• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.7
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• pp.36-45
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• 1999

In order to control the flow of traffics in ATM networks and optimize the usage of network resources, an efficient control mechanism is necessary to cope with congestion and prevent the degradation of network performance caused by congestion. In this paper, Buffered Leaky Bucket which applies the same control scheme to a variety of traffics requiring the different QoS(Quality of Service) and Neural Networks lead to the effective buffer utilization and QoS enhancement in aspects of cell loss rate and mean transfer delay. And the cell scheduling algorithms such as DWRR and DWEDF for multiplexing the incoming traffics are enhanced to get the better fair delay. The network congestion information from cell scheduler is used to control the predicted traffic loss rate of Neural Leaky Bucket, and token generation rate and buffer threshold are changed by the predicted values. The prediction of traffic loss rate by neural networks can enhance efficiency in controlling the cell loss rate and cell transfer delay of next incoming cells and also be applied for other traffic controlling schemes. Computer simulation results performed for random cell generation and traffic prediction show that QoSs of the various kinds of traffcis are increased.

• Tuberculosis and Respiratory Diseases
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• v.48 no.3
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• pp.339-346
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• 2000

Background : The moot important prognostic factor in non-small cell lung cancer is the TNM stage. Even after complete resection in early non-small cell lung cancer, the five-year survival rate is still low. However, new prognostic factors, including molecular biologic factors, have recently been found to guide the treatment of patients with non-small cell lung cancer. We evaluated the prognostic value of the loss of blood-group antigen A in tumor tissue, which has been implicated as an important prognostic factor for overall survival and the timing of the disease progression. Methods : The loss of blood-group antigen A was assessed immunohistochemically in paraffin-embedded tumor samples from 26 patients with blood types A or AB, who had undergone curative surgery. Monoclonal antibody was used to detect the blood group antigen A expression. Results : Fifteen patients (58%) expressed antigen A in their tumor tissue, whereas 11 patients (42%) did not show antigen A. The median survival time of the blood A antigen positive group was 11 months, while the median survival time of the blood A antigen negative group was 18 months. The difference in survival between the two groups was not statistically significant. Conclusion : The loss of blood-group antigen A in tumor tissue was not found to be a significant prognostic factor in patients with non-small cell lung cancer. This study needs to be extended for further evaluation.

• Biomolecules & Therapeutics
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• v.12 no.1
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• pp.25-33
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• 2004

In this study we investigated whether ATP loss was involved in the potentiated death of immunostimulated rat primary astrocytes in glucose-deprived condition. Rat primary astrocytes immunostimulated with LPS plus IFN-${\gamma}$ for 48 h underwent death upon glucose deprivation, which dependent on the production of peroxynitrite. Intracellular ATP level synergistically decreased by glucose deprivation in immunostimulated astrocytes but not in control cells, and the loss of ATP occurred well ahead of the LDH release. The synergistic cell death and ATP loss by immunostimulation and glucose deprivation were inhibited by iNOS inhibitor (L-NAME and L-NNA) or peroxynitrite decomposition catalyst (also a superoxide anion scavenger), Mn(III)tetrakis(N-methyl-4'-pyridyl)porphyrin (MnTMPyP). Exogenous addition of peroxynitrite generator, SIN-l timedependently induced ATP loss and cell death in the glucose-deprived astrocytes. Depletion of intracellular glutathione (GSH) and dis겨ption of mitochondrial transmembrane potential (MTP) were also observed under same conditions. Supply cellular ATP by the addition of exogenous adenosine or ATP during glucose deprivation inhibited ATP depletion, GSH depletion, MTP disruption and cell death in SIN-l treated or immunostimulated astrocytes. This study showed that perturbation in the regulation of intracellular ATP level in immunostimulated astrocytes might make them more vulnerable to energy challenging stimuli.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.919-924
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• 2008

Power consumption in the building thermal load could be the sum of the building fabric conduction load, building ventilation convection load and other such as radiation loss load. Dynamic Breathing Building (DBB) is the state-of-the-art to improve the wall insulation and indoor air quality(IAQ) performance as making air flow through the wall. This heat recovery type DBB contributes the power consumption saving due to the improved dynamic U-value. KIER twin test cell with static insulation(SI) and dynamic insulation(DI) at KIER was developed to test building power consumption at the real outside conditions. Then, the actual results were compared with the theory to predict the power consumption at the KIER twin test cell and introduced the building new radiation loss factor $\alpha$ to explain the difference between the both the theory and the actual case. As the results, the power consumption at the breathing DI wall building could saved 10.8% at the 2ACH(Air change per hour) compared with conventional insulation. The building radiation loss factor $\alpha$ for this test condition to calibrate the actual test was 0.55 in the test condition.

• Journal of Digital Convergence
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• v.11 no.1
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• pp.283-288
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• 2013

In this study, we introduce a 3D micro-cell simulator for radio wave propagation analysis in indoor environments. Previous studies treat only the path loss between the transmitter and receiver in 2D geometry. We provide the simulation results of indoor propagation prediction based on various ITU-R Recommendations. Simulation results described here indicate that the low and high frequency bands give quite different characteristics in presented indoor geometry. The propagation loss as a function of distance has two distinct regions. It is similar to that occurring in free space within 5-20m of the transmitter, however, increases significantly as the electromagnetic waves become obstructed by the walls at distances further away in the next region.

