• Journal of Digital Contents Society
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• v.19 no.3
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• pp.497-503
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• 2018

RHEL 7, the leader in the enterprise Linux market, has dramatically increased the maximum support specification, such as file system size, file size, etc., by changing the default file system from EXT to XFS. It's not just an increase in support specifications, it's working on daemons, and it's showing excellent performance on high-performance disks such as high-capacity disks and solid state drives. Changes in the file system mean changes in direct operating techniques, such as changing related commands, changing backup tools, and changing disk quota settings. The changes to the XFS file system are making a lot of changes to the operation of the Linux system, but we believe that the position of the Linux operating system in the server field will become stronger.

• Journal of the Korea Society of Computer and Information
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• v.10 no.5 s.37
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• pp.217-226
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• 2005

In today's cyberworld, network performance is affected not only by an increased demand for legitimate content request, but also by an increase in malicious activity. In this Paper, we research that network performance was affected by an increase in malicious Hacker who make DoS Attack, DDoS Attack, SYN Flooding, IP Spoofing, etc. in using TCP/IP. We suggest that Packet filtering in Network Level, Gateway Level, Application Level against to Protect by Hacker's attack. Also, we suggest that content distribution in Web Server approaches to mitigate Hacker's activity using Cache Sever, Mirror Sever, CDN. These suggests are going to use useful Protection methode of Hacker's attack.

• Convergence Security Journal
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• v.2 no.2
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• pp.189-198
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• 2002

In this paper, we have designed the Web_based Home Gateway Management System using SSL, which can manage subscribers using Home Gateway device in home networking technology. To manage Home Gateway devices with SNMP, management elements are classified into system. performance. fault functional area based on MIB objects from Home Gateway devices MIB. System analysis provides configuration information of each Home Gateway, and Performance analysis provides device's traffic information and state. And fault analysis provides fault logging for the unexpected events and trap message from devices. HGMS uses SSL (Secure Socket Layer) to enforce the security of communication which is between server and client, and it improved the stability of HGMS.

• Convergence Security Journal
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• v.17 no.3
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• pp.3-9
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• 2017

NFV is a technology that allows network services to be controlled and managed in software by separating various net work functions (NFs) from hardware devices in dedicated network equipment and implementing them in a high-performance general-purpose server. Therefore, standardized virtualization of network functions is one of the most important factors. However, until the introduction of NFV to provide commercial services, there are many technical issues to be solved such as guaranteeing performance, stability, support for multi-vendor environment, ensuring perfect interoperability, and linking existing virtual and non-virtual resources. In this paper, we propose a method to provide an end-to-end network virtualization service based on OSM R2 in KREONET.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.149-153
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• 2012

We propose a traffic information service for which traffic data are collected over ad-hoc networks from neighbor vehicles, processed to minimize the data size, and eventually provided to its destination. The proposed scheme simply relies on the existing navigtion systems in vehicles and wireless communication devices for vehicle-to-vehicle communication, rather than on a separately established server. It allows collecting and analyzing traffic status of large areas without incorporating separated monitoring systems, e.g., probe cars and enables to provide accurate traffic information to drivers in timely manner. We also evaluate its performance by ns-3 simulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.6
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• pp.2144-2159
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• 2015

CISCO VNI predicted an average annual growth rate of 66% for mobile video traffic between 2014 and 2019 and accordingly much academic research related to video streaming has been initiated. In video streaming, Adaptive Bitrate (ABR) is a streaming technique in which a source video is stored on a server at variable encoding rates and each streaming user requests the most appropriate video encoding rate considering their channel capacity. However, these days, ABR related studies are only focusing on real-time rate adaptation omitting energy efficiency though it is one of the most important requirement for mobile devices, which may cause dissatisfaction for streaming users. In this paper, we propose an energy efficient prefetching based dynamic adaptive streaming technique by considering the limited characteristics of the batteries used in mobile devices, in order to reduce the energy waste and provide a similar level of service in terms of the average video rate compared to the latest ABR streaming technique which does not consider the energy consumption. The simulation results is showing that our proposed scheme saves 65~68% of energy at the average global mobile download speed compared to the latest high performance ABR algorithm while providing similar rate adaptation performance.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.193-205
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• 1997

It is required for multi-users to share massive mapping data effectively that distributed data model in the Client-Server environment is developed for the replication consistency. The existing model is not effective to the long transaction just like a mapping system, since it does not account lot consistency between GUI screen and database replications even though it emphasizes on the replication consistency. The performance of concurrency control is very important for those long transactions, especially the mapping systems. This model is to support consistency between GUI screen and replicas using display locks. It suggests consistency model improving process performance by modifying memory consistency model and optimistic concurrency control for mapping data's characteristics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1142-1148
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• 2005

We proposes an algorithm of measuring computation loads to distribute workload of clients. The key of the algorithm is to transfer a suitable amount of processing demand from senders to receivers in relocating intrinsically. This amount is determined dynamically during sender-receiver negotiations. Factors considered when this amount is determined include processing speeds of different nodes, the current load state of both sender and receiver, and the processing demands of tasks eligible for relocation. We also propose a load state measurement scheme which is designed particularly for heterogeneous systems. Based on this analysis, we design new algorithm for supporting heterogeneous distributed web server system, and compare their performance against other existing algorithms. We show that the new algorithm improve the performance of CPU utilization and response time.

• The KIPS Transactions:PartA
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• v.12A no.5 s.95
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• pp.427-432
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• 2005

I studied about existent load distribution algorithms and the WLC(Weighted Least Connection) algerian that is using much at present to distribute the connection request of users to real servers efficiently in web cluster system. The efficiency of web cluster system is fallen by load imbalance between servers, because there is problem In inaccurate load status measuring of servers and measuring timing at these load distribution algorithms. In this paper, I suggest an algorithm that distributes load base on various load state of servers by real time using broadcasting RPC(Remote Procedure Call) when a user requests connection, and implement a prototype and experiment its performance. The experiment result shows that load imbalance phenomenon between reai sowers was improved greatly than existing method, and performance of web cluster system was improved by efficiency that response time is shortened.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4347-4366
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• 2015

Distinguished with traditional strategies which offload an application's computation to a single server, parallel computation offloading can promote the performance by simultaneously delivering the computation to multiple computing resources around the mobile terminal. However, due to the variability of communication and computation environments, static application component multi-partitioning algorithms are difficult to maintain the optimality of their solutions in time-varying scenarios, whereas, over-frequent algorithm executions triggered by changes of environments may bring excessive algorithm costs. To this end, an adaptive application component mapping algorithm for parallel computation offloading in variable environments is proposed in this paper, which aims at minimizing computation costs and inter-resource communication costs. It can provide the terminal a suitable solution for the current environment with a low incremental algorithm cost. We represent the application component multi-partitioning problem as a graph mapping model, then convert it into a pathfinding problem. A genetic algorithm enhanced by an elite-based immigrants mechanism is designed to obtain the solution adaptively, which can dynamically adjust the precision of the solution and boost the searching speed as transmission and processing speeds change. Simulation results demonstrate that our algorithm can promote the performance efficiently, and it is superior to the traditional approaches under variable environments to a large extent.