인공강우 항공실험을 위한 한반도 기상조건의 예비결과

정운선,장기호,고아름,구정모,노용훈,채상희,차주완,이철규 한국환경과학회 2021 한국환경과학회지 Vol.30 No.12

In this study, we investigated the optimal meteorological conditions for cloud seeding using aircraft over the Korean Peninsula. The weather conditions were analyzed using various data sources such as a weather chart, upper air observation, aircraft observation, and a numerical model for cloud seeding experiments conducted from 2018 to 2019 by the National Institute of Meteorological Sciences, Korea Meteorological Administration. Cloud seeding experiments were performed in the seasons of autumn (37.0%) and winter (40.7%) in the West Sea and Gangwon-do. Silver iodide (70.4%) and calcium chloride (29.6%) were used as cloud seeding materials for the experiments. The cloud seeding experiments used silver iodide in cold clouds. Aircraft observation revealed relatively low temperatures, low liquid water content, and strong wind speeds in clouds with a weak updraft. In warm clouds, the cloud seeding experiments used calcium chloride. Observations included relatively high temperatures, high liquid water content, and weak wind speeds in clouds with a weak updraft. Based upon these results, we determined the comprehensive meteorological conditions for cloud seeding experiments using aircraft over the Korean Peninsula. The understanding of optimal weather conditions for cloud seeding gained from this study provide information critical for performing successful cloud seeding and rain enhancement.

An Efficient Public Auditing Scheme for Multi-Cloud Storage

Jae Jung Kim,Seng Phil Hong 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.12

In cloud computing, cloud users can upload their data to cloud storage server in order to save local storage and access their data from anywhere. However, cloud storage service also brings serious security issues. Cloud users should be convinced of the correctness of their data stored remotely in the cloud. Thus, a reliable auditing scheme is desired to help cloud users check the integrity of their remote data. In this paper, we first propose an efficient cloud auditing scheme for multi-cloud storage systems, which can also preserve the privacy. Then, we extend our auditing scheme to support dynamic auditing and batch auditing for both multiple cloud users and multiple cloud service providers (CSPs), which makes the scheme more practical and efficient. Security analysis shows that our auditing scheme is provably secure. Our experiments indicate that our solution is efficient and significantly relieves the computation burden of both third party auditor (TPA) and CSP.

휘처 기반 클라우드 모델링 방법

송치양,조은숙 한국지식정보기술학회 2022 한국지식정보기술학회 논문지 Vol.17 No.1

The IT paradigm has evolved from web computing to cloud computing environment. Cloud service development has been mainly studied by object-oriented design method based on UML, but research by feature design method is weak. In order to improve the usability and reusability of feature-oriented cloud modeling, this paper proposes a meta-model-based feature cloud modeling method suitable for the characteristics of cloud computing services. To do this, the MDA-based hierarchical cloud-feature integration metamodel is established for how the elements of the cloud characteristics are expressed in the modeling elements of the feature. In terms of applying this integrated metamodel, we make a feature-oriented cloud modeling process from the requirements definition (CIM) phase to the analysis (PIM) and design (PSM) phase for cloud application development. The work activity in the development phase is defined to create a model by using the modeling elements and relationships of the formalized integrated meta-model. In terms of applying this process, case study is shown with the PDMCS system. This facilitates the design of a hierarchical cloud application using the feature cloud modeling method. In addition, by using a standardized feature-based meta-model and modeling process, it is possible to design a cloud service model that is easier and more clear. Moreover, the creation of a reusable cloud application model for each development stage by the MDA way can be further improved.

