• Title/Summary/Keyword: 일차표준

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A Control Room Dose Assessment for a 1300 MWe PWR Following a Loss of Coolant Accident (냉각재(冷却材) 상실사고시(喪失事故時) 1300 MWe 급(級) PWR원전(原電) 주제어실(主制御室)의 선량평가(線量評價))

  • Chang, Si-Young;Ha, Chung-Woo
    • Journal of Radiation Protection and Research
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    • v.14 no.1
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    • pp.34-45
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    • 1989
  • The habitability of a reactor control room in a French 1300 MWe P'4 type PWR has been evaluated through the exposure dose assessment for the reactor operator following a Loss of Coolant Accident. The main hypotheses adopted in this evaluation are based on the French Standard Safety Analysis Report. A simple computer program, named COREX(Control Room EXposure), was developed to calculate : the time-integrated radioactivities released from the reactor building, the volume factors for radionuclides concerned and the resulting time-integrated external whole body and internal thyroid doses to the reactor operators staying in the control room up to 30 days following the LOCA. The results obtained in this study, on the whole, well agreed with those proposed by the EDF(Electricite de France) except for the case of the whole body exposure, which was attributed to the differences in the volume factors for the radionuclides concerned.

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Reference Values and Water quality Assessment Based on the Regional Environmental Characteristics (해역의 환경특성을 고려한 해양환경 기준설정과 수질등급 평가)

  • Rho, Tae-Keun;Lee, Tong-Sup;Lee, Sang-Ryong;Choi, Man-Sik;Park, Chul;Lee, Jong-Hyun;Lee, Jae-Young;Kim, Seung-Su
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.17 no.2
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    • pp.45-58
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    • 2012
  • For the development of reference values and evaluation of water quality in various environmental conditions, we divided the coastal region around Korean peninsular into 5 distinctive ecological regions based on the influence of surface current, depth, tidal range, turbidity, and climate condition. We used national marine environment monitoring data collected by National Fisheries Research & Development Institute(NFRDI) from 2000-2009. For the reference values, we used maximum seasonal mean from 2000 to 2007 for DIN, DIP, and chlorophyll-a and minimum seasonal mean for secchi depth measured at stations without the influence of river runoff in each ecological regions. For the reference value of bottom dissolved oxygen saturation, we used minimum mean value of 90% calculated from minimal riverine influence stations of whole regions. We calculated enrichment score for each assessment criteria. The enrichment score of DIN, DIP, and Chlorophyll-a was 1 (=< reference value), 2 (< 110% of reference value), 3 (< 125% of reference value), 4 (< 150% of reference value), and 5 (> 150% of reference value). The enrichment score of DO saturation and Secchi depth was 1 (> reference value), 2 (> 90% of reference value), 3 (>75 % of reference value), 4 (> 50% of reference value), and 5 (< 50% of reference value). We calculated water quality index using weighted linear combination of five enrichment score for the comparison of whole regions. From the water quality index distribution calculated from all stations between 2000 and 2007 period, we classified into 5 grade based on the standard deviation calculated from total water quality index. We assigned grade very good(I), good(II), moderate(III), bad(IV), and very bad(V) when the water quality index was less than 23, minimum + 1 sd, +2 sd, +3 sd, and grater than minium+ 3 sd, respectively.

Study on Adsorption Kinetic Characteristics of Propineb Pesticide on Activated Carbon (활성탄에 대한 프로피네브 농약의 흡착동력학적 특성 연구)

  • Lee, Jong-Jib;Cho, Jung-Ho;Kim, Heung-Tae
    • Clean Technology
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    • v.17 no.4
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    • pp.346-352
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    • 2011
  • The adsorption characteristics of propineb pesticide onto activated carbon has been investigated for the adsorption in aqueous solution with respect to initial concentration, contact time and temperature in batch experiment. The Langmuir and Freundlich adsorption models were applied to described the equilibrium isotherms and isotherm constants were also determined. The Freundlich model agrees with experimental data well. slope of isotherm line indicate that activated carbon could be employed as effective treatment for removal of propineb. The pseudo first order, pseudo second order kinetic models were use to describe the kinetic data and rate constants were evaluated. The adsorption process followed a pseudo second order model, and the adsorption rate constant($k_2$) decreased with increasing initial concentration of propineb. The activation energy, change of free energy, enthalpy, and entropy were also calculated to predict the nature adsorption. The estimated values for change of free energy were -7.28, -8.27 and -11.66 kJ/mol over activated carbon at 298, 308 and 318 K, respectively. The results indicated toward a spontaneous process. The positive value for change of enthalpy, 54.46 kJ/mol, found that the adsorption of propineb on activated carbon is an endothermic process.

