Kwame Ibwe - Academia.edu (original) (raw)

Papers by Kwame Ibwe

Journal of Electrical Systems and Information Technology, Mar 23, 2023

Tanzania Journal of Engeering and Technology, Dec 31, 2022

Journal of Electrical Systems and Information Technology

The increasing availability of mobile devices with wireless communications capabilities has stimu... more The increasing availability of mobile devices with wireless communications capabilities has stimulated the growth of indoor positioning services. Indoor positioning is used to locate, in real time, devices’ positions for easy access. The indoor positioning, however, is challenging compared to outdoor positioning due to the large number of obstacles. Global positioning system is ideal for outdoor localization but fails in indoor environments with limited space. Recent development of the Internet of Things (IoT) has brought forth portable and cost-effective wireless technologies that can be used for indoor positioning. In this work, an adaptive trilateration algorithm based on received signal strength indicator (RSSI) was proposed. To assess the positioning accuracy of the proposed algorithm, Bluetooth Low Energy (BLE), Wi-Fi (IEEE 802.11n), ZigBee and LoRaWAN IoT technologies were used. Results show that the error performance is improved by 4% in BLE, 17% in ZigBee, 22% in Wi-Fi and ...

Tanzania Journal of Engineering and Technology

The fishing industry engages many Tanzanians and is among the leading sectors of Blue Economy in ... more The fishing industry engages many Tanzanians and is among the leading sectors of Blue Economy in the country. However, fishing practices are small-scale with poor and insufficient number of fishing facilities, hence limiting productivity and efficacy. Studies argue that the low level of technology currently used in the country could possibly be an impeding factor. Specifically, fishers use non-interactive gears that cannot instantaneously update status and alert them whenever the gears are ready for collection. In such scenarios, fishers not only waste their time but also scarce resources such as fuel to facilitate trips to and from the fishing sites to check status of the gears. Thus, the application of Information and Communication Technology (ICT) could improve the production and lower operational costs is hypothesized. ICT solutions can help realize the processes with minimum human interventions while adding intelligence to the systems to make informed decisions and hence improv...

Tanzania Journal of Science, Jul 16, 2019

Journal of Engineering and Technology, 2019

One major drawback of orthogonal frequency division multiplexing (OFDM) system is peak to average... more One major drawback of orthogonal frequency division multiplexing (OFDM) system is peak to average power ratio (PAPR). This effect causes high power amplifier (HPA) to introduce intermodulation and out of band radiation as the signal goes through, thus degrades the performance of OFDM systems. This paper proposes blind algorithms which takes advantage of signal transformation technique and signal distortion technique. Simulation results show that at complementary cumulative distribution function (CCDF) level of 10-3 , the proposed algorithm achieved 3.2 dB PAPR improvement compared to discrete Fourier transform with interleaved frequency division multiple access (DFT-IFDMA) based algorithm. The bit error rate (BER) performance has degraded by 2 dB compared to the original OFDM signal with no distortion under frequency selective channel (FCS) at BER of 10-4 . These presented results, mark this algorithm as a better candidate for PAPR reduction algorithm in long term evolution (LTE) ne...

To increase network capacity of a mobile communication system, three main ways can be derived fro... more To increase network capacity of a mobile communication system, three main ways can be derived from Claude Shannon equation. These are the use of smaller cells, increase of bandwidth and improvement of communication technology. Since there is only a finite amount of radio spectrum available and it is also required by other applications, there are limits to bandwidth increment. Combining the later and former, LTE small cells method is best practical way to increase system capacity of mobile communication system. However, deployment of femtocells with small coverage range leads to frequent handover initiation. The problem escalates when femtocells operate in open access mode while accommodating highly mobile users who initiate unnecessary handovers as they stay in a femtocell for short time. To tackle these challenges, a hybrid handover decision algorithm is presented. The proposed algorithm selects the most appropriate target femtocell for handover using velocity of the user, throughp...

