• Wind and Structures
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• v.17 no.2
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• pp.227-244
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• 2013

Non-stationary extreme winds such as thunderstorm downbursts are responsible for many structural damages. This research presents a time domain approach for estimating along-wind load effects on tall buildings using multiple wind speed time history samples, which are simulated from evolutionary power spectra density (EPSD) functions of non-stationary wind fluctuations using the method developed by the authors' earlier research. The influence of transient wind loads on various responses including time-varying mean, root-mean-square value and peak factor is also studied. Furthermore, a simplified model is proposed to describe the non-stationary wind fluctuation as a uniformly modulated process with a modulation function following the time-varying mean. Finally, the probabilistic extreme response and peak factor are quantified based on the up-crossing theory of non-stationary process. As compared to the time domain response analysis using limited samples of wind record, usually one sample, the analysis using multiple samples presented in this study will provide more statistical information of responses. The time domain simulation also facilitates consideration of nonlinearities of structural and wind load characteristics over previous frequency domain analysis.

• Journal of Biomedical Engineering Research
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• v.19 no.2
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• pp.143-152
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• 1998

In this paper, we present the performances of a Doppler system using single channel RF(Radio Frequency) sampling. This technique consists of undersampling the ultrasonic blood backscattered RF signal on a single channel. Conventional undersampling method in Doppler imaging system have to use a minimum of two identical parallel demodulation channels to reconstruct the multigate analytic Doppler signal. However, this system suffers from hardware complexity and problem of unbalance(gain and phase) between the channels. In order to reduce these problems, we have realized a multigate pulsed Doppler system using undersampling on a single channel, It requires sampling frequency at $4f_o$(where $f_o$ is the center frequency of the transducer) and 12bits A/D converter. The proposed " single-Channel RF Sampling" method aims to decrease the required sampling frequency proportionally to $4f_o$/(2k+1). To show the influence of the factor k on the measurements, we have compared the velocity profiles obtained in vitro and in vivo for different intersequence delays time (k=0 to 10). We have used a 4MHz center frequency transducer and a Phantom Doppler system with a laminar stationary flow. The axial and volumetric velocity profiles in the vessel have been computed according to factor k and have been compared. The influence of the angle between the ultrasonic beam and the flow axis direction, and the fluid viscosity on the velocity profiles obtained for different values of k factor is presented. For experiment in vivo on the carotid, we have used a data acquisition system with a sampling frequency of 20MHz and a dynamic range of 12bits. We have compared the axial velocity profiles in systole and diastole phase obtained for single channel RF sampling factor.ng factor.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1303-1308
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• 2008

In this study, we researched how to estimate life-stress relationship and acceleration factor through performing accelerated life test and analyzing it. The purpose of this study is to predict life of pneumatic cylinder within short time which is widely used in automation manufacturing line. In design of accelerated life test, we selected operating pressure and load that have the most influence on main failure mode of pneumatic cylinder as accelerated factor. We used two-way factorial design for arranging of test condition to accelerated factor and accelerated level.

• Korean Journal of Organic Agriculture
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• v.18 no.3
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• pp.315-329
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• 2010

This study focused on analysis of the satisfaction level of specialty shops for environment-friendly agricultural products (EFAP). To analyze the satisfaction level of EF AP, a series of household surveys were conducted. Questionnaire was prepared on the basis of the SERVQUAL model and the structural equation modeling was made on the basis of the contents surveyed. The main results of this study are summarized as follows. Firstly, tangibles structured with store clearance, neat uniform, information and others is the factor of service quality satisfaction. Secondly, reliability structured with service practice, problem solving, and service in accurate time is the factor of service quality satisfaction. Thirdly, assurance structured with the reliability of employees, sufficient knowledge of employees, courteous and good manner is the factor of service quality satisfaction. Fourthly, responsiveness structured with prompt service, voluntary help, customer response service and the like is the factor of service quality satisfaction. Fifthly, the sympathy structured in interest for each customer, provision of service in time convenient to use, encountering the customers with genuine feeling are the factors of service quality satisfaction. And sixthly, the service satisfaction factors would influence on the consumer behavior factors.

• Journal of Korean language education
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• v.29 no.3
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• pp.25-53
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• 2018

This study examined the influence of lexical factors on verbal Eojeol recognition. To meet the goal, forty-five L2 Korean learners and twenty-two Korean native speakers took Eojeol decision tasks measured with the lexical factors such as 'number of strokes', 'number of consonants and vowels', 'number of syllables', 'number of morphemes', 'whole Eojeol frequency', 'root frequency', 'first-syllable-sharing frequency', and 'number of dictionary meanings.' As a result, 'whole Eojeol frequency' was the most effective factor to predict Eojeol recognition reaction time for native speakers and L2 learners, which supports the full-list model. Other lexical factors influencing Eojeol recognition reaction time in L2 learners were different following their proficiency level.

