• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.333-335
• /
• 2010

Global warming gas caused an increase in a direct and indirect problems like the rising sea level, seawater overflowing and a coastal flooding. The loss and damage of the republic of korea are increasing because of the rising sea level. As a result, It is necessary to establish the foundation of the monitoring of the sea level changes for the flooding prevention. A new measurement technique is developed using GPS equipped ship to make up for the spatial-temporal and economical problems by this study. We compared the data using GPS with the value for height of the tide. And we corrected the errors using the more accurate data that we studied. In addition to we studied that the corrected value had statistical significance and similarity compared with the observed value using GPS. The following studies also performed : When the observed value of tide by a tide observatory and by using GPS are applied to sounding ; How the values of the water depth are being, and if the values are similar, whether the observed value of tide using GPS is valid or not.

• 한국해양학회지
• /
• v.30 no.5
• /
• pp.493-511
• /
• 1995

Analysis of the Late Quaternary benthic foraminifera in the cores from the western part of the East Sea, Korea, indicates several distinct changes in the paleoenvironments during the deposition. The palecology of biofacies of Cores PC-1 from the upper slop and PC-2 from the rise shows several distinct changes in bottom water temperatures during the late Quaternary. The Core PC-4 from the Ulleung Basin generally consists of agglutinated genus, Muiliammina, and anaerobic calcareous genus, Bolivina, in biofacies, suggesting that the anoxic bottom condition was prevailed during the deposition. Benthic foraminiferal rare or barren zones in the Cores indicate the limits of water circulation caused by lower sea-level in the regions during the glacial period through the Late Quaternary. The changes of benthic foraminiferal biofacies reflect temporal and spacial variations in overall bottom environments, such as bottom water temperature, dissolved oxygen, and water circulation pattern. The benthic foraminiferal data can be used to interpret paleoclimatic conditions and predict global sea-level changes, and the results of these studies should be useful to understand the evolutional history of the East Sea through the Late Quaternary.

• Journal of Internet Computing and Services
• /
• v.22 no.6
• /
• pp.25-32
• /
• 2021

In line with future changes in the marine environment, Aids to Navigation has been used in various fields and their use is increasing. The term "Aids to Navigation" means an aid to navigation prescribed by Ordinance of the Ministry of Oceans and Fisheries which shows navigating ships the position and direction of the ships, position of obstacles, etc. through lights, shapes, colors, sound, radio waves, etc. Also now the use of Aids to Navigation is transforming into a means of identifying and recording the marine weather environment by mounting various sensors and cameras. However, Aids to Navigation are mainly lost due to collisions with ships, and in particular, safety accidents occur because of poor observation visibility due to sea fog. The inflow of sea fog poses risks to ports and sea transportation, and it is not easy to predict sea fog because of the large difference in the possibility of occurrence depending on time and region. In addition, it is difficult to manage individually due to the features of Aids to Navigation distributed throughout the sea. To solve this problem, this paper aims to identify the marine weather environment by estimating sea fog level approximately with images taken by cameras mounted on Aids to Navigation and to resolve safety accidents caused by weather. Instead of optical and temperature sensors that are difficult to install and expensive to measure sea fog level, sea fog level is measured through the use of general images of cameras mounted on Aids to Navigation. Furthermore, as a prior study for real-time sea fog level estimation in various seas, the sea fog level criteria are presented using the Haze Model and Dark Channel Prior. A specific threshold value is set in the image through Dark Channel Prior(DCP), and based on this, the number of pixels without sea fog is found in the entire image to estimate the sea fog level. Experimental results demonstrate the possibility of estimating the sea fog level using synthetic haze image dataset and real haze image dataset.

• Proceedings of the KSRS Conference
• /
• 2002.10a
• /
• pp.317-322
• /
• 2002

Dramatic changes in the patterns of satellite-derived pigment concentrations, sea-level height anomaly, sea surface temperature anomaly, and zonal wind anomaly are observed during the 1997-1998 El Nino. By some measures, the 1997-1998 El Nino was the strongest of the 20$^{th}$ century. A very strong El Nino developed during 1997 and matured late in the year. A dramatic recovery occurred in mid-1998 and led to a La Nina conditions. The largest spatial extent of the phytoplankton bloom was followed recovery from El Nino over the equatorial Pacific. The evolution towards a warm episode (El Nino) continued in the equatorial Pacific from March 2002 and further development toward mature El Nino conditions may be possible in late 2002. The OSMI (Ocean Scanning Multispectral Imager) data can be used for detection of dramatic changes in the patterns of pigment concentration during next El Nino.

• Proceedings of the ESK Conference
• /
• 1992.10a
• /
• pp.9-17
• /
• 1992

To study on the guideline for high altitude training, physiological changes are considered. The recommanded is to deeply understand for altitude physiology, not to exposure at high for elite athlete, to climb progressively and to train at 3000 .approx. 5300m. Steady altitude exposures should be limited to periods of 2 to 4 weeks. During the training, the intermittent sea level or extremely high trips should be scheduled. It is expected that this study would be contributed to sport trainer, athlete and climber.

