Search

Natural gas loss inevitably occurs during gas injection and production operation in underground gas storage. At present, the study of gas loss is only in the qualitative description stage and cannot meet the quantitative evaluation requirements for economical gas storage. Combining the theory of inventory analysis and the experimental study of the injection-production mechanism and aimed at the phenomena of microseepage, dissolution diffusion, abnormal gas leakage and macroscale gas leakage in the process of injection and production of underground natural gas storage, gas loss evaluation mathematical models are established to quantitatively evaluate the gas loss of underground natural gas storage. The results show that the gas loss in the macrodisplacement process is the main component of geological gas loss in gas storage, which decreases with increasing injection-production cycles. On this basis, a quantitative evaluation method for the natural gas loss of gas reservoir-type gas storage is established, and the accuracy and reliability of the method are verified by the gas loss calculation results of the Banzhongnanbei (BZNB) underground natural gas storage. The validation results show that the calculation error is very small, meeting the requirements of gas storage operation accuracy and providing high application value. This calculation method can effectively reduce the loss of natural gas in gas storage, provide an early warning of leakage risk, and improve the economic benefits and injection-production safety of gas storage.

Traction transformers are one of the most important equipment in the traction power supply system. Thermal aging of transformer insulation system determines its reliable life. To achieve an estimation of the insulation life of traction power transformers operated under real load condition, the effects of traction loads on the thermal aging of oil-paper insulation in traction transformers were investigated. First, the design principles for the accelerated thermal aging experiment were studied and proposed by considering magnitude (i.e., load rate) and frequency (i.e. spare time and lasting time) of the traction load. Then, an experimental system was established in the laboratory to conduct extensive accelerated thermal aging experiments, in which the traction loads were mimicked by using positive temperature coefficient (PTC) heating plates and a programmable logic controller (PLC). Finally, the experimental results were analyzed and discussed to reveal the effects of traction load on the thermal aging of oil-paper insulation in traction transformers.

Background: Currently, no effective treatment method is available for neutrophilic asthma. Th17 play an important role in the promotion of asthma inflammation. And IDO-dependent tryptophan metabolism has been shown to act as a molecular “switch” for the conversion of Th17 cells into Tregs under certain conditions. Objective: Therefore this study aimed to regulate IDO expression in vivo and in vitro in a neutrophilic asthma animal model and investigate whether IDO could reduce Th17 cells and the secretion of related factors to ameliorate airway hyperreactivity and inflammation in neutrophilic asthma. Methods: A neutrophilic asthma model was established using ovalbumin（OVA）and lipopolysaccharide. IDO expression in the model mice was regulated using an IDO inducer and an IDO inhibitor. Th17 cells and the secretion of related factors were examined, and changes in airway hyperreactivity and inflammation were observed. Plasmacytoid dendritic cells and naive CD4+ T cells were cocultured in vitro. After OVA stimulation and IDO inhibitor treatment, changes in Th17 cells and the secretion of related factors were examined. Results: Airway hyperreactivity and inflammation were ameliorated in the neutrophilic asthma model mice in the IDO induction group. IDO reduced Th17 cells and inflammatory cytokine secretion (IL-17, IL-6, and TGF-β1). Conclusion: IDO ameliorated airway hyperreactivity and inflammation in neutrophilic asthma. The mechanisms may be associated with the influence of the differentiation direction of CD4+ T (Th0) cells and inhibition of Th17 cell production. These results will provide new bases for potential therapeutic targets for the prevention and treatment of neutrophilic asthma using IDO.

Oil-immersed bushing is one of the most important accessory equipment of a transformer, whose insulation status is crucial. Moisture is an important factor that affects the insulation status of oil-immersed bushing. It has a very important significance to estimate the moisture content of oil-immersed bushing accurately. Here, the 72.5 kV bushing samples with different moisture contents were made. Afterwards, the frequency domain dielectric spectrum (FDS) of samples were tested at 15°C. The Havriliak-Negami equation was modified based on the analysations of complex planes, then it was used to analyse the experimental results. Moreover, the characteristic parameters and method to estimate moisture content were obtained and testified. Finally, the field application of the proposed estimation method was also discussed. The results of the studies shown here indicate that the moisture content of oil-immersed bushing can be estimated based on the proposed method effectively; however, in order to estimate the moisture content of field oil-immersed bushing, the elimination of temperature effects should be considered.

