• Nuclear Engineering and Technology
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• 제53권2호
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• pp.484-497
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• 2021

This paper proposes an extended time uncertainty analysis approach in Level 2 human reliability analysis (HRA) considering severe accident management (SAM) strategies. The method is a time-based model that classifies two time distribution functions-time required and time available-to calculate human failure probabilities from delayed action when implementing SAM strategies. The time required function can be obtained by the combination of four time factors: 1) time for diagnosis and decision by the technical support center (TSC) for a given strategy, 2) time for strategy implementation mainly by the local emergency response organization (ERO), 3) time to verify the effectiveness of the strategy and 4) time for portable equipment transport and installation. This function can vary depending on the given scenario and includes a summation of lognormal distributions and a choice regarding shifting the distribution. The time available function can be obtained via thermal-hydraulic code simulation (MAAP 5.03). The proposed approach was applied to assess SAM strategies that use portable equipment and safety depressurization system valves in a total loss of component cooling water event that could cause reactor vessel failure. The results from the proposed method are more realistic (i.e., not conservative) than other existing methods in evaluating SAM strategies involving the use of portable equipment.

• 한국가스학회:학술대회논문집
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• 한국가스학회 2003년도 추계학술발표회 논문집
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• pp.14-31
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• 2003

• 한국전자통신학회논문지
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• 제16권2호
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• pp.385-394
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• 2021

본 논문에서는 다층 평면 손실 구조에 대한 반사 전력 및 전송 전력을 계산하기 위해 전자파 전송 행렬식을 새롭게 제안하였다. 적용된 인체 다리는 피부, 지방, 근육 및 뼈의 4층 평면 구조로 모델링하였으며 각 층의 손실을 고려하기 위하여 복소 유전 상수는 4극 Cole-Cole 모델 매개변수를 사용하여 계산하였다. 피부면에 전자파가 입사할 때 0.1 ~ 20.0GHz의 주파수 대역에서 총 반사 및 투과 전력과 인체 손실을 계산하였다. 그리고 다양한 근육 두께에 대해 최외곽 뼈에서 반사되어 피부에서 재방사되는 전력도 계산하였다. 그 결과 근육 두께 3.0mm, 주파수 4.6GHz일 때 반사손실은 -6.13dB로 평균값보다 3.42dB 낮게 나타났다.

• Journal of Periodontal and Implant Science
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• 제52권2호
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• pp.141-154
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• 2022

Purpose: C57BL/6 mice, which are among the most common backgrounds for genetically engineered mice, are resistant to the induction of periodontitis by oral infection with periodontal pathogens. This study aimed to develop a periodontitis model in C57BL/6 mice using coaggregation between human pathogens and the mouse oral commensal Streptococcus danieliae (Sd). Methods: The abilities of Porphyromonas gingivalis ATCC 33277 (Pg33277), P. gingivalis ATCC 49417 (Pg49417), P. gingivalis KUMC-P4 (PgP4), Fusobacterium nucleatum subsp. nucleatum ATCC 25586 (Fnn), and F. nucleatum subsp. animalis KCOM 1280 (Fna) to coaggregate with Sd were tested by a sedimentation assay. The Sd-noncoaggregating Pg33277 and 2 Sd-coaggregating strains, PgP4 and Fna, were chosen for animal experiments. Eighty C57BL/6 mice received oral gavage with Sd once and subsequently received vehicle alone (sham), Fna, Pg33277, PgP4, or Fna+PgP4 6 times at 2-day intervals. Mice were evaluated at 5 or 8 weeks after the first gavage of human strains. Results: Fnn, Fna, and PgP4 efficiently coaggregated with Sd, but Pg33277 and Pg49417 did not. Alveolar bone loss was significantly higher in the PgP4 group at both time points (weeks 5 and 8) and in all experimental groups at week 8 compared with the sham group. The PgP4 group presented greater alveolar bone loss than the other experimental groups at both time points. A higher degree of alveolar bone loss accompanied higher bacterial loads in the oral cavity, the invasion of not only PgP4 but also Sd and Fna, and the serum antibody responses to these bacteria. Conclusions: Periodontitis was successfully induced in C57BL/6 mice by oral infection with a P. gingivalis strain that persists in the oral cavity through coaggregation with a mouse oral commensal bacterium. This new model will be useful for studying the role of human oral bacteria-host interactions in periodontitis using genetically engineered mice.

