Reading on Grade Level in Third Grade: How Is It Related to High School Performance and College Enrollment?

Illustrates how third-grade reading level correlates with eighth-grade reading level, which, along with ninth-grade school traits, correlates with ninth-grade performance, which in turn correlates with high school graduation and college attendance rates

On SAT representations of XOR constraints

We study the representation of systems S of linear equations over the two-element field (aka xor- or parity-constraints) via conjunctive normal forms F (boolean clause-sets). First we consider the problem of finding an "arc-consistent" representation ("AC"), meaning that unit-clause propagation will fix all forced assignments for all possible instantiations of the xor-variables. Our main negative result is that there is no polysize AC-representation in general. On the positive side we show that finding such an AC-representation is fixed-parameter tractable (fpt) in the number of equations. Then we turn to a stronger criterion of representation, namely propagation completeness ("PC") --- while AC only covers the variables of S, now all the variables in F (the variables in S plus auxiliary variables) are considered for PC. We show that the standard translation actually yields a PC representation for one equation, but fails so for two equations (in fact arbitrarily badly). We show that with a more intelligent translation we can also easily compute a translation to PC for two equations. We conjecture that computing a representation in PC is fpt in the number of equations.Comment: 39 pages; 2nd v. improved handling of acyclic systems, free-standing proof of the transformation from AC-representations to monotone circuits, improved wording and literature review; 3rd v. updated literature, strengthened treatment of monotonisation, improved discussions; 4th v. update of literature, discussions and formulations, more details and examples; conference v. to appear LATA 201

Standard Written English Grammar and Usage in the First-Year Composition Classroom: First-Year Composition Educators\u27 Perspectives

A study was conducted to discover how first-year composition (FYC) teachers at large, public, 4-year universities respond to students who write prose with numerous Standard Written English (SWE) errors, the techniques the teachers use, and if the teachers perceive themselves as positively impacting the students’ writing. The researcher believed the teachers’ background (i.e., education and experience) would have an effect. Method: An anonymous survey was sent to FYC teachers at large, public, 4-year universities. A follow-up interview was conducted, and a web search performed. Results: One hundred and twenty-one participants completed the survey; three were interviewed. Over 49% used the majority of techniques listed in the survey at least sometimes. Most frequently used techniques include making SWE comments on students’ papers (84%), and using peer reviews (59%), mini lessons (54%), handbooks (36%), and handouts or worksheets (33%). Teachers with a creative writing degree were more likely to make comments on the students’ papers (r = .278, p = .002), as well as teachers who have taken creative writing courses (r = .271, p = .005). Those with a linguistics degree were not as likely to use the technique (r = - .359, p = .00). Participants with higher degrees were less likely to use peer reviews (r = -0.289, p = .001). Participants who have taken more graduate courses in linguistics were more likely to use non-technical terms when explaining SWE. No correlation existed for experience teaching and techniques used. A positive correlation was found between techniques teachers used and their perceived effectiveness, except for handbooks, using excerpts from students’ papers, and students keeping track of errors. However, at least one-third believed the techniques they used were not effective. Of the total participants, 73 wrote detailed comments regarding the teaching of SWE in FYC. Over half believe SWE should be taught during class; 22% during individual conferencing. Almost all felt either somewhat or very prepared to teach SWE, but those with creative writing degrees felt less prepared (r = -.194, p = .035). Teachers found the following helpful in preparing them to teach SWE: teaching (r = .304, p = .001), taking writing courses (r = .197, p = .043), and taking linguistics courses (r = .321, p = .008). Discussion: Participants would like better preparation and more effective ways to teach SWE. Better teacher preparation may include linguistic courses and writing courses, especially for those with a creative writing background. More research is needed in the area of effective ways to teach SWE

