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For the technical problems of coal and rock character recognition in fully mechanized caving faces. A method on characterization and recognition of coal and rock traits were discussed based on the time domain indexes of acoustic pressure data according to the differences of physics and mechanical parameters of coal and rock, and the differences of acoustic pressure data when coal and rock falling impact the rear beam of the sublevel caving hydraulic support. Firstly, the top coal caving experiments were carried out with mining portable vibration recorder developed by China University of Mining and Technology (Beijing) in fully mechanized caving faces in the underground mines, and the acoustic pressure data in quantity were acquired; Then, signal preprocessing were carried on to remove trend items for the selected acoustic pressure data; Finally, the acoustic pressure dates were analyzed in time domain and the time domain features were acquired. Comparison found, peak to peak, variance and kurtosis index are sensitive to the working conditions and the variance with a higher recognition rate. Accordingly proposed an analytical method that based on time-domain features of acoustic pressure date which used variance as recognition indicator, providing technical support for improving the caving automation and intelligent in the fully mechanized caving face.

This paper tries to find a more feasible method to achieve core and reduction. Against concepts "distinguishable relation of attribute set" and "distinguishable unit set of attribute set", it defines a concept "important index", and proposes an effective and quick approach for important index. After drawn out the involved theory and equivalent proposition, also presents algorithms for core and reduction upon the important index. The heuristic reduction algorithm adopts the bottom-up design, and gets reduction based on the heuristic information "important index of attribute set". The complexity of the algorithm in space is O(m), and the complexity in time is O(mn2). The theoretical analysis and results show that the ways proposed here simplify the relevant operations and are suitable to deal with the huge volume of data.

A method on the feature extraction of coal and rock character recognition was mainly put forward based on image gray level distribution and gray scale average value. In order to improve the recognition effects of the image, cropping, gray level transformation, contrast enhancement, median filtering and other preprocessing work were applied individually on the raw image of coal caving and rock caving acquired from mechanized top caving face, then gray histogram of image signal of coal and rock was abstracted and the gray scale mean were calculated. The results shows that (1) the range of gray scale of top coal caving image is mainly between 10-100, and the range of gray scale of top rock caving image mainly between 90-220, (2) the gray scale mean of top rock caving image is around 130, far higher than the gray scale mean of top coal caving image of 66.

The work is designed and made as a controlled system of rotational inverted pendulum. Small direct current machine is droved by Single chip microcomputer that it controls the angle of swinging of swinging rod when the rotating arm does reciprocating rotation motion. The MC9S12CXS128 single-chip microcomputer is adopted as the master control chip of control system, the Angle of swinging rod is measured by the incremental encoder, power of the rotary arm controlled part provided by PM35S - 048 direct current machine and the motor drive module as a control system. It can realize measurement and control of the rotation angle of the rotating arm and the swinging angle of swinging rod precisely.

Currently, there has been growing interest in unmanned aerial vehicle (UAV) during the landing. With the widespread use of the UAVs, a more precise estimation on pose and position in the process of landing is required to support the higher-level applications. In this paper, the estimation of pose and position based on the line segment detection (LSD) is proposed. By applying a vision camera, a landmark is detected using the effective LSD algorithm. Then a line-based vision model is built to calculate the pose and position of the UAV. Experimental results show that the state solutions of the proposed method are effective with different shape of landmarks, and the accuracy is minute-level in pose angle error and centimeter-level in position error.

Odor pollution means a distinctive gas that is offensively unpleasant and harmful for the living conditions, not only disturbing social activities but also being harm for human. For the character of odor pollution, a kind of odor detecting system based on photoionization detector (PID) has been developed. The capillary column has been used as separate device and the PID as detector. From stability experiment of PID sensor, the standard deviation of system is 5.88×10-3, relative standard deviation is 0.14%. Furthermore, the experimental results of the sample calibration and stability illustrated that by using ethyl alcohol, xylene and butane, system lineaity is 99.99%, 99.98%, 99.98% respectively and the limit of detection is 0.8ppm, 1ppm and 0.6ppm respectively. PID has good stability and the experimental system has better reliability and repeatability.

