34,411 research outputs found

    The discrete dynamics of small-scale spatial events: agent-based models of mobility in carnivals and street parades

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    Small-scale spatial events are situations in which elements or objects vary in such away that temporal dynamics is intrinsic to their representation and explanation. Someof the clearest examples involve local movement from conventional traffic modelingto disaster evacuation where congestion, crowding, panic, and related safety issue arekey features of such events. We propose that such events can be simulated using newvariants of pedestrian model, which embody ideas about how behavior emerges fromthe accumulated interactions between small-scale objects. We present a model inwhich the event space is first explored by agents using ?swarm intelligence?. Armedwith information about the space, agents then move in an unobstructed fashion to theevent. Congestion and problems over safety are then resolved through introducingcontrols in an iterative fashion and rerunning the model until a ?safe solution? isreached. The model has been developed to simulate the effect of changing the route ofthe Notting Hill Carnival, an annual event held in west central London over 2 days inAugust each year. One of the key issues in using such simulation is how the processof modeling interacts with those who manage and control the event. As such, thischanges the nature of the modeling problem from one where control and optimizationis external to the model to one where this is intrinsic to the simulation

    Supporting policy packages: the future of road pricing in the UK

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    Transport is already a large component of our economy and society. Historically, transport programmes were substantially about developing basic infrastructure networks. Now the emphasis is on the active management of systems and operating them to maximum advantage in the face of growing travel demand and capacity limitations. Combined developments in technology and the world economy have accelerated change to almost unpredictable levels. The change affects many areas and transport is not an exception. With new vehicle technologies, radical policies and the persistent growth in private and commercial vehicles, a new changing transport landscape is emerging. One of these changes comes in the form of sustainable transport management - managing the demand of existing infrastructure networks. The role of demand management has been illustrated in many reports and papers and it seems that governments are becoming more aware of it. This paper focuses on one particular demand management policy that is often regarded as radical and generally unacceptable. Road pricing often gets delayed or abandoned due to controversy, disagreements, unanticipated problems and a whole host of other delaying factors. There are complex interactions in transport management - there is a need for cooperation between networks, stakeholders and different authorities. Single measures that focus on 'sustainable transport' usually address a limited set of objectives and are not usually combined with other policy measures. When combined, it is sometimes unclear whether the multiple interactions between policy tools and implementation networks have been considered. An emerging case of implementation of a policy package in the UK is the support of road pricing initiatives combined with public transport improvements by the Transport Innovation Fund. The paper will present a review of the UK road pricing situation along with key implementation factors that show firstly the importance of combining policy tools and secondly the necessity in creating and maintaining strong implementation networks

    Trade, growth and geography: A synthetic

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    Economic integration affects economic development through two main channels: growth and localization of the economic activities. The theories of endogenous growth and economic geography enable us to understand these mechanisms. We study in this paper their similarities and specificities before suggesting their useful combination within a single model. Indeed, both theories are based on the same Spence-Dixit-Stiglitz monopolistic competition framework. However, they suggest two different approaches to deal with the impact of economic integration. We consider that a third path, by proposing a synthetic approach, better answers the issues raised in terms of economic convergence and divergence by these two sets of models

    Local movement: agent-based models of pedestrian flows

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    Modelling movement within the built environment has hitherto been focused on rather coarse spatial scales where the emphasis has been upon simulating flows of traffic between origins and destinations. Models of pedestrian movement have been sporadic, based largely on finding statistical relationships between volumes and the accessibility of streets, with no sustained efforts at improving such theories. The development of object-orientated computing and agent-based models which have followed in this wake, promise to change this picture radically. It is now possible to develop models simulating the geometric motion of individual agents in small-scale environments using theories of traffic flow to underpin their logic. In this paper, we outline such a model which we adapt to simulate flows of pedestrians between fixed points of entry - gateways - into complex environments such as city centres, and points of attraction based on the location of retail and leisure facilities which represent the focus of such movements. The model simulates the movement of each individual in terms of five components; these are based on motion in the direction of the most attractive locations, forward movement, the avoidance of local geometric obstacles, thresholds which constrain congestion, and movement which is influenced by those already moving towards various locations. The model has elements which enable walkers to self-organise as well as learn from their geometric experiences so far. We first outline the structure of the model, present a computable form, and illustrate how it can be programmed as a variant of cellular automata. We illustrate it using three examples: its application to an idealised mall where we show how two key components - local navigation of obstacles and movement towards points of global locational attraction - can be parameterised, an application to the more complex town centre of Wolverhampton (in the UK West Midlands) where the paths of individual walkers are used to explore the veracity of the model, and finally it application to the Tate Gallery complex in central London where the focus is on calibrating the model by letting individual agents learn from their experience of walking within the environment

    Online korean skincare decision support system

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    Despite the explosive growth of electronic commerce and the rapidly increasing number of consumers who use interactive media for pre-purchase information search and online shopping, very little is known about how consumers make purchase decisions in such settings. One desirable form of interactivity from a consumer perspective is the implementation of sophisticated tools to assist shoppers in their purchase decisions by customizing the electronic shopping environment to their individual preferences

