• 제목/요약/키워드: Trap problem

검색결과 63건 처리시간 0.025초

생분해성 PBS monofilament의 내후성 (Weatherability of biodegradable polybutylene succinate(PBS) monofilaments)

  • 박성욱;배재현
    • 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($R^2=0.98$).

Analysis of Sediment Reduction with VFS and Diversion Channel with Enhancements in SWAT Landuse-Subbasin Overland Flow and VFS Modules

  • Park, Youn-Shik;Kim, Jong-Gun;Kim, Nam-Won;Engel, Bernie;Lim, Kyoung-Jae
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2009년도 학술발표회 초록집
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    • pp.752-757
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    • 2009
  • In the last decade, many methods such as greet chamber, reservoir, or debris barrier, have been utilized to manage and prevent muddy water problem. The Vegetative Filter Strip (VFS) has been thought to be one of the most effective methods to trap sediment effectively. The VFS are usually installed at the edge of agricultural areas adjacent to stream or drainage ditches, and it has been shown that the VFS effectively removes pollutants transported with upland runoff. But, if the VFS is installed without any scientific analysis of rainfall-runoff characteristics, soil erosion, and sediment analysis, it may not reduce the sediment as much as expected. Although Soil and Water Assessment Tool (SWAT) model has been used worldwide for many hydrologic and Non-Point Source Pollution (NPSP) analysis at a watershed scale. but it has many limitations in simulating the VFS. Because it considers only 'filter strip width' when the model estimates sediment trapping efficiency, and does not consider the routing of sediment with overland flow option which is expected to maximize the sediment trapping efficiency from upper agricultural subbasin to lower spatially-explicit filter strip. Therefore, the SWAT overland flow option between landuse-subbasins with sediment routing capability was enhanced with modifications in SWAT watershed configuration and SWAT engine. The enhanced SWAT can simulate the sediment trapping efficiency of the VFS in the similar way as the desktop VFSMOD-w system does. Also it now can simulate the effects of overland flow from upper subbasin to reflect the increased runoff volume at the receiving subbasin, which is what is occurring at the field if no diversion channel is installed. In this study, the enhanced SWAT model was applied to small watershed located at Jaun-ri in South Korea to simulate diversion channel and spatially-explicit VFS. It was found that approximately sediment can be reduced by 31%, 65%, 68%, with diversion channel, the VFS, and the VFS with diversion channel, respectively.

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생분해문어단지의 제작과 Polyethylene (PE) 문어단지와의 어획 비교 (Development of the biodegradable octopus pot and its catch ability comparison with a Polyethylene (PE) pot)

  • 차봉진;이건호;박성욱;조삼광;임지현
    • 수산해양기술연구
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    • 제47권1호
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    • pp.10-17
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    • 2011
  • Biodegradable octopus pot was developed to reduce plastic pollution problem in the sea and fishing trouble between fishermen. It can be expect to recycle other wasted biodegrade fishing gear. Experimental fishing was carried out to understand the difference in fishing efficiency between Polyethylene (PE) octopus pots and biodegradable (Polybutylene Succinate and Polybutylene adipate-co-terephthalate) octopus pots which was tried to make in this study in the sea. There were caught by 237 numbers of fishing during the experimental period. Among the 237 numbers of fishing, 160 or 67.5% were PE pots which were more than the biodegradable pots. A comparison of the monthly catches between the PE pots and biodegradable pots shows that the catches were overall higher in the PE pots than in the other pots. The result is very similar with the comparison of total catches by each type of the pots. In terms of bycatch, the number of species, amount of catches and the number of fishing with bycatch were more significant in the biodegradable pots than in the PE pots.

환경대기 중 유해성 VOC 측정에 관한 동향과 전망 (Current Status and Prospective of Hazardous VOC in Ambient Air)

  • 서영교;정선호;백성옥
    • 한국대기환경학회지
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    • 제27권6호
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    • pp.734-745
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    • 2011
  • In this article, we reviewed the monitoring status of hazardous VOC in ambinet air in Korea and some developed countries such as USA, Japan, and UK. In many countries, two types of VOC monitoring stations are being operated, i.e., for hazardous VOC and photochemical VOC. Each country has different target VOC but all includes benzene. Korea, Japan, and UK have a national ambient air quality standard for benzene, but no national standard has been established in the USA. For sampling of the hazardous VOC, the adsorbent method is adopted in Korea and UK, while the canister method is used in the USA. Both of adsorbent and canister methods are used in Japan. USA and UK have only non-automatic method to measure the hazardous VOC, and the individual samples are being sent to their national laboratories for integrated analysis. On the other hand, Korea and Japan have automatic and nonautomatic methods to measure the hazardous VOC. Local governments or regional environmental agencies in Korea and Japan have the authorization for the sampling and analysis of VOC. According to a field study to evaluate the performance of automatic VOC monitoring system, controlling the moisture in the air sample was identified as the most important problem. However, careful attention must be given to using a moisture removing device such as Nafyon dryer, because of unexpected artifacts formation. In order to have reliable data, it is highly recommended not only to use internal standards, but to use appropriate hydrophobic adsorbents as a cold trap in any automatic on-line VOC monitoring system.

