Challenges and Opportunities on Parallel/Distributed Programming for Large-scale: From Multi-core to Clouds

Author(s):  
Denis Caromel
2021 ◽  
Vol 10 (6) ◽  
pp. 384
Author(s):  
Javier Martínez-López ◽  
Bastian Bertzky ◽  
Simon Willcock ◽  
Marine Robuchon ◽  
María Almagro ◽  
...  

Protected areas (PAs) are a key strategy to reverse global biodiversity declines, but they are under increasing pressure from anthropogenic activities and concomitant effects. Thus, the heterogeneous landscapes within PAs, containing a number of different habitats and ecosystem types, are in various degrees of disturbance. Characterizing habitats and ecosystems within the global protected area network requires large-scale monitoring over long time scales. This study reviews methods for the biophysical characterization of terrestrial PAs at a global scale by means of remote sensing (RS) and provides further recommendations. To this end, we first discuss the importance of taking into account the structural and functional attributes, as well as integrating a broad spectrum of variables, to account for the different ecosystem and habitat types within PAs, considering examples at local and regional scales. We then discuss potential variables, challenges and limitations of existing global environmental stratifications, as well as the biophysical characterization of PAs, and finally offer some recommendations. Computational and interoperability issues are also discussed, as well as the potential of cloud-based platforms linked to earth observations to support large-scale characterization of PAs. Using RS to characterize PAs globally is a crucial approach to help ensure sustainable development, but it requires further work before such studies are able to inform large-scale conservation actions. This study proposes 14 recommendations in order to improve existing initiatives to biophysically characterize PAs at a global scale.


Author(s):  
Balaje T. Thumati ◽  
Halasya Siva Subramania ◽  
Rajeev Shastri ◽  
Karthik Kalyana Kumar ◽  
Nicole Hessner ◽  
...  

2021 ◽  
Vol 13 (23) ◽  
pp. 13011
Author(s):  
Manuela Fritz ◽  
Michael Grimm ◽  
Patrick Keilbart ◽  
Dimas Dwi Laksmana ◽  
Nathalie Luck ◽  
...  

While there is a global consensus that agricultural systems need to be transformed to be more sustainable, possible pathways and challenges to this process are still debated. We analyse the challenges and opportunities involved in transforming smallholder farming to organic agriculture in Indonesia, where the intense application of Green Revolution technologies came at enormous environmental costs. We adopt a transdisciplinary approach to identify possible pathways towards organic agriculture, based on an analysis of farmers’ knowledge and barriers to adoption, value and belief systems, and institutional structures, including policies and regulations. We present our empirical findings as ‘system knowledge’, ‘target knowledge’ and ‘transformation knowledge’ and incorporate insights from both academics and practitioners. We draw on evidence from large-scale surveys, field experiments, in-depth interviews, participant observation and document analysis. A key insight of our research is that Indonesia does not lack initiatives towards organic farming, but that these various initiatives have different motivations, goals and strategies. This misalignment detracts from the transformational potential of organic agriculture and is responsible for the hitherto limited success of the organic transition. Our findings suggest that policy action at multiple levels is required, guided by an inclusive strategy that is drawn up in a participatory manner.


2020 ◽  
Vol 10 (4) ◽  
pp. 490-501
Author(s):  
Mozhgan Jahani ◽  
Davood Rezazadeh ◽  
Parisa Mohammadi ◽  
Amir Abdolmaleki ◽  
Amir Norooznezhad ◽  
...  

Blood vessel development is one of the most prominent steps in regenerative medicine due tothe restoration of blood flow to the ischemic tissues and providing the rapid vascularizationin clinical-sized tissue-engineered grafts. However, currently tissue engineering technique isrestricted because of the inadequate in vitro/in vivo tissue vascularization. Some challenges likeas transportation in large scale, distribution of the nutrients and poor oxygen diffusion limit theprogression of vessels in smaller than clinically relevant dimensions as well in vivo integration.In this regard, the scholars attempted to promote the vascularization process relied on the stemcells (SCs), growth factors as well as exosomes and interactions of biomaterials with all of themto enable the emergence of ideal microenvironment which is needed for treatment of unhealthyorgans or tissue regeneration and formation of new blood vessels. Thus, in the present reviewwe aim to describe these approaches, advances, obstacles and opportunities as well as theirapplication in regeneration of heart as a prominent angiogenesis-dependent organ.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Sol Ji Kang ◽  
Sang Yeon Lee ◽  
Keon Myung Lee

