• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.1
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• pp.1-8
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• 2007

Environment factors related to the distribution of organic matter in surface seawater and sediments were investigated to estimate main pollution sources and range of their influence in Gwangyang Bay. The main pollution sources for the factors that affect organic matter distribution could be divided into three main sources: fresh water runoffs from Seomjin and Dong River, Gwangyang-si domestic sewage, and Yosu Industrial Complex. Considering the characteristics in horizontal distributions of the environmental factors in water column, sediment, and water current regime, the influencing range of these main sources was likely to be divided into three areas within the bay as follows: Area I receiving lots of fresh water from Seomjin River, Area II receiving lots of domestic sewage from Gwangyang-si and fresh water of Dong River, Area III receiving lots of materials from Yosu Industrial Complex. Area I seems to be characterized as low salinity, high concentration of $NO_3-N,\;and\;SiO_2-Si$, Area II as low salinity, high concentration of $NO_3-N,\;NH_4-N,\;and\;SiO_2-Si$, and Area III as high water temperature, high concentration of $NH_4-N,\;and\;PO_4-P$ in water column, high concentration of $NH_4-N,\;PO_4-P,\;and\;SiO_2-Si$ in surface sediments.

• Parasites, Hosts and Diseases
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• v.53 no.5
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• pp.611-618
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• 2015

This study describes the first record of Globocephalus samoensis (Nematoda: Ancylostomatidae) recovered in wild boars from southwestern regions of Korea. Gastrointestinal tracts of 111 Korean wild boars (Sus scrofa coreanus) hunted from mountains in Suncheon-si, Gwangyang-si, and Boseong-gun between 2009 and 2012 were examined for their visceral helminths. G. samoensis, as identified by morphological characteristics of the head and tail, were recovered from the small intestine of 51 (45.9%) wild boars. Worms were found from 7 of 28 wild boars (25.0%) from Suncheon-si, 40 of 79 (50.6%) from Gwangyang-si, and all 4 (100%) from Boseong-gun. The length of adult females was $7.2{\pm}0.5mm$, and the thickest part of the body measured the average $0.47{\pm}0.03mm$, while those of males were $6.52{\pm}0.19$ and $0.37{\pm}0.02mm$, respectively. The buccal cavity was equipped with a pair of large and bicuspid subventral lancets near the base of the capsule. The average length of spicules of males was $0.45{\pm}0.02mm$. By the present study, G. samoensis is recorded for the first time in southwestern regions of Korea. Additionally, morphological characteristics and identification keys provided in the present study will be helpful in the faunistic and taxonomic studies for strongylid nematodes in both domestic and wild pigs. The infection of G. samoensis apparently did not elicit pathologic lesions, as revealed by macroscopic observation during the autopsy of all wild boars in this study.

• Ocean and Polar Research
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• v.33 no.2
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• pp.99-111
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• 2011

To estimate the effects of limitation nutrients for phytoplankton growth and its influences on short-term variations of a winter phytoplankton community structure, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas from 6 to 7 February in Gwangyang Bay, Korea. Also, several algal bio-assay studies were conducted to identify any additional nutrient effects on phytoplankton assemblage using surface water for the assay. The dominant species in the bay was diatom Skeletonema costatum, which occupied more than 70% of total species in most stations (St.1-16) of the inner bay. According to a cluster and multidimensional scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western parts of Myodo lsland, which can be characterized as a semien-closed eutrophic area with high phytoplankton abundance. The second group included most stations from the north-eastern part of Myodo lsland, influenced indirectly by surface water currents from offshore of the bay. The standing phytoplankton crops were lower than those of the first group. The other cluster was restricted to samples collected from offshore of the bay. In the bay, silicon (Si) and phosphorus (P) were not a major limiting factor for phytoplankton production. However, since the DIN: DIP and DSi: DIN ratios clearly demonstrated that there were potential stoichiometric N limitations, nitrogen (N) was considered as a limiting factor. Based on the algal bio-assay, in vivo fluorescence values in N (+) added experiments were higher compared to control and P added experiments. Our results suggested that nitrogen may act as one of the most important factors in controlling primary production during winter in Gwangyang Bay.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.310-319
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• 2013

The genetic diversity and structure of eight populations of Coreanomecon hylomeconoides Nakai, an endemic Korean plant, were investigated using 50 ISSR loci from eight primers. The average percentage of polymorphic loci was 47.3%. The Shannon's index (SI=0.218) and gene diversity (h=0.142) were relatively lower than those of other long-lived perennials. The Sancheong (SI=0.233, h=0153), Gwangyang (SI=0.263, h=0.171), and Suncheon (SI=0.241, h=0.159) populations showed greater genetic diversity than the Namhae and Gwangju populations, which are on the edge of the distribution. Analysis of molecular variance (AMOVA) showed that 18% of the total variation could be attributed to differences among populations, and 82% to differences within populations, indicating moderate gene flow among adjacent populations. These results were supported by value of Nm (2.184). The UPGMA conducted using the genetic distance and Bayesian cluster analysis showed a remarkable geographic trend structured into east and west regions. Overall, the results indicate that the Sancheong and Gwangyang populations, which had a large population size and higher degree of genetic diversity, should be the focus of in situ conservation.

