Adaptive Data Migration in Load-Imbalanced HPC Applications

Distributed parallel applications need to maximize and maintain computer resource utilization and be portable across different machines. Balanced execution of some applications requires more effort than others because their data distribution changes over time. Data re-distribution at runtime requires elaborate schemes that are expensive and may benefit particular applications. This dissertation discusses a solution for HPX applications to monitor application execution with APEX and use AGAS migration to adaptively redistribute data and load balance applications at runtime to improve application performance and scaling behavior. This dissertation provides evidence for the practicality of using the Active Global Address Space as is proposed by the ParalleX model and implemented in HPX. It does so by using migration for the transparent moving of objects at runtime and using the Autonomic Performance Environment for eXascale library with experiments that run on homogeneous and heterogeneous machines at Louisiana State University, CSCS Swiss National Supercomputing Centre, and National Energy Research Scientific Computing Center

Asynchronous Execution of Python Code on Task Based Runtime Systems

Despite advancements in the areas of parallel and distributed computing, the complexity of programming on High Performance Computing (HPC) resources has deterred many domain experts, especially in the areas of machine learning and artificial intelligence (AI), from utilizing performance benefits of such systems. Researchers and scientists favor high-productivity languages to avoid the inconvenience of programming in low-level languages and costs of acquiring the necessary skills required for programming at this level. In recent years, Python, with the support of linear algebra libraries like NumPy, has gained popularity despite facing limitations which prevent this code from distributed runs. Here we present a solution which maintains both high level programming abstractions as well as parallel and distributed efficiency. Phylanx, is an asynchronous array processing toolkit which transforms Python and NumPy operations into code which can be executed in parallel on HPC resources by mapping Python and NumPy functions and variables into a dependency tree executed by HPX, a general purpose, parallel, task-based runtime system written in C++. Phylanx additionally provides introspection and visualization capabilities for debugging and performance analysis. We have tested the foundations of our approach by comparing our implementation of widely used machine learning algorithms to accepted NumPy standards

An improved method for assessing mismatches between supply and demand in urban regulating ecosystem services: A case study in Tabriz, Iran

Regulating ecosystem services provided by urban forests are of great importance for the quality of life among city dwellers. To reach a maximum contribution to well-being in cities, the urban regulating ecosystem services (URES) must match with the demands in terms of space and time. If we understand the matches or mismatches between the current urban dwellers' desired quality conditions (demand) and the supply of URES by urban forests (UF) in the cities, this will facilitate integrating the concepts of ecosystem services in urban planning and management, but such an assessment has suffered from major knowledge limitations. Since it is complex and problematic to identify the direct demands for URES and the spatiotemporal patterns therein, improving the demand indicators can help to determine the actual requirements. In this paper, a methodological approach based on indicators is presented and demonstrated for two important URES: air quality improvement and global climate change mitigation provided by urban trees and shrubs. Four air quality standards and greenhouse gas reduction targets were used and compared to supplies of the URES in Tabriz, Iran. Our results show that the mean contribution of the URES supply to air quality standards and greenhouse gas reduction targets is modest. Hence, in Tabriz, there is a strong mismatch between demand and supply. Mismatches at the city scale will have to be reduced by both a reduction in pollutant emissions and an increased provisioning of URES supply through urban greenery. The presented assessment approach and the results for Tabriz make it explicit how different the demands and supplies of the two studied URES are, and we expect similar mismatches in many other cities. Therefore, our approach, relatively simple but still realistic and easy-to-apply, can raise awareness about, and the utility of, the ecosystem services concepts for urban planning and policymaking.Environmental Biolog

From Piz Daint to the Stars: Simulation of Stellar Mergers using High-Level Abstractions

