• Title/Summary/Keyword: catch rate

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PRELIMINARY TEST ON THE CREEL HOLDING OF THE ANCHOVY, ENGRAULIS JAPONICA (멸치 축양의 예비시험)

  • RARK Sing Won;LEE Byoung Gee;SU Young Tae;SON Boo Il;KIM Moo Sang
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.5 no.2
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    • pp.63-67
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    • 1972
  • Preliminary creel-holding test of live anchovies which are to be used as bait for the skipjact fishery, was conducted on the fish caught by set net and lift net. They were held in the creels constructed with bamboo frame and minnow netting, during the period of Oct. 24-Nov. 28 in 1972. If was found that the survival rate of the creel-held anchovies varied by the size of fish, the towed distance and speed of fish-carrying creel in which the fish were accomodated after catchi. 1. The survival rate of the medium size anchovies, 7.8-9.6cm in length and 4.6-4.8 g in weight, was $70-92\%$ during the holding period of 20-35 days. Whereas, only $16\%$ of juvenile anchovies, 5.3cm in length and 1.0 g in weight, were survived for 19 hours after catch. 2. During the time of transport, the farther and faster the creel containing fish were towed, the less fish were survived in the subsequent holding period. 3. Though both the set net and lift net could be fairly used to catch live anchovy, no decision between these two gears could be made in this experiment to determine the superiorness for the subsequent survival rate.

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Economic Analysis of Swimming Crab (Portunus trituberculatus) Fry Releasing Program (꽃게 방류사업의 경제성 분석)

  • Kim, Bong-Tae;Kim, Dae-Young
    • Ocean and Polar Research
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    • v.39 no.3
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    • pp.213-219
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    • 2017
  • In this study, we analyzed the economic feasibility of the swimming crab (Portunus trituberculatus) fry releasing program in the West Sea of Korea. The catch rate of released fry in 2010, measured by genetic markers, was applied to the economic surplus method to estimate benefits. As a result of our analysis, the B/C ratio, as an indicator of economic evaluation, was determined to be 2.168, which means that the releasing program was economically feasible. And it was shown that the benefits to consumers is six times greater than the benefits to producers, confirming the necessity of the releasing program as a public work.

A Study on the Economic Values and Productivity Attained through a Reduction in Fishing Vessels Engaged in Coastal and Offshore Fisheries (연근해어업 어선감척사업으로 인한 생산성 및 투자 효과에 관한 연구)

  • Choi, Jong Du
    • Ocean and Polar Research
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    • v.36 no.4
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    • pp.343-351
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    • 2014
  • The purpose of this study is to estimate the economic value and productivity achieved through a reduction in fishing vessels engaged in coastal and offshore fisheries. We found that the value of increasing catch by types in offshore and coastal fisheries was about 17,338 billion won. To examine the economic value, a cost-benefit analysis was applied. This is based on the total cost of vessel reduction (4,576 billion won) assumed to be invested equally each year for five years. BCR and NPV with a discount rate (5.5%) were used to compare the profit of fishery activities in offshore and coastal areas. The model results showed that the NPV and BCR in offshore and coastal fisheries was 5,522 billion won and 2.340 respectively.

Efficiency of the Korean Bottom Survey Trawl for Snow Crab Chionoecetes opilio

  • Choi, Jung Hwa;Somerton, David A.
    • Fisheries and Aquatic Sciences
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    • v.15 no.4
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    • pp.337-343
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    • 2012
  • The Korean bottom trawl survey was conducted using a trawl designed by the National Fisheries Research and Development Institute (NFRDI). The capture efficiency and size selectivity of this trawl for snow crab Chionoecetes opilio was investigated by experimental tows. An auxiliary sampling net (underbag) was attached beneath the trawl net to capture crabs escaping under the trawl footrope. Experimental tows were made by the same vessel speed (3.4 knots) as in the bottom trawl survey, but toing time was shortened from the standard 30 min to 10 min to reduce possible trawl distortion due to the high catch rate of mud and debris in the underbag. In averaged over 17 tows conducted between 110-383 m depth, trawl efficiency of both males and females combined increased from about 10% at 20 mm (carapace width) to about 70% at 100 mm, with a width of 50% capture equal to 78 mm.

Nutritional strategy of early amino acid administration in very low birth weight infants

  • Lee, Byong Sop
    • Clinical and Experimental Pediatrics
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    • v.58 no.3
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    • pp.77-83
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    • 2015
  • Relative to a fetus of the same gestational age, very low birth weight (VLBW) infants are more likely to be underfed and to undergo growth restriction during their early hospital stay. The current trend towards "early and aggressive" nutritional strategies in VLBW infants aims to overcome the early nutritional deficiency and thereby boost postnatal catch-up growth, simultaneously improving long-term neurodevelopmental outcomes. Although the minimum starting amino acid (AA) dose to prevent negative nitrogen balance is well established, the upper limit and the rate of increase of early AA doses are controversial. Most randomized controlled trials show that early and high-dose (target, 3.5 to 4.9 g/kg/day) AA regimens, with or without high nonprotein calories, do not improve long-term growth and neurodevelopment. High-dose AA supplementation may lead to early metabolic disturbances and excessive or disproportionate plasma AA levels, particularly in infants of very low gestational age. Further large studies are needed to clarify the optimal strategy for early administration of parenteral AA doses in VLBW infants.

