• Polymer(Korea)
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• v.31 no.3
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• pp.215-220
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• 2007

The control of the surface energy by electrohydrodynamic force provides electrospraying with various potential advantages such as simple particle size control, mono-dispersity, high recovery, and mild processing conditions. The advantages are quite helpful to improve the stability of protein drug and control its release. Herein, the nano-encapsulation of protein drugs using electrospraying was investigated. Albumin as a model protein was processed using uniaxial and co-axial electrospraying, and chitosan, polycaporlactone (PCL), and poly (ethylene glycol) (PEG) were used as encapsulation materials. The major processing parameters such as the conductivity of spraying liquids, flow rate, the distance of electrical potential gradient, etc were measured to obtain the maximum efficiency. In the chitosan systems, mean particles size decreases as flow rate and the distance between nozzle and the collecting part decreases. In the uniaxial technique of the PCL systems, mean particles size decreases as flow rate decreases. In the coaxial technique of the PCL systems, it was found that the particles size gets larger under the application of the higher ratio of inner-to-outer liquid flow rates. The primary particles formed out of an electrospraying nozzle showed narrow particle size distribution, but once they arrived to the collecting part, aggregation behavior was observed obviously. Efficient nano-encapsulation of albumin with PCL, PEG, and chitosan was conveniently achieved using electrospraying at above 12 kV.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.648-656
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• 1997

Thermal treatment of soymilk residue was carried out at 140, 150, and $160^{\circ}C$ for possible use as a raw material for dietary fiber, and some physicochemical properties of the extracts were investigated. Soluble dietary fiber(SDF) content of the extracts prepared under optimal conditions was more than 30% suggesting the conversion of insoluble dietary fiber to SDF. The main sugar components of the extracts were glucose, galactose, and arabinose. Analysis of the moelcular weight distribution by high performance size exclusion chromatography revealed that the proportion of high molecular weight fraction decreased and that of middle-sized polymer increased as the extraction temperature increased. The viscosity of aqueous solution of the extracts decreased with an increase in extraction temperature, but showed no trend as pH changed. The solubility increased with extraction temperature showing the highest at $160^{\circ}C$. The extract at $140^{\circ}C$ had the biggest calcium-binding capacity, which correlated with the changes in viscosity.

• Korean Journal of Ichthyology
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• v.27 no.4
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• pp.284-292
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• 2015

Monthly variation of species composition and abundance of fish eggs were examined to know the spawning time and location of the fishes inhabiting the coastal region of Jejudo Island. Samplings had been performed at the four locations (Jeju port, Seongsanpo, Seogwipo port and Chagwido) with a bongo net which was towed monthly at the sea surface from August 2006 to July 2007. The fish eggs were identified based on phylogenetic analyses with the DNA sequences generated through PCR-amplification and sequencing of the mitochondrial cytochrome b gene. Among a total of 43 taxa classified during the study period, 34 were identified to species, 4 to families, and the remaining 5 were unidentified. Of them, 23 taxa were occurred at Jeju port, 21 at Seongsanpo, 19 at Seogwipo port and 18 at Chagwido, whereas 15 taxa were found in September 2006, 12 in June 2007, 6 to 8 in August 2006 and January~May 2007, 5 in each October and November 2006, 3 in each December 2006 and July 2007. Among 34 species of fish eggs, Engraulis japonicus and Callanthias japonicus most frequently appeared at 16 times out of 48 observations in total. When those eggs were collected, the surface seawater temperature ranged $14.0{\sim}28.6^{\circ}C$ for E. japonicus and $14.9{\sim}20.5^{\circ}C$ for C. japonicus. The success rates of PCR-amplification and species identification in this study were 68.3% and 79.1%, respectively.

• Geophysics and Geophysical Exploration
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• v.13 no.4
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• pp.336-348
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• 2010

The Single-channel seismic survey with the source of bubble pulser and drilling survey was carried out in 2008 and 2009 for the site survey of Daecheon-Wonsando area, which was a proposed area of Korea-China subsea tunnel. The goal of this study is to analyze the depth and characteristics of acoustic basement for the stability assessment and tunnel design in this proposed area through combining drilling data with this single-channel seismic data after detailed processing. For this purpose, among the data processing schemes which are usually applied to multi-channel seismic data, we applied the F-K filtering to eliminate the AC(alternating current) noise and the post-stack depth migration to produce depth section. As a result, we verified that the improved depth section could be obtained from single-channel seismic data, and the distribution and characteristics of basement could be analyzed in survey area through the combined analysis with drilling data. However, we could not interpret the detailed structures, fault and fracture zone, due to the quality of bubble pulser source and single-channel data. We expect that those detailed structures can be analyzed when higher resolution seismic data is provided. Therefore, we recommend some items for future seismic survey of subsea tunnel to obtain the high resolution seismic data.

• Korean journal of communication and information
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• v.59
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• pp.31-49
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• 2012

This study investigates normative role model of the journalists under the changing environment. Firstly, this article explores what pressure the new media environment gives to the journalists in their routine of news production and distribution. These are stated from the angle of epistemological, professional and interactive pressure. Next, as a reference for the standard journalism in the age of mass media, the idea of Rhee Young-hee, a late journalist who won respects from many Korean journalists, is studied. His firm belief in the pursuit of hard facts, rigorous investigative writing and expertism are spelt out. Then, this study explores how, in real term, this pressure changes the journalistic value, norm and practices in the newsroom. Ten of Koran journalists are interviewed in order to get their idea about the emerging journalistic standards under the digital environment. From this in-depth interviews, it is conclued that the pursuit of hard fact, investigative writing, expertism of Rhee Young-hee are, nonetheless the change of the media technology, still effective and provide good reference points for the enhancement of the standard of journalism in Korea. However, it is also suggested that the methods to fulfil desirable journalism in the digital age should be different from that of the mass communication age. The interviewees make propose that the journalist, as a network node, news curator or coordinator, should actively interact with the audiences facilitating their enhanced potential as a news 'prosumer'(producer and consumer).

