• Environmental Analysis Health and Toxicology
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• 제24권3호
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• pp.231-240
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• 2009

We explored collective behaviors of indicator species to elucidate the effect of the chemical stress. After the treatments of an insecticide, diazinon, at low concentrations (1.0 and 10.0 ${\mu}g/L$), spatial dispersion patterns of Daphnia magna were checked in a test chamber. The I-index was used to characterize the movement data before (0~1 h) and after (1~2 h) the treatments in laboratory conditions. The slopes of the frequency distribution of I-index in semi-log scale decreased significantly, and the test populations appeared to be more dispersed with a lower degree of aggregation after the treatments. The index was feasible in indicating decrease in the ability of the specimens to keep desirable distances with neighbor individuals under chemical stress and showed a possibility of monitoring presence of toxic chemicals in environment through group behavior measurement.

• 생명과학회지
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• 제33권3호
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• pp.227-233
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• 2023

본 연구의 목적은 한국의 금정산 얼레지(Erythronium japonicum) 집단의 지리적 분포에 따른 공간적 분석을 기술한 것이다. 얼레지의 공간적 양상은 Neatest Neighbor Rule, 분산 척도에 의한 다양한 플롯 크기에 따른 집단 응집, 그리고 공간적 상관관계로 분석하였다. 교란된 프롯은 5 m × 5 m 내에서 응집되었다. 얼레지의 대부분 자연 플롯은 산림 군락에서 일정하게 분포되어 있었다. 얼레지의 이웃 패치는 평균 약 7.5 m 에서 10 m 사이에서 이격되어 있었다. 얼레지 자연집단이 인간의 활동으로 교란되었다면 7.5 m~10 m 거리보다 짧은 크기에서 발생한다. 패치 지표(patchiness index, PAI)에 근거한 모리시타 지표(Morisita index, IM)는 금정산 서쪽 사면은 2.5 m × 5 m 플롯이었고 남쪽사면은 5 m × 5 m 이내에 나타났다. 금정산의 서쪽에서 패치 크기가 2.5 m × 5 m 방형구일 때 클러스터는 식물이 가진 종의 특성과 환경적 요인에 의해 결정되었다. 금정산 얼레지 집단은 Moran's I 값의 비교에서 로지스트 회귀로 분석었고, 거리에 의한 격리가 각 개체의 분산에 높은 유의성을 가지고 설명되었다.

• KIEE International Transactions on Power Engineering
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• 제3A권1호
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• pp.7-16
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• 2003

A new method to evaluate the protection capability of distribution systems is reported in this paper. This work describes the fuzzy evaluation attributes and aggregation method of evaluation results based on a hierarchical model and the modified combination rule. An evaluation grade index called "protectability" is proposed and is expected to be a very uscful tool in defining an optimal protection and realizing the adaptive protection.rotection.

• 한국철도학회논문집
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• 제9권1호
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• pp.50-56
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• 2006

This paper presents a mathematical model of the long-term track tamping scheduling problem in the Korean highspeed railway system. The presented model encompasses various operational field constraints, moreover improves a state-of-the-art model in extending the feasible space. We show the model is sized up to intractable scale, then propose another approximation model that is possible to handle with the present computer system and commercial optimization package, directly. The aggregated index, lot, is selected, considering the resolution of the planning horizon as well as scheduling purpose. Lastly, this paper presents two test results for the approximation model. The results expose the approximation model to quite promising in deploying it into an operational software program for the long-term track tamping scheduling problem.

• 한국환경보건학회지
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• 제42권5호
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• pp.302-313
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• 2016

Objectives: This study was conducted to assess environmental health status on a local scale using environmental health-related indicators. It demonstrated the possibility of using a structural equation model, a methodological approach to provide synthesized information. Methods: Eighteen indicators were selected from official statistical data published by local governments. Each environmental health-related indicator was classified according to the PSR (pressure-state-response) model. Aggregation methods were performed using principal component analysis and fuzzy sets. Results: The five principal components were classified through principal component analysis (PCA) and obtained eigenvalues >1.0 from the initial 18 indicators. The aggregated index was obtained by condensing the original information into two broad and simple categories through fuzzy sets. Conclusion: This could be useful in that the aggregation procedure may provide a basis for establishing environmental health policies and a decision-making process. However, the availability and quality of indicators, assessment of aggregation method bias, choice of weighted scores for indicators, and other factors should be examined in future studies.

