• 인터넷정보학회논문지
• /
• 제5권6호
• /
• pp.103-110
• /
• 2004

본 논문에서는 웹 서버 성능에 있어 캐싱 정책의 영향을 분석하고 연구하였다. 새롭게 제안한 파일 타입 기반 캐싱 정책은 캐시안의 크고 작은 파일간에 균형 잡힌 결과를 갖도록 지원하며, 뿐만 아니라 작은 파일과 큰 파일에 대한 요청에 훌륭한 성능을 나타낸다. 본 논문에서는 파일 타입 기반 캐싱이 적중률과 바이트적중률 모두 다 좋은 결과를 나타냄을 보인다.

• 한국군사과학기술학회지
• /
• 제9권3호
• /
• pp.12-19
• /
• 2006

A gun barrel of infantry fighting vehicle is supported like a type of cantilever. Temperature of a gun barrel is increased by heat transfer due to the combustion of propellant charge during the firing. Thus, the muzzle of a gun barrel is deflected in accordance with its temperature and the accuracy rate is decreased by deflection of the muzzle. In this study, deflection of a gun barrel is estimated by measuring its restoration rate because measuring the deflection rate is difficult due to the vibration of the gun barrel during the firing. In order to obtain the relations between deflection rate and restoration rate of the 40mm gun barrel of Next Infantry Fighting Vehicle(NIFV) under varying temperature, measurement of deflection rate and restoration rate is carried out using 5.56mm Remington rifle barrel. Effect of the estimated deflection rate of a gun barrel of NIFV on the hit probability is also analyzed.

• 보건교육건강증진학회지
• /
• 제31권2호
• /
• pp.27-40
• /
• 2014

Objectives: While cinema is regarded in the contemporary popular leisure activities, the presentation smoking scenes in films has not been fully studied. We investigated Korean box-office hit movies by using content analysis. Methods: We sampled fifty-one hit films played in Korean cinemas during the period 2000-2013. Here, a hit film is defined as a movie viewed by at least 5,000,000 audiences. Results: We found that 78.1% of the Korean hit films contained smoking scenes, whereas only 15.6% of the American hit films were so. Films with the more frequent number of smoking scenes could be lined up in the order of crime, thriller, and action genres (p<.05). Smoking actors were leading roles, hence attractive characters appealing to the audience. Moreover, the smoking rate of female characters in the films was determined to be 3.66 times greater than the actual smoking rate of females in reality. Conclusions: Smoking scenes are likely to affect the audiences' cognitive priming and/or social learning with respect to smoking. Therefore, it would be necessary to set a restriction standard to the frequency of smoking scenes to appear Korean films, and to consider it as an important factor in the assigning a screening grade to such films.

• 한국정보과학회:학술대회논문집
• /
• 한국정보과학회 2000년도 가을 학술발표논문집 Vol.27 No.2 (3)
• /
• pp.346-348
• /
• 2000

전통적일 파일 캐쉬나 가상 메모리 시스템과 웹 캐쉬는 다르다. 웹 캐쉬는 WWW상에서 작게는 수백 바이트에서 크게는 수십 메가바이트에 이르는 다양한 크기의 개체를 다루어야 한다. 다양한 크기의 개체를 다루는데 따른 문제점은 캐쉬 성능을 판단하는 매트릭스가 단순한 hit rate가 아니라는 것이다. 기본적인 웹 캐쉬의 성능 매트릭스로는 HR(cache hit rate)와 BHR(byte cache hit rate)가 있으며, 기존에 제시된 캐쉬 정책들은 두 가지 중 하나만을 만족하거나 아니면 어느 것도 만족하지 않는 경우가 대부분이다. 트레이스 드리븐 방식을 이용한 시뮬레이션을 통하여, 기존에 우수성이 입증된 캐쉬 대체 정책과 우리가 제시한 TYPE 대체 정책을 HR과 BHR을 기준으로 비교한다. 우리가 제시한, 파일 타입에 대해 동적으로 할당된 캐쉬 공간을 갖는 캐쉬 대체기법은 각각의 두 성능 매트릭스에 대해서 골고루 우수한 성능을 보였다.

• 한국컴퓨터정보학회논문지
• /
• 제20권8호
• /
• pp.1-6
• /
• 2015

The MapReduce Program of Hadoop Distributed File System operates on any unspecified nodes due to distributed-parallel process and block replicate for data stability. Since it is difficult to guarantee the cache locality when a Solid State Drive is used as a cache in hadoop, cache hit-rate is decreased. In this paper, we suggest a method to improve cache hit rate by pre-loading the input data of the MapReduce onto the SSD cache. To perform this method, we estimated the blocks that are used on each node by using capacity scheduler and block metadata. Eventually we could increase the performance of SSD cache by loading the blocks onto SSD cache before the Map Task run.

