• Title/Summary/Keyword: 고유수와 연안수

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A Study on Geo-morphological Analysis and Risk Assessment Method Using Geospatial Information (지형공간정보를 활용한 지형형태학적 분석 및 위험도 평가 방안 연구)

  • Kim, Byung Ju;Park, Seon Jung;Choi, Il Hoon;Park, Seol Hwa;Park, Seung Min;Seo, Heui Jung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.34 no.5
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    • pp.135-143
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    • 2022
  • Rock platforms and TTP (breakwater) are dangerous environments commonly subject to tidal and high wave energy on the open coast. This paper is a study on risk assessment to provide risk information, which is a representative method for preventing coastal safety accidents. Risk assessment based on geo-morphological information was conducted for the Halmi-Halabi rock platform in Anmyeon-eup, Taean-gun, Chungcheongnam-do. As a result of the risk assessment in 16 directions, the risk was evaluated high in the NE, ENE, S, SSW, and W directions, where there are many sections with slopes exceeding ±20°, and the NW direction was the lowest. Geo-morphology on rock platform is central to understanding what makes one stretch of complex coastline more hazardous than another, and it can be used to create site-specific morphological risk item. In particular, it will be assisting coastal managers in an effort to reduce the number of injuries and drowning incidents by providing hazard information to assess the relative risk.

Research for Application of Interactive Data Broadcasting Service in DMB (DMB에서의 양방향 데어터방송 서비스도입에 관한 연구)

  • Kim, Jong-Geun;Choe, Seong-Jin;Lee, Seon-Hui
    • Broadcasting and Media Magazine
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    • v.11 no.4
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    • pp.104-117
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    • 2006
  • In this Paper, we analyze the application of Interactive Data Broadcasting in DMB(Digital Multimedia Broadcasting) in the accordance with convergence of service and technology. With the acceleration of digital convergence in the Ubiquitous period substantial development of digital media technology and convergence of broadcasting and telecommunication industry are being witnessed. Consequently these results gave rise to newly combined-products such as DMB(Digital Multimedia Broadcasting), WCDMA(Wide-band code division multiple access), Wibro(Wireless Broadband Internet), IP-TV (Internet protocol TV) and HSDPA(High speed downlink packet access). The preparatory stage for the implementation of Interactive Data Broadcasting Service will be reached by the end of December, 2006. DMB is the first result of a successful convergence service between Broadcasting and Telecommunication in new media era. Multimedia technology and services are the core elements of DMB. The Data Broadcasting will not only offer various services of interactive information such News, Weather, Broadcasting Program etc, but also be linked with characteristic function of mobile phone such as calling and SMS(Short Message Service) via Return Channel.

Annual Reproductive cycle of the File Fish, Stephanolepis cirrhifer, on the Southern Coast of Cheju Island (제주 남부 연안 쥐치, Stephanolepis cirrhifer의 생식년주기)

  • Lee, Seung-Jong;Go, You-Bong;Lee, Young-Don
    • Korean Journal of Ichthyology
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    • v.12 no.1
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    • pp.62-70
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    • 2000
  • Annual reproductive cycle of the file fish, Stephanolepis cirrhifer (Temminck et Schlegel), was histologically investigated. Samples were collected monthly in the coastal waters of Chungmun, south of Cheju Island, Korea from July 1997 to June 1999. In males and females of S. cirrhifer, the values of GSI (gonadosomatic index) were similar to the changes of water temperature and day length. GSI values in males and females were reached the maximum in June. Reproductive cycle could be divided into the following successive stages: in females, growing stage (February to May), mature stage (May to June), spawning stage (June to August), degenerative and resting stage (September to December), and in males, growing stage (February to April), mature stage (May to June), spent stage (June to August), degenerative and resting stage (September to January), respectively. Throughout histological observation of the ovary in the spawning period, the species belong to an asynchronous and multiple spawner.

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Spatio-temporal Distributions of Phytoplankton Community in the Coastal Waters of Central South Sea (CWoCSS), Korea (남해 중앙부 연안해역 식물플랑크톤 군집의 시·공간적 분포특성)

  • Yoon, Yang Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.1
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    • pp.441-453
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    • 2017
  • This paper described the spatio-temporal distributions in the phytoplankton community, such as species composition, standing crops, and dominant species, from July 2012 to April 2013 in the Coastal Waters of Central South Sea (CWoCSS) of Korea. A total of 87 species of phytoplankton belonging to 52 genera were identified. In particular, diatoms and phytoflagellates comprised more than 62.1% and 37.9% of the total species, respectively. The phytoplankton cell density fluctuated with an annual mean of $7.9{\times}10^4cells{\cdot}L^{-1}$ between the lowest value of $1.0{\times}10^3cells{\cdot}L^{-1}$ in spring and the highest value of $4.5{\times}10^5cells{\cdot}L^{-1}$ in winter. The seasonal succession of the dominant species were Chaetoceros curvisetus, Ch. debilis in summer, Eucampia zodiacus in autumn, E. zodiacus, Thalassiosira curviseriata in winter and Skeletonema costatum -ls (like species), Leptocylindrus danicus in spring. According to principal component analysis, the phytoplankton community of the CWoCSS was characterized by the mixing rate between the freshwater inflow from Somjin River and the seawater of the South Sea, Korea.

