Propagation and Decay of Injected One-Off Delays on Clusters: A Case Study

Analytic, first-principles performance modeling of distributed-memory applications is difficult due to a wide spectrum of random disturbances caused by the application and the system. These disturbances (commonly called "noise") destroy the assumptions of regularity that one usually employs when constructing simple analytic models. Despite numerous efforts to quantify, categorize, and reduce such effects, a comprehensive quantitative understanding of their performance impact is not available, especially for long delays that have global consequences for the parallel application. In this work, we investigate various traces collected from synthetic benchmarks that mimic real applications on simulated and real message-passing systems in order to pinpoint the mechanisms behind delay propagation. We analyze the dependence of the propagation speed of idle waves emanating from injected delays with respect to the execution and communication properties of the application, study how such delays decay under increased noise levels, and how they interact with each other. We also show how fine-grained noise can make a system immune against the adverse effects of propagating idle waves. Our results contribute to a better understanding of the collective phenomena that manifest themselves in distributed-memory parallel applications.Comment: 10 pages, 9 figures; title change

Green finance and sustainable development in Europe

This study provides a comprehensive analysis of whether financial development impacts environmental degradation, over time. It highlights how financial development, institutional frameworks, and foreign investment dictate the extent of green development. The sample includes 40 countries in Europe and data is collected on a large set of variables, for the years from 1990 to 2019. Financial development is measured through domestic credit to the private sector, bank credit to the private sector and foreign direct investment (FDI). Environmental degradation is measured through energy use, CO2 emissions, greenhouse emissions and natural resource depletion. The model controls for income levels, institutional quality, technology, education, population, and urbanization. Regression analysis is conducted to analyze the data. The results suggest that financial development has a negative relationship with four different measures of environmental degradation, while FDI and institutional quality appear to worsen the environmental measures. Recommendations for policy makers include development of green finance policies and strong institutions, to lower environmental degradation in the long run

Physical Oscillator Model for Supercomputing

A parallel program together with the parallel hardware it is running on is not only a vehicle to solve numerical problems, it is also a complex system with interesting dynamical behavior: resynchronization and desynchronization of parallel processes, propagating phases of idleness, and the peculiar effects of noise and system topology are just a few examples. We propose a physical oscillator model (POM) to describe aspects of the dynamics of interacting parallel processes. Motivated by the well-known Kuramoto Model, a process with its regular compute-communicate cycles is modeled as an oscillator which is coupled to other oscillators (processes) via an interaction potential. Instead of a simple all-to-all connectivity, we employ a sparse topology matrix mapping the communication structure and thus the inter-process dependencies of the program onto the oscillator model and propose two interaction potentials that are suitable for different scenarios in parallel computing: resource-scalable and resource-bottlenecked applications. The former are not limited by a resource bottleneck such as memory bandwidth or network contention, while the latter are. Unlike the original Kuramoto model, which has a periodic sinusoidal potential that is attractive for small angles, our characteristic potentials are always attractive for large angles and only differ in the short-distance behavior. We show that the model with appropriate potentials can mimic the propagation of delays and the synchronizing and desynchronizing behavior of scalable and bottlenecked parallel programs, respectively.Comment: 5 pages, 2 figure

Conditional vs unconditional cash transfers: a study of poverty demographics in Pakistan

This paper aims to provide a detailed demographic description of poverty in Pakistan with an attempt to highlight those segments of the poor who can be aided to transition out of extreme poverty through appropriate policy measures. Data are collected from the Household Integrated Economic Survey (HIES) for the years 1985–2016 and captures falling poverty, gender-wise division of the employed and unemployed, type of employment (self-employed, unpaid workers, employers, employees) by gender, labour participation of vulnerable age groups, as well as unemployed widows. The paper discusses the effectiveness of conditional (CCT) and unconditional (UCT) cash transfer programs across the world and using data indicators, highlights the appropriate target groups in need of such intervention in Pakistan. The existing components of BISP are discussed, with policy recommendations targeted to enhance its impact by focusing UCTs on the most vulnerable segments. CCTs can be used to improve health and education outcomes; given Pakistan’s lagging performance, illiteracy among youth, infant and maternal health are of particular consideration. Cash transfers can be made conditional, subject to regular health checkups for mothers and children and mandatory school attendance to improve these outcomes. The paper further suggests an extension of the program to provide short-term financial relief to the temporarily unemployed

