Showing papers by "Apple Inc. published in 1984"

A Proposed Radix- and Word-length-independent Standard for Floating-point Arithmetic

Abstract: Besides making the proposed IEEE 854 standard available for comment, this article explains how to overcome some of its implementation problems.

Three-dimensional left ventricular wall motion in man. Coordinate systems for representing wall movement direction.

Abstract: We have studied the three-dimensional (3D) motion of left ventricular (LV) epicardial points by tracking one to three dozen coronary artery bifurcations in eleven human subjects. Wall motion was analyzed using several different coordinate systems: (1) cylindrical centered about the LV long axis, (2) spherical with origin at the LV center-of-gravity (COG), and (3) spherical with origin at the LV center-of-contraction (COC), the best-fit 3D point toward which the wall moves. The coordinate systems were studied both fixed and moving with time. Three-dimensional motions were decomposed into three directional components, with high radial (in and out) percentages being regarded as the figure-of-merit of a given coordinate system. Average percentage radial motions were fixed cylindrical 16%, fixed spherical COG 35%, fixed spherical COC 47%, moving cylindrical 17%, moving spherical COG 30%, moving spherical COC 91%. Spherical systems were generally better than cylindrical systems, with the COC representing a better origin than the COG. Moving systems were appreciably better than fixed only for the COC model, indicating that the COC, which traverses up and down the LV midline, moves significantly while the other systems are more stationary. At each instant in time, almost all (91%) of the 3D motion of the entire heart wall is directed toward a single moving 3D point, the COC. Thus, there exists in principle a near-perfect 3D heart wall motion model. Approximately 25% of 3D wall motion is unseen in conventional monoplane views. Also, any model that represents 3D wall motion only along fixed straight 3D lines (eg, end-diastole to end-systole) necessarily ignores 27% of the true 3D heart wall motion.

Cable pulling device

Abstract: An improved cable paying out and taking up device particularly for use in underground or overhead cable pulling environments which includes a novel winch assembly disposed on a vehicle, a swivel fairlead disposed on a trailing portion of the vehicle bed adapted for facile removal and redeployment, the swivel fairlead provided with instrumentalities for operatively orienting a pulley sheave associated with the fairlead in 360° of direction and allowing disassociation of the pulley sheave from its associated support drum so that cable including an enlarged end unable to fit within clearances about the pulley sheave can be threaded through the swivel fairlead without disassociation of the cable from the enlarged end. The novel winch briefly includes a pair of winches modified to accommodate a removable bull wheel having a plurality of grooves on its outer face, the grooves dimensioned to receive cables corresponding to the diameter of the cable, an instrumentality for assuring level winding, a pressure responsive instrumentality associated with a reel to accommodate variations in effective reel diameter due to cable build-up and pay-out, so that hydraulic pressure and synchronization of the various rotating winches and reel can be coordinated for the accurate functioning of the apparatus.

Fingerprint development kit and process

Abstract: This invention relates to a new means, generally in kit form, for developing into a visible form fingerprints left on a solid surface, based upon the generation of a vapor-like phase of a cyanoacrylate material, alone or with functionally enhancing additives. This invention further relates to a process utilizing the exothermic polymerization reaction of cyanoacrylate compound, to generate a conjugable vapor-like phase.

Social Marketing and Community Health Promotion

Abstract: There is a long history of failure among social programs using mass media as their major sources of intervention. Health promotion programs, a subset of these social campaigns, have also failed to live up to their potential. In fact, a commonly held belief is that the mass media are impotent in changing health habits and promoting new health behaviors. Searching the literature on health promotion programs using mass media, one is at a loss to find more than a small handful of examples of campaigns that have even approximated their originally stated objectives. The Stanford Heart Disease Prevention Program’s (SHDPP) Three Community Study was initiated in 1972 to test, in realistic field settings, the potential for the use of community-based approaches in health promotion.

The architecture of the Lisa TM personal computer

Abstract: The Lisa personal computer provides a new and better way of relating to a computer This paper presents an outline of how such a complex, modern personal computer system is developed The architecture of both the hardware and the software of the Lisa is examined in detail Design goals and considerations are also discussed

The integrated software and user interface of Apple's Lisa

Abstract: In 1979 Apple began to develop Lisa, a workstation to enhance the productivity of office workers. The hardware was built around a Motorola 68000, a bit-mapped display, and a mouse. The user interface is intuitive, using real-world concepts rather than computer concepts. It is easy to learn, and provides for both novice users still learning the system and users that have mastered the system. The user interface is modeless and consistent. The uniformity of the user interface supports transferable learning---the ability to learn an operation once and apply it over and over again in another application in a different context.The user interface also supports data interchange among documents of the same or different types. This interchange of data, coupled with the multitasking operating system and the multiple windows of the Lisa, permits the use of several tools to perform a task that one tool alone could not accomplish. The Lisa user interface and its applications provide an environment that allows the user to concentrate on what is to be accomplished rather than on how to accomplish it. In this way, Lisa provides tools to improve the productivity of the office worker.

Spiral spring keyboard switch with hairpin spring tactile feedback

Abstract: An improved switch assembly is disclosed, having particular application as part of a key in a computer keyboard. The switch includes a housing including a base, having electrical contacts secured above the base of the switch housing. A generally flat and deformable electrically conductive spring having a central area with outwardly extending spiral arms is disposed above the electrical contacts. A keystem is slidably mounted for longitudinal movement within the housing above the flat spiral spring. A user activates the switch by depressing a key cap mounted to the keystem, which deforms the spiral spring downward and forcing a portion of the spring against the electrical contact, thereby completing the circuit. The keystem includes outwardly extending tapered cam nubs. A "hairpin" cam spring is provided which in an inactive state rests in an oversize slot below the outwardly extending keystem cam. The depression of the key cap forces the tapered cam to spread the cam spring. Further depression presents a narrowing of the cam shape such that the cam spring "snaps" upwardly upon encountering the narrower shape. The upward snapping motion of the cam spring provides a positive tactile feel and audible click to the user.

Freeze‐branding beaver tails

Abstract: Freeze-branding has proven useful in managing and researching a captive group of beaver (Castor canadensis) at the Minnesota Zoological Garden. Over 24 mo, 13 freeze-brands were applied to the tails of 11 beaver for varying application times. Permanence of brands increased with increasing distance from tail base. Because permanence of freeze-brands on cattle is influenced by skin thickness, the tail of a male beaver was horizontally sectioned into nine roughly equidistant segments, photographed to scale, and the epidermal/dermal thickness of the dorsal side of each section was measured to determine if skin thickness affected freeze-branding success in beaver. Thickness of the epidermal and dermal layers of the dorsal tail surface decreased 14-fold from tail base to tip. Based on our preliminary finding that freeze-brand permanence improved with decreased thickness of the epidermal/dermal layers of the tail, we recommend that beaver be freeze-branded for 25 s on the lower half of the tail for best results.