• Fashion & Textile Research Journal
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• v.17 no.1
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• pp.116-126
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• 2015

This paper compared the properties of cosmetics depending on the shopping tendency of female consumers in Korea and China. The data on Chinese women living in Korea and Korean women in their 20s was collected using an offline survey. The data on Chinese women living in China in their 20s was collected using an online survey. Three hundred twenty-seven questionnaires out of a total of 330 questionnaires were used for statistical analysis. The survey was conducted from January to February 2014. Eighteen questions on shopping tendency and eight questions on the properties of cosmetics were analyzed using a 5-point Likert scale. Data was analyzed by Descriptives, Factor Analysis, Reliability Analysis, ANOVA and Cluster Analysis, and SPSS 21 statistical program. In accordance with the analyses, the shopping tendency comprised a showing-off tendency, pleasure-seeking tendency, and practicality tendency; the properties of cosmetics were classified into conformity and functionality. On the basis of the elements in the shopping tendency, the female consumers were categorized into a low involvement consumer group, high involvement consumer group, and hedonic consumer group. The Chinese women emphasized conformity or functionality of cosmetics more than the Korean women regardless of the countries where they lived. Regardless of shopping types or countries where they lived, the Korean and Chinese women in their 20s emphasized functionality over conformity of cosmetics. Furthermore, Chinese women living in Korea showed a similar shopping tendency to Chinese living in China.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.104-111
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• 2017

This research focuses on simulation and visualization of flow field characteristics inside a centrifugal pump. The 3D numerical analysis was carried out by using a numerical CFD tool, addressing a Reynolds Average Navier-Stock code with a standard k-${\varepsilon}$ two-equation turbulence model. The simulation accounts for friction head loss due to rough walls at suction, impeller, discharge areas and volumetric head loss at impeller wear ring. A comparison of performance curves between simulation and experimentation is included, and it reveals a same trend of those results with a small difference of maximum 5 %. At best efficiency point, velocity vectors are smooth but it changes significantly under off-design point, a strong recirculation appears at the outlet of impeller passages near tongue area. A relatively uniform preassure distribution was observed around the impeller in despite of the tongue. Within the volute, because of its geometry, spiral vortexes formed, proving that the flow field in this region was relatively turbulent and unsteady.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.8
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• pp.1301-1311
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• 2006

This study rearranged a concept of Friday wear considered as casual wear by searching social background through analysis of literature study and photo materials and classifying by characteristics of casual wear. It investigated growing changes of casual wear and the progress of changes casual brands through a market survey based on departments in Seoul. And then, it examined characteristics of a design and the critical point of easy casual selecting GIORDANO, TBJ and NII of three easy casual brands. Conclusions of the study are as follows: Firstly, present casual wear showed subdivision of casual wear as abundant grouping vocabularies appeared contrary to the past. Secondly, easy casual wear has continuously increased by results of investigating departments in Seoul on the progress of changing easy casual wear brand including the concept of Friday wear. Thirdly, if a main target sets the early 20s, women workers in their 20's and 30's are likely to be reluctant to wear it according to results of investigating designs and characteristics based on GIORDANO, TBJ and NII of existing three easy casual brands through the market survey. Also, it was verified that most of these brands have no a luxurious image because they adhere to middle-low price. Fourthly, it improved problems of easy casual through developing designs of easy casual wear. Easy casual wear supplementing weak these points of easy casual wear was evaluated as suitable clothes for workers to wear in on and off their own time in Friday.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.2
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• pp.86-92
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• 1998

In this paper, it is derived the system design parameters for the J-STD-018 of the PCS mobile station(MS) minimum performance using DS/CDMA analyzed the system performance due to the receiver components. The simulation shows the selectivity is -70.96dB at 1.25MHz frequency offset from the carrier frequency while the MS noise figure to satisfy J-STD-018 is 10dB and the input 3rd harmonics intercept point of the MS class I and MS class II-V is -9.5dBm and -14dBm respectively. When the interference power level at the receiver is small, the receiver has better performance as we increase the gain of LNA. However, when the interference level at the receiver is large, the receiver performance is decreased by the effect of the spurious. Thus, the effectiveness of LNA On/Off switching technique is proved as to reduce the effect of the spurious.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.4
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• pp.299-307
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• 2018

Considering a nonlinear high power amplifier(HPA) and a predistorter, we have designed a four-dimensional 8-ary phase shift keying trellis-coded modulation(4D-8PSK-TCM) system, which is recommended for X-band satellite communications. Subsequently, we have evaluated and analyzed the spectrum, constellation characteristics, and BER performance of the system. In satellite communications, owing to the limited power, nonlinear characteristics that determine the operating point of the HPA must be analyzed because the HPA consumes high power. We herein report the design of the 4D-8PSK-TCM system, with efficiencies of 2 and 2.25 bits/channel-symbol. The simulation results confirmed that a 0.35 roll-off value is effective, considering the low peak-to-average power ratio(PAPR) characteristic and the narrow occupation bandwidth of the spectrum. It also confirmed that approximately 15~20 dB of output backoff(OBO) value is required at the HPA when the predistorter is not used, and approximately 1 dB of the OBO value is required when the predistorter is used.

