202 research outputs found
Students and Teachers’ Views of Difficult Areas in Mathematics Syllabus: Basic Requirement for Science and Engineering Education
The research investigates teachers and students’ views of difficult areas of mathematics syllabus which is a special requirement for engineering education in Nigeria using Ogbomosho South Secondary Schools in Oyo State as case study. The population of the study consisted of all the mathematics teachers and all the senior secondary III students in all the 18 Secondary schools in the Local Government Area. A simple random sampling technique was used to select 15 mathematics teachers and 180 Senior Secondary school III Students. Two self designed questionnaires were developed to elicit information for the research questions. Appropriate hypotheses were raised based on the research questions. These questionnaires were validated and their reliability ensured. The data gathered were analyzed using frequency count, percentage, t-test and Chi-square. The results of the analyses revealed that both teachers and students, qualified and unqualified, experienced and less experienced teachers have the same views of difficult areas in teaching and learning of mathematics in the secondary schools. Based on the findings, it was therefore recommended that for engineering education to advance, teachers should endeavour to improve themselves academically, be more committed, proactive in their dealings, and see their job as service to humanity; school authorities should have more time schedule for mathematics on the time table, qualified mathematics teachers should be posted to all schools, appointment of mathematics teachers should be purely on merit and should not be politicized. Curriculum planners should be up and doing in planning for teaching of mathematics with appropriate instructional materials. Keywords: Teachers, students, perceptions, mathematics, curriculum, hypotheses, T-test, Chi-square, Evaluation, Recommendation
Immigration and sentencing: does geograhical region of citizenship influence sentence longevity?
A large volume of sentencing research has examined the effects of offender characteristics on sentencing outcomes. Most of this research has focused on offender race/ethnicity. Despite the growth of immigration debates in the United States, there is limited knowledge on the role played by citizenship status. The current study builds upon that body of sentencing literature by going beyond the examination of the legal status of offenders to explore whether sentencing outcomes vary according to geographical location of citizenship. Specifically, federal sentencing data is used to assess whether the length of sentence for non-US citizens convicted of drug trafficking is influenced by the geographical region of the offender country of citizenship. Findings revealed that defendants from Asia, the Caribbean, Europe, Middle East/North Africa and the South/Central American regions were treated more severely than defendants from the Mexican region. However, once control variables were added the sentence imposed upon offenders from the Mexican region was harsher than sentences given to defendants from the Caribbean region. Implications of the findings and directions for future research are discussed
Implementation of ISO19650 based framework for asset management in logistics centres for a major food retailer
Dissertação de mestrado em Modelação de Informação na Construção de Edifícios BIM A+A relevância da informação tem acelerado a par da importância das profissões que envolvem dados,
com a gestão da informação a assumir um papel central. Para a indústria AECO (Arquitectura,
Engenharia, Construção e Operações) BIM representa dados (geométricos e não geométricos) e
verifica-se, em muitos casos, que os dados originados na construção são pouco ou nada utilizados
durante as fases de exploração dos edificios e na manutenção dos mesmos. Com base nesta realidade é
de grande importância investigar a gestão de ativos e sua integração com BIM.
Esta pesquisa aborda o tema através de pesquisa estruturada quanto á utilização passada e presente da
metodologia BIM na gestão de ativos e manutenção. A pesquisa também aponta a questões em torno
da implementação da norma ISO-19650 para as indústrias de operações e manutenção, pelo
desenvolvimento duma estruturação que identifica e lista os requisitos de informação relevantes
aplicáveis (OIR, AIR e EIR), bem como o nível de informação necessário. A revisão de literatura
aponta a que há poucos casos de implementação na área da gestão de ativos com recurso a BIM.
Verifica-se que os gestores de manutenção e ativos procuram casos de sucesso verificáveis para
convencer proprietários e/ou investidores nas vantagens da adoção de BIM. Ao definir os requisitos de
informação para a operação e manutenção de ativos utilizando os dados recolhidos no caso estudado,
esta dissertação contribuiu para o aprofundar de conhecimento na implementação da referida gestão.
