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.

Conversion of neutral nitrogen-vacancy centers to negatively-charged nitrogen-vacancy centers through selective oxidation

Abstract: The conversion of neutral nitrogen-vacancy centers to negatively charged nitrogen-vacancy centers is demonstrated for centers created by ion implantation and annealing in high-purity diamond. Conversion occurs with surface exposure to an oxygen atmosphere at 465 C. The spectral properties of the charge-converted centers are investigated. Charge state control of nitrogen-vacancy centers close to the diamond surface is an important step toward the integration of these centers into devices for quantum information and magnetic sensing applications.

SPAIN: COTS data-center Ethernet for multipathing over arbitrary topologies

Abstract: Operators of data centers want a scalable network fabric that supports high bisection bandwidth and host mobility, but which costs very little to purchase and administer. Ethernet almost solves the problem - it is cheap and supports high link bandwidths - but traditional Ethernet does not scale, because its spanning-tree topology forces traffic onto a single tree. Many researchers have described "scalable Ethernet" designs to solve the scaling problem, by enabling the use of multiple paths through the network. However, most such designs require specific wiring topologies, which can create deployment problems, or changes to the network switches, which could obviate the commodity pricing of these parts.In this paper, we describe SPAIN ("Smart Path Assignment In Networks"). SPAIN provides multipath forwarding using inexpensive, commodity off-the-shelf (COTS) Ethernet switches, over arbitrary topologies. SPAIN pre-computes a set of paths that exploit the redundancy in a given network topology, then merges these paths into a set of trees; each tree is mapped as a separate VLAN onto the physical Ethernet. SPAIN requires only minor end-host software modifications, including a simple algorithm that chooses between pre-installed paths to efficiently spread load over the network. We demonstrate SPAIN's ability to improve bisection bandwidth over both simulated and experimental data-center networks

FREE-p: Protecting non-volatile memory against both hard and soft errors

Abstract: Emerging non-volatile memories such as phase-change RAM (PCRAM) offer significant advantages but suffer from write endurance problems. However, prior solutions are oblivious to soft errors (recently raised as a potential issue even for PCRAM) and are incompatible with high-level fault tolerance techniques such as chipkill. To additionally address such failures requires unnecessarily high costs for techniques that focus singularly on wear-out tolerance. In this paper, we propose fine-grained remapping with ECC and embedded pointers (FREE-p). FREE-p remaps fine-grained worn-out NVRAM blocks without requiring large dedicated storage. We discuss how FREE-p protects against both hard and soft errors and can be extended to chipkill. Further, FREE-p can be implemented purely in the memory controller, avoiding custom NVRAM devices. In addition to these benefits, FREE-p increases NVRAM lifetime by up to 26% over the state-of-the-art even with severe process variation while performance degradation is less than 2% for the initial 7 years.

Threads cannot be implemented as a library

Abstract: In many environments, multi-threaded code is written in a language that was originally designed without thread support (e.g. C), to which a library of threading primitives was subsequently added. There appears to be a general understanding that this is not the right approach. We provide specific arguments that a pure library approach, in which the compiler is designed independently of threading issues, cannot guarantee correctness of the resulting code.We first review why the approach almost works, and then examine some of the surprising behavior it may entail. We further illustrate that there are very simple cases in which a pure library-based approach seems incapable of expressing an efficient parallel algorithm.Our discussion takes place in the context of C with Pthreads, since it is commonly used, reasonably well specified, and does not attempt to ensure type-safety, which would entail even stronger constraints. The issues we raise are not specific to that context.

Improving Business Process Quality through Exception Understanding, Prediction, and Prevention

Abstract: Business process automation technologies are being increasingly used by many companies to improve the efficiency of both internal processes as well as of e-services offered to customers. In order to satisfy customers and employees, business processes need to be executed with a high and predictable quality. In particular, it is crucial for organizations to meet the Service Level Agreements (SLAs) stipulated with the customers and to foresee as early as possible the risk of missing SLAs, in order to set the right expectations and to allow for corrective actions. In this paper we focus on a critical issue in business process quality: that of analyzing, predicting and preventing the occurrence of exceptions, i.e., of deviations from the desired or acceptable behavior. We characterize the problem and propose a solution, based on data warehousing and mining t We then describe the architecture and implementation of a tool suite that enables exception analysis, prediction, and prevention. Finally, we show experimental results obtained by using the tool suite to analyze internal HP processes.