The Drawing and Perception of Architectural Spaces through Immersive Virtual Reality

The technologies that have sought to intervene in the architectural drawing process have focused on the sense of sight, leaving aside the use of the hands and the entire body that together achieve more sensory designs. Nowadays, to the benefit of the draftsman, that ideal scenery in which sight, hands and body work holistically is returning thanks to Immersive Virtual Reality (IVR). The purpose of this research is to analyze the perception of two-dimensionally drawn spaces, the drawing of such spaces through three-dimensional sketches in IVR, and both the perception of 3D sketched spaces and those which are also modeled realistically in IVR. First and fifth year architecture students went through the four phases of the experiment: (a) the perception of a space based on 2D sketches, (b) real-scale 3D space drawing in IVR, (c) the perception of a space drawn in 3D in IVR, and (d) the perception of the same space realistically modeled in 3D in IVR. Through three questionnaires and a grading sheet, the data was obtained. The perception of two-dimensionally drawn spaces was high (70.8%), while the precision of a space drawn in an IVR was even higher (83.9%). The real or natural scale in which the spaces can be experienced in an IVR is the characteristic that was most recognized by the students; however, this and the other qualities did not allow for a reliable conclusion for a homogeneous perception of sensations within the virtual spaces.

A comparison theorem for cosmological lightcones

Let (M, g) denote a cosmological spacetime describing the evolution of a universe which is isotropic and homogeneous on large scales, but highly inhomogeneous on smaller scales. We consider two past lightcones, the first, $${{\mathcal {C}}_{L}^{-}}(p, g)$$ C L - ( p , g ) , is associated with the physical observer $$p\in \,M$$ p ∈ M who describes the actual physical spacetime geometry of (M, g) at the length scale L, whereas the second, $${\mathcal {C}_{L}^{-}}(p, \hat{g})$$ C L - ( p , g ^ ) , is associated with an idealized version of the observer p who, notwithstanding the presence of local inhomogeneities at the given scale L, wish to model (M, g) with a member $$(M, \hat{g})$$ ( M , g ^ ) of the family of Friedmann–Lemaitre–Robertson–Walker spacetimes. In such a framework, we discuss a number of mathematical results that allows a rigorous comparison between the two lightcones $${\mathcal {C}_{L}^{-}}(p, g)$$ C L - ( p , g ) and $${\mathcal {C}_{L}^{-}}(p, \hat{g})$$ C L - ( p , g ^ ) . In particular, we introduce a scale-dependent (L) lightcone-comparison functional, defined by a harmonic type energy, associated with a natural map between the physical $${\mathcal {C}_{L}^{-}}(p, g)$$ C L - ( p , g ) and the FLRW reference lightcone $${\mathcal {C}_{L}^{-}}(p, \hat{g})$$ C L - ( p , g ^ ) . This functional has a number of remarkable properties, in particular it vanishes iff, at the given length-scale, the corresponding lightcone surface sections (the celestial spheres) are isometric. We discuss in detail its variational analysis and prove the existence of a minimum that characterizes a natural scale-dependent distance functional between the two lightcones. We also indicate how it is possible to extend our results to the case when caustics develop on the physical past lightcone $${\mathcal {C}_{L}^{-}}(p, g)$$ C L - ( p , g ) . Finally, by exploiting causal diamond theory, we show how the distance functional is related (to leading order in the scale L) to spacetime scalar curvature in the causal past of the two lightcones, and briefly illustrate a number of its possible applications.

Experimental Tests of the Vector II Slab in Field Conditions, Slab and Strip Model

Vector II slab was tested on a natural scale (a slab with a dimension of 6.30 × 6.30 m) and a strip 6.30 m long and 1.20 m wide. The Vector II slab is built by precast panel 60 cm wide, 4 cm thick and 14-20 cm thick concrete overtopping on the construction site. The main purpose of the slab tests on a natural scale was to observe the “faulting” effect and temporary deflections. During the tests, the displacements in the area of the panel joints in the middle of the slab span were recorded. The maximum difference in displacement between adjacent panels of the slab model was 0.16 mm, and the vertical displacement was 1.9 mm. The strip model had no cracks that could indicate a interface cracks between the precast element and the concrete overlay. After completion of the field tests, the load was left on the slab model to verify long-term effects.

