A Project Based Approach to Statistics and Data Science

In an increasingly data-driven world, facility with statistics is more important than ever for our students. At institutions without a statistician, it often falls to the mathematics faculty to teach statistics courses. This paper presents a model that a mathematician asked to teach statistics can follow. This model entails connecting with faculty from numerous departments on campus to develop a list of topics, building a repository of real-world datasets from these faculty, and creating projects where students interface with these datasets to write lab reports aimed at consumers of statistics in other disciplines. The end result is students who are well prepared for interdisciplinary research, who are accustomed to coping with the idiosyncrasies of real data, and who have sharpened their technical writing and speaking skills

Locus of control and savings

Abstract: This paper analyzes the relationship between individuals’ locus of control and their savings behavior, i.e. wealth accumulation, savings rates, and portfolio choices. Locus of control is a psychological concept that captures individuals’ beliefs about the controllability of life events and is a key component of self-control. We find that households with an internal reference person save more both in terms of levels and as a percentage of their permanent incomes. Although the locus-of-control gap in savings rates is largest among rich households, the gap in wealth accumulation is particularly large for poor households. Finally, households with an internal reference person and average net worth hold significantly less financial wealth, but significantly more pension wealth, than otherwise similar households with an external reference person

Neighborhood Diversity and the Appreciation of Native- and Immigrant-Owned Homes

This paper examines the effect of neighborhood diversity on the nativity gap in homevalue appreciation in Australia. Specifically, immigrant homeowners experienced a 41.7 percent increase in median home values between 2001 and 2006, while the median value of housing owned by the native-born increased by 59.4 percent over the same period. We use a semi-parametric decomposition approach to assess the relative importance of the various determinants of home values in producing this gap. We find that the differential returns to housing wealth are not related to changes in the nature of the houses or the neighborhoods in which immigrants and native-born homeowners live. Rather, the gap stems from the fact that over time there were differential changes across groups in the hedonic prices (i.e., returns) associated with the underlying determinants of home values.international migration, home-ownership, decomposition analysis

Rapid Prototyping Using 3-D Welding

Rapid prototyping systems are based, almost exclusively on polymer, or paper materials. The dimensions of the parts produced are limited by the volume of the processing area within the machine, and parts tend to warp or distort due to shrinkage and lack of support. Also the mechanical properties of the part are restricted to those of the processable materials and thus, in many cases, required 'engineering properties' cannot be obtainedMechanical Engineerin

Cuprous oxide rectification

It has been shown that cuprous oxide, when formed from a copper surface by suitable heat treatment, has remarkable rectifying properties towards alternating voltages applied through the oxide and copper. The purpose of our work was to investigate, the effect fully from all angles possible, and especially from those considerations affecting the constancy and permanence in the electric circuit. The work ranged from furnace operation to tests of completed units, and further to the development of a theory explaining as completely as possible this rectifying property. It soon became apparent, that here was ideal thesis material, and so, with proper permission, I have undertaken this rather complete report and now offer it as my thesis. The work was carried on jointly by Mr. Rutger B. Colt, of Stevens Institute, Mr. Charles H. Bartlett of Brooklyn Polytechnic Institute, and myself. In all a period of one year and three months was devoted to this investigation, and during that time we all were largely employed directly, although other matters claimed attention occasionally

Structural Damage Identification from Limited Measurement Data

The research focused on the development of a new method to identify damaged structural elements from a large flexible space structure on-orbit, using limited measured modal data. Limited measured modal data is loosely defined as measured data containing only a few modal frequencies and less than 10% of the total structural degrees-of-freedom. This effort was decomposed into four specific tasks. The first is the identification of partial modal properties from measured data of the nominal space structure. Second, the finite element model must be adjusted to match the measured nominal partial data. The third task is an analysis of the extent to which structural damage can be localized to individual structural elements using the measured data. In conjunction with this task is the determination of where to best place the limited number of sensors on the structure. Lastly, the identification of structural damage must be performed using the limited measured modal data from a damaged space structure. Identification of the modal parameters was accomplished using the Eigensystem Realization Algorithm, a time domain based method, adopted for use with averaged measured frequency response functions. Model tuning was performed using the Automated Structural Optimization Software package, adapted for model tuning. The method minimizes a cost function based on the mismatch between the measured and analytical eigenstructure. The minimization is solved using the eigenvalue and eigen-vector sensitivities at each iteration step. The determination of prioritized sensor locations and damage localization is performed using the eigenvalue and eigenvector sensitivities

Storage and Behavior of Plant and Diet-Fed Adult Cereal Leaf Beetle, Oulema Melanopus (Coleoptera: Chrysomelidae)

The univoltine life cycle of the cereal leaf beetle Oulema melanopus (L.) in Michigan (Castro et al. 1965) is similar to that reported by Venturi (1942) in Europe. Adults emerge from pupal cells in the soil in mid-June to early July, feed voraciously for about three weeks, and enter aestivation sites. For the remainder of the summer and early autumn only a few adults can be found feeding on late-maturing native grasses. The beetles overwinter and usually emerge in late March to early April and resume feeding. Mating and oviposition occur, and larval development is usually completed by late June in southern Michigan. Techniques for rearing the cereal leaf beetle on greenhouse-grown small grain seedlings have been developed by Connin, et al. (1968). Maintaining these cultures requires collecting field adults, growing host material, and handling the cultures to insure that all stages will be available for study. In Michigan during July adults can be collected more economically and in greater numbers in the field than by rearing in the laboratory. A summary of collection techniques, laboratory feeding and storage conditions for large numbers of field-collected cereal leaf beetles is presented in this paper. In addition, the mortality during storage of newly emerged field collected beetles fed either barley seedlings or an artificial diet is compared

Discovery of a supernova associated with GRB 031203: SMARTS Optical-Infrared Lightcurves from 0.2 to 92 days

Optical and infrared monitoring of the afterglow site of gamma-ray burst (GRB) 031203 has revealed a brightening source embedded in the host galaxy, which we attribute to the presence of a supernova (SN) related to the GRB ("SN 031203"). We present details of the discovery and evolution of SN 031203 from 0.2 to 92 days after the GRB, derived from SMARTS consortium photometry in I and J bands. A template type Ic lightcurve, constructed from SN 1998bw photometry, is consistent with the peak brightness of SN 031203 although the lightcurves are not identical. Differential astrometry reveals that the SN, and hence the GRB, occurred less than 300 h_71^-1 pc (3-sigma) from the apparent galaxy center. The peak of the supernova is brighter than the optical afterglow suggesting that this source is intermediate between a strong GRB and a supernova.Comment: 11 pages, 3 figures, submitted to ApJ Letter

The growth kinetics of xenografts of human colorectal tumours in immune deprived mice.

The technique of labelled mitoses was used to examine cell proliferation within grafts of human colonic and rectal tumours in immune deprived mice. Most of the data were obtained on the first passage but in some cases up to the third passage was used. It was found to be difficult to obtain precise kinetic data on this type of tumour material, but the results did allow some estimates to be made, particularly of the duration of the G2 and S phases of the mitotic cycle. The average G2 duration was 6 h and the average S phase was 14 h. It is concluded that whilst xenografts may differ in a number of respects from the tumour in the patient, they nevertheless constitute a type of experimental tumour that is worthy of further study