• Journal of Nutrition and Health
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• 제36권2호
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• pp.101-108
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• 2003

Antiplatelet aggregation, anticoagulant and lipid-lowering drugs are clinically widely used for secondary preventive purpose in the cardiovascular patients, but there is no primary preventive agents to prevent these diseases. With the aim of developing effective primary agents for cardiovascular diseases, we tried to formulate an optimized mixture of natural plants extract containing Theae sinensis, Camelliae sinensis, Vitis vinifera, Gingko folium and curcuminoids from Curcuma longa and to evaluate its anti-thrombotic and anti-hypercholesterolemic effects in vivo. The inhibitory effect of curcuminoids on vascular smooth muscle cell proliferation and migration were also investigated in vitro. in the animal experiments treated with hyperlipidemic diet, oral treatment of curcuminoids and natural plants extracts mixture (100 mg/kg) into male Sprague Dawley rats for 7 week simultaneously inhibited platelet aggregation as well as improved lipid profile in the blood. Compared to control group, both of curcuminoids-treated and mixture-treated groups revealed significantly decrease of total cholesterol (24.4%, 28.6%), free cholesterol (25.1%, 24.0%), cholesterol ester (14.6%, 29.0%), LDL-cholesterol (27.0%, 32.0%) and triglyceride (15.0%, 31.0%), respectively. However, both groups showed increase of HDL-cholesterol (46.6% and 51.5%) . In particular, atherogenic index of curcuminoids and mixture treatment group was significantly decreased to 47.0% and 56.0%, respectively. Furthermore, oral treatment of curcuminoids and mixture significantly inhibited collagen-induced platelet aggregation (21.1% and 29.1%, respectively), compared to control group. The anti-thrombotic values of mixture was almost similar to that of aspirin treatment (100 mg/kg) group. These results suggest that the oral treatment of curcuminoids-based natural plant extract mixture improved cardiovascular conditions in hyperlipidemic rats.

• 수산경영론집
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• 제54권3호
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• pp.45-67
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• 2023

The purpose of this study is to construct a regional-sector-fishery-offshore and inshore fishery competitiveness index, examine the types and changes of competitiveness, and derive implications by processing data of the Survey on the Current Status of Offshore and Inshore Fishery from 2013 to 2020 for this study. The main results of this study can be summarized as follows. First, considering the competitiveness of offshore and inshore fishery by region and year, Jeonnam, Jeju, and Incheon were relatively competitive. Second, considering the competitiveness of inshore fishery by region and year, we found that Jeonnam, Chungnam, Jeonbuk, and Jeju were relatively competitive. Third, looking at the types of competitiveness based on the competitiveness index in the management sector of offshore and inshore fisheries by region and year, Ulsan, Jeonnam, and Gyeongbuk were relatively competitive between 2014 and 2020. Fourth, Jeonnam and Jeju were relatively competitive between 2014 and 2020 based on the competitiveness index in the fishing sector of offshore and inshore fisheries by region and year. Fifth, we found that Jeonnam, Jeju, and Chungnam were relatively strong in the competitiveness of offshore and inshore fishery, combining the offshore and inshore fishery indexes by region and year. The results of this study have some limitation on outlier treatment, grade assignment, and weight for aggregation, so research considering these needs to be done in the future. In conclusion, the results of this study which were derived objectively and scientifically in the era of the 4th industrial revolution, when evidence-based decision-making was becoming critical, are expected to help the central or local governments determine the priority of support projects or investments.

• ETRI Journal
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• 제45권1호
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• pp.45-59
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• 2023

In this paper, to optimize the average delay and power allocation (PA) for system users, we propose a resource scheduling scheme for wireless networks based on Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) according to the first fifth-generation standards. For delay minimization, we solve a throughput maximization problem that considers CPOFDM systems with carrier aggregation (CA). Regarding PA, we consider an approach that involves maximizing goodput using an effective signal-to-noise ratio. An algorithm for jointly solving delay minimization through computation of required user rates and optimizing the power allocated to users is proposed to compose the resource allocation approach. In wireless network simulations, we consider a scenario with the following capabilities: CA, 256-Quadrature Amplitude Modulation, millimeter waves above 6 GHz, and a radio frame structure with 120 KHz spacing between the subcarriers. The performance of the proposed resource allocation algorithm is evaluated and compared with those of other algorithms from the literature using computational simulations in terms of various Quality of Service parameters, such as the throughput, delay, fairness index, and loss rate.

