Search

Visual and quantitative evaluation of the mitral valve is an important step in the clinicalworkflow according to experts as knowledge about mitral dynamics is crucial for interventionalplanning. We consider dynamic modeling of mitral valve annulus and leaflet coaptation by cubicB-splines, and the error of every tagging point is measured to the fitted curve to decide whether asecond round fitting is needed. After modeling, four clinically important points are identified. Thismodeling and identification are significantly important for further diagnosis and evaluation of thedynamic deformation of the mitral valve apparatus.

In this paper a series of research is done on an AC chopping voltage controller which is based on DSP. And the control principle is analyzed and the control circuit based on TMS320F2812 is designed. And then the details of the power supply is presented, such as the topology structure, the working principles of the main loop and the design of the hardware control system . The power supply herein has the merits of wide range regulation of voltage, high power-factor, the ease of harmonic filtering and so on. The effectiveness and validity of the design is certified by the experimental results.

The research of diagnosis and treatment system of child mental health disorders is based on artificial neural network and expert system. It combines the diagnosis standard of ICD 10, DSM IV with 40 years clinical experiences and knowledge of senior child psychiatrists. It also combines computer science with child psychiatry, child psychology, psychological estimate, psychological therapy and so on. The learning samples come from the epidemiological data in more than a dozen nationwide hospitals. The correct rate of system diagnosis is 99%. The system can diagnose 61 kinds of child mental health disorders and give a treatment method suggestion.

The multi-hazard, wide-covered, complex factors during the large complex underground construction process pose severe challenges to the construction project. With the help of successful forecast cases, typical geological interpretation signs, optimization of combination forecasting scheme, comprehensive geological forecast system is constructed to effectively solve the disadvantage of multiple solutions coming out from the single geophysical methods, and greatly improve the accuracy of forecast of adverse geological conditions, thus ,the target of safety, economical operation and efficiency is achieved.

A sensitive cataluminescence-based detecting technology using nanosized Mo4V6Ti10O47 as a probe was proposed for determination of formaldehyde in air. Trace formaldehyde was firstly absorbed on active carbon at room temperature to concentrate, then desorbed at 75°C to determine. The method showed high selectivity to formaldehyde at wavelength of 575nm, satisfying activity at temperature of 260°C and good stability at carrier flow rate of 145 ml/min. The linear range of CTL intensity versus concentration of formaldehyde was 0.04~78 mg/m3, and the detection limit (3σ) was 0.02 mg/m3. The recovery of artificial sample was 96.8%-103.4% by this method. There was no response to CO, CO2, SO2, NH3, methanol, ethanol, benzene, toluene and xylenes.

AH Wilson coal pillar was used widely as it’s simply, but it’s appeared large error for field implementation as its difference assume conditions, mine depth H and mine thickness m. AH Wilson coal pillar formula was studied precisely by in-site stresses test and numerical simulation analysis for N3-5 top coal caving working face of CHANGCUN coal mine in Lu’an coal district of China, then modified AH Wilson formula was put forward as L = 0.008mH + 8.4,then the precise coal pillar size 18m was used in filed implementation, filed testing proved coal pillar size was reasonable.

By using the explicit nonlinear dynamic analysis program of LS-DYNA, three-dimension finite element model of rock breaking by disc cutter of tunnel boring machine is established, in which elastic material is adopted to describe the elastic behavior of cutter ring and Holmguist Johnson Concrete (HJC) model is adopted to describe the brittle behavior of rock. With the finite element method, the process of rock breaking by disc cutter is simulated, and then the movement characteristics, forces of disc cutter and rock fragmentation mechanism are analyzed. The results indicate that the numerical technique can contribute to gaining an understanding of rock breaking mechanism by disc cutter and improving the design of disc cutter parameters.

A vegetable greenhouse temperature detection and control system is described in this paper. The system is based STC89C52 microcontroller, using DS18B20 temperature sensor to detect real-time temperature, and using fuzzy control algorithm to control greenhouse temperature. Experimental results show that the system is cost-effective, long life and high degree of intelligence, has some practical value.

