• Journal of Korea Port Economic Association
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• v.17 no.1
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• pp.27-51
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• 2001

The purpose of this paper is to investigate the productive efficiency of world container ports by using the DEA (Data Envelopment Analysis) method and raw data from previous research in measuring the international competitiveness of world container ports. Ports have to cope with rapid changes in shipping environments. In order for a port to compete in the global market, it must provide port services promptly and accurately. Basically, there are two approaches to measuring the international competitiveness of a container port. First, there is the traditional productivity analysis method, which analyzes productivity based on the container port's facilities (efficiency, selectivity, land availability), and by its general capacity (handling ability, storage capacity, terminal productivity). Second there is multi-attribute utility analysis, which considers several elements including the reasons for selecting particular container ports and factors determining international competitiveness. This paper follows the first method (traditional productivity analysis) and extends the limitation of previous studies by using the DEA method newly, and suggesting: the relative productive efficiency of container ports. The main results of this paper are as follows: First, the results of the DEA analysis in terms of world container ports matches that of a previous study (Jun et al., 1993) at a level of 35%. The low ratio is due to the constrained set of input-output elements, the result of only twenty container ports being analyzed in this paper. Second, the result of the DEA analysis in terms of North-East Asia's container ports matches with that of a previous study (Ha, 1996) at a level of 100 percent. Therefore we can conclude that the DEA analysis is the best measurement method for international competitiveness. Policy implications for this study are as follows: First, when port authorities want to measure the international competition power of container ports and enhance their productive efficiency, they should consider the traditional method and newly introduce the DEA method. Second, according to the analysis results of the DEA method, pen authorities should recommend benchmarking ports as reference ports in order to enhance the productive efficiency of container ports that show an efficiency score of below 1.

• Solar Energy
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• v.16 no.2
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• pp.65-77
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• 1996

The operating thermal chracteristics of direct contact liquid-ice heat exchanger was experimentally investigated. In this paper, The effects of Ice Packing Factor(IPF), the inlet temperature and the flow rate of Heat Transfer Fluid(HTF) were stuided in the liquid-ice heat exchanger. Thermal stratification in liquid-ice heat exchanger was established clearly and faster at the higher inlet temperature and flow rate of HTF. At the end of melting of the lower flow rate is cleared the thermal stratification in liquid-ice heat exchanger. The temperature stratification is long with higher value of IPF of liquid-ice heat exchanger. The mean temperature of liquid-ice storage was changed rapidly with increasing flow rate and inlet temperature of HTF. The gradiant of ratio of total energy to latent energy was found higher with increasing inlet temperature and flow rate.

• Journal of Digital Contents Society
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• v.11 no.1
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• pp.91-97
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• 2010

Flash memory has been used by many digital devices for data storage, exploiting the advantages of non-volatility, low power, stability, and so on, with the help of high integrity, large capacity, and low price. As the fast growing popularity of flash memory, the density of it increases so significantly that its entire address mapping table becomes too big to be stored in SRAM. This paper proposes the associated page address cache with an efficient table management scheme for hybrid flash translation layer mapping. For this purpose, all tables are integrated into a map block containing entire physical page tables. Simulation results show that the proposed scheme can save the extra memory areas and decrease the searching time with less 2.5% of miss ratio on PC workload and can decrease the write overhead by performing write operation 33% out of total writes requested.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.615-626
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• 2016

In the paper, mild solvent soluble alkyl group modified epoxy resins were prepared via a three-step method; (1) the condensation reaction of dodecyl phenol (DP) and formaldehyde, (2) the crosslinking reaction of dodecyl phnol novolac compound (DPC) and bisphenol A diglycidyl ether, (3) the dodecyl phenol novolac epoxy resins containing fatty acid (DPFA) was prepared by introducing fatty acid to DPC. Equivalent ratios of DP and formaldehyde were 1.25~1.333/1.0. Equivalent ratio of DPC and bisphenol A diglycidyl ether (YD-128) was 1.0/2.0. Reactivity, viscosity, molecular weight, solvent solubility, and physical properties of DPFA were investigated. The result show that as the number of aromatic ring of DPFA increased, viscosity increased and solvent solubility improved. When we test the properties of coatings by blending the synthesized DPFA with a white pigment, DPFAC-5 using triphenylphosphine (TPP) as a ring-open catalyst showed optical performance for drying time, adhesion, hardness, impact resistance, acid resistance and storage stability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.225-229
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• 2002

The quality characteristics of sulgidduk, a steamed rice cake, with chlorellaa sulgidduk) were evaluated. Chlorella sulgidduk was prepared in the different ratio of chlorella powder (0, 0.2, 0.5 or 1%, w/w) and water content (15 or 20%, w/w). In mechanical texture characteristics, hardness, gumminess and brittleness were higher in 15% water content chlorella sulgidduk and lower in 20% water content chlorella sulgidduk than in the absence of chlorella (the control sulgidduk), wherease 20% water content chlorella sulgidduk and a significantly higher adhesiveness and cohesiveness values (p<0.05) compared with control 24 hours storage at $25^{\circ}C$, the good texture characteristics were maintained in 20% water content chlorella sulgidduk. In sensory evaluation, the most favorite quality characteristics were shown in the sulgidduk with 0.2 and 0.5% chlorella powder.

