• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.174-178
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• 1991

ATM, the core technology of BISDN, provides a high degree of flexibility with regard to varying bandwidth requirements for different services. In ATM networks, since users may exceed the traffic volume negotiated at the call setup, traffic from users may need to be monitored and enforced to comply with traffic parameters. The leakybucket mechanism is one of the typical traffic enforcement methods based on the use of transmission tokens for each cell. In this mechanism the major system parameters are size of input buffer, size of token pool, and token generation ratio. In order to represent ATM cell arrivals we assume a Poisson process. In this paper, a state transition analysis technique is used to study the cell loss rates for various values of system parameters.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.370-374
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• 2003

Cell cracking method using a non-collision was evaluated for the possibility of new red ginseng grinding technique. Based on particle size distribution analysis by 1size shaker, the ratios of 100 mesh penetrated particles were 94.9% for hammer mill (group A) and 95.6% for cell crack (group B). The ratio of 120 mesh penetrated particle of group A was higher than that in group B. The particle size distributions for 100 mesh non-penetrated Powder between 2 groups were not significantly different, and particle size distribution analysis by laser scattering analyzer showed that the particle size ranges were 0.77~128.07 ${\mu}{\textrm}{m}$ for group A and 4.24~180.07 ${\mu}{\textrm}{m}$ for group B. The Particle size distribution in group A was more broad than that in group B. The mean particle size in group B was larger than that in group A, while the standard deviation of particle size distribution in group B was less than that in group A. Structural surface characteristics, in group A, particle size distribution was broad and the distribution curve was amorphous. The structure of individual particles was similar to unequal stone which was roughly grinded and had soft cotton-like surface. In the contrary, in group B, particle size distribution was relatively narrow and also individual size particles were ubiquitously distributed. The structure of individual particles was unequal cut stone shape.

• KSBB Journal
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• v.13 no.2
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• pp.187-194
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• 1998

For mass production of polyhydroxyalkanoates (PHA), high cell density cultures of Alcaligenes eutrophus by fed-batch culture under phosphate-limitation condition has been investigated. PHA accumulation by the regulation by the regulation of initial phosphate concentration could be automatically induced, and high density cell culture above 200 g/L also could be successfully produced. The production of Poly-$\beta$-hydroxybutyrate (PHB) and dry cell weight increased with increasing the initial phosphate concentration. When the initial concentrations of phosphate were in the ranges of 1.5~4.5 g-PO$_4$/L, PHB and dry cell weight obtained were 83~266 g/L and 61~216 g/L, respectively, and PHB productivity was in the ranges of 1.35~3.10 g/L.h. When a mixture of glucose and propionic acid is used as carbon sources, poly(3-hydroxybutyrate-co-poly-3-hydroxyvalerate), P(3HB-co-3HV), could be also successfully produced under phosphate limitation condition. When the mole ratio of propionic acid to glucose in the feeding solution is 0.22, a final dry cell weight of 150 g/L and a P(3-HB-co-3HV) of 90 g/L were produced. Morphological changes and size distribution of PHB granules synthesized in A. eutrophus under phosphate-limitation condition are determined by TEM during the course of fed-batch. Mean granule diameters of PHB produced are in the range of 0.36~0.39 $\mu$m, and mean cell size was elongated from 0.54~0.59 $\mu$m$\times$ 1.3~1.5 $\mu$m to 0.83~0.89 $\mu$m $\times$2.0~2.3 $\mu$m. Phosphate concentration in media did not affect size distribution of PHB granule and cell.

• Korean Journal of Veterinary Research
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• v.57 no.3
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• pp.205-208
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• 2017

Study purposes were to evaluate ultrasonographic characteristics of transitional cell carcinoma (TCC) and quantitate bladder tumor size in dogs. Heterogeneous mass, wall involvement, and broad-based attachment were significantly associated with TCC, but not prominently the trigone region. Mass size evaluation revealed a significant correlation between progressive disease (PD) in TCC patients with piroxicam therapy. Largest diameter of target lesion/body weight (cm/kg) ratio showed a high mean value in PD. A value > 0.3 was associated with PD with 83% sensitivity and 66% specificity. The results suggest that ultrasonography can provide evidence for diagnosing and predicting a prognosis for TCC.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1295-1296
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• 2007

A lot of researches about dye-sensitized solar cell (DSC) are recently being conducted. Because DSC has several advantages to pass the limits of silicon solar cells such as a low manufacturing expense, a simple manufacturing process and its transparency. But most researches on DSC are still conducted about the unit cell and laboratory-centered. That is, present researches on DSC are not practical. Therefore, researches about large area cells and modules have to be prerequisites for DSC to have the practicality. Characteristics of large area DSC are so different from those of small area DSC in aspect of fill factor and efficiency. In this study, we made an experiment on finding suitable size of DSC that has the most effective power according to the variation of active area. In detail, the experiment was conducted about the optimum ratio of length to width and we introduced the ratio of active area to non-active area to find the active area which has the best output. Because small DSC doesn‘t have the best output in comparison with total area of cell although the smaller DSC has the better efficiency. As a result, we achieved the optimum ratio of length to width of 8:3 and active area of $8cm^2$ as the optimum size for upscaling DSC.