Randomness is an accidental, an event with a probability demonstrated uncertainty. We know CPM method does not consider the resource constraints. This deficiency can be solved by the critical chain technology. We can get more than a critical chain. In order to solve this problem, We can use the optimal method of stochastic process to schedule critical chain.

In order to raise the level of management in building construction cost, knowledge management approach is proposed in this paper. An XML (Extensible Markup Language)-based paradigm matrix is established to represent construction cost control knowledge. In the matrix, the row elements are made up of feature attributes, and construction working procedures are the components of the column. Furthermore, based on the Hamming weighted proximity, the closeness between new construction projects and target case is calculated such that the similarity is obtained, by this method the knowledge matching is achieved. These methods remedy non-standardized description of the construction cost control knowledge and inefficient retrieval of the construction cost control cases, which offers a basis for knowledge management in construction cost control.

Time-delay is a key factor that affects system performance in temperature control of boiler combustion system. It leads to slow response speed and low accuracy. A compound control strategy with the combination of Smith control, fuzzy control and adaptive control is proposed to deal with this problem. An adaptive mechanism is designed and integrated with Fuzzy-Smith control to improve control performance of boiler combustion system. With the online adjustment of scaling factors of quantization factors and proportion factor of fuzzy controller, quantization factors and proportion factor are changed indirectly. With the designed Adaptive-Fuzzy-Smith Algorithm, the effect of mechanical property, time-delay, is well compensated. MATLAB simulation results show that response speed and system accuracy are improved greatly and effectively.

In order to achieve the quantitative health diagnosis of operational tunnel, established the health diagnosis system and the evaluating criterion based on the mechanism of tunnel disease, used the weighted average operator to obtain comprehensive evaluation results, applied the asymmetric proximity to decide the grade of tunnel structure health, thus build a complete fuzzy comprehensive evaluation model. Finally, by taking the example of Lilong tunnel located at LiuHe Express way, and made analysis and evaluation to its structure health status. The results show that the improved grey relevancy method to determine the index weight can avoid the subjective arbitrariness and improve the reliability of the evaluation model, making a decision and analysis by asymmetric proximity insures the diagnosis results more correspond with the objective reality.

Magnetron power supply is one of the most important components in coating devices in applied technology. Magnetron regulated power supply with high power and high efficiency is studied and designed on the basis of high-frequency switching power supply technology. The principle of the main circuit and control circuit design are introduced. A MATLAB simulating model is composed to study parameters and waveforms of the designed circuits. The hardware circuit and software program are designed based on simulation results. The adjustment and display of the output voltage and the output current of the power supply under different work modes are achieved with TMS320F2812 DSP system. Practical applications confirm that the designed power supply has good constant current control effect, high reliability and working stability.

Aircraft training simulator has integrated combat training ability not only needs to simulate the aircraft flight and radar, inertial navigation and avionics equipment, but also to generate realistic battlefield environment and visual effects, and to simulate the interaction between the system and the complex interaction. In the realization of the simulator, using HLA/RTI as its architecture and the supporting platform, make the device emulator is to achieve interoperability, can improve the system's flexibility and scalability. [ The target and the electromagnetic reflection characteristics of ground data and radar detection model based on the dynamic radar image generation. The blackboard model is based on the virtual machine technology, which is easy to modify and evolution of CGF system. [Combat aircraft is the main weapon platform in modern war, and aircrew training level is an important factor which affects the combat effectiveness of an aircraft. Research on the domestic and abroad aircrew training methods and training methods with simulate system, develops advanced technology, which can achieve close to actual combat to training effect and save a lot of training funds.

Due to the diversity of the situation information collected in the battlefield, and the conventional way of plotting runs with low efficiency and slow speed. This paper bring forward a new method of battlefield situation collaborative plotting based on ontology, which improves the integration plotting efficiency by formulating the local ontology construction. And based on the local ontology character constructed, solved the semantic mapping problem in the process of rapid ontology integration with a new similarity calculation algorithm.In the end this paper design a battlefield situation collaborative plotting prototype system based on client-server mode consequently.

