Multi-scale 3-D Surface Description: Open and Closed Surfaces

A novel technique for multi-scale smoothing of a free-form 3-D surface is presented. Complete triangulated models of 3-D objects are constructed automatically and using a local parametrization technique, are then smoothed using a 2-D Gaussian filter. Our method for local parametrization makes use of semigeodesic coordinates as a natural and efficient way of sampling the local surface shape. The smoothing eliminates the surface noise together with high curvature regions such as sharp edges, therefore, sharp corners become rounded as the object is smoothed iteratively. Our technique for free-form 3-D multi-scale surface smoothing is independent of the underlying triangulation. It is also argued that the proposed technique is preferrable to volumetric smoothing or level set methods since it is applicable to incomplete surface data which occurs during occlusion. Our technique was applied to closed as well as open 3-D surfaces and the results are presented here

Multi-Scale Free-Form Surface Description and Curvature Estimation

A novel technique for multi-scale smoothing of a free-form 3-D surface is presented. Complete triangulated models of 3-D objects are constructed at our center [4] and using a local parametrization technique, are then smoothed using a 2-D Gaussian filter. Our method for local parametrization makes use of semigeodesic coordinates as a natural and efficient way of sampling the local surface shape. The smoothing eliminates the surface noise together with high curvature regions such as sharp edges, therefore, sharp corners become rounded as the object is smoothed iteratively. Our technique for free-form 3-D multi-scale surface smoothing is independent of the underlying triangulation. It is also argued that the proposed technique is preferrable to volumetric smoothing or level set methods since it is applicable to incomplete surface data which occurs during occlusion. The technique was applied to simple and complex 3-D objects and the results are presented here

Information and Communication Technologies(ICT), Activity Decisions,and Travel Choices: 20 years into the Second Millennium and where do we go next?

CENTENNIAL PAPERSStanding Committee on Effects of Information and Communication Technologies (ICT) on Travel Choices (ADB20)Giovanni Circella, ChairInformation and Communication Technologies(ICT), Activity Decisions,and Travel Choices: 20 years into the Second Millennium and where do we go next?JACEKPAWLAK,Imperial College LondonGIOVANNICIRCELLA, University of California, Davis andGeorgia Institute of TechnologyHANIS.MAHMASSANI, Northwestern UniversityPATRICIAL.MOKHTARIAN, Georgia Institute of TechnologyABSTRACTInformation and Communication Technologies, or ICT,have rapidly emerged asan integral element of everyday life, interactingin an essential manner with mobility and the activity patterns that engender it. The current paper reflects uponthistrendandthe opportunities and challenges itrepresents.Givenmore than three decades of research in the domain of interactions between ICT, activity decisions and travel choices, we acknowledgethe elaborate, disruptiveand oftenunexpected waysalong which ICT interact with society.Tosupport the objective of theADB20 Committee, namely tosupportand promote theemerging research questions, we identifya number of technological, societal and behavioral trends related to ICT and mobility that are likelyto be major driving forces for activity-travel behavior considerations in the next 15 years. Those include democratization of technology; personalization; shared and commoditized mobility; automation;data as the new currency; next generation connectivity, including 5G; evolving social media and socialization; new forms of shopping; digital twins;activity fragmentation; andmultitasking.We also observe that inevitably, theincreasingly interlocking relationshipbetween ICT and mobility will bring challengesrelated to balancing efficiency vs. redundancy and resilience, ensuring transparency, susceptibility to malicious activitiesandtackling the digital divide. We argue that those should not be seen as barriers to realization of the ultimate benefits for society, providing that thetransportation research agenda maintains focus on the evolution of ICTand rigorously explores the related impacts on activity decisions, travel choices and, more broadly, on transportationsystems

Teleworking practice in small and medium-sized firms: Management style and worker autonomy

In an empirical study of teleworking practices amongst small and medium-sized enterprises (SMEs) in West London, organisational factors such as management attitudes, worker autonomy and employment flexibility were found to be more critical than technological provision in facilitating successful implementation. Consequently, we argue that telework in most SMEs appears as a marginal activity performed mainly by managers and specialist mobile workers

Commute replacement and commute displacement the rise of part-day home working

Working by telecommunication has been the subject of research attention in transportation studies for many years. Particular consideration has been given to occasional working from home (home working) by (full-time, paid) employees who represent a tangible removal of commute trips on days that people work from home. However, little recognition or attention has been given to the fact that home working not only may be undertaken for part of a week but also may be undertaken for parts of given days. This paper focuses particularly on part-day home working. It defines and uses the term "varied spatiotemporal (VST) working" to describe working days in which at least 30 min of continuous working takes place at home accompanied by work taking place at the workplace. Notably, such home working does not remove the commute trips but can temporally displace one or both of them. The research reported in this paper builds on preceding survey work that had established that the number of people who practice VST working and the number of VST days worked appear to be about double those for full-day home working (which has typically been the focus of research attention). The results presented in this paper are based on 25 in-depth interviews with individuals who practice VST working. The aim of the research was to examine more closely and to understand the nature of VST working and the motivations and constraints for its practice and to consider its potential contribution as a transportation demand management measure

The emerging geography of e-commerce in British retailing

This paper explores the growth of e-commerce in British grocery retailing and examines the spatial variations in e-commerce usage. The main data source is a large commercial consumer survey (Acxiom’s Research Opinion Data) rarely used by academics to date. Using these data in combination with census data, the paper addresses a number of key questions. After outlining key trends in the dataset on e-commerce usage (by product and over time) the first research question is: How do e-commerce purchases vary by geodemographic group? To answer this question, we explore e-commerce usage by age, sex and social class. The second key question is: Does e-commerce usage vary by type of geographical region? Thus, we explore variations in usage for urban and rural areas. The dynamics of urban–rural diffusion are also addressed here – by examining, in addition, the spread of broadband use across Britain. The last question is: To what degree do e-commerce sales vary by access to physical stores? This is addressed by examining consumers’ home locations in relation to geographical accessibility. The results show that age and income are crucial demographic discriminators of e-commerce usage, as is rural location versus urban, and distance from physical stores

Information and Communication Technology (ICT) and International Business Travel: Mobility Allies?

Like forecasts about the paperless office, technological solutions to the problem of international business travel continue to be deferred. As with the increased use of office paper, international business travel is defying predictions of its decline. There is growing evidence to suggest that business sectors which seem ideally placed to substitute information and communication technology (ICT) for travel, are actually generating more physical travel than other sectors. This paper develops a case study of the Irish software industry to exemplify why international travel is not diminishing in importance how and the ICT and business travel relationship is changing in this sector. The paper presents research findings that suggest that a cycle of substitution, generation and modification relationships have occurred as mobility interdependencies have developed.Peer Reviewe

Interplay between telecommunications and face-to-face interactions - a study using mobile phone data

In this study we analyze one year of anonymized telecommunications data for over one million customers from a large European cellphone operator, and we investigate the relationship between people's calls and their physical location. We discover that more than 90% of users who have called each other have also shared the same space (cell tower), even if they live far apart. Moreover, we find that close to 70% of users who call each other frequently (at least once per month on average) have shared the same space at the same time - an instance that we call co-location. Co-locations appear indicative of coordination calls, which occur just before face-to-face meetings. Their number is highly predictable based on the amount of calls between two users and the distance between their home locations - suggesting a new way to quantify the interplay between telecommunications and face-to-face interactions