Space Reconstruction Research Articles

A Three-Dimensional Cinematographic Analysis of the Fastball and Curveball Pitches in Baseball

Three-dimensional (3-D) high speed photography was used to record the fastball (FB) and curveball (CB) actions of six members of the Australian National pitching squad. The direct linear transformation (DLT) method of motion analysis for 3-D space reconstruction from 2-D images was used to record the movement of selected anatomical features. Laterally positioned phase-locked cameras operating at 200 fps and a front-on camera operating at 300 fps were used to record the pitching action. Mean pitching velocities for the FB and the CB were recorded. A kinematic analysis of the two pitching motions from the first balance point following the completion of the pump and pivot to follow through are presented. The actions are very similar for the two pitches, as would be expected if disguised to confuse the batter. Minor differences were noted, however, for stride length, forearm action prior to release, and wrist action at release.

Reconstruction of the Middle Ear with Tragal Cartilage

A surgical technique for reconstruction of a well-ventilated middle ear space using tragal cartilage has been developed. Our technique was designed so as to secure an atticoantrum cavity and a complement of posterior tympanic annulus with a cartilage. This technique can be utilized in a radical mastoidectomy cavity at an original surgery and at a revision.

3-D reconstruction of molecular shape from microcrystal thin sections

Three-dimensional reconstruction techniques using electron microscopy have been principally developed for application to 2-D arrays (i.e. monolayers) of biological molecules and symmetrical single particles (e.g. helical viruses). However many biological molecules that crystallise form multilayered microcrystals which are unsuitable for study by either the standard methods of 3-D reconstruction or, because of their size, by X-ray crystallography. The grid sectioning technique enables a number of different projections of such microcrystals to be obtained in well defined directions (e.g. parallel to crystal axes) and poses the problem of how best these projections can be used to reconstruct the packing and shape of the molecules forming the microcrystal.Given sufficient projections there may be enough information to do a crystallographic reconstruction in Fourier space. We however have considered the situation where only a limited number of projections are available, as for example in the case of catalase platelets where three orthogonal and two diagonal projections have been obtained (Fig. 1).

Statistical analysis of a holographic system intended for the Space Shuttle

This paper reports an analytical study to determine the stability requirements for a holographic system intended for the NASA Space Shuttle. The primary emphasis is on optimization of the holographic geometry to minimize the effect of film variations between hologram exposure in space and wave-front reconstruction on the ground. It is shown that it is extremely important to use a balanced geometry (equal reference and object beam angles) and, if possible, a specific object beam angle.

Partial reconstruction of state vectors in decentralized dynamic systems

The extent to which the state vector information can be recovered in a decentralized control system from a partial observation record of the state vector measurement and also of the control vectors is discussed. That subspaces associated with partial reconstruction of the state space can be obtained recursively and that they have certain invariance properties is shown.

A software system for the automatic recognition of bubble chamber events

A FORTRAN IV program system has been completed, which allows the automatic recognition, space reconstruction and topological interpretation of arbitrary elementary particle interactions. Normal input to the program is in the form of a sequence of uncorrelated line elements, into which track chamber photographs are decomposed e.g. by a PEPR film measuring device. The output can be obtained in the form of standard input to the kinematics program GRIND or to the geometry program THRESH - in both cases either containing all tracks on the film or just selected event topologies. The program makes complete ionization analysis of all tracks. In its normal mode the program does not need any human scanning or premeasurement of the film. An optional minimum guidance mode is incorporated, which is useful for experiments where very short tracks are numerous. The program can run in 85000 words of core storage, it takes 9–11 sec per frame of CPU time on an IBM/360–65.75% of all K − interactions in hydrogen at 670 MeV/ c were found and completely reconstructed in space using the automatic mode, for the two-prong event type an efficiency of 80% was obtained. Some examples of the program's operation are presented.

Some basic experiments on the optical resolution of sampled microwave holograms

Sampling the field of a physically large microwave hologram space enables subsequent optical reconstruction of the original object space existing in various environments. It is shown fundamentally how the required resolution is related to the sample frequency. The recording of some basic microwave holograms is described, and the resultant patterns are shown. Optical reconstructions of two-point objects indicate the resolution capability of the holograms. Sampling in the prescribed manner yields optical reconstructions of the object points, but random sampling with the same number of measurements does not yield a reconstruction of the object.

Piero della Francesca's Montefeltro Altarpiece: A Pledge of Fidelity

Within the plethora of art historical discussion lavished on the Montefeltro Altarpiece (Fig. 1),1 the most significant contributions have come recently, simultaneously and independently, from two scholars. Millard Meiss and John Shearman, working from quite different starting points, arrived at reconstructions of the space in the painting that are similar in all their essential features. Both authors found that the figures—the Madonna and Christ, six saints, four angels, and the donor—are all well forward in the nave of a church, with the transept crossing behind them, and the apse some forty-five feet in the distance.2 Thus was solved the much-discussed problem of the true location of the figures within their architectural setting.

A three-dimensional reconstruction of lung parenchyma.

The mesoanatomy of the lung is poorly understood despite the numerous methods developed since the classic reconstructions of W. S. Miller (1). Pulmonary macroanatomy has been well demonstrated by dissection and casting-corrosion methods. One can study and define the larger airways in three dimensions following injection-casting of the bronchial tree. The microanatomy of the lung has been the subject' of intensive study and the finest details of alveolar structure have been demonstrated by the electron microscope. An anatomic description of a complete subgross unit of pulmonary parenchyma remains ill-defined and incompletely understood. The study of mesoanatomy fills this hiatus of knowledge between macroand microanatomy. A detailed anatomic description of the alveoli and terminal aborizations of the distal airways is essential to understand the physiologic, clinical, and pathologic significance of this area. The most logical approach to such a study is to model or reconstruct the pulmonary parenchyma. The present writers believe that reconstruction of pulmonary tissue elements (positive reconstruction) is more informative than a reconstruction of the air spaces (negative reconstruction), as it permits the investigator to look into the lung rather than studying it from the outside. Accordingly, a model of a highly magnified small area of the subpleural parenchyma of a normal dog lung has been constructed. It was planned to use this model to redefine the distal airways and alveoli, and to relate the observations to problems of ventilation and perfusion in health and disease.

Experience with On-Line Bubble Chamber Measuring Machines

About four-thousand events have now been measured at ANL using three measuring machines, each equipped with a small Recomp II computer. The computer has a 4K memory of 40 bit words and has floating point hardware. The computer guides and, in a sense, watches over the measurer, performing many elementary checks of the measuring process. A space reconstruction is not attempted, but sufficient checks are made to eliminate most mistakes and inaccuracies which would later cause failures during the reconstruction process.