The high precision of the seeker is the key to reduce the Miss-Distance and improve precision in the guidance system of missile, and the seeker stabilized platform servo system is safeguard of the overall performance of seeker. So based on the Stribeck friction model, this paper studies and compares the precision of position and velocity that controlled by PID control and BP neural network when the seeker platform working at low speed. Finally, according to the MATLAB simulation results, applying modern control theory as controller based on Stribeck friction model can improve precision and the problem of flat and dead zone at low speed.

This paper researches on the kinematics and dynamics of coupling for three-axis flight Simulator based on the high-speed rotation missile. Firstly, to define station body coordinate and the positive direction of rotation according to three-axis flight Simulator based on the high-speed rotation missile, and then the mathematical coupling model is established. Secondly, multivariable nonlinear mathematical model can be decoupling, while substituting the parameters quality attribute analysis solved by ProE into the mathematical model. Lastly, the decoupled linear equations and the decoupling solutions based on inverse system method were given, and then to finish the simulation and to analysis the simulation results.

In order to avoid the over discharge and less discharge situations, improve the coal recovery rate and promote the working environment of workers at the fully mechanized top-coal caving face, experiments for the research of the coal and rock character recognition were carried on underground. Vibration signal at the hydraulic support tail beam and the rear scraper conveyor under different conditions were acquired at the fully mechanized top-coal caving face using the self-developed mine portable data recorder. The time-domain indexes of the vibration signal were analyzed. Results show that the variance, skewness index and kurtosis index changes most obviously under various stage of top coal caving and can be used as the time-domain characteristic indicator for the coal and rock character recognition in the fully mechanized working face.

IEC 61400-25 is a series of international standards on communication of wind power plants. The service defined by information exchange models in wind power plants communicates through being mapped to web service. Web service is described by WSDL, but with the limitation of WSDL itself, web service can not realize the semantic description, the automatic discovery and composition of service. So semantic web service is introduced, the service is described by OWL-S to realize the interconnection of wind power plant hardware devices from different manufacturers, to facilitate the sharing and reuse of devices function and to realize the sharing of wind power plant knowledge in semantic level.

Seeker plays an extremely important role in precision-guided weapons, among which the high tracking precision ability of servo system is one of the key technology. This paper studies the three-loop control system applied in the rate gyro stabilized platform of an infrared seeker and researches the stability, rapidity and accuracy of speed loop ,current loop and position loop. Finally, according to the engineering project, we can verify the validity and applicability of this triple loop system.

In order to improve the efficiency of people evacuation from hazardous regions and reduce the ill effects of disasters, a distributed decision support system for large scale crowd evacuation is proposed. The system is supported by the technology of Web Geographic Information System (WebGIS). Basically, by analyzing the system framework we may acquire a novel approach to establish a distributed large-scale crowd evacuation platform for emergency management. Research results show that the proposed system is useful for devising evacuation plans in advance as well as real-time management under disaster.

In order to adapt to the harsh conditions of the coal mine, according to the MA Verified standards, we developed a set of vibration acceleration sensor signal conditioning circuit of mining, used for picking up vibration signal in the coal mine. The conditioning circuit solve the vibration signal of large equipment acquisition problems in coal mine, and lay a good foundation for the research of coal mine equipment vibration signal.

The paper analyzes the basic theory of prestressed concrete cable-beam structure in single span and single direction.The paper arranges reasonably the shape of cable,deduces the equation of cable. It introduces the reseach status and the importance of stability and demonstrates the basic relative theory on stability in concretely research and applies this theory on prestressed concrete cable-beam structure. It has significant prospect and is easy to put into practice .

A hybrid system scheme was designed for the sweeper truck, to solve the problems of high fuel consumption and poor emission performance of traditional sweeper. The control strategy was determined for the hybrid power system. The simulation model of hybrid sweeper truck was built with Matlab/Simulink, and off-line simulation was completed to verify the power system scheme and control strategy, the simulation results indicate that the hybrid sweep truck can realize functions of sweeper and improve the fuel economy.

