• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.4B
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• pp.288-299
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• 2012

To ensure data confidentiality and fine-grained access control in business environment, system model using KP-ABE(Key Policy-Attribute Based Encryption) and PRE(Proxy Re-Encryption) has been proposed recently. However, in previous study, data confidentiality has been effected by decryption right concentrated on cloud server. Also, Yu's work does not consider a access privilege management, so existing work become dangerous to collusion attack between malicious user and cloud server. To resolve this problem, we propose secure system model against collusion attack through dividing data file into header which is sent to privilege manager group and body which is sent to cloud server and prevent modification attack for proxy re-encryption key using d Secret Sharing, We construct protocol model in medical environment.

• Journal of Korea Society of Digital Industry and Information Management
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• v.19 no.1
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• pp.31-42
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• 2023

As computer performance is leveled upward, the use of IoT systems is gradually expanding. Although IoT systems are used in many fields, it is true that it is difficult to build a safe system due to performance limitations. To overcome these limitations, many researchers have proposed numerous protocols to improve security issues. Among them, Azrour et al. except. We proposed a new efficient and secure authentication protocol for remote healthcare systems in a cloud-based IoT environment, and claimed that the new protocol could solve the security vulnerabilities of the existing protocols and was more efficient. However, in this paper, through the security analysis of the remote healthcare system in the cloud-based IoT environment proposed by Azrour et al., the protocol of this system was found to be vulnerable to Masquerade attack, Lack of Perfect Forward Secrecy, Off-line password guessing attack, and Replay attack.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.2
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• pp.152-167
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• 2011

MODIS/Terra level 3 and NCEP/NCAR Reanalysis data from 2001 to 2008 have been analyzed to understand long-term aerosol and cloud optical properties, and their relationships around Korea. Interestingly, cloud fraction(CF) has the similar annual variation to aerosol optical depth (${\tau}_a$) without any temporal significant trend. Horizontal distributions of ${\tau}_a$ showed the substantial horizontal gradient from China to Korea, especially with the strong difference over the Yellow Sea, which could represent the evidence of the anthropogenic influence from China in the perspective of long-term average. Specifically the negative correlations between ${\tau}_a$ and liquid-phase cloud effective radius ($r_e$) were shown on the monthly-average basis, only in summer with significant associations over the Yellow Sea, but not in the other seasons and/or specific regions. Relationship between ${\tau}_a$ and CF for the low-level liquid-phase clouds exhibited the overall positive correlation, being consistent with cloud lifetime effect. Meanwhile static stability showed no deterministic relationships with ${\tau}_a$ as well as CF. The dependence of aerosol-cloud relationship on the meteorological conditions should be examined more in detail with the satellite remote sensing and reanalysis data.

• Asian Journal of Atmospheric Environment
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• v.8 no.4
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• pp.175-183
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• 2014

To visually and chemically verify the rainout of soot particles, a model experiment was carried out with the cylindrical chamber (0.2 m (D) and 4 m (H)) installing a cloud drop generator, a hydrotherometer, a particle counter, a drop collector, a diffusing drier, and an artificial soot particle distributer. The processes of the model experiment were as follows; generating artificial cloud droplets (major drop size : $12-14{\mu}m$) until supersaturation reach at 0.52%-nebulizing of soot particles (JIS Z 8901) with an average size of $0.5{\mu}m$-counting cloud condensation nuclei (CCN) particles and droplets by OPC and the fixation method (Ma et al., 2011; Carter and Hasegawa, 1975), respectively - collecting of individual cloud drops - observation of individual cloud drops by SEM - chemical identifying of residual particle in each individual droplet by SEM-EDX. After 10 minutes of the completion of soot particle inject, the number concentrations of PM of all sizes (> $0.3{\mu}m$) dramatically decreased. The time required to return to the initial conditions, i.e., the time needed to CCN activation for the fed soot particles was about 40 minutes for the PM sized from $0.3-2.0{\mu}m$. The EDX spectra of residual particles left at the center of individual droplet after evaporation suggest that the soot particles seeded into our experimental chamber obviously acted as CCN. The coexistence of soot and mineral particle in single droplet was probably due to the coalescence of droplets (i.e., two droplets embodying different particles (in here, soot and background mineral particles) were coalesced) or the particle capture by a droplet in our CCN chamber.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.4
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• pp.141-152
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• 2013

The applications and concerned technologies of cloud computing services, one of major trends in the information communication technology, are widely progressing and advancing. OpenStack, one of open source cloud computing platforms, is comprised of several service components; using these, it can be possible to build public or private cloud computing service for a given target application. In this study, a remote sensing image analysis processing service on cloud computing environment has designed and implemented as an operational test application in the private cloud computing environment based on OpenStack. The implemented service is divided into instance server, web service, and mobile app. A instance server provides remote sensing image processing and database functions, and the web service works for storage and management of remote sensing image from user sides. The mobile app provides functions for remote sensing images visualization and some requests.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.939-949
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• 2023

In South Korea, a cloud-based vessel traffic service (Cloud VTS) system integrating the fourth industrial revolution technologies such as cloud and AI is currently under development in contrast to the existing VTS systems. A pilot center for at Busan VTS is being established based on differentiated technology and operational programs. The roles of operators and maintenance personnel who operate the innovative Cloud VTS system must be redefined. Additionally, a demand exists for the development of new educational programs to ensure the smooth operation of the Cloud VTS. Therefore, this study introduces the development details of a Cloud VTS system and explores educational strategies aimed at operators and maintenance personnel to ensure its safe operation.

• The Journal of Bigdata
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• v.8 no.2
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• pp.55-71
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• 2023

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.

• Atmosphere
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• v.21 no.2
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• pp.131-142
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• 2011

Spectral solar irradiances were observed using a visible and UV Multi-Filter Rotating Shadowband Radiometer on the rooftop of the Science Building at Yonsei University, Seoul ($37.57^{\circ}N$, $126.98^{\circ}E$, 86 m) during one year period in 2006. 1-min measurements of global(total) and diffuse solar irradiances over the solar zenith angle (SZA) ranges from $20^{\circ}$ to $70^{\circ}$ were used to examine the effects of clouds and total optical depth (TOD) on enhancing four solar irradiance components (broadband 395-955 nm, UV channel 304.5 nm, visible channel 495.2 nm, and infrared channel 869.2 nm) together with the sky camera images for the assessment of cloud conditions at the time of each measurement. The obtained clear-sky irradiance measurements were used for empirical model of clear-sky irradiance with the cosine of the solar zenith angle (SZA) as an independent variable. These developed models produce continuous estimates of global and diffuse solar irradiances for clear sky. Then, the clear-sky irradiances are used to estimate the effects of clouds and TOD on the enhancement of surface solar irradiance as a difference between the measured and the estimated clear-sky values. It was found that the enhancements occur at TODs less than 1.0 (i.e. transmissivity greater than 37%) when solar disk was not obscured or obscured by optically thin clouds. Although the TOD is less than 1.0, the probability of the occurrence for the enhancements shows 50~65% depending on four different solar radiation components with the low UV irradiance. The cumulus types such as stratoculmus and altoculumus were found to produce localized enhancement of broadband global solar irradiance of up to 36.0% at TOD of 0.43 under overcast skies (cloud cover 90%) when direct solar beam was unobstructed through the broken clouds. However, those same type clouds were found to attenuate up to 80% of the incoming global solar irradiance at TOD of about 7.0. The maximum global UV enhancement was only 3.8% which is much lower than those of other three solar components because of the light scattering efficiency of cloud drops. It was shown that the most of the enhancements occurred under cloud cover from 40 to 90%. The broadband global enhancement greater than 20% occurred for SZAs ranging from 28 to $62^{\circ}$. The broadband diffuse irradiance has been increased up to 467.8% (TOD 0.34) by clouds. In the case of channel 869.0 nm, the maximum diffuse enhancement was 609.5%. Thus, it is required to measure irradiance for various cloud conditions in order to obtain climatological values, to trace the differences among cloud types, and to eventually estimate the influence on solar irradiance by cloud characteristics.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.101-106
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• 2014

The era came that by having fastest internet and smart phone makes cloud computing really a big merit. This paper proposes architecture for medical image volume rendering in mobile environment using cloud computing. This architecture to replace expensive workstation server and storage it use one of the service of cloud computing IaaS(Infrastructure as a Service). And this paper propose to use webGL to get rid of restriction of mobile hardware. By this research, it is expected that medical image volume rendering service in mobile environment is more effective and can be a foundation work.

• KIISE Transactions on Computing Practices
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• v.23 no.4
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• pp.232-237
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• 2017

The Maritime Cloud is a technology that enables the seamless exchange of information between several communication links in the maritime domain. Although research on The Maritime Cloud security is still at an early stage, furthering this knowledge is vital to securing the marine environment. In this paper, we propose a method for secure data transmission through The Maritime Cloud domain. The proposed technique, based on the "secret sharing" scheme, is delivered through specifically-dedicated geocasting software. Thus, only authorized vessels can restore the original information. The proposed method is safe from so-called "sniffing" and "man-in-the-middle" attacks.