The Efficacy of Mathematics Education

Evidence supports the notion that mathematics education in the United States is inadequate. There is also evidence that mathematics education deficiencies extend internationally. The worldwide mathematics education deficit appears large enough that improving student performance in this educational problem area could yield great economic benefit. To improve the efficacy of mathematics education, education’s root problems must first be understood. Often supposed educational root problems are considered and contrasted against potential deficiencies of mathematics methodologies and curricula that are based on mainstream educational philosophies. The educational philosophies utilized to form early-grade mathematics methodologies and related curricula are judged to be the main reasons for low levels of interest in the subject of mathematics by student populations. An exploration of available literature in regard to how the human brain learns is provided. Two unifications are resultantly hypothesized: interest and learning appear to be mentally intertwined, this unification may serve as the basis for a more effective educational methodology; children are nearly universally interested in the visual arts, arithmetic and geometric mathematical principles are intertwined with the visual arts principles of linear perspective and proportion. An early grade curriculum that relates those mathematical principles via artistic methods (similar to those developed and utilized by master artists and engineers of the Renaissance era) may prove broadly effective at equitably increasing students’ mathematical achievement. Future research in such a direction is highly recommended

How to Reconcile Event-Based Performance Analysis with Tasking in OpenMP

Abstract. With version 3.0, the OpenMP specification introduced a task construct and with it an additional dimension of concurrency. While offering a convenient means to express task parallelism, the new construct presents a serious challenge to event-based performance analysis. Since tasking may disrupt the classic sequence of region entry and exit events, essential analysis procedures such as reconstructing dynamic call paths or correctly attributing performance metrics to individual task region instances may become impossible. To overcome this limitation, we describe a portable method to distinguish individual task instances and to track their suspension and resumption with event-based instrumentation. Implemented as an extension of the OPARI source-code instrumenter, our portable solution supports C/C++ programs with tied tasks and with untied tasks that are suspended only at implied scheduling points, while introducing only negligible measurement overhead. Finally, we discuss possible extensions of the OpenMP specification to provide general support for task identifiers with untied tasks.

The Outcome of Patients with Melanoma Is Not Associated with the Time Point of Lymphatic Mapping with Respect to Excisional Biopsy of the Primary Tumor

Background: Sentinel lymph node biopsy (SLNB) has become the standard care for melanoma and is an important diagnostic procedure. It has been doubted whether lymphoscintigraphy detects the correct sentinel lymph node (SLN) when excision of the tumor and SLNB are not performed at the same time. This would imply that this sequential approach may have an increased risk of undetected micrometastases resulting in a worse outcome. Objective: The purpose of the present study was to compare the outcome of melanoma patients having received excision of the tumor and SLNB either at the same time or consecutively. Methods: A total of 854 patients with cutaneous melanoma were enrolled in this retrospective study between September 1996 and November 2007. Disease-free (DFS) and overall survivals (OS) were estimated using the Kaplan-Meier product limit method and were analyzed by the log rank test. Results: No statistically significant difference was found regarding DFS, progression rates and OS in patients with primary tumor excision and SLNB at the same time compared with patients with excisional biopsy of primary tumor and SLNB at different times. Conclusion: These data suggest that excisional biopsy of the primary tumor does not prevent the correct SLN mapping in melanoma patients. Copyright (C) 2010 S. Karger AG, Base

Implementation and scaling of the fully coupled Terrestrial Systems Modeling Platform (TerrSysMP) in a massively parallel supercomputing environment – a case study on JUQUEEN (IBM Blue Gene/Q)

