Cybersecurity disclosure effectiveness on public companies

On October 13, 2011, the U.S. Securities and Exchange Commission issued a guidance on corporate disclosure of cyber-risks and information security breaches (SEC, 2011). To determine if a company disclosed information on the breach, I reviewed the company’s risk factors, management’s discussion and analysis of financial conditions and results of operations, description of the business, legal proceedings, financial statement disclosures, and disclosure controls and procedures. However, the disclosure regulations from this guidance are vague and thus do little to force disclosure of valuable information. The guidance has led to companies disclosing ambiguous, generic risk factors that can be applied to any business in any industry (Ferraro, 2014)

Investigating Lipid and Secondary Metabolisms in Plants by Next-generation Sequencing

Ph.DDOCTOR OF PHILOSOPH

Investigation of the Permeability of Soil-rock Mixtures Using Lattice Boltzmann Simulations

Based on the discrete element method and the proposed virtual slicing technique for three-dimensional discrete element model, random pore-structural models of soil-rock mixtures are constructed and voxelized. Then, the three-dimensional lattice Boltzmann method is introduced to simulate the seepage flow in soil-rock mixtures on the pore scale. Finally, the influences of rock content, rock size, rock shape and rock orientation on the simulated permeability of soil-rock mixtures are comprehensively investigated. The results show that the permeability of soil-rock mixtures remarkably decreases with the increase of rock content. When the other conditions remain unchanged, the permeability of soil-rock mixtures increases with the increase of rock size. The permeability of soil-rock mixtures with bar-shaped rocks is smaller than that of soil-rock mixtures with block-shaped rocks, but larger than that of soil-rock mixtures with slab-shaped rocks. The rock orientation has a certain influence on the permeability of SRMs, and the amount of variation changes with the rock shape: when the rocks are bar-shaped, the permeability is slightly decreased as the major axes of these rocks change from parallel to perpendicular with respect to the direction of main flow; when the rocks are slab-shaped, the permeability decreases more significantly as the slab planes of these rocks change from parallel to perpendicular with respect to the direction of main flow

K-means Clustering Based Feature Consistency Alignment for Label-free Model Evaluation

The label-free model evaluation aims to predict the model performance on various test sets without relying on ground truths. The main challenge of this task is the absence of labels in the test data, unlike in classical supervised model evaluation. This paper presents our solutions for the 1st DataCV Challenge of the Visual Dataset Understanding workshop at CVPR 2023. Firstly, we propose a novel method called K-means Clustering Based Feature Consistency Alignment (KCFCA), which is tailored to handle the distribution shifts of various datasets. KCFCA utilizes the K-means algorithm to cluster labeled training sets and unlabeled test sets, and then aligns the cluster centers with feature consistency. Secondly, we develop a dynamic regression model to capture the relationship between the shifts in distribution and model accuracy. Thirdly, we design an algorithm to discover the outlier model factors, eliminate the outlier models, and combine the strengths of multiple autoeval models. On the DataCV Challenge leaderboard, our approach secured 2nd place with an RMSE of 6.8526. Our method significantly improved over the best baseline method by 36\% (6.8526 vs. 10.7378). Furthermore, our method achieves a relatively more robust and optimal single model performance on the validation dataset.Comment: Accepted by CVPR 2023 worksho

Transforming growth factor-β1 treatment of oral cancer induces epithelial-mesenchymal transition and promotes bone invasion via enhanced activity of osteoclasts

This study investigates relationships between EMT and bone invasion by OSCC. Three OSCC cell lines, SCC25, HN5, and Tca8113 were artificially induced to display EMT by adding 5 ng/mL of TGF-β1 to culture media for 1–3 days. Cell morphology and phenotypic changes was examined by immunocytochemical staining of CK and VIM. EMT markers, cell-invasion factors, and osteoclast-related molecules were analysed at mRNA, gelatine and protein levels by real-time PCR, gelatine zymography and Western blotting respectively. Mature osteoclasts differentiated from Raw264.7 cells were treated by conditioned medium (CM) of OSCC cells with/without TGF-β1. Immunohistochemistry was performed to validate proteins of CK, VIM, E-cad and Snail1 in OSCC tissue samples with bone invasion. Results showed minimal staining of VIM was found in SCC25 and HN5, while Tca8113 cells stained strongly. EMT markers Twist1 and N-cad were up-regulated; Snail1 and E-cad down-regulated in all cells. Of factors associated with invasion, MMP-2 was unchanged and MMP-9 increased in SCC25 and Tca8113, while MMP-2 was increased and MMP-9 unchanged in HN5. For osteoclast-related molecules, both MT1-MMP and RANKL were up-regulated, while OPG was down-regulated in all cells. CM of OSCC cells pre-treated with TGF-β1 showed to prolong survival of osteoclasts up to 4 days. All target molecules were validated in OSCC samples of bone invasion. These findings suggest that TGF-β1 not only induces EMT to increase the capacity of OSCC for invasion, but also promotes factors which prolong osteoclast survival. TGF-β1 may enhance the ability of MMP2/9 in resorbing bone and favouring invasion of cancer cells

