• The Journal of Engineering Geology
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• v.8 no.1
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• pp.25-34
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• 1998

It is not easy to understand exact soil properties, because soil is nonhomogeneous and anisotropic. There are raany inefficient cases in aspect of time and economy in site survey. So this study tried to analyze the correlation of cone resistance and seismic velocity in order to present an efficient method in ground investigation. A cone penetrometer is frequently used to investigate soil properties, which are especially fit to investigate coastal soft ground. A portable cone penetrometer was used in this research. A portable cone penetrometer has an advantage in investigating the state of soil swiftly and is convenient to manipulate. Also, seismic prospecting is one of the most PoPular methods among geophysical prospecting methods in the estimation of ground properties and its usage is continuously increasing in the survey of soft ground Cone resistance makes a regular group according to stratum in each depth. The results of seismic prospecting show a tendency to have a certain coherence according to the boundary of straturft Therefore, cone resistance and seisrnic prospecting have considerable relations that rnay irnprnve the efficiency of ground investigation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.85-92
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• 2013

Many efforts will have to be made on securing the stable supply of the energy due to the worldwide trend of controlling the utilization fossil fuels inducing global climate change. Renewable portfolio standard enforced to power companies over 500 MW capacity from 2012. Tidal current energy is one of the most interesting renewable and clean energy resources that have been less exploited. Especially, Korea has worldwide outstanding tidal current energy resources and it is highly required to develop a tidal current energy conversion system(TECS) in coastal region. So, we examine a tidal in-stream energy using a numerical model and estimate a tidal current potential for commercialization of tidal current power plant in the sea of the Bunamgun-do. Available tidal energy resources is also analytically estimated using a tidal farm method and the annual energy production of an optimal TECS arrays will be calculated with taking into account interference of lateral and longitudinal spacing.

• Journal of the Korean Professional Engineers Association
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• v.34 no.5
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• pp.82-88
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• 2001

Mackerel(Scomber japonicus), pacific saury (Cololabis saira) and sardine(Sardinops melanosticta) is widely distributed in coastal seawater of Korea, these fishes are not effective utilization as processing material cause by rapid lipid oxidation and off flavour. This study was attempted to lipid distribution in body section, whole body, meat, viscera, skin and head, and fatty acid composition of the oils obtained from these body section. The content of total lipid of mackerel, pacific saury and sardine were 12.48%, 12.79% and 13.81% respectively, and lipid contents in different body section of mackerel was muscle 2.31%, viscera 3.54%, skin 1.43% and head 5.20%, while in cause of sardine was muscle 4.17%, viscera 3.15%, skin 1.72%, and head4.77%. The major saturated fatty acids of mackerel, pacific saury and sardine oil were C$\_$16:0/(palmitic acid), C$\_$18:0/(stearic acid), C$\_$14:0/(myristic acid), and monoenoic acids was C$\_$18:0/(oleic acid), C$\_$16:1/ (palmitolic acid), C$\_$22:0/(erucic acid) and C$\_$20:1/(gadoleic acid), in cause of polyenoic acid was C$\_$22:6/(DHA, docosahexaenoic acid), C$\_$20:0/(EPA, eicosapentaenoic acid), C$\_$22:4/(behenic acid), C$\_$18:2/(linoleic acid) high quantity in order. When fresh oil extracted from mackerel, pacific saury and sardine was stored for 20 days at 5$\^{C}$, carbonyl and acid value of oil increased with storage day, but peroxide value decreased after 15 days.

• Korean Journal of Remote Sensing
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• v.15 no.3
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• pp.277-288
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• 1999

The aim of this review is to provide perspectives on the application of remote sensing techniques for observation of marine environmental changes on various spatio-temporal scales. Currently available remote sensing technologies are reviewed and future direction is suggested. For better utilization of remote sensing, a comprehensive plan should be developed by a demand-side and problem-solving approach. Marine environmental changes should be observed on proper spatio-temporal scales where the processes occur. For appropriate observation and monitoring of various environmental changes in coastal regions, more sensors must be utilized. Platforms other than satellites should also be utilized to expand the spatio-temporal scales of observation. Calibration/validation activities, required for accurate interpretation of remotely sensed data, could utilize buoys and ship-of-opportunity sensors. It is desirable that such systems by developed as a part of an integrated monitoring network.

