• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.6
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• pp.286-304
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• 2017

In this study, we proposed a new-type of circular perforated caisson breakwater consisting of a bundle of latticed blocks that can be applied to a small port such as a fishing port, and numerically investigated the hydraulic characteristics of the breakwater. The numerical method used in this study is OLAFOAM which newly added wave generation module, porous media analysis module and reflected wave control module based on OpenFOAM that is open source CFD software published under the GPL license. To investigate the applicability of OLAFOAM, the variations of wave pressure acting on the three-dimensional slit caisson were compared to the previous experimental results under the regular wave conditions, and then the performance for irregular waves was examined from the reproducibility of the target irregular waves and frequency spectrum analysis. As a result, a series of numerical simulations for the new-type of circular perforated caisson breakwaters, which is similar to slit caisson breakwater, was carried out under the irregular wave actions. The hydraulic characteristics of the breakwater such as wave overtopping, reflection, and wave pressure distribution were carefully investigated respect to the significant wave height and period, the wave chamber width, and the interconnectivity between them. The numerical results revealed that the wave pressure acting on the new-type of circular perforated caisson breakwaters was considerably smaller than the result of the impermeable vertical wall computed by the Goda equation. Also, the reflection of the new-type caisson breakwater was similar to the variation range of the reflection coefficient of the existing slit caisson breakwater.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.8-14
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• 2017

Due to the financial crisis in 2008, the world economy collapsed leading to an increase in oil prices and a decrease in freight by shipping. To overcome this crisis, major shipping companies ordered larger ships, changed their trading route and improved operating of ships to overcome deficits. In particular, low-speed navigation was much favored by many companies so that it can reduce fuel consumption. However, the long-term operation of high-speed optimized engines in low-speeds has affected the jacket cooling fresh water (J.C.F.W.) system as they fail to maintain the normal operational temperature. The temperature of J.C.F.W. system dropped leading to low temperature corrosion. As a result, when the engine is operating at minimal load the functioning of existing J.C.F.W cooler is decreased and the use of fresh water generator is substantially limited. Therefore, an improvement in the functioning of J.C.F.W. system is necessary. In this paper, in order to review the improvements required for the operation of J.C.F.W. of low-speed operating marine diesel, an experiment was conducted by comparing and analyzing the results of the main engine J.C.F.W. system of a Panamax class bulk carrier 82k and a Cape class bulk carrier 180k by installing and uninstalling the J.C.F.W. Cooler. Thus, this paper proposed an improved design of the J.C.F.W. system that is suitable for the present low-speed operation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.1
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• pp.25-39
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• 1990

The distributions of the temperature and salinity in Kamak bay which has two channels and three sea bottom topographic parts were studied by taking the detailed hydrographic data at the ebb and flood during four seasons from May, 1988 to Feb., 1989. The general pattern of the distributions of characteristics which the temperature and salinity has in Kamak bay is basically formed by the topography and sea water movement of the bay. The changes of these distributions by seasons mainly come from the heating and cooling of the sea surface and the increase of the run-off. The bay has three remarkable water masses and the their general characteristics are follows: the inner bay water has a stagnation character influenced by the inland and the concave of the sea bottom in the north west, Yosu harbor water has an estuary character of the low salinity caused by the run-off of Somjin river and Yon Tung brooklet in the north east, and the outer bay water has an out-sea character, as it is located near by the big mouth in the south of the bay. The distributions of those water masses at the ebb and flood show some different features due to the flow patterns, and the daily changes of oceanic conditions at the vicinity of Hangdae-ri are so big that it may influence the habitation and production of the living things in the bay.

