• 한국식생활문화학회지
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• 제10권2호
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• pp.125-132
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• 1995

The purpose of this study was to survey several aspects of food-related knowledge, attitude and behavior of college students. Seven hundred male and female students in Seoul and Kyunggi-do area were randomly selected. And self-administered questionnaires were used. It was consisted of weight concern, nutritional knowledge, meal frequency, preference of snacks and psychological aspects of eating behaviors. The results were as followes: 1. The 66.5% of males and 87.9% of females were concerned about weight control. While 42% of male respondents wanted weight gain and 43% weight loss, most of female respondents wanted to lose weight. 2. The score of nutritional knowledge of males was significantly lower than the score of females (p<0.01). 3. The meal frequency was 3.4 times a day for male students and 3.6 for female students. But males showed higher frequency rates in three regular meals and females showed higher rates in snacking. Both male and female students considered that supper was the most important meal of the day and skipped breakfast frequently. 4. Fruits, beverage and milk were favorite snacking items for college students. But there were some differences in selection of food items by snacking time. Carbonated drinks and coffee were frequently selected by morning male and female snackers. Noodles and cookies were preferred by males and cookies were preferred by females as afternoon snack. Fruits were most often preferred by both males and females in the evening. 5. Physical tiredness and/or psychological factors were observed to influence the amount of food intake. After increase of food intake, male students felt more comfortable than female students who were afraid of their weight gain.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제46권4호
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• pp.220-227
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• 2020

Objectives: Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder. These patients lose their teeth at a young age and are in need of prosthetic rehabilitation. The aim of this systematic review was to assess the success of dental implant placement in these patients. Materials and Methods: An electronic search was performed in PubMed Central, Scopus, and Web of Science using the keyword "Papillon-Lefèvre syndrome" AND "dental implant" OR "prosthodontics". Articles reporting implant placement in patients with PLS until July 2019 were included. Results: Assessment of the included 11 articles reporting 15 cases showed 136 implant placements in these patients. Implant failure occurred in 3 patients (20 implants). The peri-implantitis and failure rate was higher in the maxilla. Meta-analysis showed the probability of failure to be 7% (95% confidence interval [CI] 0%-31%) for maxillary implants and 2% (95% CI 0%-9%) for mandibular implants. The follow-up time ranged between 1 and 20 years. Healing after bone graft and implant placement in these patients was uneventful. Conclusion: Dental implants may be a viable treatment option for PLS patients. Implantation can help preserve alveolar bone if the patients' immunological and growing conditions are well-considered and proper oral hygiene and compliance with the maintenance program are continued.

• 한국컴퓨터정보학회논문지
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• 제10권1호
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• pp.133-140
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• 2005

컴퓨터와 레이싱 게임을 하다보면 플레이어 자동차가 처음부터 끝까지 순위를 앞서가거나 퍼지카(Fuzzycar)가 매일 이기게 되면 대부분의 플레이어들은 몇 번만으로 그 게임에 대하여 금방 관심을 멀리 할 것이다. 이것을 해결하고 레이싱 게임에서 많은 재미를 위해서 무엇보다 중요한 것은 순위를 결정하는 일이다. 본 논문에서는 레이싱 게임에 재미를 주기 위해서 퍼지카를 만들어 플레이어와 대결하게 하였다. 선행 퍼지카는 플레이어 자동차보다 앞서 달리고 있기 때문에 뒤에 오는 플레이어 자동차의 속도와 거리의 변화로 인하여 플레이어 자동차와의 대상 행동을 식별하여 퍼지카가 기억하고 있는 기억 내용을 변경하지만 실제의 행동은 실행하지 않는다. 퍼지카가 의사결정을 하려면 타이머가 부여된 상태에서 기억한 내용을 가지고 순위 경쟁을 위한 행동을 한다. 또한 후행 퍼지카도 기억 내용은 다르지만 앞 내용과 같은 방법으로 작동한다. 실험에서는 실제의 값을 테스트 프로그램에 적응하여 순위 경쟁을 위한 결과를 도출하였다. 단순한 if-then 보다는 fuzzy logic을 이용한 방법이 퍼지카의 다양한 행동을 모델링한다는 것을 확인할 수 있었다.

• 한국화재소방학회논문지
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• 제30권5호
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• pp.54-59
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• 2016

구조재료 중에서 강재는 불연성 재료이지만 열전도가 높고, 온도상승에 의하여 강성의 저하가 높은 편이다. 일반적으로 강재의 항복강도 및 탄성계수는 $350^{\circ}C$에서 70%, $600^{\circ}C$에서 50% 이하로 감소하기 때문에 고온에서의 철골구조의 재하능력은 급격히 감소하게 된다. 통상 내화구조로 인정받기 위해서는 공인기관으로부터의 품질시험을 거쳐야 한다. 하지만, 실물내화실험은 공간과 시간의 제약, 고비용의 문제점을 안고 있으므로, 본 연구에서는 ABAQUS 프로그램의 유한요소법을 이용한 열해석을 수행하여 압축을 받는 H-형강기둥의 내화실험과의 비교로 해석모델의 신뢰성을 입증하고, 실물실험의 보완책으로의 가능성을 제시한다.

