239 research outputs found
Research on Traffic Optimization of Urban Four-Phase Intersections Based on VISSIM
In order to effectively solve the congestion problem of mixed intersections, improve traffic efficiency, and improve the current congestion situation of urban road network, this paper takes the mixed traffic flow intersection of Shanghai Road and Guyan Street in Yuanzhou District of Guyuan City as an example to carry out optimization research, collect traffic flow and signal timing data during peak hours through field investigation, and establish a microscopic road model by using VISSIM software. Through simulation, the indexes such as vehicle delay and queue length are obtained. Then the lane function of the model is divided, the signal timing is optimized by Webster algorithm and Fuzzy algorithm, and the comparison analysis is carried out. The simulation results show that the vehicle delay and queue length after Fuzzy optimization are greatly reduced, and the traffic running condition is significantly improved, thus verifying the scientificity and rationality of the optimization scheme
Facial Data Minimization: Shallow Model as Your Privacy Filter
Face recognition service has been used in many fields and brings much
convenience to people. However, once the user's facial data is transmitted to a
service provider, the user will lose control of his/her private data. In recent
years, there exist various security and privacy issues due to the leakage of
facial data. Although many privacy-preserving methods have been proposed, they
usually fail when they are not accessible to adversaries' strategies or
auxiliary data. Hence, in this paper, by fully considering two cases of
uploading facial images and facial features, which are very typical in face
recognition service systems, we proposed a data privacy minimization
transformation (PMT) method. This method can process the original facial data
based on the shallow model of authorized services to obtain the obfuscated
data. The obfuscated data can not only maintain satisfactory performance on
authorized models and restrict the performance on other unauthorized models but
also prevent original privacy data from leaking by AI methods and human visual
theft. Additionally, since a service provider may execute preprocessing
operations on the received data, we also propose an enhanced perturbation
method to improve the robustness of PMT. Besides, to authorize one facial image
to multiple service models simultaneously, a multiple restriction mechanism is
proposed to improve the scalability of PMT. Finally, we conduct extensive
experiments and evaluate the effectiveness of the proposed PMT in defending
against face reconstruction, data abuse, and face attribute estimation attacks.
These experimental results demonstrate that PMT performs well in preventing
facial data abuse and privacy leakage while maintaining face recognition
accuracy.Comment: 14 pages, 11 figure
Hierarchical global fast terminal sliding-mode control for a bridge travelling crane system
The bridge crane system is a typical under-actuated system that is widely used in production and life. Although various scholars have conducted extensive research on the bridge crane system in recent years, there are still many problems, such as the trajectory planning of the cart and the anti-sway control of the cargo. In order to tackle the problem of the anti-sway control of the cargo, a hierarchical global fast terminal sliding-mode control (H-GFTSMC) is developed in this work. First, the Lagrange equations are used to model the system dynamics. Then, an appropriate hierarchical global fast terminal sliding-mode controller is designed to achieve anti-sway control of the cargo, and it is proved that each sliding-mode surface is progressively stable. A series of simulations were implemented to verify the effectiveness of the control method. The simulation results show that the H-GFTSMC has better control performance compared with the proportional–integral–derivative control method. When changing the cable length or adding non-negligible noise to the system, the H-GFTSMC still has good robustness
Comparison of clinical features and prognosis between ultrashort-segment and short-segment hirschsprung disease
ObjectiveTo compare the differences in clinical features, postoperative complications, and long-term bowel function outcomes of ultrashort-segment Hirschsprung disease (USHD) and short-segment Hirschsprung disease (SHD).MethodsA retrospective study was conducted to compare patients with USHD or SHD who underwent transanal endorectal pull-through (TEPT) at Beijing Children's Hospital between January 2014 and June 2021. Clinical details were collected from medical records. A long-term bowel function questionnaire (age > 4 years old) was completed by the patients' parents.ResultsA total of 84 patients (USHD = 15, SHD = 69) were included. Age at diagnosis and radical surgery in the USHD group were significantly older than the SHD group (46 [38, 66] vs. 34 [6, 55] months, p = 0.002; 51 [39, 68] vs. 37 [10, 68] months, p = 0.001, respectively). Compared with the SHD group, patients with USHD are more likely to suffer anastomosis leakage and postoperative enterocolitis after TEPT ([3/15, 33.3%] vs. [1/69, 1.4%], p = 0.017; [5/15, 33.3%] vs. [6/69, 8.7%], p = 0.023). In addition, patients in the USHD group are inclined to suffer lower bowel function scores (12.0 [7.5, 18.3] vs. 17 [15, 19], p = 0.018).Patients in the USHD group were more likely to suffer poorer ability to hold back defecation (p = 0.023), soiling (p = 0.011), fecal accidents (p = 0.004), and social problems (p = 0.004).ConclusionCompared with patients with SHD, patients with USHD are diagnosed and performed TEPT at an older age. and they are inclined to suffer postoperative enterocolitis, anastomosis leakage, and poorer long-term bowel function following TEPT
Network communications flexibly predict visual contents that enhance representations for faster visual categorization
