• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.923-926
• /
• 2009

We fabricated large-area OLED lighting device using screen printing. In order to operate full area of large-area OLED uniformly, each cell in OLED panel was designed to work separately. We connected OLED panel with a PCB electrically using jig pins so that each cell could be operated individually. In this presentation, we report a few important issues on the fabrication of large-area OLED for lighting applications.

• Journal of Advanced Marine Engineering and Technology
• /
• v.30 no.2
• /
• pp.231-238
• /
• 2006

The performance of free-breathing polymer electrolyte membrane fuel cell (PEMFC) was studied experimentally and the effect of cathode separator structure on the cell performance was investigated. Cathode separators were used for the cell with $18cm^2$ active area. In channel type, the contact resistance is low, and the nature convection. which is strongly affected by the cross-sectional shape of cathode separator channel, is dominant in a cell performance. The maximum power density with $18cm^2$ active area is $105mW/cm^2$ using the 10mm depth and 2mm width channel. A computational analysis was optimum structure of free-breathing channel type PEMFC for robotic application.

• Journal of Veterinary Clinics
• /
• v.19 no.4
• /
• pp.464-466
• /
• 2002

A case of spindle cell tumor was presented in a 16-month-old, female syrian hamster. In the left chest area, a 3cm firm elevated recurrent mass was found, surgically removed, and submitted to the Department of Veterinary Pathology, Seoul National University for diagnosis. The mass was soft to firm and tan on sectioning, and contained hemorrhagic area. Histologically, the tumor was composed of sheets of interlacing bundles of spindle-shaped cells with moderate amount of cytoplasm and oval to fusiform nuclei. They were plemorphic and contained 1 to 3 prominent nucleoli. Based on the gross and histological findings, the tumor was diagnosed as a subcutaneous spindle cell tumor. However, the exact origin of neoplastic cells remained undetermined.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.502-505
• /
• 2007

In this paper we propose a novel electrode structure for high transmittance in the Patterned Vertical Alignment (PVA) LC cell. Normally, the transmittance of PVA LC cell is depended on the shape of the electrode and cell gap. We studied the area decreasing the transmittance through the electrode structure for wide viewing angle and proposed new electrode design to change LC director configuration in the area. We use the 'TechWiz LCD' for calculation of the director configuration and optical characteristics. We show the comparison of the calculated optical transmittance between the conventional PVA mode and the proposed PVA mode. From the results, we confirm that the optical transmittance of the proposed structure of the PVA cell becomes higher.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.6 no.1
• /
• pp.71-82
• /
• 2002

A time-iterative compressible Navier-Stokes code is developed to analyze the flowfield of a two-dimensional ejector nozzle system. A parametric study has been made for two controlling parameters, duct to nozzle area ratio and nozzle pressure ratio. Results show that there is an optimum area ratio for an efficient pumping of secondary flow. At high area ratios, a freestream flow directly passes through the mixing duct without giving adequate pumping. While at low area ratios, jet boundary is acting as a blockage to incoming flow. The nozzle pressure ratio variation shows that the pumping rate increases as the pressure ratio increases provided there is no interaction between the shroud wall and the shock cell structure.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.10
• /
• pp.5303-5306
• /
• 2012

Aim: The present case-control study was conducted to explore the association of MTHFR gene polymorphism and relations of P16, MGMT and HMLH1 to MTHFR and folate intake. Methods: A total of 257 cases of esophageal squamous cell carcinoma confirmed by histopathological examination were collected. Genotyping of P16, MGMT and HMLH1 was accomplished by methylation-specific polymerase chain reaction (PCR) after sodium bisulfate modification of DNA and the MTHFR C677T genetic polymorphism was detected by PCR-restriction fragment-length polymorphism (PCR-RFLP). Results: The proportions of DNA hypermethylation in P16, MGMT and hMLH1 in cancer tissues were significantly higher than in paracancerous normal tissue. The proportion of hypermethylation in at least one gene was 88.5% in cancer tissue, and was also significantly higher than that in paracancerous normal tissue. Our finding showed individuals with homozygotes (TT) of MTHFR C677T had significant risk of DNA hypermethylation of MGMT in cancer tissues, with an OR (95% CI) of 3.15 (1.12-6.87). Similarly, patients with high intake of folate also showed a slight high risk of DNA methylation of MGMT, with OR (95% CI) of 2.03 (1.05-4.57). Conclusion: Our study found the P16, MGMT and hMLH1 demonstrate a high proportion of hypermethylation in esophageal squamous cell cancer cancer tissues, which might be used as biomarkers for cancer detection.