First Record of a Clingfish, Lepadichthys frenatus (Perciformes: Gobiesocidae), from Korea (한국산 학치과(농어목) 어류 1미기록종, Lepadichthys frenatus)

  • Kim, Byung-Jik;Go, You-Bong;Nakaya, Kazuhiro
    • Korean Journal of Ichthyology
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    • v.17 no.4
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    • pp.255-257
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    • 2005
  • A single specimen (59.3 mm in SL) of the family Gobiesocidae was collected from the northern coast of Jeju Island, Korea. It was identified as Lepadichthys frenatus by its having dorsal and anal fins with 17 and 13 rays, respectively, both fins connected to the caudal fin, and a reddish-brown body color. We describe the specimen as the first record from Korea, and propose a new Korean name "keun-ip-hak-chi" for the species.

Derivation of Inherent Optical Properties Based on Deep Neural Network (심층신경망 기반의 해수 고유광특성 도출)

  • Hyeong-Tak Lee;Hey-Min Choi;Min-Kyu Kim;Suk Yoon;Kwang-Seok Kim;Jeong-Eon Moon;Hee-Jeong Han;Young-Je Park
    • Korean Journal of Remote Sensing
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    • v.39 no.5_1
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    • pp.695-713
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    • 2023
  • In coastal waters, phytoplankton,suspended particulate matter, and dissolved organic matter intricately and nonlinearly alter the reflectivity of seawater. Neural network technology, which has been rapidly advancing recently, offers the advantage of effectively representing complex nonlinear relationships. In previous studies, a three-stage neural network was constructed to extract the inherent optical properties of each component. However, this study proposes an algorithm that directly employs a deep neural network. The dataset used in this study consists of synthetic data provided by the International Ocean Color Coordination Group, with the input data comprising above-surface remote-sensing reflectance at nine different wavelengths. We derived inherent optical properties using this dataset based on a deep neural network. To evaluate performance, we compared it with a quasi-analytical algorithm and analyzed the impact of log transformation on the performance of the deep neural network algorithm in relation to data distribution. As a result, we found that the deep neural network algorithm accurately estimated the inherent optical properties except for the absorption coefficient of suspended particulate matter (R2 greater than or equal to 0.9) and successfully separated the sum of the absorption coefficient of suspended particulate matter and dissolved organic matter into the absorption coefficient of suspended particulate matter and dissolved organic matter, respectively. We also observed that the algorithm, when directly applied without log transformation of the data, showed little difference in performance. To effectively apply the findings of this study to ocean color data processing, further research is needed to perform learning using field data and additional datasets from various marine regions, compare and analyze empirical and semi-analytical methods, and appropriately assess the strengths and weaknesses of each algorithm.

Bioecological Studies in the Upwelling Area of Cheju Island. ( I ) - Upwelling Phenomenon and Chemical Properties of Seawater in the Southwestern Coastal Area of Cheju Island (제주도 주변 용승역의 생물생태학적 기초연구 ( I )- 제주도 남서부 연안해역의 해수화학적 특성과 용승현상)

  • KANG Tae-Youn;CHOI Young-Chan;Go You-Bong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.5
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    • pp.603-613
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    • 1996
  • Hydrographic conditions (temperature, salinity, dissolved oxygen), nutrients, chlorophyll-a and suspended solid have been studied in the southwestern coastal area of Cheju Island from April 1993 to March 1994. Vertical profile of temperature, salinity and chemical properties (nutrients, chlorophyll-a) distribution in th southwestern sea of Cheju Island showed a upwelling feature. Although it was not clear in winter season, it seems to continued through out the year. In the surface water at the upwelling areas, the ranges of dissolved oxygen, nitrate, phosphate and silicate was $3.30\~8.43\;ml/l,\;0\~7.12{\mu}g/l,\;0.03\~1.75{\mu}g-at/l\;and\;2.75\~22.32\;{\mu}g-at/l$l, respectively. Nutrients was higher in the shore water than in the offshore water, because sufficient supply of nutrients from the bottom water by coastal upwelling. In November, especially high concentration silicate was observed at all the stations and depth in the study area. At all station of bottom water (down to the depth of 60 meter), concentration value of dissolved of gen was as high as 8 ml/l. Mean values of N/P was 8.0, lower than Redifield ratio of 16. The mean values of Si/P was observed to 46.3 in southwest of Cheju Island. Concentration of chlorophyll-a was in the range of $0.04\~2.36\;{\mu}g/l$. Concentration of chlorophyll-a in surface orator at all station was especially higher in spring than in other seasons. Mean concentration value of suspended solids was 3.14 mg/l $(0.75\~8.47\;mg/l)$. Ratio of the volatile suspended solids to the suspended solids was higher in the inshore water $(53\%)$ than in the offshore water $(46\%)$, and higher in the surface water than in the bottom water.

