• The Korean Journal of Applied Statistics
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• v.30 no.6
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• pp.1015-1025
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• 2017

Bayesian personalized ranking (BPR) is a state-of-the-art recommendation system techniques for implicit feedback data. Unfortunately, there might be a loss of information because the BPR model considers only the binary transformation of implicit feedback that is non-binary data in most cases. We propose a modified BPR method using a level of confidence based on the size or strength of implicit feedback to overcome this limitation. The proposed method is useful because it still has a structure of interpretable models for underlying personalized ranking i.e., personal pairwise preferences as in the BPR and that it is capable to reflect a numerical size or the strength of implicit feedback. We propose a computation algorithm based on stochastic gradient descent for the numerical implementation of our proposal. Furthermore, we also show the usefulness of our proposed method compared to ordinary BPR via an analysis of steam video games data.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.4
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• pp.437-442
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• 2012

To analyze a multibody system, this paper proposes an implicit numerical integration method for joint coordinates subsystem synthesis method. To verify the proposed method, a multibody model for an unmanned robot vehicle, which consists of six identical independent suspension systems, is developed. The symbolic method is applied to compute the system Jacobian matrix for the implicit integration method. The proposed method is also verified by performing rough terrain run-over simulation in comparison with the conventional implicit integration method. In addition, to evaluate the efficiency of the proposed method, the CPU time obtained by using this method is compared with that obtained by using the conventional implicit method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.5
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• pp.1033-1047
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• 2017

Traditional explicit authentication, which requires awareness of the user's authentication process, is a burden on the user, which is one of main reasons why users tend not to employ authentication. In this paper, we try to reduce such cost by employing implicit authentication methods, such as biometrics and location based authentication methods. We define the 4-level security assurance model, where each level is mapped to an explicit authentication method. We implement our model as an Android application, where the implicit authentication methods are touch-stroke dynamics-based, face recognition based, and the location based authentication. From user experiment, we could show that the authentication cost is reduced by 14.9% compared to password authentication-only case and by 21.7% compared to the case where 6-digit PIN authentication is solely used.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.61-68
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• 2022

This study examines the impact of consumers' subjective perception on the quality loyalty of the Internet of things, explores academic innovation schemes, and puts forward business strategies for on-site optimization of the industry. The research methods use online survey methods for Chinese consumers who have used or bought Xiaomi IoT products. The results show that the inherent attributes of Internet of things products have an impact on brand image, and brand image has an impact on customer loyalty. Brand image shows complete media effect in the relationship between hyper-connectivity and customer loyalty of Internet of things products. For the enterprises that develop the Internet of things, obtaining the perceived brand image has a very important strategic significance in expanding the loyal customer base.

• Korean Journal of Cognitive Science
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• v.15 no.1
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• pp.43-67
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• 2004

Using qualitative research methodology, this study has investigated the semantic features of 39 nouns, which are classified into the categories of grains, fruits and vegetables. A survey has been conducted with a substantial number of undergraduate students, who were asked to describe any semantic features they associated with the lexical items within the three categories. The analysis of the survey data shows that the concepts of examples of fruits are defined predominantly by intrinsic semantic features, while those of grains and vegetables are defined noticeably by extrinsic semantic features rather than intrinsic ones. Intrinsic semantic features are any properties inherent in an object itself and extrinsic semantic features are defined as any properties constructed by association with other objects or personal experiences in a certain situation. However, this study does not maintain that either intrinsic or extrinsic semantic features solely define the concepts of the examples of the three categories. Instead, it concludes that both kinds of semantic features are involved in the representation of the concepts of those vocabularies, with intrinsic features salient in the category of fruits and extrinsic features salient in the categories of gains and vegetables.