Newtonian Fractional-dimension Gravity and Rotationally Supported Galaxies

We continue our analysis of Newtonian Fractional-Dimension Gravity, an extension of the standard laws of Newtonian gravity to lower dimensional spaces including those with fractional (i.e., non-integer) dimension. We apply our model to three rotationally supported galaxies: NGC 7814 (Bulge-Dominated Spiral), NGC 6503 (Disk-Dominated Spiral), and NGC 3741 (Gas-Dominated Dwarf). As was done in the general cases of spherically-symmetric and axially-symmetric structures, which were studied in previous work on the subject, we examine a possible connection between our model and Modified Newtonian Dynamics, a leading alternative gravity model which explains the observed properties of these galaxies without requiring the Dark Matter hypothesis. In our model, the MOND acceleration constant a0 ≃ 1.2 × 10−10m s−2 can be related to a natural scale length l0, namely $a_{0} \approx GM/l_{0}^{2}$ for a galaxy of mass M. Also, the empirical Radial Acceleration Relation, connecting the observed radial acceleration gobs with the baryonic one gbar, can be explained in terms of a variable local dimension D. As an example of this methodology, we provide detailed rotation curve fits for the three galaxies mentioned above.

A motion compensation treadmill for untethered wood ants (Formica rufa): evidence for transfer of orientation memories from free-walking training

ABSTRACTThe natural scale of insect navigation during foraging makes it challenging to study under controlled conditions. Virtual reality and trackball setups have offered experimental control over visual environments while studying tethered insects, but potential limitations and confounds introduced by tethering motivates the development of alternative untethered solutions. In this paper, we validate the use of a motion compensator (or ‘treadmill’) to study visually driven behaviour of freely moving wood ants (Formica rufa). We show how this setup allows naturalistic walking behaviour and preserves foraging motivation over long time frames. Furthermore, we show that ants are able to transfer associative and navigational memories from classical maze and arena contexts to our treadmill. Thus, we demonstrate the possibility to study navigational behaviour over ecologically relevant durations (and virtual distances) in precisely controlled environments, bridging the gap between natural and highly controlled laboratory experiments.

ESTETIKA EKSPRESI STRUKTUR DI TERMINAL PENUMPANG KAPAL LAUT

Structures in architecture acts as a load-bearing element on mechanical systems. In addition, structures can also provide spatial and aesthetic expressions in architectural with the use of certain techniques and materials that bring out the structure expression. The problem discuss in this paper relates to aesthetic parameters used to examine the structural expression on architectural. The research method used is descriptive analytical method conducted with study of the literature on aesthetics, based on parameters: visual complexity, texture and colour, symmetry of the form and familiarity using the case study of Ship Passenger Terminal building such as Qingdao Cruise Passanger Terminal, Kai Tak Cruise Terminal and Salerno Maritime Terminal.The result shows that visual complexity parameter were exposure the form of curved structures and folding structures, the use of lattice, single-mass, and different building imagery. The texture and colour parameter are subtle textures with curved patterns, use of aluminium or concrete materials,and ivory white to bring out the buildings with the color of the sea.The symmetry of the form parameter shows a natural scale, a rectangular geometric shape that is subjected to addition or subtraction, and the proportion 2:1 between the envelope and open façade. The familiarity parameter is repetition of asymmetric curved patterns form make rhythm that raises perception of the visual aesthetic of the building.

