Presenting Schur superalgebras

We provide a presentation of the Schur superalgebra and its quantum analogue which generalizes the work of Doty and Giaquinto for Schur algebras. Our results include a basis for these algebras and a presentation using weight idempotents in the spirit of Lusztig's modified quantum groups.Comment: 28 pages, to appear in the Pacific Journal of Mathematic

A self-mobile skeleton in the presence of external loads

Multicore clusters provide cost-effective platforms for running CPU-intensive and data-intensive parallel applications. To effectively utilise these platforms, sharing their resources is needed amongst the applications rather than dedicated environments. When such computational platforms are shared, user applications must compete at runtime for the same resource so the demand is irregular and hence the load is changeable and unpredictable. This thesis explores a mechanism to exploit shared multicore clusters taking into account the external load. This mechanism seeks to reduce runtime by finding the best computing locations to serve the running computations. We propose a generic algorithmic data-parallel skeleton which is aware of its computations and the load state of the computing environment. This skeleton is structured using the Master/Worker pattern where the master and workers are distributed on the nodes of the cluster. This skeleton divides the problem into computations where all these computations are initiated by the master and coordinated by the distributed workers. Moreover, the skeleton has built-in mobility to implicitly move the parallel computations between two workers. This mobility is data mobility controlled by the application, the skeleton. This skeleton is not problem-specific and therefore it is able to execute different kinds of problems. Our experiments suggest that this skeleton is able to efficiently compensate for unpredictable load variations. We also propose a performance cost model that estimates the continuation time of the running computations locally and remotely. This model also takes the network delay, data size and the load state as inputs to estimate the transfer time of the potential movement. Our experiments demonstrate that this model takes accurate decisions based on estimates in different load patterns to reduce the total execution time. This model is problem-independent because it considers the progress of all current computations. Moreover, this model is based on measurements so it is not dependent on the programming language. Furthermore, this model takes into account the load state of the nodes on which the computation run. This state includes the characteristics of the nodes and hence this model is architecture-independent. Because the scheduling has direct impact on system performance, we support the skeleton with a cost-informed scheduler that uses a hybrid scheduling policy to improve the dynamicity and adaptivity of the skeleton. This scheduler has agents distributed over the participating workers to keep the load information up to date, trigger the estimations, and facilitate the mobility operations. On runtime, the skeleton co-schedules its computations over computational resources without interfering with the native operating system scheduler. We demonstrate that using a hybrid approach the system makes mobility decisions which lead to improved performance and scalability over large number of computational resources. Our experiments suggest that the adaptivity of our skeleton in shared environment improves the performance and reduces resource contention on nodes that are heavily loaded. Therefore, this adaptivity allows other applications to acquire more resources. Finally, our experiments show that the load scheduler has a low incurred overhead, not exceeding 0.6%, compared to the total execution time

Flow and Distribution of Water in Fractional Wettability Unsaturated Porous Media

In recent years, interest in fluid flow and transport in the unsaturated zone has gained more attention, due to growing concerns that the quality of the subsurface environment is adversely affected by agricultural, industrial, and municipal activities. The wettability properties (e.g., water repellency) of soil in the unsaturated zone play an important role in determining fluid movement and ultimate distributions. A number of studies have shown that preferential flow and spatially variable moisture content is likely to occur in water repellant soils. Development of appropriate constitutive relations for numerical modeling becomes even more difficult in systems that contain water repellant soils. First, flow through fractionally-wet systems often follows preferential flow paths. Preferential flow can result in fast and deep infiltration of water and may impact solute and colloid/virus transport and plant growth. Second, it is difficult to incorporate pore- and centimeter-scale processes that result in irregular water flow and distribution during and following drainage. The resulting small-scale heterogeneities may impact subsequent infiltration and evaporation/volatilization processes. In this research, mm- and cm-scale capillary pressure¡Vwater content experiments and computed x-ray microtomography (CMT) were used to obtain quantitative data describing drainage and the irreducible water distribution in fractionally-wet systems. The findings from this research showed that wettability and pore-size distribution affected the capillary pressure-water content relationship in uniform and well-graded sand. As expected, an increase in the fractional wettability caused a decrease in the air entry pressure for all the sands tested. As the fractionally wettability increased, the slope of the capillary pressure-water content became steeper for the uniform sands and shallower for the well-graded sand. Comparison of mm- and cm-scale drainage capillary pressure-water content experiments showed that columns designed for CMT experiments can be used for low values of fractional wettability (less than 25%). CMT was successfully used to image the heterogeneous distribution of water during and following drainage; water content values obtained from the images when combined with the corresponding capillary pressure head values matched the laboratory experimental data. Finally, CMT was shown to be a highly effective technique to quantitatively characterize ƒÝm-scale grain, pore, and fluid properties

