Irregular computations on heterogeneous multi-core architectures

并行计算涉及到使用多台计算机快速和协作地解决给定问题。医疗、交通网络和金融方面的问题产生了大量的数据，需要对这些信息进行实时处理。并行计算成为这些应用程序的基础。如今，通用计算机(PC)配备的不是一个CPU(中央处理器或处理器)，而是2个、4个或8个相同的处理器(或核心)，允许同时执行许多任务。最近，图形处理单元(GPU)已成为游戏、视频和多媒体等应用程序的主流。一个GPU上有数百多个处理单元，提供了大量的数据并行性(例如，可以独立处理视频屏幕上的每个像素)。这些图形处理器以单芯片的形式出现，可以安装在任何PC上。CPU和GPU一起提供了大量的并行性，被称为多核计算机。Play Station(PS3)是多核机器的典型例子。人们问的问题是，我们要用这些功能强大的计算机做什么，除了游戏之外，还可以在这些机器上编写哪些应用程序？这项研究的应用之一是医学成像。确定生物体的内部结构，并有足够的细节来提供患者的诊断信息，是实施任何程序之前的第一步。医学成像是医生评估患者身体通常不可见的区域的过程。成像技术有很多种。这项研究的重点是计算机断层扫描和新兴的微波断层扫描技术用于乳腺癌检测。任何成像技术中的图像都需要大量的存储空间，并且需要快速处理才能对患者做出实时决定。因此，这项研究的重点将是针对医学成像技术中的问题，在多核上设计复杂算法并进行性能评估。这项研究还将集中在使用强大的计算机解决交通网络和金融问题的计算问题上。

Parallel computing involves using many computers to solve a given problem fast and cooperatively. Problems in medicine, transportation networks and finance produce significant amounts of data that require processing of the information in real-time. Parallel computing becomes fundamental for these applications. These days, general-purpose computers (PC) come with not one CPU (central processing unit or processor) but with 2, 4 or 8 identical processors (or cores), allowing simultaneous execution of many tasks. Recently, graphical processing units (GPUs) have become mainstream in applications such as games, video, and multimedia. There are more than hundreds of processing elements on a single GPU providing lots of data parallelism (for example, each pixel on the video screen can be processed independently). These GPUs come as a single chip and can be installed on any PC. CPU together with GPUs provide massive amount of parallelism and are called multi-core machines. Play Station (PS3) is a typical example of a multi-core machine. The question one asks is what are we going to do with these powerful computers and what applications besides games can be programmed on these machines? One of the applications this research concentrates on is medical imaging. Determining the internal structure of an organism, with sufficient detail to yield diagnostic information of a patient, is a first step before administering any procedure. Medical imaging is the process by which physicians evaluate an area of the patient's body that is not normally visible. There are many imaging techniques. This research focuses on computed tomography and emerging microwave tomography techniques for breast cancer detection. The images in any of the imaging techniques require large amounts of storage space and need to be processed fast to make real-time decisions on the patient. Therefore, the focus of this proposed research will be on the design and performance evaluation of sophisticated algorithms on multi-cores for problems in medical imaging techniques. This research will also focus on computational issues in using the powerful computers for problems in transportation network and finance.