• Elastomers and Composites
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• 제40권3호
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• pp.196-203
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• 2005

본 논문에서는 상온 경화형 실리콘 접착제의 표면 특성, 열안정성, 접착력, 그리고 모폴로지 분석을 통하여 접착제의 내엔진 오일성 평가 및 고장분석을 시행하였다. 실험 결과, 엔진오일의 침투는 접착제 시편의 표면에서 중앙으로 진행되었으며, 열화시간에 따라 접착제 시편중에 오일의 함량은 점차 증가하였으며, 접착제의 Si-O-Si 결합은 점차 분해되었다. TGA 실험결과로부터 열분해는 접착제 시편의 표면과 밑 부분에서 발생함을 알 수 있었다. 상온 경화형 실리콘 접착제의 내엔진 오일 시험 후 접착제 시편의 인장강도, 신율, 접착력 등의 물성이 모두 현저하게 감소하였으며, 이는 엔진오일의 흡수와 열화에 의해 초기 접착제 성질을 많이 상실한 것으로 판단된다. 또한, SEM 분석을 통하여 접착제 시편의 파괴모드는 열화시간이 증가함에 따라 응집 파괴에서 계면 파괴로 나타남을 확인하였다.

• 정보화연구
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• 제10권3호
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• pp.371-378
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• 2013

다양한 형태의 학습 시스템이 생겨나고 있다. 그 중 E-러닝을 통한 동영상 학습에 대한 수요는 지속적으로 증가하고 있다. 하지만, 그렇다고 하여 모든 이가 이러한 시스템을 적합하게 활용할 수 있는 것은 아니다. 학업능력이 떨어지는 학생은 자신의 학습수준보다 높은 동영상을 학습할 경우 학습에 대한 흥미를 잃을 수 있고, 학업능력이 뛰어난 학생의 경우는 수준에 맞지 않는 동영상을 제공할 경우에는 심화 학습의 기회를 잃어버릴 수 있어 학습효율성을 저하하게 된다. 이러한 불편함을 해결하기 위해서는 사용자가 선호할 만한 정보를 예측하고 필터링 된 맞춤형 정보를 제공하는 추천시스템이 필요하다. 본 논문에서는 학생 레벨추천 시스템을 제안한다. 학생그룹과 학생간의 학습정보를 바탕으로 학습동영상과 학생의 레벨을 추론하고, 이를 토대로 동영상에 대한 학생의 상대적 난이도를 제시하고, 적합한 난이도의 동영상을 추천한다. 실험을 통하여 본 연구의 추천 서비스의 유용성을 검증하였다.

• Nuclear Engineering and Technology
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• 제48권1호
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• pp.16-25
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• 2016

In severe loss of coolant accidents (LOCA), similar to those experienced at Fukushima Daiichi and Three Mile Island Unit 1, the zirconiumalloy fuel claddingmaterials are rapidlyheateddue to nuclear decay heating and rapid exothermic oxidation of zirconium with steam. This heating causes the cladding to rapidly react with steam, lose strength, burst or collapse, and generate large quantities of hydrogen gas. Although maintaining core cooling remains the highest priority in accident management, an accident tolerant fuel (ATF) design may extend coping and recovery time for operators to restore emergency power, and cooling, and achieve safe shutdown. An ATF is required to possess high resistance to steam oxidation to reduce hydrogen generation and sufficient mechanical strength to maintain fuel rod integrity and core coolability. The initiative undertaken by Electric Power Research Institute (EPRI) is to demonstrate the feasibility of developing an ATF cladding with capability to maintain its integrity in $1,200-1,500^{\circ}C$ steam for at least 24 hours. This ATF cladding utilizes thin-walled Mo-alloys coated with oxidation-resistant surface layers. The basic design consists of a thin-walled Mo alloy structural tube with a metallurgically bonded, oxidation-resistant outer layer. Two options are being investigated: a commercially available iron, chromium, and aluminum alloy with excellent high temperature oxidation resistance, and a Zr alloy with demonstratedcorrosionresistance.Asthese composite claddings will incorporate either no Zr, or thin Zr outer layers, hydrogen generation under severe LOCA conditions will be greatly reduced. Key technical challenges and uncertainties specific to Moalloy fuel cladding include: economic core design, industrial scale fabricability, radiation embrittlement, and corrosion and oxidation resistance during normal operation, transients, and severe accidents. Progress in each aspect has been made and key results are discussed in this document. In addition to assisting plants in meeting Light Water Reactor (LWR) challenges, accident-tolerant Mo-based cladding technologies are expected to be applicable for use in high-temperature helium and molten salt reactor designs, as well as nonnuclear high temperature applications.

