27,973 research outputs found
Overlapping M-ary Frequency Shift Keying Spread-Spectrum Multiple-Access Systems using Random Signature Sequences
No full textIn this paper, a multiple-access spread-spectrum communication system using binary frequency shift keying (BFSK) or M-ary frequency shift keying (MFSK) and noncoherent demodulation is considered. In contrast to previous work typically assuming that the frequency shift keying (FSK) tones are nonoverlapping after direct-sequence (DS) spreading, here we consider a spread-spectrum multiple-access (SSMA) system under the assumption that the DS spread signals of different FSK tones are only orthogonal over the information symbol duration. Consequently, the frequency band of a spread FSK tone may be fully or partially overlapping with the other spread signals. An estimate of the variance of the multiple-access interference is obtained by assuming that the phase angles and time delays of the received signals are mutually independent random variables, provided that random signature sequences are employed for spreading. On the basis of the above assumptions, the bit error rate (BER) of our DS spread-spectrum multiple-access (DS-SSMA) and that of our hybrid DS slow frequency-hopping spread-spectrum multiple-access (DS-SFHSSMA) systems using FSK modulation is analyzed, when the channel impairments are constituted by a combination of additive white Gaussian noise (AWGN) and multiple-access interference. From our analysis and the numerical results, we concluded that, for a given system bandwidth and for a certain value of M, the system’s BER performance can be optimized by controlling the amount of overlapping and that the systems with optimized overlapping outperformed the systems using no overlapping. Index Terms—Frequency shift keying (FSK), slow frequency hopping, spread-spectrum multiple access
A process evaluation of the City of Cape Town Business Support Voucher Programme
No full textIncludes bibliographical references (leaves 74-78).This dissertation focuses on a process evaluation of the City of Cape Town (CoCT) Business Support Voucher Programme (BSVP) which assessed whether this programme was implemented as intended. The BSVP aims to provide access to quality business support services and products to entrepreneurs in order to empower them to develop and grow their businesses. The target beneficiaries of the BSVP are the over 35 year old age group (including women, youth and the disabled) who are potential or start-up entrepreneurs or who own/run existing small businesses. A service utilisation flow chart was used to review the services provided by the allocating agents and the business development service providers. Data providers included the project sponsors, the implementation agent, the allocating agents and a convenience sample of beneficiaries and service providers. Additional materials used included check lists during site visits and a review of records. The findings suggested that whilst the programme was largely implemented as planned, there could be improvements to the definition of the programme targets, the consistency of the implementation across the programme and putting monitoring and reporting systems in place. The dissertation includes selected recommendations for implementation improvement, sustainability and future outcomes and impacts
An improved optimistic three-stage model for the spread of HIV amongst injecting intravenous drug users
No full textWe start off this paper with a brief introduction to modeling Human Immunodeficiency Virus (HIV) and Acquired Immune Deficiency Syndrome (AIDS) amongst sharing, injecting drug users (IDUs). Then we describe the mathematical model which we shall use which extends an existing model of the spread of HIV and AIDS amongst IDUs by incorporating loss of HIV infectivity over time. This is followed by the derivation of a key epidemiological parameter, the basic reproduction number R0. Next we give some analytical equilibrium, local and global stability results. We show that if R0 >e 1 then the disease will always die out. For R0 > 1 there is the disease-free equilibrium (DFE) and a unique endemic equilibrium. The DFE is unstable. An approximation argument shows that we expect the endemic equilibrium to be locally stable. We next discuss a more realistic version of the model, relaxing the assumption that the number of addicts remains constant and obtain some results for this model. The subsequent section gives simulations for both models confirming that if R0 >e 1 then the disease will die out and if R0 > 1 then if it is initially present the disease will tend to the unique endemic equilibrium. The simulation results are compared with the original model with no loss of HIV infectivity. Next the implications of these results for control strategies are considered. A brief summary concludes the paper
An Environmental Perspective of Dracunculiasis and the Guinea Worm Eradication Programme on Human Behaviour in the Northern Region of Ghana
No full textThis article examines the role dracunculiasis (Guinea Worm Disease – GWD) and the Guinea Worm Eradication Programme (GWEP) played in changing community members’ behaviour towards the disease and their bio-physical environment. The research design that was used to collect data was the mixed method approach, in which questionnaire was administered, Focus Group Discussion (FGD) was held, and key informant interviews conducted. Krejcie and Morgan’s formula for determining sample population for research was used to determine the sample population of the study area, which was 860. It was found that bedrock lithology made community members to resort to unsafe sources of drinking water which exposed them to GWD. It was also realized that the educational programmes which the GWEP brought along with it changed community members’ behaviour towards their bio-physical environment, which ultimately resulted in eradicating the disease in the study area. It was therefore recommended that in carrying out disease eradication or control programmes, the environmental protection agency should be involved in the process of educating community members on methods of improving on the integrity of their natural and built environment to enhance the overall health status of the community
Potential risk of regional disease spread in west Africa through cross-border cattle trade
