• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.6
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• pp.451-459
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• 2010

This paper describes the performance comparison results for a hybrid back-to-back converter, which is composed of a 3-level 24-pulse converter and a 3-level PWM converter, in order to interconnect a large scale wind farm with the power grid. Also it describes the performance comparison results when the 24-pulse converter operates in only firing-angle control, and both firing-angle and the zero-voltage control. For the purpose of systematic performance comparison, computer simulations with PSCAD/EMTDC software were carried out, and based on simulation results a scaled hardware model with 2 kVA rating was built and tested.

• Journal of the Semiconductor & Display Technology
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• v.10 no.3
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• pp.1-6
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• 2011

In this paper, the IC(Integrated Circuit) for multi-channel synchronous communication was designed by using FPGA and VHDL language. The existing chips for synchronous communication that has been used commercially are composed for one to two channels. Therefore, when communication system with three channels or more is made, the cost becomes high and it becomes complicated for communication system to be realized and also has very little buffer, load that is placed into Microprocessor increases heavily in case of high speed communication or transmission of high-capacity data. The designed IC was improved the function and performance of communication system and reduced costs by designing 8 synchronous communication channels with only one IC, and it has the size of transmitter/receiver buffer with 1024 bytes respectively and consequently high speed communication became possible. It was designed with a communication signal of a form various encoding. To detect errors of communications, the CRC-ITU-T logic and channel MUX logic was designed with hardware logics so that the malfunction can be prevented and errors can be detected more easily and input/output port regarding each communication channel can be used flexibly and consequently the reliability of system was improved. In order to show the performance of designed IC, the test was conducted successfully in Quartus simulation and experiment and the excellence was compared with the 85C3016VSC of ZILOG company that are used widely as chips for synchronous communication.

• Journal of Korean society of Dental Hygiene
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• v.11 no.4
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• pp.595-602
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• 2011

Objectives : This study purpose were the effect of toothbrushing for decreasing halitosis for gingivitis and periodontitis patients. Methods : The university staffs were examined oral condition and analysised a change of oral health state score after using 3 types of toothbrushing. Results : The results were as followed : OHI-S shows that the decreasing effect takes place in the M. bass method and Tooth pick method, but shows no differences by each method. GI for Self test method shows decreasing effect after 2nd week during education while the M. bass method and Tooth pick method shows after 1st week during education. The M. bass method shows much greater effect of halitosis amongst 3 kind of method. PI for Self test method and Tooth pick method show decreasing effect. Decreasing effect during education shows until 2nd week by 3 kind of method, but it shows no differences after 3rd week. VSC(ppb) for M. bass method and Tooth pick method show decreasing effect. Decreasing effect during education shows after 3rd week by 3 kind of method, but it shows no differences until 2nd week. PHP for Self test method, M. bass method and Tooth pick method show decreasing effect after 2nd week during education. But, there is no differences of decreasing effect by among 3 kind of method. Conclusions : This study reports that it is necessary to carry outt further studies on the improvement of oral health management of adults based on the development of oral health education.

• Journal of Ginseng Research
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• v.33 no.4
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• pp.367-377
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• 2009

