• Title/Summary/Keyword: fast

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A NEXT GENERATION SODIUM-COOLED FAST REACTOR CONCEPT AND ITS R&D PROGRAM

  • Ichimiya, Masakazu;Mizuno, Tomoyasu;Kotake, Shoji
    • Nuclear Engineering and Technology
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    • v.39 no.3
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    • pp.171-186
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    • 2007
  • Critical issues in the development targets for the future fast reactor(FR) cycle system, including sodium-cooled FR were to ensure safety assurance, efficient utilization of resources, reduction of environmental burden, assurance of nuclear non-proliferation, and economic competitiveness. A promising design concept of sodium-cooled fast reactor JSFR is proposed aiming at fully satisfaction of the development targets for the next generation nuclear energy system. A roadmap toward JSFR commercialization is described, to be followed up in a new framework of the Fast reactor Cycle Technology development(FaCT) Project launched in 2006.

Fast food Consumption Patterns of College Students in Ulsan (울산 지역 대학생의 패스트푸드 이용실태에 관한 연구)

  • Kim, Hye-Kyung
    • Journal of the Korean Society of Food Culture
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    • v.11 no.1
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    • pp.131-141
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    • 1996
  • Food consumption patterns are predictors of nutritional status at all age levels and vary among and between different age groups. This study was designed to asses food habits and fast food eating patterns of college students in Ulsan area through questionnaries. Data from 330 useable forms was analyzed for percent differences, frequency of consumption, and statistical significance of differences between male and female students (T-test and chi square methods were utilized). Food habit score of female students was significantly higher than of male students. The reason for using fast food chain was 'convenience' or 'good taste'. The most preferred food by subjects was noodle or dumpling and least preferred food was pizza. In general, they had a higher satisfaction scores in taste and service of fast food and lower scores in amount and price of it. From this results it appears there is a need for developing domestic brand fast food to lower the price of fast food and giving the nutrition education for proper food selections and eating patterns.

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A Strategy for Kori Unit 1 Pressure Vessel Fluence Reduction through a Modification of Outer Assembly Configuration Using Monte Carlo Analysis

  • Kim, Jae-Cheon;Kim, Jong-Kyung;Kim, Jong-Oh
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.05b
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    • pp.515-519
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    • 1997
  • The purpose of this study is to reduce the fast neutron fluence at the reactor pressure vessel(RPV) and to provide a basis for plant-life extension. In this study, different neutron absorbers were employed in the core outer assemblies of Kori Unit 1 Cycle 14. The modified assemblies were used to calculate fast neutron fluence at the RPV and to evaluate reduction of outer assembly power and total power in core. By comparison with the case of no suppression fixture, the fast neutron fluence of a case with two rows stainless steel around the assembly with natural uranium pins is decreased by 85.8%. It is noted that the modification of outer assembly is more efficient than the previous low leakage loading pattern (LLLP) applied to Kori Unit 1. Also, compared fast neutron fluence in Cycle 1 with Cycle 14, fast neutron fluence at the RPV between Cycle 1 and Cycle 14 is not significantly different. It is found that LLLP applied to the Kori Unit 1 has not contributed to fast neutron fluence reduction at the RPV.

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A Study on the FAST, BRIEF, ORB Features of Image in the field of Surface Defect Inspection (표면 결함 검사에서 영상의 FAST, BRIEF, ORB 특징에 관한 연구)

  • Jeon, Young-Min;Ji, Hong-Geun;Seo, Min-Seong;Pyo, Min-Seong;Bae, You-Seok
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2019.01a
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    • pp.399-402
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    • 2019
  • 본 논문은 스마트 공장의 표면 결함 검사 시스템에서 사용할 수 있는 FAST, BRIEF, ORB 영상의 특징 활용에 관한 연구를 내용으로 다루었습니다. 본문에서는 FAST, BRIEF, ORB 특징에 대하여 원리를 소개하고, 실험에서는 이들 특징을 사용한 표면 결함 검사의 결과를 제시하였습니다.

