• Title/Summary/Keyword: Dokdo

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Vertical Distribution of Icthyoplankton in the Southern Waters of Jeju Island During Spring (봄철 제주 남부해역 난·자치어의 수직 분포)

  • Lee, Bo-Ram;Ji, Hwan-Sung;Yu, Hyo-Jae;Hwang, Kang-Seok;Kim, Doo-Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.2
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    • pp.146-153
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    • 2022
  • The vertical distribution and abundance of icthyoplankton in the southern waters of Jeju Island during June 2020 were investigated. Fish eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and the 16S rRNA gene. During this period, fish eggs of 23 taxa belonging to 21 families and larvae of 27 taxa belonging to 25 families were collected. Fish eggs were located mostly from the surface to 30 m depth of the water column. Larvae were located from the surface to 80 m depth of the water column. Vertical distributions of fish eggs and larvae were influenced by oceanography conditions such as temperature, salinity, and thermocline depth. No discernible difference in mean thermocline depth was observed between day and night.

First record of juvenile of the mirror butterflyfish, Chaetodon speculum Cuvier, 1831 (Perciformes: Chaetodontidae) collected from Pohang, Korea (한국 포항에서 채집된 나비고기과(Chaetodontidae) 어류 1미기록종, Chaetodon speculum의 유어 출현)

  • LEE, Yu-Jin;SONG, Young-Sun;KIM, Jin-Koo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.4
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    • pp.374-381
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    • 2021
  • A newly recorded chaetodontid species, Chaetodon speculum Cuvier, 1831 was collected in July, 2021 from Pohang, Korea. Its body color is yellow with black stripe across the eyes and a large spot occupying one fourth of the upper part of the body. C. speculum is very similar to congeneric species, C. zanzibarensis, but it can be distinguished by the size of the spot, shape of the lateral line, number of longitudinal line scales and geographic distribution. C. speculum is readily identified between post-larval stage and adult stage because of its similar external shape. Molecular analysis based on mitochondrial DNA COI sequences showed our specimen perfectly matched C. speculum. Therefore, we propose the new Korean name, "Heug-jeom-na-bi-go-gi" for C. speculum.

Density estimation of euphausiids and copepods by using a multi-frequency method

  • Woo Seok Oh;Geun Chang Park;Jung-Hwa Choi;Hyoung Been Lee;Kyounghoon Lee
    • Fisheries and Aquatic Sciences
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    • v.26 no.12
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    • pp.689-697
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    • 2023
  • This study used a multi-frequency acoustic method to assess the density and spatial distribution of dominant zooplankton, euphausiids and copepods, which are representative species of the zooplankton immigrating the sea around Republic of Korea. Acoustic surveys were carried out in the East Sea and South Sea from June 16 to 29, 2017, using the research vessel Tamgu 20th from the National Institute of Fisheries Science. From the results of the acoustic survey, the distribution of euphausiids was relatively higher in the East Sea than in the South Sea. Additionally, although the distribution of copepods was low in all areas, they were abundant in certain areas in the East Sea and the southern area of the Jeju Sea. Euphausiid and copepod density was estimated to be 1.2 g/m2 (CV = 19.1%) and 2.8 g/m2 (CV = 23.5%), respectively.

A Study on Improvement of Digital National Survey Map System (디지털국토통계지도 시스템 개선에 관한 연구)

  • Lee, Jong-Yong;An, Jung-Cheon;Cho, Sung-Ho
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.4
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    • pp.60-70
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    • 2006
  • National atlas map for provide various information is one part of National territorial Statatics Survey but National atlas map in 2004 year don't have stability and ability. National territorial Statatics Survey in 2005 years have octuple data compare with data in 2004 years but have only one map. One map is going to provide with stability and ability. We don't use DBMS, But We make a similarly struct in file based program. We programmed system of dynamic-linked data with spatial data. To dynamic-linked system, we make search engine to based index struct and make combobox search system. spatial data only have index codes(year, national terrial indicator, area). If spatial data request specfied data, search engine search index code and provide DB data. New system is middle step of using DBMS. We redraw map for display real Korea area (with dokdo). New map is shape and similar Korea map.

