• Journal of the Korean Home Economics Association
• /
• v.42 no.11
• /
• pp.85-107
• /
• 2004

This study classified figure types of adult males into several kinds of shape to provide fundamental data for their clothing sizing system. The subjects were 1496 men aged between 20 and 60 years old. Data were analyzed by factor analysis, cluster analysis and discriminant analysis. The results were as follows 1. For the result of the interview, the data were grouped into three age brackets: 20-35,31-45 and 41-60 years. 2. Factor analysis using values, which were measurements divided by either weight or height, was carried out to extract factors which characterize the various figures. fve factors to determine the figure types were extracted. 3. Cluster analysis using factor scores was carried out to categorize the figure types within the age groups. Figure types, describing shoulder angie and body shape, were categorized into 3 per age group. 4. Stepwise discriminant analysis w3s used to ensure that these clusters could be utilized with appropriate hit ratio. The hit ratio for each age group was around 80%.

• Journal of KIISE:Software and Applications
• /
• v.30 no.7_8
• /
• pp.780-791
• /
• 2003

Caching is a useful technique to improve the response time by reducing contention of requests in mobile computing environments with a narrow bandwidth. in the traditional cache-based systems, to improve the hit ratio has been usually one of main concerns for the time. However, in mobile computing environments, it is necessary to consider the cost of cache miss as well as the hit ratio. In this paper, we propose a new cache replacement strategy in pull-based data dissemination systems. Then, we evaluate performance of the proposed strategy by a simulation approach. The proposed strategy considers both the popularity and the wating time together, so the page with the smallest value of multiplying popularity by waiting time is selected as a victim.

• The KIPS Transactions:PartA
• /
• v.9A no.2
• /
• pp.163-170
• /
• 2002

Previous buffer cache schemes for continuous media file system only exploited the sequentiality of continuous media accesses and didn't consider looping references. However, in some video applications like foreign language learning, users mark the scene as loop area and then application automatically playbacks the scene several times. In this paper, we propose a novel buffer cache scheme for continuous media file system that sequential and looping references exist together. Proposed scheme increases the cache hit ratio by detecting reference pattern of files and appling an appropriate replacement policy to each file.

• Journal of the Korean Home Economics Association
• /
• v.35 no.2
• /
• pp.217-234
• /
• 1997

This study attempts to analyze some determinants of consumers' medical service quality and their complaining behavior. The results can be summerized as follows: 1. The determinants of consumers' perceived medical service quality could be categorized as five factors; i.e. nursery, hospital environment, medical doctors, other staffs service fee. Among them nursery sector consists of 32% variance. 2. According to the discriminant analysis, those determinants are of great value to distinguish between satisfied/unsatisfied group. The hit ratio was 85.4% which is relatively high score. 3. The type of complaining behavior could be grouped into no action, private and public complaining behavior. Most of respondents belonged to no action group and a few showed private complaining behavior. Any respondents who were willing to show public complaining behavior could not be found out. 4. These variables which influence complaining behavior were preconception toward hospital, barrier to complaining process and expected complaining behavior. Among them the first one was most influential variable. 5. In order to distinguish between complaining/non complaining behavior group, discriminant analysis was done. The result showed the above three variables had a significantly discriminatory power, the hit ratio reaching above 70%. In summary, we can see that consumers' evaluation on the whole medical service depends on the external factor such as staffs' attitude or hospital facilities due to the lack of their ability to evaluate highly specialized service like doctor's treatment.

• Journal of Digital Contents Society
• /
• v.9 no.4
• /
• pp.653-659
• /
• 2008

With the recent explosion in using of the Internet, the problem of caching web objects has gained considerable importance. Caching on the Internet differs from traditional caching in several ways. Especially, the conventional caching algorithms are not well suited for the Internet caching. The poor performance is mainly due to its unfair treatment of small objects since all the objects are treated the same even though they differ in size. In this paper, I give an overview of caching policies designed for web objects, and provide a new algorithm of my own. I also have performed trace-driven simulations about variable-size replacement algorithms, and derived a new algorithm to improve byte hit-ratio by classifying objects based on their sizes.

