Ci-STEM Journal of
Digital Technologies and Expert Systems

Design and Implementation of Multi Facility Power Postpaid Meter with Bluetooth Control
Author: Visa M. Ibrahim, Braimoh Aliyu, S. Y. Musa
Pages: 1-17
DOI::https://doi.org/10.55306/CJDTES.2024.020101
Abstract:

Welcome to the world of Nigerian electrical utilities, where we have the centralized metering infrastructure (CIM), which is either at the distribution poles or at the consumer premise, allowing easy billing. Nevertheless, aggregation energy usage in communal residential organizations with several households is difficult to be manually allocated, triggering disputes when occupants refuse to pay according to their allocated portion. To ameliorate this inefficiency, this study proposes and prototypes a multi-node (five-node) smart metering system featuring Bluetooth-enabled control. The approach focused on the creation of an embedded system architecture, integrating ambient sensors and a microcontroller to automatically measure and estimate household consumption at the individual level. Cost allocation, based on power consumption data from each node was automatically processed using computer algorithms, eliminating the need for human intervention. The real-time data and user interaction were done through a mobile application that used Bluetooth communication module. The post-implementation evaluation confirmed the effectiveness of the system in automating the equitable billing mechanism and distributing it across five households in the compound, so that trust and accountability are ensured in the process. This prototype reveals the potential for hybridizing decentralized metering technologies with networks of wireless Internet of Things (IoT), to facilitate energy management in multi-tenant settings, reduce charges disputes between consumers and suppliers due to inaccurate meters, and improve operational efficiency in utilities.
Key Words: Aggregation, Bluetooth-Enabled Control, Centralized Metering Infrastructure (CIM), Computer Algorithms, Easy Billing, Embedded System Architecture, Inefficiency, Multi-Node (Five-Node), Smart Metering System, Multi-Tenant Settings, Operational Efficiency, Wireless Internet of Things (IoT).
Citation: V.M. Ibrahim et al.,, “Design and Implementation of Multi Facility Power Postpaid Meter with Bluetooth Control,” Ci-STEM Journal of Digital Technologies and Expert Systems, Vol. 2(1), pp. 1-17, 2025, doi: 10.55306/CJDTES.2025.020101

Analysing the Integration of AES-256 Encryption and HMAC Hashing in IoT Smart Healthcare Systems
Author: Eterigho Okpomo Okpu and Onate Egerton Taylor
Pages: 18-24
DOI::https://doi.org/10.55306/CJDTES.2024.020102
Abstract:

The exponential growth of Internet of Things (IoT) technology has been a driving force in the development of smart healthcare systems, facilitating patient monitoring and clinical decision support. It uses IoT-enabled medical devices and wearable sensors under the umbrella of Internet of Medical Things (IoMT) to continuously monitor health from afar. Yet, the fundamental security weaknesses of IoT structure and the high sensitivity of medical data reveal serious security and privacy problems. Therefore, this research suggests a comprehensive security framework to provide the confidentiality, integrity, and authenticity of data transmission in IoMT ecosystems. At the physical layer, the framework utilizes AES-256 encryption and HMAC (Hash-based Message Authentication Code) hashing to minimize cyber threats and prevent unauthorized access. The only additional computation cost at any performance evaluation is negligible, but we gain a lot more in terms of security on the data. The findings confirm the seeing of implementation and demonstration of a feasible security model to protect the multifarious healthcare architecture from ever- existing threats created by the number of cyber-attacks.
Key Words: AES-256 Encryption, Cyber Threats, Data Security, HMAC Hashing, Internet of Things (IoT), Internet of Medical Things (IoMT), Patient Monitoring, Privacy Protection, Smart Healthcare Systems, Wearable Sensors.
Citation: E.O. Okpu and O. E. Taylor., “Analysing the Integration of AES-256 Encryption and HMAC Hashing in IoT Smart Healthcare Systems,” Ci-STEM Journal of Digital Technologies and Expert Systems, Vol. 2(1), pp.18-24, 2025, doi: 10.55306/CJDTES.2025.020102

Evaluation of DC-DC Converters Using MATLAB Simulink
Author: Eze Cornelius C., Obe Chinedu T., Ugbe Oluchi C., Madueme Victory and Oti Stephen Ejiofor
Pages: 25-40
DOI:: https://doi.org/10.55306/CJDTES.2025.020103
Abstract:

This study explores the design, modeling, and simulation of three important DC-DC converter topologies—buck-boost, Ćuk, and SEPIC—employing MATLAB Simulink as a robust simulation environment. Each converter is thoroughly modeled to assess its voltage regulation performance under varying operational conditions. MATLAB Simulink serves as an advanced platform for analyzing dynamic system behaviors and optimizing critical design parameters, including duty cycle, switching frequency, and passive filter components. The comparative analysis focuses on output voltage stability, conversion efficiency, and transient response characteristics. The simulation parameters, while not exhaustive, are carefully selected to exhibit the operational principles and performance trade-offs inherent to each topology. The findings elucidate the different advantages and limitations of the buck-boost, Ćuk, and SEPIC converters, providing valuable insights for selecting the optimal topology tailored to specific power electronic applications, such as renewable energy systems, electric vehicles, and portable electronics. This research contributes to the broader understanding of DC-DC converter design and its practical implications in modern power management systems.
Key Words: Buck-boost converter, Conversion efficiency, Ćuk converter, DC-DC converters, Dynamic system behaviors, MATLAB Simulink, Power electronic applications, SEPIC converter, Switching frequency, Voltage regulation.
Citation: Eze. C. C et al., “Evaluation of DC-DC Converters Using MATLAB Simulink,” Ci-STEM Journal of Digital Technologies and Expert Systems, Vol. 2(1), pp.25-40, 2025, doi: 10.55306/CJDTES.2025.020103

Author:
Pages:
DOI::
Abstract:

Key Words:
Citation:

Author:
Pages:
DOI::
Abstract:

Key Words:
Citation:

Author:
Pages:
DOI::
Abstract:

Key Words:
Citation: