6,383 research outputs found
A Low-Cost Tele-Presence Wheelchair System
This paper presents the architecture and implementation of a tele-presence
wheelchair system based on tele-presence robot, intelligent wheelchair, and
touch screen technologies. The tele-presence wheelchair system consists of a
commercial electric wheelchair, an add-on tele-presence interaction module, and
a touchable live video image based user interface (called TIUI). The
tele-presence interaction module is used to provide video-chatting for an
elderly or disabled person with the family members or caregivers, and also
captures the live video of an environment for tele-operation and
semi-autonomous navigation. The user interface developed in our lab allows an
operator to access the system anywhere and directly touch the live video image
of the wheelchair to push it as if he/she did it in the presence. This paper
also discusses the evaluation of the user experience
Accretion Disc-Jet Couplings in X-ray Binaries
When the matter from a companion star is accreted towards the central compact
accretor, i.e. a black hole (BH) or a neutron star (NS), an accretion disc and
a jet outflow will form, providing bight X-ray and radio emission, which is
known as X-ray binaries (XRBs). In the low/hard state, there exist disc-jet
couplings in XRBs, but it remains uncertain whether the jet power comes from
the disc or the central accretor. Moreover, BHXRBs have different properties
compared with NSXRBs: quiescent BHXRBs are typically two to three orders of
magnitude less luminous than NSXRBs in X-ray, whereas BHXRBs are more radio
loud than NSXRBs. In observations, an empirical correlation has been
established between radio and X-ray luminosity, , where for BHXRBs and for non-pulsating NSXRBs.
However, there are some outliers of BHXRBs showing unusually steep correlation
as NSXRBs at higher luminosities. In this work, under the assumption that the
origin of jet power is related to the internal energy of the inner disc, we
apply our magnetized, radiatively efficient thin disc model and the well-known
radiatively inefficient accretion flow model to NSXRBs and BHXRBs. We find that
the observed radio/X-ray correlations in XRBs can be well understood by the
disc-jet couplings.Comment: 8 pages, 3 figures, accepted for publication in MNRA
HC-Ref: Hierarchical Constrained Refinement for Robust Adversarial Training of GNNs
Recent studies have shown that attackers can catastrophically reduce the
performance of GNNs by maliciously modifying the graph structure or node
features on the graph. Adversarial training, which has been shown to be one of
the most effective defense mechanisms against adversarial attacks in computer
vision, holds great promise for enhancing the robustness of GNNs. There is
limited research on defending against attacks by performing adversarial
training on graphs, and it is crucial to delve deeper into this approach to
optimize its effectiveness. Therefore, based on robust adversarial training on
graphs, we propose a hierarchical constraint refinement framework (HC-Ref) that
enhances the anti-perturbation capabilities of GNNs and downstream classifiers
separately, ultimately leading to improved robustness. We propose corresponding
adversarial regularization terms that are conducive to adaptively narrowing the
domain gap between the normal part and the perturbation part according to the
characteristics of different layers, promoting the smoothness of the predicted
distribution of both parts. Moreover, existing research on graph robust
adversarial training primarily concentrates on training from the standpoint of
node feature perturbations and seldom takes into account alterations in the
graph structure. This limitation makes it challenging to prevent attacks based
on topological changes in the graph. This paper generates adversarial examples
by utilizing graph structure perturbations, offering an effective approach to
defend against attack methods that are based on topological changes. Extensive
experiments on two real-world graph benchmarks show that HC-Ref successfully
resists various attacks and has better node classification performance compared
to several baseline methods
Recommended from our members
Taking your next vacation from home: Motivations and impacts of using live-streaming tourism
The research investigates a novel and alternative form of tourism, namely, live-streaming tourism (LST). Live-streaming tourism empowers individuals to experience new destinations at home without the risks associated with large-scale travel. Meanwhile, it boosts the economy by enabling destinations and micro-entrepreneurs to launch an alternative business model and create new employment opportunities. Specifically, the current study proposes and tests a conceptual model of viewers’ motivations and consequences of using live-streaming tourism based on the United Theory of Acceptance and Use of Technology 2.0 (UTAUT2). We explore how existing UTAUT2 antecedents, together with newly incorporated LST antecedents, affect viewers’ reuse and Word-of-Mouth intention of LST through the mediated effect of co-creation value. We adopt an online survey method to collect an estimated sample of 1000 viewers who have participated in live-streaming tourism in the past twelve months
- …