• 설비공학논문집
• /
• 제29권2호
• /
• pp.89-95
• /
• 2017

This study aimed to compare the primary heating energy consumption of regional apartment houses based on the enhanced thermal insulation performance of building envelope standards. The difference of the heating energy consumption based on the enhanced thermal insulation performance of building envelope standards in the southern region, the largest regional difference in primary heating energy consumption, is $10.3kWh/(m^2{\cdot}year)$. The difference of the heating energy consumption based on the enhanced thermal insulation performance of building envelope standards in the central region is $8.0{\sim}8.5kWh/(m^2{\cdot}year)$ and that of the Jeju region is $0.5kWh/(m^2{\cdot}year)$. These energy consumption differences do not result in building energy efficiency ratings changing. The building energy efficiency ratings have the possibility to be changed.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제49권2호
• /
• pp.74-80
• /
• 2000

In this paper, we present a control method of mobile power assist systems. Most of mobile power assist systems have a heavy base for preventing easy tumbling, so continual movement of the base during operations causes high energy consumption and gives the high risk of human injury. Furthermore, the slow dynamics of the base limits the frequency bandwidth of the whole system. Thus we propose a cooperation control method of the mobile base and manipulator, which removes the unnecessary movements of the base. In our scheme, the mobile base does not move until the center of gravity(C.G) of the system goes outside a safety region. When C.G. reaches the boundary of the safety region, the base starts moving to recover the manipulator's initial configuration. By varying the parameters of a human impedance controller, the operator is warned by a force feedback that C.G. is on the marginal safety region. Our scheme is implemented by assigning a nonlinear mass-damper-spring impedance to the tip of the manipulator. Our scheme is implemented by a nonlinear mass-spring impedance to the tip of the manipulator. The experimental results show the efficacy of the proposed control method.

• 한국식품위생안전성학회지
• /
• 제21권3호
• /
• pp.164-170
• /
• 2006

Asian Branches of International Life Science Institute (ILSI), i.e. China, India, Japan, Korea and South East Asian Region, identified five key public health issue priorities of each region and compared the results. In case of China, India and South East Asian countries (Indonesia, Malaysia, Philippines, Thailand etc. ASEAN countries), communicable diseases were the first priority issue, while elderly issue and food safety were prime issues for Japan and Korea, respectively. Malnutrition was the second priority issue for India and ASEAN countries, whereas non-communicable disease like cancer and degenerative diseases was for Korea and China, and obesity far Japan. Typical issues were smoking for China, nutrition education for China and Japan, biotechnology aiming GMO for India, and functional food causing health claim problem for Korea and Japan. Although the priority varied with the socioeconomic situation of each county, food and water safety recorded the highest priority of all the countries. The key public health issues of Korea were discussed in detail.

• 동아시아식생활학회지
• /
• 제22권2호
• /
• pp.305-314
• /
• 2012

This study examined awareness and information acquisition behavior regarding food hygiene and safety and information search behavior of college students. The sample was obtained from 284 students in Yeungnam region through a self-administered questionnaire. To describe characteristics of the respondents, frequency distributions were used. In addition, $t$ tests, analysis of variance and Duncan multiple range tests were conducted. Data were analyzed by SPSS Windows V.18.0. The results of the study were as follows: (1) most respondents were concerned about food hygiene and safety. They were mostly interested in the expiration date label on breads, milk/dairy products, fish products and meat products, and price of cookies. Many respondents answered that foods produced and distributed in Korea were not safe. The respondents were most worried about endocrine disruptors among various food risk factors. The respondents received information on food hygiene and safety from blogs, mini-homepages, or Kin-searches on the Internet, electronic media, and food labeling in decreasing order.

• 한국가스학회지
• /
• 제19권5호
• /
• pp.1-6
• /
• 2015

본 연구에서는 퓨즈콕 메인몸체에 대한 강도안전성을 유한요소법으로 해석하였다. 볼밸브와 퓨즈콕 안전장치 연결부 사이에 형성되는 (T)지역의 두께를 변화시켜가면서 응력과 변위량에 대한 거동특성을 고찰하였다. FEM 해석결과에 의하면, 퓨즈콕에 공급된 가스압력이 1.5~3.5MPa일 때 (T)지역에 대한 최적의 두께는 1.55mm~1.6mm 정도인 것으로 나타났다. 이 결과는 퓨즈콕의 메인몸체에 작용하는 강도안전성과 경량화를 고려한 최적치라 할 수 있다.

