{"title":"Extended Dual-Message QR Codes With Visual Secret Sharing","authors":"Ran-Zan Wang;Liang-Yi Wang;Kun Chen","doi":"10.1109/LSENS.2025.3560787","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3560787","url":null,"abstract":"The camera serves as one of the primary sensors enabling smartphones to interact with the physical world, making it an essential tool for various interactive applications. By exploring the camera's unique way to recognize module bit values in the QR code decoding algorithm, this letter enhances dual-message QR codes by integrating visual secret sharing (VSS) functionalities. Each QR code encodes two distinct messages that can be read by standard QR code readers: one readable at close range and the other at a distance. In addition, the proposed (<italic>t</i>, <italic>n</i>) VSS scheme allows the confidential message to be revealed by stacking <italic>t</i> or more of the <italic>n</i> QR codes, while fewer than <italic>t</i> QR codes disclose no information about the secret. Readability tests confirm that both messages in each QR code are accessible via standard smartphone QR code apps, and that the confidential message is recognizable to the human eye. Security analyses validate that the confidential message is reliably protected. Compared to previously reported multilayer QR codes, the proposed scheme encodes three layers of messages within a single QR code, archiving a higher information payload. Moreover, the capability to visually reveal the additional confidential message by stacking QR codes without requiring any computational processing is a notable advantage.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Classification of Fiber Optics Anomalies Using Transforms Ensemble, Adaptive Smoothing Based on the Standardized Variable Distances Learning Algorithm and Convolutional Neural Networks","authors":"Gianmarco Baldini","doi":"10.1109/LSENS.2025.3560144","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3560144","url":null,"abstract":"Convolutional neural networks (CNN) have been applied to the classification of different types of anomalies in optical networks. On the other side, the more challenging problem of the evaluation of the severity of a specific anomaly has been scarcely investigated. This letter proposes a hybrid machine learning/convolutional neural networks (CNN) approach, where the presence of noise is mitigated by a preprocessing step based on an adaptive smoothing algorithm and an ensemble of transforms to generate a feature space given in input to a CNN. The approach is applied to a recent public dataset with sensor data collected from a real fiber optical network for the fiber bending anomaly, where it is shown to outperform the direct application of CNN on the original sensor data in the time domain.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10963893","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Safeer S S;Anoop Chandrika Sreekantan;Radhika V. N.
{"title":"An Efficient Multiphase Integration-Type Linear Digital Thermistor Front-End","authors":"Safeer S S;Anoop Chandrika Sreekantan;Radhika V. N.","doi":"10.1109/LSENS.2025.3559993","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3559993","url":null,"abstract":"This letter proffers a new integrating-type linearizing digitizer (ILD) for thermistors. The proposed ILD, in its basic form, employs an enhanced integrating-type digitizer, equipped with a couple of linearizing resistors. It works based on a novel triple-phase methodology and renders a linear direct-digital indication of temperature. The schemes use a simple architecture and do not require special parts, such as matched references and logarithmic amplifier, which are needed in prior thermistor-front-ends. Two variants of ILD, which are tailored for shorter and longer operational spans, are also discussed in this letter. The performance of the proposed schemes is analyzed and brought-forth using simulation and detailed experimental studies. Results showcase the ability of ILD (and its variant) to act as an accurate linearizing digital front-end over wide span.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Printed Single-Chip RFID Tags on Uncoated Paper for Environmental Monitoring Applications","authors":"Lukas Rauter;Lukas Neumaier;Tutku Bedük;Martin Lenzhofer;Arnold Horn;Muhammad Hassan Malik;Johanna Zikulnig;Razvan Oltean;Albert Seiler;Jürgen Kosel","doi":"10.1109/LSENS.2025.3559556","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3559556","url":null,"abstract":"The growing demand for sustainable and efficient environmental monitoring systems has driven the development of innovative sensor technologies. This study presents a hybrid ultra-high frequency radio-frequency identification (RFID) sensor tag fabricated on uncoated paper substrate, which constitutes approximately 87% of the tag's mass thereby making the sensor tag more sustainable and eco-friendly. The sensor tag integrates an AS3213C.4 RFID chip together with an antenna, an interdigitated capacitor as a humidity sensor, pads, and interconnects. Temperature sensing is facilitated by the RFID chip's internal temperature sensor, while humidity is monitored through changes in the printed capacitor. All structures except for the chip were screen printed using a conductive silver ink. The silver layer exhibited a thickness of 5.6 μm and a sheet resistance of 56.4 mΩ/sq, sufficient for wireless