• Title/Summary/Keyword: Catch data

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Analyzing the Technical Efficiency of Korean System Integration Firms Using DEA and Malmquist Productivity Analysis (자료포괄분석과 생산성지수분석을 이용한 국내 SI기업의 효율성 분석)

  • Kim, Kon-Shik
    • Journal of Information Technology Services
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    • v.5 no.1
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    • pp.1-16
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    • 2006
  • This paper analyzes the technical efficiencies of 40 Korean system integration firms using data envelopment analysis (DEA) and Malmquist productivity indices. Technical efficiencies on average had been decreased over the five year period and the efficiency difference between best practice firms and catch-up firms had been increased during this period, meaning that the industry structure has become matured and the possibilities for catch-up firms to be efficient are not remained so much. The differences in efficiency by the differences in ownership structures are statistically significant. It implies that the efficiencies of group-affiliated firms have come from benefits such as the captive market umbrellas, not from their own management competencies. In addition, the technical efficiency is highly correlated with captive market sales, information productivity, sales per employees, rates of value added, returns on invested capital, and EBITDA.

부세에 대한 음향반사강도의 체장 의존성

  • 강희영;이대재
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2003.05a
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    • pp.57-58
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    • 2003
  • 현재, 우리나라 주변해역에 있어서는 어업자원의 고갈현상이 급속히 진행되고 있고, 어업자원을 간접적으로 자원을 관리하던 방법에서 직접적으로 관리하기 위한 총 허용어획량(TAC, Total Allowable Catch) 제도를 도입하기에 이르렀다. 이들 어족 자원을 보다 효율적이고 지속적으로 관리하기 위해서는, 어류의 체장추정에 필요한 음향반사강도의 data bank를 구축하는 것이 시급하다. (중략)

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Designing Dataset for Artificial Intelligence Learning for Cold Sea Fish Farming

  • Sung-Hyun KIM;Seongtak OH;Sangwon LEE
    • International journal of advanced smart convergence
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    • v.12 no.4
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    • pp.208-216
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    • 2023
  • The purpose of our study is to design datasets for Artificial Intelligence learning for cold sea fish farming. Salmon is considered one of the most popular fish species among men and women of all ages, but most supplies depend on imports. Recently, salmon farming, which is rapidly emerging as a specialized industry in Gangwon-do, has attracted attention. Therefore, in order to successfully develop salmon farming, the need to systematically build data related to salmon and salmon farming and use it to develop aquaculture techniques is raised. Meanwhile, the catch of pollack continues to decrease. Efforts should be made to improve the major factors affecting pollack survival based on data, as well as increasing the discharge volume for resource recovery. To this end, it is necessary to systematically collect and analyze data related to pollack catch and ecology to prepare a sustainable resource management strategy. Image data was obtained using CCTV and underwater cameras to establish an intelligent aquaculture strategy for salmon and pollock, which are considered representative fish species in Gangwon-do. Using these data, we built learning data suitable for AI analysis and prediction. Such data construction can be used to develop models for predicting the growth of salmon and pollack, and to develop algorithms for AI services that can predict water temperature, one of the key variables that determine the survival rate of pollack. This in turn will enable intelligent aquaculture and resource management taking into account the ecological characteristics of fish species. These studies look forward to achievements on an important level for sustainable fisheries and fisheries resource management.

Measurement of Fishing Capacity of Offshore Fisheries in Korea (우리나라 근해어업의 어획능력 측정에 관한 연구)

  • Kim Do-Hoon
    • The Journal of Fisheries Business Administration
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    • v.37 no.1 s.70
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    • pp.1-24
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    • 2006
  • Reducing fishing capacity is one of current issues in the international fisheries. This is because that increased fishing capacity has caused not only fish stocks to be depleted, but also additional fishing costs to be incurred, which resulted in reduction of economically viability of fisheries. For this reason, FAO adopted the International Plan of Action for the Management of Fishing Capacity' in 1999 and recommended member countries to estimate fishing capacity and to implement the policy to reduce fishing capacity. This study is aimed to measure fishing capacity of the Large Purse Seines Fishery that is one of offshore fisheries in Korea using both Peak - to - Peak Analysis and Data Envelopment Analysis in order to provide a policy information for preparation of domestic plan of action for the management of fishing capacity. The results of PTP Analysis were almost similar to those of DEA Analysis. The DEA results showed that the capacity utilization in 2004 was about 75%, it was obvious the capacity did not utilize enough. The sensitivity analysis on DEA results indicated that 24% of the number of ships, 26% of the tonnages, or 29% of the horse powers should be reduced if the present catch remained. In addition, if the catch remains at the MSY base level of large purse seines, the analysis suggested that the number of ships, tonnages and horse powers should be reduced by 15%, 18%, and 21% respectively.

