• International Journal of Contents
• /
• v.8 no.4
• /
• pp.7-11
• /
• 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 the Korea Society of Computer and Information
• /
• v.12 no.6
• /
• pp.115-121
• /
• 2007

Recently, Location Based Service including tracking and way-finding services has been activated rapidly in the ubiquitous computing environment. According as the ubiquitous computing environment is developed, various types of sensor to acquire various data including location of the moving object are used widely, and acquired sensor data becomes abundant. However, the existing location management system based on a single location sensor is difficult to support LBS efficiently in the ubiquitous computing environment. In this paper, therefore, we propose the location management system in the ubiquitous computing environment that can manage the location data and the various sensor data efficiently. In addition, the location management system adopts the core technology for efficiently storing and transferring a large-volume of various data such as location data and for efficiently processing the various requests from a variety of servers and sensors. Especially, our architecture that is presented in this paper can support context-aware services and autonomous services efficiently in the ubiquitous computing environment.

• The Journal of the Korea Contents Association
• /
• v.16 no.7
• /
• pp.667-680
• /
• 2016

As distributed computing platforms like Hadoop MapReduce have been developed, it is necessary to perform the conventional query processing techniques, which have been executed in a single computing machine, in distributed computing environments efficiently. Especially, studies on similarity join query processing in distributed computing environments have been done where similarity join means retrieving all data pairs with high similarity between given two data sets. But the existing similarity join query processing schemes for distributed computing environments have a problem of skewed computing load balance between clusters because they consider only the data transmission cost. In this paper, we propose Matrix-based Load-balancing Algorithm for efficient similarity join query processing in distributed computing environment. In order to uniform load balancing of clusters, the proposed algorithm estimates expected computing cost by using matrix and generates partitions based on the estimated cost. In addition, it can reduce computing loads by filtering out data which are not used in query processing in clusters. Finally, it is shown from our performance evaluation that the proposed algorithm is better on query processing performance than the existing one.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.6
• /
• pp.19-27
• /
• 2010

Many security issues occur in cloud computing service environment such as authentication, access control, and so on. In this paper, we propose an effective authentication and access control model which provide integrated management and control when we access various resources in cloud computing environment. To address these problems, we suggest a context-aware single sign-on and access control system using context-awareness, integrated authentication, access control, and OSGi service platform in cloud computing environment. And we show design and implementation of context-aware single sign-on and access control system. Also we verified the flexibility and convenience of the proposed system through multi fact based integrated authentication in cloud computing environment. We could provide flexible and secure seamless security service by user context in cloud computing environment.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.22 no.1
• /
• pp.141-153
• /
• 2012

In the recent years, various researches on the use cases of the cloud computing service have been achieved for its standardization. Notwithstanding, we need more additory effort to refine the operating mechanisms on the cloud computing environment. In this paper, we suggest an operating mechanism on IaaS cloud computing environment that is related to the integrated security management system. By using CloudStack 2.2.4 toolkit, we have built a test-bed for IaaS cloud computing service i.e., SWU-IaaS cloud computing environment. Through operating this hierarchical SWU-IaaS cloud computing environment, we have derived the attributes and the methods of its components. Its scenarios can be described in case of both normal state and abnormal state. At the end, a special scenario has been described when it receives a security event from the integrated security management system.

