• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.04a
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• pp.97-105
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• 1997

A methodology to identify a baseline modal model of a complicated 3-D structure using limited structural and modal information is experimentally examined. In the first part, a system's identification theory for the methodology to identify, baseline modal responses of the structure is outlined. Next, an algorithm is designed to build a generic finite element model of the baseline structure and to calibrate the model by using only a set of post-damage modal parameters. In the second part, the feasibility of the methodology is examined experimentally using a field-tested truss bridge far which only post-damaged modal responses were measured for a few vibration modes. For the complex 3-D bridge with many members, we analyzed to identify unknown stiffness parameters of the structure by using modal parameters of the initial two modes of vibration.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.10a
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• pp.461-467
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• 1998

Although many methods of knowledge acquisition has been developed in the expert systems field, such a need for causal knowledge acquisition has not been stressed relatively. In this respect, this paper is aimed at suggesting a causal knowledge acquisition process, and then investigate the causal knowledge-based inference process. A vehicle for causal knowledge acquisition is FCM (Fuzzy Cognitive Map), a fuzzy signed digraph with causal relationships between concept variables found in a specific application domain. Although FCM has a plenty of generic properties for causal knowledge acquisition, it needs some theoretical improvement for acquiring a more refined causal knowledge. In this sense, we refine fuzzy implications of FCM by proposing fuzzy implications of FCM by proposing fuzzy causal relationship and fuzzy partially causal relationship. To test the validity of our proposed approcach, we prototyped a causal knowledge-driven inference engine named CAKES and then experime ted with some illustrative examples.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.4
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• pp.144-150
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• 2006

IEC 61850 is the worldwide protocol for the substation automation system. IEC 61850 transports the information which consists of different formats such as GOOSE(Generic Object Oriented Substation Event), MMS(Manufacturing Message Specification), SV(Sampled Values) and so on. For real time data transmission, GOOSE can be used. The remote-bus current data which were collected in a local-bus current differential IED can be transmitted to a distance IED at the same location by using GOOSE messages. The distance IED can eliminate the reactance effect by using the transmitted remote-bus current data. This method can improve the performance of the fault location.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.613-616
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• 2008

This study presents an IFC-based information model for standardized and integrated information management system of tunnel monitoring. Information items of tunnel monitoring were extracted from the Tunnel Design Standard of Ministry of Construction and Transportation. Then, the information items were compared with components of IFC 2x Edition3 model. Two main entities are added into the IFC model for generic representing of monitoring devices and data. IfcMonitoringElement which is composed of IfcMonitoringLogger and IfcMonitorinSensor is proposed to represent physical information of data loggers and sensors, and relationship between data logger and sensors. Besides, as an additional resource of IFC model, IfcMonitoringData is provided to express measured data from sensors and warning histories.

• Journal of Internet Computing and Services
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• v.5 no.2
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• pp.17-31
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• 2004

This paper presents a new assumptions statement generation method for developing TOE security environment section of PP. We surveyed on guides on the assumption statement in CC scheme, and collected and analyzed hundred of assumption statements which are in 26 certified and published real PPs and CC Toolbox/PKB. The CC Toolbox/PKB is included a class of pre-defined assumption statements. From the result of the survey, we developed a new generic assumption statement list, and proposed a assumption derivation method by using the list.

• Advances in aircraft and spacecraft science
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• v.4 no.2
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• pp.185-202
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• 2017

In a flexible airvehicle, an assessment of the structural coupling levels through analysis and experiments provides structural data for the design of notch filters which are generally utilized in the flight control system to attenuate the flexible response pickup. This is necessitated as during flight, closed loop control actuation driven with flexible response inputs could lead to stability and performance related problems. In the present work, critical parameters influencing servoelastic response have been identified. A sensitivity study has been carried out to assess the extent of influence of each parameter. A multi-parameter tuning approach has been implemented to achieve an enhanced analytical model for improved predictions of aircraft servoelastic response. To illustrate the model updation approach, initial and improved test analysis correlation of lateral servoelastic responses for a generic flexible airvehicle are presented.

