• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.1
• /
• pp.71-76
• /
• 2013

In this paper, end-to-end performances for some VoIP traffics are measured and analyzed over MANET(Mobile Ad-hoc Networks) with packet aggregation transmission under blackhole attacks. A VoIP simulator based on NS-2 is used for performance measure. In the simulation, MOS, call connection ratio, network delay and packet loss rate are measured for end-to-end transmission performance. With analysis of measured data, characteristics of each traffics for performance parameters of packet aggregation transmission is showed on MANET under blackhole attack, As a results of this paper, some considerations be required for packet aggregation transmission are suggested to implement VoIP services on MANET under blackhole attacks.

• The Journal of the Korea Contents Association
• /
• v.2 no.3
• /
• pp.119-126
• /
• 2002

The QoS(Quality of Service) guarantee mechanism is one of critical issues in the wireless network. Real-time applications like VoIP(Voice over IP) in All-IP networks need smooth handoffs in order to minimize or eliminate packet loss as a Mobile Host(MH) transitions between network links. In this paper, we design a new multicasting algorithm using DB(Dynamic Buffering) mechanism for Mobile-IPv6. A key feature of the new protocol is the concepts of the DB and MRA(Multicast Routing Agent) to reduce delivery path length of the multicast datagram. Particularly, the number of tunneling and average routing length of datagram are reduced relatively, the multicast traffic load is also decreased.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.11-14
• /
• 1998

Recently, the users of internet are increasing yearly with the rapid spread of internet. So, the shortage of IPv4 address is important issue to ISP. Many ISP is searching for efficient method to use IP address in ATM Network. Korea Telecom has constructed ATM Network test-bed to verify available technologies necessary for ATM Network. This paper, concerning with the configuration of subscribers in ATM Network test bed, analyze the available usage of IP address.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.89-92
• /
• 1999

This paper describes on the threats such as IP spoofing, denial of service, and ILMI based attack etc. for IP over ATM network. Especially we discuss on the threats due to ATM characteristics that are VC stealing, multiparty and multi-connection call. Also we investigate on the threats of ATM based MPLS network. Finally we discuss and suggest the various solutions of ATM security.

• Proceedings of the IEEK Conference
• /
• 2001.06a
• /
• pp.277-280
• /
• 2001

Due to the explosive popularization of the Internet, it has been researched for many mobile terminals how to receive various multimedia information. Especially, it has been considered that a mobile terminal is serviced with multimedia information through a inherent IP address. In this paper we have proposed the Handover Signaling Method and analyzed the Handover delay time of this proposed method in wireless section. This proposed method is appropriate to Broadband systems with Mobile IP. We have simulated Handover delay time with respect to the distance between a terminal and base stations

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.70-74
• /
• 1998

In this paper, by means of Lyapunov second method, we analyze the stability of IP control servo systems in the time domain for the first time. Based on the results on the stability analysis, the design rule to select the gain of IP control is suggested such that the maximum error of output to the nominal system is guaranteed for all uncertainty and load variations. An example of a speed control of brushless dc motor given to prove the unusefulness of the gain design rule.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2002.05c
• /
• pp.406-409
• /
• 2002

인터넷을 이용하여 저렴한 비용으로 음성을 전송할 수 있는 VoIP 서비스의 발전으로 머지않아 VoIP서비스가 현재의 회선 교환 전화 서비스를 대치할 것으로 보인다. 본 문서에서는 단말간에 콜을 생성, 변경, 종료할 때 쓰이는 SIP가 어떠한 특성을 가지며 동작하는지 살펴본다 SIP가 H.323과 비교해서 어떠한 장점이 있는지 서술하였고, SIP의 장점을 활용하여 IMT2000, 3GPP, ETSI 둥에서 어떻게 발전시키고 있는지 분석 및 설명한다.

• Journal of Gastric Cancer
• /
• v.20 no.1
• /
• pp.50-59
• /
• 2020

Purpose: The objective of the present retrospective analysis was to describe the experience of intraperitoneal (IP) paclitaxel and systemic chemotherapy in patients with peritoneal metastasis (PM) of advanced gastric cancer (AGC) in a multicenter setting in Korea. Materials and Methods: The medical records of patients with AGC, who were diagnosed with PM between January 2015 and December 2018, were reviewed. IP catheter was placed in the pouch of Douglas and was used for the administration of IP paclitaxel chemotherapy. Results: We reviewed the clinical outcomes of IP paclitaxel and systemic chemotherapy administration in 82 patients at six institutions in Korea. Mean number of IP chemotherapy cycles was 6.6. The mean peritoneal cancer index (PCI) was 21.9. Postoperative complications related to IP catheter and port were observed in 15 patients. The overall median survival was 20.0 months. A significant difference was observed in the survival rate according to the ascites grade (grade I and II, 24.1 months; grade III and IV, 15.3 months; P=0.014) and PCI grade (grade I, 25.6 months; grade II and III, 16.3 months; P=0.023). Conclusions: The feasibility of IP paclitaxel and systemic chemotherapy administration was demonstrated in this experience-based retrospective analysis suggesting that the procedure is beneficial in patients with PM of AGC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.291-294
• /
• 2011

4G WiBro service in Korea, the world's fourth-generation communication is standardized. VoIP service has been activated one of the application in WiBro communications infrastructure. When using VoIP in the WiBro service, complementing the existing VoIP vulnerabilities in the encryption and authentication technology is a need for research. In this paper, fourth-generation WiBro, LTE, and the definition, 1G, 2G, 3G and 4G compares. And, WiBro service in the VoIP edaehan technical, administrative, physical, and hacker attacks and vulnerability analysis is the study of security measures. Enhanced security measures for the WiBro service to VoIP security through encryption and authentication technologies are studied.

• 대한공업교육학회지
• /
• v.45 no.2
• /
• pp.108-130
• /
• 2020

In order to cope with the rapid changes in science and technology and various societies and complex economies with the advent of the 4th Industrial Revolution, intellectual property education is essential above all. In this study, therefore, intellectual property and the required competences were derived and verified for each field. As for the research method, Delphi technique was used twice for literature review and experts, and the conclusions of the research are as follows. First, the field of intellectual property required in the era of the 4th Industrial Revolution was classified, through literature review and Delphi technique, in eleven sections such as IP-R & D consulting, IP information search analysis, IP entitlement, IP strategic planning, IP transaction, IP finance, IP value evaluation, IP management, global IP management, IP commercialization, and IP disputes, of which validity was verified. Second, It was analyzed that the validity of required competencies derived from each field of intellectual property was reliable. Third, it is generally appropriate to nurture manpower in each field of intellectual property in universities or graduate schools. In addition, it is judged that regular job training of industries such as enterprises and public institutions is necessary regardless of the field.