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Objective: Current balance training systems are designed exclusively for one particular type of training and assessment. Additionally, they comprise monotonous training programs. Therefore, patients in different stages of rehabilitation must use different balance training models from different manufacturers, resulting in high treatment cost. Furthermore, large spaces are required to accommodate the balance training machines, and doctors and physiotherapists have to learn to operate multiple machines. We aimed to design a multimodal balance training and assessment system that can accommodate the assessment and training of static, dynamic, reactive and proactive balance to satisfy individual needs. Methods: The difficulty associated with combining static, dynamic, reactive and proactive balance training in a single system was to use radial and circumferential driving mechanisms together with a clutch mechanism, whereby circumferential and radial drivers were installed in the base of the system to drive a compound foot plate system with interchangeable springs, in order to adjust stiffness using the clutch. Based on the kinematic equation, the influence of system parameters on the change of the body’s center of gravity were evaluated. The parameters included the radial offset of the driving mechanism (r), circumferential angle of rotation (θ), height of the base of the balance training system (h), horizontal distance between the body’s standing center of gravity and the center of the foot plate (R), thickness of the padding mat (ΔH) and inclination angle (α). Results: The difficulties associated with combining static, dynamic, reactive and proactive balance training models in a single system were solved using radial and circumferential driving mechanisms together with a clutch mechanism. The foot plate can swing back and forth within ±20° around the X-axis, swing left and right within ±20° around the Y-axis, swing diagonally within ±20°, swing 360° around the Z-axis, and adjust the height along the Z-axis. Furthermore, the inclination angle α, circumferential angle of rotation θ, and speed (dα/dt and dθ/dt) of the system can be controlled in real time. Conclusion: The developed balance training system is suitable for patients in different stages of rehabilitation. By providing multiple functionalities, this system can ensure high use rates, reduce costs and save space.

At present, the effect of different development patterns of interlayer like the length and the longitudinal position of interlayer on thermal recovery modes such as steam stimulation (CSS) and steam flooding (SF) is still a qualitative understanding, and there is no systematic study yet. Therefore, it is difficult to control the thermal production of thick oil reservoirs according to different interlayer patterns. In order to quantitatively analyze the influence of interlayer distribution pattern on steam huff and puff and steam flooding of horizontal wells in thick heavy oil reservoir, a numerical simulation model was established based on typical parameters of LD21 heavy oil reservoir in Bohai in China. Through comparison and research on the different modes of development longitudinal position, development length and development scale in non-permeable interlayer and semi-permeable interlayer. The influence of interlayer on the expansion law of steam chamber and ultimate oil recovery degree during steam huff and puff and steam flooding, and the main controlling factors of interlayer influencing oil recovery were obtained. The research results can be used for reference to optimize the location of thermal wells in thick heavy oil reservoir and reduce the influence of interlayer on thermal production effect of horizontal wells. Key words: Heavy oil reservoir; interlayer; steam huff and puff; steam flooding; recovery.

During the construction stage of the steel-concrete composite box girder, the steel tub-girder has to support its weight, the self-weight of the wet concrete, and other construction loads. To improve the torsional stiffness of the steel tub-girder, the top flange bracing is often used to connect the top flanges to make “semi-closed” cross sections. The steel tub-girder with top flange bracing can form a closed shear flow under torsion, and thereby causing the distortion effect. However, the distortional behavior of this type of structure remains unclear. In this paper, the equivalent thickness of the fictitious top flange is first derived based on the restrained torsion theory. Subsequently, the errors of distortion loads given by the conventional load decomposition method which ignores the effect of warping restraint are derived, and are further verified by finite element analysis. It is demonstrated that the effect of warping restraint on the distortion is significant in the continuous tub-girder bridges with the top flange bracing. Therefore, the corresponding correction coefficients for the distortion loads caused by eccentric vertical loads and the girder axis curvature are proposed, and the simplified formulas for estimating these correction coefficients are established based on parametric analyses. Finally, the calculation method for the internal force of cross frames is modified and the accuracy of the proposed method is validated with results from finite element analysis.

The lateral restraint eccentricity and rotational restraint stiffness significantly influence the compressive membrane action (CMA) in reinforced concrete slabs. However, these two factors have rarely been studied and no analytical model considering them has been established. In addition, most analytical methods for evaluation of CMA were derived for slabs with constant thickness, even though slabs with variable depth are quite common in practice. Therefore, this paper develops analytical methods to predict the load capacities of laterally restrained slabs considering the effects of lateral restraint eccentricity, rotational restraint stiffness, and slab depth variation. Based on the compatibility conditions and equilibrium of forces, the axial forces and bending moments can be derived by solving equations as long as the deflection at the load application point is provided. Then the corresponding load can be determined and the load capacity of the slab can be obtained by iterative calculations. The proposed methods are then validated by comparing to finite element analysis and four groups of test results, in which the effects of lateral restraint eccentricity, rotational restraint stiffness, and slab depth variation are explicitly reflected. Finally, comprehensive parametric analyses are conducted by using the proposed models. The interaction effects of the design parameters on the CMA are revealed for slabs with strong and weak rotational restraints, respectively.