• Nutrition Research and Practice
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• 제17권6호
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• pp.1238-1254
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• 2023

BACKGROUND/OBJECTIVES: Weight loss via a mobile application (App) or a paper-based diary (Paper) may confer favorable metabolic and anthropometric changes. SUBJECTS/METHODS: A randomized parallel trial was conducted among 57 adults whose body mass indices (BMIs) were 25 kg/m² or greater. Participants randomly assigned to either the App group (n = 30) or the Paper group (n = 27) were advised to record their foods and supplements through App or Paper during the 12-week intervention period. Relative changes of anthropometries and biomarker levels were compared between the 2 intervention groups. Untargeted metabolic profiling was identified to discriminate metabolic profiles. RESULTS: Out of the 57 participants, 54 participants completed the trial. Changes in body weight and BMI were not significantly different between the 2 groups (P = 0.11). However, body fat and low-density lipoprotein (LDL)-cholesterol levels increased in the App group but decreased in the Paper group, and the difference was statistically significant (P = 0.03 for body fat and 0.02 for LDL-cholesterol). In the metabolomics analysis, decreases in methylglyoxal and (S)-malate in pyruvate metabolism and phosphatidylcholine (lecithin) in linoleic acid metabolism from pre- to post-intervention were observed in the Paper group. CONCLUSIONS: In the 12-week randomized parallel trial of weight loss through a App or a Paper, we found no significant difference in change in BMI or weight between the App and Paper groups, but improvement in body fatness and LDL-cholesterol levels only in the Paper group under the circumstances with minimal contact by dietitians or health care providers.

• 방송공학회논문지
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• 제27권2호
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• pp.174-184
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• 2022

3차원 휴먼 자세 추정 모델은 다시점 모델과 단시점 모델로 분류될 수 있다. 일반적으로 다시점 모델은 단시점 모델에 비하여 뛰어난 자세 추정 성능을 보인다. 단시점 모델의 경우 3차원 자세 추정 성능의 향상은 많은 양의 학습 데이터를 필요로 한다. 하지만 3차원 자세에 대한 참값을 획득하는 것은 쉬운 일이 아니다. 이러한 문제를 다루기 위해, 우리는 다시점 모델로부터 다시점 휴먼 자세 데이터에 대한 의사 참값을 생성하고, 이를 단시점 모델의 학습에 활용하는 방법을 제안한다. 또한, 우리는 각각의 다시점 영상으로부터 추정된 자세의 일관성을 고려하는 다시점 일관성 손실함수를 제안하여, 이것이 단시점 모델의 효과적인 학습에 도움을 준다는 것을 보인다. Human3.6M과 MPI-INF-3DHP 데이터셋을 사용한 실험은 제안하는 방법이 3차원 휴먼 자세 추정을 위한 단시점 모델의 학습에 효과적임을 보여준다.

• 해양환경안전학회지
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• 제21권5호
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• pp.515-523
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• 2015

본 연구에서는 10년간(2001 2010) IMCA에 보고된 DP 선박 LOP(Loss of Position)사고 612건에서 인적오류에 의한 사고 103건을 확인하여 이를 HFACS로 분류하였다. 그리고 이를 베이지안 네트워크에 적용하여 인적오류의 조건부 확률을 확인해 보았다. 그 결과 103건의 인적오류관련 사고는 모두 불안전한 행동에 의해서 발생하였고 이들 중 기술 기반 오류가 70건(68.00 %)으로 가장 큰 인적오류 비율을 차지하였다. 기술 기반 오류 중에서는 부주의한 DP 선박 운용 60건(58.3%), 절차 미 준수 8건(7.8%)이었고, 의사결정 오류에 의한 잘못된 조종이 21건(20.8%)을 차지하였다. 이러한 HFACS 분류의 베이지안 네트워크 적용을 통해서는 불안전한 감독(68%)이 불안전한 행동의 가장 큰 잠재적 요인으로 작용하고 있다는 것을 확인 할 수 있었다. 결론적으로 HFACS와 연계한 베이지안 네트워크는 인적오류를 분석하는 데 유용한 도구임을 확인 할 수 있었고, 분석 결과를 바탕으로 DP 선박안전 운용을 위한 정책, 내부 관계, 훈련등과 같은 인적오류를 경감 및 제거하기 위한 권고 9가지를 제안하였다.

