• JSTS:Journal of Semiconductor Technology and Science
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• 제1권3호
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• pp.158-166
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• 2001

Based on uniform hot carrier injection (optically assisted electron injection) across the $Si-SiO_2$ interface into the gate insulator of n-channel IGFETs, the threshold voltage shifts associated with electron injection of $1.25{\times}l0^{16}{\;}e/\textrm{cm}^2 between 0.5 and 7 MV/cm were found to decrease from positive to negative values, indicating both a decrease in trap cross section ($E_{ox}{\geq}1.5 MV/cm$) and the generation of FPC $E_{ox}{\geq}5{\;}MV/cm$). It was also found that FNC and large cross section NETs were generated for $E_{ox}{\geq}5{\;}MV/cm$. Continuous, uniform low-field (1MV/cm) electron injection up to $l0^{19}{\;}e/\textrm{cm}^2 is accompanied by a monatomic increase in threshold voltage. It was found that the data could be modeled more effectively by assuming that most of the threshold voltage shift could be ascribed to generated bulk defects which are generated and filled, or more likely, generated in a charged state. The injection method and conditions used in terms of injection fluence, injection density, and temperature, can have a dramatic impact on what is measured, and may have important implications on accelerated lifetime measurements.

• 수산해양교육연구
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• 제25권4호
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• pp.766-774
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• 2013

Biodegradable polybutylene succinate(PBS) is a kind of environmentally friendly plastics for fisheries, because it can mitigate the ghost fishing problem caused by gill-net and trap fisheries. To evaluate durability of PBS monofilament, each of different diameter 3 types of monofilaments were spun and exposed to 56 month outdoor and then their gravity, modification of surface, breaking strength, and elongation were analysed. The gravity of PBS monofilament was estimated to be approximately 1.24 when spinning ratio from 4.8 to 6.1. PBS monofilaments did not show any crack after 56 month exposed to outdoor and load-elastic elongation curve was showed sigmoid type. Decreasing ratio of elongation was appeared in the thinnest monofilament 0.2mm diameter and breaking strength was in the thickest monofilament 0.4mm diameter. Breaking strength and elongation at break were decreased rapidly after 48 month exposed to outdoor. Breaking strength reduced linearly after 48 month exposure, while no such linear relationship was found in the case of elongation at break. In results, it was investigated that the durability of PBS monofilament nets for gillnet and trap were 24, 50 month when keep to land, respectively.

• Parasites, Hosts and Diseases
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• 제24권1호
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• pp.15-24
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• 1986

1985년 5월부터 동년 11월까지 6개월간 경북 내륙지역에 출현하는 문종류와 계절적 출현소장을 조사함과 아울러 매개문에서의 감염형 유충의 최근 감염상을 관찰하였다. 조사기간중에 채집된 문의 종류는 4속 9종이었으며, 기중 A. sinensis가 최우점종으로 전채집수의 84.7%를 차지하였다. 조사지역에서 A. sinensis를 처음으로 채집할 수 있는 시기는 5월 초순이었으며 이 기간중 기온은 $14.3~22.8^{\circ}C$, 습도는 53~90%였으며, 그 밀도는 1.0마리였다. 4. sinensis의 최대밀도 시기는 7월 중순에서 8월 초순사이였으며 그기간중 기온은 $21.5~30.6^{\circ}C$, 습도는 72~91%였으며 최대밀도는 316.0마리였다. A. sinensis의 야간 흡혈 활동상을 알아 보기 위해 7월 17~18일과 9월 7~8일 2회에 걸쳐 저녁 17시부터 그 다음날 아침 6시까지 1시간 간격으로 채집하였던 바 활동이 가장 활발한 시간은 7월에는 22시에서 23시사이, 9월에는 20시에서 21시사이였으며 아침 6시 이후에는 한마리도 채집할 수 없었다. A. sinensis 218마리를 부검하였던 바 이 가운데 사상충 유충을 전혀 검출할 수 없었다. 이상의 성적으로 미루어 보아 경북 내륙지역의 분포 모기중 A. sinensis가 우점종이며, 매개문에서 사상충의 감염형 유충은 전혀 검출할 수 없음을 알았다.

