Single‐View Modeling of Layered Origami with Plausible Outer Shape

Modeling 3D origami pieces using conventional software is laborious due to the geometric constraints imposed by the complicated layered structure. Targeting origami models used in visual content such as CG illustrations and movies, we propose an interactive system that dramatically simplifies the modeling of 3D origami pieces with plausible outer shapes, while omitting accurate inner structures. By focusing on flat origami models with a front‐and‐back symmetry commonly found in traditional artworks, our system realizes easy and quick modeling via single‐view interface; given a reference image of the target origami piece, the user draws polygons of planar faces onto the image, and assigns annotations indicating the types of folding operations. Our system automatically rectifies the manually‐specified polygons, infers the folded structures that should yield the user‐specified polygons with reference to the depth order of layered polygons, and generates a plausible 3D model while accounting for gaps between layers. Our system is versatile enough for modeling pseudo‐origami models that are not realizable by folding a single sheet of paper. Our user study demonstrates that even novice users without the specialized knowledge and experience on origami and 3D modeling can create plausible origami models quickly.     

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.     

Topology‐based Smoothing of 2D Scalar Fields with C1‐Continuity

Data sets coming from simulations or sampling of real‐world phenomena often contain noise that hinders their processing and analysis. Automatic filtering and denoising can be challenging: when the nature of the noise is unknown, it is difficult to distinguish between noise and actual data features; in addition, the filtering process itself may introduce “artificial” features into the data set that were not originally present. In this paper, we propose a smoothing method for 2D scalar fields that gives the user explicit control over the data features. We define features as critical points of the given scalar function, and the topological structure they induce (i.e., the Morse‐Smale complex). Feature significance is rated according to topological persistence. Our method allows filtering out spurious features that arise due to noise by means of topological simplification, providing the user with a simple interface that defines the significance threshold, coupled with immediate visual feedback of the remaining data features. In contrast to previous work, our smoothing method guarantees a C¹‐continuous output scalar field with the exact specified features and topological structures.     

Development and usability testing of an operating manual for a hair‐braiding machine

The present study applied the concepts and techniques of usability testing to the development of an operating manual for a hair‐braiding machine. A preliminary version of the manual was developed in four stages: (1) profiling user characteristics, (2) defining design features of the manual, (3) preparing contents, and (4) designing the format and layout of the manual. In each development stage, design factors, such as user characteristics and operating instructions, were identified and relevant methods, such as user profile analysis and hierarchical task analysis, were applied. The preliminary manual was evaluated by 5 cosmetology students (age, 18 to 25 years; training, 60 to 700 hours) by using various performance and preference measures and surveying opinions of the participants regarding likes, dislikes, and suggestions. Based on the test results, recommendations were made for better usability of the manual and revisions were made accordingly. The design and evaluation process of an operating manual presented in the study would help practitioners to develop a user‐friendly manual. © 2007 Wiley Periodicals, Inc.     

RodSteward: A Design‐to‐Assembly System for Fabrication using 3D‐Printed Joints and Precision‐Cut Rods

We present RodSteward, a design‐to‐assembly system for creating furniture‐scale structures composed of 3D‐printed joints and precision‐cut rods. The RodSteward systems consists of: RSDesigner, a fabrication‐aware design interface that visualizes accurate geometries during edits and identifies infeasible designs; physical fabrication of parts automatically generated 3D‐printable joint geometries and cutting plans for rods; and RSAssembler, a guided‐assembly interface that prompts the user to place parts in order while showing a focus+context visualization of the assembly in progress. We demonstrate the effectiveness of our tools with a number of example constructions of varying complexity, style and parameter choices.     

Group‐in‐a‐Box Meta‐Layouts for Topological Clusters and Attribute‐Based Groups: Space‐Efficient Visualizations of Network Communities and Their Ties

An important part of network analysis is understanding community structures like topological clusters and attribute‐based groups. Standard approaches for showing communities using colour, shape, rectangular bounding boxes, convex hulls or force‐directed layout algorithms remain valuable, however our Group‐in‐a‐Box meta‐layouts add a fresh strategy for presenting community membership, internal structure and inter‐cluster relationships. This paper extends the basic Group‐in‐a‐Box meta‐layout, which uses a Treemap substrate of rectangular regions whose size is proportional to community size. When there are numerous inter‐community relationships, the proposed extensions help users view them more clearly: (1) the Croissant–Doughnut meta‐layout applies empirically determined rules for box arrangement to improve space utilization while still showing inter‐community relationships, and (2) the Force‐Directed layout arranges community boxes based on their aggregate ties at the cost of additional space. Our free and open source reference implementation in NodeXL includes heuristics to choose what we have found to be the preferable Group‐in‐a‐Box meta‐layout to show networks with varying numbers or sizes of communities. Case study examples, a pilot comparative user preference study (nine participants), and a readability measure‐based evaluation of 309 Twitter networks demonstrate the utility of the proposed meta‐layouts.     

