• Journal of Environmental Health Sciences
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• v.45 no.5
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• pp.443-456
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• 2019

Objectives: Children are exposed to various environmental pollutants through contact with children's products. We investigated the KC mark, certification number, and contained substances labeled on children's products through market research and collected the toxicological data on these substances. Methods: The environmentally hazardous substances labeled on children's products (n=6576), including toys (n=2812), personal care products (n=2212), stationary/books (n=1333), and playground equipment (n=219) were examined. For the components that could be identified by CAS number, toxicological data on oral, inhalation, and dermal routes, cancer slope factor, and reference dose were collected. Results: Among the investigated products, KC marks or certification numbers were found for 4557 products (69.3%). Except for cosmetics and cleansers, the material information was labeled on most of the products. The frequency of labeling substance information in toys and stationary/books was low since this information could be omitted if KC certification was obtained. In the target products, 617 substances were identified by CAS number, and polypropylene, acrylonitrile butadiene styrene, and polyester were the most frequently displayed. Chronic toxicity data was found for only 32.4% of individual components, and information on toxicity through the dermal route was also highly limited. Conclusion: Our study suggested that labeling guidelines should be required to identify the environmentally hazardous substances contained in children's products. In addition, the toxicological data on many ingredients in children's products were insufficient. The data gap for toxicity data should be filled for future risk assessment.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3732-3753
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• 2023

The Real-time Analysis for Particle-transport and In-situ Detection (RAPID) Code System, developed based on the Multi-stage Response-function Transport (MRT) methodology, enables real-time simulation of nuclear systems such as reactor cores, spent nuclear fuel pools and casks, and sub-critical facilities. This paper presents the application of a novel fission matrix-based burnup methodology to the well-characterized JSI TRIGA Mark II research reactor. This methodology allows for calculation of nuclear fuel depletion by combination and interpolation of RAPID's burnup dependent fission matrix (FM) coefficients to take into account core changes due to burnup. The methodology is compared to experimentally validated Serpent-2 Monte Carlo depletion calculations. The results show that the burnup methodology for RAPID (bRAPID) implemented into RAPID is capable of accurately calculating the k_eff burnup changes of the reactor core as the average discrepancies throughout the whole burnup interval are 37 pcm. Furthermore, capability of accurately describing 3D fission source distribution changes with burnup is demonstrated by having less than 1% relative discrepancies compared to Serpent-2. Good agreement is observed for axially and pin-wise dependent fuel burnup and nuclear fuel nuclide composition as a function of burnup. It is demonstrated that bRAPID accurately describes burnup in areas with high gradients of neutron flux (e.g. vicinity of control rods). Observed discrepancies for some isotopes are explained by analyzing the neutron spectrum. This paper presents a powerful depletion calculation tool that is capable of characterization of spent nuclear fuel on the fly while the reactor is in operation.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1165-1203
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• 2024

In the paper we validate theoretical models of the pulse against experimental data from the Jozef Stefan Institute TRIGA Mark II research reactor. Data from all pulse experiments since 1991 have been collected, analysed and are publicly available. This paper summarizes the validation study, which is focused on the comparison between experimental values, theoretical predictions (Fuchs-Hansen and Nordheim-Fuchs models) and calculation using computational program Improved Pulse Model. The results show that the theoretical models predicts higher maximum power but lower total released energy, full width at half maximum and the time when the maximum power is reached is shorter, compared to Improved Pulse Model. We evaluate the uncertainties in pulse physical parameters (maximum power, total released energy and full width at half maximum) due to uncertainties in reactor physical parameters (inserted reactivity, delayed neutron fraction, prompt neutron lifetime and effective temperature reactivity coefficient of fuel). It is found that taking into account overestimated correlation of reactor physical parameters does not significantly affect the estimated uncertainties of pulse physical parameters. The relative uncertainties of pulse physical parameters decrease with increasing inserted reactivity. If all reactor physical parameters feature an uncorrelated uncertainty of 10 % the estimated total uncertainty in peak pulse power at 3 $ inserted reactivity is 59 %, where significant contributions come from uncertainties in prompt neutron lifetime and effective temperature reactivity coefficient of fuel. In addition we analyse contribution of two physical mechanisms (Doppler broadening of resonances and neutron spectrum shift) that contribute to the temperature reactivity coefficient of fuel. The Doppler effect contributes around 30 %-15 % while the rest is due to the thermal spectrum hardening for a temperature range between 300 K and 800 K.

