• Journal of Distribution Research
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• v.12 no.4
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• pp.1-25
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• 2007

The purpose of this study is to provide the strategic implication of the Korean open air market by examining the factors affecting customer loyalty for various market segments as their competitive environment becomes more turbulent. We have undertaken empirical research that uses the methodology of a mixture regression modeling, as a way to ascertain the determinants of customer loyalty toward the Korean open air market, which should form the base of strategy for each segment. We construct a mixture regression model which uses perceived the Korean open air market value dimensions as explanatory variables, an income as a covariate variable, and a customer loyalty as a dependent variable. The analysis of results show that customers are statistically divided into four segments: 'Accessibility'(33.7%), 'Price'(29.7%), 'Shopping environment,'(22.0%), and 'Merchandising,'(14.5%) groups. The findings also showed that parameter estimates are different for each group, which indicates that the sensitivity to changes in the Korean traditional market perceived value and the income variable affecting customer loyalty vary among segments.

• Journal of IKEEE
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• v.8 no.1 s.14
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• pp.96-107
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• 2004

In this paper, a new integral variable structure regulation controller(IVSRC) is designed by using a special integral sliding surface and a disturbance observer for the improved regulation control of highly nonlinear robot manipulators with prescribed output performance. The sliding surface having the integral state with a special initial condition is employed in this paper to exactly predetermine the ideal sliding trajectory from a given initial condition to origin without any reaching phase. And a continuous sliding mode input using the disturbance observer is also introduced in oder to effectively follow the predetermined sliding trajectory within the prescribed accuracy without large computation burden. The performance of the prescribed tracking accuracy to the predetermined sliding trajectory is clearly investigated in detail through the two theorems together with the closed loop stability. The design of the proposed IVSRC is separated into the performance design and robustness design in each independent link. The usefulness of the algorithm has been demonstrated through simulation studies on the regulation control of a two link manipulator under parameter uncertainties and payload variations, in view of no reaching phase, no overshoot, predetermined response with prescribed accuracy, easy change of output performance, separation of design phase, and so on.

• Journal of Distribution Science
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• v.11 no.10
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• pp.93-105
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• 2013

Purpose - This empirical analysis determines the structured causal relations between perceived value, customer satisfaction, and repurchase intention among users of traditional markets. The results of this analysis would help merchants and market operators indevisingan appropriate strategy to successfully manage traditional markets. Research design, data, methodology - The perceived value model of traditional markets includes functional value (price), functional value (quality), emotional value, and social value. In this study, the perceived value of traditional markets is considered as an independent variable, while customer satisfaction and repurchase intention are shown as the dependent variables, where customer satisfaction is also considered as the mediating variable. The study aims to ascertain the extent of influence of the perceived value of traditional markets on customer satisfaction and repurchase intention. We use regression analysis to verify the effects. The measurement items were already deemed as reliable and valid in the previous study, but for this purpose, we made some modifications. We distributed questionnaires to 300 consumers on a national scale, and finally used 241 consumer responses among these as a sample. We analyzed the data using the SPSS 21.0 statistical program. Results - We obtained the following results. First, the order of perceived value dimensions of traditional markets that positively impact customer satisfaction is functional value (price), social value, emotional value, and functional value (quality). Second, the perceived value sometimes directly affects repurchase intention; its effect is typically strong with customer satisfaction as a parameter. The order of perceived value dimensions that positively impact repurchase intention is social value, functional value (price), emotional value, and functional value (quality). Third, the perceived value significantly influences repurchase intention, with customer satisfaction as the mediating variable. Conclusions - We should recognize the importance of perceived value in retail distribution markets, such as traditional markets. Moreover, we need to develop strategies to improve the perceived value. The practical implications of the study are as follows. First, with regards to functional value (quality; price) dimensions, we should have an appropriate assortment of high quality products that are reasonably priced. In addition, customers are satisfied with the friendly service, discounts, and other benefits provided by the merchants. Second, in terms of emotional value dimension, we need to develop differentiated events that provide fun and emotional experience to the customers. Third, in the context of social values dimension, we should strive to positively influence society to enhance social image through activities such as social services and contribution to community development. On the basis of these results, we present the implications, limitations, and future directions for the research. One of the policy implications of the study is that merchants of traditional markets must actively select customers and develop customer value. However, this study is limited in the fact that the population used for data collection is not fully representative, as the survey only covered some specific areas. Moreover, future studies could also benefit with additional research using moderating variables.

• Journal of Digital Convergence
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• v.12 no.5
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• pp.13-24
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• 2014

This study is the first model to apply the concept of media engagement to a political campaign by which the voters' mind toward the supporting political candidates, are read. Thus it provides the theoretical and practical implications to the political campaign, and eventually contributes to the development of democracy. For these objectives, the total of 729 people who have the right to vote were telephone surveyed using the peoplemeter, CATI program in the 18th Presidential Election (12 areas including Seoul) of Dec. 19th 2012, and Re and By-election of April 24th 2013. Research question is to examine how the 5 attributes of the media engagement (interest, immersion, relevance, satisfaction and participation), play a role as the moderating variables in cross-correlation, socio-economic status and media properties. The result shows that of the five properties of media engagement, the relevant factor is the important parameter of mediating variable to the causal relationship. The media usage (TV, SNS, print media), socio-economic status (gender, age, income, marriage and area), involvement and the Presidential Election, and Re and By-election are also effective in the five attributes of media engagement. These results suggest that the a study model can measure the campaign effectiveness. This study will contribute significantly to the development of politics, election, media, advertising, and public relations area as well as to promote interdisciplinary research.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1203-1210
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• 2020

