• 제목/요약/키워드: Catch efficiency

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안강망어구의 모형실험 (MODEL EXPERIMENT OF STOW NET)

  • 고관서;김용해
    • 한국수산과학회지
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    • 제12권4호
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    • pp.201-207
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    • 1979
  • 재래식 안강망 어구를 축소비 1/40로 줄여서 전개 장치를 한 모형어구에 대하여 회류수조에서 실험한 결과를 요약하면 다음과 같다. 1) 모형어구의 저항은 수해와 암해르 부착했을 때 $R=1.66V^{1.02}$, 수해를 떼어내고 전개건과 뜸을 달았을 때 $R=3.11V^{1.54}$ (R:kg, V:m/sec)이며 실물에서 유속 1m/sec일 때 저항은 각각 5.2ton, 6.8ton정도이다. 2) **고는 모두직선적으로 감소하여 재래식에서는 h=89.22-2.42(V-15), $(V\geqq15)$, 전개건과 뜸을 달았을 때 h=89.20-0.87V, (h:cm V:cm/sec)이며 이것은 실물에서 유속 1m/sec일 때에도 **고는 약 20m 정도가 된다. **폭은 전개건줄의 길이로 조성할 수 있다. 3) **구의 단면적은 저속일 때는 비슷하나 유속 0.25m/sec 이상에서 전개건을 달았을 때가 월등히 증가하여 실물에서 유속 1.0m/sec일 때 약 $736m^2$가 된다. 어획효율도 단면적에 비례하므로 전개건을 달았을 때 그 효율은 1.53 이 된다. 4) 재래식 안****은 유속의 증가에 따라 옆판에 주름이 너무 많이 생기므로 적당한 성형율과 사단방법이 필요하다. 5) 전개건은 숫걸리줄, 암걸리줄 및 전개건줄의 길이와 그 결부위치의 조성으로 **고, **폭 및 **형을 어느정도 조성할 수 있으며, 정조시 전개건과 그 물이 어떤 상태에 있더라고 유속과 유향의 변화가 생기면 항상 전개력을 나타낼 수 있다.

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채낚기 어선용 수랭식 LED 집어시스템의 설계 및 성능평가 (Design and performance estimation of fish-luring system using the water cooling typed LED lamp)

  • 배봉성;안희춘;권기진;박성욱;박창두;이경훈
    • 수산해양기술연구
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    • 제47권2호
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    • pp.79-87
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    • 2011
  • A fishing lamp is fishing gear to gather fish in the night. But the cost of oil which is used to a light fishing lamp, goes significantly up to almost one hundred million won for 50 tonnage vessels and forty million won in case of vessels less than 10 tonnages. This cost has almost taken 30.40% of total fishing costs. As oil price increases, the business condition of the fishery gets worse and worse. Therefore, it is very urgent to develop an economical fishing lamp, to solve the problem of fishery's business difficulty. This research aims at developing a fishing lamp for squid jigging fishery and hairtail angling fishery using the LED, which has excellent efficiency and durability. One fishing lamp has about 160Watt capacity and five fishing lamps are installed one aluminium panel in which sea water flows to emit generated heat from LED to outside. Developed fishing lamp lights to an effective direction of jigging and angling operation. This fishing lamp can be controlled to light the direction of fish shoal because the aluminium panel can be controlled to up and down direction. The wave length of fishing lamp has white and blue color. White color light is to gather fish shoal of horizontal direction and blue color light is to gather fish shoal of vertical direction. After development of this fishing lamp, 60.110 units are established on the boat, and operated fishing. Consequently, in the case of squid jigging, spent energy was reduced to 39%, in the case of hairtail angling, 68% of spent energy was reduced. And the catch was more than another boat.

참조기 유자망어업에서 어로기술개발에 따른 어획성능지수 변동 (Change of relative fishing power index from technological development in the small yellow croaker drift gillnet fishery)

  • 서영일;오택윤;차형기;김병엽;조현수;정태영;이유원
    • 수산해양기술연구
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    • 제55권3호
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    • pp.198-205
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    • 2019
  • The small yellow croaker (Larimichthys polyactis) is one of the representative high-class fish species in Korea. The catch of small yellow croaker in adjacent water fisheries has been continuously decreasing from 59,226 tons in 2011 to 19,271 tons in 2016. The small yellow croaker is caught by gillnet, stow net and bottom trawl, among which about 55~65% is caught by gillnet. For the sustainable use of small yellow croaker, the fishing power of small yellow croaker drift gillnet is very important. Therefore, the change of fishing power index were analyzed to identify the development of the vessel and gear technology that may have improved the fishing efficiency of the small yellow croaker drift gillnet fishery from 1960s to 2010s. Gross tonnage and horse power per fishing vessel was increased annually. The mesh size was 75.0 mm in the 1960s, but reduced to 60.6 mm in the 1980s and to 51.0 mm in the 2000s. In the 1960s, it was hauled out by manpower. However, the net hauler were modernized and supply rate was also increased since 1970. Due to the mechanization of the net hauler, the number (length) of used net gradually increased from 1.5 km in the 1960s to 7.5 km in the mid-1980s and to 15 km in 2010. Colour fish finders and positioning system were introduced and utilized from the mid-1980s. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the small yellow croaker drift gillnet fishery increased from 1.0 in 1980 to 0.8 in 1970, to 1.1 in 1990, to 1.6 in 2000 and to 1.9 in 2010. The results are expected to contribute to reasonable fisheries stock management of the small yellow croaker drift gillnet fishery.

