Algebraic system theory: an analyst's point of view

A systematic development of the realization theory of finite dimensional constant linear systems is presented which synthesizes the various currently available approaches.Based on representation theorems for submodules and quotient modules of spaces of polynomial matrices and vectors, this paper combines the abstract algebraic ideas centering around module theory, the use of coprime factorizations of rational transfer functions and state space equations into a unified theory.     

Advancing Diversity in STEM

Although progress has been made, greater efforts are needed to promote faculty diversity at the college and university levels, especially in STEM fields. Thus, it is important to elucidate best practices both for increasing awareness of diversity issues pertaining to higher education and for implementing change. This article focuses on the outcomes of a diversity workshop for college and university faculty hosted by the West Virginia Higher Education Policy Commission, Division of Science and Research. More specifically, it elucidates how participation in the workshop translated into practice at the faculty participants’ home institutions.     

Kindergarten children's growth trajectories in reading and mathematics: who falls increasingly behind?

The authors used a large sample of children (N ≈ 7,400) participating in the Early Childhood Longitudinal Study--Kindergarten Cohort (ECLS-K) to estimate kindergarten children's academic achievement growth trajectories in reading and mathematics. The authors were particularly interested in whether the growth trajectories of children with learning disabilities (LD) or speech language impairments (SLI)--as well as those of other groups of children--were consistent with a cumulative or compensatory developmental cycle. Both LD and SLI children displayed significantly lower levels of kindergarten reading achievement than nondisabled children. However, and over the subsequent 5 years of elementary school, only children with SLI lagged increasingly behind nondisabled peers in their reading skills growth. The authors observed a different pattern for mathematics achievement. Children with LD, but not SLI, lagged increasingly behind nondisabled children in their mathematics skills growth. The authors also observed some consistency in "poor-get-poorer" effects across reading and mathematic achievement for additional population subgroups. Those kindergarten children who were from lower socioeconomic status families, who were African American, and who more frequently displayed learning-related behavior problems initially had lower levels of reading and mathematics achievement and also lagged increasingly behind in their acquisition of these skills over time. Some groups of children, including those with SLI, experience a cumulative rather than a compensatory cycle of achievement growth.     

Cultural capital and academic achievement of first generation domestic and international students in Canadian universities

In Canada little research has been conducted on those who are the first in their families to attend university. Cultural reproduction theory suggests that such students would be less likely to engage in the type of activities that, according to the college impact model, contribute to academic achievement. In order to test these and other possibilities a longitudinal survey‐based study of domestic and international students was conducted at four Canadian universities. Overall it was found that university experiences did vary by the educational background of parents; however, such experiences were not always of consequence for academic achievement.     

Valuing the benefits of the education provided by public universities: A case study of Minnesota

This study estimates the value of the private and public benefits that accrue to Minnesota residents from state government subsidies to higher education. In 2005, the University of Minnesota and the Minnesota State Colleges and Universities system received $832 million from Minnesota's state government to support educational programs. These subsidies allow these institutions to offer lower tuition rates, increasing the number of Minnesotans with bachelor and graduate degrees. We calculate that removing these subsidies would eventually lead to 14,000 fewer graduate degree holders in Minnesota, and reduce those with bachelor's degrees or “some college” by 42,000. The annual economic cost of these subsidies is about $326 million; this is less than annual state appropriations because most of those appropriations are income transfers from taxpayers to students, not an economic cost. We estimate that the annual value of the benefits of these subsidies is between $531 and $786 million ($381 and $570 million) when a 3% (5%) discount rate is used. We also discuss some of the income distribution consequences.     

Corresponding drivability control and energy control strategy in uninterrupted multi-speed mining trucks

An hybrid uninterrupted multi-speed transmission (HUMST), based on the integration of a planetary gear set and a 3-speed automatic manual transmission (3-AMT), is developed to satisfy the specific performance indexes of mining trucks. The power-split device can alleviate and eliminate the inherent torque interruption of the 3-AMT during gear shift by implementing the designed cooperative shift control strategy which is optimized by quadratic performance index. In order to achieve fast torque coordination while guaranteeing the driving comfort performance, the torque profiles of the power split device and the traction motor are optimized by Linear-quadratic regulator (LQR) algorithm. Dynamic programming (DP) is implemented as a benchmark to demonstrate the maximum fuel efficiency of the proposed HUMST. Because of the high computational cost of optimal control strategies such as DP, an improved real-time control strategy (IRTCS) using modified Gaussian distribution function is proposed to significantly reduce the computing load. As efficiency-oriented energy control strategy would result in frequent gear shifts, to achieve a desirable tradeoff between the overall efficiency and the shift stability, multi-objective genetic algorithm (MGA) is integrated to optimize the overall performance. The detail mathematical and dynamic model shows that the proposed shifting strategy with LQR can effectively suppress shift jerk, and the proposed IRTCS with MGA can reduce shift frequency by 70.78% to improve the drivability, only sacrificing 4.86% of overall efficiency compared to that of DP.     

Documenting the doable and doing the documented: bridging strategies at the UK Stem Cell Bank

We explore the local negotiation of regulatory practice at the UK Stem Cell Bank, the first Bank of its type in the world. Basing our empirical work on a detailed analysis of one aspect of the Bank's regulatory commitment--the completion of the Cell Line Information form--we make visible the necessary judgements and labour involved in interpreting and operationalizing externally imposed regulation. The discussion opens by detailing the problems encountered when the Bank completes the form: reconciling a bureaucratic system of accountability with craft-like laboratory skills involving multiple kinds of tacit knowledge. We follow this by explicating the emergent 'bridging strategies' pursued by the Bank to address these issues, highlighting their reliance upon the formation of trust and social networks. The closing discussion emphasizes the contingent assembly of regulatory practices that emerge in the local setting.