• Proceedings of the Korea Contents Association Conference
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• 2019.05a
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• pp.425-426
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• 2019

전통적인 마이닝 기법은 다양한 디지털 매체와 센서 등에서 생산되는 빅데이터를 처리하기 어려울 뿐 아니라 신규 데이터 누적시 전체 데이터를 재분석 해야하는 비효율성과 대용량의 문서를 학습함에 있어 메모리부족 문제, 학습 소요시간 문제 등이 있다. 이러한 문제를 해결하기 위하여 본 논문에서는 자질축소 기법에 의존하지 않고 대량의 문서를 자유롭게 학습하고 부분적인 자질 추가 변경 시에 변경요소만을 추가 반영할 수 있는 범용적이고 일반적인 분류기의 구조설계 방법을 설계 및 구현하였다. 점진적 학습 모듈은 일반적인 학습 방법이 데이터의 추가 및 변동시마다 모든 데이터를 재학습하는 데 반해, 기존의 학습 결과에 증분된 데이터만 재처리 없이 추가적으로 학습한다. 재학습을 위해 사용자는 작업 수행 중 자원 관리를 통해 기존에 처리된 데이터를 자유롭게 가져와서 새로운 데이터와 병합이 가능하다. 이러한 점직적 학습 효율성은 빅데이터 기반 데이터 처리에 주요한 특성인 데이터 생산 속도를 극복하기 위한 좋은 대안이 될 수 있음을 확인하였다.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.8 no.4
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• pp.53-70
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• 1998

OMG(Object Management Group) 에서는 CORBA(Common Object Broker Architure) 환경에서의 보안 문제를 해결하기 위해서 CORBA 보안 서비스$^{[8]}$ 를 정의하였다. CORBA보안 서비스는 다양한 보안 기술을 허용하는 보안 구조를 제안하고 있으며, 사용자 인증, 접근제어, 보안 통신 등에 필요한 보안 객체를 정의하고 있다. 또한 CORBA환경에서 수행되는 응용들에게 투명한 보안 통신을 제공하는 것을 기본으로 한다. 본 논문에서는 ECMA(European Computers Association) SESAME(a Secure European System for Application in Multi-vendor Environment) Ver. 4$^{7}$ 를 사용하여 CORBA 환경에서 수행되는 응용들에게 보안 통신을 제공하는 것에 중점을 둔 CORBA보안 서비스의 설계및 구현관리 기능 등을 제공하는 보안 소프트웨어인 SESAME Ver. 4에서 제공하는 GSS-API(Generic Security Application Programming Interface)$^{[9,10,11]}$ 를 사용하여 CORBA 환경에서 보안 통신에 필요한 보안 객체들을 설계 구현하였고, CORBA 환경을 위한 전체 보안 구조를 제시하였다. 본 논문에서 제시한 보안 구조는 보안 통신을 제공하기 위해 구현된 보안 객체와 SESAME Ver. 4에서 제공하는 인증, 접근제어, 보안 정책관리 기능을 통합한 형태이다.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.315.1-315.1
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• 2003

After beginning the new medical system separating the prescription from the drug dispensary, the demand of bioequivalence test significantly increases to show the equivalence between the test and reference drugs as a result of amendment of the pharmaceutical affairs law which allows a generic substitution. Accordingly the standard protocols provided by the government are required for reducing the period andthe cost to perform the bioequivalence study. (omitted)

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.4
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• pp.1538-1552
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• 2021

Machine learning models are vulnerable to adversarial examples generated by adding a deliberately designed perturbation to a benign sample. Particularly, for automatic speech recognition (ASR) system, a benign audio which sounds normal could be decoded as a harmful command due to potential adversarial attacks. In this paper, we focus on the countermeasures against audio adversarial examples. By analyzing the characteristics of ASR systems, we find that frame offsets with silence clip appended at the beginning of an audio can degenerate adversarial perturbations to normal noise. For various scenarios, we exploit frame offsets by different strategies such as defending, detecting and hybrid strategy. Compared with the previous methods, our proposed method can defense audio adversarial example in a simpler, more generic and efficient way. Evaluated on three state-of-the-arts adversarial attacks against different ASR systems respectively, the experimental results demonstrate that the proposed method can effectively improve the robustness of ASR systems.