A model of ion energy distribution of dual frequencies capacitively coupled plasma (CCP) has been investigated, it is important to analyze these phenomenon and mechanism in order to control the microelectronic processes of integrated circuit and develop the base theories of plasma physics. We focused on the function of the ion energy distributions under high and low frequencies (dual frequencies) drive in capacitive discharges, we derived a theory model of the dual frequencies driven IEDs from analyzing theories. The model can analyze and predict the IEDs under different high and low frequencies driven, which results in accurate multi-peaks IEDs and energy width for the given control parameters, particle-in-cell (PIC) simulations are used to verify this model.

The traditional method of project cost control management by objectives based, is a passive expost control, and system dynamics model through the establishment of a strategiclevel description of the project, emphasizing the active control of project costs, focused on the complexity of factors that are difficult to accurately quantify analysis is an important complement to traditional methods. Construction phase of the project cost control of construction project management is one of the main construction phase of the construction project in accordance with established cost control feedback effect diagram, analyze the main factors affecting cost control, qualitative analysis of the impact of the construction phase of the project cost control various factors and cost control effect brought. Proven system dynamics approach applied in the construction phase of the project feasibility.

Most countries and companies begin to develop Li-ion power battery because of the serious pollution of lead-acid battery and nickel-cadmium battery. As the main component of the Li-ion power battery, the electrode has a great influence on performance of the battery. Most manufacturers take the method of traditional manual inspection which has many disadvantages, such as low efficiency and bad work condition, and is vulnerable to subjective factors. The paper designs an automatic production line of the defects inspection of electrode, in which machine vision is used to inspect the defects of the electrode, PLC to control, and speed chain to convey the electrode. The combination of static loading electrode and dynamic inspection is chosen to control the line. The design can improve the efficiency siginificiantly.

The coating and drying process of Li-ion power battery plays an important role in performance of battery. Its drying system is composed of an air inlet and return pipe, heat exchanger, air nozzle and so on. The air nozzle is a key component of drying system. Whether its design is reasonable or not, it will directly affect the distribution of the velocity, pressure and other factors in the dryer. In this paper, the simulation research of the key parameters of slit air nozzle on the coating and drying of Li-ion power battery will be achieved by using fluid simulation software. And then we determine the slit width of the air nozzle with 3mm, slit angle of air nozzle with 60° on the basis of the simulation results.

Aimed at seeking a optimal task space where robot’s flexibility is better than other task space in the whole workspace, then analyzed robot flexibility indexes which domestic and foreign scholars had described, analyzed k(J)、w andσr comprehensively in task space, proved the rationality of k(J) as the flexibility index and proposed a new method which combining the global performance index η with the minimum flexibility index Dmin(D=1/k(J))to evaluate the flexibility in task space, then proved the method effectively by genetic algorithm . It has a practical significance for solving the problem of optimal task space in robot work space.

Based on the tested data, the ANSYS finite element analysis software was adopted to establish the finite element model for the concrete beam nonlinear analysis.The finite element models were developed using 3-D solid element for concrete and shell element for the Carbon Fiber Reinforced Ploymer (CFRP) sheet. The results obtained from the ANSYS were compared with the experimental data for two strengthened beams with different thickness CFRP sheet. The comparisons were made for the curves of load-midspan deflection, yielding load and ultimate load. Models were calculated at the same condition as the experimental beams. Two reinforced beams strengthened with CFRP sheet were calculated in four-point bending. The load-deflection curves from the finite element analysis agree well with the experimental results. The average difference in ultimate load for two cases is 5.5%.

Non-convergence often occurs in the solution of highly nonlinear problem by conventional implicit finite element method. As another choice, explicit method is sometimes used by researchers. Through 2 typical static and dynamic examples this paper verifies that explicit finite element method can provide the same exactness of calculation as the implicit method even in the situation that the duration of action exceeds the natural period of structure greatly. At the same time, compared with implicit method, explicit method possesses higher speed, more robust algorithm, and stronger nonlinear capability, so that explicit method can be applied in static and dynamic analysis of structures, especially in large deformation and highly nonlinear problem.

