29 research outputs found
Spatiotemporal patterns and driving mechanism of tourism ecological security in Guangxi, China
Tourism ecological security (TES) is an important index reflecting the sustainable development of the regional economy. The construction of the China and ASEAN Free Trade Area has increased the total tourist consumption of Guangxi province by 36.48%. Unfortunately, overconsumption of resources, air pollution, disturbance of indigenous life, and other environmental degradation problems emerged due to the significant increase in tourists. Measuring the resilience of the tourism ecosystem is an urgent need to promote the high-quality development of tourism in Guangxi. To explore the dynamic changes in TES and its driving mechanism, the DPSIR (driver–pressure–state–impact–response) model for the tourism ecosystem was developed. The dynamic changes in TES and its driving mechanism from 2010 to 2019 were analyzed using fuzzy matter-element analysis, Markov chains, Geodetector, and other methods. The results show that: (1) the TES value increased steadily by 72.73%; the improvement speed was Northeast > Southwest > Southeast > Northwest; (2) TES was negatively correlated with location, 14 cities developed independently; (3) the TES has a smaller probability to shift the lower level; (4) urbanization, water consumption, green area, tourism revenue, and the number of students in colleges had significant effects on TES. Four policies were proposed to improve TES: (1) developing forest tourism; (2) implementing greening projects in abandoned mining areas; (3) increasing tourism technical personnel; and (4) reducing clearance time for inbound tourists
A Health Monitoring System Based on Flexible Triboelectric Sensors for Intelligence Medical Internet of Things and its Applications in Virtual Reality
The Internet of Medical Things (IoMT) is a platform that combines Internet of
Things (IoT) technology with medical applications, enabling the realization of
precision medicine, intelligent healthcare, and telemedicine in the era of
digitalization and intelligence. However, the IoMT faces various challenges,
including sustainable power supply, human adaptability of sensors and the
intelligence of sensors. In this study, we designed a robust and intelligent
IoMT system through the synergistic integration of flexible wearable
triboelectric sensors and deep learning-assisted data analytics. We embedded
four triboelectric sensors into a wristband to detect and analyze limb
movements in patients suffering from Parkinson's Disease (PD). By further
integrating deep learning-assisted data analytics, we actualized an intelligent
healthcare monitoring system for the surveillance and interaction of PD
patients, which includes location/trajectory tracking, heart monitoring and
identity recognition. This innovative approach enabled us to accurately capture
and scrutinize the subtle movements and fine motor of PD patients, thus
providing insightful feedback and comprehensive assessment of the patients
conditions. This monitoring system is cost-effective, easily fabricated, highly
sensitive, and intelligent, consequently underscores the immense potential of
human body sensing technology in a Health 4.0 society
Single-cell multiomics of the human retina reveals hierarchical transcription factor collaboration in mediating cell type-specific effects of genetic variants on gene regulation
BACKGROUND: Systematic characterization of how genetic variation modulates gene regulation in a cell type-specific context is essential for understanding complex traits. To address this question, we profile gene expression and chromatin accessibility in cells from healthy retinae of 20 human donors through single-cell multiomics and genomic sequencing.
RESULTS: We map eQTL, caQTL, allelic-specific expression, and allelic-specific chromatin accessibility in major retinal cell types. By integrating these results, we identify and characterize regulatory elements and genetic variants effective on gene regulation in individual cell types. The majority of identified sc-eQTLs and sc-caQTLs display cell type-specific effects, while the cis-elements containing genetic variants with cell type-specific effects are often accessible in multiple cell types. Furthermore, the transcription factors whose binding sites are perturbed by genetic variants tend to have higher expression levels in the cell types where the variants exert their effects, compared to the cell types where the variants have no impact. We further validate our findings with high-throughput reporter assays. Lastly, we identify the enriched cell types, candidate causal variants and genes, and cell type-specific regulatory mechanism underlying GWAS loci.
