Using Cyclic Genetic Algorithms to Learn Gaits for an Actual Quadruped Robot

It is a difficult task to generate optimal walking gaits for mobile legged robots. Generating and coordinating an optimal gait involves continually repeating a series of actions in order to create a sustained movement. In this work, we present the use of a Cyclic Genetic Algorithm (CGA) to learn near optimal gaits for an actual quadruped servo-robot with three degrees of movement per leg. This robot was used to create a simulation model of the movement and states of the robot which included the robot’s unique features and capabilities. The CGA used this model to learn gaits that were optimized for this particular robot. Tests done in simulation show the success of the CGA in evolving gait control programs and tests on robot show that these control programs produce reasonable gaits

The Effects of Using a Greedy Factor in Hexapod Gait Learning

Various selection schemes have been described for use in genetic algorithms. This paper investigates the effects of adding greediness to the standard roulette-wheel selection. The results of this study are tested on a Cyclic Genetic Algorithm (CGA) used for learning gaits for a hexapod servo-robot. The effectiveness of CGA in learning optimal gaits with selection based on roulette-wheel selection with and without greediness is compared. The results were analyzed based on fitness of the individual gaits, convergence time of the evolution process, and the fitness of the entire population evolved. Results demonstrate that selection with too much greediness tends to prematurely converge with a sub-optimal solution, which results in poorer performance compared to the standard roulette-wheel selection. On the other hand, roulette-wheel selection with very low greediness evolves more diverse and fitter populations with individuals that result in the desired optimal gaits

Motor Traffic Injuries in sub-Saharan Africa

Motor traffic injuries are recognized as a major public health problem in developing countries. MTIs continue to cause morbidity, mortality and disability in Sub Saharan Africa (SSA).To describe the magnitude of MTI’s in SSA and to find the magnitude of morbidity and mortality caused by MTI’s. The World Health Organization (WHO), PUBMED and EMBASE databases were used to identify documents and articles on MTIs in SSA and its effects. The literature review was supplemented by document review and interviews with a key informant in one region of Tanzania to determine the magnitude of morbidity and mortality associated with MTI’s in Tanzania. The mortality rate due to MTI’s in Lower and Middle Income Countries(LMIC’s) including SSA is about 20 per 100,000 population while in High Income Countries(HIC’s) it is about 10.3 per 100,000 population. MTI’s also represent the ninth leading cause of Disability Adjusted Life Years (DALY’s) lost and are forecasted by WHO to be the third leading cause of DALY’s lost by 2020. Total number of reported accidents in Kilimanjaro region in 2008 was 906 while in 2009 it was 1,125 accounting for an increase of 24%. The total mortality reported in 2008 was 147 and 202 in 2009 with an increase of 37%. The total morbidity was 622 in 2008 and 933 in 2009 accounting for a 50% increase. The high mortality rate in SSA of about 20 per 100,000 population is contributed mainly by human factors with the major being reckless driving and negligence of drivers, pedestrians and passengers. Morbidity and mortality due to MTI’s is increasing gradually over time as seen from the Kilimanjaro documents. The burden of MTI morbidity and mortality is predicted to rise by 80% in SSA and fall by 30% in HIC’s by 2020. MTI is still a public health problem in LMIC’s. Measures to improve human factors in causing MTA are urgently required in order to reverse the trend. I hereby conclude with the motto by the National Road Safety Council of Tanzania which says “Road safety is NO ACCIDENT” and that “Road safety is for sharing”

Quadruped Gait Learning Using Cyclic Genetic Algorithms

Generating walking gaits for legged robots is a challenging task. Gait generation with proper leg coordination involves a series of actions that are continually repeated to create sustained movement. In this paper we present the use of a Cyclic Genetic Algorithm (CGA) to learn gaits for a quadruped servo robot with three degrees of movement per leg. An actual robot was used to generate a simulation model of the movement and states of the robot. The CGA used the robot\u27s unique features and capabilities to develop gaits specific for that particular robot. Tests done in simulation show the success of the CGA in evolving a reasonable control program and preliminary tests on the robot show that the resultant control program produces a suitable gait

Knowledge, attitudes and beliefs on contributing factors among low back pain patients attending outpatient physiotherapy treatment in Malawi

