• 전자공학회논문지CI
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• 제49권3호
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• pp.62-73
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• 2012

저속, 저전력, 저가의 특징을 갖는 IEEE 802.15.4 standard는 무선 센서 네트워크 환경에서 효율적이다. IEEE 802.15.4 표준에서 사용하는 다양한 토폴로지 중에서도 많은 노드들이 참여하는 클러스터-트리 토폴로지는 싱크 노드 주변에 트래픽이 집중되어 전송 지연과 에너지 소모 증가 및 데이터 손실을 초래하게 된다. 본 논문에서는 효율적인 데이터 전송을 위해 패킷간의 충돌을 최소화하고 제한된 에너지를 효율적으로 사용하기 위해 액티브 구간을 동적으로 할당하는 MRS-DCA알고리즘을 제안한다. 이 알고리즘은 IEEE 802.15.4 standard의 액티브구간에 RP(Reservation Period)를 할당하여 사용한다. 또한, EWMA를 이용한 할당 알고리즘으로 트래픽을 예측하고 이것을 기반으로 RP와 CAP를 동적으로 할당함으로써 안정적인 데이터 전송을 보장한다. 제안하는 MRS-DCA알고리즘의 성능 비교를 위하여 IEEE 802.15.4, DCA scheme과 비교한 결과, 액티브 구간의 단축으로 전력 소모가 적어지고 충돌 회피율의 상승으로 높은 전송률을 보이는 것을 확인하였다.

• 한국식품영양학회지
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• 제28권5호
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• pp.858-865
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• 2015

The study was carried out to investigate the efficacy of current nutrition labeling of processed foods and examine awareness among university students of nutrition information given current nutrition labels, and also awareness of the one-serving size of snacks that come in differently sized packages. A total of 100 students in Chungbuk, Korea participated in this study. About 60% of the subjects knew about nutrition labeling; however, a very small percentage (11%) of the subjects reported an experience of being educated about nutrition labeling. Also, just 32% of the students checked nutrition labels when they purchased processed foods. When understanding of nutrition information on labels of snacks in differently sized packaging was tested, over 80% of the subjects understood nutrition information accurately. Five different package sizes were studied. Of these 5, packages containing about 200% of one standard serving showed the highest rate of misunderstanding of total energy contents per container. Interestingly, the students most strongly preferred containers that contained 300% of one standard serving. From these results, we conclude that students consider the current recommendation for a serving size to be small, which may be related to misreading of nutrition labels of snacks that come in packages containing less than 300% of one standard serving size. To improve accurate understanding of nutrition labels of snacks, total package labels or dual column labels on packages containing less than 300% of one standard serving size should be considered.

• 대한지역사회영양학회지
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• 제2권4호
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• pp.624-632
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• 1997

This study was conducted to evaluated the nutrition quality of the commercial supplementary foods for infants and young children and to seek a solution to the establishment of standards of nutrient requirements for supplementary foods in Korea. Information on food ingredients, nutrient contents, claims about usefulness of food components and instructions for feeding preparation were obtained from the labels of 33 commercial supplementary foods manufactured by 4 different domestic companies. According to the standard of supplementary foods for infants and young children described in the Korean Food Code, the commercial supplementary foods were categorized into two different types, weaning food and baby food. All the commercial weaning foods were in powder form and mainly composed of cereals, whereas all the baby foods were mainly composed of fruits in the form of canned juice. The weaning foods contained more nutrients than the baby foods did, and the nutrient levels of the weaning foods expressed as nutrient density on energy basis were higher than the RDA for infants aged 5 to 11 months, suggesting that the commercial weaning foods provide adequate amounts of nutrients. If one followed the instructions for feeding preparation appearing on the label, however, recommended amounts of intake of the weaning foods would provide too much energy as well as nutrients. There were many differences in nutrient standards of weaning foods between the Korean Food Code and Codex international food standard. In conclusion, the establishment of standards for nutrient requirements for the supplementary foods requires significant scientific studies on what nutrients are the most inadequate in Korean infants and young children feeds and what levels of nutrients should be added to the foods in order to supplement their nutrition. In addition, it is very important to have a strong scientific basis to support our standard when discrepancies exist between our standard and the international standard. (Korean J Community Nutrition 2(4) : 624-632, 1997)

