• Carbon letters
• /
• v.10 no.3
• /
• pp.213-216
• /
• 2009

The electrochemical deposition of Pt nanoparticles on carbon nanotubes (CNTs) supports and their catalytic activities for methanol electro-oxidation were investigated. Pt catalysts of 4~12 nm average crystalline size were grown on supports by potential cycling methods. Electro-plating of 12 min time by potential cycling method was sufficient to obtain small crystalline size 4.5 nm particles, showing a good electrochemical activity. The catalysts' loading contents were enhanced by increasing the deposition time. The crystalline sizes and morphology of the Pt/support catalysts were evaluated using X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). The electrochemical behaviors of the Pt/support catalysts were investigated according to their characteristic current-potential curves in a methanol solution. In the result, the electrochemical activity increased with increased plating time, reaching the maximum at 12 min, and then decreased. The enhanced electroactivity for catalysts was correlated to the crystalline size and dispersion state of the catalysts.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.32 no.6
• /
• pp.617-623
• /
• 2014

The rapid urbanization in developing countries has caused trasportation problems that need to be solved. For that reason, the study evaluates the potential of cycling in the densely populated part of Kathmandu valley. Slopes and existing roads have been applied as the input cost rasters for finding the shortest cost routes between stations. By taking the average cycling velocity, time to travel from station to destination were compared with the average commuting time in the public transportation. The result comes out as similar time with the public transportation. Although the cycling seems potential replacement for public transportation commuters, in fact, there are some setbacks needed to be supported by the government to make it reality in future.

• Journal of the Microelectronics and Packaging Society
• /
• v.22 no.1
• /
• pp.27-34
• /
• 2015

The correlation between crack propagation and localized recrystallization are compared in a series of cross section analyses on thermal cycled edgebond and underfilm material applied wafer level chip scale package (WLCSP) components with a baseline of no-material applied WLCSP components. The results show that the crack propagation distribution and recrystallization region correlation can explain potential degradation mechanisms and support the damage accumulation history in a more efficient way. Edgebond material applied components show a shift of damage accumulation to a more localized region, thus potentially accelerated the degradation during thermal cycling. Underfilm material applied components triggered more solder joints for a more wider distribution of damage accumulation resulting in a slightly improved thermal cycling performance compared to no-material applied components. Using an analysis on localized distribution of recrystallized areas inside the solder joint showed potential value as a new analytical approach.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.11 no.8
• /
• pp.3809-3822
• /
• 2017

Wireless Sensor Networks hold the limelight because of significant potential for distributed sensing of large geographical areas. The radio duty cycling mechanism that turns off the radio periodically is necessary for the energy conservation, but it deteriorates the network congestion when the traffic load is high, which increases the packet loss and the delay too. Although many papers for WSNs have tried to mitigate network congestion, none of them has mentioned the congestion problem caused by the radio duty cycling of MAC protocols. In this paper, we present a simple and efficient congestion control technique that operates on the radio duty cycling MAC protocol. It detects the congestion by checking the current queue size. If it detects the congestion, it extends the network capacity by adding supplementary wakeup times. Simulation results show that our proposed scheme highly reduces the packet loss and the delay.

• Journal of the Korean Society of Costume
• /
• v.67 no.3
• /
• pp.1-14
• /
• 2017

Cycling has become a popular leisure activity, and many cycling enthusiasts have used cycling clothes as a form of expression, which often comes in wide range of colors. The study shows the importance of color in cycling clothing to meet the emotional needs of consumers. Furthermore, this study aims to provide comparative analysis between color of domestic and overseas cycling clothing brands, and color preference of Korean consumers in order to provide data, which can be used in satisfying consumers' needs for personal expression and emotional demands. Thus, the study expects to identify consumers' satisfaction for cycling clothing. The consumers were categorized by the frequency of cycling and their interest in fashion, and the following categories were made:potential consumers, casual cyclists with low fashion involvement, casual cyclists with high fashion involvement and frequent cyclists with high fashion involvement. Consumers preferred dark colors for their cycling clothing including jacket, top and pants, while 'frequent cyclists with high fashion involvement' preferred more diverse colors and tones. In the cycling clothing market, white and black were major colors, while red, orange and blue were major colors of chromatic color. In terms of shade, dark shade dominated the market. Comparing between preferred color and preferred product color, black was preferred for both, but no other colors showed such tendency. This study is based on empirical analysis and verification of color, which is the emotional element appealing to specific and segmented sports-apparel market. The study revealed that the data could be applicable to the design of future products.

