• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.1 s.139
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• pp.189-197
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• 2005

The purpose of this study was to find factors affecting sun protective behavior and intention to buy UV-protective clothing among Korean golfers. Health belief (HB) model and diffusion theory(DT) were used for the study. Dependent variable of HB model was sun protective behaviors (SPBs) and dependent variable of DT model was intention to buy (ITB) UV-protective clothing. Independent variables for HB model were cancer perception, perceived benefits, behavioral/psychological barriers and cues to actions, while independent variables of DT model were relative advantage, compatibility, complexity, friability, and observability, besides demographic variables. Perceived benefits and cues to action variables in addition to gender and age were significant determinants of SPB for Korean golfers. Also, relative advantage and compatibility. behavioral barriers and cues to action were significant in affecting intention to buy UV-protective clothes. Both HB model and extended DT model were useful to predict sun protective behavior of Korean golfers.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.5
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• pp.421-424
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• 2007

Thermal behavior of $Li_{1-x}CoO_2$ has been investigated employing DSC (Differential Scanning calorimetry) and TGA (Thermogravimetry Analyzer), and the crystal parameters were calculated from XRD (X-ray diffraction).for the commercial rectangular pouch cell(1000 mAh).The cathode materials coated over aluminium foil current collector is made up of a blend consisting of active material $LiCoO_2$(size $20\;{\mu}m$, 94 wt%), conducting material super p black (SPB, 3 wt%) and binder polyvinylidene fluoride (PVDF, 3 wt%). The anode is a mix consisting of carbon (92 wt%) and PVDF(8 wt%) coated over copper foil. The cells for the experiments were first preconditioned by cycling three times and stabilized at OCV=3.0, 3.5, 4.2, 4.35 and 4.5 V. The stabilized cathode material was used for thermal and crystal parameter investigations.

• Journal of the Korean Solar Energy Society
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• v.34 no.1
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• pp.64-71
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• 2014

This study is to perform economic analysis of a PVT-GSHP (Photovoltaic Thermal-Ground Source Heat Pump) system compared to the conventional system which consists of a boiler and a chiller. This research has simulated, developed and analyzed four systems for application in a residential and an office building which was based on the hourly EPI (Energy Performance Index, $kWh/m^2yr$). Case 1 includes a boiler and a chiller to meet heating and cooling demands for a house. Case 2 is the same conventional system as Case 1 for a office. Case 3 is simple summation of Case 1 and 2. And Case 4 is utilizing a PVT-GSHP to meet the combined loads of the house and office. The economic evaluation study was based on IEA ECBCS Annex 54 subtasks C economic assessment methods. This study indicated that PVT-GSHP system can save a building's energy up to 53.9%. Also the SPB (Simple Payback) of the PVT-GSHP system with 0%, 50% initial incentive was 14.5, 6.7 year respectively.

• International Journal of Computer Science & Network Security
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• v.23 no.12
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• pp.81-90
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• 2023

Cloud computing is an emerging business model popularized during the last few years by the IT industry. Providing "Everything as a Service" has shifted many organizations to choose cloud-based services. However, some companies still fear shifting their data to the cloud due to issues related to the security and privacy. The paper suggests a novel Trust based Mutual Authentication Mechanism using Secret P-box based Mutual Authentication Mechanism (TbMAM-SPb) on the criticality of information. It uses a particular passcodes from one of the secret P-box to act as challenge to one party. The response is another passcode from other P-box. The mechanism is designed in a way that the response given by a party to a challenge is itself a new challenge for the other party. Access to data is provided after ensuring certain number of correct challenge-responses. The complexity can be dynamically updated on basis of criticality of the information and trust factor between the two parties. The communication is encrypted and time-stamped to avoid interceptions and reuse. Overall, it is good authentication mechanism without the use of expensive devices and participation of a trusted third party.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.8 s.145
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• pp.1136-1145
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• 2005

The objective of this study was to determine factors affecting sun protective behavior and intention to buy UV protective clothing among outdoor sport persons in Korea. A self-administered questionnaire was distributed to mountain climbers, bikers and in-line skaters with a convenience sampling method. Two theoretical frameworks, health belief(HB) model and diffusion theory(DT) were used for the study. Based on HB model, sun protection behaviors(SPBs) were associated with cancer perception, perceived benefits, behavioral barriers and cues to actions based on the HB model. Based on DT model, intention to buy (ITB) was determined by an individual's perceived attributes of UV protective shirt. Appearance concern variables were added to the extended HB model. The extended DT model was proposed by adding the variables in the HB model and variables of appearance concern. Multiple regression analysis was applied. Results were as follows. First, perceived benefits, behavioral barriers, cues to action, and all three appearance concern variables as well as gender and age were significant determinants of SPB for Korean outdoor consumers. Second, relative advantage, compatibility, friability, behavioral barriers and cues to action with some appearance concern variables were significant in affecting intention to buy UV protective clothes. Extended HB model and extended DT model were useful to understand SPBs of Korean outdoor consumers.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.3
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• pp.232-242
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• 2005

It has been recognized that solar water heating systems are economically inferior to conventional gas water-heaters and boilers using light oil as fuel in spite of having practical possibilities among other alternative energy facilities in Korea. The solar system, however, should be revaluated due to the sharp rise of oil prices recently. We have calculated the energy amount and cost through a series of research projects for the system by experiment and simulation, which lead to analyzing reliable life cycle costs. For the economic analysis, the gas water-heater and light oil boiler were taken as base cases while the solar systems implemented with these facilities were compared as alternatives. As a result, the solar system using the light oil as an auxiliary fuel surpassed the light oil boiler in economics. And a $50\%$ government subsidy for the initial cost is needed to maintain competitiveness with the gas hot-water heater. With this support, the simple payback period of the system can approach 12.8 years under $20\%$ additional curtailment of expenditure.

