• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.976-979
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• 2008

As internet occupies a great deal of portion in our life, a lot of mental diseases become the points at issue relating to internet addiction. The purpose of this study is to examine whether internet addiction is related with Attention Deficit Hyperactivity Disorder that is characterized with sustained inattention, hyperactivity and impulsivity and then find out which sub-factors of internet addiction are influencing effective on Attention Deficit Hyperactivity Disorder. As result of applying reliability analysis, frequency analysis, cross tabulation analysis, t-test, ANOVA, Pearson's correlation analysis and multiple regression analysis, it shows the following research results.

• Child Health Nursing Research
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• v.14 no.3
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• pp.243-251
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• 2008

Objective: School nurses should be knowledgeable about attention-deficit hyperactivity disorder (ADHD) and have tolerant attitudes to children with ADHD. This study was done to identify school nurses' knowledge about, and attitudes to, ADHD. Methods: A cross-sectional descriptive correlational study was conducted. The participants were the 245 members of a school nurse association in C province in southern part of Korea. Data were collected using a self-report questionnaire. Descriptive statistics, t-test, ANOVA, and Pearson correlation coefficients were used to analyze the data. Results: Of the 245 packets mailed to members, 126 (51.4%) were returned, and of these, 122 packets (49.8%) were suitable for data analysis. School nurses in this study lack knowledge about ADHD. Moreover, school nurses reported low tolerance in their attitudes toward children with ADHD. There was no significant correlation between knowledge and attitudes in the management of ADHD among school nurses. Conclusion: Findings from this study show that school nurses have limited knowledge about ADHD and its treatment with stimulation medication. Moreover, their attitudes toward children with ADHD were in the low tolerant range. An educational program on ADHD for school nurses need to be developed and provided to facilitate the school nurses' role in assessing and caring for children with ADHD.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.3
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• pp.575-584
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• 2021

This research aims to examine and analyze the impact of customer shifting behavior on the shopping emotion. Based on impulse buying, customers tend to behave recently based on the constructed variables of impulse buying, outlet ambience, hedonic shopping value utilitarian shopping value, and shopping emotion. This study employs samples/survey data of the population consisted of Asian women parents in Indonesia. The survey data of this research is based on observations using time series with cross-section/one-shot, which was done in 2019. The results indicate that variable outlet ambience, hedonic shopping value, and shopping emotion have a positive and significant impact on impulse buying. Whereas the utilitarian shopping value variable has a positive but not significant relationship against impulse buying. There is a positive influence between ambience outlets and utilitarian shopping value on shopping emotion. The variable hedonic shopping value has a negative and not significant relationship towards shopping emotion. The finding of this study suggests that both the retail stores and even the superstores must pay more attention to the design of outlet ambience to create the hedonic shopping value and eventually may attempt the attention of the impulse buying customers.

• Journal of the Korean Data and Information Science Society
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• v.20 no.4
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• pp.655-660
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• 2009

As the global economic crisis, the Korean foreign exchange market appears unstable with large fluctuations in exchange rate. Inevitably, there is growing attention on price variables such as exchange rate and interest rates and also on corelation between the factors. This is an empirical study on the causality of fluctuation between exchange rate and interest rate in the Korean market under global economic crisis. The fluctuations in won/dollar exchange rate and call rate are described and followed by analysis of lead-lag relationship between the two variables using Cross-correlation function and Granger causality test.

• Journal of the Korean Data and Information Science Society
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• v.28 no.5
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• pp.971-980
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• 2017

The varying coefficient regression model has gained lots of attention since it is capable to model dynamic changes of regression coefficients in many regression problems of science. In this paper we propose a varying coefficient regression model that effectively considers the errors on both input and response variables, which utilizes the kernel method in estimating the varying coefficient which is the unknown nonlinear function of smoothing variables. We provide a generalized cross validation method for choosing the hyper-parameters which affect the performance of the proposed model. The proposed method is evaluated through numerical studies.

• Smart Structures and Systems
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• v.14 no.5
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• pp.917-942
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• 2014

Multivariate statistics based damage detection algorithms employed in conjunction with novel sensing technologies are attracting more attention for long term Structural Health Monitoring of civil infrastructure. In this study, two practical data driven methods are investigated utilizing strain data captured from a 4-span bridge model by Fiber Bragg Grating (FBG) sensors as part of a bridge health monitoring study. The most common and critical bridge damage scenarios were simulated on the representative bridge model equipped with FBG sensors. A high speed FBG interrogator system is developed by the authors to collect the strain responses under moving vehicle loads using FBG sensors. Two data driven methods, Moving Principal Component Analysis (MPCA) and Moving Cross Correlation Analysis (MCCA), are coded and implemented to handle and process the large amount of data. The efficiency of the SHM system with FBG sensors, MPCA and MCCA methods for detecting and localizing damage is explored with several experiments. Based on the findings presented in this paper, the MPCA and MCCA coupled with FBG sensors can be deemed to deliver promising results to detect both local and global damage implemented on the bridge structure.

