7,993 research outputs found
A Regularized Model
We investigate a dynamic model described by the classical Hamiltonian
, where , in classical, semi-classical, and
quantum mechanics. In the high-energy limit, the phase path resembles that
of the model. However, the non-zero value of acts as a regulator,
removing the singularities that appear in the region where ,
resulting in a discrete spectrum characterized by a logarithmic increase in
state density. Classical solutions are described by elliptic functions, with
the period being determined by elliptic integrals. In semi-classical
approximation, we speculate that the asymptotic Riemann-Siegel formula may be
interpreted as summing over contributions from multiply phase paths. We present
three different forms of quantized Hamiltonians, and reformulate them into the
standard Schr\" odinger equation with -like potentials. Numerical
evaluations of the spectra for these forms are carried out and reveal minor
differences in energy levels. Among them, one interesting form possesses
Hamiltonian in the Schr\" odinger equation that is identical to its classical
version. In such scenarios, the eigenvalue equations can be expressed as the
vanishing of the Mathieu functions' value at points, and furthermore,
the Mathieu functions can be represented as the wave functions
Finding any Waldo: zero-shot invariant and efficient visual search
Searching for a target object in a cluttered scene constitutes a fundamental
challenge in daily vision. Visual search must be selective enough to
discriminate the target from distractors, invariant to changes in the
appearance of the target, efficient to avoid exhaustive exploration of the
image, and must generalize to locate novel target objects with zero-shot
training. Previous work has focused on searching for perfect matches of a
target after extensive category-specific training. Here we show for the first
time that humans can efficiently and invariantly search for natural objects in
complex scenes. To gain insight into the mechanisms that guide visual search,
we propose a biologically inspired computational model that can locate targets
without exhaustive sampling and generalize to novel objects. The model provides
an approximation to the mechanisms integrating bottom-up and top-down signals
during search in natural scenes.Comment: Number of figures: 6 Number of supplementary figures: 1
Co-Design with Myself: A Brain-Computer Interface Design Tool that Predicts Live Emotion to Enhance Metacognitive Monitoring of Designers
Intuition, metacognition, and subjective uncertainty interact in complex ways
to shape the creative design process. Design intuition, a designer's innate
ability to generate creative ideas and solutions based on implicit knowledge
and experience, is often evaluated and refined through metacognitive
monitoring. This self-awareness and management of cognitive processes can be
triggered by subjective uncertainty, reflecting the designer's self-assessed
confidence in their decisions. Despite their significance, few creativity
support tools have targeted the enhancement of these intertwined components
using biofeedback, particularly the affect associated with these processes. In
this study, we introduce "Multi-Self," a BCI-VR design tool designed to amplify
metacognitive monitoring in architectural design. Multi-Self evaluates
designers' affect (valence and arousal) to their work, providing real-time,
visual biofeedback. A proof-of-concept pilot study with 24 participants
assessed its feasibility. While feedback accuracy responses were mixed, most
participants found the tool useful, reporting that it sparked metacognitive
monitoring, encouraged exploration of the design space, and helped modulate
subjective uncertainty
Analysis of Contact Surface Wear Performance of O-Ring Dynamic Seal Based on Archard Model
With the development of hydraulic system to high pressure gradually, the leakage risk of sealing system increases, and it is necessary to confirm the performance parameters of sealing structure through analysis and calculation. The traditional analysis of the friction and wear performance of the seal ring is limited to the amount of wear, and cannot describe the surface wear characteristics of the O-ring in detail. Based on the Archard model, this paper constructs a model to analyse and calculate the friction and wear performance of the dynamic seal structure through the material characteristics and operating parameters, analyses the friction and wear characteristics of the O-ring seal structure under different compression ratio, medium pressure, relative slip velocity and temperature, and summarizes the influence of each single variable on the wear characteristics of the dynamic seal structure. According to the analysis in this paper, the increase of medium pressure of 5 MPa will cause the wear concentration area of the contact surface to move to the back pressure side, and the overall wear will be reduced, but the increase of contact area will lead to the weakening of sealing effect. By the action of 15 MPa, when the compression ratio is between 5% and 10%, the change of cumulative wear rate and the wear rate of each node is small
Monotonicity results and bounds for the inverse hyperbolic sine
In this note, we present monotonicity results of a function involving to the
inverse hyperbolic sine. From these, we derive some inequalities for bounding
the inverse hyperbolic sine.Comment: 3 page
Bioactive polydimethylsiloxane surface for optimal human mesenchymal stem cell sheet culture
Human mesenchymal stem cell (hMSC) sheets hold great potential in engineering three-dimensional (3D) completely biological tissues for diverse applications. Conventional cell sheet culturing methods employing thermoresponsive surfaces are cost ineffective, and rely heavily on available facilities. In this study, a cost-effective method of layer-by-layer grafting was utilized for covalently binding a homogenous collagen I layer on a commonly used polydimethylsiloxane (PDMS) substrate surface in order to improve its cell adhesion as well as the uniformity of the resulting hMSC cell sheet. Results showed that a homogenous collagen I layer was obtained via this grafting method, which improved hMSC adhesion and attachment through reliable collagen I binding sites. By utilizing this low-cost method, a uniform hMSC sheet was generated. This technology potentially allows for mass production of hMSC sheets to fulfill the demand of thick hMSC constructs for tissue engineering and biomanufacturing applications
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