Thin and thick YBCO films grown by MOCVD processes. Study of the angular magnetic field dependence of current transport properties

Thin and thick YBCO Films have been grown by Aerosol Assisted as well as by thermal MOCVD. The Aerosol Assisted MOCVD technique allows the growth of YBCO films from a single liquid source at deposition rates of up to 10m/h.Transport measurements (I-V) on etched microbridges using a single pulse technique have been performed. The angular magnetic field dependence J_c() of the critical current density from T_c down to 50 K has been measured. Transport properties are reported and discussed with respect to the microstructural features as determined by X-ray diffraction and electron microscopy.     

Well-posedness, regularity and exact controllability of the SCOLE model

The SCOLE model is a coupled system consisting of a flexible beam (modelled as an Euler–Bernoulli equation) with one end clamped and the other end linked to a rigid body. Its inputs are the force and the torque acting on the rigid body. It is well-known that the SCOLE model is not exactly controllable with L ² input signals in the natural energy state space H ^c , because the control operator is bounded from the input space \mathbbC²{\mathbb{C}^2} to H ^c , and hence compact. We regard the velocity and the angular velocity of the rigid body as the output signals of this system. Using the theory of coupled linear systems (one infinite-dimensional and one finite-dimensional) developed by us recently in another paper, we show that the SCOLE model is well-posed, regular and exactly controllable in arbitrarily short time when using a certain smoother state space X ì H^c{\mathcal{X}\subset H^c}.     

A fluid approach to large volume job shop scheduling

We consider large volume job shop scheduling problems, in which there is a fixed number of machines, a bounded number of activities per job, and a large number of jobs. In large volume job shops it makes sense to solve a fluid problem and to schedule the jobs in such a way as to track the fluid solution. There have been several papers which used this idea to propose approximate solutions which are asymptotically optimal as the volume increases. We survey some of these results here. In most of these papers it is assumed that the problem consists of many identical copies of a fixed set of jobs. Our contribution in this paper is to extend the results to the far more general situation in which the many jobs are all different. We propose a very simple heuristic which can schedule such problems. We discuss asymptotic optimality of this heuristic, under a wide range of previously unexplored situations. We provide a software package to explore the performance of our policy, and present extensive computational evidence for its effectiveness.     

Assessing the state of software in a large enterprise

To be relevant to the goals of an enterprise, an industrial software engineering research organization must identify problems of interest to, and find solutions that have an impact on, the software development organizations within the company. Using a systematic measurement program both to identify the problems and assess the impact of solutions is key to satisfying this need. Avaya has had such a program in place for about seven years. Every year we produce an annual report known as the State of Software in Avaya that describes software development trends throughout the company and that contains prioritized recommendations for improving Avaya’s software development capabilities. We start by identifying the goals of the enterprise and use the goal-question-metric approach to identify the measures to compute. The result is insight into the enterprise’s problems in software development, recommendations for improving the development process, and problems that require research to solve. We will illustrate the process with examples from the Software Technology Research Department in Avaya Labs whose purpose is to improve the state of software development and know it. “Know it” means that improvement should be subjectively evident and objectively quantifiable. “Know it” also means that one must be skilled at identifying the data sources, performing the appropriate analyses to answer the questions of interest, and validating that the data are accurate and appropriate for the purpose. Examples will include how and why we developed a measure of software quality that appeals to customers, how and why we are studying the effectiveness of distributed software development, and how and why we are helping development organizations to adopt iterative development methods. We will also discuss how we keep the company and the department apprised of the current strengths and weaknesses of software development in Avaya through the publication of the annual State of Software in Avaya Report. Our purpose is both to provide a model for assessment that others may emulate, based on seven years of experience, and to spotlight analyses and conclusions that we feel are common to software development today.     

Adaptive supervision of moving objects for mobile robotics applications

One of the main tasks of mobile robotics is vision. Lighting independence, adaptivity and automated learning are still the main issues when it comes to applications. In this article, we present an image understanding system and its methods targeting automatic, lighting-independent and reliable color-based object recognition under real time conditions. Its application test bed is global vision robot soccer (i.e. FIRA MiroSot und RoboCup Small Size leagues) but it has many other applications in color-based supervision of moving objects. Under typical conditions, it learns the objects of recognition automatically, has zero setup time and tolerates environmental changes during run-time.     

Development of active matrix LCD for use in high‐resolution adaptive headlights

Conventional adaptive driving beam headlamps are limited in achieving still higher quantities of switchable pixels by the number of LEDs and movable elements needed. In this paper, it is shown that by integrating an active matrix liquid crystal display module, it is possible to realize fully adaptive high‐resolution headlights without mechanical elements and a finite number of LED with 30 k switchable pixels.     

User assisted separation of reflections from a single image using a sparsity prior

When we take a picture through transparent glass the image we obtain is often a linear superposition of two images: the image of the scene beyond the glass plus the image of the scene reflected by the glass. Decomposing the single input image into two images is a massively ill-posed problem: in the absence of additional knowledge about the scene being viewed there are an infinite number of valid decompositions. In this paper we focus on an easier problem: user assisted separation in which the user interactively labels a small number of gradients as belonging to one of the layers. Even given labels on part of the gradients, the problem is still ill-posed and additional prior knowledge is needed. Following recent results on the statistics of natural images we use a sparsity prior over derivative filters. This sparsity prior is optimized using the terative reweighted least squares (IRLS) approach. Our results show that using a prior derived from the statistics of natural images gives a far superior performance compared to a Gaussian prior and it enables good separations from a modest number of labeled gradients.     

Distributed Symbolic Bounded Property Checking

In this paper we describe an algorithm for distributed, BDD-based bounded property checking and its implementation in the verification tool SymC. The distributed algorithm verifies larger models and returns results faster than the sequential version.The core algorithm distributes partitions of the state set to computation nodes after reaching a threshold size. The nodes proceed with image computation on the nodes asynchronously. The main scalability problem of this scheme is the overlap of state set partitions. We present static and dynamic overlap reduction techniques.     

The effect of axial residual stress on the mechanical behaviour of composites

The effect of axial residual stress on the properties of continuous fibre composites is calculated. It is emphasized that composite strength should be considered as a more complex phenomenon than usually done so by merely considering ultimate strength. It is shown that the information contained in ()-curves if plotted in a more suitable form as hysteresis and set versus total strain, taking into account residual stress, may be a useful means for characterizing the composite and for detecting deviations from perfect structure. Conclusions are derived as to how composite performance may be improved. The results are substantiated by metallic composite data.