On‐the‐Fly Power‐Aware Rendering

Power saving is a prevailing concern in desktop computers and, especially, in battery‐powered devices such as mobile phones. This is generating a growing demand for power‐aware graphics applications that can extend battery life, while preserving good quality. In this paper, we address this issue by presenting a real‐time power‐efficient rendering framework, able to dynamically select the rendering configuration with the best quality within a given power budget. Different from the current state of the art, our method does not require precomputation of the whole camera‐view space, nor Pareto curves to explore the vast power‐error space; as such, it can also handle dynamic scenes. Our algorithm is based on two key components: our novel power prediction model, and our runtime quality error estimation mechanism. These components allow us to search for the optimal rendering configuration at runtime, being transparent to the user. We demonstrate the performance of our framework on two different platforms: a desktop computer, and a mobile device. In both cases, we produce results close to the maximum quality, while achieving significant power savings.     

Building design‐time and run‐time knowledge for QoS‐based component assembly

Modern software systems are required to dynamically adapt to changing workloads, scenarios, and objectives and to achieve a certain Quality of Service (QoS). Guaranteeing QoS requirements is not trivial, as run‐time uncertainty might invalidate the design‐time rationale, where software components have been selected by means of off‐line analysis. In this work, we propose a QoS‐based feedback approach that makes a combined use of design‐time predictions and run‐time measurements to manage QoS data over time and support software architects while selecting software components that best fit QoS requirements. We illustrate the feasibility and efficacy of the approach on a case study, where the quantitative evaluation shows how the analysis effectively identifies the sources of QoS violations and indicates possible solutions to achieve QoS requirements.     

Analysis and testing of black‐box component‐based systems by inferring partial models

From experience in component‐based software engineering, it is known that the integration of high‐quality components may not yield high‐quality software systems. It is difficult to evaluate all possible interactions between the components in the system to uncover inter‐component misfunctions. The problem is even harder when the components are used without source code, specifications or formal models. Such components are called black boxes in literature. This paper presents an iterative approach of combining model learning and testing techniques for the formal analysis of a system of black‐box components. In the approach, individual components in the system are learned as finite state machines that (partially) model the behavioural structure of the components. The learned models are then used to derive tests for refining the partial models and/or finding integration faults in the system. The approach has been applied on case studies that have produced encouraging results. Copyright © 2013 John Wiley & Sons, Ltd.     

Articulated‐Motion‐Aware Sparse Localized Decomposition

Compactly representing time‐varying geometries is an important issue in dynamic geometry processing. This paper proposes a framework of sparse localized decomposition for given animated meshes by analyzing the variation of edge lengths and dihedral angles (LAs) of the meshes. It first computes the length and dihedral angle of each edge for poses and then evaluates the difference (residuals) between the LAs of an arbitrary pose and their counterparts in a reference one. Performing sparse localized decomposition on the residuals yields a set of components which can perfectly capture local motion of articulations. It supports intuitive articulation motion editing through manipulating the blending coefficients of these components. To robustly reconstruct poses from altered LAs, we devise a connection‐map‐based algorithm which consists of two steps of linear optimization. A variety of experiments show that our decomposition is truly localized with respect to rotational motions and outperforms state‐of‐the‐art approaches in precisely capturing local articulated motion.     

A quality‐of‐service‐based framework for creating distributed heterogeneous software components

Component‐based software development offers a promising solution for taming the complexity found in today's distributed applications. Today's and future distributed software systems will certainly require combining heterogeneous software components that are geographically dispersed. For the successful deployment of such a software system, it is necessary that its realization, based on assembling heterogeneous components, not only meets the functional requirements, but also satisfies the non‐functional criteria such as the desired quality of service (QoS). In this paper, a framework based on the notions of a meta‐component model, a generative domain model and QoS parameters is described. A formal specification based on two‐level grammar is used to represent these notions in a tightly integrated way so that QoS becomes a part of the generative domain model. A simple case study is described in the context of this framework. Copyright © 2002 John Wiley & Sons, Ltd.     

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.     

