• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.11 s.353
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• pp.149-158
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• 2006

We proposed a method for improving a performance of TCP downstream between a desktop PC as a fixed host and a PDA as a mobile host in a wired and wireless network based on IEEE 802.11x wireless LAN. With data transmission between these heterogeneous terminals a receiving time during downstream is slower than that during upstream by 20% at maximum. The reason is that their congestion window size will be oscillated due to a significantly lower packet processing rate at receiver compared to a packet sending rate at sender. Thus it will cause to increase the number of control packets to negotiate their window size. To mitigate these allergies, we proposed two distinct methods. First, by increasing a buffer size of a PDA at application layer an internal processing speed of a socket receive buffer of TCP becomes faster and then the window size is more stable. However, a file access time in a PDA is kept nearly constant as the buffer size increases. With the buffer size of 32,768bytes the receiving time is faster by 32% than with that of 512bytes. Second, a delay between packets to be transmitted at sender should be given. With an inter-packet delay of 5ms at sender a resulting receiving time is faster by 7% than without such a delay.

• The KIPS Transactions:PartC
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• v.15C no.5
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• pp.329-342
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• 2008

The Sensor Networks have limitations in utilizing energies, developing energy-efficient routing protocol and secure routing protocol are important issues in Sensor Network. In the field of data management, Tributaries and Deltas(TD) which incorporates tree topology and multi-path topology effectively have been suggested to provide efficiency and robustness in data aggregation. And our research rendered hierarchical property to TD and proposed Clustering-based Tributaries-Deltas. Through this new structure, we integrated efficiency and robustness of TD structure and advantages of hierarchical Sensor Network. Clustering-based Tributaries-Deltas was proven to perform better than TD in two situations through our research. The first is when a Base Station (BS) notices received information as wrong and requests the network's sensing data retransmission and aggregation. And the second is when the BS is mobile agent with mobility. In addition, we proposed key establishment mechanism proper for the newly proposed structure which resulted in new Sensor Network structure with improved security and energy efficiency as well. We demonstrated that the new mechanism is more energy-efficient than previous one by analyzing consumed amount of energy, and realized the mechanism on TmoteSKY sensor board using TinyOS 2.0. Through this we proved that the new mechanism could be actually utilized in network design.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3A
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• pp.209-216
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• 2005

This paper generally relates to the field of wireless local area networks(WLANs), and more particularly, to AP selection and association methods for the performance of a station. In these days, IEEE 802.11 Wireless LAN network is widely deployed and used as an emerging service to connect high-speed Internet in the public wireless environment. But, if there are many users in hot spot area, they suffer a severe decrease of performance. Thus it needs an association and access control mechanism especially when it is used in the public environment. In this paper, we suggest a selection and association method using Beacon or Probe Response frames based IEEE 802.11. Station selects AP using the information of the capacity area in a Beacon or a Probe Response frame. According to the present paper, an association method for a public WLAN service, which includes a WLAN user terminal and an AP for relaying WLAN communications to and from the user terminal, includes the steps of the user terminal asking the AP's states for access to a radio channel; and the station selects and associates with the AP According to the above-described selection in a high speed wireless Internet service based on public WLAN technologies that are currently in operations. Further, it is possible to improve the efficiency of network management.

• The KIPS Transactions:PartD
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• v.11D no.1
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• pp.133-142
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• 2004

The next generation of web applications will need to be larger, more complex, and flexible Agent-oriented systems have great potential for these e-commerce applications. Agents can dynamically discover and compose e-services and mediate interactions. Development of software agents with CBD (Component Based Development) has proved to be successful in increasing speed to market of development Projects, lowering the development cost and providing better qualify. In this thesis, we propose a systemic development process for software agents using component and UML (Unified Modeling Language). We suggest a etA (e-business Agent) CBD reference architecture for layer the related components through identification and classification of general agent and e-business agent. We also propose the ebA-CBD process that is a guideline to consider the best features of existing agent oriented software engineering methodologies, while grounding agent-oriented concepts in the same underlying semantic framework used by UML. We first developed the agent components specification and modeled it with Goal, Role, Interaction, and Architecture Model. Based on this, we developed e-CPIMAS (e-Commerce Product Information Mailing Agent System) as a case study that provides the product information's mailing service according to proposed process formality. We finally describe how these concepts may assist in increasing the efficiency reusability, productivity and quality to develop the business application and e-business agent.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.631-633
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• 2004