On the Standard Taxonomic System of Science and Technology (과학기술 표준분류의 결정문제)

  • Lee Cho-Sik
    • Journal of Science and Technology Studies
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    • v.2 no.1 s.3
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    • pp.1-38
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    • 2002
  • Recently KISTEP(Korea Institute of Science and Technology Evaluation and Planning) held an open forum for examining 'the Manuscript of National Science and Technology Standard Taxonomic System'. I submitted my opinion letter to the forum because I thought that the matter of setting the standard taxonomic system for Science and Technology is so closely related to the research concern of STS that it needs checking from the viewpoint of STS. This paper primarily focuses on making a criticism of and constructing an alternative to the mamuscript, but it goes so far as to ground the matter upon the STS viewpoint. I propose that we interpret an open forum related to science and technology as an example case of the community of inquiry. Further I try, standing in the context of learning to form a model of doing STS interdisciplinary research. In the context of decision I point out the problem with the 'scale' principle involved in categrizing criteria of the taxonomic system and argue that the problem leads to omitting STS from National Science and Technology Standard Taxonomic System although STS takes up science and technology themselves as its research concern proper. In the context or teaming I seek to set up a typical case study or STS. One of the typical STS research tasks is trying to construct a positive alternative to as well as make a criticism of a given suggestion, for clearer alternatives will, in him, provoke sharper criticisms or safer acceptances. I hope that the model in this paper will exemplify such an alternating procedure of criticism and acceptance.

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Comparison of Heart Rate Variability Indices between Obstructive Sleep Apnea Syndrome and Primary Insomnia (폐쇄성 수면무호흡 증후군과 일차성 불면증에서 심박동률 변이도 지수의 비교)

  • Nam, Ji-Won;Park, Doo-Heum;Yu, Jaehak;Ryu, Seung-Ho;Ha, Ji-Hyeon
    • Sleep Medicine and Psychophysiology
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    • v.19 no.2
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    • pp.68-76
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    • 2012
  • Objectives: Sleep disorders cause changes of autonomic nervous system (ANS) which affect cardiovascular system. Primary insomnia (PI) makes acceleration of sympathetic nervous system (SNS) tone by sleep deficiency and arousal. Obstructive sleep apnea syndrome (OSAS) sets off SNS by frequent arousals and hypoxemias during sleep. We aimed to compare the changes of heart rate variability (HRV) indices induced by insomnia or sleep apnea to analyze for ANS how much to be affected by PI or OSAS. Methods: Total 315 subjects carried out nocturnal polysomnography (NPSG) were categorized into 4 groups - PI, mild, moderate and severe OSAS. Severity of OSAS was determined by apnea-hypopnea index (AHI). Then we selected 110 subjects considering age, sex and valance of each group's size [Group 1 : PI (mean age=$41.50{\pm}13.16$ yrs, AHI <5, n=20), Group 2 : mild OSAS (mean age=$43.67{\pm}12.11$ yrs, AHI 5-15, n=30), Group 3 : moderate OSAS (mean age $44.93{\pm}12.38$ yrs, AHI 16-30, n=30), Group 4 : severe OSAS (mean age=$45.87{\pm}12.44$ yrs, AHI >30, n=30)]. Comparison of HRV indices among the four groups was performed with ANCOVA (adjusted for age and body mass index) and Sidak post-hoc test. Results: We found statistically significant differences in HRV indices between severe OSAS group and the other groups (PI, mild OSAS and moderate OSAS). And there were no significant differences in HRV indices among PI, mild and moderate OSAS group. In HRV indices of PI and severe OSAS group showing the most prominent difference in the group comparisons, average RR interval were $991.1{\pm}27.1$ and $875.8{\pm}22.0$ ms (p=0.016), standard deviation of NN interval (SDNN) was $85.4{\pm}6.6$ and $112.8{\pm}5.4$ ms (p=0.022), SDNN index was $57.5{\pm}5.2$ and $87.6{\pm}4.2$ (p<0.001), total power was $11,893.5{\pm}1,359.9$ and $18,097.0{\pm}1,107.2ms^2$(p=0.008), very low frequency (VLF) was $7,534.8{\pm}1,120.1$ and $11,883.8{\pm}912.0ms^2$ (p=0.035), low frequency (LF) was $2,724.2{\pm}327.8$ and $4,351.6{\pm}266.9ms^2$(p=0.003). Conclusions: VLF and LF which were correlated with SNS tone showed more increased differences between severe OSAS group and PI group than other group comparisons. We could suggest that severe OSAS group was more influential to increased SNS activity than PI group.

