• 한국세라믹학회지
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• 제36권2호
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• pp.178-185
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• 1999

Si3N4 겔캐스팅공정 제어를 위하여, 슬립 조성의 영향이 슬립의 점성특성과 성형체의 기계적 특성 및 소결체의 밀도에 미치는 영향에 대하여 조사하였다. 아크릴아마이드 모노머, 고분자전해질, 그리고 질화규소의 혼합물을 어트리터에 예비혼합한 후 볼밀링하여 슬립을 제조하였다. 개시제가 혼합된 슬립을 진공탈포하고 몰드에 주입하고 중합을 진행하였으며, 겔화된 슬립을 건조하여 성형체를 얻었다. 슬립의 특성과 성형체의 기계적 특성을 평가하기 위해, 슬립의 점도 측정과 직경방향 압축시험을 행하였다. 그 결과, near net shaping을 위한 낮은 점도를 갖는 46 vol%의 고농도 질화규소 슬립의 제조가 가능하였다. 성형체가 기계적 특성은 주로 모노머의 농도에 비례하여 증가하였다. 또한, 겔캐스트 성형체의 인장강도가 약 3MPa이 넘으면 기계적 가공이 가능하였으며, 겔캐스팅 성형체를 176$0^{\circ}C$, 3시간 상압소결하여 약 98.5%의 상대밀도를 얻을 수 있었다.

• 비만대사연구학술지
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• 제1권2호
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• pp.59-65
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• 2022

Obesity is a serious health concern, which has been linked to an increased risk for cardiovascular diseases and some cancers. The traditional obesity control program is expensive. Moreover, it is difficult to maintain a healthy body weight as well as reduce body fat. The long-term use of effective and tolerable medication is carefully recommended to control body weight. In addition to obesity control medications, health functional foods, related to body weight control, have become popular in the commercial market. Known mechanisms include lipolysis, appetite control, inflammation reduction, and lean body mass maintenance. Previous clinical trials have documented the efficacy of some health functional foods; however, there are limitations. Studies on the potential roles and efficacy of some health functional foods, including caffeine, green tea, protein supplement, probiotics, and arginine, were reviewed. More large-scale and randomized placebo-controlled trials should be conducted eventually.

• 한국식품과학회지
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• 제20권1호
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• pp.72-78
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• 1988

열대지방에서 재배되는 18종의 콩종자의 구조적인 특성을 분류하기 위하여 그 미세구조를 주로 광학현미경으로 조사하였다. vicieae에 속하는 종실들은 많은 단일전분입자들로 구성된 자엽세포구조를 갖는 starch-rich legume이였으며, phaseoleae중에서는 benas(phaseolus), cow pea, green gram(vigna), hyacinth bean(dolicholus)이 starch-rich legume이였다. 한편 soybean(glycine), winged bean(psophocarpus)는 자엽세포가 대부분 protein body로 구성된 protein-rich legume이고 yam bean (pachyrrhizus)와 cluster bean(cyamopsis)에서는 protein body 보이는 구형물질로 이루어진 자엽세포 구조를 볼 수 있었다. 또한 green gram과 winged bean은 soybean에 비하여 두꺼운 세포벽을 갖고 있었으며 pit-pair가 관찰되었다. Lipid body는 winged bean과 soybean에서 볼 수 있었다. starch-rich legume들은 팥고물 제조과정에서 전분입자들이 파괴되지 않음으로써 특징적인 조직감을 부여하는 red bean이나 benas와 같은 phaseolus의 대체 자원으로 제시될 수 있었다.

• 한국멀티미디어학회논문지
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• 제19권1호
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• pp.68-79
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• 2016

Electromyographic (EMG) signals have been widely used as motion commands of prosthetic arms. Although EMG signals contain meaningful information including the movement intentions of human body, it is difficult to predict the subject's motion by analyzing EMG signals in real-time due to the difficulties in extracting motion information from the signals including a lot of noises inherently. In this paper, four Ag/AgCl electrodes are placed on the surface of the subject's major muscles which are in charge of four upper arm movements (wrist flexion, wrist extension, ulnar deviation, finger flexion) to measure EMG signals corresponding to the movements. The measured signals are sampled using DAQ module and clustered sequentially. The Fuzzy C-Means (FCMs) method calculates the center values of the clustered data group. The fuzzy system designed to detect the upper arm movement intention utilizing the center values as input signals shows about 90% success in classifying the movement intentions.

• 한국세라믹학회지
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• 제48권3호
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• pp.228-235
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• 2011

Sintering behavior and lightweight characteristics of porcelain by addition of FAHM (Fly-Ash Hollow Microsphere) were evaluated. Green body of Backja composition (general porcelain) in which FAHM was added(15 and 20 wt%) was made by slip casting method. The green body was sintered at 1270 and $1290^{\circ}C$ and maintained for 1h. The bulk density and linear shrinkage of the sintered body with FAHM (20 wt%) decreased. As the contents of FAHM. increased, mullite and cristobalite phases increased. In the microstructure, FAHM shells remained after sintering, and the generation of mullite fibers around FAHM shells also were confirmed. the weight of porcelain with of 20% FAHM decreased by 40% and residual FAHM shells promoted the mullite of generation in the matrix.

