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 & Layer (electronics). The organization has 34663 authors who have published 59808 publications receiving 1467218 citations. The organization is also known as: Hewlett Packard & Hewlett-Packard Company.

Biofeedback based personal entertainment system

Abstract: A personal entertainment system calibrated and controlled by the biological or physiological condition of a user is disclosed. The entertainment system includes a media player; a sensor operative to detect biological parameters and generating a control signal in response to the detected parameters, the sensor being operably coupled to the media player; and a processing element which associates the control signal to at least one type of media preference, and causes the media player to provide media stimuli based on the control signal. Thus the media stimuli provided by the entertainment system is specific to the individual preferences and detected condition of the user.

Tour Planning for Mobile Data-Gathering Mechanisms in Wireless Sensor Networks

Abstract: In this paper, we propose a new data-gathering mechanism for large-scale wireless sensor networks by introducing mobility into the network. A mobile data collector, for convenience called an M-collector in this paper, could be a mobile robot or a vehicle equipped with a powerful transceiver and battery, working like a mobile base station and gathering data while moving through the field. An M-collector starts the data-gathering tour periodically from the static data sink, polls each sensor while traversing its transmission range, then directly collects data from the sensor in single-hop communications, and finally transports the data to the static sink. Since data packets are directly gathered without relays and collisions, the lifetime of sensors is expected to be prolonged. In this paper, we mainly focus on the problem of minimizing the length of each data-gathering tour and refer to this as the single-hop data-gathering problem (SHDGP). We first formalize the SHDGP into a mixed-integer program and then present a heuristic tour-planning algorithm for the case where a single M-collector is employed. For the applications with strict distance/time constraints, we consider utilizing multiple M-collectors and propose a data-gathering algorithm where multiple M-collectors traverse through several shorter subtours concurrently to satisfy the distance/time constraints. Our single-hop mobile data-gathering scheme can improve the scalability and balance the energy consumption among sensors. It can be used in both connected and disconnected networks. Simulation results demonstrate that the proposed data-gathering algorithm can greatly shorten the moving distance of the collectors compared with the covering line approximation algorithm and is close to the optimal algorithm for small networks. In addition, the proposed data-gathering scheme can significantly prolong the network lifetime compared with a network with static data sink or a network in which the mobile collector can only move along straight lines.

Scalability study of the ad hoc on-demand distance vector routing protocol

Abstract: As mobile networking continues to experience increasing popularity, the need to connect large numbers of wireless devices will become more prevalent. Many recent proposals for ad hoc routing have certain characteristics that may limit their scalability to large networks. This paper examines five different combinations of modifications that may be incorporated into virtually any on-demand protocol in order to improve its scalability. The scalability of current on-demand routing protocols is evaluated through the selection of a representative from this class of protocols. The performance of the un-modified on-demand protocol is compared against that of it combined with each of the scalability modifications. Each scheme's behavior is analyzed in networks as large as 10,000 nodes through detailed simulation. Based on the observations, conclusions are drawn as to the expected scalability improvement that can be achieved by each modification.

Transparent substrate light emitting diodes with directed light output

Abstract: Methods for the fabrication of TS LED chips with improved light extraction and optics, particularly increased top surface emission, and the TS LEDs so fabricated are described. Non-absorbing DBRs within the chip permit the fabrication of the LEDs. The transparent DBRs redirect light away from absorbing regions such as contacts within the chip, increasing the light extraction efficiency of the LED. The non-absorbing DBRs can also redirect light toward the top surface of the chip, improving the amount of top surface emission and the on-axis intensity of the packaged LED. These benefits are accomplished with optically non-absorbing layers, maintaining the advantages of a TS LED, which advantages include ˜6 light escape cones, and improved multiple pass light extraction.

An investigation of glasses for capillary chromatography

Abstract: An investigation was conducted of various glasses, other than soda lime or borosilicate, for use in glass capillary gas chromatography. The work has uncovered some unique chromatographic qualities in the use of potash soda lead and fused silica glasses as materials for making glass capillary columns. The fused silica proved to be an ideal material for capillary column construction, being inherently more inert than glass containing metal oxides. It has been shown that through the use of thin wall capillary tubing of high flexibility many of the mechanical problems associated with glass capillary columns, such as fragility and column straightening, can be avoided.