Showing papers by "Hewlett-Packard published in 1992"

System for automatic synchronization of common file between portable computer and host computer via communication channel selected from a plurality of usable channels there between

Abstract: A handheld computer which contains an LCD display having a digitizing surface to allow pen input. Internal storage takes several forms, such as a large flash ROM area, battery-backed up RAM and an optional hard disk drive. Several alternative communication paths are available, such as the previously mentioned modem, a parallel printer port, a conventional serial port, a cradle assembly connected to the host computer, and various wireless short distance techniques such as radio frequency or infrared transmission. The computer can readily communicate with other sources, particularly to a host desktop computer, to allow automated synchronization of information between the host and the handheld system. Preferably the remote synchronization is performed at several user selectable levels. When the handheld computer is in a cradle and actively connected to the host computer, automatic capture of updated data in the host computer is performed. Several synchronization techniques are utilized to keep track of different types of files. In addition, while communication is established the handheld computer can enter a remote control mode, allowing the user access to files and applications not included in the handheld computer.

Statistical process monitoring and feedback adjustment: a discussion

Abstract: Rationales for process monitoring using some of the techniques of statistical process control and for feedback adjustment using some techniques associated with automatic process control are explored, and issues that sometimes arise are discussed. The importance of some often unstated assumptions are illustrated. Minimum-cost feedback schemes are discussed for some simple, but practically interesting, models.

Automated measurement of polarization mode dispersion using Jones matrix eigenanalysis

Abstract: Polarization mode dispersion (PMD), which can limit the bandwidth of optical transmission links, has been difficult to measure in a manner independent of human judgment, leading to difficulties in automating the measurement. It is shown that PMD in any linear, time-invariant network can be completely characterized by eigenanalysis of Jones matrices measured at a series of discrete wavelengths, even for networks exhibiting polarization-dependent loss. A fast, automated system using a tunable laser and an accurate, real-time polarimeter affords the temporal accuracy of approximately 2% down to a limit of several femtoseconds, as demonstrated by comparison with other techniques and comparison with known samples. Both the principal states of polarization and the group delay difference were measured as a function of optical frequency. >

Introducing Objectcharts or how to use Statecharts in object-oriented design

Abstract: A notation called Objectcharts for specifying object classes is introduced. An Objectchart diagram is an extended form of a Statechart, which characterizes the behavior of a class as a state machine. The Objectchart transitions correspond to the state-changing methods that the class provides and those that it requires of other classes. Object attributes and observer methods annotate Objectchart states. Firing and postconditions are used to specify the effect of transitions on class attributes. The Objectchart notions is described through the development of an alarm clock application. How Objectcharts can be used to find subtyping inheritance relationships between classes and a systematic approach for evolving Objectchart specifications are shown. >

Sensor, apparatus and method for non-invasive measurement of oxygen saturation

Abstract: A sensor for non-invasive measurement of oxygen saturation using the reflection method comprises a red transmitter (55), an infrared transmitter (58) and a receiver (57). The distances between the transmitters and the receiver are selected such that the length of the light path (60, 61) between the red transmitter (55) and the receiver (57) is substantially equal to the length of the light path (62, 63) between the infrared transmitter (58) and the receiver (57). The sensor comprises a further red transmitter (56) which is used for another application at the human body or another tissue characteristics where the depth of penetration at the various wavelengths is different from the shown example. Together with an appropriate oximeter, manual or automatic adaptation is possible. Further signal improvement may be obtained by autocorrelating the received signal, detecting its frequency and cross-correlating it with a pattern function of the same frequency.

Roadmap for 10 Gbit/in/sup 2/ media: challenges

Abstract: The authors examine the requirements for 10 Gb/in/sup 2/ media, taking guidance from a recording model and known trends in high-performance media. They apply a read/write model to examining the media properties required for this density in a practical drive application. They find that the required magnetic and microstructural properties with the concomitant noise and supermagnetic limits demand significant improvements over existing media, to the extent that revolutionary improvements will likely be required. >

Calibration of logical cost formulae for queries in a heterogeneous DBMS using synthetic database

Abstract: A programmable machine system and method for managing electronic data access among multiple different relational databases in a network distributed database environment. The machine is programmed so that it can construct cost-effective access strategies for any of the participating databases absent any DBMS-specific cost models. The system provides query optimization across different database management systems in a network distributed database environment based on a calibrating database relying only on typical relational database statistics and cost data is developed by running queries in the various databases against the calibrating database. A logical cost model is constructed using the resulting cost data and is used to estimate the cost of a given query based on logical characteristics of the DBMS, the relations, and the query itself. The cost of a complex query is estimated using primitive queries. Optimal query access strategies are thereby designed and used to control execution of the queries across relational databases controlled by two or more different database management systems.

