• Journal of Digital Contents Society
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• v.12 no.2
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• pp.141-150
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• 2011

Recently the Solid State Drive (SSD) is widely used for storage system of various mobile devices. In this case, existing buffer replacement algorithms based on the hard disk do not consider characteristics of flash memory, so it caused performance degradation of the system. This paper proposes a novel buffer replacement policy called ABM (Asymmetric Buffer Management) policy. ABM policy separates read and write buffer space and applies different replacement unit and replacement algorithm for each buffer. In addition, write buffer delay scheme and dynamic size adaptation algorithm is applied for better performance. ABM outperforms other replacement policies, especially ABM-LRU-CLC shows 32% better performance than normal LRU policy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.10B
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• pp.1648-1664
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• 2000

This paper proposes a real-time dynamic storage allocation algorithm QSHF(quick-segregated-half-fit) that provides various memory allocation policies. that manages a free block list per each word size for memory requests of small size good(segregated)-fit policy that manages a free list per proper range size for medium size requests and half-fit policy that manages a free list per proper range size for medium size requests and half-fit policy that manages a free list per each power of 2 size for large size requests. The proposed algorithm has the time complexit O(1) and makes us able to easily estimate the worst case execution time(WCET). This paper also suggests two algorithm that finds the proper free list for the requested memory size in predictable time and if the found list is empty then finds next available non-empty free list in fixed time. In order to confirm efficiency of the proposed algorithm we simulated the memory utilization of each memory allocation policy. The simulation result showed that each policy guarantees the constant WCET regardless of memory size but they have trade-off between memory utilization and list management overhead.

• Journal of Korea Multimedia Society
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• v.22 no.10
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• pp.1199-1207
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• 2019

Video surveillance data, which is used for preemptive or post-emptive action against any event or accident, is required for monitoring the location, but is reducing the capacity of the image data by removing intervals for cost reduction and system persistence. Such a video surveillance system is fixed in a certain position and monitors the area only within a limited angle, or monitors only the fixed area without changing the angle. At this time, the video surveillance system that is monitored only within a limited angle shows that the variation object such as the floating population shows different status in the image, and the background of the image maintains a generally constant appearance. The static objects in the image do not need to be stored in all the images, unlike the dynamic objects that must be continuously shot, and occupy a storage space other than the necessary ones. In this paper, we propose a mechanism to analyze the image, store only the small size image for the fixed background, and store it as image data only for variable objects.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.141-148
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• 2013

Smart grid can two-way communication using ICT(Information & Communication Technology). Also, smart grid can supply to dynamic power that grafted to electric vehicle can activate to electric vehicle charging infrastructure and used to storage battery of home. Storage battery of home can resale to power provider. These electric vehicle charging infrastructure locate fixed on home, apartment, building, etc charging infrastructure that used fluid on user. If don't authentication for user of fluid user use to charging infrastructure, electric charging service can occurred to illegal use, electric charges and leakgage of electric information. In this paper, we propose smartcard and dynamic ID based user authentication scheme for used secure to electric vehicle service in smart grid environment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.70-81
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• 2011

In this paper, a multi-agent control system for DC-coupled photovoltaic (PV), fuel cell (FC), ultracapacitor(UC) and battery hybrid power system is studied for commercial buildings & apartment buildings microgrid. In this proposed system, the PV system provides electric energy to the electrolyzer to produce hydrogen for future use and transfer to the load side, if possible. Whenever the PV system cannot completely meet load demands, the FC system provides power to meet the remaining load. A multi-agent system based-power management and control algorithm is proposed for the hybrid power system by taking into account the characteristics of each power source. The main works of this paper are hybridization of alternate energy sources with FC systems using long and short storage strategies to build the multi-agent control system with pragmatic design, and a dynamic model proposed for a PV/FC/UC/battery bank hybrid power generation system. A dynamic simulation model for the hybrid power system has been developed using Matlab/Simulink, SimPowerSystems and Stateflow. Simulation results are also presented to demonstrate the effectiveness of the proposed multi-agent control and management system for building microgrid.

• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.61-67
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• 2020

This paper is to propose a hybrid memory adaptor using next-generation nonvolatile memory devices such as phase-change memory to improve the performance limitations of OpenStack-based object storage systems. The proposed system aims to improve the performance of the account and container servers for object metadata management. For this, the proposed system consists of locality-based dynamic page buffer, write buffer, and nonvolatile memory modules. Experimental results show that the proposed system improves the hit rate by 5.5% compared to the conventional system.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.438-449
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• 2018

Recently, various graph data have been utilized in various fields such as social networks and citation networks. As the graph changes dynamically over time, it is necessary to manage the graph historical data for tracking changes and retrieving point-in-time graphs. Most historical data changes partially according to time, so unchanged data is stored redundantly when data is stored in units of time. In this paper, we propose a graph history storage management method to minimize the redundant storage of time graphs. The proposed method continuously detects the change of the graph and stores the overlapping subgraph in intersection snapshot. Intersection snapshots are connected by a number of delta snapshots to maintain change data over time. It improves space efficiency by collectively managing overlapping data stored in intersection snapshots. We also linked intersection snapshots and delta snapshots to retrieval the graph at that point in time. Various performance evaluations are performed to show the superiority of the proposed scheme.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.5
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• pp.1708-1734
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• 2022

In the development of logistics system, the breakthrough of important technologies such as technology platform for logistics information management and control is the key content of the study. Based on Javascript and JQuery, the logistics system realizes real-time monitoring, collection of historical status data, statistical analysis and display, intelligent recommendation and other functions. In order to strengthen the cooperation of warehouse storage, enhance the utilization rate of resources, and achieve the purpose of real-time and visual supervision of transportation equipment and cargo tracking, this paper studies the VNF dynamic deployment and SFC routing problem in the network load change scenario based on the logistics system. The BIP model is used to model the VNF dynamic deployment and routing problem. The optimization objective is to minimize the total cost overhead generated by each SFCR. Furthermore, the application of the SFC mapping algorithm in the routing topology solving problem is proposed. Based on the concept of relative cost and the idea of topology transformation, the SFC-map algorithm can efficiently complete the dynamic deployment of VNF and the routing calculation of SFC by using multi-layer graph. In the simulation platform based on the logistics system, the proposed algorithm is compared with VNF-DRA algorithm and Provision Traffic algorithm in the network receiving rate, throughput, path end-to-end delay, deployment number, running time and utilization rate. According to the test results, it is verified that the test results of the optimization algorithm in this paper are obviously improved compared with the comparison method, and it has higher practical application and promotion value.

• Management Science and Financial Engineering
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• v.18 no.1
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• pp.39-48
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• 2012

This article presents a way of tackling a special class of space optimization problems that arise in a number of practical applications in industry and elsewhere. It presents an elegant solution to a problem that was considered by (Das, 2005) in optimizing storage space in warehouse of a footwear manufacturing company. In (Das, 2005), the problem was formulated as a nonlinear programming problem. In this article, it is shown that the problem can be formulated as a generalized transportation problem which is a special case of generalized network flow problems. Further, an elegant scheme is devised to handle the dynamic situation of warehousing problem which can be easily translated into a decision support system for the warehouse management system. Also, the article points out certain obscurities and gaps in (Das, 2005).

• Journal of Korean Society of Rural Planning
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• v.3 no.1
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• pp.96-104
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• 1997

The purpose of this study is to develop a dynamic DSS (Decision Support System) interfaced with GIS (Geographic Information System) and agriculture information network, In this study, DSS was developed to assist services which required tremendous and real time data in national scale. The data transmitte'd from the local area by the agriculture network were stored in DBMS (Data Base Management System) and analyzed by GIS. GIS and database tools used in this study were ARC/INFO 7.1.1 and INFORMIX 4.0. ACSAS (Agriculture Calamity Service Asist System) by the system prototype was constructed to solve the problem about the drought counterplan service which was to take the responsibility in the Ministry of Agriculture. It was easy to transfer, process, and analyze the information using the system. Specially, the meteological, the reservoir storage rate and the drought counterplan information were spatially analyzed by the functions of GIS.