Tanzania Journal of Science, 2021

Indoor Positioning Systems (IPS) plays crucial roles in indoor environment items positioning used... more Indoor Positioning Systems (IPS) plays crucial roles in indoor environment items positioning used in self-navigating robots and helping hands. To obtain position information, positioning algorithms employing Received Signal Strength Indicator (RSSI) are of great benefits since they reuse the existing radio wireless infrastructures for indoor positioning. However, the changes in the indoor environment decrease the overall accuracy of the developed indoor positioning algorithms. To cope with the challenge of environmental dependency in indoor positioning, a robust algorithm using radio signal identification was developed. The algorithm uses circle expansion and reduction mechanism to achieve better RSSI-Distance relationship. The distances from RSSI-Distance relationship are used in trilateration algorithm for position estimation. Experiments were performed to compare position accuracy of the basic RSSI-Based and the proposed algorithm. Simulation results showed that proposed algorith...

Proceedings of the 2nd Pan African International Conference on Science, Computing and Telecommunications (PACT 2014), 2014

The inherent immunity of OFDM to multipath limitations comes with the price of increased sensitiv... more The inherent immunity of OFDM to multipath limitations comes with the price of increased sensitivity to inaccuracies in the reference frequency. A carrier offset at the OFDM receiver causes losses in subcarrier orthogonality, and thus introduces inter-channel interference (ICI) which degrades the system performance. In mobile communication technology, adaptive algorithms are mostly chosen in real time signal processing because of their high speed to acquire and track changes in parameters. Unfortunately, the existing adaptive methods are not suitable in doubly selective fading channels. In this paper, an adaptive carrier frequency synchronization algorithm is proposed for applications under double dispersive fading channels. The algorithm takes advantage of the known structure of the subspace of OFDM signals. It is shown that the mean square errors of frequency offset estimates are much lower than those of existing adaptive and some non-adaptive algorithms. Simulations also show that it takes only one symbol for the proposed algorithm to track the changes in the channel, leading to high accuracy in the compensation. Since no matrix inversion is involved in the algorithm, excellent transient behaviors with very low complexity are obtained. The proposed algorithm is robust and outperforms the existing adaptive algorithms particularly in doubly dispersive channels.

Tanzania Journal of Science

The smart grid and Internet of Things (IoT) technologies play vital roles in improving the qualit... more The smart grid and Internet of Things (IoT) technologies play vital roles in improving the quality of services offered in traditional electrical grid. They open a room for the introduction of new services like distribution automation (DA) that has a significant advantage to both utility companies and final consumers. DA integrates sensors, actuators, intelligent electrical devices (IED) and information and communication technologies to monitor and control electrical grid. However, the integration of these technologies poses security threats to the electrical grid like Denial of Service (DoS) attacks, false data injection attacks, and masquerading attacks like system node impersonation that can transmit wrong readings, resulting in false alarm reports and hence leading to incorrect node actuation. To overcome these challenges, researchers have proposed a centralized public key infrastructure (PKI) with bridged certificate authority (CA) which is prone to DoS attacks. Moreover, the pr...

Tanzania Journal of Science

Advanced Metering Infrastructure (AMI) enables two-way communication between smart devices and ut... more Advanced Metering Infrastructure (AMI) enables two-way communication between smart devices and utility control centers. This involves remote monitoring and control of energy consumption as well as other parameters in the electrical power network in real time. However, increasing technologies in AMI due to huge deployment of smart meters, integration of devices and application of sensors, demand a strong architectural model with the best network topology to guarantee efficient usage of network resources with minimal latency. In this work, a resource efficient multi-hop network architecture is proposed using hybrid media access protocols. The architecture combines queuing and random-access protocol to achieve optimal network performance. Numerical results show that the probability of delay incurred by an arbitrary smart meter depends on the mean and distribution of the queue switch over a period. It is also observed that for a single queued system, the throughput performance is equal ...

Journal of Electrical Systems and Information Technology, 2022

Public institutions in developing countries, taking Tanzania as an example, are facing huge elect... more Public institutions in developing countries, taking Tanzania as an example, are facing huge electricity consumption bills caused by inefficient utilization of electrical power. The causes of inefficient power usage can be due to the users’ behavioral and inadequacy of technology deployment in electric controlling infrastructure. This study explores the users’ behavior and the consequences of inefficient power utilization in Tanzania Higher Learning Institutions (HLIs). Around 85% of the sampled participants in the selected HLIs were least concerned with power saving strategies while using office facilities. The study reveals that inefficient energy consumption may result in high electrical power bills, unnecessary energy waste, psychological effects caused by inability to pay electrical bills and distress resulting from frequent power outages. Besides, the study proposes both behavioral- and technological-based interventions for electrical power saving in HLIs.

