• Title, Summary, Keyword: User Distribution

Search Result 940, Processing Time 0.04 seconds

Performance of ZF Precoder in Downlink Massive MIMO with Non-Uniform User Distribution

  • Kong, Chuili;Zhong, Caijun;Zhang, Zhaoyang
    • Journal of Communications and Networks
    • /
    • v.18 no.5
    • /
    • pp.688-698
    • /
    • 2016
  • In this paper, we investigate the achievable sum rate and energy efficiency of downlink massive multiple-input multiple-output antenna systems with zero-forcing precoding, by taking into account the randomness of user locations. Specifically, we propose two types of non-uniform user distributions, namely, center-intensive user distribution and edge-intensive user distribution. Based on these user distributions, we derive novel tight lower and upper bounds on the average sum rate. In addition, the impact of user distributions on the optimal number of users maximizing the sum rate is characterized. Moreover, by adopting a realistic power consumption model which accounts for the transmit power, circuit power and signal processing power, the energy efficiency of the system is studied. In particular, closed-form solutions for the key system parameters, such as the number of antennas and the optimal transmit signal-to-noise ratio maximizing the energy efficiency, are obtained. The findings of the paper suggest that user distribution has a significant impact on the system performance: for instance, the highest average sum rate is achieved with the center-intensive user distribution, while the lowest average sum rate is obtained with the edge-intensive user distribution. Also, more users can be served with the center-intensive user distribution.

Attribute based User Authentication for Contents Distribution Environments

  • Yoo, Hye-Joung
    • International Journal of Contents
    • /
    • v.8 no.3
    • /
    • pp.79-82
    • /
    • 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.

Dynamic Adaptive Model based on Probabilistic Distribution Functions and User's Profile for Web Media Systems (웹 미디어 시스템을 위한 확률 분포 함수와 사용자 프로파일에 기반 한 동적 적응 모델)

  • Baek, Yeong-Tae;Lee, Se-Hoon
    • The Journal of Korean Association of Computer Education
    • /
    • v.6 no.1
    • /
    • pp.29-39
    • /
    • 2003
  • In this paper we proposed dynamic adaptive model based on discrete probabilistic distribution functions and user's profile for web media systems(web based hypermedia systems). The model represented that the application domain is modelled using a weighted direct graph and the user's behaviour is modelled using a probabilistic approach that dynamically constructs a discrete probability distribution functions. The proposed probabilistic interpretation of the web media structure is used to characterize latent properties of the user's behaviour, which can be captured by tracking user's browsing activity. Using that distribution the system attempts to assign the user to the best profile that fits user's expectations.

  • PDF

An Analysis and Visualization of Creative Tendency appeared in Query Log of a Story Database Service (스토리 검색 서비스의 사용자 기록에 나타난 창작 성향 분석 및 가시화)

  • Kim, Myoung-Jun
    • Journal of Korea Multimedia Society
    • /
    • v.19 no.8
    • /
    • pp.1609-1618
    • /
    • 2016
  • is a service providing the story synopses that match user's query. This paper analyzes the user log of which is the answers to the queries to find stories from database, and shows the tendency distribution of user creation. Specially, we analyze a joint distribution of the genres and actions of stories to get better understanding of the tendencies that cannot be found in the analysis of independent distribution. Furthermore, we define a correlation factor between genre and action, and investigate what combinations of the genres and actions are highly, less, and negatively correlated. Finally, we investigate how the tendencies of characters are related to genres and actions, and propose a visualization method to show the tendencies.