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Size Selectivity of a Shrimp Beam Trawl for the Southern Rough Shrimp Trachysalambria curvirostris with the Extended SELECT Method (확장 SELECT 방법에 의한 새우조망의 꽃새우(Trachysalambria curvirostris) 망목 선택성)

  • Park, Chang-Doo;Park, Hae-Hoon;Kim, Jung-Nyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.44 no.4
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    • pp.390-396
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    • 2011
  • Southern rough shrimp Trachysalambria curvirostris is exploited mainly by small shrimp beam trawl in coastal regions of Korea. To determine the size selectivity of a shrimp beam trawl for this species, a series of comparative fishing experiments was conducted in the sea adjacent to Geoje Island off the southern cost of Korea in June and November, 2010, using codends with four different mesh sizes(14.2, 17.8, 25.5, and 35.3 mm). The extended Share Each Length's Catch Total(SELECT) analysis method, based on a multinomial distribution, was applied to the fishing data to obtain a master selection curve. The model with the estimated split parameters fit the catch data best. The master selection curve was estimated to be: s(R)=exp(15.183R-7.872)/[1+exp(15.183R-7.872)], where the relative carapace length, R, is the ratio of carapace length to mesh size. The relative carapace length for 50% retention was 0.518, and the selection range was 0.145. The results suggest that codends with a larger mesh size allow more small-sized shrimps to escape.

Estimations on population ecological characteristics of small yellow croaker, Larimichthys polyactis by the drift gillnet fishery in Korean waters (한국 주변해역 참조기의 자원생태학적 특성치 추정)

  • Lee, Jong Hee;Seo, Young Il;Oh, Taeg Yun;Lee, Dongwoo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.4
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    • pp.440-448
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    • 2013
  • Estimations on population ecological parameters of the small yellow croaker, Larimichthy polyactis in Korean waters, were calculated using catch data based on coastal and offshore drift gillnet fishery and biological data from 2010 to 2012. The population ecological parameters included survival rate, instantaneous coefficient of natural and fishing mortality and age/length at first capture. The survival rate (S) of the small yellow croaker was estimated to be 0.20 from catch curve method. The instantaneous coefficient of natural mortality (M) was estimated to be 0.46/year with Alverson and Carney method. The instantaneous coefficient of total mortality (Z) was 1.611/year, used to be transformed the survival rate and the instantaneous coefficient of fishing mortality (F) were 1.153/year. The length at first capture ($L_c$) was 19.1cm by Pauly method, and the age at first capture ($t_c$) was 1.303 years of the small yellow croaker by the coastal and offshore drift gillnet fishery.

Species Composition and Catch of Korean Tuna Longline Fisheries in the Indian Ocean from 2010 to 2015 (인도양 해역 우리나라 원양 연승어업의 어획물 종조성과 어획동향(2010-2015년))

  • Ku, Jeong Eun;Lee, Sung Il;Kim, Doo Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.3
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    • pp.286-297
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    • 2018
  • We analyzed scientific observer data to identify species composition and catch trends of Korean tuna longline fisheries in the Indian Ocean. The data were collected by Korean scientific observers onboard Korean tuna longline fishing vessels in the Indian Ocean from 2010 to 2015. The observers identified 94 species including 5 tuna, 6 billfish, 11 shark, 7 other fish, 5 seabird and 1 sea turtle. Albacore tuna Thunnus alalunga and southern bluefin tuna Thunnus maccoyii were the dominant tuna species, and swordfish Xiphias gladius were the most commonly captured billfish. During the survey periods, 87 seabirds were incidentally bycaught. Black-browed albatross Diomedea melanophris was the dominant seabird species in bycatch, especially in 2010. Cluster analysis showed difference in the species composition of catches between the eastern and western Indian Ocean.

