• Journal of Power Electronics
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• v.12 no.4
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• pp.538-547
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• 2012

This paper presents two different robust controllers for boost converters with two stages in a cascade. The first robust controller is monovariable; that is, the duty-cycle is the same for the two switches. The monovariable controller ensures that some prescribed constraints on pole placement and control effort are met, and optimizes the load disturbance rejection, while takes into account the uncertainty in certain parameters. The first controller is then compared with a multivariable robust controller; that is, with independent duty cycles in each switch. The multivariable controller takes into account the same uncertainty, constraints and optimization function. The comparison shows that the multivariable controller performs better at the expense of a slightly more complex implementation; that is, the multivariable controller provides a better rejection of the load disturbance. The paper also describes simulations and experimental results that are in perfect agreement with theoretical derivations.

• Journal of Power System Engineering
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• v.14 no.2
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• pp.28-33
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• 2010

In this research, cascade liquefaction process was simulated using two-staged direct expansion with inter-cooler. Evaporated gaseous refrigerant which has low pressure and temperature from the inter-cooler is mixed with gaseous refrigerant from outlet of 1st compressor, and flows into 2nd compressor. Therefore this prevents superheating compression. Compressor work of process which includes inter-cooler to all cycles shows the lowest value of 338.68 MW and it is lower 16.34% than that of basic process. Refrigeration capacity shows decreasing tendency as applied inter-cooler and that of process which includes inter-cooler to all cycles shows the lowest value of 449 MW. COP was increased when the inter-cooler was applied, and process which includes inter-cooler to all cycles shows highest value of 1.33. It shows that COP was increased because decrement of compressor work by applying inter-cooler was higher than decrement of refrigeration capacity.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.1-7
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• 2012

In this paper, An X-band solid state power amplifier(SSPA) for pulse compressed microwave signal with 60Watt power and power added efficiency(PAE) above 30% is described. Designed 60Watt high power amplifier(HPA) was implemented by cascade coupled amplifiers, and it is consisted on three stage drive amplifiers with internally matched GaAs FET and one stage main power amplifier with an internally matched GaN HEMT. The designed SSPA has performance with more than total power gain 37dB and output power 48dBm(60-W) in condition of frequency range $9.41{\pm}0.03GHz$, pulse period width under 1ms and duty cycle under 10%. The implemented SSPA can apply to high quality digital marine radar applications with pulse compression technique.

• Korean Journal of Culture and Social Issue
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• v.30 no.2
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• pp.193-220
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• 2024

This study was conducted by applying Selby and Joiner (2009)'s Emotional Cascade Model to the phenomenon of non-suicidal self-injury of adolescents, focusing on the school counselor's counseling experience. To this end, a focus group interview(FGI) was conducted with 56 counselors who had experience in counseling self-injured adolescents, and this study applied Braun and Clake's thematic analysis(2012). As a result, 8 categories and 16 subtopics were derived: 'negative emotional experience', 'maladaptive cognitive emotional dysregulation strategy', 'experience of emotional cascade', 'temporary relief of psychological pain', 'aggravation of the emotional cascade state', 'emotional pain from nonsuicidal self-injury', 'vicious cycle of nonsuicidal self-injury' and 'difficulty in controlling behavior that co-occurs with nonsuicidal self-injury'. These results are significant in expanding the understanding regarding the non-suicidal self-injury of adolescents through the perspective of school counselors who are in a position to consider the various systems surrounding adolescents in an integrated manner. Based on the research results, implications, limitations and future research were discussed.

• Journal of the Korean Society of Combustion
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• v.17 no.3
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• pp.9-16
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• 2012

Nonlinear dynamics of pulsating instability in radiating counterflow diffusion flames is numerically investigated by imposing Damk$\ddot{o}$hler number perturbation. Stable limit-cycle solutions occur in small ranges of Damk$\ddot{o}$hler numbers past bifurcation point of instability. Period doubling cascade and chaotic behaviors appear just before dynamic extinction occurs. Nonlinear dynamics is also studied when large disturbances are imposed to flames. For weak steady flames, the dynamic extinction range shrinks as the magnitudes of disturbances are increased. However, strong steady flames can overcome relatively large disturbances, thereby the dynamic extinction range extending. Stable limit-cycle behaviors reappears prior to dynamic extinction when the steady flames are strong enough.

• Journal of IKEEE
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• v.11 no.4
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• pp.358-363
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• 2007

This paper presents a floating point unit(FPU) with 3 stages for a 3D graphics shader engine. It targeted to accelerate 3D graphics in portable device environments. In order to design a balanced architecture for a shader engine, we analyzed shader assembly instructions and estimated the performance of FPU with the method we propose. The proposed unit handles 4-dimensional data through separated two paths that are lead to general operation module and special function module. The proposed FPU is compiled as a form of the cascade FPU with 3 stages to efficiently handle a matrix operation with relatively low hardware overhead. Except some complex instructions that are executed using macro instructions, all instructions complete an operation in a single instruction cycle at 100MHz frequency. A special function module performs all operations in a single clock cycle using the Newton Raphson method with the look-up table.

