A vision system for on‐line inspection of CRT electron‐gun grid gaps

Abstract— A high‐resolution vision system for on‐line measurements of color CRT electron‐gun (E‐gun) grid gaps has been developed. The measurement principle is based on a digital image‐processing technique combined with a multi‐path imaging system. By utilizing the arrangement of multi‐path image processing, the measurements for different types of guns and for different gaps on a gun can be effectively executed with higher resolution. The purposes of on‐line inspection and statistical quality control are also easily implemented. Experiments were executed in the production line of a 15‐in. monitor, and the experimental results show that the system resolution is about 8.5–10 μm and the on‐line inspection index is about 300 pcs/hour.     

Substrate‐free cholesteric liquid‐crystal displays

Abstract— This paper demonstrates the first substrate‐free cholesteric liquid‐crystal displays. The encapsulated cholesteric displays are ultra‐thin (with a total thickness around 20 μm) and ultra‐lightweight (0.002 g/cm²). The displays exhibit unprecedented conformability, flexibility, and drapability while maintaining electro‐optical performance and mechanical integrity. All functional display layers are sequentially coated on a preparation substrate and then lifted‐off from the preparation substrate to form a free‐standing display. The display fabrication process, electro‐optical performance, and display flexibility are discussed.     

Novel directional projection screen using divergent corner cube retroreflector with a three‐sided curved surface (D‐CCR)

We devised and developed a novel directive projection screen for applications such as personal use, small group meeting, automotive pillar, and near‐eye. This screen reflects diffused light at an angle Δθ_view around a direction deviated by θ_view from the direction of the projector. By applying this screen to automobiles, for example, by installing a projector at a position slightly shifted from the driver, it is possible to reflect the projected light with high efficiency to a certain range around the face of driver. To realize such a characteristic, a hollow corner cube retroreflector (CCR) was modified as follows. The bottom surface of the CCR was tilted by θ_view/2 to change the direction of the reflected light by θ_view from the retroreflection direction. In addition, three sides' surfaces of the CCR were curved, so that the light to be diffused within a designed angle (θ_view ± Δθ_view/2). The novel retroreflector CCR (D‐CCR) has a single divergent surface with a three‐sided curved surface. We fabricated a prototype with θ_view = 10° and Δθ_view = 16° (i.e., the viewing angle for a single D‐CCR, 10° ± 8°), simulated, and measured its optical properties. We closely confirmed the desired characteristics in which an optical gain of 16 was obtained.     

A highly sensitive and low‐noise IR photosensor based on a‐SiGe as a sensing and noise filter: Toward large‐sized touch‐screen LCD panels

Abstract— The a‐SiGe TFT photosensor for embedded touch‐screen panels (TSPs) was characterized by comparison with an a‐Si sensor. The photoresponse of an a‐SiGe sensor at a 850‐nm wavelength was much higher than that of a‐Si, indicating that a‐SiGe is a strong candidate material for an IR sensor. In order to increase the signal‐to‐noise ratio, the incident visible light was filtered by incorporating a bandpass‐filter layer. An a‐SiGe IR‐sensor‐embedded LCD panel was successfully demonstrated, showing an excellent multitouch property independent of ambient‐light conditions. This technology can be widely used in multifunctional TSPs.     

Electron‐optics of the Fast Intelligent Tracking (F!T) tube: A CRT without a shadow mask

Abstract— In this paper, we describe the electron‐optics involved in realizing a maskless CRT based on tracking the electron beams along horizontally aligned phosphor lines. We discuss the boundary conditions in order for the system to function. Emphasis is placed on the requirements of color purity, beam current, and spot size. A dedicated electron gun has been designed and tested. Results indicate that the spot‐size requirements for the feasibility of the concept can be met. The depth of focus, in terms of the allowed mismatch of the dynamic focusing voltage, is small. Inter‐beam space‐charge repulsion turns out to be unproblematic. The cathode drive is shown to lead to beam displacements that cannot be corrected. Consequently, a grid‐1 drive has to be used.     

Dynamic intermittent Q‐learning–based model‐free suboptimal co‐design of ‐stabilization

This paper proposes an intermittent model‐free learning algorithm for linear time‐invariant systems, where the control policy and transmission decisions are co‐designed simultaneously while also being subjected to worst‐case disturbances. The control policy is designed by introducing an internal dynamical system to further reduce the transmission rate and provide bandwidth flexibility in cyber‐physical systems. Moreover, a Q‐learning algorithm with two actors and a single critic structure is developed to learn the optimal parameters of a Q‐function. It is shown by using an impulsive system approach that the closed‐loop system has an asymptotically stable equilibrium and that no Zeno behavior occurs. Furthermore, a qualitative performance analysis of the model‐free dynamic intermittent framework is given and shows the degree of suboptimality concerning the optimal continuous updated controller. Finally, a numerical simulation of an unknown system is carried out to highlight the efficacy of the proposed framework.     

