• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.846-849
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• 2008

In recent years there has been growing interest in wireless sensor networks (WSNs) for a variety of indoor applications. In this paper, we present the RSSI-based localization in indoor environments. In order to evaluate the relationship between distance and RSSI, the log-normal path loss shadowing model is used. By tagging users with a sensor node and deploying a number of nodes at fixed position in the building, the RSSI can be used to determine the position of tagged user. This system operates by recording and processing signal strength information at the base stations. It combines Euclidean distance technique with signal strength matrix obtained during real-time measurement to determine the location of user. The experimental results presented the ability of this system to estimate user's location with a accuracy.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.5
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• pp.487-497
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• 2003

There have been many filtering systems covering mail or news. Documents filtered by them consist of general text or HTML. XML is emerging as a new standard for information exchange. So, filtering systems need new approaches in dealing with XML documents. Our system suggests a method to describe user profiles with XML's ability to represent schema and structure. An user profile is made from DTD information and it is supposed to point the specific part of a document conforming to the DTD. More, it is different from the existing systems in extracting part of a document. An user profile is reflected in XML query to get part of an XML document.

• Journal of the Korea Society of Computer and Information
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• v.16 no.8
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• pp.157-164
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• 2011

As a computer technology is combined with communication technology, information and communication technology developed rapidly. As a result, The number of internet users increased quickly. Ability of human in using information was epoch-making, and it was increased through the Internet on behalf of an information-oriented society. As an Internet user hereby spreads explosively, legislations were established and revised to protect Internet users and consumers however, it is certain that the damages of Internet users are still increasing day by day. The purpose of this paper is to protect internet users and to reform the system. Also each portal site should provide fair information, and be responsible for conclusion of a contract. After they subdivide into personal service style, and analyze every situation and problems, they should improve problems.

• Proceedings of the Safety Management and Science Conference
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• 2008.04a
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• pp.157-179
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• 2008

This study demonstrates some major traits of digital contents as information, playfulness, individuality, perceived recognition as perceived usefulness and perceived ease of use, relationship quality as satisfaction and commitment, user behavior as use intention. To make an empirical analysis the study, it is hypothesized that traits of digital contents and perceived recognition, traits of digital contents and relationship quality, perceived recognition and relationship quality, relationship quality and user behavior. Proposed theoretical model was based on TAM and was tested by the structure equation model for validity, credibility, goodness of fit. The major finding of this study can be summarized as follows, traits of digital contents are positively affected by perceived recognition, satisfaction in relationship quality and use intention via perceived recognition. Theoretical implication of this study are as follows. First, users wanted to choice only needed information. Second, users recognized digital contents as a part of life. So, user's ability is very important in this environment. According to this, business related with or interested in digital contents must have developed digital contents in variety aspect. Users must have concerned using digital contents, also.

• The Journal of Information Systems
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• v.24 no.1
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• pp.147-168
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• 2015

Why people reduce or stop using social network services(SNS), which are regarded as a mean of relationship and communication, unlike the early trend? To explain the phenomenon, this study tries to predict psychological decision making process of users from perspectives of cognitive dissonance theory. From this perspective, this study attempted an integrative approach that reflected 'User's literacy' indicating the ability of individuals to use SNS, and 'negative mass media influence' such as media reports on side effects or the bad experiences of acquaintances, along with the 3 factors used in the SNS Prior research. This study conducted an empirical analysis by surveying 256 facebook users, and the major findings are as follows:- First, Social-overload, complexity, uncertainty and negative media influence are significantly affect dissonance on the use of SNS. Second, Dissonance on the use of SNS significantly affects the behavior that possibly reduces and limits the use of SNS. In other words, the users who have experienced psychological dissonance respond passively by avoiding the use of SNS to resolve the dissonance. Third, the moderating effect of User's literacy wasn't a significant. This study presents a clue to understand psychological decision making process of use of SNS and a guideline for establishing practical strategies. In addition, it is important to note that this study contributes to expansion of theoretical discussion about usage.

