• 대한원격탐사학회지
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• 제6권1호
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• pp.11-24
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• 1990

This is the study about the meteorological satellite cloud image classification by objective methods. For objective cloud classification, linear discriminant analysis was tried. In the linear discriminant analysis 27 cloud characteristic parameters were retrieved from GMS infrared image data. And, linear cloud classification model was developed from major parameters and cloud type coefficients. The model was applied to GMS IR image for weather forecasting operation and cloud image was classified into 5 types such as Sc, Cu, CiT, CiM and Cb. The classification results were reasonably compared with real image.

• International Journal of Computer Science & Network Security
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• 제21권9호
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• pp.41-50
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• 2021

Cloud computing is one of the most expanding technologies nowadays; it offers many benefits that make it more cost-effective and more reliable in the business. This paper highlights the various benefits of cloud computing and discusses different cryptography algorithms being used to secure communications in cloud computing environments. Moreover, this thesis aims to propose some improvements to enhance the security and safety of cloud computing technologies.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 추계학술발표대회
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• pp.169-171
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• 2013

Cloud computing provides access to big volumes of data and computational resources through various services. Cloud computing also supports to process these volumes of data using set of computers. Cloud computing can satisfy resource requirements through virtualization technology. Eucalyptus is an open source cloud computing environment helps the users to setup their own private cloud based on virtualization. In this paper, monitoring of virtual machines is explained with the eucalyptus cloud setup.

• 대한원격탐사학회지
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• 제31권5호
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• pp.371-384
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• 2015

GOCI 영상은 육상 관측에 적합한 공간해상도와 빠른 관측주기를 가지고 있지만, 현재까지 육상분야에 활용된 예가 많지 않다. GOCI 영상이 육상분야에 활용되기 위해서는 정교한 전처리가 수행되어 신뢰성을 갖춘 기본적인 산출물 형태로 제공되어야 한다. 본 연구에서는 GOCI 영상의 육상 활용을 위하여 구름의 영향이 최소화된 기본 산출물 제작에 필요한 구름 탐지 기법을 제안하였다. GOCI 영상은 구름 탐지에 효과적인 단파적외선(SWIR)과 열적외선(TIR) 밴드가 없기 때문에, 이 연구에서는 GOCI 영상의 장점인 빠른 관측 주기로 얻어지는 많은 다중시기영상을 이용하여 구름을 탐지하는 방법을 개발하였다. 제안한 구름탐지 기법은 세 단계로 구성된다. 1단계와 2단계에서는 1번 밴드 반사율과 1번과 8번 밴드의 반사율 비(b1/b8)에 임계값을 적용하여 완전 맑음(confident clear)과 두꺼운 구름(thick cloud)을 구분했다. 마지막 단계에서는 3일 동안 얻어진 b1/b8 값의 평균을 임계값으로 하여 얇은 구름(thin cloud)을 구분하였다. 이러한 순차적인 구름탐지 알고리즘을 적용하여 모두 4개의 등급으로 분류하였다. 본 연구에서 제안한 기법을 GOCI 영상에 적용 후 그 결과를 MODIS 구름 산출물(cloud mask products)과 비교 검증하였다. 여러 시기의 영상에서 추출된 구름 면적을 비교한 결과 평균제곱근오차(RMSE)가 10% 미만으로 MODIS 구름 산출물과 유사한 결과를 얻었다. 육안 분석을 통해 구름의 공간적인 분포를 비교한 결과, MODIS 산출물과 비슷한 구름 분포를 보여주었다.

• 대기
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• 제17권2호
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• pp.195-205
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• 2007

The influences of ice microphysical processes on urban heat island-induced convection and precipitation are numerically investigated using a cloud-resolving model (ARPS). Both warm- and cold-cloud simulations show that the downwind upward motion forced by specified low-level heating, which is regarded as representing an urban heat island, initiates moist convection and results in downwind precipitation. The surface precipitation in the cold-cloud simulation is produced earlier than that in the warm-cloud simulation. The maximum updraft is stronger in the cold-cloud simulation than in the warm-cloud simulation due to the latent heat release by freezing and deposition. The outflow formed in the boundary layer is cooler and propagates faster in the cold-cloud simulation due mainly to the additional cooling by the melting of falling hail particles. The removal of the specified low-level heating after the onset of surface precipitation results in cooler and faster propagating outflow in both the warm- and cold-cloud simulations.

