Showing papers by "Hewlett-Packard published in 1993"

Conversations over video conferences: an evaluation of the spoken aspects of video-mediated communication

Abstract: Recent trends toward telecommuting, mobile work, and wider distribution of the work force, combined with reduced technology costs, have made video communications more attractive as a means of supporting informal remote interaction. In the past, however, video communications have never gained widespread acceptance. Here we identify possible reasons for this by examining how the spoken characteristics of video-mediated communication differ from face-to-face interaction, for a series of real meetings. We evaluate two wide-area systems. One uses readily available Integrated Services Digital Network (ISDN) lines but suffers the limitations of transmission lags, a half-duplex line, and poor quality video. The other uses optical transmission and video-switching technology with negligible delays, full duplex audio, and broadcast quality video. To analyze the effects of video systems on conversation, we begin with a series of conversational characteristics that have been shown to be important in face-to-face interaction. We identify properties of the communication channel in face-to-face interaction that are necessary to support these characteristics, namely, that it has low transmission lags, it is two way, and it uses multiple modalities. We compare these channel properties with those of the two video-conferencing systems and predict how their different channel properties will affect spoken conversation. As expected, when compared with face-to-face interaction, communication using the ISDN system was found to have longer conversational turns; fewer interruptions, overlaps, and backchannels; and increased formality when switching speakers. Communication over the system with broadcast quality audio and video was more similar to face-to-face meetings, although it did not replicate face-to-face interaction. Contrary to our expectations, formal techniques were still used to achieve speaker switching. We suggest that these may be necessary because of the absence of certain speaker-switching cues. The results imply that the advent of high-speed multimedia networking will improve but not remove all the problems of video conferencing as an interpersonal communications tool, and we describe possible solutions to the outstanding problems.

The multiflow trace scheduling compiler

Abstract: The Multiflow compiler uses the trace scheduling algorithm to find and exploit instruction-level parallelism beyond basic blocks. The compiler generates code for VLIW computers that issue up to 28 operations each cycle and maintain more than 50 operations in flight. At Multiflow the compiler generated code for eight different target machine architectures and compiled over 50 million lines of Fortran and C applications and systems code. The requirement of finding large amounts of parallelism in ordinary programs, the trace scheduling algorithm, and the many unique features of the Multiflow hardware placed novel demands on the compiler. New techniques in instruction scheduling, register allocation, memory-bank management, and intermediate-code optimizations were developed, as were refinements to reduce the overhead of trace scheduling. This article describes the Multiflow compiler and reports on the Multiflow practice and experience with compiling for instruction-level parallelism beyond basic blocks.

An implementation of a log-structured file system for UNIX

Abstract: Research results [ROSE91] suggest that a log-structured file system (LFS) offers the potential for dramatically improved write performance, faster recovery time, and faster file creation and deletion than traditional UNIX file systems. This paper presents a redesign and implementation of the Sprite [ROSE91] log-structured file system that is more robust and integrated into the vnode interface [KLEI86]. Measurements show its performance to be superior to the 4BSD Fast File System (FFS) in a variety of benchmarks and not significantly less than FFS in any test. Unfortunately, an enhanced version of FFS (with read and write clustering) [MCVO91] provides comparable and sometimes superior performance to our LFS. However, LFS can be extended to provide additional functionality such as embedded transactions and versioning, not easily implemented in traditional file systems.

Computer windows management system and method for simulating off-screen document storage and retrieval

Abstract: A novel computer display interface which simulates familiar document handling activities based upon a unique display metaphor representative of a standard office filing system and work area of a desk. The display system includes multi-windows which are displayed in a central screen area designated for just active computer windows. The interface further includes designating the edge areas of the screen for displaying window tabs of inactive windows. The window tabs are arranged in a way to simulate an integrated filing system, and to provide a convenient method of organizing and viewing computer files.

Flexible scheme for admission control of multimedia streams on integrated networks

Abstract: An admission control scheme for real-time traffic requests in communication networks is disclosed. The scheme monitors tile performance of each link and predicts the traffic guarantees that can be offered when certain dummy traffic (pseudo traffic) mimicking the behavior of real-time streams is added to the existing traffic. When an application requests connection to the network, it specifies a Quality of Service (QoS) bound that it desires. A routing subsystem of tile network makes use of the predicted values while attempting to find a path over which tile application's QoS bound requirement will be satisfied. After the route is chosen, connection setup will involve verifying at each node along the route whether sufficient resources exist to support tile new connection. This explicit verification is likely to be necessary because the routing subsystem does not normally have up-to-date global state information. After admitting tile application, the network provides a soft guarantee that the QoS bound provided to it will be adhered to for most of the time. On the other hand, if no path through the network satisfies the QoS hound, tile application is denied connection to the network.

