Eric Cheng

Lung meridian acupuncture point skin impedance in asthma and description of a mathematical relationship with FEV1

Alteration in acupoint skin impedance is purportedly associated with health impairment. This study examined lung meridian acupoint skin impedance in healthy individuals and patients with controlled asthma and the relationship if any with Forced Expiratory Volume in 1s (FEV(1)). Twenty-eight subjects diagnosed with asthma and 28 age and gender-matched healthy subjects had their FEV(1) and skin impedance, at acupoints LU 7 (Lieque) and LU 9 (Taiyuan) on the lung meridian, measured. Skin impedance was significantly higher in subjects with asthma (p<0.05) and negatively correlated with percent predicted FEV(1) (r=-0.34 to -0.40, p<0.005). The Receiver Operating Characteristic (ROC) suggested the cutoff point for logarithm-transformed mean of skin impedance for asthma was ≥3.59 unit (sensitivity=82.1%, specificity=82.1%) (AUC=0.878, p<0.001). A regression prediction equation of asthma was derived. This study suggests that acupoint skin impedance on the lung meridian may reflect the asthma condition. The use of skin impedance as an adjunctive, objective assessment in asthma screening and treatment monitoring, warrants further investigation.

Lithium-titanate battery (LTO): A better choice for high current equipment

Lithium-titanate battery is a kind of new lithium-ion batteries, and it can be charged by high current, but changes in temperature and capacity have a great influence on the battery performance. The battery stability and the charging curve are examined in this paper for the high current and various test conditions. It is found that the LTO has an advanced performance in temperature rise.

Analysis of a Direct Drive 2-D Planar Generator for Wave Energy Conversion

In this paper, a novel direct drive, bilateral planar switched reluctance generator (BPSRG) is developed for 2-D wave energy conversion with a mixed type of flux circulation. The proposed BPSRG has longitudinal flux type of the magnetic circuit on one direction and transverse flux-type magnetic circulation for the other perpendicular direction. The characteristics of the magnetic flux and static inductance are calculated for the BPSRG based on the 3-D finite-element method, in order to ensure negligible coupling effect between any phases. Theoretical model of the BPSRG is derived, and parameters that impact the open-loop operation performance of the power generation are analyzed, optimized, and supported by experimental results.

Position control for the linear compound switched reluctance machine

This paper investigates a long-stroke linear switched reluctance machine (LSRM) with a primary and a secondary translator for industrial conveyance applications. The secondary one can translate according the primary one so that linear compound motions can be achieved. Experimental results demonstrate that the machine is able to realize a composite linear motion from the secondary translator to ground. The steady-state error values can be controlled within ±0.175 mm.

Compensation power generation for linear switched reluctance generators

Since the wave energy power generation has a low voltage output and poor stability in low speed, the scheme of a compensation power generation scheme of two bilateral asymmetric linear switched reluctance generators (BALSRG) is proposed. The mathematic model of the BALSRG is derived and machine characteristics are investigated. Two control methods are discussed and compared. Experiment results demonstrate that the voltage capacity and control accuracy can be improved.

Study of wireless charging lane for electric vehicles

In this paper, an inductive wireless charging lane for electric vehicles is presented. The lane proposed here consists of multiple spiral coils, which are laid down on a track. The specific parameters for the layout of the proposed lane are determined through simulation by the finite element analysis (FEA) software Maxwell. A small prototype of the wireless charging lane is constructed and experimental results show that, a modified, scaled-down model vehicle, with receiver coils attached to the bottom, can move smoothly along the lane without any external power excitation.

Measurement and analysis of EMI radiated by a high-frequency AC distribution system in vehicles

This paper presents a literature review on the high-frequency AC distribution system and an experimental relationship for the radiated electromagnetic noise level on the 50kHz AC distribution system in the vehicle system, with regards to the required safety level for human exposures, based on the ICNIRP guidelines. The Electro-Magnetic Interference (EMI) level of the 500VA/50kHz AC distribution system is measured and the experimental results are analyzed, complying with the standard CISPR16/EN55016. The experimental results verify the viability and safety of the developed high frequency AC distribution system consisting of the inverter, transmission and converter. Furthermore, the effectiveness of different topologies of transmission cables is also examined.

Design and simulation of a novel gesture control method for PV tracking system based on switched reluctance motor

In this paper, a novel method to regulate the angle displacement of solar panel for photovoltaic (PV) power generation based on the three phase curved switched reluctance motor (SRM) is proposed. The mechanical structure of the tracking system and mathematic models of curved SRM are designed and elaborated. The electromagnetic features are analyzed by using finite element method (FEM). Both open loop and closed loop control mode of the curve SRM are described and simulated through co-simulation approach, respectively. Simulation results testify the feasibility of the proposed tracking method. This method is expected to be applied in tracking systems for PV or concentrating photovoltaic (CPV) power generation in the future.