It is the key technology to position orchard fruits accurately and fast for yield forecasting and fruit harvesting. Aiming at forecasting apple orchard yield based on trees’ images, a positioning method for apple fruits was proposed based on image processing and information fusion. Firstly, a position information acquisition system of orchard fruits was designed and established, which consisted of a three-dimensional camera, a GPS (Global Positioning System) receiver and an attitude sensor, and a world coordinates calculation method for apple fruits was developed according to this system. In the information acquisition system, the three-dimensional camera was used to acquire both the RGB image and depth image of apple trees in apple orchard; the GPS receiver was used to get the position information of the three-dimensional camera; the attitude sensor was used to obtain the attitude information of the three-dimensional camera. Secondly, a relative positioning calculation model was deduced by fusing the RGB images and the corresponding depth images, which was used to calculate the coordinates of the centers of each apple in camera coordinate system. Finally, a three-dimension coordinate converting method was investigated, and the GPS and attitude information of the camera was added to establish the absolute positioning calculation model to calculate the world coordinates of apples in the world coordinate system. Thus, each apple got only one space position in the world coordinate system, which could help to avoid counting the same apple in different images repeatedly. The experimental results showed that the mean relative error of the world coordinate positioning was 0.0375m; for the absolute error of the world coordinate positioning, the mean distance error of the longitude was 0.117m, that of the latitude was 0.437m, and that of the altitude was 0.145m. It indicated that the proposed method in this paper could be used to calculate the world coordinate for each apple in the orchard and its accuracy mainly depended on the detectors’ accuracies.

With the current gradual opening of our country’s electricity sales market and the successive improvement of related policies for grid-connected micro-grids, grid-connected micro-grid power supplies and their distribution transformer capacity have received attention and development. Based on the good development of my country’s electricity sales market environment, this paper designs the grid-connected microgrid power supply optimization system and its distribution and conversion capabilities to optimize the quality of electricity sales and optimize the grid configuration. In view of the fact that the operation of the microgrid system in my country’s market environment is more flexible at this stage, after a long time simulation test, a simulation analysis of the operation status of the grid-connected microgrid is carried out. In the course of the experiment, the electricity price in the distribution point process and the real-time changes of the electricity purchase price in the market will be considered comprehensively, and the processing in the micro-electricity system based on its distribution transformer capacity optimization system and the load forecast result will be considered. This article uses a power grid project actually constructed in East China as an example to analyze the results of simulation calculations. Then the NSGA-II algorithm is used to solve the optimized model for the cost and benefit composition of the grid. The optimized configuration method of the optical storage microgrid proposed in this paper can ensure the reliable power supply of users’ important loads during the off-grid operation of the microgrid, increase the installed capacity of distributed photovoltaics, and the configured energy storage system also allows enterprises to achieve low electricity prices. Purchase electric energy at any time and use it to supplement the load’s demand for electric energy during peak electricity price periods, thereby increasing revenue. The experimental research results show that the design of the grid-connected microgrid power supply capacity optimization system under the electricity sales environment studied in this paper can effectively reduce the additional investment required by external loads and the capacity of optical storage and distribution transformers. Only then can the economic marketing profit of the microgrid be improved to a certain extent.