Pre‐tilt angle and cell‐gap measurement of vertically aligned non‐twisted liquid‐crystal displays

Abstract— A measurement method for the determination of the cell parameters of vertically aligned nematic LCOS devices has been developed. It provides the values for the pre‐tilt angle and the cell thickness in a reliable way, without the need for spectroscopic instruments. The method uses oblique incidence to separate the determination of pre‐tilt angle and cell thickness from each other and thus enhance the measurement accuracy. As a bonus, the measurement system consists only of simple optical components and does not need costly instruments.     

Touch‐screen panel integrated into 12.1‐in. a‐Si:H TFT‐LCD

Abstract— A touch‐screen‐panel (TSP) embedded 12.1‐in. LCD employing a standard existing a‐Si:H TFT‐LCD process has been successfully developed. Compared with conventional external touch‐screen panels, which use additional components to detect touch events, the new internal TSP exhibits a clearer image and improved touch feeling, as well as increased sensing speed using discrete sensing lines to enable higher‐speed sensing functions including handwriting. The new internal digital switching TSP can be fabricated with low cost because it does not require any additional process steps compared to a standard a‐Si:H TFT‐LCD.     

Self‐calibration three‐dimensional light field display based on scalable multi‐LCDs

Approach to achieve self‐calibration three‐dimensional (3D) light field display is investigated in this paper. The proposed 3D light field display is constructed up on spliced multi‐LCDs, lens and diaphragm arrays, and directional diffuser. The light field imaging principle, hardware configuration, diffuser characteristic, and image reconstruction simulation are described and analyzed, respectively. Besides the light field imaging, a self‐calibration method is proposed to improve the imaging performance. An image sensor is deployed to capture calibration patterns projected onto and then reflected by the polymer dispersed liquid crystal film, which is attached to and shaped the diffuser. These calibration components are assembled with the display unit and can be switched between display mode and calibration mode. In the calibration mode, the imperfect imaging relations of optical components are captured and calibrated automatically. We demonstrate our design by implementing the prototype of proposed 3D light field display by using modified off‐the‐shelf products. The proposed approach successfully meets the requirement of real application on scalable configuration, fast calibration, large viewing angular range, and smooth motion parallax.     

Efficient Non‐linear Optimization via Multi‐scale Gradient Filtering

We present a method for accelerating the convergence of continuous non‐linear shape optimization algorithms. We start with a general method for constructing gradient vector fields on a manifold, and we analyse this method from a signal processing viewpoint. This analysis reveals that we can construct various filters using the Laplace–Beltrami operator of the shape that can effectively separate the components of the gradient at different scales. We use this idea to adaptively change the scale of features being optimized to arrive at a solution that is optimal across multiple scales. This is in contrast to traditional descent‐based methods, for which the rate of convergence often stalls early once the high frequency components have been optimized. We demonstrate how our method can be easily integrated into existing non‐linear optimization frameworks such as gradient descent, Broyden–Fletcher–Goldfarb–Shanno (BFGS) and the non‐linear conjugate gradient method. We show significant performance improvement for shape optimization in variational shape modelling and parameterization, and we also demonstrate the use of our method for efficient physical simulation.     

Component‐wise Controllers for Structure‐Preserving Shape Manipulation

Recent shape editing techniques, especially for man‐made models, have gradually shifted focus from maintaining local, low‐level geometric features to preserving structural, high‐level characteristics like symmetry and parallelism. Such new editing goals typically require a pre‐processing shape analysis step to enable subsequent shape editing. Observing that most editing of shapes involves manipulating their constituent components, we introduce component‐wise controllers that are adapted to the component characteristics inferred from shape analysis. The controllers capture the natural degrees of freedom of individual components and thus provide an intuitive user interface for editing. A typical model usually results in a moderate number of controllers, allowing easy establishment of semantic relations among them by automatic shape analysis supplemented with user interaction. We propose a component‐wise propagation algorithm to automatically preserve the established inter‐relations while maintaining the defining characteristics of individual controllers and respecting the user‐specified modeling constraints. We extend these ideas to a hierarchical setup, allowing the user to adjust the tool complexity with respect to the desired modeling complexity. We demonstrate the effectiveness of our technique on a wide range of man‐made models with structural features, often containing multiple connected pieces.     