No full textTransboundary animal movements facilitate the spread of pathogens across large distances. Cross-border cattle trade is of economic and cultural importance in West Africa. This study explores the potential disease risk resulting from large-scale, cross-border cattle trade between Togo, Burkina Faso, Ghana, Benin, and Nigeria for the first time.; A questionnaire-based survey of livestock movements of 226 cattle traders was conducted in the 9 biggest cattle markets of northern Togo in February-March 2012. More than half of the traders (53.5%) operated in at least one other country. Animal flows were stochastically simulated based on reported movements and the risk of regional disease spread assessed. More than three quarters (79.2%, range: 78.1-80.0%) of cattle flowing into the market system originated from other countries. Through the cattle market system of northern Togo, non-neighbouring countries were connected via potential routes for disease spread. Even for diseases with low transmissibility and low prevalence in a given country, there was a high risk of disease introduction into other countries.; By stochastically simulating data collected by interviewing cattle traders in northern Togo, this study identifies potential risks for regional disease spread in West Africa through cross-border cattle trade. The findings highlight that surveillance for emerging infectious diseases as well as control activities targeting endemic diseases in West Africa are likely to be ineffective if only conducted at a national level. A regional approach to disease surveillance, prevention and control is essential
Student Experiences in Institutions of Higher learning: A Case Study of Uganda’s Leading Architecture Programme
No full textStudent experience has a strategic importance to any institution of higher learning, as it can potentially impact on the institution’s reputation, as well as long-term sustainability. The present study is an exploration of student experiences in higher institutions of learning in Uganda, taking Makerere University Architecture School (MUAS) as the case study. Using a mixed-method research approach, the study sought to evaluate students' perspectives on the architectural teaching program and their extent of success at MUAS. The study focused on 70 graduates from Makerere University's architectural program, specifically those who completed the programme within five years. Data were analysed using descriptive statistics. In the findings, students revealed that the program placed significant academic and psychological demands on them throughout the five-year duration. They revealed the intense workload, unclear academic expectations, and the emotional strain caused by harsh critique and punitive course-retake policies of the university. Equally concerning were the strained relationships between students and tutors, with over half describing these as difficult or very difficult. The physical and resource environment was identified as a critical barrier to student success. Inadequate teaching-studio spaces, lack of fulltime access, insufficient workshops, and outdated equipment have a serious impact on their innovation as Architecture students. Recommendations include revision of the curriculum to achieve a better balance between theoretical knowledge and practical skills. Others are infrastructural improvements, such as upgrading and expanding studio spaces to provide dedicated, fulltime accessible workspace will encourage creativity and collaboration and the establishment of well-equipped workshops and digital fabrication labs
Attitudes of Teachers Who Implement School Mediation Programmes: A Case Study
No full textSchool mediation (or peer mediation) is an effective practice for resolving student-centered conflicts in the school context. According to the results of this qualitative research conducted at Secondary Education Schools of Western Attica (Greece), an area with particular social characteristics, school mediation programmes are a dynamic process and can contribute to: teamwork, communication and activation of students, changing attitudes and behaviors as well as inclusion of students with behavioral problems. These results are achieved despite the heterogeneity of the education programme followed and the heterogeneity of the population attending them. Under no circumstances, however, the implementation of a school mediation programme can be considered a panacea. On the contrary, it is proposed to be accompanied by other actions that will promote a different management spirit of the school and will improve the school climate
The programme for the conservation of Cuban cacti: Achievements and challenges
No full textA brief summary of the progress made in the conservation programme for the threatened cacti of Cuba. Photography by the author. [ABSTRACT FROM THE AUTHOR]Peer reviewedfinal article publishe
A Comparative Study on Sino-UK Postgraduate Professional Degree Education and Implications
No full textChinese postgraduate professional degree education has undergone 26 years of development, and has achieved a great progress. But compared with the developed nations in the world, China is still in its infantry stage, and needs to learn from the western developed countries’ experiences in this field. This paper makes a comparative analysis of the differences between China and UK in postgraduate professional degree education. It finds that there are significant differences between the two countries in the aspects of programme setting, schooling duration, admissions, curriculum design, teaching delivery, quality control system, etc. The findings imply that China should try to give more authority to universities in programme setting and admissions, and Chinese universities should innovate ways of teaching delivery and systems of quality control
Employer of Last Resort? South Africa’s Expanded Public Works Programme (EPWP)
No full textSouth Africa’s largest active labour market intervention (ALMP) is the Expanded Public Works Programme (EPWP). Its first five-year phase has been completed and a second phase, more ambitious by far than its predecessor, has commenced. Critical analysis suggests that contrary to the hype, the programme has thus far made little lasting impact on the poverty and unemployment it is supposed to address. The analysis is in four parts: the first is an exploration of the background to the EPWP, in its role as South Africa’s largest active labour market policy; the second presents an examination of aspects of the performance of EPWP Phase 1, looking in particular at target vs. actual numbers of job opportunities and training days. This section also looks briefly at the EPWP’s proposed monitoring and evaluation (M&E) programme, before undertaking a more detailed consideration of the published information available on the training/employment nexus. The section ends with a glance at weaknesses in one of the surveys (the Labour Force Surveys, LFSs) put forward as data sources for evaluating the EPWP during Phase1; the third considers aspects of the vast increases in the scope of EPWP from Phase 1 to Phase 2, of the way in which these have been communicated, and of the way in which they are to be funded, while fourth the looks at the possible contribution that this second phase could/may make to the goal of halving unemployment by 2014. This part of the paper reproduces a set of scenarios produced by the National Treasury and published in the Budget Review 2010. These point to the extreme unlikelihood of the unemployment halving goal being attained. The paper ends with a set of recommendations, many relating to the production and distribution of knowledge about the EPWP.
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