EDULEARN Proceedings, 2018

Smart Grid is a new and growing technology to developing countries. Its implementation and sustai... more Smart Grid is a new and growing technology to developing countries. Its implementation and sustainability rely on well trained experts. Sustainability of the smart grid need local experts, hence a ...

The industry-academia cooperation to solve the real-life problems facing the societies of which t... more The industry-academia cooperation to solve the real-life problems facing the societies of which the industry and academia are serving is a common phenomenon in developed economies and even to some ...

International Journal of Engineering, 2018

The future of learning is being revolutionized by challenge based learning (CBL), where academia ... more The future of learning is being revolutionized by challenge based learning (CBL), where academia offers solutions to reallife challenges. Unfortunately, in developing countries academia overlook the importance of involving stakeholders whoare the prospective owners of the solutions developed. This is because of the weak link between academic institutions andindustry in research and development activities. However, to solve real life challenges faced by the society the researchersneed to work closely and continuously with the targeted community for them to get the sense of ownership and for thesolutions to take into account all relevant factors. This paper presents the impacts realized when eight stakeholders werefully involved from identification to developing solutions of the challenges facing the electrical power sector in Tanzaniawhich is wholly managed by a public utility company TANESCO from generation to distribution. Challenge based coursesintroducedin taught PhD and MScprogr...

Journal of Signal Processing Systems, 2021

Noise removal in images denotes an interesting and a relatively challenging problem that has capt... more Noise removal in images denotes an interesting and a relatively challenging problem that has captured the attention of many scholars. Recent denoising methods focus on simultaneously restoring noisy images and recovering their semantic features (edges and contours). But preservation of textures, which facilitate interpretation and analysis of complex images, remains an open-ended research question. Classical methods (Total variation and Perona-Malik) and image denoising approaches based on deep neural networks tend to smudge fine details of images. Results from previous studies show that these methods, in addition, can introduce undesirable artifacts into textured images. To address the challenges, we have proposed an image denoising method based on anisotropic diffusion processes. The divergence term of our method contains a diffusion kernel that depends on the evolving image and its gradient magnitude to ensure effective preservation of edges, contours, and textures. Furthermore, a regularization term has been proposed to denoise images corrupted by multiplicative noise. Empirical results demonstrate that the proposed method generates images with higher perceptual and objective qualities.

Tanzania Journal of Science, 2021

Distribution networks remain the most maintenance-intensive parts of power systems. The implement... more Distribution networks remain the most maintenance-intensive parts of power systems. The implementation of maintenance automation and prediction of equipment fault can enhance system reliability while reducing the overall costs. In Tanzania, however, maintenance automation has not been deployed in secondary distribution networks (SDNs). Instead, traditional methods are used for condition prediction and fault identification of power assets (transformers and power lines). These (manual) methods are costly and time-consuming, and may introduce human-related errors. Motivated by these challenges, this work introduces maintenance automation into the network architecture by implementing effective maintenance and fault identification methods. The proposed method adopts machine learning techniques to develop a novel system architecture for maintenance automation in the SDN. Experimental results showed that different transformer prediction methods, namely support vector machine, kernel suppor...

Tanzania Journal of Science, 2021

Using information and communication technologies (ICT) to make the electrical power network intel... more Using information and communication technologies (ICT) to make the electrical power network intelligent and smarter (smart grid) has been the focal point in transforming electrical power industry. The idea behind smart grid is to transform the Tanzanian power sector into a secure, adaptive, sustainable, and digitally enabled ecosystem that provides reliable and quality energy for all with active participation of stakeholders. Smart metering is a central segment in realizing smart grid. However, a big question is whether Tanzanian power stakeholders are ready for smart metering technology investments for household applications. Operation and maintenance of a smart metering solution is a relatively new business in Tanzania and requires investment in resources and capacity building. A case study was conducted at the utility company in Dar es Salaam offices, to investigate the deployment status and services offered. Fixed tariff rates, high cost, low rates on returns of investment and n...

