• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.12
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• pp.1662-1669
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• 2020

Google cloud includes data uploaded and synchronized by users, as well as synchronization history of all cloud services, users' smartphone usage, and location information. Therefore, Google cloud data can be useful for digital forensics from a user behavior analysis perspective. Through this paper, we have identified the types of cloud data that can be acquired using Google's Takeout service and developed a tool that can be usefully utilized in digital forensics research and investigation by screening and analyzing the data required for analyzing user behavior. Because Google cloud data is synchronized through Google accounts regardless of the type of computing device, Google service data used on various devices such as PCs, smartphones, and tablet PCs can be acquired through Google accounts without the device. Therefore, the results of this paper's research are expected to be very useful for digital forensics research and investigation in the current situation.

• Journal of Information Processing Systems
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• v.14 no.2
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• pp.377-395
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• 2018

Aiming at the problem of service reliability in resource reservation in cloud computing environments, a model of dynamic cloud resource reservation based on trust is proposed. A domain-specific cloud management architecture is designed in which resources are divided into different management domains according to the types of service for easier management. A dynamic resource reservation mechanism (DRRM) is used to test users' reservation requests and reserve resources for users. According to user preference, several resources are chosen to be candidate resources by fuzzy cluster analysis. The fuzzy evaluation method and a two-way trust evaluation mechanism are adopted to improve the availability and credibility of the model. An analysis and simulation experiments show that this model can increase the flexibility of resource reservation and improve user satisfaction.

• Journal of KIBIM
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• v.4 no.2
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• pp.17-24
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• 2014

Recently, there have been various attempts for the adoption and spread of Building Information Modeling (BIM) in the construction industry. However, the spread of BIM has been less satisfied than expected, because of the insufficient, expensive hardware and software for the authoring, analysis and so forth. As a solution to resolve the obstacles, the applications of cloud computing technology to BIM have been introduced. Due to the vendor-dependent functions and lack of verification on the work process, the spread of cloud-based BIM has been limited in Korea. Therefore, this study proposes the functions of cloud computing services which can support BIM-based design processes through the review of practitioners, questionnaire survey and analysis of design process.

• Korean Journal of Remote Sensing
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• v.11 no.1
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• pp.31-45
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• 1995

The values of brightness temperature difference (BTD) between 11um and 12um infrared channels may reflect amounts of low-level water vapor and cloud types due to the different absorptivity for water vapor between two channels. A simple method of classifying cloud types at night was proposed. Two-dimensional histograms of brightness temperature of the 11um channel and the BTD between the split window data over subareas around characteristic clouds such as Cb(cumulonimbus), Ci(cirrus), and Sc(stratocumulus) was constructed. Cb, Ci and Sc can be classified by seleting appropriate thresholds in the two-dimensional histograms. And we can see amounts of low-level water vapor in clear area as well as cloud types in cloudy area in the BTD image. The map of cloud types and low-level water vapor generated by this method was compared with 850hPa and 1000hPa relative humidity(%) of numerical analysis data and nephanalysis chart. The comparisons showed reasonable agreement.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3384-3400
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• 2021

With the advent of the data era, people pay much more attention to data corruption. Aiming at the problem that the majority of existing schemes do not support corruption detection of ciphertext data stored in cloud environment, this paper proposes a data corruption detection scheme based on ciphertexts in cloud environment (DCDC). The scheme is based on the anomaly detection method of Gaussian model. Combined with related statistics knowledge and cryptography knowledge, the encrypted detection index for data corruption and corruption detection threshold for each type of data are constructed in the scheme according to the data labels; moreover, the detection token for data corruption is generated for the data to be detected according to the data labels, and the corruption detection of ciphertext data in cloud storage is realized through corresponding tokens. Security analysis shows that the algorithms in the scheme are semantically secure. Efficiency analysis and simulation results reveal that the scheme shows low computational cost and good application prospect.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.461-463
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• 2003

The information on the cloud presence within a instantaneous field of view is the first step toward the derivation of many other geophysical parameters. Here, we first applied the current MODIS cloud detection algorithm developed by University of Wisconsin and compared the results to a visual interpretation of composite data, especially during the daytime. Most of cases, the detection algorithm performs very well, except a few cases with over-detection. One of the reasons for the false detection is due to the time independent use of land information which affects the threshold values of visible channel test. In the presentation, we show detailed analysis of the current cloud detection algorithm and suggest possible way to overcome the current shortfall.

• Journal of Information Technology Services
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• v.11 no.3
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• pp.129-159
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• 2012

Cloud-computing is in the limelight with expectation for cost reduction, because it alleviates the burden of initial investment and maintenance cost and based on pay-as-you-use billing policy. However, many suppliers of Cloud-computing service are suggesting diverse and complicated billing policies without consideration for setting reasonable service billing policy and definite criteria of properties to determine service billing system. So companies willing to use Cloud-computing service are hard to understand the billing system and often spend more expensive cost than necessary. Therefore, this study invested billing system properties of four representative suppliers. Based on these properties of billing system, this study found priorities using AHP survey which conducted to experts who are able to make decisions for adopting Cloud-computing in the company using or willing to use Cloud-computing service. We expect that this study can suggest basic guideline for comparing and analyzing properties of Cloud-computing service with standardized and objective method.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.43-49
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• 2015

As the cloud computing law was passed in March, 2015, many private companies and public organizations give consideration to introduce cloud computing services. However, most of them are still concerned about the security issues in cloud computing services. To solve the problem, a certification system of cloud security is necessary as an enabler for adoption of the trusted cloud services. There have been a number of studies about certification systems for cloud security, but only few studies exist about certification scheme of cloud security. Therefore, in this study, foreign certification systems for cloud security are analyzed to draw requirements for developing a domestic certification scheme for cloud security. Based on the result of analysis, this study proposes the three certification schemes of cloud security, which have been reviewed by the focus group interview method to draw advantages and disadvantages of each scheme.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.8
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• pp.499-509
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• 2016

The MSIP has implemented "Act on The Development of Cloud Computing and Protection of Its Users" from September 2015 and invigorated the cloud service industry. The act mainly includes the improvement cloud computing reliability and user protection for the development foundation and use activation. In order to expand the cloud market, it is important to increase the reliability of individual users. However, practical discussions and approach for cloud services adoption are still limited. In fact, there is no agreement standard for domestic cloud services. As a user agreement is not standardized, users feel difficulty compare to each agreement of cloud service provider and may be damaged because of unfair terms. Thus, it is necessary to examine the unfairness of cloud service agreement for user protection. This study analyzes domestic and foreign cloud service agreements including Practical Guide to Cloud Service Agreement of Cloud Standards Customer Council and suggests the direction of the standard agreement of cloud services.

• Journal of the Korean Solar Energy Society
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• v.30 no.3
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• pp.1-9
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• 2010

Since the horizontal global radiation and cloud cover are a main factor for designing any solar photovoltaic system, it is necessary to evaluate its characteristics all over the country. The work presented here are the investigation of horizontal global radiation and cloud cover in Korea. The data utilized in the investigation consist of horizontal global radiation and cloud cover collected for 27 years(1982. 12~2008. 12) at measuring stations across the country. The analysis shows that the annual-average daily horizontal global radiation is $3.61\;kWh/m^2$ and the annual-average daily cloud cover is 5.1 in Korea. We also constructed the contour map of cloud cover in Korea by interpolating actually measured data across the country.