• 수산경영론집
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• 제43권3호
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• pp.43-57
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• 2012

According to the result of the recent survey on the current condition of loss of the fishing gears in the East, West and South seas, it is estimated that 50% of the fishing gears used for coastal trap and gill net fisheries are lost every year and 20~30% of those used for inshore trap and gill net fisheries are lost. It is reported that such loss of fishing gears leads to the loss of about 10% of 1.7M tons of the total annual catch from the gill nets and traps along the country's coasts and shores, which amounts to 15~170K tons. Submerged marine litters that have recently been accumulated because of the washed out or lost fishing gears significantly affect the development of fisheries resources as well as the natural environment. The purpose of this study is to identify the damages that the ever-increasing submerged marine litters of washed out fishing gears would have on the fishery and to analyze the effects of the coastal and inshore submerged marine litter collection business on the fishery management. For this, the economic analysis was carried out for the coastal and inshore submerged marine litter collection business based on the fishermen's expenses and earnings and their catch. The result of the analysis shows that the submerged marine litter collection business is quite effective in certain areas but rarely effective in other areas. However, taking into consideration that the litter collection would contribute to protecting the marine environment as well as the fisheries resources, it is expected to have a significant impact on the protection of the marine environment even in those areas where it is not effective for the protection of the fisheries resources.

• 대한조선학회논문집
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• 제58권1호
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• pp.32-39
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• 2021

Korean coastal fishery suffers from profitability degradation due to a decrease in fisheries resources, pollution in coastal waters, fuel coast increase, and market opening for aquaculture products. The next generation Korean fishing vessel aims at the improvement of energy efficiency, enhancement of crew welfare, and safety. These purposes can be accomplished by adopting a new standard hull form with improved resistance performance and a modernized residence facility on the deck. In order to improve resistance performance, this study attempts to optimize design variables for stern flaps for three kinds of fishing vessels - coastal multi-purpose, coastal trap, and dredged nets. A series of model tests for these fishing vessels was carried out in the towing tank of Pusan National University. The results indicate that for some cases, the stern flap caused the stern trim of the vessel to decrease, leading to the resistance reduction.

• 해양환경안전학회지
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• 제27권1호
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• pp.81-87
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• 2021

제주해역은 많은 상선 및 어선들이 항해를 하고, 자망, 트롤 등 다양한 어구를 활용하여 어로활동을 하고 있다. 그 동안 해양폐기물 수집은 주로 제주도 해안 및 연안해역에서 시행되고 있으나, 연근해 해역에서 발생되는 해양폐기물 발생에 대한 수집 및 연구가 미미하였다. 이에 본 연구는 제주대학교 실습선을 이용하여 제주도 북서해역에 침전한 해양폐기물을 수거하고 각 폐기물별로 관련 선박의 항적을 분석하였다. 또한 일정 구역 및 선박 체류시간별로 얼마나 많은 해양폐기물을 투기하고 있는지 분석하기 위해 선박자동식별장치 항적데이터를 활용하여 대상해역에 선박이 체류한 시간을 추출하여, 어선업종별로 1 ㎢ 단위구역에서 시간당 해양폐기물 발생양을 분석하였다. 분석 결과 연근해 해역은 어선기인 폐어구가 대다수였으며, 그중 자망 및 통발 어구가 많은 비율을 차지하고 있었다. 본 연구에서 단위구역에서 시간당 해양폐기물 발생량은 자망어업이 평균 0.94 kg, 통발어업이 3.49 kg, 저인망어업이 0.10 kg, 연승어업이 0.11 kg, 기타어업이 0.02 kg으로 산출되었다. 이 결과를 활용하여 향후 연근해 수중환경 정화시 해양폐기물 발생이 높은 해역위주로 해양폐기물 수거가 가능할 것이다.

• 헤리티지:역사와 과학
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• 제55권3호
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• pp.132-150
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• 2022

