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Aiming at the problem of complex path planning in the processing of curved surface workpieces of body-in-white, a hybrid path planning method based on a memetic algorithm is proposed. The method is divided into two parts: welding sequence planning and welding path planning between weld points. By establishing the kinematic model of a spot welding robot based on the pipper criterion and z-y-z Euler angle solution method, the motion constraints of path optimization are analyzed. Under the framework of the memetic algorithm, the improved A-star algorithm with redundant node deletion and a post-smoothing process is used to obtain the smooth collision-free optimal path set between weld points and to construct the objective function of travelling all weld points with the shortest path length and highest smoothness. The multiobjective elitist-simulated annealing genetic algorithm (MESAGA) is used to achieve the welding sequence planning of all weld points. The variable neighborhood search method improves the mutation operator; the elitist strategy is introduced to improve the probability of elitist individual crossover and mutation operation, and a simulated annealing algorithm is used to jump out of local search to obtain the global optimal solution. According to the motion constraints, the joint space path is obtained by the optimal path in Cartesian space. Simulation analysis results demonstrate that the hybrid path planning method based on the memetic algorithm can effectively optimize the path of spot welding robots and lay the foundation for control and trajectory planning during welding processes.

Titanium alloy has been widely applied in industrial fields because of its excellent material properties. Electrical discharge machining (EDM) is commonly technology for processing titanium alloy. When titanium alloy was processed by EDM, a recast layer was inevitably be produced on its surface, which can adversely affect the surface quality and working life. Focus on the above problem, this paper proposed to add B4C powders into the spark oil and cooperate with the tool electrode sloshing for powder mixed electrical discharge machining (PMEDM) of titanium alloy, which can reduce the thickness of the recast layer and thereby improve the quality of the machined surface. Firstly, B4C powders were mixed in the spark oil and the PMEDM of the titanium alloy was carried out. In this step, the thickness of recast layer was preliminarily reduced and the quality of machined surface was improved. Secondly, when the PMEDM of the titanium alloy was nearly completed, the tool electrode sloshed along the machine tool spindle within the EDM gap. Combining PMEDM with the tool electrode sloshing, the recast layer on the machined surface was further eliminated and the quality of machined surface was further improved. By adding 3000 mesh B4C powders into the spark oil, the paper carried out the PMEDM of titanium alloy combining with the tool electrode sloshing. Under the action of appropriate process parameters, the micro-groove structure with surface roughness Ra of 0.205 μm was obtained in the titanium alloy and the recast layer on the machined surface was almost invisible.

Email and other forms of electronic communication are becoming increasingly more essential to our everyday lives. However, with this growth comes the paralleled increased risk of email harassment, exacerbated by the current lack of platform support for managing these harmful messages. This paper explores different interfaces for the automated detection and management of email harassment using artificial intelligence in order to investigate what degree of platform intervention email users prefer when navigating their email platform. Through conducting user studies involving three different email platform prototypes based on the Gmail platform, we employ mixed-method analysis to evaluate how varying levels of platform intervention affect users’ perceived sense of safety, agency, and trust with their email platform. Our primary findings suggest that users generally benefited from each of the system intervention strategies and desired higher intervention features when combating email harassment, as well as ways of managing this intervention based on their unique preferences.

My country is the largest installed hydropower capacity in the world, the safe, stable, and reliable operation of the unit has always been a technical problem faced by the hydropower industry. The runner is the core part of the hydropower unit for energy conversion, and its quality will directly affect the reliability and hydraulic performance of the unit. At present, the detection of the runner status of the running unit is completely manual. To solve the problems of low efficiency, high cost, and great harm to the human body of Large Francis turbine runner blades, a new type of defect detection robot for turbine runner blades was designed. The robot body structure is designed by modules, which is easy to load and unload, easy to carry, fast manufacturing, and low requirement for manual operation. Magnetic adsorption chain track is introduced into the wheel system of the robot, and two groups of tracks are adopted, which makes the robot compact and can move flexibly in the narrow space turbine runner. On the other hand, the central position of the robot is equipped with an adsorption force self-adjusting device to ensure that the robot can stably adsorb on the blade surface at a certain angle from the horizontal plane.

