• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.557-565
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• 2016

The risk of collapse in hydraulic structures has become more elevated, due to the increased probability and scale of flooding caused by global warming and the resulting abnormal climatic conditions. When a levee, a typical hydraulic structure, breaks, an enormous breach flow pours into the floodplain and much flood damage then occurs. It is important to accurately calculate the breach discharge in order to predict this damage. In this study, the variation of the breach discharge with the asymmetry in the cross-section of the levee breach was analyzed. Through hydraulic experiments, the cross-section of the breach was analyzed during the collapse using the BASD (Bilateral ASymmetry Degree), which was developed to measure the degree of asymmetry. The relationship of the breach discharge was identified using the BASD. Additionally, the variation of the breach flow measured by the BASD was investigated through a 3-D numerical analysis under the same flow conditions as those in the experiment. It was found that the assumption of a rectangular breach cross-section, which is generally used for the estimation of the inundation area, can cause the breach discharge to be overestimated. According to the BASD, the breach flow is decreased by the interference effect in the breach section of the levee. If the breach flow is calculated while considering the BASD in the numerical analysis of the flooding, it is expected that the predicted inundation area can be estimated accurately.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.71-74
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• 1998

In this paper, an interface method for MMS on ATM networks is proposed. It can apply to the realtime communication and the remote control in wide-area manufacturing complex and virtual factory. It is used for the downloading program, the reporting and gathering of data and the remote control for the remote client. The developed interface rule is basd on the rule for MMS on TCP/IP. The main goals of implementation are to verify whether MMS on ATM is able to meet the requirements of factory automation and manufacturing complex.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.463-467
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• 2002

최근 인터넷을 통한 해킹이나 바이러스 침투로 인한 사례들이 증가하고 있다. 2000년 2월, Yahoo, Amazon, CNN에 발생했던 DDoS 공격으로 인해 각 웹 사이트들은 큰 피해를 입었다. 인터넷의 개방성은 사용자들에게 매우 다양한 서비스를 제공하는 반면, 인터넷을 통한 해킹, 바이러스 등의 공격을 위한 도구로서 사용되고 있다. 본 논문은 근래 분산서비스거부 (DDoS) 공격으로 인하여 남용되고 있는 네트워크 자원의 손실을 감소시키기 위해서, 분산서비스거부 (DDoS) 공격을 탐지하고 그 공격에 대해 적절한 대응 조치를 취할 수 있는 시스템인 FDDS (Flow based DDos Detection System)를 제안한다.

• Journal of the Korea Concrete Institute
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• v.11 no.6
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• pp.69-78
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• 1999

Hydroxyethyl cellulose -based-viscosity modifying admixture and melamine-basd-superplasticizer were selected to be admixtures for self-compacting concrete based on the test results of fluidity and air content of mortar using 3 different viscosity modifying admixtures. The experimental results show that the initial and final set of self-compacting concrete and fly ash concrete with viscosity modifying admixture only have been delayed approximately 5 hours and 8~9 hours, respectively. It is found that the optimum dosage of viscosity modifying admixtures, coarse aggregate and cement content are 0.2% of water content, under 742 kg/$\textrm{m}^3$ and over 364 kg/$\textrm{m}^3$, respectively. Test results also show that the optimum fly ash in replacement of cement is 10% of cement weight for the enhancement of fluidity and long-term strength.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.547-548
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• 2018

SCM(Supply Chain Management)은 초기에 생산의 효율성 증대를 위해 생산 계획에 초점을 둔 제품으로 발전하였으나, 최근에는 수요자 중심으로의 비즈니스 패러다임 변화, 프로세스 간 상호연계 강화, 수요의 다양성 및 변동성 증가 등의 환경이 변화하면서 지능적인 SCM이 요구되고 있다. 지능적인 SCM은 IoT, 빅데이터, 인공지능 등의 기술을 활용하여 공급 사슬 전체에 대한 자동화, 자율화, 연결성을 보장하는 것을 강조하고 있다. 따라서 본 논문에서는 급변하는 비즈니스 환경변화에 대응하여 공급 사슬 최적화를 달성하기 위해 IoT와 빅데이터 기반의 SCM 시스템에 관하여 연구하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.511-520
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• 1999

An anti-reset windup (ARW) based compensation method for state constrained control systems is studied. First, a linear controller is constructed to give a desirable nominal performance ignoring state-constraints of a plant. Then, an additional compensator is introduced to provide smooth performance degradation under state-constraints of the plant. This paper focuses on the effective design method of the additional compensator. By minimizing a reasonable performance index, the proposed compensator is expressed in terms of theplant and ocntroller parameters. The resulting dynamics of the compensated controller exhibits the dominant part of the linear closed-loop system which can be seen from the singular perturbation model reducton theory. THe proposed method guarantees total stability of overall resulting systems if linear controllers were constructed to meet certain condition.

• Transactions of Materials Processing
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• v.5 no.1
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• pp.27-36
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• 1996

In this paper a computer-aided design system for axisymmetric deep drawing process will be described. An approach to the system is based on the knowledge based system. The system has been written in AutoLISP with personal computer. The system is composed of four main modules such as input geometrical design test & rectification and user modification. the system which aids designer provides powerful capabilities for the design of axisymmetric deep drawing process.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.480-484
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• 2015

As the increasing national power crises due to various environmental factor, power market change is needed more developed and systemized DSM(Demand Side Management) search at DR market. To overcome national power crisis outbreaking every year and manage the eletric power reserve ratio, we need to construct and develop the electric safety manager and general public main oriented national power plant. For the advanced national power demand management system, it is required the application development like OpenAPI, Big Data Acquisition, Web/APP basd on ICT.

• Corrosion Science and Technology
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• v.7 no.6
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• pp.332-337
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• 2008

A reaction and evaporation types of cerium based conversion coatings were developed for galvanized steel sheet. The corrosion loss Q(Cb/cm2) and protection efficiency P(%) were obtained using a polarization technique for cerium based conversion coatings on galvanized steel exposed to 0.5N NaCl for 7 days. The microstructure of coating layer was observed using SEM. An excellent corrosion reistnce of galvanized steel was obtained by two types of cerium basd conversion coating. Salt spray test was done to evaluate the corrosion resistance of three samples by visual inspection. The corrosion ranking of three samples-untreated and two treatedby electrochemical data was matched well with the results of salt spray test.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.07a
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• pp.177-178
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• 2015

본 연구에서는 사회적 문제인 맞벌이 부부가 증가함에 따라 아동범죄 및 생계형 범죄로부터 사용자의 안전의 보장과 기존의 디지털 도어락의 문제점을 보완하고자 IoT기술과 STT를 이용하여 사용자에게 안정성을 제공하여 주며, 동시에 편리성을 제공하고자 본 시스템으로 하여금 이와 같은 문제를 해결하여 줄 수 있게 한다.