• Smart Structures and Systems
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• v.26 no.6
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• pp.797-807
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• 2020

Due to the influence of nonlinearity and time-variation, it is difficult to establish an accurate model of concrete frame structures that adopt active controllers. Fuzzy theory is a relatively appropriate method but susceptible to human subjective experience to decrease the performance. This paper proposes a novel artificial intelligence based EBA (Evolved Bat Algorithm) controller with machine learning matched membership functions in the complex nonlinear system. The proposed affine transformed membership functions are adopted and stabilization and performance criterion of the closed-loop fuzzy systems are obtained through a new parametrized linear matrix inequality which is rearranged by machine learning affine matched membership functions. The trajectory of the closed-loop dithered system and that of the closed-loop fuzzy relaxed system can be made as close as desired. This enables us to get a rigorous prediction of stability of the closed-loop dithered system by establishing that of the closed-loop fuzzy relaxed system.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.513-524
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• 2009

Urban land consolidation, which is to reform land parcels to remove fragmentation and produce ideal blocks, is an effective means for urban renewal. Successful urban land consolidation brings out great benefits to the city officials as well as general public, such as improved city image, increased land value, and more effective land use. However, urban land consolidation can be detrimental to environment, especially in the ecological aspects, while the execution of land consolidation has been focused solely on development for the sake of human benefits. To remove negative effects of urban land consolidation to the ecological system, this paper is intended to establish a set of criteria for evaluating ecological impacts of an urban land consolidation plan. Firstly, key ecological indicators are identified using a special group decision-making process called "habitual domain analysis" and then individual weighting of each indicator is recorded by analytical hierarchy process. An urban ecological evaluation model with 4 levels and 23 indicators is thus developed.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.941-946
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• 2005

It is essential for project managers to make schedule adjustment based on their professional experience, in terms of rescheduling action discussed in this paper. This paper discusses the topics of resource-constrained construction rescheduling by modifying the concepts of manufacturing rescheduling. Moreover, the influence factors of construction rescheduling problems are investigated and identified in this paper. According to initial schedule plan and present progress, a new rescheduling mechanism based on Constraint Programming (CP) techniques is developed to reschedule projects with the objective of minimizing total project cost or duration, under three rescheduling policies. Through case study, the behavior of three different rescheduling policies is analyzed and discussed in this paper.

• Structural Engineering and Mechanics
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• v.60 no.3
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• pp.387-404
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• 2016

In this paper, the response and failure of sharp-notched 6061-T6 aluminum alloy circular tubes with five different notch depths of 0.4, 0.8, 1.2, 1.6 and 2.0 mm subjected to cyclic bending were experimentally and theoretically investigated. The experimental moment-curvature relationship exhibits an almost steady loop from the beginning of the first cycle. And, the notch depth has almost no influence on its relationship. However, the ovalization-curvature relationship exhibits a symmetrical, increasing, and ratcheting behavior as the number of cycles increases. In addition, a higher notch depth of a tube leads to a more severe unsymmetrical trend of the ovalization-curvature relationship. Focusing on the aforementioned relationships, the finite element software ANSYS was used to continue the related theoretical simulation. Furthermore, the five groups of tubes tested have different notch depths, from which five unparallel straight lines can be observed from the relationship between the controlled curvature and the number of cycles required to produce failure in the log-log scale. Finally, a failure model was proposed to simulate the aforementioned relationship. Through comparison with the experimental data, the proposed model can properly simulate the experimental data.

• ETRI Journal
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• v.37 no.4
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• pp.717-726
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• 2015

In this paper, we study an asymmetric two-way relaying network where two source nodes intend to exchange information with the help of multiple relay nodes. A hybrid time-division broadcast relaying scheme with joint relay selection (RS) and power allocation (PA) is proposed to realize energy-efficient transmission. Our scheme is based on the asymmetric level of the two source nodes' target signal-to-noise ratio indexes to minimize the total power consumed by the relay nodes. An optimization model with joint RS and PA is studied here to guarantee hybrid relaying transmissions. Next, with the aid of our proposed intelligent optimization algorithm, which combines a genetic algorithm and a simulated annealing algorithm, the formulated optimization model can be effectively solved. Theoretical analyses and numerical results verify that our proposed hybrid relaying scheme can substantially reduce the total power consumption of relays under a traffic asymmetric scenario; meanwhile, the proposed intelligent optimization algorithm can eventually converge to a better solution.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.293-300
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• 2022

During the decommissioning of the nuclear facilities, the radioactive gases in pressure vessels may leak due to the demolition operations. The decommissioning site has large space, slow air circulation, and many large nuclear facilities, which increase the difficulty of workers' inhalation exposure assessment. In order to dynamically evaluate the activity distribution of radionuclides and the committed effective dose from inhalation in nuclear decommissioning environment, an inhalation exposure assessment method based on the modified eddy-diffusion model and the inhaled dose conversion factor is proposed in this paper. The method takes into account the influence of building, facilities, exhaust ducts, etc. on the distribution of radioactive gases, and can evaluate the influence of radioactive gases diffusion on workers during the decommissioning of nuclear facilities.

