• Title/Summary/Keyword: mobility features

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A Study on a Multi-path ATP Protocol at Ad-hoc Networks (Ad-hoc 네트워크에서 다중경로를 지원하는 ATP 프로토콜에 대한 연구)

  • Lee, Hak-Ju;Jang, Jae-Shin;Lee, Jong-Hyup
    • Journal of the Korea Society for Simulation
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    • v.18 no.3
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    • pp.123-131
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    • 2009
  • Wireless networks have several unique features : node mobility, restricted bandwidth, time-variable bandwidth, large latency, and high bit error rates time due to channel fading. These features at wireless networks intend to decrease the performance TCP protocols are used in wireless networks. Lots of studies have been done for finding appropriate wireless transport protocols for current wireless communications. However, related studies have not provided good performance or some protocols have a good performance only in specific circumstances. Thus, these are not suitable for general wireless circumstance. Therefore, we propose a new wireless transport protocol which provides better performance than the previous ones. And we'd like to solve a problem that previous protocols cannot maintain their connections even though they have multiple paths until another path is successfully set up. To solve these problems, a new protocol ATP-M is proposed which is designed on already known TCP-M and ATP protocols. With NS-2 computer simulation, it is shown that this newly proposed protocol has better system throughput than TCP, TCP-M and ATP protocols.

A Study on the Purchase Decision Structure of Mobile Multimedia Service (이동 멀티미디어 서비스에 대한 구매의사 결정구조에 관한 연구)

  • Nam Dae-kyeong;Jeon Hyo-ri;Choi Mun-kee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.7B
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    • pp.499-506
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    • 2005
  • In this paper, mobile multimedia service is defined as a service which is used for Internet or multimedia contents without regard to place in the mobile or wireless environment. The purpose of this paper is to search consumer's purchase decision factors by means of literature review and expert's opinion and to analyze a purchase decision structure and its weight. Some implications were found. Firstly, mobile multimedia service purchase factors relating to cost and quality are more important than external causes. Secondly, cost is more important than quality, that is different from result of mobile telecommunication and high-speed Internet service. Thirdly, direct effect such as pertinent charging and terminal price is more important than indirect effect such as pricing differentiation. Finally, main features of service such as mobility and contents are more important than additional characteristics such as personalized service.

A Promising Treatment for Broncholith Removal Using Cryotherapy during Flexible Bronchosopy: Two Case Reports

  • Lee, Jong Hwan;Ahn, Joong Hyun;Shin, Ah Young;Kim, Sung Jin;Kim, Sung Jun;Cho, Gu-Min;Oh, Hyun Jin;Kim, In Ho;Kim, Ju Sang
    • Tuberculosis and Respiratory Diseases
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    • v.73 no.5
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    • pp.282-287
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    • 2012
  • Broncholiths are defined as calcified materials that occur in a tracheobronchial tree or in a cavity communicating with that. Broncholith has variable clinical features. The therapeutic options to remove broncholiths are so variable that clinicians need to select the most safe and effective methods by mass size, mobility, and location. As yet, there is no consistent guideline removing a broncholith. We report 2 successful cases of removing a fixed broncholith by flexible bronchoscopy guided cryoadhesion. With repeated technique of thawing and freezing with cryoprobe, we could extract the fixed broncholith safely. This method is promising as a way to remove broncholith in the future.

Method for Joining Mobile Nodes in Wireless Sensor Networks using Dynamic Hysteresis (무선 센서 네트워크에서 동적 히스테리시스 특성을 이용한 이동 노드의 가입 방법)

  • Lee, Jae-Hyung;Lee, Eung-Soo;Kim, Dong-Sung
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.4
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    • pp.68-76
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    • 2011
  • In this paper, we propose a method for joining mobile nodes in wireless sensor networks using hysteresis features. It is possible to use static hysteresis, whereby joining and withdrawal are carried out repeatedly when a mobile node is located at boundary points. The energy consumption of the nodes can be effectively managed by a decrease in the response packets of the neighbors under the joining requests of the mobile nodes. However, static hysteresis causes a decrease in the joining rate. In order to increase the joining rate, dynamic hysteresis is used. To evaluate the performance of the proposed technique, the joining rate is investigated and analyzed. Simulation results show that the proposed method enables efficient joining according to the mobility of nodes in wireless sensor networks.