Automatic development of operating system boot image

Abstract: A computer system which includes certain minimum capabilities in a system ROM. Device driver software is located in the system ROM or adapter ROM's. On boot the computer system collects these device drivers from ROM to develop a minimal system. If a removable medium such as a floppy disk or CD-ROM is present a configuration mode in entered when final driver files and operating system modules are stored on a selected hard disk. After this storage the device driver modules and operating system modules necessary to develop a boot image of the operating system are gathered and linked. The boot image is generated and stored, allowing use on the following boot operations. The computer system detects device changes and rebuilds the boot image as necessary. If the devices have remained the same the previously stored boot image is loaded and operating system execution commences.

Ink delivery system for an inkjet printhead

Abstract: This invention provides an improved ink flow path between an ink reservoir and vaporization chambers in an inkjet printhead. In the preferred embodiment, a barrier layer containing ink channels and vaporization chambers is located between a rectangular substrate and a nozzle member containing an array of orifices. The substrate contains two linear arrays of heater elements, and each orifice in the nozzle member is associated with a vaporization chamber and heater element. The ink channels in the barrier layer have ink entrances generally running along two opposite edges of the substrate so that ink flowing around the edges of the substrate gain access to the ink channels and to the vaporization chambers.

Systems for connection of physical/electrical media connectors to computer communications cards

Abstract: A communications card capable of being mounted in electrical communications with a computer has formed therethrough an aperture so sized and shaped as to be capable of receiving a physical/electrical media connector. The media connector has a biased retention clip, a contact pin block, and contact pins. The retention clip has several standardized characteristics including a broad fixed end protruding from an outer surface of the contact pin block. The broad fixed end tapers abruptly at a transition notch down to a narrow free end, capable of being manipulated by a user to remove the physical/electrical media connector from the aperture in the communications card. In use, a media connector is inserted directly into the aperture in the communications card, the aperture being in contact with a plurality of contact wires fixed within the communications card. The communications card is divided into a retractable access portion of the communications card which can be directly accessed by manipulating an actuating mechanism releasing a retention means thereby allowing a spring to push the retractable access portion of the card outside of the computer housing. The retractable access portion of the communications card may be reinserted back into the computer housing to be carried internally when not in use.

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.

Method and system for monitoring vital signs

Abstract: A portable hand-held monitor (1) for monitoring vital signs is connected, via a single connector (7), with a cable (9). This cable ends up in a combiner (10) which, in turn, receives plugs (12a to 12d) leading, via cables (11a to 11d), to single sensors or transducers applied to a patient. Portable hand-held monitor (1) comprises a display (3) and internal memory means, in order to store recorded vital signs and to transmit them to a remote computer later on. As only a single cable (9) is required for connection with combiner (10), patient monitoring becomes quite easy if the combiner (10), cable (9) and the associated sensors and interconnection cables are left at or near the patient. In this case, a plug (8) connected with cable (9) has simply to be inserted into connector (7), in order to start data acquisition. The same simple approach may be used to monitor the next patient, and so on.

Method and apparatus for testing a packet-based network

Abstract: In packet-based networks (10), it is often desired to test communications between two specific stations (11, 12). This can generally be effected from a first one of the stations (11) by requesting the other station (12) to `loop-back` a test packet sent from the first station. The first station (11), on receiving back the test packet, can thereby ascertain that not only is communication with the other station (12) possible, but it can also measure the round trip time. However, more complex characteristics of the transmission path between the stations (11, 12) are not ascertainable in this manner. The transmission of a predetermined sequence of packets permits such characteristics to be determined by observing the effect of the network (10) on the sequence considered as a whole. Thus by varying packet size in a sequence, characteristics such as bandwidth, propagation delay, queuing delay and the network's internal packet size can be derived. The use of bursts of packets enables buffer size and re-sequencing characteristics to be determined.

