• Title/Summary/Keyword: By-catch

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Catch state of demersal fish resources at the coastal waters off Goheung (고흥 연안 저서 어족자원의 어획실태)

  • Hwang, In-Ho;Kim, Dae-An;Jang, Duck-Jong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.4
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    • pp.248-262
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    • 2005
  • The purpose of this study was to identify the state of demersal fish resource catch by small trawlers, which live in the southern waters off Goheung. We investigated the results of catch of sample fishing vessels, and performed fishing experiments using the actual fishing operation vessels from early November in 2002 till end of October in 2003. The daily amount of catch per vessel of the 35 small trawlers selected as sample vessels was the highest in summer seasons(June and July) as 70kg and the lowest in winter seasons(January and February) as 45kg and Octopus minor occupied as 17 to 30kg nearly 30% of the total catch. Additionally the catch of Octopus minor per vessel, per dragging hour ranges 3 to 6kg, which is the highest in March and June and the low in January to February, April to May and September. In the fishing experiments using small trawler, during the study period, a total of 75 fish species were collected. The number of individuals by species consisted 58.2% in Shrimps, 17.8% in Fish, 2.3% in Cephalopod. Of these, Parapenaeopsis tenella was the highest in 29.2%, Squilla oratoria and Crangon hakodatel was 14.6% respectively and Octopus minor was 0.2% of the total number of individuals. As far as the appearance number of individuals by month was concerned, February was the highest and then May, April and June followed in order, and October showed the lowest. Additionally the monthly catch per dragging was the lowest in December to January as 20kg and the highest in July as 160kg. Specially, Octopus minor was caught throughout the year regardless of season and the catch was the highest at the period from March to June. When looking into the body mean length of dominant fishes caught, we could observe the followings; Trachurus japonicus 8.9cm, Cynoglossus robustus 10.8cm, Muraenesox cinereus 15.3cm, Setipinna taty 10.3cm, Amblchaeturichfhys hexanema 9.3 cm and Collichthys niveatus 8.9cm, most of which were in their immaturity when they were caught.

Analyzing the Relationship between Climate Change and Anchovy Catch using a Cointegration Test (공적분 검정을 이용한 기후변화의 멸치 생산량에 대한 영향 분석)

  • EOM, Ki-Hyuk;KIM, Hong-Sik;HAN, In-Seong;KIM, Do-Hoon
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.6
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    • pp.1745-1754
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    • 2015
  • This study aimed to analyze the relationship between sea temperatures and anchovy catch of Anchovy drag net fishery using annual time series data from 1970 to 2013. In the analysis, time series data on variables (CPUE, sea surface temperature, and 10m temperature) were estimated to be non-stationary from unit root tests, but one long-term equilibrium relation among variables was found from a cointegration test. From an exclusion test, a 10m temperature would not have relations with CPUE and sea surface temperature. The result of regression analysis on sea surface temperature and anchovy catch indicated that the sea surface temperature would have positive impacts on the anchovy catch. It means that when the sea surface temperature would increase, all other things including the current level of fishing effort being equal, the catch of anchovy was predicted to increase. More specifically, the result showed that when 1% of sea surface temperature increases, CPUE would be increased by 2.81%.

Catch Predictions for Pacific Anchovy Engraulis japonicus Larvae in the Yellow Sea

  • Kwon, Dae-Hyeon;Hwang, Sun-Do;Lim, Donghyun
    • Fisheries and Aquatic Sciences
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    • v.15 no.4
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    • pp.345-352
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    • 2012
  • To predict catches of Pacific anchovy Engraulis japonicus larvae, anchovy eggs were collected in the coastal waters off Gunsan, Korea, in the Yellow Sea during the main spawning season (June to July) from 2003 to 2009. A ring net was repeatedly towed vertically at 10 stations during the daytime to sample eggs. Catch data estimated by auction sales were obtained from the Fisheries Cooperatives Union of Gunsan City and daily water temperature data in the outer harbor of Gunsan City during the survey periods were obtained from the National Oceanographic Research Institute. A significant relationship was found between anchovy egg density from June to July and larval catch from July to October in the same year. Catch of anchovy larvae in Gunsan were also high when optimal growth temperatures were recorded in the coastal waters off Gunsan in July. Although the recruitment success or failure of anchovy larvae can be predicted from variability in egg density, we suggest that mean daily water temperature is a more efficient indicator for predicting variability in catches of larval anchovy in the Yellow Sea.

