This study focuses on designing and implementing a cost-effective and energy-efficient WiFi packet sniffer system using the ESP32. The ESP32-CAM module, which combines WiFi, Bluetooth, and microSD support, is used to capture IEEE 802.11 frames in real-time via promiscuous mode. Packets are stored in packet capture format, which is compatible with tools such as Wireshark and Scapy. Developed using the official ESP-IDF, it offers low-level control and high performance. Two user interfaces were implemented: a UART-based text menu and a web-based HTTPS menu hosted on the ESP32 itself. Functional and performance evaluations were conducted with a focus on capturing broadcast and management frames without payload decryption. The system achieves 99.99% packet capture accuracy at 500,000 packets with a total hardware cost of $25 and power consumption of 2.1 W during active capture, representing a 95% cost reduction and 80% power savings compared to commercial alternatives. The download and file-listing speeds through the web-based menu were also evaluated, revealing that the system performs optimally with fewer files but experiences interruptions during large-scale operations. The proposed system provides a lightweight, standalone, and highly portable alternative to conventional packet sniffing tools despite the limitations in encryption handling and resource constraints. This makes it suitable for educational, diagnostic, and preliminary network analysis, particularly in low-power scenarios.

Hand gestures are a natural means of conveying information and thus, there is an increasing interest in utilizing gestures for communication with computers. This study focuses on systematically reviewing different machine learning algorithms while assessing their working mechanisms and accuracy. Articles were analyzed for comparing the performance of K-Nearest Neighbors (KNN), Random Forest (RF), Support Vector Machines (SVM), Naive Bayes (NB), Convolutional Neural Networks (CNN), and Recurrent Neural Networks (RNN). In accordance with input data, intricacy of gestures, processing resources, and real-time demands, the study shows that each technique has distinct advantages and disadvantages. RNN showed the best accuracy of 99.28% in recognizing dynamic gestures, indicating that it can be employed in applications that need high accuracy. CNN also performed well in recognizing static gestures and provide an accuracy of 93.61% accuracy. In order to improve human-machine interaction through efficient hand gesture detection, this systematic and comprehensive analysis offers some insight into the trade-offs between choice of algorithm and performance.

In this research, the influence of audio–sonic waves on distilled water used as the working fluid in a shell-and-tube heat exchanger was examined. The audio–sonic wave frequencies and flow rates of the cold and hot liquids were varied as follows: 4.85, 6.78, and 13.43 kHz for the audio–sonic waves; 0.3, 0.4, and 0.5 l/min for the cold liquid; and 0.76, 1.0, and 1.5 l/min for the hot liquid. An increase in the audio–sonic wave frequency enhanced both the overall heat transfer coefficient (U) and the enhancement factor (EF). The optimum values of U and EF, measured at 300 W/m3 ·°C and 1.05, respectively, were achieved at the highest frequency of 13.43 kHz. Additionally, the flow rates of the hot and cold liquids in the heat exchanger significantly influenced the optimal values of U and EF.

Effective noise and vibration control remains a critical challenge in high-speed rail systems, directly influencing passenger comfort and the longevity of infrastructure. This study evaluated four advanced materials—piezoelectric materials, shape memory alloys (SMAs), magnetorheological (MR) fluids, and damping composites—focusing on their potential for mitigating noise and vibration in high-speed rail applications. A combination of experimental and simulation-based analyses was employed to assess these materials based on their noise reduction coefficient, vibration transmissibility ratio, thermal stability, and durability under varying environmental conditions. The findings revealed that damping composites and SMAs demonstrated superior performance, offering enhanced noise attenuation and vibration control compared with the other materials. Damping composites exhibited the highest noise reduction and stability across a wide frequency range, while SMAs demonstrated exceptional adaptive damping properties under fluctuating temperature conditions. In contrast, piezoelectric materials and MR fluids showed moderate performance, making them more suitable for secondary damping applications. This study identifies damping composites and SMAs as the most effective materials for primary noise and vibration control in high-speed rail systems. The findings provide valuable insights for material selection and integration in rail infrastructure, contributing to enhanced system performance, reduced maintenance costs, and compliance with stringent noise and vibration regulations.

Drift forces caused by sea waves and currents are an important aspect that needs to be studied in planning moored floating structures, especially Floating Production Units (FPU) type ships which are operated for oil and gas exploration. This study describes the drift forces on the FPU which is subjected to environmental loads in the form of waves. The slow-drift movement that occurs in a moored FPU, and experiencing irregular waves is a very important problem. The complexity of determining drift forces analytically and numerically requires the use of hydrodynamics model test. In the model test on a certain model scale the ship is equipped with several measuring instruments for measuring ship movement and the forces acting on the mooring lines. The Model testing was also carried out by providing a simulation of environmental forces in the form of currents and ocean waves which were varied in several wave headings. The magnitude of the mean wave drift force that occurs on FPU is very dependent on the heading angle of the wave excitation and current as well as the significant wave height and peak frequency.