An Entropy-based Dynamic Routing Protocol for Supporting Effective Route Stability in Mobile Ad-hoc Wireless Sensor Networks (모바일 Ad-hoc 무선 센서 네트워크에서 효과적인 경로 안정성을 지원하기 위한 엔트로피 기반 동적 라우팅 프로토콜)

  • An, Beongku
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.6
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    • pp.29-34
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    • 2008
  • In this paper, we propose an entropy-based dynamic routing protocol for supporting effective route stability in mobile ad-hoc wireless sensor networks(MAWSN). The basic ideas and features are as follows. First, construction of entropy-based stable routing route using mobility of nodes between a source node and a destination node. Second, usage of location and direction information for route construction to support resource saving. Third, We consider a realistic approach, in the points of view of the MAWSN, based on mobile sensor nodes as well as fixed sensor nodes in sensor fields while the conventional research for sensor networks focus on mainly fixed sensor nodes. The performance evaluation of the proposed routing protocol is performed via simulation using OPNET. The simulation results show the proposed routing protocol can effectively support route stability and packet delivery ratio.

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Remote O2 plasma functionalization for integration of uniform high-k dielectrics on large area synthesized few-layer MoSe2

  • Jeong, Jaehun;Choi, Yoon Ho;Park, Dambi;Cho, Leo;Lim, Dong-Hyeok;An, Youngseo;Yi, Sum-Gyun;Kim, Hyoungsub;Yoo, Kyung-Hwa;Cho, Mann?Ho
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.281.1-281.1
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    • 2016
  • Transition metal dichalcogenides (TMDCs) are promising layered structure materials for next-generation nano electronic devices. Many investigation on the FET device using TMDCs channel material have been performed with some integrated approach. To use TMDCs for channel material of top-gate thin film transistor(TFT), the study on high-k dielectrics on TMDCs is necessary. However, uniform growth of atomic-layer-deposited high-k dielectric film on TMDCs is difficult, owing to the lack of dangling bonds and functional groups on TMDC's basal plane. We demonstrate the effect of remote oxygen plasma pretreatment of large area synthesized few-layer MoSe2 on the growth behavior of Al2O3, which were formed by atomic layer deposition (ALD) using tri-methylaluminum (TMA) metal precursors with water oxidant. We investigated uniformity of Al2O3 by Atomic force microscopy (AFM) and Scanning electron microscopy (SEM). Raman features of MoSe2 with remote plasma pretreatment time were obtained to confirm physical plasma damage. In addition, X-ray photoelectron spectroscopy (XPS) was measured to investigate the reaction between MoSe2 and oxygen atom after the remote O2 plasma pretreatment. Finally, we have uniform Al2O3 thin film on the MoSe2 by remote O2 plasma pretreatment before ALD. This study can provide interfacial engineering process to decrease the leakage current and to improve mobility of top-gate TFT much higher.

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Comprehensive analysis of AHL homologous genes encoding AT-hook motif nuclear localized protein in rice

  • Kim, Ho-Bang;Oh, Chang-Jae;Park, Yung-Chul;Lee, Yi;Choe, Sung-Hwa;An, Chung-Sun;Choi, Sang-Bong
    • BMB Reports
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    • v.44 no.10
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    • pp.680-685
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    • 2011
  • The AT-hook motif is a small DNA-binding protein motif that has been found in the high mobility group of non-histone chromosomal proteins. The Arabidopsis genome contains 29 genes encoding the AT-hook motif DNA-binding protein (AHL). Recent studies of Arabidopsis genes (AtAHLs) have revealed that they might play diverse functional roles during plant growth and development. In this report, we mined 20 AHL genes (OsAHLs) from the rice genome database using AtAHL genes as queries and characterized their molecular features. A phylogenetic tree revealed that OsAHL proteins can be classified into 2 evolutionary clades. Tissue expression pattern analysis revealed that all of the OsAHL genes might be functionally expressed genes with 3 distinct expression patterns. Nuclear localization analysis using transgenic Arabidopsis showed that several OsAHL proteins are exclusively localized in the nucleus, indicating that they may act as architectural transcription factors to regulate expression of their target genes during plant growth and development.

