• The Transactions of the Korea Information Processing Society
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• v.13 no.2
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• pp.48-59
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• 2024

As functions that support virtualization on their own in hardware are developed, user applications having various workloads are operating efficiently in the virtualization system. SR-IOV is a virtualization support function that takes direct access to PCI devices, thus giving a high I/O performance by minimizing the need for hypervisor or operating system interventions. With SR-IOV, network I/O acceleration can be realized in virtualization systems that have relatively long I/O paths compared to bare-metal systems and frequent context switches between the user area and kernel area. To take performance advantages of SR-IOV, network resource management policies that can derive optimal network performance when SR-IOV is applied to an instance such as a virtual machine(VM) or container are being actively studied.This paper evaluates and analyzes the network performance of SR-IOV implementing I/O acceleration is compared with Virtio in terms of 1) network delay, 2) network throughput, 3) network fairness, 4) performance interference, and 5) multi-network. The contributions of this paper are as follows. First, the network I/O process of Virtio and SR-IOV was clearly explained in the virtualization system, and second, the evaluation results of the network performance of Virtio and SR-IOV were analyzed based on various performance metrics. Third, the system overhead and the possibility of optimization for the SR-IOV network in a virtualization system with high VM density were experimentally confirmed. The experimental results and analysis of the paper are expected to be referenced in the network resource management policy for virtualization systems that operate network-intensive services such as smart factories, connected cars, deep learning inference models, and crowdsourcing.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.479-485
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• 2013

Virtualization is a promising approach to consolidating multiple online services onto a smaller number of computing resources. A virtualized server environment allows computing resources to be shared among multiple performance isolated platforms called virtual machines. Through server virtualization software, applications servers are encapsulated into VMs, and deployed with APIs on top generalized pools of CPU and memory resources. Networking and security have been moved to a software abstraction layer that transformed computing, network virtualization. And it paves the way for enterprise to rapidly deploy networking and security for any application by creating the virtual network. Stochastic reward net (SRN) is an extension of stochastic Petri nets which provides compact modeling facilities for system analysis. In this paper, we develop SRN model of network virtualization based on virtual switch. Measures of interest such as switching delay and throughput are considered. These measures are expressed in terms of the expected values of reward rate functions for SRNs. Numerical results are obtained according to the virtual switch capacity and number of active VMs.

• Journal of Digital Convergence
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• v.10 no.9
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• pp.325-332
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• 2012

VANET(Vehicular Ad-hoc Network), which is a technology to create a network among vehicles, decides the route to the destination using information of neighbors within the transmission range as transmission nodes. The existing routing protocol which uses geographical information can cause delay and disconnection of the network when the density of nodes is not high enough to communicate because it only considers the distance of the relay nodes or destination nodes from the source nodes. To solve the problem, this dissertation suggests a routing algorithm based on zones for stable communications among vehicles in the environment of VANET. I minimize the packet loss rate by dividing the city environment into zones and taking into account not only the distance of the destination but also the density of vehicles to choose the best communications environment. This results in a better performance than the established research when the performance evaluation is implemented.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.4
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• pp.1-8
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• 2011

Traditional transactional memory systems are no longer able to guarantee the performance of diverse applications with overflowed transactions since there is the drawback that tracking the data for logging is difficult. Especially, this mechanism has a disadvantage of increasing communication delay for sustaining the state which is required to detect the conflict on the overflowed transactions from the first level cache in the transactional memory systems. To address this point, we have focused on the cache architecture of the systems to reduce the overhead caused by overflows and cache misses. In this paper, we present Supportive Cache which reduces additional overhead during transactions. Supportive Cache performs a parallel look-up with L1 private cache and uses the same replacement policy as L1 private cache. We evaluate the performance of the proposed design by comparing LogTM-SE with and without Supportive Cache. The simulation results show that our system improves the performance by 37% on average, compared to the original LogTM-SE which uses the same hardware resource.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3700-3706
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• 2010

As the number of the elderly increases, concerns about senile dementia and serious game for dementia are growing. The purpose of this study is to explore the types of attitude toward senile dementia. To identify public attitudes toward senile dementia, we conducted Q methodology. A Q set of potential public attitudes toward senile dementia was identified through literature review. From this, 52 potential public attitudes toward senile dementia were identified. Twenty subjects ranked these explanations as possible public attitudes. The attitudes toward senile dementia were classified as 4 types : 'type1 : idealistic & expectant', 'type 2 : aversive & defensive', 'type 3 : active & realistic', and 'type 4 : responsible & compensatory'. This study revealed that people have different explanatory frameworks for the attitude toward senile dementia.

