INVESTIGATION OF ELECTRO-MECHANICAL FACTORS EFFECTING PIEZOELECTRIC ACTUATOR FOR VALVELESS MICROPUMP CHARACTERISTICS

In this study, a new micropump was designed, which is suitable for medical applications regarding size and flow rate. When a micropump is used to control the amount of drug delivery, the flow rate is a key parameter and can be controlled with the diaphragm displacement. The amount of displacement depends on the thickness of the piezoelectric element, voltage, and input frequency. The simulation results showed that the displacement of the vibrating diaphragm increased with applied voltage. Moreover, when the piezoelectric thickness was increased, vibrating diaphragm displacement also was decreased. The flow rate can be adjusted by increasing or decreasing of the input voltage. Presented results also showed that the performance of the micropump was affected by the frequency of voltage. In this study, we analysed two Lead Zirconate Titanate (PZT-2) piezoelectric actuators with 50 μm and 100 μm thicknesses. The voltage values were 10 V, 20 V, 30 V, 40 V and the frequencies were 5 Hz and 10 Hz, for 3 seconds with 1 ms sensitivity. The maximum flow rate was obtained at a 50 μm thickness of PZT and its value was 3.01E-30 m3/s and the maximum displacement of the diaphragm was 1.3962 μm at 40 V and 5 Hz. Thus, the frequency and net flow rate showed an inverse correlation

Development of new descriptor for melanoma detection on dermoscopic images

Early detection of melanoma has critical importance for the success of the treatment. However, a successful early diagnosis is only possible with the existence of discriminative features. In this study, a new descriptor based on the number of colors was developed in order to successfully diagnose lesions of melanoma. The number of colors is the main feature in the identification of melanoma-type skin lesions. The user must select a threshold value when calculating the number of colors of the lesion. The incorrect threshold value selection of non-expert users disrupts the aforementioned feature and also leads to significant diagnostic errors. In this study, it was revealed that color counting threshold values have a significant effect on the distinctiveness of the number of colors. In the three dermoscopic databases, color counting threshold values that provide the maximum distinctiveness on melanoma and benign lesions were determined as 0 and 0.123 respectively. By using these color counting threshold values, the number of colors for each sample in the data sets was calculated separately. Following that, a novel attribute called the number of color difference was defined as a function of color counting threshold values. Experiments using only the proposed new descriptor yielded 52.7% higherf-measure and 84.5% higher true-positive performance than the number of colors used in the literature. The results obtained in this study revealed the importance of accurately determining the number of colors the lesions had and states that the applied color counting threshold significantly influences the classification results. Thereby, a new method is proposed for determining the critical color counting threshold. We claim that the classical ABCD rule should be improved by our new descriptor.WOS:0005644891000012-s2.0-85090061815PubMed: 3286576

Development of new descriptor for melanoma detection on dermoscopic images

Early detection of melanoma has critical importance for the success of the treatment. However, a successful early diagnosis is only possible with the existence of discriminative features. In this study, a new descriptor based on the number of colors was developed in order to successfully diagnose lesions of melanoma. The number of colors is the main feature in the identification of melanoma-type skin lesions. The user must select a threshold value when calculating the number of colors of the lesion. The incorrect threshold value selection of non-expert users disrupts the aforementioned feature and also leads to significant diagnostic errors. In this study, it was revealed that color counting threshold values have a significant effect on the distinctiveness of the number of colors. In the three dermoscopic databases, color counting threshold values that provide the maximum distinctiveness on melanoma and benign lesions were determined as 0 and 0.123 respectively. By using these color counting threshold values, the number of colors for each sample in the data sets was calculated separately. Following that, a novel attribute called the number of color difference was defined as a function of color counting threshold values. Experiments using only the proposed new descriptor yielded 52.7% higherf-measure and 84.5% higher true-positive performance than the number of colors used in the literature. The results obtained in this study revealed the importance of accurately determining the number of colors the lesions had and states that the applied color counting threshold significantly influences the classification results. Thereby, a new method is proposed for determining the critical color counting threshold. We claim that the classical ABCD rule should be improved by our new descriptor.WOS:0005644891000012-s2.0-85090061815PubMed: 3286576

