Marco Pollanen

A CATALOG OF THE YOUNGEST YSOS AND CANDIDATE PROTOSTARS

We have compiled a catalog of candidate protostars from the major astronomical journals up to the end of 1993. The Beichman-Ichikawa color criterion was used as the main test of an authors claim that a source should be deemed a candidate protostar. Names, positions (1950 and 2000), LSR velocities, information on whether there are associated outflows, and references are provided. This catalog is meant to update an earlier compilation by Wynn-Williams (1982).

A Tablet-Compatible Web-Interface for Mathematical Collaboration

Mathematical novices – including students in introductory mathematics and statistics service courses – increasingly need to engage in online mathematical collaboration. Using currently-available interfaces for their mobile and touch-enabled devices, however, this group faces difficulties, for those interfaces are text-based and not directly suitable for mathematical communication and collaboration.

The Characteristics of Writing Environments for Mathematics: Behavioral Consequences and Implications for Software Design and Usability

Effective communication and collaboration of symbolic and quantitative knowledge requires the digitization of mathematical expressions. The multi-dimensionality of mathematical notation creates a challenge for mathematical software editors. There are two different approaches for handling the multi-dimensionality of mathematical notation: either using a two-dimensional writing environment in which symbols can be placed freely (unit-based) or using an environment in which single-dimensional structural elements can be nested (structure-based). The structure-based approach constrains how users write expressions. These constraints may conflict with how mathematics is normally written. A study is reported that examines how users write mathematical expressions using two graphic based editors: one that is structure-based and one that allows the free-form manipulation of selected symbols in a diagrammatic fashion (unit-based). The results are contrasted with how users handwrite mathematics in a physical medium and implications are drawn for future software design.

The application of the Sinc-Collocation approach based on derivative interpolation in numerical oceanography

Abstract In this paper, the application of a Sinc-Collocation approach based on first derivative interpolation in numerical oceanography is presented. The specific model of interest involves a hydrodynamic model of wind-driven currents in coastal regions and semi-enclosed seas with depth-dependent vertical eddy viscosity. The model is formulated in two different but equivalent systems; a complex-velocity system and a real-valued coupled system. Even in the presence of singularities that are often present in oceanographic problems involving boundary layers, the Sinc-Collocation technique provides exponentially convergent approximations. Moreover, the first derivative interpolation approach which uses Sinc-based integration to approximate the unknown has advantages over the customary Sinc method of interpolating the unknown itself since integration has the effect of damping out numerical errors that are inherently present in numerical approximations. Moreover, the approach presented in this paper preserves the appropriate endpoints behaviors of the Sinc bases, resulting in a highly accurate and computationally efficient method. The accuracy and stability of the proposed method is demonstrated through the solution of several model problems. It is further shown that the proposed approach is more accurate and computationally less expensive than those obtained by the Sinc-Galerkin approach reported in previous studies.

Modeling Drought Option Contracts

We introduce a new financial weather derivative—a drought option contract—designed to protect agricultural producers from potential income loss due to agricultural drought. The contract is based on an index that reflects the severity of drought over a long period. By modeling temperature and precipitation, we price a hypothetical drought contract based on data from the Jinan climate station located in a dry region of China.

Identification of Errors in Mathematical Symbolism and Notation: Implications for Software Design

Mathematical user interfaces for authoring, collaboration, problem-solving and reasoning invariably rely on the ability to read, write and manipulate complex mathematical expressions. However, very little research has been done on how people read mathematical expressions, let alone how they are understood by the mind. One technique which researchers use to gain insight into how people read and comprehend symbols and complex phenomena are studies using eye-tracking hardware: focus on, and tracking of, pupils in order to determine the reader’s attention and fixation. In this paper we will explore the results of a study on two classes of students: mathematically “expert” (mathematical sciences students) and non-expert (Faculty of Science majors from outside the mathematical sciences). Each participant was presented with a series of mathematical problems (stimuli) and their eyes and attention/focus tracked as they worked through the problems mentally. We will discuss the differences in the two classes, both with respect to the correctness of responses to the problems and the structure of the scanning and identification of important components within the problem. This study has applications in mathematical software usability, accessibility, and design of interfaces, as comprehension of mathematical notation and formalism is assumed in the implementation of the modified symbolism inherent in structured mathematical software interfaces.

