• Structural Engineering and Mechanics
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• 제17권3_4호
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• pp.557-572
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• 2004

Control systems are used to limit structural lateral deflections during large external loads such as winds and earthquakes. Most recently, the semi-active control approach has grown in popularity due to inexpensive control devices that consume little power. As a result, recently designed control systems have employed many semi-active control devices for the control of a structure. In the future, it is envisioned that structural control systems will be large-scale systems defined by high actuation and sensor densities. Decentralized control approaches have been used to control large-scale systems that are too complex for a traditional centralized approach, such as linear quadratic regulation (LQR). This paper describes the derivation of energy market-based control (EMBC), a decentralized approach that models the structural control system as a competitive marketplace. The interaction of free-market buyers and sellers result in an optimal allocation of limited control system resources such as control energy. The Kajima-Shizuoka Building and a 20-story benchmark structure are selected as illustrative examples to be used for comparison of the EMBC and centralized LQR approaches.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.270-272
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• 2001

This paper deals with the analytical approach for the reliability assessment in radially operated distribution systems. The approach can estimate the expected reliability performance of distribution systems by a direct assessment of the configuration of the systems using the reliability indexes such as NDP(Non-Delivery Power) and NDE(Non-Delivery Energy). The indexes can consider the number and configuration of the load, but can not consider the characteristics of the load which is the one of the most important factor in the investment cost for the distribution systems. Therefore, This paper presents the new indexes considering the expected interruption cost for the load section and shows the effectiveness by simulating at the model systems.

• 대한전기학회논문지
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• 제35권2호
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• pp.77-84
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• 1986

The design of observers for the systems with unknown and unmeasurable disturbances is treated. A generalized observer design method is proposed and existence conditions are established by combining the existing two different approaches` disturbance modelling approach by O'Reilly and algebraic approach by Kudva et. al.. The proposed approach, therefore, takes the advantages and removes the shortcomings of the existing two approaches in view points of dimensionality and existence conditions of the observer. To show the usefulness of the approach, a numerical example is given.

• Journal of Information Processing Systems
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• 제6권4호
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• pp.563-574
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• 2010

The growing number of web applications in the global economy has made it critically important to develop secure and reliable software to support the economy's increasing dependence on web-based systems. We propose an intercepting filter approach to mitigate the risk of injection flaw exploitation- one of the most dangerous methods of attacking web applications. The proposed approach can be implemented in Java or .NET environments following the intercepting filter design pattern. This paper provides examples to illustrate the proposed approach.

• International Journal of Computer Science & Network Security
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• 제23권5호
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• pp.163-171
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• 2023

The intelligent transportation system has made a huge leap in the level of human services, which has had a positive impact on the quality of life of users. On the other hand, these services are becoming a new source of risk due to the use of data collected from vehicles, on which intelligent systems rely to create automatic contextual adaptation. Most of the popular privacy protection methods, such as Dummy and obfuscation, cannot be used with many services because of their impact on the accuracy of the service provided itself, they depend on changing the number of vehicles or their physical locations. This research presents a new approach based on the shuffling Nicknames of vehicles. It fully maintains the quality of the service and prevents tracking users permanently, penetrating their privacy, revealing their whereabouts, or discovering additional details about the nature of their behavior and movements. Our approach is based on creating a central Nicknames Pool in the cloud as well as distributed subpools in fog nodes to avoid intelligent delays and overloading of the central architecture. Finally, we will prove by simulation and discussion by examples the superiority of the proposed approach and its ability to adapt to new services and provide an effective level of protection. In the comparison, we will rely on the wellknown privacy criteria: Entropy, Ubiquity, and Performance.