Publisher's version (útgefin grein), Objective To characterize, among European and Han Chinese populations, the genetic predictors of maculopapular exanthema (MPE), a cutaneous adverse drug reaction common to antiepileptic drugs. Methods We conducted a case-control genome-wide association study of autosomal genotypes, including Class I and II human leukocyte antigen (HLA) alleles, in 323 cases and 1,321 drug-tolerant controls from epilepsy cohorts of northern European and Han Chinese descent. Results from each cohort were meta-analyzed. Results We report an association between a rare variant in the complement factor H–related 4 (CFHR4) gene and phenytoin-induced MPE in Europeans (p = 4.5 × 10–11; odds ratio [95% confidence interval] 7 [3.2–16]). This variant is in complete linkage disequilibrium with a missense variant (N1050Y) in the complement factor H (CFH) gene. In addition, our results reinforce the association between HLA-A*31:01 and carbamazepine hypersensitivity. We did not identify significant genetic associations with MPE among Han Chinese patients. Conclusions The identification of genetic predictors of MPE in CFHR4 and CFH, members of the complement factor H–related protein family, suggest a new link between regulation of the complement system alternative pathway and phenytoin-induced hypersensitivity in European-ancestral patients., This study was not industry-sponsored. The work was supported by a grant from the European Commission (7th Framework Programme Grant 279062, EpiPGX). M.M.C. and G.L.C. are supported by Science Foundation Ireland, grant 13/CDA/2223, and an RCSI seed funding grant GA 14-1899. This project was supported by the General Research Funds (HKU7623/08M and HKU7747/07M to S.C., CUHK4466/06M to P.K.) and Health and Medical Research Fund (HMRF 01120086 to P.K.) from Hong Kong. Some results presented in this article were prepared using the HPC facilities of the University of Luxembourg. This work was partly undertaken at UCLH/UCL, which received a proportion of funding from the Department of Health's NIHR Biomedical Research Centres funding scheme (J.W.S., S.M.S.). The work was also supported by the Epilepsy Society, UK (J.W.S., S.M.S.), by the foundation “no epilep,” the German Chapter of the ILAE (DGfE) (both to H.L.). F.C. and I.L.-C. are supported by Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil, through grant 2013/07559-3. J.E.Z. and M.P. thank the NHS Chair of Pharmacogenetics programme and MRC Centre for Drug Safety Science for support in Liverpool. B.C.C. and C.J.D.R. are supported by the Canadian Institutes of Health Research (CIHR) Drug Safety and Effectiveness Network (FRN-117588), the Canada Foundation for Innovation and the Canadian Dermatology Foundation. G.E.B.W. is supported by a CIHR Fellowship. The funders of the study had no role in the study design, data collection, data analysis, data interpretation, or writing of the report. M.M.C., H.G., and G.L.C. had full access to all the data in the study and the corresponding authors had final responsibility for the decision to submit for publication. The Article Processing Charge was funded by the European Commission OpenAIRE2020 project.

A solar-bio-powered refining concept has been developed to establish sustainable lignocellulosic biodiesel production. The refining concept applies a combined hydrolysis process without detoxification to release sugars from corn stover, uses aerobic oleaginous fungal fermentation to accumulate lipids on the hydrolysate for biodiesel production, and implements solar-bio-power generation to satisfy the energy demand. The results demonstrate that system integration of solar-bio-power generation and fungal lipid accumulation is an effective approach to create a sustainable lignocellulosic biodiesel production. Compared to concentrated solar power (CSP) units, photovoltaics (PV) are a more suitable solar technology to satisfy the energy needs of the lignocellulosic biodiesel production. The PV-bio-powered lignocellulosic biodiesel production has a net energy output of 28.70 MJ kg−1 biodiesel produced, and a net energy ratio (NER) of 1.08. UCR::Vicerrectoría de Docencia::Ingeniería::Facultad de Ingeniería::Escuela de Ingeniería de Biosistemas

In order to reconstruct the three-dimensional information of the hologram recorded by pre-magnification digital micro-holography (PMDMH) fast and accurately, the method of phase compensation in pre-magnification digital micro-holography with reference wavefront curvature as same as the object is studied theoretically and experimentally. The point spread function (PSF) is derived, and then the expression of reconstructed light field amplitude and phase aberration is obtained. And it is proposed that the real phase distribution of sample can be obtained by using phase mask to pre-compensate the phase aberration at first, followed by unwrapping phase and lastly combining with automatic phase compensation. The red blood cells are used as the experimental sample, and the result shows that: using phase mask to pre-compensate, on one hand, the error in phase wrapping can be avoided, and on the other hand, it can also effectively eliminate the secondary phase distortion by single automatic phase compensation method.

With the increasing permeability of distributed generation in power system, the problem of weak inertia of distributed generators cannot be ignored. By imitating the mechanical and electromagnetic characteristics of the synchronous generator, the virtual synchronous generator (VSG) has the ability of smooth power output, peak regulation and frequency modulation, and becomes a kind of grid-friendly distributed power supply. However, the traditional VSG coordinates the balance of power supply and demand through the energy storage device (ES), which requires a high capacity of ES. In this paper, a control strategy of VSG considering coordinated energy management of ES and PV is proposed. Through real-time analysis of VSG’s power output and the state of ES and PV, dynamic adjustment of power output of PV and virtual characteristics of VSG will be made to realize the coordinated control of PV and ES. This strategy effectively improves the dependence of VSG on ES’s capacity by giving priority to the adjustment of PV’s power and asymmetric control of ES’s SOC.

