• Title/Summary/Keyword: 호네트

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이동형 의료영상 장치를 위한 JPEG2000 영상 뷰어 개발

  • 김새롬;김희중;정해조;강원석;이재훈;이상호;신성범;유선국
    • Proceedings of the Korean Society of Medical Physics Conference
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    • 2003.09a
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    • pp.81-81
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    • 2003
  • 목적 : 현재, 많은 병원이 방사선과 의료영상정보를 기존의 필름형태로 판독하고, 진료하는 방식에서 PACS 를 도입하여 디지털 형태로 영상을 전송, 저장, 검색, 판독하는 환경으로 변화하고 있다. 한편, PACS 가 가지는 가장 큰 제한점은 휴대성의 결핍이다. 본 연구는 이동형 장치가 가지는 호스트의 이동성 및 휴대성의 장점들을 살리면서, 무선 채널 용량의 한계, 무선 링크 사용이라는 제약점들을 감안하여 의료영상을 JPEG2000 영상압축 방식으로 부호화한 후 무선 환경을 고려한 전송 패킷의 크기를 결정하고자 하였으며, 무선 통신 중 발생되는 패킷 손실에 대응하기 위한 자동 오류 수정 기능도 함께 구현하고자하였다. 방법 : Window 2000 운영체계에서 의료영상을 로드하고, 데이터베이스화하며, 저장하고, 다른 네트워크와 접속, 제어가 가능한 PC급 서버를 구축하였다. 영상데이터는 무선망을 통해 전송하기 때문에 가장 높은 압축비율을 지원하면서 에너지 밀도가 높은 JPEG2000 알고리즘을 사용하여 영상을 압축하였다. 또한, 무선망 사용으로 인한 패킷 손실에 대비하여, 영상을 JPEG2000 방식으로 부호화한 후 각 블록단위로 전송하였다. 결과 : PDA에서 JPEG2000 영상을 복호화 하는데 걸리는 시간은 256××256 크기의 MR 뇌영상의 경우 바로 확인할 수 있었지만, 800×790 크기의 CR 흉부 영상의 경우 약 5 초 정도의 시간이 걸렸다. CDMA 1X(Code Division Multiple Access 1st Generation) 모듈을 사용하여 영상을 전송하는 경우, 256 byte/see 정도에서는 안정된 전송 결과를 보여주었고, 1 Kbyte/see 정도의 전송의 경우 중간 중간에 패킷이 손실되는 결과를 관찰할 수 있었다. 반면 무선 랜의 경우 이보다 더 큰 패킷을 전송하더라도 문제점은 발견되지 않았다. 결론 : 현재의 PACS는 유선과 무선사이의 인터페이스의 부재로 인해 유무선 연동이 되지 못하고 있다. 따라서 이동형 JPEG2000 영상 뷰어는 PACS가 가지는 문제점인 휴대성을 보완하기 위하여 개발되었다. 또한 무선망이 가지는 데이터 손실에 대하여서도 허용할 수 있는 범위에서 재전송을 가능하게 함으로서 약한 연결성을 보완하였다. 본 JPEG2000 영상 뷰어 시스템은 기존 유선상의 PACS와 이동형 장치간에 유기적인 인터페이스 역할을 하리라 기대된다.

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k-NN Query Processing Algorithm based on the Matrix of Shortest Distances between Border-point of Voronoi Diagram (보로노이 다이어그램의 경계지점 최소거리 행렬 기반 k-최근접점 탐색 알고리즘)

  • Um, Jung-Ho;Chang, Jae-Woo
    • Journal of Korea Spatial Information System Society
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    • v.11 no.1
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    • pp.105-114
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    • 2009
  • Recently, location-based services which provides k nearest POIs, e.g., gas stations, restaurants and banks, are essential such applications as telematics, ITS(Intelligent Transport Systems) and kiosk. For this, the Voronoi Diagram k-NN(Nearest Neighbor) search algorithm has been proposed. It retrieves k-NNs by using a file storing pre-computed network distances of POIs in Voronoi diagram. However, this algorithm causes the cost problem when expanding a Voronoi diagram. Therefore, in this paper, we propose an algorithm which generates a matrix of the shortest distance between border points of a Voronoi diagram. The shortest distance is measured each border point to all of the rest border points of a Voronoi Diagram. To retrieve desired k nearest POIs, we also propose a k-NN search algorithm using the matrix of the shortest distance. The proposed algorithms can m inim ize the cost of expanding the Voronoi diagram by accessing the pre-computed matrix of the shortest distances between border points. In addition, we show that the proposed algorithm has better performance in terms of retrieval time, compared with existing works.

