• Title/Summary/Keyword: 모바일 컴퓨팅(Mobile computing)

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Design and Implementation of iATA-based RAID5 Distributed Storage Servers (iATA 기반의 RAID5 분산 스토리지 서버의 설계 및 구현)

  • Ong, Ivy;Lim, Hyo-Taek
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.2
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    • pp.305-311
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    • 2010
  • iATA (Internet Advanced Technology Attachment) is a block-level protocol developed to transfer ATA commands over TCP/IP network, as an alternative network storage solution to address insufficient storage problem in mobile devices. This paper employs RAID5 distributed storage servers concept into iATA, in which the idea behind is to combine several machines with relatively inexpensive disk drives into a server array that works as a single virtual storage device, thus increasing the reliability and speed of operations. In the case of one machine failed, the server array will not destroy immediately but able to function in a degradation mode. Meanwhile, information can be easily recovered by using boolean exclusive OR (XOR) logical function with the bit information on the remaining machines. We perform I/O measurement and benchmark tool result indicates that additional fault tolerance feature does not delay read/write operations with reasonable file size ranged in 4KB-2MB, yet higher data integrity objective is achieved.

Development of GIS based Air Pollution Information System, using a Context Awareness Model (상황인지모델을 이용한 GIS 기반의 대기오염 정보시스템 개발)

  • Kim, Taehoon;Hong, Sungchul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.6
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    • pp.4228-4236
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    • 2015
  • Due to the rapid advance in web and mobile computing technologies, normal users have become to produce, provide, and share a varied form of spatial data and information. In the domain of spatial information, numerous researches on GIS have been conducted to provide spatial information services based on a geo-sensor network and a data integration and processing technology. However, to provide user-oriented information, a context information model is necessary to associate GIS data with web and sensor data. Context awareness services is designed to provide specific information, minimizing users' interference. For which, the context information model expresses the relationship of various data from sensor networks and mobile applications and provides a user-specific information considering location and area of interest. Thus, this research aims to develops a context information model based air-pollution information system that obtains and analyses air pollution data and reflects the analysis results on an air-pollution policy. Also, this system aims to raise citizens' awareness on air-pollution and to promote citizens' participatory to improve city's air quality.

Wine Label Character Recognition in Mobile Phone Images using a Lexicon-Driven Post-Processing (사전기반 후처리를 이용한 모바일 폰 영상에서 와인 라벨 문자 인식)

  • Lim, Jun-Sik;Kim, Soo-Hyung;Lee, Chil-Woo;Lee, Guee-Sang;Yang, Hyung-Jung;Lee, Myung-Eun
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.5
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    • pp.546-550
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    • 2010
  • In this paper, we propose a method for the postprocessing of cursive script recognition in Wine Label Images. The proposed method mainly consists of three steps: combination matrix generation, character combination filtering, string matching. Firstly, the combination matrix generation step detects all possible combinations from a recognition result for each of the pieces. Secondly, the unnecessary information in the combination matrix is removed by comparing with bigram of word in the lexicon. Finally, string matching step decides the identity of result as a best matched word in the lexicon based on the levenshtein distance. An experimental result shows that the recognition accuracy is 85.8%.

IPv6 Address Autoconfiguration for AODV in Mobile Ad Hoc Networks (이동 애드혹 네트워크 환경에서 AODV를 위한 IPv6 주소 자동 설정)

  • Ahn, Sang-Hyun;Kim, Young-Min;Lee, Young-Ju
    • Journal of KIISE:Computing Practices and Letters
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    • v.13 no.1
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    • pp.1-10
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    • 2007
  • An advantage of the mobile ad hoc network (MANET) is that mobile nodes can self-organize the network topology without the help of network infrastructure. However, for the perfect self-organization of the MANET, each mobile node needs to self-configure its address. Even though a mobile node configures a unique address during the booting time, its address may conflict with nodes in other MANETs since MANETs containing the same address can be merged. The address autoconfiguration protocol implemented in this work consists of the strong DAD (Duplicate Address Detection) and the weak DAD. A unique address of a node is assigned by the strong DAD during the booting time and the weak DAD is used to detect address conflict and resolve address conflict during the ad hoc routing. In this work, we have implemented address autoconfiguration in the IPv6-based MANET using AODV as the routing protocol. We describe how the IPv6 address autoconfiguration is implemented and verify our implementation by showing the test scenarios on our testbed.

Studies of the Efficiency of Wearable Input Interface (웨어러블 입력장치의 인터페이스 효율성에 관한 연구)

  • Lee, Seun-Young;Hong, Ji-Young;Chae, Haeng-Suk;Han, Kwang-Hee
    • Science of Emotion and Sensibility
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    • v.10 no.4
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    • pp.583-601
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    • 2007
  • The desktop interface is not suitable for the environment in which mobile devices are used commonly with moving, because much attention should be paid for it. And the miniaturizing of mobile devices increases the workload for using them, makes the operation speeds lower and makes more errors. So the study of appropriate level of the input interface for this changing environment is needed. In the aspect of mobile devices. input style and the complexity of the menu hierarchy, this study will look for the way to decrease the workload when doing some primary tasks and using mobile devices simultaneously with moving. The input style was classified into gesture input style, button input style, and pointing input style. The accuracy and speed were measured when doing dual tasks, including a menu searching task and a figure memory task, through one input style of three. By Changing the level of menu hierarchy in the menu searching task, the accuracy of task execution was examined. These Experiments were done in standing state and moving state. In both state the pointing input style was the highest in the accuracy of task execution but the slowest in the speed. In contrast, the gesture input style was not high in the accuracy but the fastest in the speed. This fact shows that the gesture input style is suitable for the condition needed for speedy processing rather than accurate execution when moving.