• IMMUNE NETWORK
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• v.8 no.4
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• pp.130-136
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• 2008

Background: Human cytomegalovirus UL18, a MHC class I homologue, has been considered a natural killer (NK) cell decoy. It ligates LIR-1/ILT2 (CD85j), an NK inhibitory receptor, to prevent lysis of infected target cells. However, precise role of UL18 to NK cell cytotoxicity is yet elusive. Difficulty in clarifying the function of UL18 lies in complication in detecting UL18 mainly due to low level expression of UL18 on the surface and gradual loss of its expression. Methods: To overcome this hurdle, cDNA of cytoplasmic tail-less UL18 was constructed and expressed in swine endothelial cell (SEC). The expression level and its stability in the cell surface were monitored with FACS analysis. Results: Surface expression of UL18 is up-regulated by removing cytoplasmic tail portion from UL18F (a full sequence of UL18). SECs transfected with a cDNA of UL18CY (a cytoplasmic tail-less UL18) stably expressed UL18 molecule on the surface without gradual loss of its expression during 6 week continuous cultures. In the NK cytotoxicity assay, UL18 functions either inhibiting or activating NK cell cytotoxicity according to the source of NK cells. We found that there is individual susceptibility in determining whether the engagement of NK cell and UL18 results in overall inhibiting or activating NK cell cytotoxicity. Conclusion: In this study, we found that cytoplasmic tail is closely related to the regulatory function for controlling surface expression of UL18. Furthermore, by constructing stable cell line in which UL18 expression is up-regulated and stable, we provided a useful tool to clarify exact functions of UL18 on various immune cells having ILT2 receptor.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.1A
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• pp.122-131
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• 2000

In this paper, we propose a cell scheduling algorithm for input queueing ATM switch. The input queueing architecture is attractive for building an ultra-high speed ATM (Asynchronous Transfer Mode) switch. We proposea WMUCS (Weighted Matrix Unit Cell Scheduler) based on the MUCS which resolves HOL blocking and outputport contention. The MUCS algorithm selects an optimal set of entries as winning cells from traffic matrix (weightmatrix). Our WMUCS differs from the MUCS in generating weight matrices. This change solves the starvationproblem and it reduces the cell loss variance. The performance of the proposed algorithm is evaluated by thesimulation program written in C++. The simulation results show that the maximum throughput, the average celldelay, and the cell loss rate are significantly improved. We can see that the performance of WMUCS is excellentand the cost-effective implementation of the ATM switch using proposed cell scheduling algorithm.

• The Korean Journal of Physiology and Pharmacology
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• v.9 no.4
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• pp.247-253
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• 2005

The present study assessed the effect of calmodulin antagonists trifluoperazine and W-7 against the cytotoxicity of $MPP^+$ and 6-bydroxydoparnine (6-OHDA) in relation to the mitochondrial dysfunction and cell death in PC12 cells. Trifluoperazine (an inhibitor of the mitochondrial permeability transition and calmodulin antagonist) and W-7 (a specific calmodulin antagonist) significantly attenuated the $MPP^+-induced$ cell viability loss in PC12 cells with a maximum inhibition at $0.5{\sim}1{\mu}M$; beyond these concentrations the inhibitory effect declined. Both compounds at this concentration range did not cause cell death significantly. In contrast to $MPP^+$, the trifluoperazine and W-7 did not depress the cytotoxic effect of 6-OHDA. Addition of trifluoperazine and W-7 inhibited the cytosolic accumulation of cytochrome c and caspase-3 activation in PC12 cells treated with $MPP^+$ and attenuated the formation of reactive oxygen species and the depletion of GSH, whereas both compounds did not reduce the effect of 6-OHDA. The results show that trifluoperazine and W-7 may attenuate the cytotoxicity of $MPP^+$ by inhibition of the mitochondrial permeability transition and calmodulin. Meanwhile, the cytotoxic effect of 6-OHDA seems to be mediated by the actions, which are different from $MPP^+$.

• Journal of Electrical Engineering and Technology
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• v.12 no.5
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• pp.1891-1901
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• 2017

In this paper, optimal control of the fuel cell and design of a high-efficiency power converter is implemented to build a high-priced fuel cell system with minimum capacity. Conventional power converter devices use a non-isolated boost converter for high efficiency while the battery is charged, and reduce its conduction loss by using MOSFETs instead of diodes. However, the efficiency of the boost converter decreases, since overshoot occurs because there is a moment when the body diode of the MOSFET is conducted during the dead time and huge loss occurs when the dead time for the maximum-power-flowing state is used in the low-power-flowing state. The method proposed in this paper is to adjust the dead time of boost and rectifier switches by predicting the power flow to meet the maximum efficiency in every load condition. After analyzing parasite components, the stability and efficiency of the high-efficiency boost converter is improved by predictive compensation of the delay component of each part, and it is proven by simulation and experience. The variation in switching delay times of each switch of the full-bridge converter is compensated by falling time compensation, a control method of PWM, and it is also proven by simulation and experience.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.5 no.4
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• pp.394-399
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• 1995

Dielectric properties and crystal structure changes with temperature were observed on $(Na_{0.5}Sr_{0.5})(Ti_{0.5}Nb_{0.5})O_{3}$ which had a superstructure due to oxygen octahedron tilting. Dielectric loss peak observed at 380 K was found to have a relation with a primitive cell change from tetragonal to cubic, however, in this case, dielectric constant variation was not observed. Therefore it was found that the dielectric loss was more senstive than the dielectric constant for detecting the structure change. After the structure change of primitive cell from tetragonal to cubic, X-ray diffraction peaks of superstructure, which completely disappear above 500 K, were still observed. And no dielectric property variations were found with the disappearence of superstucture.