The Ghana National Service Scheme: Perceptions of former educational personnel, students and guardians

The purpose of this inquiry was to investigate the perceptions of former service personnel, students and their parents about the organizational effectiveness of the Ghana National Service Scheme (GNSS). The inquiry addressed the following questions: How do the participants perceive the effectiveness of the national service program on the Ghanaian society? What are the perceptions of school administrators who worked with service personnel, parents and students vis-à-vis the over all impact of the GNSS on the educational system? What are the perceptions of former service personnel, students and their parents in regard to the impact of the GNSS on them? ^ The GNSS is a part within the ministry of education, which is also part in the Ghanaian social structure. Hence, a systems theory approach which asks, “How and why a system as a whole functions as it does” (Patton, 1990), was utilized in the study. Methodologies included purposive sampling; interviews; participant observation, and follow-up interviews. The study was conducted over a six-moth period. ^ A cross-sectional survey design was used to generate data. The survey was followed up with an ethnographic study where in-depth, face-to-face interviews were conducted together with observations. The results were described and interpreted. ^ The summary of findings concludes that perceptional determinants of the effectiveness of the GNSS were biased by the age and zone of origin but not gender. This partially agrees with Marenin's (1990) except for gender. A significant difference was detected between the responses of those who were officials of the National service Secretariat and of former service personnel. The administrators defended the status quo and demonstrated their deeper knowledge about the scheme. The former personnel and parents freely criticized the program when necessary and did not seem to know much about the GNSS. Respondents mostly stressed the need for the secretariat to focus on the following areas: (1) involvement in the agricultural sector of the economy, (2) involvement in rural mass, civic and health education, (3) adequacy of remuneration and personnel welfare, and (4) ensuring posting of personnel to areas of their expertise. Recommendation for further research concluded the study. ^

Directionality based preventive link maintenance scheme for mobile ad hoc networks

The purpose of this study was to design a preventive scheme using directional antennas to improve the performance of mobile ad hoc networks. In this dissertation, a novel Directionality based Preventive Link Maintenance (DPLM) Scheme is proposed to characterize the performance gain [JaY06a, JaY06b, JCY06] by extending the life of link. In order to maintain the link and take preventive action, signal strength of data packets is measured. Moreover, location information or angle of arrival information is collected during communication and saved in the table. When measured signal strength is below orientation threshold , an orientation warning is generated towards the previous hop node. Once orientation warning is received by previous hop (adjacent) node, it verifies the correctness of orientation warning with few hello pings and initiates high quality directional link (a link above the threshold) and immediately switches to it, avoiding a link break altogether. The location information is utilized to create a directional link by orienting neighboring nodes antennas towards each other. We call this operation an orientation handoff, which is similar to soft-handoff in cellular networks. ^ Signal strength is the indicating factor, which represents the health of the link and helps to predict the link failure. In other words, link breakage happens due to node movement and subsequently reducing signal strength of receiving packets. DPLM scheme helps ad hoc networks to avoid or postpone costly operation of route rediscovery in on-demand routing protocols by taking above-mentioned preventive action. ^ This dissertation advocates close but simple collaboration between the routing, medium access control and physical layers. In order to extend the link, the Dynamic Source Routing (DSR) and IEEE 802.11 MAC protocols were modified to use the ability of directional antennas to transmit over longer distance. A directional antenna module is implemented in OPNET simulator with two separate modes of operations: omnidirectional and directional. The antenna module has been incorporated in wireless node model and simulations are performed to characterize the performance improvement of mobile ad hoc networks. Extensive simulations have shown that without affecting the behavior of the routing protocol noticeably, aggregate throughput, packet delivery ratio, end-to-end delay (latency), routing overhead, number of data packets dropped, and number of path breaks are improved considerably. We have done the analysis of the results in different scenarios to evaluate that the use of directional antennas with proposed DPLM scheme has been found promising to improve the performance of mobile ad hoc networks. ^