• 한국방사선학회논문지
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• 제17권1호
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• pp.71-77
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• 2023

북한 비핵화 문제는 남북을 넘어 세계적인 문제이다. 북한이 비핵화 의지를 밝힐 상황을 대비하여 비핵화 과정에 대한 준비가 필요하다. 북한 비핵화 과정에서 검증 장비의 정상 작동 담보가 요구된다. 카자흐스탄에서 저온으로 인해 장비가 작동되지 않은 선례를 참고했을 때 북한 환경을 고려한 성능 시험 기준이 수립된다면 향후 비핵화 과정에서 활용 가능성이 높을 것이라 판단하였다. 이를 위해 국제 기준 등 시험 기준 분석을 통해 성능 시험 기준 관련 기초 자료를 구축하였다. 이후, 북한 주요 원자력 시설이 위치한 영변군 및 풍계리의 기후, 지리적 특성을 고려하여 검증 상황 발생 시 적시 대응 가능한 성능 시험 기준 수립을 수행하였다. 여기에는 고온, 저온, 습도, 진동, 충격 시험이 포함된다. 후속 연구에서는 실제 장비 시험을 통해 시험 기준의 타당성을 수립하고자 한다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.99-99
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• 2011

Fuel cell systems are a completely different form of electricity source that has been used so far and is an aggregation of multiple technologies with multidisciplinary features that can be operated safely only when gas and electrical safety are being considered. Since fuel cells generate through electrochemical reactions there are difficulties in ensuring electricity safety, power quality assessment, effective control and reliability standards for system faults using conventional inspection techniques and even though they are necessary as a primary means for reduction of CO2 owing to the Climate Convention, electrical safety assessment and measures are required for the prevention of faults in residential facilities. Although small-scaled distributed power supplies can be utilized as important means of peak control and energy management measures, research is required for observing the effects on the system and the development of inspection technology to ensure stable operation, and the electrical safety of residential fuel cell systems need to be assessed and the problems derived for establishing electrical safety standards. From the year 2002, Japan has established laws on technical safety standards and development and rules on the product specifications and standards for the industrialization of hydrogen fuel cells. Also, a lot of effort have been made for the commercialization of fuel cells by building one-stop certification services. Internationally, the IEC TC 105 has established international standards based on fuel cells. In order to protect the national interest, the country should be able to respond accordingly meet global standards. In fact, in Korea, to comply with the international trend, Korea Energy Management Corporation is establishing a certified agenda for fuel cells and Korean Agency for Technology and Standards is enacting technical standards for fuel cells. The current terms of fuel cells are that research has been focused more on the quality and performance of manufactured products rather than stable power operation and maintenance over time. In this paper, by considering the household fuel cell as a power device, the safety standards of the fuel cell system for a reliable operation with the existing power system is being proposed.

• Asian-Australasian Journal of Animal Sciences
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• 제17권6호
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• pp.769-776
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• 2004

Data from 24 feeding trials conducted on lactating cattle from different institutes across India were subjected to regression analysis to derive requirements of ME, TDN, CP and DCP for maintenance, milk production and body weight gain. Maintenance requirements for ME, TDN, CP and DCP were 598 KJ, 39.5 g, 6.27 g and 2.90 g/kg $W^{0.75}$, respectively and the corresponding requirements for production of 1 kg 4% FCM were 5,023 KJ, 332 g, 82 g and 58 g. The corresponding requirements for one g gain in BW were 27 KJ, 1.78 g, 0.44 g and 0.19 g. Regression equations had high $R^{2}$ values (0.67 to 0.90) and the equations (Fvalue) as well as coefficients were highly significant (p<0.001). Regressed values were used to develop feeding standards. Derived values matched well with the actual intake versus performance of animals under diverse feeding conditions. The new standards so derived predicted requirements and intake of nutrients for different production levels better than existing feeding standards; as these are based on a more thorough analysis of a larger database, the new feeding standards will be appropriate for wide use in India.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.141-144
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• 2007

BLUs are major component in LCD industry which occupies 90% or more of FPD market worldwide and BLU market is expected to be expanded continuously according to the trend of miniaturization, slimness, low power consumption and low weight. The larger the BLU market scale, the more important standardization of performance evaluation techniques to clearly prescribe the product specification. Currently the government is promoting the establishment of related laws and coincidence with international standards to cope with agreements such as WTO/TBT, but the nongovernmental standardization activities are not enough to be actualized. Furthermore, BLU related components such as CCFL, EEFL, inverter and reflector are already developed for localization to substitute imports with home products but collective standardization, national standardization, and international standardization are still not done. So, performance specifications and evaluation methods for normal fluorescent lamps or industrial lamps are being adopted and used as national standards and safety certification standards instead. Making these standards enables to prepare a chance to penetrate into global market and to promote world best products. Also, by making this collective standard, it provides chances to take part in international standardization activities, to protect domestic industries and technologies, to obtain the trend of advanced technologies, and to be predominant over other countries. That is to say, CCFL standardization helps raise 21st century national strategic technology policy and go ahead of globalization of core technologies.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.39-39
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• 1999

