• Journal of Digital Contents Society
• /
• v.17 no.3
• /
• pp.111-118
• /
• 2016

Proxy mobile IPv6 (PMIPv6), which is a centralized mobility management protocol, are dependent on a local mobility anchor (LMA) to process all control and data traffics. Therefore, it has serious problems such as the tremendous traffic concentration into the core network and the triangle routing. In this paper, therefore, in order to alleviate these drawbacks, we propose a PMIPv6-based enhanced distributed mobility management scheme considering a user's traffic locality. Performance evaluation results indicate that in most cases, except for when a user's mobility rate is relatively very higher than the traffic rate, the proposed scheme shows better performance result than that of PMIPv6. Besides, it is demonstrated that the proposed scheme can be an effective alternative that can distribute the significant loads on the LMA of the core networks to the MAGs of the edge networks.

• The Journal of the Korea Contents Association
• /
• v.4 no.2
• /
• pp.43-49
• /
• 2004

SIP Caller Preference is an useful function that allows a caller to express preferences about request handling in servers. It can also feat appropriate call processing according to the callee capabilities. However, only the category of the media is considered as a criteria for target selection in the caller preference. In this case, if the callee's media information such as codec is different from the caller, an additional re­negotiation occurs for SIP call setup. Therefore, in this paper, we have suggested an extended caller preference to solve this problem. In our SIP based VoIP system, a network sewer uses detailed media informations for media stream in the session to select the target for SIP call setup. The sewer gives higher priority to the candidate which do not require re-negotiation for call setup, so that an effective call setup can be achieved in our system.

• Journal of the Korea Society of Computer and Information
• /
• v.12 no.3
• /
• pp.155-163
• /
• 2007

In this paper, Though sensors of Ubiquitous Middle-ware System based on RFID/USN can usually be reacted from six mouths to two years, they can be exhausted their power of storage battery only one day by communication rates and ranges. That is, the lifetime of sensor node is depended on how much spending power under wireless communication that can communicate its sensing data to its destination. Therefore, it is necessary that each sensor should be designed the Routing path to its destination, in order to remote collecting data. But, in order to improve lifetime of sensor node and modify inner setting, it is opposite to simple searching path method of sensor node by entering external commands. accordingly, 1:n sensor arrangement of n form command and data send-receive that is possible simulation do without interference other sensors and research to different sensor data analysis and conversion ways to convert Sensing data that accept from sensors to actuality information.

• Journal of the Korea Society of Computer and Information
• /
• v.8 no.1
• /
• pp.60-68
• /
• 2003

Now the development of using a internet and security equipment is Processed actively. But It is presented problems about compatability and availability between variable equipment as several protocol. It is able to occur the Problem which is not considered efficiency as monopoly security equipment for the standardization of some vendor As a using of VPN gateway equipment. the same equipments have been actually used only for sale a communication equipment which are not confirmed(authenticate) between of mutual equipments. These problem is remain which are not considered suitable network environment and Position by mutual authentication Processing. Because it is considered for only sale a equipment of several vendor. And You will be remain where is unable to protect from attack of using the same equipment, and You will need a actually Protected method. By authentication system of base on Pn , although there is an intended attack from the third intruder, users can be protected with safe from the physical attacks since he is not a Permitted user by employing CA-VPN gateway that is more viable than the previous VPN connection in its security and certification.

• Journal of the Korea Society for Simulation
• /
• v.16 no.3
• /
• pp.49-56
• /
• 2007

There are many application areas of wireless sensor networks, such as combat field surveillance, terrorist tracking and highway traffic monitoring. These applications collect sensed data from sensor nodes to monitor events in the territory of interest. One of the important issues in these applications is the existence of the radio-jamming zone between source nodes and the base station. Depending on the routing protocol the transmission of the sensed data may not be delivered to the base station. To solve this problem we propose a genetic algorithm based routing method for reliable transmission while considering the balanced energy depletion of the sensor nodes. The genetic algorithm finds an efficient routing path by considering the radio-jamming zone, energy consumption needed fur data transmission and average remaining energy level. The fitness function employed in genetic algorithm is implemented by applying the fuzzy logic. In simulation, our proposed method is compared with LEACH and Hierarchical PEGASIS. The simulation results show that the proposed method is efficient in both the energy consumption and success ratio of delivery.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.9 no.3
• /
• pp.101-108
• /
• 2009