Uma vez que a gestão com recurso à integração BIM é ainda nova nas operações e manutenção, há
pouca pesquisa verificável no tema, como já apontado. Para melhor percebermos o nível de
implementação BIM em operações e manutenção, o autor estudou sistematicamente o processo de
gestão de ativos da logística do maior retalhista alimentar em Portugal, SONAE MC. O objetivo desta
pesquisa é criar uma estrutura de trabalho para a implementação dum sistema de gestão de ativos
baseado na norma ISO-16950 e que será aplicável a um ‘site’ real da empresa. Esta dissertação
também procura utilizar a capacidade de visualização e exploração isométrica BIM, dando à equipa de
gestão uma nova ferramenta que garante informação geométrica e que permite melhorias no
planeamento das intervenções de manutenção, resolução de problemas e uma intervenção que se prevê
mais rápida e produtiva.
Como parte da implementação da norma ISO-19650 esta dissertação explorou ainda a modelação
direcionada à gestão de ativos, pelo estudo da importação e exportação de dados COBie no sistema
(CMMS) da empresa (IBM MAXIMO), em paralelo com a integração desses dados COBie num
‘plugin’ de visualização BIM (Autodesk Forge), que foi instalado no ambiente de gestão existente.
Este processo permitiu a reengenharia do sistema de gestão de ativos na logística SONAEMC,
permitindo um processo único, sequencial, poupando tempo e garantindo uma organização mais eficaz
dos dados e exploração dos mesmos no processo de gestão.In recent times, the relevance of information has grown in prominence with roles involving data or
information management taking centre stage. For the AECO (Architecture, Engineering, Construction
and Operations) industry BIM represents data (geometric and non-geometric). The data from
construction has been put to little or no use in the operation and maintenance stage. Based on this
proposition it is of great value to investigate BIM-asset management integration.
This research approaches the subject by carrying out structured research into the past and present use
of BIM methodology in asset management. It also highlights issues around ISO-19650 implementation
for the operations and maintenance industry, by developing a framework that promotes the creation of
relevant ISO 19650 information requirements documents (OIR, AIR and EIR) and level of information
need. The literature review reveals that there is a lack of case study implementations in the area of
BIM-asset management. Asset managers generally require verifiable data from case studies to
convince building owners and investors to adopt BIM. By defining the information requirements for
operation and maintenance using the data collected from the case study, this dissertation has
contributed to increased knowledge in BIM- asset management implementation.
Since BIM- asset management integration is still new in the operations and maintenance areas, there is
little verifiable research on this topic. To understand the status of BIM implementation in the
operations and maintenance fields, the author systematically studied the logistics operations asset
management process of the largest food and consumer goods company in Portugal, Sonae MC. The
objective of this research is to create a framework for the implementation of an ISO 19650 compliant
BIM based asset management system, for the case study in which such system will be applicable for a
chosen existing facility. This dissertation also aims to use BIM visualization capabilities to provide the
asset management team with tools containing both geometric and other asset relevant information and
that will allow for improved maintenance planning, better problem solving and faster reactive
maintenance response times.
