• Title/Summary/Keyword: Gill-net

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New Record of Cantherhines multilineatus (Tanaka, 1918) (Pisces: Monacanthidae) from Jeju Island, Korea (한국 제주도에서 채집된 쥐치과(Monacanthidae) 어류 1미기록종, Cantherhines multilineatus (Tanaka, 1918))

  • Myoung, Se Hun;Kim, Jin-Koo;Kwun, Hyuck Joon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.2
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    • pp.199-202
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    • 2018
  • A single specimen (174.5 mm in standard length) of Cantherhines multilineatus, belonging to the family Monacanthidae in the order Tetraodontiformes, was first collected from northern Jeju Island, Korea, in August 2016, using a gill net. This species is distinguished from the congeneric species C. dumerilii by the lack of spines on the sides of its caudal peduncle (vs. two pairs of spines in C. dumerilii) and from C. pardalis in having 9-10 narrow dark longitudinal bands on the cheek and side (vs. dark brown with a network of close-set polygonal spots in C. pardalis). The species also very similar to Stephanolepis cirrhifer, but its first dorsal fin spine is more elongated than the rays of its second dorsal fin rays. We have adopted the Korean common name "Jul-mu-nui-jwi-chi" for C. multilineatus, in accordance with the proposal of Yamada et al. (2009).

Study for Thirteen Weeks Subacute Toxicity of BDR-29 in Rats (BDR-29의 랫트에 대한 13주 반복투여 독성에 관한 연구)

  • Chang, Bo-Yoon;Kang, Dae-Gill;Lee, Ho-Sub;Kim, Sung-Yeon
    • Korean Journal of Pharmacognosy
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    • v.39 no.1
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    • pp.60-67
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    • 2008
  • The subcronic toxicity of BDR-29, a herbal preparation of Cassiae Semen, Prunellae Spica, Tribuli Fructus, and Uncariae Rhamulus et Uncus, was examined in male and female Sprague-Dawley rats. Rats were treated with the test substance at a dose 5 mg/kg, 50 mg/kg and 500 mg/kg intragastrically for 13 weeks. No death and abnormal clinical signs were observed throughout the administration period. There were not significantly different from control group in net body weight gain, food and water consumption, organ weight, gross pathological findings, and urine analysis among the groups rats treated with different doses of the BDR-29. Hematological findings and biochemical examination revealed no evidence of specific toxicity related to BDR-29. From these results, no observation effect level (NOEL) of BDR-29 is 500 mg/kg/day under the condition employed in this study.

New Record of the Roundbelly Cowfish, Lactoria diaphana (Ostraciidae, Tetraodontiformes) from Korea (한국산 거북복과(Ostraciidae) 어류 1미기록종, Lactoria diaphana)

  • Kim, Byeong Yeob;Han, Song Hun;Song, Choon Bok
    • Korean Journal of Ichthyology
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    • v.28 no.4
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    • pp.279-282
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    • 2016
  • This is the first report of Lactoria diaphana (Tetraodontiformes: Ostraciide) from Korea. A single specimen (208.0 mm standard length) was collected off the coast of Jejudo Island by gill net on 14 November, 2011. This species is characterized by having a pair of strong spines in front of the eyes, a slightly curved spine on the dorsal ridge, a pair of strong and short spines on the ventro-lateral ridge and various-sized spots on the body. We add L. diaphana to the Korean fish fauna and propose a new Korean name, "So-ppul-bok" for the species.

Status of J stock minke whales (Balaenoptera acutorostrata)

  • Song, Kyung-Jun
    • Animal cells and systems
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    • v.15 no.1
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    • pp.79-84
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    • 2011
  • The status of J stock minke whales (Balaenoptera acutorostrata) was assessed using potential biological removal (PBR) and mortality data. Using the estimated abundance of minke whales in this area (6260; CV = 0.212), the minimum population estimate of the stock was estimated as 5247. The PBR for J stock minke whales was calculated as 52.5 individuals using the minimum population estimate (5247), one-half of the maximum theoretical net productivity rate (0.02) and the recovery factor (0.5). The estimated mean annual level of anthropogenic mortality was 270.4 individuals. Thus, the status of this stock was considered as strategic. However, fortunately, the abundance of this population in the East Sea from 2000 to 2008 showed an increasing trend (rate of increase 0.0488; annual rate of increase 5.0%) although it is not statistically significant (P > 0.05). The primary sources of anthropogenic mortality were bycatch (set nets, pots and gill nets) and illegal catch. Because of the status of this population, it is urgently necessary to reduce the amount of bycatch and illegal catch of minke whales. Further study needs to use population health and viability analysis for investigating the long-term survival of this population more clearly.

