• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.77-82
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• 2022

Due to the recent advent of fast storage media, the memory management system needs to reconsider the configuring of a page unit. In this paper, we analyze the effect of the page size on memory performance as fast storage is adopted. Specifically, we analyze the TLB hit ratio and the page fault ratio as the workload and the page size are varied in desktop and smartphone environments. Our analysis shows that the influence of the page size depends on the system and workload conditions in desktop systems. However, in smartphone systems, the effect of the page size on memory performance is not large, and is not also sensitive to workloads. We expect that the analysis of this paper will be helpful in configuring the page size of given workloads under the system with fast storage media.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.44-46
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• 2005

Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time. Today any data storage system cannot satisfy these conditions, however holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System can be constructed without mechanical actuating part therefore fast data transfer rate and high storage capacity about $1Tb/cm^3$ can be realized. In this paper, to reduce errors of binary data stored in holographic data storage system, a new method for bit error reduction is suggested. We proposal Algorithm use The Extended Kalman filter. The Kalman filter reduce measurement noise. Therefore, By using this error reduction method following results are obtained; the effect of measurement nois of Pixel is decreased and the intensity profile of data page becomes uniform therefore the better data storage system can be constructed.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.129-133
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• 2005

Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time. Today any data storage system cannot satisfy these conditions, however holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System can be constructed without mechanical actuating part therefore fast data transfer rate and high storage capacity about $1Tb/cm^3$ can be realized. In this paper, to reduce errors of binary data stored in holographic data storage system, a new method for bit error reduction is suggested. First, find cluster centers using subtractive clustering algorithm then reduce intensities of pixels around cluster centers and fuzzy rules. Therefore, By using this error reduction method following results are obtained ; the effect of Inter Pixel Interference noise is decreased and the intensity profile of data page becomes uniform therefore the better data storage system can be constructed.

• Journal of the Korea Computer Industry Society
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• v.5 no.2
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• pp.293-300
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• 2004

In this paper, we devise both methods supporting interactive VCR-like functions for MPEG stream and minimizing the storage space. Specifically, we proposed both methods to efficiently stripe MPEG stream into multiple disks, and an access strategy to retrieve the distributed streams over the disks. To accurately locate the streams to be referred to, we introduce a table indexing the location. When client request Fast Forward(FF)/Fast Backward(FB), VOD(Video on Demand) server refer to this index table supporting FF/FB functions. Experimental result shows that the proposed method can reduce the additional storage space needed when VOD server services FF/FB functions.

• Transactions of the Society of Information Storage Systems
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• v.3 no.4
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• pp.167-172
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• 2007

The recently-developed off-line learning control approaches for the rejection of periodic disturbances utilize the specific property that the learning system tends to oscillate in steady state. Unfortunately, the prior works have not clarified how closely the learning system should approach the steady state to achieve the rejection of periodic disturbances to satisfactory level. In this paper, we address this issue extensively for the class of linear systems. We also attempt to remove the effect of other aperiodic disturbances on the rejection of the periodic disturbances effectively. In fact, the proposed learning control algorithm can provide very fast convergence performance in the presence of aperiodic disturbance. The effectiveness and practicality of our work is demonstrated through mathematical performance analysis as well as various simulation results.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1260-1263
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• 2005

Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time. Today any data storage system cannot satisfy these conditions, however holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System can be constructed without mechanical actuating part therefore fast data transfer rate and high storage capacity about 1Tb/cm3 can be realized. In this research, to reduce errors of binary data stored in holographic data storage system, a new method for bit error reduction is suggested. First, find fuzzy rule using experimental system for Element of Holographic Digital Data System. Second, make fuzzy rule table using Genetic algorithm. Third, reduce prior error element and recording Digital Data. Recording ratio and reconstruction ratio will be very good performance

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.65-70
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• 2022

As fast storage has become popular, the memory management system designed for hard disks needs to be reconsidered. In this paper, we observe that memory access latency is sensitive to the page size when fast storage is adopted. We find the reason from the TLB miss rate, which has the increased impact on the memory access latency in comparison with the page fault rate, and there is trade-off between the TLB miss rate and the page fault rate as the page size is varied. To handle such situations, we model the page fault rate and the TLB miss rate accurately as a function of the page size. Specifically, we show that the power fit and the exponential fit with two terms are appropriate for fitting the TLB miss rate and the page fault rate, respectively. We validate the effectiveness of our model by comparing the estimated values from the model and real values.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.93-98
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• 2022

Recently, fast storage media such as Optane have emerged, and memory system configurations designed for disk storage should be reconsidered. In this paper, we analyze the effect of the page size on the memory system performances when fast storage is adopted. Based on this, we design a page size model that can guide an appropriate page size for given workloads in virtualized environments. Configuring different page sizes for various workloads is not an easy matter in traditional systems, but due to the widespread adoption of cloud systems, page sizing performed in our model is feasible for virtual machines, which are generated for executing specific workloads. Simulation experiments under various virtual machine scenarios show that the proposed model improves the memory access time significantly by configuring page sizes for given workloads.

• Journal of Hydrogen and New Energy
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• v.34 no.6
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• pp.608-614
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• 2023

The fast filling process of high-pressure hydrogen has an important impact on the filling efficiency and safety. In this paper, a specific study is carried out on the thermophysical phenomena during the fast filling process. Starting from the gas state equation of hydrogen, the change law of the hydrogen storage temperature is obtained, and then the temperature rise prediction is constructed. The model can clarify the relationship between the filling parameters and the temperature rise during the fast filling process, thereby revealing the flow and heat transfer laws of the fast charging process. To improve the theoretical research basis for the evaluation of vehicle-mounted hydrogen fast charging capacity, temperature prediction and optimization of hydrogenation methods.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.3
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• pp.315-319
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• 2020

The modern transportation and mobility sector is expected to encounter high penetration of Electric Vehicles (EVs) because EVs contribute to reducing the harmful emissions from fossil fuel-powered vehicles. With the prospective growth of EVs, sufficient and convenient facilities for fast charging are crucial toward satisfying the EVs' quick charging demand during their trip. Therefore, the Fast Electric Vehicle Charging Stations (FECS) will be a similar role to gas stations. In this paper, we study a charging scheduling problem for the FECS with solar photovoltaic (PV) and an Energy Storage System (ESS). We formulate an optimization problem that minimizes the operational costs of FECS. There are two cost and one revenue terms that are buying cost from main grid power, ESS degradation cost, and revenue from the charging fee of the EVs. Simulation results show that the proposed scheduling algorithm reduces the daily operational cost by effectively using solar PV and ESS.