• Molecules and Cells
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• 제40권1호
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• pp.24-36
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• 2017

The stability of peptide-MHC complex (pMHC) is an important factor to shape the fate of peptide-specific T cell immune response, but how it influences on T cell activation process is poorly understood. To better understand that, we investigated various T cell activation events driven by $L^d$ MHCI loaded with graded concentrations of P2Ca and QL9 peptides, respectively, with 2C TCR Tg T cells; the binding strength of P2Ca for $L^d$ is measurably weaker than that of QL9, but either peptides in the context of $L^d$ interact with 2C TCR with a similar strength. When their concentrations required for early T cell activation events, which occur within several minutes to an hour, were concerned, $EC_{50}s$ of QL9 were about 100 folds lower than those of P2Ca, which was expected from their association constants for $L^d$. When $EC_{50}s$ for late activation events, which takes over several hours to occur, were concerned, the differences grew even larger (> 300 folds), suggesting that, due to weak binding, $L^d/P2Ca$ dissociate from each other more easily to lose its antigenicity in a short time. Accordingly, fixation of $L^d/P2Ca$ with paraformaldehyde resulted in a significant improvement in its immunogenicity. These results imply that binding strength of a peptide for a MHC is a critical factor to determine the duration of pMHC-mediated T cell activation and thus the attainment of productive T cell activation. It is also suggested that paraformaldehyde fixation should be an effective tool to ameliorate the immunogenicity of pMHC with a poor stability.

• 한국식생활문화학회지
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• 제19권2호
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• pp.223-238
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• 2004

In this paper, the differences between Korean and Japanese ways of seasonings are studied. The main results are summarized as follows: (1) Shouyu and Miso which are Japanese equivalents of soy sauce and bean paste of Korean foods are used in variety of different seasonings with some other ingredients while Korean counter parts are used only to add salty tastes. (2) Shouyu and Miso lose their flavors after considerable time of heating, while Korean soy sauce and bean pastes increase their tastes after heating. (3) Mirin adds sweety taste and glaze and Sake makes food soft or hard according to the moment of being added during cooking. (4) In Korean foods soy sauce, bean paste and red pepper paste are on the basis of tastes, Dashi is used in almost every Japanese food. (5) Seasoned vegetables of Korean food are prepared only with spices of green onion, garlic and sesame oil while seasoned fishes or vegetables are mixed with Shoyu or salt and vinegar in Japanese food. (6) In making Zorim, Korean traditional sauces are added from the beginning of heating. But in making Nimono, sugar, salt, vinegar, Shoyu and artificial taste are added in order during heating. (7) In grilling, main food for grilling in Korea is meat, which is prepared with a variety of spices such as soy sauce or/and red pepper pastes, garlic, green onion, sesame oil, sesame powder, pepper and sugar while mainly fishes are grilled with salt, occasionally with Shoyu or Miso in Japanese food. (8) Pan frying fishes are taken with soy sauce with vinegar in Korea but Tepura are eaten with Tentsuyu in Japan.

• 보건교육건강증진학회지
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• 제31권5호
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• pp.147-158
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• 2014

Objectives: This study aims to examine the association of depression, suicidal behaviors with smartphone use behaviors among Korean adolescents. Methods: We analyzed data from 'Youth Health and Life Skills Survey' in 2013. The survey was based on self-reported questionnaires distributed to 915 grade 7th and 8th students at four middle schools in Gangdong-gu, Seoul, Korea in 2013 to evaluate the effects of 'Youth Health and Life Skills' program. Depression and suicidal behaviors were measured in terms of the experience rate, and smartphone use behaviors were measured with average hours of smartphone use a day and overindulged behaviors in smartphone use by using 5-point Likert scales. We examined the association of depression and suicidal behaviors with smartphone use behaviors by using t-test and regression analyses. Results: 21.5% of respondents have ever felt depressed or hopeless to lose interest in school life almost everyday for 2 weeks or longer in the past year. The experience rate of suicidal ideation, suicide plan, and suicidal attempt were 21.1%, 6.1%, and 5.7%, respectively. The mean of average hours of smartphone use a day was 3.9 hours, and the mean score of overindulged behaviors in smartphone use was 2.99. The students who have experienced depression and suicidal behaviors were more likely to have more smartphone using time and higher scores of overindulged behaviors in smartphne use than those who have not. Conclusion: We concluded that for preventing addictive or problematic smartphone use behaviors among adolescents we should consider and develop more positive strategies for the moderate use of smartphone than regulatory measures, which include the implementation of skill-based health education program including life skills at schools and the development of smartphone applications useful for resolving mental stress and promoting mental health.