    Food on Wheels: Mobile Vending Goes Mainstream

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    Mobile food vending generates approximately 650millioninrevenueannually.Theindustryisprojectedtoaccountforapproximately650 million in revenue annually. The industry is projected to account for approximately 2.7 billion in food revenue over the next five years, but unfortunately, most cities are legally ill-equipped to harness this expansion. Many city ordinances were written decades ago, with a different type of mobile food supplier in mind, like ice cream trucks, hot dog carts, sidewalk peddlers, and similar operators. Modern mobile vending is a substantial departure from the vending typically assumed in outdated local regulations. Vendors utilize large vehicles packed with high-tech cooking equipment and sanitation devices to provide sophisticated, safe food usually prepared to order. Increasingly, city leaders are recognizing that food trucks are here to stay. They also recognize that there is no "one size fits all" prescription for how to most effectively incorporate food trucks into the fabric of a community. With the intent of helping city leaders with this task, this guide examines the following questions: What policy options do local governments have to regulate food trucks? What is the best way to incorporate food trucks into the fabric of a city, taking into account the preferences of all stakeholders?Thirteen cities of varying size and geographic location were analyzed for this study. Information on vending regulations within each of these cities was collected and analyzed, and supplemented with semi-structured interviews with city staff and food truck vendors

    Road User Charging – Pricing Structures.

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    This project considers the extent to which the public could cope with complex price or tariff structures such as those that might be considered in the context of a national congestion pricing scheme. The key elements of the brief were: ‱ to review existing studies of road pricing schemes to assess what information and evidence already exists on the key issues; ‱ to identify what can be learned about pricing structures from other transport modes and other industries and in particular what issues and conclusions might be transferable; ‱ to improve the general understanding of the relationship between information and people’s ability to respond; and ‱ to recommend what further research would be most valuable to fill evidence gaps and enable conclusions to be drawn about an effective structure

    Valuing the small: countingthe benefits

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    This paper contains part of a reportcommissioned by a consortium oforganisations concerned with thesuccessful development of sustainabletransport strategies, and drafted byProfessor Phil Goodwin of UCL. It followsa report, Less Traffic Where People Live,which, using case studies of experiencehere and elsewhere in Europe hasdemonstrated that small-scale, or ?softfactors? can be effective in tacklingtransport problems, especially when usedin combination. Such examples includebus priority schemes, measures forimproving walking and cycling, trafficcalming, car clubs, school and workplacetravel plans, and the use of personalisedadvice and information to assist people inreducing the congestion and pollution theycause. The DfT?s report Smarter Choices ?Changing the Way we Travel, has alsohighlighted the significant potential whichexists to reduce traffic and congestion,providing soft factors are accompanied bysupporting measures to manage demand.The DfT has established a unit dedicatedto developing experience on soft factors,including on appraisal. Coupled with therecent report, there is a gainingmomentum behind expanding the role ofsoft factors in transport policy. These areall initiatives which are supported bynational and local government, and onwhich the sponsoring organisations havein recent years become active advisers aswell as campaigners.Taken together, such relatively cheap andpotentially popular initiatives are not onlypowerful contributions to theGovernment?s transport strategy: they arealso the leading examples of initiativeswhich can produce improvements swiftly? an important consideration both forpolitical reasons, and also in order toproduce the momentum and consensusfor longer term initiatives.This attractive combination of relativecheapness, environmental advantage,demonstrated successes in good practice,and speed of delivery would ? one mightthink ? lead to such policies being very highprofile indeed. However, this is not alwaysthe case. The problem this report addressesis reflected in recurrent concerns that themerits of such initiatives are overshadowedby the bigger, longer-term, much moreambitious ? and often much morecontroversial ??big? policies: especiallymassive rail or road infrastructure projects.In some ways it is natural that the ?big?initiatives should receive more attentionthan the ?small?, especially in view of along period of inadequate or distortedinvestment. But taken too far, this can becounter-productive. The question thisreport addresses is whether there is somesystematic reason, deep in the appraisaland forecasting methods, which preventsperfectly good initiatives receiving theattention and funding they deserve. Thesuggestion is that there are indeed someimportant biases of this kind, and thatsorting them out will have very helpfuleffects in avoiding wasted opportunitiesand accelerating delivery.This report addresses the followingquestions and is intended to be a helpfulcontribution to this area of work:> what are the barriers that prevent thesmall, good value-for-money schemesbeing taken up with greaterenthusiasm than the big, poor valuefor-money projects?> are there ways of restoring a balancedimplementation process?It is obvious that such barriers will includepolitical and ideological considerations,and the role of vested interests, but theyare not the focus of this report. Rather,the concern is that there may beweaknesses in the process of appraisaland assessment, preceding anyimplementation, which produce a biasagainst the small schemes. This processis intended to resolve practical questionsof design, economic questions of value formoney, planning questions of consistency,and the relationship between short andlong term objectives: it depends on a setof formal procedures and practices ?surveys, models, forecasts, appraisalframeworks ? built up over many years,and originating in the economic costbenefitanalyses whose principles andbasic features were established in the1960s and 1970s.The suggestion is made that there aresome in-built biases in current appraisaltechniques ? developed, as they were, ina different time and for a different agenda? which discriminate against some of thebest measures, and for some of the leasteffective
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