• Journal of KIISE:Software and Applications
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• v.32 no.7
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• pp.581-591
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• 2005

Collaborative filtering systems have problems involving sparsity and the provision of recommendations by making correlations between only two users' preferences. These systems recommend items based only on the preferences without taking in to account the contents of the items. As a result, the accuracy of recommendations depends on the data from user-rated items. When users rate items, it can be expected that not all users ran do so earnestly. This brings down the accuracy of recommendations. This paper proposes a collaborative recommendation method for extracting typical group preferences using user-item matrix optimization and user profiles in collaborative tittering systems. The method excludes unproven users by using entropy based on data from user-rated items and groups users into clusters after generating user profiles, and then extracts typical group preferences. The proposed method generates collaborative user profiles by using association word mining to reflect contents as well as preferences of items and groups users into clusters based on the profiles by using the vector space model and the K-means algorithm. To compensate for the shortcoming of providing recommendations using correlations between only two user preferences, the proposed method extracts typical preferences of groups using the entropy theory The typical preferences are extracted by combining user entropies with item preferences. The recommender system using typical group preferences solves the problem caused by recommendations based on preferences rated incorrectly by users and reduces time for retrieving the most similar users in groups.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.24 no.4
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• pp.115-131
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• 2013

The goal of this study is to analyze use patterns of library collections using circulation statistics of academic library user's. For this purpose, the 264,804 circulation-related data of A-academic library which were occurred between March 2012 and February 2013 were collected and used. Five patterns of common user group (undergraduate, graduate students, professors, staffs, the others users) are identified for this study. Gross circulation statistics was analyzed and compared for different users groups and for different subjects. And based on these analysis results, author understood degree of collection use by subject, degree of collection use by user groups, latest materials preference in collection use by subject, latest materials preference in collection use by user groups.

• Journal of the Korean Institute of Educational Facilities
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• v.27 no.2
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• pp.87-95
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• 2020

The purpose of this study is presentation of architectural planning direction and program space of youth training center. For this goal, surveyed the characteristics of youth and local residents who the main user of the center Through this survey, it could be accommodated about the needs of youth training facilities and seek user-centered planning methodologies. To this end, this study conducted a survey of users of youth training facilities in Cheonan-si to suggest the importance of architectural planning direction and space to reflect users' needs and regional characteristics. In the process, this study conducted a consciousness survey and importance influence factors assessment focused on commonalities and differences between youth and adult groups, which are the main user groups of youth training facilities. It is believed that the results of consciousness survey and importance influence factors assessment will be used as basic data to select the scale and programs of space that reflect the needs of users when planning youth facilities and related facilities in the future.

• Asia pacific journal of information systems
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• v.13 no.4
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• pp.1-27
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• 2003

With a swift development of information technology, web sites get more important roles as user's living places. This quantitative and qualitative expansion of web sites requires the need for an evaluation framework of web sites from comprehensive perspectives. This study proposes two dimensions for web site categorization and three dimensions for web site evaluation. These dimensions were developed based on the architectural perspectives that have been used to evaluate buildings in the real world for more than a thousand years. First, in order to categorize various web sites, we extracted two dimensions, user's goals and user's behaviors from behavioral architect which approaches user's behaviors in designing buildings. Second, in order to evaluate four web sites groups, we suggested three dimensions, which are firmness, commodity, delight used in evaluating buildings in the real world. Then for each of the four different web sites groups an empirical survey was conducted to verify these three dimensions of architectural metrics. This ends with study implications and limitations.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.560-569
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• 2003

The purpose of this study was to investigate the usage condition of avatar, the clothing images of avatars, and the difference of self images among avatar user groups which were clustered by the clothing image of using avatar. Avatars were decorated not only to get personal satisfaction and joyfulness but also to realize the desire of relationship with other people. The clothing images of avatars were classified into 7 factors, which were labeled as cute, mature, sexy, old-fashion, unisex. and unique factors. There were no significant differences in self images among 3 avatar user groups which were clustered by 7 factors of clothing images. The result indicated that avatar users pursued various clothing images for their avatar, however, no significant relations were existed between avatar＇s images and user＇s self images and further studies would be required to find out significant variables which determined avatar＇s clothing images.

