• The KIPS Transactions:PartA
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• v.13A no.1 s.98
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• pp.45-52
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• 2006

To perform on-line maintenance for Distributed Information System, it is indispensable to disseminate files to participant nodes in the network. When users' requests for file deployment occur simultaneously in a short period a deployment server falls into overload phase, which is often called Flash Crowds. h common solution to avoid Flash Crowds is to increase hardware capacity. In this paper, we propose a software solution based on P2P, which does not cost any additional expense. In the proposed solution, nodes in the network are grouped into subnetworks one of which is composed of only neighboring nodes. In each subnetwork, copies of deployment files can be transferred to each other. Consequently, it brings about the effect of load balancing in deployment server. To raise the effectiveness, target files for deployment are packed into one package. Before being transferred, each package is divided into multiple equal-sized segments. A deployment server in a normal phase transmits a package requested from nodes in segment units. However a deployment server is overloaded, if segments already exist in the subnetwork participant nodes in the subnetwork receive necessary segments from neighboring nodes. In this paper, we propose data structures and algorithm for this approach and show performance improvement through simulation.

• Journal of Information Processing Systems
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• v.16 no.2
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• pp.301-317
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• 2020

An enterprise patch-management system (PMS) typically supplies a single point of failure (SPOF) of centralization structure. However, a Blockchain system offers features of decentralization, transaction integrity, user certification, and a smart chaincode. This study proposes a Hyperledger Fabric Blockchain-based distributed patch-management system and verifies its technological feasibility through prototyping, so that all participating users can be protected from various threats. In particular, by adopting a private chain for patch file set management, it is designed as a Blockchain system that can enhance security, log management, latest status supervision and monitoring functions. In addition, it uses a Hyperledger Fabric that owns a practical Byzantine fault tolerant consensus algorithm, and implements the functions of upload patch file set, download patch file set, and audit patch file history, which are major features of PMS, as a smart contract (chaincode), and verified this operation. The distributed ledger structure of Blockchain-based PMS can be a solution for distributor and client authentication and forgery problems, SPOF problem, and distribution record reliability problem. It not only presents an alternative to dealing with central management server loads and failures, but it also provides a higher level of security and availability.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.400-402
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• 2001

컴포넌트는 소프트웨어 재사용의 핵심 기술로 인식되고 있으며, 현재 많은 수의 컴포넌트가 개발되고 사용되고 있다[9]. 많은 수의 컴포넌트들 중에서 특정 도메인에 이미 적절하다고 판단된 컴포넌트를 검색해서 사용하는 과정이 필수적이며[6], 이를 위해서 컴포넌트에 대한 정확한 명세서가 뒷받침 되어야 한다. 본 논문에서 다루고 있는 컴포넌트 모델의 하나인 썬(Sun)社의 EJB ver1.1 은 배치설명파일(Deployment Descriptor)을 XML로 기술하고 있으며, DTD로 Validation 체크를 하고 있다. 그러나 DTD 는 표현할 수 있는 데이터 타입에서 한계를 가지며 하나의 XML은 여러 개의 DTD 파일을 가질수 없기 때문에 확장성에서도 취약함을 나타낸다. 이를 해결하기 위해서 XSchema 로 변환하였다. 또한 현재 EJB 의 배치설명파일에서는 컴포넌트의 결합 및 의존성에 대한 표현이 부족하기 때문에 이를 보완하기 위해서 컴포넌트 Contract 에 대한 속성들을 기반으로 하여 새로운 태그를 지정해보도록한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4703-4723
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• 2016

The verification of data integrity is an urgent topic in remote data storage environments with the wide deployment of cloud data storage services. Many traditional verification algorithms focus on the block-oriented verification to resolve the dispute of dynamic data integrity between the data owners and the storage service providers. However, these algorithms scarcely pay attention to the data verification charge and the users' verification experience. The users more concern about the availability of accessed files rather than data blocks. Moreover, the data verification charge limits the number of checked data in each verification. Therefore, we propose a mixed verification protocol to verify the data integrity, which rapidly locates the corrupted files by the file-oriented verification, and then identifies the corrupted blocks in these files by the block-oriented verification. Theoretical analysis and simulation results demonstrate that the protocol reduces the cost of the metadata computation and transmission relative to the traditional block-oriented verification at the expense of little cost of additional file-oriented metadata computation and storage at the data owner. Both the opportunity of data extracted and the scope of suspicious data are optimized to improve the verification efficiency under the same verification cost.

