Efficient implementations of all-to-all broadcasting in mobile ad hoc networks

In order to ease the challenging task of information dissemination in a MANET, we employ a legend: a data structure passed around a network to share information with all the mobile nodes. Our motivating application of the legend is sharing location information. Previous research shows that a simplistic legend performs better than other location services in the literature. To realize the full potential of legend-based location services, we propose three methods for the legend to traverse a network and compare their performance in simulation. Two of our proposed methods are novel, and the third is an improvement on an existing method. We also evaluate several general improvements to the traversal methods, and describe our way of making the legend transmission reliable. The result is a simple, lightweight location service that makes efficient use of network resources. Beyond using the legend as a location service, we discuss several implementation aspects of providing an efficient all-to-all broadcast operation, including legend reliability, preventing duplicate legends, using a legend in dynamic networks, and working with non-synchronized clocks. We also provide pseudocode for our legend traversal methods to aid implementation.     

“恋衣狂”张爱玲的服装设计艺术

张爱玲是现代中国自称为"恋衣狂"的仙才作家。她不仅是我国服装文化的研究者,也是身体力行的实践者。她中西交融、化俗为雅、参差对照、猎求奇异和贵族化情结的服装设计艺术,与她的小说《传奇》一样,已成为人们永远讲不完的神话故事。     

SEIS++:一个油气勘探领域软件建造和集成的模式语言

工业化的软件复用从通用类库进化到了面向领域的应用框架和设计模式,与框架相比,设计模式更集中于软件体系结构中重复出现的设计韵律,它主要由可复用的抽象设计结构组成,特定领域内一组相关的设计模式构成了该领域的模式语言,它们可在领域内重复使用以完成某类特定系统的体系结构设计。     

Experimentation with dynamic simulation models in software engineering: planning and reporting guidelines

Simulation-based studies (SBS) have become an interesting investigation approach for Software Engineering (SE). However, the reports on experiments with dynamic simulation models found in the technical literature lack relevant information, hampering the full understanding of the procedures and results reported, as well as their replicability. Apart from the limitations on the length in conferences and journal papers, some of the relevant information seems to be missing due to methodological issues not considered when conducting such studies. This is the case of missing research questions and goals, lack of evidence regarding the dynamic simulation model validity, poorly designed simulation experiments, amongst others. Based on findings from a previous quasi-systematic literature review, we propose a set of reporting guidelines for SBS with dynamic models in the context of SE aiming at providing guidance on which information the report should contain. Furthermore, these guidelines were evolved to support SBS planning by identifying potential threats to simulation study validity and in making recommendations to avoid them, through qualitative analysis and external evaluation. Finally, we conducted different evaluations regarding both the reporting and planning guidelines, apart from using them to support the planning of a SBS as regards software evolution. A set of 33 reporting and planning guidelines for different stages of the simulation lifecycle and focused on the experimentation with dynamic simulation models have been put together. The first assessments point to a comprehensive set of guidelines, supporting a comprehensive preparation and review of the plans and reports from the studies, apart from the planning of a SBS focused on software evolution, potentially reducing the threats to the experimentation with the validity of dynamic simulation models. The 33 guidelines cannot be understood as separate groups for reporting and planning as they overlap in many aspects. The main goal is to use the guidelines to support the planning of a simulation-based study with dynamic models so that experimenters may identify potential threats to validity and produce relevant information for a complete simulation experiment report in advance. Despite their initial contribution to increase the validity of SBS, the reporting and planning of simulation-based experiments with dynamic models still has to be discussed and improved in SE. Therefore, additional assessments of this set of guidelines are needed to strengthen the confidence in their completeness and usefulness.     

GLC2000: a new approach to global land cover mapping from Earth observation data

A new global land cover database for the year 2000 (GLC2000) has been produced by an international partnership of 30 research groups coordinated by the European Commission's Joint Research Centre. The database contains two levels of land cover information—detailed, regionally optimized land cover legends for each continent and a less thematically detailed global legend that harmonizes regional legends into one consistent product. The land cover maps are all based on daily data from the VEGETATION sensor on‐board SPOT 4, though mapping of some regions involved use of data from other Earth observing sensors to resolve specific issues. Detailed legend definition, image classification and map quality assurance were carried out region by region. The global product was made through aggregation of these. The database is designed to serve users from science programmes, policy makers, environmental convention secretariats, non‐governmental organizations and development‐aid projects. The regional and global data are available free of charge for all non‐commercial applications from http://www.gvm.jrc.it/glc2000.     

