• Smart Media Journal
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• v.4 no.2
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• pp.62-67
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• 2015

During several decades, hard disk drive(HDD) has been used in most computer systems as secondary storage and, however, the performance enhancement of HDD is limited by its mechanical properties. On the other hand, although the flash memory based solid state drive (SSD) has more advantages over HDD such as high performance and low noise, SSD is still too expensive for common usage and expected to take several years to replace HDD completely. Therefore, SSD caching mechanism using the SSD as a cache of high capacity HDD has been highlighted lately. The representatives of SSD caching mechanisms are typically bcache, dm-cache, Flashcache, and EnhanceIO. Each of them has its own internal mechanism and implementation, and this makes them to show their own pros. and cons. In this paper, we analyze the characteristics of each SSD caching mechanisms and compare the performance of them under various workloads. We expect that our contribution will be useful to enhance the performance of SSD caching mechanisms.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.463-470
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• 2012

This paper proposes a new profit popularity-based segment caching control mechanism for assuring a consecutive streaming QoS (Quality of Service) in the wireless channel. Then, the proposed mechanism operates SSCP (Single Segment Caching Profit) and MSCP (Multiple Segment Caching Profit) for assuring a QoS. SSCP and MSCP is to optimize the cache performance when is performed the streaming in the proxy. The proposed mechanism simulated to evaluate such mechanisms as fixed-partition mechanism, weight-based mechanism, SSCP, and MSCP. Simulation results show that the proposed mechanism has superior performance compared to other mechanisms.

• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.291-299
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• 2016

To enhance network efficiency, named-data networking (NDN) implements data caching functionality on intermediate network nodes, and then the nodes directly respond to request messages for cached data. Through the processing of request messages in intermediate node, NDN can efficiently reduce the amount of network traffic, also solve network congestion problems near data sources. Also, NDN provides a data authenticate mechanism so as to prevent various Internet accidents caused from the absence of an authentication mechanism. Hence, through applying NDN to various smart IT convergence services, it is expected to efficiently control the explosive growth of network traffic as well as to provide more secure services. Basically, it is important factors of NDN which data is cached and where nodes caching data is located in a network topology. This paper first analyzes previous works caching content based on the popularity of the content. Then ii investigates the hitting rate of caches in each node of a network topology, and then propose an improved caching scheme based on the result of the analyzation. Finally, it evaluates the performance of the proposal.

• Journal of the Korea Society of Computer and Information
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• v.8 no.2
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• pp.129-134
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• 2003

This paper describes an application level composition mechanism called Generic Modeling Environment(GME) for web caching on an Application Level Active Network(ALAN). Web caching on an ALAN requires the application level composition mechanism and a service composition to support adaptability for self-organization. ALAN was developed to solve the problems of the network level Active Network(AN) ALAN has the features of both AN as well as mobile agents. The efficient composition mechanism for the existing AN Projects has been supported primarily for the network level AN. Conversely, ALAN lacks support for the application level AN The existing web caching technology is inter-connected in a manually configured hierarchical tree. Since a self-organization system is intended to be adaptive, web caching for self-organization does not involve a manual configuration or any low-level tuning of the individual nodes of the entire system but requires service composition to support adapting intelligence and fault-tolerance to enable self-organization.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.50-56
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• 2000

In this paper, for improving the speed of query processing on distributed directory system, we proposed a caching mechanism which is store the queries and their on the remote site objects in the cache of local site. For this, first, cached information which is stored in distributed directory systems is classified as application data and system data. And cache system architecture is designed according to classified information. Second least-TTL replacement mechanism which uses the weighted value of geographical information and access frequency for replacements are developed for each cache. Finally, performance evaluations are performed by comparing the proposed caching mechanism and other mechanisms (LRU, LFU replacement). Our least-TTL mechanism shows a performance improvement of 25% over the LRU and that of 30% over LFU.

