• Title/Summary/Keyword: 상태유지

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An Experimental Study on the Spontaneous Ignition of Flaxseed Oil and Olive Oil Adsorbed on Towels (타올에 흡착된 아마인유와 올리브유의 자연발화에 대한 실험적 연구)

  • Kim, Kyoung-Su;Choi, Yu-Jung;Choi, Jae-Wook
    • Journal of the Society of Disaster Information
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    • v.18 no.2
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    • pp.324-332
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    • 2022
  • Purpose: In order to conduct a spontaneous ignition test in which a fire occurs in the absence of an ignition source due to the oil adsorbed on the towel. A phenomenon in which spontaneous ignition occurs when adsorbed to fibers using flaxseed oil, which is drying oil and olive oil, which is non-drying oil, is tested through an experiment. Method: After placing the sample container in the experimental device, observe the change in the central temperature of the sample, and when the central temperature rises above the set temperature and a fire occurs, it is judged as "ignition", and the experiment is stopped after checking the maximum value of the central temperature of the sample,When the central temperature of the sample was maintained similar to the set temperature, it was judged as "non-ignition" and the experiment was stopped. Result: In the towels with adsorbed flaxseed oil, the temperature in the sample container increased rapidly and combustion occurred in sheets 5, 10, and 15. Olive oil is a non-drying oil, does not ignite because it is difficult to dry because carbon is a single bond and it is difficult to bond with oxygen. Conclusion: It was confirmed that the more the amount of towel adsorbed to the drying oil, flaxseed oil, the longer the time to reach the set temperature and the occurrence of ignition.

A Study on Problems and Improvement Plans of Non-Face-to-Face Midi Classes (비대면 미디 수업의 문제점과 개선 방안 연구)

  • Baek, Sung-Hyun
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.4
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    • pp.267-277
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    • 2021
  • Both teachers and learners should participate in non-face-to-face class due to COVID-19. The non-face-to-face class has brought about many problems, where they made adequate preparations for such abrupt situation. This study attempted to understand and improve problems occurring during non-face-to-face midi class. The findings are as follows: First, there were differences in equipment available to contact and non-face-to-face class. Such a problem could be improved by using Reaper, DAW which can be installed and freely utilized without any functional limits, regardless of the types of operating systems. Second, latency could not be reduced, when the screen share function of Zoom was used, since it was impossible to select audio interface's drivers in DAW. This problem was improved by again receiving audio output as input and sending it, from the perspectives of teachers. In addition, learners who used the operating system of Windows and have no audio interfaces usually suffer from latency during practices. The latency can be reduced by installing Asio4all. Third, image degradation and screen disconnection phenomena occurred due to the lack of resource. Two computers were connected by using a capture board and the screen disconnection phenomena could be improved by distributing resources and maintaining high-resolution. The system for allowing non-face-to-face midi class could be successfully established, as one more computer was connected by using Vienna Ensemble Pro and more plug-ins were used by securing additional resources. Consequently, the problems of non-face-to-face midi class could be understood and improved.

Implant overdenture using milled bar and attachment in partially edentulous mandible: a case report (하악 부분 무치악 환자에서 Milled Bar와 부착장치를 이용한 임플란트 피개의치 수복 증례)

  • Kim, Min-Jung;Huh, Jung-Bo;Jeong, Chang-Mo;Yun, Mi-Jung;Lee, So-Hyoun;Jo, Yong-Bum
    • The Journal of Korean Academy of Prosthodontics
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    • v.60 no.1
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    • pp.71-79
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    • 2022
  • Excessive crown height space increases can cause crestal bone loss and screw loosening after prosthesis is placed. Milled bar and implant overdenture can be used as a treatment method for partially edentulous patients who have severe alveolar bone loss and excessive crown height space. Milled bar can provide primary splinting effect and stability between implants. Also, milled bar with additional retention device such as Advanced Dental Device-Treatment Of Choice (ADD-TOC) and magnet can provide additional retention force for implant overdenture. In this case, the patient has a partially edentulous mandible that has severe alveolar bone loss and multiple number of teeth loss after excision due to leiomyosarcoma. Because of the long-term loss of mandibular molars, the opposing teeth were extruded. Maxillary left molars were corrected to the occlusal plane through molar intrusion, and mandibular left molar region were treated with implant overdenture, using milled bar with ADD-TOC and magnet after implant placement. The clinical result was satisfactory on the aspect of esthetic and masticatory function.