• Culinary science and hospitality research
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• v.15 no.1
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• pp.94-104
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• 2009

This study examined the quality characteristics of Garaedduk with raw rice bran in addition of the control at 10%,20%,30% & 40% and to measure the mechanical and sensory quality characteristics in order to show the optimum addition ratio and production condition. As a result of supplement of raw rice bran with 10% up to 40% in all research groups, we have founded out as follows. First of all, moisture content decreased and the "L" score which represents the brightness of Garaedduk showed 68.89 in the control which was non supplemented Garaedduk. L-value decreased. However, a-value increased significantly and b-value increased except in the control group. In the experiment on hardness, it showed 0.69 in the control group and 0.92 in Garaedduk supplemented 10% of raw rice bran. Also, there was significant difference in hardness depending on supplement amount of rice bran and storage period. In the experiment on sensory evaluation of color and flavor in the panel test, all supplement groups showed higher scores than the control group. Also, there was significant difference in the taste depending on the amount of raw rice bran. As a test result, the overall acceptability by sensory evaluation was observed as 20%>10%>40%>30%> in the raw rice bran supplement group.

• Culinary science and hospitality research
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• v.23 no.7
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• pp.220-233
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• 2017

The purposes of this study were: (1) to examine the quality characteristics of the Sulgidducks added with barley sprouts by blanching (CON), freeze-drying (FBP), hot-air drying(HBP); (2) to examine the quality characteristics of Sulgidduck such as the moisture content, the color value, the textural properties and the sensory evaluation; (3) to find the optimal ratio of barley sprouts, which were made by the three different drying methods. As a result, the Sulgidduks containing barley sprouts by CON showed a lot of significance and high correlation depending on the amounts of the barley sprout(p<0.05). As the amounts of CON, FBP and HBP increased, the L and the a values of Sulgidducks significantly decreased, whereas the b values of them increased. For the textual properties of the Sulgidducks, on the first day, the concentration in CON up to 6% showed no significant differences in the hardness, cohesiveness, springiness, and chewiness. In case of FBP, the increase in the additives caused decrease in the hardness, adhesiveness, springiness, and chewiness of the Sulgidducks on storage 0 day(p<0.05). As the amounts of HBP increased, the hardness, springiness of the Sulgidducks on the first day decreased(p<0.05). Conclusionally, 6% blanched barley sprout added group, 2% FBP and HBP were highly rated in color, flavor, bitterness, chewiness, overall acceptability and all sensory quality characteristics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.429-437
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• 1999

A mathematical model was established for estimating changes in pressure and volume of permeable kimchi packages. The model comprises the CO2 gas production from kimchi and permeation of O2, CO2 and N2 through the permeable film or sheet. Using the developed model, the effects of various packaging variables on the pressure and volume changes were analyzed for rigid and flexible packag es of kimchi(3% salt content) at 15oC, and then effect of storage temperature was also looked into. In case of rigid pack of 400g, using the plastic sheet of high CO2 permeability and initial vacuumizing can help to relieve the problem of pressure build up. The lower fill weight can further reduce the pressure, but will result in higher packaging cost. For the flexible package of 3 kg, highly permeable films such as low density polyethylene(LDPE) and polypropylene can reduce the volume expansion. Higher ratio of CO2 permeability to O2 and N2 permeabilities are effective in reducing the volume expansion. Increased surface area cannot contribute to reduction of volume expansion for highly permeable flexible packages of kimchi. For the impermeable packages, pressure and volume at over ripening stage (acidity 1.0%) increase with decreased temperature, while those at optimum ripening stage(acidity 0.6%) change little with temperature. Pressure of permeable rigid LDPE package increases with tem perature at any ripening stage, and temperature affects the volume of flexible LDPE package very slightly. Experimental verification of the present results and package design with economical consid eration are needed as a next step for practical application.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.798-802
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• 2013

In a conventional DC power supply used for CO2 laser, the circuit elements such as a rectifier bridge, a current-limiting resistor, a high voltage switch, energy storage capacitors ans a high-voltage isolation transformer using high turn ratio are necessary. Consequently, those supplies are expensive and require a large space. Thus, laser resonator and power supply should be optimally designed. In this paper, we propose a new power supply using high frequency resonance phenomena for CW(Continuous wave) CO2 laser (maximum output of 23W with discharge length of 450mm). It consists of a transformer including leakage inductance, magnetizing inductance and half-bridge converter, a three-stage Cockcroft-Walton and PFC(Power factor correction) circuit. The output ripple voltage can be controlled the minimum of 0.24% under the high frequency switching of 231kHz. Furthermore, the output efficiency was improved to 16.4% and the laser output stability of about 5.6% was obtained in this laser system.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.1-6
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• 2008

Block copolymers spontaneously assemble into various nanoscale structures such as spheres, cylinders, and lamellar structures according to the relative volumn ratio of each macromolecular block and their overall molecular weights. The self-assembled structures of block copolymer have been extensively investigated for the applications such as nanocomposites, photonic crystals, nanowires, magnetic-storage media, flash memory devices. However, the naturally formed nanostructures of block copolymers contain a high density of defects such that the practical applications for nanoscale devices have been limited. For the practical application of block copolymer nanostructures, a robust process to direct the assembly of block copolymers in thin film geometry is required to be established. To exploit self-assembly of block copolymer for the nanotechnology, it is indispensible to fabricate defect-free self-assembled nanostructure over an arbitrarily large area.