Allergic rhinitis is a common respiratory disease. Acupuncture is used to treat it in traditional Chinese medicine, and generally, the L120, ST2 and ST36 acupoints are selected in clinical practice. We report a new method of acupuncture at the sphenopalatine acupoint (SPA) for treatment of persistent allergic rhinitis (PAR). The effect of this treatment was investigated using two different needling depths. The efficacy of this treatment was associated with accurate stimulation of the sphenopalatine ganglion (SPG). A total of 61 patients diagnosed with PAR were randomly allocated to either the acupuncture or the sham acupuncture group. The difference between the groups was the needle depth when acupuncture was administered, which was 50 mm and 20 mm. Alteration in total nasal symptom score (TNSS) was the primary outcome. Quality of life, medication dosages and adverse events were secondary outcomes, measured using the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). Confidence assessment was performed to evaluate data from the treatment and follow-up periods. Results were: (1) average TNSS in the treatment group was significantly lower than in the control group at week 4 (median and 25th and 75th percentiles were 5.00 (4.00, 7.00) and 8.00 (7.00, 10.00), respectively (P

Anti-reflection (AR) coating is a critical technology and an ongoing challenge for terahertz systems. The subwavelength structure (SWS) is an effective AR method, whereas the current manufacturing techniques, such as chemical etching and ultrafast laser processing, are low-efficient and low-quality for processing structures at the hundred-micron scale on hard brittle materials. We present a study of broadband SWSs directly ablated on the surface of quartz crystal by precisely controlled CO2 laser pulses, instead of commonly used ultra-fast lasers. The processing time of SWS can be shortened by two orders of magnitude compared with that by ultra-fast laser pulses. The SWS samples exhibit excellent AR properties with maximum transmittance of 97% at 0.71 THz, peak transmittance improvement of 13.5%, and optimal efficiency spectrum of 0.28–1.21 THz with transmittance >90%. The AR properties of SWS samples are in agreement with the simulated expectation and exist over a wide range of incidence angles up to ∼40°. The imaging of an object using SWS as the substrate shows an obvious improvement in imaging quality. We present an efficient and practical way to improve the transmission of optical components of materials, such as quartz crystal, alumina, and sapphire, in the terahertz band.

China’s Dalian International Airport is taken to compare the aircraft noise pollution and the cost-risk effects of the expanded an existing inland and a proposed offshore airport. The findings show that the aircraft noise pollution of the offshore airport is much less than that of the expanded inland airport; the land-use cost, noise reduction charges and other risks of the offshore airport are also much less; the creation of the offshore airport may be more favorable to the city’s development.

Optimization of vehicle driving can reduce energy consumption and carbon emission. According to differences of vehicle braking mode, two driving situations are proposed. In this context, vehicle energy- consumption models based on energy consumption minimization are built and the soft such as MATLAB is employed to solve the models. By calculating, minimal energy-consumption value and related variable values on different driving distances are got, which contribute to guiding drivers taking energy-consumption driving behaviors. Finally conclusions are drawn by comparing and analyzing results of optimization under two situations.

Sensor network is a data-centric network, which provides data collection, storage and query services. Data storage and query is one of the hot spot in the research of sensor networks. In order to solve the problem of low efficiency of storage and query, high energy consumption in sensor networks, we put forward a scheme that storing distributed data of wireless sensor network based on information processing cloud. Information processing cloud is made up of a group of sensor nodes around the network center, which have the ability to absorb and process data from other nodes of sensor network which do not belong to the information processing cloud. The group of sensor nodes around the network center respond data query requests from anywhere of the network, and sensor nodes can be adjusted dynamically according to real situation, the cloud of nodes and non-cloud of nodes can be dynamically transformed as well. When non-cloud of sensor nodes store data or send query request, they only need to do centripetal movement, centrifugal movement or circumfusing movement. The analysis shows that the proposed scheme can simplify route algorithm of data storage and data query, and it also has less computation cost and storage cost than the existing schemes.