• Journal of the Korean Electrochemical Society
• /
• v.10 no.2
• /
• pp.104-109
• /
• 2007

Single fuel cell was fabricated with a MEA (membrane electrode assembly) that had a $4cm^2$ active area and with silicon bipolar plates those were introduced to miniaturize the fuel cell by replacing heavy weight graphite plates. Optimum humidification condition for the single cell was selected based on performance results obtained varying humidifier temperature at a fixed feed rate of hydrogen and oxygen. Furthermore, to study the effect of humidification condition on the performance of a fuel cell stack, the fuel cell stack consisting of two MEAs and silicon bipolar plates was studied, then problems and characteristics of silicon-based fuel cell stack were examined.

• Carbon letters
• /
• v.8 no.1
• /
• pp.37-42
• /
• 2007

Carbon nanofiber (CNF) grown catalytically was chemically activated with KOH to attain structural change of CNF. The structural changes of CNF through KOH activation were investigated by using BET and SEM. From the results of BET, it was found that KOH activation was effective to develop particular sizes of pores on the CNF surface, increasing the surface area of CNF. Activated CNF was applied as an anode catalyst support of fuel cell. The effects of different activation conditions including the activation temperature and the activation time on the specific surface area of the CNF activated with KOH were investigated to obtain appropriate structure as a catalyst support. The 60 wt% Pt-Ru catalyst prepared was observed by using TEM and XRD.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.33 no.4
• /
• pp.353-359
• /
• 1988

Variations in photosynthetic capacities of leaves differing in thickness were explained on the basis of relationships between gas exchange and internal leaf structure. The relative importance of gas diffusion and of biochemical processes as limiting for leaf photosynthesis was also determined. Mesophyll cell surface was considered to be the limiting internal site for gas diffusion. and cell volume to be indicative of the sink capacity for CO$_2$ fixation. Increases in cell surface area were assumed to reduce proportionately mesophyll resistance to the liquid phase diffusion of CO$_2$. Increased cell volume was thought to account for a proportional increase in reaction rates for carboxylation, oxygenation. and dark respiration. This assumption was tested using chamber-grown Glycine max (L.) Merr. cv. Amsoy plants. Plants were grown under 200, 400, and 600 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR to induce development of various leaf thickness. Photosynthetic CO$_2$ uptake rates were measured on the 3rd and 4th trifoliolate leaves under 1000 ${\mu}$mol photons m$\^$-2/ s$\^$-1/ of PAR and at the air temperature of 28 C. A pseudo -mechanistic photosynthesis model was modified to accommodate the concept of cell surface area as well as both cell volume and surface area. Both versions were used to simulate leaf photosynthesis. Computations based on volume and surface area showed slightly better agreement with experimental data than did those based on the surface area only. This implies that any single factor, whether it is photosynthetic model utilized in this study was suitable for relating leaf thickness to leaf productivity.

• Journal of the Korean Society for Precision Engineering
• /
• v.26 no.7
• /
• pp.73-80
• /
• 2009

This paper describes a path planning algorithm, which is the minimal turning path based on the shape and size of the cell to clean up the whole area with two cleaning robots. Our method divides the whole cleaning area with each cell by cellular decomposition, and then provides some path plans among of the robots to reduce the rate of energy consumption and cleaning time of it. In addition we suggest how to plan between the robots especially when they are cleaning in the same cell. Finally simulation results demonstrate the effectiveness of the algorithm in an unknown area with multiple robots. And then we compare the performance index of two algorithms such as total of turn, total of time.