• Economic and Environmental Geology
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• v.48 no.3
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• pp.205-212
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• 2015

We have verified applicability of UAV(Unmanned Aerial Vehicle) photogrammetry to a mining engineering. The test mine is a smectite mine located at Gyeongju city in Gyeongnam province, Koera. 448 photos over area of $600m{\times}380m$ were taken with overlapped manner using Cannon Mark VI equipped to multicopter DJI S1000, which were processed with AgiSoft Photoscan software to generate orthophoto and DEM model of the study area. photogrammetry data with 10 cm resolution were generated using 6 ground control positions, which were exported to the 3D geological modeling software to make a topographic surface object. Monitoring of amount of ore production and landsliding could be done with less than 1 hours photographing as well as low cost. A direct link between UAV photogrammetry and 3D geological modeling technology might increase productivity of a mine due to appling the topographical surface change immediately according to the mining operation.

• Journal of Food Hygiene and Safety
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• v.17 no.3
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• pp.129-136
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• 2002

This study was conducted to Provide basic information Promoting egg qualify improvement and hygienic control by grasping of present market egg distribution system and hygienic quality. The eggs of 57 brands collected from the department food stores in Incheon Metropolitan City were examined. Eggs were kept in room temperature in all the market and 70.2% of the brands were marked the expiration date indicating that eggs would be available over 28 days after being laid. Fifty-four % of the market eggs was classified as a special or functional egg. Expiration date and date of laying were common labelling items in all brands. These items were labelled in trade mark sheet or eggs tray. Only 66.6% of the brands had the mark about net quantity of contents. The inspection about the exterior and contents of eggs has results as follows: eggshell contamination of feces and feather-9.5%, abnormal and broken eggshell -3.9%, blood and meat spots in contents -14.7% and watery whites -1.8%. Average of Haugh Unit(HU) was 56.1 and below HU 31 were 18 of 285 eggs(6.3%), in addition, more than one egg detected in 12 brands(21.1%) among 57 brands have inferior quality. Salmonella enteritidis from eggshell and antibodies directed from S. enteritidis in the yolks of eggs available in the market were not detected. Ranges of Total bacterial count (CFU/ml) on eggshell of eggs were < 10~8.2$\times$10$_3$, and isolation ratio of Escherichia coli were 4.7%. Tetracyclines were detected in 1.8% of the eggs(1 of57 brands) by CHARMII. As mentioned above, quality control and improving distribution system were required to facilitate egg consumption and improve public health by complementing labelling items and quality standards.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.282-285
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• 2009

Nanostructured OLED light extraction films have been made via roll-to-roll coating processes. Their on-axis and integrated outcoupling efficiencies reach 2X and 1.3-1.8X, respectively. Optical performance and effects of the nanostructured film on pixel blur and image ghosting will be discussed.

• Transactions of the Korean hydrogen and new energy society
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• v.17 no.4
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• pp.353-361
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• 2006

As one of the thermochemical water splitting hydrogen production cycles, which could be operated at the lower temperature below 1200 K, we investigated the feasibility of the cyclic operation of Ispra Mark 2 cycle with the addition of $ZrO_2$. The cycle is theoretically composed of three reaction steps; (1) 1st step($2MnO_2{\rightarrow}Mn_2O_3+0.5O_2$), (2) 2nd step($Mn_2O_3+4NaOH{\rightarrow}2Na_2O{\cdot}MnO_2+H_2+H_2O$) and (3) 3rd step($2Na_2O{\cdot}MnO_2H_2O{\rightarrow}4NaOH+2MnO_2$). From the TPR tests, the temperature ranges for $O_2$ production in 1st step and $H_2$ production in 2nd step were $550{\sim}750^{\circ}C$ and $650{\sim}750^{\circ}C$, respectively. In $MnO_2/Mn_2O_3/NaOH$ system, the formation of molten products due to the reaction between manganese oxides and NaOH were greatly decreased with the addition of $ZrO_2$. In addition, the results of a cyclic test were discussed with the viewpoint of $H_2$ production amounts and the feasibility of the process improvement.