A comparison of simple hierarchy and grid metaphors for option layouts on small-size screens

Modern, technologically driven society is characterized by an increase in the rate of mobile device use and an increase in the extent to which these devices are used for more complex tasks than search for phone numbers. While direct consequences of screen-size reduction on task performance are well known, data are lacking on the impact of layout of multiple options in a complex task environment. In this paper we describe the results of an end-user study in which we compared two basic interface designs for the layout of multiple options: a simple hierarchy and a single layer grid. These two designs were presented to users on two screen sizes; a larger size approximating the size of a standard laptop or desktop screen and a smaller size approximating the size of a PDA screen. This study illustrates that while task performance in accessing information was superior using the grid interface rather than the simple hierarchy interface, users preferred the simple hierarchy interface. Even as the complexity of the task increased, the physical size of the screen had a significantly bigger impact on task performance than did the task complexity. These findings indicate that the grid layout should be used when task performance is of the paramount concern and the complexity of choices is not expected to be large. When user preference/satisfaction is more important than task performance the appeal of the simple hierarchy layout may supersede the cost in performance it entails.     

Estimating modes of a complex dynamical network from impulse response data: Structural and graph‐theoretic characterizations

We examine the role played by a linear dynamical network's topology in inference of its eigenvalues from noisy impulse‐response data. Specifically, for a canonical linear‐time‐invariant network dynamics, we relate the Cramer–Rao bounds on eigenvalue estimator performance (from impulse‐response data) to structural properties of the transfer function and in turn, to the network's topological structure. We begin by reviewing and enhancing algebraic characterizations of such eigenvalue estimates, which are based on pole‐residue and pole‐zero representations of the network's dynamics. We use these results to characterize mode estimation in networks with slow‐coherency structures, finding that stimulus and observation in each strongly connected network subgraph is needed for high‐fidelity estimation. We also obtain spectral and graphical characterizations of estimator performance for other graph classes (e.g., trees) and for the general case. These characterizations are used to determine the role of measurement and actuation locations in estimation performance. Finally, application of our results in dynamical‐network security is illustrated through a simple example, and a concrete procedure for network mode estimation that draws on our structural results is introduced to conclude the article. Copyright © 2014 John Wiley & Sons, Ltd.     

Spur line integrated single‐/dual‐/triple‐notched ultra‐wideband monopole antenna

Design and realization of spur line loaded frequency‐notched planar ultra‐wideband (UWB) antenna is proposed in this article. Accommodating the spur line (lines) of quarter wavelength long on the feeding microstrip line of UWB antenna, contributes to the notch‐filtering action in the feeding section itself which in turn can provides single/double/triple notch (notches) within the UWB spectrum of the antenna. The proposed technique is very simple and radiator independent as the filtering is performed in the feed region and hence the UWB radiator can be independently designed. The spur line based filtering sections are first separately designed and verified by S‐parameter measurements of the fabricated prototypes. Single, double, and triple spur line loaded microstrip sections are separately used as the feed section of a circular monopole antenna (MPA) to invoke single‐, dual‐, and triple‐notched UWB response of the MPA. All the designed prototypes are fabricated and characterized in terms of impedance and radiation parameter measurements, yielding very close correspondence with that of results obtained from full wave simulation.     

Distance‐based undirected formations of single‐integrator and double‐integrator modeled agents in n‐dimensional space

We study the local asymptotic stability of undirected formations of single‐integrator and double‐integrator modeled agents based on interagent distance control. First, we show that n‐dimensional undirected formations of single‐integrator modeled agents are locally asymptotically stable under a gradient control law. The stability analysis in this paper reveals that the local asymptotic stability does not require the infinitesimal rigidity of the formations. Second, on the basis of the topological equivalence of a dissipative Hamiltonian system and a gradient system, we show that the local asymptotic stability of undirected formations of double‐integrator modeled agents in n‐dimensional space is achieved under a gradient‐like control law. Simulation results support the validity of the stability analysis. Copyright © 2013 John Wiley & Sons, Ltd.     