Journal of Electrical Systems and Information Technology, Mar 23, 2023

Tanzania Journal of Engeering and Technology, Dec 31, 2022

Journal of Electrical Systems and Information Technology

The increasing availability of mobile devices with wireless communications capabilities has stimu... more The increasing availability of mobile devices with wireless communications capabilities has stimulated the growth of indoor positioning services. Indoor positioning is used to locate, in real time, devices’ positions for easy access. The indoor positioning, however, is challenging compared to outdoor positioning due to the large number of obstacles. Global positioning system is ideal for outdoor localization but fails in indoor environments with limited space. Recent development of the Internet of Things (IoT) has brought forth portable and cost-effective wireless technologies that can be used for indoor positioning. In this work, an adaptive trilateration algorithm based on received signal strength indicator (RSSI) was proposed. To assess the positioning accuracy of the proposed algorithm, Bluetooth Low Energy (BLE), Wi-Fi (IEEE 802.11n), ZigBee and LoRaWAN IoT technologies were used. Results show that the error performance is improved by 4% in BLE, 17% in ZigBee, 22% in Wi-Fi and ...

Tanzania Journal of Engineering and Technology

The fishing industry engages many Tanzanians and is among the leading sectors of Blue Economy in ... more The fishing industry engages many Tanzanians and is among the leading sectors of Blue Economy in the country. However, fishing practices are small-scale with poor and insufficient number of fishing facilities, hence limiting productivity and efficacy. Studies argue that the low level of technology currently used in the country could possibly be an impeding factor. Specifically, fishers use non-interactive gears that cannot instantaneously update status and alert them whenever the gears are ready for collection. In such scenarios, fishers not only waste their time but also scarce resources such as fuel to facilitate trips to and from the fishing sites to check status of the gears. Thus, the application of Information and Communication Technology (ICT) could improve the production and lower operational costs is hypothesized. ICT solutions can help realize the processes with minimum human interventions while adding intelligence to the systems to make informed decisions and hence improv...

Tanzania Journal of Science, Jul 16, 2019

Journal of Engineering and Technology, 2019

One major drawback of orthogonal frequency division multiplexing (OFDM) system is peak to average... more One major drawback of orthogonal frequency division multiplexing (OFDM) system is peak to average power ratio (PAPR). This effect causes high power amplifier (HPA) to introduce intermodulation and out of band radiation as the signal goes through, thus degrades the performance of OFDM systems. This paper proposes blind algorithms which takes advantage of signal transformation technique and signal distortion technique. Simulation results show that at complementary cumulative distribution function (CCDF) level of 10-3 , the proposed algorithm achieved 3.2 dB PAPR improvement compared to discrete Fourier transform with interleaved frequency division multiple access (DFT-IFDMA) based algorithm. The bit error rate (BER) performance has degraded by 2 dB compared to the original OFDM signal with no distortion under frequency selective channel (FCS) at BER of 10-4 . These presented results, mark this algorithm as a better candidate for PAPR reduction algorithm in long term evolution (LTE) ne...

To increase network capacity of a mobile communication system, three main ways can be derived fro... more To increase network capacity of a mobile communication system, three main ways can be derived from Claude Shannon equation. These are the use of smaller cells, increase of bandwidth and improvement of communication technology. Since there is only a finite amount of radio spectrum available and it is also required by other applications, there are limits to bandwidth increment. Combining the later and former, LTE small cells method is best practical way to increase system capacity of mobile communication system. However, deployment of femtocells with small coverage range leads to frequent handover initiation. The problem escalates when femtocells operate in open access mode while accommodating highly mobile users who initiate unnecessary handovers as they stay in a femtocell for short time. To tackle these challenges, a hybrid handover decision algorithm is presented. The proposed algorithm selects the most appropriate target femtocell for handover using velocity of the user, throughp...

