302 research outputs found
Stochastic equations with low regularity drifts
By using the It\^{o}-Tanaka trick, we prove the unique strong solvability as
well as the gradient estimates for stochastic differential equations with
irregular drifts in low regularity Lebesgue-H\"{o}lder space with and ).
As applications, we show the unique weak and strong solvability for stochastic
transport equations driven by the low regularity drift with ) as well as the local Lipschitz estimate for stochastic strong
solutions
Optimization for heat and sound insulation of honeycomb sandwich panel in thermal environments
An optimization based on sequential quadratic programming (SQP) algorithm to increase the thermal insulation and sound transmission loss of honeycomb panel in thermal environments is presented. First, heat transfer analysis is performed to reveal the steady-state thermal performance of hexagonal aluminum honeycomb sandwich panel, by using the semi-empirical Swann and Pittman formula. Next, the influences of temperature on acoustic performance of honeycomb panel based on statistical energy analysis method (SEA) is performed. Results show that increasing the thickness of the honeycomb core can improve the acoustic performance and heat insulation behavior
Probability hypothesis density filter with adaptive parameter estimation for tracking multiple maneuvering targets
AbstractThe probability hypothesis density (PHD) filter has been recognized as a promising technique for tracking an unknown number of targets. The performance of the PHD filter, however, is sensitive to the available knowledge on model parameters such as the measurement noise variance and those associated with the changes in the maneuvering target trajectories. If these parameters are unknown in advance, the tracking performance may degrade greatly. To address this aspect, this paper proposes to incorporate the adaptive parameter estimation (APE) method in the PHD filter so that the model parameters, which may be static and/or time-varying, can be estimated jointly with target states. The resulting APE-PHD algorithm is implemented using the particle filter (PF), which leads to the PF-APE-PHD filter. Simulations show that the newly proposed algorithm can correctly identify the unknown measurement noise variances, and it is capable of tracking multiple maneuvering targets with abrupt changing parameters in a more robust manner, compared to the multi-model approaches
CircularRNA_0119872 regulates the microRNA-582- 3p/E2F transcription factor 3 pathway to promote the progression of malignant melanoma
OBJECTIVES: Malignant melanoma (MM) is an invasive tumor that poses a threat to patient health. Circular RNAs (circRNAs) are important regulators of MM carcinogenesis. In this study, we investigated the expression characteristics and biological functions of, and mechanism underlying, circ_0119872 expression in MM. METHODS: Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was employed to examine the circ_0119872, microRNA (miR)-582-3p, and E2F transcription factor 3 (E2F3) mRNA expression levels in MM tissues and cell lines. Western blotting was performed to quantify E2F3 protein expression. MM cells with circ_0119872 knockdown were established, and cell counting kit 8 (CCK-8) and transwell assays were utilized to examine the function of circ_0119872 and its effects on the malignant characteristics of MM cells. The MiRDB and TargetScan databases were used to predict the target genes of miR-582-3p. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was used to explore the biological functions of the target genes of miR582-3p. Additionally, a dual-luciferase reporter gene experiment was performed to verify the targeting relationship between circ_0119872 and miR-582-3p as well as that between miR-582-3p and E2F3. RESULTS: Circ_0119872 was remarkably upregulated in MM tissues and cell lines. Circ_0119872 knockdown suppressed the cell proliferation and metastasis In addition, miR-582-3p was identified as a downstream target of circ_0119872. The target genes of miR-193a-3p are involved in melanogenesis and cancer-related signaling pathways. Mechanistically, circ_0119872 facilitated MM progression by adsorbing miR-582-3p and upregulating E2F3 expression. CONCLUSION: Circ_0119872 is an oncogenic circRNA that participates in the promotion of MM progression by regulating the miR-582-3p/E2F3 axis
Bioactivating a bone substitute accelerates graft incorporation in a murine model of vertical ridge augmentation
OBJECTIVE: Compared to autologous bone grafts, allogeneic bone grafts integrate slowly, which can adversely affect clinical outcomes. Here, our goal was to understand the molecular mechanisms underlying graft incorporation, and then test clinically feasible methods to accelerate this process.
