Research Publications

Journal Papers:

1. C. C. Ikeagwuani, C. J. Nnonyelu, M. C. Oti, E. J. Ude and T. T. Alexander, "A Posteriori Constrained Bio-inspired algorithm for enhancing Strength and Resilient Modulus of Soft Subgrade Soil", Road Materials and Pavement Design, pp. 1 -32, March 2025.

2. C. J. Nnonyelu, M. Jiang, M. Adamopoulou and J. Lundgren, "Performance Analysis of Cardioid and Omnidirectional Microphones in Spherical Sector Arrays for Coherent Source Localization," Sensors, vol. 24, no. 23, pp. 7572, November 2024.

3. J. S. Zheng, K. T. Wong, C. J. Nnonyelu and A. Y. Song, "Unequal Directivity Orders Between Two Figure-8 Sensors Perpendicularly Colocated with a Pressure Sensor – Their “Spatial Matched Filter” Beam Steering," IEEE Transactions on Aerospace and Electronic Systems, vol. 60, no. 6, pp. 7575-7594, December 2024.

4. C. C. Ikeagwuani, C. J. Nnonyelu, and I. N. Usanga, “Bioinspired Algorithm for Performance Evaluation of Biopolymerized Expansive Subgrade Soil Blended with Industrial Waste Additive,” International Journal of Geomechanics, vol. 24, no. 12, p. 4024298, October 2024.

5. C. C. Ikeagwuani, C. J. Nnonyelu, T. C. Alexander, "Improvement of soft clay soil with a combination of pre-gelatinized corn starch and nanoparticle agro waste: A multi-objective grey wolf optimizer approach", Physics and Chemistry of the Earth, Parts A/B/C, vol. 135, 103668, October, 2024.

6. C. J. Nnonyelu and K. T. Wong, "Two Cardioid Sensors in Perpendicular Colocation—Their “Spatial Matched Filter” Beam Steering,"  IEEE Sensors Journal, vol. 24, no. 9, pp. 15033-15045, May, 2024.

7. Chidera Linda Anioke and Chibuzo Joseph Nnonyelu, "Multipaths’ statistics for scatterers with inverted elliptic–parabolic spatial density around the mobile", Physical Communication, vol. 62, pp. 102235, February 2024.

8. Meng Jiang, Chibuzo Joseph Nnonyelu, Jan Lundgren, Göran Thungström and Mårten Sjöström, "A Coherent Wideband Acoustic Source Localization Using a Uniform Circular Array", Sensors, vol. 23, no. 11, May 2023.

9. C. J. Nnonyelu, M. Jiang, and J. Lundgren, "A Lower Bound on the Estimation Variance of Direction-of-Arrival and Skew Angle of a Biaxial Velocity Sensor Suffering from Stochastic Loss of Perpendicularity", Sensors, vol. 22, no. 21, November 2022.

10. S. S. Du, K. T. Wong, Y. Song, C. J. Nnonyelu, and Y. I. Wu, "Higher-Order Figure-8 Microphones/Hydrophones Collocated as a Perpendicular Triad – Their “Spatial-Matched-Filter” Beam Steering", Journal of the Acoustical Society of America, vol. 151, no. 2, February 2022.

11. C. J. Nnonyelu, C. P. Okide, and M. A. Ahaneku, "Angle-of-Arrival and Time-of-Arrival Statistics of Multipaths Arising from Scatterers on an Elliptical Disc with Conic Spatial Density Around the Mobile", Physical Communication, vol. 49, pp. 101449, December 2021.

12. C. J. Nnonyelu, Z. N. Morris, C. A. Madukwe, "On the Performance of the L- and V-shaped Arrays of Cardioid Microphones for Direction Finding", IEEE Sensors Journal, vol. 21, no. 2, pp. 2211-2218, January 2021 . 

13. C. Nnonyelu, C. Madukwe, and K. Madukwe, "Fully Steerable Collocated First-Order Cardioid Microphone Array Acoustic Beam-Pattern", Przeglad Elektrotechniczny, vol. 2020, no. 12, pp. 76-80, December 2020.