Tanzania Journal of Science, 2021

Indoor Positioning Systems (IPS) plays crucial roles in indoor environment items positioning used... more Indoor Positioning Systems (IPS) plays crucial roles in indoor environment items positioning used in self-navigating robots and helping hands. To obtain position information, positioning algorithms employing Received Signal Strength Indicator (RSSI) are of great benefits since they reuse the existing radio wireless infrastructures for indoor positioning. However, the changes in the indoor environment decrease the overall accuracy of the developed indoor positioning algorithms. To cope with the challenge of environmental dependency in indoor positioning, a robust algorithm using radio signal identification was developed. The algorithm uses circle expansion and reduction mechanism to achieve better RSSI-Distance relationship. The distances from RSSI-Distance relationship are used in trilateration algorithm for position estimation. Experiments were performed to compare position accuracy of the basic RSSI-Based and the proposed algorithm. Simulation results showed that proposed algorith...

Proceedings of the 2nd Pan African International Conference on Science, Computing and Telecommunications (PACT 2014), 2014

The inherent immunity of OFDM to multipath limitations comes with the price of increased sensitiv... more The inherent immunity of OFDM to multipath limitations comes with the price of increased sensitivity to inaccuracies in the reference frequency. A carrier offset at the OFDM receiver causes losses in subcarrier orthogonality, and thus introduces inter-channel interference (ICI) which degrades the system performance. In mobile communication technology, adaptive algorithms are mostly chosen in real time signal processing because of their high speed to acquire and track changes in parameters. Unfortunately, the existing adaptive methods are not suitable in doubly selective fading channels. In this paper, an adaptive carrier frequency synchronization algorithm is proposed for applications under double dispersive fading channels. The algorithm takes advantage of the known structure of the subspace of OFDM signals. It is shown that the mean square errors of frequency offset estimates are much lower than those of existing adaptive and some non-adaptive algorithms. Simulations also show that it takes only one symbol for the proposed algorithm to track the changes in the channel, leading to high accuracy in the compensation. Since no matrix inversion is involved in the algorithm, excellent transient behaviors with very low complexity are obtained. The proposed algorithm is robust and outperforms the existing adaptive algorithms particularly in doubly dispersive channels.

Tanzania Journal of Science

The smart grid and Internet of Things (IoT) technologies play vital roles in improving the qualit... more The smart grid and Internet of Things (IoT) technologies play vital roles in improving the quality of services offered in traditional electrical grid. They open a room for the introduction of new services like distribution automation (DA) that has a significant advantage to both utility companies and final consumers. DA integrates sensors, actuators, intelligent electrical devices (IED) and information and communication technologies to monitor and control electrical grid. However, the integration of these technologies poses security threats to the electrical grid like Denial of Service (DoS) attacks, false data injection attacks, and masquerading attacks like system node impersonation that can transmit wrong readings, resulting in false alarm reports and hence leading to incorrect node actuation. To overcome these challenges, researchers have proposed a centralized public key infrastructure (PKI) with bridged certificate authority (CA) which is prone to DoS attacks. Moreover, the pr...

Tanzania Journal of Science

Advanced Metering Infrastructure (AMI) enables two-way communication between smart devices and ut... more Advanced Metering Infrastructure (AMI) enables two-way communication between smart devices and utility control centers. This involves remote monitoring and control of energy consumption as well as other parameters in the electrical power network in real time. However, increasing technologies in AMI due to huge deployment of smart meters, integration of devices and application of sensors, demand a strong architectural model with the best network topology to guarantee efficient usage of network resources with minimal latency. In this work, a resource efficient multi-hop network architecture is proposed using hybrid media access protocols. The architecture combines queuing and random-access protocol to achieve optimal network performance. Numerical results show that the probability of delay incurred by an arbitrary smart meter depends on the mean and distribution of the queue switch over a period. It is also observed that for a single queued system, the throughput performance is equal ...

Journal of Electrical Systems and Information Technology, 2022

Public institutions in developing countries, taking Tanzania as an example, are facing huge elect... more Public institutions in developing countries, taking Tanzania as an example, are facing huge electricity consumption bills caused by inefficient utilization of electrical power. The causes of inefficient power usage can be due to the users’ behavioral and inadequacy of technology deployment in electric controlling infrastructure. This study explores the users’ behavior and the consequences of inefficient power utilization in Tanzania Higher Learning Institutions (HLIs). Around 85% of the sampled participants in the selected HLIs were least concerned with power saving strategies while using office facilities. The study reveals that inefficient energy consumption may result in high electrical power bills, unnecessary energy waste, psychological effects caused by inability to pay electrical bills and distress resulting from frequent power outages. Besides, the study proposes both behavioral- and technological-based interventions for electrical power saving in HLIs.