• Clinical and Experimental Pediatrics
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• v.50 no.9
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• pp.896-900
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• 2007

Purpose : The aim of this study was to investigate the speech problems in benign rolandic epilepsy (BRE) according to the seizure focus in EEG and semiology. Methods : Twenty three patients [right origin (13 patients) or left side (10 patients)] who met the BRE criteria by International League Against Epilepsy (ILAE) were prospectively enrolled. We excluded the patients who had abnormal MRI or showed both side spikes in EEG. Computerized Speech Lab was used to assess the speech characteristics of the patients. Results : The error pattern of laryngeal articulation in BRE was exclusively substitution of stop consonants, these errors showed more frequent in the left group (16.0% vs 25.5%). Voice onset time (VOT) of stop consonants and Total duration (TD) of word in both groups were prolonged than normal control group, especially in left group (P<0.05). The first formant of vowel /o/ and second formant of /e/ were significantly decreased in left group (P<0.05). The right group scored wider on pitch range ($192.9{\pm}54.0Hz$) and energy range in spontaneous speech ($14.2{\pm}6.4db$) than the left group ($233.3{\pm}12.5Hz$, $19.4{\pm}9.3db$, respectively, P>0.05). Duration of counting (5 to 9) in left group slower than right group ($8.6{\pm}1.7$ vs $7.9{\pm}1.8sec$). Conclusion : Our data suggested that interictal spikes and seizures in either centrotemporal sides, especially left side group, may induce speech problems. We recommend the logopedic and phoniatric evaluations of speech in BRE patients.

• International Commerce and Information Review
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• v.15 no.2
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• pp.261-283
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• 2013

ISBP745 has new provisions about sea waybill, road, rail or inland waterway transport documents which ISBP681 did not have provisions about. The main revisions of ISBP745 which were not existent or different from ICC Opinion are as follows: First, where B/L is required when multimodal transport is used as a modes of transport, the revisions stipulates that it is subject to UCP600 article19. this differs from previous ICC Opinion. Second, when a credit requires a transport document to indicate the name, address and contact details of a delivery agent, for the place of final destination or port of discharge, the address need not be one that is located at the place of destination or port of discharge or within the same country as that of the place of destination or port of discharge. Third, in case there exist a number of shippers and a consignee, multiple transport documents are issued. This rule has a clear stipulation on this case. Transport industry regards the indication of "LCL/FCL" or "CFS/CY" common in this case as that requiring multiple transport documents. However, ISBP745 does not regard it the case as that requiring multiple transport documents. This may cause some confusion in examination of documents. Forth, when partial shipment is allowed, and more than one set of original transport documents are presented as part of a single presentation made under one covering schedule and incorporate different dates of shipment, the earliest of these dates is to be used of the calculation of an presentation period.

• Journal of Korea Port Economic Association
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• v.29 no.1
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• pp.215-245
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• 2013

In this world, the interest in the marine leisure-sports, nature friendly oriented, has been increased. The width of leisure activities has became enlarged because of expansion of leisure time and the changes of recognition on the rational management and use of marine resources. Marina ports influence significantly marine leports and this paper reviewed the maria ports status and problems. This Country has strived to develop marina ports in local areas, designing the 1st basic National Plan of Marina Development. We have keen interest in Marina but have no detail strategy and preparation. This paper suggested how marina port shall be developed for the expansion of marine leports and what strategies shall be adopted for the activation of the facilities. After reviewing the previous researches and with the results of questionnaire survey, this paper suggested two types strategies. First on the policy oriented point, it suggested 10 alternatives on the perspectives of development and operation areas. Secondly, it proposed some strategies for the activation of marina ports on the aspects of 4Ps of marketing. This paper theoretically groped the activation schemes with the knowledge and experiences of experts, but it is recommended furthermore some survey on the practical field and user attitude must be progressed.

• Journal of Life Science
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• v.30 no.8
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• pp.695-700
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• 2020