The KSTAR (Korea Superconducting Tokamak Advanced Research) tokamak is a nuclear fusion experimental device for a long pulse/steady-state plasma operation, adopting fully superconducting magnets. In accordance with completion of the basic design of the torus vacuum vessel and the enclosing cryostat, the vacuum pumping and gas fueling basic design has been developed to fulfil the physics requirements. The ultra-high vacuum pumping and sophisticated gas fueling system of the machine is essential to achieve such roles for optimized plasma performance and operation. Recently the vacuum exhaust system using dedicated pumping ports for the vacuum vessel and cryostat has been modified to meet more reliable and successful performance of the KSTAR[Fig. 1].In order to achieve the required base pressure of 5 x 10-9 torr, the total impurity load to the vessel internal is limited to ~5 x 10-5 torr-1/x, while the cryostat base pressure is kept as ~5 x 105 torr to mitigate the thermal load applied to the superconducting magnets. Each KSTAR fueling system will be separately capable of fueling gas at a rate of 50 torr-1/x, consistent with the given pumping throughput. In order to initiate a plasma discharge in KSTAR, the vacuum vessel is filled to a gas pressure of few 10-6 to few 10-4 torr, and additional gas injection is required to maintain and increase the plasma density during the course of the discharge period.

• 비파괴검사학회지
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• 제24권6호
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• pp.581-589
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• 2004

본 연구는 선행연구의 결과를 바탕으로 cMUT를 개발하여 그 특성을 분석하기 위하여 수행되었다. 미세 반도체 제작공정을 적용하여 cMUT를 제작하여 단면특성을 측정하여 분석하였다. 제작된 cMUT의 미소 진동 막의 변위를 측정할 수 있는 마이켈슨 위상변조 간섭계를 구성하여 측정결과와 이론적인 해석결과와 비교하였다. cMUT의 초음파 특성을 분석하기 위하여 송수신 시스템을 구성하였다 비접촉 방법으로 cMUT에 의해 발생되는 초음파 신호를 수신하여 수신파형의 특성을 분석한 결과 양호한 주파수 특성을 나타내었다. 본 연구에서 개발된 cMUT는 향후 비접촉식 초음파 응용분야에 다양하게 활용될 것으로 판단된다.

• 대한영양사협회학술지
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• 제19권4호
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• pp.317-342
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• 2013

The purpose of this study was to evaluate the current state of foodservice and clinical nutrition management in a hospital-based nutrition department. Nutritional guidelines and survey reports of hospital evaluation programs from 2004 to 2009 were analyzed. In total, 275 hospitals in the first period and 288 hospitals in the second period were evaluated. The division of knife and chopping board use decreased from 97.2% in 2005 to 89.7% in 2008, the maintenance of a proper freezer temperature (below $-18^{\circ}C$) increased from 82.1% in 2004 to 97.7% in 2007 (88.9% to 97.4% from large hospitals and 69.8% to 86.5% from small/medium hospitals in 2005 and 2008, respectively). In tube-feeding management, the performance rate of material cold storage and the offer rate of tube-feeding were 65.9% and 94.2% in 2007, respectively. The cold storage of material, proper use within 24 hours after opening or production, and the use of an appropriate label were 47.3%, 71.2% and 67.2% in 2009, respectively. The rate of a management system for undernourished patients was 86.0% in 2007 (56.4% for large hospitals, 18.9% for small/medium hospitals) and 14.3% in 2009. In standards of nutrition support management, the performance rates of constructing a nutrition support team, the nutrition support team activity, and organizing multidisciplinary team were 66.7%, 43.6%, and 64.1% respectively, in 2004. For large hospitals, those rates were 61.1%, 36.1%, and 58.3%, in 2005, 93.0%, 62.8%, and 91.9% in 2007, and 69.2%, 43.6%, and 69.2% in 2008, respectively. The results of this study suggest standards on sanitary foodservice preparation, production, and tube-feeding production need to correspond with HACCP regulations for small/meidium hospitals in standards of a healthcare accreditation system. It will be necessary to understand the operating conditions of nutrition departments in convalescent hospitals, psychiatric hospitals, and geriatrics hospitals. As the application of accreditation is required from 2013, standards will need to be improved and continuously updated for healthcare accreditation.

• Journal of Positioning, Navigation, and Timing
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• 제13권1호
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• pp.111-115
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• 2024

This study builds a machine learning model optimized for clocks among various techniques in the field of artificial intelligence and applies it to clock stabilization or synchronization technology based on atomic clock noise characteristics. In addition, the possibility of providing stable source clock data is confirmed through the characteristics of machine learning predicted values during holdover of atomic clocks. The proposed machine learning model is evaluated by comparing its performance with the AutoRegressive Integrated Moving Average (ARIMA) model, an existing statistical clock prediction model. From the results of the analysis, the prediction model proposed in this study (MSE: 9.47476) has a lower MSE value than the ARIMA model (MSE: 221.2622), which means that it provides more accurate predictions. The prediction accuracy is based on understanding the complex nature of data that changes over time and how well the model reflects this. The application of a machine learning prediction model can be seen as a way to overcome the limitations of the statistical-based ARIMA model in time series prediction and achieve improved prediction performance.

• 기술사
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• 제42권4호
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• pp.68-74
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• 2009

• 드라이브 ㆍ 컨트롤
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• 제7권3호
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• pp.13-19
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• 2010