Performance evaluation of optical attocells configuration in an indoor visible light communication

Visible light communication VLC is deemed as futuristic technology applied for both illumination and data communication due to the low-cost energy consumption, long life expectancy, huge bandwidth, and high security compared to radio frequency RF. Uncovered area, minimum signal-to-noise ratio (SNR) and received power results from the non-uniform distribution of small base stations (i.e. Optical attocells) in the room. In this paper, the researchers propose a new LEDs distribution of five optical attocells configuration model in order to optimize the received power distribution and SNR at the center of the room for indoor VLC system. The optical attocells configuration in terms of received power to fill the uncovered area at the center of the room has been investigated. The simulation results showed that the proposed attocells configuration saved 24.9% of the transmitted power. Besides that, the whole room was covered uniformly. As a result, the received power and SNR are improved

Visible light communication using new Flip-FBMC modulation system technique

Filter bank multi-carrier (FBMC) modulation in the visible light communication (VLC) system is one of the most promising modulation systems in optical wireless communications (OWC), especially in 5G and 6G future applications. FBMC has a wide bandwidth compared to other modulation systems. One of the highest degree essential conditions for utilising the signal in VLC is that the signal is real positive, the signal is agreeable with intensity modulation/direct detection (IM/DD), where Hermitian symmetry (H.S) is utilised to get a real signal (RE) and to be unipolar direct current (DC)-bias is used. Here the challenge arises as this method increases complicating, due to the modulation of the N number of frequency symbols, these symbols need 2N inverse fast fourier transform (IFFT) and fast fourier transform (FFT), in addition to energy consumption. This research focused on the time domain and not the frequency domain by using the traditional complex FBMC generation signal, and to obtain the RE signal by placing the RE signal side by side with the imaginary signal (IMs) in a row, and then using new Flip-FBMC technology, which saves more energy. The proposed technologies provide approximately 57% of the number of IFFT/FFT. The use of Flip-FBMC technology consumes less energy than traditional technologies with better bit error rate (BER) performance

Design and analysis of different optical attocells deployment models for indoor visible light communication system

Visible light communication (VLC) is a promising candidate that is expected to revolutionize indoor environment communications performance and fulfill fifth generation and beyond (5GB) technologies requirements. It offers high and free bandwidth, electromagnetic interference immunity, low-cost front end and low power consumption. Also, VLC has dual functions that could be utilized in both illumination and communication concurrently. The number of optical attocells (OAs) and their deployment in the room represent the main issue that should be taken into consideration in designing an optimal VLC system. In this paper, we have introduced a new model of five OAs in the typical room. In addition to an investigation of various optical attocells (OAs) deployment models, in which a multi-variable evaluation was performed in terms of received power, illumination, SNR and RMS delay spread in order to determine the optimal OAs model. Also, various modulation schemes performances were investigated which included NRZ-OOK, BPSK, and QPSK in order to improve the BER performance. Results indicated that BPSK modulation had superior BER performance when compared with all OAs models. Further, a comprehensive results analysis and comparison of all proposed models was conducted over various parameters, in which our new proposed OAs model achieved an optimal performance in comparison with the other models

Periodontal status of rheumatoid arthritis patients in khartoum state

<p>Abstract</p> <p>Background</p> <p>Few studies have investigated the periodontal condition among Rheumatoid arthritis in Sudan. The present study described the periodontal condition among Sudanese patients suffering from rheumatoid arthritis and to compare them with those of non-rheumatic subjects.</p> <p>Methods</p> <p>A group of eighty rheumatoid arthritis patients was selected from Patient's Rheumatoid Clinics in Khartoum State during the period of January to May 2010. A control group of eighty patients with the same age and gender was selected for the study. Both Rheumatoid arthritis patients and the control group were examined for their plaque index, gingival index, and clinical attachment loss.</p> <p>Results</p> <p>The results revealed that there were no significant differences in plaque and gingival index among study and control groups, with mean plaque index of (1.25 ± 0.4) for patients and (1.17 ± 0.28) for the control group (p-value is 0.3597). The mean gingival index was (1.2 ± 0.24) for the patients and (1.2 ± 0.33) for the control (p = is 0.3049). The results showed statistically significant differences in clinical attachment loss between study and control groups, with mean clinical attachment loss of (1.03 ± 0.95) for the study group and (0.56 ± 0.63) for the control group (p = 0.0002). The study revealed that no association exists between the type of drug used to treat rheumatoid arthritis (NSAIDs & DMARDs) and the periodontal parameters (plaque index, gingival index, and clinical attachment loss).</p> <p>Conclusion</p> <p>A significant relationship between periodontal disease and Rheumatoid Arthritis does exist, but no difference between plaque and gingival index has been detected among study and control groups.</p