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Analysis of Acquaintance Relations Between Parameters of RMR and Q Rock Mass Classification System (RMR 및 Q 암반분류법의 평가 요소간 친숙도 관계 분석)

  • Synn, Joong-Ho;Park, Chul-Whan;SunWoo, Choon
    • Tunnel and Underground Space
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    • v.18 no.6
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    • pp.408-417
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    • 2008
  • Rock mass classification methods such as RMR and Q system have different characteristics each other in parameters considered and applications, and so it is very important to prescribe the relationship between parameters for the analysis of correlativity of these methods. With the Held data of RMR and Q estimation in road construction sites, the acquaintance relations between RMR and Q of rock mass classifications are analyzed. The correlation equations between parameters of RMR and Q, matrix of correlation coefficients and the generalized form of acquaintance relation matrix are derived. This acquaintance relation matrix can be further extended to the form of generalized acquaintance relation network, and could be used to analyze the correlativity and to enhance the utility of common rock mass classification methods.

Cluster-based Energy-Efficient Routing Protocol using Message Reception Success Rate (메시지 수신 성공률을 이용한 클러스터 기반의 에너지 효율적인 라우팅 프로토콜)

  • Jang, You-Jin;Choi, Young-Ho;Jang, Jae-Woo
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.12
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    • pp.1224-1228
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    • 2010
  • The existing cluster-based routing protocols have some problems. Firstly, because of selecting cluster head at random, they occur a node concentration problem. Secondly, they have a low reliability for data communication due to the less consideration of node communication range. Finally, data communication overhead is greatly increased because of sending all sensor node information to sink node for constructing clusters. To solve these problems, we in this paper, propose a cluster-based routing protocol using message reception success rate. Firstly, to solve the node concentration problem, we design a cluster head selection algorithm based on node connectivity and devise cluster spliting/merging algorithms. Secondly, to guarantee data communication reliability, we use message reception success rate. Finally, to reduce data communication overhead, we use only neighbor nodes information at both cluster construction and cluster head selection.

Improved BER Performance of Non-Orthogonal Multiple Access System for Interactive Mobile Users: Maximum Likelihood Detection Perspective (상호작용 이동통신 사용자에 대한 비직교 다중접속 시스템의 BER 성능 향상: ML 검출 관점)

  • Chung, Kyu-Hyuk
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.5
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    • pp.865-872
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    • 2020
  • In the fifth generation (5G) mobile networks, non-orthogonal multiple access (: NOMA) has been considered as a promising technology, to increase the channel capacity. In NOMA, the multiple users share the channel resources and multiplex simultaneously. Recently, for the stronger channel user, it was reported that the bit-error rate (: BER) performance with interactive mobile users is degraded, compared to the BER of non-interactive users. In this paper, in order to improve such degraded BER performance, we propose the maximum-likelihood (: ML) receiver. First, the closed-form expression for the BER of the ML receiver is derived, and then it is shown that the BER of the ML receiver is improved, compared with the BER of the ideal perfect successive interference cancellation (: SIC) receiver. Additionally, based on the analytical expression, Monte Carlo simulations validates the above-mentioned results.

Globally Optimal Recommender Group Formation and Maintenance Algorithm using the Fitness Function (적합도 함수를 이용한 최적의 추천자 그룹 생성 및 유지 알고리즘)

  • Kim, Yong-Ku;Lee, Min-Ho;Park, Soo-Hong;Hwang, Cheol-Ju
    • Journal of KIISE:Information Networking
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    • v.36 no.1
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    • pp.50-56
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    • 2009
  • This paper proposes a new algorithm of clustering similar nodes defined as nodes having similar characteristic values in pure P2P environment. To compare similarity between nodes, we introduce a fitness function whose return value depends only on the two nodes' characteristic values. The higher the return value is, the more similar the two nodes are. We propose a GORGFM algorithm newly in conjunction with the fitness function to recommend and exchange nodes' characteristic values for an interest group formation and maintenance. With the GORGFM algorithm, the interest groups are formed dynamically based on the similarity of users, and all nodes will highly satisfy with the information recommended and received from nodes of the interest group. To evaluate of performance of the GORGFM algorithm, we simulated a matching rate by the total number of nodes of network and the number of iterations of the algorithm to find similar nodes accurately. The result shows that the matching rate is highly accurate. The GORGFM algorithm proposed in this paper is highly flexible to be applied for any searching system on the web.

