• Title/Summary/Keyword: herring

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Distribution and Characteristics of Pacific Herring Clupea pallasii Spawning Beds in Jinhae Bay, Korea (진해만에서의 청어(Clupea pallasii) 산란장 분포와 특성)

  • Moon, Seong Yong;Choi, Jung-Hwa;Lee, Hae-Won;Kim, Jung-Nyun;Heo, Jin Seok;Gwak, Woo Seock;Lee, Yong-Deuk
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.52 no.5
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    • pp.534-538
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    • 2019
  • The distribution and characteristics of spawning beds of the Pacific herring Clupea pallasii, were observed by scuba diving in Jinhae Bay, Korea, with a focus on marine vegetation as adhesive substrates and egg density during the spawning season. In 2017, the fertilized eggs of C. pallasii were mainly found attached to the leaves of algae species Carpopeltis cornea, Gracilaria textorii, and Acrosrium polyneurum at the rocky shore in Wonpo-dong and Jeodo. The mean density of fertilized eggs in C. pallasii spawning beds was $153,776eggs/m^2$ off Wonpo-dong and $856,430eggs/m^2$ off Jeodo, giving an estimated total of $5.345{\times}10^9$ eggs in Wonpo-dong and $3.3074{\times}10^{10}$ eggs in Jeodo. We examined spawning beds with an area of $38,619m^2$ off Wonpo-dong and $34,760m^2$ off Jeodo. The choice of spawning bed may be affected by the composition of marine vegetation, such as the algal diversity of rocky shore environments, which could affect adhesive substrates and egg density during the spawning season. The results of the present study suggest that the spawning season of C. pallasii in Jinhae Bay is in January to mid-February.

A Qualitative Study on the Use of Fallacies in the 2022 Korean Presidential Debates (20대 대선 후보 TV토론에서의 오류 사용에 관한 질적 연구)

  • Heo, Man-Sup
    • The Journal of the Korea Contents Association
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    • v.22 no.10
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    • pp.676-690
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    • 2022
  • The present study aims to explore how fallacies, arguments that seem valid but are not, appear in 2022 South Korean presidential debates. It qualitatively analyzes the candidates' remarks in the first and last presidential debates (240 minutes) using 20 formal and informal fallacy concepts as a theoretical framework. Results show that the three candidates used 23 informal fallacies from 15 categories, including the straw man, red herring, begging the question, complex question, hasty generalization, appeal to the masses, and you too. The candidates relied on fallacies to defend their image and electoral agenda from adversary attacks and to contaminate their opponent's image and agenda. The arguers, who struggled with tough questions, frequently made fallacies as pseudo-arguments to avoid the situation without lying and violating election laws. This study indicates that the fallacy system can be a framework for analyzing crucial political content. Moreover, it warns against the abuse of fallacies in TV debates.

Studios on a Trematode Parasitic in Bivalves IV. On the Metacercaria of Himasthla kusasigi YAMAGUTI, 1939(Trematoda) found in the clam, Meretrix lusoria Roding (조개류에 기생하는 흡충류에 관한 연구 IV. 백합(Meretrix lusoria)에서 검출되는 Himasthla kusasigi YAMAGUTI, 1939에 대하여)

  • KIM Young Gill;CHUN Seh Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.17 no.1
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    • pp.61-67
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    • 1984
  • The life history of a trematod fluck, Himasthla kusasigi was studied on the morphological characters of metacercariae, its infection rate in the clam and the contamination experiment to the herring gull, Larus crassiostris. The size of the metacercariae was $210{\sim}230{\times}220{\mu}m$, excysted metacercariae was $420{\times}160{\mu}m$ and it had 31 collar spines. The ventral sucker($112{\times}100{\mu}m$) was located just below the central part of the body. Esophagus was narrow and long, the intestine was branched in the upper part of the ventral sucker and extended to the hind part of the body. Excretory bladder without the infected part was located in the hind part of the body. The branched excretory tube was filled with the small granules and extended to the pharynx area. The infection rate of the metacercariae varied from place to place. In Naecho do and Puan the rates were $98.4\%$ and $95.9\%$ respectively. The infected number of Himasthla kusasigi per clam was positively proportional to the size of the clam. The adult fluckes developed from the metacercariae were obtained from the experimented herring gull. The metacercariae emerge from their cysts in the stomach of the herring gull, then they migrate it the intestine and 25 days after, most of them were found in the intestine. The size of the adult was $4.8{\sim}7.5{\times}0.22{\sim}0.24mm$, oral sucker; $68{\sim}120{\times}70{\sim}120{\mu}m$, pharynx: $80{\times}50{\mu}m$, ventral sucker: $630{\sim}680{\times}610{\sim}680{\mu}m$. The head collar $48{\sim}75{\times}10{\mu}m$ had 31 collar spines. The isolated trematod fluck from the samples was classified as a Himasthla kusasigi by the morphological characteristics of the adult flock and its metacercariae. We oberved that the second intermediate host of Himasthla kusasigi was hard clam, Meretrix lusoria, while its final host was herring gull, Larus crassiostris and Tringa ochropus.

