• Title/Summary/Keyword: mobile systems

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Position Location of Mobile Terminal in Wireless MIMO Communication Systems

  • Li, Ji;Conan, Jean;Pierre, Samuel
    • Journal of Communications and Networks
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    • v.9 no.3
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    • pp.254-264
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    • 2007
  • A promising approach to improve the performance of mobile location system is the use of antenna arrays in both transmitter and receiver sides. Using advanced array signal processing techniques, such multiple-input multiple-output (MIMO) communication systems can offer more mobile location information by exploiting the spatial properties of the multipath channel. In this paper, we propose a novel approach to determine the position of mobile terminal based on estimated multipath signal parameters using only one base station in MIMO communication systems. This approach intends to minimize the error occurring from the estimation of multiple paths and gives an optimal estimation of the position of mobile terminal by simultaneously calculating a set of nonlinear location equations. This solution breaks the bottleneck of conventional mobile location systems which have to require multilateration of at least three base stations.

Design and Specification of an Election Algorithm in Mobile Ad Hoc Distributed Systems (모바일 애드 혹 분산 시스템에서 선출 알고리즘의 명세 및 설계)

  • Park, Sung-Hoon
    • Journal of Digital Contents Society
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    • v.11 no.4
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    • pp.453-461
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    • 2010
  • Specifying and designing the election algorithm in mobile ad hoc distributed systems is very difficult task. It is because mobile ad hoc systems are more prone to failures than conventional distributed systems. The aim of this paper is to propose a specification and design of the election algorithm in a specific ad hoc mobile computing environment. For this aim, we specify and design an election algorithm in this paper. In addition, we formally verify it and show that it is correct. This solution is based on the nodes detection algorithm that is a classical one for synchronous distributed systems.

An Integrative Framework for Determining a Dominant Design : Focused on the Mobile Operating Systems (모바일 OS에서 지배적 디자인을 결정하는 요인의 통합적 프레임워크에 관한 연구)

  • Yoon, Inhwan;Lee, Heesang;Jung, Chul-Ho
    • Journal of Information Technology Applications and Management
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    • v.21 no.4_spc
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    • pp.309-329
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    • 2014
  • This paper proposes an integrative framework for determining a dominant design in the mobile operation systems. A dominant design has emerged as a de facto standard from traditional industries to ICT. ICT-related industries have been reorganized around the mobile industry in which the mobile operation system can be seen as a strategical keystone. In this paper, we develop a holistic approach for the emergence of a dominant design in the mobile operation systems. Firstly, we combined an integrative framework based on previous research findings with new determinants derived from cases of the mobile operation systems. Secondly, we categorized all determinants according to technological, firm-level and environmental factors within our proposed framework. Finally, we compared this framework to patterns coded from cases which include Android and iOS. This results show that a dominant design is likely to emerge as a result of the interaction of the determinants, not the influence of a single determinant. Furthermore, our proposed framework may extend the existing literature on dominant designs in both researchers and practitioners and provide implications to actors for establishing a competition strategy in the mobile telecommunication ecosystems.

A Study on the Factors Influencing Mobile Service Usage (모바일 서비스 사용의 영향 요인에 관한 연구)

  • Moon Hyun-Pil;Ok Seok-Jae
    • The Journal of Information Systems
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    • v.14 no.2
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    • pp.133-154
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    • 2005
  • The objective of this study is to find the factors influencing the use of mobile service. We extracted critical study variables according to literature reviews about adoption of information systems, those under the internet environment and mobile internet adoption for theoretical foundation. TAM suggested by Davis(1985) has explained the acceptance mechanism with the following constructs: perceived usefulness, perceived ease of use, attitude toward use, behavioral intention and actual usage. After studying prior literature reviews, this study investigated the group of people using mobile services. The result of study claims that it has same results with previous TAM, especially between personal innovativeness and attitude toward use have strong statistical relations. On the other hand, there haven't been any statistical relations between perceived ease of use and perceived usefulness and between perceived usefulness and behavioral intention, either. In conclusion, use of mobile service can be promoted by developing various kinds of mobile service, designing device and interface to use mobile service more convenience and familiar, stimulating user's innovative characters and recognizing mobile service more useful in real life.

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A Fault Management Architecture Using Backup FA in Hierarchical Local Registration Mobile IP (계층적 지역 등록 Mobile IP에서 백업 FA를 이용한 장애 관리 구조)

  • 임기운;홍충선;이대영
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.11C
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    • pp.1-9
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    • 2001
  • The Mobile IP protocol allows IP hosts to move between different networks without changing their IP addresses. The Mobile IP systems supporting the local registration were introduced to reduce the number of times when a home registration with the remotely located Home Agent is needed. The local registration Mobile IP protocol enhanced the performance by processing the MN\`s registration requests at a local agent. However. the local registration approach may consider other aspects of the Mobile IP systems as the FA fault tolerance. In this paper, we will briefly review previous protocols to support the FA fault tolerance in hierarchical local registration Mobile If system and will propose a fault tolerance protocol with backup FA in hierarchical local registration mobile IP t() enhance the efficiency of such systems against Foreign Agent failures.

