Ranette Halverson

Instructional testing through wireless handheld devices

In the educational field, students and faculty are looking for tools that may help to improve the learning process. Todays students, however, are usually too busy to follow a plan of study. Practice tests and questions are becoming an essential requirement of textbooks to allow the students to evaluate their current knowledge. Wireless access to the Internet has opened the door to a new range of computer applications, designed to satisfy the requirement of mobile users, equipped with a cell phone device. This paper describes the use of mobile devices as a medium for a self-evaluation tool complete with study guidelines feedback. Such an application is designed and implemented using many traditional Web methodologies, allowing a fast transition from the current wired Web system to the cell phone environment. This paper briefly discusses the Web tools used in such an implementation and presents an example of a test-feedback application appropriate for cell phone access.

Theoretical constraints on multidimensional retiming design techniques

Image signal processing depends on computation intensive programs, which include the repetition of sequences of operations coded as nested loops. An effective technique in increasing the computing performance of such applications is the design and use of Application Specific Integrated Circuits using loop transformation techniques, and in particular, multi-dimensional (MD) retiming. The MD-retiming method improves the instruction-level parallelism of uniform loops. While many have written about the multi-dimensional retiming technique, no results have been published on the possible limitations of its application. This paper presents an analysis of that technique and its constraints when applied to nested loops with known index bounds, such as those found in two and three dimensional image processing.

Precise-MD: a software tool for resources constrained scheduling of multi-dimensional applications

Nested loops, usually found within the multi-dimensional (MD) computation problems, can be modeled as MD data flow graphs (MDFGs). In order to optimize such loops, a scheduling technique able to achieve parallel execution in the loop body is required. This paper presents a software system, Precise-MD, designed to solve such problems. Precise-MD allows the user to input the MD problems represented by MDFGs through a graphical interface and then applies an MD-Scheduling algorithm, OPTIMUS, which is able to obtain the shortest schedule length for a resource constrained system in polynomial time. Experiment results demonstrate the usability and application of this tool.

VHDL design optimization for two-dimensional filters

Multi-dimensional applications, such as image processing and seismic analysis, usually require the high computer performance obtained from the implementation of Application Specific Integrated Circuits (ASICs). The critical sections of such applications consist of nested loops with the possibility of embedded conditional branch instructions. Current commercial systems use branch predication techniques, which can also be applied in the design of ASIC systems. Those techniques utilize predicate registers to control the validity of computed results. The optimized design and allocation of such registers becomes then a significant factor in the performance of the system. By using branch prediction to transform control dependencies in data dependencies, the application of a multi-dimensional retiming to an MDFG permit the iterations of the original loop body to be naturally overlapped, making the existent parallelism explicit. Based on the retiming information, predicate registers are designed as shift registers that allow the correct execution of the filter function.