키토산 관련 산업의 현황과 전망 (Current status and prospects of chitosan for industrial applications)

  • 정병옥
    • 식품과학과 산업
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    • 제53권1호
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    • pp.69-83
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    • 2020
  • 게나 새우 갑각류의 껍질로부터 추출되는 키토산은 천연고분자로서 다양한 응용분야로 폐수처리용 응집제와 중금속흡착제, 기능성 식품 및 식품첨가제, 토양개량 및 생육촉진제, 생체재료분야의 의약 및 의료용, 섬유, 화장품, 제지 등 수많은 분야에서 연구 및 상용화가 진행되고 있다. 키토산 제조의 원료인 붉은 대게 어획량이 급격히 감소하여 원료의 부족 현상을 겪고 있어, 키토산 제조에 대체 원료의 발굴이 시급히 요구되고 있는 시점에 이르고 있다. 새우와 곤충류의 껍질을 활용하기 위하여는 새우 껍질은 동남아시아 등에서 수입, 곤충류의 껍질은 국내 사육 농가의 증가로 충분한 양의 확보가 예상되어 키토산 제조의 원료로 대체하는 방법도 고려해 볼 수 있을 것이다. 키토산은 생산단계에서 강산과 강염기를 사용해서 화학반응을 시키므로 해서 많은 양의 폐수가 발생하여 환경오염은 물론 폐수처리 비용이 키토산의 원가에 큰 비중을 차지하고 있어, 키토산의 제조방법의 혁신적인 개선되지 않고서는 키토산 산업의 발전에 영향을 미칠 것으로 생각되며, 화학적 추출방법이 아닌 생물학적 추출방법(효소적 추출, 미생물 발효)에 대한 꾸준한 연구와 기술개발로 화학적 추출방법 못지 안는 생산효율을 높이고 단가를 낮출 수 있을 것으로 생각된다. 고순도 키토산의 생산과 분자량을 조절, 분리할 수 있는 기술, 고기능성 키토산 유도체의 연구개발을 위한 산·학·연의 공동연구가 절실히 요구되며 관련 기업들의 성장을 위한 제품의 혁신과 역량확대가 필연적인 과제라 할 수 있다.

성페로몬을 이용한 열대거세미나방 포획과 시토크롬 옥시다제 1(CO1)에서 종내 변이군 특이적 단일염기다형성 분포 (Sex Pheromone Trapping of Spodoptera frugiperda (Noctuidae: Lepidoptera) in Korea and the Distribution of Intraspecies-specific Single Nucleotide Polymorphisms in the Cytochrome c Oxidase Subunit 1 (CO1))

  • 서보윤;정진교;이관석;양창열;조점래;김양표
    • 한국응용곤충학회지
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    • 제59권3호
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    • pp.217-231
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    • 2020
  • 2019년에 서남해안 지역인 고창군의 옥수수 밭 주변에서 성페로몬을 이용하여 열대거세미나방(Spodoptera frugiperda) 성충을 효과적으로 모니터링하는 방법을 조사하였다. 총 함량이 300 또는 1000 ㎍인 2종류 성분 조성의 성페로몬 미끼[(100%) (Z)-9-tetradecenyl acetate and (2%) (Z)-7-dodecenyl acetate]를 설치한 깔대기형 트랩과 델타형 트랩 중에서 열대거세미나방은 300 ㎍ 미끼의 깔대기형 트랩에서 8월 6일에 처음 잡혔고 가장 많이 포획되었다. 또한 깔대기형 트랩 모두에서 비표적 종인 뒷흰가는줄무늬밤나방(Mythimna loreyi)이 많이 포획되었다. 총 함량이 1000 ㎍인 위의 2종류 성분 조성과 4종류 성분 조성의 미끼[(100%) (Z)-9-tetradecenyl acetate, (8%) (Z)-11-hexadecenyl acetate, (2%) (Z)-7-dodecenyl acetate, and (1%) (Z)-9-dodecenyl acetate]를 설치한 날개형 트랩에서 열대거세미나방은 비슷한 수준의 낮은 포획수를 보였으나 뒷흰가는줄무늬밤나방은 4종류 성분 조성의 미끼에서 훨씬 더 많이 포획되었다. 성페로몬 트랩에 포획된 열대거세미나방 70마리의 미토콘드리아 시토크롬 옥시다제 1(CO1)의 부분염기서열(1,004 bp)을 이용하여 계통수를 분석한 결과, 두 개의 종내 변이군으로 나눠졌으며 66마리가 CO1-RS로, 나머지 4마리는 CO1-CS로 분지되었다. 또한 두 개의 CO1 변이군과 기주식물계통(벼, 옥수수)에서 일관되게 차이가 있는 총 12개의 CO1 단일염기다형성(SNP)이 확인되었으며, 전체 73마리 중 4마리만 CO1-CS 그룹(옥수수계통 포함)과 동일한 패턴을 보였으며 나머지 69마리는 CO1-RS그룹(벼계통 포함)과 같았다.