• Journal of Korean Society of Forest Science
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• v.95 no.2
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• pp.220-231
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• 2006

The study was conducted to investigate the differences in carbon storage of Quercus mongolica stands with respect to latitude and altitude in Korea. Study sites were located in Mt. Joongwang, Pyeongchang-gun, Gangwon-do (altitudes 1,300 m, 1,000 m, and 800 m), Mt. Taehwa, Gwangju-si, Gyeonggi-do (altitude 350 m), Mt. Wolak, lecheon-si, Chungcheongbuk-do (altitude 300 m), Mt. Baekwoon, Gwangyang-si, Jeollanam-do (altitude 800 m), and Mt. Halla, Jeju-do (altitude 1,000 m). Total carbon storage and annual carbon storage of Q. mongolica stands were 85-210 tonC/ha and 7.2-10.6 tonC/ha, respectively. Lower latitude (NE) stands of Q. mongolica showed more carbon storage and annual carbon storage than higher latitude stands. Carbon storage and annual carbon storage of Q. mongolica stands were increased in low altitude. Carbon storage of Q. mongolica stands was higher in the northern aspect than in the southern aspect. However, there were no significant differences in annual carbon storage between the aspects.

• Journal of the Korea Society of Computer and Information
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• v.28 no.10
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• pp.247-256
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• 2023

This study was conducted with the purpose of suggesting alternatives for the efficient operation of senior day care facilities in 22 cities and counties in the Jeonnam region by analyzing the efficiency of senior day care facilities. The analysis data for the study used the National Health Insurance Corporation's long-term care insurance for the elderly (2022), the Input variables were the number of facilities, the number of workers, the number of affordable, and the number of senior long-term care insurance recipients and the Output variables were the the number of users. As a result of the analysis, CCR was most efficient in Goheung-gun, Gokseong-gun, Gwangyang-si, Boseong-gun, Yeongam-gun, and Jindo-gun, BCC was most efficient in Goheung-gun, Gokseong-gun, Gwangyang-si, Gurye-gun, Damyang-gun, Boseong-gun, and Jindo-gun, and SE was most efficient in that order: Jindo-gun, Gokseong-gun, and Gwangyang-si. It turned out to be a super efficient area. In the contribution analysis, the number of affordable and workers variables were found to be variables that had a large impact on efficiency contribution. In the improvement potential analysis, the number of facilities variable was found to be a variable that had a significant impact on efficiency. Therefore, for the efficient operation of senior day care facilities, we suggest adjusting supply and demand, such as the number of facilities and affordable, and suggest that training programs to strengthen the expertise of workers who contribute greatly are required.

• Resources Recycling
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• v.26 no.6
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• pp.45-49
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• 2017

Most Waste slurry is produced in the process of silicon manufacturing for semiconductor industry, containing silicon (Si) and silicon carbide (SiC). Waste slurry is simply stored with solidifying by cement or buried. On the other hand, it was suggested in this study that the waste slurry should be used for heating source as supplementary material in steel making process. The waste slurry was refined and pulverized, which was recycled into SiC-based sludge briquette. Chemical composition for SiC-based sludge briquette was analyzed and the feature of heating source was observed in accordance with the injection time and input amount. As a result, SiC-based sludge briquette in terms of low cost and high efficiency had an effect on increasing liquid steel temperature in steel making plants.

• Journal of Navigation and Port Research
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• v.39 no.5
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• pp.423-429
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• 2015

The expansion on the scale of international trade and rapid economic growth in Northeast Asia have caused intense competition among global companies for securing international logistics center in Northeast Asia. Analyzing location competitiveness for international logistics center in Northeast Asia, this paper aims to extract implications for enhancing locational competitiveness. Employing the relative importance among location selection factors extracted from AHP analysis in prior study, we evaluated the major five port-cities in Northeast Asia including Busan, Gwangyang, Shanghai, Qingdao and Tokyo. In the evaluations, Shanghai (3.926) ranked as the first, followed by Busan (3.859), Qingdao (3.555), Tokyo (3.013) and Gwangyang (2.915). Furthermore, the causal relationships between determinants for location choice decision (logistics factor, cost factor, market factor, service factor and environmental factor) and dependent variables (competitiveness of international logistics center, potentiality to growth, present intention to move into and future plan to move into) were analyzed to provide implications. Results provide useful insights for further improvements, and helps strategic agenda for future development of port-cities.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.45-45
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• 2009