In this paper, we present a compact high-efficiency multi-band micro strip antenna for the mobile devices. At the same time, because most of antennas are located near the ground planar, the proposed antenna is designed with a ground planar. The antenna occupies a small size of 100*60mm2 and operates in CDMA(824-894MHz),GSM(880-960MHz), DCS(1710-1880),PCS(1850-1990),UMTS(1920-2170) and 3G band. By using a long slot, two trapezoid slots and a short slot, a triple resonance around 900MHz and another wideband resonance around 2100MHz can be created, respectively. Details of the antenna design are described , and its radiation performances results are presented and discussed. Keywords-Multi-band antenna;; mobile communication devices; hige-efficency

The present study investigates the preparation of sustained release drug-loaded nanofibers using a modified coaxial electrospinning process where only solvent is exploited as sheath fluid. Drug-loaded ethyl cellulose (EC) nanofibers are successfully generated smoothly and continuously without any clogging through the coaxial process, in which ethanol is used as sheath fluid and EC and ketoprofen (KET) are taken as the filament-forming matrix and active pharmaceutical ingredient, respectively. Field-emission scanning electron microscopic observations demonstrated that the nanofibers diameter can be manipulated through the sheath fluid flow rate. The composite nanofibers are in essential a molecular solid dispersion of EC and KET based on the hydrogen bonding between them, as verified by XRD and ATR-FTIR results. In vitro dissolution tests show that KET in the nanofibers has a fine sustained release profile via a typical Fickian diffusion mechanism. The modified coaxial electrospinning with solvent as sheath fluid can be a useful tool for developing novel sustained release drug delivery nanofibers.

Vacuum heat treatment furnace temperature parameter is a large time delay, nonlinear,time-varying and complex control objects, Single-chip computer is used as the control core to achieve the temperature control through the fuzzy control algorithm, the hardware structure an software design process are given in this paper, the control precision, dynamic characteristics, and optimization of the performance are improved by this control system.

Li-ion power battery has many advantages, such as high energy, lightweight, long cycle life and so on. It has become a research hotspot in the new energy field. This paper describes the Li-ion power battery coating and drying process which has a significant effect on the performance of Li-ion power battery. According to the market research and business requirements, the project decides to apply heated-wind circulating and shock drying method to dry of the Li-ion power battery electrode. The method has been successfully applied to the production, which has achieved excellent results in energy saving and improving enterprise efficiency.

The serious pollution of lead-acid battery and nickel-cadmium battery prompts the Li-ion power battery to become the new alternative battery. As the main body of the Li-ion power battery, the electrode has a great influence on performance of the battery. Thus it is necessary to classify, analyze and research the defects of the battery electrode precisely. Combining with the practical situation of production, in this paper the characteristics of the electrode defects of Li-ion Power battery are described in detail and morphological characteristics are analyzed, which is helpful to the subsequent image processing and the production practice.

Time Petri net is a model method which describes the dynamic behavior of the system by the moving of token. This paper takes location of a nursing home in Xi’an as the research object. The best position is selected by building dynamic models with time Petri net, and solving the model with Ant Colony algorithm, based on considering some factors such as public transport, health and environment. Finally, the effectiveness of the method on the selecting of location is confirmed by empirical analysis.

The indirect air-cooling system is usually optimized for minimum annual cost. Domestic designing departments take different views on incremental power generation method and coal consumption method in calculation of operating cost. This paper analyzed the two different methods by using the optimization software of indirect air-cooling system, and modified the main parameters of indirect air-cooling system in practical engineering. In this paper, annual cost is in 10 thousand Yuan.

The migration behavior of UV ink photoinitiators from the substance of the food packaging to the food is simulated by photoinitiator spectrometry analysis. The different food simulants 10% ethanol, 95% ethanol and 97% isooctane migration behavior of the photoinitiators 1-Hydroxycyclohexyl phenyl ketone (184) are simulated on the polyethylene (PE) coated paper 4018,4025 and 4918 PE coated layer at different temperatures of 30°C, 45°C and 60°C. The qualitative and quantitative analysis is done using infrared spectroscopy and ultraviolet spectrophotometry. It is discussed that the effect of the temperature, swelling, PE lamination layer thickness as well as the paper thickness of pollutants by the different thickness of the polymer coating on the migration to food simulants.