The development of a ship's network monitoring system using SNMP based on standard IEC 61162-460

  • Wu, Zu-Xin;Rind, Sobia;Yu, Yung-Ho;Cho, Seok-Je
    • Journal of Advanced Marine Engineering and Technology
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    • 제40권10호
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    • pp.906-915
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    • 2016
  • In this study, a network monitoring system, including a secure 460-Network and a 460-Gateway, is designed and developed according with the requirements of the IEC (International Electro-Technical Commission) 61162-460 network standard for the safety and security of networks on board ships. At present, internal or external unauthorized access to or malicious attack on a ship's on board systems are possible threats to the safe operation of a ship's network. To secure the ship's network, a 460-Network was designed and implemented by using a 460-Switch, 460-Nodes, and a 460-Gateway that contains firewalls and a DMZ (Demilitarized Zone) with various application servers. In addition, a 460-firewall was used to block all traffic from unauthorized networks. 460-NMS (Network Monitoring System) is a network-monitoring software application that was developed by using an simple network management protocol (SNMP) SharpNet library with the .Net 4.5 framework and a backhand SQLite database management system, which is used to manage network information. 460-NMS receives network information from a 460-Switch by utilizing SNMP, SNMP Trap, and Syslog. 460-NMS monitors the 460-Network load, traffic flow, current network status, network failure, and unknown devices connected to the network. It notifies the network administrator via alarms, notifications, or warnings in case any network problem occurs. Once developed, 460-NMS was tested both in a laboratory environment and for a real ship network that had been installed by the manufacturer and was confirmed to comply with the IEC 61162-460 requirements. Network safety and security issues onboard ships could be solved by designing a secure 460-Network along with a 460-Gateway and by constantly monitoring the 460-Network according to the requirements of the IEC 61162-460 network standard.

폐어구로 인해 발생하는 유령어업 효과에 대한 실험적인 고찰 (Verification on the Ghost Fishing by Derelict Fishing Gears through the Tank Experiments)

  • 김성훈;양용수;정주희;송민수;이도현;최문보;차상훈;이창현;김형석
    • 수산해양교육연구
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    • 제28권5호
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    • pp.1258-1265
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    • 2016
  • The aim of this study was to evaluate the impact on the fishery resources and marine ecosystems by derelict fishing gears as part of the R & E (Research and Education) program that supervised by the busan metropolitan city office of education. In this study, we verified the ghost fishing effects caused by derelict fishing gears through the process which fish were caught to be attracted to bait for gillnet and trap in tank. In results, the dead fish to be gilled in gillnet and to enter in pot have been shown to attract other fish to the bait role. The result showed that the ghost fishing was caused by abandoned, lost or discarded fishing gears continuously. In particular, as a result of pot experiment, if the lost pot has a escape device, the entered fish could escape from the pot and the fisheries resources could protect from derelict fishing gears. In addition, the high school students are capable of raising the problem solving skills through carrying out the research project and expect to contribute to raising awareness about the protection of the marine environment.

근로장려세제의 최적 설계에 관한 연구 (A Study on the Optimal EITC Program)

  • 유한욱
    • KDI Journal of Economic Policy
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    • 제30권1호
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    • pp.131-170
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    • 2008
  • 본 연구는 제도설계(mechanism design) 이론을 이용하여 근로연계복지의 주요 정책수단인 근로장려세제의 최적화를 시도하고, 도출된 최적해의 특성을 바탕으로 곧 시행될 우리나라 근로장려세제 개선방향을 제시하기 위해 수행되었다. 분석결과에 따르면, 시행안에 제시된 급여구조를 수정하는 것이 바람직한 것으로 나타났다. 즉, 주어진 예산제약하에서 근로장려세제의 노동공급 증대효과를 극대화하기 위해서는 점증률을 점감률보다 높게 설정하는 한편, 점감구간 소득상한은 상향조정하여야 한다. 최적해의 비교정태분석 결과에 따르면, 근로장려세제는 소득(임금)분포에 따라 다르게 설계하는 것이 바람직하기 때문에 가구규모 및 취업형태별로 수혜대상을 나누어 각기 다른 급여구조를 적용해야 하며, 이는 향후 근로장려세제의 적용대상이 무자녀가구 및 자영업자가구로 확대될 것임을 고려할 때 시사하는 바가 크다.