For machine learning models to be most useful in numerous sociotechnical systems, many have argued that they must be human-interpretable. However, despite increasing interest in interpretability, there remains no firm consensus on how to measure it. This is especially true in representation learning, where interpretability research has focused on "disentanglement" measures only applicable to synthetic datasets and not grounded in human factors. We introduce a task to quantify the human-interpretability of generative model representations, where users interactively modify representations to reconstruct target instances. On synthetic datasets, we find performance on this task much more reliably differentiates entangled and disentangled models than baseline approaches. On a real dataset, we find it differentiates between representation learning methods widely believed but never shown to produce more or less interpretable models. In both cases, we ran small-scale think-aloud studies and large-scale experiments on Amazon Mechanical Turk to confirm that our qualitative and quantitative results agreed., Comment: CHI 2021 accepted paper

A wideband antenna with ±45° dual polarization is proposed. The antenna is mainly comprised of four printed trapezoidal metal walls standing on a ground plane that forms a 3-D open square aperture cavity structure with tapered cut on the four wall edges. The metal walls are fed by two orthogonally positioned (±45°) feeding networks, forming two pairs of dipole arms. Because of the excited magnetic-electric resonances, wide bandwidth can be achieved. The proposed antenna is fabricated, and the measured results show that it has an impedance bandwidth of 56% (1.62–2.87 GHz) for VSWR < 1.5. In addition, isolation of larger than 30 dB is also exhibited across the bandwidth between the two feeding ports. Because the proposed antenna has a hollow inside structure, it is a good candidate for multiband sharing aperture antenna element. Furthermore, it has a simplified fabrication process and is suitable for outdoor base station antennas that require VSWR < 1.5.

In this paper, the hydraulic efficiency optimization calculation method of a ten-stage centrifugal pump is researched. According to the hydraulic loss model, a multi-objective optimization calculation method based on surrogate models is proposed. In order to study the highly nonlinear relationship between key design variables and centrifugal pump external characteristic values, this paper builds the quadratic response surface, the radial basis Gaussian response surface, and Kriging three surrogate models using computer fluid dynamics (CFD) simulation analysis. Two types of calculation models (hydraulic loss model and three surrogate models) combined NSGA-Π genetic algorithm are applied to optimize the key design variables and to find the optimal solution of each model. The accuracy and effectiveness of the efficiency optimization methods based on the two types of calculation models are compared and analyzed. The results show that the calculation method of hydraulic loss model based on the semitheoretical and semi-empirical formula is less time-consuming but inaccurate. In contrast, the optimization method based on surrogate models using CFD simulation is accurate. What's more, comparing the surrogate models, the results based on the complete quadratic response surface model which make the efficiency of the first stage centrifugal pump reach 77.26% are more accurate.

The hydrostatic-driven power generation system is suitable for the development of unstable natural flow energy such as wind energy and water flow energy. Its principle is similar to which of the steam turbine power generation, and they are both belong to constant-speed and constant-frequency power generation system. In order to achieve faster and more accurate grid-connected control requirements, the constant speed control of the hydrostatic-driven power generation system is more challenging than which of the steam turbine , because the steam energy of the steam turbine is controllable while the natural flow energy is random and unstable. Taking the fixed displacement pump-variable motor hydrostatic-driven power generation system as the research object, the transfer function of the mathematical model of the hydraulic main drive system is analyzed. According to the factors that influence the constant speed output control precision and response speed of the variable motor under the disordered input condition , the feed forward fuzzy adaptive PID anti-interference grading control method is proposed. The effectiveness of the control method is validated by simulation and experiment, which lays a foundation for further research on the hydrostatic-driven power generation system.

Cables are the main load-bearing components of cable-stayed Bridges. The durability and reliability of cables are directly related to the safe operation and service life of the whole bridge. Aiming at the problem of cable detection and maintenance, a new type of cable detection robot is designed in this paper. To further enhance the stability of the robot, the structure adopts symmetrical arrangement to make the center of mass of the robot system coincide with the cable axis. According to the working condition of the robot, a flexible body spring that meets the parameter requirements is designed, which not only meets the required preload, but also meets the starting torque of the motor. The robot is simple in structure, standardized in parts, easy to assemble and disassemble, and has good obstacle clearance ability and detection efficiency.