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A Distributed Proxy Server System for Wireless Mobile Web Service (무선 이동 웹 서비스를 위한 분산 프록시 서버 시스템의 설계 및 구현)

  • Lee, Hyuk-Joon;Kim, Dong-Won
    • The KIPS Transactions:PartC
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    • v.9C no.1
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    • pp.79-88
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    • 2002
  • Transcoding proxy strategy has been widely used as a means to reduce the delay in retrieving Web pages over wireless mobile data service networks. However, this strategy has the serious drawbacks of being a potential point of failure or a bottleneck of the service. We developed a distributed proxy server system in which multiple proxy servers are installed at geographically dispersed locations and share the workloads among them by serving mobile hosts only within assigned regions. A new handoff message protocol to enable handoffs between proxies as the mobile hosts move between regions is proposed. According to the proxy server handoff protocol, a client agent at the mobile horst requests a proxy server to start handoff processing by which two proxy servers synchronize distilled data belonging to a HTTP session that must be maintained across the handoff. Also, we introduce the architecture of the proxy server and the client agent that handles the proxy server handoff. Finally, we evaluate the proposed system through performance test.

Implementation of Mobile Computing based RFID Reconition System (모바일 컴퓨팅 환경의 RFID 인식 시스템 구현)

  • Jung, Sung-Hun;Lee, Bong-Keun;Yim, Jae-Hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.119-122
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    • 2005
  • RFID(Radio Frequency IDentification) is appearing by point technology by Ubiquitous environment of new paradigm and Logistics' application. But, RFID chip of this is high price and short bandwidth, low power and interference etc. can become technological problem. This is getting into obstacle in common use. Reader and tag, Embedded software etc.. that is accomplishing standardization is imported paying most expensive Royalty. This paper is RFID cognition system that use PDA in Ubiquitous environment to apply to Logistics system. RFID cognition system processes input/output of fundamental information attaching tag to Logistics of products. And RFID cognition system supports quick and correct and safe synthetic Logistics managerial system through construction of database. This can prove minimization and customer service of Logistics expense. RFID cognition system is advantage that can widen range of application to area that cognition system of existent fixing style can not do. Also, It can expect economical effect through inexpensive system construction.

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A study of Reference Model of Smart Library based on Linked Open Data (링크드오픈데이터 기반 스마트 라이브러리의 참조모델에 관한 연구)

  • Moon, Hee-kyung;Han, Sung-kook
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.9
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    • pp.1666-1672
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    • 2016
  • In recent years, smart technology has been applied to various information system fields. Especially, traditional library service area is changing to Smart-Library from Digital-Library. In this environment are need to library service software platform for supporting variety content, library services, users and smart-devices. Due to this, existing library service has a limitation that inhibits semantic interoperability between different heterogeneous library systems. In this paper, we propose Linked-Open-Data based smart library as an archetype of future-library system that provide a variety content and system interaction and integration of services. It is an innovative system of the cutting-edge information intensive. Therefore, we designed system environments according to various integration requirements for smart library based on Linked-Open-Data. And, we describe the functional requirements of smart-library systems by considering the users' demands and the eco-systems of information technology. In addition, we show the reference framework, which can accommodate the functional requirements and provide smart knowledge service to user through a variety of smart-devices.

Activity Recognition based on Multi-modal Sensors using Dynamic Bayesian Networks (동적 베이지안 네트워크를 이용한 델티모달센서기반 사용자 행동인식)

  • Yang, Sung-Ihk;Hong, Jin-Hyuk;Cho, Sung-Bae
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.1
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    • pp.72-76
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    • 2009
  • Recently, as the interest of ubiquitous computing has been increased there has been lots of research about recognizing human activities to provide services in this environment. Especially, in mobile environment, contrary to the conventional vision based recognition researches, lots of researches are sensor based recognition. In this paper we propose to recognize the user's activity with multi-modal sensors using hierarchical dynamic Bayesian networks. Dynamic Bayesian networks are trained by the OVR(One-Versus-Rest) strategy. The inferring part of this network uses less calculation cost by selecting the activity with the higher percentage of the result of a simpler Bayesian network. For the experiment, we used an accelerometer and a physiological sensor recognizing eight kinds of activities, and as a result of the experiment we gain 97.4% of accuracy recognizing the user's activity.

A Mobile P2P Message Platform Enabling the Energy-Efficient Handover between Heterogeneous Networks (이종 네트워크 간 에너지 효율적인 핸드오버를 지원하는 모바일 P2P 메시지 플랫폼)

  • Kim, Tae-Yong;Kang, Kyung-Ran;Cho, Young-Jong
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.10
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    • pp.724-739
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    • 2009
  • This paper suggests the energy-efficient message delivery scheme and the software platform which exploits the multiple network interfaces of the mobile terminals and GPS in the current mobile devices. The mobile terminals determine the delivery method among 'direct', 'indirect', and 'WAN' based on the position information of itself and other terminals. 'Direct' method sends a message directly to the target terminal using local RAT. 'Indirect' method extends the service area by exploiting intermediate terminals as relay node. If the target terminal is too far to reach through 'direct' or 'indirect' method, the message is sent using wireless WAN technology. Our proposed scheme exploits the position information and, thus, power consumption is drastically reduced in determining handover time and direction. Network simulation results show that our proposed delivery scheme improves the message transfer efficiency and the handover detection latency. We implemented a message platform in a smart phone realizing the proposed delivery scheme. We compared our platform with other typical message platforms from energy efficiency aspect by observing the real power consumption and applying the mathematical modeling. The comparison results show that our platform requires significantly less power.