Papers by Dr. Lukumba Phiri, Ph.D
Fast Tracking Electric Mobility in Sub-Saharan Africa: An analysis of vehicle segment prioritization, barriers to adoption, and policy roadmap development on GHG emissions
Zenodo (CERN European Organization for Nuclear Research), Sep 12, 2023
Zenodo (CERN European Organization for Nuclear Research), Sep 3, 2023
Both upstream (to the Distribution System Operators (DSO) and Transmission System Operators (TSO)... more Both upstream (to the Distribution System Operators (DSO) and Transmission System Operators (TSO)) and downstream (via electric cars to mobility and the shutdown of substantial parts of national transport to the disruption of other vital sectors). The safe integration of e-mobility is a big problem. Additionally, any disruptions or changes in either behavior might have serious impacts on the other due to the close connection between the power grid and the e-mobility infrastructure. For instance, uncontrolled EV charging is frequently projected to have detrimental consequences on the electrical grid.
Journal of electrical electronics engineering, Mar 19, 2024
Advancements in internet technology have enabled the integration of different traffic types i.e. ... more Advancements in internet technology have enabled the integration of different traffic types i.e. data, video, and voice into a single network. This technology offers many benefits but also presents some challenges. Real-time traffic services such as VoIP require a certain Quality of Service (QoS) which cannot be guaranteed on the Internet therefore, key performance metrics become all the more important. The choice of codecs and queuing techniques becomes crucial for ensuring optimal performance, especially in networks with diverse traffic types. This research therefore compared the effects of the combinations of these tools (i.e. queuing techniques and codec schemes) on the quality of VoIP. A simulation approach using the OPNET Modeler 14.5 tool has been used to simulate a network supporting three different types of traffic namely: FTP traffic, Video conferencing traffic, and VoIP traffic. While maintaining the same topology and traffic of the network, different types of codec schemes and queuing techniques have been tested through the measurement of parameters such as delay and throughput. The custom Queuing technique showed the best performance overall while FIFO suffered the highest delay. The graphs were observed to follow the same pattern regardless of the codec scheme used however, G729 performed the better of the two as it received higher amounts of voice traffic and slightly lower delays compared to G711.
Semiconductor Science and Information Devices
Non-orthogonal multiple access (NOMA) represents the latest addition to the array of multiple acc... more Non-orthogonal multiple access (NOMA) represents the latest addition to the array of multiple access techniques, enabling simultaneous servicing of multiple users within a singular resource block in terms of time, frequency, and code. A typical NOMA configuration comprises a base station along with proximate and distant users. The proximity users experience more favorable channel conditions in contrast to distant users, resulting in a compromised performance for the latter due to the less favorable channel conditions. When cooperative communication is integrated with NOMA, the overall system performance, including spectral efficiency and capacity, is further elevated. This study introduces a cooperative NOMA setup in the downlink, involving three users, and employs dynamic power allocation (DPA). Within this framework, User 2 acts as a relay, functioning under the decode-and-forward protocol, forwarding signals to both User 1 and User 3. This arrangement aims to bolster the performa...
Performance Study of Downlink Users in Non-Orthogonal Multiple Access (NOMA) for 5G Communications
Global Journal of Computer Science and Technology
An outline of NOMA principles is provided in this article. Furthermore, this page discusses coope... more An outline of NOMA principles is provided in this article. Furthermore, this page discusses cooperative NOMA and its variations, explains power allocation in detail as a technique of resource allocation for NOMA, and gives an overview of the research challenges related to NOMA. We then, use a two-case scenario, to suggest a dynamic power allocation (DPA) plan for the downlink NOMA users, albeit it can also be expanded to many use cases. The DPA relies on channel state information (CSI) to guarantee the quality of service (QOS) for cell center customers (user c). The Outage probability (OP) as a critical performance criterion simulation data is also provided, and they demonstrate a notable performance improvement when DPA is employed compared to fixed power allocation.
Assessing the Ramifications of Electric Vehicle Charging Infrastructure on Smart Grid Systems in Zambia
2022 International Conference on Information and Communication Technology for Development for Africa (ICT4DA)
Computer Science and Engineering 2022, 12(1): 1-14 , 2022
Supervisory Control and Data Acquisition (SCADA) networks are used across the globe to manage com... more Supervisory Control and Data Acquisition (SCADA) networks are used across the globe to manage commercial and industrial control systems connected to energy, water, and telecommunications infrastructures. The connectivity provides immense benefits such as reliability, scalability, and remote connectivity, but at the same time exposes an otherwise isolated and secure system, to global cybersecurity threats. This inevitable transformation to highly connected systems thus necessitates effective security safeguards to be in place as any compromise or downtime of SCADA systems can have severe economic, safety, and security ramifications. To enhance the reliability and resilience of power grid networks there is a paradigm shift from legacy networks to smart grid networks. The Zambian power grid operator and mining companies in tandem with global players are transitioning from legacy-based protocols to Internet Protocol-based (IP-based) communications. Therefore, estimating possible cyberattack impacts and identifying system vulnerabilities are a concern in SCADA management and operations. However, it is quite difficult to plan, execute and review vulnerability analysis in critical infrastructure systems as well as in industrial control systems (such as SCADA systems) due to the complexity, and heterogeneity of these systems. A consistent domain-specific conceptual model is required to consequently establish a generic framework for cybersecurity analysis to examine and investigate security threats on smart grid systems. This paper proposes the use of Petri nets to model a framework for cyberattack response for smart grid infrastructure.
