• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.11
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• pp.861-869
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• 2013

We consider an information system where viruses arrive according to a Poisson process with rate ${\lambda}$. The information system has two types of anti-virus operation policies including 'real-time scan' and 'batch scan.' In the real-time scan policy, a virus is assumed to be scanned immediately after its arrival. Consequently, the real-time scan policy assumes infinite number of anti-viruses. We assume that the time for scanning and curing a virus follows a general distribution. In the batch scan policy, a system manager operates an anti-virus every deterministic time interval and scan and cure all the viruses remaining in the system simultaneously. In this paper we suggest a probability model for the operation of anti-virus software. We derive a condition under which the operating policy is achieved. Some numerical examples with various cost structure are given to illustrate the results.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.21 no.4
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• pp.161-178
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• 2010

The purpose of this study is to develop a collaborative model for the archiving and preservation of an electronic book(e-book). In this study the way of the archiving and preservation for the e-book to deal with the technology evolution was suggested. Accordingly, the survey was made for obtaining the present status of the production and distribution of the domestic Online e-book. It is the same as the operation status of the archiving and preservation for the Online e-book worldwide. A collaborative model for accessible to preserved data, regardless of time period, was proposed for archiving the e-book, based on the OAIS reference model. There are three different models, suggested for domestic; the safe place model by law, the individual preservation/Peer-to-Peer model, and the preservation center model for e-book archiving. Among them, the safe place model by law was proposed for the optimum model of archiving an e-book at present.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.2
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• pp.233-239
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• 2016

In this paper, a maintenance system is developed for LNG-FPSO topside and hullside equipment based CBM (Condition Based Maintenance) methodology. First, the development system defined the PWBS(Product Work Breakdown Structure) of major equipment of LNG-FPSO. Second, the development system developed the failure analysis, economic evaluation for optimal maintenance plan and database systems that save and manage information about equipment, failure mode, failure rate and failure cause. Finally, the verification of the development system was applied to the inlet system of topside and the pump tower system of hullside and the system was confirmed the effectiveness of CBMS(Condition Based Maintenance System).

• Journal of Korean Library and Information Science Society
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• v.48 no.4
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• pp.1-20
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• 2017

The most important identity of public library is local public goods that guarantee access and use of knowledge and information of local residents. To justify this, the library must create an optimal lighting environment. Particularly, since the perception rate of information through vision is over 80%, it is necessary to secure proper illuminance. This study measured the illuminance level of public libraries in Daegu. Based on the results, this study suggested a desirable illuminance level for each space and proposed plans to secure and maintain proper illuminance(prospective revision of the KS A 3011, setting the illuminance range for each space of the local government, replacing the existing lighting fixtures with LED, enhance supervision of lighting management, establishment of basic principles for proper lighting and detailed plans for each space of the library, investigation and reflection on users' complaints and satisfaction, etc.)

• International Commerce and Information Review
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• v.15 no.2
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• pp.71-82
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• 2013

The automotive supply chain is increasingly complex as automakers seek more profitable solutions with global out-sourcing and manufacturing strategies. In the automotive industry, using returnable plastic containers (RPCs) is very common for domestic operations, but for internationally, it has not been considered by many companies because of issues such as overall distance and difficulty of control. The results of this simulation can help to analyze the interactive and coherent behavior of packaging and supply chain systems. The data obtained from the model can be applied to make substantial decisions for choosing the most profitable packaging types, at the same time as it can lead to designing an optimum supply chain for RPCs used in international supply chains.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.533-538
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• 2005

Due to rapidly inc Due to rapidly Increase the number of vehicles, the number of vehicle passed over the traffic capacity which is allowable on each road. In order to disperse the traffic in the congestion area, ITS related techniques have been studied advancing. However, the cost of setting up and managing In is considerable to recently improve the problem or In, various traffic analysis technique are problem using low cost RFID. In this paper, the method of RFID-Reader location selection, which is a core technique to analyze traffic amount and traffic context is proposal. In order to systematically utilize traffic related road information, GIS is used for the proposal method. In addition, a rule-based model using O/D data that is the important information for selection the location of traffic observation.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.8
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• pp.791-797
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• 2010