As a part of the ISO 19650 implementation process, this dissertation explored subjects on modelling
for asset management purposes, importing and exporting COBie data in a Computerized Maintenance
Management Systems (CMMS) IBM Maximo. Alongside COBie data integration, a BIM viewer
plugin (Autodesk Forge) was installed within Maximo asset management environment. This
implementation process allowed the reengineering of the asset management system in Sonae MC,
namely simplifying the existing workflow, saving time spent uploading individual asset information
and improving the overall information storage and management process.Erasmus Mundus Joint Master Degree Programme – ERASMUS+
European Master in Building Information Modelling BIM A
Automatic recognition of micro-expressions using local binary patterns on three orthogonal planes and extreme learning machine
A dissertation submitted in fullment of the requirements for the degree of Master of Science to the Faculty of Science, University of the
Witwatersrand, Johannesburg, September 2017Recognition of micro-expressions is a growing research area as a result of
its application in revealing subtle intention of humans especially under high
stake situations. Owing to micro-expressions' short duration and low inten-
sity, e orts to train humans in their recognition has resulted in very low
performance. The use of temporal methods (on image sequences) and static
methods (on apex frames) were explored for feature extraction. Supervised
machine learning algorithms which include Support Vector Machines (SVM)
and Extreme Learning Machines (ELM) were used for the purpose of classi-
cation. Extreme learning machines which has the ability to learn fast was
compared with SVM which acted as the baseline model. For experimentation,
samples from Chinese Academy of Micro-expressions (CASME II) database
were used. Results revealed that use of temporal features outperformed the
use of static features for micro-expression recognition on both SVM and
ELM models. Static and temporal features gave an average testing accuracy
of 94.08% and 97.57% respectively for ve classes of micro-expressions us-
ing ELM model. Signi cance test carried out on these two average means
suggested that temporal features outperformed static features using ELM.
Comparison between SVM and ELM learning time also revealed that ELM
learns faster than SVM. For the ve selected micro-expression classes, an av-
erage training time of 0.3405 seconds was achieved for SVM while an average
training time of 0.0409 seconds was achieved for ELM. Hence we can sug-
gest that micro-expressions can be recognised successfully by using temporal
features and a machine learning algorithm that has a fast learning speed.MT201
Informal settlement intervention and green infrastructure: exploring just sustainability in Kya Sands, Ruimsig and Cosmo city in Johannesburg
A thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Engineering and the Built
Environment, University of Witwatersrand, 2016This thesis is concerned with the relationship between informal settlements and green
infrastructure. It uses the concept of just sustainability to explore the ways green
infrastructure can contribute to more just and sustainable informal settlement
interventions.
The study draws on a case study design, with three low-income areas in
Johannesburg serving as case studies. The first, Kya Sands, is an informal settlement
that has not experienced substantive intervention. The second, Ruimsig, is an
informal settlement that has experienced in situ intervention through reblocking. The
third, Cosmo City, is a green-field housing development where households from
informal settlements were relocated. The thesis utilised qualitative methods (semistructured
interviews, transect walks, focus group discussion) for data collection
across the case studies. These were supplemented by a quantitative component for
data collection in an individual case and in-depth interviews with purposively
selected key informants.
The three cases reveal how the low-income residents in these areas derive a range of
ecosystem services from natural ecosystems. A range of ecosystem disservices also
came to the fore. In Ruimsig settlement, reblocking involved spatial reconfiguration
that created opportunities for greening. Co-producing the in situ intervention
involved some processes and outcomes related to equity and inclusion but also
included situations that were exclusionary. Relocation from informal settlements into
a new housing environment in Cosmo City formally created spatial opportunities for
greening and reduced dependency on the natural ecosystem for certain basic
resources. However, the course of events leading up to relocation and postoccupancy
trajectory of green spaces reveal shortfalls in relation to justice and
incognisance on socio-ecological and socio-economic realities at the planning stage.
Juxtaposition between the cases of Ruismig and Cosmo City shows that in situ
intervention can fulfill more principles of just sustainability in comparison with
relocation.
This thesis argues that careful assessment of the relationship between poor
households living in informal settlements and green infrastructure — their interaction
with natural ecosystems should influence the approach to informal settlement
interventions. The cases reveal that achieving just sustainability in relation to green
infrastructure in informal settlement intervention is not straight-forward, but not
impossible. Progress towards just sustainability in the form of improvement in
quality of life and in the environment requires navigating (with foresight rather than
hindsight) the intricacies and dynamics obtainable in contexts into which informal
settlements are embedded.MT201
Objective localisation of oral mucosal lesions using optical coherence tomography.