Definitions of tool integration for environments

Abstract: Tool integration is not a property of a single tool, but of its relationships with other elements in the environment, chiefly other tools, a platform, and a process. Tool integration is about the extent to which tools agree. The subject of these agreements may include data format, user-interface conventions, use of common functions, or other aspects of tool construction. A framework that determines how well tools are integrated into an environment and that defines integration independently of the mechanisms and approaches used to support integration is proposed. Process, data, control, and presentation integration properties are described separately so as to identify them as clearly and independently as possible. Emphasis is placed on definitions of integration properties on relationships between tools rather than on the specific integration-support mechanisms. >

A simple intensity noise reduction technique for optical low-coherence reflectometry

Abstract: It is shown that by attenuating the reference power in an optical low-coherence reflectometry (OLCR) measurement, the reflection sensitivity can be improved, even though, in many other types of optical measurements, sensitivity is improved as optical power is increased. The difference is due to the presence of inherent intensity noise associated with low-coherence sources, which can dominate over shot noise at optical powers that are as low as 1 mu W. A reflection sensitivity of -146 dB is demonstrated using this technique. >

Heterogeneous software configuration management apparatus

Abstract: A heterogeneous configuration management tool (17) enables building of a software system in a heterogeneous network (11) of computers (13, 15). In building a desired software system, the tool (17) enables at least one component of the system to be translated by a foreign computer (13) of the network (11) and other components of the system to be translated by other computers (15) of the network (11). A reference to a version indicator (25) is passed to the foreign computer (13) to provide the foreign computer (13) an indication of user-specified version of the component being translated by the foreign computer (13). The reference is expanded during processing on the foreign computer (13). Pathname transformation files (21) are employed to provide transformation of a pathname in one computer of the network (11) to a corresponding pathname in another computer of a network (11). Binaries (30) resulting from component translations are stored in split pools (35). In turn, split releases of the built software system are enabled.

Query optimization for parallel execution

Abstract: The decreasing cost of computing makes it economically viable to reduce the response time of decision support queries by using parallel execution to exploit inexpensive resources. This goal poses the following query optimization problem: Minimize response time subject to constraints on throughput, which we motivate as the dual of the traditional DBMS problem. We address this novel problem in the context of Select-Project-Join queries by extending the execution space, cost model and search algorithm that are widely used in commercial DBMSs. We incorporate the sources and deterrents of parallelism in the traditional execution space. We show that a cost model can predict response time while accounting for the new aspects due to parallelism. We observe that the response time optimization metric violates a fundamental assumption in the dynamic programming algorithm that is the linchpin in the optimizers of most commercial DBMSs. We extend dynamic programming and show how optimization metrics which correctly predict response time may be designed.

The Geneva convention on the treatment of object aliasing

Abstract: Aliasing has been a problem in both formal verification and practical programming for a number of years. To the formalist, it can be annoyingly difficult to prove the simple Hoare formula {x = true} y := false {x = true}. If x and y refer to the same boolean variable, i.e., x and y are aliased, then the formula will not be valid, and proving that aliasing cannot occur is not always straightforward. To the practicing programmer, aliases can result in mysterious bugs as variables change their values seemingly on their own. A classic example is the matrix multiply routine mult(left, right, result) which puts the product of its first two parameters into the third. This works perfectly well until the day some unsuspecting programmer writes the very reasonable statement mult(a, b, a). If the implementor of the routine did not consider the possibility that an argument may be aliased with the result, disaster is inevitable.

Simultaneous thickness and group index measurement using optical low-coherence reflectometry

Abstract: Using high-resolution optical reflectometry, group index and physical thickness can both be determined by precisely measuring optical time delays through a sample. Optical low-coherence reflectometry offers both the high-spatial resolution and large dynamic range required to perform accurate measurements using this technique. >

Modular distributed antenna system

Abstract: A distributed antenna system is provided which is formed from a series of modular stages (104) interconnected by cables (106). Each stage may include an antenna (134), a filter (135), a compensating amplifier (138) and preferably elements for impedance matching to connecting cables (110, 112). Connecting stages also include a coupler (136) for combining the output from the stage antenna with the output from the preceding stage and passing the combined signal to the stage output (110). Where the stages are part of a transmitting system, the coupler is replaced by or functions as a splitter, an input thereto from, for example, a preceding stage, being applied to the stage antenna and to the stage output.