Analysis on Economic Effect and Resource Recovery of Major Coastal Fisheries by Vessel Buy-back Program in Korea (어선감척사업에 따른 주요 연안어업의 자원회복 및 경제적 효과 분석)

  • Cho, Hoon-Seok;Nam, Jong-Oh
    • The Journal of Fisheries Business Administration
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    • v.50 no.1
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    • pp.17-37
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    • 2019
  • The purpose of this study is to estimate the resource recovery effect and the economic effect of the fishermen by the fisheries vessel buy-back program. First, this study standardizes the fishing efforts of coastal gill net, coastal trap, and coastal composite fisheries using Gavaris general linear model. Second, the resource evaluation is performed by using vessel buy-back program data, and also the CYP model based on exponential growth function is applied. In order to derive the effect of the vessel buy-back program, the MSY with the vessel buy-back program is compared with the MSY without the vessel buy-back program. Finally, we compare and analyze producer surplus under the equilibrium of the MEY and the OA using bioeconomic model. In conclusion, the vessel buy-back program has shown an increase in resource growth and economic improvement for the remaining fishermen. The result shows that the remaining fishermen are able to obtain an increase in producer surplus of about 53% due to the vessel buy-back program under equilibrium levels of the open access and the maximum economic yield.

Learning-Based Multiple Pooling Fusion in Multi-View Convolutional Neural Network for 3D Model Classification and Retrieval

  • Zeng, Hui;Wang, Qi;Li, Chen;Song, Wei
    • Journal of Information Processing Systems
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    • v.15 no.5
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    • pp.1179-1191
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    • 2019
  • We design an ingenious view-pooling method named learning-based multiple pooling fusion (LMPF), and apply it to multi-view convolutional neural network (MVCNN) for 3D model classification or retrieval. By this means, multi-view feature maps projected from a 3D model can be compiled as a simple and effective feature descriptor. The LMPF method fuses the max pooling method and the mean pooling method by learning a set of optimal weights. Compared with the hand-crafted approaches such as max pooling and mean pooling, the LMPF method can decrease the information loss effectively because of its "learning" ability. Experiments on ModelNet40 dataset and McGill dataset are presented and the results verify that LMPF can outperform those previous methods to a great extent.

Comparison of the Spawning Characteristics of the Yellow Striped Flounder Pseudopleuronectes herzensteini in the Coastal Waters off Gangwon and Gyeongbuk, Korea (동해안에 서식하는 참가자미(Pseudopleuronectes herzensteini)의 해역별 산란특성 비교)

  • Kim, So Ra;Lee, Soo Jeong;Yang, Jae Hyeong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.3
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    • pp.318-328
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    • 2021
  • We investigated the maturity and spawning of the brown sole Pseudopleuronectes herzensteini, in the coastal waters of the East Sea off Gangwon and Gyeongbuk, South Korea, using samples collected by gill net and longline fishery from January 2018 to December 2019. We analyzed oocyte development, monthly maturity stage, gonadosomatic index (GSI) and total length at maturity. Histological analysis of ovarian development in P. herzensteini revealed that the development was group-synchronous. The spawning peak in Gangwon and Gyeongbuk occurred from April to May and from February to March, respectively. Thus, the spawning season in Gangwon was 1-2 months later than that in Gyeongbuk. The length at 50% maturity for females was estimated as 24.2 cm and 19.0 cm in Gangwon and Gyeongbuk, respectively. Similarly, the length at 50% maturity for males was estimated as 19.8 cm and 16.5 cm in Gangwon and Gyeongbuk, respectively.