• 한국태양에너지학회:학술대회논문집
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• 2012.03a
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• pp.96-101
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• 2012

An experimental study was conducted to investigate the performance of a concentrating photovoltaic cell (CPV) against temperature. It is know that a high efficiency of a CPV can be achieved only with proper cell temperature as well as high concentration ratio (CR). This study is concerned with appropriate cooling condition for a liquid-convection cooler for the best performance of a specific CPV. A series of experiments was conducted in a range of cell temperatures as a result of varying cooling conditions, while the concentration ratio was 390 and the solar irradiation flux was higher than 900 $W/m^2$ in outdoor environment. The CPV had a planar dimension of 10 by 10 mm. A Fresnel lens was used as a concentrator, of which the dimension was 221 mm(W) ${\times}$ 221 mm(L) ${\times}$ 3 mm(t) and the transmissivity was known to be 0.8. The cooler was attached to the bottom side of the CPV and had a contact area of 21 mm(W) ${\times}$ 26 mm(L), which was identical to the size of the base plate of the CPV. The coolant temperature was controlled by an isothermal bath and the flow rate was controlled and measured by a flowmeter. The experimental results showed that the average of power efficiency of the CPV decreased from 28.6 % to 24.7 % as the cell temperature increased from $36^{\circ}C$ to $97^{\circ}C$. An appropriate cooling method of a CPV might increase the power conversion efficiency by about 4% for the same concentration ratio. Discussion is included from the viewpoint of the combined efficiency in addition to the power efficiency.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.4
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• pp.601-607
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• 2003

The column type is used as the sensing element of the load cell to measure the large force in the range of 10$^4$~ 10$^{7}$ N. However. it is not easy to handle the load with large capacity due to its size. It is, therefore, necessary to design a compact load cell with a low aspect ratio. Thus this paper showed the characteristic evaluation of compact load cell with respect to the shape of supporting plate. The supporting plate of the load cell was an annular type with inner(D$_{i}$) and outer(D$_{o}$) diameters. Using the strain distribution obtained from FEM. the supporting plate was designed to get the stable output voltage of the load cell. The three designed supporting plates were manufactured, and the result of characteristic experiment of the load cell, using the 10 MN hydraulic force standard machine, was compared with FEM.M.M.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.952-957
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• 2005

A sensitivity analysis study was performed to examine the effects of cell size on a distributed non-point source pollution model. The model, AnnAGNPS, whiff is a modified version of USDA's AGNPS, was applied to Eung stream watershed, a tributary of Cheongmi stream located in the South Branch of Han River System. The model components and results, such as channel length, slope, land use, and delivery ratio, were analyzed according to the various cell sizes from 10 to 200 ha. As cell sire increases, channel length decreases due to short-circuiting of meandering creek. The decreased channel length has more significant effects on the model results than any other geomorphological change. When the effects of land use and soil distribution are excluded, sediment delivery loads increase due to shorter time to reach the outlet of the watershed in larger tell size. When those effects are included, however, sediment delivery loads decrease in larger fell size because the variety of land use types can not be inputted. The predominant land use in the applied watershed is forest with very low soil erosion such that the predicted sediment delivery might be much lower than real system. The cell size of 30 ha was determined to produce the most appropriate resolution. Surface runoff and non-point source loads of TN, TP and BOD were predicted and the results agree well with the field measurements. From this study, it was shown that the model results would be very dependent on variations of topography, land use, and soil distribution, as a function of cell size, and the optimum cell size is very important for successful application of distributed non-point source pollution model.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.323-327
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• 1999

It was shown that brain-derived neurotrophic factors (BDNFs) secreted from human neuroblastoma cells can significantly improve the growth of the neurites of PC12 nerve cells. The addition of purified BDNFs elongated the neurites of PC 12 nerve cells two to three times more than the case where the addition was not made. The perfusion rate strongly affected the change of the size of human neuroblastoma cells because the cell size decreased as the perfusion rate increased. This could also influence the productivity of BDNF from the cells. It is also important to note that the BDNF production was decreased when the cell size was reduced. BDNF production rate also decreased at a fast perfusion rate in a smaller cell size. At the relatively fast perfusion rate of 18 ml/h, the ratio of apoptotic to necrotic cells dramatically decreased, which possibly caused the decrease of BDNF production. It has been proven that the secretion of BDNF from human neuroblastoma cells was a partially growth-related process by yielding 6.2$\times l0^{-8}/g$ of BDNF/cell/h of growth related parameter and $0.48{\times}l0^{-9}/g$ of BDNF/cell/h of nongrowth-related parameter in a growth kinetic model. In addition, it was also found that the perfusion rate played a very important role in controlling the cell death mechanism.

• Plant Resources
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• v.5 no.2
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• pp.141-154
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• 2002

In this experiment, three kinds of mutations(ge, re, and eml )relating to the size of embryos were used to study their generation, genetic mechanism and developmental characteristics, and the interactions between embryo and endosperm were also examined. Giant embryo mutation comprises 7 kinds including the already isolated ge, and ge-2, which share an identical gene site. The SAM and the size of radicule for the ge showed little difference compared to a normal type. The number of embryo cells did not increased as much as it would affect the size of embryo. Therefore, the enlargement of embryo was due to the enlargement of scutellum that originated from the corpulence of each cell. Both F$_1$' s of re ]and odm 49 formed reduce embryos, and other combinations of hybridization showed all wild type of embryo sizes. Accordingly, the odm 49 must have an identical gene site of re 1, while odm 48 and odm 62 have different gene sites. Their shoots and radicules also shrank by the same ratio, however no sign of physical change was noticed. The size of embryo cell showed no change, while the number of cells was the half of that of wild types. The three gene sites of re represent all of them control the size of the entire embryo forming organs. The eml 1 was defined to have temperature sensibilities that the generation of endosperms was active at a high temperature while that was hampered at a low temperature.