• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.804-812
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• 2011

To prevent the overflow of various harmful chemicals, it is necessary to modify the chemical management system with an expansion to institutionally regulated substances. This modification should be preceded by selection of the priority chemicals, with a diverse chemical ranking system (CRS) applied to select the chemicals in developed countries. In Korea, a systematic CRS was used in a project related to soil and groundwater, however, it is inadequate to compare soil and groundwater CRS to that of surfacewater. In this study, a priority chemical ranking system for surfacewater was proposed through the analysis of international and domestic CRS cases. This was then applied to 161 chemicals to derive the priority list of harmful chemicals. As a result, Chemical RAnking of surFacewater polluTants (CRAFT) is presented for the protection of human health and the aquatic ecosystem from surfacewater pollutants. The components of CRAFT are the human health toxicity, aquatic ecosystem toxicity and reliability assessment factors. Three lists were derived from the 161 priority harmful chemicals for the protection of human health, aquatic ecosystem or both. It is expected that this result can be useful to prioritize harmful chemicals for the protection of human health and the aquatic ecosystem from Korean surfacewater.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.3
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• pp.253-267
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• 2022

Objectives: This study was performed to check whether the CRS (Chemical Ranking and Scoring) system is appropriate as a method to determine substances as candidates for substances subject to permission and to apply this system to the selection of candidates for substances subject to permission. Methods: A risk score was obtained by multiplying the hazard score and the exposure score and then ranking them. The hazard sub-indicators are carcinogenicity, germ cell mutagenicity, reproductive toxicity, specific target organ toxicity-repeated exposure, respiratory sensitization and endocrine disrupting chemicals. Exposure sub-indicators are persistence, bioaccumulation and emission volume. Sensitivity analysis was performed for missing values. Correlation analysis and multivariable linear regression analysis were performed among hazard, exposure and risk in order to confirm that CRS was an appropriate method. Results: As a result of the sensitivity analysis on missing values, it was confirmed that the effect on the risk ranking was not sensitive. Correlation and regression analysis confirmed that exposure had a greater effect on risk than hazard. Conclusions: The CRS system, which derives a risk score using a hazard and exposure score, is judged to be appropriate as a method for the selection of preliminary of candidates for substances subject to permission. Benzene, cadmium, nickel, and cobalt were selected as priority candidates for substances subject to permission.

• Smart Media Journal
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• v.12 no.6
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• pp.35-40
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• 2023

In this study paper, we examine pre-trained language models used in Multi-Goal Conversational Recommender Systems (MG-CRS), comparing and analyzing their performances of various pre-trained language models. Specifically, we investigates the impact of the sizes of language models on the performance of MG-CRS. The study targets three types of language models - of BERT, GPT2, and BART, and measures and compares their accuracy in two tasks of 'type prediction' and 'topic prediction' on the MG-CRS dataset, DuRecDial 2.0. Experimental results show that all models demonstrated excellent performance in the type prediction task, but there were notable provide significant performance differences in performance depending on among the models or based on their sizes in the topic prediction task. Based on these findings, the study provides directions for improving the performance of MG-CRS.

• Nuclear Engineering and Technology
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• v.56 no.7
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• pp.2756-2766
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• 2024

Small rod-controlled pressurized water reactors (PWR) are the ideal energy source for vessel propulsion, benefiting from their high reactivity control efficiency. Since the control rods (CRs) increase the complexity of reactivity control, this paper seeks to study the performance of CRs in small rod-controlled PWRs to extend the lifetime and reduce power offset due to CRs. This study investigates CR grouping, move-in/out strategies, and axially non-uniform design effects on core neutron physics metrics. These metrics include axial offset (AO), core lifetime (CL), fuel utilization (FU), and radial power peaking factor (R-PPF). To simulate the movement of the CRs, a "Critical-CR-burnup" function was developed in OpenMC. In CR designs, the CRs are grouped into three banks to study the simultaneous and prioritized move-in/out strategies. The results show CL extension from 590 effective full power days (EFPDs) to 638-698 EFPDs. A lower-worth prioritized strategy minimizes AO and the extremum values decrease from -0.69 and + 0.81 to -0.28 and + 0.51. Although an axially non-uniform CR design can improve AO at the beginning of cycle (BOC), considering the overall CR worth change is crucial, as a significant decrease can adversely impact axial power distribution during the middle of cycle (MOC).

• Journal of Information Processing Systems
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• v.13 no.3
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• pp.630-642
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• 2017

In this paper, we propose the opportunistic non-orthogonal multiple access (NOMA)-based cooperative relaying system (CRS) with channel state information (CSI) available at the source, where CSI for the source-to-destination and source-to-relay links is used for opportunistic transmission. Using the CSI, for opportunistic transmission, the source instantaneously chooses between the direct transmission and the cooperative NOMA transmission. We provide an asymptotic expression for the average achievable rate of the opportunistic NOMA-based CRS under Rayleigh fading channels. We verify the asymptotic analysis through Monte Carlo simulations, and compare the average achievable rates of the opportunistic NOMA-based CRS and the conventional one for various channel powers and power allocation coefficients used for NOMA.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.240-247
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• 2005

In order to analyze effects of strain rate on consolidation characteristics on Busan clay, a series of constant rate of strain(CRS) consolidation tests with different strain rate and incremental loading test(ILT) were performed. From experimental test results, it was found that the preconsolidation pressure was dependent on the corresponding strain rate occurred during consolidation process. Also, consolidation curves normalized with respect to preconsolidation pressure gave a unique stress-strain curve. Coefficient of consolidation and permeability estimated from CRS test had a tendancy to converge to a certain value at normally consolidated range regardless of strain rate. An increase in excess pore pressure without change of total stress was noted on the incremental loading test after the end of loading.