Design and Validation of a Compact 3.5GHz Antenna for 5G-based IoT Applications

Compact and small-sized antennas are crucial for 5G-based IoT applications due to their ease of integration into devices with limited space, lower power consumption, and ease of installation in urban areas. In this research, we designed a compact wideband 3.5GHz antenna for 5G-based IoT applications using CST Studio software. The antenna was fabricated on an FR-4 substrate with dimensions of 40mmx32mm and a thickness of 1.6mm, with a microstrip feeding line. Simulation results showed a return loss of -42.287dB and a VSWR of 1.016. Real measurements of S11, radiation pattern, and gain were conducted to validate the simulation results, with S11 measurements taken using a Vector Network Analyzer at the UTHM Pagoh RF Lab and radiation pattern and gain measured in a chamber at the UTeM RF Lab. The simulation and real measurement results were similar, with slight differences due to device inaccuracies and manufacturing. The designed antenna is believed to be beneficial for fifth-generation communication-based IoT application

Surgical management of eumycetoma: experience from Gezira Mycetoma Center, Sudan

Abstract Background In this study, we share our experience of different operative techniques undertaken on 584 eumycetoma patients in the Gezira Mycetoma Center. Methods This is a retrospective, descriptive, hospital-based study, conducted to review the surgical treatment of eumycetoma patients. We included all patients diagnosed with eumycetoma who underwent a surgical operation in the center during January 2013–December 2016. Results A total number of 1654 patients were seen during the study period, and their records were revised, while 584 (35.3%) of them underwent an operation and included in the study. There was a male predominance 446 (76.4%). Surgical excision of mycetoma was the commonest operation performed among 513 (87.8%) patients in comparison with amputation 71 (12.2%). Below-knee amputation and toe amputation are the commonest types of amputation in 36 (6.1%) and 14 (2.3%) patients, respectively. Clinical features determining the type of operation performed included the size of the lesion, whether or not a bone was involved, and the feasibility of primary closure. A wide surgical excision (WSE) is performed mainly when the bone is not involved and when moderate or primary closure is possible or reconstruction is feasible. Amputations will typically follow identifying bone involvement, secondary infection, and an already disabled patient. Conclusion The commonest procedure in our series was WSE and primary skin closure undertaken when the lesion was small ( 10 cm) without bone involvement were treated with excision and flap/graft. Bone involvement and large primary lesions were more likely to be managed by amputation. Recurrent and relapse of mycetoma were observed in patients with bone involvements or presented with recurrent mycetoma for the second time

Modelling and Performance Analysis of Visible Light Communication System in Industrial Implementations

Visible light communication (VLC) has a paramount role in industrial implementations, especially for better energy efficiency, high speed-data rates, and low susceptibility to interference. However, since studies on VLC for industrial implementations are in scarcity, areas concerning illumination optimisation and communication performances demand further investigation. As such, this paper presents a new modelling of light fixture distribution for a warehouse model to provide acceptable illumination and communication performances. The proposed model was evaluated based on various semi-angles at half power (SAAHP) and different height levels for several parameters, including received power, signal to noise ratio (SNR), and bit error rate (BER). The results revealed improvement in terms of received power and SNR with 30 Mbps data rate. Various modulations were studied to improve the link quality, whereby better average BER values of 5.55 × 10⁻¹⁵ and 1.06 × 10⁻¹⁰ had been achieved with 4 PAM and 8 PPM, respectively. The simulation outcomes are indeed viable for the practical warehouse model