communication over a distance of 2 m. The sensor was wirelessly interrogated using a Kathrein antenna and reader system, with data retrieved via commercial software. Temperature tests demonstrated accurate readings from 26 °C to 80 °C, aligning with the chip's specifications of −40 °C to 125 °C, with a precision of 1 °C in the range of 10 °C to 50 °C. Humidity measurements in a climate chamber, conducted between 15% and 55% relative humidity, showed an average sensitivity of 0.45% per % humidity change. Hysteresis effects of 7.4% were observed due to the moisture absorption and structural changes of the paper substrate. This work highlights the potential of paper-based sensor tags for sustainable environmental monitoring, aligning with the principles of Industry 4.0 and the Internet of Things (IoT), while addressing the growing challenge of electronic waste.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143892435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nur Syahirah Roslan;Ibrahima Faye;Hafeez Ullah Amin;Muhamad Hafiz Abd Latif
{"title":"Enhancing Extraversion Classification With Sample Entropy: A Comparison of Two EEG Epoch Lengths","authors":"Nur Syahirah Roslan;Ibrahima Faye;Hafeez Ullah Amin;Muhamad Hafiz Abd Latif","doi":"10.1109/LSENS.2025.3559549","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3559549","url":null,"abstract":"With the advancement of technology, many researchers have begun to employ electroencephalography (EEG) to assess extraversion personality traits, replacing subjective self-report questionnaires. However, most EEG studies are time-consuming and have inadequate classification accuracy. Thus, this letter proposes a framework for extraversion classification using sample entropy features extracted from resting-state EEG signals. The proposed framework compares two different EEG epoch lengths (15 and 120 s) and evaluates their impact on classification performance. To enhance the classification performance, a sequential forward selection method is applied to ensure that only the most optimal features are utilized. Using support vector machine, k-nearest neighbors, random forest, and extreme gradient boosting as classifiers, the study shows that sample entropy outperforms power and coherence features in classifying extraversion. Remarkably, the framework achieves 100% classification accuracy using a single feature: the sample entropy from a 15-s eyes-open condition at the Fpz electrode. By reducing the number of required features to just one and focusing on a shorter EEG epoch length, this finding reflects the potential of developing EEG-based sensor systems that are more practical and cost-effective in the future.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Imran Hossan;Muhammad Sudipto Siam Dip;Sumaiya Kabir;Mohammod Abdul Motin
{"title":"DeepApneaNet: A Multistage CNN-Bi-LSTM Hybrid Model for Sleep Apnea Detection From Single-Lead ECG Signal","authors":"Imran Hossan;Muhammad Sudipto Siam Dip;Sumaiya Kabir;Mohammod Abdul Motin","doi":"10.1109/LSENS.2025.3558675","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3558675","url":null,"abstract":"Obstructive sleep apnea (OSA) is a critical sleep disorder that can lead to severe health complications and even death if left untreated. Early OSA detection through non-invasive methods, such as single-lead electrocardiogram (ECG) analysis, presents a promising approach for timely intervention. In contrast to the existing single-stage convolutional neural network (CNN) and bidirectional long short-term memory-based (BiLSTM) hybrid models, this letter presents DeepApneaNet, a novel end-to-end deep learning framework that combines multiple CNN-BiLSTM-based hybrid subnetworks in a cascaded manner to detect OSA from single-lead ECG signals. With the PhysioNet Apnea-ECG Database, our implemented framework is able to achieve the best per-segment accuracy, sensitivity, and specificity of 88.61%, 84.23%, and 91.04%, respectively. For per recording classification, our model achieved 94.29% accuracy, 100% sensitivity, and 83.33% specificity. Even though using minimal preprocessing and without any hand-crafted feature extraction, the performance of our model is still comparable to the state-of-the-art methodologies. The results indicate that segmenting hybrid models into smaller networks enhances the understanding of sequence dynamics. DeepApneaNet demonstrates significant potential as a practical solution for diagnosing OSA in real-world settings.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143900545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rongjiao Wei;Pu Wei;Chao Pan;Yangyang An;Hao Zhu;Mulan Wang
