Simulation and analysis of pointto-point differential drive mobile robot

A differential drive robot and Path motion point to point are studied and implemented in this thesis. The model by the Dudek model on Instantaneous Centre of Curvature is also discussed. The simulation of the mathematical model of the mobile robot was carried out in Simulink by using the Differential Drive Forward Kinematics and Differential Drive Inverse Kinematics blocks to convert between body velocities and wheel velocities. And use the Differential Drive Simulation block to simulate the pose given wheel speeds as inputs. Point to point motion was performed to test the robustness of the controller (0.0) as starting point and (4.4) as final destination and the results were used to optimize better performance

Pattern reconfigurable metamaterial antenna for 5G base station network

Reconfiguration of an antenna’s radiation pattern in a predefined direction is very important for enhancing the performance of communication systems in terms of the quality of service, system security, avoiding interference, and economizing power. Metamaterials, on the other hand, are commonly used in antenna design to enhance the gain, bandwidth, and efficiency and recently to tilt the radiation beam. Nonetheless, few issues had been encountered especially when the frequency is pushed to higher range such as the inherent losses that restrict the variety of their applications. Hence, metamaterials structures with relatively low loss are in high demand. In this thesis, various metamaterial structures with low loss properties are proposed. Then these structures are reconfigured and integrated with the fifth-generation (5G) planar antennas at two different frequency bands i.e. millimetre-wave (MMW) band and sub-6 GHz band for beam deflection applications. The modified double square ring resonator (DSRR) and contiguous squares resonator (CSR) structures are investigated numerically and experimentally to provide low loss property at 76 GHz and around 28 GHz, respectively. DSRR and CSR achieve losses of 0.5 dB and 0.2 dB, respectively. Both structures are manufactured and measured to validate the results. Furthermore, the analytical model is introduced to predict the electromagnetic behaviour of the proposed metamaterial structures. Thereafter, the CSR, Bridge shaped resonator (BSR) and split square resonator (SSR) structures are electronically reconfigured to produce different refractive indices at MMW and sub-6 GHz spectrums, which are used for deflecting the radiation beam of the 5G planar antennas. An array of unreconfigurable adjacent square-shaped resonators (ASSRs) has been also used for tilting the radiation pattern of planar antenna at sub-6 GHz spectrum. These proposed structures are included in the substrate of the dipole antenna and bow-tie antenna for deflecting the radiation pattern in E-plane at two different 5G bands of 28 GHz and 3.5 GHz. The results of all designs at both bands show that the radiation beam of the antennas is deflected in both positive and negative directions with respect to y-direction of antenna. At 28 GHz, a high deflection angle of 34° is obtained using simple structure, BSR, with gain improvement up to 1.9 dB (26.7%). On the other hand, at 3.5 GHz, the beam deflection angle of ±39º is achieved with gain enhancement up to 2.4 dB (35.6%) using passive beam deflection antenna whereas the beam deflection of ±36º is obtained using an active beam deflection antenna. The reconfigurable metamaterial antennas are proposed to be used in 5G base station network with advantages of high deflection angles, gain enhancement, low profile structure, low cost, lightweight, and easy integration with other circuits for 5G beam deflection applications

Breast Cancer classification by adaptive weighted average ensemble of previously trained models

Breast cancer is a serious disease that inflicts millions of people each year, and the number of cases is increasing. Early detection is the best way to reduce the impact of the disease. Researchers have developed many techniques to detect breast cancer, including the use of histopathology images in CAD systems. This research proposes a technique that combine already fully trained model using adaptive average ensemble, this is different from the literature which uses average ensemble before training and the average ensemble is trained simultaneously. Our approach is different because it used adaptive average ensemble after training which has increased the performance of evaluation metrics. It averages the outputs of every trained model, and every model will have weight according to its accuracy. The accuracy in the adaptive weighted ensemble model has achieved 98% where the accuracy has increased by 1 percent which is better than the best participating model in the ensemble which was 97%. Also, it decreased the numbers of false positive and false negative and enhanced the performance metrics.Comment: 12 pages articl