Continental-scale hyper-resolution simulations constitute a grand challenge in characterizing non-linear feedbacks of states and fluxes of the coupled water, energy, and biogeochemical cycles of terrestrial systems. Tackling this challenge requires advanced coupling and supercomputing technologies for earth system models that are discussed in this study, utilizing the example of the implementation of the newly developed Terrestrial Systems Modeling Platform (TerrSysMP) on JUQUEEN (IBM Blue Gene/Q) of the Jülich Supercomputing Centre, Germany. The applied coupling strategies rely on the Multiple Program Multiple Data (MPMD) paradigm and require memory and load balancing considerations in the exchange of the coupling fields between different component models and allocation of computational resources, respectively. These considerations can be reached with advanced profiling and tracing tools leading to the efficient use of massively parallel computing environments, which is then mainly determined by the parallel performance of individual component models. However, the problem of model I/O and initialization in the peta-scale range requires major attention, because this constitutes a true big data challenge in the perspective of future exa-scale capabilities, which is unsolved

Интеллектуальный мониторинг распределенных технологических объектов с использованием информационных моделей состояния

Работа посвящена вопросам построения интеллектуальных систем мониторинга крупномасштабных распределенных технологических объектов. Отличительной особенностью таких систем от систем класса АСУ ТП является необходимость определения фактического глобального состояния системы, предполагающегося неизменным на период горизонта планирования. Знание фактического глобального состояния системы может быть использовано для решения различных комплексных оптимизационных задач. Его представление в системе названо информационной моделью состояния. Информационная модель системы конструируется динамически из информационной модели объекта и временных рядов значений параметров и событий. В качестве примера рассмотрена задача оптимизации маршрутных карт технологического транспорта нефтегазодобывающего предприятия. Предложен поход к реализации функций формирования информационных моделей состояний на базе аспектно-ориентированной парадигмы

Think Eternally: Improved Algorithms for the Temp Secretary Problem and Extensions

The Temp Secretary Problem was recently introduced by [Fiat et al., ESA 2015]. It is a generalization of the Secretary Problem, in which commitments are temporary for a fixed duration. We present a simple online algorithm with improved performance guarantees for cases already considered by [Fiat et al., ESA 2015] and give competitive ratios for new generalizations of the problem. In the classical setting, where candidates have identical contract durations gamma << 1 and we are allowed to hire up to B candidates simultaneously, our algorithm is (1/2) - O(sqrt{gamma})-competitive. For large B, the bound improves to 1 - O(1/sqrt{B}) - O(sqrt{gamma}). Furthermore we generalize the problem from cardinality constraints towards general packing constraints. We achieve a competitive ratio of 1 - O(sqrt{(1+log(d) + log(B))/B}) - O(sqrt{gamma}), where d is the sparsity of the constraint matrix and B is generalized to the capacity ratio of linear constraints. Additionally we extend the problem towards arbitrary hiring durations. Our algorithmic approach is a relaxation that aggregates all temporal constraints into a non-temporal constraint. Then we apply a linear scaling algorithm that, on every arrival, computes a tentative solution on the input that is known up to this point. This tentative solution uses the non-temporal, relaxed constraints scaled down linearly by the amount of time that has already passed

Simulation of MPI applications with time-independent traces

International audienceAnalyzing and understanding the performance behavior of parallel applications on parallel computing platforms is a long-standing concern in the High Performance Computing community. When the targeted platforms are not available , simulation is a reasonable approach to obtain objective performance indicators and explore various hypothetical scenarios. In the context of applications implemented with the Message Passing Interface, two simulation methods have been proposed, on-line simulation and off-line simulation, both with their own drawbacks and advantages. In this work we present an off-line simulation framework, i.e., one that simulates the execution of an application based on event traces obtained from an actual execution. The main novelty of this work, when compared to previously proposed off-line simulators, is that traces that drive the simulation can be acquired on large, distributed, heterogeneous , and non-dedicated platforms. As a result the scalability of trace acquisition is increased, which is achieved by enforcing that traces contain no time-related information. Moreover, our framework is based on an state-of-the-art scalable, fast, and validated simulation kernel. We introduce the notion of performing off-line simulation from time-independent traces, propose and evaluate several trace acquisition strategies, describe our simulation framework, and assess its quality in terms of trace acquisition scalability, simulation accuracy, and simulation time