Convergence speed of a fractional order consensus algorithm over undirected scale‐free networks

Scale‐free networks have been rediscovered universally in natural and man‐made systems, and the consensus protocols have been tremendously studied over the last decade. Motivated by the fractional‐order dynamics of bacteria colonies, a fractional‐order protocol is employed to achieve the consensus over scale‐free networks. The most remarkable property of scale‐free networks lies in the inverse power‐law degree distributions. The present work concerns the convergence speed with different fractional orders corresponding to different power‐law parameters. The analytic solutions of consensus protocols are given and its property is discussed, explaining the quick convergence speed in the early stage of the consensus process, and the slower performance later. Inspired by such behavior, a switching order consensus protocol is proposed, which efficiently increases the convergence speed and ensures the exponential convergence as time tends to infinity. The disagreement of the system during the consensus procedure is investigated. Theoretic analysis and simulations demonstrate that, for certain scale‐free networks, an optimal order exists so that the fractional‐order consensus algorithm can minimize the disagreement or its integral. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Model for quantifying blur‐free motion of a Briggs roam target moving at 15 deg/s

By combining data from response time measurements, charge‐coupled device images of monitor subpixels, the Briggs roam test, the limitations of the human vision system, and spatio‐temporal data analysis, it is possible to determine the prerequisites for blur‐free motion at a specified roam rate.     

Chattering‐free sliding mode control for a class of nonlinear mechanical systems

Second‐order sliding mode control (2‐smc) and dynamic sliding mode control (dsmc) eliminate the disturbing characteristic of chattering in static sliding mode control under the assumption that the derivative of the sliding surface is available or complex inequalities at the acceleration level can be constructed. In this paper, passivity‐based adaptive and non‐adaptive chattering‐free sliding mode controllers are proposed assuming that the upper bound of the norm of the derivative of the sliding surface is available, a weaker and easy to implement assumption in comparison to those of 2‐smc and dsmc. The closed‐loop system accounts explicitly for the invariance condition without reaching phase, and therefore for a desired transient response with global exponential convergence of tracking errors. Preliminary experiments are presented. Copyright © 2001 John Wiley & Sons, Ltd.     

Object‐oriented processing of Java source code

Code transformation and analysis tools provide support for software engineering tasks such as style checking, testing, calculating software metrics as well as reverse‐ and re‐engineering. In this paper we describe the architecture and the applications of JTransform, a general Java source code processing and transformation framework. It consists of a Java parser generating a configurable parse tree and various visitors (transformers, tree evaluators) which produce different kinds of outputs. While our framework is written in Java, the paper further opens an opportunity for a new generation of XML‐based source code tools. Copyright © 2004 John Wiley & Sons, Ltd.     

Single‐scan: a fast star‐join query processing algorithm

A data warehouse can store very large amounts of data that should be processed in parallel in order to achieve reasonable query execution times. The MapReduce programming model is a very convenient way to process large amounts of data in parallel on commodity hardware clusters. A very popular query used in data warehouses is star‐join. In this paper, we present a fast and efficient star‐join query execution algorithm built on top of a MapReduce framework called Hadoop. By using dynamic filters against dimension tables, the algorithm needs a single scan of the fact table, which means a significant reduction of input/output operations and computational complexity. Also, the algorithm requires only two MapReduce iterations in total–one to build the filters against dimension tables and one to scan the fact table. Our experiments show that the proposed algorithm performs much better than the existing solutions in terms of execution time and input/output. Copyright © 2014 John Wiley & Sons, Ltd.     

Formation control for a class of nonlinear multiagent systems using model‐free adaptive iterative learning

In this paper, the problem of formation control is considered for a class of unknown nonaffine nonlinear multiagent systems under a repeatable operation environment. To achieve the formation objective, the unknown nonlinear agent's dynamic is first transformed into a compact form dynamic linearization model along the iteration axis. Then, a distributed model‐free adaptive iterative learning control scheme is designed to ensure that all agents can keep their desired deviations from the reference trajectory over the whole time interval. The main results are given for the multiagent systems with fixed communication topologies and the extension to the switching topologies case is also discussed. The feature of this design is that formation control can be solved only depending on the input/output data of each agent. An example is given to demonstrate the effectiveness of the proposed method.     