• Journal of the Korean Data and Information Science Society
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• v.11 no.2
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• pp.269-277
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• 2000

We propose the Bayesian testing for the equality of two log-normal population means. Specifically we use the intrinsic Bayes factors suggested by Berger and Perichi (1996, 1998) based on the noninformative priors for the parameters. In order to investigate the usefulness of the proposed Bayesian testing procedures, we compare it with classical tests via both real data analysis and simulation.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.634-639
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• 2008

사회적 컴퓨팅(social computing)의 현상이 Web 2.0 공급사슬(supply chain)의 변화관점에서 새로운 변화의 단계를 맞이하고 있다. Web 2.0 플랫폼을 어떤 형태로 기업 활동에 활용할 것인가 하는 문제제기에 대하여 다양한 기업 활동의 변화사례가 발견되고 있다. 본 논문은 그와 같은 다양한 Web 2.0 환경 확산에 대한 기업 활동의 변화현상 중에서 Web 2.0 플랫폼을 기반으로 한 신제품개발(New Product Development) 사례연구를 통하여 진행한 결과를 반영하였다. 신제품 개발을 위한 플랫폼으로서 Web 2.0 의 협업적 환경을 설계하게 될 경우, 고객의 내재적 요구사항(latent requirement)이 제품개발에 효과적으로 반영될 수 있도록 하는 절차(process)가 기존의 제품개발방법론과 연관되어, 어떤 형태로 적용되고 개선되어 발전될 수 있는가에 대한 경험적 사례를 사례연구방법의 탐험적 경향을 활용하여 살펴보았다. 본 논문에서 다루어졌던 사례는 Web 2.0 플랫폼을 기반으로 사용자 창작 콘텐츠(User Created Content)를 생산하고 증가된 연세대학교 UCC의 양적 팽창에 의해서 수익모델이 발생하는 전형적인 Web 2.0 비즈니스 모델의 구조를 보여주는 경우였다. 본 연구를 통해서 사용자의 내재적 요구사향을 Web 2.0 기술특성을 통해서 참여적 사용자, 혹은 사용자 디자이너들의 적극적인 활동에 의해서 개선 및 구현해 가는 과정을 구체적 개발방법론의 틀로서 정착하려는 시도를 하였다.

• Korean Journal of Social Welfare Studies
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• v.42 no.4
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• pp.445-468
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• 2011

Based on the framework of self-determination theory and past relevant literature, the study develops and estimates a causal relationship between intrinsic motivation, career commitment, and turnover intention. The study utilizes data from a cross-sectional survey conducted on 353 child welfare workers of the fields of foster care, child protective services, and child residential care all over the country. The study relies on Structural Equation Modeling(SEM) method. The results of Confirmatory Factor Analysis indicate the validity of measurement model. The results of SEM tests show a good fit of the proposed model. Controlling the level of salary and the working hours of the workers, the model reveals that intrinsic motivation is positively related to career commitment, and that career commitment is negatively related to turnover intention. In other words, the effect of intrinsic motivation on turnover intention is mediated by career commitment. Implications of the findings for practice and study limitations are discussed.

• Journal of Music and Human Behavior
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• v.21 no.1
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• pp.115-132
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• 2024

The purpose of this study was to explore the impact of music therapy on enhancing self-awareness and intrinsic motivation among patients with schizophrenia, particularly those experiencing motivational deficits. This study, primarily based on quantitative analyses supplemented by qualitative insights, included six adults (three males and three females) across 8 weekly sessions proactive music activities based on the exploration of musical emotion, each lasting 60 minutes, from October 5 to November 16, 2023. Data collection and analysis focused on the last five sessions, from the fourth to the eighth. Although no statistically significant changes were detected, likely due to the study's short duration, qualitative data from in-depth interviews indicate that music therapy contributed to enhanced motivation and improved self-perception in participants. They demonstrated better emotional articulation, self-awareness, and communication skills, which not only increased their intrinsic motivation but also led to an improved perception of their life quality. Individual variability was noted, however, indicating that these outcomes could differ among participants. These results highlight music therapy's potential as a valuable intervention for enhancing self-awareness and reigniting motivation in individuals with schizophrenia, suggesting a further research to corroborate these findings over longer periods.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.111-122
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• 2013

The purpose of this study was to investigate the relationships among intrinsic motivators, psychological empowerment, affective commitment, and service quality among hotel industry employees. For this study, data were collected from 233 hotel employees in Seoul Metropolitan City with self-administered questionnaires and analyzed using structural equation modelling technique. This study found that two job characteristics variables(job challenge and job autonomy) had positive effects on hotel employees' psychological empowerment; that three job characteristics variables(job challenge, job variety and job autonomy) and psychological empowerment had positive effects on hotel employees' organizational commitment; and that psychological empowerment and organizational commitment had positive effects on hotel employees' service quality.