Establishing the evaluation index system, from their own investment capacity, corporate external financing capacity of the two dimensions, using resultant weights and TOPSIS method for comprehensive evaluation of investment capacity of the power enterprises. Set a power company for example, results show that, the evaluation results are in line with the actual investment capacity situation of the power enterprises, the established evaluation index system and evaluation model has better applicability.

In this work, 0.33BaTiO3-0.67BiFeO3 multiferroic ceramics doped with x mol% MnO2 (x= 0.1-1.0) were fabricated by solid-state reaction method, and their microstructure and dielectric property were also investigated. The perovskite phase structure of the solid solutions was confirmed by X-ray diffraction patterns, and the formation of minor impure phase of Bi2Fe4O9 was prevent effectively by Mn-doping. With increasing the Mn-doped concentration, the dielectric constants of Mn-doped 0.33BaTiO3-0.67BiFeO3 multiferroic ceramics first increased, and reached a maximum value of 340 (measured @1MHz) at the Mn-doped concentration of 0.60 mol%, and then decreased. On the other hand, the dielectric losses first decreased, and reached the minimum value at the Mn-doped concentration of 0.30 mol%, and then increased along with increasing the Mn-doped concentrations. The ferroelectric domain structures in the Mn-doped 0.33BaTiO3 - 0.67BiFeO3 multiferroic ceramics with rhombohedral symmetry were also revealed by TEM image and selected area electron diffraction patterns, and tweed-like domain structures were observed.

This paper considers nonlinear dynamics of tethered three-body formation system with their centre of mass staying on a circular orbit around the Earth, and applies the theory of space manifold dynamics to deal with the nonlinear dynamical behaviors of the equilibrium configurations of the system. Compared with the classical circular restricted three body system, sixteen equilibrium configurations are obtained globally from the geometry of pseudo-potential energy surface, four of which were omitted in the previous research. The periodic Lyapunov orbits and their invariant manifolds near the hyperbolic equilibria are presented, and an iteration procedure for identifying Lyapunov orbit is proposed based on the differential correction algorithm. The non-transversal intersections between invariant manifolds are addressed to generate homoclinic and heteroclinic trajectories between the Lyapunov orbits. (3,3)-and (2,1)-heteroclinic trajectories from the neighborhood of one collinear equilibrium to that of another one, and (3,6)- and (2,1)-homoclinic trajectories from and to the neighborhood of the same equilibrium, are obtained based on the Poincare mapping technique.

In allusion to the measurement and control system of the fracture traumatic cross-section stress, because of the manufacturing error and installation error of its mechanical components, the axial and radial force of the indicating value of the dynamometer exists at the same time, and the radial force will damage the fracture healing. According to the mechanical structure of the measurement and control system of fracture traumatic cross-section stress, analyzed the mechanics transmission, and established the mechanics transfer model of the stress measurement and control system. Based on the force method typical equations, acquired the unknown force and torque of the measurement and control system. Take the radial force of the indicating value of the fracture two-dimensional dynamometer into the mechanics transfer model expression, thus obtain the result of the fracture traumatic cross-section affected by the radial force that applied by the stress measurement and control system, and then adjust the size and direction of the radial force on the fracture trauma section applied by the stress measurement and control system, and reduce the negative effect of the radial force on fracture healing.

The dynamic characteristics of the NC machine are the important technical indicators of NC machine performance, and the precision of existing machine's dynamic characteristics evaluation analysis that based on structural dynamics modeling and simulation is poor. For this problem, this paper presents NC machine dynamic characteristics evaluation methods based on Grey Correlation Analysis. This method, by measuring the vibration signal of feature points in NC machine and making 1/3 octave spectrum analysis for vibration signal, can obtain the characteristics data sequence of vibration signal. Through the grey correlation analysis method, calculate the relevancy between the characteristics data sequence of each vibration signal and that of ideal dynamic characteristics, and quantitatively evaluate the dynamic characteristics of machine tools according to the size of the grey correlation. Took three same type NC milling machines as study objects, designed the cutting vibration resistance experiments, used this paper's method for the evaluation analysis of the comprehensive dynamic characteristics of NC milling machine, and obtained the evaluation results which is in line with the actual dynamic characteristics of machine tools, and verified the evaluation method of comprehensive dynamic characteristics that proposed in this paper.

