17 resultados para Composite Dynamic Object

em Deakin Research Online - Australia


Relevância:

90.00% 90.00%

Publicador:

Resumo:

The framework of differential optical flow has been built upon to enhance the performance of motion estimation from optical flow. By coupling optical flow and object state parameters, an effective procedure for object tracking is implemented with the dasiaSimultaneous Estimation of Optical Flow and Object Statepsila (SEOS) technique. The SEOS method utilizes dynamic object parameter information when calculating optical flow for tracking a moving object within a video stream. Optical flow estimation for the SEOS method requires minimization of an error functional containing object physical parameter data. The convergence of an energy functional to a feasible or optimal solution set is not guaranteed. Convergence criteria is often assumed and not shown explicitly. Convergence of the SEOS method for both the Jacobi and Gauss-Seidel numerical resolution methods is evaluated.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The purpose of this study is to prove the convergence of the simultaneous estimation of the optical flow and object state (SEOS) method. The SEOS method utilizes dynamic object parameter information when calculating optical flow in tracking a moving object within a video stream. Optical flow estimation for the SEOS method requires the minimization of an error function containing the object's physical parameter data. When this function is discretized, the Euler-Lagrange equations form a system of linear equations. The system is arranged such that its property matrix is positive definite symmetric, proving the convergence of the Gauss-Seidel iterative methods. The system of linear equations produced by SEOS can alternatively be resolved by Jacobi iterative schemes. The positive definite symmetric property is not sufficient for Jacobi convergence. The convergence of SEOS for a block diagonal Jacobi is proved by analysing the Euclidean norm of the Jacobi matrix. In this paper, we also investigate the use of SEOS for tracking individual objects within a video sequence. The illustrations provided show the effectiveness of SEOS for localizing objects within a video sequence and generating optical flow results.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Diglycidyl ether of bisphenol-A type epoxy resin cured with diamino diphenyl sulfone was used as the matrix for fiber-reinforced composites to get improved mechanical and thermal properties for the resulting composites. E-glass fiber was used for fiber reinforcement. The morphology, tensile, flexural, impact, dynamic mechanical, and thermal properties of the composites were analyzed. The tensile, flexural, and impact properties showed dramatic improvement with the addition of glass fibers. Dynamic mechanical analysis was performed to obtain the Tg of the cured matrix as well as the composites. The improved thermal stability of the composites was clear from the thermogravimetric analysis. Scanning electron micrographs were taken to understand the interfacial adhesion between the fiber and the matrix. The values of mechanical properties were compared with modified epoxy resin composite system. Predictive models were applied using various equations to compare the mechanical data obtained theoretically and experimentally.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Ionic polymer conductive network composite (IPCNC) actuators are a class of electroactive polymer composites that exhibit some interesting electromechanical characteristics such as low voltage actuation, large displacements, and benefit from low density and elastic modulus. Thus, these emerging materials have potential applications in biomimetic and biomedical devices. Whereas significant efforts have been directed toward the development of IPMC actuators, the establishment of a proper mathematical model that could effectively predict the actuators' dynamic behavior is still a key challenge. This paper presents development of an effective modeling strategy for dynamic analysis of IPCNC actuators undergoing large bending deformations. The proposed model is composed of two parts, namely electrical and mechanical dynamic models. The electrical model describes the actuator as a resistive-capacitive (RC) transmission line, whereas the mechanical model describes the actuator as a system of rigid links connected by spring-damping elements. The proposed modeling approach is validated by experimental data, and the results are discussed. © 2014 Elsevier B.V. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this study, a novel method for manufacturing composite tubes utilizing the QuickstepTM process has been developed. Tubes manufactured from `quick-cure' Toray G83C prepreg have demonstrated highly repeatable axial crush behavior with an average specific energy absorption (SEA) of 86 kJ/kg. The cure cycle is optimized by comparing the results from compression, dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), and porosity testing. The tube lay-up is optimized using compression and porosity test results. The effect of changes in fiber-orientation on SEA is also investigated. Process development has resulted in a robust manufacturing method capable of producing fully cured, high performance composite tubes with a cure cycle of 7 min. This corresponds to a 95% reduction in time compared to an equivalent autoclave cycle.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Some aspects of numerical simulation of Lamb wave propagation in composite laminates using the finite element models with explicit dynamic analysis are addressed in this study. To correctly and efficiently describe the guided-wave excited/received by piezoelectric actuators/sensors, effective models of surface-bounded flat PZT disks based on effective force, moment and displacement are developed. Different finite element models for Lamb wave excitation, collection and propagation in isotropic plate and quasi-isotropic laminated composite are evaluated using continuum elements (3-D solid element) and structural elements (3-D shell element), to elaborate the validity and versatility of the proposed actuator/sensor models.