Examining continuous usage of location-based services from the perspective of perceived justice

Due to the privacy risk associated with using location-based services (LBS), users are often reluctant to adopt and use them. Drawing on the justice theory, this research identified the factors affecting continuous usage of LBS. Perceived justice reflects a set of fairness perceptions and involves three dimensions: distributive justice, procedural justice and interactional justice, which reflect outcome fairness, process fairness and treatment fairness, respectively. We conducted data analysis with structural equation modeling (SEM). The results show that procedural justice is the main factor affecting privacy risk, whereas distributive justice is the main factor affecting perceived usefulness. Privacy risk and perceived usefulness influence continuous usage. Thus mobile service providers need to improve users’ perceived justice to facilitate their usage of LBS.     

An empirical examination of user adoption of location-based services

Location-based services (LBS) can present the optimal information and services to users based on their locations. This will improve their experience. However, this may also arouse users’ privacy concern and increase their perceived privacy risk. From both perspectives of flow experience and perceived risk, this research examined user adoption of LBS. We conducted data analysis with structural equation modeling. The results indicated that contextual offering affects trust and flow, whereas privacy concern affects trust and perceived risk. Trust, flow and perceived risk affect the usage intention. Among them, flow has a relatively larger effect.     

位置服务隐私保护研究综述

由于位置感知移动电子设备的繁荣,位置服务(LBS)几乎在所有的社会和商业领域广泛流行.虽然LBS给个人和社会带来了巨大利益,但也给用户的隐私造成了严重威胁.因为用户享受LBS的同时需要向不可信的LBS提供商泄露其位置和查询属性,而附加在这些信息上的上下文揭露了用户的兴趣爱好、生活习惯、健康状况等.如何保护用户的隐私免受恶意提供商的侵犯,对LBS生态系统的健康发展至关重要,因而引起了研究者的广泛关注.对LBS隐私保护的研究现状与进展进行综述.首先介绍LBS隐私的概念和威胁模型;然后,从系统结构、度量指标、保护技术等方面对现有的研究工作进行细致的分类归纳和阐述,重点阐述当前LBS隐私保护研究的主流技术:基于扭曲法的隐私保护技术;通过对各类技术性能和优缺点的分析比较,指出了LBS隐私保护研究存在的问题及可能的解决方法;最后,对未来研究方向进行了展望.     

基于位置服务的道路网数据模型综述

随着基于位置的服务(LBS)在交通管理服务中的广泛应用,获取并管理移动对象的位置信息成为必要,建立一种有效支持服务的道路网数据模型成为研究的重点和难点。道路网数据模型是对各种道路相关信息进行描述以支持移动对象位置信息获取及表示的数据模型。文中对国内外的道路网模型研究作了一个简要概述及分析。     

组件式LBS软件平台的体系结构研究

组件式LBS软件平台可以适用于不同的移动通信网，支持LBS应用的开发、定制和扩充，为迅速发展的基于位置的移动通信数据业务建立开发平台。这里主要研究和设计LBS软件平台的体系结构。     

3D树木建模技术研究进展

3D树木建模一直都是计算机图形学、计算机视觉、虚拟现实等领域最具有挑战性的研究方向之一,国外学者在该领域做了大量研究工作,但3D树木建模综述性文章的缺乏成为其发展的制约因素。侧重从计算机视觉的角度,将当前国内外经典的3D树木建模方法分为基于图像,基于规则和基于草图等三类,并跟踪了最新的3D树木建模技术进展,对他们的成果进行了深入剖析,重点阐述3D树木建模关键技术。最后,分析和比较了几种主要的3D树木建模技术,提出轻量化3D树木建模技术是今后虚拟场景中的交互应用的发展趋势。此外,根据当前研究的难点提出了基于单张图像的轻量化混合建模的研究思路。     

Changing information retrieval behaviours: an empirical investigation of users’ cognitive processes in the choice of location-based services

The introduction of smartphones and the accompanying profusion of mobile data services have had a profound effect on individuals’ lives. One of the most influential service categories is location-based services (LBS). Based on insights from behavioural decision-making, a conceptual framework is developed to analyse individuals’ decisions to use LBS, focusing on the cognitive processes involved in the decision-making. Our research is based on two studies. First, we investigate the use of LBS through semi-structured interviews of smartphone users. Second, we explore daily LBS use through a study based on diaries. The findings highlight that the decision to use LBS can be described by either a comparative mode based on the value of LBS in relation to other available options, or an intuitive mode in which past experiences trigger the use of heuristics. These modes in turn have positive influences on the continuance of LBS use and indicate changes in individuals’ information retrieval behaviours in everyday life. In particular, the distinct value dimension of LBS in specific contexts of use changes individuals’ behaviours towards accessing location-related information.     

