Subjective geometry and geometric psychology

Abstract“Subjective geometry” is a term coined by Weintraub and Krantz to describe the distortion imposed upon geometric patterns by the visual system itself—so-called optical illusions. The latter are widely regarded as being generated by misplaced “constancy” effects, i.e., they are regarded as stemming from the invariance of an object's appearance under wide variations in viewing conditions, such as obliquity, rotations, etc. The invariances represented by these constancies—shape constancy, size constancy, etc.—are spatiotemporal invariants of certain Lie subgroups of P4(R) ⊕ CO(1, 3) ⊕ GL(4, R) that govern Euclidean and non-Euclidean geometry. Tha Euclidean subgroups describe a Cyclopean visual world; the non-Euclidean, a binocular (bipolar) world of hyperbolic nature, according to the work of Luneburg, Blank, Indow, and others. The visual field of view is itself a geometric object involvingnot only “figure” and “ground” but also visual contours (orbits of the Lie groups involved), linear perspective, interposition, and contact and symplectic structures. The retina and “cortical retina” are both covered by a family of “circular-surround” cellular response fields (of a “Mexican hat” nature) which constitute an atlas for the visual manifold S. Upon this manifold are defined certain equivariant vector bundles that account for constancy phenomena and certain jet bundles, arising out of the vector bundles by prolongation, that generate the differential invariants characterizing higher form perception. The resultant theory of perceptual-cognitive processing has been termed “geometric psychology,” in analogy to MacLane's “geometrical mechanics” and Brockett–Hermann–Mayne's “geometry of systems,” the mathematical structure being very similar in all three instances. Functorial maps from the category GvFB(S) of equivariant fibre bundles to the simplicial category and the category of simplicial objects complete the theory by extending the perceptual system to cognitive phenomena and information-processing psychology

Paper Session I-C - Space Operations Management Training: Educating the Future Space Workforce for 2000 and Beyond

The Space Operations profession has been expanding, for the past 4 decades at nearly the same scale, proportionally, as space itself. Gene Roddenberry’s Star Trek1 captured the imagination and interest of several generations; many hoping to someday get a chance to work in some space related field. In 1975, a NASA study reported the proposed construction and operation of a US$200 Billion dollar, Earth-orbiting, commercial space station with 10,000 inhabitants who’s sole job would be to manufacture and operate solar-power satellites supplying Earth with energy -- generating enough revenue to pay for it’s construction and continuing operation in about 30 years2. Seeing space portrayed as a routine work environment for a world of earth citizens seemed like far fetched science fiction for decades. In 1991, space was already generating US$11.5 Billion dollars in revenue; in 1996 that jumped to US$26.7 Billion; by 2001 it will have more than doubled to US$57.5 Billion3

Age Life Evaluation of Space Shuttle Crew Escape System Pyrotechnic Components Loaded with Hexanitrostilbene (HNS)

Determining deterioration characteristics of the Space Shuttle crew escape system pyrotechnic components loaded with hexanitrostilbene would enable us to establish a hardware life-limit for these items, so we could better plan our equipment use and, possibly, extend the useful life of the hardware. We subjected components to accelerated-age environments to determine degradation characteristics and established a hardware life-limit based upon observed and calculated trends. We extracted samples using manufacturing lots currently installed in the Space Shuttle crew escape system and from other NASA programs. Hardware included in the study consisted of various forms and ages of mild detonating fuse, linear shaped charge, and flexible confined detonating cord. The hardware types were segregated into 5 groups. One was subjected to detonation velocity testing for a baseline. Two were first subjected to prolonged 155 F heat exposure, and the other two were first subjected to 255 F, before undergoing detonation velocity testing and/or chromatography analysis. Test results showed no measurable changes in performance to allow a prediction of an end of life given the storage and elevated temperature environments the hardware experiences. Given the lack of a definitive performance trend, coupled with previous tests on post-flight Space Shuttle hardware showing no significant changes in chemical purity or detonation velocity, we recommend a safe increase in the useful life of the hardware to 20 years, from the current maximum limits of 10 and 15 years, depending on the hardware

Four-terminal connector for measuring resistance of a pyrotechnic initiator

A four-terminal electrical connector device (40) for testing and measuring unknown resistances of initiators (11) used for starting pyrotechnic events aboard a Space Transportation System. The testing device minimizes contact resistance degradation effects and so improves the reliability of resistance measurement taken with the device. Separate and independent voltage sensing (19) and current supply (20) circuits each includes a pair of socket contacts (13-16) for mating engagement with the pins (17,18) of the initiator. The unknown resistance that is measured by the device is the resistance of the bridgewire (23) of the initiator which is required to be between 0.95 and 1.15 ohms

Challenger and Columbia Lessons Learned

The Space Shuttle Challenger and Columbia accidents resulted in tragic loss of life and national assets, and investigations into both accidents produced important lessons to prevent future accident

Long-range energy-state maneuvers for minimum time to specified terminal conditions.