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Food Quality Characterization and Safety of Imported Fish Roe (Japanese flyingfish roe, Capelin roe and Pacific herring roe) (수입 어란(날치 알, 열빙어 알 및 청어 알)의 품질 특성과 안전성)

  • Lee, Jong-Soo;Kim, Jin-Soo;Kim, Jeong-Gyun;Oh, Kwang-Soo;Choi, Byeong-Dae;Park, Kwon Hyun;Choi, Jong-Duck
    • Journal of agriculture & life science
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    • v.45 no.6
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    • pp.95-108
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    • 2011
  • The food quality characterization and safety Japanese flying fish roe (JFF-R), capelin roe (C-R), Pacific herring roe (PH-R) were investigated. The size of JFF-R was 1.48-1.93 mm, which was longer than those of C-R and PH-R. The moisture content of JFF-R imported from Peru (JFF-R-P) was 70.3%, which was higher than that of JFF-R imported from China (JFF-R-C) (67.4%), while was lower than that of JFF-R imported from Indonesia (JFF-R-I) (83.3%). However, the salinity of JFF-R-P was 13.6%, which was lower than that of JFF-R-C, while was higher that of JFF-R-I (1.8%). The moisture contents and salinities of the other fish roes were 80.4% and 3.2%, respectively, for capalin roe, and 65.4% and 20.0%, respectively, for Pacific herring roe. According to the results of pH, volatile basic nitrogen content, heavy metal content, viable cell count and coliform group, the fish roes could be used as sanitary sources for preparation of seasoned JFF-R. The major fatty acids of fish roes were 16:0 (27.8-30.5%), 18:1n-9 (7.2-8.0%), 20:5n-3 (5.6-8.2%) and 22:6n-3 (22.0-25.6%) in JFF-R, and 16:1n-7 (6.7-9.3%) as well as these fatty acids in C-R and PH-R. Total amino acid contents of fish roes ranged from 9.44 g/100 g to 10.39 g/100 g and their major amino acids were aspartic acid, glutamic acid, leucine and lysine. The mineral content of JFF-R were higher than those of the other fish roes expected for zinc of JFF-R-I. According to the results of sensory evaluation, the color and texture of JFF-R-P were superior to those of the other fish roes. No difference was, however, found in flavor, among JFF-R-P and the other fish roes.

Theoretical Analyses of Herringbone Grooved Air Thrust Bearings (헤링본 그루브 공기 스러스트 베어링의 해석)

  • Park, Sang-Shin;Jang, Woo-Young
    • Tribology and Lubricants
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    • v.27 no.5
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    • pp.233-239
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    • 2011
  • In this study, the characteristics of herringbone grooved air thrust berings are studied. It is shown that a generalized coordinate transformation method which was developed for handling complex geometry such as herring bone groove journal bearings is well applied to herringbone grooved air thrust bearings. The load carrying capacity and stiffness and damping coefficients are calculated according to the design parameters like groove depth or the number of grooves and compared to that of plain air journal bearings.

Biological Characteristics and Preservation of Dokdo Island

  • Kim, Ki-Tai
    • The Korean Journal of Ecology
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    • v.25 no.1
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    • pp.59-62
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    • 2002
  • Dokdo, which is located in the middle of the East Sea, is a small island tilth a total area of 0.186 $\textrm{km}^2$. However, this small island, with its mild oceanic climate, has rich bio-resources and picturesque natural surroundings. Dokdo in the crystaline waters and In the central area of the deep sea is a treasury of algaes (sea oak, sea mustard, gulf weed, laver, agar-agar, etc.), molluscs (squid, ear shell, conch, etc.) and fishes (Alaska pollack, anchovy, saucy, herring, etc.). On the other hand, there are a lot of grasses and various kinds of grasses on the land of Dokdo. And a lot of back-tailed gulls (about 20,000 Individuals) live on this island. There have been disputes on the sovereignty over Dokdo between Korea and Japan. Japan has claimed sovereignty over Dokdo since Japan incorporated the island into Japanese territory in 1905 when it occupied the Korean Peninsula by force. Korea governed Dokdo not only before 1905 but also after its liberation in 1945. The Korean government, while heavily financing building facilities like pleas and quays, is endeavoring to preserve the natural surroundings of this island.