System for configuring an input/output board in a computer

Abstract: An automatically configurable I/O board and associated software avoids any need for jumpers, switches, or other configuration changes upon installation of the board. Utilization of the main computer capability to select addresses and values likely to be available involves an installation or other routine which arrives at a unique parameter through common commands and repetitive execution. Uniqueness of the parameter or address is accomplished by checking for use elsewhere in the system prior to operation of the board. Steps are taken to avoid any inappropriate changes in conflicting I/O boards by activating components on the board through use of a state machine, by using non-destructive commands for initial checks, by tristating unnecessary lines, and by re-initializing registers whenever a conflict is encountered. Additionally no address space is used to activate the board.

Method of monitoring changes in an object-oriented database with tuned monitors

Abstract: A method of monitoring objects in a database system. A client program requests monitoring of an attribute of an object in the database according to a criterion which is any of four tuning parameters. The parameters include a change value parameter, a delay time parameter, a synchronous initiation parameter, and a nervousness parameter. When an update is committed, a tracking application of a client which has requested monitoring of an attribute is invoked if the monitoring criterion specified by that client has been satisfied. The first three parameters have the effect of reducing the reactivity of the monitor. The change value parameter is satisfied if the value of the monitored attribute has changed by an amount not less than the specified change value. The delay time parameter is satisfied if at least the specified delay time has elapsed since the occurrence of a specified previous event. The synchronous initiation parameter requires that the commit be delayed until the tracker has been invoked by the notification; this parameter is satisfied by any change in value of the monitored attribute or by any of the other parameters if specified. The nervousness parameter, which increases the reactivity, is satisfied if a screening test, typically whether there has been a write to a specified relation or part of a relation, is satisfied.

Position-sensing apparatus

Abstract: Position-sensing apparatus is provided which includes a passive coded surface formed by a pattern element with an arrangement of indicia that together form a two-dimensional windowing pattern; by "windowing pattern" is meant a pattern having the property that any local portion of the pattern of given size in terms of pattern features (a "sub-pattern"), when considered in isolation, is so characterized by its features as to permit the location of the sub-pattern to be determined, for at least one orientation of the sub-pattern relative to said pattern. The apparatus further includes an indicator element movable across the pattern, and a sub-pattern detector with a sensor for sensing the pattern indicia in the locality of the indicator element. The detector is operative to process the output of the sensor to derive sub-pattern data representative of a sub-pattern local to the indicator element in an orientation enabling its position to be uniquely determined. The sub-pattern data is passed to a position-determining unit which uses this data, together with data on the overall pattern, to determine the position of the indicator element relative to the pattern element.

Electrostatic discharge protection circuit for integrated circuits

Abstract: An ESD protection circuit that uses the well-known SCR latchup effect present in CMOS processes to divert the ESD current pulse away from sensitive circuit structures. The circuit uses an inverter trigger device, with a voltage divider on its output, to control the amount of voltage necessary to cause latchup. This feature enables the SCR to absorb a high current pulse on the CMOS pad structures caused by an ESD event, while also preventing the circuit from latching when an ordinary CMOS voltage is applied to the pad while the circuit being protected is unpowered. The circuit insures that the SCR will latch independent of breakdown effects, while also allowing the threshold voltage at which latchup occurs to be adjusted into the circuit by varying the sizes of two FETS used as the voltage divider.

Wide inkjet printhead

Abstract: A novel, wide inkjet printhead and method of forming said inkjet printhead is disclosed, wherein a pattern of orifices are formed, using a step-and-repeat process, in a flexible tape using laser ablation or other suitable etching devices. The location of the orifices corresponds to where ink will be ejected from the inkjet printhead. The pattern of orifices may extend to any length without difficulty in aligning the orifices, since the tape may be continuous along the entire length of the printhead.

Language identification system and method for a peripheral unit

Abstract: A data processing system (18) is responsive to a plurality of input languages, each language adhering to a prescribed syntax. The presence of defined portions ("For" keys) in the incoming data indicate a vote for the presence of a language and the presence of other defined portions ("Against" keys) indicate a vote Against the presence of the language. The system performs the following method for identifying the input language: analyzing, (42) for each expected language, the syntax of an incoming block of data to identify For and Against keys in the block of data; providing (52) For and Against tallies for each expected language in response to the analysis, each tally being a summation of key entries, each key entry comprising an identified key count multiplied by a skew, a skew value indicating the importance of the key in the syntax and in the context of said block of data, the For tally summing entries of For keys and the Against tally summing entries of Against keys; comparing (146) the For and Against tallies to determine whether or not they are so close as to signal uncertainty; and, based upon a further syntactical characteristic (158, 164, 168) of block of data (32), resolving the uncertainty and indicating (160, 162, 166, 170) a value based on one of the tallies: indicating (152, 156) a value derived from the larger of the tallies in the event of no uncertainty between the tallies; and deciding, (176, 178) based upon the indicated value for each expected language, the identity of a received language.

