• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.196-198
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• 2002

클러스터링 데이터베이스는 높은 가용성과 확장성을 갖으며, 예상치 못한 클라이언트 질의의 증가나 질의 패턴의 변경에 따른 작업부하의 편중에 효율적으로 대처할 수 있는 구조이다. 특히 온라인 확장 기법은 트랜잭션 처리를 중지하지 않고 새로운 노드를 클러스터에 추가하여 데이터를 재구성함으로써 임의의 노드에 질의가 집중되는 문제를 해결할 수 있다. 정적으로 구성된 시스템만으로는 두 대 이상의 서버에 작업량이 집중될 경우 재배치 시 서버 간의 데이터 이동의 반복 현상이 발생되며. 이로 인해 네트웍의 부하와 함께 실시간 트랜적션의 처리에 있어서 응답 시간이 지연되는 문제점이 발생한다. 따라서 본 논문에서는 데이터 이동의 반복 현상을 해결하기 위해 클러스터링 데이터베이스에서 온라인 확장을 고려한 CSB+ 트리 색인의 온라인 재구성 기법을 제안한다. 제안된 기법은 온라인 확장을 통한 동구 노드의 확장으로 데이터 이동의 반복을 막고 새롭게 추가된 노드를 통해 빠르고 효율적인 데이터의 분산을 수행한다 또한 각 시스템의 내부를 CS$B^{+}$ 트리로 구성하여 데이터의 재주성시에도 실시간 트랜잭션에 대한 빠른 응답 시간을 보장한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.859-862
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• 2002

The Core Support Barrel (CSB) is a major component of Reactor Internals, and is designed to support and protect the Reactor Core. In this study, Reactor Core, Core Shroud and CSB were simplified to coaxial cylinders and then the offset of Reactor Core & Core Shroud to the dynamic characteristic of CSB was analyzed. For the beam modes, natural frequencies of the cantilevered cylinder are compared with those of the cantilevered beam. And it was found out that shear modulus must be used correctly to convert the shell model to the equivalent beam model. From the dynamic characteristics of the beam model, it was found out that natural frequencies are proportional to the length of Reactor Core & Core Shroud and inversely proportional to the mass. From the comparison with the dynamic characteristics of a beam model and a lumped-mass model it was found out that the size of lumped-mass must be determined considering both the length and the mass of Reactor Core & Core Shroud.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.41-44
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• 2017

클라우드에 대한 범용적인 관리를 위해서 사용되는 CSB(Cloud Service Brokerage) 기술을 기반으로 실제 사용자들이 이용하는 서비스를 제공하는 어플리케이션을 제공하기 위한 모델로 PaaS(Platform as a Service)이 도입이 되어야 한다. 이러한 구조 제공을 위해서는 CSB 서비스의 특성과 Application 구성 요소에 대한 관리 체계에 대한 접근을 통해서 다양한 클라우드에서 호환성을 보장할 수 있어야 한다. 본 논문에서는 기존에 활용되는 도구들의 제약 사항과 함께 클라우드 기반 마켓플레이스를 통해 다양한 IT 서비스를 생산 및 유통할 수 있는 구조에 대해서 고찰하고자 한다.

• Structural Engineering and Mechanics
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• v.69 no.6
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• pp.699-712
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• 2019

A cable-stayed bridge (CSB) is one of the most complicated structures, especially when subjected to earthquakes and taking into consideration the effect of soil-structure-interaction (SSI). A CSB of a 500 m mid-span was modeled by the SAP2000 software and was subjected to four different earthquakes. To mitigate the harmful effect of the vibration generated from each earthquake, four mitigation schemes were used and compared with the non-mitigation model to determine the effectiveness of each scheme, when applying on the SSI or fixed CSB models. For earthquake mitigation, tuned mass damper (TMD) systems and spring dampers with different placements were used to help reduce the seismic response of the CBS model. The pylons, the mid-span of the deck and the pylon-deck connections are the best TMDs and spring dampers placements to achieve an effective reduction of the earthquake response on such bridges.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.116-122
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• 2019

This study evaluated the properties of Coal gasification slag(CGS) according to the CGS contents of cement mortar condition as a basic step to examine the applicability of CGS as concrete fine aggregate. Flow increased with increasing CGS contents for both Crushed sand a(CSa) and Crushed sand b+Sea sand(CSb+SS), but the amount of air contents decreased to the opposite tendency. Based on 28 days is maximum compressive strength was obtained at CGS 50% when CSa was used and CGS 75% when CSb+SS. The flexural strength were the maximum at 25% and 50% of CGS, but the tendency was similar to the compressive strength. Compared with CSa, the compressive strength and flexural strength 5% higher than those of CSb+SS, in CGS using of were about 5% higher than those of unused CGS. As a result of comprehensive study on the quality of mortar according to the CGS contents, it can be concluded that when CGS is mixed with fine aggregate at about 50%, it can contribute to securing workability and strength development positively so that resource recycling and quality improvement can be achieved at the same time.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.133-138
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• 2020

