• Title, Summary, Keyword: User

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Novel User Selection Algorithm for MU-MIMO Downlink System with Block Diagonalization (Block Diagonalization을 사용하는 하향링크 시스템에서의 MU-MIMO 사용자 스케쥴링 기법)

  • Kim, Kyunghoon
    • Journal of the Korea Society of Digital Industry and Information Management
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    • v.14 no.3
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    • pp.77-85
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    • 2018
  • Multi-User Multiple-Input Multiple-Output (MU-MIMO) is the core technology for improving the channel capacity compared to Single-User MIMO (SU-MIMO) by using multiuser gain and spatial diversity. Key problem for the MU-MIMO is the user selection which is the grouping the users optimally. To solve this problem, we adopt Extreme Value Theory (EVT) at the beginning of the proposed algorithm, which defines a primary user set instead of a single user that has maximum channel power according to a predetermined threshold. Each user in the primary set is then paired with all of the users in the system to define user groups. By comparing these user groups, the group that produces a maximum sum rate can be determined. Through computer simulations, we have found that the proposed method outperforms the conventional technique yielding a sum rate that is 0.81 bps/Hz higher when the transmit signal to noise ratio (SNR) is 30 dB and the total number of users is 100.

Feature Subset for Improving Accuracy of Keystroke Dynamics on Mobile Environment

  • Lee, Sung-Hoon;Roh, Jong-hyuk;Kim, SooHyung;Jin, Seung-Hun
    • Journal of Information Processing Systems
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    • v.14 no.2
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    • pp.523-538
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    • 2018
  • Keystroke dynamics user authentication is a behavior-based authentication method which analyzes patterns in how a user enters passwords and PINs to authenticate the user. Even if a password or PIN is revealed to another user, it analyzes the input pattern to authenticate the user; hence, it can compensate for the drawbacks of knowledge-based (what you know) authentication. However, users' input patterns are not always fixed, and each user's touch method is different. Therefore, there are limitations to extracting the same features for all users to create a user's pattern and perform authentication. In this study, we perform experiments to examine the changes in user authentication performance when using feature vectors customized for each user versus using all features. User customized features show a mean improvement of over 6% in error equal rate, as compared to when all features are used.

Ranking Decision Method of Retrieved Documents Using User Profile from Searching Engine (검색 엔진에서 사용자 프로파일을 이용한 문서 순위결정 방법)

  • Kim Yong-Ho;Kim Hyeong-Gyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.9
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    • pp.1590-1595
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    • 2006
  • This paper proposes a technique of user oriented document ranking using user refile to provide more satisfied results which reflect preference of specific users. User profile is constructed to represent his or her preference. User pfofile consists of 'term array' and 'preference vector' according to the interest field of one. And the User profile for a particular person is updated by 'user access', 'latent relaeon', 'User Profile' proposed in this paper. The latent structures of documents in same domain are analysed by singular value decomposition(SVD). Then, the rank of documents is determined by comparison of user profile with analyzed document on the basis of relevance.

A Method of Risk Assessment for Multi-Factor Authentication

  • Kim, Jae-Jung;Hong, Seng-Phil
    • Journal of Information Processing Systems
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    • v.7 no.1
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    • pp.187-198
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    • 2011
  • User authentication refers to user identification based on something a user knows, something a user has, something a user is or something the user does; it can also take place based on a combination of two or more of such factors. With the increasingly diverse risks in online environments, user authentication methods are also becoming more diversified. This research analyzes user authentication methods being used in various online environments, such as web portals, electronic transactions, financial services and e-government, to identify the characteristics and issues of such authentication methods in order to present a user authentication level system model suitable for different online services. The results of our method are confirmed through a risk assessment and we verify its safety using the testing method presented in OWASP and NIST SP800-63.

An Empirical Study of MIS CSF's for Small & Medium Business In Korea (우리 나라 중소기업 정보시스템의 성공요인에 대한 실증분석)

  • Ahn Jae-Young
    • Management & Information Systems Review
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    • v.3
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    • pp.399-417
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    • 1999
  • The purpose of this paper id to study the factors influencing MIS user satisfaction. For this purpose. I have reviewed the results of past studies on the performance factor of MIS, and introduced a new model associated with small & Medium Business. On the basis of this model, I have hypothesized that the following variables influence user satisfaction : (gender, age), individual characteristics(user attitude, training for user), managerial characteristic(top management involvement, organizational support) and task characteristics(task structure). There were 195 participants surveyed using questionnaires from 25 different small & medium Business in Pusan. The research model and associated hypotheses were tested by following statistical techniques: reliability test, regression, t-test and ANOVA. The findings of this study are follows; 1. It was found that gender and age are not correlated user satisfaction. 2. Among individual characteristics, only user attitude influence user satisfaction significantly. 3. While organizational supports influence positively user satisfaction, top management involvement do not influence it. 4. Task structure is highly correlated with user satisfaction. In spite of many factors affecting MIS success, this study did not consider all variables affect on user satisfaction. We need integrated model including more various factors.