e-비즈니스가 경영성과에 미치는 영향 -홈쇼핑을 중심으로- (The Effects of e-Business on Business Performance - In the home-shopping industry -)

  • 김세중;안선숙
    • 경영과정보연구
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    • 제22권
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    • pp.137-165
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    • 2007
  • It seems high time to increase productivity by adopting e-business to overcome challenges posed by both external factors including the appreciation of Korean won, oil hikes and fierce global competition and domestic issues represented by disparities between large corporations and small and medium enterprises (SMEs), Seoul metropolitan and local cities, and export and domestic demand all of which weaken future growth engines in the Korean economy. The demands of the globalization era are for innovative changes in businessprocess and industrial structure aiming for creating new values. To this end, e-business is expected to play a core role in the sophistication of the Korean economy through new values and innovation. In order to examine business performance in e-business-adopting industries, this study analyzed the home shopping industry by closely looking into the financial ratios including the ratio of net profit to sales, the ratio of operation income to sales, the ratio of gross cost to sales cost, the ratio of gross cost to selling, general and administrative (SG&A) expense, and return of investment (ROI). This study, for best outcome, referred to corporate financial statements as a main resource to calculate financial ratios by utilizing Data Analysis, Retrieval and Transfer System (DART) of the Financial Supervisory Service, one of the Korea's financial supervisory authorities. First of all, the result of the trend analysis on the ratio of net profit to sales is as following. CJ Home Shopping has registered a remarkable increase in its ratio of net profit rate to sales since 2002 while its competitors find it hard to catch up with CJ's stunning performances. This is partly due to the efficient management compared to CJ's value of capital. Such significance, if the current trend continues, will make the front-runner assume the largest market share. On the other hand, GS Home Shopping, despite its best organized system and largest value of capital among others, lacks efficiency in management. Second of all, the result of the trend analysis on the ratio of operation income to sales is as following. Both CJ Home Shopping and GS Home Shopping have, until 2004, recorded similar growth trend. However, while CJ Home Shopping's operating income continued to increase in 2005, GS Home Shopping observed its operating income declining which resulted in the increasing income gap with CJ Home Shopping. While CJ Home Shopping with the largest market share in home shopping industryis engaged in aggressive marketing, GS Home Shopping due to its stability-driven management strategies falls behind CJ again in the ratio of operation income to sales in spite of its favorable management environment including its large capital. Companies in the Group B were established in the same year of 2001. NS Home Shopping was the first in the Group B to shift its loss to profit. Woori Home Shopping has continued to post operating loss for three consecutive years and finally was sold to Lotte Group in 2007, but since then, has registered a continuing increase in net income on sales. Third of all, the result of the trend analysis on the ratio of gross cost to sales cost is as following. Since home shopping falls into sales business, its cost of sales is much lower than that of other types of business such as manufacturing industry. Since 2002 in gross costs including cost of sales, SG&A expense, and non-operating expense, cost of sales turned out to have remarkably decreased. Group B has also posted a notable decline in the same sector since 2002. Fourth of all, the result of the trend analysis on the ratio of gross cost to SG&A expense is as following. Due to its unique characteristics, the home shopping industry usually posts ahigh ratio of SG&A expense. However, more than 80% of SG&A expense means the result of lax management and at the same time, a sharp lower net income on sales than other industries. Last but not least, the result of the trend analysis on ROI is as following. As for CJ Home Shopping, the curve of ROI looks similar to that of its investment on fixed assets. As it turned out, the company's ratio of fixed assets to operating income skyrocketed in 2004 and 2005. As far as GS Home Shopping is concerned, its fixed assets are not as much as that of CJ Home Shopping. Consequently, competition in the home shopping industry, at the moment, is among CJ, GS, Hyundai, NS and Woori Home Shoppings, and all of them need to more thoroughly manage their costs. In order for the late-comers of Group B and other home shopping companies to advance further, the current lax management should be reformed particularly on their SG&A expense sector. Provided that the total sales volume in the Internet shopping sector is projected to grow over 20 trillion won by the year 2010, it is concluded that all the participants in the home shopping industry should put strategies on efficient management on costs and expenses as their top priority rather than increase revenues, if they hope to grow even further after 2007.

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