• The KSFM Journal of Fluid Machinery
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• v.17 no.5
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• pp.67-71
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• 2014

Recently, the cross flow turbine attracts more and more attention for its good performance over a large operating regime at off design point. This study adopts a very low head cross flow turbine that has barely been studied before, and investigates the effect of air layer on the performance of the cross flow turbine. As open duct is applied in this study and free surface model is used between the air layer and water, an engineering definition of efficiency, instead of traditional definition of efficiency, is used. As torque at the runner fluctuates up and down at a reasonable limit, statistical method is used. Pressure and water volume fraction contours are shown to present the characteristics of air-water flow. With constant air suction in the runner chamber, the water level gradually drops below the runner and efficiency of the turbine can be raised by 10 percent. All considered, the effect of air layer on the performance of turbine is considerable.

• KIEAE Journal
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• v.17 no.4
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• pp.89-94
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• 2017

Purpose: Condensation in walk-in closets attached to apartment bathroom has been known as an emerging issue that may threat occupants' comfort and health. Despite a number of design guidelines and enforcements to prevent condensation, condensation issues may still occur depending on various cases and scenarios. We aim to identify what condensation scenarios may lead to walk-in closet condensation and/or worse the existing condensation issues. Method: First we choose an actual walk-in closet of an apartment that suffers from sporadic condensation and resulting mold and mildew. Then we observe its relative humidity and temperature after the bathroom is used, in which excessive vapor is thought to be transported to the walk-in closet. We analyze Temperature Difference Ratio - a domestic indicator of condensation occurrence, and dew point temperature to compare it with surface temperature using 2D heat transfer simulation upon various condensation scenarios. Result: TDR of the test walk-in closet turns out be OK despite mold and mildew actually occurring. Hot water pipe installed in the floor would greatly reduce condensation. If hot water pipe in the upper floor, however, is not used, or hot water pipe of the closet is turned off during swing seasons, it is expected that condensations may still occur.

• The KSFM Journal of Fluid Machinery
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• v.17 no.1
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• pp.12-21
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• 2014

An organic Rankine cycle was analyzed to work at the optimal operating point when the heat source is fluctuated. R245fa was adopted as a working fluid, and an axial-type turbine as expander on the cycle was designed to convert the heat energy to the electricity since the turbo-type expander works at off-design points better than the positive displacement-type expander. A supersonic nozzle was designed to increase the spouting velocity because a higher spouting velocity can produce more output power. They were designed by the method of characteristics for the operating fluid of R245fa. Three different cases, such as various spouting velocities, various inlet total temperatures, and various nozzle numbers, were studied. From these results, an optimal operating cycle can be designed with the organic Rankine cycle when the available heat source as renewable energy is low-grade temperature and fluctuated.

• Journal of the Korean Society of Propulsion Engineers
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• v.4 no.2
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• pp.61-70
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• 2000

The performance simulation program on the turboprop engine(PT6A-62), which is a main engine of the first trainer KT-1 in republic of Korea, was developed. Characteristics of engine components were required for the steady-state performance analysis including on and off design point analysis. In most cases, these were substituted for what scaled from well known engine components characteristics with the scaling law. The developed program was compared with CASTURB program which is well known for the simulation performance analysis, such as analysis results of mass flow rate, compressor pressure ratio, fuel flow rate, power, specific fuel consumption ratio and turbine inlet temperature in the following four cases, to evaluate whether the developed program is acceptable or not. The first case was the sea level static standard condition and other cases were considered with various flight Mach numbers, altitudes. After verifying the developed program, the partload performance analysis was carried out. Transient performance analysis for various fuel schedules were performed. When the fuel step increase of 0.1sec was performed, the overshoot of the compressor turbine inlet temperature occurred. However, the fuel ramp increase for longer than 0.1sec time was performed, the overshoot could be eliminated.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.523-528
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• 2013

Background: The possibility that electromagnetic fields (EMF) exposure may increase male breast cancer risk has been discussed for a long time. However, arguments have been presented that studies limited by poor quality could have led to statistically significant results by chance or bias. Moreover, data fo the last 10 years have not been systematically summarized. Methods and Results: To confirm any possible association, a meta-analysis was performed by a systematic search strategy. Totals of 7 case-control and 11 cohort studies was identified and pooled ORs with 95% CIs were used as the principal outcome measures. Data from these studies were extracted with a standard meta-analysis procedure and grouped in relation to study design, cut-off point, exposure assessment method, adjustment and exposure model. A statistical significant increased risk of male breast cancer with EMF exposure was defined (pooled ORs = 1.32, 95% CI = 1.14-1.52, P < 0.001), and subgroup analyses also showed similar results. Conclusions: This meta-analysis suggests that EMF exposure may be associated with the increase risk of male breast cancer despite the arguments raised.