• The Korean Journal of Emergency Medical Services
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• v.7 no.1
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• pp.81-94
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• 2003

This study tries to examine the level of safety consciousness and first aid knowledge of 124 college students who attend non-public health departments in Gwangju from April 1 to 30, 2003 and apply the results of the study to curriculum. The results of this study are as follows; 1. On experiences of need of first-aid, 87.5% of respondents said 'yes' and there was a significant difference in the number of their siblings($x^2$ = 7.482, p = .048). 2. Sources of education of first aid were mostly at school(46.8%), no education(23.4%), through mass communication(22.6%) and by themselves(7.3%). There were significant differences by characteristics in sex($x^2$ = 30.230, p = .000), year($x^2$ = 10.821, p = .013) and mother's education($x^2$ = 18.932, p = .025). 3. Sources of information of first aid were mostly through TV(46.8%), followed by others (42.7%), newspapers(7.3%) and magazines(3.2%). 4. On the opinions of the most suitable period for educating first aid, elementary school was highest(41.9%), followed by kindergarten(29.0%), middle school(21.0%) and high school (8.1%) and there were significant difference by characteristics of subjects in sex($x^2$=9.689, p= .021) and year($x^2$=19.661, p= .000). 5. Score of knowledge level of safety consciousness was mean $71.58{\pm}12.05$ based on Likert 5-point scale with a full mark of 100 points and there was a significance only in current residence of subjects' general characteristics(F or t=3.894, p=.023). 6. Score of knowledge level of first aid was mean $62.73{\pm}13.29$ based on Likert 3-point scale with a full mark of 90 points and there was a significance only in residential type of subjects' general characteristics(F or t=3.058, p= .031). Although college students felt needs of first aid more than middle and high school students, it was found that their actual safety consciousness and knowledge level of first aid were low. Therefore, knowledge and ability should be developed to save human life from all kinds of emergencies and safety accident and first aid subjects should be separated in college curriculum and opportunity for actual education should be given.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.4
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• pp.1-12
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• 2008

The aim of this study is to investigate the sensitivity evaluation of human beings in reacting to the correlated color temperature of the optical properties of white LED lighting. For the sake of this study, white light-emitting diode modules have been fabricated their correlated color temperature have been measured, test cabinets for the sensitivity evaluation have been constructed with the white LED modules, and their sensitivity reactions on the test cabinets have been evaluated and analyzed. The sensitivity reaction has been evaluated by the semantic differential method with 15 selected questions, and the reliability and the content validity of their lighting have been analyzed to 3 factors which foe the activity as the first factor, the stability as the second one, the potency as the third one, respectively. For the data analysis on the sensitivity reaction, the dependent variable is the score of the sensitivity evaluation and the independent one is the correlated color temperature of the test module. The results of this study is as follows: In the case of the sensitive evaluation on the activity and the potency in the white LED lighting compared with the fluorescent lamp, the subjects have made higher mark on $MA_3$ with 8,300[K], and in the factor of the stability, they have made higher mark on $MA_1$ with 3,800[K].

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.632-634
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• 1999

현재는 HTML(Hypertext MarkUp Language) 기반의 웹 페이지가 가장 널리 사용되고 있다. 그러나 사용자의 요구는 갈수록 높아져 2차원의 HTML로서는 표현하지 못하는 3차원 세계의 구현을 갈구하고 있다. 그래서 탄생한 것이 VRML(Virtual Reality Modeling Language)이며 현재 ISO 표준안으로 지정되어 있다. 사용자는 VRML로서 3차원 세계를 구현할 수 있지만, 가상세계의 규모가 커지고 복잡해지면서 문서편집기만으로 구축하기는 거의 불가능하다. 이런 이유로, 기존의 저작도구가 출현하게 되었고, 사용자에게 많은 편이를 제공하였다. 하지만, 이것 역시 몇 가지 문제점 (객체 설계 능력, VRML에 관한 지식 숙지, 일반 사용자에게 부담되는 비용) 때문에 VRML의 대중화를 방해되는 요소로 작용하고 있다. 그러므로 앞에서 제시한 문제점을 개선하기 위해, 사용자가 복잡한 가상객체를 디자인하는 것이 아니라 웹에서 이미 디자인된 객체와 개인자료를 합성하게 함으로써 일반 사용자에게 부담을 크게 줄일 수 있는 새로운 방법으로 개발했다. 그러므로, 본 논문은 인터넷 사용자라면 누구나 쉽게 가상공간을 제작할 수 있는 웹 기반의 저작도구인 WVRAT(Web based Virtual Reality Authoring Tool)의 설계 및 구현에 대해 기술한다.