Configuration of horizontal voids and lightwell to improve natural ventilation in high-rise residential buildings in hot humid climate

Cross-flow ventilation is the most effective strategy for providing thermal comfort and ensuring air quality in buildings, while minimizing the required energy cost. In hot and humid climate, the high-rise building plan configuration incorporates different types of lightwell, either in the core or perimeter of the building, that allow for opening the windows in different directions and thus enables better cross-ventilation. The lightwell space is subjected to produce a suction effect along its space and thus adjoining indoor spaces. Lightwell at the core with opening at top trapped unwanted gases and thus reduce the fresh air flow in its space and reduce the cross flow ventilation in adjoining units. Nevertheless, having a lightwell may not be enough to provide adequate natural ventilation in high rise buildings. This study examines the internal lightwell connection to the outside through different horizontal voids as inlets. A Computational Fluid Dynamics (CFD) technique employing ANSYS Fluent code is used to predict airflow characteristics for eighteen (18) alternative ventilation configurations of a full-scale building model. The full-scale model was developed according to common configurations of high-rise residential (HRR) buildings in Kuala Lumpur, as well as referring to the minimum requirements of the Malaysian Uniform Building By-Law (1984). The results show that the existence of a direct connection of the internal lightwell through a horizontal void affects the air change per hour (ACH) and the thermal comfort in the lightwell space and adjoining units, respectively. Although the existence of double-level voids increases ACH by up to 67 % along the lightwell, it reduces the air velocity by 70 % in adjoining units compared to the lightwell without direct connection. In order to reduce such contrast and to optimize the cross-flow ventilation in the lightwell and its adjoining units, the study recommends giving more attention to the lightwell inlet design. This study provides proper guidelines to predict ventilation performance and to improve the design of naturally ventilated HRR buildings

Solving polynomial equations from 2000 B.C. through 20th century

This paper is divided into two parts. The first part traces (in details providing proofs and examples) the history of the solutions of polynomial equations(of the first, second, third, and fourth degree) by radicals from Babylonian times (2000 B.C.) through 20th century. Also it is shown that there is no solution by radicals for the quintic (fifth degree) and higher degree equations. The second part of this thesis illustrates both numerical and graphical solutions of the quintic and higher degree polynomial equations using modern technology such as graphics calculators (TI-85, and HP-48G) and software packages (Matlab, Mathematica, and Maple)

English Language Target Needs Of Medical Students At Ibb University In Yemen

Driven by the understanding that learners’ needs should be considered for an effective English for Specific Purposes (ESP) course, this study aimed to investigate the English language target needs for the development of the existing ESP course at the Faculty of Medicine and Health Sciences (FMHS) at Ibb University (IU) in Yemen. The needs analysis (NA) is a vital asset in designing and developing suitable ESP curriculum to meet the academic and professional requirements of the students. The conceptual framework of the present study is based on structuration theory and constructivism theory, along with Hutchinson and Waters’ (1987) framework utilised as a tool to identify the learners’ necessities, lacks and wants. A triangulation research method was followed in the present study. Thus, two different instruments, questionnaires and semi-structured interviews were used to collect quantitative and qualitative data. A sequential explanatory mixed-methods approach was adopted for the English language target needs analysis. The maximum variation purposive sampling strategy, the most common purposive sampling strategy, is employed in the current study to select a representative sampling of the stakeholders and to give much insight into needs analysis from different perspectives

Evaluation Of Apical Sealing Ability Of A Newly Developed Nano-Hydroxyapatite Sealer Using Cold Lateral And Continuous Wave Condensation Techniques: An In Vitro Study

Kajian ini bertujuan untuk membuat perbandingan dan menilai keupayaan pengapan apikal bahan pengap endodontik nano-HA dengan bahan pengap AH 26 menggunakan teknik kondensasi lateral sejuk dan kondensasi gelombang berterusan. Sebanyak dua ratus tiga puluh dua batang gigi manusia berakar tunggal digunakan. Korona dipotong pada bahagian “semento-enamel” menggunakan alat pemotong-Exakt. The aim of this study was to evaluate the apical sealing ability of an experimental nano-HA containing endodontic sealer and compare it with AH 26 sealer using cold lateral and continuous wave condensation techniques. Two hundred and thirty two extracted single rooted human teeth were used. Crowns were amputated at the cemento-enamel junction using Exakt-cutting system. The root canals were prepared using a crown-down technique with ProTaper nickel titanium rotary system and randomly divided into 4 experimental groups of 53 teeth each