• Korean journal of food and cookery science
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• v.26 no.5
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• pp.511-520
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• 2010

The purpose of this article was to study how the 7Ps influence consumers' risk perception of eating at family restaurants in Seoul. In this study, frequency analysis, reliability analysis, factor analysis and path analysis (SEM) of the data were performed. First, reliability analysis confirmed that the 7Ps performance and risk data could be used in this investigation. Path analysis showed that the 7Ps significantly influenced customers' risk perception of eating at restaurants in Seoul. According to the results, product negatively influenced performance risk (p<0.05) and financial risk (p<0.001); price negatively influenced performance risk (p<0.001), financial risk (p<0.001), and time risk (p<0.01); place negatively influenced performance risk (p<0.01) and time risk (p<0.001); promotion negatively influenced financial risk (p<0.05) and time risk (p<0.001); process negatively influenced performance risk (p<0.001) and time risk (p<0.001); physical evidence negatively influenced performance risk (p<0.05) and financial risk (p<0.001); and people negatively influenced performance risk (p<0.05), financial risk (p<0.001), and time risk (p<0.001). As a result, we confirmed that 7Ps were an effective marketing tactic for reducing consumers' risk perception of eating at restaurants. Therefore, family restaurant companies are recommended to administer the 7Ps without additional cost.

• Journal of Families and Better Life
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• v.10 no.2
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• pp.19-36
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• 1992

The purpose of this paper is to analyze empirically the tendency of household consumption expenditure according to the change of social and economical condition, and the factor which influences consumption expenditure of urban household. The data used in analysis are time-series. The data are statistic form Urban Household Economy Survey published by the Economic Planning Board, dating form the first quarter of 1970 to the fourth quarter of 1989. The income of household and consumption expenditure materials were deflated as consumer price index to exclude the influence of prices and the influence of household composition are considered to deflated as the size of the household under assumption of homogeneity. The consumption expenditure items were categorized to 12 relatively large range items. The time-series data were analyzed by using the Two Stage Least Squares and the Ordinary Least Squares. The following is the result of analysis. 1) Rather than the income increase of previous years. the average income increase for two years influences more significantly on consumption expenditure of household. In the case of influence on consumption expenditure for each item by increase in disposable income, such categories as furniture and utensils. clothing and footwear, housing, medical care, culture and recreation, and transportation and communication have significant influence. 2) Among consumption expenditure categories, the increasing factors were furniture and utensils, and clothing and footwear. And the decreasing factors were housing, medical care, culture and recreation ,and transportation and communication. The relative prices, however, had significant influence on categories such as housing, furniture and utensils, medical care , culture and recreation, and transportation and communication and all of them were the decreation factors. 3) Among with changes of social and economical conditions, miscellaneous showed the highest increase in marginal propensity to consume and foods was the lowest. Also culture and recreation and housing brought up a great change of the income elasticity of demand.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.157-164
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• 2004

Air voids in hardened concrete have an important influence on concrete durability such as resistance of freezing and thawing, permeability and surface scaling resistance. Linear traverse method and point count method in ASTM standard method have been widely used to estimate the air void system in hardened concrete. However, these methods are not used at present time, because they are is exhausted much time and effort. In previous study, air voids system of concrete was estimated by spacing factor. The purpose of this study organizes image analysis method by analyzing air contents, air voids distributions by diameters, air voids system as well as spacing factors after hardened concrete. The experimental variables institute of depth of specimen(top, middle, bottom), air contents(AE contents 0, 0.01, 0.03%).

• Journal of Power Electronics
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• v.18 no.1
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• pp.129-136
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• 2018

An accurate state-of-charge (SOC) estimation ensures the reliable and efficient operation of a lithium-ion battery management system. On the basis of a combined electrochemical model, this study adopts the forgetting factor least squares algorithm to identify battery parameters and eliminate the influence of test conditions. Then, it implements online SOC estimation with high accuracy and low run time by utilizing the low computational complexity of the unscented Kalman filter (UKF) and the rapid convergence of a particle filter (PF). The PF algorithm is adopted to decrease convergence time when the initial error is large; otherwise, the UKF algorithm is used to approximate the actual SOC with low computational complexity. The effect of the number of sampling particles in the PF is also evaluated. Finally, experimental results are used to verify the superiority of the combined method over other individual algorithms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.3
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• pp.234-238
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• 1990

The effects of salt concentration immersion time in a salt solution prior to air dehydration and heating of air temperature during dehydration upon the browning reaction and pyruvic acid content of air dried garlics to a 6.5% moisture content(wet basis) were analyzed by a response surface methodology(RSM), Those values were also predicted by using a second degree polynomial regression model. Heating of air temperature was the most significant factor affecting the both browning reaction and pyruvic acid content. Salt concentration had more influence to browning reaction than immersion time whereas immersion time was more impor-tant factor than salt concentration on a retention of pyruvic acid sugested different processing conditions. While the processing conditions to minimize the browning reaction(O.D=0.009) were 0.3% of salt solution 9 min of immersion time and 5$0^{\circ}C$ of air temperature compared to control(O.D=0.022) of air dehydration at 5$0^{\circ}C$ Pyruvic acid contents were maximized(174 $\mu$mole/g garlic solid) at the 0.1% of salt solution 3 min of immersion time and 5$0^{\circ}C$ of air temperature compared to control(147 $\mu$mole/g garlic solid) of air dehydration at 5$0^{\circ}C$