• Journal of the Korean Home Economics Association
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• v.44 no.5 s.219
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• pp.79-87
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• 2006

The purpose of this study is to analyze whether service quality and perceived risk have an effect on purchase intention and satisfaction of the fashion merchandise in internet shopping malls. To this end, a survey was conducted from June 20 to July 30 in 2005, among married women aged in their 20s and 30s, on their purchase experience of fashion merchandise from internet shopping malls. The survey was conducted over the internet with 306 subjects. The statistical analysis methods were frequency analysis, reliability analysis, factor analysis, and multiple regression analysis. First, the service quality factors were determined to be reliability, responsibility, ease of transaction, order convenience, and site characteristics. Perceived risk factors were determined to be merchandise risk, information exposure risk, social psychological risk, and function risk. Second, service quality factors of responsibility, ease of transaction, order convenience, site characteristics and perceived risk factor of social psychological risk had an effect on internet purchase intention of the fashion merchandise. Greater site use convenience, lower price, simpler ordering, and lower social psychological risk were all positively correlated with higher internet purchase intention of fashion merchandise. Third, nice quality factors and social psychological risk had an effect on satisfaction degree in internet shopping.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.8
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• pp.792-799
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• 2008

Motion estimation is crucial in a remote control for its convenience or accuracy. Time delays, however, can occur in the problem because data communication is required through a network. In this paper, state estimation problem with uncertain time delayed measurements is addressed. In dynamic system with noise, after taking measurements, it often requires some time until that is available in the filter algorithm. Standard filters not considering this time delays cannot be used since the current measurement is related with a past state. These delayed measurements are solved with augmented extended Kalman filter, and the uncertainty of delayed time is also resolved based on an explicit formulation. The proposed method is analyzed and verified by simulations.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.3
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• pp.399-406
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• 1996

This paper presents a method of hierarchical state estimation of the time-varying linear systems via Block-pulse function(BPF). When we estimate the state of the systems where noise is considered, it is very difficult to obtain the solutions because minimum error variance matrix having a form of matrix nonlinear differential equations is included in the filter gain calculation. Therefore, hierarchical approach is adapted to transpose matrix nonlinear differential equations to a sum of low order state space equation from and Block-pulse functions are used for solving each low order state space equation in the form of simple and recursive algebraic equation. We believe that presented methods are very attractive nd proper for state estimation of time-varying linear systems on account of its simplicity and computational convenience. (author). 13 refs., 10 figs.

• International Journal of Contents
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• v.14 no.1
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• pp.39-44
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• 2018

Today, cars have developed into intelligent automobiles that combine advanced control equipment and IT technology to provide driving assistance and convenience to users. These vehicles provide infotainment services to the driver, but this does not improve the safety of the driver. Accordingly, V2X communication, which forms a network between a vehicle and a vehicle, between a vehicle and an infrastructure, or between a vehicle and a human, is drawing attention. Therefore, various techniques for improving channel estimation performance without changing the IEEE 802.11p standard have been proposed, but they do not satisfy the packet error rate (PER) performance required by the C-ITS service. In this paper, we analyze existing channel estimation techniques and propose a new channel estimation scheme that achieves better performance than existing techniques. It does this by applying the updated matrix for the data pilot symbol to the construct data pilot (CDP) channel estimation scheme and by further performing the interpolation process in the frequency domain. Finally, through simulations based on the IEEE 802.11p standard, we confirmed the performance of the existing channel estimation schemes and the proposed channel estimation scheme by coded PER.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.5 no.1
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• pp.17-25
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• 2011

This paper aims to find the optimal control gain for enhancing the convenience of electric walking frames and design a control algorithm. With the recent advances in medical technology, there has been a rapid increase in the aging population and a variety of mobile walking frames have been developed for improvement of the quality of life. However, the manual walking frames of such mobile aids don't have any electric motor which helps facilitate elderly users' walking and thus are not efficient enough for the old people of weak strength to use especially when moving on uneven surfaces such as slopes or thresholds. The types of electric walking frames have been developed to overcome such inefficiency. Electric walking frames require users' control operations for motor driving unlike manual frames. Therefore, when they are not properly handled, it causes considerable inconvenience to their users. The present study compared the electric walking frames with manual ones in terms of operational convenience and attempted to improve the user convenience of walking frames varying the control value for user convenience based on certain standards. This paper presented a haptic sensor designed to recognize the will to walk and measure the degree of convenience and proposed a control algorithm for improvement of convenience. For user convenience, this paper evaluated the relative convenience of walking frames in view of changing differences between the center of vehicle (COV) and the center of position (COP). With the employment of an electric walking frame and a new measuring method, all the processes were experimentally tested and validated.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.3
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• pp.306-313
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• 1999

To measure the accurate position of mobile robot, dead-reckoning method using the encoder attached to each wheel is conventionally used, since it is easy to compute and inexpensive to develop. However, that method is useless when slip occurs and error is accumulated with time. This paper proposes a position estimation method using encoder trailer composed of 2 encoders only(ET-2). This method provides accurate position information even when slip occurs, and can reduce accumulated error if we select the proper link lengths of encoder trailer. Experimental results show the performance of ET-2 when slip occurs. Finally, accumulated systematic error from encoder resolution is analyzed in comparison with an existing method with encoder trailer composed of 3 encoders. (As a matter of convenience, we will call the existing encoder trailer ‘ET-3’)

• Journal of the Korean housing association
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• v.6 no.2
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• pp.123-137
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• 1995

This paper presents the directions for the settling environment improvement of 244 Eups and Myeons in the Kyung buk province. Depending on their regional types. The analysis results are as follows : 1) According to the index of general estimation each regional group is classified into the developing country. suburban country. flatland country or mountain country. 2) The regional type is classified into densly-inhabitated district. less-dense district. non-developing district or perishing district. 3) The results of the dwelling environment estimation pointed out that social protection. living convenience. and neighborship are important factors for environmental improvement, depending on the regional type. From above, each region has different regional characteristics and environmental estimation structure. It is suggested to establish improvement directions. based on them.

• Toxicological Research
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• v.20 no.4
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• pp.321-324
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• 2004

Lethal dose 50% ($LD_{50}$) has been commonly used as a parameter for the estimation of acute toxicity not only in animal experiment, but also in human study. Several methods to estimate $LD_{50}$ had been introduced, but Spearman-Karber and Berens-Karber method have been widely used due to their relative convenience and accuracy. However, $LD_{50}$ values estimated from the two methods showed inconsistency and variation depending on the characteristics of mortality data. In this study, the two methods were comparatively investigated in terms of accuracy and stability for the estimation of $LD_{50}$.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.250-251
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• 2019

Lots of infrastructures have been newly constructed through the rapid economic growth of 1970's. Since the infrastructures has mostly deteriorated and this circumstance makes the need for maintenance and rehabilitation(M&R) of infrastructures to obtain the convenience and safety of users even more essential. Although markets for M&R project become larger, the construction standards for cost estimation of M&R work are insufficient. Thus, the purpose of this study is to examine the present state of standards for cost estimation of M&R works using case studies. Finally, this work could be utilized as the basis for the development of national standard for estimation of M&R work.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.8
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• pp.13-18
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• 2018

The purpose of this study was to study on the estimation of green remodeling energy reduction tool in building construction. Green Remodeling Decision System that can predict the energy reduction effect in green remodeling is developed as a tool for simple remodeling of green remodeling considering users' convenience, so that it can quickly and comprehensively determine power peak load reduction factor technology. A preliminary simulation result of a short preliminary remodeling evaluation is DB. It will be developed as a tool that can be easily accessed by users such as web and apps.