristics. By the design of experiment and regression analysis, the regression model function of toe angle is obtained. The design variables which make the toe angle optimized ae extracted using the optimum design program DOT. The single lane change simulation and test of the full vehicle model are carried out to survey the handling performances of vehicle with toe angle optimized. The results of the single lane change simulation show that the optimized vehicle has the more improved understeer tendency than the initial vehicle.

• Journal of Biosystems Engineering
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• 제41권4호
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• pp.408-417
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• 2016

Purpose: Yield monitoring systems are an essential component of precision agriculture. They indicate the spatial variability of crop yield in fields, and have become an important factor in modern harvesters. The objective of this paper was to review research trends related to yield monitoring sensors for grain crops. Methods: The literature was reviewed for research on the major sensing components of grain yield monitoring systems. These major components included grain flow sensors, moisture content sensors, and cutting width sensors. Sensors were classified by sensing principle and type, and their performance was also reviewed. Results: The main targeted harvesting grain crops were rice, wheat, corn, barley, and grain sorghum. Grain flow sensors were classified into mass flow and volume flow methods. Mass flow sensors were mounted primarily at the clean grain elevator head or under the grain tank, and volume flow sensors were mounted at the head or in the middle of the elevator. Mass flow methods used weighing, force impact, and radiometric approaches, some of which resulted in measurement error levels lower than 5% ($R^2=0.99$). Volume flow methods included paddle wheel type and optical type, and in the best cases produced error levels lower than 3%. Grain moisture content sensing was in many cases achieved using capacitive modules. In some cases, errors were lower than 1%. Cutting width was measured by ultrasonic distance sensors mounted at both sides of the header dividers, and the errors were in some cases lower than 5%. Conclusions: The design and fabrication of an integrated yield monitoring system for a target crop would be affected by the selection of a sensing approach, as well as the layout and mounting of the sensors. For accurate estimation of yield, signal processing and correction measures should be also implemented.

• 한국산학기술학회논문지
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• 제12권4호
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• pp.1523-1531
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• 2011

본 다축 차량은 험지와 야전에서 높은 이동성 때문에 비포장도로를 주행해야 하는 군용차량으로 사용된다. 특히 군용차량은 군 요구 사항에 의거 기본적으로 60% 경사로에서 안정적인 등판 성능을 지녀야 한다. 따라서 본 논문은 최적 타이어 힘 분배 방법을 통한 6WD/6WS차량의 등판능력 향상을 다루었다. 경사로 등판 시 사용할 최적 타이어 힘 분배 방법을 위하여 운전자로부터, 목표로 하는 종 방향 힘과 횡 방향 힘, 요 모멘트를 계산하였고, 마찰 원이론과 목적함수에 따른 최적화 된 토크가 각 륜에 분배되었다. 알고리즘 성능을 확인하기 위해서, 트럭심 소프트웨어를 이용하여 시뮬레이션 하였고, 비교를 위하여 2대의 차량을 제안하였다. 한 대의 차량은 최적타이어 힘 분배 방법이 적용되었고, 나머지 한 대는 궤도 차량과 같은 균등 힘 분배 방법이 적용되었다. 경사로에서 등판능력은 최적 타이어 힘 분배 방법에 의해서 향상 되어졌다.

• 한국항해학회지
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• 제20권2호
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• pp.1-13
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• 1996

Most of the ShipHandling Simulators of full-mission-bridge system need vast area to install and even PC-based maneuvering simulators are often equipped with Steering Wheel or Engine Telegraphe etc. of data input interface, which necessarily makes the user face with excessive financial burden. These have been one of the obstacles for the officers, captains, pilots and students in access to maneuvering simulation whenever they want to try it in advance prior to actual ship maneuvering. Subsequently, all the officers and captains come to have little chances to train themselves until they arualified as a pilot after a long period of time of realship maneuvering practice on board, which means they have to control they have to control their own ship at sea without clear understanding on her maneuverability when they are forced to do it on the way. And these lack of capability for maneuvering have used so often to result in marine casualties of collision with other ships or pier facilities while maneuvering in harbor. To prevent those accidents by means of enhancing their maneuvering ability, PC-based DeskTop Simulator that allows anyong to access readily at anytime is needed and in conformation to such demand this simulator has been developed. The Software this simulator written in Turbo Pascal Ver. 5.0 has adopted MMG mathmatical model theoretically in part and also it was designed to make it possible that all numeric data inputs and outputs with graphic presentation for maneuvering operation be carried out just only with keyboard and monitor console. With the Simulation software, all the officers, captains, pilots and even students who has a proper computer at hand are expected to be able to make an attempt to simulate the maneuvering of their ownship or any other types of them at any port in which they want to do it.

• Journal of Nutrition and Health
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• 제22권1호
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• pp.1-8
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• 1989

The study was attempted to observe effects of voluntary exercise on energy expenditure and on storage of excessive energy into body fat in adult mice. Mice, body weight 25-30g, were divided into two groups, exercise and sedentary group. Voluntary exercize by running wheel was allowed for former group but not for the mice of the latter group which were restricted by limiting space allowance 13.5$\times$11.5$\times$15.0cm per mouse. During a period of 4 weeks of feeding trial, they were fed ad libitum starch-casein based diet added with $^3\textrm{H}$-glucose (D-[1-$^3\textrm{H}$(N)]-glucose) at a level of 20 nCi per g of diet. Measurements were made to study hematology, lipase activity in epididymal adipose tissue, total contents of body waste and fat, and radiactivity of $^3\textrm{H}$-glucose incoporated into body fat. Dietary intake, body weight gain and amount of voluntary physical activities were also measured. The results obtained ard summarized as follows; 1) Amount of metabolizable energy intake, body weight gain and body fat were not statistically different between the two group. However, mice of the exercise group tended to show lower body weight gain body fat contants, but higher energy expenditure than those of the sedentary group. 2) Radioactivity of $^3\textrm{H}$-glucose incoporated into body fat appeared lower for exercise group expressd on a whole body fat basis. The activity was, however, higher for exercise group when expressed based on per g of fat compared to that of sedentary group. 3) Exercise group showed also higher activity of lipase in epididymal adipose tissue than the other group. 4) Mice whose physical activities were restricted appeared to have lower levels of hemoglobin and hematocrit values than of the exercise group. These results seem to support the theory that turn-over rate of body fat is activated by exercise and to suggest that consumed energy is to be converted primarily into body fat before its use as energy source by oxidation even during a period of continuous energy expenditure by exercise.

• 한국수산과학회지
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• 제31권4호
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• pp.477-482
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• 1998

치어의 먹이사료인 동물성 플랑크톤은 단세포조류인 Chlorella를 먹이로 하고 있으며, 우리 나라에서는 현재까지 Chlorella를 연못형 배양조에서 배양하고 있다. 본연구에서는 Chlorella의 생산성을 높이기 위하여 Chlorella 배양 조건 중, 빛의 공급율을 높이는 데에 중점을 두고 여섯 형태의 모형 배양조를 제작하고 Chlorella vulgalis 211-11b의 최대 비증식속도와 생산성을 비교하였다. 모형 배양조 중, ${\mu}_{max}$와 생산성이 가장 큰 것은 HS-Pbr이었으며. 최대 비증식속도와 생산성이 반드시 배양조의 S/V에 비례하지는 않았다.