• Journal of Software Engineering Society
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• v.26 no.2
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• pp.45-52
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• 2013

A cloud computing service provider must assure Service Level Agreement (SLA) to provide reliable and consistent quality of service to a user. The SLA is a contract between the user and the service provider that connects to assure constant level such as availability to target provided service. The cloud computing is classified into IaaS, PaaS, and SaaS according to IT resources of the various cloud service. The existing SLA is difficult to reflect quality factors of service because it only considers factors about the physical Network environment. In this paper, we suggest the UDDI-based interchange process with the architecture and the specification language having a XML schema for the SLA specification. The quality requirements of SaaS are defined by a proposed specification language in the cloud environment. It is stored in the repository of a quality specification and exchanged on during the service binding time based on the exchange architecture.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.1
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• pp.1-8
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• 2021

Vapor cloud explosions show different characteristics from that caused by ordinary TNT explosives and their loading effect is similar to pressure waves. Typical methods used for blast pressure calculations are the TNT-equivalent method and multi-energy method. The TNT-equivalent method is based on shock waves, similar to a detonation phenomenon, and multi-energy method is based on pressure waves, similar to a deflagration phenomenon. This study was conducted to derive an appropriate blast pressure by applying various plant explosion cases. SDOF analysis and nonlinear dynamic analysis were performed to compare the degree of deformation and damage of the selected structural members for the explosion cases. The results indicated that the multi-energy method was more exact than the TNT-equivalent method in predicting the blast pressure of vapor cloud explosions. The blast pressure of vapor cloud explosion in plants can be more accurately calculated by assuming the charge strength of multi-energy method as 7 or 8.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.8
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• pp.2450-2463
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• 2024

Many legacy information systems are currently being clouded. This is due to the advantage of being able to respond flexibly to the changes in user needs and system environment while reducing the initial investment cost of IT infrastructure such as servers and storage. The infrastructure of the information system migrated to the cloud is being integrated through the API connections, while being subdivided by using MSA (Micro Service Architecture) internally. DBMS (Database Management System) is also becoming larger after cloud migration. Scale calculation in most layers of the application architecture can be measured and calculated from auto-scaling perspective, but the method of hardware scale calculation for DBMS has not been established as standardized methodology. If there is an error in hardware scale calculation of DBMS, problems such as poor performance of the information system or excessive auto-scaling may occur. In addition, evaluating hardware size is more crucial because it also affects the financial cost of the migration. CPU is the factor that has the greatest influence on hardware scale calculation of DBMS. Therefore, this paper aims to calculate the conversion factor for CPU scale calculation that will facilitate the cloud migration between heterogeneous DBMS. In order to do that, we utilize the concept and definition of hardware capacity planning and scale calculation in the on-premise information system. The methods to calculate the conversion factor using TPC-H tests are proposed and verified. In the future, further research and testing should be conducted on the size of the segmented CPU and more heterogeneous DBMS to demonstrate the effectiveness of the proposed test model.

• ETRI Journal
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• v.36 no.2
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• pp.197-205
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• 2014

This paper proposes a novel framework for virtual content delivery networks (CDNs) based on cloud computing. The proposed framework aims to provide multimedia content delivery services customized for content providers by sharing virtual machines (VMs) in the Infrastructure-as-a-Service cloud, while fulfilling the service level agreement. Furthermore, it supports elastic virtual CDN services, which enables the capabilities of VMs to be scaled to encompass the dynamically changing resource demand of the aggregated virtual CDN services. For this, we provide the system architecture and relevant operations for the virtual CDNs and evaluate the performance based on a simulation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.132-133
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• 2017

The International Maritime Organization (IMO) has defined e-Navigation for the purpose of providing safe and efficient maritime information and communication services. Currently, a maritime cloud is being developed as a communication infrastructure for e-Navigation services. In this paper, we design the structure of vessel ID importation system which can efficiently register the maritime ID in the maritime cloud environment.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.142-145
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• 2014