An Adaptive Approach to Learning the Preferences of Users in a Social Network Using Weak Estimators

  • Oommen, B. John;Yazidi, Anis;Granmo, Ole-Christoffer
    • Journal of Information Processing Systems
    • /
    • v.8 no.2
    • /
    • pp.191-212
    • /
    • 2012
  • Since a social network by definition is so diverse, the problem of estimating the preferences of its users is becoming increasingly essential for personalized applications, which range from service recommender systems to the targeted advertising of services. However, unlike traditional estimation problems where the underlying target distribution is stationary; estimating a user's interests typically involves non-stationary distributions. The consequent time varying nature of the distribution to be tracked imposes stringent constraints on the "unlearning" capabilities of the estimator used. Therefore, resorting to strong estimators that converge with a probability of 1 is inefficient since they rely on the assumption that the distribution of the user's preferences is stationary. In this vein, we propose to use a family of stochastic-learning based Weak estimators for learning and tracking a user's time varying interests. Experimental results demonstrate that our proposed paradigm outperforms some of the traditional legacy approaches that represent the state-of-the-art technology.

문헌정보학의 학문적 역할 및 위치 -이용자 연구 중심의 문헌정보학-

  • 박홍석
    • Journal of Korean Library and Information Science Society
    • /
    • v.26
    • /
    • pp.505-540
    • /
    • 1997
  • The library collects relevant documents, organizes these documents, retrieves and provides relevant documents, and helps the user use provided documents. These library activities are the distribution process of relevant documents in a society, and the role of library science is to deal with several problems in this process. This process is to facilitate the production of socially relevant documents, to select documents relevant to an individual user, and to enable the user to use the selected documents. As a result, this process should be based on the concept of "relevance". As a result, the academic role of library science should be considered based on "relevance". "Relevance" is getting more important to meet the change of the environment of library services, which is getting more complex and changing rapidly because of the computer and the computer network. It is true that these are very important tool for document distribution. However, the problems in the document distribution can not be solved only by the simple development of these tools because these have been caused by the simple development of these tools. These problems can be solved only through many studies of the user, which is the destination of document distribution, and through a n.0, pplying the results of these studies to designing these tools.dies to designing these tools.

  • PDF

Analysis of Requirements Using Quality Function Deployment (QFD) in Virtual Reality(VR) (가상현실(VR)에서 품질기능전개(QFD)를 활용한 요구사항 분석)

  • Park, Jihye;Kim, Mincheol
    • The Journal of Distribution Science
    • /
    • v.17 no.2
    • /
    • pp.101-107
    • /
    • 2019
  • Purpose - The purpose of this study is to analyze the user requirements and developer requirements in virtual reality(VR), and suggest ways to increase the satisfaction of users who experience virtual reality. Specifically, focused on experience store of VR as a distribution retailer, user requirements were analyzed according to the results of previous research that the characteristics of Affordance, Presence, and Head Mounted Display (HMD) affect user satisfaction. Research, design, data, and methodology - Based on previous studies, in this study, we analyzed the importance of immerse, interaction, perception, and presence for the satisfaction of the user through the questionnaire, and the user experiences virtual reality (VR) The importance of HMD, Presence, Affordance, and experience satisfaction were analyzed. Based on this, we analyzed the user requirements and the developer requirements based on the questionnaires and interviews of the experts, starting from the user's desire or preference using QFD technique. Results - As a result of the analysis, the development factors that occupied a big part in the virtual reality field appeared to be visual. In detail, this showed that there was a lack of sense of presence for users. This should be improved. This paper shows that the requirements for visual, auditory, and tactile development are necessary. For the satisfaction of the users of virtual reality (VR) users, it is necessary to develop them according to their priority in consideration of importance and difficulty in the future. Conclusions - In this study, it was suggested that development according to priority should be considered, considering the difficulty level. Based on the results of this study, the following suggestions are made. First, we tried to search the list of user requirements as much as possible, but it is likely to change due to the development of VR technology. Therefore, it is necessary for developers to continually supplement user requirements with recent research literature. Second, development priorities according to difficulty level should be considered. This aspect should be considered in the actual VR development process, so if the numerical value of the difficulty is calculated, it should be presented in the research.

