• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.466-468
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• 1999

현재 인터넷 프로토콜인 IPv4의 주소 부족 등의 문제를 해결하기 위해 차세대 인터넷 프로토콜 IPv6에 대한 연구가 활발히 진행되고 있다. 그러나 새로운 프로토콜 IPv6 상에서 기존의 다른 상위 프로토콜 및 응용이 어떠한 영향을 받게 될지는 의문이다. 한편, IPv6 상에서 새로운 프로토콜 및 응용을 개발할 때에 많은 시험이 요구된다. 이와 같은 이유로 인해 새로운 통신 프로토콜에 있어서 모니터링은 필수적이다. 그러나 지금까지의 많은 모니터링 라이브러리들은 텍스트에 기반하고 있으며, 그래픽 데이터를 제공하는 도구들도 대부분 통계정보의 제공에 초점을 두고 있다. 이를 두고 프로토콜이 그 표준에 따라 정확한 원리에 맞게 동작하는 지를 파악하는 데는 큰 도움이 되지 않고 있다. 이에 본 연구에서는 대상 프로토콜의 실제적인 동작 과정이나 원리를 알 수 있도록 그래픽 기반의 사용자 친화적 모니터링 도구를 제작한다. 이를 위해, 먼저 IPv6가 다른 프로토콜에 영향을 미칠 수 있는 사항들을 분석한다. 다음으로 본 교에 구축되어 있는 IPv6 호스트에 모니터링에 필요한 환경을 구축하고, Java Applet을 이용한 모니터 프로그램을 제작한다. 현재 개발하는 모니터 프로그램은 TCP의 슬라이딩 윈도우(Sliding Window) 기법에 관련된 사항을 모니터링 해주는 것으로 그 범위를 한정한다. 개발된 도구를 이용하여 IPv6 상에서 FTP가 TCP를 이용하여 파일을 전송하는 경우의 모니터링을 실시하고, 그 결과를 분석 제시한다. 이로써, 개발된사용자 친화적 모니터링 도구가 얼마나 쉽게 슬라이딩 윈도우 기법을 이해시켜 주고, 내포된 의미를 파악할 수 있게 해주는지를 알 수 있다.한 것으로 연구되었다. 정상조 직에 비해 산소가 부족하여 염기성대사(anaerobic metabolism)를 많이 함으로 그 부산물인 유산 (lactic acid)이 많이 생성됨으로 정상조직보다 pH가 낮아 암 조직이 정상조직에 비해 고온온열치료에 더 잘 듣는 원인이 된다. 3) 영양이 부족한 상태의 세포는 고온온열치료에 훨씬 예민하다. 4) 암조직은 혈관상태가 정상조직에 비해 좋지 않음으로 정상조직보다 쉽게 가온이 되며, 일단 가온된 온도는 잘 식지 않음으로 정상조직에 비해 훨씬 효율적이다. 5)고 온온열치료는 4$0^{\circ}C$~43.5 $^{\circ}C$정도에서만 이 작용이 일어남으로 정상인체에서 43$^{\circ}C$이상의 가온 은 쉽지 않음으로 이 효과는 암조직에서 주고 일어나게 된다. 6)고온온열치료는 방사선치료 후에 생기는 손상의 재생을 억제함으로 방사선의 치료효과를 높인다. 7)38.5$^{\circ}C$~41.5$^{\circ}C$의 낮 은 온도에서도 암조직의 산소 상태를 호전시켜 방사선 치료효과를 증대시키는 역할을 한다.alization)가 나타난다. 그러나 무의식에 대칭화만 있는 것은 아니며, 의식의 사고양식인 비대칭도 어느 정도 나타나며, 대칭화의 정도에 따라, 대상들이 잘 구분되어 있는 단계, 의식수준의 감정단계, 집단 내에서의 대칭화 단계, 집단간에서의 대칭화 단계, 구분이 없어지는 단계로 구분하였다.systems. We believe that this taxonomy is a significant contribution because it ad

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.1025-1033
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• 2011

This paper presents a realization of a peer-to-peer communication system for a UAV navigational monitoring using a commercial HSDPA(High Speed Download Packet Access) mobile communication device. The realized system consists of a communication server, an air data terminal and multiple ground monitoring devices, where the server transfers navigational data from a UAV to multiple monitoring devices in real-time with commercial HSDPA modem. Through ground and flight tests, data were obtained to observe the realized system. Test results show that, depending on communicational environment, about 300msec delay, congestion and packet-loss between air data terminal and ground monitoring devices. Nevertheless, through high-speed long range test on a ground vehicle and altitude test with a UAV flight, the feasibility of a UAV navigational monitoring system was observed.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.573-588
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• 2009

In this paper, we propose a novel video quality degradation monitoring scheme titled VR-VQMS(Visual Rhythm based Video Quality Monitoring Scheme) over an IPTV service prone to packet losses during network transmission. Proposed scheme quantifies the amount of quality degradation due to packet losses, and can be classified into a RR(reduced-reference) based quality measurement scheme exploiting visual rhythm data of H.264-encoded video frames at a media server and reconstructed ones at an Set-top Box as feature information. Two scenarios, On-line and Off-line VR-VQMS, are proposed as the practical solutions. We define the NPSNR(Networked Peak-to-peak Signal-to-Noise Ratio) modified by the well-known PSNR as a new objective quality metric, and several additional objective and subjective metrics based on it to obtain the statistics on timing, duration, occurrence, and amount of quality degradation. Simulation results show that the proposed method closely approximates the results from 2D video frames and gives good estimation of subjective quality(i.e.,MOS(mean opinion score)) performed by 10 test observers. We expect that the proposed scheme can play a role as a practical solution to monitor the video quality experienced by individual customers in a commercial IPTV service, and be implemented as a small and light agent program running on a resource-limited set-top box.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.2
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• pp.135-145
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• 2002

