• Journal of the Korea Society of Computer and Information
• /
• v.16 no.6
• /
• pp.131-142
• /
• 2011

In this paper, we propose a new multipath routing protocol and compare it with other multipath routing protocols in mobile ad hoc network (MANET) environments. The new multipath routing establishes the main route using a mechanism based on Ad Hoc On-demand Distance Vector(AODV), after which data transmission starts immediately. The backup route search process takes place while data are transmitted, to reduce the transmission delay. The protocol can also operate in a hybrid node-disjoint/link-disjoint mode, where the protocol finds the node-disjoint backup route first; if the node-disjoint does not exist, the protocol discovers the link-disjoint backup route from the main route. When either of the main route or the backup route is broken, data are transmitted continuously through the other route and the broken route is recovered by the route maintenance process. The results of simulations, based on the Qualnet simulator, show that the proposed multipath routing protocol increases the packet transmission success rate and reduces end-to-end delays, when compared with AODV and AOMDV protocols.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.342-342
• /
• 2000

We present 3-axis stabilized spacecraft attitude determination algorithm using the magnetometer. The magnetometer has been used as a reliable, light-weight and inexpensive sensor in attitude determination and reaction wheel momentum dumping system. Recent studies have attempted to use the magnetometer when other attitude sensor, such as star tracker, fails. The differences between the measured and computed the Earth's magnetic field components are spacecraft attitude errors. In this paper, we propose extended Kalman filter(EKF) to determine spacecraft attitude with the magnetometer data and gyro-measured body rates. We develop and simulate this algorithm using MATLAB/SIMULINK. This algorithm can be used as a backup attitude determination system.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.25 no.2
• /
• pp.101-114
• /
• 2000

Multicasting is the simultaneous transmission of data to multiple destinations. In multicast ATM networks the effect of failures on transmission links or nodes can be catastrophic so that the issue of survivability is of great importance. However little attention has been paid to the problem of multicast restoration. This paper presents an efficient heuristic technique for routing backup virtual paths in ulticast networks with link failure. Genetic algorithm is employed here as a heuristic. In the application of genetic algorithm to the problem, a new genetic encoding and decoding method and genetic operators are proposed in this paper. The other several heuristics are also presented in order to assess the performance of the proposed algorithm. Experimental results demonstrate that our algorithm is a promising approach to solving the problem.

• ETRI Journal
• /
• v.41 no.2
• /
• pp.207-223
• /
• 2019

Network function virtualization can significantly improve the flexibility and effectiveness of network appliances via a mapping process called service function chaining. However, the failure of any single virtualized network function causes the breakdown of the entire chain, which results in resource wastage, delays, and significant data loss. Redundancy can be used to protect network appliances; however, when failures occur, it may significantly degrade network efficiency. In addition, it is difficult to efficiently map the primary and backups to optimize the management cost and service reliability without violating the capacity, delay, and reliability constraints, which is referred to as the reliability-aware service chaining mapping problem. In this paper, a mixed integer linear programming formulation is provided to address this problem along with a novel online algorithm that adopts the joint protection redundancy model and novel backup selection scheme. The results show that the proposed algorithm can significantly improve the request acceptance ratio and reduce the consumption of physical resources compared to existing backup algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.1B
• /
• pp.37-42
• /
• 2011

The change in performance of the mobile communication field took place due to jumping development of technology, so high performance terminals that anyone can directly search and amend desired information anywhere and anytime, namely, the mobile communication terminals called Smartphone were released to the market. The terminal can store informations that an individual stored, for example, call log, where to make contact and address of acquaintances, transmit/receive message and mail, photographs and videos, etc., but there are worries on surreptitious use of other people due to leaking of personal information through loss or theft of these terminals because of several reasons, so the present thesis aims to realize a method that remotely control information inside a terminal in case of loss of a mobile communication terminal.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38C no.7
• /
• pp.563-572
• /
• 2013

Based on this paper, in case of the on-line account system in finance industry temporarily stops working because of the on-line data change from 00:00 to 00:30, it conducts in extra placement server and the director update is carried out via center cut or on-line server to make the service possible through customer director reproduction revision. So, from the simulation result in financial operating system, We retain the batch director & backup director securely about the important time data in each account classes on-line director without even one second interruption.

• The KIPS Transactions:PartC
• /
• v.16C no.3
• /
• pp.335-346
• /
• 2009

Mobile environments are evolving the main communication environment as a develops of communication technology. In mobile environments, sensitive information can be compromised on-line, so demand for security has increased. Also, mobile devices that provide various services are in danger from malware and illegal devices, phishing and sniffing etc, and the privacy. Therefore, MTM(Mobile Trusted Module) is developed and promoted by TCG(Trusted Computing Group), which is an industry standard body to enhance the security level in the mobile computing environment. MTM protects user privacy and platform integrity, because it is embedded in the platform, and it is physically secure. However, a security approach is required when secret data is migrated elsewhere, because MTM provides strong security functions. In this paper, we analyze the TCG standard and migration method for cryptographic key, then we propose a secure migration scheme for cryptographic key using key Backup/Recovery method.

• Journal of Astronomy and Space Sciences
• /
• v.26 no.1
• /
• pp.127-140
• /
• 2009

COMS DATS C&M software is an integrated management system providing control and monitoring functionalities for COMS IDACS (Image Data Acquisition and Control System). DATS C&M S/W consists of a system management module, a control and monitoring module, a data management module, and a trend analysis module. COMS SOC is supposed to operate IDACS as a backup of MSC. Especially, for the backup operation, the control and monitoring module of DATS C&M S/W is designed to support the synchronization of the two IDACS systems. This paper describes design, implementation, and result of development of DATS C&M S/W.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.9
• /
• pp.2040-2048
• /
• 2010

In contemporary society, though convenience and efficiency of work using information system is growing high, adverse effect problems of malignant code, system hacking, information leak by insiders due to the development of the network are raising their head daily. Because of this, enormous work forces and expenses for the recovery and management of system is needed. The existing system can be divided into two aspects: security solution which surveils and treats virus and malignant codes, and network management solution which observes the system of computer, and practices maintenance and repair such as management, recovery, backup. This treatise applied Active Write Filter mechanism and the technology based on NFS and complemented the maintenance problems of user data of the existing system and designed the system which enables solving problems of intellectual property right such as information protection and illegal work.

• International Journal of Knowledge Content Development & Technology
• /
• v.13 no.1
• /
• pp.75-100
• /
• 2023

With research data generation on the rise, Institutional Repositories (IR) are one of the tools to manage it. However, the variety of data practices across institutions, domains, communities, etc., often requires dedicated studies in order to identify the research data management (RDM) require- ments and mapping them to IR features to support them. In this study, we investigated the data practices for a few national universities in North Macedonia, including 110 participants from different departments. The methodology we adopted to this end enabled us to derive some of the key RDM requirements for a variety of data-related activities. Finally, we mapped these requirements to 6 features that our participants asked for in an IR solution: (1) create (meta)data and documentation, (2) distribute, share, and promote data, (3) provide access control, (4) store, (5) backup, and (6) archive. This list of IR features could prove useful for any university that has not yet established an IR solution.