With problem size and complexity increasing, several parallel and distributed programming models and frameworks have been developed to efficiently handle such problems. This paper briefly reviews the parallel computing models and describes three widely recognized parallel programming frameworks: OpenMP, MPI, and MapReduce. OpenMP is the de facto standard for parallel programming on shared memory systems. MPI is the de facto industry standard for distributed memory systems. MapReduce framework has become the de facto standard for large scale data-intensive applications. Qualitative pros and cons of each framework are known, but quantitative performance indexes help get a good picture of which framework to use for the applications. As benchmark problems to compare those frameworks, two problems are chosen: all-pairs-shortest-path problem and data join problem. This paper presents the parallel programs for the problems implemented on the three frameworks, respectively. It shows the experiment results on a cluster of computers. It also discusses which is the right tool for the jobs by analyzing the characteristics and performance of the paradigms.


2018 ◽  
Vol 8 (2) ◽  
pp. 20170048 ◽  
Author(s):  
M. I. Disney ◽  
M. Boni Vicari ◽  
A. Burt ◽  
K. Calders ◽  
S. L. Lewis ◽  
...  

Terrestrial laser scanning (TLS) is providing exciting new ways to quantify tree and forest structure, particularly above-ground biomass (AGB). We show how TLS can address some of the key uncertainties and limitations of current approaches to estimating AGB based on empirical allometric scaling equations (ASEs) that underpin all large-scale estimates of AGB. TLS provides extremely detailed non-destructive measurements of tree form independent of tree size and shape. We show examples of three-dimensional (3D) TLS measurements from various tropical and temperate forests and describe how the resulting TLS point clouds can be used to produce quantitative 3D models of branch and trunk size, shape and distribution. These models can drastically improve estimates of AGB, provide new, improved large-scale ASEs, and deliver insights into a range of fundamental tree properties related to structure. Large quantities of detailed measurements of individual 3D tree structure also have the potential to open new and exciting avenues of research in areas where difficulties of measurement have until now prevented statistical approaches to detecting and understanding underlying patterns of scaling, form and function. We discuss these opportunities and some of the challenges that remain to be overcome to enable wider adoption of TLS methods.


Author(s):  
Haipeng Wang

Protein identification (sequencing) by tandem mass spectrometry is a fundamental technique for proteomics which studies structures and functions of proteins in large scale and acts as a complement to genomics. Analysis and interpretation of vast amounts of spectral data generated in proteomics experiments present unprecedented challenges and opportunities for data mining in areas such as data preprocessing, peptide-spectrum matching, results validation, peptide fragmentation pattern discovery and modeling, and post-translational modification (PTM) analysis. This article introduces the basic concepts and terms of protein identification and briefly reviews the state-of-the-art relevant data mining applications. It also outlines challenges and future potential hot spots in this field.


Domain Walls ◽  
2020 ◽  
pp. 311-339
Author(s):  
S. Liu ◽  
I. Grinberg ◽  
A. M. Rappe

This chapter focuses on recent studies of ferroelectrics, where large-scale molecular dynamics (MD) simulations using first-principles-based force fields played a central role in revealing important physics inaccessible to direct density functional theory (DFT) calculations but critical for developing physically-based free energy functional for coarse-grained phase-field-type simulations. After reviewing typical atomistic potentials of ferroelectrics for MD simulations, the chapter describes a progressive theoretical framework that combines DFT, MD, and a mean-field theory. It then focuses on relaxor ferroelectrics. By examining the spatial and temporal polarization correlations in prototypical relaxor ferroelectrics with million-atom MD simulations and novel analysis techniques, this chapter shows that the widely accepted model of polar nanoregions embedded in a non-polar matrix is incorrect for Pb-based relaxors. Rather, the unusual properties of theses relaxor ferroelectrics stem from the presence of a multi-domain state with extremely small domain sizes (2–10 nanometers), giving rise to a greater flexibility for polarization rotations and the ultrahigh dielectric and piezoelectric responses. Finally, this chapter discusses the challenges and opportunities for multiscale simulations of ferroelectric materials.


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