{"title":"Multisensor-Based Fault Detection Method for Air-Exchange Device in EMU Train","authors":"Rongjiao Wei;Pu Wei;Chao Pan;Yangyang An;Hao Zhu;Mulan Wang","doi":"10.1109/LSENS.2025.3558957","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3558957","url":null,"abstract":"In this letter, we introduce and experimentally demonstrate a fault detection method for the air-exchange devices in the electric multiple unit (EMU) train, which utilizes the abnormal sound and vibration generated by the devices when the faults occur. The sound and vibration signals are fused, and the time–frequency matrix is extracted using a short-time Fourier transform (STFT). Fault recognition is performed using the trained support vector machine (SVM) classifier. A sound detection system is built for experiments, in which the package of the sound sensor is designed to shield the sound from adjacent devices. The system includes an field programmable gate array (FPGA) and an embedded system and can be used for fault detection in the future. The experiment shows that the accuracy of the fused signals is higher than the single sensor, up to 0.995. In addition, the performances of the algorithm are evaluated, and the precision, recall, accuracy, and F1-score are all up to 0.99, which meet the actual fault detection requirements. Our method effectively improves the efficiency and accuracy of fault detection for the air-exchange device and can be widely used in the EMU train.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Integration of Bionic Olfactory Model With MEMS Sensor Array Enhances Odor Classification","authors":"Chen Luo;Yujie Yang;Dongcheng Xie;Zhe Wang;Yongfei Zhang;Xiaolei Shen;Lei Xu","doi":"10.1109/LSENS.2025.3558967","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3558967","url":null,"abstract":"This letter presents a solution that integrates a microelectromechanical systems sensor array with a bionic olfactory model (BOM) to simplify data processing and enhance odor classification accuracy. The integrated sensor array adopts a quadrilateral cantilever beam structure with four resistive sensors, each sputtered with a different sensitive material, including indium oxide (<inline-formula><tex-math>$mathrm{In_{2}O_{3}}$</tex-math></inline-formula>) doped with Au, Ag, Pt, and Pd. The BOM consists of a bionic olfactory receptor layer and a bionic olfactory bulb layer, capable of encoding sensor signals and efficiently extracting odor features without manual feature engineering. This system focuses on the classification of food types based on odor characteristics. To verify the performance of the system, data collection and performance analysis were performed on seven kinds of fruits (apple, banana, orange, mango, strawberry, pear, kiwi). The proposed model can directly extract odor features from sensor signals without feature engineering. Compared with traditional method, the system achieves an improvement in classification accuracy from 78.1% to 91.9% when using the k-nearest neighbors classifier.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Hybrid LPF-LSTM Model for Enhanced Epileptic Seizure Detection in EEG Signals","authors":"Vaddi Venkata Narayana;Prakash Kodali","doi":"10.1109/LSENS.2025.3558422","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3558422","url":null,"abstract":"Accurate prediction and detection of epileptic seizures using electroencephalogram (EEG) signals are crucial for advancing clinical diagnostics and improving patient outcomes. This letter proposes a distinctive hybrid framework that combines a linear prediction filter with a long short-term memory network, designed to address challenges in noise reduction and temporal pattern recognition in EEG signals. The detection performance, particularly specificity, is enhanced by applying dynamic thresholding based on residual energy analysis. The proposed method, with key aspects of the validation framework, enhances cross-patient generalization by validating the model on the CHB-MIT Scalp EEG Database across four distinct age groups: infants, children, adolescents, and young adults. The hybrid approach achieved 98.4% accuracy, 97.8% sensitivity, 96.2% specificity, and 0.98 area under the curve, outperforming traditional approaches by 3%–5%.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143848850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High-Efficiency and Compact RF Rectifier Design for Wireless Sensors in Extreme Environments","authors":"Changzhen Liao;Guanghua Liu;Huaijin Zhang;Guozheng Zhao;Tao Jiang","doi":"10.1109/LSENS.2025.3557455","DOIUrl":"https://doi.org/10.1109/LSENS.2025.3557455","url":null,"abstract":"Radio frequency (RF) energy harvesting garners significant attention for prolonging the lifespan of wireless sensor networks (WSNs). However, its deployment in extreme environments is constrained by low RF power. Therefore, to guarantee the sustained functionality of WSNs, it is imperative to enhance rectification efficiency at low incident power. This letter proposes a novel rectifier with highly efficient operation at low incident power. The rectifier comprises a T-type power divider with a <inline-formula><tex-math>${CLC}$</tex-math></inline-formula> <inline-formula><tex-math>$pi$</tex-math></inline-formula> network and two identical subrectifiers. Utilizing this, the reflected power from the subrectifiers can be reinjected into the rectifier so that it can be reused, and the rectification efficiency can be improved. Theoretical analysis and performance comparison are carried out. The experimental results indicate that the proposed rectifier is capable of achieving high rectification efficiency at low incident power. The recorded efficiency remains notably above 10% at an incident power of −<inline-formula><tex-math>$ 30text{ dBm}$</tex-math></inline-formula>, with an operating bandwidth of up to <inline-formula><tex-math>$ 320text{ MHz}$</tex-math></inline-formula>.","PeriodicalId":13014,"journal":{"name":"IEEE Sensors Letters","volume":"9 5","pages":"1-4"},"PeriodicalIF":2.2,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143871057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}