• Title/Summary/Keyword: catch

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Characteristics of egg and larval distributions and catch changes of anchovy in relation to abnormally high sea temperature in the South Sea of Korea (이상 고수온에 따른 남해안 멸치 알과 자어 분포 및 어획량 변동 특성)

  • YOO, Joon-Taek;KIM, Yeong Hye;SONG, Se Hyun;LEE, Seung Hwan
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.54 no.3
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    • pp.262-270
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    • 2018
  • We examined the characteristics of egg and larval distributions and catch changes of anchovy in relation to abnormally high sea temperature in the South Sea of Korea in summer 2015 and 2016. The densities of anchovy eggs and larvae in the southern coastal region were lower in July-August 2016 than in July-August 2015. In particular, anchovy eggs and larvae (approximately 5 mm TL) were rarely observed in the coastal region in August 2016 due to the abnormally high SST (up to $28^{\circ}C$), which was above the optimum spawning temperature of anchovy. The catch of non-swimming stage (< 2 cm TL) larval anchovy was lower in July-August 2016 than in July-August 2015. The decreased catch of larval anchovy in July-August 2016 could be attributed to decreased spawning density in June-July 2016. In contrast, the catch of swimming stage (> 2 cm TL) anchovy was increased in July-August 2016. In the summer of 2016, prominent sea temperature near the southern coast of Korea and sea temperature higher than $30^{\circ}C$ in the offshore region of the South Sea of Korea could greatly enhance the retention of swimming anchovies in the coastal fishing grounds.

Determination factors for catch rate of the target species between circle hook and straight shank hook in the Korean tuna longline fishery (우리나라 다랑어연승어업에 있어서 환형낚시와 재래식낚시를 사용하여 목표종의 어획률을 결정하는 요인 분석)

  • An, Doo-Hae;Kwon, You-Jung;Bigelow, Keith;Moon, Dae-Yeon;Lee, Sung-Il
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.47 no.4
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    • pp.344-355
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    • 2011
  • We conducted experiments to compare the catch rate of bigeye tuna and yellowfin tuna between circle hooks and straight shank hook in the Korean tuna longline fishery at the eastern and central Pacific Ocean from 2005 to 2007. We analyzed difference of fork length, survival and hooking location between a circle hook and a straight shank hook for both tunas, respectively. There was no difference in the mean fork length size of yellowfin tuna caught on the two type of hook but bigeye tuna was significant. In case of survival, there was no difference between two hook type, but the difference of hooking location was significant for both species. We also analyzed to find determinants of both tunas catch rate using generalized linear models (GLMs) which were used latitude, longitude, year, month, depth, hook type, bait type and so on as independent variables. Spatial factors, latitude and longitude, and temporal factors, year and month, affected catch rate of bigeye tuna and yellowfin tuna. And also, depth such as a marine environment factor was influenced on catch rate.

Making a Technological Catch-up: Barriers and Opportunities

  • Lee, Keun
    • Journal of Technology Innovation
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    • v.13 no.2
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    • pp.97-131
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    • 2005
  • This paper has discussed several issues regarding the barriers and opportunities for technological catch-up by the late-comer countries and firms. As one of the barriers to technological catch-up, the paper emphasizes the uncertainty involved with the third stage of learning how to design. The barriers arise because as the forerunner firms refuse to sell or give license to successful catching-up firms who thus have to design the product by themselves. The paper discusses how to overcome this barrier. It also notes that if the crisis of design technology is a push factor for leapfrogging, arrival of new techno-economic paradigm can serve as a pull factor for leapfrogging, serving as a winder of opportunity. The, it emphasized the two risks with leapfrogging, namely the risk of choosing right technology or standards and the risk of creating initial markets, and how to overcome these risks. It discusses how to overcome these risks in leapfrogging, and differentiates diverse forms of knowledge accesses. Then, the paper takes up the issue of whether there can be a single common or several models for catch-up. A common element of catching-up is to enter new markets segments quickly, to manufacture with high levels of engineering excellence, and to be first-to-market by means of the best integrative designs. This observation is supported by the fact that Korea and Taiwan has achieved higher levels of technological capabilities in such sectors as featured by short cycle time of technology. The possibility of two alternative models for catch-up is also discussed in terms of the key difference between Korean and Taiwan, especially in the position toward the source of foreign knowledge and the paths taken toward the final goal of OBM. Taiwan followed the sequential steps of OEM, ODM and OBN, in collaboration or integration with the MNCs. Korean chaebols jumped from OEM directly to OBM even without consolidating design technology.

