An epidemiology of disease control in Ghana 1901-1990

An inaugural lecture delivered at the University of Ghana, Legon on 17th January, 199

Ground-Based Localization of Mars Rovers

The document discusses a procedure for localizing the Mars rovers in site frame, a locally defined reference frame on the Martian surface. MER onboard position within a site frame is estimated onboard and is based on wheel odometry. Odometry estimation of rover position is only reliable over relatively short distances assuming no wheel slip, sinkage, etc. As the rover traverses, its onboard estimate of position in the current site frame accumulates errors and will need to be corrected on occasions via relocalization on the ground (mission operations). The procedure provides a systematic process for ground operators to localize the rover. The method focuses on analysis of acquired images used to declare a site frame and images acquired post-drive. Target selection is performed using two main steps. In the first step, the user identifies features of interest from the images used to declare the current site. Each of the selected target s position in site frame is recorded. In the second step, post-traverse measurements of the selected features positions are recorded again, this time in rover frame, using images acquired post-traverse. In the third step, we transform the post-traverse target s positions to local level frame. In the fourth step, we compute the delta differences in the pre- and post-traverse target s position. In the fifth step, we analyze the delta differences with techniques that compute their statistics to determine the rover s position in the site frame

Tourism and Its Impact on Economic Development

The relevant nature of tourism has been clearly found in this study. Tourism is recognized as the developmental factor for an economy. The study therefore chose to conduct the effect of tourism on economic development in Ghana. The study sought to analyze the relationship between tourism and infrastructural development in Ghana. It also examined the relationship between crime rate and tourism in Ghana and analyze the trend of tourism and economic growth in Ghana. The study also focused on examining the effect of tourism on the economic growth of Ghana and finally, analyzed the effectiveness of policy on tourism in Ghana. The study adopted quantitative approach through the use of secondary data from 1990 to 2019. Research analysis used for this study was the instrumental variable and correlation. The outcome of the study suggested that infrastructure development of the economy shows a positive relationship with tourism. It was also estimated in the study that when crime is high tourism tends to be low and vice versa. On the part of the estimation, natural resource was the variable used as the instrumental variable. The outcome from controlled variables such as international trade and exchange rate was found to be positively related to economic growth and development in Ghana. Also, instrumental variable estimation showed that tourism had a positive effect on the economic growth of Ghana. The outcome of the study revealed how the sector had reduced the unemployment rate in Ghana through the provision of both direct and indirect job for its people. The sector however is now coupled with challenges such policy issues and COVID 19 as revealed by players in the sector indicates the overreliance on government. Per the outcome of the study, it was recommended that long term policy should be put in place to ensure that successive government follow to prevent the distortion of the progress of the sector. It is recommended that infrastructure development and tourism should be investigated extensively by focusing on the effect of tourism on economic growth in Ghana. Keywords: Tourism, Economic Development DOI: 10.7176/JTHS/60-03 Publication date: March 31st 2022

Converting CSV Files to RKSML Files

A computer program converts, into a format suitable for processing on Earth, files of downlinked telemetric data pertaining to the operation of the Instrument Deployment Device (IDD), which is a robot arm on either of the Mars Explorer Rovers (MERs). The raw downlinked data files are in comma-separated- value (CSV) format. The present program converts the files into Rover Kinematics State Markup Language (RKSML), which is an Extensible Markup Language (XML) format that facilitates representation of operations of the IDD and enables analysis of the operations by means of the Rover Sequencing Validation Program (RSVP), which is used to build sequences of commanded operations for the MERs. After conversion by means of the present program, the downlinked data can be processed by RSVP, enabling the MER downlink operations team to play back the actual IDD activity represented by the telemetric data against the planned IDD activity. Thus, the present program enhances the diagnosis of anomalies that manifest themselves as differences between actual and planned IDD activities

Dig Hazard Assessment Using a Stereo Pair of Cameras

This software evaluates the terrain within reach of a lander s robotic arm for dig hazards using a stereo pair of cameras that are part of the lander s sensor system. A relative level of risk is calculated for a set of dig sectors. There are two versions of this software; one is designed to run onboard a lander as part of the flight software, and the other runs on a PC under Linux as a ground tool that produces the same results generated on the lander, given stereo images acquired by the lander and downlinked to Earth. Onboard dig hazard assessment is accomplished by executing a workspace panorama command sequence. This sequence acquires a set of stereo pairs of images of the terrain the arm can reach, generates a set of candidate dig sectors, and assesses the dig hazard of each candidate dig sector. The 3D perimeter points of candidate dig sectors are generated using configurable parameters. A 3D reconstruction of the terrain in front of the lander is generated using a set of stereo images acquired from the mast cameras. The 3D reconstruction is used to evaluate the dig goodness of each candidate dig sector based on a set of eight metrics. The eight metrics are: 1. The maximum change in elevation in each sector, 2. The elevation standard deviation in each sector, 3. The forward tilt of each sector with respect to the payload frame, 4. The side tilt of each sector with respect to the payload frame, 5. The maximum size of missing data regions in each sector, 6. The percentage of a sector that has missing data, 7. The roughness of each sector, and 8. Monochrome intensity standard deviation of each sector. Each of the eight metrics forms a goodness image layer where the goodness value of each sector ranges from 0 to 1. Goodness values of 0 and 1 correspond to high and low risk, respectively. For each dig sector, the eight goodness values are merged by selecting the lowest one. Including the merged goodness image layer, there are nine goodness image layers for each stereo pair of mast images

