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.

Informal workplace communication: what is it like and how might we support it?

Abstract: We present new findings about the nature of informat communications, derived from a naturalistic study of people’s everyday working activities. We identify why such interactions are so common, and valuable and how they are achieved in the workplace. We also address weaknesses in current systems that support such interactions remotely and identify further requirements for better support. We also discuss the implications of this work for conversational theories.

Perfect Transfer of Arbitrary States in Quantum Spin Networks

Abstract: We propose a class of qubit networks that admit perfect state transfer of any two-dimensional quantum state in a fixed period of time. We further show that such networks can distribute arbitrary entangled states between two distant parties, and can, by using such systems in parallel, transmit the higher-dimensional systems states across the network. Unlike many other schemes for quantum computation and communication, these networks do not require qubit couplings to be switched on and off. When restricted to $N$-qubit spin networks of identical qubit couplings, we show that $2\phantom{\rule{0.2em}{0ex}}{\mathrm{log}}_{3}N$ is the maximal perfect communication distance for hypercube geometries. Moreover, if one allows fixed but different couplings between the qubits then perfect state transfer can be achieved over arbitrarily long distances in a linear chain. This paper expands and extends the work done by Christandl et al., Phys. Rev. Lett. 92, 187902 (2004).

Generalised Reed-Muller codes and power control in OFDM modulation

Abstract: Controlling the peak-to-mean envelope power ratio (PMEPR) of orthogonal frequency-division multiplexed (OFDM) transmissions is a notoriously difficult problem, though one which is of vital importance for the practical application of OFDM in low-cost applications The utility of Golay complementary sequences in solving this problem has been recognized for some time In this paper, a powerful theory linking Golay complementary sets of polyphase sequences and Reed-Muller codes is developed Our main result shows that any second-order coset of a q-ary generalization of the first order Reed-Muller code can be partitioned into Golay complementary sets whose size depends only on a single parameter that is easily computed from a graph associated with the coset As a first consequence, recent results of Davis and Jedwab (see Electron Lett, vol33, p267-8, 1997) on Golay pairs, as well as earlier constructions of Golay (1949, 1951, 1961), Budisin (1990) and Sivaswamy (1978) are shown to arise as special cases of a unified theory for Golay complementary sets As a second consequence, the main result directly yields bounds on the PMEPRs of codes formed from selected cosets of the generalized first order Reed-Muller code These codes enjoy efficient encoding, good error-correcting capability, and tightly controlled PMEPR, and significantly extend the range of coding options for applications of OFDM using small numbers of carriers

Backup and restore system for a computer network

Abstract: In a computer network environment (200), multiple clients (210) and multiple servers (230) are connected via a local area network (LAN) (220) to a backup file server (240). Each client (210) and each server is provided with backup agent software (215), which schedules backup operations on the basis of time since the last backup, the amount of information generated since the last backup, or the like. An agent (215) also sends a request to the backup server (240), prior to an actual backup, including information representative of the files that it intends to back up. The backup server (240) is provided with a mechanism to receive backup requests from the client agents (215) and accept or reject backup requests on the basis of backup server loading, network loading, or the like. The backup server (240) is further provided with mechanisms to enact redundant file elimination (RFE), whereby the server indicates to the client agents, prior to files being backed up, that certain of the files to be backed up are already stored by the backup server. Thus, the clients do not need to send the redundant files to be backed up.

Embedding web access mechanism in an appliance for user interface functions including a web server and web browser

Abstract: Web access functionality is embedded in a device to enable low cost widely accessible and enhanced user interface functions for the device A web server in the device provides access to the user interface functions for the device through a device web page A network interface in the device enables access to the web page by a web browser such that a user of the web browser accesses the user interface functions for the device through the web page