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Differential optical flow methods are widely used within the computer vision community. They are classified as being either local, as in the Lucas-Kanade method, or global, as in the Horn-Schunck technique. As the physical dynamics of an object is inherently coupled into the behavior of its image in the video stream, in this paper, we use such dynamic parameter information in calculating optical flow when tracking a moving object using a video stream. Indeed, we use a modified error function in the minimization that contains physical parameter information. Further, the refined estimates of optical flow is used for better estimation of the physical parameters of the object in the simultaneous estimation of optical flow and object state(SEOS).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Sport video data is growing rapidly as a result of the maturing digital technologies that support digital video capture, faster data processing, and large storage. However, (1) semi-automatic content extraction and annotation, (2) scalable indexing model, and (3) effective retrieval and browsing, still pose the most challenging problems for maximizing the usage of large video databases. This article will present the findings from a comprehensive work that proposes a scalable and extensible sports video retrieval system with two major contributions in the area of sports video indexing and retrieval. The first contribution is a new sports video indexing model that utilizes semi-schema-based indexing scheme on top of an Object-Relationship approach. This indexing model is scalable and extensible as it enables gradual index construction which is supported by ongoing development of future content extraction algorithms. The second contribution is a set of novel queries which are based on XQuery to generate dynamic and user-oriented summaries and event structures. The proposed sports video retrieval system has been fully implemented and populated with soccer, tennis, swimming, and diving video. The system has been evaluated against 20 users to demonstrate and confirm its feasibility and benefits. The experimental sports genres were specifically selected to represent the four main categories of sports domain: period-, set-point-, time (race)-, and performance-based sports. Thus, the proposed system should be generic and robust for all types of sports.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Polyvinyl alcohol (PVA) nanofibers and single-walled carbon nanotube (SWNT)/PVA composite nanofibers have been produced by electrospinning. An apparent increase in the PVA crystallinity with a concomitant change in its main crystalline phase and a reduction in the crystalline domain size were observed in the SWNT/PVA composite nanofibers, indicating the occurrence of a SWNT-induced nucleation crystallization of the PVA phase. Both the pure PVA and SWNT/PVA composite nanofibers were subjected to the following post-electrospinning treatments: (i) soaking in methanol to increase the PVA crystallinity, and (ii) cross-linking with glutaric dialdehyde to control the PVA morphology. Effects of the PVA morphology on the tensile properties of the resultant electrospun nanofibers were examined. Dynamic mechanical thermal analyses of both pure PVA and SWNT/PVA composite electrospun nanofibers indicated that SWNT–polymer interaction facilitated the formation of crystalline domains, which can be further enhanced by soaking the nanofiber in methanol and/or cross-linking the polymer with glutaric dialdehyde.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Requirements engineering is a commencing phase in the development of either software applications or information systems. It is concerned with understanding and specifying the customer's requirements of the system to be delivered. Throughout the literature, this is agreed to be one of the most crucial and, unfortunately, problematic phases in development. Despite the diversity of research directions, approaches and methods, the question of process understanding and management is still limited. Among contemporary approaches to the improvement of the current practice of Requirements Engineering, Formal Object-Oriented Method (FOOM) has been introduced as a new promising solution. The FOOM approach to requirements engineering is based on a synthesis of socio-organisational theory, the object-oriented approach, and mathematical formal specification. The entire FOOM specification process is evolutionary and involves a large volume of changes in requirements. During this process, requirements evolve through various forms of informal, semi-formal, and formal while maintaining a semantic link between these forms and, most importantly, conforming to the customer's requirements. A deep understanding of the complexity of the requirements model and its dynamics is critical in improving requirements engineering process management. This thesis investigates the benefits of documenting both the evolution of the requirements model and the rationale for that evolution. Design explanation explains and justifies the deliberations of, and decisions made during, the design activity. In this thesis, design explanation is used to describe the requirements engineering process in order to improve understandability of, and traceability within, the evolving requirements specification. The design explanation recorded during this research project is also useful in assisting the researcher in gaining insights into the creativity and opportunistic characteristics of the requirements engineering process. This thesis offers an interpretive investigation into incorporating design explanation within FOOM in order to extend and advantage the method. The researcher's interpretation and analysis of collected data highlight an insight-driven and opportunistic process rather than a strictly and systematically predefined one. In fact, the process was not smoothly evolutionary, but involved occasional 'crisis' points at which the model was reconceptualised, simplified and restructured. Therefore, contributions of the thesis lie not only in an effective incorporation of design explanation within FOOM, but also a deep understanding of the dynamic process of requirements engineering. The new understanding of the complexity of the requirements model and its dynamics suggests new directions for future research and forms a basis for a new approach to process management.