들뢰즈, 가타리의 분열분석에서억압과 무의식의 문제 (The Problem of the Repression and the Unconscious in Delueze and Guattari's schizo-analysis)

  • 연효숙
    • 철학연구
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    • 제121호
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    • pp.93-121
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    • 2018
  • 들뢰즈, 가타리는 "안티-오이디푸스"에서 프로이트, 라캉의 욕망론을 결핍으로서의 욕망인 관념론적 환상이라고 비판하면서 유물론적 욕망론의 가능성을 모색한다. 이들은 프로이트, 라캉이 욕망을 오이디푸스 가족 모델에 가두고, 욕망의 리비도의 흐름을 차단했다고 비판한다. 이 글은 욕망에 대한 정신분석 계열과 분열분석 계열의 해석이 상이한 이유를 이들의 주요 개념 가운데, '억압'과 '무의식'에 대한 해석의 차이에서 찾는다. 그에 따라 우선 프로이트, 라캉의 억압의 양상을 살피고, 이들이 보지 못한 '심리적 억압'과 '사회적 억압'의 구별의 유의미를 들뢰즈, 가타리의 해석에 따라 추적한다. 그 다음, 프로이트, 라캉은 무의식을 정신 활동의 방어 기제에 의해 축출된 영역이나, 언어처럼 구조화된 무의식의 차원으로 이해한다. 이에 반해 들뢰즈, 가타리는 이들의 무의식에 대한 해석과 전혀 다르게 접근한다. 이 글은 이들의 무의식에 대한 다양하고도 새로운 해석 가운데, 특히 고아인 무의식, 생산적 무의식, 분자적 무의식을 집중해서 분석한다. 결론적으로 무의식에 대한 새로운 해석에 따라 욕망과 억압의 문제도 전혀 다르게 볼 수 있음을 보이고자 한다. 이들의 분열분석이 과연 현실에서 어떻게 적용 가능한지에 대한 실천적 적용 가능성을 탐색해 보고자 한다.

파골세포 분화에 미치는 노회(蘆會) 추출물의 효과 (Effect of Water Extract of Aloe in RANKL-induced Osteoclast Differentiation)

  • 이정휴;이명수;채수욱;김하영;문서영;전병훈;조해중
    • 동의생리병리학회지
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    • 제25권6호
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    • pp.1008-1013
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    • 2011
  • Osteoporosis is the leading underlying cause of fractures, particularly in postmenopausal women, due to the loss of estrogen-mediated suppression of bone resorption. More than 50% of adults 50 years of age or older are estimated to have osteoporosis. Osteoclast which is main target for treatment of osteoporosis is originated from hematopoietic cell line. Aloe has been widely used in worldwide country as a coadjuvant medicine. Extracts of the leaves of Aloe have been used in condition to improve dermatologic problem such as seborrheic dermatitis, aphthous stomatitis, xerosis, lichen planus and has been known to exert anti-inflammatory, anti-oxidant and anti-tumor effects. However, despite the popularity of aloe as a plant food supplements, the evaluation of its efficacy as a possible therapeutic option for osteoporosis remains scarce. Thus, we evaluated the effect of Aloe on receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. Here we found that Aloe significantly inhibited osteoclast differentiation induced by RANKL. Aloe suppressed the activation of p38 pathway and $NF{\kappa}B$ in bone marrow macrophages (BMMs) treated with RANKL. Also, Aloe significantly inhibited the mRNA expression of c-Fos, tartrate-resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR), nuclear factor of activated T cells (NFAT)c1 and cathepsin K in BMMs treated with RANKL. Particularly, Aloe greatly inhibited the protein expression of c-fos and NFATc1. Taken together, our results suggested that Aloe may be useful tool for treatment of osteoporosis by inhibition of osteoclast differentiation.

백하수오(白何首烏) 물 추출물의 파골세포 분화에 미치는 영향 (Effect of Water Extract of Cynanchi Wilfordii Radix in RANKL-induced Osteoclast Differentiation)

  • 안용환;오재민;이명수;정종혁;채수욱;문서영;전병훈;최민규
    • 동의생리병리학회지
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    • 제26권2호
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    • pp.160-165
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    • 2012
  • Osteoporotic fracture became a serious social problem, which related with mortality and morbidity in old age population. Osteoclast which is responsible for bone resorption is originated from hematopoietic cell line and plays a key role osteoporotic bone loss. Cynanchum wilfordii (Asclepiadaceae) roots have been used in Korean folk medicine for the treatment of diabetes mellitus and aging progression. Also, recent studies have shown that the extract and fractions of Cynanchi Wilfordii Radix have various pharmacological actions including scavenging free radicals, enhancing immunity, reducing high serum cholesterol, and anti-tumor activity. However, the effect of extract of Cynanchi Wilfordii Radix in osteoclast differentiation had not been reported. Thus, we evaluated the effect of Cynanchi Wilfordii Radix on receptor activator of nuclear factor-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. Through our study, we found that Cynanchi Wilfordii Radix significantly inhibited osteoclast differentiation induced by RANKL. Cynanchi Wilfordii Radix suppressed the activation of p38 pathway and $NF{\kappa}B$ in bone marrow macrophages (BMMs) treated with RANKL. Also, Cynanchi Wilfordii Radix significantly inhibited the mRNA expression of c-Fos, tartrate-resistant acid phosphatase (TRAP), osteoclast-associated receptor (OSCAR), nuclear factor of activated T cells (NFAT)c1 and cathepsin K in BMMs treated with RANKL. Particularly, Cynanchi Wilfordii Radix inhibited the protein expression of c-fos and NFATc1. Taken together, our results demonstrated that Cynanchi Wilfordii Radix may be useful treatment option of bone-related disease such as osteoporosis leads to fracture of bone and rheumatoid arthritis.