Method of remotely installing software directly from a central computer

Abstract: A method for remote installation of software over a computer network allows a user to interactively select each remote computer system for software installation, or to provide a file containing a list of all remote computer systems. Before attempting to install the software, the method ensures that the remote system can be reached through the network, that the remote system has the capability of running processes remotely, that the remote system has all the commands necessary to perform the installation, that the remote system has the correct hardware and software to support the installation, and that sufficient disk space exists on the remote computer system for the installation. The method then combines all files that are being remotely installed into a single data stream, sends this single data stream over the network to the remote computer system, and separates the data stream into the original files on the remote system.

System for analyzing and debugging embedded software through dynamic and interactive use of code markers

Abstract: A system (Figure 10) for inserting code markers for observing indications (external to the microprocessor upon which the software operates) of the occurrence of an event in the execution of the software. Additional instructions or markers are added to the software to be debugged to produce simple, encoded, memory references to otherwise unused memory or I/O locations that will always be visible to a logic analyzer as bus cycles. Although the code markers cause a minimal intrusion in the underlying software, they make tracing events by a conventional logic analyzer much simpler and allow for performance evaluations in manners not heretofore possible. In particular, the inserted code markers provide a method of dynamically extracting information from a running host or real-time "black box" embedded system (902) under test using simple low intrusion print statements, encoded I/O writes on procedure entries and exits, and/or an interface to service calls and the like which writes out the passed parameters. Generally, the code markers are inserted at compile time or interactively during the debug session to make visible critical points in the code execution, such as function calls, task creation, semaphore operations and other resource usage so as to speed isolation of problems at test points during debugging. Performance analysis and event analysis use the code markers of the invention to cut through the ambiguities of microprocessor prefetch and cache operations. Because of these features, the invention is particularly advantageous for use by software design teams developing complex embedded host or real-time operating systems using multi-task operating systems and/or object oriented systems.

Patient alarm detection using trend vector analysis

Abstract: A method and apparatus for detecting an alarm in a patient monitoring system. The patient monitoring system executes the steps of measuring values representative of a physiological parameter of a patient, determining whether the parameter values are within safe zone limits, initiating calculation of a trend vector that is a function of changes in the parameter values, when the parameter values go outside the safe zone limits, comparing the trend vector with an alarm limit function and issuing an alarm when the trend vector exceeds the alarm limit function. The alarm limit function typically varies with time after initiating calculation of the trend vector. The trend vector is calculated for each measured value until an alarm is issued or the parameter value returns to within the safe zone limits.

Fourier volume rendering

Abstract: In computer graphics we have traditionally rendered images of data sets specified spatially, Here, we present a volume rendering technique that operates on a frequency domain representation of the data set and that efficiently generates line integral projections of the spatial data it represents, The motivation for this approach is that the Fourier Projection-Slice Theorem allows us to compute 2-D projections of 3-D data seta using only a 2-D slice of the data in the frequency domain. In general, these “X-ray-like” images can be rendered at a significantly lower computational cost than images generated by current volume rendering techniques, Additionally, assurances of image accuracy can he made.

Orienteering in an information landscape: how information seekers get from here to there

Abstract: We studied the uses of information search results by regular clients of professional intermediaries. The clients in our study engaged in three different types of searches: (1) monitoring a well-known topic or set of variables over time, (2) following an information-gathering plan suggested by a typical approach to the task at hand, and (3) exploring a topic in an undirected fashion. In most cases, a single search evolved into a series of interconnected searches, usually beginning with a high-level overview. We identified a set of common triggers and stop conditions for further search steps. We also observed a set of common operations that clients used to analyze search results. In some settings, the number of search iterations was reduced by restructuring the work done by intermediaries. We discuss the implications of the interconnected search pattern, triggers and stop conditions, common analysis techniques, and intermediary roles for the design of information access systems.

Conversion of data and objects across classes in an object management system

Abstract: In response to a user pasting data within a clipboard to a desktop for an object management facility, a new object for the data is created. The data is placed within the new object, and an icon is displayed on the desktop for the new object. When the data is text, the new object is created to be of a type which contains text. When the data is bitmapped, the new object is created to be of a type which contains bitmaps. The data is placed in the clipboard, for example, in response to a Cut command or in response to a Copy command from an application process originally processing the data. The data can reformatted, for example, before exporting the data from the application process, before importing the data to the new object or after importing the data to the new object. Also, in response to a user selecting a first object and issuing a conversion command, classes of objects into which the first object may be converted are displayed to the user. Upon the user selecting a class of objects into which the first object is to be converting, the first object is converted into a new object of the selected class of objects. The new object is created, data from the first object is extracted and sent to the new object. The data may be converted to a format usable by the first object, by the new object or by the object management facility.

