Maintenance of communication in primary classrooms : some evidence for the role of elicitation and code-switching in English medium schools in Kenya, with implications for teaching

This is a study of specific aspects of classroom interaction primary school level in Kenya. The study entailed the identification of the sources of particular communication problems during the change-over period from Kiswahili to English medium teaching in two primary schools. There was subsequently an examination of the language resources which were employed by teachers to maintain pupil participation in communication in the light of the occurrence of possibility of occurrence of specific communication problems. The language resources which were found to be significant in this regard concerned firstly the use of different elicitation types by teachers to stimulate pupils into giving responses and secondly teachers' recourse to code-switching from English to Kiswahili and vice-versa. It was also found in this study that although the use of English as the medium of instruction in the classrooms which were observed resulted in certain communication problems, some of these problems need not have arisen if teachers had been more careful in their use of language. The consideration of this finding, after taking into account the role of different elicitation types and code-switching as interpretable from data samples had certain implications which are specified in the study for teaching in Kenyan primary schools. The corpus for the study consisted of audio-recordings of English, Science and Number-Work lessons which were later transcribed. Relevant data samples were subsequently extracted from transcripts for analysis. Many of the samples have examples of cases of communication breakdowns, but they also illustrate how teachers maintained interaction with pupils who had yet to acquire an operational mastery of English. This study thus differs from most studies on classroom interaction because of its basic concern with the examination of the resources available to teachers for overcoming the problem areas of classroom communication

Analysis of The Impact of Fuzzy Logic Algorithm On Handover Decision in A Cellular Network

Fuzzy logic is one of the intelligent systems that can be used to develop algorithms for handover. For success in handing over, the decision-making process is crucial and thus should be highly considered. The performance of fixed parameters is not okay in the changing cellular system environments. The work done on this paper aims to analyse the impact of utilising the fuzzy logic system for handover decision making considering the Global System for Mobile communication (GSM) network. The results from the different simulations show that the need to handover varies depending on the input(s) to the Fuzzy Inference System (FIS). By increasing the number of data, thus the criteria parameters used in the algorithm, an Optimised Handover Decision (OHOD) is realised

An Optimal Eigenvalue Based Spectrum Sensing Algorithm for Cognitive Radio

Spectrum is a scarce resource, and licensed spectrum is intended to be used only by the spectrum owners. Various measurements of spectrum utilization have shown unused resources in frequency, time and space. Cognitive radio is a new concept of reusing licensed spectrum in an unlicensed manner. The unused resources are often referred to as spectrum holes or white spaces. These spectrum holes could be reused by cognitive radios, sometimes called secondary users. All man-made signals have some structure that can be potentially exploited to improve their detection performance. This structure is intentionally introduced for example by the channel coding, the modulation and by the use of space-time codes. This structure, or correlation, is inherent in the sample covariance matrix of the received signal. In particular the eigenvalues of the sample covariance matrix have some spread, or in some cases some known features that can be exploited for detection. This work aims to implement, evaluate, and eventually improve on algorithms for efficient computation of eigenvalue-based spectrum sensing methods. The computations will be based on power methods for computation of the dominant eigenvalue of the covariance matrix of signals received at the secondary users. The proposed method endeavors to overcome the noise uncertainty problem, and perform better than the ideal energy detection method. The method should be used for various signal detection applications without requiring the knowledge of the signal, channel and noise power

Using UNII-3 (Wi-Fi) Frequencies to Establish Long Distance Point-to-Point Links Capable of Providing Broadband Internet Access to Rural Areas: Experimental Validation

This paper demonstrates use of UNII-3 (Wi-Fi) frequencies, 5.725 - 5.825GHz in setting up long distance point-to-point links, capable of providing broadband internet in rural areas. Although this frequency band was intended for indoor wireless local area networks, its lack of licensing and inexpensive off-shelf networking devices has prompted many researchers and technology enthusiasts to extend its use to outdoor settings. This paper presents a long distance point-to-point test-bed model that uses high-gain directional antennas that may be replicated to provide broadband internet access in rural areas particularly in developing countries. Six long-distance point-to-point links have been set up. A link distance of 24.3kilometers, the longest so far, has been achieved. A peak throughput of 98.4Mbps has been observed on all of the links set up, irrespective of their link lengths. This test-bed model is easy and inexpensive to implement and it may be replicated to provide broadband internet access in the rural areas. This paper validates the use of these unlicensed frequencies and proves that as long as a clear line of sight between the nodes is achievable, high bandwidth link may be achieved capable of serving 1000+ simultaneous users each utilizing at least 100kbps. Keywords: Point-to-point links, long distance Wi-Fi, broadband for rural areas, directional antenna

Handover Parameter Optimisation of a Cellular Network The Kenyan Case

Handover, also known as Handoff is a key procedure that ensures that the cellular users move freely through the network while still being connected and being offered quality services. It is an event taking place whenever a mobile node moves from one wireless cell to another, abandoning the connection with the first base station and getting attached to the second one.  Since its success rate is a key indicator of user satisfaction, it is vital that this procedure happens as fast and as seamlessly as possible. This paper aims to optimize the handover decision process of a cellular radio network for an in-vehicle mobile station. This is first by determining the optimal handover parameters then developing an algorithm that determines the best time to handover using the fuzzy logic system

