• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1990.11a
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• pp.69-72
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• 1990

최근의 전자및 광학기기 분야에 있어서의 준부신 발전은 다면경 가공기나 초정밀 절삭, 연삭기와 같은 초정밀 가공기계의 개발과 실용화에 힘입은 바 크다. 이러한 초정밀 가공기의 성능을 좌우하는 핵심 요소로서 주축계를 들 수 있으며, 비교적 소형 경량의 공작물을 가공하는 기계의 주축용 베어링으로는 볼 베어링이나 오일 베어링을 대신하여 공기베어링이 점차 널리 사용되고 있다. 일반적으로 주축으로 사용되는 베어링은 원통형 레이디얼 베어링과 원판형 스러스트 베어링이 결합된 형식이 주류를 이루나 이러한 베어링은 스러스트 판과 축의 직가곧 가공오차가 존재하기 때문에 가공하기는 쉬우나 회전시에 의의 영향에 의해 회전 정밀도 유지가 어렵다는 단점을 지니고 있다. 이러한 단점을 보완하기 위하여 사용되는 베어링에는 원추형(conical) 베어링과 구면형(spherical) 베어링이 쓰이고 있다. 이러한 원추형 베어링과 구면형 베어링은 가공오차를 베어링과 축의 현압 연마로써 없애줄 수 있으며 베어링이 축방향 하중과 경방향 하중을 동시에 지지하여 줌으로써 기계 전체의 부피를 줄이고 회전 정밀도를 향상시켜 주는 것으로 알려져 있다. 그러나 구면의 베어링 간극을 정확히 가공하기 어려운 단점이 있어 축과 베어링을 현압연마하여 가공한 후에 두부품을 중심선상에서 분리시키므로써 요구되는 간극을 얻을 수 있는 원추형 베어링이 많이 쓰이고 있다. 본 연구에서는 직접 수치 해법을 이요하여 원추형 베어링의 유막내의 압력 분포를 계산하고 이 합력인 하중지지 용량이 축방향 하중과 경방향 하중을 지지하는 특성을 이론적으로 검토하여 외부 가압 원추형 베어링으 특성수를 파악하여 설계자료를 제시하고자 한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.83-86
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• 2012

RFID는 국가 신성장 동력 분야로서 미래 성장성이 매우 클 것으로 예상되며, 이미 물류관리 등 다양한 분야에 활용되고 있다. 그러나 RFID리더의 인식률은 95%~98%대에 머무르고 있어, 오 인식된 2%~5%의 처리를 위하여 많은 시간과 자본이 투입되어야 하는 실정이다. 이에 본 연구에서는 하드웨어의 인식률의 한계를 극복하고 보다 정교한 인식시스템을 구축할 수 있도록 화상인식을 통해 사물의 개수를 파악하는 기술을 RFID기술에 접목한 융합 시스템을 제안하고자 한다. 구체적으로는 RFID 리더기를 통해 물품의 개수를 파악하고, 이와 더불어 화상인식 기술을 이용하여 사물의 개수를 파악한다. 이때 두 개의 서로 다른 방법으로 인식한 사물의 개수를 비교하여, 동일하면 그 인식 결과를 신뢰하고, 그렇지 않은 경우 RFID전파의 출력세기 및 카메라 촬영각도 등을 보정하여 RFID 인식률을 향상시키는 것이다. 본 논문에서는 현재 개발이 진행 중인 이 시스템의 구성, 상호연동 알고리즘 및 구현방법에 대해 설명하고자 한다.

• Journal of Mushroom
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• v.14 no.4
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• pp.184-190
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• 2016

This study was performed to determine the optimal condition for Lentinula edodes JMI-10079 mycelium cultivation on the root of Polygonum multiflorum. We also analyzed the proximate composition, total amino acids, and minerals in the root of P. multiflorum cultivated with L. edodes JMI-10079 mycelia. The optimal temperature and pH for L. edodes JMI-10079 mycelium cultivation on the P. multiflorum root were $25^{\circ}C$ and pH 5-6 respectively, whereas the optimal carbon and nitrogen sources were glucose and maltose, respectively. The content of crude protein, crude fat, and ash in the P. multiflorum root cultivated with L. edodes JMI-10079 mycelia was higher than that in the uncultivated P. multiflorum root. The content of crude fiber was the highest in the control. Total amino acid analysis revealed that the contents of total amino acids and total essential amino acids were increased by higher root of P. multiflorum concentration.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.469-474
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• 2011

Ginger (Zingiber officinale Rosc.) is a well known edible plant that is traditionally used to treat various illnesses related to inflammation and oxidative stress. Steam distillated ginger oil or water extract are mainly used for related products; however, it is unclear whether these fractions contain most of the bioactive compounds or the highest efficacy. This investigated the antioxidant effects of extracts prepared by supercritical fluid extraction (SFE). 6-Gingerol was the most abundant component in hexane fraction of ethanol extract from ginger. The antioxidative properties of SFE oil and Marc ethanol fractions were demonstrated using the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azinobis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals scavenging assays. A clear correlation was observed between total polyphenol contents and $RC_{50}$ values in the Marc ethanol fraction. These results indicate that not only SFE oil but the marc after SFE could be good sources for the food industry.