Parallel, self-organizing, hierarchical neural networks withcontinuous inputs and outputs

Parallel, self-organizing, hierarchical neural networks (PSHNN's) are multistage networks in which stages operate in parallel rather than in series during testing. Each stage can be any particular type of network. Previous PSHNN's assume quantized, say, binary outputs. A new type of PSHNN is discussed such that the outputs are allowed to be continuous-valued. The performance of the resulting networks is tested in the problem of predicting speech signal samples from past samples. Three types of networks in which the stages are learned by the delta rule, sequential least-squares, and the backpropagation (BP) algorithm, respectively, are described. In all cases studied, the new networks achieve better performance than linear prediction. A revised BP algorithm is discussed for learning input nonlinearities. When the BP algorithm is to be used, better performance is achieved when a single BP network is replaced by a PSHNN of equal complexity in which each stage is a BP network of smaller complexity than the single BP network.     

Evaluation of a job‐aiding tool in inspection systems

Visual inspection plays a very important role in ensuring quality in the manufacturing and service industries. Two determinants of inspection performance are visual search and decision‐making. Improvement in any one of the components will have an impact on system performance. Job‐aids, accompanied by training, have proven to be effective in enhancing accuracy and reducing search time in visual inspection systems. This article aims to investigate the effects of search strategy along with task complexity and pacing on inspection performance using a job‐aiding tool. To facilitate the experiments, an enhanced job‐aiding tool in a simulated visual inspection environment was developed. This tool enables an inspector to track his or her search path in visual inspection systems. A pilot study and two experiments were conducted using this tool. The pilot study examined the effectiveness of the job‐aiding tool. The first experiment studied the effect of search strategy and task complexity on inspection system performance and the second experiment studied the impact of search strategy, task complexity, and pacing on system performance. Results from this research can be used to better design an inspection system. © 2007 Wiley Periodicals, Inc.     

Cost‐effective queue schemes for reducing head‐of‐line blocking in fat‐trees

The fat‐tree is one of the most common topologies among the interconnection networks of the systems currently used for high‐performance parallel computing. Among other advantages, fat‐trees allow the use of simple but very efficient routing schemes. One of them is a deterministic routing algorithm that has been recently proposed, offering a similar (or better) performance than adaptive routing while reducing complexity and guaranteeing in‐order packet delivery. However, as other deterministic routing proposals, this deterministic routing algorithm cannot react when high traffic loads or hot‐spot traffic scenarios produce severe contention for the use of network resources, leading to the appearance of Head‐of‐Line (HoL) blocking, which spoils the network performance. In that sense, we describe in this paper two simple, cost‐effective strategies for dealing with the HoL‐blocking problem that may appear in fat‐trees with the aforementioned deterministic routing algorithm. From the results presented in the paper, we conclude that, in the mentioned environment, these proposals considerably reduce HoL‐blocking without significantly increasing switch complexity and the required silicon area. Copyright © 2011 John Wiley & Sons, Ltd.     

Supporting Focus and Context Awareness in 3D Modelling Tasks Using Multi‐Layered Displays

Most 3D modelling software have been developed for conventional 2D displays, and as such, lack support for true depth perception. This contributes to making polygonal 3D modelling tasks challenging, particularly when models are complex and consist of a large number of overlapping components (e.g. vertices, edges) and objects (i.e. parts). Research has shown that users of 3D modelling software often encounter a range of difficulties, which collectively can be defined as focus and context awareness problems. These include maintaining position and orientation awarenesses, as well as recognizing distance between individual components and objects in 3D spaces. In this paper, we present five visualization and interaction techniques we have developed for multi‐layered displays, to better support focus and context awareness in 3D modelling tasks. The results of a user study we conducted shows that three of these five techniques improve users' 3D modelling task performance.     

Solution‐processable double‐layered ionic p‐i‐n organic light‐emitting diodes

Abstract— Solution‐processed double‐layered ionic p‐i‐n organic light‐emitting diodes (OLEDs), comprised of an emitting material layer doped with an organometallic green phosphor and a photo‐cross‐linked hole‐transporting layer doped with photo‐initiator is reported. The fabricated OLEDs were annealed using simultaneous thermal and electrical treatments to form a double‐layered ionic p‐i‐n structure. As a result, an annealed double‐layered OLED with a peak brightness over 20,000 cd/m² (20 V, 390 mA/cm²) and a peak efficiency of 15 cd/A (6 V, 210 cd/m²) was achieved.     

