When are we guessing? An investigation of the impact of guessing on the validity of results in the assessment of students in large-scale assessment programs

The 21st century shift towards economic rationalism has included a trend towards measuring the outcomes of education and, equipped with these data, placing a higher priority on accountability in all sectors of the educational community. Corresponding to this shift, policy makers and government officials continue to demand better quality information on which to make data-informed decisions and allocate resources. To measure educational outcomes, for instance, stakeholders routinely look to national and international large-scale testing programs for indicators of success in achieving national goals and to identify areas for systemic attention. A majority of these large-scale assessments use multiple-choice item types to assess student ability for the reporting of the outcomes of student achievement against curriculums and national or international standards. Students are encouraged to attempt all questions in these assessments. By doing so it is likely that students will guess the answers to those items where the concepts assessed are beyond their capabilities and be rewarded with an incremental increase in their results. This has the potential to threaten the validity of students’ overall results, due to the chance of correctly guessed responses inflating assessment results beyond students’ actual ability levels. This PhD research investigated the potential impact of – and proposed a statistical solution for – guessing in large-scale education assessments. Specifically, it examined the outcomes from a novel application of the Rasch analysis technique, which quantified and adjusted for the measurement error associated with guessing and, consequently, increased the validity of the outcomes of the assessments

Water rights, conflict and policy: Proceedings of a workshop held in Kathmandu, Nepal, January 22-24, 1996

IrrigationIrrigation managementWater rightsWater lawConflictFarmers' associations

Advanced Methods and Models for Employee Timetabling Problems

This thesis is focused on the design of efficient models and algorithms for employee timetabling problems (ETPs). From our point of view, there are two significant gaps in the current state of the art. The first one, also important in practice, concerns the ETP with strongly varying workforce demand. Unlike the classical Nurse Rostering Problem (NRP) this problem considers dozens of shift types that can cover the demand more precisely than early, late and night shift type used in NRP. In this work we call this problem the Employee Timetabling Problem with a High Diversity of shifts (ETPHD). It comes as no surprise that the exact methods like Integer Linear Programming are not able to find its solution in reasonable time. Therefore, a transformation of ETPHD based on mapping of shift types to shift kinds was proposed. The transformation allows one to design a multistage approach (MSA). The aim of the first two stages is to find an initial ETPHD solution, where a rough position of assigned shifts is determined. This proved to be substantial for the last stage of MSA, where the solution is consequently improved in terms of its quality. In order to verify the MSA performance, a cross evaluation methodology was proposed. It is based on the comparison of the performance provided by more approaches on more combinatorial problems. Therefore, real life ETPHD instances from an airport ground company and also standard benchmark NRP instances were considered. The experiments confirmed the better or equal performance of our approach in the most of the cases. The second gap in the literature is an absence of parallel algorithms for ETPs. We focused on the Nurse Rerostering Problem (NRRP) that appears when a disruption in the roster occurs, e.g., when one of the employees becomes sick. For this purpose, the parallel algorithm solving NRRP was proposed in order to shorten needed computational time. This algorithm was designed for a Graphics Processing Unit (GPU) offering a massive parallelization. To the best of our knowledge, this is the first usage of GPU for ETPs. The performance of the GPU parallel algorithm was tested on the real life NRRP benchmark instances and evaluated from two points of view. Firstly, the quality of the results was compared to the known results from the state of the art. Secondly, the speedup achieved by the parallel algorithm related to the sequential one was verified. In average, the parallel algorithm is able to provide the results of the same quality 15 times faster than the sequential one.Katedra řídicí technik

Proceedings of the Third International Workshop on Proof-Carrying Code and Software Certification

This NASA conference publication contains the proceedings of the Third International Workshop on Proof-Carrying Code and Software Certification, held as part of LICS in Los Angeles, CA, USA, on August 15, 2009. Software certification demonstrates the reliability, safety, or security of software systems in such a way that it can be checked by an independent authority with minimal trust in the techniques and tools used in the certification process itself. It can build on existing validation and verification (V&V) techniques but introduces the notion of explicit software certificates, Vvilich contain all the information necessary for an independent assessment of the demonstrated properties. One such example is proof-carrying code (PCC) which is an important and distinctive approach to enhancing trust in programs. It provides a practical framework for independent assurance of program behavior; especially where source code is not available, or the code author and user are unknown to each other. The workshop wiII address theoretical foundations of logic-based software certification as well as practical examples and work on alternative application domains. Here "certificate" is construed broadly, to include not just mathematical derivations and proofs but also safety and assurance cases, or any fonnal evidence that supports the semantic analysis of programs: that is, evidence about an intrinsic property of code and its behaviour that can be independently checked by any user, intermediary, or third party. These guarantees mean that software certificates raise trust in the code itself, distinct from and complementary to any existing trust in the creator of the code, the process used to produce it, or its distributor. In addition to the contributed talks, the workshop featured two invited talks, by Kelly Hayhurst and Andrew Appel. The PCC 2009 website can be found at http://ti.arc.nasa.gov /event/pcc 091

