• Journal of Information Technology Services
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• v.14 no.4
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• pp.159-169
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• 2015

Customer reviews are one of the important sources for purchase decision makings in online stores. Online stores have tried to provide useful reviews in product pages to customers. To assess the usefulness of customer reviews before other users have voted enough on the reviews, diverse aspects of reviews were utilized in prevous studies. Style and semantic information were utilized in many studies. This study aims to test diverse alogrithms and datasets for identifying a proper classification method and threshold to classify useful reviews. In particular, most researches utilized ratio type helpfulness index as Amazon.com used. However, there is another type of usefulness index utilized in TripAdviser.com or Yelp.com, count type helpfulness index. There was no proper threshold to classify useful reviews yet for count type helpfulness index. This study used reivews and their usefulness votes on restaurnats from Yelp.com to devise diverse datasets and applied text mining approaches to classify useful reviews. Random Forest, SVM, and GLMNET showed the greater values of accuracy than other approaches.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.560-569
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• 2017

With a remarkable and rapid change of universities in Korea, the role of universities has been changed from a traditional education supplier to a demander. Both the remarkable decrease of the number of entering students and the advent of an open education market are enforcing the universities to be changed. Universities should provide a variety of educational services in accordance with the students' needs. This study is based on the systematical Kuh's model which the educational service quality provide a decision making of alternative plan. This research is purposed to empirically study the effects of educational service quality(circumstance index, input index, participate index, output index) provided by universities on student satisfaction and educational performance(Perceived usefulness, Education Achievement). The results of this research follows; first, circumstance index, input index and output index significantly effect student satisfaction, but participate index does not effect satisfaction. Second, student satisfaction significantly effects on the educational performance.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.283-290
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• 2020

The purpose of this study was to evaluate the usefulness of the triglyceride and glucose(TyG) index to predict the risk of hyperuricemia in Korean adults. This study included 14,266 men and 9,033 women over 20 years old who underwent health screenings from 2017 to 2019 at a general hospital in Seoul. To confirm the risk of hyperuricemia and predictive ability of the TyG index, logistic regression analysis and ROC curves were obtained. The accuracy of the TyG index for predicting hyperuricemia was 0.68, 0.61 for men and 0.67 for women(respectively p<0.001). The risk of hyperuricemia in the TyG index was 1.69 times higher in the fourth quartile than in the first quartile, 2.03 times higher in men and 2.07 times higher in women(respectively p<0.05). Thus the TyG index was not of high diagnostic usefulness as a screening test for hyperuricemia, but it was related to the TyG index and hyperuricemia.

• The Journal of Information Systems
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• v.18 no.3
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• pp.351-373
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• 2009

An index fund is a collective investment scheme that aims to replicate the movements of an index of a specific financial market regardless of market conditions. An index fund is a popular investment alternative because it is much cheaper to run than an active fund and it performs better than actively managed funds. This paper illustrates the usefulness of wavelet analysis in constructing an index fund. The wavelet analysis can decompose the time series data in frequency domain as well as in time domain. The major findings of this paper are as follows. First, the beta coefficient that represents the systematic risk has the scale dependent property. This result can provide important information to the investors with various investment time frequency. Investors can use the betas corresponding to their investment frequencies among the various scale betas estimated by wavelet analysis. Second, we can find the usefulness of wavelet analysis in constructing index fund because the wavelet technique gives less tracking error(difference between the index performance and the index fund performance) than the traditional constructing techniques. The result of this study implies that the wavelet techniques can be an important analytic method to the other financial markets such as option market, futures market, bond markets and currency market.

