Dynamic Friction Control Using Dynamic Structured RFNN and Friction Parameter Estimator

A nonlinear dynamic friction control is dealt with using dynamic friction observer and intelligent control.The adaptive dynamic friction observer based on the LuGre friction is proposed to estimate the friction parameters and a directly immeasurable friction state variable.The dynamic structured Recurrent Fuzzy Neural Network(RFNN)is designed to give additional robustness to the control system under the presence of the friction model uncertainty.A proposed composite control scheme is applied to the position tracking control of the servo system.The performances of the proposed friction observer and the friction controller are demonstrated by simulation.     

An improved neural network model for the prediction of cutting tool life

In recent years, the backpropagation neural network has been shown to be a good modelling method for complex problems because of its self-adjusting ability, and the fact that it can be used with small amounts of data. However, some factors in the data may be insignificant and correlated, or there may be some noise present. These phenomena will cause the model to predict inaccurately. In this research, we propose a statistical method to avoid such situations, by screening variables and testing for normality. The model built by using screened variables shows a better fit and yields accurate predictions. To demonstrate the proposed method, we conduct cutting experiments and build cutting tool life models as an example. Then we compare the results of the constructed models among the backward stepwise regression, the neural network and the proposed neural network methods. The proposed neural network method shows the most accurate prediction.     

An Assessment of the Impact of Inland Surface Water Input to the Bacteriological Quality of Coastal Waters

The introduction of ultraviolet disinfection in Jersey has achieved significant improvements in water quality. However, bathing waters in St Aubin's Bay and shellfish flesh have failed to comply with microbial standards. Streams and seepages from coastal structures were investigated as potential indicator organism sources (total and faecal coliforms, faecal streptococci). Seepages were an unimportant bacterial source as concentrations were low. Geometric mean concentrations in streams were up to four orders of magnitude higher than in final sewage-treatment works effluent, and concentrations increased significantly at high stream discharge. Rainfall-induced pulses of poor water quality occurred two to three times per week during the 1993 summer season. Natural discharges from island catchments thus contribute significantly to the bacterial load received at the coast, especially during high flow events. These observations have implications for other UK and European schemes using tertiary disinfection technology to attain water quality targets in coastal waters.     

INDUCTION OF APOPTOSIS BY GINSENG SAPONIN METABOLITE IN U937 HUMAN MONOCYTIC LEUKEMIA CELLS

We report the cytotoxicity of the ginseng saponin metabolite, Compound K (20‐O‐D‐glucopyranosyl‐20(S)‐protopanaxadiol, IH901) on various human leukemia cell lines. Compound K had the most effect on U937, a human monocytic leukemia cell line among the tested cell lines. Compound K‐treated U937 cells showed characteristics of apoptosis: an exposure of phosphatidylserine from the inner cell membrane to the outer cell membrane, the formation of apoptotic bodies and DNA fragmentation. Compound K induced apoptosis by up‐regulating Bax, disrupting the mitochondrial membrane potential, and by activating caspase 9 and caspase 3. Therefore, we suggest that Compound K inhibits U937 cell growth by inducing apoptosis through the up‐regulation of Bax and caspase activation.     

Associativity modelling of a mould assembly for expandable polystyrene foam

The design and fabrication of a mould for expandable polystyrene (EPS) buffers involves an approach which is radically different from that associated with conventional plastic injection moulding. This is because the EPS mould design encompasses both the classical tooling specifications and considerations of the actual moulding process itself. This paper discusses the notion of associativity modelling in the CAD design of a mould assembly for the manufacture of EPS buffers. This modelling paradigm aims to integrate 5 mould design factors with 25 process (moulding) parameters. Through a better understanding of the interactions between design factors and process parameters, and among the process parameters themselves, a harmonious decision table can be derived which compromises the competing demands of factors and parameters. Because of the visibility of the interactions among parameters, the notion of associativity modelling offers the designer a better insight into mould assembly design, leading to practical mould design solutions that harmonize the functions of the different sub-assemblies.     

Cost modelling for electrical interconnect design justification

It is vital, in this competitive global market, that a product be well designed with ease of assembly as well as low product cost and yet meet its functionality objectives. It is therefore essential that a tool be developed to estimate the manufacturing cost of the product during its conceptual design phase. In this paper, the development of cost models for electrical interconnect design is discussed. The cost models can be used by designers in estimating the manufacturing cost of their designs and selecting the design that is economical to produce and functionally, meets the required specifications.     

Kinematic design of an anthropomimetic 7-DOF cable-driven robotic arm

In this paper, an anthropomimetic design of a 7-DOF dexterous robotic arm is proposed. Similar to the human arm, the arm consists of three sequentially connected modules, i.e., a 3-DOF shoulder module, a 1-DOF elbow module, and a 3-DOF wrist module. All three arm modules are also driven by cables in order to mimic the driving scheme and functionality of the human muscles. This paper addresses three critical design analysis issues, i.e., the displacement analysis, the tension-closure analysis, and the workspace analysis. A closed-form solution approach is presented for the forward displacement analysis, while the inverse displacement solution is obtained through an efficient optimization algorithm, in which both task-decomposition and dimension-reduction techniques are employed. An effective tension-closure analysis algorithm is also formulated based on the theory of convex analysis. The orientation workspace for the 3-DOF shoulder and wrist modules are then analyzed using a new equi-volumetric partition scheme based on the intuitive Tilt-and-Torsion angle parameterization. An optimization approach is then investigated for the kinematic design of the three joint modules, in which the design objective is to maximize the matched workspace of the robotic arm joints with that of the human arm joints. A research prototype of the 7-DOF cable-driven robotic arm has also been developed in order to demonstrate the anthropomimetic design concept. With a lightweight structure of 1 kg, the cable-driven robotic arm can carry a payload of 5 kg and has motion repeatability of±2.5mm.