The reliability of a water meter for measuring the water flow-rate and subsequent analysis of the measured water depends on the accuracy of measurement. The under registration of a water meter causes many problems for operators, such as loss in revenue and a decrease in the rate of measured water. The purpose of this study is to support and development core technology, such as efficient operations management and adoption of the best mechanism for providing different services by experimentally. In this study, experiments were conducted using water meters with different diameters, manufacturers, years of usage and the specific uses. On the basis of the results, the water meter confirmed that the error of minimum flow rate which will use long becomes larger more in the direction of minus.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.108-115
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• 2011

용수공급 계획의 수립이나 수자원시설물 운영에서 주어진 목적의 달성여부를 판단하는 기준은 사회적 합의를 바탕으로 한 공개념으로 작용하기 때문에 기준 적용은 매우 신중하게 다루어져야 한다. 이런 기준들은 신규용수공급시설 설계나 기존시설의 경우 이행도를 평가하는 척도가 되며 경제성이나 대안을 결정하는데 이용된다. 또한 이런 기준들은 국가 수자원 정책의 지표가 될 뿐만 아니라 물 공급 서비스를 받는 사람들에게 최소 필요로 하는 물을 어느 수준으로 얼마를 어떻게 공급할 것인가를 약속하는 의미를 갖는다. 이를 위해 우선 검토하여야 할 사항은 용수공급신뢰도 조사를 위한 기본체계를 제공하고 현재 신뢰도가 어떻게 정의되었으며 물 공급관리지표에 맞추어 예상되는 물 수요의 증가를 언제 어떻게 맞출 것인가라는 측면에서 신규시설물을 계획하면서 공급신뢰도에 의한 계획공급량(목표공급량)을 정하였다. 물을 공급받는 수요자는 공급에 대한 신뢰도가 높은 상태를 원하며 자신이 원하는 물을 아무런 장애없이 지속적으로 공급될 수 있는 조건을 전제로 물 공급계약을 체결한다. 이와 같은 신뢰도가 늘 엄격히 지켜지는 것은 아니나 현대 사회에서도 수요와 공급관계에서 지켜져야 할 기준으로 인식되고 있다. 아울러 수자원 기술자들에게 는 최적으로 달성해야할 업무목표가 된다. 그러나 제한된 정보를 이용하여 용수공급의 신뢰도를 정하게 되며 설계치를 초과하는 수문사상의 불확실성 및 수리구조물의 불안정 등으로 물 공급의 위험도는 항시 발생할 수 있다. 또한 인구증가나 새로운 산업입지에 의한 물 수요의 증가는 기존 시설물의 용량을 초과하여 물 공급의 신뢰도를 악화시킬 수 있다. 가장 널리 이용되고 있는 공급신뢰도 개념은 목표한 용수공급량 혹은 수요량을 충족시키느냐 못하느냐의 정도를 발생빈도 확률로 나타내는 것이다. 그러나 신뢰도의 적용에 대한 기준은 국내뿐만 아니라 외국에서도 종종 논란거리가 되고 있다. 또한 한 국가 내에서나 수자원을 개발하는 기관 내에서도 동일 목적의 사업별로 적용기준이 천차만별이다. 본 연구에서는 국내 외 이수안전도에 대한 정의와 적용사례를 분석하고 각각의 기준이나 지표의 장단점을 비교 평가하고자한다. 아울러 도출된 문제점을 바탕으로 개선방향을 제시하고자 하며, 궁극적으로 국내의 이수안전도 기준설정에 대한 종합적 의견을 제시 하고자 한다.

• Journal of KIISE
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• v.44 no.7
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• pp.719-725
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• 2017

To reduce management costs and improve performance, the European Telecommunication Standards Institute (ETSI) introduced the concept of network function virtualization (NFV), which can implement network functions (NFs) on cloud/datacenters. Within the NFV architecture, NFs can share physical resources by hosting NFs on physical nodes (commodity servers). For network service providers who support NFV architectures, an efficient resource allocation method finds utility in being able to reduce operating expenses (OPEX) and capital expenses (CAPEX). Thus, in this paper, we analyzed the network service chain embedding problem via an optimization formulation and found a close-optimal solution based on the Markov approximation framework. Our simulation results show that our approach could increases on average CPU utilization by up to 73% and link utilization up to 53%.