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.

Electronically Configurable Molecular-Based Logic Gates

Abstract: Logic gates were fabricated from an array of configurable switches, each consisting of a monolayer of redox-active rotaxanes sandwiched between metal electrodes. The switches were read by monitoring current flow at reducing voltages. In the “closed” state, current flow was dominated by resonant tunneling through the electronic states of the molecules. The switches were irreversibly opened by applying an oxidizing voltage across the device. Several devices were configured together to produce AND and OR logic gates. The high and low current levels of those gates were separated by factors of 15 and 30, respectively, which is a significant enhancement over that expected for wired-logic gates.

Unsupervised segmentation of color-texture regions in images and video

Abstract: A method for unsupervised segmentation of color-texture regions in images and video is presented. This method, which we refer to as JSEG, consists of two independent steps: color quantization and spatial segmentation. In the first step, colors in the image are quantized to several representative classes that can be used to differentiate regions in the image. The image pixels are then replaced by their corresponding color class labels, thus forming a class-map of the image. The focus of this work is on spatial segmentation, where a criterion for "good" segmentation using the class-map is proposed. Applying the criterion to local windows in the class-map results in the "J-image," in which high and low values correspond to possible boundaries and interiors of color-texture regions. A region growing method is then used to segment the image based on the multiscale J-images. A similar approach is applied to video sequences. An additional region tracking scheme is embedded into the region growing process to achieve consistent segmentation and tracking results, even for scenes with nonrigid object motion. Experiments show the robustness of the JSEG algorithm on real images and video.

Gaussian Interference Channel Capacity to Within One Bit

Abstract: The capacity of the two-user Gaussian interference channel has been open for 30 years. The understanding on this problem has been limited. The best known achievable region is due to Han and Kobayashi but its characterization is very complicated. It is also not known how tight the existing outer bounds are. In this work, we show that the existing outer bounds can in fact be arbitrarily loose in some parameter ranges, and by deriving new outer bounds, we show that a very simple and explicit Han-Kobayashi type scheme can achieve to within a single bit per second per hertz (bit/s/Hz) of the capacity for all values of the channel parameters. We also show that the scheme is asymptotically optimal at certain high signal-to-noise ratio (SNR) regimes. Using our results, we provide a natural generalization of the point-to-point classical notion of degrees of freedom to interference-limited scenarios.

Split multipath routing with maximally disjoint paths in ad hoc networks

Abstract: In recent years, routing has been the most focused area in ad hoc networks research On-demand routing in particular, is widely developed in bandwidth constrained mobile wireless ad hoc networks because of its effectiveness and efficiency Most proposed on-demand routing protocols however, build and rely on a single route for each data session Whenever there is a link disconnection on the active route, the routing protocol must perform a route recovery process In QoS routing for wired networks, multiple path routing is popularly used Multiple routes are however, constructed using link-state or distance vector algorithms which are not well-suited for ad hoc networks We propose an on-demand routing scheme called split multipath routing (SMR) that establishes and utilizes multiple routes of maximally disjoint paths Providing multiple routes helps minimizing route recovery process and control message overhead Our protocol uses a per-packet allocation scheme to distribute data packets into multiple paths of active sessions This traffic distribution efficiently utilizes available network resources and prevents nodes of the route from being congested in heavily loaded traffic situations We evaluate the performance of our scheme using extensive simulation

Web services orchestration and choreography

Abstract: Combining Web services to create higher level, cross-organizational business processes requires standards to model the interactions. Several standards are working their way through industry channels and into vendor products.