JAMES: An object‐oriented Java framework for discrete optimization using local search metaheuristics

This paper describes the Java Metaheuristics Search framework (JAMES, v1.1): an object‐oriented Java framework for discrete optimization using local search algorithms that exploits the generality of such metaheuristics by clearly separating search implementation and application from problem specification. A wide range of generic local searches are provided, including (stochastic) hill climbing, tabu search, variable neighbourhood search and parallel tempering. These can be applied to any user‐defined problem by plugging in a custom neighbourhood for the corresponding solution type. Using an automated analysis workflow, the performance of different search algorithms can be compared in order to select an appropriate optimization strategy. Implementations of specific components are included for subset selection, such as a predefined solution type, generic problem definition and several subset neighbourhoods used to modify the set of selected items. Additional components for other types of problems (e.g. permutation problems) are provided through an extensions module which also includes the analysis workflow. In comparison with existing Java metaheuristics frameworks that mainly focus on population‐based algorithms, JAMES has a much lower memory footprint and promotes efficient application of local searches by taking full advantage of move‐based evaluation. Releases of JAMES are deployed to the Maven Central Repository so that the framework can easily be included as a dependency in other Java applications. The project is fully open source and hosted on GitHub. More information can be found at http://www.jamesframework.org . Copyright © 2016 John Wiley & Sons, Ltd.     

Development of a 42‐in. 2‐D/3‐D switchable display using multi‐view technology for public‐information‐display applications

Abstract— A 42‐in. 2‐D/3‐D switchable display operating in a parallax‐barrier‐type system consisting of liquid‐crystal displays (LCDs) has been developed. The system displays 2‐D images in full resolution, without any degradation to the original 2‐D images, and 3‐D autostereoscopic images with resolutions higher than SVGA with wide viewing zones electrically controlled by the parallax‐barrier system. The system is intended for use in public‐information displays (PIDs), a booming field, and as displays for gaming, medical, and simulation applications.     

结合全局与局部信息的点云目标识别模型库构建

目的 点云目标识别流程分为离线与在线阶段。离线阶段基于待识别目标的CAD模型构建一个模型库,在线基于近邻查找完成识别。本文针对离线阶段,提出一种新的模型库构建方法。方法 首先将CAD模型置于一个二十面体中心,使用多个虚拟相机获取CAD模型在不同视角下的点云;然后将每个不同视角下的点云进行主成分分析并基于主成分分析的结果从多个选定的方向将点云切分为多个子部分,这些子部分包含点云的全局及局部信息;接着对每个子部分使用聚类算法获取其最大聚类,去除离群点;最后结合多种方式删减一些冗余聚类,减小模型库规模。结果 在多个公开数据集上使用多种点云描述子进行对比实验,识别结果表明,相对于传统的模型库构建方法,基于本文方法进行识别正确率更高,在某些点云描述子上的识别正确率提升达到10%以上。结论 通过将CAD模型在不同视角下点云的全局与局部信息都加入模型库中,本文提出的模型库构建方法可有效提高点云目标识别正确率,改善了场景目标发生遮挡时,近邻查找识别精度不高的问题。     

360°‐viewable cylindrical integral imaging system using a 3‐D/2‐D switchable and flexible backlight

Abstract— A 360°‐viewable cylindrical three‐dimensional (3‐D) display system based on integral imaging has been implemented. The proposed system is composed of a cylindrically arranged electroluminescent (EL) pinhole film, an EL film backlight, a barrier structure, and a transmission‐type flexible display panel. The cylindrically arranged point‐light‐source array, which is generated by the EL pinhole film reconstructs 360°‐viewable virtual 3‐D images at the center of the cylinder. In addition, the proposed system provides 3‐D/2‐D convertibility using the switching of EL pinhole film from a point light source to a surface light source. In this paper, the principle of operation, analysis of the viewing parameters, and the experimental results are presented.     

Analysis of angular dependence of 3‐D technology using polarized eyeglasses

Abstract— The cause of the angular dependence of 3‐D technology that requires the use of eyeglasses with linear or circular polarization is analyzed. For 3‐D technology that requires the use of eyeglasses, anisotropic media such as a polarizer or retardation film determines the polarization state. Therefore, the angular behavior of 3‐D display performance is also affected by the characteristics of the anisotropic media that have intrinsic angular dependence. Various conditions of the optic axes of the imaging display and eyeglasses are investigated to understand their effect on 3‐D display performance. The result shows that some conditions of the optic axes can cause non‐negligible degradation of 3‐D display performance.     

