• Science of Emotion and Sensibility
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• v.22 no.2
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• pp.49-58
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• 2019

In the era of the 4th Industrial Revolution, artificial intelligence (AI) has become one of the core technologies in terms of the business strategy among information technology companies. Both international and domestic major portal companies are launching AI search services. These AI search services utilize voice, images, and other unstructured data to provide different experiences from existing text-based search services. An unfamiliar experience is a factor that can hinder the usability of the service. Therefore, the usability testing of the AI search services is necessary. This study examines the usability of the AI search service on the Naver App 8.9.3 beta version by comparing it with the search services of the current Naver App and targets 30 people in their 20s and 30s, who have experience using Naver apps. The usability of Smart Lens, Smart Voice, Smart Around, and AiRS, which are the Naver App beta versions of their artificial intelligence search service, is evaluated and statistically significant usability changes are revealed. Smart Lens, Smart Voice, and Smart Around exhibited positive changes, whereas AiRS exhibited negative changes in terms of usability. This study evaluates the change in usability according to the application of the artificial intelligence search services and investigates the correlation between the evaluation factors. The obtained data are expected to be useful for the usability evaluation of services that use AI.

• The Korean Journal of Applied Statistics
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• v.32 no.2
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• pp.173-185
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• 2019

Causal questions are prevalent in scientific research, for example, how effective a treatment was for preventing an infectious disease, how much a policy increased utility, or which advertisement would give the highest click rate for a given customer. Causal inference theory in statistics interprets those questions as inferring the effect of a given intervention (treatment or policy) in the data generating process. Causal inference has been used in medicine, public health, and economics; in addition, it has received recent attention as a tool for data-driven decision making processes. Many recent datasets are observational, rather than experimental, which makes the causal inference theory more complex. This review introduces key concepts and recent trends of statistical causal inference in observational studies. We first introduce the Neyman-Rubin's potential outcome framework to formularize from causal questions to average treatment effects as well as discuss popular methods to estimate treatment effects such as propensity score approaches and regression approaches. For recent trends, we briefly discuss (1) conditional (heterogeneous) treatment effects and machine learning-based approaches, (2) curse of dimensionality on the estimation of treatment effect and its remedies, and (3) Pearl's structural causal model to deal with more complex causal relationships and its connection to the Neyman-Rubin's potential outcome model.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.14 no.3
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• pp.13-26
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• 2019

There is a growing interest in the entrepreneurial activity that has long been considered essential for sustainable economic development and value creating. Although it is strongly encouraged by focusing on the positive aspects of venturing, less has been paid attention to entrepreneurial failure, which is the biggest cause of hesitation in starting a business. The uncertain and risky nature of entrepreneurship implies a considerable possibility of failure. Even if it fails, the experience and knowledge of entrepreneurs acquired through entrepreneurship indeed offers valuable lessons for the re-venturing, which can serve as an important social asset that should not be lost. It has been argued that re-entering the same industry for the subsequent venture maximizes the learning effect through utilizing potential benefits from industry-specific knowledge. Although the re-startup after entrepreneurial failure is a very important topic in the studies on serial entrepreneurs, there is a paucity of systematic empirical investigation. This study responds to calls for more research on the re-startup after entrepreneurial failure, and specifically complements existing studies on serial entrepreneurs. Focusing on the entrepreneurs' attribution for the failure, we conducted an empirical analysis of how this affects the re-startup process. Moreover, we also examined the moderating effects of entrepreneurial self-efficacy and resilience. For the analyses, we surveyed the entrepreneurs who tried to re-start the subsequent business after the entrepreneurial failure through the "Revitalization Center for Strained Entrepreneur". The results found that failed entrepreneurs who blamed internal factors for their previous venture failures were likely to keep the same industry for their subsequent business. In addition, the positive effect of internal attribution on maintaining the same industry for the re-startup was found to be stronger when entrepreneurial self-efficacy and resilience were high.

• The Journal of the Korea Contents Association
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• v.19 no.9
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• pp.57-66
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• 2019

This study investigates the factors influencing to users' intention to retain monthly movie subscription VOD service in the Pay-TV. A dual model of a dedication-based mechanism and constraint-based mechanism used as the analytical framework for the service subscription retention. This study surveyed the total of 366 respondents who aged 15 years or older among the subscribers who use monthly movie subscription VOD service in Pay-TV from May 8 to May 14, 2018 through online surveys. And the study used SPSS 25 and AMOS 21 for data analysis. The results of the analysis are as follows. First, the price, the contents diversity and the ease of use were found to affect the user satisfaction. From three components, the price is the most effective and the ease of use is the next. Second, user satisfaction were found to affect the intention to retain a subscription in the dedication-based mechanism. Third, procedural switching cost were found to affect the intention to retain a subscription in the constraint-base mechanism.