We study the simulation of stellar mergers, which requires complex simulations with high computational demands. We have developed Octo-Tiger, a finite volume grid-based hydrodynamics simulation code with Adaptive Mesh Refinement which is unique in conserving both linear and angular momentum to machine precision. To face the challenge of increasingly complex, diverse, and heterogeneous HPC systems, Octo-Tiger relies on high-level programming abstractions. We use HPX with its futurization capabilities to ensure scalability both between nodes and within, and present first results replacing MPI with libfabric achieving up to a 2.8x speedup. We extend Octo-Tiger to heterogeneous GPU-accelerated supercomputers, demonstrating node-level performance and portability. We show scalability up to full system runs on Piz Daint. For the scenario's maximum resolution, the compute-critical parts (hydrodynamics and gravity) achieve 68.1% parallel efficiency at 2048 nodes.Comment: Accepted at SC1

Urban Trees and Hydrological Ecosystem Service: A Novel Approach to Analyzing the Relationship Between Landscape Structure and Runoff Reduction

Urban stormwater runoff has posed significant challenges in the face of urbanization and climate change, emphasizing the importance of trees in providing runoff reduction ecosystem services (RRES). However, the sustainability of RRES can be disturbed by urban landscape modification. Understanding the impact of landscape structure on RRES is crucial to manage urban landscapes effectively to sustain supply of RRES. So, this study developed a new approach that analyzes the relationship between the landscape structural pattern and the RRES in Tabriz, Iran. The provision of RRES was estimated using the i-Tree Eco model. Landscape structure-related metrics of land use and cover (LULC) were derived using FRAGSTATS to quantify the landscape structure. Stepwise regression analysis was used to assess the relationship between landscape structure metrics and the provision of RRES. The results indicated that throughout the city, the trees prevented 196854.15 m3 of runoff annually. Regression models (p ≤ 0.05) suggested that the provision of RRES could be predicted using the measures of the related circumscribing circle metric (0.889 ≤ r2 ≤ 0.954) and the shape index (r2 = 0.983) of LULC patches. The findings also revealed that the regularity or regularity of the given LULC patches' shape could impact the patches' functions, which, in turn, affects the provision of RRES. The landscape metrics can serve as proxies to predict the capacity of trees for potential RRES using the obtained regression models. This helps to allocate suitable LULC through optimizing landscape metrics and management guidance to sustain RRES

Hydrogel nanocomposite based on alginate/zeolite for burn wound healing: In vitro and in vivo study

Objective(s): The main objective of the current assay was to evaluate the antibacterial and regenerative effects of hydrogel nanocomposite containing pure natural zeolite (clinoptilolite) integrated with alginate (Alg) as wound healing/dressing biomaterials.Materials and Methods: The zeolites were size excluded, characterized by SEM, DLS, XRD, FTIR, and XRF, and then integrated into Alg hydrogel followed by calcium chloride crosslinking. The Alg and alginate zeolite (Alg/Zeo) hydrogel was characterized by swelling and weight loss tests, also the antibacterial, hemocompatibility, and cell viability tests were performed. In animal studies, the burn wound was induced on the back of rats and treated with the following groups: control, Alg hydrogel, and Alg/Zeo hydrogel.Results: The results showed that the hydrodynamic diameter of zeolites was 367 ± 0.2 nm. Zeolites did not show any significant antibacterial effect, however, the hydrogel nanocomposite containing zeolite had proper swelling as well as hemocompatibility and no cytotoxicity was observed. Following the creation of a third-degree burn wound on the back of rats, the results indicated that the Alg hydrogel and Alg/Zeo nanocomposite accelerated the wound healing process compared with the control group. Re-epithelialization, granulation tissue thickness, collagenization, inflammatory cell recruitment, and angiogenesis level were not significantly different between Alg and Alg/Zeo nanocomposite.Conclusion: These findings revealed that although the incorporation of zeolites did not induce a significant beneficial effect in comparison with Alg hydrogel, using zeolite capacity in hydrogel for loading the antibiotics or other effective compounds can be considered a promising wound dressing

Spatio-temporal analysis and simulation pattern of land use/cover changes, case study: Naghadeh, Iran