ExPregel: a new computational model for large‐scale graph processing

These days, large‐scale graph processing becomes more and more important. Pregel, inspired by Bulk Synchronous Parallel, is one of the highly used systems to process large‐scale graph problems. In Pregel, each vertex executes a function and waits for a superstep to communicate its data to other vertices. Superstep is a very time‐consuming operation, used by Pregel, to synchronize distributed computations in a cluster of computers. However, it may become a bottleneck when the number of communications increases in a graph with million vertices. Superstep works like a barrier in Pregel that increases the side effect of skew problem in distributed computing environment. ExPregel is a Pregel‐like model that is designed to reduce the number of communication messages between two vertices resided on two different computational nodes. We have proven that ExPregel reduces the number of exchanged messages as well as the number of supersteps for all graph topologies. Enhancing parallelism in our new computational model is another important feature that manifolds the speed of graph analysis programs. More interestingly, ExPregel uses the same model of programming as Pregel. Our experiments on large‐scale real‐world graphs show that ExPregel can reduce network traffic as well as number of supersteps from 45% to 96%. Runtime speed up in the proposed model varies from 1.2× to 30×. Copyright © 2015 John Wiley & Sons, Ltd.     

Graphics processing unit‐accelerated bounding for branch‐and‐bound applied to a permutation problem using data access optimization

Branch‐and‐bound (B&B) algorithms are attractive methods for solving to optimality combinatorial optimization problems using an implicit enumeration of a dynamically built tree‐based search space. Nevertheless, they are time‐consuming when dealing with large problem instances. Therefore, pruning tree nodes (subproblems) is traditionally used as a powerful mechanism to reduce the size of the explored search space. Pruning requires to perform the bounding operation, which consists of applying a lower bound function to the subproblems generated during the exploration process. Preliminary experiments performed on the Flow‐Shop scheduling problem (FSP) have shown that the bounding operation consumes over 98% of the execution time of the B&B algorithm. In this paper, we investigate the use of graphics processing unit (GPU) computing as a major complementary way to speed up the search. We revisit the design and implementation of the parallel bounding model on GPU accelerators. The proposed approach enables data access optimization. Extensive experiments have been carried out on well‐known FSP benchmarks using an Nvidia Tesla C2050 GPU card. Compared to a CPU‐based single core execution using an Intel Core i7‐970 processor without GPU, speedups higher than 100 times faster are achieved for large problem instances. At an equivalent peak performance, GPU‐accelerated B&B is twice faster than its multi‐core counterpart. Copyright © 2013 John Wiley & Sons, Ltd.     

The effects of directive self‐explanation prompts to support active processing of multiple representations in a simulation‐based learning environment

Processing of multiple representations in multimedia learning environments is considered to help learners obtain a more complete overview of the domain and gain deeper knowledge. This is based on the idea that relating and translating different representations leads to reflection beyond the boundaries and details of the separate representations. To achieve this, the design of a learning environment should support learners in adequately processing multiple representations. In this study, we compared a scientific inquiry learning environment providing instructional support with directive self‐explanation prompts to relate and translate between representations with a scientific inquiry learning environment providing instructional support with general self‐explanation prompts. Learners who received the directive prompts outperformed the learners who received general prompts on test items assessing domain knowledge. These positive results did not stretch to transfer items and items measuring learners' capabilities to relate and translate representations in general. The results suggest that learner support should promote the active relation of representations and translation between them to foster domain knowledge, and that other forms of support (e.g. extended training) might be necessary to make learners more expert processors of multiple representations.     

Application of re‐crystallized metal‐induced unilaterally crystallized polycrystalline‐silicon thin‐film‐transistor technology to reflective liquid‐crystaldisplay

Single‐polarizer reflective twisted‐nematic (RTN) liquid‐crystal modes offer larger viewing angles, higher contrast ratios and lower power dissipation compared to regular double‐polarizer transmissive‐ reflective liquid‐crystal implementations. The application of re‐crystallized metal‐induced unilaterally crystallized polycrystalline‐silicon thin‐film‐transistor (TFT) technology to realize active matrices and peripheral circuit components for hand‐held direct‐view RTN‐mode video displays is reported.     

The performance of commercial banks based on a context‐dependent range‐adjusted measure model

Performance measures play an important role in assisting firms to identify the right business strategies and choose the best firms for benchmarking. The scope of conventional data envelopment analysis (DEA) is limited to performance improvement in the same context. A context‐dependent range‐adjusted measure (RAM) model is proposed for policy makers and bank managers to provide a reliable means of exploring operational performance in different evaluative contexts, taking into consideration negative and undesirable outputs. This empirical research utilizes three inputs and two outputs (a desirable one and an undesirable one) to measure the relative attractiveness and progress of 23 Taiwanese commercial banks in 2008. The results demonstrate the ranking of these banks based on their attractiveness and progress in different evaluative contexts, and indicate their respective market positions. The Wilcoxon matched‐pairs signed‐ranks test shows that there is a tendency to overestimate operational efficiency when banks neglect undesirable outputs. A managerial decision‐making matrix is presented to analyze whether competitive strategies based on attractiveness and progress should be adopted by banks at levels 2 and 3.