Survey of glyph-based visualization techniques for spatial multivariate medical data

In this survey article, we review glyph-based visualization techniques that have been exploited when visualizing spatial multivariate medical data. To classify these techniques, we derive a taxonomy of glyph properties that is based on classification concepts established in information visualization. Considering both the glyph visualization as well as the interaction techniques that are employed to generate or explore the glyph visualization, we are able to classify glyph techniques into two main groups: those supporting pre-attentive and those supporting attentive processing. With respect to this classification, we review glyph-based techniques described in the medical visualization literature. Based on the outcome of the literature review, we propose design guidelines for glyph visualizations in the medical domain.     

Navigating in a shape space of registered models

New product development involves people with different backgrounds. Designers, engineers, and consumers all have different criteria, and these criteria interact. Early concepts evolve in this kind of collaborative context, and there is a need for dynamic visualization of the interaction between design shape and other shape-related design criteria. In this paper, a Morphable Model is defined from simplified representations of suitably chosen real cars, providing a continuous shape space to navigate, manipulate, and visualize. Physical properties and consumer-provided scores for the real cars (such as 'weight' and 'sportiness') are estimated for new designs across the shape space. This coupling allows one to manipulate the shape directly while reviewing the impact on estimated criteria, or conversely, to manipulate the criterial values of the current design to produce a new shape with more desirable attributes.     

Do we need formal education in visualization?

The following three reasons are sufficient to answer this question in the affirmative: careless mapping from data to pictures may lead to erroneous interpretation; a substantial amount of knowledge is necessary to generate images depicting complex information in a way that prevents erroneous interpretation; and decision making is increasingly based on visual representations. The organization and content of the core topics of visualization were finalized at a 1997 workshop at the Colorado School of Mines. These comprise the following eight themes: introduction to visualization; the data; the user and the task; mapping process; the representations; interaction issues; concepts of the visualization process; and systems and tools. The needs of educators and students vary too widely to bring one curriculum into focus. Instead, the eight themes recommended can be expanded into a curriculum, or compressed into several subtopics of a high-performance computing or computer graphics course. The themes can stand as separate modules, taught in a different order from that suggested. While my collaborators and I strongly recommend covering each of the core topics, we also encourage educators to expand individual themes to encompass the particular objectives of their students     

分子三维结构可视化软件建模的研究与实现

本文针对生物信息学中的分子三维结构显示软件的建模问题进行了分析和研究，介绍了Java3D技术中关于场景图等概念以及基于Web的可视化系统的分析和设计方法。在此基础上，我们详细讨论了分子的几何模型和运动模型，提出了一种基于Java3D的交互式分子三维结构显示软件的建模方法。最后，在相应软件系统HJMV的实现中，给出了几种提
高该软件运行速度的方法。     

Effects of video placement and spatial context presentation on path reconstruction tasks with contextualized videos

Many interesting and promising prototypes for visualizing video data have been proposed, including those that combine videos with their spatial context (contextualized videos). However, relatively little work has investigated the fundamental design factors behind these prototypes in order to provide general design guidance. Focusing on real-time video data visualization, we evaluated two important design factors--video placement method and spatial context presentation method--through a user study. In addition, we evaluated the effect of spatial knowledge of the environment. Participants' performance was measured through path reconstruction tasks, where the participants followed a target through simulated surveillance videos and marked the target paths on the environment model. We found that embedding videos inside the model enabled realtime strategies and led to faster performance. With the help of contextualized videos, participants not familiar with the real environment achieved similar task performance to participants that worked in that environment. We discuss design implications and provide general design recommendations for traffic and security surveillance system interfaces.     

Art and Chartjunk: A Guide for NEUVis

In the fast-changing and multi-disciplinary practice of artful information visualization, the act of translating data into an image can be fraught with peril. There is considerable debate around modes of visualization and their relationships with the underlying data. This paper outlines the debate between the opposing ideologies through assessment of design considerations and comparisons of creative practice and visual analytics. The authors summarise the current nexus of influences and circumstances and proceed to formulate a set of guidelines for creative practitioners developing visualizations for Non-Expert Users (NEUVis).     

