Volume 12 (2012): Issue 1 (January 2012)

Determination of realistic uncertainty values in coordinate metrology is a challenging task due to the complexity of the implementation of numerical algorithms involved. Monte-Carlo error propagation is used to estimate the uncertainty of a position tolerance using least-squares criterion. In this paper all the required steps are sequentially performed using a number real-world datasets. Since no reference data sets are available for position tolerance evaluation hence drawings and numerical values of such data sets are proposed.

A novel low-cost electronic tongue system for sugar content determination in sugar solutions is proposed. The system consists of a sine wave generator, a resistor, and an interdigital capacitor sensor forming a first-order electronic high-pass filter circuit. The interdigital capacitor sensor has the planar interdigital structure and the consecutive fingers are connected to positive and negative electrodes. The system has been assembled and the experiments were conducted. The experimental results show that the proposed system has a great potential to determine the sugar content in sugar solutions. It also provides an opportunity for the development of a microcontroller-based low-cost sensing system as an electronic tongue system.

Resolvers have been widely used in motion control systems as position sensors. This paper deals with the analysis of Axial Flux Resolvers. Axial flux resolvers are a group of resolvers which can be used in high performance servomechanisms. The accuracy of resolver detected position is affected by errors. Some of these errors are caused by speed fluctuations, permeance ripples, unbalanced voltages, and eccentricity between rotor and stator. Among these errors the static eccentricity > and L_q values and then, the static eccentricity effect based on the developed model is studied. A novel algorithm is proposed for suppressing the eccentricity error. This method is based on analytical model and modern control fundamentals. In a comparison, simulation and experimental results show good agreement. Finally, the effect of air gap length, pole number and excitation voltage on position error of eccentric AFR is investigated, practically.

The performance of bone age assessment is highly correlated with the extraction of bony tissue from soft tissues, and the key problem is how to successfully separate epiphyseal/metaphyseal region of interests (EMROIs) from the background and soft tissue. In our experiment, a series of image preprocessing procedures are used to exclude the background and locate the EMROIs of left-hand radiographs. Subsequently, automatic gamma parameter enhancement is applied to test the two segmentation methods (adaptive two-means clustering algorithm and gradient vector flow snake) among children of different age (the age from 2 to 16 years for 80 girls and boys). Four error measurements of misclassification error, relative foreground area error, modified Hausdorff distances, and edge mismatch, are included to evaluate the segmentation performance. The result shows that the two segmentation algorithms are corresponding to different ranges of optimal gamma parameters. Furthermore, the margin of EMROIs can be obtained more precisely by developing an automatic bone age assessment method with the gamma parameter enhancement.

Muscle fatigue is the decline in ability of a muscle to create force. Electromyography (EMG) is a medical technique for measuring muscle response to nervous stimulation. During a sustained muscle contraction, the power spectrum of the EMG shifts towards lower frequencies. These effects are due to muscle fatigue. Muscle fatigue is often a result of unhealthy work practice. In this research, the effectiveness of the wavelet transform applied to the surface EMG (SEMG) signal as a means of understanding muscle fatigue during walk is presented. Power spectrum and bispectrum analysis on the EMG signal getting from right rectus femoris muscle is executed utilizing various wavelet functions (WFs). It is possible to recognize muscle fatigue appreciably with the proper choice of the WF. The outcome proves that the most momentous changes in the EMG power spectrum are symbolized by WF Daubechies45. Moreover, this research has compared bispectrum properties to the other WFs. To determine muscle fatigue during gait, Daubechies45 is used in this research to analyze the SEMG signal.

This paper studies the microwave antenna characterization in intracardiac ablation for frequencies 915 and 2450 MHz. The theoretical study is validated by experimental measurements in vitro on electromagnetic phantom muscle tissue. The Specific Absorbed Rate (SAR) measurement setup is described. Two types of antennas have been designed, implemented and used, a monopoly antenna and a helical antenna. The Specific Absorbed Rate (SAR) and the measured reflection coefficient (S11) were obtained for antennas for the two frequencies. We show that each frequency can be adapted to a region where the ablation is necessary. According to the doctors, the goal is to have a lesion on the surface as the atria or in depth.