• The Journal of Information Technology
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• v.12 no.2
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• pp.13-29
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• 2009

ERP in the past, primarily centering on large enterprises and the introduction of competition in the global e-business, but along with the proliferation of small and medium-sized enterprises are now in earnest, or to take advantage of the introduction of the ERP plan. However, the introduction of the ERP cost and the effort required to develop, because many never previously introduced ERP expect that the introduction of cost and performance comparisons with the measurement is necessary. Until now, however, the introduction of a framework of analysis followed the introduction of ERP primarily to measure performance of a major improvement. This research, in addition to improving the performance of these tasks have been overlooked until now for the system's user satisfaction BSC (Balanced Scorecard) models and techniques using AHP-specific understanding of the Company (Group executives, middle managers groups, and user groups) Importance of priorities you want to analyze. In summary, the key findings of this study follows. First, ERP user satisfaction measurement for the balanced scorecard indicators in terms of the redevelopment. Second, the information system user satisfaction to the user layer (Layer 3), grouped by the measure. Thirdly, the user satisfaction of the important topics for attention as quantified by measuring the hierarchy. This model is for satisfaction levels as quantitative of future users of the new system, information systems and the introduction of a new model of development based on the evaluation data will be able to take advantage of.

• Journal of the Ergonomics Society of Korea
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• v.29 no.5
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• pp.797-810
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• 2010

This study examined perceived discomforts encountered in residential facilities such as individual houses and apartments, and suggested a procedure for improving the problems in the living residence. The participants consisted of two groups of people: normal and underprivileged people; the underprivileged group was classified into 3 sub-groups: elderly people (over 65 years old), handicapped people and pregnant women. To identify inconvenient places and design factors in the residential housing, a total of 200 subjects (50 for each group) participated in the survey using the 7-point Likert scale. As a result, all the user groups mainly answered a high degree of discomfort due to narrow parking places, doorsills, and height differences between floors. The elderly, the handicapped, and the pregnant women replied that it is uncomfortable to use ramps and utility rooms. In a follow-up study, one-to-one in-depth interviews were conducted with some of the participants to analyze the detailed causes of inconvenient places and design factors. This study also suggested the procedure for solving the problems in various design factors from perspective of universal design, by considering prior studies which focused on a certain user group like the elderly. This procedure was suggested to consider as many user groups as possible at the same time. The results can be used to understand the discomforts of various user groups on residential housing. The procedure can also be used to develop universal design guidelines for the living residence.

• Journal of Korean Library and Information Science Society
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• v.44 no.4
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• pp.421-442
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• 2013

The importance of users on library catalogs cannot be overemphasized. However little is verified about how well the users' needs have been met. The purpose of this research is to explore the characteristics and differences between user groups on library catalogs, and to draw implications for follow-up research. To the end, this research classified the users into four groups: elementary students, middle and high school students, college students, and the general public. Investigated are unique features and differences in searching behavior on library catalogs between the four groups. The data was collected through a survey with 544 users, and analyzed for both frequency test and Chi-square test. The major research results shows that there were statistically meaningful differences between the four groups. Also discussed are several suggestions for more in-depth research.

• Journal of KIISE:Software and Applications
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• v.36 no.10
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• pp.777-785
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• 2009

Collaborative filtering is a technique used to predict whether a particular user will like a particular item. User-based or item-based collaborative techniques have been used extensively in many commercial recommender systems. In this paper, a hybrid collaborative filtering method that combines user-based and item-based methods using a low-dimensional linear model is proposed. The proposed method solves the problems of sparsity and a large database by using NMF among the low-dimensional linear models. In collaborative filtering systems the methods using the NMF are useful in expressing users as semantic relations. However, they are model-based methods and the process of computation is complex, so they can not recommend items dynamically. In order to complement the shortcomings, the proposed method clusters users into groups by using NMF and selects features of groups by using TF-IDF. Mutual information is then used to compute similarities between items. The proposed method clusters users into groups and extracts features of groups on offline and determines the most suitable group for an active user using the features of groups on online. Finally, the proposed method reduces the time required to classify an active user into a group and outperforms previous methods by combining user-based and item-based collaborative filtering methods.

• ETRI Journal
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• v.31 no.5
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• pp.481-488
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• 2009

This paper proposes a new multiuser scheduling algorithm that can simultaneously support a variety of different quality-of-service (QoS) user groups while satisfying fairness among users in the same QoS group in MIMO broadcast channels. Toward this goal, the proposed algorithm consists of two parts: a QoS-aware fair (QF) scheduling within a QoS group and an antenna trade-off scheme between different QoS groups. The proposed QF scheduling algorithm finds a user set from a certain QoS group which can satisfy the fairness among users in terms of throughput or delay. The antenna trade-off scheme can minimize the QoS violations of a higher priority user group by trading off the number of transmit antennas allocated to different QoS groups. Numerical results demonstrate that the proposed QF scheduling method satisfies different types of fairness among users and can adjust the degree of fairness among them. The antenna trade-off scheme combined with QF scheduling can improve the probability of QoS-guaranteed transmission when supporting different QoS groups.