With the emergence of the Internet of Things (IoT), there has been a proliferation of urban studies using big data. Yet, anoth-er type of urban research innovations that involve interdisciplinary ...thinking and methods remains underdeveloped. This paper repres-ents an attempt to adopt a Hidden Markov Model (HMM) toolbox developed in Computer Science for the analysis of eye movement pat-terns in Psychology to answer urban mobility questions in Geography. The main idea is that both people's eye movements and travel be-havior follow the stop-travel-stop pattern, which can be summarized using HMM. Methodological challenges were addressed by adjust-ing the HMM to analyze territory-wide travel survey data in Hong Kong, China. By using the adjusted toolbox to identify the activity-travel patterns of working adults in Hong Kong, two distinctive groups of balanced (38.4％) and work-oriented (61.6％) lifestyles were identified. With some notable exceptions, working adults living in the urban core were having a more work-oriented lifestyle. Those with a balanced lifestyle were having a relatively compact zone of non-work activities around their homes but a relatively long commut-ing distance. Furthermore, working females tend to spend more time at home than their counterparts, regardless of their marital status and lifestyle. Overall, this interdisciplinary research demonstrates an attempt to integrate spatial, temporal, and sequential information for understanding people's behavior in urban mobility research.
Objectives. To evaluate the effects of Ving Tsun (VT) martial art training on the upper extremity muscle strength and eye-hand coordination of middle-aged and older adults. Methods. This study used a ...nonequivalent pretest-posttest control group design. Forty-two community-dwelling healthy adults participated in the study; 24 (mean age ± SD = 68.5 ± 6.7 years) underwent VT training for 4 weeks (a supervised VT session twice a week, plus daily home practice), and 18 (mean age ± SD = 72.0 ± 6.7 years) received no VT training and acted as controls. Shoulder and elbow isometric muscle strength and eye-hand coordination were evaluated using the Lafayette Manual Muscle Test System and a computerized finger-pointing test, respectively. Results. Elbow extensor peak force increased by 13.9% ( P = 0.007 ) in the VT group and the time to reach peak force decreased (9.9%) differentially in the VT group compared to the control group ( P = 0.033 ). For the eye-hand coordination assessment outcomes, reaction time increased by 2.9% in the VT group and decreased by 5.3% in the control group ( P = 0.002 ). Conclusions. Four weeks of VT training could improve elbow extensor isometric peak force and the time to reach peak force but not eye-hand coordination in community-dwelling middle-aged and older adults.
We examined whether embedding human attention knowledge into saliency-based explainable AI (XAI) methods for computer vision models could enhance their plausibility and faithfulness. We first ...developed new gradient-based XAI methods for object detection models to generate object-specific explanations by extending the current methods for image classification models. Interestingly, while these gradient-based methods worked well for explaining image classification models, when being used for explaining object detection models, the resulting saliency maps generally had lower faithfulness than human attention maps when performing the same task. We then developed Human Attention-Guided XAI (HAG-XAI) to learn from human attention how to best combine explanatory information from the models to enhance explanation plausibility by using trainable activation functions and smoothing kernels to maximize XAI saliency map's similarity to human attention maps. While for image classification models, HAG-XAI enhanced explanation plausibility at the expense of faithfulness, for object detection models it enhanced plausibility and faithfulness simultaneously and outperformed existing methods. The learned functions were model-specific, well generalizable to other databases.
We present UBVR photometry of eclipses in the post-common-envelope binary BE UMa. The eclipse is partial in all colours. We fit the eclipses to determine the orbital inclination and the radius of ...each star. For our best fit we find i = 82°4 ± 0°l, R1/a = 0.0781 ± 0.0001 and R2/a = 0.138 ± 0.001. Using the measured radial velocity of the secondary star, which we correct to account (approximately) for the asymmetric distribution of the line emission, we can calculate the system parameters of the binary for a given mass ratio. We find that for all mass ratios the primary star is a subdwarf and the secondary star lies well inside its Roche lobe. We use the fitted secondary star fluxes to determine its spectral type (G6V-K4V) and hence its mass, 0.69 <M2/M⊙ <0.89. This in turn limits the range of mass ratios possible to 0.64 < q <0.83. For these limits on q we find 0.83 < M1M⊙ <1.33 and 0.063 <R1/ R⊙ <0.077. Using model atmospheres we used the fitted primary star fluxes to determine the distance to the subdwarf. For a temperature of 90 000 <Te<125 000 K we find limits on the distance of 851 < D <1205 pc. The distance of the secondary star is consistent with the primary star's distance if the secondary star has spectral type K3-K4 and hence a distance of ˜ 1230-1071 pc.
We present the results of high time resolution UV spectroscopy and simultaneous high-speed UBVR photometry of AE Aqr. The UV spectra were obtained with the Faint Object Spectrograph aboard the Hubble ...Space Telescope (HST), and the photometry was carried out with the 82 sec telescope at McDonald Observatory. Our study focuses on the coherent 33 sceond oscillations, whose amplitude is found to be very large in the UV (40% of the mean quiescent level). The mean pulse profile has two broad unequal peaks spaced by half an oscillation cycle. The pulse profiles in the UV and optical bands appear quite similar in shape, with no discernible shifts. The orbital delay curve of the UV pulses establishes the white dwarf as their origin. The (UV+optical) spectrum of the pulsations is well described by a white dwarf atmosphere model with a temperature of about 26,000 K. We find no oscillations in the UV emission-line fluxes, nor in their velocities, down to a limit of 800 km/s. Based on the properties of the UV and optical pulsations we suggest that they originate in the X-ray heated magnetic polar caps of the white dwarf. Under this assumption we produce maximum entropy maps of the brightness distribution of the white dwarf surface. Using this model we are able to reproduce the observed mean pulse profile and interpret fluctuations in the oscillation amplitude as small fluctuations in the accretion rate. We find that the amplitudes and profiles of the pulses are not strongly affectd by the large aperiodic flares exhibited by the system. This suggests that the large flares are not related to the process of depositing material onto the white dwarf and argues against models that place their origin at the white dwarf magnetosphere.
We have obtained simultaneous UBVR photometry of the binary star HW Vir, a detached system with an orbital period of 2 h 48 min. The light curves show primary and secondary eclipses and a pronounced ...reflection effect. We analyse the light curves using the Wilson-Devinney code. We deduce that the orbital inclination is 80°.6 ± 0°.2, that the primary star has a temperature in the range 29 000 < T1 < 36 000 K, and that the secondary star has T2 ~ 3700 K. Using the published amplitude of the radial velocity curve of the primary star, 87.9 ± 4.8 km s–1, we calculate the possible masses and radii of the two stars. For the primary star we find that 4.9 < log g1 ≤ 5.8. These values of log g1 and T1 are consistent with those of sdB stars. If the primary star has a mass of 0.50 ± 0.04 Mʘ, as is usual for sdB stars, then 0.28 < q < 0.34. If the secondary star lies on the main sequence, then 0.30 < q < 0.48. From the temperature and gravity of the primary star, we find that its distance is in the range 42 < D < 151 pc. The system will begin mass transfer when the orbital period has decreased enough to bring the secondary star into contact with its Roche lobe. For q ~ 0.3, contact will occur when the orbital period is 109 min, well below the gap in the distribution of orbital periods of cataclysmic variables. If angular momentum is lost by gravitational radiation alone, for q ~ 0.3, contact will occur in 2 × 109 yr.
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