Time-synchronised hardware-in-the-loop simulation — Applied to sheet-metal press line optimisation

This paper presents an off-line process parameter tuning method, focussing on complex control functions for automated manufacturing systems. The proposed method is based on a combination of simulation-based optimisation and time-synchronised hardware-in-the-loop simulation. Real industrial control systems, e.g., PLCs, are included in the simulation, executing the unchanged control code from the manufacturing plant. This approach allows all plant control functions to be included, even time-critical feedback loops and vendor secret blocks such as motion control. Consequently, the method suggested manages the problems identified in previously presented simulation-based approaches. Furthermore, a case study of an automotive sheet-metal press line has been performed to verify the proposed method, with successful results.     

安防产业融合脚步加快十大因素捧红网络摄像机

网络摄像机最初的设计目标就是为了利用数字图像、网络和Internet所具有的优势来拓展基于网络的新应用,因此在最开始视频监控应用被模拟技术所统治的时候,从来没有人想过会把它们应用到专业的视频监视应用当中.这一情况目前显然已经发生了变化:近两年来,网络摄像机的技术水平已经赶上了模拟摄像机,能够完全满足专业视频监控的实际需求和技术规范,在一些与视频监控相关的重要因素方面,网络摄像机的性能甚至已经超过了模拟摄像机.因此,用户有足够的理由在专业视频监控应用中选择网络摄像机.     

Exploring agile values in method configuration

The Method for Method Configuration (MMC) has been proposed as a method engineering approach to tailoring information systems development methods. This meta-method has been used on a variety of methods, but none of these studies have focused on the ability to manage method tailoring with the intention to promote specific values and goals, such as agile ones. This paper explores how MMC has been used during three software development projects to manage method tailoring with the intention to promote agile goals and values. Through content examples of method configurations we have shown that it is possible to use MMC and its conceptual framework on eXtreme Programming and we report on lessons learned with regard to maintaining coherency with the overall goals of the original method.     

Global Optimization through Rotation Space Search

This paper introduces a new algorithmic technique for solving certain problems in geometric computer vision. The main novelty of the method is a branch-and-bound search over rotation space, which is used in this paper to determine camera orientation. By searching over all possible rotations, problems can be reduced to known fixed-rotation problems for which optimal solutions have been previously given. In particular, a method is developed for the estimation of the essential matrix, giving the first guaranteed optimal algorithm for estimating the relative pose using a cost function based on reprojection errors. Recently convex optimization techniques have been shown to provide optimal solutions to many of the common problems in structure from motion. However, they do not apply to problems involving rotations. The search method described in this paper allows such problems to be solved optimally. Apart from the essential matrix, the algorithm is applied to the camera pose problem, providing an optimal algorithm. The approach has been implemented and tested on a number of both synthetically generated and real data sets with good performance. NICTA is funded by the Australian Government’s Backing Australia’s Ability initiative, in part through the Australian Research Council.     

On-line monitoring of fuel moisture-content in biomass-fired furnaces by measuring relative humidity of the flue gases

Combustion of biomass for heat and power production is continuously growing in importance, because of incentives for replacing fossil energy resources with renewable ones. In biomass combustion, the moisture content of the fuel is an essential operation parameter, which often fluctuates for biomass fuels. Variation in moisture content complicates the operation of the furnaces and results in an uncertainty in the energy content of the fuel delivered to a plant. The fuel moisture-content in a furnace may be determined either by direct measurement on the entering fuel or by measuring the moisture and oxygen contents of the flue gases deriving the moisture content of the fuel. However, reliable methods of a motivated cost for the small to medium-scale furnaces are today not available. An exception is if the furnace is equipped with flue-gas condenser, which can be used to estimate the moisture content of the flue gases. A limitation of this method is, though, that not all furnaces have flue-gas condensers and that the measured signal has an inherent time delay.In this work, measurement of the relative humidity (RH) of the flue gases from a furnace is investigated as the central component in the on-line monitoring of the moisture content of the fuel in a furnace. The method was analysed with humid air in a laboratory environment and tested for accuracy and dynamical behaviour in two biomass-fired heat-production units, one circulating fluidised-bed boiler (CFB) and one grate furnace. The results show that the method, which is easy to calibrate on site, can be used to predict the moisture content of the biomass fuel in the grate furnace with very good precision (<4% error). Furthermore, the method detects variations in moisture content of the furnace flue gases due to changes in the moisture content of the combusted fuel within the order of seconds. Since the transport time of the flue gases from the furnace to the measurement position is of the same order of magnitude, the total time for detection of a change in the moisture content of the fuel is small enough for the signal to be used to control both the fuel feed and the combustion air in a grate furnace.     

On the stability of delamination growth at scratching of thin film structures

Scratching of thin film/substrate structures is studied theoretically and numerically. The results are discussed in connection to delamination initiation and in particular subsequent growth at scratching. The material behavior of the film is described by classical elastoplasticity accounting for large deformations. The deformation of the substrate is neglected indicating that the results are pertinent to soft thin films. The numerical investigation is performed using the finite element method (FEM) and the numerical strategy is discussed in some detail. The results from this study show that delamination growth at thin film scratching is a stable feature with crack arrest occurring at a decreasing load.     

Addressing the gut microbiome and implications for obesity

Identification of the gut microbiota as an environmental factor that modulates obesity and metabolic diseases has provided the medical and functional food industry with new targets to treat metabolic diseases. However, only limited knowledge about the mechanisms by which the gut microbiota contributes to these lifestyle diseases are known. The gut microbiota is involved in energy harvest from the diet, modulation of endocrine signalling, and promoting metabolic inflammation. This review will discuss how the gut microbiota is altered in obesity, some of the mechanisms by which it promotes disease development, and how pre- and probiotics may be used to improve metabolic diseases.     

Controlling the turn-on-voltage in low-voltage Al2O3 organic transistors with mixed self-assembled monolayers

In this paper we present a method of using blends of two silanes with different functional groups to precisely tune the turn-on-voltage to 0 V. In addition, we show how the transistor behaviour of an amorphous polymer low-voltage transistor is affected by modification of the Al₂O₃ dielectric with self-assembled monolayers of molecules with different functional groups. Controlling the turn-on voltage is essential for any practical applications, especially for low-voltage transistors. This method opens new doors to designing stable, low-voltage organic circuitry in a reproducible manner.