Method for Designing Adaptive UI Based on User's Context in the Environment Including Mobile Device and Public Display Device (모바일 장치와 공용 디스플레이 장치를 포함하는 환경에서 사용자의 특성에 기반한 Adaptive UI 설계 방안)

  • Kang, Seung-Soo;Ko, Hyun;Youn, Hee Yong
    • Journal of Information Technology Services
    • /
    • v.11 no.4
    • /
    • pp.181-194
    • /
    • 2012
  • The one of the most meaningful change in the recent ubiquitous environment is the omnipresence of public digital display device for providing ubiquitous information. It is the important issue to provide publicity as well as adaptive information to each user in the field of the public digital display device. This research proposes the idea ensuring fast response speed by the selection of user preference function. The preference function is selected by statistics using Zipf distribution in the system comprising mobile device and digital display device based on NFC (Near Field Communication). The idea is proved by CPM-GOMS model and the improvement of user response can be achieved.

The Effect of Congruency between User Participation and Producer Response on User Generated Content (컨텐츠 유통 플랫폼에서 이용자 참여와 생산자 반응의 적합성 효과에 관한 연구)

  • Son, Jung-Min;Lee, Jun-Seop
    • The Journal of Distribution Science
    • /
    • v.13 no.8
    • /
    • pp.73-80
    • /
    • 2015
  • Purpose - This study's objective is to analyze the content of the communications between users and producers based on the construal level theory. User generated content refers to content created in an online-based service where users and producers communicate interactively with each other. In a user generated content platform, the messages sent and received between the many players, the users and producers who use the content, may be analyzed at the psychological level based on construal level theory. Research design, data, and methodology - This study gathered user and producer participation through a snow-bowling sampling method. The data analyzed includes 125 video clips and 2,912 comments. The period of the data collection was from September 2014 to December 2014. The collected data was analyzed using a t-test and two-way ANOVA. Results - This study obtained the following research results. First, users who were a short social distance from producers responded to user participatory activities stated in concrete language rather than abstract language. In contrast, users who were at a longer social distance from producers tended to respond to the content requesting user participation through abstract language. Second, if users and producers were at a short social distance from each other, user preference increased more when a producer response to user participation was expressed concretely rather than when it was expressed abstractly. In contrast, if the users were at a longer social distance, users' preferences increased more when producer response was expressed abstractly rather than when it was expressed concretely. Conclusion - This study found that the effect of suitability, in which the social distance and the content were in congruence at the construal level, could be observed. Therefore, based on this, academic and practical implications were drawn. The three main insights of the study are as follows. First, firms can use psychological factors to analyze the message content of users in their distribution platforms. This study reveals managerial implications for marketing managers who want to take make use of this analysis of user and producer communications. This study indicates that the main factors include the concrete and abstract scores and social distance between users and producers. Second, we also provide the strategic guidelines to maximizing user preferences and other outcomes. The main dependent variable in this study is the user preference shift; the variable increases through the congruence effect; and the construal level is determined by the social distance between the users and producers and the type of producer response. The outcomes here from users can be utilized to develop several systemic strategies. One process to use the outcomes could be: (1) firms could measure the users and producers social distance; (2) calculate the concreteness or abstractness of the messages; and, (3) predict the user preference outcomes by the congruence between user and producer social distance and the abstractness or concreteness of the message content.

A Design and Implementation of DRM System by Applying System Authentication Method (시스템 인증기법을 적용한 DRM 시스템 설계 및 구현)

  • Jang, Eun Gyeom;Lee, Bum Suk
    • Journal of the Korea Society of Digital Industry and Information Management
    • /
    • v.5 no.2
    • /
    • pp.177-184
    • /
    • 2009
  • The digital contents distribution system via network provides comfortability, usability, and diversified functions to content's users. However, for the characteristic of easy access of digital contents, the copyright infringements and indiscreet contents distribution are realized in this days. In other words, any users with the authentication key can access to copyright contents with any restrictions. To solve this problems, we proposed a user authentication mechanism which prevent indiscreet access to the digital content by using user system information. Also, to provide safe distribution of digital content, we used user's unique content authentication key.