Fishing efficiency of LED fishing lamp for squid jigging vessels (오징어 채낚기어선용 LED 집어등의 어획성능)

  • An, Young-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.4
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    • pp.385-394
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    • 2013
  • This study has conducted a comparative analysis on the fishing efficiency of LED fishing lamps by squid jigging vessels, the Yeongrak-ho (16 tons) and Somang-ho (9.77 tons), which operated during September and October 2010 and during October 2011, comparing with MH (Metal Halide) fishing lamp-equipped fishing vessels. This study has also examined vessel's fuel consumption level. The light powers of LED fishing lamps of the Yeongrak-ho and Somang-ho were 25.8kW and 32kW, respectively. Those of the MH fishing vessels, that is, the MH fishing lamp-equipped fishing vessels, were 105kW and 81kW, respectively. The average squid catch in number of an LED vessel, Yeongrak-ho, was 39.2% of the MH fishing lamp-equipped fishing vessels; however, that of the Somang-ho improved to 78.7% of the MH fishing lamp-equipped vessels. Average catch in number by Yeongrak-ho crew was 2.6 times more than catch in number by automatic jigging machines. Average catch in number by MH fishing vessel crew was 1.8 times more than that by automatic jigging machines. An LED vessel, Yeongrak-ho's fishing rate was 17.5%~152.2% of the MH fishing vessels, that is, 61.1% on average, in comparison of combined catch in number per automatic jigging machine and per crewmember. Somang-ho's fishing rate was 6.7%~127.6% of the MH fishing vessels, that is, 73.1% on average. The average fuel consumption level of the Somang-ho, throughout its departure from to arrival at the port, was 475.7l, and that during fishing hours was 109.6l, or 23.0% of the total fuel consumption level. Somang-ho's fuel consumption level per fishing hour was 9.7l on average.

Environmental Factors and Catch Fluctuation of Set Net Grounds in the Coastal Waters of Yosu - 4 . Water Temperature and Salinity and Fluctuation of Catch - (여수연안 정치망어장의 환경요인과 어황변동에 관한 연구 - 4 . 수온 염분과 어획량 변동 -)

  • Kim, Dong-Su;Rho, Hong-Gil
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.2
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    • pp.125-131
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    • 1996
  • In order to investigate the relation between the environmental properties and the catch fluctuation of set net fishing grounds located in the coastal waters of Yosu, oceanographic observations on the fishing grounds were carried out by the training ship ofYosu Fisheries University from January, 1990 to September, 1992, and the data obtained were compared with the catch data from the joint market ofYosu fisheries cooperative society from 1984 to 1993. The resuItes obtained are summerized as follows : 1. The ranges of water temperature and salinity in the fishing ground was 7.0 to $27^{\circ}C.$and 26.6 to 33.2${\textperthousand}$, and water temperature increased from March to August and decreased from September to February of following year. 2. The salinity in the fishing grounds was relatively high without significant changes from November to June of the following year. From July, however, the salinity decreased to continue a low value till September and then increased. The salinity in the fishing ground was dominated mainly by the precipitation and its variation was large at the north entrance of set net fishing ground, influenced greatly by the land waters from the river of Somjin, but small in the offshore of the fishing grounds. 3. The fishes caught by the set nets were arranged in order of catch as follows; Spanish mackerel> Horse mackerel > Sardine > Anchovy > Hair tail. The catches of Anchovy and Sardine were high in April to May and those of Hair tail in June to July, but Spanish mackerel and Horse mackerel were caught for whole period of fishing. Spanish mackerel was caught most in September and least in April and their means were largest in August and smallest in June. 4. The ranges of optimum water temperature for fishing by the set nets was 13.5 to $25^{\circ}C.$, and in the ranges the catches increased with increasing temperature. The ranges of optimum salinity for fishing varied between 25.0 and 32.0${\textperthousand}$.

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A Study on the Catch-Up Strategy of Hyundai·Kia by Comparing and Analyzing the Global Competitiveness with the Three Global Leading Companies (글로벌 3강과 국제경쟁력 비교분석을 통한 현대·기아차의 추격전략 연구)

  • Park, Chanyong;Cho, Keuntae
    • Korean Management Science Review
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    • v.33 no.3
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    • pp.31-51
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    • 2016
  • The objective of the study is to propose the catch-up strategy of Hyundai Kia to become the globally leading company in the automobile industry. For this, we try to compare Hyundai Kia with three leading automobile companies: Toyota, VW, and GM by using the Generalized Double Diamond Model. As a result, we present three ways that Hyundai Kia can become a "First Mover." The three strategies are : 1) controlling increase of wage, raising productivity, and increasing R&D investment 2) increasing overseas investment of the small and medium sized automobile factories 3) pursuing the two tracks strategy of a public car and a prestige car more aggressively. This study is significant in the fact that it presents the catch-up strategy of Hyundai Kia in the automobile industry, of which the leaders can not be changed easily, by the Generalized Double Diamond Model approach.

