• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2151-2159
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• 2015

Unlike an existing IP routing methods, the Content Centric Network(CCN) is new networking paradigm to find the contents by content name. The CCN can effectively process the content requested repeatedly by the user because of the cache which can be storing a content. This paper proposes a popularity based cache replacement scheme. The proposed scheme improves the hit rate better than a existing scheme. Accordingly reducing the load of server and Round Trip Time(RTT).

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.563-565
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• 2003

최근 클러스터에 대한 연구는 내용 기반 클러스터의 부하 분배와 캐시 정책에 집중되고 있다. 본 논문에서는 웹 서비스의 고가용성 및 확장성을 제공하는 클러스터 환경에서 힌트 기반 협력적 캐싱의 캐시 적중률을 향상시키기 위해 기존의 DFR 기법을 개선하였다. 서비스 접근 확률을 이용하여 주 복사본과 종속 복사본을 선택적으로 제거하는 메모리 교체 방법을 제시하였으며, DFR 방식과 성능을 비교, 분석한 결과 DFR 방식보다 적은 디스크 접근률을 얻을 수 있었다.

• Proceedings of the IEEK Conference
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• 2000.06c
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• pp.47-50
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• 2000

In this paper, we propose a new destage algorithms, called the Dynamic Adaptive Threshold which determines turn-on and turn-off thresholds dynamically depending on the current write cache occupancy level and the differential rate of the host write requests. For performance evaluation, the proposed algorithm is compared with the wellknown High-Low Water Mark (HLWM) algorithm. Performance tests are fulfilled with our cached RAID 5 simulator. The simulation results show that the proposed algorithm outperforms the HLWM algorithm in terms of response time of host reads and write cache hit ratio under various workloads.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.793-795
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• 2005

영속적인 데이터 저장이 가능한 차세대 비휘발성 메모리를 휘발성 메모리와 혼용하여 버퍼캐처로 사용하면, 안정성과 성능향상의 효과를 얻을 수 있다. 본 연구에서는 기존의 연구에서 제시한 캐처관리 정책을 시뮬레이터를 이용하여 실험하고 실험 결과를 분석하여 비휘발성 메모리가 추가된 캐처의 새로운 특성을 밝혀냈다. 비휘발성 메모리가 캐쉬에 포함되면 읽기 쓰기의 요청의 종류, 미스(miss)되었을 경우 캐쉬될 블록의 더티(dirty)여부, 읽기 요청이 적중(hit)되었을 때, 적중된 블록의 메모리 종류에 따라 각각의 요청을 처리하기 위한 디스크 접근횟수가 달라지는 특성을 나타낸다. 이 특성 때문에 비휘발성 메모리가 추가된 버퍼캐처는 적중률(hit rate) 보다는 디스크 접근횟수를 측정하는 것이 정확한 성능측정을 가능하게 한다.

• Journal of KIISE
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• v.41 no.11
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• pp.871-877
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• 2014

Cache replacement algorithms have been developed in order to reduce miss counts. In modern processors, the performance gap between the processor and main memory has been increasing, creating a more important role for cache replacement policies. The Least Recently Used (LRU) policy is one of the most common policies used in modern processors. However, recent research has shown that the performance gap between the LRU and the theoretical optimal replacement algorithm (OPT) is large. Although LRU replacement has been proven to be adequate over and over again, the OPT/LRU performance gap is continuously widening as the cache associativity becomes large. In this study, we observed that there is a potential chance to improve cache performance based on existing LRU mechanisms. We propose a method that enhances the performance of the LRU replacement algorithm based on the access proportion among the lines in a cache set during a period of two successive replacement actions that make the final replacement action. Our experimental results reveals that the proposed method reduced the average miss rate of the baseline 512KB L2 cache by 15 percent when compared to conventional LRU. In addition, the performance of the processor that applied our proposed cache replacement policy improved by 4.7 percent over LRU, on average.

• Journal of the Korea Computer Industry Society
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• v.2 no.11
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• pp.1453-1464
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• 2001

Explosive growth of Internet populations results performance degradations of web service. Popular web sites cannot provide proper level of services to many requests, and such poor services cannot give user a satisfaction. Web caching, the remedy of this problem, reduces the amount of network traffic and gives fast response to user. In this paper, we analyze the characteristics of web cache traffics using traces of NLANR(National Laboratory for Applied Network Research) root caches and Education network cache in Seoul National University. Based on this analysis, we suggest a method of prefetching and we discuss the gains of our prefetching. As a result, we find proposed prefetching enhances hit rate up to 3%, response time up to 5%.

• Journal of Digital Contents Society
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• v.16 no.2
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• pp.257-262
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• 2015

Recently, the interests of mobile GIS technology is increasing with the spread of wireless network, the improvement of mobile device's performances, and the growth of demands about mobile services. Providing services in a wireless environment with existing wired-based GIS solutions have many limitations such as slow communication, processing rates and screen size. In this paper, we propose a cache algorithm on client side to solve the above problems. The proposed algorithm demonstrates the performance improvement over known studies by utilizing unit time and spatial proximity. In addition, this paper conducts a performance evaluation to measure the improvement in algorithm efficiency and analyzes the results of the performance evaluation. When spatial data queries are conducted, according to our performance evaluation, hit rate has been improved over the existing algorithms.

• Journal of the Korea Society of Computer and Information
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• v.26 no.1
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• pp.111-118
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• 2021

This paper proposes a novel method of caching contents that can be encoded into multiple quality levels in device-to-device (D2D)-assisted caching networks. Different from the existing caching schemes, the author allows caching fractions of an individual file and considers the self cache hit event, which the user can find the desired content in its device. The author analyzes the tradeoff between the quality of cached contents and the cache hit rate, and proposes the device caching method maximizing the expected quality that the user can enjoy. Depending on the parameter of the relationship between the quality and the file size, the optimal caching method can be obtained by solving the convex optimization problem and the DC programming problem. If the file size increases faster than the quality, the cached fractions of the contents continuously increase as the popularity grows. Meanwhile, if the file size increases slower than the quality, some of the high-popularity files are entirely cached but others are not cached at all.

• Journal of Internet Computing and Services
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• v.1 no.1
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• pp.27-34
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• 2000

Recently, the use of Geographic Information System in each field of our society is on the increase according to the development of the Internet. But, thereis a problem of the user access latencies, the network traffic, and the server overload in Internet Geographic Information System because spatial data are transferred in large volumes. In this paper, we propose a cache algorithm on client side to solve the above problems. The proposed algorithm demonstrates the performance improvement over known studies by utilizing unit time and spatial proximity. In addition, this paper conducts a performance evaluation to measure the improvement in algorithm efficiency and analyzes the results of the performance evaluation. When spatial data queries are conducted, according to our performance evaluation, hit rate has been improved over the existing algorithms.

• Journal of Digital Contents Society
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• v.10 no.3
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• pp.395-400
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• 2009

The wide spread of the Internet service has brought in web GIS development. But, there are problems of the user access latencies, the network traffic, and the server overload in Internet Geographic Information System because spatial data are transferred in large volumes. In this paper, I propose a cache algorithm on client side to solve the above problems. The proposed algorithm demonstrates the performance improvement over known studies by utilizing unit time and spatial proximity. In addition, this paper conducts a performance evaluation to measure the improvement in algorithm efficiency and analyzes the results of the performance evaluation. When spatial data queries are conducted, according to our performance evaluation, hit rate has been improved over the existing algorithms.