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ON THE CATCH OF GILL NET IN THE JEJU ISLAND -Comparison of mackerel catch in monofilament and multifilament gill nets- (제주도 자망이망율에 관하여 -고등어 자망의 이망율 비교-)

  • SHON Tae Jun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.8 no.1
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    • pp.7-10
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    • 1975
  • The catches of mackerel by monofilament and multifilament net were compared by means of $x^2$ and t-test method. In order to improve the netting twine of drift nets, 6 shoots 5 different mesh and nylon-monofilament netting twines $(B\times2,\;C\;D,\;F,)$ and 2 shoe nylon-multifilament $(A\times2)$ which are using near the Jeju Island in contemporary days were used for the experiment. These gill no were connected in order of A, ,B, C, A, B, E, F and operated fly fishing boat Taeann Ho (7T) near sea of Jeju Ialand from May 1974 to August 1974. The results obtained are as follows: 1. B type nylon-monofilament gill nets were superior to nylon-multifilament gill nets in catch according to the result of $X^2$ test and t-test, and the catch ratio was $M_A:\;M_B=1:1.8$. 2. 75mm mesh size C, D nylon-monofilament gill nets were superior to 85mm mesh size nylonmonofilament gill nets, and their catch ratio were E, F: C, D=1:2.8. 3. The catch ratio C, D and E, F type nets were compared by means of t-teat, however could not recognized their relationship.

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Catch and Bycatch of Dredge in the Yeongil Bay, Pohang (포항 영일만 형망어업의 어획 및 혼획 실태)

  • AN, Heui-Chun;PARK, Hae-Hoon;PARK, Jong-Myung;HONG, Sung-Eic;YOON, Byoung-Sun;PARK, Chang-Doo;BAE, Jae-Hyun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.4
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    • pp.493-503
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    • 2015
  • Species composition and bycatch rate of the catches by dredge with bycatch reduction device to reduce bycatch were estimated around Yeongil Bay, Korea at June, 2015. Total catches were collected 31 species as Chordata 10 species, mollusca 8 species, arthropoda 6 species, echinodermata 5 species, sipunculida 1 species, annelida 1 species during the experiment at the Yeongil Bay. The dominant species were Scapharca broughtonii, Callithaca adamsi, and Atrina pectinata and they reached 79.9% of the total catch. The catch rate of Scapharca broughtonii and Callithaca adamsi was 69.6% and 10.4% respectively. The rate of bycatch was 20.1%, consisted with Echinodemata 13.0%, Chordata 3.6%. The catch of ordinary dredge was 27 species 1,307 number 85,052g and that of dredge with escapement device was 21 species 1,690 number 91,648g. In conclusion, the dredge gear with bycatch reduction device has higher catch rate of target species and lower bycatch rate to non-target species than ordinary one.

An Artificial Intelligence Method for the Prediction of Near- and Off-Shore Fish Catch Using Satellite and Numerical Model Data

  • Yoon, You-Jeong;Cho, Subin;Kim, Seoyeon;Kim, Nari;Lee, Soo-Jin;Ahn, Jihye;Lee, Eunjeong;Joh, Seongeok;Lee, Yang-Won
    • Korean Journal of Remote Sensing
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    • v.36 no.1
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    • pp.41-53
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    • 2020
  • The production of near- and off-shore fisheries in South Korea is decreasing due to rapid changes in the fishing environment, particularly including higher sea temperature in recent years. To improve the competitiveness of the fisheries, it is necessary to provide fish catch information that changes spatiotemporally according to the sea state. In this study, artificial intelligence models that predict the CPUE (catch per unit effort) of mackerel, anchovies, and squid (Todarodes pacificus), which are three major fish species in the near- and off-shore areas of South Korea, on a 15-km grid and daily basis were developed. The models were trained and validated using the sea surface temperature, rainfall, relative humidity, pressure,sea surface wind velocity, significant wave height, and salinity as input data, and the fish catch statistics of Suhyup (National Federation of Fisheries Cooperatives) as observed data. The 10-fold blind test results showed that the developed artificial intelligence models exhibited accuracy with a corresponding correlation coefficient of 0.86. It is expected that the fish catch models can be actually operated with high accuracy under various sea conditions if high-quality large-volume data are available.

