• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.3
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• pp.309-319
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• 2011

We experimentally investigated lifted propane jet flames diluted with nitrogen to obtain flame-stability maps based on heat-loss-induced self-excitation. We found that heat-loss-induced self-excitations are caused by conductive heat loss from premixed flame branches to trailing diffusion flames as well as soot radiation. The conductive-heat-loss-induced self-excitation at frequencies less than 0.1 Hz is explained well by a suggested mechanism, whereas the oscillation of the soot region induces a self-excitation of lift-off height of the order of 0.1 Hz. The suggested mechanism is also verified from additive experiments in a room at constant temperature and humidity. The heat-loss-induced self-excitation is explained by the Strouhal numbers as a function of the relevant parameters.

• School Mathematics
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• v.6 no.2
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• pp.119-134
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• 2004

China becomes more and more important for Koreans in political and social aspects as well as in educational aspect. However, there hasn't been any study regarding the mathematics curriculum of China. Thus, it is necessary to introduce the recent mathematics curriculum of China, compare the curriculum of China with that of Korea, and find the features of the curriculum. Several characteristics of the mathematics curriculum of China were identified; 1) mathematics strands were combined, 2) condensed and linear structure of contents, 3) providing examples for mathematics topics stated in the curriculum, and etc. Based on these characteristics, some implications were elicited for the next mathematics curriculum revision in Korea.

• Fire Science and Engineering
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• v.34 no.2
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• pp.86-93
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• 2020

This study aims to maintain the safety of an outdoor storage tank through the fundamental case analysis of explosion and fire accidents in the storage tank. We consider an accident caused by the explosion of fire inside the tank, as a result of the gradual spreading of the residual fire generated by wind lamps flying off a workplace in the storage tank yard. To determine the cause of the accident, atmospheric diffusion conditions were derived through CCTV image analysis, and the wind direction was analyzed using computational fluid dynamics. Additionally, the amount of oil vapor inside the tank when the floating roof was at the lowest position, and the behavior of the vapor inside the tank when the floating roof was at the highest position were investigated. If the cause of the explosion in the storage tank is identified and the level of the storage tank is maintained below the internal floating roof, dangerous liquid fills the storage tank, and the vapor in the space may stagnate on the internal floating roof. We intend to improve the operation procedure such that the level of the storage tank is not under the Pontoon support, as well as provide measures to prevent flames from entering the storage tank by installing a flame arrester in the open vent of the tank.

• Journal of the Korean Society for Nondestructive Testing
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• v.31 no.5
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• pp.472-478
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• 2011

The purpose of this study was to analyze the kinetic effect of Soft-$golf^{TM}$ instrument on the human body structure. To analyze the kinetic effect of Soft-$golf^{TM}$ instrument, Golf swing using Soft-$golf^{TM}$ instrument and regular golf instrument was captured. And then Upper limbs and lumbar joint torques was calculated via computer simulation. Five man participated this study. Subjects performed golf swing using a regular golf and Soft-$golf^{TM}$ instrument. Golf swing motion was captured using three position sensor, active infrared LED maker and force plate. Golf swing model was generated and simulated using ADAMS/LifeMOD program. As a results, joint torque during Soft-golf swing were lower than regular golf swing. Thus soft-golf swing have joint load lower than regular golf swing and contribute to reduce joint injury.

• Journal of the Korea Society of Computer and Information
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• v.29 no.6
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• pp.131-141
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• 2024

The aging population and worsening lifestyle habits have increased the risk of chronic diseases. This has heightened the importance of preventive healthcare, particularly through personalized health management services based on individual health data. Despite this, the domestic digital healthcare industry remains underdeveloped. Given the need for acceptance from both consumers and providers, this study uses the Analytic Hierarchy Process (AHP) to identify success factors for health management service platforms. AHP evaluates the relative importance of various factors to aid decision-making. Results show that providers prioritize data analysis and platform design, laws and regulations, and data standardization, while consumers prioritize system stability, laws and regulations, and system security. These findings highlight the need for strategies to bridge the expectation gap to effectively promote health management service platforms.