A Study on the Use and Provision of Urban Parks in Kwang Ju City (광주시 도시공원의 이용과 공급에 관한 연구)

  • 오병태
    • Journal of the Korean Institute of Landscape Architecture
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    • v.22 no.4
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    • pp.1-21
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    • 1995
  • Parks in Kwang Ju ar determined by the development of a housing project under the regulations of land development rather than the planning approach of park provision. This study tries to identify who is the provider of parks, to estimate the size of urban parks per person in the area of the housing project, to look at the spatial allocation patterns of park provision and to identify the character profiles of users and the social profile of an ares(Dong). This research has produced the following major conclusions : 1. The city government should set up a master plan of park provision to control park delivery system to avoid maldistribution. 2. A positive discrimination policy should be introduced to disadvantaged areas in terms of park provision. 3. The null hypothesis - there is no relationship between distance and park Use - is rejected by the correlation rate of 0.4984. 4. The ratio of parks per a person ; 10.43㎡/person in 1990 has decreased to 10.41㎡ /person in 1994. This means that the increase of parks in terms of quantity could not catch up the increase of population.

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Enhancing Harmful Animal Recognition At Night Through Image Calibration (이미지 보정을 통한 야간의 유해 동물 인식률 향상)

  • Ha, Yeongseo;Shim, Jaechang;Kim, Joongsoo
    • Journal of Korea Multimedia Society
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    • v.24 no.10
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    • pp.1311-1318
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    • 2021
  • Agriculture is being damaged by harmful animals such as wild boars and water deer. It need to get permission to catch a wild boar and farmers are using a lot of methods to chase harmful animals. The methods through deep learning and image processing capture harmful animals with cameras. It is difficult to analyze harmful animals that are active at night. In this case, In this case, using deep learning by image correction can achieve a higher recognition rate.

Effects of Nitrogen Fertilization Levels and Some Additives on the Chemical Composition and Silage Quality of Forage Rape (Brassica napus Subsp. oleifera) II. Effects of N fertilization levels and formaldehyde treatment on the chemical composition of forage rape silage (질소시비수준과 첨가제가 사초용 유채의 사료가치 및 사일리지의 품질에 미치는 영향 II. 질소시비수준과 포름알데히드 처리가 유채 사일리지의 품질에 미치는 영향)

  • Jo, Mu-Hwan;Kim, Dong-Am;Seo, Sung
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.8 no.1
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    • pp.40-46
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    • 1988
  • This study was carried out to determine the effects of nitrogen (N) fertilization levels (0, 100 and 200kg/ha) and formaldehyde (0.4,0.8 and 1.2%: w/w CM) on the chemical composition, dry matter (DM) yield and in-vitro dry matter digestibility (IVDMD) of forage rape (Brassica napus Subsp. oleifera) silage. The results obtained are summarized as follows : 1. Forage rape was a catch crop which was highly digestible and low concentration in NDF, ADF, cellulose and lignin. 2. The concentration of the water soluble carbohydrate (WSC) and buffering capacity (PK) was 17.9% and 6.77g/100g, respectively, provided the WSC to PK ratio was 2.65. 3. DM content of silage decreased as the rate of N fertilization increased, but concentration of ammonia-N decreased. IVDMD was not affected by the rate of N fertilization. 4. By the addition of formaldehyde, the pH and IVDMD were increased, but the DM, lactic acid, total organic acid and ammonia-N content of rape silage were decreased, that was effective as a silage additive for forage rape.

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Fallow Cover Crop Species and Nitrogen Rate of Fertigated Solution on Cucumber Yield and Soil Sustainability in Greenhouse Condition

  • Lee, Seong Eun;Park, Jin Myeon;Noh, Jae Seung;Lim, Tae Jun
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.1
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    • pp.23-27
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    • 2014
  • Nutrient accumulation in surface soil has become a serious problem for cucumber production in greenhouse. However, still in many cases, soil management practices are only focused on maintaining crop yield, regardless of sustainability related with soil chemical properties. This study was conducted to propose a sustainable soil management practice by investigating the impact of cover crop species and nitrogen rate of fertigated solution on cucumber yield and soil chemical properties in greenhouse condition. Rye and hairy vetch were tested as a fallow cover crop, and each amount of urea (1/2, 3/4, 1 times of N fertilizer recommendations), determined by soil testing result, was supplied in fertigation plots as an additional nitrogen source. The result showed that the yield of cucumber was higher in rye treatment than control and hairy vetch treatment. In addition, rye effectively reduced EC and accumulated nutrients from the soil. Meanwhile, N concentration of fertigated solution showed no significant effect on the growth and yield of cucumber. Consequently, these results suggest that it is desirable to choose rye as a fallow catch crop for sustainable cucumber production in greenhouse.

A Population ecological study of the hen clam(Mactra chinensis) in the Dong-li self-regulatory community of Busan (부산 동리어촌계 개량조개, Mactra chinensis의 자원생태학적 연구)

  • Park, Hee-Won;Zhang, Chang-Ik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.44 no.2
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    • pp.129-140
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    • 2008
  • This study was performed to estimate biomass and to provide management plan through population ecological characteristics, including growth parameters, survival rate, instantaneous coefficient of natural and fishing mortalities, and age at first capture of hen clam, Mactra chinensis, in the Dong-li self-regulatory community of Busan. The von Bertalanffy growth parameters estimated from a non-linear regression were $SH_{\infty}=86.24mm$, K=0.12/year, and = -1.37year. Survival rate(s) of the hen clam was 0.515. The instantaneous coefficients of natural mortality(M) was estimated to be 0.232/year and fishing mortality(F) 0.432/year for hen clam. The current biomass of the hen clam in the study area was estimated to be 713mt and the acceptable biological catch(ABC) was estimated under various harvest strategies based on $F_{0.1}$ and $F_{40%}$.