System for integrating processing by application programs in homogeneous and heterogeneous network environments

Abstract: System Configuration files in source code are created from a high level definition of the distributed system which is to be integrated. The configuration files include data such as the types and formats of data for each process on each node of the system, identification of all applications and machine types, topography and the data manipulations needed for sending messages and files and the like from an application program in a first computer language and of a first data type to an application program in a second computer language and of a second data type. Node-specific data manipulation modules are formed at each node during start-up of the system, and these modules are automatically distributed to nodes on the network having the same architecture. The invention allows applications having different physical data characteristics to communicate by using the data manipulation modules so formed to manipulate the data at the source program into a common data representation (CDR) having data types common to all of the languages represented by the system and then reconverting the data to the local representation at the destination node.

Integrated circuit printhead for an ink jet printer including an integrated identification circuit

Abstract: An integrated circuit for use in the printhead of an ink jet printer includes an array circuit for heating an ink reservoir to produce a pattern of ink jets, the array circuit including a plurality of resistor cells arranged into rows and columns. A corresponding number of row and column lines are coupled to the integrated circuit array for selecting and energizing the resistor cells according to the desired printing pattern. An identification circuit integrated into the same substrate as the array circuit includes one or more programmable paths, the programmable paths corresponding and coupled to each row line. The programmable paths each include the serial combination of a programmable fuse and an active device. The opposite end of the programmable paths are coupled together at a common node, which in turn is coupled to an output circuit for providing a single output signal in response to a polling of the row lines. The identification circuit can be programmed and polled without adversely affecting or energizing the array circuit.

Object oriented distributed computing system processing request to other object model with code mapping by object managers located by manager of object managers

Abstract: An object oriented distributed computing system is provided. Processing means call a location service within automatically generated stubs in response to a request for a service provided by a particular object. The location service is automatically called on behalf of the requester to locate the target object when the request is issued. Multiple Object Managers reflecting multiple Object Models are permitted in the system. Programmers and users do not need to know the Object Model adhered to by an Object Manager. A request to any object in the system is independent of the Object Model of the sought object's Object Manager. A generic interface enables new Object Managers reflecting new Object Models to be easily added to the system. Availability of the target object is independent of association of the target object with a process at the time the request was issued. Deactivation of processes is automatically accomplished in response to the system needing resources.

Method for use of color and selective highlighting to indicate patient critical events in a centralized patient monitoring system

Abstract: A centralized patient monitoring system includes a central station which receives patient information from bedside monitors. The patient information is presented on a video display screen and may include patient demographic information, physiological parameters and a waveform. The display screen is divided into sectors, with each sector containing information for one patient. When an alarm condition occurs at one of the bedside monitors, the alarm condition is transmitted to the central station and is displayed in the corresponding sector of the video display screen. In addition, the alarm condition is highlighted by changing the background in the alarming sector from its normal color, typically black, to a neutral color such as blue, which is easily distinguishable from the normal color and which does not obscure the patient information being displayed. The background of the sector is changed back to the normal color when the alarm is acknowledged by a user. The highlighted background is easily visible from a distance and provides a clear indication of unacknowledged alarms without obscuring other patient information.

Transparent peripheral file systems with on-board compression, decompression, and space management

Abstract: A Transparent Peripheral File System (TPFS) includes a Peripheral File System Adapter (PFSA) which communicates with a host operating system at the vnode level of file operation by packaging such communications for transmission over an I/O system interface, such as SCSI. A file peripheral system remote from the host and in a peripheral relation thereto is responsive to the PFSA, without an intervening file server. The peripheral file system produces hardware commands for the mass storage device whose space it manages. The peripheral file system may be embedded in a mass storage device, a lump in the interconnecting interface cable, or a smart interface card in the backplane of the host. The peripheral file system may include a daisy chain connection to allow the propagation of vnode communication to other peripheral file systems. In this way a hierarchy of peripheral file systems may be physically mounted to one another in a way that corresponds to how they are logically mounted. A Character To File Translator (CFX) allows a TPFS to emulate raw mode access, even if the host system is not equipped with a vnode file operation interface. CFX does this by converting to and from streams of characters communicated with an application using this ersatz raw mode, while instead of storing the data on the storage medium itself, actually relying upon the remote peripheral file system for storing, or having stored, the streams of characters as a file.