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Slab-girder bridges are widely used in Australia. The shear connection between reinforced concrete slab and steel girder plays an important role in composite action. In order to test the suitability and efficiency of various vibration-based damage identification methods to assess the integrity of the structure, a scaled composite bridge model was constructed in the laboratory. Some removable shear connectors were specially designed and fabricated to link the beam and slab that were cast separately. In this test, two static loads were acted in the 1/3 points of the structure. In the first stage, dynamic test was conducted under different damage scenarios, where a number of shear connectors were removed step by step. In the second stage, the static load is increased gradually until concrete slab cracked. Static tests were conducted continuously to monitor the deflection and loading on the beam. Dynamic test was carried out before and after concrete cracking. Both static and dynamic results can be used to identify damage in the structure.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The relationship of the migrant figure and the house has been explored in previous research on the migrant house. In addition, the relationship between the migrant house and 1ts perception and representation within the local and national communities within the immigrant-receiving city has been analyzed. The approach and theoretical frameworks for this research involved an understanding of the relationship between the human subject and the object of architecture. Given that much poststructuralist theory has attended to the rethinking of human subjectivity and to rethinking the humanbody, traditional conceptualizations of the relationship between human subject and Object m architecture also need to be re-examined. This paper thus presents an exammatlon of one approach to this relationship, focusing on the exploratory and creative work of the late John Hejduk. Hejduk's Vladivostok presents an assembly of figure-objects that together are a literary metaphor for both society and the city. The paper Will argue that the human subject is imagined within an already ordered architectural sett1ng, and that the human subject cannot be thought prior to and outside the stage of architecture. Rather than searching for a causal or determining relat1onsh1p between subject and object this conceptual underpinning between the subject and object asks for an understanding of the dynamic and animated cultivation between them. In examining Hejduk's entry on the 'subjecUobject' in Vladivostok, the paper Will present an account of the mutual responsiveness that arises between human beings and architecture. It will argue that culture and subjectivity is internal rather than external or marginal to architecture.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper proposes an effective VAR planning based on reactive power margin for the enhancement of dynamic voltage stability in distribution networks with distributed wind generation. The analysis is carried over a distribution test system representative of the Kumamoto area in Japan. The detailed mathematical modeling of the system is also presented. Firstly, this paper provides simulation results showing the effects of composite load on voltage dynamics in the distribution network through an accurate time-domain analysis. Then, a cost-effective combination of shunt capacitor bank and distribution static synchronous compensator (D-STATCOM) is selected to ensure fast voltage recovery after a sudden disturbance. The analysis shows that the proposed approach can reduce the size of compensating devices, which in turn, reduces the cost. It also reduces power loss of the system.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This paper proposes an optimal linear quadratic Gaussian (LQG) controller for D-STATCOM to improve the dynamic performance of distribution networks with photovoltaic generators. The controller is designed based on the H∞ norm of the uncertain system. The change in system model due to the variation of load compositions in the composite load is considered as an uncertain term in the design algorithm. The performance of the designed controller is demonstrated on a widely used test system. Simulation results indicate that the proposed controller can be a potential solution for improving the voltage stability of distribution networks.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Molecular dynamics (MD) together with the adaptive biasing force (ABF) and metadynamics free energy calculation methods was used to investigate the permeation properties of salt water through poly(amide) thin film composite reverse osmosis membranes. The thin films were generated by annealing an amorphous cell of poly(amide) chains through an MD method. The MD results showed they have typical structural properties of the active layer of thin film composite membranes and comparable water diffusivity (2.13×10-5cm2/s for the film with a density of 1.06g/cm3) and permeability (9.27×10-15cm3cm/cm2sPa) to experimental data. The simulations of water permeation through the films under different transmembrane pressures revealed the behaviours of water molecules in the thin films and the dynamic regimes of water permeation, including Brownian diffusion, flush and jump diffusion regimes. The intermolecular interactions of water and ions with poly(amide) chains showed a strong dependence on the local structure of films. The attraction between water and ploy(amide) molecules can be up to 8.5kcal/mol in dense polymer regions and 5kcal/mol in the pores of about 3nm. The ABF and metadynamics simulations produced the profiles of free energy potential of water and ions along the depth of the thin films, which provided important information for quantitatively determining the barrier energy required for water permeation and rejection of ions. The thin film with a density of 1.06g/cm3 and a thickness of 6nm offers a rejection to Na+ but a slight absorption of Cl- (0.25kcal/mol) at 0.3-0.4nm distance to its surface. Water molecules must overcome 63kcal/mol energy to move to the centre of the film. The dependences of the barrier energy and the water-polymer interaction energy on the local free volume size in the thin film were analysed. The simulations of water permeation under high transmembrane pressures showed a nonlinear response of the concentration and distribution of water molecules in the film to the imposed pressure. Compaction of the film segments close to the porous substrate and water congestion in dense regions significantly influenced the water permeation when the membrane was operated under pressures of more than 3.0MPa.