Dynamic-Threshold-Limited Timed-Token (DTLTT) Protocol

An improved version of the Static-Threshold-Limited On-Demand Guaranteed Service Timed-Token (STOGSTT) Media Access Control (MAC) protocol for channel capacity allocation to the asynchronous trac in Multiservice Local Area Network (MLANs) was developed and analyzed. TLODGSTT protocol uses static value of threshold bandwidth to allocate available bandwidth to the asynchronous trac, as such, the throughput of STLODGSTT protocol drops signi cantly under non-uniform heavy load of asynchronous trac. The DTLTT protocol dynamically adjusts the threshold bandwidth in response to the variations in the load distribution of the asynchronous trac. In view of this dynamic mechanism, under various load distributions of the asynchronous trac, the DTLTT protocol maintains higher throughput than the STLODGSTT protocol. The improvement is demonstrated through analytical computations and simulation results.Keywords: multi-access, multiservice, network, synchronous, asynchronous, trac, timed-toke

Optimal Guaranteed Services Timed Token (OGSTT) Media Access Control (MAC) Protocol for Networks That Support Hard Real-Time and Non Real-Time Traffic

In networks that support real-time traffic and non-real-time traffic over the same physical infrastructure, the challenge to the Media Access Control (MAC) protocol of such network is the ability to support  the different traffic without compromising quality of service (QoS) for any of them. Generally, timed-token MAC protocols group the diverse real-time traffic into one category and then dedicate certain portion of the available bandwidth to them. At the same time, some bandwidth are left unassigned but available to the non real-time traffic. The unassigned bandwidth, and in some cases, the unused bandwidth left by the real-time traffic are assigned to the non-real-time traffic on best effort basis. In this paper, Optimal Guaranteed Services Timed Token (OGSTT) MAC protocol is developed and analyzed. In order to provide better support for both real-time traffic and non-real-time on the same local area network, OGSTT employs the timed-token mechanisms in the Timely-Token protocol along with that of Budget Sharing Token (BuST) protocol. Some bounds on the behavior of OGSTT protocol are discussed along with the ability of OGSTT protocol to support real-time and non-real time traffic. In particular, the paper demonstrated that the performance achieved by OGSTT is better than the Timely-Token and BuST. Furthermore, OGSTT protocol can be incorporated into the Ethernet network to provide real-time performance guarantees to multimedia applications and hard and soft real-time traffic

Computer Aided Design Of The Magnetic Circuit Of A 3- Phase Power Transformer

In this paper, a computer program was developed in C++ language to determine the parameters of the magnetic circuit of a three-phase power transformer. A typical case study was used to demonstrate the effectiveness of the program. The program was developed using the mathematical models derived for the parameters to be determined, Apart from being flexible and speedy, the program removed the drudgery involved in the design and demonstrated the usefulness of software as both a teaching and research aid. Tables and graphs obtained from the program showed how the design problems were dealt with and how the parameters of the magnetic circuit were determined

Preliminary Context Analysis of Community Informatics Social Network Web Application

Preliminary context analysis is always part of the feasibility study phase in the development of information system for Community Development (CD) purposes. In this paper, a context model and a preliminary context analysis are presented for Social Network Web Application (SNWA) for CD in the Niger Delta region of Nigeria. The context model helps CD facilitators to visualize how SNWA fits into the wider information system for CD and also shows the essential context factors that must be considered in order to tailor the SNWA for CD purposes. Furthermore, the preliminary context analysis used case study research method to provide answers to pertinent questions concerning the situated context of use for the niche SNWA. In all, the context model and context analysis are useful for setting research agenda for the development and diffusion of niche social network for local CD purposes

Upper-air meteorological dataset for Uyo, using radiosonde.

Weather pattern anomalies and climate change have greatly impacted human activities and the environment in varying ways. Whether induced naturally or by anthropogenic activities, it remains a menace to global public health. A foreknowledge of the weather/climate change can help in mitigating the impact of disasters emanating from these changes. Upper-air meteorological data play an exceptionally large role in weather and climate prediction. However, there is a paucity of ground truth meteorological data in Nigeria and many parts of Africa. Consequently, the need to measure and archive these data. Internet of things and blockchain technologies are employed to build a system that captures and records meteorological data at up to 9,000 metres above sea level. Spanning between January 18, 2021 and July 26, 2021, in Uyo local government area, upper air pressure, temperature, dew point, time and the elevation at which they were captured, are the meteorological data presented in this data article. [Abstract copyright: © 2023 The Authors. Published by Elsevier Inc.