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Monitoring of the Estuary Sand Bar Related with Tidal Inlet in Namdaecheon Stream using Landsat Imagery (Landsat 위성 영상을 활용한 강원도 양양군 남대천 연안 하구사주 갯터짐 환경 모니터링)

  • Jang, Jiwon;Eom, Jinah;Cheong, Daekyo;Lee, Changwook
    • Korean Journal of Remote Sensing
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    • v.33 no.5_1
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    • pp.481-493
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    • 2017
  • Estuary sand bar of Namdaecheon Stream is located in Yangyang-gun, Gangwon-do in Korea. This unique place is situated between end of Namdaecheon Stream and East Sea. It is an important environment area of the global ecosystem from the transition zone of land and marine environments by forming a variety of coastal circumstance. Some endemic species should be protected which is appearing in the Namdaecheon Stream because of preservation for future generations. Especially, the salmon return to this stream as adults in order to breed which is more than 70 % of the salmon in Korea peninsular. The monitoring of estuary sand bar is need to analyze ecological environment and sustainable development with time. First of all we represents a different shape of estuary sand bar of Namdaecheon Stream from 1984 to 2015 using Landsat satellite imagery series. Particularly movement of the "tidal inlet" is most important factor to investigate the condition of the change for estuary sand bar. The location of tidal inlet is compared with precipitation, height of tide and oceanic current data according to time variation.

Empirical Orthogonal Function Analysis on the Monthly Variation of Flow Pattern in the East Sea of Kore (경험적 고유함수법에 의한 한국동해 해황변동해석)

  • CHANG Sun-Duck;LEE Jong-Sup;SUH Jong-Moon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.6
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    • pp.323-330
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    • 1988
  • The spatial distribution of sea water temperature variation pattern in the South-eastern coastal region of Korea was studied by empirical orthogonal function (E. O. F) analysis in several depths from surface to 300m using the monthly mean water temperature averaged for 23 years, water mass analysis by T. S diagram and sectional diagram of water temperature. Typical type of water temperature variation in this area can be divided into surface (0m-50m), subsurface (100m-150m) and intermediate (200m-300m) layer. The first mode value of water temperature change on the surface layer showed $99\%$ of total variation, and decreased with the increase of the depth. It is deduced to be in the range of $60-70\%$ on the 300m layer. The representative type of water temperature fluctuation by the first mode in each layer is as follows. Water temperature change in the surface layer showed a seasonal variation. In the subsurface layer, it is governed by the interaction of the Tsushima Warm Current water with the cold water and by the heat transfer process from the upper layer. In the intermediate layer, water temperature variation seems to be governed by the advection of the bottom cold water.

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Study on the Fish Community in the Seagrass Belt around Cheju Island II. Growth, reproduction and food habit of Tubesnout, Aulichthys japonicus Brevoort (제주도 연안 해초지대의 어류군집에 관한 연구 II. 실비늘치 (Aulichthys japonicus Brevoort)의 성장, 산란 및 식성)

  • Go, You-Bong;Cho, Sung-Hwan;Go, Gyung-Min
    • Korean Journal of Ichthyology
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    • v.9 no.1
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    • pp.61-70
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    • 1997
  • The spawning season, growth and feeding habit of tubesnout, Aulichthys japonicus were examined from the samples collected by a small beam trawl in the Zostera marina belt at the coastal water off Hamduck, Cheju Island, from May 1993 to May 1994. Tubesnout was the dominant species of overall 58 species collected in the study area throughout the year. The larvae and juvenile of tubesnout in the frequency distributions of body length began to appear in the Z. marina belt in March, and adults disappeared after May in the following year. The gonad weight index (GWI) and the condition factor (K) were high from November 1993 to January 1994 for males, while females were high from February to May 1994. Although tubesnout is an oviparous fish, males have the urogenital papilla. These results suggest that they were fertilized between November and January, and then males seemed to be died or move into other places. Females were examined to spawn from February to May. The stomach contents of tubesnout were dominated by copepoda smaller than ca. 1mm, Paracalanus, Oithona, Acartia, Oncaea and Harpacticoidae, accounting for 97% of total food items. The feeding habit of tubesnout did not vary by size. The fishes fed on Calanus, Euchaeta and decapoda larvae larger than ca. 3mm in March and April during the spawning season.

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