5,693 research outputs found

    Pengiraan Persentil Taburan Panjang Larian bagi Carta Kawalan Purata Bergerak Berpemberat Eksponen Multivariat

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    Prabhu dan Runger (1997) telah mengemukakan cadangan dalam pemilihan parameter-parameter untuk skema carta kawalan purata bergerak berpemberat eksponen multivariat (MEWMA). Walau bagaimanapun, cadangan tersebut hanya berdasarkan prestasi panjang larian purata (average run length - ARL). Oleh itu, dalam makalah ini, kami akan mengira nilai-nilai persentil untuk taburan panjang larian bagi pelbagai skema carta kawalan MEWMA yang dikemukakan oleh Prabhu dan Runger (1997). Persentil-persentil yang dikira akan membekalkan maklumat tambahan seperti kekerapan isyarat luar kawalan palsu yang awal (early false out of control signals), panjang larian median (median run length - MRL) dan kepencongan taburan panjang larian untuk sesuatu skema tertentu. Maklumat-maklumat tambahan ini mungkin berguna dalam membekalkan jurutera kawalan mutu pengetahuan mendalam dan lengkap tentang sesuatu skema carta kawalan MEWMA yang dipilih berdasarkan cadangan Prabhu dan Runger (1997)

    Seasonal variation in breast cancer diagnosis in Singapore

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    This study investigates seasonality in the diagnosis of 3219 female breast carcinoma cases reported between 1995–8 in Singapore. There is little evidence of marked seasonal variation. Angular regression suggested that observed differences in peak diagnosis with respect to menopausal status, tumour size, ER and PR status may be chance. © 2001 Cancer Research Campaign http://www.bjcancer.co

    Heated Motorized Stage for Nanoscale Thin Film Deposition

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    ME450 Capstone Design and Manufacturing Experience: Fall 2015Thin film deposition is a technology of applying a very thin film of material onto a substrate surface to be coated, or onto a previously deposited coating to form layers. As a modified Atomic Layer Deposition (ALD) method, Spatial ALD greatly improves the efficiency of the process by separating the half-reactions spatially instead of through the use of purge steps in convectional ALD. This paper proposes the use of heated motorized stage as a research prototype to further study the effect of deposition conditions such as gap size, gap alignment and substrate temperature on the SALD coating results. This strategy utilized three stepper motors and high precision non-contact gap sensors to control gap alignment and gap size between the substrate and the depositor. The details of the involved methodology, engineering analysis, validation of the final design and the design critiques are discussed in this paper.http://deepblue.lib.umich.edu/bitstream/2027.42/117338/1/ME450-F15-Project19-FinalReport.pd

    Assessment of the variability of airborne contamination levels in an intensive care unit over a 24 hour period

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    Introduction: The objective of this study was to evaluate the variability in the dynamics and levels of airborne contamination within a hospital ICU in order to establish an improved understanding of the extent to which airborne bioburden contributes to cross-infection of patients. Microorganisms from the respiratory tract or skin can become airborne by coughing, sneezing and periods of increased activity such as bed changes and staff rounds. Current knowledge of the clinical microflora is limited however it is estimated that 10-33% of nosocomial infections are transmitted via air. Methods: Environmental air monitoring was conducted in Glasgow Royal Infirmary ICU, in the open ward and in patient isolation rooms. A sieve impactor air sampler was used to collect 500 L air samples every 15 minutes over 10 hour (08:00-18:00 h) and 24 hour (08:00-08:00 h) periods. Samples were collected, room activity logged and the bacterial contamination levels were recorded as CFU/m3 of air. Results: A high degree of variability in levels of airborne contamination was observed over the course of a 10 hour day and a 24 period in a hospital ICU. Counts ranged from 12-510 CFU/m3 over 24 hours in an isolation room occupied for 10 days by a patient with C. difficile infection. Contamination levels were found to be lowest during the night and in unoccupied rooms, with an average value of 20 CFU/m3. Peaks in airborne contamination showed a direct relation to an increase in room activity. Conclusions: This study demonstrates the degree of airborne contamination that can occur in an ICU over a 24 hour period. Numerous factors were found to contribute to microbial air contamination and consideration should be given to potential improved infection control strategies and decontamination technologies which could be deployed within the clinical environment to reduce the airborne contamination levels, with the ultimate aim of reducing healthcare-associated infections from environmental sources

    Educational aspirations in inner city schools

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    The research aimed to assess the nature and level of pupils’ educational aspirations and to elucidate the factors that influence these aspirations. A sample of five inner city comprehensive secondary schools were selected by their Local Authority because of poor pupil attendance, below average examination results and low rates of continuing in full-time education after the age of 16. Schools were all ethnically mixed and co-educational. Over 800 pupils aged 12-14 completed a questionnaire assessing pupils’ experience of home, school and their peers. A sub-sample of 48 pupils selected by teachers to reflect ethnicity and ability levels in individual schools also participated in detailed focus group interviews. There were no significant differences in aspirations by gender or year group, but differences between ethnic groups were marked. Black African, Asian Other and Pakistani groups had significantly higher educational aspirations than the White British group, who had the lowest aspirations. The results suggest the high aspirations of Black African, Asian Other and Pakistani pupils are mediated through strong academic self-concept, positive peer support, a commitment to schooling and high educational aspirations in the home. They also suggest that low educational aspirations may have different mediating influences in different ethnic groups. The low aspirations of White British pupils seem to relate most strongly to poor academic self-concept and low educational aspirations in the home, while for Black Caribbean pupils disaffection, negative peers and low commitment to schooling appear more relevant. Interviews with pupils corroborated the above findings and further illuminated the factors students described as important in their educational aspirations. The results are discussed in relation to theories of aspiration which stress its nature as a cultural capacity

    Simple model for decay of superdeformed nuclei

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    Recent theoretical investigations of the decay mechanism out of a superdeformed nuclear band have yielded qualitatively different results, depending on the relative values of the relevant decay widths. We present a simple two-level model for the dynamics of the tunneling between the superdeformed and normal-deformed bands, which treats decay and tunneling processes on an equal footing. The previous theoretical results are shown to correspond to coherent and incoherent limits of the full tunneling dynamics. Our model accounts for experimental data in both the A~150 mass region, where the tunneling dynamics is coherent, and in the A~190 mass region, where the tunneling dynamics is incoherent.Comment: 4 page

    Treatment for Landfill Leachate via Physicochemical Approaches: An Overview

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    Leachate waste consists of various mixtures of organic, inorganic, and heavy metal contaminants, which are responsible for groundwater and surface water contamination. Landfills apply physical, chemical, and biological processes for the treatment of leachate. Most studies on leachate treatment by coagulation and flocculation are based on the selection and performance of natural based biopolymers in comparison with various inorganic metal salts and grafted polymers used for the removal of contaminants. In addition, adsorption processes utilizing non-conventional activated carbons as absorbents are the current emerging focus of the researchers in leachate treatment. These adsorbents are low-in-cost, efficient, and renewable compared to conventional adsorbents. The present paper aimed to evaluate and review the technology utilising various greener approaches in coagulation, flocculation, and adsorption as the physicochemical approaches to leachate treatment. The challenges and future work regarding the development of these green products in the commercial markets were comprehensively evaluated. This work is licensed under a Creative Commons Attribution 4.0 International License

    Correlating low energy impact damage with changes in modal parameters: diagnosis tools and FE validation

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    This paper presents a basic experimental technique and simplified FE based models for the detection, localization and quantification of impact damage in composite beams around the BVID level. Detection of damage is carried out by shift in modal parameters. Localization of damage is done by a topology optimization tool which showed that correct damage locations can be found rather efficiently for low-level damage. The novelty of this paper is that we develop an All In One (AIO) package dedicated to impact identification by modal analysis. The damaged zones in the FE models are updated by reducing the most sensitive material property in order to improve the experimental/numerical correlation of the frequency response functions. These approximate damage models(in term of equivalent rigidity) give us a simple degradation factor that can serve as a warning regarding structure safety
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