Applying 3D micro-electrodes in micro-electrical discharge machining (micro-EDM) can process a 3D micro-structure with up and down reciprocating machining method. However, this method has some shortcomings, such as the formation of ridges on 3D micro-structure surface and a relatively low processing efficiency. To resolve these shortcomings, this study fabricated 3D micro-electrode and applied it in micro-electrochemical machining (micro-ECM). Based on the principle of electrolytic polishing, the ridges on the 3D micro-structure surface were basically eliminated and make the ridges have little influence on the 3D micro-structure surface. Moreover, with a feeding speed of 50 μm/min, it takes only 8 min to process a 3D micro-structure (360-μm depth) by using micro-ECM. With the improvement of surface quality and processing efficiency, it is believed that this study could improve the application possibility of 3D micro-electrodes in industrial fields.

A $6 \times 6$ wideband antenna array with ±45° dual polarizations is proposed. To achieve good radiation efficiency, cavity antenna is used in this work as the basic element. Feeding probes and strip line feeding networks are printed on general PCB substrate. The feeding circuits for exciting different polarizations are stacked and multilayer substrate step structure is used. Here, strip line to downward SMA connector transitions is also designed, which aids in integrating the proposed array with T/R modules located below and extending it to larger phased array. The antenna array is fabricated and measured. Simulated and measured impedance and radiation performances are also given and compared. The proposed antenna arrays show wide bandwidth of 30% from 10.9 to 14.8 GHz, and isolation of higher than 33 dB is also exhibited across the bandwidth. Furthermore, symmetrical patterns and cross-polarizations of below −25 dB are also demonstrated.

A cavity-backed antenna with low-profile, dual-polarization, and wide operating bandwidth characteristics is proposed. In this design, two orthogonally positioned triangular bowtie antennas printed on a low-cost substrate are loaded onto a square cavity, so that two orthogonal linear polarizations can be excited. By further introducing four extended ground stubs from each side of the square cavity, the proposed antenna can also acquire low-profile characteristic of approximately 0.1λ 15 mm. To achieve good impedance matching, additional circular slots are introduced into each bowtie design. The measured results show that the proposed antenna can cover a wide operating bandwidth of 62% 2.0-3.8 GHz with a VSWR of 2:1. Besides exhibiting good isolation >20 dB between the two feeding ports, desirable realized gains 6.0-10.5 dBi over the wide operation band are also demonstrated. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:724-730, 2016.

A wideband full-metal planar antenna array with full-corporate feed-network is proposed. Cavity and slot are used as the basic radiation element and T-shaped walls are employed in the cavity to achieve wide bandwidth. $E$ -plane waveguide feed-network configuration is utilized so as to suppress wave leakage between adjacent layers when the antenna is fabricated by a conventional machining technique. An $8 \times 8$ antenna array prototype with optimized parameters is tested. Experimental results show that the bandwidth of ${\text{VSWR}} is up to 36.9% ( $10.24-14.87\;{\text{GHz}}$ ). More than 60% aperture efficiency and higher than 23.4 dBi gain are achieved over the operational bandwidth.

It is well known that generating electricity in the deep-sea has always been a very challenging problem. Aiming at the power demand of the underwater observation system, this paper presents a novel distributed ocean current energy hydrostatic transmission (HST) power generation solution, which can generate electricity efficiently and continuously in large depth and low flow velocity environment. The proposed solution adopts a dual-pump confluence design. According to this, the working pressure of the HST is reduced to avoid overflow compared to the single pump design, and therefore the dispersed micro-energy in deep-sea can be aggregated together to convert continuously to active power rather than to the heat. Furthermore, the solution employs an energy-saving strategy involving constant pressure pump and seawater cooling and improves effectively the efficiency to some extent. Besides, it was found that the working pressure of the system depends not only on load torques but also on turbine speeds reversely, while the speed of hydraulic variable displacement motor maintains constant. Therefore, dual-pump confluence implies power aggregation and plays a key role in generating electricity in deep-sea. Simulation results and the tests based on the 5 kW prototype verifies the feasibility of the proposed distributed HST solution. Accordingly, at the current status, the distributed HST power generation is the most probable solution applied to the deep ocean.