Design and analytically full-wave validation of the invisibility cloaks, concentrators, and field rotators created with a general class of transformations

We investigate a general class of electromagnetic devices created with any continuous transformation functions by rigorously calculating the analytical expressions of the electromagnetic field in the whole space. Some interesting phenomena associated with these transformation devices, including the invisibility cloaks, concentrators, and field rotators, are discussed. By carefully choosing the transformation function, we can realize cloaks which are insensitive to perturbations at both the inner and outer boundaries. Furthermore, we find that when the coating layer of the concentrator is realized with left-handed materials, energy will circulate between the coating and the core, and the energy transmits through the core of the concentrator can be much bigger than that transmits through the concentrator. Therefore, such concentrator is also a power flux amplifier. Finally, we propose a spherical field rotator, which functions as not only a wave vector rotator, but also a polarization rotator, depending on the orientations of the spherical rotator with respect to the incident wave direction. The functionality of these novel transformation devices are all successfully confirmed by our analytical full wave method, which also provides an alternate computational efficient validation method in contrast to numerical validation methods.Comment: 22 pages, 3 figure

Numerical modelling of radiative heat transfer in a polydispersion of ceramic particles under direct high-flux solar irradiation

The effects of polydispersity on radiative and interfacial convective heat transfer are investigated in particle–gas two-phase media for solar particle receiver applications. Non-grey radiative transfer is analysed using the collision-based Monte Carlo ray-tracing method. The Mie theory is employed to calculate radiative properties of particles. The finite volume method and the explicit Euler time integration scheme are used to solve the transient energy equations for the particle and gas phases. Three alternative approaches to modelling particle properties and thermal conditions are employed: (i) a novel discrete size model, in which particle groups within discrete size intervals are assigned individual properties and temperatures locally; (ii) a lumped size model, in which integral properties and a single temperature are assigned to the particle phase locally; and (iii) a monodisperse size model, in which properties are evaluated for the Sauter mean diameter of the polydispersion and a single temperature is assigned to the particle phase locally. Strongly size-dependent radiation absorption and interfacial convective heat transfer are predicted with the discrete size model for alumina particles. Particles smaller than 27.4μm located near the aperture absorb the solar irradiation and transfer heat to the gas phase most effectively. The angular spread of the incident solar radiation is found to have a negligible effect on the overall absorption, although the most uniform thermal conditions occur for the solar irradiation with the smallest confinement angle. The overall absorptance of alumina particles is higher by 3.4% and 2.7% than that of iron (III) oxide and mullite particles, respectively. The lumped and monodisperse size models allow for reduction of the computational time at the expense of lower accuracy and limited information about particle properties and thermal conditions. © 2021 The Author(s

Controlling the Emission of Electromagnetic Sources by Coordinate transformation

The coordinate transformation on the space that contains electromagnetic sources is studied. We find that, not only the permittivity and permeability tensors of the media, but also the sources inside the media will take another form in order to behave equivalently as the original case. It is demonstrated that, a source of arbitrary shape and position in the free space can be replaced by an appropriately designed metamaterial coating with current distributed on the inner surface and would not be detected by outer observers, because the emission of the source can be controlled at will in this way. As examples, we show how to design conformal antennas by covering the sources with transformation media. The method proposed in this letter provides a completely new approach to develop novel active EM devices

Change‐Point Detection on Solar Panel Performance Using Thresholded LASSO

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135028/1/qre2077.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135028/2/qre2077_am.pd