PSkel: A stencil programming framework for CPU‐GPU systems

The use of Graphics Processing Units (GPUs) for high‐performance computing has gained growing momentum in recent years. Unfortunately, GPU‐programming platforms like Compute Unified Device Architecture (CUDA) are complex, user unfriendly, and increase the complexity of developing high‐performance parallel applications. In addition, runtime systems that execute those applications often fail to fully utilize the parallelism of modern CPU‐GPU systems. Typically, parallel kernels run entirely on the most powerful device available, leaving other devices idle. These observations sparked research in two directions: (1) high‐level approaches to software development for GPUs, which strike a balance between performance and ease of programming; and (2) task partitioning to fully utilize the available devices. In this paper, we propose a framework, called PSkel, that provides a single high‐level abstraction for stencil programming on heterogeneous CPU‐GPU systems, while allowing the programmer to partition and assign data and computation to both CPU and GPU. Our current implementation uses parallel skeletons to transparently leverage Intel Threading Building Blocks (Intel Corporation, Santa Clara, CA, USA) and NVIDIA CUDA (Nvidia Corporation, Santa Clara, CA, USA). In our experiments, we observed that parallel applications with task partitioning can improve average performance by up to 76% and 28% compared with CPU‐only and GPU‐only parallel applications, respectively. Copyright © 2015 John Wiley & Sons, Ltd.     

On‐demand transmission model for remote visualization using image‐based rendering

Interactive distributed visualization is an emerging technology with numerous applications. However, many of the present approaches to interactive distributed visualization have limited performance because they are based on the traditional polygonal processing graphics pipeline. In contrast, image‐based rendering uses multiple images of the scene instead of a three‐dimensional geometrical representation, and so has the key advantage that the final output is independent of the scene complexity and depends on the desired final image resolution. Furthermore, the discrete nature of the light field dataset maps well to a hybrid solution, which can overcome the identified drawbacks. In this paper, we propose an on‐demand solution for efficiently transmitting visualization data to remote users/clients. This is achieved through sending selected parts of the dataset based on the current client viewpoint, and is done instead of downloading a complete replica of the light field dataset to each client, or remotely sending a single rendered view back from a central server to the user each time the user updates their viewing parameters. The on‐demand approach shows stable performance as the number of clients increases because the load on the server and the network traffic are reduced. Furthermore, detailed performance studies show that the proposed scheme outperforms the current solution in terms of interactivity measured in frames per second. Copyright © 2012 John Wiley & Sons, Ltd.     

Bird's‐Eye ‐ Large‐Scale Visual Analytics of City Dynamics using Social Location Data

The analysis of behavioral city dynamics, such as temporal patterns of visited places and citizens' mobility routines, is an essential task for urban and transportation planning. Social media applications such as Foursquare and Twitter provide access to large‐scale and up‐to‐date dynamic movement data that not only help to understand the social life and pulse of a city but also to maintain and improve urban infrastructure. However, the fast growth rate of this data poses challenges for conventional methods to provide up‐to‐date, flexible analysis. Therefore, planning authorities barely consider it. We present a system and design study to leverage social media data that assist urban and transportation planners to achieve better monitoring and analysis of city dynamics such as visited places and mobility patterns in large metropolitan areas. We conducted a goal‐and‐task analysis with urban planning experts. To address these goals, we designed a system with a scalable data monitoring back‐end and an interactive visual analytics interface. The monitoring component uses intelligent pre‐aggregation to allow dynamic queries in near real‐time. The visual analytics interface leverages unsupervised learning to reveal clusters, routines, and unusual behavior in massive data, allowing to understand patterns in time and space. We evaluated our approach based on a qualitative user study with urban planning experts which demonstrates that intuitive integration of advanced analytical tools with visual interfaces is pivotal in making behavioral city dynamics accessible to practitioners. Our interviews also revealed areas for future research.     

Interactive deformation and cutting simulation directly using patient‐specific volumetric images

This paper systematically advocates an interactive volumetric image manipulation framework, which can enable the rapid deployment and instant utility of patient‐specific medical images in virtual surgery simulation while requiring little user involvement. We seamlessly integrate multiple technical elements to synchronously accommodate physics‐plausible simulation and high‐fidelity anatomical structures visualization. Given a volumetric image, in a user‐transparent way, we build a proxy to represent the geometrical structure and encode its physical state without the need of explicit 3‐D reconstruction. On the basis of the dynamic update of the proxy, we simulate large‐scale deformation, arbitrary cutting, and accompanying collision response driven by a non‐linear finite element method. By resorting to the upsampling of the sparse displacement field resulted from non‐linear finite element simulation, the cut/deformed volumetric image can evolve naturally and serves as a time‐varying 3‐D texture to expedite direct volume rendering. Moreover, our entire framework is built upon CUDA (Beihang University, Beijing, China) and thus can achieve interactive performance even on a commodity laptop. The implementation details, timing statistics, and physical behavior measurements have shown its practicality, efficiency, and robustness. Copyright © 2013 John Wiley & Sons, Ltd.