User preferences, information transactions and location-based services: A study of urban pedestrian wayfinding

Though research into location-based services (LBS) is being carried out across a number of disciplines, user aspects of LBS remains a cross-cutting theme. In this paper, the research focuses on investigating the user information requirements from LBS at individual level, with emphasis on the interactive nature of information transactions between environments, individuals and mobile devices. Based on a proposed conceptual model, urban pedestrian wayfinding experiments have been implemented in an immersive virtual reality test environment. Automated and semi-automated methods of data collection have allowed an integrated picture of participant behaviour and information preferences to be constructed and analysed. The results of this study show that there are clear user preferences in information requirements in completing wayfinding tasks. However, changes in user preferences during the wayfinding tasks do occur in response to levels of confidence, different spatial layouts and the wayfinding situations individuals encounter. The outcomes indicate that the proposed conceptual interaction model and adopted implementation approach assist in understanding user behaviour and information preferences for LBS.     

Analysing students' shared activity while modeling a biological process in a computer-supported educational environment

Abstract  This paper reports on a case study with three dyads of high school students (age 14 years) each collaborating on a plant growth modeling task in the computer-supported educational environment ' ModelsCreator '. Following a qualitative line of research, the present study aims at highlighting the ways in which the collaborating students as well as the facilitator who supported them are engaged in the computer-based modeling 'activity'. The analysis is carried out with a two-level analytic tool that has been derived within the theoretical framework of 'activity theory'. Our results show that a wide range of modeling 'operations' is activated in the context of the three major modeling 'actions' of 'analysis', 'synthesis' and 'testing-interpreting', which take place in the light of the facilitator-driven 'action' of cognitive and technical support. Moreover, these actions are combined into 'modeling units' of various forms which are repeated several times until the modeling process comes to an end. These many-fold repeats of the 'modeling unit' appear to shape a pattern which characterizes the computer-supported shared 'activity' as a whole.     

基于互联网图像集的室外场景建模技术综述

目前在互联网上有海量的室外场景照片,它们不仅内容覆盖面广,对同一场景有大量不同视点和光照条件下的采样,而且获取成本很低.如何利用这些照片中包含的丰富场景信息,快速、方便地构造各种逼真的虚拟场景,是互联网迅猛发展给虚拟现实、计算机图形学和计算机视觉带来的新的研究课题之一.文中分析、总结了近年来国内外互联网图像的真实场景几何建模、自然光照建模和材质反射属性建模的最新研究进展,并对其未来的发展趋势提出了一些看法.     

树的建模技术研究综述与展望

树的建模技术是计算机图形学近年来研究的热点问题之一.侧重从计算机图形学的研究角度,对树的建模技术分别从基于规则的树建模技术、基于草图的树建模技术、基于图像的树建模技术3个方面进行了总结和综述,介绍了近年来提出的典型的树建模方法及最新研究进展,对其中涉及的关键技术进行了总结分析,给出了这些技术的基本思想、局限性和使用范围,并加以分析比较,最后对树的建模技术的未来研究方向给出展望.     

A field study of the industrial modeling process

This paper analyzes the modeling process by means of a field study in the chemical industries. A diversified set of experienced modelers from two different countries have been interviewed using a case study approach. The interviews focussed on the modeling process. Other issues like life-cycle perspectives and the use of modeling in the process industries were treated as well. The information has been summarized and presented in a structured manner imposing the least possible bias from the authors. Based on the interview information the modeling process is discussed in detail. Further, fundamental research issues are identified, and a research agenda is proposed.     

