• Journal of Biomedical Engineering Research
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• v.45 no.2
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• pp.75-80
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• 2024

This research investigates the influence of chair tilt functionality on biometric signals and user comfort, addressing the ergonomic challenges posed by modern sedentary lifestyles. Through an experimental study involving eight male participants, the impact of chair tilt on electromyography (EMG), heart rate, metabolic rate, pressure distribution, and distance between the lumbar spine and the lumbar support part of the chair was measured across different seating postures. The study utilized chairs with both synchronous and non-synchronous tilt mechanisms to explore how adjustments in chair design affect user comfort and physiological responses during prolonged sitting. Key findings suggest that chair tilt functionality can significantly reduce muscle activity and energy expenditure, enhancing user comfort and potentially mitigating health risks associated with prolonged sedentary behavior. Notably, the study revealed a preference among participants for chairs that aligned the rotational center of the tilt with the hip joint, highlighting the importance of this ergonomic feature in enhancing user comfort. Additionally, the research proposes a novel methodology for assessing seating comfort through the analysis of both biometric and physical signals, providing valuable insights for the development of ergonomic chair designs focused on user health and comfort.

• Journal of Intelligence and Information Systems
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• v.26 no.2
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• pp.43-56
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• 2020

Recommender systems help users make the best choice among various options. Especially, recommender systems play important roles in internet sites as digital information is generated innumerable every second. Many studies on recommender systems have focused on an accurate recommendation. However, there are some problems to overcome in order for the recommendation system to be commercially successful. First, there is a lack of transparency in the recommender system. That is, users cannot know why products are recommended. Second, the recommender system cannot immediately reflect changes in user preferences. That is, although the preference of the user's product changes over time, the recommender system must rebuild the model to reflect the user's preference. Therefore, in this study, we proposed a recommendation methodology using topic modeling and sequential association rule mining to solve these problems from review data. Product reviews provide useful information for recommendations because product reviews include not only rating of the product but also various contents such as user experiences and emotional state. So, reviews imply user preference for the product. So, topic modeling is useful for explaining why items are recommended to users. In addition, sequential association rule mining is useful for identifying changes in user preferences. The proposed methodology is largely divided into two phases. The first phase is to create user profile based on topic modeling. After extracting topics from user reviews on products, user profile on topics is created. The second phase is to recommend products using sequential rules that appear in buying behaviors of users as time passes. The buying behaviors are derived from a change in the topic of each user. A collaborative filtering-based recommendation system was developed as a benchmark system, and we compared the performance of the proposed methodology with that of the collaborative filtering-based recommendation system using Amazon's review dataset. As evaluation metrics, accuracy, recall, precision, and F1 were used. For topic modeling, collapsed Gibbs sampling was conducted. And we extracted 15 topics. Looking at the main topics, topic 1, top 3, topic 4, topic 7, topic 9, topic 13, topic 14 are related to "comedy shows", "high-teen drama series", "crime investigation drama", "horror theme", "British drama", "medical drama", "science fiction drama", respectively. As a result of comparative analysis, the proposed methodology outperformed the collaborative filtering-based recommendation system. From the results, we found that the time just prior to the recommendation was very important for inferring changes in user preference. Therefore, the proposed methodology not only can secure the transparency of the recommender system but also can reflect the user's preferences that change over time. However, the proposed methodology has some limitations. The proposed methodology cannot recommend product elaborately if the number of products included in the topic is large. In addition, the number of sequential patterns is small because the number of topics is too small. Therefore, future research needs to consider these limitations.

• Design Convergence Study
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• v.18 no.1
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• pp.49-60
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• 2019

While one person household and nuclear family have been increasing, supermarkets began to launch home meal replacement(HMR) promotion. Each brand competes over various types of HMR such as box lunch. In particular, the sales of HMR have been increasing due to one-person households. Experts predicted HMR market will be increased in the future as well. This study presents design evaluation with regards to HMR package design for elders. The methods of this study are: First, research literature review on senior society and analyse the design for both domestic and foreign HMR products. Second, survey on product design for evaluation was conducted. Third, user's evaluation survey was conducted on elders. As a result, containers mostly came in cup or box shaped package designs. The package provided both still and illustration image of food. The HMR design for elders are recommended as follows: first, HMR should be service designed for users. Second, the design should be for elders as well. Third, the design should be empathetic and abundant. For user-interface, the packaging material shall not be slippery and the shape of grip should be considered thoroughly for the elder's design.

• Journal of the Korean Society for information Management
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• v.38 no.2
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• pp.113-127
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• 2021

The purpose of this study is to propose a personalized book recommendation system to promote the use of university libraries. In particular, unlike many recommended services that are based on existing users' preferences, this study proposes a method that derive evaluation metrics using individual users' book rental history and tendencies, which can be an effective alternative when users' preferences are not available. This study suggests models using two matrix decomposition methods: Singular Value Decomposition(SVD) and Stochastic Gradient Descent(SGD) that recommend books to users in a way that yields an expected preference score for books that have not yet been read by them. In addition, the model was implemented using a user-based collaborative filtering algorithm by referring to book rental history of other users that have high similarities with the target user. Finally, user evaluation was conducted for the three models using the derived evaluation metrics. Each of the three models recommended five books to users who can either accept or reject the recommendations as the way to evaluate the models.

