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Estimating Effective Reproduction Number for SIR Compartmental Model:A Stochastic Evolutionary Approach

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Journal of Social Computing 2022年第2期3卷 182-189页

作者： W.k.wong Filbert H.Juwono the Department of Electrical and Computer Engineering Curtin University MalaysiaMiri 98009Malaysia

Compatmental pandemic models have become a significant tool in the battle against disease *** this,pandemic models sometimes require extensive modification to accuately reflect the actual epidemic condition The Susceptble-Infectious-Removed(SIR)model,in particular,contains two primary parameters:the infectious rate parameter ρ and the removal rate parameter r,in addition to additional unknowns such as the initial infectious *** to the complexity,there is an obvious challenge to tack the evolution of these parameters,especially ρ and γ,over time which leads to the estimation of the reproduction number for the paticular time window,^(κ)*** reproduction mumber may provide better understanding on the efectiveness of isolation or control *** changing ^(κ)T values(evolving over time window)will lead to even more possible parameter *** the present Coronavirus Disease 2019(COVID-19)pandemic,a stochastic optimization stategy is proposed to ft the model on the basis of parameter changes over *** are encoded to reflet the changing parameters of Tρ and γT,alwing the changing ^(κ)T to be *** our approach,an Adaptive Differential Evolution(ADE)and Paricle Swam Optimization(PSO)are used to ft the curves into previously recorded *** eliminates the need to tume the parameters of the Differential Evolution(DE)to balance the exploitation and exploration in the solution *** show that the proposed optimized model can generally ft the cuves well albeit high variance in the solutions.

关键词： Susceptible-Infectious-Removed(SIR)model adaptive differential evolution Coronavirus Disease 2019(COVID-19)

Activation of human fibroblast-like synoviocytes by uric acid crystals in rheumatoid arthritis

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Cellular & Molecular Immunology 2011年第6期8卷 469-478页

作者： Da P Chen Chun k.wong Lai S Tam Edmund k Li Christopher Wk Lam Department of Chemical Pathology The Chinese University of Hong KongPrince of Wales HospitalShatinNTHong KongChina Department of Clinical Laboratory Children’s Hospital of Chongqing Medical UniversityChongqingChina Department of Medicine and Therapeutics The Chinese University of Hong KongPrince of Wales HospitalNgan Shing StreetShatinNTHong KongChina Macao Institute for Applied Research in Medicine and Health Macao University of Science and TechnologyAvenida Wai LongTaipaMacaoChina

Hyperuricemia-mediated uric acid crystal formation may cause joint inflammation and provoke the destruction of joints through the activation of inflammasome-mediated innate immune ***,the immunopathological effects and underlying intracellular regulatory mechanisms of uric acid crystal-mediated activation of fibroblast-like synoviocytes(FLS)in rheumatoid arthritis(RA)have not been ***,we investigated the in vitro effects of monosodium urate crystals,alone or in combination with the inflammatory cytokines tumor-necrosis factor(TNF)-a or interleukin(IL)-1b,on the activation of human FLS from RA patients and normal control subjects and the underlying intracellular signaling mechanisms of treatment with these *** urate crystals were able to significantly increase the release of the inflammatory cytokine IL-6,the chemokine CXCL8 and the matrix metalloproteinase(MMP)-1 from both normal and RA-FLS(all P,0.05).Moreover,the additive or synergistic effect on the release of IL-6,CXCL8 and MMP-1 from both normal and RA-FLS was observed following the combined treatment with monosodium urate crystals and TNF-a or *** experiments showed that the release of the measured inflammatory cytokine,chemokine and MMP-1 stimulated by monosodium urate crystals were differentially regulated by the intracellular activation of extracellular signal-regulated kinase and c-Jun N-terminal kinase pathways but not the p38 mitogen-activated protein kinase *** results therefore provide a new insight into the uric acid crystal-activated immunopathological mechanisms mediated by distinct intracellular signal transduction pathways leading to joint inflammation in RA.

关键词： cytokines fibroblast-like synoviocytes rheumatoid arthritis signal transduction uric acid

Biomedical applications of shape-memory polymers:how practically useful are they?

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Science China Chemistry 2014年第4期57卷 476-489页

作者： wong YeeShan kONG JenFong WIDJAJA Leonardus k VENkATRAMAN Subbu S School of Materials Science & Engineering College of Engineering Nanyang Technological University

Shape-memory effect(SME) is the ability of a material to change its dimension in a predefined way in response to an external stimulus. Polymers that exhibit SME are an important class of materials in medicine, especially for minimally invasive deployment of devices. However, the rate of translation of the concept to approved products is extremely low, with mostly nitinolbased devices being approved. In this review, the general aspects of the different types of stimuli that can be used to activate SME are reviewed and sterilization issues of shape-memory polymer(SMP)-based medical devices are addressed. In addition, the general usefulness as well as the limitations of the shape-memory effect for biomedical applications are described.

