Modeling of Electrolyte Thermal Noise in Electrolyte-Oxide-Semiconductor Field-Effect Transistors

Chan Hyeong Park,In-Young Chung 대한전자공학회 2016 Journal of semiconductor technology and science Vol.16 No.1

Thermal noise generated in the electrolyte is modeled for the electrolyte-oxide-semiconductor field-effect transistors. Two noise sources contribute to output noise currents. One is the thermal noise generated in the bulk electrolyte region, and the other is the thermal noise from the double-layer region at the electrolyte-oxide interface. By employing two slightly-different equivalent circuits for two noise current sources, the power spectral density of output noise current is calculated. From the modeling and simulated results, the bulk electrolyte thermal noise dominates the double-layer thermal noise. Electrolyte thermal noise are computed for three different concentrations of NaCl electrolyte. The derived formulas give a good agreement with the published experimental data.

Modeling of Electrolyte Thermal Noise in Electrolyte-Oxide-Semiconductor Field-Effect Transistors

Park, Chan Hyeong,Chung, In-Young The Institute of Electronics and Information Engin 2016 Journal of semiconductor technology and science Vol.16 No.1

Thermal noise generated in the electrolyte is modeled for the electrolyte-oxide-semiconductor field-effect transistors. Two noise sources contribute to output noise currents. One is the thermal noise generated in the bulk electrolyte region, and the other is the thermal noise from the double-layer region at the electrolyte-oxide interface. By employing two slightly-different equivalent circuits for two noise current sources, the power spectral density of output noise current is calculated. From the modeling and simulated results, the bulk electrolyte thermal noise dominates the double-layer thermal noise. Electrolyte thermal noise are computed for three different concentrations of NaCl electrolyte. The derived formulas give a good agreement with the published experimental data.

Investigation of Thermal Noise Factor in Nanoscale MOSFETs

Jeon, Jong-Wook,Park, Byung-Gook,Shin, Hyung-Cheol The Institute of Electronics and Information Engin 2010 Journal of semiconductor technology and science Vol.10 No.3

In this paper, we investigate the channel thermal noise in nanoscale MOSFETs. Simple analytical model of thermal noise factor in nanoscale MOSFETs is presented and it is verified with accurately measured noise data. The noise factor is expressed in terms of the channel conductance and the electric field in the gradual channel region. The proposed noise model can predict the channel thermal noise behavior in all operating bias regions from the long-channel to nanoscale MOSFETs. From the measurement results, we observed that the thermal noise model for the long-channel MOSFETs does not always underestimate the short-channel thermal noise.

Investigation of Thermal Noise Factor in Nanoscale MOSFETs

Jongwook Jeon,Byung-Gook Park,Hyungcheol Shin 대한전자공학회 2010 Journal of semiconductor technology and science Vol.10 No.3

In this paper, we investigate the channel thermal noise in nanoscale MOSFETs. Simple analytical model of thermal noise factor in nanoscale MOSFETs is presented and it is verified with accurately measured noise data. The noise factor is expressed in terms of the channel conductance and the electric field in the gradual channel region. The proposed noise model can predict the channel thermal noise behavior in all operating bias regions from the long-channel to nanoscale MOSFETs. From the measurement results, we observed that the thermal noise model for the long-channel MOSFETs does not always underestimate the short-channel thermal noise.

시험과 해석 모델을 이용한 피스톤 슬랩음 개발

진재민,정인수 한국자동차공학회 2023 한국 자동차공학회논문집 Vol.31 No.8

Piston slap noise from the dynamic motion of a piston depends on the clearance between the piston and the cylinder liner of an engine. Clearance would change based on the distortion from the thermal variations of the cylinder block and the piston. An integrated thermal management module helps improve fuel consumption rate by reducing time durations to heat the engine. However, rapid thermal changes could make piston slap noise much louder because of a wider clearance. This paper presents an analytic model and corresponding experiments to demonstrate piston slap noise. Data such as gas pressure, temperature, and acceleration are measured through experiments to set the boundary conditions and validate the analytic model. Test conditions are based on the logged data in vehicle tests when piston slap noise is audible. The accuracy of the analytic model is then validated with correlations to the measured data from the experiments. Through simulations, thermo-structural distortion and NVH response are modelled, and distortions of the cylinder liner and the piston from a cold start to fully warmed-up states are estimated. Using the analytic model, the mechanism to emit piston slap noise is analyzed, and the effects on NVH and durability performance are verified based on the variations of the design parameters.

Electromagnetic, Vibration and Thermal Analysis of 1.1 kw Switched Reluctance Motor for Electric Vehicle Application

Karunakaran Vijayalakshmi,Kandadai Nagaratnam Srinivas 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.3

This paper presents the electromagnetic analysis, vibration analysis and thermal analysis of a 6/4 pole, 1.1 kW switched reluctance motor (SRM), focusing on its application to EV, in the sense that the vibration and thermal analyses are carried out at speeds of range more than 1000 rpm, which usually experienced by EV SRM. At first, electromagnetic analysis is performed for six different silicon steel materials viz., 35JN210, 35JN300, 50JN470, 50JNA350, 50JNA600 and 50JNE350, and from the results, it has been noted that the material 35JN210 has less torque ripple and a good efficiency compared to all other materials. So this material is selected for SRM structure to perform thermal and vibration analysis. SRM proves to be a suitable candidate in electric vehicle application with the limitation with respect to its vibration and noise. The noise generation during motor operation is a major concern for SRM. The main source of vibration, the radial force, is calculated using two- dimensional (2D) transient finite-element analysis (FEA).The electromagnetic analysis is performed to find out the force exerted on the stator and deformations due to that. Using these nodal forces as input, transient analysis is performed to examine the motor's vibration characteristics. By this analysis, the motor modal frequencies are examined so that the motor operation could be skipped from operating in this vibrating region when it is used in electric vehicle applications. For thermal analysis, FEA is used to calculate the heat generation and temperature distribution on different parts of the machine to estimate the thermal behaviour of the motor.

