Tank monitoring: a pAMN case study

The introduction of probabilistic behaviour into the B-method is a recent development. In addition to allowing probabilistic behaviour to be modelled, the relationship between expected values of the machine state can be expressed and verified. This paper explores the application of probabilistic B to a simple case study: tracking the volume of liquid held in a tank by measuring the flow of liquid into it. The flow can change as time progresses, and sensors are used to measure the flow with some degree of accuracy and reliability, modelled as non-deterministic and probabilistic behaviour respectively. At the specification level, the analysis is concerned with the expectation clause in the probabilistic B machine and its consistency with machine operations. At the refinement level, refinement and equivalence laws on probabilistic GSL are used to establish that a particular design of sensors delivers the required level of reliability.     

如何在向3G演讲中保护投资?

移动运营商推出3G业务的道路上存在着很多困难,其中最为严峻的挑战莫过于建立既能支持现有2G网络,又能为下一代用户提供广泛业务的移动基础设施.由于一段时期内,2G业务仍是移动运营商的主要收入流,因此移植到UMTS或者EDGE等更高速率的分组交换网,需要同时管理运行两种异构网络.     

Visible tunable lighting system based on polymer composites embedding ZnO and metallic clusters: from colloids to thin films

The development of phosphor devices free of heavy metal or rare earth elements is an important issue for environmental reasons and energy efficiency. Different mixtures of ZnO nanocrystals with Cs₂Mo₆I₈(OOC₂F₅)₆ cluster compound (CMIF) dispersed into polyvinylpyrrolidone matrix have been prepared by very simple and low cost solution chemistry. The resulting solutions have been used to fabricate highly transparent and luminescent films by dip coating free of heavy metal or rare earth elements. The luminescence properties of solution and dip-coated films were investigated. The luminescence of such a system is strongly dependent on the ratios between ZnO and CMIF amounts, the excitation wavelength and the nature of the system. By varying these two parameters (ratio and wavelength), a large variety of colors, from blue to red as well as white, can be achieved. In addition, differences in the luminescence properties have been observed between solutions and thin films as well as changes of CMIF emission band maximum wavelength. This may suggest some possible interactions between the different luminophore centers, such as energy transfer or ligands exchange on the Mo₆ clusters.     

Intelligent phase plane switching control of a pneumatic muscle robot arm with Magneto-Rheological Brake

Pneumatic cylinders are one kind of low cost actuation sources which have been applied in industrial and robotics field, since they have a high power/weight ratio, a high-tension force and a long durability. To overcome the shortcomings of conventional pneumatic cylinders, a number of newer pneumatic actuators have been developed such as McKibben Muscle, Rubber Actuator and Pneumatic Artificial Muscle (PAM) Manipulators. However, some limitations still exist, such as the air compressibility and the lack of damping ability of the actuator bring the dynamic delay of the pressure response and cause the oscillatory motion. In addition, the nonlinearities in the PAM manipulator still limit the controllability. Therefore, it is not easy to realize motion with high accuracy and high speed and with respect to various external inertia loads. To overcome these problems, a novel controller which harmonizes a phase plane switching control method (PPSC) with conventional PID controller and the adaptabilities of neural network is newly proposed. In order to realize satisfactory control performance a variable damper, Magneto-Rheological Brake (MRB), is equipped to the joint of the robot. The mixture of conventional PID controller and an intelligent phase plane switching control using neural network (IPPSC) brings us a novel controller. The experiments were carried out in a robot arm, which is driven by two PAM actuators, and the effectiveness of the proposed control algorithm was demonstrated through experiments, which had proved that the stability of the manipulator can be improved greatly in a high gain control by using MRB with 1PPSC and without regard for the changes of external inertia loads.     

