As the effectiveness of an early detection of breast cancer using the mammography method alone is uncertain, it is crucial to provide an alternative method instead. This paper analyzes two optical flow algorithms utilizing a gradient method to aid current imaging techniques for a potential alternative method in aiding early breast cancer detection. The gradient method is a cost effective method that has the potential to be a mass screening method for this purpose. This paper compares two optical flow algorithms that are capable to detect the motion of breast tumor on B-mode ultrasound images. An analysis of 2D images of breast cancer lesions are compared using two gradient optical flow algorithms: Horn & Schunck and Lucas & Kanade. Both algorithms successfully show the direction of the tumor motion. However, while Lucas & Kanade can handle the short motion displacement of the tumor on the tested ultrasound images, Horn & Shunck failed to do so. This implies that the Lucas & Kanade algorithm is potentially more effective in handling ultrasound images of breast tumor. The results obtained showed that the Lucas&Kanade give better accuracy compared to Horn&Schunk.

This paper deals with a Band Anti-Crossing (BAC) modelling to investigate the tailoring of band gap energy of Ga1-xInxNyAs1-y alloy based on nitrogen fractions. Three different numerical methods have been adopted to estimate the extended state of conduction band () parameters. The first two methods used Vegard’s law and Varshni’s equation to estimate by considering Ga1-xInxAs as ternary alloy based on temperature dependence, with values of bowing parameter of 0.475 and 0.477, respectively. The third method used excitonic band gap theory for Ga1-xInxAs alloy temperature dependence by considering Passler fitting () and average phonon temperature (). Results depict that optimum nitrogen fraction was in the range of 0.012 to 0.018% to achieve the device response at 1.3 μm wavelength, with an energy band gap in range of 0.955 ± 0.005 eV. Future work shows a potential study on influence of indium fractions in tailored energy band gap of Ga1-xInxN yAs1-y alloy and compressive strain of material. KEYWORDS Band Anti-Crossing, Dilute Nitride, Gallium Arsenide, Ga1-xInxN yAs1-y Alloy, Band Gap, 1.3 μm Wavelength

After Leo Esaki had reported the first tunnel diode in the early of 1960, there are development of Asymmetric Spacer Tunnel (ASPAT) diode. This device appears to have unique I-V characteristic, where it has zero turn on bias with minimum leakage current. Hence, with respects to this unique characteristics, this study will perform the physical modelling of Gallium Arsenide/ Aluminium Arsenide (GaAs/AlAs) of single barrier asymmetric spacer tunnel diode in COMSOL by considering all the parameters involved in designing the device such as the dimensions of ASPAT, the concentration, materials and numerical modelling involved. These parameters are significant in the calculation of current density when the device being applied with external voltage. At the end of this study, the I-V characteristics of ASPAT in COMSOL will be analysed and compared with the reported I-V characteristics of ASPAT diode in SILVACO to determine either it is reciprocated in terms of zero voltage switching and minimum reverse bias.

We have investigated the self-lasing effect of the linear multiwavelength Brillouin-Erbium fiber laser with different tunable bandpass filter's bandwidth. Two 3dB bandwidth of 1 nm and 3 nm filter were used in this study. The experimental results show that the width of the TBF bandwidth plays an important role in shaping the self-lasing effect. By using the tunable bandpass filter with a broader bandwidth, the self-lasing effect can be suppressed efficiently thus producing higher Brillouin Stokes lines. At 0 dBm Brillouin pump power, up to 11 stable output laser channels can be obtained with the utilization of the 3 nm TBF as compared to only 5 output channels with the utilization of 1 nm TBF.

