• Journal of Digital Convergence
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• v.10 no.11
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• pp.59-65
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• 2012

The evolution of cloud computing service over the recent years is potentially one of the major advances in information and communication technology. However, if cloud computing service is to achieve its potential, there needs to be a clear understanding of the various issues such as service security, performance and availability and so on, both from the perspectives of the providers and the consumers of the cloud service. As more and more information on individuals, companies and public sectors are placed in the cloud service, concerns are beginning to grow about just how safe and reliable an environment it is. In order to overcome these situations, the Korea cloud service certification system and U.S. FedRAMP were performed in each country. This paper aims at comparing and analyzing between Korean cloud service certification systems and U.S. FedRAMP and describing the difference between them. Eventually, we propose the improvement strategy of Korea cloud service certification systems based on the comparison results between them.

• Journal of Digital Convergence
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• v.12 no.1
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• pp.405-414
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• 2014

It is very important to IT users that the Cloud service provides dynamic extension of IT resources and cost-saving. However, the reliability for Cloud service hinders utilizing Cloud service actively. Existing studies on assessment program for Cloud Service are executed by extracting information security assessment articles and adding features of cloud services by referencing ISO/IEC 27001:2005. This paper will review the recently released ISO/IEC 27001:2013 for the addition, reduction, and changing of articles for Controls and Control objectives. Comparative analysis for the Controls of ISO/IEC 27001:2013 with those of CSA CCMv.3, FedRAMP which is an assessment program for Cloud service will suggest Control Objects of Information Security Management System for related Cloud service. The suggestion of Controls will be an important reference index for the security policy of companies which manage the information security management system based on Cloud service.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2305-2309
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• 2016

Cloud Computing Service should support efficiency and stability. United States of America, for example, provides FedRAMP (Federal Risk and Authorization Management Program) accreditation to certify cloud computing service and hence growth of computing service industry is giving benefits of cost reduction and efficiency to companies. However, the use of computing service brings more risk than ever. Because cloud computing holds all the data of multiple companies, problems such as hacking bring out control loss of service and as a result total data of companies can be lost. Unfortunately, cloud computing certification programs do not have any good solutions for this data loss and companies may lose all the important data without any proper data backup. This paper studies such problems in terms of backup problem and provides Data Availability Zone solution for recovery and safe saving of data so that computing service can offer better efficiency and stability.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.6
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• pp.1231-1238
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• 2013

In the background of rapidly increasing domestic cloud service demand, worries about security and privacy incidents can hinder the promotion of cloud service industry. Thus, it is crucial that the independent 3rd party assures the reliability for using the cloud service. This paper compares several external and internal cloud service certification cases, for example CSA certification, FedRAMP certification, KCSA certification, and concludes that insufficient security and privacy controls are prevailing. As a consequence, several enhanced countermeasures by using ISO/IEC 27017, KISA's ISMS considering manageability and expertise are proposed in the cloud service certification system.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.863-866
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• 2003

Multi-walled carbon nanotubes (CNTs) were synthesized on glass substrates in the different ramp-up heating ambient of vacuum, He, Ar, and $N_{2}$ by thermal chemical vapor deposition. CNTs with higher crystallinity were developed in the buffer gases with faster growth rates than in vacuum. Field emission characteristics were strongly related to the relative position of CNT emitters to the cathode electrodes. The areal-spread emission and instability were overcome by locating the emitters far away from the edges of cathode electrodes. The electrical conditioning of emitters improved their emission uniformity over a large area although it decreased the emission current. This study also discussed the long-term stability of CNT emitters.

• Journal of Electrical Engineering and Technology
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• v.6 no.2
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• pp.215-225
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• 2011

In this paper, a buck DC-DC bridge converter is used as a power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (PMBLDCM) drive. The front end of the PFC converter is a diode bridge rectifier (DBR) fed from single phase AC mains. The PMBLDCM is used to drive the compressor of an air conditioner through a three-phase voltage source inverter (VSI) fed from a variable voltage DC link. The speed of the air conditioner is controlled to conserve energy using a new concept of voltage control at a DC link proportional to the desired speed of the PMBLDC motor. Therefore, VSI operates only as an electronic commutator of the PMBLDCM. The current of the PMBLDCM is controlled by setting the reference voltage at the DC link as a ramp. The proposed PMBLDCM drive with voltage control-based PFC converter was designed and modeled. The performance is simulated in Matlab-Simulink environment for an air conditioner compressor load driven through a 3.75 kW, 1500 rpm PMBLDC motor. To validate the effectiveness of the proposed speed control scheme, the evaluation results demonstrate improved efficiency of the complete drive with the PFC feature in a wide range of speed and input AC voltage.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.3
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• pp.55-63
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• 1996

In this paper, a vector control system is implemented to drive CRPWM inverter fed induction motor. The rotor flux is estimated using the rotor coordinates flux model and the stator coordinates ramp comparison controller is used as a current controller. The microcontroller 80C196 is used for the computation of the estimation of the rotor flux, the speed controller, the flux controller, the vector rotation, and the phase transformation The current controller is implemented using the analog circuit in order to reduce the burden of the microcontroller. For the proposed system, the digital simulation is performed to examine the feasibility and the superior characteristics of the current controller and the system transient response is verified through the experiment.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1-6
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• 1991

This paper is concerned with the design of a robust tracking controller using a state observer on a robotic manipulator under the disturbance. The controller is designed to follow a step or ramp reference input without steady state error in the presence of a disturbance and a system parameter variation. In most cases, since all the state vectors are not measured, unmeasurable state vectors must be estimated or reconstructed. A reduced order observer is proposed to estimate unmeasurable state vectors of the non-linear system. Some problems are caused by the Coulomb friction, the disturbance, and the spring effect of a link between the drive motor and the manipulator arm. The state variables, directly measured and estimated by the reduced order observer, are fed back to the controller. When the robot system exhibits the 'limit cycle, the feedback gains initially obtained by optimal control theory are changed. As a result, the limit cycle is eliminated by the new controller gains,

• The Journal of Society for e-Business Studies
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• v.20 no.4
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• pp.103-126
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• 2015

Compared to other countries, cloud computing in Korea is not popular especially in the government sector. One of the reasons for the current not-fully-blossomed situation is partly by early investment in huge government datacenters under Korea's e-government initiative; let alone, there was no strong control tower as well as no enforcing law and ordinances for driving such cloud computing initiative. However, in 2015 March 'Cloud Computing and Privacy Security Act' (hereinafter, Cloud Act) had been passed in the Parliament and from September 2015 Cloud Act was deployed in Korea. In U.S., FedRAMP (Federal Risk Assessment and Management Program) along with Obama Adminstration's 'Cloud First' strategy for U.S. federal institutions is the key momentum for federal cloud computing adoption. In 2015 January, U.S. Congressional Research Service (CRS) has published an extensive monitoring report for cloud computing in U.S. federal institutions. The CRS report which monitored U.S. government cloud computing implementation is indeed a good guideline for Korean government cloud computing services. For this reason, the purpose of the study is to (1) identify important aspects of the enacted Korean Cloud Act, (2) describe recent U.S. federal government cloud computing status, (3) suggest strategy and key strategy factors for facilitating cloud adoption in public organizations reflecting SDLC strategy, wherein.