• Korean Journal of Ecology and Environment
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• v.54 no.3
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• pp.209-220
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• 2021

Pacific herring, Clupea pallasii, a keystone species with significant ecological and commercial importance, is declining globally throughout much of its range. While traditional fishing equipment methods remain limited, new sensitive and rapid detection methods should be developed to monitor fisheries resources. To monitor the presence and quantity of C. pallasii from environmental DNA (eDNA) extracted from seawater samples, a pair of primers and a TaqMan^® probe specific to this fish based on mitochondrial cytochrome b (COB) sequences were designed for the real-time PCR (qPCR) assay. The combination of our molecular markers showed high specificity in the qPCR assay, which affirmed the success of presenting a positive signal only in the C. pallasii specimens. The markers also showed a high sensitivity for detecting C. pallasii genomic DNA in the range of 1 pg~100 ng rxn^-1 and its DNA plasmid containing COB amplicon in the range of 1~100,000copies rxn^-1, which produced linear standard calibration curves (r²=0.99). We performed a qPCR assay for environmental water samples obtained from 29 sampling stations in the southeastern coastal regions of South Korea using molecular markers. The assay successfully detected the C. pallasii eDNA from 14 stations (48.2%), with the highest mean concentration in Jinhae Bay with a value of 76.09±18.39 pg L^-1 (246.20±58.58 copies L^-1). Our preliminary application of molecular monitoring of C. pallasii will provide essential information for efficient ecological control and management of this valuable fisheries resource.

• Journal of Hydrogen and New Energy
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• v.30 no.3
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• pp.282-288
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• 2019

When liquefied natural gas (LNG) is vaporized to form natural gas for industrial and household consumption, a tremendous amount of cold energy is transferred from LNG to seawater as a part of the phase-change process. This heat exchange loop is not only a waste of cold energy, but causes thermal pollution to coastal fishery areas by dumping the cold energy into the sea. This project describes an innovative new design for reclaiming cold energy for use by cold storage warehouses (operating in the 35 to $62^{\circ}C$ range). Conventionally, warehouse cooling is done by mechanical refrigeration systems that consume large amounts of electricity for the maintenance of low temperatures. Here, a closed loop LNG heat exchange system was designed (by simulator) to replace mechanical or vapor-compression refrigeration systems. The software PRO II with PROVISION V9.4 was used to simulate LNG cold energy, gas re-liquefaction, and the vaporized process under various conditions. The effects on sensible and latent heats from changes to the array type of heat exchangers have been investigated, as well as an examination of the optimum.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.5
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• pp.407-428
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• 1991

The eastern coastal area having variability of climate is located within Taebaek mountain range and the east coast of Korea. It is therefore ease to cause the wind damages in paddy field during rice growing season. The wind damages to rice plant in this area were mainly caused by the Fohn wind (dry and hot wind) blowing over the Taebaek mountain range and the cold humid wind from the coast. The dry wind cause such as the white head, broken leaves, cut-leaves, dried leaves, shattering of grain, glume discolouration and lodging, On the other hand the cold humid wind derived from Ootsuku air mass in summer cause such symptom as the poor rice growth, degeneration of rachis brenches and poor ripening. To minimize the wind damages and utilize as a preparatory data for wind injury of rice in future, several experiments such as the selection of wind resistant variety to wind damage, determination of optimum transplanting date, improvement of fertilizer application methods, improvement of soils and effect of wind break net were carried out for 8 years from 1982 to 1989 in the eastern coastal area. The results obtained are summarized as follows. 1. According to available statisical data from Korean meteorological services (1954-1989) it is apperent that cold humid winds frequently cause damage to rice fields from August 10th to September 10th, it is therefore advisable to plan rice cultivation in such a way that the heading date should not be later than August 10th. 2. During the rice production season, two winds cause severe damage to the rice fields in eastern coastal area of Korea. One is the Fohn winds blowing over the Taebaek mountain range and the other is the cold humid wind form the coast. The frequency of occurrence of each wind was 25%. 3. To avoid damage caused by typhoon winds three different varieties of rice were planted at various areas. 4. In the eastern coastal area of Korea, the optimum ripening temperature for rice was about 22.2$^{\circ}C$ and the optimum heading date wad August 10th. The optimum transplanting time for the earily maturity variety was June 10th., medium maturity variety was May 20th and that of late maturity was May 10th by means of growing days degree (GDD) from transplanting date to heading date. 5.38% of this coastal area is sandy loamy soil while 28% is high humus soil. These soil types are very poor for rice cultivation. In this coastal area, the water table is high, the drainage is poor and the water temperature is low. The low water temperature makes it difficult for urea to dissolve, as a result rice growth was delayed, and the rice plant became sterile. But over application of urea resulted in blast disease in rice plants. It is therefore advise that Ammonium sulphate is used in this area instead of urea. 6. The low temperature of the soil inhibits activities of microorganism for phosphorus utilization so the rice plant could not easily absorb the phosphorus in the soil. Therefore phosphorus should be applied in splits from transplanting to panicle initiation rather than based application. 7. Wind damage was severe in the sandy loamy soil as compared to clay soils. With the application of silicate. compost and soil from mointain area. the sand loamy soil was improved for rice grain colour and ripening. 8. The use of wind break nets created a mocro-climate such as increased air. soil and water temperature as well as the reduction of wind velocity by 30%. This hastened rice growth, reduced white head and glume discolouration. improved rice quality and increased yield. 9. Two meter high wind break net was used around the rice experimental fields and the top of it. The material was polyethylene sheets. The optimum spacing was 0.5Cm x 0.5Cm. and that of setting up the wind break net was before panicle initiation. With this set up, the field was avoided off th cold humid wind and the Fohn. The yield in the treatment was 20% higher than the control. 10. After typhoon, paddy field was irrigated deeply and water was sprayed to reduce white head, glume discolouration, so rice yield was increased because of increasing ripening ratio and 1, 000 grain weight.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.179-192
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• 2023