Models of visual cognition generally assume that brain networks predict the contents of a stimulus to facilitate its subsequent categorization. However, understanding prediction and categorization at a network level has remained challenging, partly because we need to reverse engineer their information processing mechanisms from the dynamic neural signals. Here, we used connectivity measures that can isolate the communications of a specific content to reconstruct these network mechanisms in each individual participant (N=11, both sexes). Each was cued to the spatial location (left vs. right) and contents (Low vs. High Spatial Frequency, LSF vs. HSF) of a predicted Gabor stimulus that they then categorized. Using each participant’s concurrently measured MEG, we reconstructed networks that predict and categorize LSF vs. HSF contents for behavior. We found that predicted contents flexibly propagate top-down from temporal to lateralized occipital cortex, depending on task demands, under supervisory control of prefrontal cortex. When they reach lateralized occipital cortex, predictions enhance the bottom-up LSF vs. HSF representations of the stimulus, all the way from occipital-ventral-parietal to pre-motor cortex, in turn producing faster categorization behavior. Importantly, content communications are subsets (i.e. 55-75%) of the signal-to-signal communications typically measured between brain regions. Hence, our study isolates functional networks that process the information of cognitive functions
Coherent Dynamics of Charge Carriers in {\gamma}-InSe Revealed by Ultrafast Spectroscopy
For highly efficient ultrathin solar cells, layered indium selenide (InSe), a
van der Waals solid, has shown a great promise. In this paper, we study the
coherent dynamics of charge carriers generation in {\gamma}-InSe single
crystals. We employ ultrafast transient absorption spectroscopy to examine the
dynamics of hot electrons after resonant photoexcitation. To study the effect
of excess kinetic energy of electrons after creating A exciton (VB1 to CB
transition), we excite the sample with broadband pulses centered at 600, 650,
700 and 750 nm, respectively. We analyze the relaxation and recombination
dynamics in {\gamma}-InSe by global fitting approach. Five decay associated
spectra with their associated lifetimes are obtained, which have been assigned
to intraband vibrational relaxation and interband recombination processes. We
extract characteristic carrier thermalization times from 1 to 10 ps. To examine
the coherent vibrations accompanying intraband relaxation dynamics, we analyze
the kinetics by fitting to exponential functions and the obtained residuals are
further processed for vibrational analysis. A few key phonon coherences are
resolved and ab-initio quantum calculations reveal the nature of the associated
phonons. The wavelet analysis is employed to study the time evolution of the
observed coherences, which show that the low-frequency coherences last for more
than 5 ps. Associated calculations reveal that the contribution of the
intralayer phonon modes is the key determining factor for the scattering
between free electrons and lattice. Our results provide fundamental insights
into the photophysics in InSe and help to unravel their potential for
high-performance optoelectronic devices
Reading skill modulates the effect of parafoveal distractors on foveal lexical decision in deaf students
In low-level perceptual tasks and reading tasks, deaf individuals show a redistribution of spatial visual attention toward the parafoveal and peripheral visual fields. In the present study, the experiment adopted the modified flanker paradigm and utilized a lexical decision task to investigate how these unique visual skills may influence foveal lexical access in deaf individuals. It was predicted that irrelevant linguistic stimuli presented in parafoveal vision, during a lexical decision task, would produce a larger interference effect for deaf college student readers if the stimuli acted as distractors during the task. The results showed there was a larger interference effect in deaf college student readers compared to the interference effect observed in participants with typical levels of hearing. Furthermore, deaf college student readers with low-skilled reading levels showed a larger interference effect than those with high-skilled reading levels. The current study demonstrates that the redistribution of spatial visual attention toward the parafoveal visual regions in deaf students impacts foveal lexical processing, and this effect is modulated by reading skill. The findings are discussed in relation to the potential effect that enhanced parafoveal attention may have on everyday reading for deaf individuals
Relationship between serum iPTH and peritonitis episodes in patients undergoing continuous ambulatory peritoneal dialysis
BackgroundPeritonitis is considered as one of the most serious complications that cause hospitalization in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). There is limited evidence on the impact of the parathyroid hormone (PTH) on the first peritoneal dialysis (PD)-associated peritonitis episode. We aimed to investigate the influence of serum intact parathyroid hormone (iPTH) on peritonitis in patients undergoing PD.MethodsThis was a retrospective cohort study. Patients undergoing initial CAPD from a single center in China were enrolled. The baseline characteristics and clinical information were recorded. The primary outcome of interest was the occurrence of the first PD-associated peritonitis episode. Five Cox proportional hazard models were constructed in each group set. In group set 1, all participants were divided into three subgroups by tertiles of the serum concentration of iPTH; in group set 2, all participants were divided into three subgroups based on the serum concentration of iPTH with 150 pg/ml interval (<150, 150–300, and >300 pg/ml). Hazard ratios and 95% confidence intervals (CIs) were calculated for each model. The multivariate linear regression analysis elimination procedure assessed the association between the clinical characteristics at baseline and the iPTH levels. Restricted cubic spline models were constructed, and stratified analyses were also conducted.ResultsA total of 582 patients undergoing initial PD (40% women; mean age, 45.1 ± 11.5 years) from a single center in China were recruited. The median follow-up duration was 25.3 months. Multivariate Cox regression analysis showed that, in the fully adjusted model, a higher serum iPTH level (tertile 3, iPTH >300 pg/ml) was significantly associated with a higher risk of PD-associated peritonitis at 3 years [tertile 3: hazard ratio (HR) = 1.53, 95%CI = 1.03–2.55, p = 0.03; iPTH > 300 pg/ml: HR = 1.57, 95%CI = 1.08–2.27, p = 0.02]. The hazard ratio for every 100 pg/ml increase in serum iPTH level was 1.12 (95%CI = 1.05–1.20, p < 0.01) in the total cohort when treating iPTH as a continuous variable.ConclusionsAn elevated iPTH level was significantly associated with an increased risk of peritonitis in patients undergoing CAPD
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