METHODS: Wild-type and transgenic Wnt reporter mice were used in a vertical ridge augmentation procedure. The surgery consisted of tunneling procedure to elevate the maxillary edentulous ridge periosteum, followed by the insertion of bone graft. Micro-computed tomographic imaging, and molecular/cellular analyses were used to follow the bone graft over time. Sclerostin null mice, and mice carrying an activated form of β-catenin were evaluated to understand how elevated Wnt signaling impacted edentulous ridge height and based on these data, a biomimetic strategy was employed to combine bone graft particles with a formulation of recombinant WNT protein. Thereafter, the rate of graft incorporation was evaluated.
RESULTS: Tunneling activated osteoprogenitor cell proliferation from the periosteum. If graft particles were present, then osteoprogenitor cells attached to the matrix and gave rise to new bone that augmented edentulous ridge height. Graft particles alone did not stimulate osteoprogenitor cell proliferation. Based on the thicker edentulous ridges in mice with amplified Wnt signaling, a strategy was undertaken to load bone graft particles with WNT; this combination was sufficient to accelerate the initial step of graft incorporation.
SIGNIFICANCE: Local delivery of a WNT protein therapeutic has the potential to accelerate graft incorporation, and thus shorten the time to when the graft can support a dental implant
PKU-I2IQA: An Image-to-Image Quality Assessment Database for AI Generated Images
As image generation technology advances, AI-based image generation has been
applied in various fields and Artificial Intelligence Generated Content (AIGC)
has garnered widespread attention. However, the development of AI-based image
generative models also brings new problems and challenges. A significant
challenge is that AI-generated images (AIGI) may exhibit unique distortions
compared to natural images, and not all generated images meet the requirements
of the real world. Therefore, it is of great significance to evaluate AIGIs
more comprehensively. Although previous work has established several human
perception-based AIGC image quality assessment (AIGCIQA) databases for
text-generated images, the AI image generation technology includes scenarios
like text-to-image and image-to-image, and assessing only the images generated
by text-to-image models is insufficient. To address this issue, we establish a
human perception-based image-to-image AIGCIQA database, named PKU-I2IQA. We
conduct a well-organized subjective experiment to collect quality labels for
AIGIs and then conduct a comprehensive analysis of the PKU-I2IQA database.
Furthermore, we have proposed two benchmark models: NR-AIGCIQA based on the
no-reference image quality assessment method and FR-AIGCIQA based on the
full-reference image quality assessment method. Finally, leveraging this
database, we conduct benchmark experiments and compare the performance of the
proposed benchmark models. The PKU-I2IQA database and benchmarks will be
released to facilitate future research on
\url{https://github.com/jiquan123/I2IQA}.Comment: 18 page
Measurement report: The promotion of low-level jet and thermal-effect on development of deep convective boundary layer at the southern edge of the Taklimakan Desert
A vigorous development process of the deep convective boundary layer (CBL) was observed at the southern edge of the Taklimakan Desert on 6 June, 2022. Based on coherent Doppler wind lidar and ERA5 data, the formation mechanism of the deep CBL exceeding 5 km was well analyzed, which was mainly promoted by the low-level jet (LLJ) and thermal-effect. The LLJ has made sufficient momentum, energy and material preparations for the development of the deep CBL. Firstly, the cold downhill airflow of the Tibet Plateau leading to LLJ weakens the height and intensity of the temperature inversion layer, which reduces the energy demand for the broken of the IL. Secondly, the LLJ not only supplements the material and energy in the residual layer, but also suppresses the exchange with the lower atmosphere. In addition, the LLJ provides a driving force for the development of the deep CBL. In terms of thermal factors, the Tibet Plateau sensible heat driven air-pump and cold front transit provide additional impetus for the development of the deep CBL. Finally, the formation of deep CBL was catalyzed by the extreme thermal effects of the underlying surface, such as the furnace effect and the atmospheric superadiabatic expansion process. The study of the development of the deep CBL is important for revealing the land-air exchange process of momentum, energy, and material between the Taklimakan Desert and the Tibetan Plateau
Icosahedral B\u3csub\u3e12\u3c/sub\u3e-containing core–shell structures of B\u3csub\u3e80\u3c/sub\u3e
Low-lying icosahedral (Ih) B12-containing structures of B80 are explored, and a number of core–shell isomers are found to have lower energy than the previous predicted B80 fullerene. The structural transformation of boron clusters from tubular structure to core–shell structure may occur at a critical size less than B80
- …