• The KIPS Transactions:PartA
• /
• v.8A no.3
• /
• pp.201-208
• /
• 2001

Explosive growth of the Web and the non-uniform characteristics of client requests result in the performance degradation of Web servers, and server cache has been recognized as the solution. We analyzed Web server accessing characteristics-repetition, size, and locality of access. Based on the result, we analyzed the cache removal policies and proposed a prefetch strategy to improve the hit ratio of server caches. In addition, through the trace-driven simulation based on the traces from real Web sites, we showed the performance improvement by our proposal.

• Journal of the Korea Society of Computer and Information
• /
• v.22 no.7
• /
• pp.1-7
• /
• 2017

As the capacity of NAND flash module increases, the amount of RAM increases for caching and maintaining the FTL mapping information. In order to reduce the amount of mapping information managed in the RAM, a demand-based address mapping method stores the entire mapping information in the flash and some valid mapping information in the form of cache in the RAM so that the RAM can be used efficiently. However, when cache miss occurs, it is necessary to read the mapping information recorded in the flash, so overhead occurs to translate the address. If the RAM space is not enough, the cache hit ratio decreases, resulting in greater overhead. In this paper, we propose a method using two tables called TPMT(Translation Page Mapping Table) and SMT(Segmented Translation Page Mapping Table) to utilize both temporal locality and spatial locality more efficiently. A performance evaluation shows that this method can improve the cache hit ratio by up to 30% and reduces the extra translation operations by up to 72%, compared to the TPM scheme.

• Journal of KIISE:Computer Systems and Theory
• /
• v.30 no.10
• /
• pp.556-568
• /
• 2003

This paper presents and analyzes the performance of a weighted-window based cache replacement policy for the efficient media caching in streaming media cache servers. The proposed policy makes, for each cached object, use of the reference count, reference time, amount of media delivered to clients and, in particular, the periodic patterns of user requests. Also, by giving weights to the recently referenced media contents, the replacement policy adequately and swiftly reflects the ever-changing characteristics of users preferences. The simulation studies show that the performance of the proposed policy has improved over the conventional policies such as LRU, LFU and SEG - in terms of hit ratio, byte hit ratio, delayed start and cache input.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.4
• /
• pp.1-8
• /
• 2018

In this paper, we propose an adaptive partition cache replacement policy and evaluate the performance of our scheme using various monitoring ratios to help lifetime extension of non-volatile main memory systems without performance degradation. The proposal combines conventional LRU (Least Recently Used) replacement policy and Early Eviction Zone (E2Z), which considers a dirty bit as well as LRU bits to select a candidate block. In particular, this paper shows the performance of non-volatile memory using various monitoring ratios and determines optimized monitoring ratio and partition size of E2Z for reducing the number of writebacks using cache hit counter logic and hit predictor. In the experiment evaluation, we showed that 1:128 combination provided the best results of writebacks and runtime, in terms of performance and complexity trade-off relation, and our proposal yielded up to 42% reduction of writebacks, compared with others.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2022.05a
• /
• pp.110-113
• /
• 2022

인터넷을 통해 주위 사물과 연결된 차량은 사용자에게 편리성을 제공하기 위해 다양한 콘텐츠를 요구하는데 클라우드로부터 가져오는 시간이 비교적 오래 걸리기 때문에 차량과 물리적으로 가까운 위치에 캐싱하는 기법들이 등장하고 있다. 본 논문에서는 기반 시설이 밀집하게 설치된 도시 환경에서 maximum distance separable(MDS) 코딩을 사용해 road side unit(RSU)에 캐싱하는 방법에 대해 연구하였다. RSU의 중복된 서비스 커버리지 지역을 고려하여 차량의 콘텐츠 요구에 대한 RSU hit ratio를 높이기 위해 deep Q-learning(DQN)를 사용하였다. 실험 결과 비교 알고리즘보다 hit raito 측면에서 더 높은 성능을 보이는 것을 증명하였다.