197 research outputs found
China's automotive industry development from the perspective of industrial clusters
Masteroppgave i bedriftsøkonomi - Universitetet i Nordland, 201
Sampling Deviation Real-time Calibration Method for Wideband Simulator
Hardware-in-the-loop simulation is an efficient method for research on radar system.Target’s echo which offered by the simulator should be synchronized with radar on frequency, time, and range bin. However, because simulator needs to take into account of the requirements of various types of radar, it is difficult to make the clock of simulator synchronized with the clock of radar. To solve the problem, synchronous sampling deviation model is established. Influence of sampling deviation on imaging is analyzed. An engineering method is put forward to eliminate the sampling deviation. This method not only provides a reference for simulation system, but also provides a reference for the design of radar system
Double-Flow-based Steganography without Embedding for Image-to-Image Hiding
As an emerging concept, steganography without embedding (SWE) hides a secret
message without directly embedding it into a cover. Thus, SWE has the unique
advantage of being immune to typical steganalysis methods and can better
protect the secret message from being exposed. However, existing SWE methods
are generally criticized for their poor payload capacity and low fidelity of
recovered secret messages. In this paper, we propose a novel
steganography-without-embedding technique, named DF-SWE, which addresses the
aforementioned drawbacks and produces diverse and natural stego images.
Specifically, DF-SWE employs a reversible circulation of double flow to build a
reversible bijective transformation between the secret image and the generated
stego image. Hence, it provides a way to directly generate stego images from
secret images without a cover image. Besides leveraging the invertible
property, DF-SWE can invert a secret image from a generated stego image in a
nearly lossless manner and increases the fidelity of extracted secret images.
To the best of our knowledge, DF-SWE is the first SWE method that can hide
large images and multiple images into one image with the same size,
significantly enhancing the payload capacity. According to the experimental
results, the payload capacity of DF-SWE achieves 24-72 BPP is 8000-16000 times
compared to its competitors while producing diverse images to minimize the
exposure risk. Importantly, DF-SWE can be applied in the steganography of
secret images in various domains without requiring training data from the
corresponding domains. This domain-agnostic property suggests that DF-SWE can
1) be applied to hiding private data and 2) be deployed in resource-limited
systems
Novel Multiferroic‐Like Nanocomposite with High Pressure‐Modulated Magnetic and Electric Properties
Individual Differences in the Neural Basis of Response Inhibition After Sleep Deprivation Are Mediated by Chronotype
Sleep deprivation (SD) has been reported to severely affect executive function, and interindividual differences in these effects may contribute to the SD-associated cognition impairment. However, it is unclear how individual differences in chronotypes (morning-type, MT; evening-type, ET) influence neurobehavioral functions after SD. To address this question, we used functional magnetic resonance imaging (fMRI) to evaluate whether 24 h of SD differentially affect response inhibition, a core component of executive function, in MT and ET individuals. Accordingly, MT and ET participants were instructed to follow their preferred 7–9-h sleep schedule for 2 weeks at home both prior to and throughout the course of the study, and then performed a go/no-go task during fMRI scanning at 08:00 a.m. both at rested wakefulness (RW) and following SD. We also examined whether the neurobehavioral inhibition differences in the chronotypes in each session can be predicted by subjective ratings (sleepiness, mood, and task) or objective attention. Behaviorally, SD led to an increased response time of go trials (hit RT), more attentional lapses, higher subjective sleepiness, and worse mood indices, but it did not impair the accuracy of go trials (hit rate) and no-go trials (stop rate). Regardless of the presence of SD, ET individuals exhibited a lower stop rate, higher subjective ratings of sleepiness, exhausted mood, and task difficulty in comparison with MT individuals. On the neural level, SD resulted in decreased inhibition-related activation of the right lateral inferior frontal gyrus (rIFG) in MT individuals and increased rIFG activation in ET individuals. Moreover, the rIFG activation in ET individuals after SD was positively correlated to the subjective ratings of sleepiness and effort put into the task, which was considered as a compensatory response to the adverse effects of SD. These findings suggest that individual differences in inhibition-related cerebral activation after SD are influenced by chronotypes. In addition, ET individuals may be vulnerable to response inhibition. Thus, it is essential to take into consideration the chronotype in SD research and sleep medicine
- …