Blasting-induced seismic wave imposes cyclic loadings on adjacent buildings and structures with a combined loading mode of tension, compression, bending, shear and torsion, and it leads to flaking of floated coat, wall cracking, developing of original cracks, etc. This paper presents a blasting case study for the excavation of Wucun tunnel in Xiamen Success Avenue. Field monitoring and numerical calculation of a typical brick masonry structure are adopted to analyze the relationships among the maximum structural displacement, peak vibration velocity of blasting-induced foundation vibration and the change rate of crack width. On the basis of the study above, a method of calculating the safe vibrating velocity for single-layer masonry structure is proposed. Meanwhile, a suggested value of the safe vibrating velocity for single-layer masonry structure is given. All the research results can be useful for the similar construction and research.

t has been a bottleneck for the application of vibration-related techniques in the coal mine that the vibration data cannot be acquired due to lack of mining vibration instrument. This paper discussed the development of a portable mining vibration recorder, introduced its overall scheme, as well as its hardware and software design in detail. The developed recorder is a coal mine intrinsically safety instrument based on ARM system, with features of 4 channels analog input, 2GB large volume storage memory, 250kHz sampling frequency, no less than 3.5h full-payload continuous working time with battery supply, fitted to record and deposit the vibration signal of the equipment in atmospheres with methane and coal dust explosive mixture. The authors carried out a series of testing application in ChengZhuang coal mine. The experimental results show that the data acquired by the recorder is true and valid. Study provides an instrumental basis of apparatus to carry out the supervision of machine based on vibration detection in coal mine.

“strong beam and weak column”is the main failure states of reinforced concrete frame structure in the earthquake．This paper is the experimental study of the influence on the virtual cross-section bearing capacity on extremity of frame beam in reinforced concrete，which is affected by some element，such as slab reinforcement，the rigidity of orthogonal beam and so on．Exploring the mechanism of slab and frame work together to determine the width of effective flange，which provides references for structural design and engineering application．

Based on the analysis of the mathematical model of the three-phase asynchronous motor and sine pulse width modulation principle, According to the theory of asynchronous motors vector control , software is building simulation model of asynchronous motors vector control system according to the rotor flux in Matlab/Simulink, analysis dynamic characteristics of rotational speed, torque and stator current ,provided the simulation results of the control system, verify the vector control is effective and feasible.

Polynomial method in digital image geometric correction of a wide range of applications, this correction method does not consider the image spatial geometric process, but directly to the image itself is simulated, in order to achieve correction purposes, has simple and flexible features such as. This paper expounds the polynomial correction method, and combining with the features of MATLAB, designed and developed the digital image correction program. In order to verify the accuracy of the program to program, a series of image was corrected from experiment, result analysis, program design thinking is correct.

The corrosion behavior of 316L stainless steel and alloy 625 were deteced in superciritical water oxidation (SCWO) process for coking wastewater treatment. The operation conditions were 500 °C, 25 MPa, oxygen ratio of 3.5 and the reaction time of 150 h. Surface morphologies of metal samples, oxide structure and compositions across the oxide thickness of the metal samples after SCWO were analyzed using SEM and ESD, and the corrosion rates for both samples were obtained. Pitting corrosion was found on the surface of 316L stainless steel with a corrosion rate of 0.334 mm/a. While no remarkable corrosion was found on the surface of alloy 625, and the corrosion rate is 0.052 mm/a.

The microstructure of magnesium alloy sheets (nominal composition Mg–6Zn–Y in at. %) was investigated with the Optical Microscope (OM), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) technique after the annealing treatment. Tensile test at room temperature was performed to show the influence of annealing treatment on mechanical properties. Experimental results indicate that there are a large number of twin crystals appearing in microstructure of the extruded Mg-Zn-Y alloy sheet at 350 °C. The distinct icosahedral phase appears on the α-Mg matrix in granular form and the strength gets largely improved to the maximum. The uniform distribution of isometric crystal contributes to the best elongation at the annealing temperature of 400 °C.