Electrical impedance normalization for an ultrasonic transducer array.

Abstract: A two-dimensional ultrasonic transducer array includes a plurality of transducer elements, with each element having a plurality of piezoelectric layers. The transducer elements vary in transverse areas of radiating regions. The effect of the variations in transverse areas on the electrical impedances of the elements is at least partially offset by varying the specific impedance, i.e., impedance per unit area, of the transducer elements in the array. In a preferred embodiment, the specific impedance is varied by selecting the electrical arrangements of piezoelectric layers in each element according to the transverse area of the element. Series, parallel and series-parallel arrangements are employed. This impedance normalization improves the electrical connection of the transducer elements to driving circuitry. In alternative embodiments, impedance normalization is achieved by varying element thicknesses, element materials and/or degrees of poling across the two-dimensional array.

Graphical user interface for computer management system and an associated management information base

Abstract: A management system for a file server having a system board, an expansion board, a disk storage system and a server manager for collecting management information from the system board. The management system arranges MIB information for the file server into a first manageable device specific subsystem containing management information describing the system board, a second, manageable device specific, subsystem containing management information describing the expansion board, a third, manageable device specific, subsystem containing management information describing the disk storage system, a fourth, non-manageable device specific, subsystem containing management information describing the configuration of the file server, a fifth, non-manageable device specific, subsystem containing management information describing the security configuration for the file server, a sixth, manageable device specific, subsystem containing management information describing the server manager, a seventh, non-manageable device specific, subsystem containing management information describing I/O ports of the file server, an eighth, non-manageable device specific, subsystem containing management information describing internal environmental conditions of the file server. The management information for each of the first, second, third, fourth, fifth, sixth, seventh and eighth subsystems may then be selectively accessed using a series of GUIs.

Serial architecture for memory module control

Abstract: An expandable memory system including a central memory controller and one or more plug-in memory modules, each memory module having an on-board memory module controller coupled in a serial network architecture which forms a memory command link Each memory module controller is serially linked to the central memory controller. The memory system is automatically configured by the central controller, each memory module in the system is assigned a base address, in turn, to define a contiguous memory space without user intervention or the requirement to physically reset switches. The memory system includes the capability to disable and bypass bad memory modules and reassign memory addresses without leaving useable memory unallocated.

Fabrication of ink fill slots in thermal ink-jet printheads utilizing chemical micromachining

Abstract: An ink fill slot can be precisely manufactured in a substrate utilizing photolithographic techniques with chemical etching, plasma etching, or a combination thereof These methods may be used in conjunction with laser ablation, mechanical abrasion, or electromechanical machining to remove additional substrate material in desired areas The ink fill slots are appropriately configured to provide the requisite volume of ink at increasingly higher frequency of operation of the printhead by means of an extended portion that results in a reduced shelf length and thus reduced fluid impedance imparted to the ink The extended portion is precisely etched to controllably align it with other elements of the printhead

Space efficient conservative garbage collection

Abstract: We call a garbage collector conservative if it has only partial information about the location of pointers, and is thus forced to treat arbitrary bit patterns as though they might be pointers, in at least some cases. We show that some very inexpensive, but previously unused techniques can have dramatic impact on the effectiveness of conservative garbage collectors in reclaiming memory. Our most significant observation is that static data that appears to point to the heap should not result in misidentified references to the heap. The garbage collector has enough information to allocate around such references. We also observe that programming style has a significant impact on the amount of spuriously retained storage, typically even if the collector is not terribly conservative. Some fairly common C and C++ programming style significantly decrease the effectiveness of any garbage collector. These observations suffice to explain some of the different assessments of conservative collection that have appeared in the literature.

Heat sink assembly with thermally-conductive plate for a plurality of integrated circuits on a substrate

Abstract: A heat sink assembly for a multichip module. A thermally conductive plate is bonded to integrated circuit chips on a multichip module by indium solder. The plate in turn is thermally coupled to a heat sink such as finned aluminum by thermal paste. The plate is made of a material such as silicon carbide or copper-tungsten alloy having a relatively low coefficient of expansion to minimize mechanical stress resulting from lateral motion of the chips due to thermal expansion. Relatively low-power chips may be thermally coupled to the plate by thermal paste instead of being bonded by solder.