Braking performance and noise in excessive worn brake discs coated with HVOF thermal spray process

Ali Öz,Habib Gürbüz,Ali Kemal Yakut,Selami Sağiroğlu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

In this paper, two excessive worn brake discs of a light commercial vehicle were coated with High velocity oxygen fuel (HVOF) thermal spray process for reuse. The coated discs were compared with uncoated Original equipment manufacturer (OEM) D1 disc in terms of braking performance and noise. The D2 disc was coated with tungsten-carbide-cobalt (88 %WC-12 %Co) powder and NiCr (80/20) binder, and 500 µm thick coating was obtained. The D3 disc was coated with Colmonoy-88 (Ni-W-Cr-B-Si) powder and NiCr (80/20) binder and 600 µm thick coating was obtained. Several test procedures (e.g. bedding, vibration, and structural-strength tests) was applied to three discs using inertia brake dynamometer. Results showed that coated D2 disc with tungsten carbide cobalt provided lower brake noise and higher brake performance compared with OEM disc. Considering the coefficient of friction and temperature, coated D3 disc has approximately equal braking performance with OEM D1 disc despite the high braking noise value.

A Controller for Motor Thermal Aging Protection Based on the Real-time Sensing of Motor Operations

김지현,이동호 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.1

In this study, we designed a controller for motor thermal aging protection based on the real-time sensing of motor operation using semiconductors. The motor power technology generally used in automobiles for side mirror folding controllers, wiper controllers, antenna controllers, and power window controllers is based on DC motors combined with switching elements and relays. These types of systems, however, suffer from lack of reliability and durability and generate a great deal of noise. To minimize the thermal aging of motors, we used real-time sensing of motor operations according to varying load using a precise time-control method with charging/discharging time constants of R (resistance) and C (capacitance). We designed the controller to be stable and durable by adapting metal oxide semiconductor field effective transistor (MOSFET) semiconductors as switching elements. Analysis of our controller demonstrated that it has superior repeated operation time, cut-off time, operating voltage range, and lower power noise generation than those of conventional controllers.

마찰열을 고려한 디스크 브레이크 스퀼 해석

이성엽(Seong-Yeop Lee),최주호(Joo-Ho Choi),강진혁(Jin-Hyuk Gang) 대한기계학회 2016 대한기계학회 춘추학술대회 Vol.2016 No.12

In this study, complex eigenvalue analysis is conducted considering frictional heat to predict the squeal noise of the brake system with more accuracy. The finite element analysis software ABAQUS is used to calculate the frictional heat generation and dynamic instability. Modal analyses and experimental modal tests of the brake disc components are performed to ensure the validity of the finite element model. As opposed to the previous studies that employed uniform temperatures for simplicity, the analytical temperature distribution is obtained by using a thermal-structure coupled field analysis in this study. The distribution is compared with the real measurements of the disc surface temperature during the squeal noise test. Finally, the effect of applying the temperature distribution is examined by comparing with the results by assuming the uniform temperatures.

북극해 해빙 탐지를 위한 Sentinel-1 HV자료의 방사보정 연구

김윤지,김덕진,권의진,김현철 대한원격탐사학회 2018 大韓遠隔探査學會誌 Vol.34 No.6

Recently, active research on the Arctic Ocean has been conducted due to the influence of global warming and new Arctic ship route. Although previous studies already calculated quantitative extent of sea ice using passive microwave radiometers, melting at the edge of sea ice and surface roughness were hardly considered due to low spatial resolution. Since Sentienl-1A/B data in Extended Wide (EW) mode are being distributed as free of charge and bulk data for Arctic sea can be generated during a short period, the entire Arctic sea ice data can be covered in high spatial resolution by mosaicking bulk data. However, Sentinel-1A/B data in EW mode, especially in HV polarization, needs significant radiometric correction for further classification. Thus, in this study, we developed algorithms that can correct thermal noise and scalloping effects, and confirmed that Arctic sea ice and open-water were well classified using the corrected dual-polarization SAR data. 최근 북극항로와 온난화 등의 영향으로 인해 북극해에 대한 활발한 연구가 진행되고 있다. 기존에 수동 마이크로파 복사계를 이용하여 북극해 해빙의 정량적 면적을 산출하는 연구는 진행되어 왔으나, 보다 고해상도로 해빙의 가장자리에서 발생하는 융해 및 표면 거칠기 변화에 대한 연구는 잘 이루어지지 않았다. 또한, 최근 Sentinel1-A/B자료가 무료로 배포되고, 특히 북극해 영역에 대한 수많은 자료들이 짧은 기간 동안 생산 및 제공되고 있기에, 이러한 대용량 자료들을 모자익(mosaic)하여 북극해 전체에 대한 고해상도 해빙정보 이용이 가능하게 되었다. 그러나 Sentienl-1A/B의 광역관측(Extended Wide, EW)모드 자료를 효과적으로 사용하기 위해서는 보다 정확한 방사보정이 수행되어야 한다. 이를 위해 이중편파 Sentinel-1A/B 자료에 나타나는 thermal noise와 scalloping 효과를 자동적으로 보정할 수 있는 방사보정 기법을 개발하였으며, 나아가 방사보정 된 이중편파 SAR자료를 이용할 경우 해빙과 open-water를 보다 더 잘 구분할 수 있음을 확인하였다.