• Journal of KIISE:Computing Practices and Letters
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• 제8권5호
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• pp.583-589
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• 2002

The Internet is absolutely contributed to information telecommunication revolution nowadays. Realizing local network at the various type of buildings such as a company and a university, ethernet is used for subnet and FDDI, ATM are used for backbone mainly in order to get internet services. Processing TCP/IP protocol suite and analyzing the protocol exactly is essential to detecting the problem occurring in the network and developing communication equipment. This paper presents implementation of ethernet LAN protocol analyser which monitors and simulates ICP/IP protocol suite carrying the Internet and non-Internet protocol such as Netware and NetBIOS. MS window98 and visual C are used for development environment and application program operates on the NDIS firmware. The performance analysis on the proposed system is carried out as monitoring and simulating the traffic over LAN of a university. In the result of monitoring the system, the processing time of a packet captured over the LAN is about 1.5ms. In case of simulating the system, the processing time to be taken carrying out TCP connection and disconnection once is packet is about 8.6ms. The performance analysis of monitoring and simulation results satisfies with 10 Mbps ethernet LAN environment.

• Journal of the Korean Society of Radiology
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• 제15권5호
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• pp.575-584
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• 2021

The aim of this study was to achieve optimal portal phase while reducing contrast medium by applying weight-based dose protocol compared to standard fixed dose protocol to performing of pediatric abdominal CT examination. Discovery 750HD (General Electric Medical Systems, Milwaukee, USA) was used, and a total of 167 children consisting of 85 men and 82 women under the age of 18 were studied. The group in which the 300 mgI/ml(Xenetix, Guerbet, France) contrast medium was fixedly injected at twice body weight and the group injected with physiological saline while gradually decreasing the injection amount by 10% while applying the weight-based protocol were distinguished. Also, the CT number and SNR of abdominal organs were compared and evaluated while changing the scan delay time. Subjective image quality of enhancement and beam-hardening artifacts of around the heart was assessed with five-point criterion. The group adapted weight-based protocol with 20% reduction in contrast medium was most similar in contrast enhancement in the group with fixed injection at twice body weight. Furthermore, the group with a delay time of 20% had the highest contrast enhancement effect, and the difference in CT attenuation coefficient from the group scanned immediately after injection of the contrast media. Therefore, the appropriate delay time after injection of the contrast agent increased the contrast enhancement of the parenchymal organ. In addition, the weight-based injection protocol with normal saline reduced artifacts around the heart, and the effect of contrast enhancement could be maintained. In conclusion, it is possible to reduce dosage of contrast media through the application of weight-based injection protocols and appropriate latency, and to characterize optimal portal phase imaging on pediatric abdominal CT.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2006년도 춘계학술발표대회
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• pp.1247-1250
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• 2006

바코드나 기계적 접촉이 요구되는 스마트카드의 단점과 저장능력의 한계를 극복한 인식시스템 RFID(Radio Frequency Identification)는 사물에 부착된 전자태그로부터 무선 주파수를 이용하여 정보를 송 수신하고 이와 관련된 서비스를 제공하는 기술이다. 또한 일련의 IETF공식 규격인 IPv6(Internet Protocol Version 6)은 IPv4를 개선하기 위한 진화적 세트로서 설계되었다. 본 논문의 목적은 RFID의 효율적 활용을 위한 IPv6 기술과의 융화에 있다. 위험물건으로 취급되는 총과 같은 특정 무기류에 RFID와 IPv6이 연계 적용된 물류추적 시스템을 설계하고자 한다. 본 시스템은 크게 특정 물류 정보 데이터베이스 기능과 웹 조회 기능으로 나뉜다. 결론적으로 RFID와 IPv6의 기술을 결합한 형태의 시스템의 개발로 RFID와 IPv6의 특징 및 장점 등을 살리고자 한다. IPv6 기반 RFID물류 추적시스템은 유비쿼터스 환경에서 산업전반에 활용 가능할 것이다.

• Proceedings of the KIEE Conference
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.86-88
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• 2004

As the rapid incensement of the number of internet users has occurred recently, many multimedia application services have been emerging. To improve quality of service, traffic can be suggested to be classified with priority in EPON(Ethernet Passive Optical Network), which is supporting the multimedia application services. In this paper, multimedia application services treat bandwidth classifying device in serving both delay sensitive traffic for real-time audio, video and voice data such as VoIP(Voice over Internet Protocol), and nonreal-time traffic such as BE(Best Effort). With looking through existing mechanisms, new mechanism to improve the quality will be suggested. The delay performances and packet losses of traffic achieved by supporting bandwidth allocation of upstream traffic in suggested mechanism will be analyzed with simulation.