• Archives of design research
• /
• v.17 no.3
• /
• pp.403-412
• /
• 2004

Ubiquitous computing will bring on comprehensive changes of environment. We need to understand how this change will change human life and what will be needed in this circumstances. Then we have to develope the appropriate sonics in ubiquitous computing environment. The design of ubiquitous computing environment has the concept of designing human life. Thus to develope the scenarios which are able to predict human life is to make a foundation of developing design concepts effectively. However there is a gap due to the lack of the dear methodology between the analyzing trend of technology and the process of estimating the future life and developing the service scenarios. So, most of the scenarios which have developed up to now do not present the service that exactly reflects all the complicated and pluralistic sides of environment. The service in the ubiquitous computing environment should take the form of grasping the user's context and offering the information with the most adequate way. Therefore we have to know when they need services, where they use services and what kind of services they want. It means that we should understand the life and the environment of user clearly and wholly with the prospect of developing service. We also need the method for developing UC(ubiquitous computing) service based on this. This study focuses on the future family life and analyzes the user's context from a point of view of service development and in this ground, we have progressed the research about the methodology to develop the UC service scenario for suggesting the service. Through the applying of this methodology, we could analyze the user's context systematically and could make the best use of the analyzed data for proposal service idea. And the UC service scenarios which reflect future life on the basis of various use's context could be developed.

• Journal of Platform Technology
• /
• v.9 no.2
• /
• pp.10-25
• /
• 2021

Although many studies have been conducted on risk analysis and evaluation in the on-premises environment in information security, studies on effective methodologies of risk analysis and evaluation for cloud computing systems are lacking. In 2015, the Cloud Computing Development Act was enacted, which served as an opportunity to promote the introduction of cloud computing. However, due to the increase in security incidents in the cloud computing system, activation is insufficient. In addition, the cloud computing system is not being actively introduced because of the difficulty in understanding the cloud computing system technology of the person in charge who intends to introduce the cloud computing system. In this regard, this study presented an effective risk analysis and evaluation method by examining the characteristics, concepts, and models of cloud computing systems and analyzing how these characteristics affect risk analysis and evaluation.

• Journal of Intelligence and Information Systems
• /
• v.15 no.2
• /
• pp.15-31
• /
• 2009

The next generation IT environment is expected to be an open computing environment based on Grid computing technologies, which allow users to access to any type of computing resources through networks. The open computing environment has benefits in aspects of resource utilization, collaboration, flexibility and cost reduction. Due to the variation in performance of open computing resources, however, resource allocation simply based on users' budget and time constraints often fails to meet the Service Level Agreement(SLA). This paper proposes the Mean-Absolute Deviation(MAD) portfolio optimization approach, in which service brokers consider the uncertainty of performance of resources, and compose resource portfolios that minimize the uncertainty. In order to investigate the effect of this approach, we simulate an open computing environment with varying uncertainty levels, users' constraints, and brokers' optimization strategies. The simulation result concludes threefolds. First, the MAD portfolio optimization improves the success ratio of delivering the required performance to users. Second, the success ratio depends on the accuracy in predicting the variability of performance. Thirdly, the measured variability can also help service brokers expand their service to cost-critical users by discounting the access cost of open computing resources.

• Proceedings of the Korean Society of Computer Information Conference
• /
• 2008.06a
• /
• pp.163-167
• /
• 2008

본 논문에서는 광범위 Community Computing 환경에서의 Community Computing Network의 에너지 효율과 신뢰성을 높이기 위한 수정된 SPaC(Simple Packet Combining)를 제안한다. 제안하는 수정된 SPaC는 같은 패킷을 두 개 이상의 오류가 있는 패킷을 이용하여 에러를 복구하는 기존의 SPaC를 수정하여 특정 threshold 값을 사용하여 감청 시 CPU의 처리량을 줄이고 패리티 패킷을 이용하여 높은 신뢰성과 보다 향상된 에너지 효율을 가진다.

• 한국전산유체공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.35-40
• /
• 2005

Up to recently, with the improvement of a computer power and high speed of network technology, advanced countries have researched a construction of the e-Science environment. As a major application part, a construction for environment of CFD, also, have studied together. During the research, people realize that not sharing hardware but also appropriate software development is really important to realize the environment. This paper describes about a construction of a collaborative research environment in the KISTI: Clients can connect to the computing resources through the web portal, run the Cactus simulation.: According to the computing resources, the simulation can migrate to some site to find better computing power.: Result of the calculation visualize at the web portal directly so that researchers of remote site can be share and analyze the result collaborative ways.