144 research outputs found

    Viewing a Graph in a Virtual Reality Display is Three Times as Good as a 2D Diagram

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    An experiment is reported which tests whether network information is more effectively displayed in a three dimensional space than in a two dimensional space. The experimental task is to trace a path in a network and the experiment is carried out in 2D, in a 3D stereo view, in a 2D view with head coupled perspective, and in a 3D stereo view with head coupled perspective; this last condition creates a localized virtual reality display. The results show that the motion parallax obtained from the head coupling of perspective is more important than stereopsis in revealing structural information. Overall the results show that three times as much information can be perceived in the head coupled stereo view as in the 2D view

    Representing Nodes and Arcs in 3D Networks

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    This paper introduces six graphical principles for 30 network displays. These are justified with examples from GraphVisualizer3D, a system developed by the authors to investigate the problems of 30 visualization of information networks. GraphVisualizer3D enables the exploration of sulface color, surface texture, object shape, arc shape and labeling conventions

    Visualizing Object Oriented Software in Three Dimensions

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    There is increasing evidence that it is possible to perceive and understand increasingly comple x information systems if they are displayed a s graphical objects in a three dimensional space . Object-oriented software provides an interestin g test case - there is a natural mapping fro m software objects to visual objects . In this paper we explore two areas. 1) Information perception : we are running controlled experiments to determine empirically if our initial premise is valid; how much more (or less) can be understoo d in 3D than in 2D? 2) Layout: our strategy is to combine partially automatic layout with manua l layout. This paper presents a brief overview of the project, the software architecture and some preliminary empirical results

    SHRINKAGE IN TERNARY MIXES OF CONTAINER MEDIA

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    Based on functional relationships established for binary mixes of container media, a mathematical model is proposed for ternary component mixtures. Shrinkage values are generated for three-component mixtures based on mathematical equations. Empirically observed shrinkage values for corresponding three-component mixtures are determined and used as the basis for assessing the reliability of the proposed mathematical model for characterizing shrinkage in mixtures of container media. . Regression equations were developed and compared for both theoretical and empirical results

    Experimental Demonstration of Time-Delay Interferometry for the Laser Interferometer Space Antenna

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    We report on the first demonstration of time-delay interferometry (TDI) for LISA, the Laser Interferometer Space Antenna. TDI was implemented in a laboratory experiment designed to mimic the noise couplings that will occur in LISA. TDI suppressed laser frequency noise by approximately 10^9 and clock phase noise by 6x10^4, recovering the intrinsic displacement noise floor of our laboratory test bed. This removal of laser frequency noise and clock phase noise in post-processing marks the first experimental validation of the LISA measurement scheme.Comment: 4 pages, 4 figures, to appear in Physical Review Letters end of May 201

    Techniques for Solution- Assisted Optical Contacting

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    A document discusses a solution-assisted contacting technique for optical contacting. An optic of surface flatness Lambda/20 was successfully contacted with one of moderate surface quality, or Lambda/4. Optics used were both ultra-low expansion (ULE) glass (Lambda/4 and Lambda/20) and fused silica (Lambda/20). A stainless steel template of the intended interferometer layout was designed and constructed with three contact points per optic. The contact points were all on a common side of the template. The entire contacting jig was tilted at about 30 . Thus, when the isopropanol was applied, each optic slid due to gravity, resting on the contact points. All of the contacting was performed in a relatively dusty laboratory. A number of successful contacts were achieved where up to two or three visible pieces of dust could be seen. These were clearly visible due to refraction patterns between the optic and bench. On a number of optics, the final step of dropping isopropyl between the surfaces was repeated until a successful contact was achieved. The new procedures realized in this work represent a simplification for optical contacting in the laboratory. They will both save time and money spent during the contacting process, and research and development phases. The techniques outlined are suitable for laboratory experiments, research, and initial development stages

    Progress in Interferometry for LISA at JPL

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    Recent advances at JPL in experimentation and design for LISA interferometry include the demonstration of Time Delay Interferometry using electronically separated end stations, a new arm-locking design with improved gain and stability, and progress in flight readiness of digital and analog electronics for phase measurements.Comment: 11 pages, 9 figures, LISA 8 Symposium, Stanford University, 201

    High-Speed Digital Interferometry

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    Digitally enhanced heterodyne interferometry (DI) is a laser metrology technique employing pseudo-random noise (PRN) codes phase-modulated onto an optical carrier. Combined with heterodyne interferometry, the PRN code is used to select individual signals, returning the inherent interferometric sensitivity determined by the optical wavelength. The signal isolation arises from the autocorrelation properties of the PRN code, enabling both rejection of spurious signals (e.g., from scattered light) and multiplexing capability using a single metrology system. The minimum separation of optical components is determined by the wavelength of the PRN code

    Impact of Menstrual Cycle on Resting and Postprandial Metabolism in Recreationally Active, Eumenorrheic Females

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    Changes in estrogen and progesterone across the menstrual cycle impact many biological systems including resting and postprandial metabolism. PURPOSE: To investigate whether menstrual cycle phase impacted resting and postprandial energy expenditure (EE) and substrate utilization in recreationally active, eumenorrheic females. METHODS: In this study, 8 eumenorrheic females (mean±SD age: 33±8 years, BMI: 22.5±2.2 kg/m2; VO2max: 36.9±3.8 ml/kg/min) had resting energy expenditure (REE) and substrate utilization continuously measured with indirect calorimetry for 45 min at rest after an overnight fast, and for 3 h after a mixed meal (490 kcal, 53% carbohydrate, 31% fat, 20% protein) during three distinct phases of the menstrual cycle (early follicular, late follicular, and mid luteal). Menstrual cycle phase was determined using calendar-based counting, ovulation test strips, and confirmed via serum hormone levels (estrogen and progesterone). REE (kcal/day) was calculated using the abbreviated Weir Equation. Diet-induced thermogenesis (DIT) was calculated by subtracting REE (kcal/min) from postprandial EE (kcal/min). This value (kcal/min) was then multiplied by the testing time (180 min) to obtain DIT (kcal) for the 3-h postprandial period. A one-way, repeated measures ANOVA was used to assess differences in REE, respiratory quotient (RQ), and DIT across menstrual cycle phase. All data reported as mean±SD. RESULTS: REE was higher during mid luteal (1486±178 kcal/day) compared to early follicular (1409±108 kcal/day) and late follicular (1390±103 kcal/day) phases (F[2,14]=2.28, p=0.14; effect size=0.25). Resting RQ did not differ across menstrual cycle phase. DIT was higher during early follicular (34±8 kcal) and late follicular (32±12 kcal) than mid-luteal (23±12 kcal) phase (F[2,14]=3.02, p=0.08; effect size=0.30). Postprandial RQ was higher during early follicular (0.87±0.04) and late follicular (0.87±0.03) than mid-luteal (0.85±0.04) phase (F[2,14]=3.22, p=0.07; effect size=0.32). CONCLUSION: These preliminary results on 8 recreationally active, eumenorrheic females suggest that resting and postprandial metabolism may differ across the menstrual cycle. It is unclear whether the magnitude of these differences is clinically meaningful

    The value of targeted biological surveys: an assessment of Australia's Bush Blitz programme

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    Biodiversity assessment and decisions rely on knowledge of the spatial distribution of species, yet most global biodiversity is inadequately represented by occurrence records. Efforts to improve our knowledge of biodiversity distribution include targeted taxon survey programmes aimed at generating records of new, or previously unrecorded, species. Here, we evaluate nearly 8 years of biodiversity record collection by Bush Blitz, Australia's largest species discovery programme, to test how efficiently knowledge was added through the programme
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