• Journal of Information Processing Systems
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• 제2권3호
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• pp.170-177
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• 2006

Recently, RFID technology has attracted considerable attention in many industry fields. The RFID environment requires a standard architecture for the smooth exchange of data between heterogeneous networks. The architecture should offer an efficient standard environment, such as a communication environment based on Web Services, PKI or Kerberos-based security, and abstract business processes which could be used in the diverse domains. Therefore, in this paper, we propose an Enterprise Application Framework (EAF) which includes a standard communication protocol, security functions, and abstract level business processes. The suggested architecture is expected to provide a more secure and flexible security management in the dynamic RFID application environments, and is expected to provide an abstract business event for the development of business processes which could apply RFID technology to the existing systems.

• Nuclear Medicine and Molecular Imaging
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• 제42권2호
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• pp.164-171
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• 2008

Medical internal radiation dosimetry (MIRD) is an important part of nuclear medicine research field using therapeutic radioisotope. There have been many researches using MIRD for the development of new therapeutic approaches including radiopharmaceutical, clinical protocol, and imaging techniques. Recently, radionuclide therapy has been re-focused as new solution of intractable diseases, through to the advances of previous achievements. In this article, the basic concepts of radiation and internal radiation dosimetry are summarized to help understanding MIRD and its application to clinical application.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권3호
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• pp.1152-1167
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• 2018

In this paper, I propose an application layer cooperative congestion control scheme for safety message broadcast in vehicular networks, called CMS, that adaptively controls a vehicle's safety message rate and transmit timing based on the channel congestion state. Motivated by the fact that all vehicles should transmit and receive an application layer safety message in a periodic manner, I directly exploit the message itself as a means of estimating the channel congestion state. In particular, vehicles can determine wider network conditions by appending their local channel estimation result onto safety message transmissions and sharing them with each other. In result CMS realizes cooperative congestion control without any modification of the existing MAC protocol. I present extensive NS-3 simulation results which show that CMS outperforms conventional congestion control schemes in terms of the packet collision rate and throughput, especially in a high-density traffic environment.

• Journal of Industrial Technology
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• 제26권A호
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• pp.147-152
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• 2006

Wireless Sensor Networks provide a new paradigm for sensing and disseminating information from various environments, with the potential to serve many and diverse applications. Recent advancement in wireless communications and electronics has enabled the development of low-cost sensor networks. The sensor networks can be used for various application areas. For different application areas, there are different technical issues that researchers are currently resolving. The current state of the art of sensor networks is captured in this article, where solutions are discussed under their related protocol stack layer sections. This article also points out the open research issues and intends to spark new interests and developments in this field. In order to evaluate the application of field monitoring system, lab tests, field test and FEM analysis are conducted. Therefore the accuracy of RFID wireless sensor data is verified.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권1호
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• pp.34-40
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• 2014

Today, with the wide use of mobile devices, the amount of business transactions conducted through such devices is increasing drastically. However, there are several limitations in the area of authentication for mobile use, which requires strong authentication mechanisms to satisfy security and convenience requirements. The proposed model and application system provide a framework to ensure the security and reliability of the flow of biometric information for telebiometric applications using mobile devices. We also specify protocols for each model and implement a mobile telebiometric application to improve security vulnerabilities compared to storage in a microSD match on card (MOC) based on the proposed model. As a consequence of this implementation, we propose substantial guidelines for security countermeasures from both technical and managerial perspectives in order to establish a safe mobile environment for the use of telebiometric systems.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.149-152
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• 2003

In this paper, we propose a scheme that applies to the VoIP application based on H.323 protocol to enhance the bandwidth efficiency. We multiplex the audio and video stream. In this scheme, audio frame is carried with video stream. And we applies not only multiplexing but also (in header compressing to the real audio/video stream to increase the bandwidth efficiency. With the multiplexing and RTP header compressing, we gain the bandwidth efficiency. In the finite network environment, We can assign bandwidth to other users who want to use other service. and other VoIP users. If we can apply the real time network situation to the our VoIP application, we can get more efficient performance.