Effect of Some Variables on the Level of Health Behavior among Faculty Members at the University of Science and Technology – Yemen

هدفت الدراسة إلى التعرف على مستوى السلوك الصحي لدى أعضاء هيئة التدريس في جامعة العلوم والتكنولوجيا اليمنية، ومدى تأثره بالمتغيرات: (الجنس، العمر, الحالة الاجتماعية, المستوى الأكاديمي, الكلية وسنوات الخبرة)، ولتحقيق هدف الدراسة تم استخدم المنهج الوصفي، وقد استخدم اختبار السلوك الصحي الذي يحتوي على مظاهر معينة من السلوك الصحي وأبعاده الخمسة، وقامت الباحثة بإضافة وتعديل عدد من الفقرات لتتناسب مع البيئة اليمنية، تكونت العينة من (125) فرداً، بلغ عدد المستجيبين (94) فرداً، وأظهرت نتائج الدراسة أن مستوى السلوك الصحي بين أعضاء هيئة التدريس كان متوسطا، كما أشارت الدراسة إلى عدم وجود فروق ذات دلالة إحصائية في مستوى السلوك الصحي في ضوء متغيرات: (الجنس, العمر والكلية)، ينما بينت النتائج وجود فروق ذات دلالة إحصائية في مستوى السلوك الصحي في ضوء متغيرات: (الحالة الاجتماعية، المستوى الأكاديمي، وسنوات الخبرة)، وأوصت الباحثة الاستفادة من نتائج الدراسة في المساعدة في الإعداد والتخطيط والتطوير لبرامج تعزيز السلوك الصحي، ورفع مستوى التوعية الصحية وثقافة التغيير التنظيمي في الجامعة بشكل خاص وفي المجتمع اليمني بشكل عام. الكلمات المفتاحية: السلوك الصحي, أعضاء هيئة التدريس، المتغيرات الديمغرافية.The aim of this study was to identify the level of health behavior of faculty members at the University of Science and Technology- Yemen; and to what extent this level is affected by some variables, such as gender, age, marital status, academic level, college type and years of experience. To achieve the study objectives, the descriptive method was followed; and a test of the level of health behavior, consisting of certain health aspects and five dimensions, was used. Some items of the test were modified by the researcher in order to adapt them to the Yemeni context. The study sample consisted of 125 faculty members, but 94 of them took the test. The study results revealed that the level of health behavior among faculty members was medium. There were no statistically significant differences in the level of health behavior attributed to these variables: gender, age and college type. However, there were statistically significant differences in the level of health behavior attributed to these variables: marital status, academic level and years of experience. It was recommended that the study findings be taken into consideration to develop and plan programs for promoting health behavior and raising the level of health awareness and culture of organizational change in the university in particular and in the Yemeni society in general. Keywords: health behavior, faculty members, demographic variables

Evaluating the Prediction Performance of Random Forest in Classification of Carbonate Lithology

Accurate lithology prediction in carbonate reservoirs is essential for hydrocarbon exploration but remains challenging due to their complex heterogeneity. Traditional methods (e.g., seismic and well-log analysis) often fail to capture subtle lithological variations, while machine learning approaches such as Random Forest (RF) remain underexplored for carbonates. Previous research has not sufficiently compared Random Forest with advanced models such as XGBoost and deep learning approaches, nor provided detailed feature importance analyses specific to carbonate lithology classification. This study employs a dataset comprising 4,624 samples characterized by ten petrophysical properties to evaluate the classification performance of RF. Our optimized RF framework demonstrates superior accuracy while reducing dependence on costly core sampling, thereby improving the precision of carbonate reservoir models