SPH-EXA: Enhancing the Scalability of SPH codes Via an Exascale-Ready SPH Mini-App

Numerical simulations of fluids in astrophysics and computational fluid dynamics (CFD) are among the most computationally-demanding calculations, in terms of sustained floating-point operations per second, or FLOP/s. It is expected that these numerical simulations will significantly benefit from the future Exascale computing infrastructures, that will perform 10^18 FLOP/s. The performance of the SPH codes is, in general, adversely impacted by several factors, such as multiple time-stepping, long-range interactions, and/or boundary conditions. In this work an extensive study of three SPH implementations SPHYNX, ChaNGa, and XXX is performed, to gain insights and to expose any limitations and characteristics of the codes. These codes are the starting point of an interdisciplinary co-design project, SPH-EXA, for the development of an Exascale-ready SPH mini-app. We implemented a rotating square patch as a joint test simulation for the three SPH codes and analyzed their performance on a modern HPC system, Piz Daint. The performance profiling and scalability analysis conducted on the three parent codes allowed to expose their performance issues, such as load imbalance, both in MPI and OpenMP. Two-level load balancing has been successfully applied to SPHYNX to overcome its load imbalance. The performance analysis shapes and drives the design of the SPH-EXA mini-app towards the use of efficient parallelization methods, fault-tolerance mechanisms, and load balancing approaches.Comment: arXiv admin note: substantial text overlap with arXiv:1809.0801

Next Stop: California: The Benefits of High-Speed Rail Around the World and What's in Store for California

Outlines the advantages of high-speed rail systems replacing short-haul air and inter-city car travel, including energy, environmental, and economic benefits. Makes recommendations for land use, planning, and design to maximize benefits for California

Western Institution Building:The War, Hayek’s Cosmos and the WTO

Despite the shortcomings of Hayek’s spontaneous order, there is a positive side, perhaps even a positive feedback. Hayek left us with a “what if” question and returns us to that initial opening of Pandora’s Box, or perhaps the initial onset of neo-realism, neo-liberalism, developmentalism, globalism, transnationalism and other concepts, precepts and adjectives justifying institution building by bargaining and military force. In terms of new world order, institution building by necessity requires fundamental changes in governmental structures in non-Western cultures and nation-states such as China, Afghanistan and Iraq. Such changes are being prompted by means of political, economic and military powers of the U.S. and other developed nation-states, and international intergovernmental organizations dominated by developed nation-states such as the World Trade Organization. However arguably well intended there remains the question of what will eventually result from the introduction of Western institutions into non-Western cultures and developing countries. This article explores F. A. Hayek’s discourse concerning taxis and cosmos (Kosmos), in terms of institution building. This article addresses why China presents an instance of institution building by bargaining, while countries such as Iraq and Afghanistan offer instances of institution building by military force, then directs emphasis toward institutional and constitutional reform, and an evolution of Western law in non-Western cultures and developing nation- states such as China, Afghanistan, and Iraq. Although Hayek may have had contrary intentions, his discourse on taxis and cosmos (Kosmos), and spontaneous order, nonetheless, challenges a modern Western world to rethink its priorities and policies, and perhaps even foundational ideologies, especially in the realm of rebuilding non-Western cultures and developing countries.Western, Institution building, F. A. Hayek, War, WTO, Cosmos, constitutions, laws, international, politics, economics, military, force, neo-realism, neo-liberalism, developmentalism, globalism, transnationalism

A Hobbesian Bundle of Lockean Sticks: The Property Rights Legacy of Justice Scalia

No modern United States Supreme Court Justice has stimulated more thought and debate about the constitutional meaning of property than Antonin Scalia. This essay evaluates his efforts to change the prevailing interpretation of the Takings Clause. Scalia sought to ground it in clear rules embodying a reactionary defense of private owners’ prerogatives against environmental and land use regulation. Ultimately, Scalia aimed to authorize federal judicial oversight of state property law developments, whether through legislative or judicial innovation. In hindsight, he stands in a long tradition of conservative judges using property law as a constitutional baseline by which to restrain regulation

A Track Record of Success: High-Speed Rail Around the World and Its Promise for America

Highlights the economic and transportation benefits of high-speed rail in Japan and Europe, including creating jobs, saving energy, protecting the environment, and encouraging sustainable land use and development. Details lessons for the United States

Prolonged and arbitrary arrest and detention: an access to justice dilemma for South Sudan

South Sudan gained independence on 9 June 2011 after a prolonged period of oppression and conflict which was fuelled by a combination of factors including race, religion, the denial of human rights and dignity for the people of the south. Independence from Sudan ushered in a hope that the conflict-affected population could have a homeland of their own to live in peace and dignity. However, since independence, the achievement of good governance and the protection of human rights have been considerable challenges for South Sudan. The outbreak of civil war barely two years into independence further heightened the woes of the country creating a protracted humanitarian situation, rolling back development gains and weakening the functionality of governance institutions including those relevant to justice and law enforcement. Within this context of conflict, poverty and bad governance, an emerging concern is the prevalence of prolonged and arbitrary arrest and detention (PAD) in the criminal justice sector of South Sudan. While recognising that PAD occurs due to a combination of factors in any context, the thesis identifies three cardinal factors which have rendered PAD an inevitable component of the criminal justice sector in South Sudan. These include 1) the substantial geographic size and coverage of the country; 2) the limited financial and logistical resources available to justice and law enforcement institutions and; 3) limited human rights awareness and culture in South Sudan. The thesis investigates the historical, socio-economic and political context of South Sudan and demonstrates how the intervening factors passively or actively contribute towards PAD in post-independent South Sudan. The thesis also investigates the definition and peculiarities of the various acts and omissions that constitute PAD and analyses how it contravenes national and international law and human rights principles and standards. The thesis also highlights the social, economic and cultural impact of PAD and determines that these cumulative factors render PAD an inevitable component of the criminal justice system in South Sudan. The thesis relies on pre-existing theoretical and basic research for information and data relevant to the study. These materials include publications such as academic materials and human rights monitoring reports principally from three sources: Amnesty International, Human Rights Watch, and the United Nations Mission in South Sudan. The thesis also makes significant references to legislation, case laws, reports and statistical data from relevant institutions in South Sudan and other jurisdictions. Finally, international human rights treaties and conventions (some of which South Sudan has acceded to) are also reviewed in explaining and determining the legality and applicability of human rights law, concepts and practices locally. The thesis finds that the negative and harmful consequences of PAD occur at the individual, family, and national levels. Among others, the thesis identifies the right to access justice, including the rights to due process and liberty and security of persons as the main human rights violated by PAD. The thesis further notes that PAD significantly undermines the confidence and trust of the population in the justice and law enforcement institutions in South Sudan. Finally, the thesis also finds that unless the Government of South Sudan takes deliberate action to address the three cardinal factors, preventing and responding to PAD will be a difficult proposition. The thesis makes several recommendations for preventing and responding to PAD in South Sudan. Recommendations include capacity building at the sectoral and institutional levels, including the development of sectoral strategic planning; effective coordination of justice and law enforcement institutions; promoting human rights awareness, making legal aid available and accessible to all; effective data and harnessing information, communication technology (ICT) for justice and law enforcement and promoting the full engagement and participation of the demand side in addressing PAD in South Sudan