• Transactions on Control, Automation and Systems Engineering
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• v.4 no.4
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• pp.319-323
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• 2002

In this paper, we consider the track-following control problem in the optical data storage systems in the presence of the eccentricity. The eccentricity results in the radial deviation of the objective lens so that it degrades the reliability of the data decoding system. To cope with the eccentricity, an adaptive disturbance compensation technique is newly proposed in the time domain based on a disturbance observer of reduced order, which effectively estimates the low frequency components of the disturbance. The proposed compensator is simply added to the conventional feedback control. The error dynamics of the observer and the sensitivity analysis are given to illustrate the effectiveness of the proposed approach. Finally, through experiments in an optical storage system, the feasibility of the proposed approach is verified.

• Smart Media Journal
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• v.7 no.2
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• pp.71-77
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• 2018

This paper proposes the components of the energy management system (EMS) for optimum operation of renewable energy and associated energy storage system (ESS), the functions to be considered in designing, the analysis of operational effects, and finally the reduction of electricity costs. To accomplish the objectives, a lithium-ion battery system and an energy management system have installed in a PV system, and it presents the results analyzed with operation data for a year. To increase the system operation efficiency, we propose the effect that EMS is used to replace the demand power at the peak time with the charge power at the light load time, which suggests the influence of contributing to the charge benefit and load leveling according to the ESS tariff.

• Proceedings of the KAIS Fall Conference
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• 2008.05a
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• pp.218-219
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• 2008

Solid State Disks(SSD) are one of the best candidates to support next storage technology in desktop and server computing environment. The features of non-volatility, low power consumption, and fast access time for read operations are sufficient grounds to support SSD as major components of future storages. This paper describes a technical trend of HDD based RAID technology and proposes a new RAID system for SSD.

• Journal of Digital Contents Society
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• v.10 no.3
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• pp.461-468
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• 2009

In a recent year, the broadcasting system has been changed from analogue to digital all over the world, not just in Korea, and Korea aims at accomplishing 100% digital broadcasting by 2013. The HD(High Definition) Video Format, which currently plays a key role in digital broadcasting system, has been gradually extended in the field of broadcasting and movie. Additionally, many kinds of camcoders and editing systems have been rapidly converted into the digital types, and they are supporting to photograph and video editing systems with the various types of image formats such as SD(Standard Definition) format, HD format, 2K, 4K, etc. Tape Video Storage System, which has been usually used in the stage of photographing by this day, is gradually evolving into Tapeless Video Data Storage System. Thus in this study, Video Compression method of HD format photographed by Sony PMW-EX3, one of major tapeless camcoders, is studied and also the way of applying it effectively in Avid Media Composer, a non-linear editing system, is discussed.

• IE interfaces
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• v.8 no.2
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• pp.171-183
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• 1995

A special purpose automated storage and retrieval system is developed in which information media such as compact disc or video tapes can be stored. Hardware system includes rack, stacker crane with robot arm, conveyor, and bar code reader. Software system includes database for address management, user interface for quick scanning of information media by displaying moving image, and algorithms for selecting the closest open location. Such system is widely applicable to CD library or broadcasting station in the forthcoming information age. In this paper we present detailed procedure and tools that are used in designing and implementing such a special AS/R system.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.15-20
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• 2015

Bit patterned media (BPM) is a high capacity storage system and has attracted a great deal of attention as next generation data storage. When BPM is made with high density, the space between the islands narrows, because BPM records one bit in an island. For this reason, BPM has inter-symbol interference in all directions, unlike in current storage systems where it is in only one direction. In this paper, we propose an equation for compensating two-dimensional ISI. We conduct experiments on track misregistration. When using the proposed inter-symbol interference preprocessing, the BER performance is improved, regardless of the amount of track misregistration.

• Journal of Internet of Things and Convergence
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• v.9 no.1
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• pp.19-24
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• 2023

Recently, with the recent rapid development of memory technology, various types of memory are developed and are used to improve processing speed in data management systems. In particular, NAND flash memory is used as a main media for storing data in memory-based storage devices because it has a nonvolatile characteristic that it can maintain data even at the power off state. However, since the recently studied memory-based storage device consists of various types of memory such as MRAM and PRAM as well as NAND flash memory, research on memory management technology is needed to improve data processing performance and efficiency of media in a storage system composed of different types of memories. In this paper, we propose a memory mapping scheme thought technique for efficiently managing data in the storage device composed of various memories for data management. The proposed idea is a method of managing different memories using a single mapping table. This method can unify the address scheme of data and reduce the search cost of data stored in different memories for data tiering.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2010.07a
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• pp.360-363
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• 2010

Streaming Technology can support the real-time playback without downloading and storing multimedia data in local HDD. So, client browser or plug-in can represent multimedia data before the end of file transmission using streaming technology. Recently, the demand for efficient real-time playback and transmission of large amounts of multimedia data is growing rapidly. But most users' connections over network are not fast and stable enough to download large chunks of multimedia data. In this paper, we propose an intelligent IP streaming system based on personalized media service. The proposed IP streaming system enables users to get an intelligent recommendation of multimedia contents based on the user preference information stored on the streaming server or the home media server. The supposed intelligent IP streaming system consists of Server Metadata Agent, Pumping Server, Contents Storage Server, Client Metadata Agent and Streaming Player. And in order to implement the personalized media service, the user information, user preference information and client device information are managed under database concept. Moreover, users are assured of seamless access of streamed content event if they switch to another client device by implementing streaming system based on user identification and device information. We evaluate our approach with manufacturing home server system and simulation results.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.475-480
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• 2000

The transient dynamic-response analysis of fuel-storage tanks of flying vehicles accelerating in the vertical direction is achieved with finite element method. A fuel-storage tank is a representative example of the fluid-structure interaction problem, in which structure and fluid media interact strongly. For the accurate analysis of this complicated fluid-structure system, we employed ALE(arbitrary Lagrangian-Eulerian) coupling method. Two types of fuel-storage tanks, one with two baffles and the other without baffle, are considered to examine the effect of baffles. The fuel-storage tank with baffles shows more uniform hydrodynamic pressure distribution, resulting effective stress in structural region and faster convergence from transient to steady states. MSC/Dytran, a commercial FEM software for the 3D coupled dynamic analysis, is used for this analysis.

• Information Systems Review
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• v.9 no.3
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• pp.133-156
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• 2007

The wide spread of the Internet and personal computers does not only alter the form of content from analog to digital, but also lead to the emergence of a new digital media system that is different from analog media system. The digital media system is a convergent media that includes both public and private systems from the perspective of use-limitation, as well as storage and enjoyment systems from the perspective of use-purpose. The major goal of this research is to suggest and empirically verify an effective way of presenting the perception of places that are converged in the digital media system. Involvement and motivation are suggested as key conceptual factors and color contrast and hue are suggested as concrete design factors to make people perceive corresponding places. Results of our controlled experiment indicated that the color contrast and hue significantly affected the perception of place, and consequently, influenced usability of the digital media system. This paper ends with implications that can be used to construct appropriate perception of places for the media system of digital products.