A new method to detect cracks in concrete bridge images for bridge inspection automation is developed in this study. The algorithm divides the image into small blocks and identifies linear structures. A training set i...
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ISBN:
(纸本)0784407940
A new method to detect cracks in concrete bridge images for bridge inspection automation is developed in this study. The algorithm divides the image into small blocks and identifies linear structures. A training set is generated by also segmenting them into blocks. Each block is treated as an individual entity in the training set. PCA algorithm is used to identify test image as an image with or without cracks. This local usage of PCA on small neighborhoods is to enhance the results as opposed to global search for the cracks. Real concrete bridge images with cracks of different sizes and shapes as well as non-cracked images are used. The algorithm development and implementation results are presented.
An estimation of random fatigue processes in structural steel components requires the time-expensive execution of multiple numerical simulations. In the given case of wind loaded structures, the randomness is implied ...
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ISBN:
(纸本)0784407940
An estimation of random fatigue processes in structural steel components requires the time-expensive execution of multiple numerical simulations. In the given case of wind loaded structures, the randomness is implied by the stochastic properties of the material and, additionally, the stochastic nature of the oncoming wind. To minimize the necessary computational runtime, a new software framework for parallel computations - based on agent technologies - has been implemented and tested. The parallelization has been accomplished by the usage of mobile software agents which can migrate from their original workstation to other computers.
This paper describes a software paradigm for composing engineering web services. Software modules have been designed and implemented to facilitate the construction and integration of web services. The paradigm employs...
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ISBN:
(纸本)0784407940
This paper describes a software paradigm for composing engineering web services. Software modules have been designed and implemented to facilitate the construction and integration of web services. The paradigm employs a distributed data flow approach that supports direct data exchanges among web services, and thus avoid many performance bottlenecks attending centralized processing. The performance and flexibility are further improved by using mobile classes to distribute computations within the service framework and to reduce the amount of data traffic by moving computations closer to the data. A system has been prototyped to integrate several project management and scheduling software applications. It is shown that distributed data flow, combining with the utilization of mobile classes, is an effective approach for integrating large engineering software services.
Small world networks recently have attracted much interest in studying the properties of networks. They were initially used for the study of social networks but recently have been shown to be relevant models in other ...
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ISBN:
(纸本)0784407940
Small world networks recently have attracted much interest in studying the properties of networks. They were initially used for the study of social networks but recently have been shown to be relevant models in other application areas. However, when analyzing real complex systems, such as water distribution networks, there are a number of problems that make the analysis very difficult. In this paper, a small world network approach is applied for analyzing the efficiency of a real water distribution network. In order to apply such an approach to water distribution networks, a refined analysis method is developed and this is presented in the paper. The application of the developed model is demonstrated by means of simple case study that highlights how such an approach can provide useful insights into the efficiency analysis of water distribution networks.
In future, ecological aspects will play a major role for planning processes in coastal engineering. Coastal protection measures interfere with the environment, mostly restricting natural processes with sometimes undes...
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ISBN:
(纸本)0784407940
In future, ecological aspects will play a major role for planning processes in coastal engineering. Coastal protection measures interfere with the environment, mostly restricting natural processes with sometimes undesired effects on coastal ecosystems. It is necessary to have appropriate tools to estimate these influences. In this paper, a numerical simulation model which describes hydro- and ecological processes is presented. This consists of a discrete ecological model based on a Cellular Automaton and a hydrodynamic finite element model component. Possible transfer strategies, which allow a direct coupling between these different model paradigms, are presented. Main effects and possible influences on a changed hydro- and morphodynamic are shown with first academic tests. At last, an asynchronous parallel implementation for the efficient parallel computation of the Cellular Automaton ist introduced.
A diversion weir is a headwork facility built across a river to raise water level and to divert water for various purposes, such as irrigation, hydropower generation, etc. In this study, a Windows-based, visual, and u...
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ISBN:
(纸本)0784407940
A diversion weir is a headwork facility built across a river to raise water level and to divert water for various purposes, such as irrigation, hydropower generation, etc. In this study, a Windows-based, visual, and user friendly program named WINDWEIR is developed in Visual *** programming language for the optimum design of a diversion weir with sidewise intakes. The methodology used in the program is developed with reference to the design guidelines reported in the literature and in accordance with the common engineering practice. The program determines the overall dimensions and the total cost of a diversion weir. It also performs stability analyses. The program is relatively flexible such that a design engineer can assess various dimensions of the structure by performing quick successive test runs to achieve an optimum solution among various alternatives. An application is presented to demonstrate the use of the program.