This paper introduces a method for improving accuracy using the first convolution layer, which is not used in most modified CNN(: Convolution Neural Networks). In CNN, such as GoogLeNet and DenseNet, the first convolution layer uses only the traditional methods(3×3 convolutional computation, batch normalization, and activation functions), replacing this with RGB-csb. In addition to the results of preceding studies that can improve accuracy by applying RGB values to feature maps, the accuracy is compared with existing CNN using a limited number of images. The method proposed in this paper shows that the smaller the number of images, the greater the learning accuracy deviation, the more unstable, but the higher the accuracy on average compared to the existing CNN. As the number of images increases, the difference in accuracy between the existing CNN and the proposed method decreases, and the proposed method does not seem to have a significant effect.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.3
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• pp.247-252
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• 2017

The aim of this research is the feasibility analysis of the reject ash premixed cement mortar with combined aggregate. Namely, for the combined aggregate with two different qualities of aggregates, a fundamental properties of cement mortar was evaluated depending on various replacing ratios of reject ash(Ri). According to the experimental results, the combined aggregate consisted with low-quality aggregate and sea sand did not change the flow value depending on the reject ash while the combined aggregates consisted with low quality aggregate and sea sand; and consisted exploded debris sand and sea sand the increasing reject ash increased the air content with increased replacing ratio of reject ash. In the case of compressive strength, as the replacing ratio of reject ash was increased, the compressive strength was increased. It is considered that when 5% of reject ash replacing ratio made similar quality of cement mortar with favorable quality aggregate, hence, it can be suggested that 5% replacement of reject ash for desirable fluidity and compressive strength of concrete.

• The Journal of Korean Association of Computer Education
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• v.14 no.3
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• pp.37-49
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• 2011

A user can use resources on the Semantic Web using a Semantic Web browser. In order to utilize the functions of Semantic Web browsers in education, we compared the functions of well-known Semantic Web browsers such as Tabulator, Contextual Search Browser (CSB), Magpie, and Piggy Bank. In order to utilize Semantic Web browsers in education, a user needs to understand the features of each Semantic Web browser and our work can help both teachers and students. Tabulator is an RDF browser that can help to check whether resources can be used for learning and relevance of resources. CSB can be used to search educational resources using a conrtext file that contains the subjects of learning. It can also help learning by showing semantic web resources in the form of triple set as well as by supporting highlighting function. Magpie can help learners without basic knowledge on learning materials by providing interpretation based on a glossary file and related background knowledge. Piggy Bank supports conversion of web resources into semantic web resources and allows to browse semantic web resources in various views as well as to share semantic web resources.

• Journal of KIISE
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• v.42 no.11
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• pp.1361-1371
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• 2015

Depending on the increase amongst various cloud services, the technology of the Cloud Service Broker (CSB) to find the most appropriate services to meet the needs of cloud service consumers has emerged. In order to advance for cloud services to be used through the CSB, it is important to ensure the quality level that meets the demands of consumers through a negotiation process based on the Service Level Agreement (SLA). However, quality metrics of cloud services are different from each other based on the measurement scale, which represents the quality level, and the calculation for each type of cloud services. Therefore, it is necessary to analyze the variability of the quality of cloud services and establish a SLA model for ensuring and improving the level of quality. In this paper, we analyze the quality metrics for the specific type of cloud services by applying the cross-cutting concept and propose a Virtual SLA (VSLA) meta-model.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.11
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• pp.2061-2066
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• 2016

Currently, cloud systems are not interoperable due to low interoperability between cloud systems as operators build up cloud environments with their own way. For example, users of the Google cloud system can not use the Microsoft (Microsoft) cloud system unless they go through an additional log-in process. In order for Google cloud system's users to use MS cloud system services, they must log in to the MS cloud system again after logging out of Google cloud system. In order to solve these problems, Cloud Service Broker(CSB) technology has emerged to resolve the interoperability problem between cloud systems, but many researches and developments are still needed. In this paper, we design an integrated user authentication system, which is a fundamental problem of cloud user interoperability among CSB (Cloud Service Broker) technologies, which is emerging as a service intervention technology of heterogeneous distributed cloud environment.