Computer simulations vs. building guidance to enhance evacuation performance of buildings during emergency events

Computer technologies can play an important role in the establishment of dynamic building information by introducing predictive modelling where behaviours of structures or groups of people can be simulated and observed. This way they can facilitate the design of the built environment to cope with emergency events. Modelling and simulation applications can be particularly useful at pre-planning, predicting possible damage, training responders, raising public awareness, and performance evaluation for reconstruction. They can be used for the development of virtual scenarios that include aspects of rescue operations, social behaviour of building occupants, and basic design requirements to test the current building codes and regulations. Within this context, the contribution of crowd simulation to improving the design of the built environment and guidelines is highlighted in this paper. Current building guidance for emergencies are summarised and the methodology developed to use crowd modelling to define design information associated with exit preferences of people during evacuations is explained. The results of the case studies underlined that there is a difference between the assumptions used for static information in current building guidance.     

State‐of‐the‐art in Multi‐Light Image Collections for Surface Visualization and Analysis

Multi‐Light Image Collections (MLICs), i.e., stacks of photos of a scene acquired with a fixed viewpoint and a varying surface illumination, provide large amounts of visual and geometric information. In this survey, we provide an up‐to‐date integrative view of MLICs as a mean to gain insight on objects through the analysis and visualization of the acquired data. After a general overview of MLICs capturing and storage, we focus on the main approaches to produce representations usable for visualization and analysis. In this context, we first discuss methods for direct exploration of the raw data. We then summarize approaches that strive to emphasize shape and material details by fusing all acquisitions in a single enhanced image. Subsequently, we focus on approaches that produce relightable images through intermediate representations. This can be done both by fitting various analytic forms of the light transform function, or by locally estimating the parameters of physically plausible models of shape and reflectance and using them for visualization and analysis. We finally review techniques that improve object understanding by using illustrative approaches to enhance relightable models, or by extracting features and derived maps. We also review how these methods are applied in several, main application domains, and what are the available tools to perform MLIC visualization and analysis. We finally point out relevant research issues, analyze research trends, and offer guidelines for practical applications.     

Coherent time-varying graph drawing with multifocus+context interaction

We present a new approach for time-varying graph drawing that achieves both spatiotemporal coherence and multifocus+context visualization in a single framework. Our approach utilizes existing graph layout algorithms to produce the initial graph layout, and formulates the problem of generating coherent time-varying graph visualization with the focus+context capability as a specially tailored deformation optimization problem. We adopt the concept of the super graph to maintain spatiotemporal coherence and further balance the needs for aesthetic quality and dynamic stability when interacting with time-varying graphs through focus+context visualization. Our method is particularly useful for multifocus+context visualization of time-varying graphs where we can preserve the mental map by preventing nodes in the focus from undergoing abrupt changes in size and location in the time sequence. Experiments demonstrate that our method strikes a good balance between maintaining spatiotemporal coherence and accentuating visual foci, thus providing a more engaging viewing experience for the users.     

Towards a dynamic balance between humans and automation: authority, ability, responsibility and control in shared and cooperative control situations

Progress enables the creation of more automated and intelligent machines with increasing abilities that open up new roles between humans and machines. Only with a proper design for the resulting cooperative human–machine systems, these advances will make our lives easier, safer and enjoyable rather than harder and miserable. Starting from examples of natural cooperative systems, the paper investigates four cornerstone concepts for the design of such systems: ability, authority, control and responsibility, as well as their relationship to each other and to concepts like levels of automation and autonomy. Consistency in the relations between these concepts is identified as an important quality for the system design. A simple graphical tool is introduced that can help to visualize the cornerstone concepts and their relations in a single diagram. Examples from the automotive domain, where a cooperative guidance and control of highly automated vehicles is under investigation, demonstrate the application of the concepts and the tool. Transitions in authority and control, e.g. initiated by changes in the ability of human or machine, are identified as key challenges. A sufficient consistency of the mental models of human and machines, not only in the system use but also in the design and evaluation, can be a key enabler for a successful dynamic balance between humans and machines.     