A Graph-Transformation Modelling Framework for Supervisory Control

Formal design methodologies have the potential to accelerate the development and increase the reliability of supervisory controllers designed within industry. One promising design framework which has been shown to do so is known as supervisory control synthesis (SCS). In SCS, instead of manually designing the supervisory controller itself, one designs models of the uncontrolled system and its control requirements. These models are then provided as input to a special synthesis algorithm which uses them to automatically generate a model of the supervisory controller. This outputted model is guaranteed to be correct as long as the models of the uncontrolled system and its control requirements are valid. This accelerates development by removing the need to verify and rectify the model of the supervisory controller. Instead, only the models of the uncontrolled system and its requirements must be validated. To address problems of scale, SCS can be applied in modular fashion, and implemented in hierarchical and decentralized architectures. Despite the large body of research con rming the bene ts of integrating SCS within the development process of supervisory controllers, it has still not yet found widespread application within industry. In the author's opinion, this is partly attributed to the non-user-friendly nature of the automaton-based modelling framework used create the models of the uncontrolled system (and control requirements in even-based SCS). It is believed that in order for SCS to become more accessible to a wider range of non experts, modelling within SCS must be made more intuitive and user-friendly. To improve the usability of SCS, this work illustrates how a graph transformation-based modelling approach can be employed to generate the automaton models required for supervisory control synthesis. Furthermore, it is demonstrated how models of the speci cation can be intuitively represented within our proposed modelling framework for both event- and state-based supervisory control synthesis. Lastly, this thesis assesses the relative advantages brought about by the proposed graph transformation-based modelling framework over the conventional automaton based modelling approach

Assemblage Comparisons of Living Benthic Foraminifera at Bathyal Sites Oiled and Un-Oiled by the Deepwater Horizon Blowout in the Northeastern Gulf of Mexico

Live benthic foraminiferal assemblages were studied at contaminated and uncontaminated bathyal sites around the wellhead of the Deepwater Horizon oil spill. Samples collected in October of 2010 and 2011 and summer of 2012 were divided into uncontaminated (GIP 12, 21, K, and 25 and Obs0), moderately oiled (GIP 16 and 17) and heavily oiled groups (GIP 15), in which the TPAH concentrations ranged from 29 to 7,553 ng/g in 2010. Metric multidimensional scaling (MDS) and cluster analyses were conducted to compare all surface samples. Additionally, the heavily oiled site (GIP 15) and an uncontaminated site (GIP 25) were studied downcore to assess the impact on the foraminiferal depth of habitation (DOH). A total of 284 species from 6 suborders have been identified in the ≥ 45-μm size fraction. Three pseudo-replicates at Obs0 had more similarity in species distribution and diversity than any other site. The MDS and cluster analyses show that the surface assemblages are within a single biofacies except for two sites (GIP 21 and K). The assemblages from the heavily oiled and un-oiled cores were distinctly different. In 2010, the standing stock was nearly two times greater at the heavily oiled site, but the DOH was half the depth of the un-oiled site. In 2011, the standing stock of the two sites was similar, but the DOH remained shallower at the oiled site. The trends in density, DOH, standing stock, diversity, and abundance of an opportunistic species (Bulimina aculeata) at the heavily oiled site appear consistent with hypertrophy

Optimal Control Applications in Space Situational Awareness

There are currently more than 19,000 trackable objects in Earth orbit, 1,300 of which are active. With so many objects populating the space object catalog and new objects being added at an ever increasing rate, ensuring continued access to space is quickly becoming a cornerstone of national security policies. Space Situational Awareness (SSA) supports space operations, space flight safety, implementing international treaties and agreements, protecting of space capabilities, and protecting of national interests. With respect to objects in orbit, this entails determining their location, orientation, size, shape, status, purpose, current tasking, and future tasking. For active spacecraft capable of propulsion, the problem of determining these characteristics becomes significantly more difficult. Optimal control techniques can be applied to object correlation, maneuver detection, maneuver/spacecraft characterization, fuel usage estimation, operator priority inference, intercept capability characterization, and fuel-constrained range set determination. A detailed mapping between optimal control applications and SSA object characterization support is reviewed and related literature visited. Each SSA application will be addressed starting from first principles using optimal control techniques. For each application, several examples of potential utility are given and discussed

