• Journal of Radiation Protection and Research
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• v.42 no.2
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• pp.130-140
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• 2017

Background: With the need for a domestic level 3 probabilistic safety assessment (PSA), it is essential to develop a Korea-specific code. Health effect assessments study radiation-induced impacts; in particular, long-term health effects are evaluated in terms of cancer risk. The objective of this study was to analyze the latest cancer risk models developed by foreign organizations and to compare the methodology of how they were developed. This paper also provides suggestions regarding the development of Korean cancer risk models. Materials and Methods: A review of cancer risk models was carried out targeting the latest models: the NUREG model (1993), the BEIR VII model (2006), the UNSCEAR model (2006), the ICRP 103 model (2007), and the U.S. EPA model (2011). The methodology of how each model was developed is explained, and the cancer sites, dose and dose rate effectiveness factor (DDREF) and mathematical models are also described in the sections presenting differences among the models. Results and Discussion: The NUREG model was developed by assuming that the risk was proportional to the risk coefficient and dose, while the BEIR VII, UNSCEAR, ICRP, and U.S. EPA models were derived from epidemiological data, principally from Japanese atomic bomb survivors. The risk coefficient does not consider individual characteristics, as the values were calculated in terms of population-averaged cancer risk per unit dose. However, the models derived by epidemiological data are a function of sex, exposure age, and attained age of the exposed individual. Moreover, the methodologies can be used to apply the latest epidemiological data. Therefore, methodologies using epidemiological data should be considered first for developing a Korean cancer risk model, and the cancer sites and DDREF should also be determined based on Korea-specific studies.

• Nuclear Engineering and Technology
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• v.47 no.5
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• pp.523-533
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• 2015

Three-dimensional flow phenomena in a wire-wrapped 37-pin fuel assembly mock-up of a Japanese loop-type sodium-cooled fast reactor, Monju, were investigated with a numerical analysis using a general-purpose commercial computational fluid dynamics code, CFX. Complicated and vortical flow phenomena in the wire-wrapped 37-pin fuel assembly were captured by a Reynolds-averaged Navier-Stokes flow simulation using a shear stress transport turbulence model. The main purpose of the current study is to understand the three-dimensional complex flow phenomena in a wire-wrapped fuel assembly to support the license issue for the core design. Computational fluid dynamics results show good agreement with friction factor correlation models. The secondary flow in the corner and edge subchannels is much stronger than that in an interior subchannel. The axial velocity averaged in the corner and edge subchannels is higher than that averaged in the interior subchannels. Three-dimensional multiscale vortex structures start to be formed by an interaction between secondary flows around each wire-wrapped pin. Behavior of the large-scale vortex structures in the corner and edge subchannels is closely related to the relative position between the hexagonal duct wall and the helically wrapped wire spacer. The small-scale vortex is axially developed in the interior subchannels. Furthermore, a driving force on each wire spacer surface is closely related to the relative position between the hexagonal duct wall and the wire spacer.

• Journal of the Korean Institute of Educational Facilities
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• v.24 no.4
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• pp.15-24
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• 2017

This paper aims to investigate in what extent subject-centered clusters are different from one another in terms of message system, which is composed of curriculum, pedagogy and evaluation. For this, Bernstein's pedagogic transmission code(i.e., classification and framing) and school typology(i.e., open-type or close-type) have been explored, and then applied into Shimin Junior School, Japan, in order to find out substantial characteristics between subject-centered clusters. In this case study, VGA(visibility graph analysis), as one of syntactical methodologies in space syntax theory, has been used to measure to what degree they are actually different. Throughout in-depth investigation of spatial configurations, it can be said that the square of clusters is strongly connected and integrated very well, so that it acts as an anchor place for school life within a cluster. However, it works in different ways according to message systems. In the subjects like Japanese and Science whose message system are characterized by strong classification and strong framing, integration values are relatively low, and this means that it is hard to expect cross-referencing activities through the subject squares. On the contrary, the subject of Social Studies defined by weak classification and weak framing shows the highest mean integration values, and this can be expected that there are inter-changeable learning activities in the square.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.12-17
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• 2014

With a rapid growth of domestic industry in korea, now about 25,000 kinds of chemicals are being distributed, and it has been known that just about 15% of them has toxic substances. Recently, South Koreans have an anxiety about the stability and accidents of chemicals because chemical accidents like Gumi hydrofluoric acid accident have occurred. The U.S. has adopted the systems like EPCRA (Emergency Planning and Community Right-to-Know Act), TRI (Toxic Release Inventory) and TSCA (Toxic Substances Control Act), and is also managing the hazardous chemicals by providing the information about them to its people and site workers. Japan's Ministry of Health, Labor and Welfare also has adopted J-CHECK system and is implementing it to let Japanese people know the information of safety of chemicals about REACH. However, the Korean government has a difficult situation to mediate the different idea with the Korean industry to make lower statute of Pre-legislation registration & evaluation of chemicals that will be implemented and Chemical Material Control Association that is being implemented. Especially city and country areas located in the industrial areas need political improvement focusing on vulnerable area through the check about current situation of hazardous chemicals of jurisdiction and management method, but the information about the management situation of small scale work places is insufficient. Therefore this study set up the urgent management area in Ansan Smart Hub through NFPA code according to the types of accident and dander characteristics of each chemical being used in the companies that have less than 50 workers and deal with chemicals located in Ansan Smart Hub in Gyeonggi-do.

