Early diagnosis is crucial in the treatment of heart diseases. Researchers have applied a variety of techniques for cardiovascular disease diagnosis, including the detection of heart sounds. It is an efficient and affordable diagnosis technique. Body organs, including the heart, generate several sounds. These sounds are different in different individuals. A number of methodologies have been recently proposed to detect and diagnose normal/abnormal sounds generated by the heart. The present study proposes a technique on the basis of the Mel-frequency cepstral coefficients, fractal dimension, and hidden Markov model. It uses the fractal dimension to identify sounds S1 and S2. Then, the Mel-frequency cepstral coefficients and the first- and second-order difference Mel-frequency cepstral coefficients are employed to extract the features of the signals. The adaptive Hemming window length is a major advantage of the methodology. The S1-S2 interval determines the adaptive length. Heart sounds are divided into normal and abnormal through the improved hidden Markov model and Baum-Welch and Viterbi algorithms. The proposed framework is evaluated using a number of datasets under various scenarios.

A zinc oxide‐based multiquantum well light‐emitting diode is proposed in this paper. MgZnO is used as the barrier, and CdZnO compound is used as the quantum well. Due to difficulties toward synthesis of p‐ZnO, a p‐GaN layer is used as the top layer. Also, a p‐MgZnO layer is utilized as electron‐blocking layer. The performance and efficiency droop (ED) of the modeled device then are studied with different Mg and Cd concentration, thickness of quantum barrier, number of quantum well, and carrier concentration of p‐GaN layer. During an optimization operation, the optimized values of these parameters are determined. It is revealed that the carrier concentration of p‐GaN layer is the most influencing parameter on the quantum efficiency and ED of the modeled device.

A plasmonic D-shaped photonic crystal fiber (PCF) sensor for refractive index (RI) and temperature is designed and studied in this paper. The RI channel is made up of a silver thin layer deposited on the plane of the D-type structure, and the temperature sensing channel is formed by a silver nanowire and benzene filled in an elliptical hole in the PCF. The designed structure can be used for temperature and RI sensing via coupling between the core-guided modes and the surface plasmon modes around Ag nanowire and Ag thin layer. The coupling characteristic and sensing performance of the proposed dual-functional sensor is studied in the present work. Results show that the maximum sensitivity in terms of RI units (RIU) is 6.9 μm/RIU in the range of 1.33-1.38, and the maximum temperature sensitivity is 3 μm /°C in the range of 27 °C-67 °C.

A plasmonic D–shaped photonic crystal fiber (PCF) sensor for refractive index (RI) and temperature is designed and studied in this paper. The RI channel is made up of a silver thin layer deposited on the plane of the D–type structure, and the temperature sensing channel is formed by a silver nanowire and benzene filled in an elliptical hole in the PCF. The designed structure can be used for temperature and RI sensing via coupling between the core–guided modes and the surface plasmon modes around Ag nanowire and Ag thin layer. The coupling characteristic and sensing performance of the proposed dual–functional sensor is studied in the present work. Results show that the maximum sensitivity in terms of RI units (RIU) is 6.9 µm/RIU in the range of 1.33–1.38, and the maximum temperature sensitivity is 3 µm /°C in the range of 27°C–67°C.