• 한국환경과학회지
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• 제30권10호
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• pp.779-787
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• 2021

This study analyzes structural landscape changes over a time-series for a small and medium-sized city, Gangneung-Si, based on area and distribution patterns, and according to the type of land cover. Among the types of land cover, the area ratio of urbanized areas increased by 2.02% in the late 2010s as compared to the late 1980s, while there was a decrease of 2.69% in farmland and 0.69% in grassland areas. On analyzing the changes in land cover use by applying the Fragstats program, it was confirmed that landscape changes in urban and management areas were relatively severe according to the Landscape Shape Index, Largest Patch Index, and Aggregation Index. A pattern of concentrated expansion was also found around certain areas. In particular, from the analysis, it was established that the proportion of urbanized area had considerably increased and that the extent of farmland damage to management areas, including planned management areas, was large. Additionally, the Total Core Area generally indicated a reduction in the core areas of farmland and forest within urban and management areas. A medium-sized city showed significant changes besides large cities in terms of landscape structure. The developmental pressure on management areas, in particular, was quite high.

• Journal of Nutrition and Health
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• 제41권5호
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• pp.381-390
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• 2008

본 실험은 콜레스테롤식이와 운동수행이란 두 조건을 심순환기 질환의 관련지표로서 혈장 및 간의 지질, 적혈구막의 Na efflux 그리고 혈소판 응집성에 어떠한 영향을 미치는지 조사하였다. 운동에 의해서 체중이 다소 감소하였지만 그렇게 크지는 않았다. 라드를 주 지방원으로 사용한 식이에 0.5% 콜레스테롤첨가는 혈중 콜레스테롤을 2배 이상, 간 콜레스테롤을 8배 이상 증가시켰고 HDL-콜레스테롤을 절반 이하로 떨어뜨렸는데, 특히 운동효과로 예상했던 HDL-콜레스테롤증가는 대조군식이나 콜레스테롤식이에서 나타나지 않았다. 혈중 중성지방은 콜레스테롤 식이군에서 오히려 감소하였고 간의 경우 지방 축척으로 인해 간의 크 기뿐만 아니라 간의 중성지방은 현저히 증가되었다. 체액량 조절 및 혈압과 관계에서 조사된 적혈구의 Na efflux는 Na-K ATPase가 콜레스테롤 식이에 의해 그 활성을 감소되었고 운동이 이를 다소 회복시키는 경향을 보였다. 혈압과의 상관성이 높다고 알려진 Na passive leak은 콜레스테롤과 운동이 각각 독립적으로 증가시키는 요인으로 작용하여 콜레스테롤-운동군이 대조군식이-비운동군에 비해 현저히 증가된 것으로 나타났다. 총 Na efflux는 실험군 간에 큰 차이가 없었고 intracellular Na와의 상관성도 보이질 않았다. 혈소판응집성에 있어서 콜레스테롤식이가 혈소판 응집을 증가시키고 특히 운동이 초기응집을 증가시키는 경향을 보였다. 혈장 GOT 및 GPT수치는 콜레스테롤식이로 인해 현저히 증가됨으로서 간의 병리적 상태를 잘 반영하였고 운동에 의해 감소됨으로서 운동수행이 술이나 고지방식으로 인한 지방간을 호전시켜 줄 수 있으리라 기대할 수 있다. 고지혈증이나 고혈압 환자에 있어서 비약물적 요법으로 식이나 운동을 통한 치료나 예방의 가능성을 규명하기 위한 실험의 결과로서 특히 운동에 대해 일관되고 가시적인 효과가 미흡한 것은 6주간의 짧은 실험기간을 생각할 수 있는데 혈청 지질, Na flux 및 체액, 혈소판 응집성 등 심순환기 질환의 예방에 도움이 되는 운동의 형태나 강도 혹은 지속 기간에 대한 더 많은 연구가 필요하리라 생각된다.