EXAMINING READING-RELATED TEACHER EDUCATION AMONG TEACHERS OF STUDENTS WITH LEARNING DISABILITIES IN SAUDI ARABIA

The purpose of this study was to examine the relationship between reading-related training (university courses and professional development beyond university training) and the implementation of reading instruction among teachers of students with LD in Saudi schools. A survey was sent to both male and female teachers of students with LD (N = 2158) in Saudi schools, asking them about their demographic information, reading-related courses, reading- related professional development activities, and their implementation of reading instruction in their classroom. A multiple regression analysis was conducted to examine the correlation between teachers’ reading-related training and their implementation of 17 reading practices for students with LD. The results indicated that teachers’ reading-related training was significantly related to their implementation of ten reading practices. The implications and recommendations for future research, policy, and practice are discussed

A model for characterising the collective dynamic behaviour of evolutionary algorithms

Exploration and exploitation are considered essential notions in evolutionary algorithms. However, a precise interpretation of what constitutes exploration or exploitation is clearly lacking and so are specific measures for characterising such notions. In this paper, we start addressing this issue by presenting new measures that can be used as indicators of the exploitation behaviour of an algorithm. These work by characterising the extent to which available information guides the search. More precisely, they quantify the dependency of a population's activity on the observed fitness values and genetic material, utilising an empirical model that uses a coarse-grained representation of population dynamics and records information about it. The model uses the k-means clustering algorithm to identify the population's "basins of activity". The exploitation behaviour is then captured by an entropy-based measure based on the model that quantifies the strength of the association between a population's activity distribution and the observed fitness landscape information. In experiments, we analysed the effects of the search operators and their parameter settings on the collective dynamic behaviour of populations. We also analysed the effect of using different problems on algorithm behaviours.We define a behavioural landscape for each problem to identify the appropriate behaviour to achieve good results and point out possible applications for the proposed model

The change in capacity and service delivery at public and private hospitals in Turkey: A closer look at regional differences

<p>Abstract</p> <p>Background</p> <p>Substantial regional health inequalities have been shown to exist in Turkey for major health indicators. Turkish data on hospitals deserves a closer examination with a special emphasis on the regional differences in the context of the rapid privatization of the secondary or tertiary level health services.</p> <p>This study aims to evaluate the change in capacity and service delivery at public and private hospitals in Turkey between 2001-2006 and to determine the regional differences.</p> <p>Methods</p> <p>Data for this retrospective study was provided from Statistical Almanacs of Inpatient Services (2001-2006). Hospitals in each of the 81 provinces were grouped into two categories: public and private. Provinces were grouped into six regions according to a development index composed by the State Planning Organisation. The number of facilities, hospital beds, outpatient admissions, inpatient admissions (per 100 000), number of deliveries and surgical operations (per 10 000) were calculated for public and private hospitals in each province and region. Regional comparisons were based on calculation of ratios for Region 1(R1) to Region 6(R6).</p> <p>Results</p> <p>Public facilities had a fundamental role in service delivery. However, private sector grew rapidly in Turkey between 2001-2006 in capacity and service delivery. In public sector, there were 2.3 fold increase in the number of beds in R1 to R6 in 2001. This ratio was 69.9 fold for private sector. The substantial regional inequalities in public and private sector decreased for the private sector enormously while a little decrease was observed for the public sector. In 2001 in R1, big surgical operations were performed six times more than R6 at the public sector whereas the difference was 117.7 fold for the same operations in the same regions for the private sector. These ratios decreased to 3.6 for the public sector and 13.9 for the private sector in 2006.</p> <p>Conclusions</p> <p>The private health sector has grown enormously between 2001-2006 in Turkey including the less developed regions of the country. Given the fact that majority of people living in these underdeveloped regions are uninsured, the expansion of the private sector may not contribute in reducing the inequalities in access to health care. In fact, it may widen the existing gap for access to health between high and low income earners in these underdeveloped regions.</p