Deformation Transfer to Multi‐Component Objects

We present a simple and effective algorithm to transfer deformation between surface meshes with multiple components. The algorithm automatically computes spatial relationships between components of the target object, builds correspondences between source and target, and finally transfers deformation of the source onto the target while preserving cohesion between the target's components. We demonstrate the versatility of our approach on various complex models.     

Single‐ridge waveguide T‐junctions for compact multilayer beam forming networks

In this work, an H‐plane and an E‐plane single‐ridge waveguide T‐junction exhibiting compact size and broadband performance are presented. Thanks to these features the proposed devices turn out to be key components for the implementation of high‐performance multilayer antenna beam‐forming networks. Effectiveness and suitability of such T‐junctions are demonstrated through the design of a broadband array antenna feeding network. The presented components operate at Ku band, nevertheless the adopted architectures are fully scalable to other frequency band of interest.     

Large improvements in application throughput of long‐running multi‐component applications using batch grids

Computational grids with multiple batch systems (batch grids) can be powerful infrastructures for executing long‐running multi‐component parallel applications. In this paper, we evaluate the potential improvements in throughput of long‐running multi‐component applications when the different components of the applications are executed on multiple batch systems of batch grids. We compare the multiple batch executions with executions of the components on a single batch system without increasing the number of processors used for executions. We perform our analysis with a foremost long‐running multi‐component application for climate modeling, the Community Climate System Model (CCSM). We have built a robust simulator that models the characteristics of both the multi‐component application and the batch systems. By conducting large number of simulations with different workload characteristics and queuing policies of the systems, processor allocations to components of the application, distributions of the components to the batch systems and inter‐cluster bandwidths, we show that multiple batch executions lead to 55% average increase in throughput over single batch executions for long‐running CCSM. We also conducted real experiments with a practical middleware infrastructure and showed that multi‐site executions lead to effective utilization of batch systems for executions of CCSM and give higher simulation throughput than single‐site executions. Copyright © 2011 John Wiley & Sons, Ltd.     

Converting command‐line applications into binary components

A binary component is a separately compiled program that can be used as a part of a larger program. Binary components generally conform to an accepted technology such as JavaBeans or ActiveX, and generally support a rich program interface containing properties, methods and events. Binary components are generally used in a graphical user interface (GUI) environment. There are a number of benefits to be realized by converting command‐line software into binary components. The most important of these is that GUI environments are more popular and more familiar to most people than command‐line environments. Using binary components can greatly simplify a GUI implementation, to the point where it is only slightly more complicated than a typical command‐line implementation. However there are benefits that go beyond mere convenience. Binary components have much richer interfaces than command‐line programs. Binary components are service‐oriented rather than task‐oriented. A task‐oriented program has a main routine that is devoted to accomplishing a single task. A service‐oriented component has no main routine or main function, but instead provides a variety of services to its clients. Binary components can be easily integrated with one another, which permits a design where each major feature of an application is implemented in a different component. Such a design encourages software reuse at the component level and facilitates low‐impact feature upgrades. We first delineate a design‐pattern‐based methodology for converting command‐line programs into components. We then illustrate these principles using two projects, a simulation system for digital circuits, and a data generation system for software and hardware testing. Copyright © 2005 John Wiley & Sons, Ltd.     

A current‐mode tunable low‐supply‐voltage ring oscillator

A new circuit topology using a current‐mode low‐pass filter for sinusoids has been presented. The technique is relatively simple, in the proposed circuit, only three identical current‐mode low‐pass filters are connected to each other to realize the small signal path. No external passive components are required except for three capacitors. When compared with LC oscillators, the die area of this work, without inductors, is much smaller. When compared with voltage‐mode ring oscillators, the supply voltage of this work is much lower. As a particular example, a 2.4 GHz, 1.2‐V power supply, 5‐mW sinusoidal oscillator is demonstrated. The oscillation frequency is tuned by the value of that three capacitors, over ～900 MHz, and the tuning range is 37.5%. The phase noise results in ?94 and ?120 dBc/Hz at 1 and 10 MHz from the carrier, respectively. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010.     