본 논문에서는 유비쿼터스 홈 네트워킹 환경에서 사용자의 위치 이동을 실시간 추적하고 가정 내 주거 활동의 편의를 제공하는 정보가전기기들을 제어할 수 있는 능동형 홈 서비스 시스템을 제안한다. 본 시스템은 다계층의 분산시스템 환경으로 구성된다. 즉, 물리 센서와 정보가전기기 등이 존재하는 물리층과 유/무선 지원 인터넷/인트라넷 통신 플랫폼을 포함하는 시스템층, 그리고 물리적 장치들로부터 시스템층을 통해 들어오는 정보를 처리하는 응용층으로 구성되며 실 생활 공간 및 시간을 응용 시뮬레이션 환경으로 반영시킨다. 능동형 홈 서비스 시스템의 개발 목적은 실버아파트에서 독거노인의 위치기반 건강관리 정보 서비스 및 아파트 내 정보가전기기들의 맞춤형 제어를 제공하기 위함이다. 이와 같은 시스템을 구축하기 위해서는 홈 네트워크 내에서 사용자의 이동 위치를 파악하는 실시간 위치추적 기술과 정보가전기기들의 동작을 실시간 제어하기 위한 기술이 요구된다. 제안한 시스템에서는 UC at Irine의 DREAM Lab.에서 개발한 TMO(Time-triggered Message -triggered Objecl) 스킴을 적용하여 각 물리 센서와 정보가전기기들을 응용의 구성요소로 개발했다. 이를 통해 가정 내에 이동하는 TMO로 매핑된 이동객체를 추적하고 또한 홍 네트워크로 연결된 정보가전기기들을 정보가전 TMO 동작객체로 매핑하여 이들 사이의 능동적인 상호동작을 통해 맞춤형 서비스 및 실시간 제어가 가능하도록 했다. 마지막으로, 실시간 위치추적 및 정보가전제어 응용 시뮬레이션을 통해 능동형 홈 서비스 시스템을 구성하는 개별 동작객체들의 기능성과 수행성을 검증했다.황에 대하여 소개한다.이스는 실험정보가 저장된 데이터베이스, 분석결과가 저장된 데이터베이스, 그리고 유전자 정보 탐색을 위한 데이터베이스로 분류해 데이터를 효율적으로 관리할 수 있게 하였다. 본 시스템은 LiNUX를 운영체계로 하고 데이터베이스는 MYSQL로 하여 JSP, Perl. 통계처리 언어인 R로 구현되었다.프트웨어를 사용하지 않고도 국내의 순수 솔루션인 리눅스 기반의 LonWare 3.0 다중 바인딩 기능을 통해 저 비용으로 홈 네트워크 구성 관리 서버 시스템 개발에 대한 비용을 줄일 수 있다. 기대된다.e 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.469-482
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• 2018

This research has developed the criteria and index for systematically and objectively assessing the quality of river water by fixing the various factors that affect Gyeongin ARA waterway's water quality through analysis with the Delphi Technique and analytic hierarchy program (AHP) Method. Based on the results, the highest criteria are, in order of importance, physical and environmental factors 28%, administrative factors 26%, natural fixed factors 26% and finally, cultural and social factors 20%. The three dimensions of the criteria show that for the internal physical and environmental factors, the most important are the loss of self-purification capacity, and the external factors are Gulpocheon and the sludge deposit due to Gyulhweon-weir the bridge. The facility factor in management was affected by the coagulation and waste water disposal facilities. The problem for the policy and institutional factors was seen in the regulatory area. The aquatic ecology/ point pollution source for the natural fixed factors show that it is due to the polluted water of Gulpo-cheon and the living environment/ non-point pollution source is shown through the inflow water from other rivers. Cultural and social factors show that the economical causes were due to the cargo and passenger flight operations and the external factors of having a lack of sewage treatment equipment have an importance effect. In order to estimate the order of priority through logical evidence and objectivity, future research must be continued on the evaluation indexes to measure the specific methodology and technique needed to improve the Gyeongin ARA Waterway.

• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.149-155
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• 2003

This paper generally relates to the field of wireless local area networks(WLANs), and more particularly, to AP selection and association methods for the performance of a station. In these days, IEEE 802.11 Wireless LAN network is widely deployed and used as an emerging service to connect high-speed Internet in the public wireless environment. But, if there are many users in hot spot area, they suffer a severe decrease of performance. Thus it needs an association and access control mechanism especially when it is used in the public environment. In this paper, we suggest a selection and association method using Beacon or Probe Response frames based IEEE 802.11. Station selects AP using the information of the capacity area in a Beacon or a Probe Response frame. According to the present paper, an association method for a public WLAN service, which includes a WLAN user terminal and an AP for relaying WLAN communications to and from the user terminal, includes the steps of the user terminal asking the AP's states for access to a radio channel; and the station selects and associates with the AP. According to the above-described selection in a high speed wireless Internet service based on public WLAN technologies that are currently in operations. Further, it is possible to improve the efficiency of network management.

• The KIPS Transactions:PartD
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• v.14D no.3 s.113
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• pp.355-362
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• 2007

With development of mobile communications terminal and expansion of mobile Internet, a large number of users can use mobile web contents at anytime and anywhere and will demand service of greater contents. Due to such demand, many studies are being carried out on transcoding contents so that wired web contents can be used in mobile web. However, transcoding and creation of mobile web contents involve difficulties because specifications available from telecommunications companies and mobile terminals have not been standardized. Especially, in order for serving dynamic object of wired web page contents to dynamically change according to time or user, it is required not only to program scripts to suit each terminal, but also to transcode the resources used in advance. for solution to this problem, this study uses the hierarchy structure of DOM (document object model) to display structural characteristics of wired web page. In other words, this study proposes the following technique. Wired web pages are analyzed and the results are established as data structure. Then, dynamic object is extracted and the domain is indexed so that, when serving mobile web page, information can be extracted at the indexed position to create mobile web contents for service on real-time basis. Also, this study aims at developing an editing device to edit mobile web contents and mobile web service server to service the edited contents by applying the above technique.

• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.249-254
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• 2011

FGS (fine granularity scalability) supporting scalability in MPEG-4 Part 2 is a scalable video coding scheme that provides bit-rate adaptation to varying network bandwidth thereby achieving of its optimal video quality. In this paper, we proposed FGS coding scheme which performs one more bit-plane coding for residue signal occured in the enhancement-layer of the basic FGS coding scheme. The experiment evaluated in terms of video quality scalability of the proposed FGS coding scheme by comparing with FGS coding scheme of the MPEG-4 verification model (VM-FGS). The comparison was conducted by analysis of PSNR values of three tested video sequences. The results showed that when using rate control algorithm VM5+, the proposed FGS coding scheme obtained Y, U, V PSNR of 0.4 dB, 9.4 dB, 9 dB averagely higher and when using fixed QP value 17, obtained Y, U, V PSNR of 4.61 dB, 20.21 dB, 16.56 dB averagely higher than the existing VM-FGS. From results, we found that the proposed FGS coding scheme has higher video quality scalability to be able to achieve video quality from minimum to maximum than VM-FGS.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.545-559
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• 2020

In this paper, we propose a content creation framework that enables users without programming experience to easily create interactive media content that responds to user gestures. In the proposed framework, users define the gestures they use and the media effects that respond to them by numbers, and link them in a text-based configuration file. In the proposed framework, the interactive media content that responds to the user's gesture is linked with the dynamic projection mapping module to track the user's location and project the media effects onto the user. To reduce the processing speed and memory burden of the gesture recognition, the user's movement is expressed as a gray scale motion history image. We designed a convolutional neural network model for gesture recognition using motion history images as input data. The number of network layers and hyperparameters of the convolutional neural network model were determined through experiments that recognize five gestures, and applied to the proposed framework. In the gesture recognition experiment, we obtained a recognition accuracy of 97.96% and a processing speed of 12.04 FPS. In the experiment connected with the three media effects, we confirmed that the intended media effect was appropriately displayed in real-time according to the user's gesture.