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The Design of the Selection and Alignment Queries Using Mobile Program (J2ME) for Database Query Optimization

  • Ko, Wan-Suk;Min, Cheon-Hong
    • 한국디지털정책학회:학술대회논문집
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    • 2003.12a
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    • pp.263-273
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    • 2003
  • Recognizing the importance of the database query optimization design methods, we implemented mobile database with mobile program (J2ME) which is a useful database procedures. In doing so, we emphasize the logical query optimization which brings mobile database to performance improvement. The research implies that the suggested mobile program (J2ME) would contribute to the realization of the efficient mobile database as the related technology develops in the future.

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Research on Commercialization of IP-based CDMA Mobile Communication Systems (IP 기반의 CDMA 이동통신 시스템 상용화 사례 연구)

  • Yi, Seung-Hee
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.350-354
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    • 2008
  • IP-based mobile communication system is one of the key research items in the mobile networks for a long time. But, due to some technical issues and no need of markets, it is still not full-fledged. Recently, CDMA and WCDMA service providers want to introduce IP-based network connectivity. Even though their efforts, the main network intra-structure depends on ATM or HDLC technology. This article describes a good example of commercialization of IP-based mobile communication systems. Our research is not experimental system but a in-service system - replacing the existing equipments with new IP-based systems. In this paper, we introduce IP related technologies used in our research such as IP-based ATCA(Advanced Telecommunications Computing Architecture) platform, HA(High Availability) redundancy, IP multicast, network redundancy techniques, multi-link bundling and IP header compression. These are already well-known to internet domain. We mix them with mobile communication systems concretely.

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Accuracy Analysis for a Mobile Mapping System

  • Lee, Seung-Yong;Kim, Seong-Baek;Choi, Ji-Hoon;Jang, Byoung-Tae
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.603-605
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    • 2003
  • Constructing a geo-spatial database of Graphic Information Systems(GIS) in various applications is suffering from the difficulty of data acquisition, which is labor-intensive and time consuming. In order to provide the spatial data rapidly and accurately, 4S-Van, a prototype mobile mapping system, has been developed. This paper presents a novel approach for an analysis for Mobile Mapping Systems. Furthermore, we discuss the accuracy of measurements using images acquired from the 4S-Van. The first part of this paper introduces accuracies of other mobile mapping systems. Then, we describe main features of the 4S-Van and our proposed method for an analysis accuracies, which can be applicable to other mobile mapping systems. The last part of paper concludes with a summary and our suggestions for implementation of mobile mapping system.

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Can Coupon Holding Duration and Message Framing Increase the Effect of Push Notifications on Mobile Coupon Redemption? Evidence from A Randomized Field Experiment

  • Soonki Hwang;Jai-Yeol Son;Sunju Park;Kil-Soo Suh
    • Asia pacific journal of information systems
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    • v.33 no.3
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    • pp.812-830
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    • 2023
  • We propose a mobile coupon strategy designed to increase the effect of push notifications on redemption. The proposed strategy recommends that firms deliver mobile coupons with distant expiration dates and remind them through push notifications framed negatively once these expiration dates become imminent, rather than frequently sending coupons with near expiration dates. We test the effectiveness of the proposed strategy using data collected through a randomized field experiment. The findings indicate that push notifications enhance coupon redemption rates for coupons that are held longer by customers than those that are recently received. Additionally, we found that sending negatively framed push notification messages to remind customers of imminent coupon expiration dates further resulted in higher coupon redemption rates. The findings can be employed to offer useful guidance on how to effectively design mobile coupons for achieving higher redemption rates.

Design of Fuzzy Logic Control System for Segway Type Mobile Robots

  • Kwak, Sangfeel;Choi, Byung-Jae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.15 no.2
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    • pp.126-131
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    • 2015
  • Studies on the control of inverted pendulum type systems have been widely reported. This is because this type of system is a typical complex nonlinear system and may be a good model to verify the performance of a proposed control system. In this paper, we propose the design of two fuzzy logic control systems for the control of a Segway mobile robot which is an inverted pendulum type system. We first introduce a dynamic model of the Segway mobile robot and then analyze the system. We then propose the design of the fuzzy logic control system, which shows good performance for the control of any nonlinear system. In this paper, we here design two fuzzy logic control systems for the position and balance control of the Segway mobile robot. We demonstrate their usefulness through simulation examples. We also note the possibility of simplifying the design process and reducing the computational complexity. This possibility is the result of the skew symmetric property of the fuzzy rule tables of the system.