• The KIPS Transactions:PartA
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• v.19A no.3
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• pp.155-160
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• 2012

This paper designed a smartphone application with sequence problems which users can improve their learning ability and this application is implemented as serious game which is designed for the special purposes of education with entertainment and game-like fun at anytime and anywhere during the spare time. Also to prove learning effects through sequence of number application under ubiquitous environment which is popular these days, the proposed serious game which has various types of sequence questions is implemented based on the iphone and android environments. User characteristics and learning effects which are based on game record of proposed application are analyzed according to socio-demographic characteristics.

• Journal of Intelligence and Information Systems
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• v.6 no.1
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• pp.35-50
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• 2000

Diverse requirements of users on web-based model management force a system agent to develop user-adaptive building a model in reality and providing an adequate solution method of the model. The relationship between models is important knowledge for the agent to effectively build a new model to adaptively adjust an existing model under a problem and to efficiently connect the new model into an adequate solution method. Since the generating process of the inter-model relationship is more difficult than the building a new model however the process mostly depends on the knowledge of operation research experts. Without the adequate scheme of the inter-model relationship the burden of the management for the agent increases rapidly and the quality of the services may worsen. This study shows that meta-knowledge generated from relationship between models is important for the user to build a model in reality and to acquire the solver appropriate to the model. The relationship that consists of common and exclusive objects between models can be represented by frames. The system under development to implement the idea includes user-adaptive ability which identifies a model through forward chaining method and searches the solver appropriate to the model by using the meta knowledge. We illustrate the meta knowledge with an applied delivery system in supply chain management.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.8
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• pp.2606-2626
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• 2022

In this paper, a unmanned aerial vehicle (UAV) access deployment algorithm is proposed, which is based on an improved virtual force model to solve the poor coverage quality of UAVs caused by limited number of UAVs and random mobility of users in the deployment process of UAV base station. First, the UAV-adapted Harris Hawks optimization (U-AHHO) algorithm is proposed to maximize the coverage of users in a given hotspot. Then, a virtual force improvement model based on user perception (UP-VFIM) is constructed to sense the mobile trend of mobile users. Finally, a UAV motion algorithm based on multi-virtual force sharing (U-MVFS) is proposed to improve the ability of UAVs to perceive the moving trend of user equipments (UEs). The UAV independently controls its movement and provides follow-up services for mobile UEs in the hotspot by computing the virtual force it receives over a specific period. Simulation results show that compared with the greedy-grid algorithm with different spacing, the average service rate of UEs of the U-AHHO algorithm is increased by 2.6% to 35.3% on average. Compared with the baseline scheme, using UP-VFIM and U-MVFS algorithms at the same time increases the average of 34.5% to 67.9% and 9.82% to 43.62% under different UE numbers and moving speeds, respectively.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.17 no.2
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• pp.239-259
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• 2006

The purpose of this study is to propose some strategic directions which can promote the government libraries to provide the most effective and efficient information services. The study analyzes user opinion and demand in terms of the Web-based Information Services. For the analysis, the questionnaires were distributed to the 300 users in 18 government libraries. In the results, the study finds that the government libraries with homepage need to advertise homepage service. to provide the training programs, and to improve the system utility for better valuable homepage services. The government libraries without homepage, first of all, must construct their own homepage reflected in the users demand requiring the powerful retrieval ability, the diversity of contents, the high properness of information services.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.9
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• pp.403-408
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• 2015

Kinect sensors have the ability to recognize the behavior and voice of the user. Due to its low-cost and high accessibility, Kinect sensors have been used in various fields, including healthcare, education and so on. In this paper, we propose to use Kinect in piano education. Specifically, the proposed method first recognizes the coordinate values of user's posture, compares them with coordinate values of teacher's posture and provide real-time feedbacks to the user. This enables user to keep the correct posture even when he is learning piano without a teacher. However, since the piano education is a long process, it is difficult to achieve the correct posture as a teacher immediately. Thus, we propose a user-oriented method to measure the error tolerance rate. The proposed method is the first feedback based piano education system that uses Kinect sensors.