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76474/1/AIAA-1973-229-104.pd

Health Professionals and Public Awareness of Carbon Monoxide Poisoning in Vermont

Introduction. Carbon monoxide (CO) is the second leading cause of non-medical poisoning death in the United States. Between 1999 and 2012, Vermont saw the highest rates of CO poisoning deaths in New England. Public education and the use of CO alarms have been identified as important prevention strategies. We developed and distributed a survey to assess public and health professional knowledge of CO. Methods. A 21-question survey was designed, based on the validated Chicago Lead Knowledge Test, to assess knowledge about sources of CO exposure and symptoms and treatment of poisoning. Fifteen additional questions collected occupational and demographic information and preferred sources of educational information. Surveys were distributed over two months to the public, healthcare professionals, and emergency responders within Chittenden County, as well as physicians throughout Vermont. Survey responses were analyzed using SPSS. Results. There were 256 respondents. Healthcare professionals performed better than public respondents overall (public: mean correct=15.69, SD= 2.83, N=104; healthcare provider and emergency responder: mean correct= 17.5, SD= 2.23, N= 152). The survey questions which were most frequently answered incorrectly related to treatment and sources of exposure, as well as the similarity of CO poisoning to symptoms of influenza. Respondents preferred to receive information from printed and internet sources. Discussion. Medical professionals are more knowledgeable about carbon mon- oxide than the general public. Public education should include printed and online for- mats, focusing on important sources of exposure (particularly ice rinks), seeking treatment following symptoms, and similarity to flu symptoms.https://scholarworks.uvm.edu/comphp_gallery/1267/thumbnail.jp

Four-terminal electrical testing device

The invention relates to a four-terminal electrical connector device for testing and measuring unknown resistances of initiators used for starting pyrotechnic events aboard the space shuttle. The testing device minimizes contact resistance degradation effects and so improves the reliability of resistance measurements taken with the device. Separate and independent voltage sensing and current supply circuits each include a pair of socket contacts for mating engagement with the pins of the initiator. The unknown resistance that is measured by the device is the resistance of the bridgewire of the initiator which is required to be between 0.95 and 1.15 ohms

Public Awareness of Medical Imaging as a Source of Ionizing Radiation Exposure

Background. Biological effects of exposure to ionizing radiation (IR) are well known. Literature suggests most patients and physicians lack proficient understanding of risks associated with ionizing radiation. Our study goals were to: assess the extent to which productive, informed conversations regarding ionizing radiation are occurring between patients and providers; characterize public awareness of medical imaging procedures as sources of IR exposure; and investigate best practices in patientprovider communications. Methods. We developed and administered a 17-question survey to 303 adults at five locations across Chittenden County, Vermont, over a 6-week period in fall 2016. Descriptive and statistical analyses were conducted using SPSS. Results. The three age groups of respondents had different knowledge levels about ionizing radiation (p Conclusions/Recommendations. 1. A standard oral presentation for pre-imaging patient-provider communication, along with a written handout, be developed; 2. A section of the electronic medical record (also accessible through the patient portal) containing IR exposure be created for patients and physicians to track individuals\u27 information.https://scholarworks.uvm.edu/comphp_gallery/1249/thumbnail.jp

Resistance training and youth

This is the publisher's version, also found at http://ehis.ebscohost.com/ehost/detail?vid=4&sid=34ab1967-2aea-457b-b261-e90e7b05e38c%40sessionmgr11&hid=2&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=s3h&AN=20752095The use of resistance training for children has increased in popularity and interest. It appears that children are capable of voluntary strength gains. Exercise prescription in younger populations is critical and requires certain program variables to be altered tTom adult perspectives. Individualization is vital, as the rate of physiological maturation has an impact on the adaptations that occur, The major difference in programs for children is the use of lighter loads (i.e., > 6 RM loads). It appears that longer duration programs (i.e., 10-20 wks) are better for observing training adaptations. This may be due to the fact that it takes more exercise to stimulate adaptational mechanisms related to strength performance beyond that of normal growth rates. The risk of injury appears low during participation in a resistance training program, and this risk is minimized with proper supervision and instruction. Furthermore, with the incidence of injury in youth sports, participation in a resistance training program may provide a protective advantage in one's preparation for sports participation