• Journal of Radiation Protection and Research
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• v.30 no.1
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• pp.9-15
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• 2005

This study was conducted to investigate the patient exposure dose during a CT examination and the present position in utilization of the CT equipments. To this end Questionnaire were sent out to 278 medical facilities registered at Korea Hospital Association and replies of 161 medical facilities were analyzed. The results were as follows ; 1) The distribution of CT examination was. Brain 40.7%, Abdomen 27.8%, Chest 15.7%, Spine 4.8%, Pelvis 4.1%, PNS 3.2%, Facial bone 2.5% and Extremity 1.1% respectively. 2) The statistics for dose index according to each part of examination were Brain 38.0mGy, Abdomen 12.0mGy for adults : Brain 13.6mGy, Abdomen 6.2mGy for infant. Our surveyed dose index appeared lower than the IAEA recommends. 3) Most medical facilities have selected the parameters for radiographic exposure in the range of $100{\sim}120kVp,\;100{\sim}250mA\;and\;1{\sim}2$ seconds.

• Journal of the Korean Geographical Society
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• v.50 no.6
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• pp.677-694
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• 2015

This paper aims to discuss and develop theories of social sustainability as an alternative of urban development, recognizing that urban development paradigm needs to turn to the qualitative perspective. Urban development in Korea has mainly focused on quantitative expansion disregarding qualitative development so far. Korean cities has achieved the quantitative accumulation of wealth due to the strategy. However, as a result, it is also certain that socio-economic problems such as urban poverty, social polarization, deterioration of welfare and quality of life are getting more serious. In the context that social sustainability meets social needs of urban residents based on equity and focuses on social development, it has an important meaning in relation of social and economic problems such as inequality and distribution of urban development. Furthermore, social sustainablity can foster urban residents' endogenous capability and governances. The importance of social sustainablity has been standed out and its concept and practical problems have been discussed diversely among researchers in the Western advanced countries for the last decade. However, social sustainability is still unattractive and its institutional strategy are insufficient in Korea. Concepts and practical problems of social sustainability have implications on the development path of Korean cities which have been accumulated contradiction due to the quantitative development for a long time.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.451-466
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• 2017

Deep-sea fishing vessel No. 501 Oryong was fully flooded through its openings and sunk to the bottom of the sea due to the very rough sea weather on the way of evasion after a fishing operation in the Bearing Sea. As a result, many crew members died and/or were missing. In this study, a full-scale ship flooding sinking simulation was conducted, and the sinking process was analyzed for the precise and scientific investigation of the sinking accident using highly advanced Modeling & Simulation (M&S) system of Fluid-Structure Interaction (FSI) analysis technique. To objectively secure the weather and sea states during the sinking accident in the Bering Sea, time-based wind and wave simulation at the region of the sinking accident was carried out and analyzed, and the weather and sea states were realized by simulating the irregular strong wave and wind spectrums. Simulation scenarios were developed and full-scale ship and fluid (air & seawater) modeling was performed for the flooding sinking simulation, by investigating the hull form, structural arrangement & weight distribution, and exterior inflow openings and interior flooding paths through its drawings, and by estimating the main tank capacities and their loading status. It was confirmed that the flooding and sinking accident was slightly different from a general capsize and sinking accident according to the simple loss of stability.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.2
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• pp.263-268
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• 2016

A rapid increase of data amount, used in ship-to-ship transmission of safety and logistics information, ships in the inland sea have trouble transmitting real-time information transmission due to an increase in traffic load caused by data transmitted by land station and offshore ships. In this study, therefore, communication is carried out by adaptively controlling the detailed beam width based on the distribution of offshore ships in land station durable in marine environment. Then after the adaptive sector system enabling real-time communication support between ships concentrated in an inland sea and land station is applied, the performance verification is conducted based on the respective Call Blocking Rates of an omnidirectional antenna, fisted sector system, and adaptive sector system. The performance verification result shows that adaptive sector system has better performance than the fixed sector system as the density of ship, q value, increases, and that the smaller the beam width is, the better performance of adaptive sector system will be.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.5
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• pp.311-317
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• 2000

Acid sulfate soil and potential acid sulfate soil material are worldwide in distribution and are problematic in agriculture and environment due to their present and potential acidity developed by the oxidation of sulfides. Most of them are sedimentary origin and a few cases are reported as volcanic or metamorphic origin. We report a potential acid sulfate soil material originated from volcanic activity during Mesozoic. A profile of Bongsan series-weathered nonpyritic andesite-hydrothermally altered pyrite rich andesite was studied with field examination, chemistry, and mineralogy. Once, the pyrite rich andesite was exposed to atmosphere by excavation and leveling works for a residential area and the lay out site had subsequent acidification problem of soil and surface water. The parent material and soil profile of Bongsan series had no signs of presence of pyrite and acid sulfate weathering such as yellow mottles. However, the hydrothermally altered andesite substrata contained significant amount of pyrite showing characteristics of hydrothermal origin such as cubic and pyritohedron morphology and occurrence along cracks.