Drought is caused by a combination of various hydrological or meteorological factor, so it is difficult to accurately assess drought event, but various drought indices have been developed to interpret them quantitatively. However, the drought indexes currently being used are calculated from the lack of a single variable, which is a problem that does not accurately determine the drought event caused by complex causes. Shortage of a single variable may not be a drought, but it is judged to be a drought. On the other hand, research on developing indices using unstructured data, which is widely used in big data analysis, is being carried out in other fields and proven to be superior. Therefore, in this study, we intend to calculate the drought index by combining unstructured data (news data) with weather and hydrologic information (rainfall and dam inflow) that are being used for the existing drought index, and to evaluate the utilization of drought interpretation through verification of the calculated drought index. The Clayton Copula function was used to calculate the joint drought index, and the parameter estimation was used by the calibration method. The analysis showed that the drought index, which combines unstructured data, properly expresses the drought period compared to the existing drought index (SPI, SDI). In addition, ROC scores were calculated higher than existing drought indices, making them more useful in drought interpretation. The joint drought index calculated in this study is considered highly useful in that it complements the analytical limits of the existing single variable drought index and provides excellent utilization of the drought index using unstructured data.

• Journal of Korea Water Resources Association
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• v.53 no.12
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• pp.1143-1157
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• 2020

In this study, a criteria for the SWAT model calibration method in SWAT-CUP which considers multi-site and multi-variable observations was presented. For its application, the SWAT model was simulated using long-term observed flow, soil moisture, and evapotranspiration data in Yongdam study watershed, investigating the hydrological runoff characteristics and water balance in the water cycle analysis. The model was calibrated with different parameter values for each sub-watershed in order to reflect the characteristics of multiple observations through one-by-one calibration, appropriate settings of model simulation run/iteration number (1,000 simulation runs in the first iteration and then 500 simulation runs for the following iterations), and executions of partial and all run in SWAT-CUP. The flow simulation results of watershed outlet point, ENS 0.85, R2 0.87, and PBIAS -7.6%, were compared with the analysis results (ENS 0.52, R2 0.54, and PBIAS -22.4%) applied in the other batch (i.e., non one-by-one) calibration approach and showed better performances of proposed method. From the simulation results of a total of 15 years, it was found that the total runoff (streamflow) and evapotranspiration rates from precipitation are 53 and 39%, and the ratio of surface runoff and baseflow (i.e., sum of lateral and return flow, and recharge deep aquifer) are 35 and 65%, respectively, in Yongdam watershed. In addition, the analytical amount of available water (i.e., water yield), including the total annual streamflow (daily average 21.8 m3/sec) is 6.96 billion m3 per year (about 540 to 900 mm for sub-watersheds).

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.229-236
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• 2022

The goal of this research is to understand the extent to which active seniors' mobile app usage level affects their lifestyle and life satisfaction. For this, we surveyed for 15 days in early December 2021 targeting about 150 users nationwide. As the questionnaire content, the independent variable was "mobile app usage level", the parameter was "lifestyle", and the dependent variable was "life satisfaction". As a result of empirical analysis, reliability and exploratory factors between each variable were verified, and it was confirmed that internal consistency was secured. It was investigated that the concentration validity of each item was generally well confirmed. As a result of hypothesis testing by the structural equation, 'App usage level ⇨ Lifestyle' was 0.244, 'Lifestyle ⇨ Life satisfaction' 0.707, and 'App usage level ⇨ Life satisfaction 0.141' was adopted. This study shows that the higher the level of mobile app usage of active seniors, the higher the lifestyle. Also, the better the lifestyle, the better the quality of life. It is analyzed that life satisfaction will improve as the level of mobile app use increases. Therefore, in order to improve life satisfaction, it seems necessary to increase the level of app use and lifestyle.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4C
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• pp.269-275
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• 2005

In this paper, we propose a new efficient motion vector coding algorithm for the video sequence with slow motion. In the proposed algorithm, the amount of motion for a given video sequence is determined by a Skip_rate parameter. The motion difference for slow motion is encoded with a combined codeword which is generated from the conventional codewords. The simulation results show that the proposed algorithm achieves approximately $15\%$ bits gain compared to the conventional methods. Moreover, additional memory and calculations for statistical observation are not required in the proposed algorithm.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.217-218
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• 2008

In this paper proposed the solar tracking system to use a fuzzy based on PC in order to increase an output of the PV array. The solar tracking system operated two DC motors driving by signal of photo sensor. The control of dual axes is not an easy task due to nonlinear dynamics and unavailability of the parameters. The fuzzy control made a nonlinear dynamics to well perform and had a robust and highly efficient characteristic about a parameter variable as well as a nonlinear characteristic. Hence the fuzzy control was used to perform the tracking system after comparing with error values of setting-up, nonlinear altitude and azimuth. In this paper designed a fuzzy controller for improving output of PV array and evaluated comparison with efficient of conventional PI controller. The data which were obtained by experiment were able to show a validity of the proposed controller.

• Communications for Statistical Applications and Methods
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• v.21 no.1
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• pp.69-80
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• 2014

This paper considers the problem of monitoring the mean of a normally distributed process variable when the objective is to effectively detect both a sustained shift and a linear drift. The design and application of a generalized likelihood ratio (GLR) chart for simultaneously monitoring a sustained shift and a linear drift are evaluated. The GLR chart has the advantage that when we design this chart, we do not need to specify the size of the parameter change. The performance of the GLR chart is compared with that of other control charts, such as the standard cumulative sum (CUSUM) charts and the cumulative score (CUSCORE) charts. And we compare the proposed GLR chart with the GLR charts designed for monitoring only a sustained shift and for monitoring only a linear drift. Finally, we also compare the proposed GLR chart with the chart combinations. We show that the proposed GLR chart has better overall performance for a wide range of shift sizes and drift rates relative to other control charts, when a special cause produces a sustained shift and/or a linear drift in the process mean.