• 한국지역지리학회지
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• 제3권1호
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• pp.115-134
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• 1997

본 연구는 세계화시대에 적실한 지역연구방법론을 새롭게 모색하기 위하여, 지리학에서 개발된 다양한 지역연구방법론을 검토하고, 그 가운데 세계화 현상을 이론적으로 설명해주는 세계체제론에 기초한 세계체제론적 지역지리학의 내용을 자세히 살펴보았으며, 아울러 그것이 세계화시대에 보다 적실한 지역연구방법론이 될 수 있도록 그 문제점을 보완하여 수정된 세제체제론적 지역지리학을 제시하여 보았다. 수정된 세계체제론적 지역지리학에서는, 지역(역사지역)은 세제경제체제의 재생산적인 일반 메커니즘이 지역의 정치적, 경제적, 사회적 요소 또는 동인 이외에 위치적, 자연적, 문화적 요소와도 함께 작용하여 형성된다고 보았으며, 지역성은 경제적 특성에만 치중할 것이 아니라 공간적, 사회적, 문화적, 정치적 등의 특성도 분석하여 보다 종합적으로 규명될 필요가 있으며, 지역구분에서는 세계경제의 일반메커니즘에 의한 경제적 경계와 함께 정치적 경계도 동시에 고려할 필요가 있으며, 아울러 국가단위지역도 중요한 연구대상 지역으로 다루어져야 한다고 수정 제안하였다.

• 제어로봇시스템학회논문지
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• 제13권4호
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• pp.309-314
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• 2007

This paper presents an adaptive neural computation algorithm for multi-layered neural networks which are applied to identify the characteristic function of dynamic systems. The main feature of the proposed algorithm is that the initial learning rate for the employed neural network is assigned systematically, and also the assigned learning rate can be adjusted empirically for effective neural leaning. By employing the approach, enhanced modeling of dynamic systems is possible. The effectiveness of this approach is veri tied by simulations.

• Transactions on Control, Automation and Systems Engineering
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• 제3권1호
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• pp.27-31
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• 2001

In this paper, we consider the guaranteed cost filtering design method for time-varying delay system with parameter uncertainties by LMI(Linear Matrix Inequality) approach. The objective is to design a stable guaranteed cost filter which minimizes the guaranteed cost fo the closed loop systems in filtering error dynamics. The sufficient conditions for the existence of filter, the guaranteed cost filter design method, and th guaranteed cost upper bound are proposed by LMI technique in terms of all finding variables. Finally, we give an example to check the validity of the proposed method.

• 한국터널공학회:학술대회논문집
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• 한국터널공학회 2005년도 학술발표회 논문집
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• pp.87-104
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• 2005

Rock masses represent natural systems that are inherently complex and in which multiple mechanisms occur. Rock engineering systems such as tunnel and slope interact with surrounding systems through an exchange of both mass and energy. Accordingly the complex nature of rock masses calls for a system approach, and the open nature of rock engineering even requires the engineering to be controlled by a system approach for surrounding environments. However, traditional methods cannot take all variables and their interactions into account and are limited to the system with single mechanisms. Therefore, they are not proper for a complex and open system, and also cannot portray the whole system. Thus, a system approach is indispensable to rock engineering for dealing with the whole of a complex and open system. In this paper Mechanism Path Analysis Methodology (MPAM) Is Introduced for a system approach to rock engineering. The analysis by the methodology gives us all the information of systems behavior in the context of the whole system in order to accomplish the optimum design in accordance with the project objectives and analysis purposes. As an application a conventional model for the evaluation of TBM tunneling performance system is analyzed by MPAM and the result is compared with that by a traditional method.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제13권2호
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• pp.91-99
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• 2013

An autonomous unmanned underwater vehicle is a type of marine self-propelled robot that executes some specific mission and returns to base on completion of the task. In order to successfully execute the requested operations, the vehicle must be guided by an effective navigation algorithm that enables it to avoid obstacles and follow the best path. Architectures and principles for intelligent dynamic systems are being developed, not only in the underwater arena but also in related areas where the work does not fully justify the name. The problem of increasing the capacity of systems management is highly relevant based on the development of new methods for dynamic analysis, pattern recognition, artificial intelligence, and adaptation. Among the large variety of navigation methods that presently exist, the dynamic window approach is worth noting. It was originally presented by Fox et al. and has been implemented in indoor office robots. In this paper, the dynamic window approach is applied to the marine world by developing and extending it to manipulate vehicles in 3D marine environments. This algorithm is provided to enable efficient avoidance of obstacles and attainment of targets. Experiments conducted using the algorithm in MATLAB indicate that it is an effective obstacle avoidance approach for marine vehicles.