169 research outputs found
An Empirical Study on use of Social Media in the Hotel Industry in China: A Study of Customers’ Preferences and Attitudes
With the development of the technology, business corporations start to use social media to promote their businesses. This study focuses on the preferences and attitudes of travelers’ in China with the relationship between usage of social media (based on WeChat and Sina Weibo) with the option of hotel choice in the hospitality industry. There are two instruments used in this study: (1) sending out online surveys and (2) scheduled interviews with people who are working in the hotel industry. From our survey data (N=245) were participants who completed questionnaires located all over China. However, the results of the study indicate that participating hotels and online tickets firms prefer to use social media to attract guests and even potential consumers. The top about three elements that influence decision making of hotel choice are: price (71.84%); location (68.16%); and online rating (33.06%)
MUSE-Fi: Contactless MUti-person SEnsing Exploiting Near-field Wi-Fi Channel Variation
Having been studied for more than a decade, Wi-Fi human sensing still faces a
major challenge in the presence of multiple persons, simply because the limited
bandwidth of Wi-Fi fails to provide a sufficient range resolution to physically
separate multiple subjects. Existing solutions mostly avoid this challenge by
switching to radars with GHz bandwidth, at the cost of cumbersome deployments.
Therefore, could Wi-Fi human sensing handle multiple subjects remains an open
question. This paper presents MUSE-Fi, the first Wi-Fi multi-person sensing
system with physical separability. The principle behind MUSE-Fi is that, given
a Wi-Fi device (e.g., smartphone) very close to a subject, the near-field
channel variation caused by the subject significantly overwhelms variations
caused by other distant subjects. Consequently, focusing on the channel state
information (CSI) carried by the traffic in and out of this device naturally
allows for physically separating multiple subjects. Based on this principle, we
propose three sensing strategies for MUSE-Fi: i) uplink CSI, ii) downlink CSI,
and iii) downlink beamforming feedback, where we specifically tackle signal
recovery from sparse (per-user) traffic under realistic multi-user
communication scenarios. Our extensive evaluations clearly demonstrate that
MUSE-Fi is able to successfully handle multi-person sensing with respect to
three typical applications: respiration monitoring, gesture detection, and
activity recognition.Comment: 15 pages. Accepted by ACM MobiCom 202
DASICS: Enhancing Memory Protection with Dynamic Compartmentalization
In the existing software development ecosystem, security issues introduced by
third-party code cannot be overlooked. Among these security concerns, memory
access vulnerabilities stand out prominently, leading to risks such as the
theft or tampering of sensitive data. To address this issue, software-based
defense mechanisms have been established at the programming language, compiler,
and operating system levels. However, as a trade-off, these mechanisms
significantly reduce software execution efficiency. Hardware-software co-design
approaches have sought to either construct entirely isolated trusted execution
environments or attempt to partition security domains within the same address
space. While such approaches enhance efficiency compared to pure software
methods, they also encounter challenges related to granularity of protection,
performance overhead, and portability. In response to these challenges, we
present the DASICS (Dynamic in-Address-Space Isolation by Code Segments) secure
processor design, which offers dynamic and flexible security protection across
multiple privilege levels, addressing data flow protection, control flow
protection, and secure system calls. We have implemented hardware FPGA
prototypes and software QEMU simulator prototypes based on DASICS, along with
necessary modifications to system software for adaptability. We illustrate the
protective mechanisms and effectiveness of DASICS with two practical examples
and provide potential real-world use cases where DASICS could be applied.Comment: 16 pages, 6 figure
A novel dual-rotor ultrasonic motor for underwater propulsion
Micro underwater vehicles (MUVs) have been highlighted recently for underwater explorations because of their high maneuverability, low price, great flexibility, etc. The thrusters of most conventional MUVs are driven by electromagnetic motors, which need big mechanical transmission parts and are prone to being interrupted by the variance of ambient electromagnetic fields. In this paper, a novel dual-rotor ultrasonic motor with double output shafts, compact size, and no electromagnetic interference is presented, characterized, and applied for actuating underwater robots. This motor was composed of a spindle-shaped stator, pre-pressure modulation unit, and dual rotors, which can output two simultaneous rotations to increase the propulsion force of the MUV. The pre-pressure modulation unit utilized a torsion spring to adjust the preload at the contact faces between the stator and rotor. The working principle of the ultrasonic motor was developed and the vibration mode of the stator was analyzed by the finite element method. Experimental results show that the no-load rotary speed and stalling torque of the prototype ultrasonic motor were 110 r/min and 3 mN m, respectively, with 150 V peak-to-peak driving voltage at resonance. One underwater robot model equipped with the proposed ultrasonic motor-powered thruster could move at 33 mm/s immersed in water. The dual-rotor ultrasonic motor proposed here provides another alternative for driving MUVs and is appropriate for developing specific MUVs when the electromagnetic interference issue needs to be considered. © 2019 by the authors
Kalman Filtering for Genetic Regulatory Networks with Missing Values
The filter problem with missing value for genetic regulation networks (GRNs) is addressed, in which the noises exist in both the state dynamics and measurement equations; furthermore, the correlation between process noise and measurement noise is also taken into consideration. In order to deal with the filter problem, a class of discrete-time GRNs with missing value, noise correlation, and time delays is established. Then a new observation model is proposed to decrease the adverse effect caused by the missing value and to decouple the correlation between process noise and measurement noise in theory. Finally, a Kalman filtering is used to estimate the states of GRNs. Meanwhile, a typical example is provided to verify the effectiveness of the proposed method, and it turns out to be the case that the concentrations of mRNA and protein could be estimated accurately
Role model moms post-secondary academy: A university–community collaboration to encourage access to postsecondary for marginalized women
The Role Model Moms (RMM) program supports low-income mothers completing their General Equivalency Diplomas. Postsecondary education (PSE) can break cycles of intergenerational poverty; however, existing PSE orientation resources were not designed for this group. A need existed for a new university resource utilizing a collaborative and community-engagement approach to provide tailored information on PSE for RMM participants. The RMM Post-Secondary Academy was developed to bridge this gap. It was evaluated via facilitator debriefing sessions, post-event surveys, and participant interviews, with results analyzed using basic statistics and descriptive thematic analysis. The event has run for three iterations, inviting 42, 45, and 38 women, respectively. Participants improved their understanding of and outlook on PSE. Their PSE concerns included family, financial, and academic barriers. This event provides a replicable model for responsive and cost-effective community programming. Community engagement ensured the content was relevant and applicable to the target audience
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