Aspect-oriented concepts are currently exploited to model systems from the beginning of their development. Aspects capture potentially crosscutting concerns and make it easier to formulate desirable properties and to ...
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The paper deals with the modelling of riveted joints in aircraft structures with Finite Element Method. Presented works were carried out within Eureka project No. E!3496 called IMPERJA. The goal of the IMPERJA project...
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ISBN:
(纸本)9789048127450
The paper deals with the modelling of riveted joints in aircraft structures with Finite Element Method. Presented works were carried out within Eureka project No. E!3496 called IMPERJA. The goal of the IMPERJA project is to increase the fatigue life of riveted joints, which will lead to an increase of the aircraft service life, a smaller number of inspections and lower operation costs of an aircraft. The project assumed FEM modelling of the operating aircraft's structure at three different complexity levels, namely considering the complete structure, a structural detail and a single riveted joint. The paper presents analyses of various rivet models and calculations of a structure and a riveted joint. In the first part examples of various models, at global and local level, were presented and usefulness of them was discussed, influence of the following simplification was analysed;• neglection of rivets in a model (elements are jointed continuously) • rivet as a rigid element (MPC) • neglection of contact phenomenon • neglection of secondary bending • neglection of residual stresses after riveting process The basis of the analysis was the asymmetric butt joint model with 14 rivets. The model which took into account secondary bending and contact phenomenon was analysed as well. The method of modelling residual stresses with temperature and thermal coefficient was used. In the second part, the example of analysis of riveted joint was demonstrated for a wing of PZL M28 Skytruck aircraft. It's is a twin-engine, high-wing, cantilever monoplane of all-metal structure with maximum take-off and landing weight 7500 kg. A submodeling technique was used there. At first, part of the wing model, based on a CAD model, was built. It includes 7 ribs and 6 bulkheads between them. Dimensions of the model eliminate stress perturbation, connected with boundary conditions, in the area near the middle rib. It was a shell model. The boundary conditions were taken on a basis of operation data
This paper proposes a field-programmable gate array (FPGA)-based integrated circuit (IC) for computing apparent powers and power factors of power systems. In a nonsinusoidal and unbalanced three-phase power system, th...
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This paper proposes a field-programmable gate array (FPGA)-based integrated circuit (IC) for computing apparent powers and power factors of power systems. In a nonsinusoidal and unbalanced three-phase power system, the calculation of apparent powers and power factors has many definitions. Load characteristics of harmonic and unbalance can not be expressed in the traditional apparent power and power factor, which only consider the fundamental and three-phase balanced sinusoidal conditions. This paper utilizes the FPGA chip to develop the platform to implement the calculation methods of apparent powers and power factors. The proposed design scheme is developed using the very high speed integrated-circuit hardware description language (VHDL), which provides high flexibility and technology indep.ndence. This paper discussed the effective power and power factor, the arithmetic power and power factor, and the fundamental power and power factor. The design of filters for the computation of fundamental frequency components is given. ModelSim is used at first to simulate the calculation of apparent powers and power factors to ensure the accuracy of timing and function. Research results show that the designed chip can compute accurately the apparent powers and power factors considering the effects of nonsinusoidal and unbalanced conditions.
Tool support is essential to allow the use of Model-Driven engineering (MDE) in the design of distributed embedded real-time systems. GenERTiCA is a flexible tool that supports a MDE approach, which uses concepts of A...
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This paper describes an interactive tool focused on teaching and learning basic concepts on multivariable control systems. Most industrial processes are represented by multivariable systems and thus the teaching and l...
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Tool support is essential to allow the use of Model-Driven engineering (MDE) in the design of distributed embedded real-time systems. GenERTiCA is a flexible tool that supports a MDE approach, which uses concepts of A...
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Tool support is essential to allow the use of Model-Driven engineering (MDE) in the design of distributed embedded real-time systems. GenERTiCA is a flexible tool that supports a MDE approach, which uses concepts of Aspect-Oriented Development (AOD) to handle non-functional requirements from real-time and embedded systems domain. This paper presents a comprehensive case study that illustrates GenERTiCA usage to generate source code from UML models. GenERTiCA also performs aspects weaving using aspect's information specified in UML models. Results regarding source code generation for a Java platform based on the Real-Time Specification for Java (RTSJ) are presented. Additionally, this paper discusses the implementation of some aspects of a high-level aspects framework, named DERAF, using the mentioned platform.
In this paper we present a fully automated morphology-based technique for segmentation of nuclei in cancer tissue images and we compare it with a common technique for biomedical image processing, namely active contour...
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ISBN:
(纸本)9781424428458
In this paper we present a fully automated morphology-based technique for segmentation of nuclei in cancer tissue images and we compare it with a common technique for biomedical image processing, namely active contours. We discuss the limitations of active contours in the processing of immunohistochemical images characterized by heterogeneously stained nuclear region and noise caused by the presence of multiple tissue layers in the sample. We describe the integration of the proposed approach in a fully automated protein activity quantification tool. Finally, we demonstrate and motivate through extensive experiments that our fully automated morphology-based approach provides better accuracy compared to various active contours implementations.
In real world, expert search is not just only name matching. Since each kind of people has their own features, we try two methods to judge whether the person we have found is more likely to be an expert. One method is...
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In real world, expert search is not just only name matching. Since each kind of people has their own features, we try two methods to judge whether the person we have found is more likely to be an expert. One method is to determine the role of a person by the context of the pages;the other is to judge the authority of a person by the forms of pages where he appears considering the structure of the Intranet. The evaluation results show these new methodologies have been helpful to improve the performance of the expert search on TREC 08 queries.
Unlinkability describes the inability of an observer to decide whether certain items of interest are related or not. Privacy aware protocol designers need a consistent and meaningful unlinkability measure to asses pro...
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ISBN:
(纸本)9781605582894
Unlinkability describes the inability of an observer to decide whether certain items of interest are related or not. Privacy aware protocol designers need a consistent and meaningful unlinkability measure to asses protocols in face of different attacks. In this paper we show that entropy measures are not sufficient for measuring unlinkability. We propose an alternative measure that estimates the error made by an attacker. We show by example that our expected distance provides a consistent measure that offers a better estimation of message-unlinkability. Copyright 2008 ACM.
The increasing test-data volumes needed for the testing of system-on-chip (SOC) lead to long test times and high memory requirements. We present an analysis to highlight the fact that the impact of a test-data compres...
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