In this study, changes in the microbial ecosystem of the Yeongheungdo island coastal waters were investigated for five years to collect basic data. To evaluate the influence of distance from the coast on the microbial ecosystem, four sites, coastal Site (S1) and 0.75, 1.5, and 3 km away from the coast, were set up and the changes in physicochemical and biological factors were monitored. The results showed seasonal changes in water temperature, dissolved oxygen, salinity, and pH but with no significant differences between sites. For nutrients, the concentration of dissolved inorganic nitrogen increased from 6.4 μM in April-June to 16.4 μM in July-November, while that of phosphorus and silicon phosphate increased from 0.4 μM and 2.5 μM in April-June to 1.1 μM and 12.0 μM in July-November, respectively. Notably, phosphorus phosphate concentrations were lower in 2014-2015 (up to 0.2 μM) compared to 2016-2018 (up to 2.2 μM), indicating phosphorus limitation during this period. However, there were no differences in nutrients with distance from the coast, indicating that there was no effect of distance on nutrients. Phytoplankton (average 511 cells mL^-1) showed relatively high biomass (up to 3,370 cells mL^-1) in 2014-2015 when phosphorus phosphate was limited. Notably, at that time, the concentration of dissolved organic carbon was not high, with concentrations ranging from 1.1-2.3 mg L^-1. However, no significant differences in biological factors were observed between the sites. Although this study revealed that there was no disturbance of the ecosystem, further research and more basic data on the microecosystem are necessary to understand the ecosystem of the Incheon.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.2
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• pp.79-89
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• 2009

For preliminary diagnosis on current fishing ground environment and basic information for establishment of effective and rational management policy in fisheries resources protection area, water and sediment quality and changes of total area in the 10 marine protection areas designated for fisheries resources management in Korea were assessed. Results showed that environmental quality in these areas has been degraded by pollution sources, coastal utilization and development stress, etc. The pattern and degree of contamination differed by protection areas, suggesting that it is necessary for optimum environmental management plan considering the regional characteristics. The total designated area of protection areas in 2003 changed by $-22.9{\sim}2.4%$, on average -6.4%, compared with the first year of designation; Wando-Doam Bay showd the highest increase rate (2.4%), and Hansan Bay has the highest decrease rate (-22.9%) Decrease rate of land and sea in total area showd 6.1% and 6.6%. An integrated management of environmental data in protection areas is required for systematic assessment. Therefore, the suitable environmental and information management is needed specifically considering the environment characteristics such as development and utilization conditions of land and sea area Furthermore, bemuse urbanization and industrialization threats the junctions of the protection areas, authorized ministry (MIFAFF) should develope and establish monitoring and management procedures based on the related laws.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.4
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• pp.1-14
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• 2012

A river is defined as the watercourse flowing through its channel, and the mapping tasks of a river plays an important role for the research on the topographic changes in the riparian zones and the research on the monitoring of flooding in its floodplain. However, the utilization of the ground surveying technologies is not efficient for the mapping tasks of a river due to the irregular surfaces of the riparian zones and the dynamic changes of water level of a river. Recently, the spatial information data sets are widely used for the coastal mapping tasks due to the acquisition of the topographic information without human accessibility. In this research, we tried to extract a river from the RapidEye imagery by using the ISODATA(Iterative Self_Organizing Data Analysis) classification algorithm with the two different parameters(NIR (Near Infra-Red) band and NDVI(Normalized Difference Vegetation Index)). First, the two different images(the NIR band image and the NDVI image) were generated from the RapidEye imagery. Second, the ISODATA algorithm were applied to each image and each river was generated in each image through the post-processing steps. River boundaries were also extracted from each classified image using the Sobel edge detection algorithm. Ground truths determined by the experienced expert are used for the assessment of the accuracy of an each generated river. Statistical results show that the extracted river using the NIR band has higher accuracies than the extracted river using the NDVI.