Electrical And Electronic Engineering

We report on a Chirped Pulse Amplification (CPA)-based Titanium:Sapphire (Ti:Al2O3 or Ti:Sapphire) amplifier that uses a single grating stretcher and compressor configuration. The 8-pass amplifier configuration is able to yield 70 μJ pulse energy at 10 Hz repetition rate, which corresponds to a gain of 7000 times. The amplified pulses are expected to be transform-limited with pulse duration of 85 fs. This amplifier will expand the application of our Ti:Sapphire laser at the Vietnam Academy of Sciences (VAST).

Towards industry 4.0, monitoring the degradation of machine tools’ components becomes a key feature so that smooth productivity is achieved. To preserve the functionality and performance of the machine tools, proper maintenance activities must be planned and carried out. V-belt is important component in machine tools that transmits power from the electric motor spindle in order to machine to work and cut desired material properly. The purpose of this research is to develop a predictive maintenance system for v-belt milling machine Krisbow 31N2F using machine learning. The machine learning algorithm models using multiple and simple linear regression algorithm was developed in an open-source program. The test results show that the machine learning model has a high accuracy value in both the training data and the testing data. The multiple linear regression model has MSE value of 5.8830x10-6 and MAE value of 0.002. The Simple linear regression model has an MSE value of 0.0004x10-6 and ...

Improved switching characteristics were obtained from high-κ oxides AlOx, GdOx, HfOx, and TaOx in IrOx/high-κx/W structures because of a layer that formed at the IrOx/high-κx interface under external positive bias. The surface roughness and morphology of the bottom electrode in these devices were observed by atomic force microscopy. Device size was investigated using high-resolution transmission electron microscopy. More than 100 repeatable consecutive switching cycles were observed for positive-formatted memory devices compared with that of the negative-formatted devices (only five unstable cycles) because it contained an electrically formed interfacial layer that controlled ‘SET/RESET’ current overshoot. This phenomenon was independent of the switching material in the device. The electrically formed oxygen-rich interfacial layer at the IrOx/high-κx interface improved switching in both via-hole and cross-point structures. The switching mechanism was attributed to filamentary conduc...

Three centuries ago, Isaac Newton reported the experimental observation of the tunnelling of a light ray between two prisms separated by a small gap once one of them was shinned in total internal reflection. This article describes a modern revisit of this seminal Newton’s experiment, generally known as the Frustrated Total Internal Reflection. This experiment was created in the framework of a series of lectures about near-field optics and nanophotonics for Master students. During a 4h lab work session, the students are running the experiment to evidence and quantify the evanescent wave on top of a glass prism once illuminated above the critical angle.

This paper is concerned with aspects of the analytical fuzzy solutions of the parabolic Volterra partial integro-differential equations under generalized Hukuhara partial differentiability and it consists of two parts. The first part of this paper deals with aspects of background knowledge in fuzzy mathematics, with emphasis on the generalized Hukuhara partial differentiability. The existence and uniqueness of the solutions of the fuzzy Volterra partial integro-differential equations by considering the type of [gH - p]-differentiability of solutions are proved in this part. The second part is concerned with the central themes of this paper, using the fuzzy Laplace transform method for solving the fuzzy parabolic Volterra partial integro-differential equations with emphasis on the type of [gH - p]-differentiability of solution. We test the effectiveness of method by solving some fuzzy Volterra partial integro-differential equations of parabolic type.

In this paper, the generalized Taylor’s expansion is presented for fuzzy-valued functions. To achieve this aim, fuzzyfractional mean value theorem for integral, and some properties of Caputo generalized Hukuhara derivative are necessarythat we prove them in details. In application, the fractional Euler’s method is derived for solving fuzzy fractionaldifferential equations in the sense of Caputo differentiability. The effectiveness of the proposed method is verified bythree examples.

Present work reports the application of a composite of ZIF-67/rGO for the simultaneous detection of traces of lead and cadmium via square wave anodic stripping voltammetry (SWASV) technique. For this, graffoil sheets were modified with synthesized composite for the electrode fabrication [(ZIF-67/rGO)/Graffoil] for its use in sensing studies. The SWASV response of (ZIF-67/rGO)/Graffoil electrode was optimized against deposition potential (-1.0 V) and time (350 s), required for the accumulation of metal ions onto the sensor electrode. The performance of the sensing electrode was then evaluated for lead (Pb2+) and cadmium (Cd2+) ions at various concentrations. The sensor displayed linear response in a wide concentration range of 5-100 ppb. The peak current of the electrode was found to be shifted towards the higher potential at higher metal ion concentrations. Based on the response measured, the limit of detection (LOD) of the fabricated sensor has been estimated and found to be 5 and ...

This paper proposes a supervised classification algorithm capable of continual learning by utilizing an Adaptive Resonance Theory (ART)-based growing self-organizing clustering algorithm. The ART-based clustering algorithm is theoretically capable of continual learning, and the proposed algorithm independently applies it to each class of training data for generating classifiers. Whenever an additional training data set from a new class is given, a new ART-based clustering will be defined in a different learning space. Thanks to the above-mentioned features, the proposed algorithm realizes continual learning capability. Simulation experiments showed that the proposed algorithm has superior classification performance compared with state-of-the-art clustering-based classification algorithms capable of continual learning.

The aquatic ecosystem is continuously threatened by the infiltration and discharge of anthropogenic wastewaters. This issue requires the unending improvement of monitoring systems to become more comprehensive and specific to targeted pollutants. This review intended to elucidate the overall aspects explored by researchers in developing better water pollution monitoring tools in recent years. The discussion is encircled around three main elements that have been extensively used as the basis for the development of monitoring methods, namely the dissolved compounds, bacterial indicator, and nucleic acids. The latest technologies applied in wastewater and surface water mapped from these key players were reviewed and categorized into physicochemical and compound characterizations, biomonitoring, and molecular approaches in taxonomical and functional analyses. Overall, researchers are continuously rallying to enhance the detection of causal source for water pollution through either conven...