A cataluminescence (CTL)-based gas sensor utilizing nano-sized Mn1.5Zr2O7 as the sensing material for the determination of hydrogen sulfide in air was proposed. The gas sensor showed high selectivity for hydrogen sulfide at 450 nm and satisfying activity at 320°C. The linear range of the CTL intensity versus concentration of hydrogen sulfide was 2~95 mg/m3, and the detection limit (3σ) was 1.5 mg/m3. No interference was observed while the foreign substances, such as formaldehyde, ammonia, ethanol, benzene, carbon monoxide and sulfur dioxide, were passing through the sensor. The gas sensor displayed good stability for continuously introducing hydrogen sulfide over 60 h, and allowed real-time monitoring of hydrogen sulfide in air.

By using the computational fluid dynamics code, FLUENT, Numerically simulation is investigated for Youngshou power plant. Under the constant ambient temperature, the effects of different wind speed and wind direction on the thermal flow field are qualitatively considered. It was found that when considering about the existing and normally operating power plants, the thermal flow field is more sensitive to wind direction and wind speed. Based on the above results, three improved measures such as: increasing the wind-wall height and accelerating the rotational speed of the fans near the edge of the ACC platform and lengthen or widen the platform are developed to effectively improving the thermal flow field, and enhanced the heat dispersal of ACC.

A highly sensitive, simple and selective gas sensor was developed for the determination of trace acetaldehyde in air based on cataluminescence (CTL) on nano-sized Al2Ti2O7. The gas sensor showed high selectivity for acetaldehyde at 515 nm and satisfying activity at 295°C. The linear range of the CTL intensity versus concentration of acetaldehyde was 1~65 mg/m3, and the detection limit (3σ) was 0.5 mg/m3. No interference was observed while the foreign substances, such as ammonia, ethanol, formaldehyde, benzene, carbon monoxide and sulfur dioxide, were passing through the sensor. The gas sensor displayed good stability for continuously introducing 10 mg/m3 acetaldehyde over 60 h, and allowed real-time monitoring of acetaldehyde in air.

Besides the performances of handling, stability, ride comfort, power and fuel economy, the sound pressure levels in the automobile passenger compartments heavily influence the customer’s purchasing decision. The interior acoustics of automobile passenger compartment was analyzed in this paper. The frequency response analysis was performed on the vehicle body due to road roughness. The frequency response of vehicle body’s output spectrum, nodes’ velocity is used as the boundary condition of the acoustic cavity. With boundary element method and acoustic transfer vector method, the panel acoustic contribution was analyzed. By modifying the stiffness, damping or mass of the corresponding panel, the acoustic pressure levels at the driver’s and passenger’s ear were decreased.

In many cases, pouring concrete automatically instead of manually will lessen the operator’s labor intensity and increase productivity dramatically. An automatic pouring system was schemed in this paper, as well as the planning of pouring trajectory. A simulation model was built based on virtual prototyping, and the impact of new automatic pouring system on the boom system was verified with the co-simulation method. Since the complexity of the work environment, the obstacle avoidance of boom system was analyzed and planned. A 3D program based on virtual reality technology was built to simulate the automatic pouring process.

The author established the mathematical model of single-phase flow of gas based on the k-ε two-equation model and numerically simulated the eddy air-curtain dust controlled flow field in hard rock mechanized driving face with the help of FLUENT software.The result showed that, after all the pressure ventilation blown out by the radial clearance of mural cylinder, a full-face eddy air-curtain flow field is formed at the roadway section, forming the air-curtain dust controlled flow field that presses the tunneling place equally in front of the driver of roadheader. After the application of the development of new light polymer materials radial cylinder eddy air-curtain dust controlled system was adopted in hard rock mechanized driving face of north conveyor main roadway, reducing the local dust concentration effectively.

The system of a simply continuous beam was looked on as one span beam with several internal elastic supports of inexhaustible stiffness. There were two types of models such as the dynamic models by a moving concentrated force and by a moving mass. A three-span beam was introduced as example solved with the present model by a moving concentrated force and FEM, which verified that the present model was correct. Two cases of the example bridge by a moving concentrated force and by a moving mass were considered. The results indicate that mass of the moving load has little influence over the dynamic responses of the simply continuous beam bridge.