• Proceedings of the Korea Society for Simulation Conference
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• 2004.05a
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• pp.77-82
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• 2004

자동차 공장에서의 생산스케줄은 차체공장에서부터 시작되는데 가장 이상적인 생산스케줄은 차체공장의 생산스케줄이 최종 조립라인의 조립스케줄과 동일하게 구성이 되는 것인데 차체공장, 도장공장, 조립공장의 생산 방식이 서로 다르므로 각각의 생산스케줄 목표에 맞게 투입순서를 조절해야 한다. 이를 위해서 WBS(White Body Storage), CRS(Color Rescheduling Storage), PBS(Painted Body Storage)라는 세 개의 주요 완충공간을 이용한다. 본 논문에서는 시뮬레이션 사례연구를 통하여 CRS와 PBS의 효율적인 운영을 위해 전용레인 설치를 검토하였다. 그 결과 전용레인을 설치하였을 경우 CRS에서는 그룹화비율이 감소하고, 동시에 회송차량이 증가하므로 효과적인 방법이 아님을 알 수 있었다. PBS에 전용레인을 설치한 경우에도 접근금지조건을 위반하는 차량과 회송차량이 증가하여 효율적이지 못함을 알 수 있었다.

• Journal of Auto-vehicle Safety Association
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• v.7 no.1
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• pp.13-19
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• 2015

Recently, Child safety has become one of the issue with Q10 dummy representing large child. The objective of this paper was to evaluate performance of three child restraints system (backless booster, high-back booster and without booster) by changing D-ring location in the rear seat. Sled tests were carried out with a Q 10 in 64km/h frontal impact. Before the dynamic sled tests, we assessed dummy positioning with difference in CRS types and height adjustment positions. Dynamic sled test results indicated that there is different performance of CRS types and belt routing. These test results will use as base line data for development CRS safety performance for Q 10.

• Reproductive and Developmental Biology
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• v.38 no.3
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• pp.129-136
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• 2014

This study was carried out to elucidate the effect of antibiotic-free rearing system(ARS) on cortisol level, stress hormone, and fatty acid content in the edible muscle tissues, that were of M. longissimus in Hanwoo. These cattle were reared in two different systems including antibiotic-free (ARS) and conservative system (CRS). To increase the experimental reliability, the muscle samples were purchased 3 times from 3 Korean brands of beef produced with ARS or CRS. In the muscle tissue, cortisol level was significantly lower in ARS than CRS, (p=0.0176). But the levels of total saturated- and unsaturated-fatty acids were not significantly different between ARS and CRS (p>0.05). Of total fatty acids, the total saturated fatty acid tended to be greater in CRS and the total unsaturated fatty acid tended to be greater in ARS. However, of the total unsaturated fatty acids, the level of n-6 unsaturated fatty acids was significantly higher in ARS than CRS (p=0.0040). Especially, ${\alpha}$-linolenic acid (ALA) and ${\gamma}$-linolenic acid (GLA) levels were significantly higher in ARS (p<0.01). The n-6 fatty acid content and cortisol level in muscle tissue were negatively correlated at p=0.0140. In conclusion, ARS may produce beef with higher quality which contains lower cortisol and greater n-6 fatty acids, such as ALA and GLA.

• Journal of the Korean Geotechnical Society
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• v.20 no.8
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• pp.113-121
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• 2004

The present study is suggested to estimate the degree of secondary consolidation caused by various changes of stress such as loading, unloading and reloading in improving poor subsoil through pre-compression loading construction method and, for this purpose, examined the characteristics of the consolidation of Kunsan clay through incremental loading test (IL) using standard consolidation tester and constant loading rate test (CLR), which were adapted from the constant rate of strain test (CRS). In addition, after CRS test, this study determined the characteristics of secondary consolidation and relationships among void ratio, effective stress and time according to the ratio of effective over-consolidation on reloading at the point of time of random expansion. Kunsan clay had larger expansion and smaller secondary consolidation settlement when the ratio of effective over-consolidation was high. In addition, when loading was applied after the load was removed at once, the secondary consolidation coefficient $C'_{\alpha}$ was smaller than that when the load was removed gradually, and when the ratio of effective over-consolidation was over 1.4 a similar value was produced. Based on the entire settlement resulting from reloading, the secondary consolidation coefficient $C"_{\alpha}$ increased non-linearly with the lapse of time but the final value was similar to that in the case of rapid removal. The strain velocity of void ratio was in a regular linear relationship with the increase of loading time regardless of the ratio of effective over-consolidation in both tests and it grew smaller with the increase of the ratio of effective over-consolidation.tion.