1,721,230 research outputs found
Psychology of experimental mathematics
No full textComputers provide an environment in which mathematicians can experiment. The webpage linked to this discussion paper provides some examples of that, with the aim to provoke discussion about the need for proof and the conjectural nature of experimental mathematics, and the implications that would come from classroom sessions in experimental mathematics. The relevance for the study of the psychology of mathematics education is the possibility to record and analyse the creative and social aspects of students and teachers in their engagement with unsolved mathematical problem
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Improving the Estimation of Travel Demand for Traffic Simulation: Part II
No full textThis report examined several methods for estimating Origin- Destination (OD) matrices for freeways using loop detector data. Least squares based methods were compared in terms of both off- line and on- line estimation. Simulated data and observed data were used for evaluating the static and recursive estimators. For off- line estimation, four fully constrained least squares methods were compared. The results showed that the variations of a constrained least squares approach produced more efficient estimates. For on- line estimation, two recursive least squares algorithms were examined. The first method extends Kalman Filtering to satisfy the natural constraints of the OD split parameters. The second was developed from sequential quadratic programming. These algorithms showed different capabilities to capture an abrupt change in the split parameters. Practical recommendations of the choice of different algorithms are given.ITS InstituteWu, Yao; Davis, Gary; Levinson, David. (2004). Improving the Estimation of Travel Demand for Traffic Simulation: Part II. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/808
Understanding Urban Travel Demand: Problems, Solutions, and the Role of Forecasting
No full textThis report is a general examination and critique of transportation policy making, focusing on the role of traffic and land use forecasting. There are four major components:
1. Current, historical, and projected travel behavior in the Twin Cities.
2. The standard travel forecasting model, and some of its shortcomings.
3. The potential application of integrated land use and transportation models.
4. Specific transportation problems and proposed policies in the Twin Cities.
The most important result is that the standard traffic forecasting model in its current form is not well suited for evaluating many of the policies of greatest current interest, in particular, those that seek to reduce the overall amount of travel through changes in land use or travel behavior. This model was developed to predict road capacity needs, taking the quantity of travel as more or less uninfluenced by policy.
However, currently available improvements, including integrated transportation and land use models, often add little value because they are not based on a well-established theoretical and empirical understanding of travel behavior. The most urgent need in forecasting is not for more complex models, but for a better understanding of the real world processes that the models are attempting to capture.Center for Transportation StudiesBarnes, Gary; Davis, Gary. (1999). Understanding Urban Travel Demand: Problems, Solutions, and the Role of Forecasting. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/1032
Land Use and Travel Choices in the Twin Cities, 1958-1990
No full textThis report examines the effects of land development patterns on travel choices by residents of the Twin Cities area. A historical analysis studies changes in travel behavior between 1958 and 1990, focusing in particular on total daily time spent traveling. The conclusion is that daily time per traveler changed only very slightly over this time, despite very significant changes in land use.
The second major analysis in the report looks at travel choices in 1990 in greater detail. Again, the conclusion was that land use per se did not play a significant role in travel choices when other factors were controlled for. Dense central areas generated much less mileage per person, but this was almost entirely because of lower speeds, not because central city residents spent much less time driving. Overall, there was less than a 20% difference in average time spent driving per day between central city and outer suburbs, and this difference arose entirely from commute times. Non-work travel time showed no systematic variation by location, in contrast to expectations. The one area in which land use played a significant role was that large dense job locations attracted very high shares for non-auto modes.Minnesota Department of TransportationBarnes, Gary; Davis, Gary. (2001). Land Use and Travel Choices in the Twin Cities, 1958-1990. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/660
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