원가 측면에서 유리한 저항점용접(Resistance Spot Welding)이 차체 용접에 80%이상으로 가장 많이 적용되고 있다. 첨단고강도강(Advanced High Strength Steel)의 저항점용접성 및 용접부 특성에 미치는 공정 변수의 영향에 대한 연구결과는 많으나, 합금원소의 영향에 대해서는 전무하다. 특히, Si는 DP(Dual Phase)강에 첨가 시 균일한 마르텐사이트의 분포를 촉진하는 원소로 저항 점용접성 및 용접부 특성에 영향을 미칠 것으로 예상되며, 이에 대한 연구는 보고된바 없다. 본 연구에서는 냉연 DP강의 저항 점용접시 중요한 인자 중 하나인 너깃경과 전단인장강도에 미치는 Si함유량의 영향을 검토하였다. 사용된 강재 및 용접기는 1.2mm 두께의 Si함유량(0, 0.5, 1.0, 1.5wt%)이 다른 인장강도 780~1000MPa급 냉연 DP강과 단상 AC용접기를 사용하였다. 용접조건은 ISO 18278-2규격에 따라 가압력 4kA, 초기가압시간 40cycle, 유지시간 17cycle로 고정하고, 용접전류만 변화하여 용접을 실시하였다. 너깃경은 용접부 단면을 컷팅 후 폴리싱 하여, 광학현미경과 Image Pro plus를 이용하여 측정했으며, 인장시편규격은 JIS Z 3137를 이용하였다. Si함유량이 증가에 따라 스패터 발생 전류는 감소했고, 너깃경은 직선적으로 증가했다. Si함유량 증가에 따른 너깃경 증가 이유는 저항(R) 측정결과, Si함유량 증가에 따라 모재의 저항이 높아져, 따라서 입열량($Q=I^2Rt$)이 많아지기 때문으로 판단되었다. 인정전단강도는 Si함유량 증가에 따라 직선적으로 증가했다. 이러한 이유는 Si함유량 증가에 따라 너깃경이 증가되기 때문으로 판단되었고, 너깃경과 인장전단강도 사이에 직선적 관계(PL(kN)=$3.2N_{dia.}$-0.81, $R^2$=0.93)를 가지고 있었다. 파단양상은 Si함유량에 상관없이 5.4kA이하에서는 계면파단이 일어났고, 6.0kA이상에서는 풀 아웃 파단이 일어났다. 계면파단주원인은 용접부 가장자리에 지름이 약 $5{\mu}m$이하의 예리한 노치가 존재하여 노치응력집중과 HAZ계면 근처에 미접합부가 존재하기 때문으로 판단되었다. 6.0kA이상에서는 예리한 노치가 없었고, HAZ부가 완전히 접합되어 있기 때문에 풀 아웃 파단이 일어난 것으로 판단되었다. 따라서, Si함유량 증가에 따라 적정용접전류 구간은 감소했고, 너깃경은 직선적으로 증가했다. 또한, Si함유량 증가에 따라 인장전간강도는 증가 했으며, 너깃경과 인장전단강도 사이에 직선적 관계를 가지고 있었다. 파단 양상은 Si함유량에 상관없이 5.2kA이하에서는 계면파단이, 6.0kA이상에서는 풀 아웃 파단이 일어났다.

• Journal of Environmental Health Sciences
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• v.37 no.3
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• pp.182-192
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• 2011

Objectives: This study aims to identify the influential factors on the pulmonary function of targeted general residents in the areas surrounding Gwangyang Steel Mill. Methods: An PFT (Pulmonary Function Test) was conducted from May 2007 to November 2007 on 974 target residents (438 male, 536 female), including an exposed group (674 people) who resided within a radius of 5 km from Gwangyang Steel Mill in Gwangyang-si, Jeollanam-do and a control group (300 people) who resided outside a radius of 15 km. A survey related to personal characteristics, life habits, respiratory diseases and allergic symptoms, medical histories and living environments of the residents was also conducted to identify influential factors on pulmonary function. Results: As %$FEV_1$ and %FVC of the exposed group are 99.17% and 96.98%, respectively, and those of the control group are 105.47% and 101.91%, respectively, with the PFT values of the exposed group being lower than those of the control group (p<0.001), it turns out that the pollution in the industrial complex is likely to trigger a reduction in the pulmonary function of local residents. The odds ratio analysis result for asthma diagnosis history indicates that the odds ratios tend to be higher among surveyed residents who are living near above-average traffic volumes and are using beds, where it is statistically meaningful that especially the odds ratios are higher if the residences are closer to roads (p<0.01, CI=1.12-4.52). The factors that affect the FEV1 are identified as smoking, passive smoking, asthma diagnosis history, nasal congestion symptoms and allergic eye disease ($R^2$=0.154, p<0.001). The factors that affect the FVC are identified as smoking, passive smoking, asthma diagnosis history and allergic coryza ($R^2$=0.158, p<0.001). In addition, the analysis result for the relevance of air pollution levels to pulmonary function ($FEV_1$, FVC) shows that FEV1 and FVC tend to decrease as the concentration of $O_3$ increases. Conclusions: We believe that this study may provide preliminary data for the development of preventive measures for health effects on the residents and environmental health control measures for environmental pollution in the industrial complex area.