Use of FBG optical sensors for structural health monitoring: Practical application

This paper describes the development of FBG Optical sensors for their practical application on structural health monitoring. The sensors were installed on the Tsing Ma Bridge for a trial run. The results using FBG sensors were in excellent agreement with those acquired by the bridge WASHMS

Factorial structure of the Chinese version of the 12-item General Health Questionnaire in adolescents

Aims. To evaluate the underlying factor structure of the Chinese version of General Health Questionnaire-12 using exploratory and confirmatory factor analyses in Chinese adolescents and find out which factor model proposed by previous empirical research is the best-fit model. Background. The 12-item General Health Questionnaire has been extensively used with adolescents in the West. Yet, it has not been used with adolescents in a Hong Kong Chinese context. Design. A cross-sectional study was employed. Method. Chinese students between the ages of 12-19 from four secondary schools were invited to participate in the study using the multiple-stage stratified random sampling method during the period from December 2007-February, 2008. The total sample size included in the final analysed was 1883. Results. The General Health Questionnaire-12 was found to be internally consistent. The results of exploratory factor analysis showed that there are two factors underlying the General Health Questionnaire-12. Of nine factor models were tested by means of confirmatory factor analysis, only three factor model: the eight-item two-factor model, 12-item three-factor model and 10-item two-factor model, demonstrated good model fit across all model fit indices. Conclusion. This study addressed a gap in the literature by evaluating the factorial structure of the Chinese version of General Health Questionnaire-12 using exploratory and confirmatory factor analyses in Chinese adolescents. The findings revealed that the eight-item two-factor model is the best-fit model. Relevance to clinical practice. The adolescent mental health problem is alarming and aggravating and warrants special attention. It is essential for community nurses to differentiate psychological distress in adolescents and to identify those adolescents who are at a higher risk of suffering from mental health problems. The availability of a valid and reliable instrument that measures adolescents' psychological distress is crucial before any nursing interventions to promote their mental health can be appropriately planned, implemented and evaluated. © 2009 Blackwell Publishing Ltd.postprin

Reference-free detection of semiconductor assembly defect

This paper aims at developing a novel defect detection algorithm for the semiconductor assembly process by image analysis of a single captured image, without reference to another image during inspection. The integrated circuit (IC) pattern is usually periodic and regular. Therefore, we can implement a classification scheme whereby the regular pattern in the die image is classified as the acceptable circuit pattern and the die defect can be modeled as irregularity on the image. The detection of irregularity in image is thus equivalent to the detection of die defect. We propose a method where the defect detection algorithm first segments the die image into different regions according to the circuit pattern by a set of morphological segmentations with different structuring element sizes. Then, a feature vector, which consists of many image attributes, is calculated for each segmented region. Lastly, the defective region is extracted by the feature vector classification. © 2005 SPIE and IS&T.published_or_final_versio

Carcinoid tumour of the kidney in a Chinese woman presenting with loin pain

Renal carcinoid tumours are uncommon. The aetiology is not yet fully understood and there is still no useful diagnostic tool for detecting them. We report our experience managing a Chinese woman with a primary renal carcinoid tumour.published_or_final_versio

Increased burden of cardiovascular disease in people with liver disease: unequal geographical variations, risk factors and excess years of life lost

BACKGROUND: People with liver disease are at increased risk of developing cardiovascular disease (CVD), however, there has yet been an investigation of incidence burden, risk, and premature mortality across a wide range of liver conditions and cardiovascular outcomes. METHODS: We employed population-wide electronic health records (EHRs; from 1998 to 2020) consisting of almost 4 million adults to assess regional variations in disease burden of five liver conditions, alcoholic liver disease (ALD), autoimmune liver disease, chronic hepatitis B infection (HBV), chronic hepatitis C infection (HCV) and NAFLD, in England. We analysed regional differences in incidence rates for 17 manifestations of CVD in people with or without liver disease. The associations between biomarkers and comorbidities and risk of CVD in patients with liver disease were estimated using Cox models. For each liver condition, we estimated excess years of life lost (YLL) attributable to CVD (i.e., difference in YLL between people with or without CVD). RESULTS: The age-standardised incidence rate for any liver disease was 114.5 per 100,000 person years. The highest incidence was observed in NAFLD (85.5), followed by ALD (24.7), HCV (6.0), HBV (4.1) and autoimmune liver disease (3.7). Regionally, the North West and North East regions consistently exhibited high incidence burden. Age-specific incidence rate analyses revealed that the peak incidence for liver disease of non-viral aetiology is reached in individuals aged 50–59 years. Patients with liver disease had a two-fold higher incidence burden of CVD (2634.6 per 100,000 persons) compared to individuals without liver disease (1339.7 per 100,000 persons). When comparing across liver diseases, atrial fibrillation was the most common initial CVD presentation while hypertrophic cardiomyopathy was the least common. We noted strong positive associations between body mass index and current smoking and risk of CVD. Patients who also had diabetes, hypertension, proteinuric kidney disease, chronic kidney disease, diverticular disease and gastro-oesophageal reflex disorders had a higher risk of CVD, as do patients with low albumin, raised C-reactive protein and raised International Normalized Ratio levels. All types of CVD were associated with shorter life expectancies. When evaluating excess YLLs by age of CVD onset and by liver disease type, differences in YLLs, when comparing across CVD types, were more pronounced at younger ages. CONCLUSIONS: We developed a public online app (https://lailab.shinyapps.io/cvd_in_liver_disease/) to showcase results interactively. We provide a blueprint that revealed previously underappreciated clinical factors related to the risk of CVD, which differed in the magnitude of effects across liver diseases. We found significant geographical variations in the burden of liver disease and CVD, highlighting the need to devise local solutions. Targeted policies and regional initiatives addressing underserved communities might help improve equity of access to CVD screening and treatment