• Journal of Environmental Science International
• /
• v.22 no.1
• /
• pp.99-107
• /
• 2013

This study surveyed the distribution and characteristics of epiphytes and host trees in Jejudo's warm-temperate evergreen forests area. The gathered data will be used for evaluating ecological changes according to climate change. The study found 46 species of epiphytes in Jejudo; 12 of which were species of pteridophytes and 5 species of orchids, totaling 17 species of epiphytes. The appearance frequency was the greatest with Lepisorus thunbergianus, followed by Lemmaphyllum microphyllum and Lepisorus onoei. The area with the greatest diversity of epiphytes was nutmeg tree forests which have the largest number of 2.89 average species. Lemmaphyllum microphyllum had the greatest percent cover of the epiphytes whose importance was found to be the greatest. The factors involved were the epiphytes' diversity index (0.64), maximum species diversity (1.23), evenness (0.52), and dominance (0.48). The study has noted the distribution characteristics of epiphytes according to altitudes above sea level. The Lemmaphyllum microphyllum can survive at an altitude of 600 m above sea level, Lepisorus thunbergianus at 200 - 1,400m above sea level, Lepisorus onoei. at 400 - 1,000 m, and Gonocormus minutus at an altitude above 800 m. The host trees, consisting of Quercus serrata, Castanopsis cuspidata var. sieboldii, and Carpinus laxiflora, stands at 2-19 m high and 2.5 - 120 cm wide, showing diverse kinds of trees and sizes. Jejudo's warm-temperate evergreen forests have lower epiphyte diversity compared with those of subtropical and tropical areas in Japan and China. Based on the characteristics of the host trees order, epiphytes' distribution associated with the altitude above sea level was typical.

• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.32 no.1
• /
• pp.85-93
• /
• 2020

The basic information of mean sea level data of all tidal monitoring stations in Korea was reviewed, and the correlation coefficients between the stations were analyzed. Mean sea level changes expected due to global climate change effects were found to show a high correlation of more than 0.75 regardless of the distance between the stations were analyzed. The data between certain stations were found to have negative correlation and low correlation of 0.25 or less, but this was determined by the influence of small data numbers and outliers. However, since these correlations assume a linear increase and a linear relationship, the estimation results may be distorted for data with fluctuating trends that deviate from this assumption. Based on the results of the changing patterns of the MSL data, it shows that a number of the MSL data do not follow the linear trend.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.52 no.6
• /
• pp.685-695
• /
• 2019

To assess the state of Todarodes pacificus fisheries, we examined changes in major fishing and ecological characteristics by comparing jigging fishery data between high (HCLP, 1996-2000) and low (LCLP, 2013-2017) catch level periods. The peak catch occurred in October during the HCLP compared with December during the LCLP. The average catch per unit effort was higher during the HCLP (1.3 tons/jigging vessel) than LCLP (1.0 ton/jigging vessel). During the HCLP, fishing grounds were highly concentrated in the southwestern East Sea and Yamato bank, whereas during the LCLP, the distribution of grounds extended to the South Sea, West Sea, and northern East Sea (near Russian waters) at a low density. Water temperatures in the main fishing ground in the southwestern East Sea were higher at 0, 50, and 100 m depths during the LCLP than HCLP. Meanwhile, the average mantle length of catches decreased from 23.5 cm during the HCLP to 22.21 cm during the LCLP. The mantle length at 50% maturity also decreased between the two periods from 22.06 (HCLP) to 18.77 cm (LCLP). These findings will help guide future management strategies for T. pacificus.

• Environmental Analysis Health and Toxicology
• /
• v.25 no.1
• /
• pp.19-26
• /
• 2010

Discharged materials from the point or non-point source are released into the sea, and as the results, marine environment is directly affected. We must estimate the impacts of contaminants to marine pollution rapidly and accurately. Therefore, it is needed on early warning system for appreciating marine environmental impacts, and required a bioassay to evaluate abnormal changes. A bioassay test was developed to examine the effects of heavy metal contaminants on the early life stages of the marine annimals. We have studied the effects of metals on early development of a sea urchin species, Strongylocentrotus intermedius. S. intermedius embryos were tested with six metals (Cu, Ag, Zn, Cd, Cr, Ni) and showed the highest sensitivity to Cu as well as the lowest sensitivity to Cd. The order of biological impact for metals was Cu>Ag>Ni>Zn>Cr>Cd. In accordance with the results, sea urchins embryos can provide biological criteria for seawater quality assessment. The sensitivity of developmental bioassay whith S. intermedius is at intermediate level among marine organisms commonly used in aquatic bioassays. And this sea urchin can be routinely employed as a test organism for ecotoxicity assays.

• The Korean Journal of Quaternary Research
• /
• v.1 no.1
• /
• pp.21-34
• /
• 1987

In the present study area, a part of intertidal flat in the Seosan Bay, west coast of Korea, characteristic three dominant tidal sedimentary facies and their related several typical sedimentary structures are described, Furthermore, a possible interpretation about the time stratigraphic developments of these intertidal deposits is suggested by introducing very late Quaternary (Holocene) sea-level rise in Korean Seas.