• International Journal of Contents
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• v.8 no.4
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• pp.7-11
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• 2012

Cloud Computing can be viewed as a dynamically-scalable pool of resources. Virtualization is one of the key technologies enabling Cloud Computing functionalities. Virtual machines (VMs) scheduling and allocation is essential in Cloud Computing environment. In this paper, two dynamic VMs scheduling and allocating schemes are presented and compared. One dynamically on-demand allocates VMs while the other deploys optimal threshold to control the scheduling and allocating of VMs. The aim is to dynamically allocate the virtual resources among the Cloud Computing applications based on their load changes to improve resource utilization and reduce the user usage cost. The schemes are implemented by using SimPy, and the simulation results show that the proposed adaptive scheme with one threshold can be effectively applied in a Cloud Computing environment both performance-wise and cost-wise.

• Journal of Information Technology Services
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• v.11 no.1
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• pp.155-171
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• 2012

With the continuous and outstanding development of information technology(IT), human being is coming to the new computing era which is called cloud computing. This era brings lots of huge benefits also at the same time release the resources of IT infrastructure and data boom for man. In the future no longer, most of IT service providers, enterprises, organizations and systems will adopt this new computing model. There are three main deployment models in cloud computing including public cloud, private cloud and hybrid cloud; each one also has its own cons and pros. While implementing any kind of cloud services, customers have to choose one of three above deployment models. Thus, our paper aims to represent a practical framework to help the adopter select which one will be the best suitable deployment model for their requirements by evaluating each model comprehensively. The framework is built by applying the analytic hierarchy process(AHP), namely benefit-cost-opportunity-risk(BCOR) model as a powerful and effective tool to serve the problem. The gained results hope not only to provide useful information for the readers but also to contribute valuable knowledge to this new area. In addition, it might support the practitioners' effective decision making process in case they meet the same issue and have a positive influence on the increase of right decision for the organization.

• Electronics and Telecommunications Trends
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• v.35 no.2
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• pp.79-88
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• 2020

Quantum computing is regarded as one of the revolutionary computing technologies, and has attracted considerable attention in various fields, such as finance, chemistry, and medicine. One of the promising candidates to realize fault tolerant quantum computing is quantum dot qubits, due to their expectation of high scalability. In this study, we briefly introduce the international tendencies for quantum dot quantum computing. First, the current status of quantum dot gate operations is summarized. In most systems, over 99% of single qubit gate operation is realized, and controlled-not and controlled-phase gates as 2-qubit entangling gates are demonstrated in quantum dots. Second, several approaches to expand the number of qubits are introduced, such as 1D and 2D arrays and long-range interaction. Finally, the current quantum dot systems are evaluated for conducting quantum computing in terms of their number of qubits and gate accuracies. Quantum dot quantum computing is expected to implement scalable quantum computing. In the noisy intermediate-scale quantum era, quantum computing will expand its applications, enabling upcoming questions such as a fault-tolerant quantum computing architecture and error correction scheme to be addressed.

• Journal of Information Processing Systems
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• v.15 no.2
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• pp.440-448
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• 2019

The Internet of Things (IoT) is one of the main enablers for situation awareness needed in accomplishing smart cities. IoT devices, especially for monitoring purposes, have stringent timing requirements which may not be met by cloud computing. This deficiency of cloud computing can be overcome by fog computing for which fog nodes are placed close to IoT devices. Because of low capabilities of fog nodes compared to cloud data centers, fog nodes may not be deployed with all the services required by IoT devices. Thus, in this article, we focus on the issue of fog service placement and present the recent research trends in this issue. Most of the literature on fog service placement deals with determining an appropriate fog node satisfying the various requirements like delay from the perspective of one or more service requests. In this article, we aim to effectively place fog services in accordance with the pre-obtained service demands, which may have been collected during the prior time interval, instead of on-demand service placement for one or more service requests. The concept of the logical fog network is newly presented for the sake of the scalability of fog service placement in a large-scale smart city. The logical fog network is formed in a tree topology rooted at the cloud data center. Based on the logical fog network, a service placement approach is proposed so that services can be placed on fog nodes in a resource-effective way.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.4
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• pp.293-298
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• 2000

