MPI Meets Cloud: Case Study with Amazon EC2 and Microsoft Azure

Author(s):  
Shulei Xu ◽  
S. Mahdieh Ghazimirsaeed ◽  
Jahanzeb Maqbool Hashmi ◽  
Hari Subramoni ◽  
Dhabaleswar K. Panda
Keyword(s):  
2014 ◽  
Author(s):  
Maicon Alves ◽  
Lúcia Maria Drummond

A computação em nuvem (cloud computing) é considerada como um novo paradigma de computação distribuída em que os clientes podem acessar recursos diretamente da Internet. Estudos recentes avaliam o uso dos recursos providos pela nuvem para executar aplicações científicas que demandam alto poder computacional. Neste sentido, este trabalho apresenta uma análise de desempenho de um simulador de reservatórios de petróleo a fim de avaliar o comportamento de tal aplicação científica em um ambiente de computação em nuvem provido pelas plataformas Amazon EC2 e Microsoft Azure. Essa análise leva em conta a observação de métricas do sistema operacional e a execução de benchmarks específicos. Os resultados mostram que o overhead de virtualização e o compartilhamento de recursos causam um descréscimo significativo de desempenho em tais aplicações.


Charity ◽  
2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Heru Suhartanto ◽  
Arry Yanuar ◽  
Ari Wibisono ◽  
Yohanes Gultom

Masalah pertama yang dihadapi terkait kegiatan ini adalah Penggunaan sumber daya High Performance Computing (HPC) membutuhkan fasilitas superkomputer yang sangat mahal, baik pengadaan maupun perawatannya. Sehingga fasilitas HPC tersebut hanya dimiliki institusi tertentu yang memiliki sumber pendanaan cukup besar. Terutama di Indonesia, mungkin hanya segelintir lembaga pendidikan dan penelitian yang mampu memilikinya. Hal ini mengakibatkan, pemanfaatan HPC untuk penelitian menjadi terbatas, karena sangat sedikit sekali aktivitas penelitian yang memiliki akses ke fasilitas HPC tertentu. Sehingga hal ini menjadi suatu hambatan tersendiri, terutama untuk kasus penelitian yang menuntut sumber daya komputasi besar. Masalah kedua yakni para peneliti yang umumnya berasal dari berbagai macam disiplin ilmu pengetahuan sering tidak memiliki kemampuan tentang bagaimana menggunakan infrastruktur HPC tersebut. Umumnya, pengguna HPC cloud akan diberikan beberapa server virtual, kemudian server virtual tersebut harus disiapkan secara mandiri sesuai kebutuhan aplikasinya. Setup tersebut berkaitan dengan instalasi Sistem operasi, midleware, aplikasi, serta beberapa konfigurasi yang tidak sederhana. (Rajan et all, 2011) Sehingga, peneliti tersebut harus bertambah pekerjaan dan waktu tambahan untuk mempelajari suatu kemampuan lain yang cukup rumit di luar esensi penelitian itu sendiri agar mampu menggunakan cloud IAAS tersebut Untuk mengatasi masalah masalah pertama tersebut, muncul satu alternatif solusi, yaitu dengan penggunaan layanan cloud Infrastruktur-as-a-Service (IAAS), di mana layanan cloud tersebut menyediakan infrastruktur HPC. Layanan infrastruktur tersebut meliputi prosesor, memory, storage, jaringan internet, listrik serta perawatan. Saat ini banyak bermunculan vendor IAAS, seperti Amazon EC2 (Elastic Computing Cloud for Computing Service), S3 (Simple Storage Service), Microsoft Azure (PAAS), Google AppEngine, dan lainnya. Penulis telah mengembangkan prototype portal Sumber Daya HPC untuk simulasi dinamika molekuler sebagai output dari kegiatan penelitian beberapa tahun belakangan ini. Dalam kegiatan ini, dilakukan ujicoba implementasi prototype tersebut kepada usernya yakni para peneliti baik dosen dan mahasiswa. Sosialisasi pengenalan dan ujicoba prototype tersebut telah dilakukan kepada beberapa rekan dosen, peneliti dan mahasiswa di Universitas Padjajadan dan Institute Teknologi Bandung. Berdasarkan hasil kuesioner kegiatan sosialisasi ini, seluruh peserta merasa puas dengan kegiatan sosialisasi ini dan menganggap prototype tersebut dapat membantu memperbaiki kondisi mereka. Sistem yang diperkenalkan ini juga dianggap sesuai oleh seluruh peserta untuk mengangkat potensi bidang mereka (farmasi/kimia). Sebagian besar peserta juga merasa puas dengan acara yang diselenggarakan ini dan merasa cukup mampu untuk memanfaatkan sistem ini secara mandiri tanpa bantuan/pendampingan dari tim UI.


2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.


2020 ◽  
Vol 43 ◽  
Author(s):  
Michael Lifshitz ◽  
T. M. Luhrmann

Abstract Culture shapes our basic sensory experience of the world. This is particularly striking in the study of religion and psychosis, where we and others have shown that cultural context determines both the structure and content of hallucination-like events. The cultural shaping of hallucinations may provide a rich case-study for linking cultural learning with emerging prediction-based models of perception.


2019 ◽  
Vol 42 ◽  
Author(s):  
Daniel J. Povinelli ◽  
Gabrielle C. Glorioso ◽  
Shannon L. Kuznar ◽  
Mateja Pavlic

Abstract Hoerl and McCormack demonstrate that although animals possess a sophisticated temporal updating system, there is no evidence that they also possess a temporal reasoning system. This important case study is directly related to the broader claim that although animals are manifestly capable of first-order (perceptually-based) relational reasoning, they lack the capacity for higher-order, role-based relational reasoning. We argue this distinction applies to all domains of cognition.


2019 ◽  
Vol 42 ◽  
Author(s):  
Penny Van Bergen ◽  
John Sutton

Abstract Sociocultural developmental psychology can drive new directions in gadgetry science. We use autobiographical memory, a compound capacity incorporating episodic memory, as a case study. Autobiographical memory emerges late in development, supported by interactions with parents. Intervention research highlights the causal influence of these interactions, whereas cross-cultural research demonstrates culturally determined diversity. Different patterns of inheritance are discussed.


Author(s):  
D. L. Callahan

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.


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