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101.
In this paper, a new multi-sensor calibration approach, called iterative registration and fusion (IRF), is presented. The key idea of this approach is to use surfaces reconstructed from multiple point clouds to enhance the registration accuracy and robustness. It calibrates the relative position and orientation of the spatial coordinate systems among multiple sensors by iteratively registering the discrete 3D sensor data against an evolving reconstructed B-spline surface, which results from the Kalman filter-based multi-sensor data fusion. Upon each registration, the sensor data gets closer to the surface. Upon fusing the newly registered sensor data with the surface, the updated surface represents the sensor data more accurately. We prove that such an iterative registration and fusion process is guaranteed to converge. We further demonstrate in experiments that the IRF can result in more accurate and more stable calibration than many classical point cloud registration methods. 相似文献
102.
Cost optimization for workflow applications described by Directed Acyclic Graph (DAG) with deadline constraints is a fundamental and intractable problem on Grids. In this paper, an effective and efficient heuristic called DET (Deadline Early Tree) is proposed. An early feasible schedule for a workflow application is defined as an Early Tree. According to the Early Tree, all tasks are grouped and the Critical Path is given. For critical activities, the optimal cost solution under the deadline constraint can be obtained by a dynamic programming strategy, and the whole deadline is segmented into time windows according to the slack time float. For non-critical activities, an iterative procedure is proposed to maximize time windows while maintaining the precedence constraints among activities. In terms of the time window allocations, a local optimization method is developed to minimize execution costs. The two local cost optimization methods can lead to a global near-optimal solution. Experimental results show that DET outperforms two other recent leveling algorithms. Moreover, the deadline division strategy adopted by DET can be applied to all feasible deadlines. 相似文献
103.
A simple and reliable method was proposed for preparing a selective dopamine (DA) sensor based on a molecularly imprinted electropolymer of o-aminophenol. The sensor is selective for the determination of DA in the presence of high concentrations of ascorbic acid (AA), with a maximum molar ratio of 1/1000. The molecular imprinted (MIP) sensor was tested by cyclic voltammetry (CV) as well as differential pulse voltammetry (DPV) to verify the changes in oxidative currents of ferricyanide. In optimized conditions, DA at concentrations of 2 × 10−8 to 0.25 × 10−6 mol/L could be determined with a detection limit of 1.98 × 10−9 mol/L (S/N = 3). The MIP sensor showed high selectivity, sensitivity, and reproducibility. Determination of DA in simulated samples of dopamine hydrochloride showed good recovery. 相似文献
104.
Heng Qi Yuhong Liu Xuan Wang Feng Shen Yong Yu Tao Chen Tiechuan Zuo 《Microsystem Technologies》2009,15(2):297-300
Excimer laser ablation technique was introduced into this work to fabricate a passive planar micromixer on the PMMA substrate.
T-junction shaped and width-changed S-shaped microchannels were both designed in this micromixer to enhance mixing effect.
The mixing experiment of distilled water and Rhodamine B with injection flow rate of 500 and 1,500 μm/s validates the mixing
effectivity of this micromixer, and indicates the feasibility of excimer laser ablation in the microfabrication of μ-TAS device. 相似文献
105.
Van Thanh Dau Thien Xuan Dinh Tanaka Katsuhiko Sugiyama Susumu 《Microsystem Technologies》2009,15(7):1039-1044
A gas-jet micro pump with novel cross-junction channel has been designed and fabricated using a Si micromachining process.
The valveless micro pump is composed of a piezoelectric lead zirconate titanate (PZT) diaphragm actuator and fluidic network.
The design of the valveless pump focuses on a cross-junction formed by the neck of the pump chamber and one outlet and two
opposite inlet channels. The structure of cross-junction allows differences in fluidic resistance and fluidic momentum inside
the channels during each PZT diaphragm vibration cycle, which leads to the gas flow being rectified without valves. The flow
channels were easily fabricated by using silicon etching process. To investigate the effects of the structure of the cross-junction
on the gas flow rate, two types of pump with different cross-junction were studied. The design and simulation were done using
ANSYS-Fluent software. The simulations and experimental data revealed that the step-nozzle structure is much more advantageous
than the planar structure. A flow rate of 5.2 ml/min was obtained for the pump with step structure when the pump was driven
at its resonant frequency of 7.9 kHz by a sinusoidal voltage of 50 Vp–p. 相似文献
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