Optical scatterometry, as a fast, low-cost, and non-contact measurement instrument, is widely used in the profile characterization of nanostructure in the semiconductor manufacturing industry. In general, it involves two procedures, i.e. the forward optical modeling of sub-wavelength nanostructures and the reconstruction of structural profiles from the measured signatures. Here, the general term signature means the scattered light information from the diffractive grating structure, which can be in the form of reflectance, ellipsometric angles, Stokes vector elements, or Mueller matrix elements. The profile reconstruction process is an inverse problem with the objective of optimizing a set of floating profile parameters (e.g., critical dimension, sidewall angle, and height) whose theoretical signatures can best match the measured ones through regression analysis or library search. During solving the inverse problem, the refractive index and distinction coefficient of the material of nanostructure are assumed to be constants and they are generally fixed. This assumption is valid for most of the materials in semiconductor industry, but not for certain materials that are very photosensitive. That is, the optical constants of photosensitive materials may vary with the illumination time of the incident light beam in spectroscopic ellipsometer, and the error caused by the variation of optical constants propagates to the final extracted results of structural profiles, which should not be neglected, especially for high precision and accuracy metrology.Experiments performed on SiO2 and polymethyl methacrylate (PMMA) thin films are conducted and demonstrate that the extracted geometric parameters and optical constants of SiO2 film do not change with illumination time increasing, while the twenty groups of values of extracted refractive index n and distinction coefficient k of PMMA resist film vary obviously, and the difference between the extracted maximum and minimum film thickness has reached 40.5 nm, which to some extent illustrates that the above assumption is not valid for PMMA resist, so that the incident light beam of spectroscopic ellipsometer has a great influence on the extracted film thickness. Further, simulations based on a three-dimensional PMMA grating also indicate that the error of optical constant has considerably transferred to the extracted profile parameters. This finding is of significance for improving the accuracy of nanostructure characterization in optical scatterometry.

To analyze the efficacy and safety of benign esophageal disease used biodegradable (BD) stent or metal stent. The English literatures of benign esophageal disease that were treated by biodegradable or metal stents implantation were retrieved and summarized. In all 323 benign esophageal disease, the most common etiologies were benign refractory stricture, surgical anastomotic stricture and esophageal fistula/leak/perforation, but the main characteristics between the two groups were not significantly different. One hundred fifty-four cases were completely healed by using BD stents or self-expandable metal stents (SEMS) (47.7 %). Clinical success was achieved in 47.7 % of all patients and there was no significant difference between BD stents (51 %) and SEMS (46.2 %) (P = 0.472), while stent migration occurred more frequently with SEMS (33.9 %) than with BD stent (19.6 %) (P ≤ 0.05), and tissue in- or overgrowth occurred more frequently with SEMS (22.2 %) than with BD stents (8.8 %) (P ≤ 0.05). Furthermore, the time about degradation of BD stents in esophageal was longer than removal of SEMS from the esophagus (P ≤ 0.05). Placement of BD stents or SEMS provides effective and safe relief for benign esophageal disease. Clinical success and mortality were not significantly different. BD stents offers an advantage of fewer complications. Although stent placement is a viable strategy in patients with benign esophageal disease, the ideal treatment strategy and further randomized trials with large number of patients are needed.

Aiming at improving the 3D shape measurement speed and accuracy, the design of floating point algorithm for 3-D shape measurement using FPGA, is proposed. By using four-step phase shifting method for measuring 3D measurement system, using CORDIC algorithm to achieve phase calculation of the phase shift method, the algorithm is realized by Verilog language in FPGA, and to make simulation and verification in Modelsim. The study of 3D shape measurement system have a breakthrough from the design performance and hardware.Finally, the MATLAB simulation proved its effectiveness and viability.The experimental results show that the advantages of high data processing speed, high efficiency and high precision,etc.