In this paper, software platform and its application to develop a novel wide-band (WB) measurement system for ac PD pulse current signals with adjustable sampling rate up to 1 GS/s and bandwidth of 10 kHz ∼ 300 MHz are introduced. The software platform was realized based on the Measurement Studio with some designed algorithms and procedures, to display waveforms in time and frequency domains respectively of the detected pulse current sequence (PCS) and its corresponding PRPD pattern, the feature extraction results on 2D parameters plane of the PCS using the equivalent time-frequency method (ETFM), and the grouping or separation results, etc. Application to measure a test of two PD sources and a random pulsed interference in high voltage (HV) laboratory is described, which gives a good grouping and separation result to show practicability and effectiveness of the developed ac PD measurement system.

Partial discharge (PD) is one of the major causes of insulation degradation/ageing in power equipment, it is significant to detect PD accurately for guarantee equipment's safety and reliable operation. To achieve an accurate PD monitoring and PD location, a new type of PD on-line monitoring system was presented in this paper. The PD phenomena taking place of equipment's surface and/or interface was detected by 32∗32 ultrasonic array sensors, which is capable of collecting and processing multi-sensor synchronized ultrasonic signal came from PD taking place. Based on Acoustic Doppler theory, the measured sound intensity is decided by received the number of entire waves in unit time, which produced by PD. According to the measured sound intensity sequence, a mapping relationship in plane-coordinate between PD event and its location system could be established. Furthermore, 2D image of object is taken by HD camera in this system, the PD location visualization could be achieved by digital image fusion. The system can intuitively show the discharge location in the image and its status in the development and changes, timely find power equipment's failure and has extensive application value.

For the tunnel point clouds acquired by 3-d laser scanner, a method of automatically retrieving cross-sectional contours of tunnels is proposed. By the use of abundant normal vectors embedded in point clouds, this method can accurately identify the tunnel axis, and build a coaxial cylinder to project 3-d points to the cylindrical coordinate system, which takes a 2-d form of coordinates. An improved 2-d Delaunay triangulation algorithm is employed to construct the triangulated mesh by the spatial distribution of these projection points in their 2-d space. Following this mapping correspondence, the 3-d triangulated mesh of tunnel is finally constructed in accordance with the 2-d triangulation result. By intersecting the tunnel mesh with cutting planes always perpendicular to the tunnel axis, a series of contours are generated. In every position to generate contours, a fine tuning operation on the cutting plane is conducted to make its normal direction always keep consistent with the ever-changing direction of curved tunnels. At the last part, this paper demonstrates effectiveness and high efficiency of this method by the use of the point clouds of a real curved tunnel.

A joy stick transducer based on fiber Bragg grating(FBG)is presented.The sensitivity is analyzed theoretically via discussing the mechanical properties of the elastic element and the strain sensing characteristics of the FBG.By detecting the changing of central wavelength of FBG at different load forces,the response characteristics of the aircraft Joy stick transducer based on fiber Bragg grating are investigated.The experimental results demonstrate that there exists a linear relationship between the central wavelength of FBG and load force,which is consistent with the theoretical analysis.The sensitivities of horizontal and vertical are 2.07 pm·N-1 and 1.80 pm·N-1,respectively,which are consistent with the simulation.

A kind of common-optical-path SPR imaging interferometry for micro-array detection is presented. It is a combination of SPR and spatial phase modulation measurement. In this method, the SPR sensing chip surface is illuminated with collimated parallel light beam, and a Wollaston prism is introduced into the reflected light path to produce the interference of polarized light reflected from SPR sensing chip. The p-polarization and s-polarization lights serve as measurement and reference beam, respectively. The information of biochemical reactions can be obtained by extracting the phase change from the SPR interference patterns. As a common-optical-path interferometry, it can reduce disturbances from the ambient conditions. Furthermore, this method is competent for real-time array detection. Various solution concentration and antigen–antibody interaction have been measured with this method. The experiment results indicate that the method can detect micro-array chips in real time. It opens up a new avenue for high-throughput SPR micro-array phase detection, which will benefit the drug discovery and proteomics study.