• Korea Journal of Hospital Management
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• v.23 no.2
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• pp.54-66
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• 2018

Purpose: This study was to figure out relationships of perceived Technology Readiness Index(TRI), usefulness, acceptance intension, and the recognition of substitute employment of medical personnel on the artificial intelligence (AI) and internet of things (IoT) among main technologies. Methodology: To achieve the purpose, this study utilized structured survey tools to conduct a questionnaire survey of nursing, administrative and medical technology professionals at six university hospitals in Korea metropolitan area. A PLS(Partial Least Square) Path analysis was utilized To analyze the material. Findings: In the relation with the technology readiness and perceived usefulness, it had a positive influence to the perceived usefulness when the optimism and innovativeness were higher and the discomfort was lower. In the relation with the technology readiness and acceptance intension, it showed a positive influence when the innovativeness was higher and the discomfort was lower. In the relation with the perceived usefulness and acceptance intension, it had a positive influence to the acceptance intension when the perceived usefulness was higher. In the relation with the acceptance intension and the recognition of substitute employment, it showed a positive influence to the recognition of substitute employment when the acceptance intension was higher. Practical Implications: Judging based on the above study results and reference reviews, it confirmed that it is necessary to prepare in the level of hospital organization in the $4^{th}$ Industrial Revolution. They should increase the efficiency of human resources through the technological factors or changes of employment types for the additional demands of human resources to handle increasing medical demands or induce to secure necessary abilities which are changing at the right time by performing the $4^{th}$ Industrial Revolution related re-training continuously to develop the value of existing human resources.

• Journal of Intelligence and Information Systems
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• v.22 no.1
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• pp.43-61
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• 2016

Customer reviews help potential customers make purchasing decisions. However, the prevalence of reviews on websites push the customer to sift through them and change the focus from a mere search to identifying which of the available reviews are valuable and useful for the purchasing decision at hand. To identify useful reviews, websites have developed different mechanisms to give customers options when evaluating existing reviews. Websites allow users to rate the usefulness of a customer review as helpful or not. Amazon.com uses a ratio-type helpfulness, while Yelp.com uses a count-type usefulness index. This usefulness index provides helpful reviews to future potential purchasers. This study investigated the effects of sentiment and readability on useful votes for customer reviews. Similar studies on the relationship between sentiment and readability have focused on the ratio-type usefulness index utilized by websites such as Amazon.com. In this study, Yelp.com's count-type usefulness index for restaurant reviews was used to investigate the relationship between sentiment/readability and usefulness votes. Yelp.com's online customer reviews for stores in the beverage and food categories were used for the analysis. In total, 170,294 reviews containing information on a store's reputation and popularity were used. The control variables were the review length, store reputation, and popularity; the independent variables were the sentiment and readability, while the dependent variable was the number of helpful votes. The review rating is the moderating variable for the review sentiment and readability. The length is the number of characters in a review. The popularity is the number of reviews for a store, and the reputation is the general average rating of all reviews for a store. The readability of a review was calculated with the Coleman-Liau index. The sentiment is a positivity score for the review as calculated by SentiWordNet. The review rating is a preference score selected from 1 to 5 (stars) by the review author. The dependent variable (i.e., usefulness votes) used in this study is a count variable. Therefore, the Poisson regression model, which is commonly used to account for the discrete and nonnegative nature of count data, was applied in the analyses. The increase in helpful votes was assumed to follow a Poisson distribution. Because the Poisson model assumes an equal mean and variance and the data were over-dispersed, a negative binomial distribution model that allows for over-dispersion of the count variable was used for the estimation. Zero-inflated negative binomial regression was used to model count variables with excessive zeros and over-dispersed count outcome variables. With this model, the excess zeros were assumed to be generated through a separate process from the count values and therefore should be modeled as independently as possible. The results showed that positive sentiment had a negative effect on gaining useful votes for positive reviews but no significant effect on negative reviews. Poor readability had a negative effect on gaining useful votes and was not moderated by the review star ratings. These findings yield considerable managerial implications. The results are helpful for online websites when analyzing their review guidelines and identifying useful reviews for their business. Based on this study, positive reviews are not necessarily helpful; therefore, restaurants should consider which type of positive review is helpful for their business. Second, this study is beneficial for businesses and website designers in creating review mechanisms to know which type of reviews to highlight on their websites and which type of reviews can be beneficial to the business. Moreover, this study highlights the review systems employed by websites to allow their customers to post rating reviews.