This paper introduces the field programmable gate array (fpga) application in high-speed visual inspection system.ALTERA EP1K30QC208-2 are used in the system for system calculation and control of the core, to perform high-speed real-time visual detection algorithm, this paper adopts a yawning based on eye closure and to detect driver fatigue, the method of in YCr, Cb in the color space using gaussian model skin detection of human face area, in the face of a gray binarization figure using a priori knowledge of facial features geometry in rough positioning the human eye, eye contour are obtained by region growing and morphological operation and calculation of the closure of the eye;Best threshold detection lips when using lip color roughly locate the lips, on the basis of accurate positioning lips by face grey value characteristics, and then through the mouth level to determine whether a driver yawn;Based on the two characteristics of driving fatigue, experiments show that this system detection speed, excellent versatility, and can improve the detection accuracy.

Buses running state based on the technology of "4G" wireless monitoring system has bus dynamic information query, vehicle dynamic tracking, vehicle scheduling, vehicle classification management four big functions. The system has nine subsystems respectively complete vehicle GPS positioning, operations management, IC card charging management, large screen display control center, vehicle operation coordination, GIS data query and selection, mobile communications, exception handling, information service, etc. The system applied to public transport vehicle scheduling management, the results show that can alleviate the urban public traffic congestion, improve line of vehicle safety, improve the efficiency of the vehicle running, reduce the air pollution in cities.

The article main introduction take the STC monolithic integrated circuit as master control MCU,through MCU in car license inserting realization to vehicles information read,as well as carries on localization tracing to the vehicles,and through special-purpose equipment read car license in information.

This paper describes the design of a low profile and wideband antenna array with circular polarization. The antenna consists of 2 × 2 elements. Loop coupled structure and sequential rotation feeding technique are used to obtained wideband VSWR and axial ratio performances. The proposed antenna array is analyzed with HFSS software. The VSWR, Axial Ratio, and Radiation Patterns of the array are presented. The simulated results show that the VSWRs are below 1.5 over the frequency band of 1.88–2.26 GHz while the axial ratio is below 3.0 dB over the band of 1.96–2.25 GHz

Image segmentation is a huge task and challenge in the magnetic resonance images (MRI) and infrared images because of the intensity inhomogeneity, noisy and other problems. It is of importance to distinguish each region accurately to obtain a perfect segmentation result. Methods based on bias field theory can effectively overcome the intensity inhomogeneity. However, the edges can not be segmented well, especially for complicated shape target. Therefore, a new regularization term based on gradient is proposed to further improve the accuracy of segmentation edges in the paper. Compared with some improvement methods which based on the standard FCM and level set algorithm, the results show that the proposed method is more accurate in image segmentation for MRI and infrared images.

The control of the roll gap of the segment is one of the key links to ensure the quality of cast billet. In this paper, the big data in traditional continuous casting production operations is studied through in-depth experimental comparative analysis of linear and nonlinear dimension reduction method. The method is suitable for continuous casting to obtain the data of the dimension reduction. The method of principal component analysis is improved by using standardized data increment method. A faster and more efficient method of dimension reduction is obtained when the unrelated data, training time and reconstruction error are removed. Actual data simulation results show that this method is more efficient and suitable for continuous casting than any other dimension reduction method.

It is important to establish reliability analysis model of secondary system for the intelligent substation. In this paper, a method is proposed to evaluate the reliability of secondary system in smart substation. Firstly, according to the reliability indices of secondary system structures for different smart substations, the evaluation matrix are determined and the matrix can be orthogonalized to makes it non dimensional. Secondly, the mean, standard deviation, coefficient of variation, and weighted vector of the matrix are calculated. Then, the weighted data matrix of ideal sample and negative sample is determined. Finally, according to the correlation degree ranking method, the reliability evaluation of each index is obtained. For practical examples, this method can be used to identify the factors influencing realiability of intelligent substation. The method can be used to select an appropriate network topology, improving the reliability of the design level of substation communication system.

Spectrum sensing is used to detect spectrum holes and find active primary users, while randomly selecting channel for sensing leads to secondary user's lower throughput in high traffic cognitive radio networks. Spectrum prediction forecasts future channel states on the basis of historical information. A new frame structure is proposed in this paper for the imperfect spectrum prediction, improving SU's throughput through selecting sensing channels from the channels predicted to be idle. Simulation results show that secondary user's throughput is significantly enhanced by the imperfect spectrum prediction. The effects of traffic intensity, probability of wrong prediction, and channel number on the throughput are also investigated in this study.