基于LBS的自绘地图实时漫游系统的设计与研究

随着移动计算技术、网络通信技术及LBS技术的快速发展和普及,移动端搭载的LBS应用也越来越受到研究者的关注。然而,市面上原有的移动端LBS应用并不适合低成本环境下为特殊地点提供特殊信息服务的需求。为了解决这种问题,经过基于LBS的自绘地图实时漫游系统的设计与研究,提出三种关于自绘地图与经纬度信息结合提供特殊信息的实现思路,并且以浙江工业大学的校园地图为例制作Android应用进行演示。     

Big data and urban system model - Substitutes or complements? A case study of modelling commuting patterns in Beijing

The emergence of urban big data is transforming the existing research paradigms in urban studies. New theories and analytical methods are required to meet the methodological challenges. This paper empirically compares a data-driven approach and an urban-system-model approach through a case study of modelling the commuting patterns in Beijing. For the data-driven approach, the novel location-based-services (LBS) data are explored to identify the employment-residence location of the service users. For the modelling approach, a spatial equilibrium model is calibrated for base year 2010 and is used to simulate the commuting patterns for Beijing 2015 based on exogenous development projections. The results of the two approaches are then compared against the benchmark statistics for Beijing 2015. The comparison shows that the LBS data perform better in detecting residence locations than employment locations. The model prediction fits better with the benchmark, while the errors of the LBS data tend to vary significantly across space. For amplifying the LBS sample data to represent the full population, uniform scale factor thus should be avoided. In addition, the ineffectiveness of representing short-distance commuting for the LBS data is revealed by the comparison with the model predicted flows. In light of the strength and weakness of the respective approach, the prospect of a collaborative use of big data and urban system models is explored in the conclusion.     

基于网络与自主导航结合的LBS终端软硬件设计

分析了位置服务信息终端的特点,针对其不足,采用了网络与自主导航相结合的设计方案,提出了预先存储地图数据和实时下载增量更新的思想,并在此基础上设计了基于网络与自主导航相结合的LBS移动信息终端,旨在为LBS应用层的研究提供硬件支撑.介绍了终端的主要功能,重点描述了终端的软硬件设计,基于该终端,实现了一个原型系统.     

浅谈实体建模：历史、现状与未来

实体建模技术是CAD软件的“功能心脏”,相关基础理论与算法是CAD发展历史上最关键的成果之一,成功回答了为使计算机能够辅助产品设计与制造,需在计算机中存什么几何信息以及怎么存的问题。本文对实体建模的主要历史发展脉络做了简要介绍,同时对各发展阶段的关键问题以及研究现状进行了讨论,最后选取了3个方向对实体建模的未来做出展望,重点关注从Computer-Aided Design到Computer-Automated Design的发展趋势。     

青鸟面向对象软件建模工具的研究与实现

讨论了青鸟面向对象软件建模工具JBOO（Jade Bird object-oriented)的设计和实现方法，对JBOO所支持的青鸟面向对象规范作了简介，对JBOO的系统结构和功能进行了详细地描述，并提出了一种面向对象的软件建模工具的实现方法，最后，将JBOO与典型的 类工具作了比较。     

移动位置服务应用平台研究与开发

提出了一种移动位置服务的体系结构,开发、设计了其中的关键部件移动位置服务网关和位置服务应用平台,给出了实现位置服务的应用程序设计流程。经过实际测试表明,系统能够应用于移动通信网络为用户提供位置服务。     

支持区间查询的基于位置服务外包数据隐私保护方案

随着云计算技术的迅猛发展,越来越多的LBS服务被外包到云上运行以减少本地的计算和存储成本.然而,外包环境下的云服务器通常被认为是一个半可信的实体,LBS提供商的数据安全和用户的个人隐私将会面临新的安全挑战.针对现有基于位置服务数据外包方案中不支持区间查询和隐私保护不足等问题,文章提出一种支持区间查询的LBS外包数据隐私...     

基于ProA的产品开发过程建模

为了有效对制造企业产品开发过程管理,在应用IDEF0模型、分层Petri网和面向对象设计方法并在分析活动和过程关系的基础上,提出了基于活动及其实现过程(ProA)建模单元的过程模型的建立方法.详细对ProA数学建模,定义了ProA、ProA的输入/输出展开、ProA建模单元的典型运作、产品开发过程建模步骤.通过基于ProA的机电产品开发过程建模实例研究说明了其实用性.