532 research outputs found
Beyond the Threshold: Investing in Women-led Small and Growing Businesses
This collaborative research project was designed to address the need for greater depth, insight, and clarity on the problems of underinvestment in Women-led Small and Growing Businesses (WSGBs), including those led by younger women (18-35 years old). It is an intentionally exploratory process intended to foster collaboration among ANDE members while also contributing to the existing body of knowledge and identifying areas for further exploration, study, and action. The research recognizes that women entrepreneurs are not a homogenous group, and attempts where possible to make distinctions based on other socioeconomic and demographic factors, as well as to acknowledge the variance in preferences even among those narrower groups
Constructing monotone homotopies and sweepouts
This article investigates when homotopies can be converted to monotone
homotopies without increasing the lengths of curves. A monotone homotopy is one
which consists of curves which are simple or constant, and in which curves are
pairwise disjoint. We show that, if the boundary of a Riemannian disc can be
contracted through curves of length less than , then it can also be
contracted monotonously through curves of length less than . This proves a
conjecture of Chambers and Rotman. Additionally, any sweepout of a Riemannian
-sphere through curves of length less than can be replaced with a
monotone sweepout through curves of length less than . Applications of these
results are also discussed.Comment: 16 pages, 6 figure
ACCUMULATION AND RENTAL BEHAVIOR IN THE MARKET FOR FARMLAND
A farmerÂ’s choices of tenure and farm size result from a complex interplay of economic factors technology, entrepreneurial ability, and personal preferences. This paper examines the qualitative effects of these factors on tenure and farm size in a dynamic optimization framework. One implication of the theoretical model is that changes in technology should cause systematic differences to be observed between rates of return on farmland and rates earned on comparable long-term assets. This implication is supported by an empirical test.Land Economics/Use,
On the complexity of optimal homotopies
In this article, we provide new structural results and algorithms for the
Homotopy Height problem. In broad terms, this problem quantifies how much a
curve on a surface needs to be stretched to sweep continuously between two
positions. More precisely, given two homotopic curves and
on a combinatorial (say, triangulated) surface, we investigate the problem of
computing a homotopy between and where the length of the
longest intermediate curve is minimized. Such optimal homotopies are relevant
for a wide range of purposes, from very theoretical questions in quantitative
homotopy theory to more practical applications such as similarity measures on
meshes and graph searching problems.
We prove that Homotopy Height is in the complexity class NP, and the
corresponding exponential algorithm is the best one known for this problem.
This result builds on a structural theorem on monotonicity of optimal
homotopies, which is proved in a companion paper. Then we show that this
problem encompasses the Homotopic Fr\'echet distance problem which we therefore
also establish to be in NP, answering a question which has previously been
considered in several different settings. We also provide an O(log
n)-approximation algorithm for Homotopy Height on surfaces by adapting an
earlier algorithm of Har-Peled, Nayyeri, Salvatipour and Sidiropoulos in the
planar setting
The ‘Little Ice Age’ in the Southern Hemisphere in the context of the last 3000 years : Peat-based proxy-climate data from Tierra del Fuego
DM’s research (at Department of Earth Sciences, Uppsala University) was supported through a European Community Marie Curie Fellowship (Contract HPMF-CT-2000-01056).Peer reviewedPostprin
An approach to assess the quality of Jupyter projects published by GLAM institutions
GLAM organizations have been digitizing their collections and making them available for the public for several decades. Recent methods for publishing digital collections such as “GLAM Labs” and “Collections as Data” provide guidelines for the application of computational methods to reuse the contents of cultural heritage institutions in innovative and creative ways. Jupyter Notebooks have become a powerful tool to foster use of these collections by digital humanities researchers. Based on previous approaches for quality assessment, which have been adapted for cultural heritage collections, this paper proposes a methodology for assessing the quality of projects based on Jupyter Notebooks published by relevant GLAM institutions. A list of projects based on Jupyter Notebooks using cultural heritage data has been evaluated. Common features and best practices have been identified. A detailed analysis, that can be useful for organizations interested in creating their own Jupyter Notebooks projects, has been provided. Open issues requiring further work and additional avenues for exploration are outlined
Personal Food Computer: A new device for controlled-environment agriculture
Due to their interdisciplinary nature, devices for controlled-environment
agriculture have the possibility to turn into ideal tools not only to conduct
research on plant phenology but also to create curricula in a wide range of
disciplines. Controlled-environment devices are increasing their
functionalities as well as improving their accessibility. Traditionally,
building one of these devices from scratch implies knowledge in fields such as
mechanical engineering, digital electronics, programming, and energy
management. However, the requirements of an effective controlled environment
device for personal use brings new constraints and challenges. This paper
presents the OpenAg Personal Food Computer (PFC); a low cost desktop size
platform, which not only targets plant phenology researchers but also
hobbyists, makers, and teachers from elementary to high-school levels (K-12).