Cloud radio access network fronthaul solution using optimized dynamic bandwidth allocation algorithm

In order to address the challenges that have come with the exploding demand for higher speed, traffic growth and mobile wireless devices, Mobile network operators have decided to move to the notion of small cells based on cloud radio access network. The merits of cloud based RAN includes the ease of infrastructure deployment and network management as well as the fact that its performance are optimized and it is cost effective the merits of cloud based RAN includes the ease of infrastructure deployment and network management as well as the fact that its performance are optimized and it is cost effective. Notwithstanding, cloud radio access network comes with so many strict requirements to be fulfilled for its fronthaul network. In this paper, we have presented these requirements for a 5G fronthaul network. Particular interest on the time division multiplex passive optical network’s challenge of latency was treated by proposing an optimized version of the round robin dynamic bandwidth allocation algorithm. Results obtained show an improvement in the latency of the original algorithm which meets the fronthaul requirement. Other test parameters like jitter and BER were also improved by our proposed optimized algorithm

First In First Out (FIFO) And Priority Packet Scheduling Based On Type Of Service (TOS)

Mobile Ad Hoc Networks (MANETs) require prudent resource allocations especially in scheduling mechanisms that manage buffering of packets during waiting time. Various scheduling algorithms may be implemented to govern packet transmission and control packet loss hence managing the Quality of Service (QoS). Such mechanisms include first-in-first-out (FIFO), priority queuing (PQ), and weighted-fair queuing (WFQ). In this research paper, a comparison is made between FIFO and PQ mechanisms in a mixed traffic scenario (HTTP, FTP and VoIP applications). PQ is implemented on the basis of packet Type of Service (ToS), with VoIP data packets being given the upper hand. OPNET simulator is utilized in this paper. The study has been carried out on some issues like: Traffic dropped Traffic Received and packet end to end delay and the simulation results shows that WFQ technique has a better-quality than the other techniques. Keywords: MANETS, QoS, PQ, FIFO, Queuing, ToS, OPNE

The challenges of ethical leadership: a case study of secondary school leader's experiences in Kenya

Research has shown that school leaders today face more numerous ethical challenges than before, however little is known about the ethical challenges school leaders in Africa, and more specifically Kenya, encounter. This single case study investigated the nature of the ethical challenges that secondary school leaders face in conforming to the demands for ethical leadership and professionalism. It explores the perspectives of school leaders using semi-structured individual interviews: five school principals, 16 heads of department, five school boards of governors, and five school bursars, in five categories of secondary schools. The views and perspectives of nine parents on the leaders' ethical decision-making were also sought through interviews, because as stakeholders they are recipients of decisions made by the leaders. Drawing on a social constructivist theoretical framework and Eurocentric and Afrocentric paradigms for analysis and interpretation, the study revealed that the school leaders' ethical problems emanated from dealing with the realities of the context which creates conflicting demands for ethical conduct. A critical analysis of these themes using Foucauldian concepts of subjectification, power and governmentality illustrated that school leaders' ethical challenges were intensified because of their forced accommodation to Euro-western global policies. These policies, in particular the Structural Adjustment Programmes policy, the Education For All policy and the Good Governance Agenda are geared towards attaining the utopian dream of development. In view of this goal, the Kenyan state and school leaders are exposed to global interventions propagated on terms of discourses of improvement. The thesis argues that ethical challenges are intensified and persist because school leaders and the State have failed to critically reflect on these external influences, and allowed international global bodies to define the nation's needs, values and destiny. This study recommends that the State and education policy makers need to take a lead in developing their own value systems and policies, taking into account local Kenyan contextual needs and giving greater valence to Afrocentric values

GPON and V-band mmWave in green backhaul solution for 5G ultra-dense network

Ultra-dense network (UDN) is characterized by massive deployment of small cells which resulted into complex backhauling of the cells. This implies that for 5G UDN to be energy efficient, appropriate backhauling solutions must be provided. In this paper, we have evaluated the performance of giga passive optical network (GPON) and V-band millimetre wave (mmWave) in serving as green backhaul solution for 5G UDN. The approach was to first reproduce existing backhaul solutions in Very Dense Network (VDN) scenario which served as benchmark for the performance evaluation for the UDN scenario. The best two solutions, GPON and V-band solutions from the VDN were then deployed in 5G UDN scenario. The research was done by simulation in MATLAB. The performance metrics used were power consumption and energy efficiency against the normalized hourly traffic profile. The result revealed that GPON and V-band mmWave outperformed other solutions in VDN scenario. However, this performance significantly dropped in the UDN scenariodue to higher data traffic requirement of UDN compared to VDN. Thus, it can be concluded that GPON and V-band mmWave are not best suited to serve as green backhaul solution for 5G UDN necessitating further investigation of other available backhaul technologies