Vehicle will cross the pole when using the Pc-Crash to reconstruct a side pole impact accident. In order to overcome this problem, a fractional step method based on Pc-Crash was proposed. In this method, the motion of the vehicle before impact is reconstructed firstly, and then the impact between the vehicle and the pole will be reconstructed, these two steps will be repeated to obtain a reasonable simulation results. Finally, a side pole impact accident was given, the steps of the fractional step method were demonstrated, and results showed that this new method is feasible in practice. The practical step method will reduce the difficulty of accident reconstruction and make the reconstruction results more credible.

It studies failure mechanism of optical glass with impact stress from grit, according to the dynamic impact effect in the process of optical glass grinding with single grit. With the distribution regularity of crack which from the grit dynamic impact, it established mathematical model of cylindrical stress wave which coaxial with wavefront. Analyzing and establishing the control equations for cylindrical stress wave, using finite-difference technique to simulate the dynamic impact effect for optical glass grinding with single grit and adopting Zwas numerical methods with source term hyperbolic curve partial differential equations to analysis and study the dissemination rule, diffusion rule and change rule, the simulation analysis shows that in the dissemination process of grit impact wave , wavefront occurred diffusion and there are tensile stress generated as well as oscillation.

The most obvious characteristic of Cognitive Radio is spectrum cognition. Spectrum sense is the primary question of spectrum cognition. Quick sense in wideband is the most important way for improving the efficiency of spectrum utilization and avoiding interference to licensed user. It is one of the key techniques which need be resolved imminently in Cognitive Radio. In this paper, phototropism in biology is introduced for spectrum sense in Cognitive Radio. Phototropism based sense technology is researched. The features of “light source” in spectrum sense are analyzed. Comparing the commonness and difference between plant growth and spectrum sense, the node sense model is modeled for phototropism based sense, respectively. Based on Smart Antenna technology and the features of wireless channel, the application schemes at one node are designed. Through analyzing the bionic arithmetic and mathematic optimizing methods, we research the phototropism based sense method with fast speed and wide band in order to sense spectrum optimally. The results of researching in this paper give a novel technical scheme for sensing and are valuable in theory and engineering in Cognitive Radio.

Considering the scenario of cognitive radio network (CRN) single channel opportunistic spectrum access, the minimum rate gap-based access strategy (MRG-CPA) is established which provides CR QoS guarantee and also promises interference-free to primary radios (PRs). The corresponding channel and power allocation algorithm and MAC protocol is demonstrated too. Compared with the existing strategies such as FFD, BFD and minimum rate based channel and power allocation (MR-CPA), the proposed strategy provides more useful CRN network throughput as well as improves the CR QoS guarantee.

This paper presents a memetic algorithm for optimization of urban transit route network. The objective of this research is to minimize the users cost and the unsatisfied user demand. The local search operator of the memetic algorithm combines three types of moves: 2-opt moves, exchange of two stops and relocation of one stop. The move of the most direct travel passengers increased in terms of the operation time of routes is chosen as a local search to improve the convergence of the algorithm. The algorithm has been tested with problems reported in the existing literature, and the results show that the algorithm could improve the solution to the transit route network optimization problem in acceptable time and reasonable computing resources.

Traditional spectrum management mode results in spectrum scarcity and deployment difficulty and new spectrum management is desiderated. To overcome this problem, autonomous spectrum management system based on viable system model is proposed. It decouples policy from behavior and protocol in order to reduce the deployment complexity, and exploits viable system model to partitions the system into six function modules. The interconnections between these modules bring autonomy to networks and radios which enable the self-management of spectrum. Finally, the spectrum utilization and deployment efficiency is analyzed and simulated in a scenario of dynamic spectrum allocation among heterogeneous networks.

