• KEPCO Journal on Electric Power and Energy
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• v.3 no.2
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• pp.79-88
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• 2017

In this paper, the wind tunnel test for the measurement of aerodynamic characteristics of transmission conductors with asymmetric sections is described. A single conductor model and bundled conductor models with ice accreted shapes are tested both in steady and turbulent flow, and the aerodynamic coefficients are acquired. Transmission conductor galloping is a kind of wind-induced vibration which is characterized by primarily vertical oscillation with a very low frequency and a high amplitude. It is well known that transmission conductor galloping is generally caused by moderately strong, steady winds when a transmission conductor has an asymmetric cross-section shaped by accreted ice. Galloping should be considered from the design stage of overhead lines because it can cause severe wear and fatigue damage to attachments as well as transmission conductors. It is reported that there have been normally 20 events of galloping per year in Korea, which may be followed by serious consequences in the electric power system. Therefore, this research is performed to measure aerodynamic characteristics of ice accreted transmission conductors to understand and control transmission conductor galloping so that it would help to prevent unexpected failures and reduce the maintenance costs caused by galloping.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.4
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• pp.408-413
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• 2018

In this paper, the particle size, bulk density, friction coefficient and angle of repose were measured for the automatic processing of solar salt, which was classified with 5 levels of moisture content (16.5, 13.2, 8.2, 4.9, 3.7%). Average diameter was 1.98~1.60mm according to moisture content, and bulk density increased with increasing moisture content. As a result of measuring the coefficient of dynamic friction, the maximum value was shown in the stainless steel plate according to the material, and ABS plate and acrylic plate were lower in the order. Movement occurred at the moisture content of 8.2% or less, and the empty angle of repose was increased and the filling angle of repose was decreased as the moisture content increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.319-323
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• 2010

This study was carried out to investigate proximate compositions, acidity, and soluble solids of various blueberries produced in Korea and to prepare jam with optimized overall palatability by a response surface methodology. Proximate compositions were 75~88% in moisture, 0.32~0.62% in crude protein, 0.12~0.39% in crude lipid, and 10.18~23.80% in carbohydrate. Acidity and soluble solids of blueberries showed 0.82~1.58% and $7~12^{\circ}Brix$, respectively. The effect of sucrose ($X_1$, 200~300 g), pectin ($X_2$, 0~10 g), and citric acid ($X_3$, 0~0.5 g) on overall palatability of blueberry jam were investigated at five levels using a central composite design. Overall palatability of blueberry jam showed maximum score in 200 g blueberry, 248 g sucrose, 4.8 g pectin, and 0.26 g citric acid.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.471-480
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• 2015

The market of public-private partnership (PPP) projects has reduced from 9.4 trillion won in 2007 to 4.5 trillion won in 2012. However, the need of PPP projects is brought up by a massive down scale of government financial business. Previous studies regarding PPP projects mostly evaluate profitability from the financial perspective or analyze risk factors as a whole. Although PPP projects generally have complex structure involving diverse stakeholders, such as contractor, financial investor, and special purpose company (SPC) operators, existing studies have rarely considered the different viewpoints of PPP project stakeholders. Therefore, purpose of this study is to develop a structural equation model (SEM) considering the diverse stakeholders of PPP projects. To this end, the authors first reviewed the organizational structure of PPP projects. Next, the identification of the factors affecting project profitability are done via comprehensive literature reviews. After that, we conducted in-depth interviews and questionnaire surveys to reflect stakeholders' perspectives (contractors, financial investors, and SPC operators). As a result, a SEM model is developed to analyze direct and indirect effect on the PPP project performances. Finally, using the analysis results, relevant implications and directions for improvements are discussed. The prediction of the business performance of contractor, financial investor, and SPC operator is expect to be possible through the model developed and supports the strategy deduction that is appropriate for the participants.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.12
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• pp.1325-1333
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• 2014

The dispersion pattern of a near miss neutralizer has a great effect on the disablement of a threatening projectile. This study numerically investigated the dispersion pattern of cylindrical tungsten impactors by an explosion in the near miss neutralizer. The mass and shape of the explosive were considered as influencing factors on the dispersion pattern. The explosives were set using two shape models: a parallel shape with the same upper and lower thicknesses and a tapered shape with different upper and lower thicknesses. In the simulation results, the dispersed impactors formed a ring-shaped pattern on a two-dimensional plane in an arbitrary space. In addition, the fire net area increased with the explosive mass when the explosive shapes were identical. In particular, the tapered shape explosive formed a larger fire net area than the parallel shape explosive. Based on the analysis of the fire net area along with the dispersion density, both the explosive mass and shape representing the physical characteristics should be considered for controlling the dispersion pattern of impactors in a near miss neutralizer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.2
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• pp.238-242
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• 2014

