5 research outputs found
An Analysis of the Delivery of Health Education by Upper Basic Stage Science Teachers in Jordan
This study investigates the delivery of health education within the upper basic stage
science curriculum in Jordan, which covers the crucial age range 13-16. It begins by exploring
various definitions and models relating to health education with a view to selecting the most
appropriate for use in this study. This is followed by a review of the literature to examine the different ways in which health education is delivered.
Within Jordan, the policy on health education, as revealed by official documents and guidance
issued to science teachers, is analysed. The teaching methods used by science teachers in the
delivery of health education are also investigated, together with the content and nature of the various health education topics delivered.
A variety of data collection methods were employed; questionnaires to establish the amount and
content of health education taught, semi-structured interviews to find out the range of
teaching and learning methods being employed and analysis of documentary materials.
The study attempts to determine whether there are any particular factors that affect the amount and
content of health education taught; these are teacher gender, region of Jordan, teaching
subject (biology, chemistry or physics), qualifications in that subject, and teaching
qualifications and experience. The data were collected in Jordan between September 1999 and January 2000.
One of the major findings of the study was that the current policy regarding health education in
Jordan is not clear. There is a tendency to emphasise theoretical aspects rather than practical ones, and the affective domain, resulting in values and behaviour change, receives very little attention. It was found that at present, five health areas are being delivered within the science curriculum; these are personal health, nutritional health, disease and prophylaxis, environmental health and education for married life. The amount of health education taught was in the 'moderate' or 'low' categories used in the study, with environmental health receiving the greatest emphasis, and education for family life the least. The latter was particularly variable, with significant differences among male and female teachers. This could be due to religious and cultural factors.
The study suggests that the variation in the delivery of health education by science teachers is probably related to the lack of a clear policy from the Jordanian Ministry of Education, and the
fact that health education topics are not clearly identified in the official curriculum documents.
It recommends that a national policy is developed, from which regional and local policies can be
adapted to meet different needs. Schools should also develop their own policies, particularly for
the teaching of education for family life, with teachers, health professionals and local community
leaders also involved. A greater precision in the description of health topics in the curriculum
and the production of teacher guidance and relevant textbooks are also recommended.
It is hoped that this study will help develop new strategies for the future of health education
in Jordan and the future health of the nation
Dynamic probabilistic routing discovery and broadcast schemes for high mobility Ad-hoc networks
Mobile Ad-hoc Networks (MANETs) have lately come to be widely used in everyday applications. Their usability and capability have attracted the interest of both commercial organizations and research communities. Recently, the Vehicular Ad-hoc Network (VANET) is a promising application of MANETs. It has been designed to offer a high level of safety for the drivers in order to minimize a number of roads accidents. Broadcast communication in MANETs and VANETs, is essential for a wide range of important services such as propagating safety messages and Route REQuest (RREQ) packets. Routing is one of the most challenging issues in MANETs and VANETs, which requires high efficient broadcast schemes.The primitive and widely deployed method of implementing the broadcast is simple ‘flooding’. In this approach, each node ‘floods’ the network, with the message that it has received, in order to guarantee that other nodes in the network have been successfully reached. Although flooding is simple and reliable, it consumes a great deal of network resources, since it swamps the network with many redundant packets, leading to collisions contention and huge competition, while accessing the same shared wireless medium. This phenomenon is well-known in MANETs, and is called the Broadcast Storm Problem.The first contribution of this thesis is to design and develop an efficient distributed route discovery scheme that is implemented based on the probabilistic concept, in order to suppress the broadcast storm problem. The proposed scheme is called a Probabilistic Disturbed Route Discovery scheme (PDRD), and it prioritizes the routing operation at each node with respect to different network parameters such as the number of duplicated packets, and local and global network density. The performance of the proposed scheme PDRD has been examined in MANETs, in terms of a number of important metrics such as RREQ rebroadcast number and RREQ collision number. Experimental results confirm the superiority of the proposed scheme over its counterparts, including the Hybrid Probabilistic-Based Counter (HPC) scheme and the Simple Flooding (SF) scheme.The second contribution of this thesis is to tackle the frequent link breakages problem in MANETs. High mobility nodes often have frequent link breakages; this potentially leads to re-discovery of the same routes. Although different probabilistic solutions have been suggested to optimize the routing in MANETs, to the best of our knowledge they have not focused on the problem of frequent link breakages and link stability.IIUnlike other existing probabilistic solutions, this thesis proposes a new Velocity Aware-Probabilistic (VAP) route discovery scheme, which can exclude unstable nodes from constructing routes between source and destination. The main idea behind the proposed schemes is to use velocity vector information to determine the stable nodes and unstable nodes. A proper rebroadcast probability and timer are set dynamically according to the node stability. Simulation results confirm that the new proposed scheme has much better performance in terms of end-to-end delay, RREQ rebroadcast number and link stability.The routing in VANETs is very critical and challenging in terms of the number of broken links and packet overheads. This is mainly due to the fast vehicles’ speed and different vehicles’ movement directions. A large number of routing protocols such as Ad-hoc On-demand Distance Vector (AODV) and Dynamic Source Routing (DSR) have been proposed to deal with the routing in MANETs. However, these protocols are not efficient and cannot be applied directly to VANETs context due to its different characteristics. Finally toward this end, this thesis proposes new probabilistic and timer probabilistic routing schemes in order to improve the routing in VANETs. The main aim of the proposed schemes is to set up the most stable routes to avoid any possible link breakage. These schemes also enhance the overall network performance by suppressing the broadcast storm problem, which occurs during the route discovery process. The proposed schemes also make AODV protocol suitable and applicable for VANETs. Simulation results show the benefit of the new routing schemes in terms of a number of metrics such as RREQ rebroadcast number, link stability and end-to-end delay
A New Load-Balancing Aware Objective Function for RPL’s IoT Networks
The IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) has been recently standardized as the de facto solution for routing in the context of the emerging Internet of Things (IoT) paradigm. RPL, along with other standards, has provided a baseline framework for IoT that has helped advance communications in the world of embedded resource-constrained networks. However, RPL still suffers from issues that may limit its efficiency such as the absence of an efficient load-balancing primitive. In this study, we show how RPL suffers from a load-balancing problem that may harm both the reliability of the protocol and its network lifetime. To address this problem, a novel load-balancing scheme is introduced that significantly enhances the reliability of RPL and fosters the protocol’s efficiency in terms of power consumption
New efficient velocity-aware probabilistic route discovery schemes for high mobility Ad hoc networks
Most existing route discovery schemes in MANETs are based on probabilistic models by which MANETs usually deploy broadcast mechanisms to discover routes between nodes. This is implemented by flooding the network with routing requests (RREQ) packets which usually result in the well-known broadcast storm problem. Due to the high mobility, frequent breakages are more likely to occur, leading to re-discovering the same routes frequently uncontrolled RREQ packets. Thus, the network may incur more channel contention and high packets collision rate. Existing solutions cannot accommodate the desired performance levels, especially in high mobility. Thus, this paper is the first that considers the velocity vector probabilistic route discovery in MANETs. Two new velocity-aware probabilistic route discovery models are presented to exclude unstable nodes while constructing routes between the source and its destination. The simulation experiments confirm the superiority of the proposed schemes in terms of RREQ packet overhead and link stability