The paper introduces the importance of stability and current reseach status on prestressed concrete cable-beam structure system.It demonstrates the basic relative theory on stability in concretely research and applies this theory into the prestressed concrete cable-beam structure system,the formula of stability on this system is come true to make the analyze prestressed concrete cable-beam structure system precisely.

Put building information modeling concept into the historic building restoration field. Restoration by "layer" sequence as the object of building base portion, main structure, electrical and plumbing pipes and building surface information, greatly expand the historic building data information. Through the project practice of digital restoration, we establish a good connection with historical building research and architectural design teaching, and the most important harvest is that it provides a feasible implementation measures for the historic building protection problem in the process of the city industrial structure adjustment, and builds a general platform at the same time.

Escherichia coli and Bacillus subtilis as objects of the study, ultrasonic fragmentation acted on the bacterial cells in different growth stages, results showed that, it’s similar to the crushing effect of ultrasound on E. coli and B. subtilis cells of different growth stages, the highest crushing rate in the logarithmic phase, reached to 95.8% and 94.3% respectively, the crushing rate of adjustment phase is lowest, maintained at around 60%, the crushing rate stability cell was centered, which can be achieved 90%. The structure of the bacterial cell wall didn’t the main factor to decide the ultrasonic fragmentation effect, but different growth periods of bacterial cells did the determinant.

In order to predict the result of impact test in the design phase and reduce the experimental times, which can save cost and shorten development cycle, a finite element model of aluminum alloy wheel 13-degree impact test is established based on Abaqus. All mechanical parts such as the standard impact block, the assembly of the wheel and the tire, the support and bolts are included in the finite element model. The predicted result of finite element analysis and the experimental result agree very well shows the finite element model is correct. The equivalent plastic strain value was also put forward as fracture criterion for the wheel in the impact test which realizes the transition from the qualitative analysis to the quantitative analysis in the development process of aluminum alloy wheel.

The article presents the method of research, introduces the relative theory, researches the force statement of prestressed concrete cable-beam structure system by the method of model test. The results of test and theory is consistent. Prestressed concrete cable-beam structure systems has lots of advantages than ordinary reinforced concrete, such as high bearing capability, less cost, less weight, the longer span and shorter construction period. It is easy to put into practice and has significant prospect.

The postgraduate education is the top education in our country. To cultivate the innovative postgraduates is the responsibility and mission that the time entrust the university and the postgraduate supervisors. The postgraduates’ innovative quality education has been a hot topic that attracts general attention from both the society and the higher education society. Building an innovation-oriented country lies in the talent, particularly in the innovative scientific and technological talents. With the arrival of the knowledge economy era, postgraduate education in our country is facing a new historical opportunity for development. Postgraduates is the most active force among higher institutions, and the main group in building an innovation-oriented nation, and their ability to innovate has a direct impact on the country’s overall innovation ability.

Ventilation is important for controlling the airborne transmission of infectious respiratory diseases, particularly in crowed and enclosed spaces, where exist higher risks of cross-infection. This paper studies the spatial concentration distribution and particle tracks of students talking continuously in a classroom with two air distribution methods, including mixing ventilation (MV) and displacement ventilation (DV) using CFD simulations. The classroom is occupied by 10 students with a seating arrangement of 5 rows and 2 columns. The objective of this study is to find out which ventilation mode is more effective in removing respiratory aerosols. The simulation results indicated that the displacement ventilation with the low air supply velocity magnitude and low turbulence could remove the respiratory aerosol droplets and minimize the risk of infectious effectively compared with mixing ventilation.

The article analyzes the prestressed concrete cable-beam structure system when it is on the condition of sigle span and sigle direction.The paper summaries the application of cale and presents the design ideas of cable,arranges reasonably the shape of cable,deduces the equation of cable when it is under the condition of curve,and gets the conclusion. The height of the middle bar decides the height of the cable-beam,so it limits the ratio of sag and span to make the reasonable design in the paper and to embody the superiority of prestressed concrete cable-beam structure system.

