Chayada Surawanitkun

Khon Kaen University | KKU · Faculty of Interdisciplinary Studies

A novel way to enhance modulation performance is through the design of a hybrid plasmonic optical modulator that integrates multi-layer graphene and TiO2 on silicon waveguides. In this article, a design is presented of a proposed modulator based on the use of the two-dimensional finite difference eigenmode solver, the three-dimensional eigenmode ex...

Measurement of fluorescence emission for quantitative analysis is always based on the traditional spectrofluorometer, which limits the onsite detection approach. Thus, an alternative device should be developed for fulfilling the...

This work presents a novel contribution to graphene/TiO2 electro-optical modulators based on silicon-on-silica waveguide with a hybrid plasmonic waveguide to achieve ultrafast switching and low-voltage states. Waveguide structure consists of a rectangular silicon core covered by a high relative permittivity TiO2 dielectric layer with two layers of...

Sentiment analysis is becoming a very popular research technique. It can effectively identify hidden emotional trends in social networks to understand people’s opinions and feelings. This research therefore focuses on analyzing the sentiments of the public on the social media platform, YouTube, about the Thailand-China high-speed train project and...

Triboelectric nanogenerators (TENGs) are crucial for applications such as smart sensors and bio-electronics. In the current work, we aimed for improved performance of TENGs with BaTiO3 powder, which is known for its strong ferroelectric properties, and combined it with epoxy resin to improve the flexibility of our devices. We observed that our TENG...

Human activities have been limited by coronavirus disease 2019 (COVID-19), and the normal conditions of our lifestyles have changed, particularly in terms of electricity usage. The aim of this study was to investigate the impact of COVID-19 on the power sector in the Lao PDR in 2020, as well as the challenge of using solar energy to supply power to...

The COVID-19 pandemic has caused significant changes in many aspects of daily life, including learning, working, and communicating. As countries aim to recover their economies, there is an increasing need for smart city solutions, such as crowd monitoring systems, to ensure public safety both during and after the pandemic. This paper presents the d...

The complexity and uncertainty of power sources connected to transmission networks need to be considered. Planners need information on the sustainability and economics of transmission network expansion planning (TNEP). This work presents a newly proposed method for TNEP that considers high-penetration solar energy by using the particle swarm optimi...

A simple, portable device for the detection of NO2– via a fluorescence method was developed. The proposed device consisted of a dark box containing a blue LED as a low-power excitation light source and a smartphone with a mobile application for RGB analysis as a light detector. Detection was mediated by using synthesized cetyltrimethylammonium brom...

Capital investment in underground duct bank cables is very expensive. Therefore, the design and planning for underground power cables is important. It is often done with analysis of the power demands minimizing costs over the lifetime of the cables. This work presents an evaluation of underground power cable ampacity and the total costs during the...

Spin-transfertorque magnetic random-access memory (STT-MRAM) based on a single-barrier magnetic tunnel junction (SBMTJ) and a double-barrier magnetic tunnel junction (DBMTJ) has evolved along with a low switching current and low energy consumption to obtain a high areal density and a fast switching speed. The increment of initial temperature, T <su...

This paper proposes a novel adaptive optimization algorithm to solve the network reconfiguration and distributed generation (DG) placement problems with objective functions including power loss minimization and voltage stability index (VSI) improvement. The proposed technique called Adaptive Shuffled Frogs Leaping Algorithm (ASFLA) was performed fo...

Spin transfer torque random access memory (STT-RAM) based on magnetic tunnel junction (MTJ) is a popular type of memory because of its non-volatility, small size, and nanosecond access time. The temperature effect on the magnetic properties and the initial angle between the free and pinned layer magnetizations in the MTJ cell are significant for th...

Network reconfiguration of an electrical distribution system is an outstanding technique to improve the performance of a distribution system. The main factors indicating the performance of the system are the electrical power loss and the system reliability. In this paper, the multi-objective reconfiguration of a large-scale electrical distribution...

In smart distribution network, optimal planning of Energy Storage Systems (ESS) can lead to voltage profile improvement, network loss reduction and increasing the profit of distribution company (DISCO). This paper proposes the application of Modified Differential Evolution Algorithm (MDEA) which is very strong global search capability for maximizin...

This paper presents a new methodology for solving multi-stage distribution substations expansion planning (MSDSEP) problem. The proposed method can determine the optimal location, capacity, associated service area and construction timing of substations with aiming to the maximum profit for supplying the forecasted demand. The objective function is...

Photovoltaic (PV) systems are one of the most popular technologies to produce electricity from renewable energy, which can efficiently accommodate electricity demand. However, there are some issues occurring at high PV penetration levels in the distribution system. In order to increase the PV penetration level, battery energy storage system (BESS)...

Spin transfer torque random access memory (STT-RAM) based on magnetic tunnel junction (MTJ) is a popular type of memory because of its non-volatility, small size, and nanosecond access time. The temperature effect on the magnetic properties and the initial angle between the free and pinned layer magnetizations in the MTJ cell are significant for th...

This paper proposes electrical distribution system reconfiguration and capacitor placement for power loss reduction based on a combination of salp swarm algorithm and real-coded genetic algorithm (SSA-GA). The 33 bus distribution system was focused in network reconfiguration and capacitor placement problems. The simulation results obtained by the S...

Recently, the increase in high areal density of hard disk drive with the small bit cells affects the structural variation in the magnetic recording head. Therefore, the structural size effect on the altered temperature in the tunneling magetoresistance (TMR) head with the MgO-based magnetic tunnel junction structure was investigated. Results indica...

Modeling of switching energy of magnetic tunnel junction devices with tilted magnetization

A new alternative data storage technology of nonvolatile memory, thermoelectric spin-transfer torque MRAM (TSTT-MRAM), is discussed in this paper. In principle, in the TSTT-MRAM mechanism the current is applied in the thermoelectric cell and the magnetic tunnel junction (MTJ) cell. The finite-element method and micromagnetic model were used to expl...

Recently, there has been a growing interest in the thermal stability in magnetic tunnel junction (MTJ) devices with an aspect of the temperature increment during current-induced magnetization switching (CIMS) process. In this work, the temperature increment is explored with factors of the tile of the initial magnetization direction in free layer, θ...

For spin transfer torque (STT), the switching energy and thermal stability of magnetic tunnel junctions (MTJ) bits utilized in memory devices are important factors that have to be considered simultaneously. In this article, we examined the minimum energy for STT induced magnetization switching in MTJ devices for different in-plane angles of the mag...

Recently, the temperature increment in magnetic tunnel junction (MTJ) nanopillars with relevant current induced magnetization switching for spin transfer torque magnetic random access memory (STT-MRAM) has become interesting because it affects the reliability of devices. In this work, the magnetic stability and the temperature rise in the MTJ nanop...

Recently, there has been a growing interest in the effects of electrostatic discharge (ESD) failure on tunneling magnetoresistive (TMR) recording heads because it directly affects reliability in manufacturing of these heads. Therefore, we study the magnetic degradation in TMR junctions caused by the temperature increase using three different ESD mo...

MRAM relevant to current induced magnetization switching (CIMS) is studied due to thermal increment caused by CIMS. In this paper, the instability of storage and the thermal increment caused by the transient current from the HBM ESD in nanopillars of MRAM are studied. We determine the voltage which can cause erroneous switching in MRAM by inducing...