scispace - formally typeset
Search or ask a question

Answers from top 9 papers

More filters
Papers (9)Insight
Experimental results verify that the proposed inverter shows lower noise and higher efficiency than conventional inverter.
Open accessJournal ArticleDOI
Zhihao Fang, Dong Jiang, Yechi Zhang 
27 Sep 2018
28 Citations
Therefore, the combination of an advanced modulation strategy and EMI filter is proposed for suppressing of EMI noise in an inverter.
Open accessJournal ArticleDOI
Yitao Liu, Ching-Ming Lai 
25 Jun 2018-Energies
17 Citations
The grid-injected current total harmonics distortion (THD) and electromagnetic interference (EMI) noise must be considered in a transformer-less grid-connected inverter for a more electric aircraft (MEA) system.
For a PWM inverter drive, the electromagnetic noise due to the switching harmonics could dominate the total sound power level at low motor speeds; however, the effects of switching harmonics appear to be insignificant at high motor speeds where the noise due to the fundamental frequency is dominant.
These findings show that a natural sound may be restored during noise due to the suppression of 4 Hz AC activity evoked early during the noise.
Therefore, the noise immunity of the inverter is also improved greatly.
Proceedings ArticleDOI
Peng Xu, Pamela Abshire 
01 Dec 2007
12 Citations
This study provides a detailed understanding of how noise affects the operation of the CMOS inverter at low power supply voltages.
Proceedings ArticleDOI
Zhiqiang Gao, Ke Shen, Jianze Wang, Qichao Chen 
28 Mar 2010
12 Citations
Therefore, it decreases the THD of AC output effectively and improves the efficiency of the inverter, and its theoretical analysis is verified to be effective.
The proposed ac-ac inverter is attractive for low power (up to 250 W) high frequency applications.

See what other people are reading

What can students do to address noise in terms of Operations of Algebraic Expressions?
5 answers
To address noise in terms of Operations of Algebraic Expressions, students can apply noise filtering techniques like the high gain observer (HGO) approach, which is effective in controlling perturbed systems. Additionally, for recognizing mathematical expressions, students can utilize segmentation methods involving pre-processing, segmentation, and post-processing stages to reduce noise effects and improve recognition outcomes. Moreover, in signal analysis problems related to noise, the concept of noise operators can be employed to analyze signal in noise scenarios, especially in radar and sonar applications. By implementing these strategies, students can enhance their understanding and accuracy when working with algebraic expressions in the presence of noise.
What are the effects of refrigerant charge amount on the vibration and noise of refrigeration systems?
5 answers
The refrigerant charge amount significantly impacts the vibration and noise levels in refrigeration systems. Studies have shown that different refrigerants lead to varying vibration and noise performances in sealed reciprocating compressors, with values closely related to the type of refrigerant used. Additionally, the cooling performance of a transcritical cycle is greatly affected by the refrigerant charge amount, with undercharging conditions leading to increased expansion losses and higher noise levels. Furthermore, optimizing the refrigerant charge amount is crucial for heat pump systems, as it influences the condensing pressure, subcooling, and ultimately the coefficient of performance (COP) of the system, highlighting the importance of charge optimization for system efficiency and noise reduction.
Why use gaussian noise in cGAN model?
5 answers
Gaussian noise is utilized in conditional Generative Adversarial Network (cGAN) models for various reasons. Firstly, the application of additive Gaussian noise in GANs can enhance convergence speed. Secondly, Gaussian noise is crucial for simulating real-world noise scenarios accurately, especially in the context of image denoising using deep learning models. Additionally, Gaussian noise models play a significant role in evaluating the impact of factors like inter-channel stimulated Raman scattering on optical Kerr nonlinearity in transmission systems, providing a more accurate representation of signal power profiles along the link. Lastly, Gaussian noise can also be leveraged to address issues related to posterior approximation accuracy in generative models like Variational Autoencoders, offering a principled approach to handling uncertainty in posterior approximation.
Overview of Hearing Loss in Teenagers?
5 answers
Hearing loss in teenagers is a growing concern due to various factors such as exposure to high volumes from headphones and environmental noise like concerts and discos. Studies show that hearing impairment in school-aged children and adolescents can have significant impacts on academic success and quality of life, with prevalence ranging from 0.88% to 46.70%. Adolescents with deafness face unique challenges, including limited access to information and biased attitudes, affecting their self-esteem and identity development. Research on 13-year-old adolescents in the Netherlands revealed a prevalence of sensorineural hearing loss (SNHL) at 6.4% and noise-induced hearing loss (NIHL) at 12.4%, with SNHL decreasing but NIHL increasing between ages 9 and 13. Early detection, prevention strategies, and support systems are crucial in addressing hearing loss issues in teenagers.
What is the typical efficiency of fuel cells?
5 answers
The efficiency of fuel cells varies significantly across different types and applications, as highlighted by the research contexts provided. Proton exchange membrane fuel cells (PEMFCs), for instance, are noted for their rapid startup time and potential efficiency improvements through cogeneration schemes, with efficiencies up to 95% in ideal conditions but more commonly around 85% when cogeneration is involved. Solid oxide fuel cell systems (SOFCs) demonstrate high efficiency in converting biogas to electricity and heat, achieving electric efficiencies between 50–55% and total efficiencies of 80–90%. This is in line with the general efficiency range of fuel cells, which is approximately 40%–60% for direct conversion of chemical energy into electrical energy. Specific applications, such as fuel cell electric vehicles (FCEVs), show varying efficiencies based on their design and operational parameters. For example, a high-precision model of a FC stack in a vehicle demonstrated hydrogen consumption consistent with high efficiency under test conditions. Another study on electric vehicles with passive hybridization of fuel cells and supercapacitors reported total powertrain energy efficiency between 53%–71% during propulsion. Regenerative fuel cells (RFCs), on the other hand, have lower efficiencies due to the long conversion chain, with unitized RFCs (URFCs) showing a maximum efficiency of about 35% and discrete RFCs (DRFCs) up to 40%, although solid oxide RFCs (SO-RFCs) can reach efficiencies around 45%. Innovative approaches to increase the efficiency of power generation include the integration of SOFC technology with existing power units, which has demonstrated electrical efficiencies up to 49.4%. Research into optimizing the external parameters of fuel cell stacks, such as oxygen concentration and temperature, has also shown potential for efficiency improvements. The record-setting fuel cell electric vehicle "Maxwell" exemplifies the high efficiency that can be achieved with careful design and optimization, boasting an extremely low energy consumption rate. In summary, while the typical efficiency of fuel cells can range broadly from 35% to over 90% depending on the type, application, and operational conditions, most fuel cells operate within a 40%–60% efficiency range for converting chemical energy directly into electrical energy.
What factors contribute to the overall experience of students living in rental houses?
5 answers
Various factors significantly impact the overall experience of students living in rental houses. The cost of housing, housing insecurity, unaffordability, and living conditions play crucial roles in shaping students' perceptions of their academic attainment. Additionally, the location of the accommodation, availability of basic facilities, safety, and security measures in the rental housing also influence students' living experiences. Factors such as distance from educational institutions, dampness, heating, noise levels, and the presence of a written contract are found to affect rental prices and subsequently impact students' choices and experiences in rental housing. These findings underscore the importance of addressing housing challenges to enhance students' overall well-being and academic success.
How can EEG be used by Human resource professionals to enhance employee productivity?
5 answers
EEG can be utilized by Human Resource professionals to enhance employee productivity by implementing systems like the "EEG-Based Aptitude Detection System". This system helps in assigning proper job roles based on employees' working aptitude, leading to increased productivity and reduced stress levels caused by improper role assignments. Additionally, integrating real-time EEG workload indices into the man-machine interface can optimize human-system interaction, adjusting tasks based on the user's cognitive workload. Furthermore, EEG-based mental workload estimators trained on specific tasks can be enhanced using cross-task performance-based feature selection and regression models, improving MW estimation across different tasks and ultimately enhancing performance. By leveraging EEG technology in these ways, HR professionals can tailor job roles, optimize task allocation, and improve overall productivity in the workplace.
What is the average lifespan of a 300kw screw compressor in industrial settings?
5 answers
The average lifespan of a 300kW screw compressor in industrial settings can vary based on maintenance and operational conditions. Research suggests that the lifespan of key components in a screw compressor can be predicted and maintained through qualitative and quantitative analyses. Additionally, the design of screw compressors includes features like noise isolation enclosures for noise control, bearing lubrication systems for longevity unaffected by compressed gas properties, and lip seals with specific gap settings to prevent premature wear. Vibration analysis is also crucial for assessing the service life of screw compressors. Therefore, with proper maintenance and monitoring based on these findings, a 300kW screw compressor can potentially have a long and efficient operational lifespan in industrial applications.
How is depth perception measured?
5 answers
Depth perception can be measured using various methods outlined in the research papers. One approach involves utilizing a system with a 3D display screen, cameras, and a processing unit to measure distances between points in space and the display screen or the patient's eyes. Another method involves a depth measurement assembly (DMA) with a structured light projector and depth camera assembly synchronized to capture depth and tracking information of objects based on structured light pulses. Binocular depth-perception systems utilize phase-antisymmetric gratings to cast point-source responses onto photosensitive pixels, enabling accurate depth perception with minimal noise interference. Additionally, depth perception can be measured by analyzing shadow areas in classical paintings using a positioning array of cameras to capture 3D effects and relative depth information.
How does time enhance attentional tasks?
5 answers
Temporal attention enhances attentional tasks by selectively increasing gain for target features. This improvement in perception can occur through mechanisms such as stimulus enhancement (increasing gain across sensory channels), signal enhancement (selectively increasing gain in channels encoding the target stimulus), or external noise exclusion (reducing gain in channels encoding irrelevant features). Studies suggest that temporal attention acts by a combination of signal and stimulus enhancement, leading to improved perceptual performance across varying levels of noise. Additionally, the modulation of modality-nonspecific temporal attention plays a role in enhancing attentional capture by deviant stimuli, particularly under conditions of increased task difficulty. These findings highlight how temporal attention mechanisms can effectively enhance performance in attentional tasks by focusing on relevant target features.
Why does pv generate non linear dc source?
5 answers
Photovoltaic (PV) systems generate non-linear DC sources due to the nature of their power generation process, which involves converting sunlight into electricity through semiconductor materials. This non-linearity arises from the varying output of PV arrays based on factors like solar irradiance and temperature fluctuations, leading to non-linear current-voltage characteristics. The use of Maximum Power Point Tracking (MPPT) techniques in PV systems, such as in the SEPIC DC-DC converter, helps optimize energy extraction by dynamically adjusting the operating point to track the maximum power output. Additionally, the integration of PV systems with power converters like DC/DC boost converters and DC/AC voltage source convertersfurther contributes to the non-linear behavior of the generated DC power, especially when interfacing with loads or the grid.