• 신재생에너지
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• 제1권3호
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• pp.24-34
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• 2005

Ministry of Commerce, Industry [MOCIE] has taken it into consideration to introduce a Renewable Portfolio Standard (RPS) that is a purchase obligation program as an alternative plan to the FIT. We conducted a survey of renewable energy companies and experts to ask their opinions about renewable energy policy, the introduction of the RPS, and the scheme for aid of North Korea with renewable energy. Korean renewable energy companies show an impartial opinion about a FIT and a RPS system overall, although they tend to have distinctive opinions by technology each other. With respect to eligible resources for a RPS, the industries want to extend the scope of it as broad as possible. In addition, experts prefer the multi-tiered and energy production based RPS to the sing1e-tiered and installed capacity based RPS. We also conducted a surrey to find the best renewable energy sources. Wind, Geothermal, Solar-thermal, and Photovoltaic were selected to have the best potential capacities to support North Korea by renewable energy experts. However, these energy resources also have several problems to overcome in the aid of North Korea, and thus, the plans for solving them and for giving efficient support to North Korea in the area of Renewable Energy are discussed.

• KIEAE Journal
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• 제13권4호
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• pp.69-74
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• 2013

It is difficult to apply a design standard uniformly to university buildings because various education courses are conducted. However, a design guideline for saving energy is necessary in order to prepare for low-energy days. A library in any university is one of the buildings that a lot of people use and most of the energy is spent. Therefore, the investigation on the energy savings of library facilities is very important and urgent. This study finally presents the design guideline of those facilities for low-energy. In this paper, the trend of space layout, utilization schedule and performance of materials are investigated, and the impact on energy savings and effective energy saving strategies are analyzed and illustrated by energy simulation. As a result of energy analysis from the case of 'H' university, it is confirmed that the utilization schedule effects mostly to energy consumption and the layout and orientation of the rooms in the library are the major parameters. Among the investigated saving strategies, green roofs are found as the most effective part for heating energy savings, and outdoor air cooling is known as the most effective method for cooling energy savings.

• Nuclear Engineering and Technology
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• 제41권8호
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• pp.989-994
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• 2009

We at Mitsubishi have lined up Gen-III+ solutions for a wide variety of global customers: ATMEA1 of the 1100MWe class, and an APWR with the largest capacity of 1700MWe. In this paper, we would like to introduce the APWR. With an increased requirement for nuclear power generation as an effective countermeasure against global warming, we have established the APWR plant, a large-capacity Mitsubishi standard reactor combining our accumulated experience and technology as an integrated PWR plant supplier. The APWR plant has achieved high reliability, safety and enhanced economy based on a technology that has been developed with the support of the government and utilities through improvement and standardization programs of light water reactors. Currently, Tsuruga Units 3 and 4, the first two APWRs, are undergoing licensing, while we are making efforts to obtain the standard design certification (DC) of US-APWR and preparing for the European Utility Requirements (EUR) compliance assessment of EU-APWR. Mitsubishi Heavy Industries, Ltd. (MHI) positions the APWR as a core technology that will contribute to the prevention of global warming and meet worldwide requirements.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1266-1270
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• 2020

A code is developed to correct for the coincidence summing effect in detecting a voluminous gamma source, and this code is applied to a¹⁵²Eu standard source as a test case. The source is 1000 mL of liquid in a cylindrical shape. To calculate the coincidence summing effect, the cylindrical source is considered as 10(radial) × 8(height) sectional sources. For each sectional source, the peak efficiency and total efficiency are obtained by Monte Carlo simulation at each energy for 10 energies between 50 keV and 2000 keV. The efficiencies of each sector are then expressed as polynomials of gamma energy. To calculate the correction coefficients for the coincidence summing effect, the KORSUM code is used after modification. The magnitudes of correction are 4%-17% for the standard ¹⁵²Eu source measured in this study. The relative deviation of 4.7% before the coincidence correction is reduced to 0.8% after the correction is applied to the efficiency based on the measured gamma line. Hence, this study has shown that a new method has been developed that is applicable for correcting the coincidence effect in a voluminous source, and the method is applied to the measured data of a standard ¹⁵²Eu cylinder source.