2.5D Metabolic Pathway Drawing based on 2-layered Layout (2-계층 레이아웃을 이용한 2.5차원 대사 경로 드로잉)

  • Song, Eun-Ha;Ham, Sung-Il;Lee, Sang-Ho;Park, Hyun-Seok
    • Journal of KIISE:Software and Applications
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    • v.36 no.11
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    • pp.875-890
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    • 2009
  • Metabolimics interprets an organism as a network of functional units and an organism is represented by a metabolic pathway i.e., well-displayed graph. So a software tool for drawing pathway is necessary to understand it comprehensively. These tools have a problem that edge-crossings exponentially increase as the number of nodes grows. To apply automatic graph layout techniques to the genome-scale metabolic flow, it is very important to reduce unnecessary edge-crossing on a metabolic pathway layout. In this paper, we design and implement 2.5D metabolic pathway layout modules. Metabolic pathways are represented hierarchically by making use of the '2-layered layout algorithm' in 3D. It enhances the readability and reduces unnecessary edge-crossings by using 3D layout modules instead of 2D layout algorithms.

A Traffic-Classification Method Using the Correlation of the Network Flow (네트워크 플로우의 연관성 모델을 이용한 트래픽 분류 방법)

  • Goo, YoungHoon;Lee, Sungho;Shim, Kyuseok;Sija, Baraka D.;Kim, MyungSup
    • Journal of KIISE
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    • v.44 no.4
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    • pp.433-438
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    • 2017
  • Presently, the ubiquitous emergence of high-speed-network environments has led to a rapid increase of various applications, leading to constantly complicated network traffic. To manage networks efficiently, the traffic classification of specific units is essential. While various traffic-classification methods have been studied, a methods for the complete classification of network traffic has not yet been developed. In this paper, a correlation model of the network flow is defined, and a traffic-classification method for which this model is used is proposed. The proposed network-correlation model for traffic classification consists of a similarity model and a connectivity model. Suggestion for the effectiveness of the proposed method is demonstrated in terms of accuracy and completeness through experiments.

A Study of Wired and wireless VoIP vulnerability analysis and hacking attacks and security (유무선 VoIP 취약점 분석과 해킹공격 및 보안 연구)

  • Kwon, Se-Hwan;Park, Dea-Woo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.4
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    • pp.737-744
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    • 2012
  • Recently VoIP has provided voice(both wired and wireless from IP-based) as well as the transmission of multimedia information. VoIP used All-IP type, Gateway type, mVoIP etc. Wired and wireless VoIP has security vulnerabilities that VoIP call control signals, illegal eavesdropping, service misuse attacks, denial of service attack, as well as wireless vulnerabilities etc. from WiFi Zone. Therefore, the analysis of security vulnerabilities in wired and wireless VoIP and hacking incidents on security measures for research and study is needed. In this paper, VoIP (All-IP type, and for Gateway type) for system and network scanning, and, IP Phone to get the information and analysis of the vulnerability. All-IP type and Gateway type discovered about the vulnerability of VoIP hacking attacks (Denial of Service attacks, VoIP spam attacks) is carried out. And that is a real VoIP system installed and operated in the field of security measures through research and analysis is proposed.

Variable Backoff Stage(VBS) Algorithm to Reduce Collisions in IEEE 802.11 DCF (IEEE 802.11 DCF 에서의 충돌 감소를 위한 가변 백오프 스테이지(VBS) 알고리즘)

  • Kang, Seongho;Choo, Young-yeol
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.6
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    • pp.1333-1340
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    • 2015
  • IEEE 802.11 MAC(Media Access Control) defines DCF(Distributed Coordination Function) for data transmission control. BEB(Binary Exponential Backoff) algorithm of DCF has a problem that if the number of stations connected are over a certain threshold, it degrades network performance because of packet collisions caused from the minimum contention window size. To cope with this problem, we proposed a novel algorithm, named as VBS(Variable Backoff Stage) algorithm, which adjusts the rate of backoff stage increment depending on the number of stations associated with an AP(Access Point). Analytic model of proposed algorithm was derived and simulations on the BEB and the VBS algorithms have been conducted on the OFDM (Orthogonal Frequency Division Multiplexing) method. Simulation results showed that when the rate of backoff state increment was 5 and 10, the number of retransmission were reduced to 1/5 and 1/10 comparing to that of BEB, respectively. Our algorithm showed improvement of 19% and 18% in network utilization, respectively. Packet delay was reduced into 1/12.