EDULEARN Proceedings, 2018

Smart Grid is a new and growing technology to developing countries. Its implementation and sustai... more Smart Grid is a new and growing technology to developing countries. Its implementation and sustainability rely on well trained experts. Sustainability of the smart grid need local experts, hence a ...

The industry-academia cooperation to solve the real-life problems facing the societies of which t... more The industry-academia cooperation to solve the real-life problems facing the societies of which the industry and academia are serving is a common phenomenon in developed economies and even to some ...

International Journal of Engineering, 2018

The future of learning is being revolutionized by challenge based learning (CBL), where academia ... more The future of learning is being revolutionized by challenge based learning (CBL), where academia offers solutions to reallife challenges. Unfortunately, in developing countries academia overlook the importance of involving stakeholders whoare the prospective owners of the solutions developed. This is because of the weak link between academic institutions andindustry in research and development activities. However, to solve real life challenges faced by the society the researchersneed to work closely and continuously with the targeted community for them to get the sense of ownership and for thesolutions to take into account all relevant factors. This paper presents the impacts realized when eight stakeholders werefully involved from identification to developing solutions of the challenges facing the electrical power sector in Tanzaniawhich is wholly managed by a public utility company TANESCO from generation to distribution. Challenge based coursesintroducedin taught PhD and MScprogr...

Journal of Signal Processing Systems, 2021

Noise removal in images denotes an interesting and a relatively challenging problem that has capt... more Noise removal in images denotes an interesting and a relatively challenging problem that has captured the attention of many scholars. Recent denoising methods focus on simultaneously restoring noisy images and recovering their semantic features (edges and contours). But preservation of textures, which facilitate interpretation and analysis of complex images, remains an open-ended research question. Classical methods (Total variation and Perona-Malik) and image denoising approaches based on deep neural networks tend to smudge fine details of images. Results from previous studies show that these methods, in addition, can introduce undesirable artifacts into textured images. To address the challenges, we have proposed an image denoising method based on anisotropic diffusion processes. The divergence term of our method contains a diffusion kernel that depends on the evolving image and its gradient magnitude to ensure effective preservation of edges, contours, and textures. Furthermore, a regularization term has been proposed to denoise images corrupted by multiplicative noise. Empirical results demonstrate that the proposed method generates images with higher perceptual and objective qualities.

Tanzania Journal of Science, 2021

Distribution networks remain the most maintenance-intensive parts of power systems. The implement... more Distribution networks remain the most maintenance-intensive parts of power systems. The implementation of maintenance automation and prediction of equipment fault can enhance system reliability while reducing the overall costs. In Tanzania, however, maintenance automation has not been deployed in secondary distribution networks (SDNs). Instead, traditional methods are used for condition prediction and fault identification of power assets (transformers and power lines). These (manual) methods are costly and time-consuming, and may introduce human-related errors. Motivated by these challenges, this work introduces maintenance automation into the network architecture by implementing effective maintenance and fault identification methods. The proposed method adopts machine learning techniques to develop a novel system architecture for maintenance automation in the SDN. Experimental results showed that different transformer prediction methods, namely support vector machine, kernel suppor...

Tanzania Journal of Science, 2021

Using information and communication technologies (ICT) to make the electrical power network intel... more Using information and communication technologies (ICT) to make the electrical power network intelligent and smarter (smart grid) has been the focal point in transforming electrical power industry. The idea behind smart grid is to transform the Tanzanian power sector into a secure, adaptive, sustainable, and digitally enabled ecosystem that provides reliable and quality energy for all with active participation of stakeholders. Smart metering is a central segment in realizing smart grid. However, a big question is whether Tanzanian power stakeholders are ready for smart metering technology investments for household applications. Operation and maintenance of a smart metering solution is a relatively new business in Tanzania and requires investment in resources and capacity building. A case study was conducted at the utility company in Dar es Salaam offices, to investigate the deployment status and services offered. Fixed tariff rates, high cost, low rates on returns of investment and n...