BACKGROUND: Low back pain (LBP) affects many people globally. Its aetiology is not clear. Patients lack knowledge of its contributing factors and have negative perception about their LBP. This study aimed to identify knowledge, attitudes and beliefs regarding the perceived contributing factors to LBP among patients attending physiotherapy outpatient departments in Malawi. This information can possibly facilitate planning of a LBP education programme in Malawi. METHODS: A quantitative cross-sectional survey was conducted, using a six-part selfadministered questionnaire with questions on demographic information, participants’ attitudes and beliefs regarding their LBP, knowledge about the course and causes of LBP, beliefs regarding nine contributing factors to LBP (identified in a Delphi study) and the sources of the participants’ knowledge. Data were analysed descriptively using the Statistical Package for Social Sciences (version 19.0). A Chi-square test was used to determine any association between variables (alpha 0.05). All ethical procedures were strictly followed. RESULTS: Most participants (186, 91.2 %) did not manage to answer all six questions regarding knowledge correctly and were regarded as ‘partially knowledgeable’ about the course and causes of LBP. More than half (67%) portrayed negative attitudes and beliefs about LBP in general. The findings also showed a statistically significant relationship between knowledge, attitudes and beliefs (p = 0.04). CONCLUSION: This study highlighted that many patients with LBP in Malawi are not adequately knowledgeable about LBP and hold negative attitudes and beliefs regarding their LBP. Therefore, LBP management programmes in Malawi should include education programmes aimed at empowering patients with knowledge regarding LBP, as well as changing their negative attitudes and beliefs about their pain. Patients’ understanding of the cause and nature of their pain may enhance the achievement of treatment goals.DHE

Irrigation Scheduling Scenarios Studies for a Maize Crop in Tanzania Using a Computer-based Simulation Model

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 8 (2006): Irrigation Scheduling Scenarios Studies for a Maize Crop in Tanzania Using a Computer-based Simulation Model. Manuscript LW 06 007. Vol. VIII. November, 2006

A Qualitative Study of Perceived Risk for HIV Transmission among Police Officers in Dar es Salaam, Tanzania.

Understanding people's views about HIV transmission by investigating a specific population may help to design effective HIV prevention strategies. In addition, knowing the inherent sexual practices of such a population, as well as the risky circumstances that may facilitate HIV transmission, is crucial for the said strategies to become effective. In this article, we report how police officers in Dar es Salaam, Tanzania, perceived the problem of HIV and AIDS in their local context, particularly in relation to unsafe sexual practices. The study was done with the view to recommending ways by which HIV transmission could be minimised within the police force. The study was conducted among members of the police force in Dar es Salaam, Tanzania. Eight focus group discussions (FGDs) were conducted, with a total of 66 participants who were mixed in terms of age, gender, and marital status. Some of these were caregivers to patients with AIDS. Data were analysed using the interpretive description approach. The participants believed that both individual sexual behaviour and work-related circumstances were sources of HIV infection. They also admitted that they were being tempted to engage in risky sexual practices because of the institutional rules that prohibit officers from getting married during their training and for three years after. Nevertheless, as members of the Police Force, they stressed the fact that the risky sexual behaviour that exposes them to HIV is not limited to the force; it is rather a common problem that is faced by the general population. However, they complained, the nature of their job exposes them to road accident victims, subjecting them further to possible infection, especially when they have to handle these road accident casualties without proper protective gear. Individual sexual behaviour and job-related circumstances are worth investigating if proper advice is to be given to the police regarding HIV prevention strategies. In order to improve the lives of these police officers, there is a need to review the existing institutional rules and practices to accommodate individual sexual needs. In addition, improving their working environment may minimize the risk of HIV transmission from handling casualties in emergency situations

Sugarcane Production, Processing and Marketing in Tanzania

Sugarcane is one of the important food and commercial crops of Tanzania. Its production is concentrated mainly in three regions, Morogoro, Kagera and Kilimanjaro. Most of the sugar produced in the country is for home consumption and only a small proportion is exported to service foreign debts. This paper briefly reviews the agronomic, production and marketing aspects of sugarcane in Tanzania, with special emphasis on the factors associated with variation in production during the past ten years. During the 1983/84 season, the country produced slightly over 130, 000 tons of processed sugar, but 1988/89 production had dropped to just about 96, 000 tons. During the 1990's (1991/92-1993/94), production increased in response to the trade liberalization policy of the country. To increase and sustain the country's future sugar pruduction, improved soil management of sugarcane fields, irrigation technology and the use of improved clones need to be introduced. The current marketing and handling structure in the sugar industry requires reform in order to increase efficiency and reduce storage overheads paid by the consumers