PhDIdentification of the most representative location for biopsy is critical in establishing
the definitive diagnosis of oral mucosal lesions. Currently, this process involves
visual evaluation of the colour characteristics of tissue aided by topical application of
contrast enhancing agents. Although, this approach is widely practiced, it remains
limited by its lack of objectivity in identifying and delineating suspicious areas for
biopsy. To overcome this drawback there is a need to introduce a technique that
would provide macroscopic guidance based on microscopic imaging and analysis.
Optical Coherence Tomography is an emerging high resolution biomedical imaging
modality that can potentially be used as an in vivo tool for selection of the most
appropriate site for biopsy. This thesis investigates the use of OCT for qualitative
and quantitative mapping of oral mucosal lesions. Feasibility studies were performed
on patient biopsy samples prior to histopathological processing using a commercial
OCT microscope. Qualitative imaging results examining a variety of normal, benign,
inflammatory and premalignant lesions of the oral mucosa will be presented.
Furthermore, the identification and utilisation of a common quantifiable parameter in
OCT and histology of images of normal and dysplastic oral epithelium will be
explored thus ensuring objective and reproducible mapping of the progression of oral
carcinogenesis. Finally, the selection of the most representative biopsy site of oral
epithelial dysplasia would be investigated using a novel approach, scattering
attenuation microscopy. It is hoped this approach may help convey more clinical
meaning than the conventional visualisation of OCT images
Practices of Child Labour Among Parents in Ekiti State, Nigeria: Implication for School Administrators
The study investigated the practices of child labour among parents in Ekiti State, Nigeria. The descriptive research design of the survey type was used for the study. Multistage random sampling technique was used to select four hundred (400) parents living in Ekiti State. A self-designed questionnaire was used as instrument for the study. The face and content validity of the instrument was ensured by experts while the reliability of the instrument was ensured using test-retest method. The reliability coefficient of 0.84 was obtained. The data collected was analyzed using t – test, one way ANOVA and scheffe post hoc analysis. One general question and four hypotheses were generated for the study. The study confirmed the existence of child labour practice in the state and that it is predominant in the domestic sector. The study revealed that there was significant difference in the practice of child labour by male and female parents; there was also significant difference in the practice in terms of marital status and employment status of parents. There was no difference in the practice of child labour among parents of different religions. It was recommended among others that parents should be economically empowered to reduce poverty and urge to involve their children in labour. Laws on child labour should be enforced by relevant agencies with a view to reducing incidence of child labour on our streets. School administrators should implore various organisations like the media, religious bodies and others to campaign against the practice of Child Labour. Key words: Child labour, school administrators, parents, prevalence, practice
EFFECT OF LITHIUM COATING ON THE IMPURITIES AND SHIELDING EFFECT OF PLASMA ON THE RESONANT MAGNETIC PERTURBATIONS FIELD IN THE STOR-M TOKAMAK PLASMA
Effects of lithium coating of the chamber wall on the impurities in the STOR-M tokamak plasma were studied in this thesis work. Impurities have been identified as one of the major concerns since the beginning of tokamak plasma research, as they enhance the radiation losses and prevent plasma from being heated to a desired high temperature. The radiation losses are primarily due to line radiation from incomplete stripped impurity ions. Impurities are introduced into the plasma from the walls of the tokamak due to plasma-wall interactions, and the type of impurities observed in a tokamak is partially determined by the kind of material used for the tokamak chamber wall and the gases absorbed in the wall. In the STOR-M tokamak, inner surface walls are made of bare stainless steel, and the major impurities observed are from carbon and oxygen. The emission lines from these impurities are in the visible range of the electromagnetic spectrum. They are CIII which is observable at 464.74 nm, CVI at 529.05 nm, and OV at 650.02 nm.