Since the use of wireless communication instruments was standardized, users expect to be provided with seamless information whenever and wherever they use the instruments. Also, some technology is required to satisfy the users' needs which will cover their mobility. To support the mobility of host, the Internet Engineering Task Force (lETF) Mobile IP Working Group proposed a protocol called MIPv6 (Mobile IPv6). But in the case of the existing MIPv6, sometimes Mobile Node cannot receive data packet if Handover occurs although it is a temporal phenomenon. For solving these Handover problems, there are many methods like FMIPv6 (Fast Handover for Mobile IPv6) and HMIPv6 (Hierarchical Mobile IPv6) have been suggested. This paper suggested the use of Dual Buffer of Access Point and an effective way of registration as a way of reducing delayed time caused by Handover. Also, it analyzed and compare the existing MIPv6 with a proposed scheme concerning delayed time of Handover. Finally, the main objective of this paper is to proposed scheme that can reduce the delayed time of Handover compare to the existing MIPv6.

• IMMUNE NETWORK
• /
• v.2 no.1
• /
• pp.49-52
• /
• 2002

Background: The possibility that G-CSF recruits leukemic cells from the G0 to S phase, which may lead to a greater susceptibility to cytotoxic drugs, such as ara-C, has been presented in Harada's study. Methods: In this study, we referred to the protocol of Harada et al 1 to try G-CSF combined marrow-ablative chemotherapy and autologous PBSCT, for the treatment of AML patients in CR1 status. Between January 1997 and March 1998, six AML patients (3: children, 3: adults) in CR1 status were autografted and followed up to 3 years. Results: The major regimen related toxicity was composed of mucositis and diarrhea without death. The time of ANC recovery to 500/L and 1,000/L was 11~48 and 16~81 days, respectively. The mean time of platelet recovery to 20,000/L and 50,000/L was 21~233 and 35~370 days, respectively. The platelet recovery time to 50,000/L was markedly prolonged for more than 100 days in four patients (66.7%). Moreover, four patients (66.7%) experienced a relapse of leukemia after transplantation, with a mean interval of 147.5 days after PBSCT. Two patients were in CR status for 53 and 51 months after PBSCT, respectively. Conclusion: The G-CSF combined marrow-ablative chemotherapy and autologous PBSCT resulted in a markedly delayed platelet recovery and no advantages for decreasing the relapse rate of AML. But, further studies will be warranted.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.2
• /
• pp.36-43
• /
• 2009

In this paper, we propose a Cooperative Routing using ARQ-based Transmission (CRARQ) in Mobile Ad-hoc Wireless Sensor Networks (MAWSN). The goals of the CRARQ are to improve both the efficiency of transmission and the reliability of transmission together. The main features and contributions of the proposed CRARQ for supporting these goals are as follows. First, CRARQ uses a reactive concept to construct a route from a source to a destination. Second, CRARQ chooses the most stable relay at each hop along the route by mobility-based strategy. Third, cooperative transmission using the ARQ technique which can improve reliability is used at each hop to send data packets from source to destination. Finally, we present a theoretical analysis model for the proposed CRARQ. The performance evaluation of our protocol is implemented via simulation using Optimized Network Engineering Tool (OPNET) and analysis. The results of both simulation and analysis show that CRARQ achieves the improved packet delivery ratio (PDR) and outage probability.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.3
• /
• pp.661-666
• /
• 2016

The Internet of Things (IoT) is an infrastructure of physical objects that could be connected to the Internet. Most of these are low performance to ensure a reasonable cost for the smart physical objects. Thus, these devices usually use a lightweight messaging protocol: message queue telemetry transport with SSL/TLS. Cipher suites in device are fixed by default and selected based on preference in SSL/TLS. However, the selected cipher suite provides high security level more than expected. This limitation causes energy waste and overhead of devices. In order to counter this problem, we proposed fuzzy logic based cipher suite decision method to improve energy efficiency. Our proposed method saved 36.03% energy.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.6
• /
• pp.1096-1101
• /
• 2004

By a tremendous expansion of Internet users, there's a number effects that cause the phenomenon of bottlenecked switching packets from routers. In order to tear down this problem, distributed system is applicable to almost every highly performed router systems. The main processor of distributed system, which manages routing table, commands IPC to delivering the forwarding table line processor that eases functionalities of the router. This makes the system having wired-speed forwarding function based on the hardware so that the performance of the network can be enhanced. Therefore, IPC, which assign a part of router, is necessary to exchange data smoothly and the constitution of IPC using Ethernet is widely adapted as a method for saving investment. In this paper, R-IPC mechanism improve the packet-processing rate over 10% through changed from defect of conventional Ethernet IPC, that is, 2 layer processing to TCP/IP or UDP/ IP into 1 layer processing for efficient packet forwarding.