Individuals, corporations and governments constantly face the extremely complex problem of ordering and prioritizing their numerous decisions according to urgency and importance. They need to sequence expenditures and allocate scarce resources to optimize the returns on their investments over time. Prioritization requires general and diverse economic, social, political, environmental, cultural ...

A metamorphic robotic system is an aggregate of identical robot units which can individually detach and reattach in such a way as to change the global shape of the system. We introduce a mathematical framework for defining and analyzing general metamorphic systems. This formal structure combined with ideas from geometric group theory leads to a natural extension of a configuration space for met...

Huimin Cui, Institute of Computing Technology, Chinese Academy of Sciences Jingling Xue, School of Computer Science and Engineering, University of New South Wales Lei Wang, Institute of Computing Technology, Chinese Academy of Sciences Yang Yang, Institute of Computing Technology, Chinese Academy of Sciences Xiaobing Feng, Institute of Computing Technology, Chinese Academy of Sciences Dongrui F...

Execution environments are used as specifications for specialization of input-output programs in the derivation of product lines. These environments, formalized as color-blind I/O-alternating transition systems, are tolerant to mutations in a given program’s outputs. Execution environments enable new compiler optimizations, vastly exceeding usual reductions. We propose a notion of context-depen...

In theory, increasing alias analysis precision should improve compiler optimizations on C programs. This paper compares alias analysis algorithms on scalar optimizations, including an analysis that assumes no aliases, to establish a very loose upper bound on optimization opportunities. We then measure optimization opportunities on thirty-six C programs. In practice, the optimizations are rarely...

Phase classification has frequently been discussed the recent years as a method to guide scheduling, compiler optimizations and program simulations. In this paper, we propose a new classification method called setvectors. We show that the new method outperforms classification accuracy of state of the art methods by approximately 6 to 25 percent, while it has comparable computational complexity ...

In pipelined parallel computations the inner loops are often implemented in a block fashion. In such programs, an important compiler optimization involves the need to statically determine the grain size. This paper presents extensions and experimental validation of the previous results of Andonov and Rajopadhye on optimal grain size determination.

This paper describes the Orbit Scheme optimizing compiler. Orbit was one of the first practical compilers for Scheme, whereas most existing Scheme compilers at the time were research prototypes. The paper walks us through the phases of the compiler, explaining design decisions along the way. The result of this research is a production-quality Scheme compiler. It generates code that is competiti...

In the rapidly evolving and growing environment of the internet, website owners aim to maximize interest for their website. In this article we propose a model, which combines the static structure of the internet with activity based data, to compute a website interest ranking. This ranking can be used to gain more insight into the flow of users over the internet, optimize the position of a websi...