CONCLUSIONS: Overall, genetic effects on gene regulation are highly context dependent. Our results suggest that cell type-dependent genetic effect is driven by precise modulation of both trans-factor expression and chromatin accessibility of cis-elements. Our findings indicate hierarchical collaboration among transcription factors plays a crucial role in mediating cell type-specific effects of genetic variants on gene regulation
Anything in Any Scene: Photorealistic Video Object Insertion
Realistic video simulation has shown significant potential across diverse
applications, from virtual reality to film production. This is particularly
true for scenarios where capturing videos in real-world settings is either
impractical or expensive. Existing approaches in video simulation often fail to
accurately model the lighting environment, represent the object geometry, or
achieve high levels of photorealism. In this paper, we propose Anything in Any
Scene, a novel and generic framework for realistic video simulation that
seamlessly inserts any object into an existing dynamic video with a strong
emphasis on physical realism. Our proposed general framework encompasses three
key processes: 1) integrating a realistic object into a given scene video with
proper placement to ensure geometric realism; 2) estimating the sky and
environmental lighting distribution and simulating realistic shadows to enhance
the light realism; 3) employing a style transfer network that refines the final
video output to maximize photorealism. We experimentally demonstrate that
Anything in Any Scene framework produces simulated videos of great geometric
realism, lighting realism, and photorealism. By significantly mitigating the
challenges associated with video data generation, our framework offers an
efficient and cost-effective solution for acquiring high-quality videos.
Furthermore, its applications extend well beyond video data augmentation,
showing promising potential in virtual reality, video editing, and various
other video-centric applications. Please check our project website
https://anythinginanyscene.github.io for access to our project code and more
high-resolution video results
A sensitivity approach for computation of the probability density function of critical clearing time and probability of stability in power system transient stability analysis
WOS: 000238658100018This paper presents a linear approximation method to determine the probability density function (PDF) of the critical clearing time (CCT) and probability of stability for a given disturbance in power system transient stability analysis. The CCT is the maximum time interval by which the fault must be cleared in order to preserve the system stability. The CCT depends on the system load level and thus, is modeled as a random variable due to the probabilistic nature of system load demand. The proposed method first determines the sensitivity of the CCT with respect to the system load, and using these sensitivities it computes the PDF of the CCT based on the PDF of the system load. The probability of system being transiently stable for a particular disturbance and for a given fault clearing time is calculated using the PDF of CCT. This approach is verified to be accurate under the condition of small load deviation by Monte Carlo simulations method. Moreover, the proposed method reduces the computational effort significantly in Monte Carlo simulations indicating that it could be used in real-time on-line applications. (c) 2005 Elsevier Inc. All rights reserved
Research on the transformerless connection mode for DC power distribution system
The connection mode of the flexible DC distribution network and the AC network is not only the basis of the system design but also is one of the key technologies in the DC distribution. This paper demonstrates the feasibility of the transformerless system using modular multilevel converters (MMC) in the power distribution system. Here, in allusion to the DC power distribution network without transformer, the influence of AC system fault on DC system and the influence of DC system fault on AC system are analysed in detail separately. By establishing the simulation model with the PSCAD/EMTDC software, the transformerless system proposed is verified feasible at the appropriate voltage and the appropriate earthing way of AC system. The research proposed a solution of saving economic cost and space which is the critical issue in the conventional DC power distribution system with the transformer
Research on an Asymmetric Fault Control Strategy for an AC/AC System Based on a Modular Multilevel Matrix Converter
This paper studies control strategies for an AC/AC system based on a modular multilevel matrix converter (M3C) when an asymmetric fault occurs in the secondary side ac system. Firstly, the operating principle of M3C is briefly introduced and verified by simulation. Then, based on its mathematical model by double αβ0 transformation, the decoupled control strategies for the primary side and secondary side systems are designed. In view of the asymmetric fault condition of the secondary side system, the positive sequence and negative sequence components of voltages and currents are separated and extracted, and then a proportional resonant controller (PR) is used to regulate the positive and negative sequence currents at the same time to realize decoupled current control in the αβ reference frames. The capacitor voltage balancing control, which consists of an inter-subconverter balancing control and an inner-subconverter balancing control, is realized by adjusting four circulating currents. Finally, the proposed control strategy is validated by simulation in the PSCAD/EMTDC software (Manitoba HVDC Research Center, Canada). The result shows that during the period of the BC-phase short-circuit fault occurring in the secondary side system, the whole system can still operate stably and transmit a certain amount of active power, according to their set values. Furthermore, the capacitor voltages are balanced, with a slight increase during the fault period. The simulation results verify the effectiveness of the proposed control strategy
Modified Modeling and System Stabilization of Shunt Active Power Filter Compensating Loads with μF Capacitance
The interactions between shunt active power filter (APF) and capacitance load tend to result in stability problems and resonance. The conventional model of a shunt APF is not precise enough to reflect this phenomenon. To address it, this paper proposes a modified shunt APF system model to accurately reflect various stability problems. This paper also studies the mechanism of positive feedback resonance brought by capacitance load and proposes a modified hybrid controller to improve the stable margin of the system, making the shunt APF work stably under different working conditions where there are μF capacitors on the demand side. The correctness and validity of the proposed strategy are verified by simulation analysis and prototype experiments