• 한국IT서비스학회지
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• 제10권3호
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• pp.149-166
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• 2011

While the importance of adopting cloud computing service has been emerged, comparatively little research has been conducted on examining factors of an individual user's intention to switch toward cloud computing service. Hereafter, this study presents and empirically tests users' intention to switch to cloud computing. Our model posits that the characteristics of cloud computing such as collaboration support, accessability, trust to cloud service affect perceived value, which in turn, influences intention to switch. An experimental study using student subjects provided empirical validation for our proposed model. Survey data from 106 respondents was used to test the model using partial least square analysis. According to our results, the characteristics of cloud computing were found to have significant impact on users' intention to switch that partially mediated by perceived value. Based on our research findings, we hope that this research will stimulate researchers' interest in the emerging area of cloud computing adoption.

• 한국정보시스템학회지:정보시스템연구
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• 제25권4호
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• pp.37-61
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• 2016

Purpose This study examines firms at various industries to identify key organizational characteristics that positively drive the evaluation of cloud computing. In addition, this study tests the impact of one's evaluation has on the adoption and integration of cloud computing within their respective firm. Design/methodology/approach A total of 172 responses from various firms currently using cloud computing service were analyzed using the structural equation modeling(SEM). Findings Results show that organizational Needs(Mobility and Job Relevance), Perceived Factors(Relative Advantages and Cost Savings), and Organizational Readiness(Technical Knowledge, Financial Supports, and Managerial Supports) have a significant impact on cloud computing evaluation; and evaluation influences its adoption, and integration. However, two variables(IT Performance Gaps and Compatibility) have no significant impact on cloud computing evaluation. Finally, Evolutional Leadership has a significant moderating effect within the relationship among variables in the process of cloud computing implementation.

• International Journal of Internet, Broadcasting and Communication
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• 제8권1호
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• pp.83-90
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• 2016

The emergence of cloud has been able to provide a variety of IT service to the user. As organizations and companies are increased that provide these cloud service, many problems arises on integration. However, with the advent of latest technologies such as big data, document-oriented database, and MapReduce, this problem can be easily solved. This paper is intended to design the Cloud Aggregator to provide them as a service to collect information of the cloud system providing each service. To do this, we use the DBaaS(DataBase as a Service) and MapReduce techniques. This makes it possible to maintain the functionality of existing system and correct the problem that may occur depending on the combination.

• 융합보안논문지
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• 제14권4호
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• pp.101-108
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• 2014

최근 클라우드 컴퓨팅 기술은 전 세계적으로 중요한 이슈로 부각되고 있으며, 이산화탄소 배출을 경감하는 것으로도 많은 주목을 받고 있다. 그러나 클라우드 컴퓨팅의 탄소배출은 긍정적인 측면과는 달리, 여러 취약점들로 인해, 경감정도에 차이를 갖고 있다. 따라서 본 논문은 클라우드 컴퓨팅의 이산화탄소 배출과 관련한 보안 시스템의 배출량 측정 실험과 클라우드 이산화탄소 배출 관련 사례연구를 통해 배출 요인을 분석함으로써, 향후, 클라우드 컴퓨팅의 보안 설계와 성능 향상을 위한 자료로 활용될 것으로 기대한다.

• 한국대기환경학회지
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• 제15권6호
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• pp.747-755
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• 1999

Effects of precipitation and cloud cover on high ozone days are examined by investigating the precipitation and average cloud cover before the ozone peak time within a day. High ozone days above 100 ppb in the Greater Seoul Area(GSA) for the ozone season from May to September are chosen for the analyses in terms of the surface meteorological data during 1990~1997. The result shows that the effect of precipitation on the rise of ozone concentration is definitely negative so that ozone concentration could not rise above 100ppb immediately after precipitation. But, the effect of cloud cover is associated with the variations of other meteorological parameters. The number of high ozone days with "zero" cloud cover is rather less than that with cloud cover of 1 to 4 since temperature is usually lower in "zero" cloud cover days. Furthermore, ozone concentration can rise above 100ppb even with full cloud cover when the wind is weak and the temperature is high.temperature is high.