• Journal of Biomedical Engineering Research
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• v.30 no.4
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• pp.279-287
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• 2009

Magnetic resonance electrical impedance tomography (MREIT) is a new medical imaging modality providing cross-sectional images of a conductivity distribution inside an electrically conducting object. MREIT has rapidly progressed in its theory, algorithm and experimental technique and now reached the stage of in vivo animal and human experiments. Conductivity image reconstructions in MREIT require various steps of carefully implemented numerical computations. To facilitate MREIT research, there is a pressing need for an MREIT software package with an efficient user interface. In this paper, we present an example of such a software, called CoReHA which stands for conductivity reconstructor using harmonic algorithms. It offers various computational tools including preprocessing of MREIT data, identification of boundary geometry, electrode modeling, meshing and implementation of the finite element method. Conductivity image reconstruction methods based on the harmonic $B_z$ algorithm are used to produce cross-sectional conductivity images. After summarizing basics of MREIT theory and experimental method, we describe technical details of each data processing task for conductivity image reconstructions. We pay attention to pitfalls and cautions in their numerical implementations. The presented software will be useful to researchers in the field of MREIT for simulation as well as experimental studies.

• Proceedings of the KSPS conference
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• 1996.10a
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• pp.343-348
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• 1996

This paper examines the contribution of vocalic information (after the onset of voicing) to the perception of Korean alveolar stops: the aspirated /$t^{h}$/, the lenis /t/, and the fortis /$t^{*}$/. These stops have been analyzed as differing in VOT (Abramson & Lisker, 1964), the glottal width or aspiration (Kim, 1970), and F0 and intensity build-up (Han & Weitzman, 1970). These studies focused on the articulatory and acoustic qualities of the consonants and often assumed that the consonantal portion before the onset of voicing plays the main role in maintaining the three-way distinction. In contrast, the role of the following vowels was given less attention. In order to investigate the contribution of the following vowels, a perceptual study was conducted using stimuli cross-spliced from three naturally produced syllables [$t^{h}al$] 'mask', [tal] 'moon', and [$t^{*}al$]) 'daughter'. Stimuli were presented to 12 Korean listeners for identification. Each subject responded to a total of 486 tokens. The results show that vowels play the primary role when the cut occurs at the star of voicing. Even with cuts at 10 ms and 40 ms into voicing, the following vowel still plays a clear role. This suggests that vowels carry the important information for distinguishing the three stops.

• Knowledge Management Research
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• v.20 no.4
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• pp.169-183
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• 2019

The growth of mobile commerce (m-commerce) has been accelerated around the world. Why do e-retailers have to put a great deal of effort for the distribution of their mobile apps? The literature has paid little attention to the influence of the introduction of an e-commerce app on shopping behaviors of consumers. By analyzing the dataset of 2,342 users in Korea, this study aims to broaden our understanding of mobile shopping app usage across competing e-retailers and different channels. We found that a user's prior usage of a specific e-commerce mobile app increases her subsequent usage of its website through a mobile web browser. Thus, mobile apps do not cannibalize the mobile web channel, and there could be a complementary relationship. We also found that a user's usage of competitors' apps is positively associated with her subsequent usage of a specific e-commerce app. Because many consumers search products and compare prices across multiple e-retailers, having a mobile app helps an e-retailer be exposed to more potential consumers. This study is among the first to study the role of mobile apps in e-commerce by showing the dynamics of cross-channel and cross-vendor usage by a user.

• Journal of Microbiology and Biotechnology
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• v.21 no.11
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• pp.1159-1165
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• 2011

Biodiesel is methyl and ethyl esters of long-chain fatty acids produced from vegetable oils or animal fats. Lipase enzymes have occasionally been used for the production of this biofuel. Recently, biodiesel production using immobilized lipase has received increased attention. Through enhanced stability and reusability, immobilized lipase can contribute to the reduction of the costs inherent to biodiesel production. In this study, methanol-tolerant lipase M37 from Photobacterium lipolyticum was immobilized using the cross-linked enzyme aggregate (CLEA) method. Lipase M37 has a high lysine content (9.7%) in its protein sequence. Most lysine residues are located evenly over the surface of the protein, except for the lid structure region, which makes the CLEA preparation yield quite high (~93%). CLEA M37 evidences an optimal temperature of $30^{\circ}C$, and an optimal pH of 9-10. It was stable up to $50^{\circ}C$ and in a pH range of 4.0-11.0. Both soluble M37 and CLEA M37 were stable in the presence of high concentrations of methanol, ethanol, 1-propanol, and n-butanol. That is, their activities were maintained at solvent concentrations above 10% (v/v). CLEA M37 could produce biodiesel from olive oil and alcohols such as methanol and ethanol. Additionally, CLEA M37 generated biodiesel via both 2-step methanol feeding procedures. Considering its physical stability and reusability, CLEA M37 may potentially be used as a catalyst in organic synthesis, including the biodiesel production reaction.