Depth‐ and viewing‐angle‐enhanced 3‐D/2‐D switchable display system with high contrast ratio using multiple display devices and a lens array

Abstract— An improved 3‐D/2‐D switchable display system with enhanced depth and viewing angle by adding two LCD panels to an integral imaging system has been realized. The proposed system uses the see‐through property of an LCD panel and displays multiple sets of elemental images on the LCD panels to integrate them on multiple locations simultaneously. As a result, the depth of the 3‐D image can be enhanced. For wide viewing angles, the time‐multiplexing method was adopted by displaying mask patterns on the front LCD panel. In addition, another technique to increase the contrast ratio of the proposed system has also been developed. Some experimental results will be provided.     

High‐resolution autostereoscopic 3‐D projection display with a space‐dividing iris‐plane shutter

Abstract— A high‐resolution autostereoscopic 3‐D projection display with a polarization‐control space dividing the iris‐plane liquid‐crystal shutter is proposed. The polarization‐control iris‐plane shutter can control the direction of stereo images without reducing the image quality of the microdis‐play. This autostereoscopic 3‐D projection display is 2‐D/3‐D switchable and has a high resolution and high luminance. In addition, it has no cross‐talk between the left and right viewing zones, a simple structure, and the capability to show multi‐view images.     

A dual‐response strategy for global logistics under uncertainty: a case study of a third‐party logistics company

This paper examines global logistics problems experienced by a third‐party logistics (3PL) company that is responsible for transporting goods from one country to another by road, as well as warehousing goods in two countries. Because of the limited fleet capacity, the logistics company has to hire additional trucks from two countries in advance. However, customer's shipment information is uncertain, and the accurate shipment notice is only available on the shipping day. This paper proposes a dual‐response logistics strategy to be as responsive as possible for coping with short shipment notice time and uncertainty involved. A two‐stage stochastic mixed 0–1 programming model is formulated to satisfy customer demand while minimizing the total logistics cost. A series of experiments demonstrate the effectiveness of the proposed stochastic model. Compared to the corresponding expected value model, the stochastic model provides a more responsive and less expensive global logistics system.     

Design of a compact projection display for the visualization of 3‐D images using polarization sensitive eyeglasses

Abstract— A compact optical architecture of a three‐dimensional projection display that simultaneously generates two full‐color images with an orthogonal polarization state is presented. The minimal size of the optical engine was investigated and a compact illumination system using light‐emitting diodes as light sources was designed. The effect of dichroic mirrors in the illumination path on the stereoscopic images was also investigted.     

High‐visibility 2‐D/3‐D LCD with HDDP arrangement and its optical characterization methods

Abstract— A 3.1‐in.‐diagonal 2‐D/3‐D LCD with a novel pixel arrangement, called horizontally double‐density pixels (HDDP), for high‐quality 3‐D images has been developed. 3‐D visibility has been improved by broadening the qualified stereoscopic viewing space (QSVS) where high‐quality 3‐D images can be seen. In order to evaluate the QSVS, optical characterization methods, based on the ergonomics for stereoscopy, such as 3‐D crosstalk, interocular luminance difference and 3‐D moiré have been proposed. The implementation results show that these methods can correctly evaluate high‐visibility autostereoscopic displays.     

基于点线关系从透视画隐线图重构三维平面立体

提出了一种基于点与直线关系从透视投影画隐线图建立平面立体线框模型的新方法。给出了基于点线关系的基本约束,根据透视投影画隐线图中隐含的点与直线位置关系建立约束方程,建立一个线性系统,通过求解该线性系统得到平面立体的三维信息。用算例进行验证,得到了平面立体的三维信息。     

Non‐destructive recognition of dielectric coated conducting objects by using WD type time–frequency transformation and PCA‐based fusion

This article demonstrates the applications of a non‐destructive electromagnetic target recognition method, called Wigner distribution‐principal component analysis (WD‐PCA) method, to dielectric coated conducting spheres. These spheres are chosen to be highly similar having the same overall size but slightly different permittivity and thickness values in coating layers. Four different classifiers are simulated by using the WD‐PCA method for varying sizes of object libraries under different noise conditions. High correct decision rates are demonstrated even for challenging classifier libraries containing a large number of coated conductors while the method is also shown to be highly robust against noise both in design and test stages. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