• The KIPS Transactions:PartA
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• v.15A no.1
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• pp.17-26
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• 2008

This paper proposes an efficient caching mechanism appropriate for the integrated RFID middleware which can integrate wireless sensor networks (WSNs) and RFID (radio frequency identification) systems. The operating environment of the integrated RFID middleware is expected to face the situations of a significant amount of data reading from RFID readers, constant stream data input from large numbers of autonomous sensor nodes, and queries from various applications to history data sensed before and stored in distributed storages. Consequently, an efficient middleware layer equipping with caching mechanism is inevitably necessary for low latency of request-response while processing both data stream from sensor networks and history data from distributed database. For this purpose, the proposed caching mechanism includes two optimization methods to reduce the overhead of data processing in RFID middleware based on the classical cache implementation polices. One is data stream cache (DSC) and the other is history data cache (HDC), according to the structure of data request. We conduct a number of simulation experiments under different parameters and the results show that the proposed caching mechanism contributes considerably to fast request-response times.

• The Transactions of the Korea Information Processing Society
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• v.6 no.11
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• pp.3077-3085
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• 1999

Conventional caching system doesn't support Real-Time attributes and load balance. To solve these problems, this paper describes the design and implementation of the RIOP(Real-Time Inter-ORB Protocol) to provide QoS guarantees mechanism integrating RSVP and TAO ORB. Futhermore, it provides fast XCSLS(Extended Caching System for Load Balance) implementing main memory cache in Primary Server using locality of objects. In this paper, a key feature is presented : QoS enforcement, PS(Primary Server) and RS(Replicated Server)

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.89-97
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• 2011

In semantic web information system like ontology that access distributed information from network, efficient query processing requires an advanced caching mechanism to reduce the query response time. P2P network system have become an important infra structure in web environment. In P2P network system, when the query is initiated, reducing the demand of data transformation to source peer is important aspect of efficient query processing. Caching of query and query result takes a particular advantage by adding or removing a query term. Many of the answers may already be cached and can be delivered to the user right away. In web environment, semantic caching method has been proposed which manages the cache as a collection of semantic regions. In this paper, we propose the semantic caching technique in cluster environment of peers. Especially, using schema data filtering technique and schema similarity cache replacement method, we enhanced the query processing efficiency.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.1025-1034
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• 2008

In this paper, we developed GridGML for efficiently supplying a GML and visualizing the map with partitioning map and caching method to a mobile device. In order to overcome the weighting of a file, which is the biggest weakness of a GML, GridGML extracts only the most necessary parts for the visualization of the map among GML attributes, and makes the file light as a class instance by applying an offset value. GridGML manages a partition based on the visualization area of a mobile device to visualize the map to a mobile device in real time, and transmits the partition area by serializing it for the benefit of transmission. Also, the received partition area is compounded in a mobile device and is visualized by being partitioned again as four visible areas based on the display of a mobile device. Then, the area is managed by applying a caching algorithm in consideration of repetitiveness for a received map for the efficient operation of resources. Also, in order to prevent the delay in transmission time as regards the instance density area of the map, an adaptive map partition mechanism is proposed for maintaining the transmission time uniformly.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.4
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• pp.420-430
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• 2000

Several caching schemes for realtime multimedia systems have been proposed, but they focus only on increasing the hit ratio without providing any means to utilize the saved disk bandwidth due to cache hits. One of the most important metrics in multimedia systems is the number of clients that the systems can service simultaneously guaranteeing Quality of Service(QoS). Preemptive but Safe Interval Caching(PSIC) was proposed as a caching scheme which makes it possible to provide deterministic QoS.. However, it has no ability to adapt to the change of system environments since it has no mechanism to change the cache size. In this paper, we present a new caching scheme, Dynamic Interval Caching(DIC), which maximizes the performance, regardless of the change of system environments, providing hiccup-free service, by managing memory buffers dynamically. And it is demonstrated that DIC allocates buffer cache optimally, by comparing with PSIC through trace-driven simulations.