A kind of micro-array detecting system based on SPR imaging has been developed. The light source of this system is a semiconductor laser. The light emitted from the source becomes round and parallel after going through a pinhole and being collimated. This parallel light beam arrives at a polarizer, its s-light component is shielded and p-light component passes through. The p-light component which is of a rectangular shape after going through a rectangular slip is cast onto the glass surface of a sensing chip, and generates an evanescent wave which excites surface plasmon resonance (SPR). The SPR images are accepted by a 2D CCD camera and processed in real time by a computer. The chips are made into bare gold film array by photoetching and cause the linker layer to cover the gold thin film by self-assembling. Then, rabbit IgG is immobilized onto the liker layer, which finished the preparation of array sensing chip. Once the sensing chip is installed, the detecting system begins the investigation of the interaction between rabbit IgG and its antibody. The experimental results indicate that the 2D SPR biosensor is able to detect a number of units in real time for gene expression products. The improvement of technology and the increase of array number can realize high throughput detection, which is significant to proteomics study and new drug discovery and development.

For high-power UV laser facilities, one of the key problems limiting the maximum light influence and safe routine operation is that the UV laser induces damage to fused silica optics. The most effective mitigation protocol of the damaged optics is the CO2 laser processing that leads to make locally melt or evaporate the damage. While the mitigated damage sites possess particular morphology, which may modulate the passing laser beam and induce the downstream intensification that will ruin the neighbor optics. In this work, the morphology features of the mitigated damage pits of fused silica optics are systematically investigated. According to the measured morphology features, a 3D grid model of mitigated pit is built, and the downstream light intensity distribution of the mitigated pit model under incident 351 nm laser is studied by scalar diffraction theory and fast fourier transform (FFT) methods. Results indicate that there are two kinds of downstream intensification: off-axis and on-axis intensifications. In the former intensification, the maximum intensity is located near the output surface of the optics and comes mainly from the depth of the mitigated pit; it increases with the depth. In the alter intensification, the maximum intensity is located far from the output surface of the optics and is mainly dependent on the height of the rim structure at the fringe of the mitigated damage pit; so it increase with increasing height. In addition, it is found that the location of the maximum off-axis or on-axis intensity can approach the output surface of the optics with increasing maximum intensity. For comparison, experimental measurements of downstream intensification induced by the mitigated pits are carried out, and the experimental results are almost consistent with the numerical simulation, implying the validity of the numerical simulation of the mitigated pit model. Results of this research indicate that the downstream intensification of mitigated pits can be suppressed by controlling the morphology features of mitigated pits. this is significant for the development and improvement of the mitigated techniques of damage optics.

Flashover characteristics of the upper frame air gaps for ±500kV DC double line transmission towers are researched by impulse flashover test on real size simulation tower, and the test curves are presented. Tests about Flashover characteristics impacts of the lower crossbeam on the upper frame air gaps are carried out, the test curves are given in this paper under the precondition that the distance of upper line to upper crossbeam and tower body is 4.4m and the distance of upper line to lower crossbeam is 2.7m∼4.2m. Combined with the test result curves when the upper frame gaps have the same distance and the correction formula with different tower width, the curves of lower frame air gaps are also given in this paper. Based on the over-voltage and the switching impulse flashover characteristics on air gaps, the minimum clearances for the air gaps of upper and lower frame of ±500kV DC double line transmission towers from the Three Gorges Hydropower Station to Shanghai are presented.

By analyzing the information embedding and retrieving process, we combine the encrypting algorithm with chaotic mapping using the logistic mapping and system time random factor generator to realize the encryption of dynamic key to resolve the algorithm security and key sensitive problem. By modifying the digital image color or bit plane of color component and adjusting the sensitive-less important pixels to represent the information of secret files to embed secret files. For the cipher texts is arranged at the low bits, so the secret file is invisible and realize the image communication security. Experimental results show that in specific secret information hiding transportation situations this method can achieve the image commutation security and guarantee the security of transportation image on network.

A flexible proximity sensor fully fabricated by inkjet printing is proposed in this paper. The flexible proximity sensor is composed of a ZnO layer sandwiched in between a flexible aluminum sheet and a web-shaped top electrode layer. The flexible aluminum sheet serves as the bottom electrode. The material of the top electrode layer is nano silver. Both the ZnO and top electrode layers are deposited by inkjet printing. The fully inkjet printing process possesses the advantages of direct patterning and low-cost. It does not require photolithography and etching processes since the pattern is directly printed on the flexible aluminum sheet. The prototype demonstrates that the presented flexible sensor is sensitive to the human body. It may be applied to proximity sensing or thermal eradiation sensing.