The stress response of fracture trauma section has certain inertia and pure lag, conventional PID control can not obtain optimal stress control accuracy. In allusion to this problem, this paper proposes using fuzzy adaptive PID control, aims at the optimal physiological stimulation stress (Jorgensen curve) in the course of fracture healing, conducts real-time control to the fracture trauma section stress. According to the established fracture trauma system model, the fuzzy self-adaptive PID controller has been designed, and conducts simulation research on real-time stress control in the Matlab/Simulink simulation environment. The simulation results show that the stress control accuracy of fuzzy self-adaptive PID control is obviously better than that of the classical PID control and classical fuzzy control, which can effectively control the stress of trauma section in fracture healing, to promote bone repair and bone growth towards the optimal level, and then to ensure the speed and quality of fracture healing.

The radial basis function (RBF) neural network is superior to other neural network on the aspects of approximation ability, classification ability, learning speed and global optimization etc., it has been widely applied as feedforward networks, its performance critically rely on the choice of RBF centers of network hidden layer node. K-means clustering, as a commonly method used on determining RBF center, has low neural network generalization ability, due to its clustering results are not sensitive to initial conditions and ignoring the influence of dependent variable. In view of this problem, fuzzy clustering and grey relational clustering methods are proposed to substitute K-means clustering, RBF center is determined by the results of fuzzy clustering or grey relational clustering, and some researches of RBF neural networks modeling accuracy are done. Practical modeling cases demonstrate that the modeling accuracy of fuzzy clustering RBF neural networks and grey relational clustering RBF neural networks are significantly better than K-means clustering RBF neural networks, applying of fuzzy clustering or grey relational clustering to determine the basis function center of RBF neural networks hidden layer node is feasible and effective.

采用化学自组织方法在SrTiO 3 (100)及Nb-掺杂 SrTiO 3 (100) 单晶衬底上制备了外延BiFeO 3 纳米岛, 并利用X射线衍射、扫描电子显微镜和原子力显微镜对纳米岛的相结构及形貌进行了表征. 结果表明, 在650~800℃下后退火1h可获得外延的BiFeO 3 纳米岛, 岛横向尺寸在50~150 nm之间, 纵向尺寸在6~12 nm之间. 随着纳米岛后退火温度的升高, 其(100)面内的几何形貌由三角形状转向四边形状, 然后再趋向于长棒状. 利用压电力显微镜, 对单个BiFeO 3 纳米岛(横向尺寸~50 nm, 高度12 nm)的铁电特性进行表征. 结果表明, 单个外延BiFeO 3 纳米岛内存在分形铁电畴和自偏压极化现象, 其中自偏压极化现象来源于外延BiFeO 3 纳米岛与SrTiO 3 单晶衬底之间的界面应力.

Four rice samples of long grain type were tested using an electronic nose (Cyranose-320). Samples of 5 g of each variety of rice were placed individually in vials and were analyzed with the electronic nose unit consisting of 32 polymer sensors. The Cyranose-320 was able to differentiate between varieties of rice. The chemical composition of the rice odors for differentiating rice samples needs to be investigated. The optimum parameter settings should be considered during the Cyranose-320 training process especially for multiple samples, which are helpful for obtaining an accurate training model to improve identification capability. Further, it is necessary to investigate the E-nose sensor selection for obtaining better classification accuracy. A reduced number of sensors could potentially shorten the data processing time, and could be used to establish an application procedure and reduce the cost for a specific electronic nose. Further research is needed for developing analytical procedures that adapt the Cyranose-320 as a tool for testing rice quality.

BaTiO3 (BT) nanoparticles were prepared by the hydrothermal technique using different starting materials and the microstructure examined by XRD, SEM, TEM and HRTEM. X-ray diffraction and electron diffraction patterns showed that the nanoparticles were the cubic BaTiO3 phase. The BT nanoparticles prepared from the starting materials of as-prepared titanium hydroxide and barium hydroxide have spherical grain morphology, an average size of 65 nm and a fairly narrow size distribution. A uniform diffraction contrast across each single grain is observed in the TEM images, and the clear lattice fringes (with d110 = 0.28 nm) observed in HRTEM images reveal that well-crystallized BT nanoparticles are synthesized by the hydrothermal method. The edges of the particles are very smooth, with no surface steps. BT nanoparticles with average grain size of 90 nm, synthesized using barium hydroxide and titanium dioxide as the starting materials, show surface facets. In this case a bimodal size distribution of large faceted and smaller particles is observed. Diffraction contrast variation across the particles caused by high strains within the particles is clearly observed. The high strains obviously stem from structural defects formed during hydrothermal synthesis, presumable in the form of lattice OH− ions and their compensation by cation vacancies. HRTEM images demonstrate that surface facets parallel to the (100) and (110) planes and small islands with 3 ~ 4 atomic layer thickness are frequently observed around the edge of the particles.