• Journal of Korea Multimedia Society
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• v.15 no.2
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• pp.266-272
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• 2012

Multilingual support of software is necessary for entering global market. 3-tier architecture is a solution for problems of 2-tier architecture. It divides an application into a client-tier and an application-tier, and presentation logic and database are connected by middleware. The advantage of 3-tier architecture is the enhanced performance through load balancing, scalability, easier maintenance and reusability. This paper proposes a multilingual support method that utilizes common resource files for 3-tier enterprise softwares, applies the proposed method to development of multilingual version of billing solution, and verify the usefulness of it. It is easy for development and maintenance of software, the addition of language supported. Proposed method holds a resource file for each language and provides a multilingual support class library. Therefore this method reduces a waste of memory and disk space. Deployment of a class library into an application tier makes development and maintenance of software, the addition of new language supported easy. To avoid inappropriate modification of a resource file, a multilingual support class library is provided in a dll file.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.447-448
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• 2021

The boundary-based security architecture has the advantage of easy deployment of security solutions and high operational efficiency. The boundary-based security architecture is easy to detect and block externally occurring security threats, but is inappropriate to block internally occurring security threats. Unfortunately, internal security threats are increasing in frequency. In order to solve this problem, a zero trust model has been proposed. The zero trust model requires a real-time monitoring function to analyze the behavior of a subject accessing various information resources. However, there is a limit to real-time monitoring of file access of a subject confirmed to be trusted in the system. Accordingly, this study proposes a method to monitor user's file access in real time. To verify the effectiveness of the proposed monitoring method, the target function was verified after the demonstration implementation. As a result, it was confirmed that the method proposed in this study can monitor access to files in real time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.628-631
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• 2014

Recently, the proliferation of new applications, e.g., mobile TV, Internet gaming, large file transfer, and the various of user terminals, e.g., smart phones and notebooks, has dramatically increased user traffic and network load. In order to meet this traffic growth, vendors and cellular operators are working on the development of new technologies and cellular standards. Within them, small cell deployment has been heralded as one of most promising way to increase both coverage and capacity of future cellular network. Small cell technology enables to improve capacity of cellular radio network by tight cooperation between small cell and macro cell in multi-tier network where small cells are densely deployed within macro cell coverage. In this paper, we describe the deployment scenarios for cooperation between macro cell and small cells and state-of-the-art technologies related to dense small cell deployment. Then, we also provide design principles and standardization trends for small cell enhancement in 3GPP.

• Journal of Broadcast Engineering
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• v.6 no.3
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• pp.246-259
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• 2001

Due to recent rapid deployment of Internet streaming service and digital broadcasting service, the issue of how to efficiently support streaming workload in so called "Internet Home Appliance" receives prime interests from industry as well as academia. The underlying dilemma is that it may not be feasible to put cutting edge CPU, boards, disks and other peripherals into that type of device. The primary reason is its cost. Usually, Internet Home Appliances has its dedicated usage, e.g. Internet Radio, and thus it does not require high-end CPU nor high-end Va subsystem. The same reasoning applies to I/O subsystem. In Internet Home Appliances dedicated to handle compressed moving picture, it is not equipped with high end SCSI disk with fast rotational speed. Thus, it is mandatory to devise elaborate software algorithm to exploit the available hardware resources and maximize the efficiency of the system. This paper presents our experiences in the design and implementation of a new multimedia file system which can efficiently deliver the required disk bandwidth for a periodic I/O workload. We have implemented the file system on the Linux operating system, and examined itsperformance under streaming I/O workload. The results of the study show that the proposed file system exhibits superior performance than the Linux Ext2 file system under streaming I/O workload. The result of this work not only contribute to advance the state f art file system technology for multimedia streaming but also put forth the software which is readily available and can be deployed. deployed.

• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1200-1208
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• 2003

Java Card technology allows us to run Java applications on smart cards and other memory-constrained devices. Java Card technology supports high security, portability and ability of storing and managing multiple applications. However, constrained memory resources of the Java Card Platform hinder wide deployment of the Java Card applications. Therefore, in this paper we propose a bytecode optimization algorithm to use the memory of a Java Card efficiently. Our algorithm can reduce the size of the bytecode by sharing the memory of the parameters of the catch clause in the try-catch-finally sentence.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.7
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• pp.4536-4544
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• 2014

This paper proposes a development tool to efficiently develop node software for various operating system platforms in a sensor network. The proposed tool consisted of several modules, such as writing graphical model diagram, PIM and PSM design, code generation, and deployment file generation. Through the proposed tool, the users can graphically draw a sensor network model and design the PIM and PSM of the node software by setting the values of the predefined attributes. The source code of the node software is generated automatically from the PSM using the code templates of the target platform. The deployment files for installing node software on each node are generated automatically. The proposed tool helps the users to develop node software easily for a range of target platforms, even though they do not have details of the low-level information for a sensor network.