Development of Real-time Oceanographic Information System for Pelagic Fishery Based on Argo Data (Argo 자료를 이용한 해외어장 실시간 해황정보시스템 개발연구)

  • Yang, Joon-Yong;Suk, Moon-Sik;Suh, Young-Sang;Jeong, Hee-Dong;Heo, Seung
    • Journal of Environmental Science International
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    • v.17 no.4
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    • pp.461-468
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    • 2008
  • Competitive power of pelagic fishery in Korea has been weakened by the domestic and international problems such as wage increase and exclusive economic zone. To make it worse, fishing fleet spends more than 80% of fishing time on searching fishing grounds. Real-time information on oceanographic data, temperature in particular, are likely to contribute to raise efficiency of fishing. However, available data obtained by satellite remote sensing, fixed buoy and drifting buoy, limited to sea surface or fixed positions. ARGO (Array for Real-time Geostrophic Oceanography), an international program, has delivered vertical profiles of temperature and salinity in the upper 2000m of the world ocean every 10 days using freely moving floats. We have developed real-time oceanographic information system for pelagic fishery based on the Argo data which has the contents of vertical profile, horizontal distribution and vertical section of temperature around fishing grounds and searched data can be download unrestrictedly. Comparison of skipjack catch with sea surface temperature and depth of $20^{\circ}C$ derived from Argo data in the West Equatorial Pacific revealed that Argo data are able to help fishing fleet to find fishing grounds and to increase catch.

Stock Assessment and Optimal Catch of Blackfin Flounder Glyptocephalus stelleri in the East Sea, Korea (한국 동해안 기름가자미(Glyptocephalus stelleri)의 자원평가 및 적정어획량 추정)

  • Sohn, Myoung Ho;Yang, Jae Hyeong;Park, Jeong-Ho;Lee, Haewon;Choi, Young Min;Lee, Jae Bong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.5
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    • pp.598-606
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    • 2013
  • The blackfin flounder Glyptocephalus stelleri is a commercially important species in the East Sea of Korea, but its catches and biomass have decreased gradually in recent years. This study estimated the optimal catch (acceptable biological catch, ABC) for the effective management of this species by estimating population ecology parameters and the stock biomass of blackfin flounder in the East Sea of Korea. The estimated instantaneous coefficient of total mortality (Z) of blackfin flounder was 1.0542/year, the survival rate (S) was 0.3485, and the instantaneous coefficient of natural mortality (M) was 0.3637/year. From the values of S and M, the instantaneous coefficient of fishing mortality (F) was calculated to be 0.6905/year. The age at first capture was 1.304 years, and the total length was 11.5 cm at that time. On the basis of these parameters, the annual biomass was estimated by a biomass-based cohort analysis using annual catch data in weight by year for 1991-2012 in the East Sea of Korea. The annual biomass peaked in 1997 at about 12,800 mt and then subsequently declined continuously to a level of 10,500 mt in 2004 and to 9,800 mt in 2011 and 2012. The maximum sustainable yield and $F_{0.1}$ were estimated as 3,547 mt and 0.3595/year, respectively. Using these estimations, the ABC was estimated to be 3,571 mt in tier 5, 3,397 mt in tier 4, and 2,622 mt in tier 3.

Annual changes of fisheries production in the shore of Jeonbuk Province, Korea (전북연안 어업자원생산량의 경년변화)

  • Park, Jong-soo
    • Journal of Fisheries and Marine Sciences Education
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    • v.20 no.3
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    • pp.400-409
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    • 2008
  • The purpose of this study is to examine annual changes of coastal fisheries production in the shore of Jeonbuk Province in Korea. The catch data of an experimental vessel that used dredge nets were used to study fish species and catch per unit of fishing effort carried out from April 2002 to November 2004. The total number of fish species caught in 2002 was 23, and 15 in 2004. Total number of individuals were 6,008 and their total weight was 376.38 kg in 2002. In 2004, total number of fishes was 2,469, and their weight was 211.99 kg. The annual changes in fisheries production in the western coast of Korea were also analyzed from 1990 to 2007. The total near shore fisheries products in Korea has been relatively stable around 1,4000,000 metric tons to 1,8000,000 tons during this period. Similarly the Chungnam Province's annual fish catch had steadily risen from about 51,187 tons in 1990 to 85,637 tons in 2007. However, Jeonbuk Province's annual fish catch declined dramatically at around 133, 000 tons in 1990 to 45,000 tons in 2007. In summery, while the overall Korea's fisheries production has been stable over the past decade, that of Jeonbuk Province suffered drastic decline in the period. This decline was reflected in the decreased number of fish species, total individuals, and total catch in surverys performed with an experimental vessel.