103 research outputs found
[DC] Outdoor AR Tracking Evaluation and Tracking with Prior Map
We are very interested in addressing the problem of building city-scale AR systems where users can travel anywhere at any time and see the correct graphics registered in the world around them. One crucial requirement for this is accurate tracking and localisation. In my work, I propose to tackle two themes. The first is to examine what good registration means in uncontrolled outdoor environments. The second is to explore how prior information can be used to support wide-area tracking efficiently and robustly
Quantum-trajectory analysis for charge transfer in solid materials induced by strong laser fields
We investigate the dependence of charge transfer on the intensity of driving
laser field when SiO2 crystal is irradiated by an 800 nm laser. It is
surprising that the direction of charge transfer undergoes a sudden reversal
when the driving laser intensity exceeds critical values with different carrier
envelope phases. By applying quantum-trajectory analysis, we find that the
Bloch oscillation plays an important role in charge transfer in solid. Also, we
study the interaction of strong laser with gallium nitride (GaN) that is widely
used in optoelectronics. A pump-probe scheme is applied to control the quantum
trajectories of the electrons in the conduction band. The signal of charge
transfer is controlled successfully by means of theoretically proposed
approach
Automated Multimodal Data Capture for Photorealistic Construction Progress Monitoring in Virtual Reality
Construction monitoring is vital for the timely delivery of projects. However manual data collection and fusion methods are arduous. We propose a framework for autonomous multimodal data collection and VR visualisation. Based on “work-in-progress” results we demonstrate its capabilities in-the-lab and validate its functionality on a real site. We explore how such a framework could complement construction-centric deep learning and 4D as-built datasets to aid human decision-making using V
Inhibitory effect and mechanism of action of tanshinone IIA on human bladder cancer cell J82
Purpose: To investigate the therapeutic influence of tanshinone IIA on human bladder cancer cell J82, and the possible signal route involved.
Methods: Cell proliferative potential was measured using MTT assay, while the expressions of associated genes were determined by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunoblot assays.
Results: Tanshinone IIA decreased J82 cell survival rate by > 42 % and inactivated apoptosis by suppressing PI3K/AKT/mTOR signal route. Moreover, it decreased Bcl-2, but upregulated caspase and Bax (p < 0.05).
Conclusion: The inhibitory effect of TIIA on human bladder cancer suggests that TIIA can be developed into an anti-tumor agent
Reviving the Euston Arch: A Mixed Reality Approach to Cultural Heritage Tours
Augmented Reality (AR) and Virtual Reality (VR) users have distinct capabilities and experiences during Extended Reality (XR) collaborations: while AR users benefit from real-time contextual information due to physical presence, VR users enjoy the flexibility to transition between locations rapidly, unconstrained by physical space.Our research aims to utilize these spatial differences to facilitate engaging, shared XR experiences. Using Google Geospatial Creator, we enable large-scale outdoor authoring and precise localization to create a unified environment. We integrated Ubiq to allow simultaneous voice communication, avatar-based interaction and shared object manipulation across platforms.We apply AR and VR technologies in cultural heritage exploration. We selected the Euston Arch as our case study due to its dramatic architectural transformations over time. We enriched the co-exploration experience by integrating historical photos, a 3D model of the Euston Arch, and immersive audio narratives into the shared AR/VR environment
Fast ZZ-Free Entangling Gates for Superconducting Qubits Assisted by a Driven Resonator
Engineering high-fidelity two-qubit gates is an indispensable step toward
practical quantum computing. For superconducting quantum platforms, one
important setback is the stray interaction between qubits, which causes
significant coherent errors. For transmon qubits, protocols for mitigating such
errors usually involve fine-tuning the hardware parameters or introducing
usually noisy flux-tunable couplers. In this work, we propose a simple scheme
to cancel these stray interactions. The coupler used for such cancellation is a
driven high-coherence resonator, where the amplitude and frequency of the drive
serve as control knobs. Through the resonator-induced-phase (RIP) interaction,
the static ZZ coupling can be entirely neutralized. We numerically show that
such a scheme can enable short and high-fidelity entangling gates, including
cross-resonance CNOT gates within 40 ns and adiabatic CZ gates within 140 ns.
Our architecture is not only ZZ free but also contains no extra noisy
components, such that it preserves the coherence times of fixed-frequency
transmon qubits. With the state-of-the-art coherence times, the error of our
cross-resonance CNOT gate can be reduced to below 1e-4
Completely Positive Map for Noisy Driven Quantum Systems Derived by Keldysh Expansion
Accurate modeling of decoherence errors in quantum processors is crucial for analyzing and improving gate fidelities. To increase the accuracy beyond that of the Lindblad dynamical map, several generalizations have been proposed, and the exploration of simpler and more systematic frameworks is still ongoing. In this paper, we introduce a decoherence model based on the Keldysh formalism. This formalism allows us to include non-periodic drives and correlated quantum noise in our model. In addition to its wide range of applications, our method is also numerically simple, and yields a CPTP map. These features allow us to integrate the Keldysh map with quantum-optimal-control techniques. We demonstrate that this strategy generates pulses that mitigate correlated quantum noise in qubit state-transfer and gate operations
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