Bifurcations and Chaos in Time Delayed Piecewise Linear Dynamical Systems

We reinvestigate the dynamical behavior of a first order scalar nonlinear delay differential equation with piecewise linearity and identify several interesting features in the nature of bifurcations and chaos associated with it as a function of the delay time and external forcing parameters. In particular, we point out that the fixed point solution exhibits a stability island in the two parameter space of time delay and strength of nonlinearity. Significant role played by transients in attaining steady state solutions is pointed out. Various routes to chaos and existence of hyperchaos even for low values of time delay which is evidenced by multiple positive Lyapunov exponents are brought out. The study is extended to the case of two coupled systems, one with delay and the other one without delay.Comment: 34 Pages, 14 Figure

Mutual Information for the Detection of Crush

Fatal crush conditions occur in crowds with tragic frequency. Event organizers and architects are often criticised for failing to consider the causes and implications of crush, but the reality is that both the prediction and prevention of such conditions offer a significant technical challenge. Full treatment of physical force within crowd simulations is precise but often computationally expensive; the more common method of human interpretation of results is computationally “cheap” but subjective and time-consuming. This paper describes an alternative method for the analysis of crowd behaviour, which uses information theory to measure crowd disorder. We show how this technique may be easily incorporated into an existing simulation framework, and validate it against an historical event. Our results show that this method offers an effective and efficient route towards automatic detection of the onset of crush

An open multi-physics framework for modelling wildland-urban interface fire evacuations

Fire evacuations at wildland-urban interfaces (WUI) pose a serious challenge to the emergency services, and are a global issue affecting thousands of communities around the world. This paper presents a multi-physics framework for the simulation of evacuation in WUI wildfire incidents, including three main modelling layers: wildfire, pedestrians, and traffic. Currently, these layers have been mostly modelled in isolation and there is no comprehensive model which accounts for their integration. The key features needed for system integration are identified, namely: consistent level of refinement of each layer (i.e. spatial and temporal scales) and their application (e.g. evacuation planning or emergency response), and complete data exchange. Timelines of WUI fire events are analysed using an approach similar to building fire engineering (available vs. required safe egress times for WUI fires, i.e. WASET/WRSET). The proposed framework allows for a paradigm shift from current wildfire risk assessment and mapping tools towards dynamic fire vulnerability mapping. This is the assessment of spatial and temporal vulnerabilities based on the wildfire threat evolution along with variables related to the infrastructure, population and network characteristics. This framework allows for the integration of the three main modelling layers affecting WUI fire evacuation and aims at improving the safety of WUI communities by minimising the consequences of wildfire evacuations

Enhancing Egress Drills: Preparation and Assessment of Evacuee Performance

This article explores how egress drills-specifically those related to fire incidents-are currently used, their impact on safety levels, and the insights gained from them. It is suggested that neither the merits of egress drills are well understood, nor the impact on egress performance well characterized. In addition, the manner in which they are conducted varies both between and within regulatory jurisdictions. By investigating their strengths and limitations, this article suggests opportunities for their enhancement possibly through the use of other egress models to support and expand upon the benefits provided. It is by no means suggested that drills are not important to evacuation safety-only that their inconsistent use and the interpretation of the results produced may mean we (as researchers, practitioners, regulators, and stakeholders) are not getting the maximum benefit out of this important tool

A review of post-incident studies for wildland-urban interface fires

Abstract Post-incident studies provide direct and valuable information to further the scientific understanding of Wildland-Urban Interface (WUI) fires. Most post-incident studies involve data collection in the field (i.e. a "research field deployment"). In this review, technical reports of post-incident studies for WUI fire and other natural disasters were analyzed and professionals directly involved in WUI fire research field deployments were interviewed. The goal of this review is to provide a resource for future WUI studies regarding the development of safe and effective fieldwork procedures, the collection and integration of accurate and relevant data, and the establishment of practical lessons learned. Three main stages of WUI fire post-incident studies are identified and described in detail. Data collection methodologies, data attributes, logistical practices and lessons-learned were compiled from various past studies and are presented here in the context of application to WUI fire