The purpose of this study is to evaluate the anti-oxidant and anti-microbial activity of syringin isolated from Cortex Fraxini to investigate their potential for use as safe natural compounds. Purified syringin was dissolved in distilled water for each concentration and used in each experiment. Syringin showed higher 2,2-Diphenyl-1-picrylhydrazyl radical scavenging than butylated hydroxytoluene (BHT) at a concentration of 50 ㎍/ml. In 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging, activity was similar to that of BHT at all concentrations. In antioxidant protection factor measurement, activity of syringin slightly increased as the concentration increased, as did the inhibitory effect of thiobarbutric acid reactive substances. In evaluating anti-microbial activity, the clear zones of Listeria monocytogenes KCTC 13064, Staphylococcus aureus KCTC 1916, Escherichia coli KCTC 2571, and Helicobacter pylori HPKCTC B0150 at a concentration of 200 ㎍/ml were found to be 17.8 mm, 20.45 mm, 17.05 mm, and 16.8 mm, respectively, but no clear zone was observed in the case of Candida albicans ATCC 10231. The activity against water-soluble antioxidants was therefore superior to that against lipid-soluble antioxidants. Anti-microbial activity was examined by inhibiting growth against gram-positive and -negative strains, and anti-fungal activity was not observed. Based on the results of this study, syringin has possible applications as a natural anti-oxidant and anti-microbial material.

• Journal of Korea Port Economic Association
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• v.24 no.3
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• pp.37-55
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• 2008

This paper attempts to examine the effect of EXPO 2012 Yeosu on the economy of Gwangyang bay area. Based on previous successful EXPOs, We identified four major positive effects (direct economic impact, regional infrastructure developments, redevelopment of slum areas and industrial complex, and internationalization of Gwangyang bay area). Especially, EXPO 2012 Yeosu will contribute to make the job creation of 97,842 employees and promote tourism industry. To maximize the above positive effects of EXPO 2012 Yeosu, we suggest several strategic alternatives in this paper. First of all, we need to make several plans for realizing the specialized theme of EXPO 2012 Yeosu. Second, local governments should create a more favorable business environment for foreign investors. Third, we have to make the strategic tourism programs to attract foreign tourists. Finally, local governments need to make the several communication strategies of utilizing mass media and non-mass media.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.5
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• pp.393-400
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• 2011

The mass transport is very complicated at the area which has the macro tide and complex geometry such as Gyeonggi bay. Especially, the long period current has a strong influence on the estuarine ecosystem and the long-term distribution of substances. The long period current is caused by several external forcing, whose unique characteristic varies spatially and temporally. The variation characteristics of long period current is analysed and its generation mechanism is studied. The tidal nonlinear constituents such as overtide and compound tide are generated due to nonlinear interaction and it causes mean sea level setup. The tidal wave propagating up into estuary is transformed rapidly by decrease of cross-sectional area and depth. Therefore the mean sea level is getting rise toward upriver. The high and low tide level is similar between down-river(Incheon) and up-river(Ganghwa) during neap tide when the tidal deformation is decreased. The tidal phase difference between two tidal stations causes a periodic fluctuation of sea level difference. The low water level of Ganghwa station during spring tide does not descend under EL(-)2.5 m, but the low water level of Incheon fall down under EL(-)4.0 m. The variation of tidal range and its sea level are increased during spring tide. It is found that the long period current $M_{sf}$ is quite similar to that of sea level difference between the two tidal stations. It means that the sea surface inclination caused by the spatial difference of tidal deformation is important forcing for the generation of long period current.

• Journal of Digital Convergence
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• v.15 no.5
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• pp.207-215
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• 2017

With rapid development of IT technology and biotechnology, human lifespan is extended rapidly, and we are living in the era where aging becomes the social issue. Due to this aging problem, manpower is mainly replaced by Automated Guided Vehicles (AGV) in manufacturing factories or warehouse logistics transportation. Rate of AGV use increases sharply every year. AGVs, which were used only in Smart Factories, extends its usage into indoor and outdoor operation by changing their usages to container transportation that can carry huge containers in the harbor. With the expansion of AGVs usage, the importance of RCS (Remote Control System) is also increased. In this study, we surveyed and analyzed the characteristics and technology trends of technical features of AGV's RCS that are developing in various ways to establish quality evaluation system of AGV RCS. Based on this, and by referring to international quality assessment standards, ISO/IEC 25000 series, we derived evaluation items on functional suitability and usability to secure reliability of AGV RCS. Also, it is our intention to develop evaluation model using those derived usability and reliability evaluation items.