• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1613-1621
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• 2015

This paper analyzes the rate adaptation scheme and suggests applicable strategy of the MCS(Modulation and Coding Scheme) for improving DCF throughput in the IEEE 802.11ad and 802.11ad wireless LAN. IEEE 802.11ac and 802.11ad wireless LAN provide MCS technique that dynamically adjusts modulation level and code rate to the time-varying channel conditions in order to obtain considerably high data rates. But these standards did not provide rate adaptation algorithm, so this paper surveyes rate adaptation algorithm and suggests MCS scheme applied to IEEE 802.11ac and 802.11ad wireless LAN. Specially A MAC(Medium Access Control) layer throughput is evaluated over error-prone channel in the IEEE 802.11ac-based wireless LAN. In this evaluation, DCF (Distributed Coordination Function) protocol and A-MPDU (MAC Protocol Data Unit Aggregation) scheme are used. Using theoretical analysis method, the MAC saturation throughput is evaluated with the PER (Packet Error Rate) on the condition that the number of station, transmission probability, the number of parallel beams and the number of frames in each A-MPDU are variables.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3A
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• pp.269-276
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• 2008

In this paper, we analyze the M-WiMAX UL capacity limits under 2-Tier cell layout, considering the effects of random user position, path loss models, fading channel and adjacent channel interference from WCDMA system. In order to make the analysis approximate to the practical system capacity, we propose a MCS-based capacity analysis method considering the effects of PER requirement and the utilized MCS levels in M-WiMAX system. The proposed MCS-based method is validated through a system-level Monte Carlo simulation. Furthermore, a comparison between the conventional Shannon method and the proposed MCS-based method is presented and the optimum cell radius is suggested.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.2
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• pp.154-162
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• 2011

A reliability analysis model is developed for evaluating the crest freeboard of vertical breakwaters based on the concepts of maximum overtopping volume of individual wave. A reliability function is formulated by defining the margin of admissible overtopping volume and maximum overtopping volume that is depend on the number of overtopping waves, dimensionless crest freeboard, and mean overtopping discharge. In addition, Level III MCS technique is straightforwardly suggested by which the related empirical parameters to reliability function can be considered to be random variables with the wide range of different uncertainties. It can be possible to calculate the probabilities of failure according to the relative crest freeboard with the variations of the incident wave directions, the structural types of vertical breakwaters, and admissible overtopping volumes in conditions of the long and short crested-waves.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1433-1446
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• 2013

In this study, we proposed a methodology to develop Rating Curves for high water level using rainfall generation by the Monte Carlo Simulation (MCS) technique, optimized rainfall-runoff model, and flood routing model in an urban stream. The developed stage discharge Rating Curve based on observed data was contained flow measurement errors and uncertainties. The standard error ($S_e$) for observations was 0.056, and the random uncertainty ($2S_{mr}$) was analyzed by ${\pm}1.43%$ on average, and up to ${\pm}4.27%$. Moreover, it was found that the Rating Curve extensions by way of logarithmic and Stevens methods were overestimated to compare with the urban basin scale. Finally, we confirmed that the high water level extension by random generation of hydrological data using MCS can be reduced uncertainty of the high water level, and it will consider as a more reliable approach for high water level extension. In the near future, this results can be applied to real-time flood alert system for urban streams through construction of the high water level extension system using MCS procedures.

• Journal of Biomedical Engineering Research
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• v.41 no.6
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• pp.235-246
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• 2020

This study aimed to evaluate the inhibitory effect of micro-current stimulation(MCS) on adipogenesis regarding with Wnt/β-catenin pathway using the ob/ob mouse and 3T3-L1 cell line. 6-week old ob/ob male mice were equally assigned to four groups: obese group(ob), obese with MCS groups(50 μA, 200 μA, and 400 μA). 6-week old C57BL/6J male mice were assigned to the control group(CON). We analyzed abdominal adipose tissue volume by using in vivo micro-CT and measured the body weight, feed intake, liver weight and triglycerides in serum. All the MCS groups showed that significantly reduced body weight and triglycerides in serum. In the case of liver weight and abdominal adipose tissue volume, the inhibitory effect of adipogenesis was shown in the 200 μA and 400 μA groups. To elucidate the anti-obesity effect of MCS, β-catenin, C/EBPα and FAS protein expressions were analyzed by western blotting. β-catenin expression was upregulated, C/EBPα and FAS expression were down-regulated in the relatively high-intensity groups(200 μA and 400 μA). Thus, the 200 μA and 400 μA for the intensity of MCS were chosen for cell experiments. In the 3T3-L1 cell line, Wnt/β-catenin pathway including Wnt10b, Wnt3a, β-catenin and Cyclin D1 was activated in all MCS groups. Accordingly, the expression level of C/EBPα was decreased during the differentiation and lipid droplet was significantly reduced in Oil red O staining results. These results suggest that the Wnt/β-catenin signaling might be activated by MCS with current intensities between 200-400 μA and it may lead to anti-obesity effects.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.342-347
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• 2009