Active Lamb Wave Propagation-based Structural Health Monitoring for Steel Plate (능동 램파 전파에 기초한 강판의 구조건전성 모니터링)

  • Jeong, Woon;Seo, Ju-Won;Kim, Hyeung-Yun
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.421-431
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    • 2009
  • This paper is the study on the verification of structural health monitoring (SHM) algorithm based on the ultrasonic guided wave. An active inspection system using Lamb wave (LW) for SHM was considered. The basic study about the application of this algorithm was performed for detecting the circular notch defect in steel plate. LW testing technique, pitch-catch method, was used for interpretation of circular notch defect with depth of 50% of plate thickness and 7 mm width. Damage characterization takes place by comparing $S_0$ mode sensor signals collected before and after the damage event. By subtracting the signals of both conditions from each other, a scatter signal is produced which can be used for damage localization. The continuous Gabor wavelet transform is used to attain the time between the arrivals of the scatter and sensor signals. A new practical damage monitoring algorithm, based on damage monitoring polygon and pitch-catch method, has been proposed and verified with good accuracy. The possible damage location can be estimated by the average on calculated location points and the damage extent by the standard deviation.

Study on the Improvement of Gill Nets and Trap Nets Fishing for the Resource Management at the Coastal Area of Yellow Sea-Improvement of Gill Nets for Croacker,Miichthys miiuy - (서해구 자원관리형 자망·통발 어구어법 기술개발에 관한 연구 - 민어 Miichthys miiuy 자망의 개량-)

  • Chang, Ho-Young;Cho, Bong-Kon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.2
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    • pp.95-100
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    • 2005
  • In order to improve the gill nets for croaker, Miichthys miiuy which is proper to the fishermen's income ans fisheries resource management, we had studied to the net height of present gill nets (mesh size 160mm, 50 mesh in depth), experimental gill nets-I(mesh size 150mm, 68 mesh in depth) and experimental gill nets-II(mesh size 142mm, 75 mesh in depth) in wter using the gill nets design ans analysis simulation system, and then investigated and analyzed the catch efficiency of each gill nets through the field fishing experiments. The net height of emperimental gill nets-I and experimental gill nets-II in water were estimated respectively about 1.5 times and 1.3 times higher than present gill nets which the net height is about 3.5m as the results of simulation considering the current of fishing fields. Total number of croakers which were caught by the persent gill nets was 62(body length 300~1,200mm), total catch weight was 398.7kg (mean 0.6kg/sheet). Total number of croakers which were caught by the experimental gill nets- I was 68(body length 600~1,100mm), total catch weight was 391.6kg (mean 1.2kg/sheet). Total number of croakers which were caught by the experimental gill nets-II was 28(body length 400~900mm), total catch weight was 99.2kg (mean 0.3kg/sheet).

The Development of Data Base Program on the Catch of Long-Iine Tuna (원양 다랭이 연승어업의 어획량 데이터 베이스 프로그램 개발)

  • 배봉성
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.32 no.4
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    • pp.356-362
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    • 1996
  • In order to suggest the useful information of fishing ground, a data base system on 32bit personal computer was developed and handled by using the catch data of Korean tuna long -line. This data base system was programmed using Quick Basic, and consisted of three kinds of programs, one for displaying the catch rate on the fishing ground by fishing area and year ranges, another for indicating the catch rate or number on table or graph, and the other for estimating the fishing ground in economical points, mainly targeting total tunas, yellowfin and bigeye tuna respectively. When this system was started, the map of oceans such as the Pacific, the Indian and the Atlantic, is drawn on the monitor. And then the catch rates of all species and each one are indicated by the figured symbols on the sea divisions of$5^{\circ}$ space of latitute and longitude.

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Technology Risk and Social Responsibility of Innovation: The Shut-Down Law and On-line Game as a Post Catch-up Innovation (기술위험과 혁신의 사회적 책임 - 셧다운제와 탈추격형 혁신으로서 온라인게임 -)

  • Jung, Byung Kul
    • Informatization Policy
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    • v.20 no.4
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    • pp.71-88
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    • 2013
  • Probability of technology risk is expected to increase as the post catch-up innovation, characterized by high uncertainty and high risk, would dominate in the coming era of post catchup. Social controversy on online game as a post catch-up innovation is still ongoing, though the shutdown law was enacted by the government. Socio-technical vulnerability causing technology risk paradoxically arose from the world top-level ICT infrastructures and has been reinforced by developmentalism. While both the pros and cons of the regulation fail to recognize dilemma objectively, social cost is brought about and accumulated. With recognizing dilemma between technology innovation and risks, we can tackle technology risks and ensure responsible innovation in post catch-up era.

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