• 한국조명전기설비학회지:조명전기설비
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• 제10권5호
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• pp.43-51
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• 1996

박물관에서 조명에 의한 전시물의 손상이 일어나는 것을 최소화하기 위해서 적절한 조명 기준이 요구된다. 이러한 조명 기준의 작성을 위한 기초 자료를 얻기 위하여, 방사에너지의 파장의 함수로 전시물의 변색을 측정할 수 있는 장치를 구성하였다. 크세논 램프를 광원으로 사용하고, 빛은 여러 가지 차광 필터를 통과하여 시료에 입사한다. 여러 차광 필터 밑의 시료의 색을 측정함으로써 특정 파장 범위의 방사 에너지에 의한 사료의 변색을 추정하였다. 측정 결과, 식물 염료들은 단시간에 심한 변색을 보였으나, 전래 종이는 상대적으로 거의 변색이 되지 않았다. 측정 결과를 이용하여 다른 광원에 의한 변색을 예측할 수 잇으며, 이는 조명 기준 작성의 근거가 된다.

• 한국태양에너지학회 논문집
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• 제27권4호
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• pp.59-65
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• 2007

This study is to propose the basic data for deciding remodeling of wornout educational facilities. In order of it, the indoor environmental standard, the actual conditions of thermal environment and sound insulation of walls were examined through field measurement in the subjected open elementary school(J school) and modernization model of elementary school(Y school) which they are located in Seoul. As the result, standard for indoor environmental factors of educational facilities which is established by Ministry of Education is not subdivided into indoor environmental performances considering usages and characteristics of classrooms for comfortable indoor environment. The vertical temperature difference in general classroom and in open classroom showed to be $11.2^{\circ}C$ and $12.1^{\circ}C$ respectively, while indoor temperature of special classroon was, on the whole, higher than that of any other classroom due to its specific heat flux of wall materials. The sound insulation performance of the masonry brick wall of classroom satisfied the minimum standard of AIJ, Architectural Institute of Japan, in the open elementary school and the modernization model of elementary school. That is to say, the movable partition wall between the classroom and the corridor disturbed students in their class in the open school.

• Nuclear Engineering and Technology
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• 제47권5호
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• pp.559-566
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• 2015

The thermalehydraulic characteristics for the CANadian Deuterium Uranium Flexible (CANFLEX)-burnable poison (BP) fuel channel, which is loaded with a BP at the center ring based on the CANFLEX-RU (recycled uranium) fuel channel, are evaluated and compared with that of standard 37-element and CANFLEX-NU (natural uranium) fuel channels. The distributions of fuel temperature and critical channel power for the CANFLEX-BP fuel channel are calculated using the NUclear Heat Transport CIRcuit Thermohydraulics Analysis Code (NUCIRC) code for various creep rate and burnup. CANFLEX-BP fuel channel has been revealed to have a lower fuel temperature compared with that of a standard 37-element fuel channel, especially for high power channels. The critical channel power of CANFLEX-BP fuel channel has increased by about 10%, relative to that of a standard 37-element fuel channel for 380 channels in a core, and has higher value relative to that of the CANFLEX-NU fuel channel except the channels in the outer core. This study has shown that the use of a BP is feasible to enhance the thermal performance by the axial heat flux distribution, as well as the improvement of the reactor physical safety characteristics, and thus the reactor safety can be improved by the use of BP in a CANDU reactor.