• International Journal of Advanced Culture Technology
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• 제10권1호
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• pp.248-252
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• 2022

The environment refers to what is surrounded by something during human life. This environment is related to the way humans live, and presents various problems on how to perceive the surrounding environment and how the behaviors that constitute the environment support the elements necessary for human life. Humans have an interest in the supportability of the environment as the interrelationship increases as humans perceive and understand the environment and accept the factors supported by the environment. In space, human movement starts from one space to the next and exchanges stimuli and reactions with the environment until reaching a target point. These human movements start with subjective judgment and during gait movement, the spatial environment surrounding humans becomes a collection of information necessary for humans and gives stimulation. will do. In this process, in particular, humans move along the movement path through movement in space and go through displacement perception and psychological changes, and recognize a series of spatial continuity. An image of thinking is formed[1]. In this process, spatial experience is perceived through the process of filtering by the senses in the real space, and the result of cognition is added through the process of subjective change accompanied by memory and knowledge, resulting in human movement. As such, the spatial search behavior begins with a series of perceptual and cognitive behaviors that arise in the process of human beings trying to read meaning from objects in the environment. Here, cognition includes the psychological process of sorting out and judging what the information is in the process of reading the meaning of the external environment, conditions, and material composition, and perception is the process of accepting information as the first step. It can be said to be the cognitive ability to read the meaning of the environment given to humans. Therefore, if we can grasp the perception of space while moving and human behavior as a response to perception, it will be possible to predict how to grasp it from a human point of view in a space that does not exist. Modern people have the theme of reminiscing dog-friendly hotels for the healing of petloss syndrome, and this thesis attempts to approach the life of companions.

• 융합경영연구
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• 제12권2호
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• pp.1-10
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• 2024

Purpose: This study conducted an empirical study to estimate the loss aversion rate of individual investors in the Seoul condominium market. Research design, data and methodology: A survey was conducted with Seoul residents ranging from 30's to 60's with various backgrounds. Descriptive statistical analysis and a paired sample t-test were conducted using SPSS 27.0 statistical package. Results: The results of the t-test showed that Seoul residents are indeed more sensitive to loss than gains, as pointed out in various researches related to behavioral economics. Also, the loss aversion rate associated with KRW 50 million risk was found to be 2.14. Finally, the same question was asked with KRW 100 million risk, doubled associated risk of previous question, using the same scenario, and it's been verified that the loss aversion rate increases as the associated risk or stake increases. The loss aversion rate with double risk is 2.26 which is about 5% higher than the one with KRW 50 million risk. Conclusions: This study can help many groups of people in society who need to establish rewards and punishment policies within any organization. In particular, incorporating human cognitive biases, such as loss aversion can help the South Korean government shape more effective reward and punishment policies when building rewards and punishments using taxes.

• Journal of the Korean Wood Science and Technology
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• 제47권5호
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• pp.644-654
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• 2019

참오동나무의 섬유방향기체투과성(gas permeability), 횡단방향 흡음율(sound absorption coefficient)과 음향투과손실(sound transmission loss)을 평가하고 열처리의 영향을 파악하고자 참오동나무 원반을 100, 160, $200^{\circ}C$로 열처리하고 기체투과성, 흡음율, 음향투과손실을 각각 측정하여 무처리 원반의 결과와 비교하였다. 그 결과, 두께 20 mm 참오동나무 원반의 섬유방향 기체투과성(specific permeability)은 무처리, 100, 160, $200^{\circ}C$ 열처리의 경우 각각 0.254, 0.279, 0.314, 0.452로 열처리에 의해 기체투과성이 약간 증가하였다. 두께 20 mm 무처리 참오동나무 원반의 50-6400 Hz 평균흡음율은 0.101이었으며 온도 100, 160, $200^{\circ}C$로 열처리한 목재의 50-6400 Hz 평균흡음율은 0.109, 0.096 그리고 0.106이었다. NRC (noise reduction coefficient) 는 각각 0.060, 0.067, 0.062 그리고 0.071 이었다. 두께 20 mm 무처리 참오동나무 원반의 50-6400 Hz 주파수범위에서 음향투과손실은 평균 36.93 dB이었다. 열처리에 의해 참오동나무 원반의 기체투과성과 흡음율은 열처리에 의해 그리고 열처리 온도 증가에 의해 약간 증가하였으나 증가정도는 미미하였다.