• Journal of Information Display
• /
• v.2 no.4
• /
• pp.46-51
• /
• 2001

Using ray-optics code incorporated with three-dimensional PDP cell simulation, we have analysed the energy flow in the PDP cell from the electric power input to the visible light output. Also, the visible light output profile and viewing angle distribution were obtained. We applied our code to the analysis of the barrier rib height effect on the visible light luminance and efficiency of the sustaining discharge. Although cells with higher barrier rib generate more VUV photons, less ratio of visible photons are emitted toward front panel due to the shadow effect. Thus, there exists optimal barrier rib height giving the highest visible luminance and efficiency. This kind of code can be a powerful tool in designing cell geometry.

• Korean Journal of Plant Taxonomy
• /
• v.53 no.2
• /
• pp.166-169
• /
• 2023

Carex brevispicula (Cyperaceae) is endemic to Korea and is characterized by constricted achenes, short lateral spikes, and awned staminate and pistillate scales. The species classified in sect. Mitratae occurs throughout South Korea, perennating on mountains and/or rocky slopes under half shadow conditions. Meiotic chromosomes of the species were examined in this study, in which 33 meiotic cells from seven populations were found to be less than 2 ㎛ long with non-constricted chromosomes (n = 34_II). The stable chromosome number may be related to the narrow geographical distribution and/or distinct achene morphology. Further investigations of the distribution, morphological character variation, and chromosome characteristics should be conducted with closely related taxa to understand the derivation of the species and its endemism in Korea.

• Proceedings of the KIEE Conference
• /
• 1996.07a
• /
• pp.540-542
• /
• 1996

A detailed model of a photo voltaic array written in PSPlCE is presented in this paper. It is likely that solar cell arrays in photovoltaic system is shadowed partly by clouds, buildings. By the effects of partial shadowing, not only the output power of solar cell arrays is decreased, but also shadowed cells are reversely biased and damaged in some cases. In this paper, by analyzing the output characteristics of solar cell arrays according to various shadow patterns, we investigate solar cell arrays connection of prevention the shadowing effects to the utmost.

• Journal of Environmental Science International
• /
• v.21 no.6
• /
• pp.757-761
• /
• 2012

The purpose of this study was to determine optimum conditions for the cultivation of Tetraselmis suecica (T. suecica) under illumination of four different types of LEDs (i.e., blue, red, white, and mixed). Initial cell concentration was $4{\times}10^4$ cells/mL and temperature of reactor was maintained between 21-$24^{\circ}C$. Specific growth rates were 0.72 $day^{-1}$(white), 0.58 $day^{-1}$(red), 0.49 $day^{-1}$(mixed), and 0.49 $day^{-1}$(blue). Thus, white LEDs was used for the cultivation of T. suecica. Tests with white LEDs under different light intensity, which was conducted to determine optimum light intensity of white LEDs, showed that 9,000 lux of illumination resulted in fastest cell growth and greatest cell concentrations. To avoid shadow effects by dense cell populations, aeration was performed. Cell concentration increased 3.8 times when aeration was used.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.597-598
• /
• 2006

In this study, we used the ESD method to prepare the protein microarrays for observation the stem cell responses to pattern size, space and shapes. The ESD method allows a reduction in spot size, high efficiency of substance transfer, and high rate in fabrication as a result of ability to simultaneously deposit thousands of identical spots. Typical electro spraying conditions for the deposition of proteins were a voltage of $3{\sim}5keV$ and the humidity under 30%. The patterns of masks have a variety of shapes, spaces, and hole sizes from 10 um to $300{\mu}m$. Three kinds of proteins(collagen, fibronectin, and vitronectin dissolved in PBS) are deposited in a dry state, preserving the functional activity of proteins. Stem cells were cultured on each protein patterned sample at $37^{\circ}C$ for 1day.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.2
• /
• pp.283-290
• /
• 2006

The cellular neural networks have the structure that consists of an array of the same cell which is a simple processing element, and each of the cells has local connectivity and space invariant template properties. So, it has a very suitable structure for the hardware implementation. But, it is impossible to have a one-to-one mapping between the CNN hardware processors and the pixels of the practical large image. In this paper, a $5{\times}5$ CNN hardware processor with pipeline input and output that can be applied to the time-multiplexing processing scheme, which processes the large image with a small CNN cell block, is designed. the operation of the implemented $5{\times}5$ CNN hardware processor is verified from the edge detection and the shadow detection experimentations.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.12 no.1
• /
• pp.57-63
• /
• 2009