关键词： shape memory biodegradable sterilization biomedical polymer

Afteruse development of former landfll sites in Hong kong

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Journal of Rock Mechanics and Geotechnical Engineering 2013年第6期5卷 443-451页

作者： C.T.wong M.k.Leung M.k.wong W.C.Tang Architectural Services Department HKSAR Government

Landfll is one of the major methods in disposing of municipal solid waste(MSW) in Hong kong. There are now 13 closed landfll sites in Hong kong, and a restoration program has been launched since 1999 to transform the closed landfll sites back into recreational area. The MSW underneath these closed landfll sites will biodegrade slowly and gradually, releasing toxic gases and leachate. As there have only been a few afteruse development ever completed in Hong kong, this paper describes the consideration in planning and design of two former landfll sites in Hong kong–Ngau Chi Wan(NCW) and Jordan Valley(JV) landflls, in particular a discussion on the MSW settlement. Various models in predicting the longterm MSW settlement have been available. This paper reviews the applicability of these models to predict MSW settlement. However, as the predicted settlements can be signifcantly in error, they need sitespecifc calibration and validation. This paper therefore presents the settlement monitoring data in these former landfll sites over the last 30 years, and suggests modifying the Bjarngard and Edgers’ method for estimating this long-term settlement as well as the effect of additional surcharge due to afteruse development. Based on the regression of these data, compression indices Cce and C at different stages of the settlement in the modifed method have been calibrated and validated.

关键词： Afteruse development Closed landflls Municipal solid waste(MSW) settlement Modifed Bjarngard and Edgers' method

Complex reconstruction of the lower extremity following sarcoma resection: a literature review

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Plastic and Aesthetic Research 2018年第1期5卷 16-27页

作者： Beina Azadgoli Antoine L.Carre David P.Perrault Alex k.wong Division of Plastic and Reconstructive Surgery Department of SurgeryKeck School of Medicine of USCLos AngelesCA 90033USA

While amputation was traditionally the only option available for patients with sarcomas of the extremities, chemotherapy, radiation, and advances in microsurgical technique have allowed many patients to undergo limb-salvaging procedures. Given the low incidence and heterogeneity of these tumors, there is currently no standard treatment algorithm for limb reconstruction after large sarcoma resection. Thus, we systematically reviewed the various types of free tissue transfer used for the reconstruction of lower limbs after sarcoma resection. Techniques were described based on anatomic location. This literature review supports free tissue transfer as a safe and acceptable modality for reconstruction after sarcoma resection of the lower limb. It allows for the application of healthy vascularized tissue to the defect while also providing freedom of flap positioning. Flap choice is dependent on tumor and defect size, tissue type and function, as well as donor site availability.

关键词： Lower extremity sarcoma reconstruction

Hepatocellular carcinoma in patients with non-alcoholic fatty liver disease

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World Journal of Gastroenterology 2016年第37期22卷 8294-8303页

作者： Carrie R wong Mindie H Nguyen Joseph k Lim Department of Internal Medicine Yale University School of Medicine Division of Gastroenterology and Hepatology Stanford University School of Medicine Yale Liver Center Section of Digestive Diseases Yale University School of Medicine

Nonalcoholic fatty liver disease(NAFLD) is the most common chronic liver disease in the United States and represents an increasingly important etiology of hepatocellular carcinoma(HCC) with annual cumulative incidence rates ranging from 2% to 12% in cohorts of NAFLD cirrhosis. While the risk of progression of NAFLD to HCC remains higher among patients with fibrosis or cirrhosis, an increasing amount of literature describes NAFLD-HCC as a disease that can occur in the absence of cirrhosis. Efforts to characterize the pathogenesis of NAFLD-HCC have suggested mechanisms that strongly associate with states of hyperinsulinemia and chronic inflammation, cellular mechanisms including adaptive immune responses and hepatic progenitor cell populations, and genetic polymorphisms including mutations of PNPLA3. Current literature describes NAFLD-HCC mostly as a disease of late presentation with lower rates of receipt of curative therapy and worse prognosis. However, a growing body of evidence has reported comparable and potentially more favorable disease-free and overall survival rates among patients with NAFLD-HCC after receipt of curative treatment. This review summarizes current evidence of epidemiology, pathophysiology, disease presentation, demand and receipt of curative therapy, post-treatment outcomes, and overall survival of NAFLD-associated HCC.