Three-dimensional reconstruction of wafer solder bumps using binary pattern projection

As the electronic industry advances rapidly, the shrunk dimension of the device leads to more stringent requirement on process control and quality assurance. For instance, the tiny size of the solder bumps grown on wafers for direct die-to-die bonding pose great challenge to the inspection of the bumps' 3D quality. Traditional pattern projection method of recovering 3D is about projecting a light pattern to the inspected surface and imaging the illuminated surface from one or more points of view. However, image saturation and the specular nature of the bump surface are issues. This paper proposes a new 3D reconstruction mechanism for inspecting the surface of such wafer bumps. It is still based upon the light pattern projection framework, but uses the Ronchi pattern - a pattern that contrasts with the traditionally used gray level one. With the use of a parallel or point light source in combination with a binary grating, it allows a discrete pattern to be projected onto the inspected surface. As the projected pattern is binary, the image information is binary as well. With such a bright-or-dark world for each image position, the above-mentioned difficult issues are avoided. Preliminary study shows that the mechanism holds promises that existing approaches do not. © 2005 SPIE and IS&T.published_or_final_versio

Structured-light based sensing using a single fixed fringe grating: Fringe boundary detection and 3-D reconstruction

Advanced electronic manufacturing requires the 3-D inspection of very small surfaces like the solder bumps on wafers for direct die-to-die bonding. Yet the microscopic size and highly specular and textureless nature of the surfaces make the task difficult. It is also demanded that the size of the entire inspection system be small so as to minimize restraint on the operation of the various moving parts involved in the manufacturing process. In this paper, we describe a new 3-D reconstruction mechanism for the task. The mechanism is based upon the well-known concept of structured-light projection, but adapted to a new configuration that owns a particularly small system size and operates in a different manner. Unlike the traditional mechanisms which involve an array of light sources that occupy a rather extended physical space, the proposed mechanism consists of only a single light source plus a binary grating for projecting binary pattern. To allow the projection at each position of the inspected surface to vary and form distinct binary code, the binary grating is shifted in space. In every shift, a separate image of the illuminated surface is taken. With the use of pattern projection, and of discrete coding instead of analog coding in the projection, issues like texture-absence, image saturation, and image noise of the inspected surfaces are much lessened. Experimental results on a variety of objects are presented to illustrate the effectiveness of this mechanism. © 2008 IEEE.published_or_final_versio

Multimorbidity patterns and risk of hospitalisation in children: A population cohort study of 3.6 million children in England, with illustrative examples from childhood cancer survivors

Background: Population-level estimates of hospitalisation risk in children are currently limited. The study aims to characterise morbidity patterns in all children, focusing on childhood cancer survivors versus children without cancer. Methods: Employing hospital records of children aged <19 years between 1997 to 2018 in England, we characterised morbidity patterns in childhood cancer survivors compared with children without cancer. The follow-up began on the 5th anniversary of the index hospitalisation and the primary outcome was the incidence of comorbidities. Findings: We identified 3,559,439 eligible participants having 12,740,666 hospital admissions, with a mean age at study entry of 11.2 years. We identified 32,221 patients who survived for at least 5 years since their initial cancer diagnosis. During the follow-up period and within the whole population of 3.6 million children, the leading conditions for admission were (i) metabolic, endocrine, digestive renal and genitourinary conditions (84,749, 2.5%), (ii) neurological (35,833, 1.0%) and (iii) musculoskeletal or skin conditions (23,574, 0.7%), fever, acute respiratory and sepsis (22,604, 0.7%). Stratified analyses revealed that females and children from socioeconomically deprived areas had a higher cumulative incidence for morbidities requiring hospitalisation (p < 0.001). At baseline (5 years after the initial cancer diagnosis or initial hospitalisation for survivors and population comparisons, respectively), cancer survivors experienced a higher prevalence of individual conditions and multimorbidity (≥ 2 morbidities) compared with children without cancer. Cox regression analyses showed that survivors had at least a 4-fold increase in the risk of hospitalisation for conditions such as chronic eye conditions (hazard ration (HR):4.0, 95% confidence interval (CI): 3.5-4.7), fever requiring hospitalisation (HR: 4.4, 95% CI: 3.8-5.0), subsequent neoplasms (HR: 5.7, 95% CI:5.0-6.5), immunological disorders (HR: 6.5, 95% CI:4.5-9.3) and metabolic conditions (HR: 7.1, 95% CI:5.9-8.5). Interpretation: The overall morbidity burden among children was low in general; however, childhood cancer survivors experienced a higher prevalence and subsequent risk of hospitalisation for a range of morbidities. Targeted policies may be required to promote awareness on health vulnerabilities and gender disparity and to improve advocacy for healthcare in deprived communities. Funding: Wellcome Trust, National Institute for Health Research (NIHR) University College London Hospitals Biomedical Research Centre, NIHR Great Ormond Street Hospital Biomedical Research Centre and Academy of Medical Sciences. The funders of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report

An ARIMA-intervention analysis model for the financial crisis in China's manufacturing industry

2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Using integer programming for airport service planning in staff scheduling

Author name used in this publication: George Ho2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe