783 research outputs found

    Study on an integrated system of rapid prototyping and manufacturing for 3D Digitizer to CNC Mill : a thesis presented in partial fulfilment of the requirements for the degree of Master in Technology at Massey University, Palmerston North, New Zealand

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    The main purpose of this project is to develop a low cost, effective, user friendly interface software for staff and students to integrate the designing and manufacturing facilities in the Institute of Technology and Engineering (ITE) at Massey University, Palmerston North, New Zealand. The project involves establishment of an integrated CAD/CAM/CAE system, the identification of software requirements, selection of software development tool kit, definition of hardware configuration, software development and final experiments and tests. ITE has a laboratory, where are equipped with one CNC milling machine, one CNC lathe, one Injection Moulding machine, one desktop 3D scanner and one 3D plotter. In addition, all the CAD/CAM/CAE software have been installed on the PCs. Based on the analysis and utilisation of these existing facilities, it is found that they are not smoothly integrated; no linkage between the CAD/CAM/CAE system and desktop Rapid Prototyping facilities; file formats used by each of the system are not compatible. Through this project, the investigation of the possibility to integrate the system and the feasibility to develop a software to bridge the 3D scanner and the CNC mill, was carried out. A first try was successfully made using Borland C++5.0 to convert the 3D scanned data into NC program. Then, using Borland C++ Builder 5.0 created a user-friendly interface for conversion of 3D Digitizer to CNC Mill. Next, the different scales of wax models were satisfactorily processed on the CNC milling machine by inputting the converted NC program

    Hormonal Regulation of Cholesterol Homeostasis

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    Cholesterol homeostasis is tightly regulated by a group of endocrine hormones under physiological conditions. Hormonal dysregulation is often associated with disturbed cholesterol homeostasis, resulting in many clinical disorders including atherosclerosis, fatty liver and metabolic syndrome. Circulating hormones regulate cholesterol metabolism by altering levels of relative genes either through their interactions with nuclear receptors or by interfering with bile acid signaling pathways. A better understanding of hormonal regulation of cholesterol metabolism would improve our likelihood of identifying effective and selective targets for the intervention of disturbed cholesterol. In this review, we discuss selected hormones critical for the cholesterol balance, including thyroid hormone, sex hormones, growth hormone, glucagon and irisin. We focus our discussion on the most recent advance in clinical epidemiology, animal mechanistic studies and the clinical application

    A BP Neural Network Model to Predict Reservior Parameters

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    This paper proposes an artificial neural network (ANN) method to calculate reservoir parameters. By improving the algorithm of BP neural network, convergence speed is enhanced and better result can be achieved. Practical applications prove that neural network technique is of significant importance for reservoir description

    IMPRESS: Evaluating the Resilience of Imperceptible Perturbations Against Unauthorized Data Usage in Diffusion-Based Generative AI

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    Diffusion-based image generation models, such as Stable Diffusion or DALL-E 2, are able to learn from given images and generate high-quality samples following the guidance from prompts. For instance, they can be used to create artistic images that mimic the style of an artist based on his/her original artworks or to maliciously edit the original images for fake content. However, such ability also brings serious ethical issues without proper authorization from the owner of the original images. In response, several attempts have been made to protect the original images from such unauthorized data usage by adding imperceptible perturbations, which are designed to mislead the diffusion model and make it unable to properly generate new samples. In this work, we introduce a perturbation purification platform, named IMPRESS, to evaluate the effectiveness of imperceptible perturbations as a protective measure. IMPRESS is based on the key observation that imperceptible perturbations could lead to a perceptible inconsistency between the original image and the diffusion-reconstructed image, which can be used to devise a new optimization strategy for purifying the image, which may weaken the protection of the original image from unauthorized data usage (e.g., style mimicking, malicious editing). The proposed IMPRESS platform offers a comprehensive evaluation of several contemporary protection methods, and can be used as an evaluation platform for future protection methods.Comment: 21 pages, 11 figures, 9 tables. Accepted by NeurIPS 202

    Combinatorial administration of insulin and vitamin C alleviates the cerebral vasospasm after experimental subarachnoid hemorrhage in rabbit

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    <p>Abstract</p> <p>Background</p> <p>Cerebral vasospasm (CVS) is a common serious complication after the spontaneous subarachnoid hemorrhage (SAH). Despite recent advances in medical and surgical treatments, the 30-day mortality rate of SAH remains high, and there is lack of especially effective clinical treatment to alleviate and improve CVS. The present study has investigated the therapeutic effect of insulin and vitamin C on CVS after SAH.</p> <p>Results</p> <p>Five days after SAH, there is obvious basilar artery spasm in SAH group, whose average vascular cross-sectional area (233,099 ± 16,750 μm<sup>2</sup>) is significantly smaller than that in control group (462,128 ± 74,756 μm<sup>2</sup>), which is also significantly different from those in SAH + insulin group (221,114 ± 43,457 μm<sup>2</sup>) and SAH + vitamin C group (237,820 ± 21,703 μm<sup>2</sup>). SAH + insulin + vitamin C group shows no evident vasospasm and maintains a vascular cross-sectional area of 425,530 ± 45,503 μm<sup>2</sup>, which is significantly different from that in SAH group. Insulin receptor α (InRα) expression is significantly downregulated in the vascular endothelial cells of SAH, SAH + insulin, and SAH + vitamin C groups (<it>P </it>< 0.01) but remains unchanged in vascular endothelial cells of SAH + insulin + vitamin C group (<it>P </it>> 0.05). Five days after SAH, serum and cerebrospinal fluid NO levels in SAH, SAH + insulin, and SAH + vitamin C groups decrease significantly (<it>P </it>< 0.01) compared to that in control group, whereas the reduction is not evident in SAH + insulin + vitamin C group (<it>P </it>> 0.05).</p> <p>Conclusion</p> <p>Combinatorial treatment with insulin and vitamin C has effectively relieved the CVS after SAH in rabbit, possibly through increasing the InRα expression and NO level, whereas treatment with insulin or vitamin C alone fails to do so.</p
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