Pakistan’s poverty puzzle: role of foreign aid, democracy & media

In theory, poverty reduction is associated with economic growth and equal access to opportunities for all citizens, regardless of their age, gender and income. Pakistan has reduced its poverty headcount by nearly 66% between 2002–2016, despite poor governance, weak institutions, mediocre economic growth, and poor social indicators. Using ADL/VAR and Granger causality tests, the paper empirically proves that change in political regimes, openness of media and foreign aid have contributed to alleviation of poverty in the country. The paper finds that the shift towards a stable democratic regime has facilitated the delivery of social services, regardless of the motive. Furthermore, it finds that free flow of information through the media has created an awareness among the masses about their rights; the access to information has led to a more equitable distribution of social services. Foreign aid has also contributed to alleviating poverty by focusing on targeted programs towards different groups with the help of various international organizations. These finding have important implications for interactions between the developed and underdeveloped economies as well as the economic and social benefits of democratic regimes

Isoniazid induced hepatotoxicity and its amelioration with ethanolic extract of stem bark of Berberis lycium Royale in mice

Background: To study the hepatoprotective effect of Ethanolic extract of Stem Bark of Berberis lycium Royale in isoniazid (INH) induced hepatotoxicity in mice model.Methods: The study design was lab based randomized controlled in-vivo study in mice conducted from 9th April 2014 till 9th May 2014 at animal house of National Institute of Health, Islamabad. Group A was on normal diet and water and hepatotoxicity was produced by giving isoniazid (50mg/kg BW) in mice of Group B. Group C and D were given isoniazid (INH) plus low dose and high dose of Ethanolic extract of stem bark of Berberis Lycium Royle respectively.Results: INH induced hepatotoxicity was depicted by elevated serum LFT’s, hepatocytic ballooning, severe steatosis and inflammation. Mice getting concurrent treatment of INH, low and high dose of Ethanolic extract of Berberis Lycium Royle showed decreased serum levels of biomarkers and their liver sections manifested improved histological picture but more significant reduction in toxic effects were observed in animals receiving high dose.Conclusions: High dose of Ethanolic extract of stem bark of Berberis lycium Royale showed more marked hepatoprotective activity as compare to low doses. The hepatotoxicity of INH can be reduced by concurrent use of INH with ethanolic extracts of Berberis Lycium Royle

SPEChpc 2021 Benchmarks on Ice Lake and Sapphire Rapids Infiniband Clusters: A Performance and Energy Case Study

In this work, fundamental performance, power, and energy characteristics of the full SPEChpc 2021 benchmark suite are assessed on two different clusters based on Intel Ice Lake and Sapphire Rapids CPUs using the MPI-only codes' variants. We use memory bandwidth, data volume, and scalability metrics in order to categorize the benchmarks and pinpoint relevant performance and scalability bottlenecks on the node and cluster levels. Common patterns such as memory bandwidth limitation, dominating communication and synchronization overhead, MPI serialization, superlinear scaling, and alignment issues could be identified, in isolation or in combination, showing that SPEChpc 2021 is representative of many HPC workloads. Power dissipation and energy measurements indicate that the modern Intel server CPUs have such a high idle power level that race-to-idle is the paramount strategy for energy to solution and energy-delay product minimization. On the chip level, only memory-bound code shows a clear advantage of Sapphire Rapids compared to Ice Lake in terms of energy to solution.Comment: 9 pages, 6 figures; corrected links to system doc