Abstract 14757: Impact of Including Smoking Duration Data in Atherosclerotic Cardiovascular Disease Risk Estimation

Recent results from 5 decades of Framingham Heart Study (FHS) data suggest former heavy smokers (≥20 pack-years) have higher ASCVD risk than never smokers up to 16 years after quitting. However, the ASCVD Risk Estimator Plus, which is based on the 2013 Pooled Cohort Equations (PCE) does not account for pack-years smoked and considers former smokers to have ASCVD risk equal to never smokers after 5 years quit. Using data from 18,400 person-exams (exams 1-8) on 3,908 white FHS Offspring cohort participants, and follow-up through 12/31/2016, we built 5 sex-specific ASCVD risk prediction models to assess the added value of smoking history data. Models used pooled repeated Cox proportional hazards regression with 10-year follow-up blocks and age, SBP, antihypertensive medications, diabetes, total and HDL cholesterol, lipid-lowering medications, smoking status, pack-years smoked, and years since quitting smoking as predictors. We refit the 2013 PCE in the FHS person-exam sample (model 1) for fair model comparison. Subsequent models refit model 1 with continuous predictors on their natural scale (i.e., not logarithmically transformed) with polynomials to account for nonlinearity (model 2), and cumulatively adjusted for: former smoking (model 3), pack-years smoked (model 4), and years since quitting (model 5). We compared models by change in c-index, continuous net reclassification improvement (NRI(>0)), and relative integrated discrimination improvement (rIDI).We included 1,895 men (358 events) and 2,013 women (197 events) with a mean age of 55 years and similar risk factor profiles. Over pooled examinations, ever smoking prevalence was high in men (77%) and women (78%), as was median pack-years smoked (M:39; W:32). Utilizing former smoking status, pack-years, and years quit (model 5) had significant but modest NRI(>0) and rIDI values compared to the 2013 PCE on the natural scale in both sexes {Men: NRI(>0)=0.23, rIDI=0.19; Women: NRI(>0)=0.34, rIDI=0.11); the change in c-index (0.01) was significant only in men}. Pack-years smoked and years since quitting improved ASCVD risk prediction significantly but modestly in our sample. If validated in other race/ethnicity groups, these variables should be considered for improving ASCVD risk prediction tools.

Why quadratic log-log dependence is ubiquitous and what next

Purpose In many real-life situations ranging from financial to volcanic data, growth is described either by a power law – which is linear in log-log scale or by a quadratic dependence in the log-log scale. The purpose of this paper is to explain this empirical fact. Design/methodology/approach The authors use natural scale invariance requirements. Findings In this paper, the authors used natural scale invariance requirement to explain the ubiquity of quadratic log-log dependencies. The authors also explain what to do if quadratic log-log models turn out to be insufficiently accurate. In this case, scale-invariance requirements lead to dependencies which in the log-log scale take cubic, 4th order, etc. form. Originality/value To the best of authors’ knowledge, this is the first theoretical explanation of the empirical quadratic log-log dependence.

Suppression of the instrumental disturbance effect by locally invariant scaling of the physical model of spacecraft angular stabilization

The study introduces a method of ground conditions physical modeling of the spacecraft motion around a fixed axis. On a natural scale of parameters and variables, the dynamic modes under consideration can be implemented only with an extremely small amount of kinetic energy dissipation. The feasible minimum friction for a test bed of simple design significantly exceeds the required values. In current modes of economical limit cycles, the characteristics of the simulated process are distorted so much that the physical modeling test bed is unsuitable for practical use. The solution to this problem is usually sought by complicating the design of the test bed through the use of air or magnetic suspension. The paper proposes an innovative method of “invariant scaling”, based on the principle of dynamic similarity of self-oscillating processes. Its application makes it possible to drastically reduce the effect of friction on the characteristics of physically modeled modes during ground developmental testing of control algorithms. Computer modeling with the use of this method has confirmed its high efficiency. It has been shown analytically and numerically that the modeling accuracy can be radically improved. An example of reducing the modeling error by 200 times is given.