수치 예보를 이용한 구름 예보

김영철 ( Young Chul Kim ) 한국항공운항학회 2007 한국항공운항학회지 Vol.15 No.3

In this paper, we attempted to produce the cloud forecast that use the numerical weather prediction(NWP) MM5 for objective cloud forecast. We presented two methods for cloud forecast. One of them used total cloud mixing ratio registered to sum(synthesis) of cloud-water and cloud-ice grain mixing ratio those are variables related to cloud among NWP result data and the other method that used relative humidity. An experiment was carried out period from 23th to 24th July 2004. According to the sequence of comparing the derived cloud forecast data with the observed value, it was indicated that both of those have a practical use possibility as cloud forecast method. Specially in this Case study, cloud forecast method that use total cloud mixing ratio indicated good forecast availability to forecast of the low level clouds as well as middle and high level clouds.

Reference Architecture and Operation Model for PPP (Public-Private-Partnership) Cloud

( Youngkon Lee ),( Ukhyun Lee ) 한국정보처리학회 2021 Journal of information processing systems Vol.17 No.2

The cloud has already become the core infrastructure of information systems, and government institutions are rapidly migrating information systems to the cloud. Government institutions in several countries use private clouds in their closed networks. However, because of the advantages of public clouds over private clouds, the demand for public clouds is increasing, and government institutions are expected to gradually switch to public clouds. When all data from government institutions are managed in the public cloud, the biggest concern for government institutions is the leakage of confidential data. The public-private-partnership (PPP) cloud provides a solution to this problem. PPP cloud is a form participation in a public cloud infrastructure and the building of a closed network data center. The PPP cloud prevents confidential data leakage and leverages the benefits of the public cloud to build a cloud quickly and easily maintain the cloud. In this paper, based on the case of the PPP cloud applied to the Korean government, the concept, architecture, operation model, and contract method of the PPP cloud are presented.

영동지역의 극한 대설에 대한 위성관측으로부터 구름 추적

조영준 ( Young Jun Cho ),권태영 ( Tae Yong Kwon ) 대한원격탐사학회 2014 大韓遠隔探査學會誌 Vol.30 No.1

본 연구에서는 겨울철 영동지역에서 2001 ~ 2012(12년) 동안 일신적설 50 cm 이상의 3개 극한 대설사례를 선정하여 위성에서 관측된 구름을 추적하여 공간적 특성을 분석하였다. 그리고 그 특성을 레이더 강수와 비교하였다. 이 연구에서 선정된 영동지역 극한 대설사례는 영동지역(영동 앞바다)에서 발생하여 발달하거나 동한만 부근에서 발생하여 영동지역으로 이동해 들어오는 독립되고 잘 발달된 그리고 크기가 작은 대류형 구름과 관련이 있다. 주강수 시기의 이 구름덩어리의 최저휘도온도는 -40 ~ -50℃로 낮고, 휘도온도 -35℃ 혹은 -40℃ 이하의 구름 크기는 약 17,000 ~ 40,000 km2로 중규모 대류복합체(-52℃ 이하 구름크기 50,000 km2)보다 작은 크기이다. 이 때 레이더의 강수면적(0.5 mm/hr 이상)도 약 4,000 ~ 8,000 km2로 작고 독립된 강수 형태를 보인다. 위성의 구름영역과 레이더 강수영역은 영동 앞바다에 비슷하게 위치하였으나 레이더 강수의 중심이 상대적으로 영동 해안에 인접해 위치하였다. 또한 구름이 발달하는 과정에서 구름의 극값과 강수의 극값이 일치하지 않는 경우도 나타났다. 그러나 모든 사례에서 주강수 시기에 구름은 영동 앞바다에 위치하였다. 따라서 구름덩어리의 위치가 극한 대설에 있어 무엇보다 중요한 요소인 것으로 판단된다. 수증기 영상은 건조구역(암역)의 가장자리 북쪽에서 구름덩어리가 발달함을 보여주었다. 따라서 위성관측의 구름영상과 지상 레이더에 의한 강수관측 값과 비교하여 보았을 때, 위에 선정된 극한 대설 사례는 부저기압 혹은 소용돌이의 발달과 관련되어 있는 것으로 생각된다. 영동지역 극한 대설에 대한 초단기 예보에 있어 초기에 동한만 혹은 영동지역에서 작고 발달된 대류형 구름을 탐지하고 추적하는 것이 중요하다. This study presents spatial characteristics of cloud using satellite image in the extreme heavy snowfall of the Yeongdong region. 3 extreme heavy snowfall events in the Yeongdong region during the recent 12 years (2001 ~ 2012) are selected for which the fresh snow cover exceed 50 ㎝/day. Spatial characteristics (minimum brightness temperature; Tmin, cloud size, center of cloud-cell) of cloud are analyzed by tracking main cloud-cell related with these events. These characteristics are compared with radar precipitation in the Yeongdong region to investigate relationship between cloud and precipitation. The results are summarized as follows, selected extreme heavy snowfall events are associated with the isolated, well-developed, and small-scale convective cloud which is developing over the Yeongdong region or moving from over East Korea Bay to the Yeongdong region. During the period of main precipitation, cloud-cell Tmin is low (-40 ~ -50℃) and cloud area is small (17,000 ~ 40,000 km2). Precipitation area (≥ 0.5 mm/hr) from radar also shows small and isolated shape (4,000 ~ 8,000 km2). The locations of the cloud and precipitation are similar, but in there centers are located closely to the coast of the Yeongdong region. In all events the extreme heavy snowfall occur in the period a developed cloudcell was moving into the coastal waters of the Yeongdong. However, it was found that developing stage of cloud and precipitation are not well matched each other in one of 3 events. Water vapor image shows that cloud-cell is developed on the northern edge of the dry(dark) region. Therefore, at the result analyzed from cloud and precipitation, selected extreme heavy snowfall events are associated with small-scale secondary cyclone or vortex, not explosive polar low. Detection and tracking small-scale cloud-cell in the real-time forecasting of the Yeongdong extreme heavy snowfall is important.

Performance Analysis of Cloud-Net with Cross-sensor Training Dataset for Satellite Image-based Cloud Detection

김미정,고윤호 대한원격탐사학회 2022 大韓遠隔探査學會誌 Vol.38 No.1

Since satellite images generally include clouds in the atmosphere, it is essential to detect or mask clouds before satellite image processing. Clouds were detected using physical characteristics of clouds in previous research. Cloud detection methods using deep learning techniques such as CNN or the modified U-Net in image segmentation field have been studied recently. Since image segmentation is the process of assigning a label to every pixel in an image, precise pixel-based dataset is required for cloud detection. Obtaining accurate training datasets is more important than a network configuration in image segmentation for cloud detection. Existing deep learning techniques used different training datasets. And test datasets were extracted from intra-dataset which were acquired by same sensor and procedure as training dataset. Different datasets make it difficult to determine which network shows a better overall performance. To verify the effectiveness of the cloud detection network such as Cloud-Net, two types of networks were trained using the cloud dataset from KOMPSAT-3 images provided by the AIHUB site and the L8-Cloud dataset from Landsat8 images which was publicly opened by a Cloud-Net author. Test data from intra-dataset of KOMPSAT-3 cloud dataset were used for validating the network. The simulation results show that the network trained with KOMPSAT-3 cloud dataset shows good performance on the network trained with L8-Cloud dataset. Because Landsat8 and KOMPSAT-3 satellite images have different GSDs, making it difficult to achieve good results from cross-sensor validation. The network could be superior for intra-dataset, but it could be inferior for cross-sensor data. It is necessary to study techniques that show good results in cross-senor validation dataset in the future.

A Review of Cloud Computing Security Issues

Manpreet Kaur,Hardeep Singh 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.5

Cloud Computing is an emerging paradigm which has become today’s hottest research area due to its ability to reduce the costs associated with computing. In today’s era, it is most interesting and enticing technology which is offering the services to its users on demand over the internet. Since Cloud computing stores the data and its disseminated resources in the environment, security has become the main obstacle which is hampering the deployment of cloud environments. There are number of users used cloud to store their personal data, so that data storage security is required on the storage media. The major concern of cloud environment is security during upload the data on cloud server. Data storage at cloud server attracted incredible amount of consideration or spotlight from different communities. For outsourcing the data there is a need of third party. The importance of third party is to prevent and control unauthorized access to data store to the cloud. This research paper discusses the security issues of cloud storage.

