929 research outputs found
Time-evolving measures and macroscopic modeling of pedestrian flow
This paper deals with the early results of a new model of pedestrian flow,
conceived within a measure-theoretical framework. The modeling approach
consists in a discrete-time Eulerian macroscopic representation of the system
via a family of measures which, pushed forward by some motion mappings, provide
an estimate of the space occupancy by pedestrians at successive time steps.
From the modeling point of view, this setting is particularly suitable to
treat nonlocal interactions among pedestrians, obstacles, and wall boundary
conditions. In addition, analysis and numerical approximation of the resulting
mathematical structures, which is the main target of this work, follow more
easily and straightforwardly than in case of standard hyperbolic conservation
laws, also used in the specialized literature by some Authors to address
analogous problems.Comment: 27 pages, 6 figures -- Accepted for publication in Arch. Ration.
Mech. Anal., 201
Pedestrian flows in bounded domains with obstacles
In this paper we systematically apply the mathematical structures by
time-evolving measures developed in a previous work to the macroscopic modeling
of pedestrian flows. We propose a discrete-time Eulerian model, in which the
space occupancy by pedestrians is described via a sequence of Radon positive
measures generated by a push-forward recursive relation. We assume that two
fundamental aspects of pedestrian behavior rule the dynamics of the system: On
the one hand, the will to reach specific targets, which determines the main
direction of motion of the walkers; on the other hand, the tendency to avoid
crowding, which introduces interactions among the individuals. The resulting
model is able to reproduce several experimental evidences of pedestrian flows
pointed out in the specialized literature, being at the same time much easier
to handle, from both the analytical and the numerical point of view, than other
models relying on nonlinear hyperbolic conservation laws. This makes it
suitable to address two-dimensional applications of practical interest, chiefly
the motion of pedestrians in complex domains scattered with obstacles.Comment: 25 pages, 9 figure
What do We Know about Social Entrepreneurship: An Analysis of Empirical Research
Despite the growing attention to social entrepreneurship as a scholarly field of research, it is still in a stage of infancy. Research in the past two decades has been primarily dedicated to establishing a conceptual foundation, which has resulted in a considerable stream of conceptual papers. Empirical articles have gradually appeared since the turn of the century. Although they are still outnumbered by conceptual articles, empirical articles are of considerable significance for the evolution of social entrepreneurship as a field of scientific inquiry. The purpose of this paper is to gauge the current state of empirical research in the field by reviewing 31 empirical research studies on social entrepreneurship, classifying them along four dimensions and summarising research findings for each of these dimensions. To serve this purpose in a meaningful fashion requires discriminating between different perspectives on social entrepreneurship. Hence, four different schools of thought are presented, and the articles in our sample are classified accordingly
Social Entrepreneurship in the Modern Economy: Warm Glow, Cold Feet
This study tests and extends current knowledge on the causes of social entrepreneurship: a type of entrepreneurship that concerns the process of discovering, evaluating, and pursuing opportunities aimed at the creation of social value. In contrast to what is common in this research domain, this study applies a research design based on unique, large-scale and internationally comparable survey data. Various research themes are addressed such as the occurrence and drivers of social entrepreneurship at the macro-level, factors that influence the survival of social ventures at the firm level, and the differences and commonalities between social and commercial entrepreneurs at the individual level.
At the macro-level it is concluded that social entrepreneurship clearly is a global phenomenon with a prevailing role for the level of income in a country as one of the drivers of its occurrence. At the micro-level results indicate a deviating entrepreneurial profile for social entrepreneurs that tends to be, in some respects, less favorable compared to commercial entrepreneurs in terms of effort put into the organisation, self-confidence, ambition, funding and progression to more mature stages of the entrepreneurial process.