Molecular biomarkers in type 2 diabetes and colorectal cancer

Globally, Type 2 Diabetes (T2D) and Colorectal Cancer (CRC) are among the most prevalent metabolic diseases and cancers, respectively. T2D is a progressive disease encompassing two underlying progressive conditions, insulin resistance and pancreas functional β-cell loss. CRC mostly arise from the aberrant proliferation of colonic epithelial cells in the form of colorectal polyps. T2D and CRC are chronic diseases and understanding the underlying molecular mechanism to identify biomarkers of their progression could help prevent or delay the course of the two diseases. Additionally, obesity is the major risk factor of T2D, and they are both considered as CRC risk factors. Therefore, there are common factors involved in the progression of T2D and CRC. In this regard, my thesis aimed to investigate T2D and CRC progression in four sections. Telomere length shortening is one of the hallmarks of cellular senescence. Shorter leukocyte telomere length in T2D has been reported previously. Firstly, I aimed to investigate cellular senescence and assess telomere biology using a cell model of human pancreas islet-derived progenitor cells (hIPCs). The second section studied was on how T2D progression was related to gut hormones regulating the insulin secretion from pancreas islets. Thirdly, SCFA was studied in relation to CRC progression. By conducting a systematic review and meta-analysis, a link between faecal SCFA level and the risk and incidence of CRC was established. Finally, in the fourth section, the concerning rising incidence of early-onset CRC (EOCRC: CRC diagnosed earlier than 50 years of age) led us to investigate this further by analysing a consecutive series of 3609 patients that underwent colorectal surgery over a 26-year period at Concord Hospital (NSW, Australia). The focus was on the incidence trend, clinicopathological features and survival in this age group. The current National Bowel Cancer Screening Program commences at the age of 50 years. Our findings including a significantly higher percentage of metastasis in EOCRC, as well as significantly higher risk of developing an advanced tumour in this age group provides supporting evidence for lowering the commencement age for CRC screening

Enhanced Modular Signal Processor Timing Simulator

A timins simulator for a static Sisnal Processins GraPh Notation sraPh was develoPed for the Enhanced Modular Sisnal Processor, a data flow comPuter develoPed by Bell TelePhone Laboratories for the United States NavY. The user inPuts the sYstem confisuration and the toPoloSY of the To imPlement channels, a constant rate for each channel is read and the timins simulator uses this rate to detect inPut queues over threshold. The outPut consists of the sYstem confisuration, queue data information, Functional element-utilization, node execution information, and an oPtional timins diasram. This allows the user to simulate sraPhs For comParison or to simulate modifications to the sYstem and test the feasibilitY of the ProPosed modification.ComPutins and Information Science

Effect of energy restriction on appetite regulation and metabolism at rest and during exercise

Current methods of energy restriction are not successful for achieving long-term weight loss and maintenance for the majority of individuals. As a result, the prevalence of obesity and obesity related diseases continue to increase. This calls for the development of novel lifestyle interventions to combat the obesity epidemic. Hunger has been highlighted as a major factor influencing the long-term success of weight management methods and therefore how a given dietary intervention affects the appetite regulatory system may dictate the success of the diet by augmenting long-term adherence. In addition, the effect of a given dietary intervention on exercise may determine its suitability for exercising individuals and may influence the energy deficit that can be achieved by the diet. This thesis investigated the acute effects of two novel methods of dietary restriction; breakfast omission and severe energy restriction. The main aims for this thesis were to determine the effect of these methods of energy restriction on ad-libitum energy intake, subjective appetite sensations, and peripheral concentrations of hormones involved in appetite regulation. In addition, this thesis also investigated the effects of these methods of energy restriction on metabolism and glycaemic control at rest, and performance and perceived exertion during exercise. This work found that moderate and severe energy deficits induced by breakfast omission and 24 h of severe energy restriction, respectively, resulted in either no (Chapter VIII) or partial (Chapters IV and VII) energy intake compensation over the subsequent 24-48 h. Subjective appetite was increased during (Chapters IV, V, VII and VIII) and shortly after (Chapter VII) energy restriction, but this effect was transient and was offset after an ad-libitum (Chapters IV and VII) or standardised (Chapters V and VIII) meal. In addition, none of the work presented in this thesis demonstrated an appetite hormone response to energy restriction that was indicative of compensatory eating behaviour. Compared to breakfast omission, breakfast consumption resulted in an increased in resting energy expenditure and carbohydrate oxidation, with a concurrent reduction in fat oxidation during the morning. However, there were no differences after lunch (Chapter V). In response to a standardised breakfast, resting energy expenditure was suppressed (Chapter VII) or not different (Chapter VIII) the following morning, after 24 h severe energy restriction compared to energy balance. Plasma NEFA and fat oxidation was greater, carbohydrate oxidation was reduced, and postprandial insulin sensitivity was impaired in the after 24 h severe energy restriction (Chapter VI, VII and VIII). In Chapter IV, omission of breakfast in the morning was shown to reduce exercise performance in evening, even after provision of an ad-libitum lunch 4 h before. However, there was no difference in perception of effort during steady state exercise, independent of breakfast consumption or omission in the morning (Chapters IV and V). Collectively, breakfast omission and 24 h severe energy restriction reduce energy intake and promote an appetite regulatory response conducive to maintenance of a negative energy balance. Chronic intervention studies are now required to confirm whether these effects persist after long-term practice of these dietary interventions