This study is to present a framework for assessing structural reliability in association with fatigue damage at critical locations of long span bridges by making use of in-situ wind and structural health monitoring sy...
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ISBN:
(纸本)9783905594522
This study is to present a framework for assessing structural reliability in association with fatigue damage at critical locations of long span bridges by making use of in-situ wind and structural health monitoring systems. The Tsing Ma Bridge in Hong Kong, a long suspension bridge that carries both highway and railway, is taken as an example. The bridge has been continuously monitored for the past ten years by a system known as Wind and Structural Health Monitoring system (WASHMS), which measures the loadings and structural responses of the bridge. Railway, highway and wind loadings are considered to be major contributors to the fatigue damage of the bridge. Random parameters in probabilistic loading models are represented by mixture distribution functions and established by the expectation-maximization (EM) algorithm on the basis of the monitoring data acquired by WASHMS. Daily stochastic stress processes in response to railway, highway and wind loadings at critical locations are developed by virtue of the probabilistic loading models and the finite element stress analysis. With a Monte-Carlo simulation, a location-dependent probabilistic distribution function of daily stress ranges is then derived on the basis of a large number of virtual daily stochastic stress processes. Meanwhile, structural fatigue resistance is also considered as a random variable in the Miner's rule taking account uncertainties in fatigue life assessment. Finally, a limit state function of fatigue reliability is elaborated and a fatigue reliability index is estimated, depending on combined wind, and railway and highway loadings. It is found that the fatigue reliability index decreases nonlinearly with time, and it will be less than 3.7 after 95 years for some critical elements.
The climate of Taiwan poses restrictions for the development of remote sensing-cloud-free images over the island in the past took months to retrieve. Removing haze from these images to restore surface information shou...
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In this paper, we consider the scheduling of appointments at a service facility, such as a health clinic. There are M customers requesting service with service times being independent and identically distributed rando...
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This paper studies to establish the quantitative assessment model of combined noise in areas due to transportation source using the three-dimensional noise map and field survey. The three-dimensional noise map is used...
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ISBN:
(纸本)9781615676903
This paper studies to establish the quantitative assessment model of combined noise in areas due to transportation source using the three-dimensional noise map and field survey. The three-dimensional noise map is used to calculate the noise level in each building and the field survey is performed to investigate annoyance response and non-noise factors. The three-dimensional city spatial model of noise map is obtained from city spatial information, which consists of digital elevation model and three-dimensional building ones, for finding the distribution of transportation noise in urban areas. The field survey is conducted to investigate the annoyance response of 693 households affected by of combined noise. Annoyance prediction models in three dominant areas of noise are made by the relationship between annoyance response rate and transportation noise level for the quantitative assessment to environmental noise standard of the combined noise. In this study, annoyance response rate to transportation noise level is compared to those by previous researches in European countries.
Complicated and time-consuming cell purification processes prevent a micro cell lysis device from integrating with LOC (Lab-on-a-chip) or μ-TAS (μ-Total Analysis system) devices for cell analysis. In this paper, we ...
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Unmanned aerial vehicles (UAVs) are seeing more widespread use in military, scientific, and civilian sectors in recent years. This study presents algorithms for the visual-servo control of an UAV. The helicopter has b...
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ISBN:
(纸本)9781424448081
Unmanned aerial vehicles (UAVs) are seeing more widespread use in military, scientific, and civilian sectors in recent years. This study presents algorithms for the visual-servo control of an UAV. The helicopter has been stabilized with visual information through the control loop. Unlike previous study that use pose estimation approach which is time consuming and subject to various errors, the visual-servo control is more reliable and fast. The model involves the camera speed and visual sensor blocks. Visual sensor block consists of the camera model and feature extraction blocks. Various simulations are developed on MATLAB, in which the quadrotor aerial vehicle has been visual-servo controlled. In order to show the effectiveness of the algorithms, experiments were performed on a model UAV which suggest successful performance.
We have been developing a new approach to layered hybrid (inorganic/organic) photovoltaic materials for fabrication by Roll-to-Roll (R2R) manufacturing. In this report, we combine the low cost and processability of or...
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We have been developing a new approach to layered hybrid (inorganic/organic) photovoltaic materials for fabrication by Roll-to-Roll (R2R) manufacturing. In this report, we combine the low cost and processability of organic electrically conducting polymers with the efficiency of dye sensitized titanium dioxide, semi-conductor quantum dots (CdSe) self-assembled on layered clay materials (Laponite) onto indium tin oxide coated flexible polyethylene terephthalate (PET) substrates. We have shown electron transfer, guest-guest and host-guest interactions, charge separation, spectral line broadening, and quenching of fluorescence signals which indicate electronic coupling of the dye [Ru(bpy)3]2+ on a CdSe nanocrystal and titanium dioxide nanoparticles. Scanning electron microscopy and atomic force microscopy demonstrate successful nanoparticle formation and thin film self-assembly, as well as surface morphology and polymer thickness.
The actin filament, which is the most abundant component of the cytoskeleton, plays important roles in fundamental cellular activities such as shape determination, cell motility, and mechanosensing. In each activity, ...
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The actin filament, which is the most abundant component of the cytoskeleton, plays important roles in fundamental cellular activities such as shape determination, cell motility, and mechanosensing. In each activity, the actin filament dynamically changes its structure by polymerization, depolymerization, and severing. These phenomena occur on the scales ranging from the dynamics of actin molecules to filament structural changes with its deformation due to the various forces, for example, by the membrane and solvent. To better understand the actin filament dynamics, it is important to focus on these scales and develop its mathematical model. Thus, the objectives of this study were to model and simulate actin filament polymerization, depolymerization, and severing based on the Brownian dynamics method. In the model, the actin monomers and the solvent were considered as globular particles and a continuum, respectively. The motion of the actin molecules was assumed to follow the Langevin equation. The polymerization, which increases the filament length, was determined by the distance between the center of the actin particle at the barbed end and actin particles in the solvent. The depolymerization, which decreases the filament length, was modeled such that the number of dissociation particles from the filament end per unit time was constant. In addition, the filament severing, in which one filament divides into two, was modeled to occur at an equal rate along the filament. Then, we simulated the actin filament dynamics using the developed model, and analyzed the filament elongation rate, its turnover, and the effects of filament severing on the polymerization and depolymerization. Results indicated that the model reproduced the linear dependence of the filament elongation on time, filament turnover process by polymerization and depolymerization, and acceleration of the polymerization and depolymerization by severing, which qualitatively agreed with those observed in ex
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