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SNS Big-data Analysis and Implication of the Marine and Fisheries Sector (해양수산 SNS 빅데이터 분석 결과 및 시사점)

  • Park, Kwangseo;Lee, Jeongmin;Lee, Sunryang
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.20 no.2
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    • pp.117-125
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    • 2017
  • SNS Big-data Analysis means to find potential value from big data which has produced by the social media. In this paper, SNS Big-data has been analysed to find Korean concerns by using 24 key words from the marine and fisheries sector. Among 24 key words, seafood, shipping and Dokdo Island are the most mentioned ones. Some key words such as ocean policies and marine security that have less concerns have bess mentioned less. Also, key words that are led by government are mostly mentioned by news media, but key words that are led by private sector and have intimate relationship with people's lives are mostly mentioned by Blogs and Twitters. Therefore, reflecting close national concerns by SNS Big-data Analysis and especially resolving negative factors are the most significant part of the policy establishment. Also, differentiated promotion methods need to be prepared because the frequency of key words mentioned from each type of media are different.

The paleo-shoreline and formation age of the 1st marine terrace in Heunghae-eup Pohang City, South Korea : evaluation of the mode and rate of the late Quaternary tectonism (I) (포항시 흥해읍 일대 해안단구 제1면의 구정선 고도와 형성 시기 - 한반도 제4기 후기 지각운동의 양식과 변형률 산출을 위한 연구(I) -)

  • Shin, Jae Ryul;Park, Kyung Geun
    • Journal of the Korean association of regional geographers
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    • v.22 no.3
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    • pp.703-713
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    • 2016
  • This study documents the altitude of paleo-shoreline and formation age of the $1^{st}$ marine terrace emerged around Heunghae-eup Pohang City (South Korea). As a result, the $1^{st}$ terrace representing 10 m of the paleo-shoreline was formed at MIS 5c around 100,000 BP and was influenced repetitive sedimentation of sea-wave till regression of MIS 5a. The result is recognized as a definite truth for the $1^{st}$ terrace in the eastern coast of the Korean peninsula based on synthetic reviews of previous studies and cross-validation of absolute age data. Furthermore, this study deduces a sea stand at MIS 5c from the geomorphological contrast method, but precise determination of paleo-shoreline of the $2^{nd}$ terrace should be required to estimate that of MIS 5c.

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Strategic Approaches and the Role of Naval Forces to Counter Increasing Maritime Threats (해양안보 위협 확산에 따른 한국 해군의 역할 확대방안)

  • Park, Chang-Kwoun
    • Strategy21
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    • s.31
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    • pp.220-250
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    • 2013
  • South Korean national security strategy should be developed to effectively handle and counter increasing maritime threats and challenges. There are three major maritime threats South Korea faces today; maritime disputes on the EEZ boundary and Dokdo islet issues, North Korean threats, and international maritime security. Maritime disputes in the region are getting intensified and turned into a military confrontation after 2010. Now regional countries confront each other with military and police forces and use economic leverage to coerce the others. They are very eager to create advantageous de facto situations to legitimize their territorial claims. North Korean threat is also increasing in the sea as we witnessed in the Cheonan incident and Yeonpyoung shelling in 2010. North Korea resorts to local provocations and nuclear threats to coerce South Korea in which it may enjoy asymmetric advantages. The NLL area of the west sea would be a main hot spot that North Korea may continue to make a local provocation. Also, South Korean national economy is heavily dependent upon foreign trade and national strategic resources such as oil are all imported. Without an assurance on the safety of sea routes, these economic activities cannot be maintained and expanded. This paper argues that South Korea should make national maritime strategy and enhance the strength of naval forces. As a middle power, its national security strategy needs to consider all the threats and challenges not only from North Korea but also to maritime security. This is not a matter of choice but a mandate for national survival and prosperity. This paper discusses the importance of maritime security, changing characteristics of maritime threats and challenges, regional maritime disputes and its threat to South Korea's security, and South Korea's future security strategy and ways to enhance the role of naval forces. Our national maritime strategy needs to show middle and long term policy directions on how we will protect our maritime interests. Especially, it is important to build proper naval might to carry out all the roles and missions required to the military.

