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The current backdoor program is executed in user mode, which is called application mode, it is possible to find backdoors by the integrity check of system file. However, for the backdoor program is executed in kernel module, it is impossible to find its existence by the integrity check of system file. Current detection system has limitation to detection this LKM (Loadable Kernel Module) backdoor because they just examine the changes on the System Call Table. In this paper, we suggest the method using log file and password to overcome the limitation which the current integrity check system can’t prevent attack using the kernel module.

This paper, which is based on the research in the personal color diagnoses system, uses the fuzzy logic and fuzzy inference rule to improve the personal color selection method of the existing personal color system and to get more objective and reliable result for personal color. We propose the method which constructs more systematic color selection system using personal color database and fuzzy logic.

Location Positioning is a major technology for ubiquitous computing. A research on Location Positioning using UWB is ongoing. In order to construct an indoor location network, synchronization of base stations is very important. NTP is popularly used as a clock synchronization protocol ranging from LAN to WAN. The Master-Slave scheme, however, is the simplest method for synchronizing an indoor network that uses UWB. In this paper, we compare and analyze the NTP and Master-Slave schemes according to the statistical channel model for an indoor multi-path propagation environment. Error ranges are calculated at various circumstances such as when the indoor network expands from one primary base station to several base stations. In particular, we compare the correctness of the NTP and Master-Slave synchronization methods. We have found that NTP is a more reasonable synchronization protocol in UWB positioning.

This paper proposes multi-filtering method to prevent DDoS attack. Several filtering methods are applied in two firewall architecture for effective DDoS prevention. In the first firewall, R-PA filtering algorithm and strict hop counter filtering method are applied by analyzing packet paths. In the second firewall, packets are examined to distinguish abnormal packets from normal packets. Security policy system monitors each user sessions and if the traffic is over the threshold value, the system blocks the session for an assigned time.

This paper, which is based on the research in the personal color decision system, uses the fuzzy logic and fuzzy ratiocination rule to improve the personal color decision method of the existing personal color system and to get more objective and reliable result for personal color. We propose the method which constructs more systematic color selection system using personal color database and fuzzy logic.

The field that is the key issue of wire, wireless environment is security and many routing protocols are studied also at the ad-hoc network. In the mobile ad-hoc network which has no fixed base structure, the weakest point is security. This paper analyzed AODV protocol, which is a routing protocol, the important routing protocol in ad-hoc network, so that it can overcome the problem in security threats. It used the lightest and fastest message authentication code, so was able to design rather safer AODV routing protocol.

Monitoring systems used at present to operate air handling unit(AHU) optimally do not have a function that enables to detect faults properly when there are faults of such as operating plants or performance falling, so they are unable to manage faults rapidly and operate optimally. In this paper, we have developed a classified rule-based fault detection system which can be inclusively used in AHU system of a building by installation of sensor which is composed of AHU system and required low costs compare to the model based fault detection system which can be used only in a special building or system. In order to experiment this algorithm, it was applied to AHU system which is installed inside environment chamber(EC), verified its own practical effect, and confirmed its own applicability to the related field in the future.

The VoIP (voice over IP) has been worldwide used and already put to practical use in many fields. However, it is needed to ensure secret of VoIP call in a special situation. It is relatively difficult to eavesdrop the commonly used PSTN in that it is connected with 1:1 circuit. However, it is difficult to ensure the secret of call on Internet because many users can connect to the Internet at the same time. Therefore, this paper suggests a new model of Internet telephone for eavesdrop prevention enabling VoIP (using SIP protocol) to use the VPN protocol and establish the probability of practical use comparing it with Internet telephone.

This paper proposes the method which traverses and codes the quadtree by breadth first. Quadtree coded by breadth first (breadth first quadtree) has the same compression ratio with the quadtree coded by depth first (depth first quadtree). In breadth first quadtree, nodes in high level and low level appear in level by level, not at random. This makes it better for operation efficiency, especially in geometric property operation (perimeter calculation, area calculation, search, object labelling, neighbor finding) which needs long operation time. In this paper we show the advantage of breadth first quadtree by the worst case analysis and the general case analysis. >