A Framework for Megascale Agent Based Model Simulations on Graphics Processing Units

Agent-based modeling is a technique for modeling dynamic systems from the bottom up. Individual elements of the system are represented computationally as agents. The system-level behaviors emerge from the micro-level interactions of the agents. Contemporary state-of-the-art agent-based modeling toolkits are essentially discrete-event simulators designed to execute serially on the Central Processing Unit (CPU). They simulate Agent-Based Models (ABMs) by executing agent actions one at a time. In addition to imposing an un-natural execution order, these toolkits have limited scalability. In this article, we investigate data-parallel computer architectures such as Graphics Processing Units (GPUs) to simulate large scale ABMs. We have developed a series of efficient, data parallel algorithms for handling environment updates, various agent interactions, agent death and replication, and gathering statistics. We present three fundamental innovations that provide unprecedented scalability. The first is a novel stochastic memory allocator which enables parallel agent replication in O(1) average time. The second is a technique for resolving precedence constraints for agent actions in parallel. The third is a method that uses specialized graphics hardware, to gather and process statistical measures. These techniques have been implemented on a modern day GPU resulting in a substantial performance increase. We believe that our system is the first ever completely GPU based agent simulation framework. Although GPUs are the focus of our current implementations, our techniques can easily be adapted to other data-parallel architectures. We have benchmarked our framework against contemporary toolkits using two popular ABMs, namely, SugarScape and StupidModel.GPGPU, Agent Based Modeling, Data Parallel Algorithms, Stochastic Simulations

Large Scale Winter Time Disturbances in Meteor Winds over Central and Eastern Europe

Daily zonal wind data of the four pre-MAP-winters 1978/79 to 1981/82 obtained over Central Europe and Eastern Europe by the radar meteor method were studied. Available temperature and satellite radiance data of the middle and upper stratosphere were used for comparison, as well as wind data from Canada. The existence or nonexistence of coupling between the observed large scale zonal wind disturbances in the upper mesopause region (90 to 100 km) and corresponding events in the stratosphere are discussed

The Total Talent Portfolio: Using Different Data to Gain a More Holistic View of Our Learners

This study determined how the collection of student data could help a team of teachers learn more about their pupils and increase instructional efficacy. 121 students of 8th grade white house team at Spry Middle School in Webster, NY were selected to pilot this study. Student inventories measured 4MAT Thinking Styles, Learning Styles, Multiple Intelligences, and Interest. Student cumulative file information, eg. past years\u27 grades and standardized test scores, was combined with the inventory results to form the Total Talent Portfolio, or TTP. The team then used this data to aid in classroom grouping. The teachers found that the TTP was a powerful tool for enhancing teacher familiarity with student strengths and needs

A Balance of Interests: the Concordance of Copyright Law and Moral Rights in the Worldwide Economy

LECTURE IN INTERNAL MEDICINE PROPAEDEUTIC

A study of phase separation processes in presence of dislocations in binary systems subjected to irradiation

Dislocation-assisted phase separation processes in binary systems subjected to irradiation effect are studied analytically and numerically. Irradiation is described by athermal atomic mixing in the form of ballistic flux with spatially correlated stochastic contribution. While studying the dynamics of domain size growth we have shown that the dislocation mechanism of phase decomposition delays the ordering processes. It is found that spatial correlations of the ballistic flux noise cause segregation of dislocation cores in the vicinity of interfaces effectively decreasing the interface width. A competition between regular and stochastic components of the ballistic flux is discussed.Comment: 22 pages, 11 figure

Free amino acids of the blood and some organs in hypokinesia

The metabolic fund of amino acids of the blood and tissues of rats under hypokinesia was investigated. The content of free amino acids was determined for the liver, kidney, brain, and the skeletal and cardiac muscles after established periods of hypokinesia. It was found that the total content of free amino acids in the experimental animals was, on the average 19 percent lower than in the controls. The results of the quantity of individual compounds indicate that the level of some were reduced while others were increased. It was also found that there was an unequal content of individual amino acids in the different tissues

Принцип оптимальності для траєкторії виведення динамічної системи з альтернативою

Lagrange problem with the account of functional limitation at any functional limitations atany moment in a given interval is presented. The required conditions for optimal trajectories of thedeterminated dynamic system synthesized as space vehicle trajectories have been obtainedРассмотрена задача Лагранжа с учетом действия функционального ограничения в каждый момент времени назаданном интервале. Получены необходимые условия оптимальности траектории детерминированной динамической системы, интерпретируемой как траектория выведения космического летательного аппаратаРозглянуто задачу Лагранжа з урахуванням дії функціонального обмеження в кожен момент часу на заданому інтервалі. Отримано необхідні умови оптимальності траєкторії детермінованої динамічної системи, що інтерпретується як траєкторія виведення космічного літального апарат

Application of Circular Statistics During Analysis of the Eddy Current Testing Signals

Eddy current non-destructive testing (ECNDT) is an extremely informative test method for conductive materials and products [1]. It is known that eddy currents are usually generated by sinusoidal signals of one or more frequencies and the major part of the information about test objects is contained in the fault characteristics of signals generated by the eddy current. Such characteristics can be defined, for example, through the Hilbert transform of the signals

Информационное общество как теория и практика современности

У статті аналізується виникнення терміну «інформаційне суспільство». Розглядаються різноманітні теорії становлення інформаційного суспільства.The paper analyses emergence of the notion of ‘information society’ and discusses various theories of the information society development.В статье анализируется появление термина «информационное общество». Рассматриваются различные теории становления информационного общества