Deformation Mechanism Map for Creep and Superplastic Deformation in $YBa_2Cu_3O_{7-x}$ Ceramic Superconductors ($YBa_2Cu_3O_{7-x}$ 세라믹 초전도체의 크리프와 초소성변형에 대한 변형기관도)

  • 윤존도;초우예
    • Journal of the Korean Ceramic Society
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    • v.33 no.6
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    • pp.718-724
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    • 1996
  • Deformation mechanism map of Langdon-Mohammed type for YBa2Cu3O7-x superconducting ceramic was constructed by considering mechanisms of Nabarro-Herring Coble and powder-law creep and grain boundary sliding (GBS) with an accommodation by grain boundary diffusion. The map was found consistent with experi-mental results not only of the creep the also of the superplastic deformation. It showed the transition from interface reaction-controlled to the grain boundary diffusion-controlled GBS mechanism at about 1 ${\mu}{\textrm}{m}$ grain size and 100 MPa flow stress in agreement with the experimental results.

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Effect of Minor Additives on the MgO Creep (MgO의 고온 Creep에 미치는 미량 첨가물의 영향)

  • Kim, Hwan
    • Journal of the Korean Ceramic Society
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    • v.14 no.3
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    • pp.182-186
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    • 1977
  • Compression creep of polycrystalline magnesia at about 1$600^{\circ}C$ under 5-40kg/$\textrm{cm}^2$ was examined, and also the effects on it of minor additives such as B2O3, CaO and SiO2 were examined. The high temperature creep of high purity magnesia was primarily controlled by the Nabarro-Herring type lattice diffusion of Mg in magnesia. B2O3 was included in the molten state and showed on increasing B2O3 contents. Some of the CaO and SiO2 were also included in the molten state, promoted the grain boundary sliding, so that creep rate was increased with an increasing content of them.

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A Numerical Analysis Study on Plate Heat Exchanger Heat Transfer Characteristic by Corrugation Angle and Pitch (주름 각도와 피치에 따른 판형 열교환기 전열특성에 관한 수치해석 연구)

  • Kang, Dae-Ki;Kim, Si-Pom;Hwang, Il-Ju;Lee, Jae-Hoon;Do, Tae-Wan;Yeo, Woon-Yeop
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.11 no.3
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    • pp.154-159
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    • 2012
  • For numerical analysis of the plate heat exchanger, a lot of time are required in modeling work and calculation. Whereas, this paper was purposed to identify characteristic of the plate heat exchanger through simplification of modeling by interpreting the numerical analysis proximity with the actual model. This study was also examined temperature difference between inlet side and outlet side, inner pressure drop, heat transfer area of plate and change of heat transfer coefficient on the plate depending on the inner corrugation angle and corrugation pitch of a herring bon pattern of the plate heat exchanger among chevron types of the plate exchanger.

Environmental Factors and Natural Resource Stock - Atlantic Herring Case - (환경요인과 대서양 청어자원량과의 관계)

  • Cho, Jung-Hee;Gates, John M.
    • Environmental and Resource Economics Review
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    • v.10 no.4
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    • pp.471-482
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    • 2001
  • 대서양 청어는 바닷가재 어업에 있어 주요 미끼로서 사용되어지고 있고 해양 생태계내에서 다른 어류들의 먹이로서 중요한 위치를 차지하고 있다. 그러나 해양생태계의 환경적인 요소, 즉 해수면 온도, 플랑크톤량, 서식지 해저퇴적물 상태에 따라 자원이 민감하게 영향을 받는다. 특히 미성어의 단계에서는 낮은 해수 온도에 대해 영향을 받기가 쉽다. 이 연구에서는 인공위성을 이용하여 측정된 해수면 온도와 2년생 가입자원의 상관관계를 분석하였다. 해수면 온도의 측정지역은 대서양 청어의 산란지역으로 한정하였다. 연구 결과 상관계수는 0.69로 나타났고 이는 어업자원의 변동성을 설명함에 있어 환경적인 요인이 중요하게 고려되어야 한다는 것을 의미한다.

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