• Nuclear Engineering and Technology
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• v.50 no.3
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• pp.396-410
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• 2018

To assist operators to properly assess the current situation of the plant, accurate fault diagnosis methodology should be available and used. A reliable fault diagnosis method is beneficial for the safety of nuclear power plants. The major idea proposed in this work is integrating the merits of different fault diagnosis methodologies to offset their obvious disadvantages and enhance the accuracy and credibility of on-line fault diagnosis. This methodology uses the principle component analysis-based model and multi-flow model to diagnose fault type. To ensure the accuracy of results from the multi-flow model, a mechanical simulation model is implemented to do the quantitative calculation. More significantly, mechanism simulation is implemented to provide training data with fault signatures. Furthermore, one of the distance formulas in similarity measurement-Mahalanobis distance-is applied for on-line failure degree evaluation. The performance of this methodology was evaluated by applying it to the reactor coolant system of a pressurized water reactor. The results of simulation analysis show the effectiveness and accuracy of this methodology, leading to better confidence of it being integrated as a part of the computerized operator support system to assist operators in decision-making.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.614-617
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• 2003

Recently the demand of constructing high-rised building grows larger. So it becomes more important to make an exact plan of a tower cranes which has an important position in high-rised building construction. Nevertheless businessmen of construction sites only depend on a great store of experience without a clear process of locating tower cranes. The object of this study is to set up the process model for locating tower cranes. The study went off through a study of related documents, an interview with some experts and a visiting of job sites. In result the study suggests a process model which has four steps of considering an establishing, disjointing, a radius of working, easy working. Case study was examined to estimate the feasibility and applicability of the proposed model. As a result, the model is proven to be a method to locate tower cranes quickly and cleary, and to operate properly as a decision-making tool.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.1231-1245
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• 2015

People have transferred their business model from traditional commerce to e-commerce in recent decades. Both shopping and payment can be completed through the Internet and bring convenience to consumers and business opportunities to industry. These trade techniques are mostly set up based on the Secure Sockets Layer (SSL). SSL provides the security for transaction information and is easy to set up, which makes it is widely accepted by individuals. Although attackers cannot obtain the real content even when the transferred information is intercepted, still there is risk for online trade. For example, it is impossible to prevent credit card information from being stolen by virtual merchant. Therefore, we propose a new mechanism to solve such security problem. We make use of the disposable dynamic security code (DSC) to replace traditional card security code. So even attackers get DSC for that round of transaction, they cannot use it for the next time. Besides, we apply visual secret sharing techniques to transfer the DSC, so that interceptors cannot retrieve the real DSC even for one round of trade. This way, we can improve security of credit card transaction and reliability of online business. The experiments results validate the applicability and efficiency of the proposed mechanism.

• Structural Engineering and Mechanics
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• v.26 no.2
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• pp.127-150
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• 2007

The objective of this paper is to develop a finite element procedure for predicting the compressive strength and ultimate axial strain of Carbon Fiber Reinforced Plastics (CFRP) confined circular concrete columns and to study the effective parameters of confinement efficiency for helping design of CFRP retrofit technology. The behavior of concrete confined with CFRP is studied using the nonlinear finite element method. In this paper, effects of column size, CFRP volumetric ratio and plain concrete strength are studied. The confined concrete nonlinear constitutive relation, concrete failure criterion and stiffness reduction methodology after concrete cracking or crushing are adopted. First, the finite element model is verified by comparing the numerical solutions of confined concrete with experimental results. Then the effects of column size, CFRP volumetric ratio and plain concrete strength on the peak strength and ductility of the confined concrete are considered. The results of parametric study indicate that the normalized column axial strength increases with increasing CFRP volumetric ratio, but without size effect for columns with the same CFRP volumetric ratio. As the same, the increase in column ductility depends on CFRP volumetric ratio but without size effect for columns with the same CFRP volumetric ratio.