• The Journal of the Korea Contents Association
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• v.19 no.5
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• pp.417-425
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• 2019

Storage snapshot technology allows to preserve data at a specific point in time, and recover and access data at a desired point in time. It is an essential technology for storage protection application. Existing snapshot methods have some problems in that they dependent on storage hardware vendor, file system or virtual block device. In this paper, we propose a new snapshot method for solving the problems and creating snapshots on-line. The proposed snapshot method uses a method of extracting the log records of update operations at the virtual file system layer to enable the snapshot method to operate independently on file systems, virtual block devices, and storage hardwares. In addition, the proposed snapshot mehod creates and manages snapshots for directories and files without interruption to the storage service. Finally, through experiments we measure the snapshot creation time and the performance degradation caused by the snapshot.

• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.172-175
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• 2003

The enterprise find a solution to the problems such as a reduction of manufacturing period, accurate analysis for customer demand, improvement for customer service and rise of manufacture accomplishment. Internet is a good solution to such problems. Internet offers WWW(World Wide Web), remote control, file transfer and e-mail service. Among the services, WWW takes large portion because of convenient GUI, easy information search and unlimited information registration. Remote Monitoring Server(RMS) system that uses network service is constructed for chip mounter. Hardware base consists of RMS, chip mounter and C/S(Customer Service) server. Software includes DBMS and various modules in server home page. This provide product number, bad product number, trouble code, content and countermeasure in real-time information module, user information in setup module, detailed error information in fault diagnosis module, fault history in fault history module and customer information in customer service management module.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.355-364
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• 2005

An example of such a new device is a mobile phone. The demand for wireless data communication is growing rapidly. However, agencies have not yet completed the standardization of the markup language. Due to the evolution of the Mobile Device, the agencies in this field have provided different data formats with each Mobile Device Platform. Traditionally, contents are hand-tailored to suit the target devices. A key problem is that the characteristics and capabilities of mobile devices are too diverse to service the most suitable mobile contents. Owing to this problem, the need for a reusable document description language increases. In this paper, we defined Template file that is common data to service mobile devices. We proposed method that could be effective wireless web service though design and the implementation of the Call Manager & the XSL Generator. In the methodology, when requesting wireless internet service, the mobile device finds out Markup language and hardware specification of the mobile device through the Call Manager component supports. The XSL Generator component creates XSL file dynamically that is the most suitable to device. Finally, contents is serviced to each device by XSLT.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.05a
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• pp.459-462
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• 2009

The Growth in wireless Internet has made Networking possible at anytime and anywhere so that application program development is vigorous for mobile service implementation. In particular, mobile service has a feature that can present flexible service at anytime, and anywhere. This study proposes a system which is able to make a remote control of computer by means of mobile as an example of the production of application for such mobile service. This paper researches a RDP(Remote Desktop Protocol), VNC(Virtual Network Computing) system that control screen of remote computer and input devices by using smart-phone. The advantage of this system is the function that turning on and off the computer, file transfer, file upload/download, and paperwork. Therefore users are expected to use more conveniently.

• The Journal of the Korea Contents Association
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• v.12 no.2
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• pp.30-39
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• 2012

In these day, some of IT venders already were going to cloud computing market, as well they are going to expand their territory for the cloud computing market through that based on their hardware and software technology, making collaboration between hardware and software vender. Distributed file system is very mainly technology for the cloud computing that must be protect performance and safety for high levels service requests as well data store. This paper introduced distributed file system for cloud computing and how to use this theory such as memory database, Hadoop file system, high availability database system. now In the market, this paper define a very large distributed processing architect as a reference by kind of distributed file systems through using technology in cloud computing market.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.541-548
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• 2017

The smartphone operates the media server daemon to handle audio service requests. Media server daemons, running with a high privilege in the background, caused many vulnerabilities to applications most frequently used in smart devices including smartphones. Fuzzing is a popularly used methodology to find software vulnerabilities. Unfortunately, fuzzing itself is not much effective in such format-strict environments as media services. In this paper, we propose a file format-aware fuzzing in order to efficiently detect vulnerabilities of media server daemon. We acquired a remote arbitrary code execution vulnerability on iOS/tvOS/MacOS/watchOS, and we verified the effectiveness by comparing our methodology with the fuzzers FileFuzz and ZZUF.

• KSCI Review
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• v.14 no.2
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• pp.109-115
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• 2006

In this paper, we proposed service security model and remote management service on OSGi computing environment. The model is used to make access control decisions like permission-based security inside the java2 platform. In model, policies are defined using a flat text file and include bundles. It method granted flexibility and extendability of access control of bundles and services. Also, we proposed service architecture efficiently for remote management service.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.2
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• pp.72-74
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• 2006

In this paper, a wireless multimedia service interacting with key input of a phone number is Presented. In the conventional handset, when the key button is pressed, numbers are displayed or the embedded sound is played. Also, the contents are fixed and cannot be changed. In this paper, we propose a wireless multimedia service playing multimedia contents in accordance with the key input of a phone number. The contents can be downloaded from the wireless internet server. To implement this service, file format, fast codec and download structure are proposed. Using the presented structure, this service is being provided by a telecommunication company in Korea. Various applications based on this service are being expected.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.662-671
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• 1992

The purpose of this study was to develop a software system for menu planning program in an institutional food service. In this research, a Qnix-7700/AT(16 bit personal computer) compatible with IBM-PC/AT was used and all the files and programs were created by using COBOL. This study provides food service managers with more effective management system by personal computerized menu planning program. Software programs developed in this study were summerized as follows : (1) Programs for outputing standard amounts of the basic food groups. (2) Programs for inputing the cooking type code, the food code and the food amount of the menu. (3) Programs for outputing distribution of the basic food groups of the computerized menu. (4) Programs for calculating the price of each food and menu. (5) Programs for calculating the nutrient content of each food and menu. (6) Programs for outputing the purchasing amount of food. (7) Programs for outputing the menu table. (8) Programs for inputing and modifing the food composition in the food composition file. (9) Programs for inputing and modifing the cooking types in the cooking types file. (10) Programs for inputing and modifing the food prices in the food prices file.