In this study, the immunomodulatory activities of crude polysaccharides from makgeolli were investigated. Crude polysaccahrides from makgeolli (RWW) were isolated by hot water extraction ($100^{\circ}C$, 30 min), ethanol precipitation (four volumes of 95% ethanol), dialysis (MWCO: 6,000~8,000), and lyophilization. The major constituents in RWW were neutral sugar (87.3%), uronic acid (2.5%), and protein (10.2%). RWW showed potent anti-complementary activity as well as increased cell proliferation of RAW 264.7 macrophages. The immunomodulatory effects of RWW were also analyzed based on cytokine production of macrophages. Macrophages stimulated with RWW produced cytokines such as interleukin (IL)-6, IL-12, and tumor necrosis factor-${\alpha}$ in a dose-dependent manner. These data indicate that RWW may have immunomodulatory effects through activation of the complement system and macrophages, which are a part of natural immunity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1153-1161
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• 2016

For prevention of moisture adsorption, the fermented red ginseng extract spherical granules were coated by using hydrophobic fractions. The hydrophobic parts were extracted from red ginseng such as the perfect soluble part in 90% ethanol (PSE) and non-soluble part in hot water (NSHW). The optimum operating conditions for making fermented red ginseng extract spherical granules coated with PSE were a feeding rate (FR) of 0.49 mL/min, atomization air pressure (AP) of 2.14 bar, and product temperature (PT) of $48.96^{\circ}C$., whereas conditions for granules coated with NSHW were a FR of 0.61 mL/min, AP of 2.75 bar, and PT of $46.30^{\circ}C$. The solubility of coated fermented red ginseng extract spherical granule was lower than that of not coated. The fermented red ginseng extract spherical granules coated with NSHW showed more preventative effects for moisture adsorption than those coated with PSE, although there were no differences in solubility and fluidity. In the sensory evaluation, granules coated with hydrophobic fractions extracted from red ginseng were shown to be bitterer and less soluble than those not coated spherical granules. In conclusion, fermented red ginseng extract spherical granules coated with hydrophobic extracts from red ginseng showed a preventative effect against moisture.

• Journal of Korean Society of Forest Science
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• v.84 no.3
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• pp.369-376
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• 1995

Black and White aerial photogrphs are much useful to obtain the information on the channel-bed fluctuation in the following aspects. 1. In the decision of river width, the linear regression formula between the value of aerial photograph interpretation and that of field surveying is Y=1.0+0.94X(the decision coefficient is $r^2=0.98$). Therefore, aerial photographs are proved effective for the measurement of river width. 2. Aerial photograph interpretation makes it possible to classify the plane channel and the deposits in river, and suggests the situation of the plane distribution of deposits, the size of channel and the course of channel formation. 3. The periodical channel situation can be figured out through the interpretation of aerial photographs pictured in different times. Also, the comparing and analyzing each interpretated information can be able to guess the course of the variation of channel influencing powerfully channel - bed fluctuation. 4. The microtopographic map of river can be made through the decision of river with, the interpretation of the plane shape of channel - bed and the analysis of variation of channel. On the basis of this map, the plane analysis of deposit is possible.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.6
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• pp.1302-1308
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• 2005

Propose Cellular-IP/PRC network with united paging and Cellular IP special duality that use roof information administration cache to secure lake acceptance method in wireless Internet environment and QoS in lesser extent cell environment. When speech quality is secured considering increment of interference to receive in case of suppose that proposed acceptance method grooves base radio station capacity of transfer node is plenty, and moat of contiguity cell transfer node was accepted at groove base radio station with a blow, groove base radio station new trench lake acceptance method based on transmission of a message electric power estimate of transfer node be. Do it so that may apply composing PC(Paging Cache) and RC(Routing Cache) that was used to manage paging and router in radio Internet network in integral management and all nodes as one PRC(Paging Router Cache), and add hand off state machine in transfer node so that can manage hand off of transfer node and Roaming state efficiently, and studies so that achieve connection function at node. Analyze benevolent person who influence on telephone traffic in system environment and forecasts each link currency rank and imbalance degree, forecast most close and important lake interception probability and lake falling off probability, GoS(Grade of Service), efficiency of cell capacity in QoS because applies algorithm proposing based on algorithm use gun send-receive electric power that judge by looking downward link whether currency book was limited and accepts or intercept lake and handles and displays QoS performance improvement.

• Journal of Navigation and Port Research
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• v.26 no.1
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• pp.146-151
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• 2002

Efficiency of dredging work depends on the types of equipment used, the sediments encountered, whether the work to be performed is new or for maintenance, pre and/or post hydrographic surveying and so forth. Among those, surveying accuracy which is directly determined by the control of the dredge's position and depth surveying accuracy being surveyed at the dredging point are important factors. The purpose of this study is to develop an integrated process management system for pump dredge. The system is composed of 4 sub-systems such as LADGPS for dredge positioning dredging point determination, tidal gauge and angular depth sensor for depth determination, and GIS and ENC process management. The process management system for pump dredge developed was installed on the pump dredge "EUNJIN PD-2" but is now producing work data for comparison with performance of the existing dredge. The data retrieved from the pump dredge process management system up to now shows similar result from the grab dredge management system which was developed previously. It is easy to operate, achieves good accuracy with only 45cm unevenness, reduces working perioa by 20 percint,. More precise evaluation of the system comes later after the dredging work is completed.completed.