국가무형문화재로 지정된 어살은 전통어로방식의 하나로 우리나라 연안어업을 대표하는 어구였다. 그런데 1970년대 이후 연근해 어선어업이 발달하면서 어살을 포함한 전통어로방식은 상대적으로 쇠퇴하기 시작하였다. 현재 어살은 돌살과 죽방렴 형태로 전승되고 있는데, 경상남도 남해군과 사천시에서는 죽방렴을 이용하여 멸치를 어획하고 있다. 죽방렴의 기본 형태는 물고기가 모이는 공간인 '발통'과, 조류에 의해 물고기가 발통 안으로 들어가게 도움을 주는 V자 혹은 U자 형태의 '할가지'로 구성되어 있다. 어업방식은 밀물 때 연안으로 들어왔다가 썰물 때 조류를 따라 발통 안에 갇힌 물고기를 그물이나 뜰채로 어획한다. 이 논문에서는 남해와 사천 지역의 죽방렴 구조와 어업방식의 비교분석을 통해 전통어로방식의 전승 과정을 알아보았다. 먼저 현재의 죽방렴 구조가 완성되는 역사적 과정을 분석했다. 과거 방렴과 어살의 공존 속에서 두 어구의 특성을 조합한 죽방렴이라는 어구가 지족해협과 삼천포해협을 중심으로 완성된 것으로 보인다. 다음으로는 물고기가 모이는 공간(발통)이 원형이거나 방형으로 만들어진 두 가지 형태의 죽방렴의 구조와 어업방식에 대해서 살펴보았다. 이를 통해 자연환경에 순응하고, 획득 가능한 자원(재료)을 적극 활용하면서 죽방렴 어업이라는 전통 어로기술을 변화시켜 적합한 기술로 발전시킨 어민들의 모습을 살펴보았다. 마지막으로는 죽방렴 멸치에 부여된 새로운 가치를 분석하였다. 더 좋은 멸치라는 죽방렴 멸치의 새로운 가치는 다른 멸치어업에 비해 소량 생산되는 죽방렴 멸치어업의 명맥을 유지시켜 주는 하나의 기제로 작동하고 있다. 이처럼 죽방렴 어업은 전통어로방식을 전승하고 있다는 역사성과 함께 다른 어로를 통해서 생산한 멸치보다 더 좋은 멸치라는 차별성까지 획득하면서 계승되고 있다.

• 수산해양기술연구
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• 제44권4호
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• pp.265-272
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• 2008

Biodegradable polybutylene succinate(PBS) is an environment friendly plastics for fisheries, because it can mitigate the ghost fishing problem caused by gill-net and trap fisheries. To evaluate photodegradability of PBS monofilament in comparison with polyamide(PA) and polyethylene(PE) monofilament, these 3 types of monofilaments were spun and exposed to ultraviolet light(UV) of weather-ometer for 900 hours, and then their modification, crystal structure, strength, and extensibility were analysed. PBS monofilament did not show any crack and maintained its crystal structure after 900 hour exposure to UV whereas PE monofilament began showing cracks and structure modification after 600 hour exposure. Under UV exposure, the strength and extensibility decreased more rapidly in PBS than in PA and PE. We estimate that gill nets made of PBS monofilament can endure for about 1 year. The breaking strength and elongation decreased linearly with the exposure time for the 3 types of monofilaments. The derived regression equations of the residual tenacity(RT, kg/$mm^2$) and the residual extensibility(RE, %) with the exposure time in year(Y) for each monofilament were; PBS : RT=48.598 - 8.6437Y($R^2=0.93$), RE=28.165 - 7.3233Y($R^2=0.98$), P A : RT=59.771 - 8.6437Y($R^2=0.98$), RE=32.198 - 5.2772Y($R^2=0.92$), P E : RT=60.898 - 5.6528Y($R^2=0.98$), RE=11.887 - 0.7188Y($R^2=0.98$).

• 수산해양기술연구
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• 제43권4호
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• pp.281-290
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• 2007

This study was aimed not only to develop the gill net and trap made of biodegradable monofilaments in order to prevent a ghost fishing and to protect marine ecosystem, but also to analyze their spinning process and physical properties. Results showed that the spinning speed of biodegradable polybutylene succinate(PBS) monofilament was estimated to be approximately 100m/min when spinning temperature and cooling water temperature were adjusted at $180^{\circ}C$ and $3^{\circ}C$, respectively. The breaking loads of PBS monofilaments were estimated to be $35.3kg/mm^2$ at ${\phi}0.2mm$, $46.5kg/mm^2$ at ${\phi}0.3mm$, and $49.7kg/mm^2$ at ${\phi}0.4mm$ in the dry condition, respectively. However, its breaking loads in the wet condition were reduced by 2.4-5.5%, compared to those in the dry condition. The knotted strength of PBS monofilament at ${\phi}0.2mm$ was estimated to be 98.6% of PE in the dry condition. The breaking load of PBS monofilament at ${\phi}0.3mm$ was evaluated to be 81.8% of PA, and its softness showed 3 times less than that of PA in the wet condition. The breaking load of PBS monofilament at ${\phi}0.4mm$ was 95.3% of PA, and its softness showed 1.6 times less than that of PA in the wet state. However, the load elastic elongations of two kinds of monofilaments were estimated to be 1% higher than that of PA.