Cognitive Radio (CR) is a revolution in wireless communication and enables flexible spectrum assess. This paper addresses the topology management problem in cognitive radio Ad Hoc networks (CRAHNs). Distributed multihop architecture, mobility of CR users, spectrum availability variance in different time and location are some of the key distinguish challenges for spectrum access in CRAHNs. Cluster structure is an efficient way to organize CRs and coordinate their spectrum sharing. Based on the analysis of CRAHNs environment, we propose a local control channel topology management scheme (LCCTM) in this paper. The scheme considers both the cluster size and stability of the structure and provides a desirable balance between them by the assignment of backup heads and control channels. Extensive simulation results demonstrate the efficient and reliability of the scheme.

It is important but difficult to analyze transient signal of Radio Frequency Fingerprinting (RFF), especially to extract the features of RFF signal. Method of analyzing transient signal based on Empirical Mode Decompositions (EMD) is introduced in this paper. EMD can dynamically achieve signal's Time-Frequency Distribution (TFD) and amplify the feature's difference between RFF's transient signals from different radio transmitters. EMD is efficient to process transient signal and can extract efficient features in RFF system. The results of simulation show that EMD method has the advantages that signal processing speed of EMD is fast and can achieve very high correct rate of recognizing to transmitter.

Jamming detection and jamming recognition are the key technologies of intelligent anti-jamming in the satellite communication. To solve the problem that the jamming is difficult be recognized in the satellite communication, a new algorithm for jamming recognition based on the high order cumulants(HOC) and wavelet transform is proposed. The algorithm analyzes the familiar jamming with the high order cumulants in frequency domain and extracts feature parameters of each jamming; The classified models of each jamming has been established for recognition. In the process of recognition, we adopt the wavelet transform for denoising the received jamming. It is proved that the mentioned algorithm can recognize the familiar jamming correctly in satellite communication under low SNR.

Low-molecular-weight hyaluronan produced by hyaluronan synthase 3 (HAS3) has been shown to play a role in acute lung injury secondary to high-tidal-volume ventilation. Phosphodiesterase 3 inhibitors have been shown to decrease HAS3 expression. We hypothesized that low-molecular-weight hyaluronan (LMW HA) produced by HAS3 mediates LPS-induced lung injury in the mechanically ventilated rat and that milrinone (MIL), by blocking HAS3 mRNA expression, would prevent the injury. Rats were randomized to four groups: controls with mechanical ventilation at 7 cc/kg MV, MV+LPS, MV+MIL, and MV+LPS+MIL. Rats were intubated and ventilated without PEEP for 4 h. Lipopolysaccharide (LPS) (1 mg/kg) was infused into the arterial line 1 h prior to MV. MIL 10 microg/kg/min (or an equivalent volume of saline) was infused through the venous line at the beginning of MV. Bronchoalveolar lavage fluid (BAL) was collected after 4 h of ventilation and lungs were saved for histopathology. LPS significantly increased neutrophil infiltration and protein concentration in the BAL and augmented lung injury score on histology. MIL significantly lowered alveolar protein and neutrophil infiltration as well as lung injury in response to LPS. Furthermore, MIL decreased the mRNA expression for HAS3 and MIP2 in lung tissue and decreased the protein content in BAL. MIL, a commonly used inotropic agent, inhibited LPS-induced lung inflammation and lung injury in mechanically ventilated rats. The anti-inflammatory properties of MIL may be mediated by inhibition of HAS3 and/or MIP2 and could be beneficial in the treatment of sepsis.

Combining theory of MANET with satellite communication constellation in paper, the model of satellite communication constellation based on MANET is introduced. According to analyzing on this model, the system simulating frame is designed in OPNET and the model is simulated. Meantime, we analyze the delay and throughput, conclude the advantage and disadvantage of the model.

Based on the discrete-time signal processing, the representation of Doppler effect on code acquisition performance is analyzed and the principle of combining partial-matched filter with FFT is given in this paper. A fast code acquisition architecture by using partial-matched filter with FFT for the large Doppler offset frequency and long PN code spread spectrum communication system is designed and realized in FPGA and DSP. This architecture provides a very good trade-off between acquisition performance and complexity. Application results show this architecture is very attractive for LEO satellite communication.