Halitosis is a generally accepted marker of diseases in the oral cavity and of systemic and gastrointestinal disorders. Based on these authors' previous findings (that (1) there is a close association between H. pylori infection and halitosis; (2) Korea red ginseng may suppress the colonization of H. pylori, fight H. pylori-induced cytotoxicity, and impose significant anti-inflammatory actions in patients with chronic gastritis; and (3) H. pylori infection is linked with the generation of significant levels of volatile sulfur compounds (VSCs), and the levels of VSCs correlate significantly with H. pylori-associated mucosal damages), in the current study, the authors documented the molecular mechanisms of Korea red ginseng's efficacy in ameliorating halitosis. When the RAW 264.7 cells were treated with the $H_2S$ releasing compound NaHS, the mRNA expression of cystathionine ${\gamma}$-lyase (CSE), IL-6, COX-2, and iNOS were more significantly induced compared with the vehicle-treated group. The cytoskeletal components of ezrin's and moesin's mRNA expressions were elevated by NaHS treatment accompanied by the activation of MAPK, p38, and ERK. Korea red ginseng pretreatment reduced both the NaHS-induced CSE expression and the proinflammatory genes (e.g., IL-6, COX-2, and iNOS) in a concentration-dependent manner. The ERM expression and the phosphorylation of p38 were also significantly reduced by Korea-red-ginseng pretreatment. Overall, Korea red ginseng pretreatment imposed significant anti-inflammatory effects through the downregulation of the NaHS-triggered proinflammatory gene expression, CSE, and ERM mRNA expression. Korea red ginseng could thus be said to be a key remedy of halitosis and to be effective in relieving gastric inflammation.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.999-1004
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• 2005

An algorithm for a hybrid controller consists of a sliding mode control part and a fuzzy logic part which ar purposely for nonlinear systems. The sliding mode part of the solution is based on "eigenvalue/vector"-type controller is used as the backstepping approach for tracking errors. The fuzzy logic part is a Mamdani fuzzy model. This is designed by applying sliding mode control (SMC) method to the dynamic model. The main objective is to keep the update dynamics in a stable region by used SMC. After that the plant behavior is presented to train procedure of adaptive neuro-fuzzy inference systems (ANFIS). ANFIS architecture is determined and the relevant formulation for the approach is given. Using the error (e) and rate of error (de), occur due to the difference between the desired output value (yd) and the actual output value (y) of the system. A dynamic adaptation law is proposed and proved the particularly chosen form of the adaptation strategy. Subsequently VSC creates a sliding mode in the plant behavior while the parameters of the controller are also in a sliding mode (stable trainer). This study considers the ANFIS structure with first order Sugeno model containing nine rules. Bell shaped membership functions with product inference rule are used at the fuzzification level. Finally the Mamdani fuzzy logic which is depends on adaptive neuro-fuzzy inference systems structure designed. At the transferable stage from ANFIS to Mamdani fuzzy model is adjusted for the membership function of the input value (e, de) and the actual output value (y) of the system could be changed to trapezoidal and triangular functions through tuning the parameters of the membership functions and rules base. These help adjust the contributions of both fuzzy control and variable structure control to the entire control value. The application example, control of a mass-damper system is considered. The simulation has been done using MATLAB. Three cases of the controller will be considered: for backstepping sliding-mode controller, for hybrid controller, and for adaptive backstepping sliding-mode controller. A numerical example is simulated to verify the performances of the proposed control strategy, and the simulation results show that the controller designed is more effective than the adaptive backstepping sliding mode controller.

• Journal of Life Science
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• v.23 no.3
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• pp.443-447
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• 2013

This study was conducted to investigate the antimicrobial and anti-oral malodor effect of Schizandra chinensis extracts against oral pathogens. S. chinensis methanol (MeOH) extract showed better antimicrobial activities against oral pathogens than the S. chinensis hot water extract did. In particular, ethylacetate (EA) fraction of S. chinensis MeOH extract had the greatest effects against Streptococcus mutans, S. sanguinis, S. salivaris subsp. thermophols and Porphyromons gingivalis. The anti-malodor effect of S. chinensis against the generation of volatile sulfur compounds (VSC), such as hydrogen sulfide, methyl mercaptan, and dimethyl sulfide, was estimated using oral chroma in a practical study. The results showed that 2% MeOH extract of S. chinensis against the production of hydrogen sulfide, methyl mercaptan, and dimethyl sulfide had inhibitions of 91.15, 78.72 and 71.58%, respectively. These results showed that Schizandra chinensis extract had antimicrobial activity against several oral pathogens and exhibited significant effects on the inhibition of VSCs. Thus, Schizandra chinensis extract could be an alternative to available synthetic chemicals and oral hygiene products.