• Journal of Electrochemical Science and Technology
• /
• v.12 no.2
• /
• pp.167-172
• /
• 2021

he progressively improved sensing sensitivity (∆λ_SPR/∆n, nm/RIU) to detect the refractive index is observed on the SPR platform of an Au-covered epoxy gratings in an increase in potential cycling in a typical three-electrode cell. Here, a DVD-R optical disc was used as a structure template to prepare an Au-covered epoxy gratings, and the newly formed reverse track pitch structure on the epoxy substrate was used as a working electrode directly in aqueous sulfuric acid solution. It is expected that Au reconstruction by potential cycling in sulfuric acid electrolyte increases the packing density of Au atoms in the grain boundary and improves the propagation of electromagnetic waves.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.42 no.3
• /
• pp.486-502
• /
• 2018

Mass-production caused by industrialization has led to environmental pollution; however, a potential solution to this problem is the Up-cycling fashion design belonging to the sustainable design category. This study analyzed the material characteristics of each brand fashion product by selecting 21 domestic Up-cycling fashion brands. The product types manufactured by domestic Up-cycling fashion brands could be divided into fashion clothing, bag, and fashion accessories. The materials used for each item included special material, waste fiber, waste leather, waste paper, and others. In the results of analyzing the material characteristics into the external characteristics and internal characteristics, the external characteristics included the durability with less abrasiveness and deformation as well as a mixture with other different materials, while the internal characteristics included a story arousing consumers' empathy, and scarcity without the same design due to the limitation of material.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.2
• /
• pp.319-322
• /
• 2009

Gel polymer electrolytes were prepared by immersing a porous poly(vinylidene fluoride-co-hexafluoropropylene) membrane in an electrolyte solution containing small amounts of polymerizable additive (3,4-ethylenedioxythiophene, thiophene, biphenyl). The organic additives were electrochemically oxidized to form conductive polymer films on the electrode at high potential. With the gel polymer electrolytes containing different organic additive, lithium-ion polymer cells composed of carbon anode and LiCo$O_2$ cathode were assembled and their cycling performances were evaluated. Adding small amounts of thiophene or 3,4-ethylenedioxythiophene to the gel polymer electrolyte was found to reduce the charge transfer resistance in the cell and it thus exhibited less capacity fading and better high rate performance.

• Transactions on Electrical and Electronic Materials
• /
• v.2 no.3
• /
• pp.28-32
• /
• 2001

It was studied in the present work how the thermal cycling performance of LOC (lead on chip) packages depends on the package construct or leadframe materials. First, package body thickness and Au wire diameter were manipulated for the selection of proper package design. Secondly, two different types of leadframe materials (i.e. copper and 52%Fe-48%Ni alloy) were tested to determine the better material for improved reliability margin of plastically encapsulated microelectronic packages. This work shows that manipulating package body thickness was more effective than an increase of Au wire from 23$\mu\textrm{m}$ to 33$\mu\textrm{m}$ for the prevention of wire debonding failure. Further, this work indicates that the LOC packages including the copper leadframes can be more susceptible to thermal cycling reliability degradation due to chip cracking than those including the alloy leadframes.

• Journal of Environmental Science International
• /
• v.6 no.6
• /
• pp.697-709
• /
• 1997

Sequencing Batch Reactor(SBR) experiments for organics and nutrients removal have been conducted to find an optimum anaerobic/anoxic/aerobic cycling time and evaluate the applicability of oxidation-reduction potential(ORP) as a process control parameter. In this study, a 61 bench-scale plant was used and fed with night-soil wastewater in K city which contained TCODcr : 10, 680 mg/l, TBm : 6, 893 mg/l, $NH_4^+-N$ : 1, 609 mg/l, $PO_4^{3-}-P$ : 602 mg/l on average. The cycling time In SBRs was adjusted at 12 hours and 24 hours, and then certainly included anaerobic, aerobic and inoxic conditions. Also, for each cycling time, we performed 3 series of experiment simultaneously which was set up 10 days, 20 days and 30 days as SRT From the experimental results, the optimum cycling time for biological nutrient removal with nlght-soil wastewater was respctively 3hrs, 5hrs, 3hrs(anaerobic-aerobic-anoxic), Nitrogen removal efficiency was 77.9%, 77.9%, 81.7% for each SRT, respectively. When external carbon source was fed in the anoxic phase, ORP-bending point indicating nitrate break point appeared clearly and nitrogen removal efficiency increased as 96.5%, 97.1%, 98.9%. Phosphate removal efficiency was 59.8%, 64.571, 68.6% for each SRT. Also, we finded the applicability of ORP as a process control parameter in SBRs.