Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Effect of Thermal Cycle Loadings on Mechanical Properties and Thermal Conductivity of a Porous Lead-Free Solder Joint

Abstract: This paper demonstrates to what extent the number of thermal cycles affects the mechanical properties as well as the thermal conductivity of a porous solder joint in an insulated-gate bipolar transistor discrete. The blind mode voids were used for a finite-element method (FEM) simulation to obtain the results close to the actual conditions. The FEM results indicate that the concentration of creep strain at the interface of the solder/chip is in its maximum value, and it slightly decreases along with the depth of the solder layer. FEM also reveals that the boundaries of voids act as critical regions for strain concentration. An upward in the number of thermal cycles also leads to the void growth and coalescence process. The enhancement of void volume from 0 to 15 cycles is about 4% volume of the solder layer. Moreover, scanning electron microscope micrographs approve the FEM results and show the void growth and the damage accumulation during thermal cycling. The thermal analyses indicate that the increase in thermal cycles (creep strain) leads to a significant rise in thermal impedance. This event can be due to the increase in the void volume of the solder layer leading to the decrease in the effective area of heat path.

MSENet: Multi-Modal Squeeze-and-Excitation Network for Brain Tumor Severity Prediction

Abstract: Classification of brain tumors is one of the daunting tasks in medical imaging and incorrect decisions during the diagnosis process may lead to increased human fatality. Latest advances in artifici...

Vibration-based tool condition monitoring in milling of Ti-6Al-4V using an optimization model of GM(1,N) and SVM

Abstract: Titanium alloys are the difficult to cut metals due to their low thermal conductivity and chemical affinity with tool material. Since the tool vibration is a replica of tool wear and surface roughness, the present study has proposed a methodology for estimating tool wear and surface roughness based on tool vibration for milling of Ti-6Al-4V alloy using cemented carbide mill cutter. Experiments are conducted at optimum levels of cutting speed, feed per tooth, and depth of cut, and experimental results for the tool vibration, tool wear, and surface roughness are collected until the flank wear reached 0.3 mm (ISO3685:1993). In the next stage, an optimization model of grey prediction GM(1,N) system and support vector machine (SVM) are used and estimated tool wear and surface roughness related to tool vibration. The predicted values of tool wear and surface roughness are compared with the experimental results. The optimization model of GM(1,N) predicted the tool wear and surface roughness with an average error of 3.03% and as 0.7% respectively while the SVM predicted with an average error of 7.67% and 4.45%, respectively.

Estimation of biodiesel properties based on fatty acid profiles of Chlamydomonas sp. BTA 9032 and Chlorella sp. BTA 9031 obtained under mixotrophic cultivation conditions

Abstract: The sustainability of microalgal biodiesel industries depends not only on the development of a low-cost production system but also on the selection of the species used to produce commercially accep...

International Currency Translator using IoT for shopping

Abstract: Now-a-days, there is a bar code or QR code reader that reads bar or QR code on the item and evaluates as a price. In the view of international passengers need, an app with integrated sensor to be built that caters needs of international customers or passengers. Especially, those passengers who would like to do shopping at air ports or intermediate cities, there this IoT based app will translate the one country's money to another country's money. Hence, the proposed IoT for translation of your currency into desired country currency without any intermediate brokers who will charge some percentage than the defined service charge of that country. This proposed Internet of Things (IoT) app is built by keeping international customer service into consideration and the yields many advantages such as accuracy without loss or profit, minimization of brokerage service charges, and transparency among the countries tax service rules. The proposed app with integrated sensor feeds the input amount into desired country's currency by taking service rules of the country. The performance of this IoT is demonstrated in results and its working is sketched in the novel app. In this, GPS is used to take the location of the country to which the source currency to be translated.