Two‐way multi‐view 2‐D/3‐D display combining LC lens and HVxDP panel using novel pixel arrangement

We have developed a two‐way multi‐view 2‐D/3‐D display combining a liquid crystal lens and horizontally and vertically x times‐density pixels (HVxDP) arrangement. The two‐way multi‐view display features the same display resolution in 2‐D and 3‐D modes and a quite small color moiré for landscape and portrait, respectively, when using the HVxDP arrangement. In this paper, we realized suitable 3‐D properties for achieving a good balance between 3‐D moiré and 3‐D crosstalk for landscape and portrait by a two‐way liquid crystal lens with two kinds of focal lengths for the edge part and the center part of the lens.     

Robust non‐fragile H ∞ ∕ L2 − L ∞ control of uncertain linear system with time‐delay and application to vehicle active suspension

This paper presents an approach to design robust non‐fragile H _∞ ∕ L₂ ? L _∞ static output feedback controller, considering actuator time‐delay and the controller gain variations, and it is applied to design vehicle active suspension. According to suspension design requirements, the H _∞ and L₂ ? L _∞ norms are used, respectively, to reflect ride comfort and time‐domain hard constraints. By employing a delay‐dependent Lyapunov function, existence conditions of delay‐dependent robust non‐fragile static output feedback H _∞ controller and L₂ ? L _∞ controller are derived, respectively, in terms of the feasibility of bilinear matrix inequalities. Then, a new procedure based on LMI optimization and a hybrid algorithm of the particle swarm optimization and differential evolution is used to solve an optimization problem with bilinear matrix inequality constraints. Simulation results show that the designed active suspension system still can guarantee their own performance in spite of the existence of the model uncertainties, the actuator time‐delay and the controller gain variations. Copyright © 2014 John Wiley & Sons, Ltd.     

Effect and experiment of curvature radius of 3‐D printed conformal load‐bearing antenna array on EM performance

Prototypes of a special conformal load‐bearing antenna array (CLAA) which has nondevelopable surface, are designed, fabricated, and tested, and the effect of the substrate curvature radius on its EM performance is also researched in this work. A novel three‐dimensional (3‐D) printing technology and fabrication equipment based on micro‐droplet spraying and metal laser sintering are proposed to create patch array and divider network on a non‐developable curved rigid substrate. In order to compare with conventional technology (such as chemical etching), a planar CLAA prototype with two patches, operating frequency at 5GHz, is designed and fabricated by two different technologies, the surface roughness, fabrication tolerance, and EM performance are tested and compared. Finally, a spherical CLAA prototype with eight patches, operating frequency at 13GHz, is designed and fabricated by the novel 3D printing, measured EM performance demonstrate the applicability of additive manufacturing for this special CLAA.     

Coplanar waveguide‐fed electrically small dual‐polarized short‐ended zeroth‐order resonating antenna using Ω‐shaped capacitor and single‐split ring resonator for GPS/WiMAX/WLAN/C‐band applications

This work explains the design and analysis of a triple‐band electrically small (ka = 0.56 < 1) zeroth‐order resonating (ZOR) antenna with wideband circular polarization (CP) characteristics. The antenna compactness is obtained due to ZOR frequency of composite right/left‐handed (CRLH) transmission line (TL) and wideband CP radiation are achieved due to the introduction of single‐split ring resonator and asymmetric coplanar waveguide fed ground plane. The proposed antenna obtains an overall electrical size including the ground plane of 0.124 λ₀ × 0.131 λ₀ × 0.005 λ₀ at 1.58 GHz and physical dimension of 23.7 × 25 × 1 mm³ are achieved. The antenna provides a size reduction of 44.95% compared to a conventional monopole antenna. The novelty behind the ohm‐shaped capacitor is the generation of extra miniaturization with better antenna compactness. The antenna provides dual‐polarized radiation pattern with linear polarization radiation at 1.58 and 3.54 GHz, wideband CP radiation at 5.8 GHz. The antenna measured results shows good impedance bandwidth of 5%, 6.21%, and 57.5% for the three bands centered at 1.58, 3.54, and 5.8 GHz with a wider axial ratio bandwidth (ARBW) of 25.47% is obtained in the third band. The antenna provides a higher level of compactness, wider ARBW, good radiation efficiency, and wider S₁₁ bandwidth. Hence, the proposed antenna is suitable for use in GPS L1 band (1.565‐1.585 GHz), WiMAX 3.5 GHz (3.4‐3.8 GHz) GHz, WLAN 5.2/5.8 GHz (5.15‐5.825 GHz), and C‐band (4‐8 GHz) wireless application systems.     