An investigation of the use of health building notes by UK healthcare building designers

Building design in the healthcare industry presents a complex architectural challenge. This paper reports a qualitative study to investigate the use of building design guidance by healthcare architects and planners in the United Kingdom. Sixteen architects, healthcare planners and facilities managers participated in 11 group and individual interviews. The data were analysed using NVivo2, resulting in three main themes: changes in the design culture over 20 years for the context of guidance use; quality of the evidence base to support the guidance; and future guidance needs to include patient expectations, new building techniques and generic room templates. The use of guidance was variable, with some participants seeing a clear role for new (more standardised) guidance in the future, whereas others were more concerned about loss of design freedom. Two clear roles for ergonomics were identified to: (1) facilitate the participation of patients and clinicians in the design process; and (2) generate new research evidence with respect to spatial requirements for clinical activities to support standardisation. These recommendations pertain specifically to healthcare facility design for the National Health Service in the UK.     

Identification of metaphors for virtual environment training systems

The objective of this effort was to develop potential metaphors for assisting wayfinding and navigation in current virtual environment (VE) training systems. Although VE purports a number of advantages over traditional, full-scale simulator training devices (deployability, footprint, cost, maintainability, scalability, networking), little design guidance exists beyond individual instantiations with specific platforms. A review of metaphors commonly incorporated into human-computer interactive systems indicated that existing metaphors have largely been used as orientation aids, mainly in the form of guided navigational assistance, with some position guidance. Advanced metaphor design concepts were identified that would not only provide trainees with a useful orienting framework but also enhance visual access and help differentiate an environment. The effectiveness of these concepts to aid navigation and wayfinding in VEs must be empirically validated.     

Developing spatial visualization and mental rotation with a digital puzzle game at primary school level

Spatial ability has been recognized as a significant human skill involving the retrieval, retention, and transformation of visual information in a special context. The enhancement of the spatial ability and the effective method of training are rarely considered as an area of study in the education field. This study focuses on the enhancement of spatial visualization and mental rotation, which are two major components of spatial ability, through the practice of puzzle games. This study adopts an experimental approach to test whether the game is effective in facilitating student's development of spatial visualization and mental rotation. 79 primary school students in Taiwan are included to be volunteer participants. Two instruments are adopted to measure the participants' performance of spatial visualization and mental rotation. The research findings show that the designed puzzle games effectively improve the participants' abilities in spatial visualization and mental rotation and that the traditional puzzle games can only enhance participants' mental rotation. This study suggests that the theory-based design of multimedia games can offer a more effective learning environment for developing and improving cognitive skills.     

Identification of metaphors for virtual environment training systems

The objective of this effort was to develop potential metaphors for assisting wayfinding and navigation in current virtual environment (VE) training systems. Although VE purports a number of advantages over traditional, full-scale simulator training devices (deployability, footprint, cost, maintainability, scalability, networking), little design guidance exists beyond individual instantiations with specific platforms. A review of metaphors commonly incorporated into human—computer interactive systems indicated that existing metaphors have largely been used as orientation aids, mainly in the form of guided navigational assistance, with some position guidance. Advanced metaphor design concepts were identified that would not only provide trainees with a useful orienting framework but also enhance visual access and help differentiate an environment. The effectiveness of these concepts to aid navigation and wayfinding in VEs must be empirically validated.     

The development of guidelines for the design and evaluation of warning signs for young children

We report a study which aimed to provide further development and refinement of a set of guidelines (Waterson et al., 2012) for the design and evaluation of warning signs and other visual material for young children (i.e., aged 5–11 years). The study involved a set of semi-structured interviews and focus groups with the parents of young children, teachers, human factors experts and other groups (n = 38). The findings from the study provided broad support for the guidelines, as well as highlighting a number of issues which need to be addressed. These included the need to consider the target audience in more detail and provide additional guidance covering possible tie-ins with safety campaigns, sign location, age differences, gender and children's special needs. Similar findings were obtained with regard to the evaluation guidelines and their coverage of methods and activities for testing signs (e.g., simulation, role playing). We discuss our findings within the context of a revised set of guidelines and a set of suggestions aimed at working towards a more comprehensive approach to the design/evaluation of signs for young children. The paper concludes with a set of future topics for research including a discussion of ways forward in terms of improving support for design and evaluation including behavioural testing with children, their parents and other care givers.