Hewlett-Packard

About: Hewlett-Packard is a company organization based out in Palo Alto, California, United States. It is known for research contribution in the topics: Signal & Substrate (printing). The organization has 34663 authors who have published 59808 publications receiving 1467218 citations. The organization is also known as: Hewlett Packard & Hewlett-Packard Company.

A Comprehensive Memory Modeling Tool and Its Application to the Design and Analysis of Future Memory Hierarchies

Abstract: In this paper we introduce CACTI-D, a significant enhancement of CACTI 5.0. CACTI-D adds support for modeling of commodity DRAM technology and support for main memory DRAM chip organization. CACTI-D enables modeling of the complete memory hierarchy with consistent models all the way from SRAM based L1 caches through main memory DRAMs on DIMMs. We illustrate the potential applicability of CACTI-D in the design and analysis of future memory hierarchies by carrying out a last level cache study for a multicore multithreaded architecture at the 32nm technology node. In this study we use CACTI-D to model all components of the memory hierarchy including L1, L2, last level SRAM, logic process based DRAM or commodity DRAM L3 caches, and main memory DRAM chips. We carry out architectural simulation using benchmarks with large data sets and present results of their execution time, breakdown of power in the memory hierarchy, and system energy-delay product for the different system configurations. We find that commodity DRAM technology is most attractive for stacked last level caches, with significantly lower energy-delay products.

Associating image and location data

Abstract: Location stamping of digital photos provides a convenient way to subsequently catalogue the photos. However, most digital cameras are not provided with a location discovery mechanism. To overcome this, arrangements are provided for enabling location data to be separately recorded (for example using a cell phone) at the time a photo is taken and then subsequently united with the photo.

Decoding the ancient Greek astronomical calculator known as the Antikythera Mechanism

Abstract: The Antikythera Mechanism is a unique Greek geared device, constructed around the end of the second century bc. It is known1, 2, 3, 4, 5, 6, 7, 8, 9 that it calculated and displayed celestial information, particularly cycles such as the phases of the moon and a luni-solar calendar. Calendars were important to ancient societies10 for timing agricultural activity and fixing religious festivals. Eclipses and planetary motions were often interpreted as omens, while the calm regularity of the astronomical cycles must have been philosophically attractive in an uncertain and violent world. Named after its place of discovery in 1901 in a Roman shipwreck, the Antikythera Mechanism is technically more complex than any known device for at least a millennium afterwards. Its specific functions have remained controversial11, 12, 13, 14 because its gears and the inscriptions upon its faces are only fragmentary. Here we report surface imaging and high-resolution X-ray tomography of the surviving fragments, enabling us to reconstruct the gear function and double the number of deciphered inscriptions. The mechanism predicted lunar and solar eclipses on the basis of Babylonian arithmetic-progression cycles. The inscriptions support suggestions of mechanical display of planetary positions9, 14, 15, now lost. In the second century bc, Hipparchos developed a theory to explain the irregularities of the Moon's motion across the sky caused by its elliptic orbit. We find a mechanical realization of this theory in the gearing of the mechanism, revealing an unexpected degree of technical sophistication for the period.

Thermally-actuated microminiature valve

Abstract: A microminiature valve having radially spaced, layered spider legs, with each leg having first and second layers of materials having substantially different coefficients of thermal expansion. The legs include heating elements and are fixed at one end to allow radial compliance as selected heating of the legs causes flexure. Below the legs is a semiconductor substrate having a flow orifice aligned with a valve face. Flexure of the legs displaces the valve face relative to the flow orifice, thereby controlling fluid flow through the orifice.

Operating system support for NVM+DRAM hybrid main memory

Abstract: Technology trends may soon favor building main memory as a hybrid between DRAM and non-volatile memory, such as flash or PC-RAM. We describe how the operating system might manage such hybrid memories, using semantic information not available in other layers. We describe preliminary experiments suggesting that this approach is viable.