Taner Akkan

Active T‐shirt

Purpose – The purpose of this paper is to realize an electronic circuit design on the fabric surfaces to form a fully integrated functional active T‐shirt structure.Design/methodology/approach – Functional products combining textile, electronics and the software have attracted great attention in recent years. The integration of the electrical and electronic devices on the garment surface using conductive threads is a challenging issue considering conductiveness, long durability, washability and manufacturing process. As an application, a group of light emitting diode (LED) lights controlled by a light sensor, accelerometer and related electronic control circuits were placed on a fabric construction.Findings – The brightness of LED lights is controlled by using a light sensor depending on the perceived ambient light intensity. LED lighting patterns are controlled by means of an accelerometer which senses the physical activities of the wearer, such as walking, running and standing.Originality/value – In thi...

Design of TENS electrodes using conductive yarn

Purpose – The purpose of this paper is to develop textile-based transcutaneous electrical nerve stimulation (TENS) electrodes using conductive yarn to bring a solution to uncomfortable feelings and hygiene problems of conventional conductive hydrogel electrodes. It proposes washing process, resistance measurements and subjective tests to evaluate the performance of the developed textile-based electrode. Design/methodology/approach – In this study, six different textile electrode pairs were designed and produced with different patterns. Designed electrodes were washed for ten times. In order to evaluate the effect of pattern differences and washing process on electrode performances, two different tests were realized before and after washing. The first of these tests is resistance measurement with a multimeter, and the second one is subjective test carried out on subjects. Findings – The results obtained from resistance measurements indicated that the pattern differences cause resistance values of electrode...

Microcomputer controlled high performance PWM modulator for a three phase inverter

The design of a fully digital EPROM based and microcomputer controlled modulator for a pulse width modulated (PWM) inverter supplying a three phase induction motor is presented. It has a high frequency resolution and changes in the frequency and voltage commands are transient free. Smooth speed variations are achieved in the whole range. The laboratory hardware implementation and specifications of the modulator are given. An original dead time generator circuit is presented. Some experimental results are also included in the paper.

Power management for Wireless Sensor Networks in underground mining

Due to the challenging working conditions in the underground mining, some difficulties are being experienced in sensing and monitoring of important physical environmental parameters. The requirement for a Wireless Sensor Network has gained significant importance in recent years for the measurement and transmission of various data from different areas of an underground operation to a central monitoring station. The sensor nodes in Wireless Sensor Network, capable of microcontroller controlled wireless data transferring, could work with electricity in the main roads of the underground mine, however, the necessity of using sensor nodes using batteries in various fields like production and abandoned areas emerges. The working life of each sensor nodes depends on the efficiently managed battery lifespan. The battery life depends on the battery type selection, the standby and active mode power consumption of microcontrollers, wireless transmitters and receivers, sensors and miscellaneous electronic circuits. In this study, applicable methods to reduce the battery consumption for Wireless Sensor Networks in underground mining are examined.

A test apparatus to measure vertical wicking of fabrics – a case study on shirting fabrics

A test apparatus based on electrical conduction principle was designed and manufactured to overcome some difficulties and deficiencies in vertical wicking measurements of fabrics, which is one of the test methods used to determine liquid moisture transmission performance of fabrics. In order to test effectiveness of the apparatus, capillary time with regard to height was measured for woven shirting fabrics, which have different raw material, weave type and weft density. It was found that twill weave type and fabric looseness improved the wickability of fabrics. It was also revealed that raw material was an important factor for vertical wicking. The wicking rate of fabrics obtained from the new test apparatus correlated well with DIN 53924. Consequently, the test apparatus clearly demonstrated differences between the fabrics used in the study, and can be used to determine vertical wicking behaviour of fabrics.

Measurement of human walking on sagittal plane for exoskeleton walking pattern generation

Researchers have been worked on exoskeletons and active orthoses since 1960s. There are many competitions on these searches area. One of them is Human Exoskeleton Assistance System Prototype (HEASP) that is developed at Dokuz Eylül University. HEASPs goal is to assist one leg extremity persons. In this paper, the capturing of human walking parameters on sagittal plane is introduced. These parameters used for walking pattern generation and making pattern decision control strategies on HEASP.

A quantitative description of immunofluorescein images using mathematical morphology.

This study investigates whether automatic image shape analysis measurements improved by feedforward neural networks [(FFNN), a software application model] showing the activity of small neural groups can be used as an image analysis tool in the interpretation of skin biopsies evaluated by direct immunofluorescence, by identification of local shape characteristics of patterns. An FFNN software was designed with 4 inputs: the “selected digital characteristics” (SDIC), that is, the proportion of node, link, end point, and branch pixels to total pixels; and 6 outputs: “patterns of direct immunofluorescence images” (PDI), that is, basement membrane linear, basement membrane granular, epidermal intercellular, vascular, negative, and nonspecific background staining; and 10 hidden layers for training process. Microscopic images from anti-IgG, IgA, IgM, C3, and fibrinogen stained sections were collected to a computer; 292 direct immunofluorescence images from 72 patients. The FFNN training set included 192 images from 32 patients. SDIC values and a possibility range for PDI category suggested by an experienced pathologist were transferred to FFNN for training. SDIC values were analyzed statistically according to PDI. After the training phase, for determining the accuracy of automatic self-decision process, 100 images from 40 cases were analyzed by FFNN proposing the possibility of PDI. SDIC values were significantly different for PDI groups (1-way ANOVA; P<0.001) whereas SDIC values of epidermal intercellular group were different from others. FFNN predicted the correct PDI as the first possibility in 83% and second possibility in 14% of the cases. Direct immunofluorescence SDIC measurements processed by FFNN may help inexperienced pathologists in future.

A low-cost multi-channel simultaneous sound capturing system for independent component analysis

The sound processing applications require powerful and easily controlled hardware. Generally channel switched analog-digital converters are used on that hardware and they donpsilat achieve parallel data recordings. But, multichannel simultaneous recording is needed for some sound processing applications.

Capturing and analysis of knee-joint signals using acceleremoters

Complaints about knee-joint problems exist especially at older ages. Methods of X-ray, MRI and an invasive method of artroscopy can be used for diagnosing. Purpose of this study is to develop a diagnosing aid device and a non-invasive method that supports diagnosing. With the developed USB interfaced data capturing system, acceleration and vibration data obtained from accelerometers placed onto a knee-joint have been analyzed by using independent component analysis (ICA). Thus, knee signals on the desired location can be obtained noise-free and independently from signals of other locations. Since, simultaneous data capturing is necessary to increase the success of ICA, accelerometers, hardware and software have been selected and designed to provide simultaneous run. ICA is a statistical method for blind source separation and separates a mixture signal into its independent components. Data extracted from desired location can be analyzed easily. ICA is also a successful method in noise removal.