• (The)Study of the Eastern Classic
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• no.37
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• pp.63-91
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• 2009

This study presents an investigation into the Sahyang process and activities of the individuals whose Sahyang(receiving Gwanhyang from the king) was confirmed in the Shilrok documents of early Chosun among naturalized citizens(Hyanghwains). In early Chosun, there were four Chinese(Oh Jin, Lee Min-do, Dang Seong, and Mae Woo) in the Sahyang cases with more of those cases found among Hoigol-in(Seol Jang-soo, an Uighur) and Oioa-guk nationality(Lee Hyeon) from the countries bordering on Western China and two Japanese(Pyeong Sun and Pi Sang-ui). They were naturalized from the reign of King Chungryeol of Goryeo to the first year of King Jeongjong's reign of Chosun. They were diverse to include the great grandfather, grandfather, and father of the individual that received Gwanhyang and himself. There were one case of Sahyang during the reign of King Taejo, four during the reign of King Taejong, one during the reign of King Sejong, and three during the reign of King Sejo. The Gwanhyang they received was wide spread across the nation including Gyerim, Imju, Haeju, Sangju, Milyang, Chungju, Changwon, Dongrae, and Taean. It's very likely that the place of Sahyang was Cheohyang. Many of those who received Gwanhyang were translators and achieved great feats in Chosun's diplomacy with Ming Dynasty and Japan. There were also those who worked in medicine, art of divination, and articles of a criminal code. Seol Jang-su, who passed the state exam of Chosun, was in charge of Jigonggeo, and Lee Min-do and Dang Seong made a contribution to the establishment of Chosun and became big or small meritorious retainers at the founding of Chosun. It's all thanks to those performances that they had the honor of Sahyang of receiving Gwanhyang. Although they were the Gwanhyang with the honor of Sahyang, there is no confirmation of the descendents of the Lee family of Imju, the Pyeong family of Changwon, and the Pi family of Dongrae. While the descendents of the naturalized Chinese still remain in the nation, those of naturalized Japanese ceased to exist, which must be closely related to Chosun's perceptions of other nations those days.

• Toxicological Research
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• v.32 no.3
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• pp.195-205
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• 2016

This study was performed to select single nucleotide polymorphisms (SNPs) related to the body burden of heavy metals in Koreans, to provide Korean allele frequencies of selected SNPs, and to assess the difference in allele frequencies with other ethnicities. The candidate-gene approach method and genome-wide association screening were used to select SNPs related to the body burden of heavy metals. Genotyping analysis of the final 192 SNPs selected was performed on 1,483 subjects using the VeraCode Goldengate assay. Allele frequencies differences and genetic differentiations between the Korean population and Chinese (CHB), Japanese (JPT), Caucasian (CEU), and African (YIR) populations were tested by Fisher's exact test and fixation index ($F_{ST}$), respectively. The Korean population was genetically similar to the CHB and JPT populations ($F_{ST}$ < 0.05, for all SNPs in both populations). However, a significant difference in the allele frequencies between the Korean and CEU and YIR populations were observed in 99 SNPs (60.7%) and 120 SNPs (73.6%), respectively. Ten (6.1%) and 26 (16.0%) SNPs had genetic differentiation ($F_{ST}$ > 0.05) among the Korean-CEU and Korean-YIR comparisons, respectively. The SNP with the largest $F_{ST}$ value between the Korean and African populations was cystathionine-${\beta}$-synthase rs234709 ($F_{ST}$: KOR-YIR, 0.309; KOR-CEU, 0.064). Our study suggests that interethnic differences exist in SNPs associated with heavy metals of Koreans, and it should be considered in future studies that address ethnic differences in heavy-metal concentrations in the body and genetic susceptibility to the body burden of heavy metals.