LH: Linear Hashing for distributed files

Abstract: LH* generalizes Linear Hashing to parallel or distributed RAM and disk files. An LH* file can be created from objects provided by any number of distributed and autonomous clients. It can grow gracefully, one bucket at a time, to virtually any number of servers. The number of messages per insertion is one in general, and three in the worst case. The number of messages per retrieval is two in general, and four in the worst case. The load factor can be about constant, 65-95%, depending on the file parameters. The file can also support parallel operations. An LH* file can be much faster than a single site disk file, and/or can hold a much larger number of objects. It can be more efficient than any file with a centralized directory, or a static parallel or distributed hash file.

Computer display system and method for facilitating access to patient data records in a medical information system

Abstract: To improve access to patient information in medical information system for a health care facility, a computer display system, and a method for such a display system, includes a displayed representation of the duration of the stay of an identified patient in the health care facility. In such a medical information system patient data is stored in data files in a database, wherein each data file in the database is comprised of a plurality of data records. A user positions a cursor on the displayed representation using an input unit and signals the computer of a desired date and time. The computer, in response to the signal determines the desired date and time from the position of the cursor and accesses a data record or records from the data file based on the desired date and time. The accessed data record or records may then be displayed. The data records may be time-stamped. In that case, the duration of the patient's stay is the time period between the earliest and latest time stamps.

Software reuse: from library to factory

Abstract: Systematic software reuse is a key business strategy that software managers can employ to dramatically improve their software development processes, to decrease time-to-market and costs, and to improve product quality. Effective reuse requires much more than just code and library technology. We have learned that careful consideration must be given to people, process, and technology. One approach to the systematic integration of these three elements is the concept of the software factory. At Hewlett-Packard Co., we have initiated a multifaceted corporate reuse program to help introduce the best practices of systematic reuse into the company, complemented by multidisciplinary research to investigate and develop better methods for domain-specific, reuse-based software engineering. This essay discusses our experiences. Key aspects include domain-specific kits, business modeling, organization design, and technology infrastructure for a flexible software factory.

Computer management system and associated management information base

Abstract: A method of managing a plurality of networked manageable devices which include at least one file server having a system board, a drive array subsystem associated with the file server and a server manager installed in the file server for monitoring the system board from a manager console using a management information base or "MIB". First, second and third plurality of objects which describe the system board, the drive array subsystem and the server manager, respectively, are collected and assembled into a MIB. The assembled MIB is then used to manage the file server.

High speed data transfer over twisted pair cabling

Abstract: A method provides for a first network node in a plurality of network nodes to transmit a data packet to a hub. The hub and the network nodes are interconnected within a local network system. Control signals are exchanged between the first network node and the hub. The exchange of control signals is done in a first signal frequency range. A data packet is sent from the first network node to the hub. The data packet is sent using data signals within a second signal frequency range. The first signal frequency range and the second signal frequency range do not overlap.

Interactive medical information display system and method for displaying user-definable patient events

Abstract: An interactive medical information display system and method for displaying user-definable patient events is provided. The system includes a mechanism for acquiring physiological parameters from a patient and a mechanism for storing the parameters in a real-time database. In addition, the system includes a mechanism for users to define event types in an event defintion language and a mechanism for users to modify existing event types. Users then select a set of event types for display, and an event generator accesses the database to monitor the physiological parameters in order to detect event occurrences as defined by the event types. A display mechanism displays the event occurrences and provides users with the ability to select event occurrences randomly or sequentially. Upon selection, other information is displayed.

Architectural support for translation table management in large address space machines

Abstract: Virtual memory page translation tables provide mappings from virtual to physical addresses. When the hardware controlled Translation Lookaside Buffers (TLBs) do not contain a translation, these tables provide the translation. Approaches to the structure and management of these tables vary from full hardware implementations to complete software based algorithms.The size of the virtual address space used by processes is rapidly growing beyond 32 bits of address. As the utilized address space increases, new problems and issues surface. Traditional methods for managing the page translation tables are inappropriate for large address space architectures.The Hashed Page Table (HPT), described here, provides a very fast and space efficient translation table that reduces overhead by splitting TLB management responsibilities between hardware and software. Measurements demonstrate its applicability to a diverse range of operating systems and workloads and, in particular, to large virtual address space machines. In simulations of over 4 billion instructions, improvement of 5 to 10% were observed.

Ink cartridge for a hard copy printing or plotting apparatus

Abstract: An improved pen for a hard copy printing device. Reservoirs within the central chamber of an ink cartridge housing are sealingly coupled to individual ink channels connecting each reservoir individually and directly to an exterior surface of the cartridge housing. An ink filter, downstream of any ink contaminating features of the construction, is also provided.