Decentralized control design for large-scale systems with strong interconnections using neural networks

We propose a decentralized neural network (NN) controller for a class of large-scale nonlinear systems with the strong interconnections. The NNs are used to approximate the unknown subsystems and interconnections. Due to the functional approximation capabilities of NNs, the additional precautions are not required to be made for avoiding the possible control singularity problems. Semiglobal asymptotic stability results are obtained and the tracking error converges to zero. Furthermore, the issue of transient performance of the subsystems is also addressed under an analytical framework.     

3D Micro-PIXE at atmospheric pressure: A new tool for the investigation of art and archaeological objects

The paper describes a novel experiment characterized by the development of a confocal geometry in an external Micro-PIXE set-up. The position of X-ray optics in front of the X-ray detector and its proper alignment with respect to the proton micro-beam focus provided the possibility of carrying out 3D Micro-PIXE analysis. As a first application, depth intensity profiles of the major elements that compose the patina layer of a quaternary bronze alloy were measured. A simulation approach of the 3D Micro-PIXE data deduced elemental concentration profiles in rather good agreement with corresponding results obtained by electron probe micro-analysis from a cross-sectioned patina sample. With its non-destructive and depth-resolving properties, as well as its feasibility in atmospheric pressure, 3D Micro-PIXE seems especially suited for investigations in the field of cultural heritage.     

A Study of Surface Deformation during Wire‐Rod Rolling of High Speed Steels using Experimental and Computational Techniques

The evolution of surface defects during shape rolling of high‐speed steel billets is studied using longitudinal surface defects prepared by machining and welding. The reduction of the defects during rolling in a production mill is compared to the total area reduction of the billets. Samples are collected after pass 4, 6, 8, 14, 19 and the final pass, 28, representing the finished 5.5mm wire. By inspecting the cross sections, the rotation of the billets from pass to pass is evaluated. Results from FE simulations on solid billets are compared to the experimental results. Generally, simulations predict less reduction than observed experimentally. In most cases cracks reduce most effectively followed by carbon steel welds and stainless steel welds.     

Cathodic reduction of acids in dimethylformamide on platinum

A linear correlation was shown to exist between the acidity and the cyclic voltammetric half-potential of the reduction of acids in DMF for carboxylic and N-acids in the pK_a range of 6-16. Chlorophenols are reduced at slightly lower potentials giving a separate parallel line. Applying the obtained equation and employing the same method to literature data in DMSO, the pK_a values for conjugate aids of DMF and DMSO can be calculated, showing DMSO·H⁺ to be more acidic (pK_a = 2.9) than DMF·H⁺ (pK_a = 5.7). The analysis of cyclovoltammetric data demonstrated that a CE mechanism operates in the reduction of strong acids, including the conjugate acid of DMF. Weaker acids are reduced by direct discharge or a mixed mechanism.     

Predictive value of biological markers in etiopathogenesis of juvenile diabetes--reviewing the role of insulin antibodies

The lack of complete concordance for diseases in monozygotic twins prevents application of genetic markers for a thorough identification of the subjects who will develop the type I diabetes. Furthermore, the impact of the environmental factors precipitating beta cells destruction in genetically sensitive subjects has not been completely enlightened yet. The identification of high risk markers for the development of diabetes is aimed at detection of the early immune response activation markers. Islet cell antibodies are the most valuable markers, whose presence can be discovered even up to 7-8 years prior to the onset of symptoms. They are found in 50-80% of the newly discovered insulin-dependent diabetics. Their prevalence in the general population is 0.5-2%. These are commonly concomitant with insulin antibodies, found in 20-40% of the newly discovered diabetics, as reported in the literature. In our circumstances it was possible to determine the insulin antibodies only. We have concluded that they appear in 13.6% of children with a newly discovered diabetes, presenting a significant marker for predicting the course of the disease.     

An approach to automatic display layout using combinatorial optimization algorithms

The introduction of automatic display layout (ADL), i.e. the automatic placing and sizing of windows in a window-oriented graphical user interface, is a major contribution towards an improved user interface. Our approach to ADL is to treat this problem as a combinatorial optimization problem. In this article we describe the concepts we used for implementing an experimental system which controls the computer screen contents and its layout. We give two examples of different standard applications into which we included ADL successfully, namely hypertext for a window layout problem and graph-browser for a hierarchical graph layout problem within a particular window. The results show that automatic (and tool independent) display layout will be possible in the near future even in an interactive environment.     

电视监控系统云台控制器设计

电视监控系统是一种典型的分布式计算机信号采集系统。为了提高监控的范围和效果,云台控制器的优劣直接影响监控的范围和效果,因此对云台控制器的设计具有重要的意义。本系统采用串型通信,通过Modbus协议把控制信号输入单片机,经过对AT89S52单片机的编程,从而对八路继电器输出进行控制。系统不仅结构简单,而且还可以方便的对镜头、防护罩的控制进行扩展,功能强大,可以广泛应用于电视监控系统中的云台控制。     

基于模型修正技术的模拟集成电路几何规划优化方法

为了兼顾模拟集成电路设计优化的求解精度和计算效率,提出一种基于正项式模型修正技术的几何规划优化方法.首先将模拟集成电路的设计目标与约束简化为正项式模型,然后在采用几何规划方法迭代优化的过程中利用晶体管级SPICE仿真不断修正这一正项式模型.实例表明,与传统基于公式的优化方法和基于仿真的优化方法相比,该方法能够在尽量保证计算效率和全局最优解的前提下使优化精度满足晶体管级SPICE仿真的要求.     

FastUDP: a highly scalable user-level UDP framework in multi-core systems for fast packet I/O

The Journal of Supercomputing - Nowadays, many applications, e.g., network routers, distributed data process engines, firewall, need to transfer packets at linear rate. With the increasing data...     

Context relevance assessment and exploitation in mobile recommender systems

In order to generate relevant recommendations, a context-aware recommender system (CARS) not only makes use of user preferences, but also exploits information about the specific contextual situation in which the recommended item will be consumed. For instance, when recommending a holiday destination, a CARS could take into account whether the trip will happen in summer or winter. It is unclear, however, which contextual factors are important and to which degree they influence user ratings. A large amount of data and complex context-aware predictive models must be exploited to understand these relationships. In this paper, we take a new approach for assessing and modeling the relationship between contextual factors and item ratings. Rather than using the traditional approach to data collection, where recommendations are rated with respect to real situations as participants go about their lives as normal, we simulate contextual situations to more easily capture data regarding how the context influences user ratings. To this end, we have designed a methodology whereby users are asked to judge whether a contextual factor (e.g., season) influences the rating given a certain contextual condition (e.g., season is summer). Based on the analyses of these data, we built a context-aware mobile recommender system that utilizes the contextual factors shown to be important. In a subsequent user evaluation, this system was preferred to a similar variant that did not exploit contextual information.