In fuzzy expert systems or database systems that have volumes of fuzzy data or large fuzzy rules, the inference time is much increased. Therefore, a high performance parallel fuzzy computing environment is needed. In this paper, we propose a parallel fuzzy inference mechanism in parallel computing environments. In this, fuzzy rules are distributed and executed simultaneously. The ONE_TO_ALL algorithm is used to broadcast the fuzzy input input vector to the all nodes. The results of the MIN/MAX operations are transferred to the output processor by the ALL_TO_ONE algorithm. By parallel processing of fuzzy or data, the parallel fuzzy inference algortihm extracts effective and achieves and achieves a good speed factor.

• The Journal of Korean Association of Computer Education
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• v.17 no.6
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• pp.9-20
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• 2014

With the change of global awareness of Computing education and introspection about Computer education focused on ICT literacy, efforts are being made to reflect computational thinking in the new curriculum. But if computational thinking would be possible at school, it require tremendous cost to prepare computers for school. In this study, we investigate potentiality and constraints of the one board computer to teach computational thinking in school. We study fundamental performance, application of physical computing and programming education, maintenance of the computers, power consumption of the one board computers which is raspberry pi, beagle bone black, and pcduino3. The result of the study show that one board computer can substitute desktop of the school unless tasks related to require massive data storage and processing. We draw a conclusion that Pcduino3 is well-suited for computational thinking education.

• Journal of Computing Science and Engineering
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• v.5 no.3
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• pp.237-245
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• 2011

The use of technology within the home has gained wide spread acceptance as one possible approach to be used in addressing the challenges of an ageing society. A number of rudimentary assistive solutions are now being deployed in real settings but with the introduction of these technology-orientated services come a number of challenges, which to date are still largely unsolved. At a fundamental level, the management and processing of the large quantities of data generated from multiple sensors is recognised as one of the most significant challenges. This paper aims to present an overview of the types of sensor technologies used within Ambient Assisted Living. Subsequently, through presentation of a series of case studies, the paper will demonstrate how the practical integration of multiple sources of sensor data can be used to improve the overall concept and applications of Ambient Assisted Living.

• International Journal of Computer Science & Network Security
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• v.21 no.9
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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.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.3
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• pp.67-72
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• 2018

Recently, noise reduction in an axial fan producing the small pressure rise and large flow rate, which is one type of turbomachine, is recognized as essential. This study describes the design and optimization techniques of MPI parallel program to simulate the flow-induced noise in the axial fan. In order to simulate the code using 100 million number of grids for flow and 70,000 points for noise sources, we parallelize it using the 2D domain decomposition. However, when it is involved many computing cores, it is getting slower because of MPI communication overhead among nodes, especially for the noise simulation. Thus, it is adopted the one-sided communication to reduce the overhead of MPI communication. Moreover, the allocated memory and communication between cores are optimized, thereby improving 2.97x compared to the original one. Finally, it is achieved 12x and 6x faster using 6,144 and 128 computing cores of KISTI Tachyon2 than using 256 and 16 computing cores for the flow and noise simulations, respectively.

• Journal of Internet Computing and Services
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• v.20 no.1
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• pp.25-37
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• 2019

Inspired by the rapid development of deep learning and online biometrics-based authentication, we propose a handwritten one-time password authentication system which employs deep learning-based handwriting recognition and writer verification techniques. We design a convolutional neural network to recognize handwritten digits and a Siamese network to compute the similarity between the input handwriting and the genuine user's handwriting. We propose the first application of the second edition of NIST Special Database 19 for a writer verification task. Our system achieves 98.58% accuracy in the handwriting recognition task, and about 93% accuracy in the writer verification task based on four input images. We believe the proposed handwriting-based biometric technique has potential for use in a variety of online authentication services under the FIDO framework.