The electrical characteristic of a Ga 0.952 In 0.048 N0.016 As 0.984 p-i-n diode with quantum wells was characterized by current-voltage (I-V) measurement at room temperature. The electrical parameters of the diode such as a leakage current (𝐼𝑜), the threshold voltage (VT) and dynamic resistance (𝑅𝑑) were extracted from the I-V characteristics. The p-i-n diode has a leakage current of 0.010 µA, threshold voltage of 0.22 V and dynamic resistance of 262 kΩ. Moreover, the Schottky parameters of the Ti-Au/n-GaAs pi-n diode such as an ideality factor (η), a Schottky barrier height (Φb) and series resistance (Rs) were determined using thermionic emission (TE) analysis of the forward-bias I-V characteristic as well as Norde and Cheung functions. The Schottky diode parameters showed an ideality factor of 4.79 with a barrier height of 0.79 eV were obtained using forward-bias I-V characteristics. On the other hand, barrier heights determined from the Norde and Cheung functions were calculated at 0.87 eV and 0.71 eV, respectively. As there is an inconsistency between the current-voltage characteristics and the models, the necessity to investigate the temperature dependence diode parameters for accurate determination of the mechanism responsible for the charge transfer and Schottky barrier height of GaInNAs p-i-n diode. Keywords: GaInNAs; p-i-n diode; current-voltage; barrier height; thermionic emission theory

One of the most crucial issues in mobile networks is ensuring reliable and stable connectivity during mobility. In recent years, numerous research has examined Fourth Generation (4G) and Fifth Generation (5G) mobile networks to address issues related to handover (HO) self-optimisation. Different approaches have been developed to identify the best Handover Control Parameters (HCPs) settings, including Time-To-Trigger (TTT) and Handover Margin (HOM), since managing HCP values is a key factor in determining the efficiency and accuracy of handover decisions. The purpose of this work is to address the challenges associated with HO management in Sixth Generation (6G) mobile networks, where a massive number of diverse devices, high mobility, and varying network conditions (e.g., Ultra Dense Network (UDN), Heterogeneous Network (HetNet) and Millimetre Waves (mmWaves)) are established. This, in turn, presents complex HO issues which require solutions that can adapt to different deployment settings. To provide a brief background of mobility management, the paper presents the basic HO concept, HO history, and HO procedure. Additionally, a comparison of HO in 4G to 6G is discussed to gain a better understanding of technology development and its effect on HO solutions. Furthermore, the basics of Mobility Robustness Optimisation (MRO) is explained, which involve HCP values. Previous MRO approaches have made significant advancements; however, they often lack adaptability and robustness to dynamic network conditions. By leveraging Artificial Intelligence (AI) algorithms with MRO techniques, this approach offers an improved solution to optimize handover decisions in a self-optimizing manner, thereby enhancing the overall network performance. To achieve this goal, it is necessary to analyze previous MRO and AI-integrated solutions and make comparisons between them. Additionally, the advantages and disadvantages of these solutions are considered. The contribution of this work lies in identifying the directions for HO self-optimization in 6G deployment. It demonstrates that deploying an AI-based solution would benefit future MRO deployments. This survey will aid in the analysis of mobility management challenges, particularly for the future mobile MRO self optimization implementation in future technologies.

This paper describes the implementation of the modified cryptographic algorithm namely A5/1 stream cipher which is widely used in Global System for Mobile (GSM) communication. While there are numerous published work on the A5/1 stream, very few have implemented the modified design into hardware and none of them, to the best of the author’s knowledge, has clearly analyzed as to how the different characteristics of the conventional A5/1 stream cipher would affect performance at hardware level implementation. Two modified designs with different total bits and combinational functions are implemented into hardware by means of an Field Programmable Gate Array (FPGA) board and the throughput, area consumption, power consumption as well as the throughput-to-area ratio performance of the hardware are analysed and compared with that of the conventional design of the A5/1 stream cipher. While the algorithms in use have the same level of randomness, and hence strength in terms of security, at the hardware level, when total bits in use is increased, the total power consumed actually reduces. It is also observed that the use of the XOR logic has the better power consumption rate, compared to when a multiplexer is implemented as the combinational function. Index Terms—A5/1 stream cipher, field programmable gate array, FPGA, throughput, cryptographic algorithm.