Mathematics Classroom Collaborator (MC2): Technology for Democratizing the Classroom

In any classroom, different groups of students may have unequal voices. This “lack of democracy” may be particularly problematic in STEM fields. To promote a more inclusive classroom, we developed and tested an online, real-time communication tool: the Mathematics Classroom Collaborator (\(MC^2\)). \(MC^2\) makes the entry of mathematics easy and intuitive, it includes an option for anonymity, and it works on a variety of platforms, including smart phones, tablets, and notebook computers. In this paper, we share our experience with employing \(MC^2\) in a statistics service course and an introductory probability course. We describe how this tool creates new communication models for the technologically-enhanced class — models that may help overcome social barriers to create a more inclusive environment, and that may lead to further democratization of learning, including increased participation by women and/or English-language learners. The results of an experiment to measure the effectiveness of \(MC^2\) compared to Microsoft Word Equation for novice users are also presented.

Manipulation of Mathematical Expressions in Collaborative Environments

Recent decades have seen phenomenal growth in the use of communication and collaborative technologies in many academic disciplines. There has, however, been little adoption of tools for online collaboration in post-secondary mathematics education. In this paper, we argue both that this may be due to limitations of mathematical interfaces and that the adoption of collaborative tools may provide significant pedagogical benefits. To date, mathematical user-interface research has focused primarily on mathematical expression input, and mostly from a perceptive of document creation or computer algebra system use by expert users. Little work has been done on the specific needs of novice users, including students, and even less work has considered the manipulation of mathematical expressions. In this paper, we outline some user-interface challenges of current input systems with respect to entry and manipulation of mathematical expressions by novice users, and we introduce a model that makes entry and manipulation easier for those users.

Analysis and Calibration of Empirical Relationships for Estimating Evapotranspiration in Qatar: Case Study

AbstractKnowledge of evapotranspiration (ETo), which is the process of water loss from vegetated soils due to evaporation and transpiration, is important in real-time irrigation management and water-resource allocation, particularly in water-scarce regions. In this study, several methods used in estimating evapotranspiration, including the Blaney-Criddle, Hargreaves-Samani, Jensen-Haise, Linacre, and Turc methods were calibrated and validated against the Penman-Monteith model, which is considered as the standard method of estimating evapotranspiration. The paper utilizes data from the Doha International Airport meteorological station over a period of 30 years (January 1985–December 2014). ETo values were estimated using the different methods. These values were then compared to those obtained by the Penman-Monteith method. Using appropriate indicators, the Turc method was found to be the best for estimating ETo over Doha (R2=0.9519, RMSE=1.4511  mm day−1, and MAE=1.1633  mm day−1). The Turc method comes in...

The Evidentiary Value of Big Data Analysis

Big data is transforming the way governments provide security to, and justice for, their citizens. But it also has the potential to increase surveillance and government power. Indeed, information gathered from license plate recognition, mobile phone usage, biometric matches of DNA, facial recognition, financial transactions, and internet search history is increasingly allowing government agencies to search and cross-reference. The opportunity for big data searches then raises the question: what is the probative value of the information that results? The scientific method begins with the development of a hypothesis that is then tested against data that will either support or refute the hypothesis. That method is essentially followed in a conventional criminal investigation in which, after a suspect is first identified, evidence is gathered to either build a case against, or rule out, that suspect. The analysis of big data, by contrast, may at times be more akin to trawling for data first, only to subsequently define a hypothesis. In this paper, we investigate the conditions in which this approach may lead to problematic outcomes, including higher rates of false positives. We then sketch a big data analysis legal/policy framework that may address these problems.