• Journal of KIISE:Computer Systems and Theory
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• v.32 no.11_12
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• pp.557-565
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• 2005

This paper presents the development and implementation of a zero-copy file transfer mechanism that improves the efficiency of file transfers for PC cluster systems using hardware-based VIA(Virtual Interface Architecture) network adapters. VIA is one of the representative user-level communication interfaces, but because there is no library for file transfer, one copy occurs between kernel buffer and user boilers. Our mechanism presents a file transfer primitive that does not require the file system to be modified and allows the NIC to transfer data from the kernel buffer to the remote node directly without copying. To do this, we have developed a hardware-based VIA network adapter, which supports the PCI 64bit/66MHz bus and Gigabit Ethernet, as a NIC, and implemented a zero-copy file transfer mechanism. The experimental results show that the overhead of data coy and context switching in the sender is greatly reduced and the CPU utilization of the sender is reduced to $30\%\~40\%$ of the VIA send/receive mechanism. We demonstrate the performance of the zero-copy file transfer mechanism experimentally. and compare the results with those from existing file transfer mechanisms.

• Journal of Digital Contents Society
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• v.16 no.3
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• pp.389-395
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• 2015

Digital image provides many conveniences at the internet environment recently. A great number of applications, like Digital Library, Stock Image, Personal Image and Important Information, require the use of digital image. However it has fatal defect which is easy to be modified because digital image is only electronic file. Numerous digital image forgeries have become a serious problem due to the sophistication and accessibility of image editing software. Copy-Move forgery is the simplest type of forgery that involves copying portion of an image and paste it on different location within the image. There are many approaches to detect Copy-Move forgery, but all of them have their own limitations. In this paper, visual and invisible feature based forgery detection techniques are tested and analyzed. The analysis shows that pros and cons of these two techniques compensate each other. Therefore, a hybrid of visual based and invisible feature based forgery detection that combine the merits of both techniques is proposed. The experimental results show that the proposed algorithm has enhanced performance compared to individual techniques. Moreover, it provides more information about the forgery, like identifying copy and duplicate regions.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.269-279
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• 2024

The study explores the evolving landscape of overseas expansion strategies by Korean corporations, focusing on recent geopolitical tensions, the COVID-19 pandemic, and disruptions in global supply chains. It emphasizes the challenges faced by industries producing high-value products and delves into the concept of "Friend-Shoring" policies in the United States, leading major Korean companies to invest in local semiconductor, battery, and automotive factories. Recognizing the potential fragmentation of Korea's manufacturing sector, the paper introduces the "Mother Factory" strategy as a policy initiative, inspired by Japan's model, to establish core production facilities domestically. The discussion unfolds by examining the cases of major companies in Japan and the United States, highlighting the need for Korea to adopt a mother factory strategy to mitigate risks associated with friend-shoring policies. Inspired by Intel's "Copy Exactly" approach, the paper proposes a Korean mother factory model integrating smart factory technology and digital twin systems. This strategic shift aims to enhance responsiveness to geopolitical challenges and fortify the competitiveness of Korean high-tech industries. Finally, the paper proposes a Korean Mother Factory based on smart factory concepts. The suggested model integrates smart factory technology and digital twin frameworks to enhance responsiveness and fortify competitiveness. In conclusion, the paper advocates for the adoption of a comprehensive Korean Mother Factory model to address contemporary challenges, foster advanced manufacturing, and ensure the sustainability and competitiveness of Korean high-tech industries in the global landscape. The proposed strategy aligns with the evolving dynamics of the manufacturing sector and emphasizes technological advancements, collaboration, and strategic realignment.

• Journal of KIISE:Software and Applications
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• v.26 no.8
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• pp.955-963
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• 1999

다단계 보안 실시간 데이타베이스 시스템은 데이타베이스의 일관성 유지와 실시간 요구인 마감시간의 만족, 그리고 기밀성을 띤 데이타가 노출될 수 있는 비밀채널(covert-channel)의 방지라는 요구사항을 모두 만족해야 한다. 기존의 SRT-2PL(Secure Real-Time 2 Phase Locking)은 원본과 복사본으로 데이타 객체를 분리시켜 다른 등급간에 불간섭(non-interference)을 유지하여 비밀채널의 방지를 가능하게 하였으나, 복사본이 모든 데이타 객체에 대해 항상 존재하므로 메모리의 낭비가 있을 수 있고, 복사본의 갱신을 위한 갱신 큐의 관리에 따르는 오버헤드와 그에 따른 예측성 결여라는 문제점을 갖고 있다. 이를 개선하기 위하여 본 논문에서는 다단계 보안 실시간 데이타베이스 시스템의 요구사항을 모두 만족하는 동적 복사 프로토콜을 제안한다. 동적 복사 프로토콜은 로킹 기법을 기초로 동작하고, 트랜잭션의 작업에 따라 동적으로 복사본을 생성하고 삭제한다. 모의 실험 결과 제안한 동적 복사 프로토콜은 비밀채널을 방지하고 동적인 복사본의 생성으로 SRT-2PL의 단점인 메모리 낭비를 줄일 수 있으며, 예측성을 높여 마감시간 오류율을 감소시켰다.Abstract Concurrency control of real-time secure database system must satisfy not only logical data consistency but also timing constraints and security requirements associated with transactions. These conflicting natures between timing constraints and security requirements are often resolved by maintaining several versions(or secondary copies) on the same data items. In this paper, we propose a new lock-based concurrency control protocol, Dynamic Copy Security Protocol, ensuring both two conflicting requirements. Our protocol aims for reducing the storage overhead of maintaining secondary copies and minimizing the processing overhead of update history. Main idea of our protocol is to keep a secondary copy only when it is needed to resolve the conflicting read/write operations in real time secure database systems. For doing this, a secondary copy is dynamically created and removed during a transaction's read/write operations according to our protocol. We have also examined the performance characteristics of our protocol through simulation under different workloads while comparing the existing real time security protocol. The results show that our protocol consumed less storage and decreased the missing deadline transactions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.91-99
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• 2014