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A Study on Building Structures and Processes for Intelligent Web Document Classification (지능적인 웹문서 분류를 위한 구조 및 프로세스 설계 연구)

  • Jang, Young-Cheol
    • Journal of Digital Convergence
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    • v.6 no.4
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    • pp.177-183
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    • 2008
  • This paper aims to offer a solution based on intelligent document classification to create a user-centric information retrieval system allowing user-centric linguistic expression. So, structures expressing user intention and fine document classifying process using EBL, similarity, knowledge base, user intention, are proposed. To overcome the problem requiring huge and exact semantic information, a hybrid process is designed integrating keyword, thesaurus, probability and user intention information. User intention tree hierarchy is build and a method of extracting group intention between key words and user intentions is proposed. These structures and processes are implemented in HDCI(Hybrid Document Classification with Intention) system. HDCI consists of analyzing user intention and classifying web documents stages. Classifying stage is composed of knowledge base process, similarity process and hybrid coordinating process. With the help of user intention related structures and hybrid coordinating process, HDCI can efficiently categorize web documents in according to user's complex linguistic expression with small priori information.

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Attribute based User Authentication for Contents Distribution Environments

  • Yoo, Hye-Joung
    • International Journal of Contents
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    • v.8 no.3
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    • pp.79-82
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    • 2012
  • In digital contents distribution environments, a user authentication is an important security primitive to allow only authenticated user to use right services by checking the validity of membership. For example, in Internet Protocol Television (IPTV) environments, it is required to provide an access control according to the policy of content provider. Remote user authentication and key agreement scheme is used to validate the contents accessibility of a user. We propose a novel user authentication scheme using smart cards providing a secure access to multimedia contents service. Each user is authenticated using a subset of attributes which are issued in the registration phase without revealing individual's identity. Our scheme provides the anonymous authentication and the various permissions according to the combination of attributes which are assigned to each user. In spite of more functionality, the result of performance analysis shows that the computation and communication cost is very low. Using this scheme, the security of contents distribution environments in the client-server model can be significantly improved.

A Robust Mutual Authentication between User Devices and Relaying Server(FIDO Server) using Certificate Authority in FIDO Environments

  • Han, Seungjin
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.10
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    • pp.63-68
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    • 2016
  • Recently, Biometrics is being magnified than ID or password about user authentication. However, unlike a PIN, password, and personal information there is no way to modify the exposure if it is exposed and used illegally. As FIDO(Fast IDentity Online) than existing server storing method, It stores a user's biometric information to the user device. And the user device authentication using the user's biometric information, the user equipment has been used a method to notify only the authentication result to the server FIDO. However, FIDO has no mutual authentication between the user device and the FIDO server. We use a Certificate Authority in order to mutually authenticate the user and the FIDO server. Thereby, we propose a more reliable method and compared this paper with existed methods about security analysis.

User Modeling Using User Preference and User Life Pattern Based on Personal Bio Data and SNS Data

  • Song, Hyejin;Lee, Kihoon;Moon, Nammee
    • Journal of Information Processing Systems
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    • v.15 no.3
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    • pp.645-654
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    • 2019
  • The purpose of this study was to collect and analyze personal bio data and social network services (SNS) data, derive user preference and user life pattern, and propose intuitive and precise user modeling. This study not only tried to conduct eye tracking experiments using various smart devices to be the ground of the recommendation system considering the attribute of smart devices, but also derived classification preference by analyzing eye tracking data of collected bio data and SNS data. In addition, this study intended to combine and analyze preference of the common classification of the two types of data, derive final preference by each smart device, and based on user life pattern extracted from final preference and collected bio data (amount of activity, sleep), draw the similarity between users using Pearson correlation coefficient. Through derivation of preference considering the attribute of smart devices, it could be found that users would be influenced by smart devices. With user modeling using user behavior pattern, eye tracking, and user preference, this study tried to contribute to the research on the recommendation system that should precisely reflect user tendency.

Balancing Fun and Learning through a User Interface: A Case Study of Wii Game

  • Kim, Si Jung;Lee, Kichol;Park, Yeonjeong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.7
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    • pp.3638-3653
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    • 2019
  • Designing a user interface is important because the user interface determines the level of physical and mental engagement of the user resulting in their level of learning. This paper investigated how physical engagement through a different user interfaces is associated with fun and learning and presented a theoretical physical engagement model called, PEM, developed based on an empirical user study. The PEM model describes how a game user interface is associated with the level of fun and learning, particularly in playing a full body engaged game. There are many different types of games but the Wii Tennis, an embodied interactive game, was chosen as an instance of full body engaged game. A user study with 32 participant's age ranged from 21 to 40 years old revealed that there is a positive correlation between both fun and learning and the level of physical engagement through two different user interfaces. The results of the study showed that the extent of fun and learning are associated with the physical engagement of the player through an interface. As an implication from the study, the result recommend that the level of user engagement is realized by an effective user interface, and the level of physical engagement is determined by the level of authenticity bridged by the user interface.