Active networks represent a new approach to network architecture. Nodes(routers, switches, etc.) can perform computations on user data, while packets can carry programs to be executed on nodes and potentially change the state of them. While active networks provide a flexible network iufrastructure, they are more complex than traditional networks and raise considerable security problems. Nodes are Public resources and are essential to the proper and contract running of many important systems. Therefore, security requirements placed upon the computational environment where the code of packets will be executed must be very strict. Trends of research for active network security are divided into two categories: securing active nodes and securing active packets. For example, packet authentication or monitoring/control methods are for securing active node, but some cryptographic techniques are for the latter. This paper is for transferring active packets securely between active nodes. We propose a new method that can transfer active packets to neighboring active nodes securely, and execute executable code included in those packets in each active node. We use both public key cryptosystem and symmetric key cryptosystem in our scheme

• Journal of Biomedical Engineering Research
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• v.18 no.4
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• pp.373-380
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• 1997

In this paper, we describe the intrabed network in a patient monitoring system we developed The intrabed network handles data communication between the main unit of a bedside patient monitor and parameter modules plugged in it. We designed the intrabed network based on RS-485 and HDLC protocol with 1 Mbps data rate. Message exchanges are implemented based on three data structures of packet frame. and stream. We present the specification and the performance of the data communication network for the developed patient monitor.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.4
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• pp.813-820
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• 2009

This paper describes the realization of ubiquitous healthcare monitoring system using wearable pulse oximeter based on a wireless sensor network. In order to obtain information of oxygen saturation from a patient, a small size and low power consumption wearable pulse oximeter was designed. Information of oxygen saturation collected by wireless sensor node was transmitted wirelessly to a base-station for storage and display purposes via wireless sensor network. Wireless sensor nodes were programmed by TinyOS application to perform data acquisition and transmission. Lab VIEW server program was designed to monitor information of oxygen saturation and process the measured PPG (photo plethysmogram) signals to APG(Accelerated plethysmogram) signals by appling second order derivatives. PPG signals are simple and cost effective technique to measure blood volume change.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.601-606
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• 2008

U-Healthcare is one of the major applications in ubiquitous sensor network. U-Healthcare has potential to become a critical service for the people who immediately require emergency ambulatory attention. This paper describes about the real time pulse monitoring and reporting system, consisting of two components: thus, the one is a reliable bio-sensor that continuously monitors the pulse information of the subject, and the other is the automatic transfer system that transmits pulse information to both his/her family and hospital care system through the Base Station. In the hospital, this bio-information can be used to treat the patient accordingly. I designed the pulse information monitored by a bio-sensor module that transfers the pulse information to both the Base Station and the central monitoring system through transmitting protocols such as Zigbee and TCP/IP, as well as designed the architecture of information packets for the corresponding protocols. Furthermore, the central monitoring system automatically parses the pulse information of the subject into the web database server, which can continuously provides the real time information and status of the subject via an internet browser to the clients who are family members of the subject and the authenticated medical care personnel as well.

• Convergence Security Journal
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• v.8 no.2
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• pp.41-50
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• 2008

Recently amount of traffic into the network rapidly increase since multimedia streaming services is generally adopted for application. In addition, various network management systems have been suggested for providing a stable service and QoS guarantee. It is necessary for such systems to have QoS monitoring module in order to evaluate acceptance or violation of QoS requirements by analogizing a state information of each node within network. In this paper, we suggest a network management system to evaluate QoS level between end-to-end agents and analysis traffics transmitted between them. The proposed system is implemented for the purpose of collecting network traffic information and monitoring of the view. The proposed system makes user easily understand information of QoS parameters such as throughput, delay and jitter by adopting a method of visual and numerical representation. To achieve this, we purportedly generate test packet into network for confirming acceptance or violation of QoS requirements from point of view of multimedia application service.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.12
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• pp.1160-1167
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• 2012

Identifying traffic is an important issue for many networking applications including quality of service, firewall enforcement, and network security. Once we know the purpose of using the traffic in the firewall, we can allow or deny it and provide quality of service, and effective operation in terms of security. However, a number of applications encrypts traffics in order to enhance security or privacy. As a result, effective traffic monitoring is getting more difficult. In this paper, we analyse SSH encrypted traffic and identify differences among SSH tunneling, SFTP, and normal SSH traffics. By using EM clustering, we identify traffics and validate experiment results.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.112-114
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• 2004

최근에 널리 사용되고 있는 IEEE 802.l1b의 QoS보장은 중요한 기술적 이슈가 되고 있다. IEEE 802.l1b의 QoS를 보장하기 위한 정책을 효율적으로 수립하기 위해서는 현재 채널에서의 사용 가능한 대역폭을 예측할 수 있어야 한다. 본 논문은 기존에 제시 되었던 IEEE 802.l1b의 채 널 saturation 대역폭 모델을 확장하여 채널 상태의 모니터링을 기반으로 한 현재 의 채널에서 사용 가능한 대역폭의 예측 모델을 제안한다. 또한 실제 무선 환경을 구현하여 실험한 결과와 제안한 모델에서의 결과 비교를 통해 제안한 모델이 채널의 가용 대역폭을 효과적으로 예측할 수 있음을 확인하였다.