Mission Reliability Estimation for Repairable Robot Teams

A mission reliability estimation method has been designed to translate mission requirements into choices of robot modules in order to configure a multi-robot team to have high reliability at minimal cost. In order to build cost-effective robot teams for long-term missions, one must be able to compare alternative design paradigms in a principled way by comparing the reliability of different robot models and robot team configurations. Core modules have been created including: a probabilistic module with reliability-cost characteristics, a method for combining the characteristics of multiple modules to determine an overall reliability-cost characteristic, and a method for the generation of legitimate module combinations based on mission specifications and the selection of the best of the resulting combinations from a cost-reliability standpoint. The developed methodology can be used to predict the probability of a mission being completed, given information about the components used to build the robots, as well as information about the mission tasks. In the research for this innovation, sample robot missions were examined and compared to the performance of robot teams with different numbers of robots and different numbers of spare components. Data that a mission designer would need was factored in, such as whether it would be better to have a spare robot versus an equivalent number of spare parts, or if mission cost can be reduced while maintaining reliability using spares. This analytical model was applied to an example robot mission, examining the cost-reliability tradeoffs among different team configurations. Particularly scrutinized were teams using either redundancy (spare robots) or repairability (spare components). Using conservative estimates of the cost-reliability relationship, results show that it is possible to significantly reduce the cost of a robotic mission by using cheaper, lower-reliability components and providing spares. This suggests that the current design paradigm of building a minimal number of highly robust robots may not be the best way to design robots for extended missions

Exploring Small Ghanaian and U.S. Banks\u27 Efficiency During the 2007-2009 Financial Crisis

The adverse effect of small bank closures in the United States from 2007 to 2009 required $7 trillion from United States taxpayers to rescue the United States economy. This comparative case study explored the reasons that led to differences in efficiency in small banks in the United States and Ghana during the 2007 to 2009 period. This research was driven by the contingency theory, which states leaders perform well if they change their styles of leadership to suit the situation at hand. Semistructured interviews were employed to gather data from 20 senior and chief executives of small banks: 10 from the United States and 10 from Ghana. Data were formatted into matrices using the van Kaam method and then coded and organized into categories, which led to the identification of the 2 themes: (a) policies and practices and (b) reasons that contributed to the differences in efficiency between small banks in the United States and Ghana. The participants expressed concerns regarding the impact of increased regulations and bank reserves, and the resulting impact on the future of small banks. Findings from this study suggest that small banks that relaxed their mortgage qualification requirements during the 2007 to 2009 financial crisis had more losses compared to the small banks that did not. Additionally, findings from the United States and Ghana revealed small banks focusing on commercial loans had less losses compared to small banks investing in residential real estate. This study may contribute to social change by providing bank leaders with additional tools to prevent future bank failures and the confidence to make new commercial and residential mortgage loans, thereby creating jobs, lowering poverty, increasing income levels, and contributing to a more stable economy in which small banks operate

Fusing Image Data for Calculating Position of an Object

A computer program has been written for use in maintaining the calibration, with respect to the positions of imaged objects, of a stereoscopic pair of cameras on each of the Mars Explorer Rovers Spirit and Opportunity. The program identifies and locates a known object in the images. The object in question is part of a Moessbauer spectrometer located at the tip of a robot arm, the kinematics of which are known. In the program, the images are processed through a module that extracts edges, combines the edges into line segments, and then derives ellipse centroids from the line segments. The images are also processed by a feature-extraction algorithm that performs a wavelet analysis, then performs a pattern-recognition operation in the wavelet-coefficient space to determine matches to a texture feature measure derived from the horizontal, vertical, and diagonal coefficients. The centroids from the ellipse finder and the wavelet feature matcher are then fused to determine co-location. In the event that a match is found, the centroid (or centroids if multiple matches are present) is reported. If no match is found, the process reports the results of the analyses for further examination by human experts

Site Tamper and Material Plow Tool - STAMP

A non-actuated tool has been developed for preparing regolith for in situ measurement by smoothing uneven surfaces and excavating fresher subsurface material for planetary exploration. The STAMP tool contains two tools to prepare regolith for in situ measurement: a tamper to smooth uneven surfaces, and a blade to excavate fresher subsurface material