• Economic and Environmental Geology
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• v.34 no.3
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• pp.255-269
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• 2001

The geochemical studies on groundwater in the borehole, which is straddled by multi-packer (MP) system, were carried out from a volcanic terrain in the Yeosu area. The pH of groundwater collected from selected sections in the MP-installed borehole is much higher (up to 9.6) than that of the borehole groundwater (7.0-7.9) collected using conventional pumping technique. Hydrochemistry shows that the groundwater has a typical chemical change with increasing sampling depth, suggesting that the groundwater is evolved through water-rock interaction along the fracture-controlled flow paths. The groundwater from the deeper part (138-175 m below the surface) in borehole KI is characterized by the Ca-C11 type with high Ca (up to 160 mg/L) and Cl (up to 293 mg/L) contents, probably reflecting seawater intrusion. The groundwater also has high sodium and sulfate contents compared to the waters from other boreholes. These observed groundwater chemistry is explained by the cation exchange, sulfide oxidation, and mixing process with seawater along the flow path.

• The Korean Journal of Quaternary Research
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• v.19 no.2
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• pp.35-37
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• 2005

Sediment samples from five stations at the Shihwa Lake sewage outfall, west coast of Korea, were collected to evaluate the effect of the outfall on benthic foraminifera. Heavy metal (Cu and Zn) polluted eastern part of the Shihwa Lake, adjacent to the Shihwa-Banwol Industrial Complexes, shows barren or nearly barren of benthic foraminifera, and the lowest number of species both at the core top and downcore. Excepting for the barren zone, pyritized benthic foraminifera abundantly occur both at the surface and downcore sediments in the western part of the Shihwa Lake, suggesting that foraminiferal disease by anoxic bacteria. Recent intrusion of pollutants from the Shihwa-Banwol Industrial Complexes and adjacent six major streams severely polluted the Shihwa Lake as shown by the low abundance (number/10 g) of benthic foraminifera, low number of A. beccarii, low species diversity, and absence of both Elphidium spp. and ostracodes at the surface sediments compared to the downcore. Except the barren zone, both pyritized and non-pyritized Ammonia beccarii occur dominantly in the surface sediments and downcore. Elphidium spp. (either pyritized or non-pyritized) do not occur in the surface sediments of whole stations. However, they occur from the entire downcore sediments except in the eastern part of Shihwa Lake. Arenaceous foraminifera do not inhabit in the heavily polluted areas as evidenced by the occurrence of relatively deep core depth (11-50 cm). Ostracodes occur at the downcore sediments, but they do not occur at the surface sediments. Ostracodes also do not occur at the heavily polluted areas in the eastern part of the Shihwa Lake both at the surface and downcore sediments, indicating that the abundance of ostracodes also can be used for a pollution indicator.

• Ocean and Polar Research
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• v.33 no.spc3
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• pp.371-383
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• 2011

To investigate the physical characteristics and variations of oceanic parameters in the tropical central North Pacific, oceanographic surveys were carried out in summer of 2006 and 2007. The survey periods were classified by Oceanic Ni$\tilde{n}$o Index as a weak El Ni$\tilde{n}$o in 2006 and a medium La Ni$\tilde{n}$a in 2007. The survey instruments were used to acquire data on CTD (Conductivity Temperature and Depth), XBT (Expendable Bathythermograph), and TSG (Thermosalinograph). The dominant temporal variation of surface temperature was diurnal. The diurnal variation in 2007, when the La Ni$\tilde{n}$a weather pattern was in place, was stronger than that in 2006. Surface salinity in 2006 was affected by a northwestward branch of North Equatorial Current, which implies that the El Ni$\tilde{n}$o affects surface properties in the North Equatorial Current region. Two salinity minimum layers existed at stations east of Chuuk in both year's observations. The climatological vertical salinity section along $180^{\circ}E$ shows that the two salinity minimum layers exist in $2^{\circ}N{\sim}12^{\circ}N$ region, consistent with our observations. Analysis of isopycnal lines over the salinity section implies that the upper salinity minimum layer is from intrusion of the upper part of North Pacific Intermediate Water into the lower part of South Pacific Subtropical Surface Water and the lower salinity minimum layer is from Antarctic Intermediate Water.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.149-155
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• 2010

Currently various safety tests are being performed in many countries with growing interest in vehicle safety. However the vehicles which have good safety performance in these tests could not secure the good performance in real car to car accident. So new test protocol using progressive deformable barrier (PDB) was proposed by EEVC in Europe, NHTSA in USA and some vehicle manufacturers, etc. The target of PDB test is to control partner protection in addition to self-protection on the same test. The proposal is to update current ECE R.94 frontal ODB test. So barrier, impact speed, overlap are changed to avoid bottoming-out in the test configuration. In this paper 3 different tests (R.94, EuroNCAP and PDB test) were carried out using current production vehicles with same structure. The results of these tests were compared to understand PDB test. As a result PDB test shows the highest vehicle deceleration and dummy injury because PDB offers a progressive increase in stiffness in depth and height. However vehicle intrusion was affected with rather test velocity than stiffness of deformable barrier. PDB deformation data is used for partner protection assessment using PDB software and it shows that the test vehicle is rather not aggressive.