Post Catch-up Theory: Direction and Agenda (탈추격 연구의 이론적 지향성 및 과제)

  • Hwang, Hye-Ran;Choung, Jae-Yong;Song, Wi-Chin
    • Journal of Technology Innovation
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    • v.20 no.1
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    • pp.75-114
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    • 2012
  • Transition from imitation based catch-up to new value creation based post catch-up innovation system is becoming the main issue for Korea. The notion of post catch-up research highlights the understanding of new patterns of innovation and the interrelationship among innovating agents within systems of innovation. More specifically, it is a context specific framework which accommodates discontinuum of technological innovation from the past and a creation of new organizational arrangement and institutions. Moreover, post catch-up approach follows the tradition of development, institutional and evolutionary theories context. This paper, therefore, explores whose focus is on the possibility of new theoretical development and new research agenda.

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Octopus fisheries in the coastal waters of Gangneung - I - Pot fishery - (강릉시 연안 문어어업에 관한 연구- I - 통발어업 -)

  • An, Young-Il;Park, Jin-Young
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.41 no.4
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    • pp.271-278
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    • 2005
  • In order to study the catch situation of the octopus pot fishery in the coastal waters of Gangneung, catch quantities and weight per month and depth, the soaking time & loss of fishing gear were studied based on 62 fishing times (1 set consisted of 150 pots which is equivalent to 1 fishing time) over a period of 10 months from February to December 2003 using commercial fishing vessels and training ships. The monthly CPUE was generally high in the months of june - September, and during this period July showed the highest quantity (134g/pot, 19.21kg/haul). In consideration of the fact that octopus below the weight of 2kg is protected in foreign countries, the majority of the catch was small with 76% (486 octopuses) below 1kg. The octopus catch quantity was high in depth of more than 40m, and the average catch number per set of pots in depths of over 50m was the highest with 13 octopuses. CPUE(g/pot) was the highest at a depth of over 60m recording 101. In terms of catch quantity per soaking time (4-18 days) the highest was on the 7th day, and 13-18 days also recorded high catches, and this suggests the possibility of ghost - fishing with the loss of fishing gear. Loss of fishing gear was the highest in terms of loss frequency and amount at depths of 20-30m. Consequently, it seems that octopus pot fishing at depths of more than 30m would relieve friction with other types of fishing and increase fishing efficiency.

Catch characteristics of the biodegradable gill net for flounder (생분해성 가자미 자망어업의 어획 특성)

  • Bae, Bong-Seong;Cho, Sam-Kwang;Park, Seong-Wook;Kim, Seong-Hun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.48 no.4
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    • pp.310-321
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    • 2012
  • There are many studies of the biodegradable net for fishing to prevent marine pollution in Korea and the snow crab gill nets is developed effectively. Recently, the biodegradable gill net for fishes is being developed. This study is the experiment of the catch characteristics for the biodegradable flounder gill net. The 8 experiments were carried out using the nylon gill net and the biodegradable gill net in from August to October, 2011 in the southern East Sea. The results obtained from the above approaches are summarized as follows; A total of 16 species was caught with most dominant species of Cleisthenes pinetorum followed by Liparis tanakai, Glyptocephalus stelleri, Buccinum striatissimum and Dasycottus setiger. A total of catch of the nylon net was 342,885g and that of the biodegradable net was 236,857g. Thus catch of the nylon net was 1.45 times more than that of the biodegradable net. The length composition of Cleisthenes pinetorum, caught by the biodegradable net was very similar to that of nylon. As a result of analysis on the effect of submerged time, small fish escaped more easily than large fish as the submerged time is getting longer. And catches of the biodegradable net was less than the nylon net's as higher as wave height. Wave height was more influential factor for fishing capacity than submerged time based on the results of a comparison between catch difference of two kinds of gill nets and catch characteristics.

A Catch-up Strategy of the K-Pop Firms in the Latecomer Environment (후발산업국 환경에서의 K-Pop기업 추격전략)

  • Choi, Hyundo
    • The Journal of the Korea Contents Association
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    • v.15 no.5
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    • pp.119-131
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    • 2015
  • The rise of K-Pop in the latecomer environment is unusual. There is little research on K-Pop from the catch-up perspective though it would yield some insight into a strategic direction of creative industries in the latecomer environment. Thus, this study aims to compare the firm capability, market development, and product strategy of K-Pop firms with ones of manufacturing firms during the catch-up period. It reveals first that K-Pop firms developed project execution capability to carry out discrete projects effectively by adopting in-house (vertical) system in music production and increasing the size of firms. Second, they pursued global market and utilized the window of opportunities based on a proven music genre. Third, K-Pop firms pursued the incremental innovation in the product development. Since these characteristics have many similarities with the catch-up strategy in the manufacturing sector, Korean catch-up experience could provide valuable insight into the development of creative industries in Korea.