An Empirical Study on the Industrial Cluster in Korea (한국의 산업클러스터에 관한 실증연구)

  • Jeong, Byeong-Sun;Pak, Rae-Hyeon
    • Journal of the Economic Geographical Society of Korea
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    • v.10 no.1
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    • pp.19-43
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    • 2007
  • The purpose of this study is to distinguish industrial clusters in Korea. Based on I/O table in 2000, coefficient matrix was calculated and factor analysis was performed on the matrix. Among 38 derived industrial clusters, 5 of them were unreported clusters, which were indistinguishable. Once these 38 industrial clusters were differentiated according to I/O table, final results of clusters were produced as I/O table was converted into KSIC (Korean Standard Industry Code). Since existing studies on industrial cluster have been focused on qualitative methods such as case studies and interviews, it is expected that this study could contribute to carry out more systematic and efficient methodology.

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On the Effective Thermal Diffusivity of Water-Protein-Fat Food System ($\cdot$단백질$\cdot$지질계(불균질계) 식품의 유효열확산율)

  • KONG Jai-Yul
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.15 no.2
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    • pp.154-160
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    • 1982
  • One dimensional unsteady heat conduction was studied on soybean curd as a water-protein-fat food system. This heterogeneous soybean curd could be treated as homogeneous material as for the unsteady heat conduction by 'effectiver' thermal diffusivity. Measurements were made with a apparatus designed and constructed by the author and also made with ice to establish the reliability, the reproducibility and the accuracy of the apparatus. It was found that the effective thermal diffusivity of soybean curd was substantially dependent on the fraction of protein and fat as well as water.

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Design Methodology of the CMOS Current Reference for a High-Speed DRAM Clocking Circuit (초고속 DRAM의 클록발생 회로를 위한 CMOS 전류원의 설계기법)

  • Kim, Dae-Jeong
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.37 no.2
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    • pp.60-68
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    • 2000
  • This paper describes a design methodology for the CMOS current source which can be implemented in standard memory process. The proposed techniques provide a good characteristic against the power-supply variation by utilizing a self-bias circuit and the reduction of the first-order component of the temperature variation through the new temperature compensation technique and include a new current-sensing start-up circuit enabling a robust operation against the voltage noise generated during the operation of the chip. In addition to the circuit-design technology, techniques where the proposed CMOS current-reference circuit can be applied to the clocking circuits of a very high-speed DRAM are presented. The feasibility of the suggested design methodology for the CMOS current reference is demonstrated by both the analytical method and the circuit simulation.

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Reliability-based Flaw Assessment of a Mooring Chain Using FORM and SORM (FORM 및 SORM을 이용한 무어링 체인의 신뢰성 기반 결함평가)

  • Lee, Choong-Hyun;Kim, Yooil
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.5
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    • pp.430-438
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    • 2017
  • This study presents the reliability-based flaw assessment for the crack in the mooring chain of a floating type offshore structure. BSI(British Standard Institution) flaw assessment procedure BS7910 was combined with first- and second-order reliability method (FORM, SORM) so that the acceptance of a given flaw can be assessed considering the uncertainties of parameters that play important role in the flaw assessment. Considering the probabilistic nature of the crack size and long-term distribution of the stresses acting on the crack in mooring chain, the failure probability was calculated using FORM and SORM. To check the validity of the FORM and SORM, Monte Carlo simulation was also carried out to derive the true limit state function and compared with the results of FORM and SORM.

Performance Analysis of Paging Channel in CDMA Cellular Network (CDMA Cellular Network에서 페이징 채널의 성능 분석)

  • 곽민곤;이규영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.12A
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    • pp.1868-1875
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    • 1999
  • The design of LAI(Local Area Identifier), the first paging area for searching the mobile terminal has a close relation with the performance of paging channel in CDMA cellular network. This paper discussed the performance of the forward channel of IS-95 CDMA standard, known as the paging through the related messages such as call control message, channel assignment message, etc. Modeling and simulation work were conducted to quantify the performance of paging channel in terms of traffic handling capacity and blocking levels. The results shown are based on a specific system call model based on the operating system of cell cite. This serves as illustrative guidelines for the proper engineering of common control channel, which has a major impact on the overall performance of cellular network.

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