• Journal of the Korean Society for information Management
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• v.28 no.2
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• pp.195-208
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• 2011

This study presents the findings from research on the Everyday Life Information Seeking (ELIS) behaviors of Korean government officials in their 50s. 500 survey respondents participated and the quantitative data were analyzed through Structural Equation Model having six key concepts such as personal information environment, information-seeking attitudes, online information attitudes, barriers to information seeking, retirement expectations, and library expectations. The findings showed the important relationships between expectations of the retirement and two constructs (personal information environment and information-seeking attitudes). This study can be used as a strategic implication for library practitioners to develop their library management process in accordance to the potential and powerful evolving user group in a future aged society.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.242-245
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• 2003

Most engineering tasks require collaboration between many users in major hospital Construction Projects that have many risks. Loss of cost and change orders occurred in factors such as information exchange, misunderstandings, advanced Technology in hospital projects. Moreover, changes in context, costs, requirements, deadlines, etc. require negotiation of issues that may modify important project characteristics. Each part of the major hospital construction projects have been rapidly changed technology of equipments. Therefore it is a major challenge to make a high level of communication and to have mutual understanding. The objective of this paper is to reduce risks for the design process and construction process of hospital projects.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.145-151
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• 2009

Recently the water quality management policy has been changed from managing the point source to controlling the nonpoint sources (NPSs) because of TMDL program. Most NPSs are accumulated on the surface during dry periods. These accumulated pollutants are washed-off during a storm event and highly impairing the water quality of the receiving water bodies. Usually NPS has high uncertainty and is hard to control because of the variability of the rainfall and watershed characteristics. Also, NPS is derived from various land uses. The Ministry of Environment (MOE) is studying and monitoring the pollutant loads from each land use since 2007 to determine the unit pollutant loads. This research was a part of long-term monitoring program conducted to characterize the washoff and provide the mean EMC of artificial grassland. The average EMCs result of BOD, COD, DOC, SS, TN, NH4-N, NO3-N, TP, and PO4-P of the artificial grassland were deterined to 8.2, 17.5, 11.3, 110.1, 3.07, 0.20, 0.75, 0.86 and 0.08 mg/L, respectively. The results of statistical analysis conducted showed a low correlation to the contaminants.

• Journal of Practical Engineering Education
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• v.7 no.1
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• pp.47-55
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• 2015

This study has the objective of proposing the basic data for the political and administrative support needs so that the Echo generation can be prepared with the supper-aged society, by verifying the perception level and degree of necessity about the outplacement support service, whether they want to be serviced or not, and necessary contents in the service with the employed people and non-employed people as objects among the Echo generation in the Southeast region. The study result derived from these effort is illustrated as follows. The perception level of the Echo generation about outplacement support service showed to be significantly different according to the gender, age, industry type, and career. The degree of needs was significantly different depending on the age. For the provision period of the outplacement support service, the opinions were that 3 months before the retirement was most appropriate. The intention of participation when the outplacement support service is provided showed to be significantly different depending on the age.

• Environmental and Resource Economics Review
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• v.18 no.1
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• pp.1-22
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• 2009

The primary purpose of ITQ (individually transferable quota) is to reduce the overcapitalization problem in the open-access fishery. It has been argued that the least cost-efficient vessels under ITQ may exit first from the fishing by selling their quotas, thereby also reducing the excess capital. The purpose of this paper is to provide a case when ITQ may prompt the exit of less cost-inefficient vessels in the presence of irreversible exit cost which is proportional to the cost-inefficiency. Real option model is adopted in order to analyze the source of hysteresis associated with fishery exit decision. By linking the interaction between vessels' adjustment costs, cost-efficiency of harvest and uncertainty of fishery return, we show that cost-inefficient vessels will not exit always first from the fishery in contrast to the conventional wisdom. Relevant policy implications is discussed.