conventional power resources since it is clean and renewable. The PV system allows the Sun’s energy to be converted to electricity using solar cells which currently is made by silicon. This project aims to evaluate the impact of ideality factor and semiconducting material variations on the I-V and P-V characteristics of the PV cell. For the purpose, five mathematical equations used to replicate the operations of PV module are modelled in MATLAB/SIMULINK and the electrical performances of the PV modules are analyzed. The results indicated that the electrical performances of a PV cell are highly dependent on the types of semiconducting material used and the ideality factor. From the tested material, it is found that at a temperature below the standard temperature condition (STC) of 25°C, Gallium Phosphide, GaP with a bandgap of 2.26eV would be the better option. An improved of 9.52% in maximum power is observed at 10°C when compared to silicon. However, at a temperature above the STC of 25°C, the use of Germanium with a bandgap of 0.67eV would be the better option than silicon as an increased of the maximum power of 4.97% is found at 40°C. Besides, the improper fabrication process (e.g. n= 2.0) would reduce the Pmax of the PV modules by 12%.

Background: A5/1 is well-known as the encryption standard for GSM communication, one of the most largely used cellular system in the world. Despite the popularity, its credibility was severed when its design was leaked in 1999 which consequently posed a threat to user’s privacy and confidentiality. The disclosure, incidentally, unveiled some weaknesses of the A5/1 stream cipher design such as short register phase, collision problem and simple combinational function. In this paper, a modified A5/1 is described. The proposed design looked at the effect of altering the combinational function from that of XOR to one using a 4-to-1 multiplexer (Mux) to increase the complexity of the algorithm which in turn will enhance its random features, and thus making it more secure overall. The generated output from the proposed design will be tested using the National Institute of Standard and Technology (NIST) test suite. The result will then be compared with that obtained using the modified design by Zakaria et. al. (2014), and next, analyzed. Objective: The objective for this study is to analyze and compare the use of different parameter toward the randomness of modified A5/1 structure by using the NIST test suite. Results: The analysis computed by the NIST test suite shows that the author’s proposed version is more secure compared to that of Zakaria et. al.’s version. Conclusion: The author’s version is shown to be more secure compared to that of Zakaria et. al. (2011), and while its randomness is comparable to that of the original A5/1 version, its structure is not that of public’s knowledge and will therefore minimize its probability of being deciphered.

Nowadays, with a good design and available facilities of high impulse generators that can be taken to field sites for measurements, much research work can be found on the field measurement on the study of the grounding under fast transients. Moreover, field tests on earthing systems have become interesting since it can provide the closest scenario of the characteristics of grounding system when fast transient current discharged to the earthing systems. However, the field measurements have some limitations on the standard methodologies that should be adopted during the field measurements. There is also very little being mentioned on the arrangements/values of the remote earth. As generally known, the remote/auxillary earth is important not only for the purpose of discharging any high fault current during the tests on the electrode under tests, but also to ensure that the remote earth is not being included in the measurements, hence affect the accuracy of the measurements. Due to these factors, this paper is to aimed to study how different configurations and resistance values of remote earth on the characteristics of main earthing systems. It was found that different results were obtained when higher earth resistance values of remote earth were used for impulse tests on main earthing systems.

The need of a long battery life span is crucial in portable devices. Following that, this study is conducted to extensively monitor the current performance drawn from the Arduino Nano and ST Arm Core ST32L152RE used as the controller in a portable dialysis system, specifically at the Active and Low Power Mode. The results obtained showed that the ST Arm Core ST32L152RE managed to achieve 99.99% current saving as opposed to the Arduino which gave a rate of 99.74%, despite the fact that the former runs at twice the frequency of the latter. � 2018 IEEE.

A random laser is an optical device that depends on multiple light scattering and gain to provide the feedback mechanism and light amplification respectively. A random laser is different with a regular laser where the regular laser needs a cavity for the feedback mechanism. Multiple light scattering can be considered detrimental in the regular laser but in the random laser, multiple light scattering can increase the path length of light in the active medium. This article studies the operation principles and characteristics of random lasers including the history and applications of the lasers. The theories of light scattering and light amplification are properly explained, followed by a discussion on characteristics of random lasers in terms of random laser emission, emission linewidth and coherence. Furthermore, the unique characteristics of random lasers can contribute to many applications leading to promising element for the future medical and biosensing development.