关键词： Fatty liver Nonalcoholic steatohepatitis Hepatocellular carcinoma Liver cirrhosis Liver cancer

A minimalist approach for detecting sensor abnormality in oil and gas platforms

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Petroleum Research 2022年第2期7卷 177-185页

作者： Pauline wong W.k.wong Filbert H.Juwono Lenin Gopal Mohd Amaluddin Yusoff Curtin Malaysia Digital Innovation(CMDI) Curtin University Malaysia98009MiriSarawakMalaysia Department of Electrical and Computer Engineering Curtin University Malaysia98009MiriSarawakMalaysia

Compressors play an important role in day-to-day operation in most oil and gas platforms,especially in the case for maintaining gas pressure in transportation *** complex problem to detect the sensors health and abnormality as the sensor reading would reflect the various states of the *** ideal situation,sensor readings offer vast amounts of information on compressor health and could possibly indicate early fault of ***,due to harsh site and process operating conditions,sensors are often found to have drifted or failed,and there is no standard methodology to predict abnormality apart from applying emerging industrial smart sensor *** this paper,we investigate a minimalist approach for detecting abnormality of compressor's shaft's RPM *** the sensors in the compressor are correlated,we first use the outputs of other sensors to predict the shaft's RPM using regression-based models(neural networks and multiple linear regression).Second,we calculate the histogram of residuals by taking the difference between the predicted sensor value and the actual sensor value plus the abnormality in terms of bias/miscalibration and *** histogram of residuals can be used for sensor abnormality *** general,sensor states can be monitored by observing the shifting of the mean in the histogram of *** sensor readings contaminated with noise can be seen by a shifted mean whose value is between the normal condition mean and the biased condition *** method is compact and would be relevant to monitor irregularity of the sensors.

关键词： Sensor fault detection Multistage turbine air compressor Multiple linear regression Neural network Oil and gas industry

Decontamination of Landfill Leachate by Soil Infiltration

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Biomedical and Environmental Sciences 1989年第4期2卷 341-357页

作者： M.H.wong k.C.LEUNG Department of Biology Hong Kong Baptist CollegeKowloonHong Kong Department of Biology The Chinese University of Hong KongShatinHong Kong

A soil column study was conducted to evaluate the efficiency of soil to attenuate pollutants in landfill *** was found that more than 60% of the initial alkalinity,COD,and total nitrogen was removed after the leachate had percolated through the soil *** effi- ciencies were observed for the removal of dissolved cations,ammonia nitrogen,and nitrate *** previously percolated leachate was recirculated through the soil column,sig- nificant removal(93.6%)of ammonia nitrogen was ***,a further reduction in COD,total nitrogen,nitrate nitrogen,and potassium was *** tests of seed germi- nation and root growth of Brassica chinensis were performed to compare the phytotoxicities of untreated,percolated,and recirculated *** phytotoxicity was reduced by both treatments,with the greatest detoxification observed in the leachate recirculation *** values ofpH and Olsen phosphorus were significantly reduced(P<0.01)in the treated column *** significant increases(P<0.05)in electrical conductivity(EC),various forms of nitrogen,exchangeable sodium percentage(ESP),potassium,magnesium,zinc,and iron were ***,ESP,potassium,magnesium,sodium,iron,and various forms of nitrogen accu- mulated at the soil surface(10 cm).On the other hand,manganese was deposited at 20 to 50 cm below the soil surface of the treated column.1989 Academic ***.

关键词：刀口井群

Tuning electroluminescence performance in Pr-doped piezoelectric bulk ceramics and composites

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Journal of Materiomics 2021年第2期7卷 264-270页

作者： Hailing Sun Manchung wong Guofu Zhou k.W.kwok Guangdong Provincial key Laboratory of Optical Information Materials and Technology&Institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China Department of Applied Physics The Hong Kong Polytechnic UniversityKowloonChina

Alternating current electroluminescence(ACEL)shows great potential in lighting,display and intelligent ***,the ACEL properties of Pr3þ-doped Ba0$85Ca0$15Ti0$90Zr0$10O3 ceramic and its PDMS-based composite have been *** red EL emission was obtained in the ceramic sample whereas blue EL emission of Pr3þwas observed for the first time in the composite *** red EL emission should be attributed to the impact of hot electrons driven by the large piezoelectric electric *** to the cross-relaxations through the 4f5d levels and Pr-to-metal charge transfer state,the 3 PJ emissions were completely quenched,and thus leading to an enhancement in red ***,external E field induced a large local piezoelectric deformation of the ceramic particles embedded in the PDMS matrix,which in turn caused a bending of CB and then a downwards shift of the 4f5d levels from the *** the cross-relaxations were hindered,and the blue EL emission was observed in the *** results would attract attention of functional materials studies and expand our understanding of such facile structure and oxide EL devices to facilitate their use in integral part of flexible device systems.

关键词： Electroluminescence Emission color tuning Ferroelectric. Piezoelectric Doping