Coarsening to Chaos-Stabilized Fronts

We investigate a model for pattern formation in the presence of Galilean symmetry proposed by Matthews and Cox [Phys.\ Rev.\ E \textbf{62}, R1473 (2000)], which has the form of coupled generalized Burgers and Ginzburg-Landau-type equations. With only the system size $L$ as a parameter, we find distinct "small-$L$" and "large-$L$" regimes exhibiting clear differences in their dynamics and scaling behavior. The long-time statistically stationary state contains a single $L$-dependent front, stabilized globally by spatiotemporally chaotic dynamics localized away from the front. For sufficiently large domains, the transient dynamics include a state consisting of several viscous shock-like structures which coarsens gradually, before collapsing to a single front when one front absorbs the others.Comment: 4 pages, 7 figures; submitte

The role of histidine-rich glycoprotein in necrotic cell clearance and regulation of degradative enzymes

Histidine-rich glycoprotein (HRG) is an abundant multi-functional protein that is present in the plasma of many vertebrates. HRG has a multi-domain structure that allows the molecule to interact with many ligands including heparin, heparan sulfate (HS), Fcy receptors (FcyR), plasminogen, fibrinogen, IgG, Clq, haem and Zn2+. The ability of HRG to interact with various ligands simultaneously has suggested that HRG can act as an adaptor molecule and regulate numerous biological processes such as immune complex/necrotic cell/pathogen clearance, cell adhesion, angiogenesis, coagulation and fibrinolysis. Although HRG is thought to play an important role in both immunity and vascular biology, the molecular mechanisms underpinning its action remain largely undefined. Thus, the aim of this thesis was to characterize the molecular components that are involved in HRG-mediated uptake of necrotic cells and to further examine the role of HRG in regulating degradative enzymes, such as plasminogen/plasmin and heparanase...In summary, the studies presented in this thesis have delineated the molecular mechanisms underlying necrotic cell removal mediated by plasma-derived HRG and may have important implications for the development of autoimmune disease caused by defective clearance of dying/dead cells. In addition, the ability of HRG to regulate degradative enzymes, such as plasmin and heparanase, further supports the view that HRG may play an important role in angiogenesis, leukocyte migration and cancer metastasis.The Australian Government, John Curtin School of Medical Research, Australian National University, National Health and Medical Research Council, Australasian Society for Immunology, Australian Society for Medical Research, Federation of Immunological Societies of Asia-Oceania and Riken Research Center for Allergy and Immunology

Modelling and control of variability in PCB copper electroplating

This thesis is concerned with the modelling and control of the acid copper electroplating process for the manufacturing of printed circuit boards (PCB). The objectives of this study were to investigate the effects of process and product parameters on the workpiece level uniformity during the acid copper plating of lithographic patterns, plated-through holes (PTH) and blind-via (BV), and to explore the minimization of the deposit thickness variation. The parameters studied were the average current density (ACD), plating duration, concentration of additive and sulphuric acid, electrode separation (ES), line width and active area density ratio (AADR) of the circuit pattern. The effects of the copper sulphate concentration, aspect ratio (CAR) and depth ratio were also studied for the PTH and BV plating. The results of the study enhance the understanding of the limitations of applying current distribution and statistical models to the copper electroplating of PCB at a workpiece level. Multifactor two-level factorial and the central composite rotatable five-level experiments were designed, and a total of fourteen sets of experiment were conducted sequentially and used to generate statistical process models. For the plating of uniform patterns, ACD, ES and their quadratic effects were found to be significant and a 6- term second order model was built and verified to predict and minimize the workpiece level variability. The existence of a minimum plating variability was attributed to the minimum deviation from the Faraday's nominal thickness observed under a particular combination of ACD and ES. For non-uniform patterns, ACD, AADR and the ACD x ES interaction were found significant and an 8-term first-order prediction model was constructed. The minimum variability achievable was found to increase with the AADR, and was explained by the scattering effect of AADR on the average plating thickness. Verification of the model with patterns of same AADR but different line width revealed the limitation of the continuum concept, i. e. AADR alone is not sufficient to characterize a non-uniformly patterned substrate. Subsequent verification runs using a simple circuit pattern showed further that a composite parameter involving the overall active area density, the continuum area and the number of AAD contrasts, was appropriate. For the PTH plating, ACD, CAR, ACD2 and the ACD x ES, ES x CAR interactions were found significant but only ES, ES2 and ACD x ES were active for BV plating. Second-order models were also developed for the two processes in their respective optimum regions and verified experimentally. The optimum values of ACD and ES, and the minimum variability achievable were found to increase with the corrected aspect ratio of the through-hole. Given the difference in the optimum regions of the PTH and BV plating, a new response surface of the PTH process was constructed at the optimum region of the BV process and vice versa. The process limiting the workpiece level uniformity under different combinations of ACD and ES was found by the intersections of these responses surfaces. Finally, process parameters limiting the simultaneous minimization of the plating variability of pattern, PTH and BV were discussed. It showed that under most situations, the workpiece level variability of BVs was higher than that of the PTHs

An empirical study of the determinants of serviced apartment rent in Hong Kong

Thesis (B.Sc)--University of Hong Kong, 2005.published_or_final_versio

Evaluation of deformed image-based dose calculations for adaptive radiotherapy of nasopharyngeal carcinoma