Calcifying fibrous tumors (CFTs) are unusual benign tumors of childhood, located primarily in soft tissues, pleura, and peritoneum. The cause and pathogenesis are unclear. We report a rare case of a CFT in a 2-year-old boy who presented with vomiting and abdominal distension. An abdominal X-ray showed an elliptical, calcific shadow in the LUQ area mimicking a foreign body. An internally protruding mass along the lesser curvature of the gastric body was an incidental finding during upper endoscopy, biopsies of which were negative. Abdominal CT showed a 4.5${\times}$3.2 cm soft tissue mass of the gastric wall with calcifications. A diagnosis of gastric submucosal mass was suspected and a wedge resection of the stomach was performed. On microscopic examination, the tumor was composed of whorls of dense hyalinized collagen bundles with a few fibroblasts. There were also amorphous dystrophic calcifications and nodular aggregates of mononuclear inflammatory cells. Immunohistochemically, spindle cells did not stain for anaplastic lymphoma kinase-1 (ALK-1), CK, smooth muscle actin (SMA), or desmin. Taken together, the mass was compatible with a CFT of the gastric wall. This is the first reported case of CFT in a Korean child.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.67-67
• /
• 2008

Application of organic materials with low cost, easy fabrication and advantages of flexible device are increasing attention by research work. Recently, one of them, organic solar cells were rapidly increased efficiency with regioregular poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyricacidmethylester (PCBM) used typical material. To increased efficiency of organic solar cell has tried control of domain of PCBM and crystallite of P3HT by thermal annealing and solvent vapor annealing. [4-6] In those annealing effects, be made inefficiently efficiency, which is increased fill factor (FF), and current density by phase-separated morphology with blended P3HT and PCBM. In addition, increased conductivity by modified hole transfer layer (HTL) such as Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), increased both optical and conducting effect by titanium oxide (TiOx), and changed cathode material for control work function were increased efficiency of Organic solar cell. In this study, we had described effect of organic photovoltaics by conductivity of interlayer such as PEDOT:PSS and TCO (Transparent conducting oxide) such as ITO, which is used P3HT and PCBM. And, we have measured with exactly defined shadow mask to study effect of solar cell efficiency according to conductivity of hole transfer layer.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.24 no.12A
• /
• pp.1883-1890
• /
• 1999

Wireless communication in an urban area, the accurate prediction of wave propagation characteristics are very important to determine communication service areas, select optimal base-stations, and design cells, etc. The CCIR model is a propagation prediction model using a shadowing by the buildings in an urban area. This model represent the shadowing rate by the means of the effect of shadowing between base-station and mobile unit in a shaped linear plane. But, This one occurred a lot of prediction error because it did not consider that density area by the buildings and terrain configurations by the hill and mountain on Line-Of-Sight. In this thesis, an improved propagation prediction model is proposed to reduce prediction error. We presents a new equation, which is using the SAS. This equation is associated with the shadow height by the buildings that considers the topology and the number of blocks that can affect the building shadow in the Line-Of-Sight. We measure the received electrical field level of base-station that high density area, medium density area, and low density area, and then compare and analysis the result to prediction of CCIR model and proposed model. The result compared with the measurement, the proposed model has the improvement of 9.71dB in a high density area, 9.66dB in a medium density area, and 4.02dB in a low density area better than the CCIR model. The result compared with the measurement, the proposed model has the improvement of 9.71dB in a high density area, 9.66dB in a medium density area, and 4.02dB in a low density area better than the CCIR model.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.15 no.2
• /
• pp.105-112
• /
• 1993

A case of calcifying odontogenic cyst associated with an unerupted tooth which appeared in the left maxillary sinus of a 16-year-old woman, was reported. Clinical examination revealed painless swelling on the left maxillary posterior region and the cheek. Radiographically, this lesion showed a monolocular radiolucent shadow with calcified materials and unerupted maxillary second premolar. Histological examination revealed cystic structure with presence of the ghost cells, calcified tissue and unerupted tooth. This lesion was classified as Type IB of COC according to classification of the Praetorius. After surgical removal of the cyst, the wound healed uneventfully and the lesion is now free of symptoms.