This study investigated the offset voltage and phase shift of characteristic curves caused by current injection direction and voltage measurement direction in a planar Hall magnetoresistance sensor with a NiFe/IrMn bilayer structure. Using analytical methods, we separated the sensor signals to distinguish the offset voltage unrelated to the magnetic field and the offset voltage caused by the phase shift of magnetoresistance. We then analyzed the ratio of AMR signals and PHMR signals caused by phase shifts and changes in the sensitivity of the magnetic sensor. Under certain conditions, the current injection direction and voltage measurement direction increased the output voltage and exhibited high sensitivity. These results are expected to contribute to optimizing sensor design and fabrication processes and improving sensor performance.

The characteristics of pulse waveforms measured using pulsimeter equipped with a magnetic hall device and an optical sensor, which are used as the digital healthcare devices, were investigated. The average and standard deviation values of the output values of the amplitude and time values of feature points were compared from the data obtained by analyzing the pulse waveforms obtained with the clip-type pulsimeter and PPG at the location of maximum pulse in the radial artery. In the case of the clip-type pulsimeter, the average values of systolic time (S.time) and period (P.time) were 103.6 ms and 638.8 ms, respectively. On the other hand, in the case of PPG, the average values of S.time and P.time were 165.0 ms and 677.6 ms, respectively. The pulse rate of the pulse wave by the pulsimeter was about 5 faster than one of the pulse wave by the flow of blood passing through the radial artery. As a data-based smart peripheral blood flow rate monitor, a magnetic Hall element pulsimeter on the wrist capable of measuring stable pulse waveforms is effective to wear a PPG sensor on the middle finger.

In order to analyze the permeability measurement performance of the PHR sensor, Type A and Type B sensors with different driving current directions were fabricated. In Type A and B sensors, the magnetic field dependence of the PHR signal V_f and the signal by self-field V_2f was measured, and these results were well agreed with the calculated results by single domain model. In particular, V_2f was reflected the magnetic sensitivity of V_f, and increased as much as ΔV_2f by the NiFe disk array specimen placed on the sensor. The permeability measurement performance of Type A and B sensors obtained from ΔV_2f were high resolution of Δμ = 0.45 and 0.75, respectively.

This study proposes an initial design method for an interior permanent magnet synchronous machine (IPMSM) considering the requirements and limitations of an electric propulsion ship with the number of series turns per phase and shape ratio as design variables. The magnetic equivalent circuit method was used to calculate the flux linkage and the d-q axis inductance, and a design method based on loading distribution method was presented. Based on the number of series turns per phase and shape ratio, the design area that satisfies the requirements and limitations of IPMSM was presented, and a design model was derived considering the number of parallel circuits that can be manufactured. The validity of the proposed method was verified through modeling and performance analysis using finite element analysis. The proposed design method can be used for sizing and initial design in various electric machine applications as well as electric propulsion ships.

In this paper, an analytical solution for the discharge current in the form of an impulse generated in an air-cored solenoid coil connected to a discharge circuit composed of a high-voltage capacitor, thyristor, and freewheeling diode was derived from equivalent models of RLC and RL series circuits. It was confirmed that the form of discharge current showed three different forms according to the combination of capacitance of capacitor, inductance and resistance of coil, and the expression for discharge current in the most general case was derived as a closed function of the main variables. Finally, by using the expression for the discharge current, expressions for three physical properties: the maximum value of the discharge current that can represent the characteristics of the discharge current, its arrival time, and the full discharge time of the capacitor were derived. The validity of the proposed equations was performed through comparison with CAE analysis results for discharge circuits with specific specifications.

Spin-orbitronics devices based on spin Hall effect is a strong candidate for new generation memory devices. To realize this device the bilayer structure composed of a ferromagnet and a heavy metal layer should show sizable spin-orbit torque to manipulate magnetization of the devices. In this study, we investigate orbital transport in Cr-based heterostructures, because Cr has sizable orbital Hall angle and good conductivity. We found that orbital Hall magnetoresistance shows strong Cr-thickness dependence with the obtained diffusion length ~3 nm. Through a comparative experiment with the Cr/Pt/CoFeB structure in which the Pt layer was inserted, the orbital-spin conversion phenomenon by spin-orbit coupling can be understood. This study provides important information about orbital-related transport phenomenon in the Cr layer.