Failure Mode Effects and Criticality Analysis (FMECA) is one of most widely used methods in modern engineering system to investigate potential failure modes and its severity upon the system. While performing FMECA, the experts evaluates criticality and severity of each failure mode and visualize the risk level matrix putting those indices to column and row variable respectably. Which results uncertainty in the result. In order to handle the uncertainty and conclude risk level matrix, this paper proposes a new FMECA procedure using minimal cut set (MCS) and fuzzy theory. Severity is calculated by proposed structural importance while criticality is determined by typical equipment failure rate data from IEEE Std 493. Finally, the risk level is compounded of these indices.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.1
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• pp.1-17
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• 2008

Objective : This research was done to discover whether or not workers' health related quality of life(HRQOL) depends on their own Yangseng(養生) level, which is also known as one's care of one's health, and also if their HRQOL is affected by the level, to what extent. The subjects of the study were blue-collar workers of a workplace. Method : Blue-collar workers of a workplace were asked to fill out their pre-organized questionaires given to them by their company as a process of health examination. The questionaires carried questions regarding their levels of Yangseng and their HRQOL. For the purpose of the research, a total of 961 data were selected from the questionaires filled out by the blue-collar workers and then analyzed. Result : Each workers's level of Yangseng becomes high or low by one or all of general characteristics. With regard to Yangseng level according to health-related lifestyle were found to have a relatively higher level of Yangseng. With reference to HRQOL according to general characteristics, those in the 20s were found to have a physical summary scale(PCS), but no significant difference was found in the other scales. As regards the quality of life(QOL) according to health-related lifestyle, those who exercise regularly were found to have a relatively higher PCS, while no smokers, those who do not drink alcoholic, and those who sleep at least seven hours a day were found to have a relatively higher mental summary scale(MCS). As to the relation between the level of Yangseng and HRQOL, the level of Yangseng was found to have an interrelation with PCS and MCS in terms of its degree. Statistics also show that each area of Yangseng level has a significant impact on the two qualities-PCS and MCS. Conclusion : One who has a higher level of Yangseng was found to be the one who enjoys a higher HRQOL. Specially, the three kinds of habits that are good for good health -non-smoking, no drinking and seeping seven hours a day- were found to be able to improve the QOL. In this respect, those who want to stay healthy are recommended to cultivate a healthier habit of living.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.4
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• pp.500-508
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• 2016

This study was conducted to investigate the effects of Momordica charantia saponin (MCS) on ruminal fermentation of maize stover and abundance of selected microbial populations in vitro. Five levels of MCS supplements (0, 0.01, 0.06, 0.30, 0.60 mg/mL) were tested. The pH, $NH_3-N$, and volatile fatty acid were measured at 6, 24, 48 h of in vitro mixed incubation fluids, whilst the selected microbial populations were determined at 6 and 24 h. The high dose of MCS increased the initial fractional rate of degradation at t-value = 0 ($FRD_0$) and the fractional rate of gas production (k), but decreased the theoretical maximum of gas production ($V_F$) and the half-life ($t_{0.5}$) compared with the control. The $NH_3-N$ concentration reached the lowest concentration with 0.01 mg MCS/mL at 6 h. The MSC inclusion increased (p<0.001) the molar proportion of butyrate, isovalerate at 24 h and 48 h, and the molar proportion of acetate at 24 h, but then decreased (p<0.05) them at 48 h. The molar proportion of valerate was increased (p<0.05) at 24 h. The acetate to propionate ratio (A/P; linear, p<0.01) was increased at 24 h, but reached the least value at the level of 0.30 mg/mL MCS. The MCS inclusion decreased (p<0.05) the molar proportion of propionate at 24 h and then increased it at 48 h. The concentration of total volatile fatty acid was decreased (p<0.001) at 24 h, but reached the greatest concentration at the level of 0.01 mg/mL and the least concentration at the level of 0.60 mg/mL. The relative abundance of Ruminococcus albus was increased at 6 h and 24 h, and the relative abundance of Fibrobacter succinogenes was the lowest (p<0.05) at 0.60 mg/mL at 6 h and 24 h. The relative abundance of Butyrivibrio fibrisolvens and fungus reached the greatest value (p<0.05) at low doses of MCS inclusion and the least value (p<0.05) at 0.60 mg/mL at 24 h. The present results demonstrates that a high level of MCS quickly inhibits in vitro fermentation of maize stover, while MCS at low doses has the ability to modulate the ruminal fermentation pattern by regulating the number of functional rumen microbes including cellulolytic bacteria and fungi populations, and may have potential as a feed additive applied in the diets of ruminants.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.1
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• pp.133-143
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• 2002

