Streaming Memory Research Articles

Cost-effective VLSI architectures and buffer size optimization for full-search block matching algorithms

This paper presents two efficient very large scale integration (VLSI) architectures and buffer size optimization for full-search block matching algorithms. Starting from an overlapped data flow of search area, both systolic- and semisystolic-array architectural solutions are derived. By means of exploiting stream memory banks, not only input/output (I/O) bandwidth can be minimized, but also processor element efficiency can be improved. In addition, the controller structure for both solutions are very straightforward, making them very suitable for VLSI implementation to meet computational requirements. Moreover, by exploring the dependency graph, we focus on the problem of reducing the internal buffer size under minimal I/O bandwidth constraint to derive guidelines on reducing redundant internal buffer as well as to achieve area-efficient VLSI architectures. Simulation results show that, for N=P=16 (N is the reference block size and P is the search range), I/O bandwidth can be reduced by 2.4 times, while buffer size increases less than 38%. Two prototype chips for N=P=16 have been designed and fabricated. Test results show that clock rate can be up to 90 MHz, implying that more than 87.9-K motion vectors per second can be achieved to meet real-time requirements specified in MPEG-2 MP@ML coding standard.

Decoupling local variable accesses in a wide-issue superscalar processor

Providing adequate data bandwidth is extremely important for a wide-issue superscalar processor to achieve its full performance potential. Adding a large number of ports to a data cache, however, becomes increasingly inefficient and can add to the hardware complexity significantly. This paper takes an alternative or complementary approach for providing more data bandwidth, called the data-decoupled architecture. The approach, with support from the compiler and/or hardware, partitions the memory stream into two independent streams early in the processor pipeline, and feeds each stream to a separate memory access queue and cache. Under this model, the paper studies the potential of decoupling memory accesses to program's local variables that are allocated on the run-time stack. Using a set of integer and floating-point programs from the SPEC95 benchmark suite, it is shown that local variable accesses constitute a large portion of all the memory references, while their reference space is very small, averaging around 7 words per (static) procedure. To service local variable accesses quickly, two optimizations, fast data forwarding and access combining, are proposed and studied. Some of the important design parameters, such as the cache size, the number of cache ports, and the degree of access combining, are studied based on simulations. The potential performance of the proposed scheme is measured using various configurations, and it is concluded that the scheme can become a viable alternative to building a single multi-ported data cache.

Development, reliability, and validity of a dissociation scale.

Dissociation is a lack of the normal integration of thoughts, feelings, and experiences into the stream of consciousness and memory. Dissociation occurs to some degree in normal individuals and is thought to be more prevalent in persons with major mental illnesses. The Dissociative Experiences Scale (DES) has been developed to offer a means of reliably measuring dissociation in normal and clinical populations. Scale items were developed using clinical data and interviews, scales involving memory loss, and consultations with experts in dissociation. Pilot testing was performed to refine the wording and format of the scale. The scale is a 28-item self-report questionnaire. Subjects were asked to make slashes on 100-mm lines to indicate where they fall on a continuum for each question. In addition, demographic information (age, sex, occupation, and level of education) was collected so that the connection between these variables and scale scores could be examined. The mean of all item scores ranges from 0 to 100 and is called the DES score. The scale was administered to between 10 and 39 subjects in each of the following populations: normal adults, late adolescent college students, and persons suffering from alcoholism, agoraphobia, phobic-anxious disorders, posttraumatic stress disorder, schizophrenia, and multiple personality disorder. Reliability testing of the scale showed that the scale had good test-retest and good split-half reliability. Item-scale score correlations were all significant, indicating good internal consistency and construct validity. A Kruskal-Wallis test and post hoc comparisons of the scores of the eight populations provided evidence of the scale's criterion-referenced validity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cassandra: A Novel and Four Essays

Cassandra, daughter of the King of Troy, is endowed with the gift of prophecy but fated never to be believed. After the fall of Troy, in a stream of memories, associations, reflections she comes to an understanding of her own life and of war. This is a recreation of a classical myth.

Piercing the Shimmering Bubble: David Shahar'sThe Palace of Shattered Vessels

Within the steadily growing body of fiction written by David Shahar over the past three decades, his trilogy of novels,The Palace of Shattered Vessels, stands out as his most remarkable achievement to date. It is a complex, often puzzling work, steeped in the spirit of Jerusalem, in which it is set, bold in the narrative techniques it employs, and ambitious in its thematic aspirations a meandering stream of fragmented memories flowing through the mind of its unnamed narrator. As the flow continues, these fragments gradually cohere into broad arcs of interlocking narrative circles that effect a vivid evocation of Jerusalem and its inhabitants as they were in the early decades of this century. ButThe Palace of Shattered Vesselsaims at being much more than a memorial tribute to a nearly forgotten era in a rapidly changing city.

Proust Confirmed by Neurosurgery

Marcel Proust stated clearly and repeatedly in his vast A la recherche du temps perdu his determining theory of involuntary memory. Proust's entire work was based upon experiences of total recall from a store of memories unconsciously preserved in the mind. In a paper delivered in 1957 by Dr. Wilder Penfield of the Montreal Neurological Institute are to be found physiological bases for Proust's esthetic experiences. Wilder reported that forgotten experiences were revealed to patients in great detail when electrodes were applied to various parts of their brains. Penfield thus supports Proust's view of a stream of memories (or, as Penfield calls it, a continuous filmstrip) preserving an individual's total experiential responses from childhood onward. The juxtaposition of Proust's statements with those of the neurosurgeon about the nature of this stream of unconscious memories, their relation to conscious memory, and the conditions under which they are recalled throws light upon the validity of Proust's technique.