Traditional finite elements are based on simple geometrical elements such as edges in the one-dimensional space, triangles and quadrangles in the plane as well as tetra-and hexahedrons in the three-dimensional space. ...
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ISBN:
(纸本)0784407940
Traditional finite elements are based on simple geometrical elements such as edges in the one-dimensional space, triangles and quadrangles in the plane as well as tetra-and hexahedrons in the three-dimensional space. The extension of the geometrical basis to any polyhedron is enabled by the definition of a local coordinate system called the natural element coordinates. The formulation of interpolation and test functions in natural element coordinates enables the formulation of generalized finite elements. The differentiation and integration of these interpolation and test functions are essential for finite element approximations. In the paper convex and special non convex polyhedron are considered as geometrical basis for generalized finite elements as well as for the formulation of interpolation and test functions on natural element coordinates. Furthermore, methods for the numerical differentiation and integration of functions on these generalized finite elements are introduced. The paper closed with two applications in the range of fluid mechanic and structural mechanics.
High strength concrete columns reinforced with concrete filled steel tube (HSCCRST), which is an ordinary reinforced-concrete column where there is a steel tube designed to be put in the core additionally, are used qu...
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ISBN:
(纸本)0784407940
High strength concrete columns reinforced with concrete filled steel tube (HSCCRST), which is an ordinary reinforced-concrete column where there is a steel tube designed to be put in the core additionally, are used quite extensively in high buildings in recent years in China. In this paper, the general situation about earthquake-resistant behavior experiments of the columns is presented. Based on the experimental results, the numerical analysis of the sectional moment-curvature relationship for the columns is proposed using fiber model. Comparison of experimentally obtained ultimate sectional moments and those predicted by numerical analysis are given and reasonable agreement is observed. Additionally, effects of different parameters on the sectional moment-curvature relationship of the columns are studied with the proposed analysis method. The results of the experiments and analysis both indicate that the existence of concrete filled steel tube in core of section of HPC column plays an important role in improving its ductility and strength.
作者：
Jarský, ČeněkDept. of Technology of Stuctures
Czech Technical University Faculty of Civil Engineering Thákurova 7 166 29 Praha 6 Czech Republic CONTEC
Mánesova 819 278 01 Kralupy n. Vlt. Czech Republic
The process of preserving and reconstructing historical buildings poses several specific questions and raises problems which must be solved in the planning and management stage of the building process - from questions...
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ISBN:
(纸本)0784407940
The process of preserving and reconstructing historical buildings poses several specific questions and raises problems which must be solved in the planning and management stage of the building process - from questions of architectural and art-historical significance, via the future purpose of use of the building, links to the surrounding buildings, environmental questions, questions of cost, time analysis, and quality assurance problems. Many of these problems can be solved with the help of a computer model of the course of the rehabilitation and reconstruction of the building created by a construction technology network diagram. The CONTEC integrated project planning, management and quality control system based on these diagrams has been used for bidding, planning and managing the reconstruction process of several significant historical buildings in Prague and other cities.
This paper discusses the advantages and challenges of using speech recognition on mobile devices, for field data collection and real-time communication. Multimodal and voice technology, for speech-enabled information ...
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ISBN:
(纸本)0784407940
This paper discusses the advantages and challenges of using speech recognition on mobile devices, for field data collection and real-time communication. Multimodal and voice technology, for speech-enabled information retrieval and input, using mobile phones or handheld computing devices is explained. Multimodal technology enables more complete information communication and supports timely and effective decision-making. It also helps to overcome the limitations imposed by the small screen of mobile devices. The paper describes several prototype, industrial, mobile solutions developed for the field entry of data and real-time communication that utilize voice and multimodal interaction. In one of these projects, a field concrete inspector can enter inspection results using variable interaction modalities such as speech, stylus, or keyboard on a handheld device, or speech-only on a mobile phone. The author describes prototype applications developed, and presents several usage scenarios for field and maintenance applications, as well as for emergency response.
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