2020 Dietary Reference Intakes for Koreans: vitamin A (2020 한국인 영양소 섭취기준: 비타민 A)

  • Kim, Yuri
    • Journal of Nutrition and Health
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    • v.55 no.2
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    • pp.201-210
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    • 2022
  • Vitamin A (Vit A) is a lipid-soluble vitamin required for diverse normal body functions, including good vision, reproduction, growth, development, and cellular differentiation. The therapeutic effects of Vit A have been demonstrated for the treatments of inflammation, low immunity, and cancer. The present review discusses the scientific evidence for establishing the 2020 Dietary Reference Intakes for Koreans (KDRI) for Vit A, issues caused by unit change of Vit A, and suggestions for the 2025 KDRI revision. Due to the changes in the standard bodyweight observed in several age groups, the 2020 KDRI had minor revisions as compared to the 2015 KDRI. In the 2015 KDRI, the Vit A unit has changed from retinol equivalent (RE) to retinol activity equivalent (RAE) and the activity of carotenoids became half with RAE compared to RE due to this unit change. Since the Vit A intake of Koreans relies heavily on plant-based carotenoids, the dietary intake of Vit A in Koreans as determined by considering the RAE was much lower than values obtained with RE. The analysis for Vit A intake by the Korean National Health and Nutrition Survey only reflects intakes of retinol and beta-carotene. Thus, it would be necessary to include the consumption of other provitamin A, such as alpha-carotene and beta-cryptoxanthin. Moreover, assessing the amounts of Vit A in foods should be customized to Korean diets since there are seasonal variations in the carotenoid concentration of plants. Moreover, other factors such as age- and sex-specific intake data and considerations of baseline micronutrient status, body mass index, and dietary patterns should be considered for developing more precise KDRI. In particular, the Vit A requirement needs to be met by consuming diverse foods, including animal foods.

Suppression of Coupled Pitch-Roll Motions using Quasi-Sliding Mode Control (준 슬라이딩 모드 제어를 이용한 선박의 종동요 및 횡동요 억제)

  • Lee, Sang-Do;Cuong, Truong Ngoc;Xu, Xiao;You, Sam-Sang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.2
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    • pp.211-218
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    • 2021
  • This paper addressed the problems of controlling the coupled pitch-roll motions in a marine vessel exposed to the regular waves in the longitudinal and transversal directions. Stabilization of the pitch and roll motions can be regarded as the essential task to ensure the safety of a ship's navigation. One of the important features in the pitch-roll motions is the resonance phenomena, which result in unexpected large responses in terms of pitch and roll modes in some specific conditions. Besides, owing to its inherent characteristics of coupled combination and nonlinearity of restoring terms, the vessel shows various dynamical behaviors according to the system parameters, especially in the pitch responses. Above all, it can be seen that suppression of pitch rate remains the most significant challenge to overcome for ship maneuvering safety studies. To secure the stable upright condition, a quasi-sliding mode control scheme is employed to reduce the undesirable pitch and roll responses as well as chattering elimination. The Lyapunov theory is adopted to guarantee the closed stability of the pitch-roll system. Numerical simulations demonstrate the effectiveness of the control scheme. Finally, the control goals of state convergences and chattering reduction are effectively realized through the proposed control synthesis.

Medical Narrative Texts and Medical Ethics (의료 서사와 의료 윤리)

  • Choi, Sung-Min
    • Journal of Popular Narrative
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    • v.26 no.3
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    • pp.291-323
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    • 2020
  • In this paper, I review Pellegrino's Reader, The Philosophy of Medicine Reborn. Pellegrino has emphasized the humanities' reflection on the ethics of medicine. He insists that medical ethics should be re-established as modern society changes. This paper, based on Pellegrino's view, noted the problematic situation in literature and popular narrative texts. Indeed, I wanted to see what answer medical ethics could provide for us. Medical personnel had a philosophical dilemma or a conflict between reality and ethics. Pellegrino argues that medical personnel, above all, need to sympathize with the patient's pain and respond to their needs through interaction with them. This may seem like a very legitimate declaration. But a physician in literary texts and popular narrative texts is often exposed to this ethical dilemma. Through Lee Cheongjun's novel, we can reflect on how a medical personnel could lead a patient to a state of "goodness". And through medical dramas, we can grasp what ethical behaviors the public demands from a medical personnel. Now that the world is suffering from COVID-19, medical workers are in a great trouble, but at the same time, they are respected by the public and are also enhancing their value as ethical beings. Now that medical care has become an everyday narrative, medical ethics is becoming a prerequisite for living. This paper attempted to recognize the importance of medical ethics and to review the ethical issues embodied in medical narratives.

Reframing the National Art Museum: the Trajectory and Controversy towards the Operational Autonomy: the Case of the National Museum of Modern and Contemporary Art, Korea (국립미술관의 재구성: 운영의 자율성을 향한 궤적 그리고 논란 - 국립현대미술관의 사례를 중심으로 -)

  • Kim, Yon Jai
    • Korean Association of Arts Management
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    • no.53
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    • pp.71-99
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    • 2020
  • This study focuses on the case of the National Museum of Modern and Contemporary Art, Korea (hereafter MMCA) that has faced the issue of securing autonomy as an art institution in association with the neoliberal logic of economy as part of globalization. The MMCA was opened with limited operational autonomy due to the government's development-driven national system and bureaucratic perspective. Since being selected as an institution subject to a range of restructuring consequent to the IMF crisis in 1997, the MMCA is being assessed for its operational autonomy since then. This paper examines the socio-cultural background of the implementation of the Korean type of 'Executive Agency' and 'Non-Departmental Public Body'. Furthermore, regardless of the result of either implementation or withdrawal after the projects, this paper explains how these administrative reforms lead the conflicts between stakeholders, which would promote the MMCA's autonomy. As a result, the institutional restructuring process based on the neoliberal perspective might result in the operational dilemma that must simultaneously fulfil the publicness in a different context. Moreover, unlike the original intent to establish a performance-based system based on the principle of competition while minimizing government intervention, this study illuminates that the influence of the nation(or government) as the actual agent of the projects may become permanent. It implies that since the establishment and development project of MMCA has initialized the concept of statism based on legal authority, the operational autonomy of the MMCA which is premised on the reinforcement of expertise and publicness cannot be prioritized over the direction and control of the government.