• Journal of the military operations research society of Korea
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• v.36 no.3
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• pp.135-145
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• 2010

The submarine is very threatening and secretive weapon system that achieves missions under the sea. However, the submarine is faced with danger that can be attacked from the enemy when is detected by sensor or rose to the surface. This study will be planned optimal path to maximize the survival rate that considers submarine navigation capability in underwater and search activity of hostile warships. A mathematical programming model and a heuristic algorithm will be suggested in this study. The mathematical programming model is verified by using ILOG CPLEX. The submarine path, unit time(distance) of navigation, survival rate, and computation time is computed by using a heuristic algorithm.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.9-17
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• 2000

The objective of this study was to identify and evaluate indicators which offer the significant influence on recreationists' experiences. Delphi survey technique with a panel of professionals was employed to collect data for this study. The Delphi process was designed with three round questionnaires. The identified indicators in this study should be basic information for Benefit-Based Management (BBM) Model for forest recreation areas. A list of 38 indicators relating to physical/biological, managerial and social components of recreation experiences submitted from three round questionnaires. From the results, indicators included in physical/biological category suggested as more important ones than other categories of indicators.

• Electronics and Telecommunications Trends
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• v.22 no.2 s.104
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• pp.79-91
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• 2007

현대는 정보통신의 발전으로 산업은 물론이고, 정치.사회.문화의 모든 측면에서 변화가 빨라 미래를 내다보고 대비하지 않으면 살아남을 수 없는 상황이고, 정보통신의비전을 미래 사회 예측을 통해 도출하는 것은 의미가 크다. 또한 유무선 통신.방송 통합 인프라 환경은 전 세계가 네트워크로 연결되는 정보통신의 본질적 특성과 맞물려 영역간 새로운 접합점을 만들어 내고, 다양한 서비스와 기기 간의 원활한 소통을 위한 표준의 중요성을 증대시키고 있다. 특히 1994년 WTO 체제의 출범을 계기로 글로벌경쟁시대가 본격 개막됨에 따라 국가 간 FTA 협정 체결로 국가 간 무관세화 등 경제의 블록화가 급진전되고 있고, 국제표준은 세계시장 선점을 위한 전략적 도구로 부상하고있다. 따라서 21세기 지식정보사회에서 우리나라가 정보화를 조기에 실현하여 지식정보강국으로 도약하고, 세계 정보통신 시장에서 주도적인 위치를 확보하기 위해서는 미래사회 및 사용자의 요구를 기반으로 정보통신시장을 주도할 미래 핵심 기술에 대한국제 표준화를 추진할 수 있는 정보통신 표준화 전략의 수립 및 체계적인 추진이 필요하다. 본 논문에서는 미래 정보통신 동향 및 표준화 환경과 국내외 미래 연구 동향을 분석함으로써 향후 바람직한 표준화 추진 전략을 모색하여 국내 기술의 국제 표준화에 도움을 주려고 한다.

• Convergence Security Journal
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• v.22 no.3
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• pp.13-18
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• 2022

With the rapid development of IT technology, integration with existing industries has led to an increase in smart manufacturing that simplifies processes and increases productivity based on 4th industrial revolution technology. Security threats are also increasing and there are. In the case of supply chain attacks, it is difficult to detect them in advance and the scale of the damage is extremely large, so they have emerged as next-generation security threats, and research into detection technology is necessary. Therefore, in this paper, we collect, store, analyze, and visualize logs in multiple environments in real time using ELK Stack and Sysmon, which are open source-based analysis solutions, to derive information such as abnormal behavior related to supply chain attacks, and efficiently We try to provide an effective detection method.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.7-16
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• 2003

To minimize the death and injury by a collision, the installation of an air bag is recommended as a mandatory practice together with the wearing of the seat belt. By using simulated collision experiments, this research focused on the effect of an air bag and seat belt on the driver safety. The vehicle deceleration characteristics were obtained from impact experiment. LSDYNA, a software program for vehicle collision analysis, and MADYMO. a software program for driver motion after collision, were used for simulated experiment. Four cases such as air bag installed and seat belt wearing (case A), air bag installed but seat belt not wearing (case B), air bag not installed but seat belt wearing (case C), air bag not installed and seat belt not wearing (case D) were analyzed. The impact of acceleration on the injury of driver's head was analyzed by Head Injury Criterion (HIC) as well. It was found that having air bag and wearing seat belt effectively reduced driver's head injury about 52.9% to 70.5% compared with the case of having neither air bag nor wearing seat belt.