14. C. J. Nnonyelu, K. T. Wong, and C. H. Lee, “Higher-Order Figure-8 Sensors in a Pair, Skewed and Collocated --Their Azimuthal "Spatial Matched Filter" Beam-Pattern”,  Journal of the Acoustical Society of America, vol. 147, no. 2, pp. 1195 - 1206, February 2020. 

15. C. J. Nnonyelu and Z. N. Morris, "Acoustical Direction Finding using a Bayesian Regularized Multilayer Perceptron Artificial Neural Networks on a Tri-Axial Velocity Sensor", International Journal of Mechatronics, Electrical and Computer Technology, vol. 10, no. 35, pp. 1193-4501, January 2020.

16. K. T. Wong, Z. N. Morris, and C. J. Nnonyelu, "Rules-of-Thumb to Design a Uniform Spherical Array for Direction Finding -- Its Cramer-Rao Bounds' Nonlinear Dependence on the Number of Sensors", Journal of the Acoustical Society of America, vol. 145, no. 2, pp. 714-723, February 2019.

17. C. J. Nnonyelu, Y. I. Wu, and K. T. Wong, “Cardioid microphones/ hydrophones in a collocated/orthogonal triad - a new beamformer with no beam-pointing error", Journal of the Acoustical Society of America, vol. 145, no. 1, pp. 575-588, January 2019.

18. C. J. Nnonyelu, "Pointing bias in “spatial matched filter” beamforming at a tri-axial velocity-sensor due to non-perpendicular axes", World Journal of Innovative Research, vol. 5, no. 2, pp. 24-29, August 2018.

19. K. T. Wong, C. J. Nnonyelu, and Y. I. Wu, "A triad of cardioid sensors in orthogonal orientation and spatial collocation - its spatial-matched-filter-type beam-pattern", IEEE Transactions on Signal Processing, vol. 66, no. 4, pp. 895-906, February 2018. 

Conference Publications:

1. C. J. Nnonyelu, M. Jiang, V. Gallo, V. Laino, M. Carratu, and J. Lundgren, "Signal First-Difference as Augmentation Method for CNN-Based Heart Sound Classification", 2025 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), Chemnitz, Germany, 18 - 22 May, 2025.

2. M. Jiang, C. J. Nnonyelu, M. Carratu, M. Adamopoulou, Göran Thungström and J. Lundgren, "Signal First-Difference as Augmentation Method for CNN-Based Heart Sound Classification", 2025 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), Chemnitz, Germany, 18 - 22 May, 2025.

3. C. J. Nnonyelu, M. Jiang, M. Adamopoulou and J. Lundgren, "A Machine- Learning -based approach to Direction-of-arrival Sectorization using Spherical Microphone Array," 2024 IEEE 13rd Sensor Array and Multichannel Signal Processing Workshop (SAM), Corvallis, USA, 8 – 11 July 2024.

4. M. Adamopoulou, M. Jiang, C. J. Nnonyelu, M. Carratù, C. Liguori and J. Lundgren, "Improving Cardiac Auscultation Signal Quality by using 4-Channel Stethoscope Array," 2024 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), Glasgow, United Kingdom, 2024, pp. 1-6.

5. J. Lundgren, M. Jiang, V. Laino, V. Gallo, M. Carratù and C. J. Nnonyelu, "Accuracy Impact of Increased Measurement Quality when using Pretrained Networks for Classification," 2024 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), Glasgow, United Kingdom, 2024, pp. 1-5.

6. M. Jiang, C. J. Nnonyelu, J. Lundgren, M. Sjöström, G. Thungström and S. Gao, "Performance Comparison of Omni and Cardioid Directional Microphones for Indoor Angle of Arrival Sound Source Localization," 2022 IEEE International Instrumentation and Measurement Technology Conference (I2MTC), 16 - 19 May, 2022, pp. 1-6.