Before the chamber was coated with lithium, the intensities of the impurity lines were measured and then compared to the intensities after the lithiumization of the chamber wall. The intensities of the impurity lines were recorded during the stable period of plasma before and after the lithium coating using a spectrometer and an intensified charge-coupled device (ICCD) camera. It was observed that the intensities of the impurities reduced during the discharges immediately after the lithium coating. Further experimental analysis revealed that the freshly coated lithium caused plasma density to decrease, and increase after 300 plasma discharge shots. It was also found that after 600 and 900 plasma discharge shots, lithium coating does not appear to play any role in the reduction of the impurity intensities, but repetitive plasma discharge cleaning may be responsible for the decrease in the impurity intensities.
In another experiment, an internal radial magnetic probe array was used to investigate effects of plasma and tokamak chamber wall on resonant magnetic perturbation (RMP) field applied externally to plasma. An internal magnetic probe array was used to measure the magnetic field at four radial locations at plasma edge after the application of RMP current. The plasma response magnetic field measured was subtracted from the vacuum field measured when RMP current was fired without plasma. The time delay caused by the plasma and tokamak chamber wall to the RMP field was also studied by calculating the difference between the RMP current waveform peak time and the magnetic field waveforms peak times in plasma. It was observed that RMP field in vacuum was 50% larger than the RMP field in plasma, and the penetration time of the RMP fields decreased as they penetrate through the vacuum wall into the plasma. The RMP field was found to travel faster in plasma than in vacuum
Development of a dual purpose refrigeration system for domestic use
Refrigeration and air conditioning are very important in the daily activities of man, particularly in the tropical regions of the world; used in the preservation of perishable items, storage of pharmaceutical drugs, controlling of an atmospheric environment either for human/animal thermal comfort or effective performance of a scientific process. This paper is aimed at the design and construction of a dual purpose domestic refrigeration system, that can simultaneously function as a refrigerator and as well as an air conditioner henceforth known as REFACON. The refrigeration system employed was a vapour compression system. The machine was a split configuration with an Indoor and an outdoor unit (condensing unit). The machine used a singular 1,119 W single phase hermetically sealed reciprocating compressor, a fabricated condenser and split evaporator operated by temperature controlled solenoid valve. The system used 0.620 kg of R 22 refrigerant, with a discharge pressure of 1,355 kPa and suction pressure of 360 kPa. The input power was 1,350 W with an output cooling effect of 5,280 W. The combined cooling load/cooling capacity of the machine was 4,500 W. The results of tests conducted showed a total heat rejected of 6,680 W and a total evaporator heat absorption of 5,179 W. The Energy Efficiency Ratio was 3.91 while the Coefficient of Performance was 4.72. This research has shown that the design employed for the heat exchangers was appropriate and Thermal contact resistance cannot be neglected. http://dx.doi.org/10.4314/njt.v35i4.1
INFORMATION DISSEMINATION AND DECISION MAKING IN SECONDARY SCHOOLS IN OYO STATE
The study investigated the relationship between information dissemination and decision making in secondary schools. The studyexamined the predominant mode of information dissemination, level of decision making participation of teachers, the influence of school location and experience of teachers on information dissemination and decision making. The descriptive research design of the survey type was used. The population of the study consisted of all the teachers in all the public secondary schools in OyoState. The multistage random sampling technique was used to select 300 respondents consisting of teachers from 15 secondary schools in the state. Two research questions and two hypotheses were generated. A self designed questionnaire titled Information Dissemination and Decision making Questionnaire†(IDDMQ) was used to collect data from the respondents. The data was analysed using Pearson Product Moment Correlation and t-test Statistics. The hypotheses was tested at 0.05 level of significance. The study revealed that the predominant mode of disseminating information is by the school principal and heads of department while the level of decision making participation of teachers is moderately high to certain extents.There was positive relationship between information dissemination and decision making. It was also found that there was difference in the dissemination of information and decision making in schools located in rural and urban areas while there was no difference in the information and decision making of teacher based on their years of experience at work. It was recommended that all bottlenecks hindering information dissemination and decision making in schools should be dealt with. All teachers should be carried along while taking decisions regardless of experience and location of schools. All schools should be supplied with necessary infrastructures by the government that can aid information dissemination no matter the location of the school
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