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Turn-off time improvement by fast neutron irradiation on pnp Si Bipolar Junction Transistor

  • Ahn, Sung Ho;Sun, Gwang Min;Baek, Hani
    • Nuclear Engineering and Technology
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    • v.54 no.2
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    • pp.501-506
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    • 2022
  • Long turn-off time limits high frequency operation of Bipolar Junction Transistors (BJTs). Turn-off time decreases with increases in the recombination rate of minority carriers at switching transients. Fast neutron irradiation on a Si BJT incurs lattice damages owing to the displacement of silicon atoms. The lattice damages increase the recombination rate of injected holes with electrons, and decrease the hole lifetime in the base region of pnp Si BJT. Fast neutrons generated from a beryllium target with 30 MeV protons by an MC-50 cyclotron were irradiated onto pnp Si BJTs in experiment. The experimental results show that the turn-off time, including the storage time and fall time, decreases with increases in fast neutron fluence. Additionally, it is confirmed that the base current increases, and the collector current and base-to-collector current amplification ratio decrease due to fast neutron irradiation.

Comparison of dietary habits, perception and consumption frequency of fast foods between youths working part-time at fast food restaurants and other food-related services (패스트푸드점 아르바이트생과 그 외 음식관련 서비스업 아르바이트생의 식습관, 패스트푸드에 대한 인식 및 섭취빈도 비교)

  • Jo, Mi Yang;Hyun, Taisun
    • Journal of Nutrition and Health
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    • v.47 no.3
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    • pp.206-213
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    • 2014
  • Purpose: The purpose of the study was to compare dietary habits, perception, and consumption frequency of fast foods between part-time working youths at fast food restaurants and those at other food-related services. Methods: The study subjects were part-time working youths in 13 fast food restaurants (n = 118) and in 25 other places including bakeries, cafes, convenience stores, and other restaurants (n = 115) in Cheongju. Demographic characteristics, dietary habits, perception regarding fast foods, and consumption frequencies of food groups and fast foods were assessed using a self-administered questionnaire. Results: Female youths working at fast food restaurants had unhealthier dietary habits, such as meal skipping and night snacking compared to those working at other places. Consumption frequencies of fruits in males and beans/bean products in females working at fast food restaurants were significantly lower than those working at other places. Perception score on fast foods was significantly lower in males working at fast food restaurants than in males working at other places. However, the consumption frequencies of hamburgers, pizzas, and a total of six fast foods among both males and females working at fast food restaurants were significantly higher than those working at other places after adjusting for confounding variables including age, status, type of residence, allowance, alcohol, smoking, working hours, and hourly pay. Conclusion: Part-time working youths at fast food restaurants had worse dietary habits, such as meal skipping and night snacking, and consumed fast foods more frequently than those working at other places. Interventions for part-time working youths at fast food restaurants may be needed in order to reduce fast food consumption and increase the intake of fruits and vegetables.

Experimental and Analytical Studies on the Characteristics of Fast Switch in Combinations of Various Superconducting Tapes (다양한 선재 조합에 따른 이종 초전도 스위치의 특성 실험 및 분석)

  • Lee, Ji-Ho;Kim, Young-Jae;Na, Jin-Bae;Choi, Suk-Jin;Jang, Jae-Young;Hwang, Young-Jin;Kim, Jin-Sub;Ko, Tae-Kuk
    • Progress in Superconductivity and Cryogenics
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    • v.13 no.1
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    • pp.31-35
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    • 2011
  • A Hybrid Fault Current Limiter(FCL) which has more advantages in fast response and thermal characteristics than a simple resistive FCL had been proposed by our group. The Hybrid FCL consists of a resistive FCL for the magnitude of the first peak of fault current, and a fast switch for detecting fault current and generating the repulsive force within a cycle in fault situation. In ideal case, the impedance of the fast switch wound with two other kinds of HTS tape is negligibly zero in normal operation. But, during the fault situation, each HTS tape has different quench characteristics because of asymmetric current distribution. And this phenomenon causes effective flux and this flux opens the switch through the repulsive force applied to a metal plate of the fast switch. The magnitude of the repulsive force affects the switching characteristics of the fast switch. It should be large enough to raise the metal plate up. Otherwise the arc re-out break which are caused by not enough repulsive force to raise the metal plate up can cause unintended operation of the fast switch. In this paper, the numerical calculation of the repulsive force applied to the metal plate of the fast switch in various combinations of HTS tapes was performed by using the short-circuit test and finite element method.

Design of Fast Handover Mechanism in Proxy Mobile IPv6 Networks (Proxy Mobile IPv6 네트워크에서 Fast Handover 기법 설계)

  • Park, Byung-Joo;Han, Youn-Hee;Kim, Bong-Ki
    • Journal of KIISE:Information Networking
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    • v.35 no.4
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    • pp.301-310
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    • 2008
  • In the existing literature, the handover process reveals numerous problems manifested by high movement detection latency. FMIPv6 can reduce packet loss using a tunnel-based handover mechanism. However, this mechanism may cause performance degradation due to the out-of-sequence packets. Recently. Proxy Mobile IPv6 is proposed for network-based mobility management to reduce overhead in mobile node. PMIPv6 can decrease handover latency which related overhead in MN by using network agent. In this paper, we proposed optimized fast handover scheme called Fast Proxy Mobile IPv6 (EF-PMIPv6). The proposed EF-PMIPv6 can support fast handover using fast IAPP and ND schemes. Further, a mathematical analysis is provided to show the benefits of our scheme. In the analysis, various parameters are used to compare our scheme with the current procedures, while our approach focuses on the reduction of handover latency.

Snack Culture and Fast Fashion (스낵 컬처와 패스트 패션)

  • Yun, Eul-Yo
    • The Journal of the Korea Contents Association
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    • v.16 no.9
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    • pp.612-627
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    • 2016
  • This study is research on the snack culture and fast fashion. The purpose of this study is to examine the common attributes of snack culture and fast fashion as a cultural phenomenon. The following results were obtained: First, snack culture and fast fashion have attributes of 3S represented by Speed, Short time, and Simplification. Second, snack culture and fast fashion meet consumer demands by fun and various contents and a variety of designs, respectively. Third, although snack culture has developed on the basis of information technology, fast fashion has grown based on the technological innovation of business, organization, and distribution system. Fourth, snack culture communicates with the world through opening and sharing to be globalize a context, and fast fashion is globalized to multinational corporations by increasing sales and development of scale. Fifth, snack culture has a synergistic effect by maximizing the multiple interactions through social campaigns based on the attribute to communicate with many-to-many relationship. In addition, fast fashion produces a synergistic effect through collaborative strategic alliances.

The Qualitative Analysis of Single Shot Fast Spin Echo (SSFSE) and Maximum Intensity Projection (MIP) on Magnetic Resonance Cholangiopancreatography

  • Park, Cheol-Soo;Cho, Jae-Hwan;Lee, Hae-Kag;Dong, Kyung-Rae;Chung, Woon-Kwan;Seok, Jong-Min;Han, Man-Seok;Lee, Sun-Yeob;Goo, Eun-Hoe;Kim, Eng-Chan
    • Journal of Magnetics
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    • v.17 no.2
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    • pp.138-144
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    • 2012
  • 3-dimensional magnetic resonance cholangiopancreatography (MRCP) images reconstructed using the maximum intensity projection technique were analyzed qualitatively in patients diagnosed with pancreatobiliary diseases to determine their diagnostic utility. Single shot fast spin echo (SSFSE), fast spin echo (FSE) and 3-dimensional reconstructive images were acquired from 20 patients diagnosed histologically with pancreatobiliary diseases using a 3.0T MR scanner. According to qualitative analysis, the fast spin echo images and 3-dimensional reconstructed images of the hepatic duct, gall bladder and common bile duct had a higher signal to noise ratio (SNR) than the single shot fast spin echo images. Fast spin echo images and 3-dimensional reconstructed images did not show any differences. The contrast to noise ratio of the hepatic duct, gallbladder and common bile duct on the fast spin echo images and 3-dimensional reconstructed images was higher than that of the single shot fast spin echo images. The fast spin echo images and 3-dimensional reconstructed images showed similar quality.