• 한국안전학회지
• /
• 제26권5호
• /
• pp.1-6
• /
• 2011

Flame extinction and the chemistry of stoichiometric methane/air mixture were investigated numerically in the PSR(perfectly stirred reactor). For the study, PSR code was modified to be possible to unsteady calculation, and the sinusoidal fluctuation was subjected to the residence time. In the region of residence time far from the extinction limit, combustion mode was strongly dependent on the frequency. The low frequency excitation provided the quasi-steady behavior on the temperature and the concentrations of related species, but small variation of temperature was observed under high frequency. In the region of residence time near the extinction limit, the mixture subjected above 1 KHz was still reacting even though extinction had to be occurred under quasi-steady concept. The attenuation of extinction limit resulted from that chemical time was comparable to the flow time. The mean mole fractions of both NO and CO were almost same regardless of imposed frequency. However, the average mole fraction of $C_2H_2$ was decreased as increasing frequency, which implies that soot yield might be reduced at the higher frequency of flow excitation. The result provides the basic concept for flame stabilization, and it will be used to design a mild combustor.

• Nuclear Engineering and Technology
• /
• 제54권6호
• /
• pp.2084-2093
• /
• 2022

Probabilistic safety assessment is widely used to quantify the risks of nuclear power plants and their uncertainties. When the lognormal distribution describes the uncertainties of basic events, the uncertainty of the top event in a fault tree is approximated with the sum of lognormal random variables after minimal cutsets are obtained, and rare-event approximation is applied. As handling complicated analytic expressions for the sum of lognormal random variables is challenging, several approximation methods, especially Monte Carlo simulation, are widely used in practice for uncertainty analysis. In this study, a theoretical approach for analyzing the sum of lognormal random variables using an efficient numerical integration method is proposed for uncertainty analysis in probability safety assessments. The change of variables from correlated random variables with a complicated region of integration to independent random variables with a unit hypercube region of integration is applied to obtain an efficient numerical integration. The theoretical advantages of the proposed method over other approximation methods are shown through a benchmark problem. The proposed method provides an accurate and efficient approach to calculate the uncertainty of the top event in probabilistic safety assessment when the uncertainties of basic events are described with lognormal random variables.

• 대한기계학회논문집B
• /
• 제39권11호
• /
• pp.905-911
• /
• 2015

본 연구에서는 하부지지구조물 바닥판의 외곽영역에 위치한 구멍의 크기 변경(구멍 직경 감소)이 노심 입구 유량분포에 미치는 영향을 조사하기 위해 상용 전산유체역학 소프트웨어인 ANSYS CFX R.15를 사용하여 계산을 수행하였고, 기존 바닥판 구멍 형태에 대한 계산 결과와 비교하였다. 결론적으로 하부지지구조물 바닥판의 외곽영역에 위치한 구멍의 직경 감소를 통해 노심 입구에서 보다 균일한 유량 분포를 얻을 수 있었다. 따라서 원자력 규제측면에서 볼 때 본 연구에서 제시한 하부지지구조물 바닥판의 외곽영역 구멍 형태의 설계 변경은 연료집합체의 기계적 건전성 및 노심 열적여유도를 향상시킬 수 있다는 측면에서 바람직할 것으로 판단된다.

• 한국안전학회지
• /
• 제31권3호
• /
• pp.22-27
• /
• 2016

The use of electromagnetic wave has been interested in various energy industry because it enhances a flame stability and provides higher safety environments. However it might increase the pollutant emissions such as NOx and soot, and have harmful influence on human and environments. Therefore, it is very important to understand interaction mechanism between flame and electromagnetic wave from environmental point of view. In this study, an experiment was performed with jet diffusion flames induced by electromagnetic wave. Microwave was used as representative electromagnetic wave and a flickering flame was introduced to simulate the more similar combustion condition to industry. The results show that the induced microwave enhances the flame stability and blowout limit. The unstable lifted flickering flames under low fuel/oxidizer velocity is changed to stable attached flames or lift-off flames when microwave applied to the flames, which results from the abundance of radical pool. However, NOx emission was increased monotonically with increasing the microwave power as microwave power increased up to 1.0 kW. The effects might be attributed to the heating of combustion field and thermal NOx mechanism will be prevailed. Soot particle was examined at the post flame region by TEM grid. The morphology of soot particle sampled in the microwave induced flames was similar to the incipient soot that is not agglomerated and contain a lots of liquid phase hydrocarbon such as PAH, which soot particle formed near reaction zone is oxidized on the extended yellow flame region and hence only unburned young particles are emitted on the post flame region.

• Journal of international Conference on Electrical Machines and Systems
• /
• 제2권1호
• /
• pp.51-56
• /
• 2013

With the active development of hybrid electric vehicle (HEV), the application of interior permanent magnet synchronous motor (IPMSM) has been expanded. As wide driving region of IPMSM for electric vehicle (EV) traction motor is required, many studies are conducted to improve characteristics of a motor in both low and high-speed driving regions. A motor in high-speed driving region generates (produces) large stress to the rotor. Thus, the rotor needs to be designed considering the mechanical safety. Therefore, in this paper, we conducted stress analysis and electromagnetic analysis to determine the centerpost's distance which is considered important during the design of IPMSM for EV traction motor in order to secure mechanical safety and satisfy specifications of output requirement.