A brief review on the respiratory aerosols transportation in ventilated built environment using CFD method was carried. Performs in-depth literature study about room model, manikin, respiratory aerosols, ventilation type and aerosol particulate matter model. Based on this study, summarizes the research status in quo and the main problem existed at home and abroad. The results showed that (1) recent studies mainly concerned on specific environment such as treatment room, aircraft cabin mock-up, office room, bus and high-speed rail cabin and based on the specific environment to simulate, (2) some studies put emphases only on droplet or droplet nuclei, and at the same time, evaporation, deposition and coagulation were neglected sometimes, (3) there were lack of studies on moving manikins (4) there was no finial conclusion about which ventilation pattern was better for reducing the risk of cross-infection from airborne transmission diseases in a certain place, (5) to choose the Lagrangian method or the Eulerian method for a certain problem generally depends on the subjects, targets, and the computer resources available.

It introduces the current research status about prestressed concrete cable-beam structure system at home and abroad, and anylyzes the phase of elasticity-plasticity by the FEM software.In this paper ,it builds the geometric models of slabs in different thickness and gets all kinds of results.It compares the results of different slabs and gets the conclusion that the working mechanism of beam changes with the quantity adding of cable.

Graphene-modified glassy carbon electrode was made by dropping. In phosphate-citric acid buffered saline, the modified electrode was shown to possess an excellent selective electrocatalytical effect on the redox of catechol, and further used to determine catechol in the presence of resorcin and hydroquinone by cyclic voltammetry. The oxidation peak currents Ipa showed a linear relationship with the concentrations (c) of catechol in the range of 2.97×10-7 mol•L-1~9.31×10-6 mol•L-1 and 9.31×10-6 mol•L-1~1.03×10-4 mol•L-1 with a correlation coefficient as follows: Ipa1(A)= -4.10×10-6-2.31c, R=0.Superscript text9971; Ipa2 (A) =-1.50×10-5-0.60c, R=0.9953, respectively, and the detection limit is 2.50×10-8 mol•L-1. The modified electrode is high sensitivity, selectivity, stability, and has been successfulSuperscript textly applied to analyzing catechol in wastewater.

With the development of the pioneering deployments in multi-hop wireless networks, although the relative research have not proven successful. The performance of routing and transport is often unstable due to contention induced packet losses, especially when the network is large and the offered load is high. A reliable wireless network architecture by using distributed control for large-scale multi-hop wireless networks has been present in this paper, The design objective is to optimize the control performance. This control performance is a complex function of the network parameters, such as throughput, packet delay and packet loss probabilities. The goal of optimizing the control performance imposes implicit tradeoffs on the wireless network design as opposed to the explicit tradeoffs typical in wireless data and voice applications. Our analysis suggests that our approach will deliver improved service to users while greatly reducing support effort and cost.

In underwater acoustic signal processing, flank enlarges the apertures of array and establishes a better foundation in weak signal detection; it includes two steps that are the processing in space domain and detection in time domain. Optimal detection is the basis of system design and can approximate the up limit performance of real ones. This paper presented an optimal detection method and derived its test statistics; in space domain, the maximum output SNR criterion is used and implemented by spatial whitening and match processing, in which the spatial difference between target signal and noise are utilized fully; in time domain, based on the N-P criteria, after the noise whitening and Wiener filter the output energy is then calculated, where the differences in spectral shape and spectral level between signal and noise are fully taken into account.

This paper introduces the research status of bearing capacity of ashes foundation,presents the purpose of bearing capacity ashes foundation,and shows the research content and may encounter difficulties. The study on bearing capacity of ashes foundation will change the history that the ashes can't be directly used as the foundation, which finds the cheaper the foundation material for some area, and saves a lot of money. The study also can solve the problems of housing which has been built to provide references for the study of civil engineers.