As a result of the growing impacts on global environments, it has become important for land use planners to extract, detect, monitor and predict land use/cover changes (LUCCs). The monitoring of LUCCs within a certain time period and predicting future trends of temporal and spatial changes are absolutely necessary. The aim of this research was to analyze and monitor LUCCs in Naghadeh County, Iran over a time span of 27 years and predict the future trend of changes during the period of 2014–2041. Land use/cover (LULC) maps were extracted (as built-up regions, water body, agricultural and bare lands) for 1987, 2000 and 2014 via RS images obtained from Landsat TM, ETM+ and OLI, respectively. The overall classification and Kappa index for all the classified maps were over 85% and 0.8, respectively. The C-A Markov model was used to predict future trend of LULC for the next 27-years. The obtained Kappa agreement statistics results from comparing actual and simulated maps of 2014 suggested the high capability of the model in LUCCs simulation in the study area. The results indicated the growth of built-up regions (urban area) from 1989 to 2014, while there was decrease in bare land. The projected land use for 2041 revealed more urbanization with potential expansion in agricultural and bare lands. Therefore, if the current management trends continue without any attention to sustainability measures, remnant water body and bare lands decline will ensue. This research provides useful and up-to-date information to local land use planners, managers and policy-makers to step up towards sustainable development in the study area

The Effectiveness of Rule-Governed Democracy Classroom Management Style on Self-Esteem of 3rd-grade High School Male Students

By utilizing classroom management styles, teachers will be able to get rid of possible students’ misconducts and promote a friendly atmosphere which will in effect promote students’ participation in learning activities. Additionally, increased self-esteem, which is an achievement of such utilization, will influence various aspects of students’ future lives. Taking this point into consideration, the present study aimed at determining the efficacy of rule-governed democracy classroom management style on self-esteem of 3rd-grade high-school male students. All 3rd-grade high-school male students of Abdanan city in the academic year 2013 comprised the statistical population to this study. Using convenience sampling, 38 subjects were selected and randomly assigned to experimental and control groups. The research design was pretest-post-test. Cooper Smith's self-esteem questionnaire was used as the research instrument which was administered to the two groups at the outset. The experimental group was given seven 90-minutes sessions of treatment and twice-a-week. The two groups were asked to fill out the same questionnaire for the post-test stage afterwards. Descriptive statistics, including the analysis of covariance was used to analyze the data. The results revealed that the utilization of rule-governed democracy classroom management style in the classroom had significantly increased the self-esteem (public-family-social- and scholastic-professional) of male students in the post-test (p<0/001)

Effectiveness of the Integrated Rehabilitation Program Based on Vibroacoustics and Virtual Reality on the Visual Processing of Children with Autism: Treatment Reports of Five Patients

The visual processing disorder is broadly observed among individuals with autism. This study was conducted to develop an integrated rehabilitation program based on vibroacoustics and virtual reality and to assess its effectiveness on the visual processing of autistic children. This experimental case report was conducted using an Aberrant Behavior Checklist (ABC) design on 5 children with autism referred to Zehnara Rehabilitation Clinic in the second half months of 2021. First, the integrated program was implemented for ten 30-minute sessions on 2 subjects randomly selected from among the samples. After determining the program validity, 3 more subjects were entered into the study. The sensory profile questionnaire-2 was used. The questionnaires were filled out at the baseline stage, at the end of each intervention session, and at the one-month follow-up stage. The visual analysis, the percentage of recovery, the percentage of non-overlapping data (PND), and the percentage of overlapping data (POD) were used for data analysis. The implemented intervention was evaluated to be effective for all five subjects so that for Subjects No. 1, 2, 3, 4, and 5, the PND rates were obtained to be 90%, 90%, 70%, 100%, and 90%, respectively. The results of this study demonstrated that the integrated sensory rehabilitation program could be used to improve the visual processing of children with autism