• Korean journal of communication and information
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• v.31
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• pp.51-84
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• 2005

The purpose of this paper is to investigate characteristics of active information and opinion giver in the interactive-public communication space of internet. More specifically, this study explores that the active information and opinion giver have the same traits with opinion leader, which are personal attributes (topic involvement and individuation), social activity, source of information and influentials, and socio-demographic attributes. The research consisted of a questionnaire, which was administered using e-mail, and 175 replies were returned. The results show that higher activity of sending information and opinion is associated with characteristics of opinion leader. First, It was found that higher activity group in sending information and opinion have higher degree of topic involvement and individuation than lower group. Second, the former is more active behavior than the latter in social activity. Third, it was examined that behaviors of sending and giving information and opinion with interpersonal communication channel was connected with those of the interactive-public communication space in internet. Also, the result of analysis with mass communication channel was found the distinction in three different kinds of magazines which is related with specific media. Finally, characteristics of socio-demography were not different between two group, with the exception of gender.

• Journal of Life Science
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• v.20 no.8
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• pp.1230-1234
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• 2010

The effects of inhaling three essential oils (lavender [Lavendular angustifolia], silver fir [Abies alba], and grapefruit [Citrus paradise]) against restraint stress were investigated in mice. Serum cortisol levels were significantly increased in the 1h-restraint group. Also, silver fir and grapefruit oils prevented the elevation of cortisol levels under experimental conditions. Inhalation of 10% lavender oil for 30 min before inducing stress significantly inhibited restraint-induced hypothermia. We also investigated the effects of restraint stress on triglycerides, total cholesterol, and high-density lipoprotein cholesterol. It was found that the concentration of triglycerides in the serum samples increased after restraint stress. Silver fir essential oil inhibited elevation of triglyceride levels. Taken all together, the correlation of herb essential oil inhalation against restraint stress in animals can partly be explained.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.5
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• pp.105-118
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• 2009

In modern society, as the rapid development of IT technology combined with the computer-based high-speed communication networks makes it possible to provide a wide spectrum of services and devices, we have been confronting a new cultural transformation era, referred to as the information society. However, the requirements to be considered in security aspect have became more complicated and diversified, and there remains the same security weaknesses as in the existing media or protocol. Particularly, the office network device with roaming is susceptible to the different kinds of attacks such as terminal hacking, virus attacks, and information leakage because the computing capacity is relatively low and the loading of already developed security functions is difficult. Although developed as one solution to this problems, PKI security authentication technology isn't suitable for multi-domain environments providing uonments proffice network service, and so the development of a novel authentication system is needed. Therefore, in this paper researched the roaming and device authentication/auth for multitechnology using an ID-based public key, authorization ticket, and Sub-device ticket with a purpose to contribute to the development of the secured and efficient technology.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.2
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• pp.93-98
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• 2021

This study aims to find a discriminatory way that can lower the dependence on imports of aroma essential oils and increase the value of herb plants that are growing in domestic demand and cultivation. To this end, through a study that analyzes and reproduces fragrance components without damaging the original material of domestically grown lavender flowers using the SPME method, we are trying to confirm the difference in fragrance composition from lavender essential oil and find the fragrance originality of domestically grown herb plants. A total of 38 kinds of lavender essential oils and 27 kinds of lavender flowers were analyzed as fragrance ingredients, Among them, the common ingredients were myrcene, d-limonene, 1,8-cineol, ocimene, p-cymene, α-terpinolene, camphor, linalool, linalyl acetate, bornyl acetate, 4-terpineol, and a-terpineol. In addition, among the fragrance components of the two samples, it was confirmed that the type and content of allergens of domestically cultivated lanvender flowers were low. As a result of the sensuality evaluation of 15 panels, domestic cultivated lavender flower reproduction scent was higher in favor of lavender essential oil, which has been used in the industry until now. It is also believed that lavender fragrance, which lowers the content of allergy-causing ingredients, can expand industrialization.

• Journal of Korean Biological Nursing Science
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• v.13 no.2
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• pp.156-163
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• 2011

Purpose: The purpose of this study was to examine the effects of a bergamot essential oil-inhalation on chronic pain after surgery for lumbar spinal stenosis. Methods: Fifty-two subjects were randomly assigned to the experimental (bergamot essential oil-inhalation) and control (almond oil-inhalation) group. All patients understood the purpose of this study and a written informed consent for the study was obtained. Results: Bergamot essential oil-inhalation was conducted during twenty minutes. Visual analog scale, blood pressure, heart rate, and respiratory rate were measured before and after treatment in the two groups. The visual analog scale score, heart rate, and respiratory rate in bergamot essential oil-inhalation group were significantly lower than those in almond oil-inhalation group. However, there was no significant difference in systolic and diastolic blood pressure between the two groups. Conclusion: Therefore, bergamot essential oil-inhalation is effective in alleviating pain, heart rate, and respiratory rate. These results suggest that bergamot essential oil-inhalation can be a useful method for the relief of chronic pain during the treatment after spinal surgery.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.118-125
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• 2011

Conventional erosion function apparatus (EFA) which has been used to measure the hydraulic resistance of soil was improved to consider direction change of the current flow. Using improved apparatus, hydraulic resistance capacities of the artificially composed clayey soil and sandy soil were compared. Test result shows that scour rates which were measured under the bi-directional flow were much higher than those measured under unidirectional flow for both type soils. Scour rate of sandy soil was higher than that of clayey soil. Velocity averaged scour rate of specimen which was consolidated under the relatively large consolidation pressure is higher than that of specimen which is consolidated under small consolidation pressure, which means scour problem under bidirectional flow may be more serious for the deep seabed ground.