• Archives of design research
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• v.18 no.2 s.60
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• pp.123-132
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• 2005

In the highly developing industrial society, design has been playing the central role in the managerial strategy of a company and has been one of the central agendas in determining the economical competence of a country, and has also been regarded as a means to acquire sustainable superior competence. Thus, these trends suggest that the aesthetic value of a product has become more important than its technological function. In this study we reviewed theoretically esthetic factors influencing the preference and the evaluation of a product and made a list of eight esthetic factors based on various referential studies which include simplicity, balance, unity, rhythm, style, novelty, typicality, and proportion. We investigated the esthetic factors affecting consumers preferences and the basis for evaluating a product. Conclusively, this study aimed at providing materials for developing product design by presenting an esthetic guideline and to put these materials to practical use. The study also investigated other considered elements classified by manufactures and the importance of esthetic factors and its influence on consumer tastes.

• Science of Emotion and Sensibility
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• v.8 no.3
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• pp.203-212
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• 2005

In the highly developing industrial society the design has been playing the central role in the managerial strategy of a company and has been one of the central agendas in determining the economical competence of a country, and it is also regarded as a means to acquire sustainable superior competence And these trends suggest that the esthetic value of a product has become more important than the technological function. In this study we review theoretically esthetic factors influencing the preference of a product, so that we can make a list of eight esthetic factors based on the various referential studies. They are simplicity, balance, unity, rhythm, style, novelty, typicality, and proportion. We research esthetic factors affecting consumers' preferences and evaluation of a product and typical esthetic factors specific to the characteristics of each product. Therefore, in this study we tried to provide available materials in developing product design by present of esthetic guideline and to put this materials to practical use in product design by finding considered elements and importance of esthetic factors which had important effects on the tastes of the consumers classified by manufactures.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.223-233
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• 2021

MyData industry became possible with the revision of the three data-related bills on August 2020, and from February 2021, each individual can make MyData financial service through the app provided by MyData providers. In this study, in order to understand the user experience trend of MyData-based financial asset management apps in the user-centered financial service era, the usability evaluation of 11 apps from 8 MyData providers was conducted for 300 adults, then average value comparison, radial graph analysis, and heatmap analysis were conducted. In app design preference, asset list type was the most preferred type, followed by asset comparison·list type. As for the expected perception of the future benefits that can be enjoyed through My Data, 'diversification of convenient services' was the highest at 45.3%, and as a negative factor felt by users, personal information-related factors were the highest at 71.4%. The results of this study can be used as basic data for the development and improvement of user interfaces for MyData platforms.

• Journal of Korea Multimedia Society
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• v.17 no.9
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• pp.1115-1124
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• 2014

The objective of this study is to present a new design method at the idea brainstorming process, which requires a great deal of time and effort to seek their own ideas in existing design process and to develop a user support idea forms generation system called OCIGS (Openware Creative Idea Generation System) that makes it possible to create a variety and 3D forms as well as a quantitative evaluation data for the actual types that compose the aesthetic factors and designs of qualitative standards. In order to achieve these objectives : First, overcoming the limitation of 3D form generation ability by establishing visual application system, Second, accepting users' opinions by generating 3D images dynamically, analysing and giving information on the preferred ones on the web on real time, Third, identifying tendency of preference so that they can generate preferred colors and images in future by updating image combination and dropping low-preferred ones. This system would play a role as an idea or form generation application in the actual 3d form design development process.

• Proceedings of the ESK Conference
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• 1993.04a
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• pp.134-144
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• 1993

The psychophysical magnitude estimation thechnique can provide a useful tool for determining the best design features of a product in terms of user preference, especially when it is difficult or almost impossible to obtain objective and quantitative data on the user performance. In this research, several interior design features of a high speed train such as arrangement of passenger seats, and availability of interior facilities were examined quantitatively to provide interior design recommendations for the high speed train. A train simulator was built to provide a realistic interior enviror enviroment of the high speed train, and individual design features were manipulated by using a three-factor within-subject experimental design. At the same time, a psychophysical scale of verbal descriptors ranging from "extremly like" to "extremly dislike" was developed to explain the magnitude estimates of the design features in ordinary language.n ordinary language.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.1
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• pp.29-42
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• 2019

In order to expand the qualitative aspects of public facility, this study used SNS data to derive user-oriented preference factors for public facilities and then were quantified in terms of supply side and demand side. To derive preference factor, LDA, one of topic modeling, was used and attraction index was calculated for each facility. In addition we analyzed spatial accessibility to measure the degree of service experience of users by using 2SFCA model. The study area covered public libraries of Seoul, Korea. As a result of study, five topics were extracted as preference factors for the public library: Circumstance, Scale of facility, Cultural program, Parenting, Books and materials. In particular topic of circumstance and parenting were newly derived preference factors unknown in previous studies. As a result of calculating attraction index for each library, the index of Songpa Library, Jungdok Library, and Namsan Library was high. Songpa library has received good evaluation in parenting factor, and Jungdok & Namsan library in circumstance factor. The accessibility of each region seems to better in center of Seoul where public libraries are crowded, but shrinking toward the outskirts. We expect that the proposed method will contribute to user-oriented public facility evaluation and policy decision making.