Cloud-Native의 확산: 정성적・정량적 연구기법을 이용한 공공부문의 클라우드 활성화 방안

이재혁,김상현 사)한국빅데이터학회 2023 한국빅데이터학회 학회지 Vol.8 No.2

Cloud Native refers to the Technical Maturity Level of a cloud environment that can utilize all cloud resources to fully function. In converting public sector information resources to the cloud, the characteristics of the cloud are not being used well. Therefore, in this study, the qualitative research method cloud expert interview technique and the quantitative research method used text network analysis for domestic and foreign related articles. Through this, we analyzed the utilization trends related to domestic and foreign cloud natives and the cloud policies of developed countries. Through previous research, the core components of cloud-native were examined, and the need for agile methodologies that were not addressed in previous studies was raised. It is believed that these core components will be applied in the public sector to contribute to business innovation through digital innovation. In addition, this study aims to provide important implications for the use of cloud native in Korea through an in-depth discussion on how to spread cloud native in the public sector. 클라우드 네이티브(Cloud Native)는 클라우드 환경에서 모든 클라우드 자원을 활용하여 완벽히 작동할 수있는 기술적 발전 상태(Technical Maturity Level)를 의미한다. 공공부문의 정보자원을 클라우드로 전환하는데 있어 클라우드의 특성을 잘 활용하지 못하고 있는 실정이다. 이에 본 연구에서는 정성적 연구방법인클라우드 전문가 인터뷰 기법과 정량적인 연구 방법으로 국내⋅외 관련 기사를 대상으로 텍스트 네트워크 분석을 이용하였다. 이를 통해 국내⋅외 클라우드 네이티브와 관련된 활용 동향 및 선진국의 클라우드 정책을 분석하였다. 선행연구를 통해 클라우드 네이티브 핵심 구성요소를 알아보고, 기존 연구에서 다루어지지 않은애자일 방법론의 필요성을 제기하였다. 이러한 핵심 구성요소를 공공부문에서 적용하여 디지털 혁신을 통한업무혁신에 기여할 것으로 생각된다. 또한, 본 연구에서는 공공부문의 클라우드 네이티브의 확산 방안에 대한 심도 있는 논의를 통해 국내 클라우드 네이티브 활용에 대한 중요한 시사점을 제공하고자 한다.

Cloud-Enabled Data Center Organization using K-D Tree

Sandip Roy,Rajesh Bose,Tanaya Roy,Debabrata Sarddar 보안공학연구지원센터 2015 International Journal of Database Theory and Appli Vol.8 No.3

An efficient load balancing algorithm in the field of cloud computing is absolutely essential in order to have a cloud network with graceful performance satisfying user expectation. Inspite of the existence of handful lightly loaded data centers, numerous heavily overloaded data centers may lead to a performance degradation of overall cloud network. Proper workload distribution may improve the overall performance of the cloud system. Now a day’s eminent cloud division rules are highly demanding algorithm for distributing workloads among various cloud server nodes deployed in cloud-enabled data centers scattered over the geographical regions. For the researcher, cloud division rule and optimal cloud server node searching are the most demanding jobs in load balancing leading towards more efficient cloud network and improve users’ satisfaction. This paper presents an expeditious cloud division rule based on geographical location of the cloud-enabled data centers distributed over earth surface and builds a two-dimensional space partition k-d tree to partition them in order to search intended cloud server node efficiently. Our proposed organization scheme can be utilized for active monitoring load balancing algorithm to improve the resource utilization for high performance in present cloud computing environment.