Testing‐based process for component substitutability

Software components have emerged to ease the assembly of software systems. However, updates of systems by substitution or upgrades of components demand careful management due to stability risks of deployed systems. Replacement components must be properly evaluated to identify if they provide the expected behaviour affected by substitution. To address this problem, this paper proposes a substitutability assessment process in which the regular compatibility analysis is complemented with the use of black‐box testing criteria. The purpose is to observe the components' behaviour by analysing their internal functions of data transformation, which fulfils the observability testing metric. The approach is conceptually based on the technique Back‐to‐Back testing. When a component should be replaced, a specific Test Suite TS is built in order to represent its behavioural facets, viz. a Component Behaviour TS. This TS is later exercised on candidate upgrades or replacement components with the purpose of identifying the required compatibility. Automation of the process is supported through the testooj tool, which constrains the conditions and steps of the whole process in order to provide a rigorous and reliable approach. Copyright © 2010 John Wiley & Sons, Ltd.     

Space‐in‐Time and Time‐in‐Space Self‐Organizing Maps for Exploring Spatiotemporal Patterns

Spatiotemporal data pose serious challenges to analysts in geographic and other domains. Owing to the complexity of the geospatial and temporal components, this kind of data cannot be analyzed by fully automatic methods but require the involvement of the human analyst's expertise. For a comprehensive analysis, the data need to be considered from two complementary perspectives: (1) as spatial distributions (situations) changing over time and (2) as profiles of local temporal variation distributed over space. In order to support the visual analysis of spatiotemporal data, we suggest a framework based on the “Self‐Organizing Map” (SOM) method combined with a set of interactive visual tools supporting both analytic perspectives. SOM can be considered as a combination of clustering and dimensionality reduction. In the first perspective, SOM is applied to the spatial situations at different time moments or intervals. In the other perspective, SOM is applied to the local temporal evolution profiles. The integrated visual analytics environment includes interactive coordinated displays enabling various transformations of spatiotemporal data and post‐processing of SOM results. The SOM matrix display offers an overview of the groupings of data objects and their two‐dimensional arrangement by similarity. This view is linked to a cartographic map display, a time series graph, and a periodic pattern view. The linkage of these views supports the analysis of SOM results in both the spatial and temporal contexts. The variable SOM grid coloring serves as an instrument for linking the SOM with the corresponding items in the other displays. The framework has been validated on a large dataset with real city traffic data, where expected spatiotemporal patterns have been successfully uncovered. We also describe the use of the framework for discovery of previously unknown patterns in 41‐years time series of 7 crime rate attributes in the states of the USA.     

A new class of harmonic components for millimeter‐wave applications

This article presents several new harmonic components for millimeter‐wave applications. These components include a commonly used patch antenna and a bandpass filter operating at 35 GHz. The components have the advantages of easier fabrication and feeding compared with the commonly used traditional components operating at fundamental frequencies. The harmonic components are also used to build an antenna array. Good performance is obtained from these harmonic components in comparison with the traditional components. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2008.     

A compact planar inverted‐F antenna with U‐shaped strip for all‐metal‐shell handset application

A compact dual‐band planar inverted‐F antenna (PIFA) with U‐shaped strip is proposed in this work for all‐metal‐shell mobile telephone application. As metal‐shell handsets are getting more and more popular nowadays, it raises a big challenge in antenna design as the metal‐shell associated with surrounding electronic components like front‐back‐cameras and telephone receiver would affect the antenna performance. This work provides an optional solution to alleviate this problem, where the metal shell of the handset and a U‐shaped strip are utilized as part of the antenna. The proposed antenna is able to generate radiation at 2.4 GHz for Wi‐Fi application with the help of the metal shell while using the U‐shaped strip can achieve a resonance at 1.575 GHz for GPS application. A prototype has been fabricated to verify the radiation performance in a practical handset test environment.