• 대한조선학회논문집
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• 제29권4호
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• pp.66-74
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• 1992

유한수심의 해역에서 운동하는 잠수체 혹은 부유체의 조파저항을 계산하기 위하여 Hess & Smith(1962)와 Dawson(1977)류의 패널법을 개발하였다. 수면상에서의 경계조건은 소위 Poisson 식을 사용하였는데, 비슷한 문제에 대해 Yasukawa(1989)는 이중물체유동을 기본유동으로 하는 Damson식을 사용한 바 있다. 수저면에서의 경계조건을 자동적으로 만족시키기 위하여 Rankine 쏘오스와 수저면에 대한 경상 쏘오스의 합을 Green 함수로 취하였으며, 따라서 특이점은 선체와 자유표면 상에만 분포시키면 되므로 필요한 패널의 수는 Yasukawa의 방법에 비해 절반이하로 감소되었다. 계산예로서는 잠수한 구와 Wigley선형을 택하였으며, 기존의 해석해 및 수치해와 비교하여 잘 일치하는 결과를 얻었다.

• 한국환경과학회지
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• 제18권11호
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• pp.1199-1206
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• 2009

Obesity affects various kinds of adult diseases and is a principal cause of injuring people's health. Physical activities are very important to solve the obesity problem and green spaces are good place to take physical activities. In order to examine the utilization of green spaces for physical activities to improve health, the survey was implemented in regards to recognition of health, forms of use of green spaces for physical activities. Only 8.1% of respondents didn't care about health, but 91.9% of them were interested in health more than 'commonness'. 95.2% of respondents knew that obesity has an effect on various adult diseases, and 93.1% of respondents cognized that it's possible to prevent obesity by doing physical activities. More than half of respondents replied that the types of green spaces utilized for physical activities were small-scale neighborhood parks and mini parks around house. About 70% of respondents took walking as a type of physical activities. 53% of respondents utilized green spaces one or two times a week, while 25% of them utilized the places at least three times a week to take physical activities. 91.8% of respondents took exercise for more than 30 minutes. These results are expected to promote health because many experts encourage people to take physical activities at least three times a week because fats of human body begins to bum after 30 minutes from start of physical activities. In the utilizing time of green spaces, evening or after work(56.7%) was higher than morning or before work(35.1%). 71% of respondents usually visited green spaces by walking. This study shows green spaces are good places for physical activities and have boundless potentialities improving people's health.

• 한국버섯학회지
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• 제12권4호
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• pp.258-262
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• 2014

LED혼합광에 따른 자실체의 생육특성을 조사한 결과 갓직경은 녹색광+적색광을 제외한 모든 처리구가 형광등 처리구와 대등하였으며, 갓직경/대길이는 청색광+백색광에서 가장 컸다. 대의 길이는 무광과 녹색광+적색광에서 가장 길었고, 수량은 녹색광+적색광을 제외한 혼합광에서 대조구와 대등하였으며, 상품수량은 청색광+백색광에서 가장 많았다. 또한 버섯류의 대표적인 항산화물질인 ergothioneine은 청색광+백색광에서 다른 처리구에 비해 가장 높았다. 광량에 따른 생육특성 중 갓직경은 광량이 작을수록 작아지는 경향이었고, 대길이는 $1{\mu}mol/m^2/s$에서 가장 길었으며, 갓직경/대길이는 $1{\mu}mol/m^2/s$에서 0.34로 다른 처리구에 비해 가장 작았다. 수량은 모든 처리구에서 대등하였으나 광량이 작을수록 유효경수와 상품수량이 많았다.

• 한국생산제조학회지
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• 제22권2호
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• pp.248-255
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• 2013

The objective of this study is to optimize the Metal Injection Molding(MIM) process with design of experiments(DOE) and numerical analysis. To derive the optimal process condition, experiment or numerical analysis was performed under various process conditions. To analyze the interaction among influential factors contributing to the temperature at flow front and response surface in MIM, both central point and axial point were added to the full factorial design with 2 levels and 5 factors and then their impacts on response variable in 43 experimental conditions were analyzed and the significance was evaluated. As a result, sprue, runner, and gate were completely filled in about 0.247 seconds after injection, the front part of the green body was filled in about 0.3344 seconds, the green body except gate, etc changed to almost solid state in about 3.29 seconds, the Packinging pressure was completed in about 6.29 seconds, and the green body inside and outside and sprue, etc became solid in 13.2 seconds. The impact of individual or reciprocal action of factors on the temperature at flow front was analyzed through regular probability, test statistics, main effect, and interaction effect. As a result, of a total of 31 combinations of factors, 9 unit factors and reciprocal actions were significant, and the screening was also possible. A proper regression equation was drawn with regression analysis and response surface design on the response variable of temperature at flow front, and the applicability could be verified.

• Fisheries and Aquatic Sciences
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• 제16권1호
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• pp.35-39
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• 2013

The aim of this study was to assess visible implant fluorescent elastomer (VIE) tagging in greenling Hexagrammos otakii. The experiental fish were anesthetized individually and marked with orange, yellow, red, and green elastomer at the following five body locations, respectively: the adipose eyelid, the surface of the dorsal fin base, the inside surface of the pectoral fin base, the inside surface of the pelvic fin base, and the surface of the anal fin base. Control fish were anesthetized but not marked. During the 20-month trial, fish growth and retention, underwater visibility, and readability of the tags were determined. After 20 months, body length of marked greenling ($43.2{\pm}3.5cm$, mean ${\pm}$ standard deviation [SD]) did not differ from that of the control ($41.4{\pm}3.7cm$). Additionally, the body weight of marked greenling ($527.4{\pm}39.8g$, mean ${\pm}$ SD) did not differ from that of the controls ($505.9{\pm}31.7g$). Greenling retained >90% of the tags at the surface of the dorsal fin base. The anal fin base showed a higher tag retention rate than the inside surfaces of the pectoral fin and the pelvic fin bases (P < 0.05). Red and orange tags were identified more easily underwater than green and yellow tags. Green and yellow tags emitted fluorescence in response to a narrower range of light wavelengths. Thus, the VIE mark was easy to apply to greenling (< 1 min per fish) and was readily visible when viewed under an ultraviolet lamp.