The ultimate goal of adaptive radiotherapy (ART) is to deliver truly customized radiation treatments. Currently, the quality of cone-beam computed tomography (CBCT) images is still inferior to that of conventional CT images in contour delineations and dose calculations for replanning purposes. This retrospective study aims to evaluate the dosimetric accuracy of using deformed conventional CT images for dose calculations, in the hope of inferring the feasibility of ART using planning CT (PCT) images that deformed to up-to-date CBCT images for patients with nasopharyngeal carcinoma (NPC). Thirty consecutive patients with NPC who had undergone 1 replan in their radiotherapy treatments were selected. The pretreatment PCT images were deformed to match the mid-treatment PCT images by deformable image registration. The same volumetric modulated arc therapy plan was then calculated on the deformed PCT images. The resulting dose distributions and dose volume histograms of the tumors and organs at risk (OARs) were compared with the original plan. Five dose levels, D98%, D95%, D50%, D5%, and D2%, were recorded for 9 NPC targets. Four dose levels, Dmax, D10%, D50%, and Dmean, were recorded for 15 OARs. The greatest percentage difference in observed dose for D98%, D95%, D50%, D5%, and D2% of the targets were 1.71%, 1.55%, 0.64%, 0.97%, and 1.13%, respectively. The greatest percentage difference in observed dose for Dmax, D10%, D50%, and Dmean of the OARs were -26.51% (left optic nerve), -17.06% (left optic nerve), 56.70% (spinal cord), and 18.97% (spinal cord), respectively. In addition, 29 of 45 (64%) dosimetric end points of the targets showed statistically significant dose differences (p < 0.05) between the original plan and the plan calculated on deformed images. Forty-nine of 60 (82%) dosimetric end points of the OARs also showed statistically significant dose differences (p < 0.05). Dose calculations using deformed PCT images could result in significant dose uncertainties in target volumes and OARs. Larger dose deviations were found in OARs in comparison with target volumes. The spinal cord and optic nerve showed the greatest percentage dose differences and the clinical significance has yet to be determined. Deformable registration error was believed to be the problem causing the dose deviations. Owing to unknown clinical significanceof dose deviation results obtained from this study, a conventional CT scan is still required for replanning in patients with NPC who are experiencing significant anatomical changes during the course of radiation treatment. [Abstract copyright: Copyright © 2017 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Overview of Radiosurgery for Intracranial Meningiomas

Meningiomas are the second common Central Nervous System (CNS) neoplasm, and are the most common benign intracranial tumor. They approximately constitute up to 30% of all intracranial tumors. They arise from the arachnoidal coverings of brain. Presentation varies and depends on size, number and location of tumors. Symptoms include those related to increased in intracranial pressure, local irritative features including seizure and local pressure effect to eloquent areas, white matter tracts and cranial nerves. Management of meningiomsa is always challenging and multi-disciplinary approaches includes surgery, radiotherapy and possible chemotherapy and immunotherapy. Among radiation therapy treatment, stereotactic radiosurgery (SRS) or stereotactic radiosurgery (SRT) is getting the popularity compared to traditional conformal radiotherapy with comparable tumor control rate

蛙崇拜 : 以二元對立論探討原始人生死觀

中國是主張泛神論的國家，各地域各民族信奉不同的宗教，崇拜不同的事物，很多神明獲人間歷朝皇帝賜封，成為官方認可的祠祀，夢天后、玄天上帝、福德正神（俗稱土地公），亦有諸多民間俗神遠古時期已受人們膜拜，青蛙神便是一例。跟據何星亮的說法，在自然神觀念形成之初，人們直接祭拜自然物或自然現象本身，隨著抽象思維發展，自然神形象才由非人轉為人形偶像，將自然神神格化和人格化，蛙神做為少數民族的信仰以動物原型呈現，尚未人格化，屬於早期的動物崇拜。 青蛙，學名為黑班蛙，壯族地區多稱為「螞蚱」，與蟾蜍統稱「蛤蟆」，屬於水陸兩棲類動物，遍佈世界各地，多居於潮濕之處。中國肎新石器時付成為農業社會，尤其南方地區提供溫暖濕潤的環境，有冺青蛙繁衍。各族先民夢壯族、黎族、納西族、彝族、佤族、藏族及中原地區等經常與青蛙接觸並視之為神。蛙的神格多樣，包括司雨神、生殖神、始祖神、創世神，有不死神性，後來職能社會化，具趨吉避凶、治瘟疫、治病、帶來財富、祝福戲團的神職。本論文主要探討蛙崇拜中生殖神、始祖神、創世神和不死神格，嘗試以李維史陀（Claude Lévi–Strauss, 1908–2009）提出的二元對立論（binary opposition）分析先民對於動物及人類的生死觀以及兩者之間的關係

A New Recognition Algorithm for “Head-and-Shoulders” Price Patterns

Savin et al. (2007) and Lo et al. (2000) analyse the predictive power of head-and-shoulders (HS) patterns in the U.S. stock market. The algorithms in both studies ignore the relative position of the HS pattern in a price trend. In this paper, a filter that removes invalid HS patterns is proposed. It is found that the risk-adjusted excess returns for the HST pattern generally improve through the use of our filter