Investigation of Color Difference in Diagnosis of Melanoma

28th Signal Processing and Communications Applications Conference (SIU) -- OCT 05-07, 2020 -- ELECTR NETWORKSkin cancer has become more common in recent years. Melanoma is the deadliest type of skin cancers. Early diagnosis increases the success of treatment in all types of cancer. The success of early diagnosis depends on the attributes used to identify the disease. Weak attributes require more complex classifiers and increase diagnostic error. Color features were an important indicator in the diagnosis of melanoma. The most important of these was the number of color, but no specific method has been proposed in the literature for its calculation. In this study, a method that provides the determination of the required threshold values to accurately calculate the number of colors of the lesions was proposed and a new attribute named color difference has been defined. For the threshold values determined in the proposed method and the threshold values in the literature, the color numbers and color difference attribute of all samples were calculated. Calculated attributes were analyzed statistically. The results of the analysis showed that the number of colors and color difference attribute calculated with the proposed method were significant. However, it was observed that the number of colors calculated with the threshold values used in the literature did not have statistical significance. Finally, univariate classification was made with the proposed color difference attribute and the number of colors calculated according to the methods in the literature. The classification results were compared in terms of f-measure and it was found that the color difference attribute was 25.8% to 31.9% more successful than the other number of colors used in the literature. The results obtained showed that the importance of correctly determining the number of colors of the lesions and the proposed color difference attribute were quite effective.Istanbul Medipol UnivWOS:0006531361001892-s2.0-8510031687

A Novel GUI Design for Comparison of ROS-Based Mobile Robot Local Planners

The studies such as navigating the AMR between stations, docking to the station, and assigning autonomous tasks to other stations are costly in terms of time and energy consumption. This situation creates the need for an interface where the entire work area can be observed and AMRs can be controlled from a single center in the installation of the system in the field. In this study, an interface that can be used in AMR control and monitoring was designed. With this interface; It is thought to prevent costly situations such as determining the stations, calculating the time spent in the transportation of products between stations, determining the movement route. The interface developed in this context was used in an application where ROS-based path planning algorithms were compared. A total of six different stations was identified. With three different local planners: DWA, TEB and Trajectory planner, AMR was given the task of acting autonomously to each station. Thanks to the developed interface, the distance and time required to reach each station were calculated by performing autonomous movement to the desired points. In this way, a comparison of ROS-based path planning algorithms was made. It was calculated that the DWA was 10.55% more successful than the TEB and 2.33% more successful than the Trajectory in terms of distance covered. Additionally, when examined in terms of arrival time, it was calculated that the DWA was 24.64% more successful than the TEB and 2.39% more successful than the Trajectory

Complex bio rhythms

Complex biorhythms are characteristic of ubiquitous phenomena appearing in many disciplines of human knowledge. This Special Issue collects articles devoted to different complex biorhythms phenomena such as cardiac dynamics, Covid-19 dynamics, dynamics of neural networks, cell dynamics, and a few articles devoted to general methods. It furnishes a rich overview of the field and can stimulate and inspire further researches

A novel security and authentication method for infrared medical image with discrete time chaotic systems

Objective:Hand vein images have become important biometric signs used for identification systems. Also, dorsal hand vein images have noteworthy advantages in terms of reliability and contactless procedure. Surgically changing the vascular pattern under the skin is extremely difficult. Therefore, the use of such patterns in identity recognition applications is increasing day by day. In this context, many studies have been carried out in essential areas such as image acquisition for different textures, image preprocessing, data security, image feature extraction and recognition.Methods:In this article, a new dorsal hand vein identification application has been carried out with the chaos-based security mechanism to protect personal data and the Improved SURF method to reduce the error matches of traditional SURF method in the current application. There are two improvements in the presented system. The first one finds the features representing only the vein segments, not the remaining tissue or hairly parts. The second one eliminates the mismatching points to increase the accuracy.Results:Both encryption and data hiding techniques are preferred together to protect person data. In addition, dorsal hand vein images taken with a camera for matching and recorded in the database of the people have been improved with the newly developed I-SURF feature extraction method. Thereby, with the developed application, in addition to keeping the personal identity information securely in the database with chaos-based methods, higher accuracy rate has been achieved in matching the new image taken with the camera