Experimental Design Depicted on Hussein Chalayan' Works (Hussein Chalayan의 실험적 디자인)

  • 장애란
    • Journal of the Korean Society of Costume
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    • v.52 no.5
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    • pp.91-107
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    • 2002
  • The purpose of this study was to investigate the experimental design by using deconstructive design and mobile design depicted on Hussein Chalayan' works. Hussein Chalayan, the Turkish-Cypriot who is based in London, says' Challenging is the best word for me'. And so word, 'radical' that has difficult connotations was chosen for this study It implies two menainigs for the word. The first thing is "extreme" - something that is drastic. And 'Applied to clothes', it can probably mean "experimental". He has iconoclastic ideas and his ramp shows are always high on concept, experimentation of art and utility. His approach to fashion derives from philosophical and intellectual theories of deconstruction and mobility, which he expresses through his designs. Deconstructionism, in fashion, rejects customary rules and breaks all conventions. It questions aesthetic norms about bodily proportions and the criteria of beauty, emphasizes the adding on, or discovery of, an irrational moment, and reveals the processes of tailoring in clothing. The shape and the construction of the garment is more important than the color. Cuts. tears, asymmetries, matching different materials are among the most evident features of the deconstructive design. And Chalayan performed the mobile design of transforming furniture into clothes. Chair covers became dresses. a coffee table became a skirt which were designed by Chalayan, with geometric and architectural references. Chalayan says he was inspired by the idea of refugees fleeing. Besides Chalayan uses clothing as an art to reinterpret and reform the human body in a continuous tour de force of body/identity conceptualism and dressmaking. He reflect the body's function in the cultural context of architecture, science, or nature - and then attempt to translate his findings into clothing.dings into clothing.

A Study on Design of K-12 e-Learning System for Utilization Smartphone (스마트폰 활용을 위한 초.중등 교육용 이러닝 시스템 설계에 관한 연구)

  • Kim, Yong;Shon, Jin-Gon
    • Journal of Internet Computing and Services
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    • v.12 no.4
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    • pp.135-143
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    • 2011
  • The smartphone allows learners to be involved in learning environments in which students actively study from anywhere and at anytime. Because learners can keep engaged in the environment where they can access to the internet, they can efficiently study in transit using various features and functions of smartphone. Smart learning is a unique learning based on mobility and functions of mobile digital devices including searching and sharing information and using various applications. For the effective use of smartphones in e-learning systems, the contents and learning management systems should be designed to meet effective teaching and learning principles, such as interactivity and collaborations. In smart learning, learning contents for effective learning need to be integrated with typical functions of smartphones and to develop small pieces of learning contents according to learning topics. In the case of learning management systems, it should reflect understanding of learners' environment using a PA agent program and provide personalized learning services.

A Lossless Multicast Handoff Method for Wireless ATM Networks (무선 ATM 망을 위한 손실없는 멀티캐스트 핸드오프 기법)

  • 하은용
    • The KIPS Transactions:PartC
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    • v.8C no.1
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    • pp.88-96
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    • 2001
  • Future mobile communication networks, which consist of ATM-based B-ISDN backbone networks and wireless ATM networks, will provide u user with broadband connection and QoS service. These network systems need the lossless handoff methods which support user mobility, satisfy ATM features such as ATM cell ordering and no ATM cell duplication and minimize buffer requirement for ATM cell buffering. In this paper we suggest a multicast-based handoff method to supp$\alpha$t lossless connection as well as to minimize buffer overhead. It establishes a dynamic multicast connection between source terminal and wireless member AP (access point)s. When the mobile terminal receives data packet correctly, it notifies the positive acknowledgement of the packet to all member APs. And member APs then release the MT related temporary buffer space for MT's future movement. Therefore member APs can eliminate unnecessary buffer usage and manage the buffer space efficiently. Analysis result shows that our handoff method has better performance in buffer requirement for lossless and seamless connection services over VCT (virtual connection tree) method and other dynamic multicast-based handoff methods.

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