Species Composition and Seasonal Variation of Fish Assemblage of the Western Coastal Waters of Jeju Island, Korea (제주도 서부연안 어류군집의 종조성 및 계절변동)

  • Lee, Seung Jong;Ko, Joon Chul;Yoo, Joon Taek;Im, Yang Jae;Kim, Byung Yeob;Kim, Joo Il
    • Korean Journal of Ichthyology
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    • v.21 no.3
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    • pp.167-176
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    • 2009
  • Species composition and seasonal variation of fish assemblages in the western coastal waters of Jeju Island were determined using samples collected by a trammel net, gill net and fish pot in 2008. During the survey period, a total of 81 species (45 families and 13 orders) of fishes were identified, and Perciformes and Scorpaeniformes accounted for 69.1% of the total number. The number of species was higher in warm months than in cold months, showing a peak in July at 54 species and a low in April at 42 species. The number of individuals and the biomass peaked in September at 895 inds. and 135 kg, and were lowest in December at 450 inds. and 52 kg. The diversity indices of fish catches in trammel net and fish pot were 2.88~3.22 and 1.31~1.87, respectively, and were highest in September. Sebastiscus marmoratus, Stephanolepis cirrhifer, Choerodon azurio and Pseudolabrus sieboldi were dominant species, which occurred abundantly during the entire survey period.

Characteristics on the Motion of Purse Seine(II) -An Analysis on the Sinking Characteristics of Model Purse Seine by Different Netting Material- (건착망의 운동특성(II) -그물감이 다른 건착망의 침강특성 해석-)

  • Kim, Suk-Jong;Park, Jeong-Sik
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.31 no.4
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    • pp.372-378
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    • 1995
  • This study describes an analysis on the sinking characteristics in purse seine. The experiment was carried out using three simplified model seines in a flume tank under still water condition. The densities($\rho$) of netting materials were 0.91g/$cm^3$ for PP seine, 1.14g/$cm^3$ for PA seine and 1.38g/$cm^3$ for PES seine. Differential equations were derived from the conservation of momenta of the model seines and used to determine the sinking speeds of the depths of leadline and the other portions of seines. An analysis carried out by simultaneous differential equations for numerical method by subroutine Runge-Kutta-Gill. The results obtained were as follows: 1) Sinking speed of net margin was fastest for PP seine, followed by PA and PES seines. 2) The coefficient of resistance for netting of seine was estimated to be $K_D=0.061({\frac{\rho}{{\rho}_w}})^4$. 3) The coefficient of resistance for netting bundle of seine was estimated to be $C_R=0.91({\frac{\rho}{{\rho}_w}}$. 4) In all seines, the calculated depths of leadline closely agreed with the measured ones(meas.=0.99cal.).

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Development and physical properties on the monofilament for gill nets and traps using biodegradable aliphatic polybutylene succinate resin (생분해성 지방족 폴리부틸렌 석시네이트 수지를 이용한 자망과 통발용 단일섬유의 방사기술 개발 및 물리적 특성)

  • Park, Seong-Wook;Bae, Jae-Hyun;Lim, Ji-Hyun;Cha, Bong-Jin;Park, Chang-Doo;Yang, Yong-Su;Ahn, Heui-Chun
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.43 no.4
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    • pp.281-290
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    • 2007
  • This study was aimed not only to develop the gill net and trap made of biodegradable monofilaments in order to prevent a ghost fishing and to protect marine ecosystem, but also to analyze their spinning process and physical properties. Results showed that the spinning speed of biodegradable polybutylene succinate(PBS) monofilament was estimated to be approximately 100m/min when spinning temperature and cooling water temperature were adjusted at $180^{\circ}C$ and $3^{\circ}C$, respectively. The breaking loads of PBS monofilaments were estimated to be $35.3kg/mm^2$ at ${\phi}0.2mm$, $46.5kg/mm^2$ at ${\phi}0.3mm$, and $49.7kg/mm^2$ at ${\phi}0.4mm$ in the dry condition, respectively. However, its breaking loads in the wet condition were reduced by 2.4-5.5%, compared to those in the dry condition. The knotted strength of PBS monofilament at ${\phi}0.2mm$ was estimated to be 98.6% of PE in the dry condition. The breaking load of PBS monofilament at ${\phi}0.3mm$ was evaluated to be 81.8% of PA, and its softness showed 3 times less than that of PA in the wet condition. The breaking load of PBS monofilament at ${\phi}0.4mm$ was 95.3% of PA, and its softness showed 1.6 times less than that of PA in the wet state. However, the load elastic elongations of two kinds of monofilaments were estimated to be 1% higher than that of PA.