• Journal of the Korean Society of Marine Environment & Safety
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• v.9 no.2
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• pp.65-72
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• 2003

Oceanic conditions of the Tsushima Warm Current (TWC) region in the southern area of the East Sea (Japan Sea) are examined using data obtained from a CREAMS (Circulation Research if the East Asian Marginal Seas) cruise in June 1996. In 1990s, a lower temperature appears in 1996 and in this period, two branches of the TWC exist and the first branch of the TWC flows inshore of the Japanese coastal region compared to that in the other years, especially in the shallower water layer at depth less than about 200 m. The TWC cored with the higher salinity (>34.6 psu) is clearly observed over the continental shelf in the Japanese coastal region and offshore and identified by geostrophic calculation. Intrusion of the TWC into the East Sea through the Korea Strait (the Tsushima Strait) makes the density structure in the water column change and the water mass in the TWC region is unstable based on Brunt­Vaisala frequency.

• Journal of Korean Society of Transportation
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• v.25 no.3
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• pp.29-43
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• 2007

An automobile black box can provide sufficient and accurate information for investigating the causes of vehicle accidents as well as preventing them in the future. The database of accident information from stored data in the black box can provide a variety of services to the general public when it is accessed in a reasonable manner. minimizing intrusion into drivers' privacy. Therefore, the black box could become the main intelligent automobile Part, with extensive benefits for all associated industries as well as government agencies and insurance companies. While the introduction and spread of the black box are imminent in Korea, this paper reviews technology and product trends of the black box. In particular, this paper presents findings on the investigation of black box-related patent applications and an in-depth study of core patents from several leading counties, including the United States. In addition, this paper describes trends of standardization and legislation in leading countries and presents methods of standardization with suggestions for some development topics related to black box technology.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• v.26 no.1
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• pp.59-73
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• 1998

Sediment samples from five stations at the Shihwa Lake sewage outfall, west cost of Korea, were collected to evaluate the effect of the outfall on benthic foraminifers. Heavy metal (Cu and Zn) polluted the eastern part of the Shihwa Lake, adjacent to the Shihwa-Banwol Industrial Complexes, shows barren or nearly barren of benthic foraminifers, and the lowest number of species both at the core top and downcore. Excepting for the barren zone, pyritized benthic foraminifers abundantly occur both at the surface and downcore sediments in the western part of the Shihwa Lake, suggesting that foraminiferal disease by anoxic bacteria. Recent intrusion of pollutants form the Shihwa-Banwol Industrial Complexes and adjacent six major streams severely polluted the Shihwa Lake as shown by the low abundance (number/10 g) of benthic foraminifers, low number of Ammonia beccarii, low species diversity, and absence of both Elphidium spp. and ostracodes at the surface sediments compared of both downcore. Except the barren zone, both pyritized and non-pyritized Ammonia beccarii occur dominantly in the surface sediments and downcore. Elphidium spp. (either pyritized or non-phyritized) do not occur in the surface sediments of whole stations. However, they occur from the entire downcore sediments except in the eastern part of Shihwa Lake. Arenaceous foraminifers do not inhabit in the heavily polluted areas as evidenced by the occurrence of relatively deep core depth (11-15 cm). Ostracodes occur at the downcore sediments, but they do not occur at the surface sediments. Ostracodes also do not occur at the heavily polluted areas in the eastern part of the Shihwa Lake both at the surface and downcore sediments, indicating that the abundance of ostracodes also can be used for a pollution indicator.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.19-26
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• 2003