Protocols such as TCP and congestion control mechanisms like TFRC (TCP-friendly rate control) suffer in a hybrid wired-cum-wireless scenario where losses can occur for reasons other than congestion, viz., due to bit errors in the wireless link. The existing solutions to address the problem either misclassify the losses, violate end-to-end semantics, do not coexist with IPSec or are TCP-specific. We have previously proposed an innovative mechanism, secure performance enhancing proxy (SPEP), which preserves end-to-end semantics, ensures end-to-end security and enhances performance. We show that the decoupling of loss differentiation from the loss recovery mechanism enables SPEP to serve as a generic loss differentiation mechanism at the network layer. We show by means of test bed experiments that SPEP works in conjunction with any transport layer and protocols such as UDP with TFRC.

Objectives The value of radial displacement (RD) by speckle tracking echocardiography in locating target coronary artery disease has not been able to determine. We hypothesised that the myocardial RD by speckle tracking echocardiography during rest status could be used in locating target coronary artery and would be better compared to radial strain (RS). Methods Study population composited of 31 patients with first ST elevated myocardial infarction after primary percutaneous coronary intervention (PCI). Men 26, mean age 63 ± 10 years. The time between onsets to treatment was 5.7 ± 2.0 hours. The lesion involved the left anterior descending artery (LAD) in 17 patients, left circumflex artery (LCX) in 4 patients and right coronary artery (RCA) 10 patients. Speckle tracking echocardiography was performed within 72 hours after PCI during rest status. Myocardial RDs and radial strain 17 myocardial segments were measured by an Echo-PAC computer workstation for automatic function imaging. Results The territorial coronary arteries had been successfully recanalised in all patients. The AUCs of RD to predict LAD, LCX and RCA were significantly greater compared to RS (0.85- 1.0 vs 0.6- 0.87 for LAD, 0.85–0.94 vs 0.79–0.81 for LCX and 0.86 vs 0.55). The sensitivity and specificity of RD in relative segments to predict LAD, LCX and RCA were higher compared to RS. The sensitivity and specificity of RD in anterior septum at the papillary muscle level and apical level to predict LAD were 100% and 93- 100%, respectively. The sensitivity and specificity of RD in inferior lateral wall at the basal level to predict LCX was 100% and 89%, respectively. The sensitivity and specificity of RD in inferior wall to predict RCA was 90% and 81%, respectively. Conclusions RD by speckle tracking echocardiography is a novel index to locate target coronary artery and is much better compared to RS.

Objectives Behcet Disease (BD) is a multi-system inflammatory disorder as its underlying pathological process. Cardiovascular involvements have been reported in 7–46% of cases with Behcet9s disease. We reported a case of Behcet9s disease with severe aortic root vasculitis. Traditional two-dimensional echocardiography (2DE) demonstrated a dissection between anterior wall of the aortic root and interventricular septum associated with a rupture of left Valsalva sinus aneurysm into the left ventricular outflow tract. However, preoperative transesophageal real- time three-dimensional echocardiography (3DE) revealed that the aneurysm-like structure in left ventricular outflow tract involved the most part of the left ventricular outflow tract wall. The diagnosis was corrected by 3DE as the dissection between the ventricular septum and aortic root associated with a perforation of left Valsalva sinus and a prolapse of the exfoliated endocardium into the left ventricular outflow tract. These findings were confirmed during open heart surgery. Conclusion: 3DE is helpful to differentiate the dissection in the aortic root from the rupture of Valsalva aneurysm, especially in demonstrating the extent of aneurysm-like structure in the left ventricular outflow tract. Methods Results Conclusions

This paper presents a novel framework to extend the dynamic range of images called Unbounded High Dynamic Range (UHDR) photography with a modulo camera. A modulo camera could theoretically take unbounded radiance levels by keeping only the least significant bits. We show that with limited bit depth, very high radiance levels can be recovered from a single modulus image with our newly proposed unwrapping algorithm for natural images. We can also obtain an HDR image with details equally well preserved for all radiance levels by merging the least number of modulus images. Synthetic experiment and experiment with a real modulo camera show the effectiveness of the proposed approach., United States. Dept. of Defense. Assistant Secretary of Defense for Research & Engineering (United States. Air Force Contract FA8721-05-C-0002), SUTD-MIT (Joint Doctoral Fellowship)