Genetic algorithm optimization of a planar slot array using full wave method‐of‐moments analysis

Waveguide‐fed slot arrays in standing wave mode have been employed successfully in space based remote sensing radars because of their high efficiency, ease of deployment and their ability to withstand the radiation environment. Although the bandwidth requirement in such systems is minimal, at Ka band and above manufacturing tolerances in the order of 1 mil (25 μm), achieved in the dip brazing process, may affect their performance. To produce designs that are less sensitive to manufacturing tolerance, genetic algorithm (GA) optimization is employed in conjunction with a full wave analysis utilizing the method‐of‐moments solution to the pertinent integral equations of slot apertures of a planar array. In this work, a single 8 × 10 sub‐array of an interferometric antenna, proposed previously for a planetary mapping application, was investigated. The array was first designed by the Elliott's procedure and subsequently the design parameters were perturbed by GA optimization using the moment method analysis. The fitness parameter is a weighted function of return loss and gain over a number of frequencies in the operating band. A matching waveguide section consisting of inductive irises is also optimized using GA and mode matching technique. Optimum designs producing nearly constant gain and good return loss over 6% bandwidth are found to be less sensitive to manufacturing tolerance than the initial Elliott design. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013.     

Design of a 10 W high‐efficiency balanced power amplifier using a combination of load‐pull and load‐line methods for ISM band

In this article, a 10 W power amplifier has been designed and constructed at 2.4 GHz. The source and load‐pull impedance data published by the manufacturer at a nearby frequency of 2.5 GHz have been adopted to power match the transistor at the intended design frequency. For this purpose, the linear model of the GaN transistor has been derived from the S‐parameter data. The load‐line at the dependent current source plane and the impedance at the intrinsic gate‐source capacitance have been simulated in the presence of the source and load‐pull impedances at 2.5 GHz. The extracted impedances have been retained in the design of the power amplifier at 2.4 GHz. In a novel approach, the input and output matching circuits interacted with the linear model of the transistor to provide the same load‐line conditions at the virtual drain plane and the intrinsic gate‐source capacitance plane. In contrast to conventional load‐pull methods that give no information about the harmonic terminations, harmonic terminations can be easily controlled in this method. The insight into the transistor linear model allows the harmonic terminations at the virtual drain plane to be set to low values for proper class‐B operation.     

The construction and performance of a multiviewer 3‐D television display

Abstract— The De Montfort University (DMU) autostereoscopic 3‐D display, intended for television applications, is described. It provides freedom of viewer movement over a typical “living room” sized area, with no restrictions on viewer's head positions. The display is capable of supplying 3‐D images to multiple viewers who do not need to wear special glasses. It operates by producing regions (exit pupils) in the viewing field where either a left or a right image is perceived. The positions of the exit pupils are steered to the viewers' eyes by the use of head tracking. Design issues that became apparent during the construction of a first prototype, and the findings from tests on it, are described. In addition, the current status of a more advanced prototype is reported.     

A pixel structure for simultaneous programming and emission method for shutter‐glasses‐type stereoscopic 3‐D AMOLED displays

Abstract— A pixel structure for shutter‐glasses‐type stereoscopic 3‐D active‐matrix organic light‐emitting‐diode (AMOLED) displays is proposed. The proposed pixel programs data to the pixel during the light‐emission time of an OLED. Because the emission time of the proposed pixel is extended, it is expected that the proposed pixel not only decreases the peak current of the OLED during the emission period but also reduces flicker. Moreover, the aperture ratio of the proposed pixel is 58.69% for a 50‐in. full‐high‐definition (FHD) condition by minimizing the number of thin‐film transistors (TFTs), capacitors, and control signal lines as seven TFTs, two capacitors, two power lines, and four control lines per unit pixel. Simulation results show that the error in the emission current of the proposed pixel is from ?0.82% to +0.90% when the threshold‐voltage variation of the driving TFT is ±1.00 V, and the maximum variation of the emission current is ?1.35% when a voltage drop in the power line is ?0.50 V on a full‐white‐image display.