지금까지 교통사고 예방을 위한 도로 정보 등을 제공하기 위해 차량 간 통신 네트워크인 Vehicular Ad hoc NETwork (VANET)연구가 활발히 진행되어왔다. 그러나 각 자동차의 On board unit (OBU)의 계산 능력, 저장 공간 등을 효율적으로 사용하는 연구는 진행되어 오지 않았다. 2011년 Olariu et al. 가 cloud computing을 기존의 VANET에 적용하는 개념인 Autonomous Vehicular cloud[1]를 제시하면서 새로운 VANET 연구의 새로운 장을 열었다. 기존의 VANET연구는 지금까지의 각각의 자동차의 통신 성능을 높이는 것에 초점을 맞추었지만, 새로운 아이디어는 높아진 각 자동차의 능력을 효율적으로 이용하여, 유용하게 사용하는 것에 초점을 맞추었다. 이것은 Intelligent Transport System (ITS)의 구축에 한발 더 나아갈 수 있게 하였다. 그 이후 VANET cloud computing (VCC)에 관한 많은 연구들이 진행되었으나 보안적인 측면에서는 아직 연구가 미흡한 실정이다. 그래서 본 논문에서는 보안을 보완한 VCC 아키텍처를 제안한다.

• International Journal of Computer Science & Network Security
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• v.22 no.1
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• pp.276-282
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• 2022

One of the most essential foundations upon which big institutions rely in delivering cloud computing and hosting services, as well as other kinds of multiple digital services, is the security of infrastructures for digital and information services throughout the world. Distributed denial-of-service (DDoS) assaults are one of the most common types of threats to networks and data centers. Denial of service attacks of all types operates on the premise of flooding the target with a massive volume of requests and data until it reaches a size bigger than the target's energy, at which point it collapses or goes out of service. where it takes advantage of a flaw in the Transport Control Protocol's transmitting and receiving (3-way Handshake) (TCP). The current study's major focus is on an architecture that stops DDoS attacks assaults by producing code for DDoS attacks using a cloud controller and calculating Round-Tripe Time (RTT).

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.444-461
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• 2016

A power-saving mechanism for smartphone devices is developed by analyzing the features of data that are received from Internet of Things (IoT) sensors devices to optimize the data processing policies. In the proposed GreenIoT architecture for power-saving in IoT, the power saving and feedback mechanism are implemented in the IoT middleware. When the GreenIoT application in the power-saving IoT architecture is launched, IoT devices collect the sensor data and send them to the middleware. After the scanning module in the IoT middleware has received the data, the data are analyzed by a feature evaluation module and a threshold analysis module. Based on the analytical results, the policy decision module processes the data in the device or in the cloud computing environment. The feedback mechanism then records the power consumed and, based on the history of these records, dynamically adjusts the threshold value to increase accuracy. Two smart living applications, a biomedical application and a smart building application, are proposed. Comparisons of data processed in the cloud computing environment show that the power-saving mechanism with IoT architecture reduces the power consumed by these applications by 24% and 9.2%.

• Journal of Digital Convergence
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• v.14 no.2
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• pp.235-243
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• 2016

Legacy data centers are transforming toward cloud data centers according to the advance of mobile and Internet of Things technology, processing of big data, and development of cloud computing technology. The goal of cloud data centers is to efficiently manage energy and facility, and to rapidly provide service demands to users by operating virtualized ICT(Information and Communication Technology) resources. Accordingly, it requires to configure and operate networks for efficiently providing virtualized ICT resources. This paper analyzes networking technologies suitable for cloud data centers and presents ways to efficiently operate the data center.

• Journal of the Korea Society of Computer and Information
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• v.19 no.2
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• pp.1-10
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• 2014

Cloud computing provides flexible and efficient mass data analysis platform. In this paper, we define a new resource provisioning architecture in the public cloud, named PCIA. In addition, we provide a service model of PCIA and its new naming scheme. Our model selects the proper number of physical or virtual resources based on the requirements of clients. By the analysis of performance variation in the PCIA, we evaluate the relationship between performance variation and resource provisioning, and we present key standards for cloud system constructions, which can be an important resource provisioning criteria for both cloud service providers and clients.