Journal Article, 2022
A cyberattack on a power grid facility could have repercussions for other infrastructure in the c... more A cyberattack on a power grid facility could have repercussions for other infrastructure in the chain, causing a domino effect if the repercussions are not addressed, damaging the entire power system. Our objective was the investigation and quantification of the impact of cyberattacks on interdependent power systems facilities. In this paper, a novel technique based on Stochastic Petri Nets is presented, as well as a comprehensive model of the major impacts of blackouts and cascading events in the power systems of the IEEE 24 bus system is presented in form of loss of revenue. The paper also hypothesizes cyberattacks or digital control system failure as possible causes for cascaded power blackouts. Furthermore, the limitations of current preventive methods and research gaps in the area of power system blackouts and cascade occurrences are identified. Future power system blackout studies and risk assessments shall take this into account as well.
International Journal of Advances in Scientific Research and Engineering
The number of successful attacks on vital infrastructure has increased, as has the sophistication... more The number of successful attacks on vital infrastructure has increased, as has the sophistication of the attacks. Many cybersecurity strategies include traditional best practices, but they frequently overlook organizational circumstances and unique critical infrastructure protection requirements. The goal of this qualitative multiple case research was to look into the cybersecurity tactics employed by IT managers and compliance officers to protect critical infrastructure from cyber threats. The participants in this study were IT managers and compliance officials from four Zambian case organizations. The conceptual framework was based on the routine activity theory published by criminologists Cohen and Felson in 1979. Interviews with two IT managers, three compliance officers, and 25 papers relating to cybersecurity and policy governance were used to gather data. Four significant themes emerged from data triangulation: the need for a robust worker training program, prioritizing infra...
An Assessment in Zambian work places on the standard of electronic monitoring AcasestudyofLusakaDistrictZambia
The purpose of this study was to examine the implementation of surveillance cameras and the publi... more The purpose of this study was to examine the implementation of surveillance cameras and the public perception in various Zambian workplaces. The research aimed to measure variables on the issues of surveillance and human rights including the standard of the surveillance cameras. This study was focused on the policy that governs surveillance cameras in workplaces. The question was to address if the implementation is done considering Human Rights. The general objective was to ascertain the effects that electronic monitoring has on personnel privacy in workplaces. The specific objective was to establish the standards of electronic monitoring in Zambian workplaces, evaluating electronic monitoring with Zambian laws on rights of privacy, and discuss the challenges of implementing electronic monitoring in Zambian workplaces. However, it was found that the extent of adoption was relatively minimal given the potential that exists in Zambia
Computer Science and Engineering 2022, 12(1): 15-29, 2021
The use of hydro energy to generate electric power is crucial to meet the increasing energy deman... more The use of hydro energy to generate electric power is crucial to meet the increasing energy demand of a modern
economy and maintains the stability of power supply for unstable sources of power like solar, and wind. In newly constructed
hydropower plants (HPPs), the trend among control systems is to adopt contemporary digital and cyber-based systems at the
expense of obsolete analog hard-wired systems. Therefore, cyber-physical security is a critical issue in reliability-constrained
HPPs. In this paper, we present different levels/layers of protection to manage cyber security. We adopt generalized
stochastic Petri nets to quantitatively evaluate the intrusion probability. We then propose a new cyber framework and show
that the proposed framework conforms to NIST cybersecurity regulations. Finally, we discuss dependability through three
metrics, i.e., reliability, maintainability, and availability. A case study is presented to demonstrate that the proposed cyber
framework is highly dependable through analyzing steady-state probabilities.
Drafts by Dr. Lukumba Phiri, Ph.D
Article, 2020
The purpose of this study was to examine the implementation of surveillance cameras and the publi... more The purpose of this study was to examine the implementation of surveillance cameras and the public perception in various Zambian workplaces. The research aimed to measure variables on the issues of surveillance and human rights including the standard of the surveillance cameras. This study was focused on the policy that governs surveillance cameras in workplaces. The question was to address if the implementation is done considering Human Rights. The general objective was to ascertain the effects that electronic monitoring has on personnel privacy in workplaces. The specific objective was to establish the standards of electronic monitoring in Zambian workplaces, evaluating electronic monitoring with Zambian laws on rights of privacy, and discuss the challenges of implementing electronic monitoring in Zambian workplaces. However, it was found that the extent of adoption was relatively minimal given the potential that exists in Zambia
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Papers by Dr. Lukumba Phiri, Ph.D
economy and maintains the stability of power supply for unstable sources of power like solar, and wind. In newly constructed
hydropower plants (HPPs), the trend among control systems is to adopt contemporary digital and cyber-based systems at the
expense of obsolete analog hard-wired systems. Therefore, cyber-physical security is a critical issue in reliability-constrained
HPPs. In this paper, we present different levels/layers of protection to manage cyber security. We adopt generalized
stochastic Petri nets to quantitatively evaluate the intrusion probability. We then propose a new cyber framework and show
that the proposed framework conforms to NIST cybersecurity regulations. Finally, we discuss dependability through three
metrics, i.e., reliability, maintainability, and availability. A case study is presented to demonstrate that the proposed cyber
framework is highly dependable through analyzing steady-state probabilities.
Drafts by Dr. Lukumba Phiri, Ph.D