The PFC is completely open-source and it is intended to become a tool that can
be used for collective data sharing and plant growth analysis. Thanks to its
modular design, the PFC can be used in a large spectrum of activities.Comment: 9 pages, 11 figures, Accepted at the 2017 Future Technologies
Conference (FTC
A Family of Metrics from the Truncated Smoothing of Reeb Graphs
In this paper, we introduce an extension of smoothing on Reeb graphs, which we call truncated smoothing; this in turn allows us to define a new family of metrics which generalize the interleaving distance for Reeb graphs. Intuitively, we "chop off" parts near local minima and maxima during the course of smoothing, where the amount cut is controlled by a parameter ?. After formalizing truncation as a functor, we show that when applied after the smoothing functor, this prevents extensive expansion of the range of the function, and yields particularly nice properties (such as maintaining connectivity) when combined with smoothing for 0 ? ? ? 2?, where ? is the smoothing parameter. Then, for the restriction of ? ? [0,?], we have additional structure which we can take advantage of to construct a categorical flow for any choice of slope m ? [0,1]. Using the infrastructure built for a category with a flow, this then gives an interleaving distance for every m ? [0,1], which is a generalization of the original interleaving distance, which is the case m = 0. While the resulting metrics are not stable, we show that any pair of these for m, m\u27 ? [0,1) are strongly equivalent metrics, which in turn gives stability of each metric up to a multiplicative constant. We conclude by discussing implications of this metric within the broader family of metrics for Reeb graphs
Improvements to Drinking Water: Monitoring, Reporting and Record-keeping Needed to Protect Health
Taumata Arowai, the new independent water services regulator, recently consulted publicly on the drinking water rules for water suppliers. We use a case study on nitrate and official information requests to demonstrate the current weaknesses in the drinking water monitoring and reporting systems and why the reforms proposed by Taumata Arowai seem unlikely to substantively address many of these deficiencies. To ensure sufficient public health surveillance and robust epidemiological research into the potential health impacts of drinking water contaminants, Taumata Arowai should: 1) establish a national database for water supply and quality; 2) mandate the standardisation of reporting requirements across water suppliers; 3) increase the frequency and range of water quality testing; and 4) maintain a national map of water supplies. These upgrades are particularly important in an era of rapid land use changes and climate change
Application of palaeoecology for peatland conservation at Mossdale Moor, UK
In a recent discussion of research priorities for palaeoecology, it was suggested that palaeoecological data can be applied and used to inform nature conservation practice. The present study exemplifies this approach and was conducted on a degraded blanket mire in Yorkshire, UK, in collaboration with a field-based moorland restoration agency. High-resolution, multiproxy palaeoecological analyses on a peat core from Mossdale Moor reconstructed mid to late-Holocene vegetation changes. Humification, pollen, plant macrofossil and charcoal analyses carried out throughout the peat profile show marked changes in species composition and indicate their potential causes. Results suggest that human clearance in the Mesolithic–Neolithic transition may have initiated peat growth at Mossdale Moor, making this landscape ‘semi-natural’ in its origin. Further human-induced changes are identified at 1300 cal years BP, most likely clearance by fire, and between 20 and 0 cm depth where a substantial charcoal increase is interpreted as recent (<400 years) management practices using burning to encourage browse on the moor. The long-term ecological history of the moor, derived using palaeoecological techniques, will be used to inform conservation practice and to help set feasible targets for restoration and conservation at Mossdale Moo
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