Journal of Sensors

With the rapid development, extensive knowledge, and diverse application scenarios of target perception and positioning technology in sensor networks, a passive target perception and localization platform based on Wireless Sensor Networks (WSN) has been designed. The platform is mainly applied for the teaching of electronic information, communication, and Internet of Things (IoT) engineering. The platform follows the teaching concept of “developing students’ ability to solve complex engineering problems” in the emerging engineering discipline and combines experimental simulation with real-world testing, as well as integrating scientific research and teaching. It encompasses technical elements such as perception and localization theory, sparse representation classification modeling, solving underdetermined equations, data analysis, and sparse coding, as well as nontechnical aspects such as team collaboration and cost budgeting. The platform boasts high fidelity and scalability, providing students with the opportunity to develop comprehensive practical and innovative skills in solving complex engineering problems.

The aim of this paper is to investigate the effectiveness of combining mobile technologies and sensors to detect harmful particles in the air and address the problem of air pollution caused by traffic and exhaust emissions. The paper contains a systematic literature review of information technology research related to pollution detection in order to point out the main obstacles in the field and propose solutions. Furthermore, the paper presents the development of an Android smartphone-based real-time monitoring system that utilizes an external analog sensor board to acquire and evaluate physical measurements. The proposed system is calibrated for CO gas measurements, and it is compared with a commercial gas analyzer instrument. Results imply that the developed system is capable of detecting concentration levels in the air and that the accuracy is within the range of the industrial device’s accuracy.

Background. The mainly lethal ability of ammunition fragments on creatures is achieved by hitting the effective organs or key parts of the biological body with high-speed projectiles. How to efficiently and accurately obtain the projectile speed and hitting position coordinates when the fragment hits the creature after the ammunition blast is the key to the scientific evaluation of ammunition power. Materials and Methods. For the measurement of fragment velocity and hitting coordinates, a series of flexible film circuit sensors can be generated by printing comb-like circuits on polyethylene terephthalate substrates using silver paste printing technology. These sensors are cheap, flexible, and easy to fold and can be printed into different shapes according to the characteristics of the test target to simulate the biological key organs or lethal parts. At the same time, the software and hardware design of the high-speed data signal reading and processing module can realize the data rapidly recording and processing and quickly give the ammunition fragment parameter test results. Results. The test accuracy of the fragment velocity of the laser light screen target and the flexible circuit sensor is compared through the live-fire test. It is proved that the test accuracy of the flexible sensor based on the polymer substrate can meet the accuracy requirements. The flexible sensor based on the organ simulation can quickly give the accurate hit position of the fragment. Conclusion. The newly polymer substrate printed circuit sensor system is a new type of sensor used to replace the laser screen target, and the copper comb printed circuit in the ammunition power test, which can improve the parameter test accuracy, reduce the test consumption, and improve the test quality.

Identifying objects in surveillance and reconnaissance systems with the human eye can be challenging, underscoring the growing importance of employing deep learning models for the recognition of enemy weapon systems. These systems, leveraging deep neural networks known for their strong performance in image recognition and classification, are currently under extensive research. However, it is crucial to acknowledge that surveillance and reconnaissance systems utilizing deep neural networks are susceptible to vulnerabilities posed by adversarial examples. While prior adversarial example research has mainly utilized publicly available internet data, there has been a significant absence of studies concerning adversarial attacks on data and models specific to real military scenarios. In this paper, we introduce an adversarial example designed for a binary classifier tasked with recognizing helicopters. Our approach generates an adversarial example that is misclassified by the model, despite appearing unproblematic to the human eye. To conduct our experiments, we gathered real attack and transport helicopters and employed TensorFlow as the machine learning library of choice. Our experimental findings demonstrate that the average attack success rate of the proposed method is 81.9%. Additionally, when epsilon is 0.4, the attack success rate is 90.1%. Before epsilon reaches 0.4, the attack success rate increases rapidly, and then we can see that epsilon increases little by little thereafter.

Realization of screen-printed disposable microchip based on organic membrane sensitive layer highly responsive to lead has been demonstrated for the first time. Fabrication, potentiometric characterization and analytical application of the novel microchip have been reported. A sensitive layer comprises TiO₂ nanoparticles and multiwalled carbon nanotubes “MWCNTs” composite incorporated in PVC membrane has uploaded on the plastic screen-printed microelectrode substrate surface using novel protocol. The new chip provided a linear behavior for Pb²⁺ ions over the lead concentration range of 1 × 10⁻⁶–1 × 10⁻¹ mole L⁻¹ with super Nernstian sensitivity (49 mV), relatively long life span (>4 months), and a fast response time (10 s). The advantages showed by the microchip include simple fabrication, small size, mass production, cost effectiveness, and automation and integration feasibility. The realized new microchip has been successfully utilized in the quantification of some lead (II) samples with average recovery of 101.9% and the RDS was <3.

The present study investigated the influence of key design parameters on the seismic performance of prefabricated precast assembled piers’ connection parts to better adapt to the industrialized construction of prefabricated precast assembled pier connected using grouting sleeves. Relying on a prefabricated assembled bridge in the actual project, the ABAQUS software was used to establish a refined solid finite element model of prefabricated assembled piers connected with grouting sleeves. Numerical simulation analysis was conducted for the piers with low circumferential reciprocating loading. The seismic performance of the prefabricated assembled piers was evaluated in terms of hysteresis characteristics, dissipation characteristics, and damage development. The effects of the length of the grouting sleeve and the diameter of the longitudinal reinforcement on the seismic performance were also investigated. The maximum error between the numerical simulation results and the test results was 5.7%, and the plastic region of the precast assembled pier obtained from the numerical simulation was consistent with the test results, indicating that the numerical simulation method is accurate and reliable. When the length of the grouting sleeve increased from 0.6 to 1.2 m, the yield load, peak load, and dissipation of energy of prefabricated assembled piers increased by 11.6%, 10.9%, and 11.4%, respectively; no significant change in residual displacement; ductility coefficient decreased by a small amount. When the longitudinal reinforcement diameter increased from 20 to 50 mm, prefabricated assembled piers yield load, peak load, and dissipation increased by 99.6%, 89.3%, and 218.9%, respectively, whereas the residual displacement increased by 137.3%, and the ductility coefficient decreased more. Increasing the length of the grouting sleeve or increasing the diameter of longitudinal reinforcement improved the stiffness of the piers, causing the piers to displace less and damage less under the same force, but the residual displacement would increase.