Recently, CAO et al. proposed an efficient electronic voting scheme based on the polynomial function. They claimed to satisfy the fairness, uniqueness, eligibility, anonymous, accuracy and robustness. In this paper, we show that the electronic voting can guarantee neither robustness nor anonymity. Some candidate can add the ballot number by altering data, and any candidate can know the accurate content of each vote after the tallying stage.

As to the existing shortcomings of the traditional method for fault diagnosis of turbine generator, A new method based on wavelet packet PCA-SVM is proposed in this paper. First of all, take a wavelet packet transformation of the fault samples to extract the energy of each frequency band, and use them as the initial samples, and then make a data compression and feature extraction of the initial samples using the principal component analysis(PCA), eliminating the correlation between data and extracting the principal components which contain sufficient information of initial samples. Finally, we take the principal components as the input vectors of the support vector machines(SVM), this will reducing the dimension of the sample space and computing complexity. Simulation results shows that this method can effectively improve the diagnostic accuracy.

To improve the quality of the reconstructed image, the common used three reconstruction algorithms in digital holographic microscopy, Fresnel transform algorithm, angular spectrum algorithm, and convolution algorithm, all based on fast-Fourier-transform (FFT) are investigated and compared. By using off-axis lensless Fourier setup the digital hologram of a USAF test target is recorded and reconstructed numerically with the three algorithms at different reconstruction distances. The results show that by Fresnel transform algorithm the lensless Fourier transform digital hologram can be reconstructed at any distances. For convolution and angular spectrum algorithms, there is an optimal reconstruction distance. For convolution algorithm, when the reconstruction distance is different from the optimal distance, the image resolution is decreased, particularly for small distance. When the reconstructing distance is slightly smaller and very larger than the optimal one the high quality image can also be obtained by using angular spectrum algorithm. Angular spectrum algorithm is better than convolution algorithm. The Fresnel transform algorithm is the optimal numerical reconstruction algorithm in digital holographic microscopy.

Vibration is one of the most common faults for hydropower units; traditional signal processing methods can not effectively extract the eigenvectors of the fault signals. In this paper, using wavelet packet analyze the spectrum of the vibration signals for hydropower units, extracting the frequency eigenvectors of the signal and use them as the classification data, taking good advantage of the feature of the data and extracting the quantified values of the contribution which the indicators made to classifications, what’s more, taking the weighted distances in place of Euclidean distances, establishing the iterative algorithm to search optimal representative points. Therefore, we can apply this algorithm to diagnosis the fault for hydropower units. The experiment results shows that it is very appropriate for us to use the proposed method to diagnosis the vibration fault for hydropower units.

With the development of manufacturing engineer, the aeroengine structure and operating condition have become more complex and the circumstance is generally under mal-condition with high temperature and pressure, so keeping its reliability and safety of airplane is essential. An effective method for aeroengine fault diagnosis using wavelet neural networks is proposed. The wavelet transform can accurately detect and localize the characteristics of transient signal in time-frequency domain. The advantage of wavelet transform is in achieving flexible frequency resolution logarithmic time frequency bands, thus making it able to extract both high-frequency and low-frequency components from the vibration signal. The characteristic information obtained are input nodes of neural network for fault pattern recognition. The mathematics model for aeroengine fault diagnosis is established and the improved optimization technique for neural network training algorithm is used to accomplish the network parameter identification. By means of enough experiment samples to train the neural network, the fault mode can be obtained from the network output result. Furthermore, the robustness of wavelet network for fault diagnosis is discussed. The results obtained from the application of the method on monitored data collected from a facility validate the utility of this approach.

In power system network, the voltage and current signal exhibit fluctuations in amplitude, phase, and frequency due to nonlinear devices utilized for power generation, transmission and distribution. The power quality problems can cause electric equipment malfunction and consume great electric energy. Therefore, it is necessary to monitor these disturbances. A novel approach is put forward to detect and analyze voltage stability by combining wavelet transform with pattern recognition technique. In signal denoising process, the statistic rule is proposed to determine the threshold of each order of wavelet space, which can determine the decomposition level adaptively, increasing the signal-noise-ratio. The wavelet transform coefficients as feature vector are presented for extracting disturbance signal. The effectiveness of training algorithm for pattern recognition is described, which can be realized by feature vector acquisition. The method incorporates the advantages of morphological filter and multi-scale wavelet transform to extract signal feature meanwhile restraining various noises. The simulation results prove that the proposed method is correct and effective for voltage stability analysis.