We developed a method to facilitate measurements of aluminum (Al) positive lines in bone biopsies from patients with renal osteodystrophy by modifying solochrome azurine (SA) methods for tissue A1 staining so that background staining of calcium (Ca) deposits, soft tissues, and glycol methacrylate (GMA) did not interfere with gray level thresholding of Al-positive deposits in video images processed by a semiautomated image analysis system. Detailed studies of the SA staining characteristics at various pHs of each component in histologic sections and of the solubility of the resulting SA-complexes in aqueous and alcoholic solutions indicated that optimal staining of A1 deposits could be obtained by staining GMA embedded sections for 16 hr at pH 5. Subsequent destaining with deionized water, ethylenediaminetetraacetic acid (EDTA), and deionized water removed background staining without loss of A1 staining. Sections prepared by these methods were satisfactory for obtaining, enhancing, and measuring A...

This paper developed a three-step process of projection, characteristics, and knowledge for color object identification and moving object capture. Four factors of shape, color, size and knowledge have been considered in the process from the view of human vision system. A simulated experiment has shown how efficient and effective the proposed method is in which a color object had been identified and recognized in a complicated environment. A real visual servo control system has also been developed based on the proposed process. The experiment results have shown that the proposed method could efficiently realize the real-time color object recognition and capture.

Batch processes are usually complex and highly nonlinear systems. Modeling error can be the cause of bad performance when optimal input profiles computed for a particular model are applied to the actual plant. The approach followed in this paper uses the available model and actual plant measurements to modify the operation of the next batch, without requiring the remodeling the process. The effect of model error on the convergence of the iterative batch to batch input profile determination is investigated. The method is applied through computer simulations to the determination of the optimal feedrate profile for a cell mass production process. A model parameter update scheme is also proposed, based on the convergence analysis. This is applied to the determination of the optimal temperature profile of bulk polymerization of the optimal temperature profile of styrene.

This paper presents a new method of hierarchical control for large-scale linear time-varying systems via the single-term Walsh series (STWS). Certainly, the STWS method has definite advantages over the Walsh function (WF) method and block-pulse function (BPF) method. Both the discrete values and block-pulse values of the results are obtained for any length of time and selecting any positive integer as the number of intervals. The proposed method is simple and computationally advantageous. An illustrative example is given to the solutions obtained by the hierarchically recursive method together with those obtained by the globally recursive method.

This paper presents a new method of hierarchical control for large-scale time-varying systems via block pulse transformation. The resulting solutions are piecewise constant with minimal mean-square error. The proposed method is simple and computationally advantageous. A numerical example is given to compare the solutions obtained by the hierarchically recursive method with those obtained by the globally recursive method.

This paper presents a development of the hierarchical optimal control for distributed parameter systems via block pulse operator. The proposed algorithm enables one to solve optimal control of distributed parameter systems with hierarchical structure and as a result, the resulting solutions are piecewise constant with minimal mean-square error, The algorithm is simple in form and computationally advantageous. An illustrative example shows the applicability of the proposed method in practice.

This paper proposes a hierarchical recursive algorithm for non-linear optimal control systems through combining the improved new predication method of large-scale system theory with the single-term Walsh series approach. Piecewise constant and discrete-time solutions with minimal mean-square error are obtained, and the proposed method has merits in both computation and efficiency. The numerical examples show that the proposed method is very effective even for systems with lower dimensions.

Effect of aluminum on bone matrix inductive properties. The effect of aluminum on the bone inductive properties of implanted bone matrix was studied in rats. After decalcification femur sections were placed in either 0.1 or 0.01 M AlCl3 or a solution of similar pH without Al for 24 hours. Following 28 days of implantation in subcutaneous pouches the aluminum content was 3232 ± 1020 and 51 ± 6 mg/kg in the matrix pretreated with 0.1 and 0.01 M AlCl3. At the same time period following implantation the matrix calcium content was 794 ± 539 and 3038 ± 692 mmol/kg in the 0.1 and 0.01 M AlCl3 pretreated groups versus 4252 ± 579 mmol/kg in the control group (P < 0.01). In the control group bone histology showed extensive osteoblastic and osteoclastic remodeling, tetracycline labeling and bone formation. In contrast all of these histological features were virtually absent in aluminum treated matrix. Aluminum-induced resistance of bone matrix to collagenase degradation and restoration of bone inductive properties with chelation suggests that aluminum forms intermolecular cross links between collagen fibrils. Aluminum-induced cross links of collagen fibrils and/or its effects on bone inductive proteins present in bone matrix could explain the mechanism by which aluminum induces osteomalacia.

Modelling error can be the cause of bad performance when optimal feed-rate profiles computed for a particular model are applied to the actual plant. This paper suggests the modification of the input trajectory from batch to batch, by using information from previous batches to modify the trajectories that are applied to the subsequent ones. The proposed approach does not required the remodeling of the process, but instead it redermines the input profile directly, so that a steady improvement is accomplished from batch to batch.