The textile industry is petting increased effort to manufacture the value-added products that gives the differentiated characters at every level of fiber and fabric production. The color is an important element to be used strategically in order to push up the value-added design. The colors of apparel products have a close relationship with the skin colors of consumers and their preference colors. This study was carried out to cluster the skin colors of the Korean women into several similar skin colors and to analyze their preference colors by the classified groups. We measured the skin colors of 354 Korean women. With color spectrometer, JX-777, we measured 4 points of the body; cheek with removing cosmetics off, forehead, rear neck and arm on the interior part near elbow. All subjects had been shown with 40 color chips and answered the preference colors and preference colors of apparel. Data were analysed to classify skin colors using K-means Cluster Analysis and Duncan test, Frequency and Chi square test on the preference colors about the clustered 3 groups. In doing so, we used in SPSS Win 10 statistical package. Findings were as fellows: 1) The skin colors of the Korean women were clustered into YR, R, and Y skin colors. The majority of the subjects, 324 observations had YR skin colors and the subjects were classified into 3 kinds of skin color groups who had YR skin colors. 2) The average skin colors of total 324 subjects was 5.23YR 6.49/4.09 in Munsell Color System(MCS), 66.56 in L value, 10.53 in a value, and 20.67 in b value. 3) The average skin color of Type 1 was 7.98YR 6.24/4.14 in MCS, 64.10 in L value, 15.05 in a value, and 24.0 in b value. For Type 2 was 7.30 YR 6.56/3.28 in MCS, 67.24 in L value, 6.89 in a value, and 18.4 in b value, and Type 3 was 7.01 YR 7.20/4.38 in MCS, 73.53 in L value, L 16.04 in a value, and 24.87 in b value. 4) The average face color of total 324 subjects was 7.31YR 6.65/3.56 in MCS, 68.13 in L value, 9.53 in a value, and 20.18 in b value. 5) The average face color of Type 1 was 4.19 YR 6.92/5.05 in MCS, 70.78 in L value, 13.2 in a value, and 25.32 in b value. For Type 2 was 5.24YR 6.33/3.79 in MCS, 64.94 in L value, 9.84 in a value, and 19.08 in b value. Type 3 was 5.4YR 6.85/4.68 in MCS, 70.1 in L value, 11.73 in a value, and 23.92 in b value. 6) The difference of mean values between the clustered 3 skin color groups showed significantly different except the a value of neck and H value of cheeks and H value of foreheads. 7) All 3 groups showed that the most preference colors and the most preference colors of apparel was 5R 4/14. and their preference colors were much more than the preference colors of apparel.

• Atmosphere
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• v.27 no.4
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• pp.455-466
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• 2017

In Korea, property and human damages occur annually due to heavy precipitation during the summer. On August 8, 2015, heavy rainfall occurred in the Seoul metropolitan area due to an outflow boundary, and $77mmhr^{-1}$ rainfall was recorded in Gwangju, Gyeonggi Province. In this study, the simulation of the WRF numerical model is performed to understand the cause and characteristics of heavy rainfall using the Conditional Instability of the Second Kind (CISK), potential vorticity (PV), frontogenesis function, and convective available potential energy (CAPE) analyses, etc. Convective cells initiated over the Shandong Peninsula and located on the downwind side of an upper level trough. Large amounts of water vapor were supplied to the Shandong Peninsula along the southwestern edge of a high pressure system, and from the remnants of typhoon Soudelor. The mesoscale convective system (MCS) developed through CISK process and moved over to the Yellow Sea. The outflow boundary from the MCS progressed east and pushed cold pool eastward. The warm and humid air over the Korean Peninsula further enhanced convective development. As a result, a new MCS developed rapidly over land. Because of the latent heat release due to convection and precipitation, strong potential vorticity was generated in the lower atmosphere. The rapid development of MCS and the heavy rainfall occurred in an area where the CAPE value was greater than $1300Jkg^{-1}$ and the fronto-genesis function value of 1.5 or greater coincided. The analysis result shows that the MCS driven by an outflow boundary can be identified using CISK process.