The Effect of the Job Satisfaction, the Employment Barriers and the Risk-taking Orientation on the Entrepreneurial Intention of Undergraduates Majoring in Cultural and Arts (문화예술전공 대학생의 직무만족, 고용장벽, 위험감수성향이 창업의도에 미치는 영향)

  • Jeong, Jae-Yeob
    • Journal of Korea Entertainment Industry Association
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    • v.14 no.8
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    • pp.11-23
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    • 2020
  • Many former studies for the entrepreneurial intention dealt with the opportunity-driven motivation, but the actual entrepreneurial motivation is the necessity-driven motivation such as maintaining a living. It is necessary to study the necessity-driven factors for entrepreneurship such as employment barriers and job dissatisfaction. This study focused on the fact that the majority of cultural artists are freelancers or self-employed entrepreneurs. For those who majored in culture and arts, this study was conducted to investigate how an individual's internal and external environment affects the entrepreneurial intention considering the theory of planned behavior. I explored the factors that led individuals to choose entrepreneurial intention between employment and entrepreneurship, and studied the relationship between these factors and the entrepreneurial intention. As the result of the study, the job dissatisfaction and the employment barriers were the pressure factors for entrepreneurship. Job satisfaction had a negative effect on the entrepreneurial outcome expectation and the entrepreneurial intention. The perceived employment barrier had a positive effect on the entrepreneurial outcome expectation and the entrepreneurial intention. An individual's risk-taking orientation is one of the entrepreneurship and had the positive effect on the entrepreneurial self-efficacy. The entrepreneurial outcome expectation and the entrepreneurial self-efficacy had a positive effect on the entrepreneurial intention.

Study on the Material and Deterioration Characteristics of the Stone Seated Buddha Triad and Stone Standing Buddha in Bijung-ri, Cheongju, Korea (청주 비중리 석조여래삼존상 및 석조여래입상의 재질특성과 손상특성 연구)

  • Yoo, Ji Hyun;Choie, Myoungju;Lee, Myeong Seong;Kim, Yuri
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.778-790
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    • 2021
  • The Stone Seated Buddha Triad and Stone Standing Buddha in Bijung-ri are state-designated heritage (treasure) statues having the Buddha style of the Goryeo dynasty from the 6th century. Conservation scientific investigations were conducted to understand the preservation status of these stone Buddha statues and to establish a conservation plan. The Stone Seated Buddha Triad and Stone Standing Buddha are composed of fine-medium grained biotite granite, which is considered to be of the same origin owing to their low magnetic susceptibility distribution of less than 0.2 (×10-3 SI unit) and similar mineral characteristics. The Stone Seated Buddha Triad has highly homogenous mineral composition and particle size, whole-rock magnetic susceptibility, and geochemical characteristics very similar to those of the nearby outcrop. It was confirmed that a combination of physical, chemical, and biological factors affects the Stone Buddha statues. In particular, both the Stone Seated Buddha Triad and Stone Standing Buddha tend to be chipped off from the front and cracked and scaled from the back. The Stone Standing Buddha located outdoors experiences granularity decomposition and black algae formation, which accelerate the weathering under unfavorable conservation environments. The result of non-destructive physical property diagnosis using ultrasonic velocity showed that both the Stone Seated Buddha Triad and Stone Standing Buddha have been completely weathered (CW), indicating very poor physical properties.

Burn-back Analysis for Propellant Grains with Embedded Metal Wires (금속선이 삽입된 추진제 그레인의 Burn-back 해석)

  • Lee, Hyunseob;Oh, Jongyun;Yang, Heesung;Lee, Sunyoung;Khil, Taeock
    • Journal of the Korean Society of Propulsion Engineers
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    • v.26 no.2
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    • pp.12-19
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    • 2022
  • Propellant grains with embedded metal wires have been used for enhancement of burning rate while maintaining high loading density. For the performance design of a solid rocket motor using propellant grain with embedded metal wires, burn-back analysis is required according to number, location, arrangement angle of metal wires, and augmentation ratio of the propellant burning rate near a wire region. In this study, a numerical method to quickly calculate a burning surface area was developed in response to the design change of the propellant grain with embedded metal wires. The burning surface area derived from the developed method was compared with the results of a CAD program. Error rate decreased as the radial size of the grid decreased. Analysis for characteristics of burning surface area was performed according to the number and location of metal wires, the initial and final phases were shortened and the steady-state phase was increased when the number of metal wires increased. When arranging the metal wires at different radii, the burning surface area rapidly increased in the initial phase and sharply decreased in the final phase compared to the case where the metal wires were disposed in the same radius.