• Journal of the Korean Society of Tobacco Science
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• v.15 no.2
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• pp.174-184
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• 1993

This is to investigate the methodology for the simultaneous determination of Wk, mk and TSNA using gas chromatography(GC) in combination with chemiluminescence detector, thermal energy analyzer(TEA) . The simultaneous analysis has been estimated by evaluating tobacco. The TEA was linked to GC equipped with non -polar SPB -5 fused silica capillary column which was introduced into the ceramic pyrolysis tube by the point of 16cm from the end of TEA. Quantification was carried out by internal standardization with WDPA after calibration of retention times and response factors with authentic nitrosoamines. It was demonstrated that WDPA was most preferable as internal standard for the simultaneous analysis. The recoveries of the internal standard were in the range of 83∼96% . Nitrosoamines in this method were detected with determination limit of 0.1ng and was made by a straight line in calibration curve by TEA response. The suitability of nitrosoamines extraction in tobacco leaf was investigated. It was most suitable to extract nitrosoamines from tobacco leaves with 0.01 M NaOH within a period of 8 hours. Thimerosal as an antibacterial agent was added to NaOH solution to prevent artifactual formation. The fractionation and the purification of nitrosoamines form alkaline extracts were conveniently performed using Extrelut multilayer column and dichloromethane. Reproducible and reliable results were obtained for the determination of nitrosamines in a relatively short time compared to previous known method. TSNA contents in burley were about 4 times higher as those in the fluecured tobacco.

• Korean Journal of Materials Research
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• v.15 no.9
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• pp.598-603
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• 2005

To develope new lead-free solders with the melting temperature close to that of Sn-37Pb$(183^{\circ}C)$, Sn-0.7Cu-5Pb-1Ga, Sn-0.7Cu-5Pb-1Ag, Sn-0.7Cu-5Pb-5Bi-1Ag, and Sn-0.7Cu-SBi-1Ag alloys were composed by adding low-netting elements such as Ga, Bi, Pb, and Ag to Sn-0.7Cu. Then the melting temperatures, microstructures, wettability, and adhesion properties of these alloys were evaluated. DSC analysis showed that the melting temperature of Sn-0.7Cu-SPb-1Ga was $211^{\circ}C$, and those of other alloys was in the range of $192\~200^{\circ}C$. Microstructures of these alloys after heat-treatment at $150^{\circ}C$ for 24 hrs were basically composed of coarsely- grown $\beta-Sn$ grains, and $Cu_6Sn_5$ and $Ag_3Sn$ intermetallic precipitates. Sn-0.7Cu-5Pb-1Ga and Sn-0.7Cu-5Pb-5Bi-1Ag showed excellent wettability, while Sn-0.7Cu-5Bi-1Ag and Sn-0.7Cu-5Pb-5Bi-1Ag revealed good adhesion strength with the Cu substrates. Among 4 alloys, Sn-0.7Cu-5Pb-5Bi-1Ag with the lowest melting temperature $(192^{\circ}C)$ and relatively excellent wettability and adhesion strength was suggested to be the best candidate solder to replace Sn-37Pb.

• Journal of Powder Materials
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• v.31 no.2
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• pp.119-125
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• 2024

The n-type Bi_2-xSb_xTe₃ compounds have been of great interest due to its potential to achieve a high thermoelectric performance, comparable to that of p-type Bi_2-xSb_xTe₃. However, a comprehensive understanding on the thermoelectric properties remains lacking. Here, we investigate the thermoelectric transport properties and band characteristics of n-type Bi_2-xSb_xTe₃ (x = 0.1 - 1.1) based on experimental and theoretical considerations. We find that the higher power factor at lower Sb content results from the optimized balance between the density of state effective mass and nondegenerate mobility. Additionally, a higher carrier concentration at lower x suppresses bipolar conduction, thereby reducing thermal conductivity at elevated temperatures. Consequently, the highest zT of ~ 0.5 is observed at 450 K for x = 0.1 and, according to the single parabolic band model, it could be further improved by ~70 % through carrier concentration tuning.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.388-395
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• 2019

The object of the present study was to examine the effect of selenium-treated Spinacia oleracea L. on antioxidative defense system and oxidative damage in rats fed high-fat and high-cholesterol diets. Experimental rats were divided into six groups which were composed of normal diet group (N), high-fat and high-cholesterol diet group (HF), high-fat and high-cholesterol diet with 5% or 10% non-treated spinach supplemented group (SPA or SPB) and high-fat and high-cholesterol diet with 5% or 10% selenium-treated spinach-supplemented group (SSA or SSB). In the antioxidant enzyme activities of hepatic glutathione peroxidase and superoxide dismutase, activities increased in supplementation of non-treated or selenium-treated spinach groups compared to HF group. However, there was no significant difference in the activity of hepatic catalase among all experimental groups. The microsomal superoxide radical content of the SSB group was significantly reduced compared to the HF group. The mitochondrial carbonyl values of the SSB group were significantly reduced compared to the HF group. Thiobarbituric acid reaction substance (TBARS) values in RBC and liver were also reduced in non-treated or selenium-treated spinach-supplemented groups compared to the HF group. The hepatic TBARS values of the supplementation of selenium-treated spinach groups significantly decreased compared to the supplementation of non-treated spinach groups. These results suggest that selenium-treated spinach may reduce oxidative damage by the activation of antioxidative defense system in rats fed high-fat and high-cholesterol diets.