• Journal of Nutrition and Health
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• v.46 no.3
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• pp.226-238
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• 2013

Omega-3 polyunsaturated fatty acids are essential fatty acids because humans cannot synthesize them de novo and must obtain them in their diet. Fish and fish oil are rich sources of omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Significant evidence of the beneficial role of dietary intake of omega-3 fatty acids in blood flow has been reported and putative mechanisms for improvement of blood flow include anti-thrombotic effects, lowered blood pressure, improved endothelial function, and anti-atherogenic effects. Edible oils containing omega-3 fatty acids were registered as functional ingredients in the Korea Health Functional Food Code. Although omega-3 fatty acids have been evaluated by the Korea Food and Drug Administration (KFDA) based on scientific evidence, periodic re-evaluation may be needed because emerging data related to omega-3 fatty acids have accumulated. Therefore, in this study, we re-evaluated scientific evidence for the effect of omega-3 fatty acids as a functional ingredient in health functional food on improvement of blood flow. A comprehensive literature search was conducted for collection of relevant human studies using the Medline and Cochrane, KISS, and IBIDS databases for the years 1955-2012. Search keywords were used by combination of terms related to omega-3 fatty acids and blood flow. The search was limited to human studies published in Korean, English, and Japanese. Using the KFDA's evidence based evaluation system for scientific evaluation of health claims, 112 human studies were identified and reviewed in order to evaluate the strength of the evidence supporting a relation between omega-3 fatty acids and blood flow. Among 112 studies, significant effects on improvement of blood flow were reported in 84 studies and the daily intake amount was ranged from 0.1 to 15 g. According to this methodology of systematic review, we concluded that there was possible evidence to support a relation between omega-3 fatty acid intake and blood flow. However, because inconsistent results have recently been reported, future studies should be monitored.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4A
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• pp.475-485
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• 2008

This paper intends to enhance the reliability and performance of domestic elastomeric bearings through the proposal of directions for the improvement of their stiffness regard to the Korean industrial standard KS F 4420 relative to the evaluation of design/fabrication/quality. Therefore, comparative analysis of the compressive elastic modulus, stiffness measurement method and performance evaluation method of KS F 4420 with those of Eurocode, Japanese bearing manual, and ISO code was performed, and measurement tests on the compressive stiffness and shear stiffness of common elastomeric bearings produced in Korea were conducted. The experimental results reveal that differences of about 20% and 13% occurred respectively for the compressive stiffness and shear stiffness according to the definition adopted for the stiffness. The measured values for the stiffness of the domestic elastomeric bearings were also verified to exhibit large deviation from the formula proposed by KS F 4420. Elastomeric bearings that does not have appropriate compressive stiffness required at the design can result in uneven deflection at supports of bridges and excessive stress in girders. Accordingly, the establishment of compressive elastic modulus formula and performance evaluation criteria fitted to the domestic circumstances through the execution of performance evaluation of bearings presenting diversified shapes and shape factors appears to be necessary for the domestic bearings to meet the performance required in design.

• Journal of Food Hygiene and Safety
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• v.20 no.3
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• pp.134-140
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• 2005

Boiling point and distillation range, melting range, and identification methods in general test method of Korea, Japan, Joint FAO/WHO Expert Committee of Food Additives (JECFA), and USA on chemical food additives were compared. Boiling point of propylene glycol was indicated as boiling point in Korea, distillate in Japan, distillation range in JECFA and USA, and its value was up to the standard. Distillation range of propionic acid was indicated as distillate in Korea and Japan, distillation range in JECFA and USA, and its value was up to the standard. There is no standard on distillation range of isopropyl alcohol in Japanese method. Test method of melting range on synthetic food additives was identical in all organizations, and there are 28 items to which this test method applies in Korean Food Additives Code. The standards on molting range of D-mannitol were different in various organizations, and in USA method there are no standards to which L-ascorbic acid, calciferol, and fumaric acid apply. Synthetic food additives performing the identification test were 251 items in Korean Food Additives Code, but there are no items to which manganese, glycerophosphate, bromate, thiosulfate, and bromide apply. Calcium benzoate was dissolved by heating in benzoate test and we could not identify the citrate in ferric citrate by method (2) of Korea and Japan. Identification test methods for ammonium, lactate, magnesium, copper, sulfate, phosphate, and zinc were identical in all organizations, and these could be identifed by current identification methods.

• Computational Structural Engineering
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• v.7 no.3
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• pp.95-103
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• 1994

The safety related components in the nuclear power plant should be designed to withstand the seismic load. Among these components the integrity of reactor internals under earthquake load is important in stand points of safety and economics, because these are classified to Seismic Class I components. So far the modelling methods of reactor internals have been investigated by many authors. In this paper, the dynamic behaviour of reactor internals of Yong Gwang 1&2 nuclear power plants under SSE(Safe Shutdown Earthquake) load is analyzed by using of the simpled Global Beam Model. For this, as a first step, the characteristic analysis of reactor internal components are performed by using of the finite element code ANSYS. And the Global Beam Model for reactor internals which includes beam elements, nonlinear impact springs which have gaps in upper and lower positions, and hydrodynamical couplings which simulate the fluid-filled cylinders of reactor vessel and core barrel structures is established. And for the exciting external force the response spectrum which is applied to reactor support is converted to the time history input. With this excitation and the model the dynamic behaviour of reactor internals is obtained. As the results, the structural integrity of reactor internal components under seismic excitation is verified and the input for the detailed duel assembly series model could be obtained. And the simplicity and effectiveness of Global Beam Model and the economics of the explicit Runge-Kutta-Gills algorithm in impact problem of high frequency interface components are confirmed.