The results of this thesis are of particular interest for public policy-makers, private foundations, and support organizations who want to promote social entrepreneurship and improve the sector infrastructure. This study advocates taking account for this deviating entrepreneurial profile
Social Entrepreneurship and Performance: The Role of Perceived Barriers and Risk
This study investigates if and in what way social entrepreneurs are hampered in turning their efforts into sustainable organizations. Using binary logit regressions and unique data containing approximately 26,000 individual-level data points for 36 countries, this
Sustainable Entrepreneurship: The Role of Perceived Barriers and Risk
Entrepreneurs who start a business to serve both self-interests and collective interests by addressing unmet social and environmental needs are usually referred to as sustainable entrepreneurs. Compared with regular entrepreneurs, we argue that sustainable entrepreneurs face specific challenges when establishing their businesses owing to the discrepancy between the creation and appropriation of private value and social value. We hypothesize that when starting a business, sustainable entrepreneurs (1) feel more hampered by perceived barriers, such as the institutional environment and (2) have a different risk attitude and perception than regular entrepreneurs. We use two waves of the Flash Eurobarometer survey on entrepreneurship (2009 and 2012), which contains information on start-up motivations, start-up barriers, and risk perceptions of approximately 3000 (prospective) business owners across 33 countries. We find that sustainable entrepreneurs indeed perceive more institutional barriers in terms of a lack of financial, administrative, and informational support at business start-up than regular entrepreneurs. Further, no significant differences between sustainable and regular entrepreneurs are found in terms of their risk attitudes or perceived financial risks. However, sustainable entrepreneurs are more likely to fear personal failure than regular entrepreneurs, which is explained by their varied and complex stakeholder relations. These insights may serve as an important signal for both governments and private capital providers in enhancing the institutional climate
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Co-construction of knowledge through Participatory Action Research: People-First Tourism methodology and research tools
People-First Tourism (P1t) research examines the role of tourism microentrepreneurship on equity and sustainability among people with vulnerable livelihoods. Studying the subaltern carries inherent challenges, which can be best addressed through PAR methodologies. Accordingly, P1t research includes tourism microentrepreneurs as partners in the research process so that they participate in a process of conscientization that helps them identify forces undermining their livelihoods. Our involvement with participants develops gradually as we coach them and collect data. This process earn us entry to more in-depth insights and stronger-inference longitudinal findings. In addition, P1t is associated with a social venture that sells experiences provided by participating microentrepreneurs. Consequently, in addition to expected project impacts on policy, P1t is generating direct benefits to the participants’ livelihoods. In this presentation we will discuss the PAR methodology guiding P1t and will train session participants on how to use some of the P1t research tools
The valuation of European financial firms
We extend the recent literature concerning accounting based valuation models to investigate financial firms from six European countries with substantial financial sectors: France, Germany, Italy, Netherlands, Switzerland and the UK. Not only are these crucial industries worthy of study in their own right, but unusual accounting practices, and inter-country differences in those accounting practices, provide valuable insights into the accounting-value relationship. Our sample consists of 7,714 financial firm/years observations from 1,140 companies drawn from 1989-2000. Sub-samples include 1,309 firm/years for banks, 650 for insurance companies, 1,705 for real estate firms, and 3,239 for investment companies. In most countries we find that the valuation models work as well or better in explaining cross-sectional variations in the market-to-book ratio for financial firms as they do for industrial and commercial firms in the same countries, although Switzerland is an exception to this generalization. As expected, the results are sensitive to industrial differences, accounting regulation and accounting practices. In particular, marking assets to market value reduces the relevance of earnings figures and increases that of equity
Disjunct perceptions? Climate change threats in two-low lying South African coastal towns.
Coastal towns rely heavily on the quality and expanse of their beaches to attract tourists. Climate is an important tourism determinant, controlling the length and timing of peak arrivals. South African tourism is particularly reliant on these factors. Perceptions of tourists and tourist accommodation establishment regarding climate change threats to tourism are explored for the towns of St Francis Bay and Cape St Francis. Tourism accommodation establishments were predominantly concerned with day-to-day changes in weather, investing in small-scale infrastructural changes to improve the comfort of their guests. By contrast, tourists demonstrated greater concern for the risk of flooding, sea-level rise and the degeneration of the beaches. This reflects concerning disjunctures between perceptions of tourists and accommodation establishments regarding climate change threats. This may portray to tourists insufficient investment in adaptation at accommodation establishments, resulting in decreased tourist visitations in the short-term in favour of destinations perceived as better prepared.SP201
Goal heterogeneity at start-up: are greener start-ups more innovative?
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