Applied Mechanics and Materials Vols. 687-691

Abstract: Plenoptic camera provides us with the capability of refocusing photographs after exposure and extended depth of field. But the registration error for the micro lens array and image sensor influences on the quality of extracted 4D light field and thus leads to a degradation of the reconstructed image. The paper discusses two type of registration errors based on the structure of focused plenoptic camera and proposes a correction algorithm to acquire accurate light field from the sensor data. The simulation shows that registration errors deteriorate the reconstructed image and the artifact will be reduced significantly after using the algorithm.

Abstract: Colorimetric sensor array (CSA) is proved to be a low-cost, simple and sensitive method for the detection and identification of volatile organic compounds (VOCs) from food or beverage. The common strategy for sensor design is relied on experiment and experience that require so much money and time and limit the application of CSA method in the food and beverage industry. In this study, theoretical method named density functional theory (DFT) had been carried out to investigate the ability of CSA senor to bind VOCs. The energy change profile for each model was obtained by subtracting the energies of the CSA sensor before and after binding with VOCs. The result reflects that Manganese porphyrin (MnP) avoids the common interference of oxygen (O₂) from the environment and is sensitive to the VOCs called trimethylamine (L1), propanol (L2), propane (L3), ethyl acetate (L4), butanone (L5), and propionaldehyde (L6) and the similar VOCs. This study suggests that MnP is an important and useful dye in the CSA sensor for its application in the food and beverage industry.

Abstract: The pulse wave is a very useful physiological signal which can reveal the information of human organs. D-peak change is an important change of pulse. To study the spectrum of the D-peak changed pulse wave quantitatively and get the statistics result of such kind of change, a new algorithm was proposed and a kind of processing software was designed and implemented. The software was tested by more than 200 person-times PPG pulse waves and showed good performance.

Abstract: Array induction tools can be used to measure the resistivities of thin beds with 1ft or 2ft thickness in theory. The measurements were affected by formation thickness and shoulder resistivity.The array of 1ft resolution has good vertical recognition ability. For thick beds, both 1ft and 2ft resolution matching data tent to the same and all apparent resistivities have less variation with bed thickness H. The influence of shoulder resistivity on AIT measurements decreased with the increasing of formation thickness. The greater is the difference between shoulder resistivity and formation resistivity, the poorer is the vertical resolution.

Abstract: We use LabVIEW software and PCI-6024E data acquisition card to design the virtual digital storage oscilloscope. The oscilloscope makes full use of the capabilities of computer storage and connected with the external device.The measurement waveform can storage once, long-term preservation and multiple display,so that we can observe the signal of single change and slow change. Waveform have a variety of ways output. The hardware is open, we can increase the software module by modifying to increase the function of the instrument.

Abstract: Portable breath acetone sensor has great potential in diabetes diagnosis for acetone is a selective breath maker for diabetes. In this paper, we propose a multilayer semiconductor sensor for acetone gas sensing. Device is designed with stress adjustment layer, support layer, metal layer, insulator and sensing film. Simulation is performed, electrothermal and thermomechanical analyses demonstrate that this device has good performance in power consumption and thermomechanical reliability.

Abstract: Echo fidelity is an important characteristic of radar simulator and it influences accuracy and reliability of radar test directly. This paper introduces the research status of simulator fidelity and sort out the definition and property of radar echo simulation fidelity. Then we propose the numerical calculation methods for individual indicators, including similarity calculation, dissimilarity computing and interval changes three parts. Finally, on the basis of the evaluation system, we propose two calculation methods for entirety fidelity, they are weighted numerical calculation and umbrella figure methods.

Abstract: Austenitic stainless steel shows clear acoustic anisotropy. How to detect and evaluate the material becomes research difficulty and popular problem in acoustic detection field. In the paper, Civa software is applied for simulating ultrasonic wave propagation in austenitic stainless steel cladding layer. The influence of included angle between acoustic wave propagation direction and crystal axis on acoustic wave propagation is studied. The study results show that: the focusing property is good when the included angle is 30°-45°, which is beneficial for ultrasonic testing of cladding layer. When the included angle is greater than 70° or so, actual propagation path of acoustic wave and propagation direction of acoustic wave have certain deviation angle with poor acoustic wave focusing property and rapid acoustic attenuation speed, which is not conducive to acoustic detection of cladding layer.

Abstract: The movement reflects the health of dairy cows. In this paper, each cattle installs wireless sensor nodes in their neck to collect information about the position of the cows. In order to avoid the influence of the environment on network nodes ranging accuracy, at the same time improve positioning accuracy, this paper give Ranging optimization and positioning optimization, combines the RSSI ranging with APIT algorithm, and proposes APIT localization algorithm based on RSSI correction for real-time positioning ,the simulation shows that compared with traditional method, the improved algorithm has high positioning accuracy, low requirement for the distribution of beacon nodes.

Abstract: The work investigates the different situations of navigation measurements coming from multiple heterogeneous sensors using nonlinear sequential filtering techniques to enable a small spacecraft formation to autonomously navigate in the proximity of small bodies. Non-collaborative, part-collaborative and collaborative cases are investigated to find a simple and robust method which can achieve the best navigation precision. The sensor failure is taken into consideration to assess the navigation performances. The results show that the inter-spacecraft measurements make great contribution to autonomous navigation performance and the part-collaborative navigation strategy achieves the best estimation.