Glucocorticoids exacerbate kainic acid-induced extracellular accumulation of excitatory amino acids in the rat hippocampus.

Abstract: Glucocorticoids (GCs) compromise the ability of hippocampal neurons to survive various insults, and do so, at least in part, by exacerbating steps in the glutamate/N-methyl-D-aspartate (NMDA)/calcium cascade of damage. As evidence, GCs impair uptake of glutamate by hippocampal astrocytes, the GC endangerment of the hippocampus is NMDA receptor dependent, and GCs exacerbate kainic acid (KA)-induced calcium mobilization. These observations predict that GCs should also exacerbate KA-induced accumulation of extracellular glutamate and aspartate. To test this, adrenalectomized rats were given replacement GCs in either the low or high physiological range. Three days later, rats were anesthetized and 1 mM KA was infused through a dialysis probe placed in the dorsal hippocampus. Extracellular amino acid concentrations in the dialysate were then assessed by HPLC. After KA infusion, high-GC rats (30 ± 3 μg/dl) had significantly elevated concentrations of glutamate and aspartate compared with low-GC rats (all <0.95 μg/dl). The glutamate accumulation was due to GCs raising pre-KA concentrations, whereas the aspartate accumulation was due to GCs exacerbating the KA-induced rise. Glutamine concentrations were unaffected by KA, whereas the high-GC regimen elevated glutamine concentrations both before and after KA. Taurine concentrations rose after infusion of KA, but were unaffected by GC regime, whereas alanine concentrations were unaffected by either manipulation. Serine concentrations were unaffected by KA, but were depressed both before and after KA in high-GC rats. The high-GC effects on glutamate, aspartate, and serine concentrations could be reversed by supplementing rats with the sugar mannose; this agrees with prior observations that GC endangerment of the hippocampus and GC exacerbation of other steps in the glutamate/NMDA/calcium cascade are reversible with energy supplementation. A variety of steps are suggested by which GCs, exerting their known disruptive effects on hippocampal energetics, could cause excessive accumulation of extracellular glutamate and aspartate during neurological insults and thus exacerbate the subsequent toxicity.

Measurement of Rayleigh backscattering at 1.55 mu m with 32 mu m spatial resolution

Abstract: Rayleigh backscattering at a wavelength of 1.55 mu m is measured in standard single-mode fiber with a spatial resolution of 32 mu m and a dynamic range of over 30 dB. A minimum reflection sensitivity of -148 dB is the best reported to date using optical low-coherence reflectometry. >

LEDs challenge the incandescents

Abstract: Past, present, and future developments in the field of light-emitting diode (LED) chips are discussed. It is argued that the performance of AlGaAs has enabled LEDs to penetrate markets requiring high flux and/or low power consumption and that AlInGaP technology, which yields high performance from red-orange to green, will accelerate the use of LEDs in new applications. Emerging blue devices and recent ZnSe developments which suggest that blue performance comparable to AlGaAs and AlInGaP may be possible are described. The development of an adequate blue device would permit the fabrication of full-color, large-area, sunlight-viewable, flat-panel displays. >

Page printer having adaptive data compression for memory minimization

Abstract: A peripheral unit converts an input data flow to page-arranged outputs and includes a random access memory capacity that is insufficient in size to accommodate an entire page of raster data. The peripheral unit also includes a processor and a control memory that holds a plurality of data compression procedures, each procedure exhibiting a different performance characteristic. The peripheral unit performs a method for compressing portions of the input data flow that includes the steps of: allocating the random access memory to portions of the input data flow; determining when an insufficient amount of random access memory is available for such allocation; employing a first data compression procedure on the input data flow portions to produce a compressed data portion; testing the compressed data portion to determine if a level of compression has been achieved that exceeds a threshold and, if not, employing succeeding data compression procedures and repeating the test for each procedure against a threshold, whereby the compression procedure that first enables a threshold level of compression to be achieved is the compression procedure employed to compress the data flow portion. Improved compression methods and techniques for handling input data flows with both integral and independent image descriptors are also described.