• Journal of Sasang Constitution and Immune Medicine
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• v.31 no.3
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• pp.34-47
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• 2019

Introduction Cloninger's Novelty-Seeking (NS) and Harm-Avoidance (HA) were found to be the biopsychological characteristic of Sasang typology, and the So-Yang type has high NS and low HA however the So-Eum type as contrary. The purpose of this study was to show the clinical usefulness of these measures as objective clinical index of Sasang typology in foreign countries lacking validated measures. Methods The Sasang type of 103 university students was diagnosed using Questionnaire for Sasang Constitution Classification (QSCC) II and clinical specialist, and biopsychological and physical features with NS, HA, Sasang Personality Questionnaire (SPQ) and BMI. These measures were normalized to make a noble index of 'NS(100-HA)', and the correlation among these were examined with Pearson's correlation. The differences of biopsychological and physical features between Sasang type groups were attested with ANCOVA, and the comparison of clinical usefulness of SPQ and NS(100-HA) were examined with discriminant analysis. Results SPQ and BMI were clinically useful for Sasang typology as shown in previous studies, and the substitution of SPQ with normalized NS(100-HA) was found acceptable. The NS(100-HA) is significantly correlated with SPQ (r=0.466, p<0.01), however not with BMI (r=0.079, ns). The SPQ and NS(100-HA) scores were found to be distinctive between Sasang type groups, and these were found to predict Sasang type of participants with similar correctness. Discussion and Conclusion The current study reviewed the theoretical backgrounds and confirmed the clinical usefulness of Cloninger's biopsychological theory in Sasang typology. These might provide foundations for integrative medicine and cross-cultural biopsychology of the East and West.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1335-1351
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• 2015

In order to effectively understand the perception of businesses and consumers, the Bank of Korea has released Economic Sentiment Index (ESI), a composite indicator of business survey index (BSI) and consumer survey index (CSI), since 2102. The usefulness of ESI has been widely recognized. However, there exists a margin for improvement in terms of its predictive power. In this study, we evaluated the usefulness of ESI and improved the ESI by complementing its defaults. Our results of empirical analysis proved that dynamic optimal weight navigation process using the sliding window method is very useful in determining the optimal weights of configurations item of ESI based on economic situation.

• Journal of the HCI Society of Korea
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• v.9 no.2
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• pp.53-59
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• 2014

The objectives of this research is to compare UX elements influencing the satisfaction of users in Korea and North America according to product types of mobile commerce services, to determine UX INDEX suitable for each type of service, and to derive positively influencing UI factors through analyzing the relationship between UX INDEX and UX design detail factors. This research showed that there was difference in perceived reliability according to selling product types and there was difference in both perceived usefulness and reliability according to users in Korea and North America. Also, this research found out that, in analysis of relationship between UX INDEX and UX design detail factors, UI factors to understand a service structure generally showed close relationship but factors such as troubleshooting and help showed difference between users in Korea and users in North America.

• Journal of the Korean Society of Radiology
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• v.12 no.2
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• pp.185-191
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• 2018

The purpose of this study was to evaluate the usefulness of BMI application to Urography CT by applying different tube voltages in accordance with body mass index. Group A (n = 38) with body mass index of lower than 25 was examined with tube voltage of 100 kVp while Group B (n = 45) with a BMI of 25 and higher was examined with tube voltage of 120 kVp. C group (n = 37) with body mass index (BMI) of lower than 25 was examined with tube voltage of 120kVp. Although the difference in average dose between group A (100 kVp) and group C (120 kVp) with low body mass index (BMI) of lower than 25 was $214.8mGy{\cdot}cm$, there was no significant difference in qualitative evaluation and, compared with patient group with body mass index of 25 and higher, results obtained were rather good. Therefore, this study verified that the tube voltage of lower than 100 kVp does not have adverse effect on the quality of image for patients with body mass index (BMI) of lower than 25.