• Journal of Acupuncture Research
• /
• 제29권5호
• /
• pp.61-74
• /
• 2012

Objectives : This study is perfomed for preparation of oriental medicine clinical guidelines for drawing up the standards of oriental medicine demonstration and diagnosis classification about the knee pain. Methods : Statistical analysis about Crane's-knee wind(鶴膝風), arthralgia syndrome(痺症), knee injury(膝傷), gout arthritis(痛風), Youk jeol poung(歷節風) classified experts' opinions about knee pain patients by Delphi method is conducted by using oriental medicine diagnosis questionnaire. The result was classified by using linear discriminant analysis(LDA), diagonal linear discriminant analysis(DLDA), diagonal quadratic discriminant analysis(DQDA), K-nearest neighbor classification(KNN), classification and regression trees(CART), support vector machines(SVM). Results : The results are summarized as follows. 1. The result analyzed by using LDA has a hit rate of 81.65% in comparison with the original diagnosis. 2. The result analyzed by using DLDA has a hit rate of 63.3% in comparison with the original diagnosis. 3. The result analyzed by using DQDA has a hit rate of 65.14% in comparison with the original diagnosis. 4. The result analyzed by using KNN has a hit rate of 74.31% in comparison with the original diagnosis. 5. The result analyzed by using CART has a hit rate of 75.23% in comparison with the original diagnosis when the test of selected 13 significant questions based on analysis of variance was performed. 6. The result analyzed by using SVM has a hit rate of 87.16% in comparison with the original diagnosis. Conclusions : Statistical analysis using oriental medicine diagnosis questionnaire on knee pain generally turned out to have a significant result.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제13권5호
• /
• pp.2319-2337
• /
• 2019

In this paper, we study the distributed cooperative caching for Internet content providers in a small cell of heterogeneous network (HetNet). A general framework based on bankruptcy game model is put forth for finding the optimal caching policy. In this framework, the small cell and different content providers are modeled as bankrupt company and players, respectively. By introducing strategic decisions into the bankruptcy game, we propose a caching value assessment algorithm based on analytic hierarchy process in the framework of bankruptcy game theory to optimize the caching strategy and increase cache hit ratio. Our analysis shows that resource utilization can be improved through cooperative sharing while considering content providers' satisfaction. When the cache value is measured by multiple factors, not just popularity, the cache hit rate for user access is also increased. Simulation results show that our approach can improve the cache hit rate while ensuring the fairness of the distribution.

• 한국안전학회지
• /
• 제35권3호
• /
• pp.72-78
• /
• 2020

The accident fatality rate has decreased by more than 90% compared to 2006, due to the safety management and safety investment based on the Rail Safety Act. Most railway safety indicators, including fatality rates, have improved significantly from 60% to 80%, reaching the level of developed countries in terms of most railway safety indicators. However, the only staff fatality rate at work is not improved, and it is 3 to 5 times higher than that of developed countries. Most of the fatality occurred during employee's work recently occurred due to accidents hit by train while track work. In principle, when operating track need to check or maintenance, the operation of the train should be stopped and the work carried out. However, in Korea, due to the highest passenger density and train operating density in the world, it is caused by a structural problem that requires workers to enter the track while the train is running and perform various tasks such as maintenance and inspection. In this study, we analyzed the risk of accidents caused by hit by trains on the track, which is the biggest cause of staff fatality, using the main statistics of the last 10 years. In detail, the scenarios of the main causes of hit by trains and workers were formed to suggest the effectiveness of the current preventive measures and supplementary.

• 비파괴검사학회지
• /
• 제31권1호
• /
• pp.53-61
• /
• 2011

본 연구는 편측 노치가 삽입된 A16061-T6 알루미늄 합금 평판 시편에 대해 유리섬유강화플라스틱(GFRP) 복합재 패치의 적층수를 변수로 하여 보수히고, 인장 하중에 따른 시편의 손상 과정을 음향방출법(acoustic emission, AE)으로 실시간 분석하였다. AE 에너지 발생률(AE energy rate), hit 발생률(hit rate), AE 진폭(AE amplitude) 거통과 파형 및 1차 중심주파수(1st peak frequency)의 대역을 조사하여, 시편 파괴시 알루미늄 크랙(Al cracking), 섬유 파단(fiber breakage), 수지 균열(resin cracking), 층간 분리(delamination)로 분류하였다. 시편의 변위를 음향방출 특성에 따라 구간(region) I, II, III으로 나눌 수 있었으며, 패치 자체가 실제 파괴되는 구간인 구간 II를 세부적으로 분석하여 패치의 적층수에 따른 AE 특성 차이를 구하였다.

• 한국심리학회지:법
• /
• 제12권2호
• /
• pp.151-169
• /
• 2021

P300 숨긴정보검사에서 거짓말 여부를 판단하기 위하여 가장 많이 사용되는 기법은 부트스트랩 진폭차이(BAD) 방법과 부트스트랩 상관차이(BCD) 방법이다. 두 방법의 정확판단율을 비교한 선행연구들은 일관되지 않은 결과를 보고하였다. 일부의 연구들에서 BAD 방법이 BCD 방법보다 더 정확하다고 보고되고 있지만, 다른 연구에서는 BCD 방법이 BAD 방법보다 더 정확한 것으로 나타났다. 본 연구의 목적은 BAD 방법의 정확도가 더 높은 조건과 BCD 방법의 정확도가 더 높은 조건을 확인하는 것이다. 몬테 카를로 연구결과, 전반적으로 BAD 방법의 오경보율이 BCD 방법의 오경보율보다 더 높았으며, BAD 방법의 적중률이 BCD 방법의 적중률보다 더 높았다. 관련자극과 무관련자극의 P300 잠재시간이 비슷한 경우에 비교하여 관련자극의 P300 잠재시간이 약 100ms 빠른 경우에는 BCD 방법의 적중률이 크게 감소하였으며, 약 100ms 느린 경우에는 BCD 방법의 적중률이 증가하였다. 관련자극의 P300 진폭이 무관련자극의 P300 진폭보다 약간 더 크면서 관련자극의 P300 잠재시간이 목표자극의 P300 잠재시간보다 긴 경우에는 BCD 방법의 적중률이 BAD 방법의 적중률보다 더 높았다. BAD 방법의 오경보율이 높은 이유와 BCD 방법의 적중률이 관련자극의 P300 잠재시간에 영향을 받는 이유에 대해서 논의하였다.