• Journal of the Korean Society for information Management
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• v.37 no.4
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• pp.131-150
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• 2020

This study was conducted to ascertain a better understanding of researchers' perception of open peer review (OPR), which is being attempted to improve the problems of traditional peer review methods in recent journal publications. A survey was conducted on the Korean authors of a mega open access (OA) journals and the results were analyzed. The subjects of the survey were selected as Korean corresponding authors published on PLOS, an international OA journal and mega journal. The survey was conducted as an online questionnaire and a total of 238 responses were collected; the analysis was based on 202 valid responses. Data were analyzed by performing frequency analysis and average comparison between groups for the collected questionnaire results. As a result of analyzing whether there is a difference in perception of OPR depending on the age, research experience, and OPR experience of the researcher, researchers under the age of 44, researchers with research experience of 9 years or less, and researchers with OPR participation experience had differences in some OPR perceptions. Results show that researchers under the age of 44 want to change the current peer review approach, but they are not yet actively accepting OPR. As a result of analyzing the reasons why the researcher disagrees with OPR, they raised questions about lack of objectivity, increased burden of reviewers, emotions and relationships, and responded that the right to be forgotten was also necessary.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.31-41
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• 2021

The purpose of this study is to analyze the properties of previous studies related to vocations in the construction field. The results of the analysis are as follows. First, The paper has not been published at the beginning of the establishment of the academic foundation for vocational studies, but there was a marked increase over the next 15 years. Second, research related to vocations in the construction field has been more active in engineering than in social science. Third, the primary data method was used much more than the secondary data method, and the quantitative research method through a questionnaire was the most common research method. Fourth, human objects showed the highest frequency as 78.9%, and among them, technicians was the most. Fifth, as the research topic, psychological and behavioral aspects such as job satisfaction, job stress, turnover intention, and organizational commitment were dealt with most, and structural and environmental aspects such as national job competency standards, job analysis, construction accidents, and career development. It was also found that the topic of the research was actively being dealt with.

• Korean Journal of Construction Engineering and Management
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• v.22 no.2
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• pp.63-71
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• 2021

This paper looks into how to enhance construction project management, focusing on the change order, which is often considered one of the major causes for construction delays, disputes, and claims in the middle east construction. First, this paper categorizes the major causes of change orders. It suggests a detailed classification standard for affecting factors resulting from change orders based on a case study result of an on-going construction project in the Middle East. In particular, this paper presents a method to apply a machine learning-based feature selection to quantify the importance of change order triggers and affecting factors. As a result, the case study identifies six major change order triggers and eight affecting factors. Also, a meaningful relationship between change order triggers and affecting factors by each category is presented. This paper will contribute to setting a clear guideline for change order management for the international plant construction field while helping prevent construction delays and cost run-ups by reducing the time required for change order resolution between project owners and contractors.

• Journal of Korea Water Resources Association
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• v.54 no.6
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• pp.433-442
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• 2021

In order to examine the characteristics of tidal wave from the estuary to upsteam of tidal river, tidal asymmetry was identified based on analysis of the harmonic constants of M2 and M4 tidal constituents in the domestic western coastal regions. As shallow water tide is greatly developed in the estuary, flood dominance in Han River and Keum River, and ebb dominance in Youngsan River are developed. These tidal asymmetries can be reconfirmed by analyzing the tidal current data. Unlike having reciprocating tidal current patterns in Keum and Youngsan estuaries, rotaing tidal current pattern is shown in the Han River estuary due to the complex topography and waterways around Ganghwa Island area. However, when residual current is removed, flood dominance is shown in consistency with the tide data. The tidal asymmetry in the estuary tends to intensify with the growth in shallow water tide as the tidal wave propagates to upstream of tidal river. Energy dissipation, in shallow Han River and Keum River classified as SD estuaries, is very large regarding bottom friction characteristics. On the other hand, the deep Youngsan River, classified as a WD estuary, shows less energy dissipation.

• Korean Journal of Food Science and Technology
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• v.52 no.6
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• pp.649-654
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• 2020

This study was conducted to investigate the quality of wine, produced from 11 different grape varieties. Black Sun, CB, Gaeryangmeoru, MW52, MW55, and Narsha with 0.6-0.8% total acids were good for wine. The total acid content of Wangmeoru wine was too high (1.41%). Black Sun, CB, Gaeryangmeoru, MW52, MW55, MBA, WB, and Wangmeoru showed excellent chromaticity (90dE or higher). Total polyphenols, total anthocyanin and tannin, contents were the highest in Gaeryangmeoru, WB, Wangmeoru, and CB and would be advantageous for wine aging. The results of this study deemed Gaeryangmeoru and CB to be suitable for red wine preparation.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.2
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• pp.45-56
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• 2021

In platoon driving, several autonomous vehicles communicate to exchange information with each other and drive in a single cluster. The platooning technology has various advantages such as increasing road traffic, reducing energy consumption and pollutant emission by driving in short distance between vehicles. However, the short distance makes it more difficult to cope with an emergency accident, and accordingly, it is difficult to ensure the safety of platoon driving, which must be secured. In particular, the unexpected situation, i.e., variability that may appear during driving can adversely affect the safety of platoon driving. Because such variability is difficult to predict and reproduce, preparing safety guards to prevent risks arising from variability is a challenging work. In this paper, we studied a simulation method to avoid the risk due to the variability that may occur while platoon driving. In order to simulate safe platoon driving, we develop diverse scenarios considering the variability, design and apply safety guards to handle the variability, and extends the detail functions of VENTOS, an open source platooning simulator. Based on the simulation results, we have confirmed that the risks caused form the variability can be removed, and safe platoon driving is possible. We believe that our simulation approach will contribute to research and development to ensure safety in platoon driving.