In order to remove the hidden danger resulted by distortion of weak surrounding rock in tunnel, the GM(1,1) of the distortion data of weak surrounding rock is used to predict the distortion trend of weak rock vault in the next phase. According to the actual data, a GM(1,1) of the distortion is built, and it is shown that the predict result of GM(1, 1) is accurate, and the calamity can be reduced by the way.

The second development of Duncan-Chang － model suitable for geomaterials widely used home and abroad is made in ADINA with FORTRAN. The applicability of User-Defined Materials in ADINA is proved by engineering case.

Objective：The aim of the study was to explore most effective way to control infection during implant treatment. Methods: The study was carried out in two implant operating surgeries (Surgery A, Surgery B), which were set up air disinfectant machine and ultraviolet disinfection respectively. For baseline measurements, the number of bacterials in the air of the two surgeries was counted at 5min, 15min, 30min, 45min and 60min before sanitizing. To compare sanitizing effect of static air disinfection, air samples from these surgeries were collected for bacterial cultivation after sanitizing for 5min, 15min, 30min, 45min and 60min, and the the sterilization rate was calculated. To compare dynamic air disinfection, the two surgeries were sterilized before implant surgery, and the air samples were collected at 5min, 15min, 30min, 45min, 60min after implant operation. Results: There were no significant differences between air disinfectant machine and ultraviolet disinfection in static air disinfection (p

An optimal guidance law for interception of ballistic missile during the boost phase is presented in this paper. The kinematics characteristics of tactical missile during its boost phase are analyzed firstly. Then based on the kinematics given and assumption, the relative kinematics equations between target and missile are established. Optimal guidance law via LQ optimization is derived under the specified cost function. The time-to-go estimation method is also given in the paper. In the end of this paper, simulation is executed and the results validate that the deduced guidance law satisfy the direct hit index.

An enterprise should establish an emergency management mechanism that includes accident warning mechanism and fast reaction mechanism. Accident warning mechanism can let the enterprise do predictive analysis and judgment and make reasonable strategies and suggestions. Fast reaction mechanism can help the enterprise make correct decisions in a short time and improve efficiency and effectiveness of emergency management. Rules and regulations are necessary to ensure smooth implementation of accident warning mechanism and fast reaction mechanism.

The paper presents a vehicle dynamics control strategy devoted to prevent vehicles from spinning and drifting out. With vehicle dynamics control system, counter braking are applied at individual wheels as needed to generate an additional yaw moment until steering control and vehicle stability were regained. The Linear Quadratic Regulator (LQR) theory was designed to produce demanded yaw moment according to the error between the measured yaw rate and desired yaw rate. The results indicate the proposed system can significantly improve vehicle stability for active safety.

Rollover and jack-knifing of tractor semitrailer on high speed obstacle avoidance under emergency are serious threats for motorists. A tractor semitrailer model was built with multi-rigid-body method in this paper. The steering performance of tractor semitrailer has been analyzed, as well as the stability control theory, including yaw rate following, anti-rollover. The dynamics simulation for yaw rate following and anti-rollover has been performed on the dynamic tractor semitrailer. The results show that the vehicle dynamics control proposed in this paper can stabilize the tractor semitrailer, rollover and jack-knifing are prevented and the tractor semitrailer more accurately follows the driver's desired path.

A there-dimensional finite element model of the working device of a single backhoe-bucket hydraulic excavator was developed to analyze and evaluate the rationality of structure design of the working device in this study. By finite element modal analysis, the resonant frequencies and vibration modes of the working device system were obtained. By dynamic response analysis, the changing trends of stress and strain of the device were obtained. In addition, the influence of different excavating resistance forces to the working device on dynamic response of the device system was compared for large and small resistance forces at the beginning excavation moment. The results show that a large resistance force at the initial excavating moment may result in the device vibrating with large vibration amplitude at the beginning excavation moment. These results might provide useful reference on design improvement of the excavator working device.