The dispersion of recycled particulates in the complex coastal terrain containing Kangnung city, Korea was investigated using a three-dimensional non-hydrostatic numerical model and lagrangian particle model (or random walk model). The results show that particulates at the surface of the city that float to the top of thermal internal boundary layer (TIBL) are then transported along the eastern slope of the mountains with the passage of sea breeze and nearly reach the top of the mountains. Those particulates then disperse eastward at this upper level over the coastal sea and finally spread out over the open sea. Total suspended particulate (TSP) concentration near the surface of Kangnung city is very low. At night, synoptic scale westerly winds intensify due to the combined effect of the synoptic scale wind and land breeze descending the eastern slope of the mountains toward the coast and further seaward. This increase in speed causes development of internal gravity waves and a hydraulic jump up to a height of about 1km above the surface over the city. Particulate matter near the top of the mountains also descends the eastern slope of the mountains during the day, reaching the central city area and merges near the surface inside the nocturnal surface inversion layer (NSIL) with a maximum ground level concentration of TSP occurring at 0300 LST. Some particulates were dispersed following the propagation area of internal gravity waves and others in the NSIL are transported eastward to the coastal sea surface, aided by the land breeze. The following morning, particulates dispersed over the coastal sea from the previous night, tend to return to the coastal city of Kangnung with the sea breeze, developing a recycling process and combine with emitted surface particulates during the morning. These processes result in much higher TSP concentration. In the late morning, those particulates float to the top of the TIBL by the intrusion of the sea breeze and the ground level TSP concentration in the city subsequently decreases.

• Ocean Science Journal
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• v.40 no.2
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• pp.67-78
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• 2005

Complex physical, chemical and biological interactions off the Korean coast created several striking patterns in the phytoplankton blooms, which became conspicuous during the measurements of ocean color from space. This study concentrated on analyzing the spatial and temporal aspects of phytoplankton chlorophyll variability in these areas using an integrated dataset from a Sea-viewing Wide Field-of-view Sensor (SeaWiFS), Advanced Very High Resolution (AVHRR) sensor, and Conductivity Temperature Depth (CTD) sensor. The results showed that chlorophyll concentrations were elevated in coastal and open ocean regions, with strong summer and fall blooms, which appeared to spread out in most of the enclosed bays and neighboring waters due to certain oceanographic processes. The chlorophyll concentration was observed to range between 3 and $54\;mg\;m^{-3}$ inside Jin-hae Bay and adjacent coastal bays and 0.5 and $8\;mg\;m^{-3}$ in the southeast sea offshore waters, this gradual decrease towards oceanic waters suggested physical transports of phytoplankton blooms from the shallow shelves to slope waters through the influence of the Tsushima Warm Current (TWC) along the Tsushima Strait. Horizontal distribution of potential temperature $(\theta)$ and salinity (S) of water off the southeastern coast exhibited cold and low saline surface water $(\theta and warm and high saline subsurface water $({\theta}>12^{\circ}C; S>34.4)$ at 75dBar, corroborating TWC intrusion along the Tsushima Strait. An eastward branch of this current was called the East Korean Warm Current (EKWC), tracked with the help of CTD data and satellite-derived sea surface temperature, which often influenced the dynamics of mesoscale anticyclonic eddy fields off the Korean east coast during the summer season. The process of such mesoscale anticyclonic eddy features might have produced interior upwelling that could have shoaled and steepened the nutricline, enhancing phytoplankton population by advection or diffusion of nutrients in the vicinity of Ulleungdo in the East Sea.

• Journal of Biosystems Engineering
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• v.43 no.3
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• pp.202-210
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• 2018

Purpose: Due to the growing demand for vegetables all year round, the use of vegetable transplanters has become widespread in agricultural production. However, the type of planting device used for the transplanter affects its overall efficiency. Problems such as inaccurate planting angles and inefficiently wide transplanting hole diameters of the planting device has limited the efficient use of some vegetable transplanters. Our goal in this study was to improve the efficiency of the transplanter by analyzing and modifying the linkages of the planting device of a vegetable transplanter. Methods: Because of its widespread usage in Korea, a linkage-type planting device was used for the experiment, which was divided into three parts. In the first part, the physical trajectory of the tranplanter was extracted using a CCD (charge-coupled device) camera and analyzed. In the second part, a simulated trajectory was developed using Recurdyn 3D software. The simulated and actual trajectories were then compared and analyzed. In the third part, based on the results of the comparison, improvements were made on the linkages of the transplanter and a demonstrative exercise was conducted. Finally, in experiment B, the performance was evaluated through an exercise using both the existing and improved planting devices. Results: The results demonstrated that the average planting angle was improved by 4.96 mm, the soil intrusion diameter was improved by 11.30 mm, and the planting depth was improved by 0.68 mm. Conclusion: It was concluded that the efficiency of a vegetable transplanter can be improved by modifying the linkages through simulations and field demonstrations.