A novel hybrid intelligent model of support vector machines and the MultiBoost ensemble for landslide susceptibility modeling

The main aim of this study is to propose a novel hybrid intelligent model named MBSVM which is an integration of the MultiBoost ensemble and a support vector machine (SVM) for modeling of susceptibility of landslides in the Uttarakhand State, Northern India. Firstly, a geospatial database for the study area was prepared, which includes 391 historical landslides and 16 landslide-affecting factors. Then, the sensitivity of different combinations of these factors for modeling was validated using the forward elimination technique. The MBSVM landslide model was built using the datasets generated from the best selected factors and validated utilizing the area under the receiver operating characteristic (ROC) curve (AUC), statistical indexes, and the Wilcoxon signed-rank test. Results show that this novel hybrid model has good performance both in terms of goodness of fit with the training dataset (AUC = 0.972) and the capability to predict landslides with the testing dataset (AUC = 0.966). The efficiency of the proposed model was then validated by comparison with logistic regression (LR), a single SVM, and another hybrid model of the AdaBoost ensemble and an SVM (ABSVM). Comparison results show that the MBSVM outperforms the LR, single SVM, and hybrid ABSVM models. Thus, the proposed model is a promising and good alternative tool for landslide hazard assessment in landslide-prone areas.

     

Synthesis and characterization of phenylsiloxane‐modified bismaleimide/barbituric acid‐based polymers with 3‐aminopropyltriethoxysilane as the coupling agent

The preparation and characterization of phenylsiloxane (PhSLX)‐modified N,N′‐bismaleimide‐4,4′‐diphenylmethane (BMI)/barbituric acid (BTA) (10/1 mol/mol) oligomers are described. 3‐Aminopropyltriethoxysilane (APTES) was used as the coupling agent. The resultant hybrid BMI/BTA‐APTES‐PhSLX polymers were characterized primarily using thermogravimetric analysis in combination with differential scanning calorimetry and Fourier transform infrared measurements. The thermal stability of the BMI/BTA oligomer was improved significantly by incorporation of a small amount (20–30 wt%) of the copolymer of PhSLX and APTES (PASi). After adequate post‐curing reactions, the PASi‐modified BMI/BTA oligomers (HYBRID20 and HYBRID30 containing 20 and 30 wt% PASi, respectively) exhibited greatly reduced thermal degradation rates in the temperature range 300–800 °C and an increased level of residues at 800 °C as compared to the native BMI/BTA oligomer. This was further confirmed by thermal degradation kinetic studies, in which the activation energies for the thermal degradation reactions of the cured PASi‐modified BMI/BTA oligomers were shown to be higher than that of the pristine BMI/BTA oligomer. © 2012 Society of Chemical Industry     

Bioavailability and antioxidant potential of rooibos flavonoids in humans following the consumption of different rooibos formulations

In a complete crossover design, a human study with twelve healthy male volunteers has been conducted using a placebo and different rooibos drinks (rooibos tea and an isolated active fraction) from unfermented rooibos (Aspalathus linearis). Blood and urine samples were collected before and up to 24 h after consumption of the drinks.     

）istortion-Free Data Embedding Scheme for Hig Dynamic Range Images

Distortion-free data embedding is a technique which can assure that not only the secret data is correctly extracted but also the cover media is recovered without any distortion after secret data is extracted completely. Because of these advantages, this technique attracts the attention of many researchers. In this paper, a new distortion-free data embedding scheme for high dynamic range (HDR) images is proposed. By depending on Cartesian product, this scheme can obtain higher embedding capacity while maintaining the exactly identical cover image and stego image when using the tone mapping algorithms. In experimental results, the proposed scheme is superior to Yu et al.'s scheme in regard to the embedding rate-an average embedding rate of 0.1355 bpp compared with Yu et al.'s scheme (0.1270 bpp).     

Static,free vibration,and buckling analysis of laminated composite Reissner–Mindlin plates using NURBS‐based isogeometric approach

This paper presents a novel numerical procedure based on the framework of isogeometric analysis for static, free vibration, and buckling analysis of laminated composite plates using the first‐order shear deformation theory. The isogeometric approach utilizes non‐uniform rational B‐splines to implement for the quadratic, cubic, and quartic elements. Shear locking problem still exists in the stiffness formulation, and hence, it can be significantly alleviated by a stabilization technique. Several numerical examples are presented to show the performance of the method, and the results obtained are compared with other available ones. Copyright © 2012 John Wiley & Sons, Ltd.