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The Regional Development Strategy by Public-Private Activities: A Case Study of the Tsushima Arirang Festival, Tsushima, Nagasaki Province, Japan (민.관의 활동에서 본 쓰시마시의 지역 활성화 정책: 아리랑 축제를 사례로)

  • Shin, Young-Kun
    • Journal of the Korean Geographical Society
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    • v.43 no.6
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    • pp.951-960
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    • 2008
  • This paper examines how Tsushima has used the Arirang festival as a place marketing apparently targeting at Korean tourists, which has been historically achieved at the Arirang festival though public-private activities. Tsushima has tried to advertise Tsushima city to Korean tourists, with methods including the 'Chosen Agency Parade' and the title of the Arirang festival, but due to the Dokdo problem, the people of Tsushima objected to holding the Arirang festival. Therefore, Tsushima city had a meeting to solve it, and it was agreed that they need not stop the festival nor change of the title of the Arirang festival for the regional development, but instead they decided that the title of Arirang festival is to be used as a subtitle from 2007. By deciding this, The residents of Tsushima are sometimes against the opinion of Tsushima government, but they have eagerly participated in everything from the operation of the festival to the performances themselves. In this sense, it is thought that the Arirang festival is utilized as a local identity and also a place marketing, and the process for the regional development strategy is organized by public-private actors together.

Change of fishing power index by technological development in the offshore squid jigging fishery (근해오징어채낚기어업에서 어로기술발달에 따른 어획성능지수 변동)

  • OH, Taeg-Yun;SEO, Young-Il;CHA, Hyung-Kee;JO, Hyun-Su;AN, Young-Su;LEE, Yoo-Won
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.54 no.3
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    • pp.224-230
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    • 2018
  • Squid is one of the important fisheries resources in Korea. Therefore, squid has been designated and managed as a target species of total allowable catch (TAC) since 2007, but the catch amount is gradually decreasing. The analysis was conducted to identify the change of relative fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the offshore squid jigging fishery from 1960s to 2010s. Gross tonnage per fishing vessel increased with the increase in size until 1990, but then gradually decreased to 41.0 tons in 2000 and 37.1 tons in 2010. The illuminating power (energy consumption) by fishing lamps increased to 180 kW in 2005 and stabilized to 120 kW in 2015. Jigging machine started to be supplied to fishing vessels from the early 1970s, and fish finders began to be supplied in the early 1980s and gradually increased. Therefore, the relative fishing power index in the offshore squid jigging fishery increased from 1.0 in 1980 to 1.1 in 1990, to 3.5 in 2000 and to 2.5 in 2010, but the increment rate slowed down gradually. The results are expected to contribute to reasonable fisheries stock management.

Stock assessment of elkhorn sculpin (Alcichthys alcicornis) along the Uljin area in the East Sea of Korea

  • Lee, Soo-Jeong;Zhang, Chang-Ik;Choi, Young-Min;Lee, Dong-Woo;Lee, Jae-Bong
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.49 no.4
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    • pp.432-439
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    • 2013
  • This study was performed to assess the current stock condition of elkhorn sculpin along the Uljin area in the East Sea of Korea. To assess the state of the stock, yield-per-recruit (YPR) and spawning biomass-perrecruit (SBPR) analyses were performed. Estimates of $F_{max}$ and $F_{0.1}$ were 2.10/year and 0.48/year, respectively, and those of $F_{35%}$ and $F_{40%}$ were 0.66/year and 0.54/year, respectively. Current fishing mortality was estimated at 0.63/year and the current age at first capture was 2.41years. $F_{40%}$ was set as the target reference point of the stock. SBPR at $F_{40%}$ and current SBPR were estimated to be 41.85g and 37.77g, respectively. Estimated FOTY which is the fishing mortality for the overfished threshold yield was 0.49/year. The ratio of SBPR/$SBPR_{MSY}$ was calculated as 0.90 and that of $F/F_{OTY}$ was 1.05. The ratio of $t_c/t_{c\;opt}$ was calculated as 1.15 and that of $F/F_{OTY}$ was 1.17. Therefore, the current stock condition of elkhorn sculpin along the Uljin area of Korea has not been overfished, however, it indicates that a light overfishing is going on this stock.