The main game architectures for multiplayer online games are the traditional client-server architectures, multi-server architectures and P2P(peer-to-peer) architectures. P2P architectures, due to their distributed and collaborative nature, have low infrastructure costs and can achieve high scalability as well as fast response time by creating direct connections between players. However, P2P architectures face many challenges. Distributing a game among peers makes maintaining control over the game more complex. These architectures also tend to be vulnerable to churn and cheating. Providing consistency control in P2P systems is also more difficult since conflicting updates might be executed at different sites resulting in inconsistency. In order to avoid or correct inconsistencies, most multiplayer games use a primary-copy replication approach where any update to the object has to be first performed on the primary copy. This paper presents the primary-copy model with the update dissemination mechanism that provides consistency control over an object in P2P architectures for multiplayer online games. The performance for this model is evaluated through simulation experiments and analysis.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.57-67
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• 2015

This paper describes and analyzes IBC (intra block copy) in HEVC (high efficiency video coding) SCC (screen content coding) to improve the coding efficiency of IBC. HEVC SCC reference software SCM 2 is employed to analyze the selection ratio of IBC which is newly adopted in HEVC SCC, and the tools for IBC such as the block vector prediction and block vector coding method are evaluated. Experimental results show the average IBC selection ratio is 31.08% and 0.33% in I-Slice and B-Slice, respectively. Based on this results, the coding efficiency of IBC could be improved by utilizing IBC selectively. In addition, analysis tests of block vector prediction and the block vector coding method show the current methods are not efficient to screen content videos, and the analysis results are presented to improve these methods.

• KIISE Transactions on Computing Practices
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• v.21 no.12
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• pp.786-791
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• 2015

The environment of Internet of Things (IoT) wherein various devices are connected through the Internet with value-added network functions, is currently a subject of active study. Accordingly, the existing computing environment based on desktop or mobile systems is being expanded into a computing environment of more diverse devices. Because the response of program launching is important in terms of User Experience (UX) in IoT environments, the technology for guaranteeing rapid response of program launching in IoT devices is getting the focus of much current research. In this paper we analyze the Zygote technique, which is being used for faster program execution in Android systems, and, based on our results, we propose an address space maintaining scheme for the rapid launching of programs for use in Linux-based systems. Our scheme utilizes the Copy on Write (CoW) technique in Linux systems as well as the Zygote technique of Android systems. In order to evaluate the proposed scheme, we implemented our scheme on Linux systems and performed several experiments. The experimental results show that the proposed scheme shortens the launching time up to 99%, compared to the existing technique.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.807-811
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• 2007

In this paper, we introduce an application virtualization method that could be supported without changing and modifying any resources and execution environment on host system, using non-installable portable software format that could be executed by one-click on any host without installing process. For the purpose of designing and implementing an application virtualization method, we construct virtual supporting system that includes virtual file system and virtual registry hive on kernel level of Windows operating system. Also, when users execute portable software on any hosts to provide consistency on using portable software, we describe method of processing information of appending and modifying files and registry datum on virtual file system and virtual registry hive through Copy-on-Write scheme.

• The KIPS Transactions:PartD
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• v.18D no.2
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• pp.89-100
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• 2011

The CNV (Copy Number Variation) which is one of the genetic structural variations in human genome is closely related with the function of gene. In particular, the genome-wide association studies for genetic diseased persons have been researched. However, there have been few studies which infer the genetic function of CNV with normal human. In this paper, we propose the analysis method to reveal the functional relationship between common CNV and genes without considering their genomic loci. To achieve that, we propose the data integration method for heterogeneity biological data and novel measurement which can calculate the correlation between common CNV and genes. To verify the significance of proposed method, we has experimented several verification tests with GO database. The result showed that the novel measurement had enough significance compared with random test and the proposed method could systematically produce the candidates of genetic function which have strong correlation with common CNV.

• Journal of IKEEE
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• v.20 no.4
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• pp.432-434
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• 2016

In conventional SIDO(Single Inductor Dual Output) boost converter, charging time is changed by load power consumption. In this case, if the power consumption of one load is changed to such a degree that switching frequency of the boost converter must be changed, another load charge time is also changed, which this causes cross regulation. In this paper, the charge copy technique is proposed to reduce cross regulation. When the switching frequency is changed to an integer ratio, another load charge time is also changed to integer ratio. Simulation result shows that proposed method reduces the 10.24mV cross regulation and 39.118us recover-time compared with conventional method.