Biomass development has been a key issue for the past few decades and will remain attractive in the future because of its cleanliness, renewability, carbon neutrality, and other advantages. This study aims to determine the optimal holding time for heating system briquettes by testing the heating value of empty fruit bunches fibers. The process of this research involves the use of one unit of briquette molding equipment by providing a heating system to the mold cylinder. Fibers were manually finetuned until they reached a size of 20 mesh (0.84 mm). Densification temperature is an essential factor that could affect the combustion properties, especially the calorific value. The Arduino program is used for setting the heating resistance time of the mold, which is 15, 20, and 25 min at a temperature of 200 ºC, and the thermal controller is used to adjust the temperature variation. Results showed that the highest calorific value of the three varieties of holding time was at 25 min with a calorific value of 4480.2 cal/g, and the lowest cost at 15 min was 4022 cal/g. Meanwhile, a calorific value of 4432.5 cal/g was found at 20 min. This finding is due to the low moisture content and high charcoal content of the sample in the 25 min briquette mold. Therefore, briquettes at 25 min have a higher heating value compared with those at 15 and 20 min holding time.

This paper presents a novel idea of establishing a low cost and highly efficient heating apparatus. This apparatus can be used along with any universal testing machines (UTM) for various tests, such as fracture, fatigue, torsion, and shear. This low cost and highly efficient option for researchers in solid mechanics may be used in a broad range of promising research areas. Moreover, this novel apparatus is beneficial for all researchers interested in high-temperature solid mechanics and applications. An extensive literature review presented reveals the existing heating apparatus currently used in mechanical testing labs globally, along with their pros and cons. A comparative study of the new heating apparatus and the current ones shows the advantages of the new heating apparatus and reveals how it overcomes the drawbacks of the existing heating apparatuses. The setup and connection of the new heating apparatus illustrate its secure operation and its easy commercial acquisition.

Augmented reality (AR) is a trending technology with many potential applications. In architecture, AR can help visualize and document historic buildings by virtual reconstruction. Colonial buildings in Jakarta Old Town are cultural heritage buildings that are vulnerable to damage by aging and environmental factors. The mitigation of this damage as the first step toward restoration is important. The storage and maintenance of records of threatened buildings for posterity are also important. The objective of this study is to develop a methodology for AR-based reconstruction. AR technology is implemented through mobile phones or smartphones. The modeling process is simple and interactive and has potential applications in both education and tourism. The reconstruction method of colonial buildings uses markerless AR and a database of historical knowledge of colonial architecture. The architectural style is identified using the database. Then, an AR-Reconstruction prototype, which provides a visual description of the building reconstruction process using 3D graphics animation models of colonial buildings, is developed. The model reproduces the building in its original condition and actual location. In the trial run, access to building details is delayed. Therefore, in the future, the geometric details and marker quality need to be optimized.

This paper presents the design of the inter-integrated circuit (I2C) protocol with different types of features, such as combined messages, addressing modes, different data patterns and start addresses, clock frequencies, and types of modes between the field-programmable gate array (FPGA) and test card. Moreover, all these features can be randomized and run for long hours. The FPGA and the test card respectively act as master and slave. The design architecture comprises master and slave. The master generates a START condition, in which the serial data will transact between high to low levels and the serial clock will remain high. Then, the master also generates the STOP condition. Additionally, a few types of messaging modes, such as PIO read, PIO write, PIO write–read, and PIO read–write, are available. By contrast, the master also transfers and receives data to or from slave devices by using different addressing modes. The implemented addressing modes are 7 and 10 bits. This paper also focuses on randomizing the sent data byte and the start address. Particularly, data sending, reading, and writing operations are conducted and stimulated by capturing the signal using a logic analyzer. The signal is then examined and compared with the actual I2C protocol format. A stress test is performed by randomizing all the features and running for long hours (4 h). The stress test aims to stress the IP and ensure the health of IP.

Soil is one of the most important aspects of an infrastructure given its functions of receiving and holding structural loads. However, not all soils have good physical and mechanical properties. To overcome those conditions, stabilization of the soil is practiced to meet the technical requirements. This study aims to determine the behavior of high plasticity clay stabilized with lime, fly ash, and bottom ash. These additives can be used as a stabilizing agent to increase soil strength. The percentage of additives varied from 5%–25% then mixed with clay and were tested through the (Unconfined Compression Strength (UCS) test. The UCS test was carried out with 6 treatments, including consecutively non-curing and unsoaked, non-curing and soaked, curing for 7 days and unsoaked, cured for 7 days and soaked, cured for 28 days and unsoaked, and cured for 28 days and soaked. Results show that the UCS value increased along with the span of curing time. Meanwhile, the soaking treatment of the sample decreased the UCS value.