7. C. J. Nnonyelu, D. C. Uzosike & U. H. Nnonyelu, "Continuously Steerable Second-Order Beam for Higher-order Horizontal-Only Ambisonics", in the Proceedings of the 2nd International Conference on Electrical Power Engineering (ICEPENG 2021), pp. 135-138, 18 - 22 May, 2021.

8. J. Ben & C. J. Nnonyelu, "Design and Construction of a Smart Gang Isolator Switch for Safe Fault Tracing in a Distribution System", in the Proceedings of the 2nd International Conference on Electrical Power Engineering (ICEPENG 2021), pp. 11 - 15, 18 - 22 May, 2021.

9. C. Nwosu, U. Ogbuefi, C. Okoli, C. Nnonyelu, C. Eya, C. Ohanu, I. Uzoeto, C. Ogbuka, B. Anyaka & E. Ejiogu, "Energy Audit and Assessment: The Need to Curtail Electric Energy Wastages in the University of Nigeria, Nsukka", in the Proceedings of the 2nd International Conference on Electrical Power Engineering (ICEPENG 2021), pp. A.1 - A.5, 18 - 22 May, 2021.

10. C. D. Uzosike and C. J. Nnonyelu, “Pointing Mismatch in the Spatial-Matched-Filter Beam-Pattern of a L-shaped Array of First-Order Cardioid Microphones suffering from Orthogonality Perturbation” in the Proceedings of the 2020 LGT-UNN 2nd International Conference, Nsukka, Nigeria, pp. 110 - 116, 21- 22 September, 2020.

11. C. J. Nnonyelu, I. S. Okoro, and C. L. Anioke, “Wearable Ultrasonic Device for Ranging to Prevent the Spread of the COVID-19 Virus” in the Proceedings of the 2020 LGT-UNN 2nd International Conference, Nsukka, Nigeria, 21- 22 September, 2020.

12. V. K. Ugah and C. J. Nnonyelu, "A Wemos-D1-R2-Based Remote-Switching Module for Home Internet of Things Applications", in the Proceedings of 2019 LGT-UNN 1st International Conference, Nsukka, 10-11 December, 2019.

13. C. J. Nnonyelu, Z. N. Morris, and C.-C. L. Cheung, "Acoustical Direction Finding using a Bayesian Regularized Multilayer Perceptron Artificial Neural Networks on a Tri-Axial Velocity Sensor", in the Proceedings of the 1st International Conference on Mechatronics, Automation and Cyber-Physical Computer Systems (MAC-2019), Owerri, Nigeria, 7 - 8 March, 2019. 

14. C. J. Nnonyelu, C. H. Lee, and K. T. Wong, “Directional pointing error in “spatial matched filter" beamforming at a tri-axial velocity-sensor with non-orthogonal axes", Proc. Mtgs. Acoust.; 33 (1): 055004, 7 May 2018.

15. C. J. Nnonyelu, C. H. Lee, and K. T. Wong, "An array of two biaxial velocity-sensors of non-identical orientation— Their “spatial matched filter” beam-pattern's pointing error", Proc. Mtgs. Acoust.; 30 (1): 055017, 25 June 2017.

16. C. J. Nnonyelu, B. O. Anyaka & T. C. Madueme, “Power System Contingency Analysis: A Study of Nigeria’s 330 KV Transmission Grid”, in the Proceedings of the 4th Electrical Engineering National Conference on Energy Sources for Power Generation”, Nsukka, pp. 248 -256, July 21 – 22, 2013. 

Thesis

Nnonyelu, C. J. (2018). "An array of directional sensors (cardioid sensors or figure-8 sensors), diversely orientated but spatially collocated: Their beam-patterns (Doctoral dissertation", The Hong Kong Polytechnic University, 2018.  

Software Published:

PDFEmailExtractor: A free desktop application which enables users extract email address in either the first few pages or all the pages of a PDF file. The extracted email addresses are arranged in a tabular form and can be saved as a Microsoft's ".xls" file. Unlike other available applications for similar purpose, this allows multiple source file attachment and email extractions. Visit the Facebook page  or feel free to download the software.