Key Engineering Materials Vols. 474-476

Abstract: To assist stroke patients with rehabilitation training, an upper limb rehabilitation robot with an exoskeleton structure and three degrees of freedom (DOF) was developed in this paper. Under the guidance of the theory of rehabilitation medicine, the mechanical design of the robot was completed. Then, the kinematics equations were established by means of homogeneous transformation, including the forward kinematics and the inverse kinematics. The kinematical analysis was carried out and the algebraic solution of inverse kinematics was derived, which provided a theoretical basis for realizing the intelligent control. To validate the performance, the kinematical simulation was conducted, and the simulation results showed that the design of the exoskeleton robot was feasible.

Abstract: Nitrogen-doped titanium oxide (N-TiO₂) films deposited on unheated glass slides at various flow rates of N₂ in an atmosphere of Ar and O₂ gas mixture by direct current sputtering technique were investigated. The Ti2p, O1s and N1s spectra by X-ray photoelectron spectroscopy (XPS) verified N-substitution into TiO₂ lattice which is responsible for the band gap narrowing. The oxygen total ratio (r_OT) in the gas mixture had profound influence on the photocatalytic properties of the N-doped films. At a ratio of r_OT≦0.18, heterogeneous phases, such as titanium oxynitride (TiN_xO_y) and titanium nitride (TiN), with low crystallinity were formed in the TiO₂ lattice, showing low photocatalytic activity. On the other hand, the N-TiO₂ films prepared at r_OT≧0.20 were found to have improved photocatalytic activity on methylene blue degradation under visible-light irradiation at wavelengths longer than 500 nm, due to the substitutional N ions in the TiO₂ lattice.

Abstract: In this paper, a model based on ELM is proposed to predict the air-conditioning load under drought conditions by analyzing the daily average air- conditioning load during the drought. The main meteorological factors that impact the air-conditioning load are considered in the model, and then the air-conditioning load under drought conditions can be predicted by training the samples by the single hidden layer feed forward neural network of ELM. Thus, the model is used to provide good theoretical basis for management on the demand side of power sector. Finally, an example is showed to prove that the curve of the air-conditioning load forecasting model and the curve of the actual cooling load of the power are almost consistent, and the prediction is accurate, reliable, and can be applied to other load forecasting.

Abstract: The motion system of a toy robotic snake is discussed. This study is expected to provide the best design for this toy and to help widen future application. A mathematical model was constructed after a literature and mechanical design survey. Tribotix AI 1001 motors are used to operate the snake. By an analysis of the mathematical model, transformation of the D-H matrices, and the introduction of forward and inverse kinematics, the relationship between the angle and the coordinate of each section of the robotic snake were determined. The trace curve of a real snake was also studied to arrive at a description of the motion and parameter changes for the robotic snake within a single time unit. MATLAB was used for the simulation and to plot the figures. Experiments and trace analyses were also performed to obtain the design rule and an approach to an improved mechanism for the toy robotic snake. Finally, the experimental results and the possibility of future development are discussed.

Abstract: A novel low-profile reconfigurable CPW-fed slot antenna that is designed using a half-wavelength slot-line resonator is proposed in this paper. Frequency hopping can be easily achieved by incorporating a pair of PIN diodes, being controlled in either their on or off state. Benefited from the magnetic current distribution of a half-wavelength slot-line resonator, the radiation patterns at the two operating frequencies (1.8GHz and 2.45GHz) are very stable, being almost identical. The proposed antenna is designed and fabricated, and the theoretical and measured results are presented and show good agreement.

Abstract: An optimal inventory model is proposed in this paper. Firstly, the prerequisite of this model is given out. Under the supposed condition of deterioration, the demand rate of articles depends on the inventory level, meanwhile the status of shortage and partial back-order. The optimal inventory model of fixed free back orders is on this basis. With those numerical values in this model, the optimal ordering cycle and ordering batch of stock system are counted out and the sensitivity is analyzed by using the mathematical software Mathmatica 7.0.

Abstract: Automatic blood vessel analysis plays an important role in computer-aided diagnosis of the vessels. In the blood vessel analysis system, extraction and navigation of vessels are two crucial components, and fast extraction and automatic navigation algorithms attract more and more attention. In this paper, to accelerate the extraction of blood vessel, an initial contour algorithm is proposed to produce an initial contour for level-set method. Then, the level-set method is introduced to extract the vessel more precisely. Finally, the navigation of the extracted blood vessel is realized based on a 3D texture volume rendering algorithm based on graphics processing unit (GPU). The experimental results illustrate the effectiveness of the proposed vessel extraction and navigation scheme.

Abstract: Steam-injection pressing technology is a kind of new hot-pressing technology researched and developed in recent years, its hot-pressing performance significantly better than traditional hot-pressing. The technical principle, method and research progress of steam-injection pressing technology was reviewed in detail and its future research trend is also outlined.

Abstract: In this paper, a new construct of hierarchical identity-based signature(HIBS) scheme is proposed at first. It has many advantages over those available, such as fully secure without using random oracles, efficient signing algorithm. Additionally, it is provably secure under the computational Diffie-Hellman(CDH) assumption. This assumption is more natural than many of the hardness assumptions recently introduced to HIBS in the standard model. However, the length of its private key and signature increases as the hierarchy depth expands. Then a modified scheme is presented. The signature of modified scheme consists of three group elements and the private keys size shrinks as the identity depth increases. Under the h-CDH assumption, it is provable security in full security model without using random oracles.

Abstract: Along with our country foreign trade considerable development and international competitiveness increasing enhancement, the environment question is prominent actually day by day. The paper selected the data of the foreign trade and industrial waste discharge from 1998 to 2009 to establish the Hebei Province prediction model. It shows that GA-BP neural network had higher accuracy, tolerant and excellent generalization ability about ecology environment. It provides a guidance to forecast foreign trade environment.