• Journal of Microbiology and Biotechnology
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• v.23 no.7
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• pp.923-931
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• 2013

Rapamycin, known as an inhibitor of Target of Rapamycin (TOR), is an immunosuppressant drug used to prevent rejection in organ transplantation. Despite the close association of the TOR signaling cascade with various scopes of metabolism, it has not yet been thoroughly investigated at the metabolome level. In our current study, we applied mass spectrometric analysis for profiling primary metabolism in order to capture the responsive dynamics of the Chlamydomonas metabolome to the inhibition of TOR by rapamycin. Accordingly, we identified the impact of the rapamycin treatment at the level of metabolomic phenotypes that were clearly distinguished by multivariate statistical analysis. Pathway analysis pinpointed that inactivation of the TCA cycle was accompanied by the inhibition of cellular growth. Relative to the constant suppression of the TCA cycle, most amino acids were significantly increased in a time-dependent manner by longer exposure to rapamycin treatment, after an initial down-regulation at the early stage of exposure. Finally, we explored the isolation of the responsive metabolic factors into the rapamycin treatment and the culture duration, respectively.

• Clean Technology
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• v.1 no.1
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• pp.34-46
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• 1995

Clean Technology goes beyond Clean-UP (or "End of PiPe) Technologies to include Pollution prevention, waste minimisation, and cleaner production. However, the concept of Clean Technology goes deeper than changes in technology, to ways in which human needs can be satisfied sustainably. In other words, Clean Technology, concentrates on delivering a human benefit rather than making a product. Introducing cleaner technology may therefore involve new commercial relationships as well as new technological practices. In some economic sectors, this involves leasing or providing a service rather than selling a product. Life Cycle Assessment (LCA) is an important tool in Clean Technology. LCA involves determining all the resources used and all the wastes and emissions produced in providing the human benefit. Use of LCA ensures that improved environmental performance in one part of the Life Cycle is not achieved merely at the expense of more environmental damage elsewhere. Going beyond LCA, the concepts of Life Cycle Design and "metabolised" use of materials are approaches to obtain maximum benefit from materials as they pass through the human economy. "Closed-loop" use can be a component of clean technology. Looking beyond simple re-use and recycling, a material may pass through a "cascade of uses". typically a series of applications with progressively lower performance specifications. Closed-loop use necessarily involves a change in commercial practice, because the material or product must be recovered after use.

• Journal of Periodontal and Implant Science
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• v.49 no.3
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• pp.138-147
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• 2019

Purpose: Several studies have shown that the oral cavity is a secondary location for Helicobacter pylori colonization and that H. pylori is associated with the severity of periodontitis. This study investigated whether H. pylori had an effect on the periodontium. We established an invasion model of a standard strain of H. pylori in human periodontal ligament fibroblasts (hPDLFs), and evaluated the effects of H. pylori on cell proliferation and cell cycle progression. Methods: Different concentrations of H. pylori were used to infect hPDLFs, with 6 hours of co-culture. The multiplicity of infection in the low- and high-concentration groups was 10:1 and 100:1, respectively. The Cell Counting Kit-8 method and Ki-67 immunofluorescence were used to detect cell proliferation. Flow cytometry, quantitative real-time polymerase chain reaction, and western blots were used to detect cell cycle progression. In the high-concentration group, the invasion of H. pylori was observed by transmission electron microscopy. Results: It was found that H. pylori invaded the fibroblasts, with cytoplasmic localization. Analyses of cell proliferation and flow cytometry showed that H. pylori inhibited the proliferation of periodontal fibroblasts by causing G2 phase arrest. The inhibition of proliferation and G2 phase arrest were more obvious in the high-concentration group. In the low-concentration group, the G2 phase regulatory factors cyclin dependent kinase 1 (CDK1) and cell division cycle 25C (Cdc25C) were upregulated, while cyclin B1 was inhibited. However, in the high-concentration group, cyclin B1 was upregulated and CDK1 was inhibited. Furthermore, the deactivated states of tyrosine phosphorylation of CDK1 (CDK1-Y15) and serine phosphorylation of Cdc25C (Cdc25C-S216) were upregulated after H. pylori infection. Conclusions: In our model, H. pylori inhibited the proliferation of hPDLFs and exerted an invasive effect, causing G2 phase arrest via the Cdc25C/CDK1/cyclin B1 signaling cascade. Its inhibitory effect on proliferation was stronger in the high-concentration group.

• Natural Product Sciences
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• v.18 no.1
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• pp.16-21
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• 2012

Honokiol, a naturally occurring neolignan mainly found in Magnolia species, has been shown to have the anti-angiogenic, anti-invasive and cancer chemopreventive activities, but the molecular mechanism of actions has not been fully elucidated yet. In the present study, we investigated the effect of honokiol on the growth inhibitory activity in cultured SNU-638 human gastric cancer cells. We found that honokiol exerted potent antiproliferative activity against SNU-638 cells. Honokiol also arrested the cell cycle progression at the G0/G1 phase and induced the apoptotic cell death in a concentration-dependent manner. The cell cycle arrest was well correlated with the downregulation of Rb, cyclin D1, cyclin A, cyclin E, and CDK4 expression, and the induction of cyclin-dependent kinase inhibitor p27. The increase of sub-G1 peak by honokiol was closely related to the induction of apoptosis, which was evidenced by the induction of DNA fragmentation, the cleavage of poly(ADPribose) polymerase, and the sequential activation of caspase cascade. These findings suggest the cell cycle arrest and induction of apoptosis might be one possible mechanism of actions for the anti-proliferative activity of honokiol in human gastric cancer cell.