scholarly journals On the impact of sampling frequency on software energy measurements

2015 ◽  
Author(s):  
Rubén Saborido ◽  
Venera Venera Arnaoudova ◽  
Giovanni Beltrame ◽  
Foutse Khomh ◽  
Giuliano Antoniol
Keyword(s):  
Energy Consumption ◽  
Mobile Applications ◽  
Low Frequency ◽  
Battery Life ◽  
Low Frequencies ◽  
Fine Grain ◽  
Rough Approximation ◽  
Median Error ◽  
Real Picture ◽  
The Impact

Energy consumption is a major concern when developing and evolving mobile applications. The user wishes to access fast and powerful mobile applications, which is usually in contrast to optimized battery life and heat generation. The software engineering community have acknowledged the relevance of the problem and researchers are investigating ways to reduce energy consumption, for example by examining which library, device configuration, and applications parameters should be used to promote long battery life. We conjecture that these studies are at the border between hardware and software and we must be careful on how the energy consumption is measured and how the energy consumption is attributed to methods and libraries.To the best of our knowledge, no previous work investigates how much energy and power consumption is due to high frequency events missed when sampling at low frequencies such as 10 kHz and verified the error at the precision of method level. Low frequency sampling is a rough approximation that hinders the understanding of fine grain details: the real picture of energy consumption as well as the root causes are missed. This has profound implications on the choice of methods to evolve or components to replace.In this paper, we propose an approach for accurate measurements of the energy consumption of mobile applications. We apply the proposed approach to assess the energy consumption of 21 mobile, closed source, applications and four open source Android applications.We show that by sampling at 10 kHz one may expect a median error of 8%, however, such error may be as high as 50% for short fast executing methods. Finally, we revisit a previous approach that estimates the energy consumption of methods based on execution time and found that it can miss as much as 84% of the energy, with a median of 30%.

scholarly journals On the impact of sampling frequency on software energy measurements

2015 ◽  
Author(s):  
Rubén Saborido ◽  
Venera Venera Arnaoudova ◽  
Giovanni Beltrame ◽  
Foutse Khomh ◽  
Giuliano Antoniol
Keyword(s):  
Energy Consumption ◽  
Mobile Applications ◽  
Low Frequency ◽  
Battery Life ◽  
Low Frequencies ◽  
Fine Grain ◽  
Rough Approximation ◽  
Median Error ◽  
Real Picture ◽  
The Impact

Energy consumption is a major concern when developing and evolving mobile applications. The user wishes to access fast and powerful mobile applications, which is usually in contrast to optimized battery life and heat generation. The software engineering community have acknowledged the relevance of the problem and researchers are investigating ways to reduce energy consumption, for example by examining which library, device configuration, and applications parameters should be used to promote long battery life. We conjecture that these studies are at the border between hardware and software and we must be careful on how the energy consumption is measured and how the energy consumption is attributed to methods and libraries.To the best of our knowledge, no previous work investigates how much energy and power consumption is due to high frequency events missed when sampling at low frequencies such as 10 kHz and verified the error at the precision of method level. Low frequency sampling is a rough approximation that hinders the understanding of fine grain details: the real picture of energy consumption as well as the root causes are missed. This has profound implications on the choice of methods to evolve or components to replace.In this paper, we propose an approach for accurate measurements of the energy consumption of mobile applications. We apply the proposed approach to assess the energy consumption of 21 mobile, closed source, applications and four open source Android applications.We show that by sampling at 10 kHz one may expect a median error of 8%, however, such error may be as high as 50% for short fast executing methods. Finally, we revisit a previous approach that estimates the energy consumption of methods based on execution time and found that it can miss as much as 84% of the energy, with a median of 30%.

scholarly journals On the impact of sampling frequency on software energy measurements

2015 ◽  
Author(s):  
Rubén Saborido ◽  
Venera Arnaoudova ◽  
Giovanni Beltrame ◽  
Foutse Khomh ◽  
Giuliano Antoniol
Keyword(s):  
Energy Consumption ◽  
Mobile Applications ◽  
High Frequency ◽  
Sampling Frequency ◽  
Low Frequencies ◽  
Median Error ◽  
Android Applications ◽  
Reduce Energy Consumption ◽  
The Impact ◽  
Closed Source

Energy consumption is a major concern when developing and evolving mobile applications and researchers are investigating ways to reduce energy consumption. We conjecture that these studies are at the border between hardware and software and we must be careful on how the energy consumption is measured. To the best of our knowledge, no previous work investigates how much energy and power consumption is due to high frequency events missed when sampling at low frequencies such as 10 kHz and verified the error at the precision of method level. In this paper, we propose an approach for accurate measurements of the energy consumption of mobile applications. We apply the proposed approach to assess the energy consumption of 21 mobile, closed source, applications and four open source Android applications. We show that by sampling at 10 kHz one may expect a median error of 8%, however, such error may be as high as 50%.

scholarly journals Low-frequency sound affects active micromechanics in the human inner ear

2014 ◽  
Vol 1 (2) ◽  
pp. 140166 ◽  
Author(s):  
Kathrin Kugler ◽  
Lutz Wiegrebe ◽  
Benedikt Grothe ◽  
Manfred Kössl ◽  
Robert Gürkov ◽  
...  
Keyword(s):  
Inner Ear ◽  
Hair Cells ◽  
Otoacoustic Emissions ◽  
Low Frequency ◽  
Short Exposure ◽  
Low Frequencies ◽  
Spontaneous Otoacoustic Emissions ◽  
Human Cochlea ◽  
Human Hearing ◽  
The Impact

Noise-induced hearing loss is one of the most common auditory pathologies, resulting from overstimulation of the human cochlea, an exquisitely sensitive micromechanical device. At very low frequencies (less than 250 Hz), however, the sensitivity of human hearing, and therefore the perceived loudness is poor. The perceived loudness is mediated by the inner hair cells of the cochlea which are driven very inadequately at low frequencies. To assess the impact of low-frequency (LF) sound, we exploited a by-product of the active amplification of sound outer hair cells (OHCs) perform, so-called spontaneous otoacoustic emissions. These are faint sounds produced by the inner ear that can be used to detect changes of cochlear physiology. We show that a short exposure to perceptually unobtrusive, LF sounds significantly affects OHCs: a 90 s, 80 dB(A) LF sound induced slow, concordant and positively correlated frequency and level oscillations of spontaneous otoacoustic emissions that lasted for about 2 min after LF sound offset. LF sounds, contrary to their unobtrusive perception, strongly stimulate the human cochlea and affect amplification processes in the most sensitive and important frequency range of human hearing.

scholarly journals Optimization of mobile device energy consumption in a fog-based mobile computing offloading mechanism

2021 ◽  
Vol 29 (1) ◽  
pp. 53-62
Author(s):  
Anastasia V. Daraseliya ◽  
Eduard S. Sopin
Keyword(s):  
Energy Consumption ◽  
Response Time ◽  
Mobile Devices ◽  
Mobile Device ◽  
Mobile Applications ◽  
Optimization Problem ◽  
Fog Computing ◽  
Computing System ◽  
Battery Life ◽  
Average Response Time

The offloading of computing tasks to the fog computing system is a promising approach to reduce the response time of resource-greedy real-time mobile applications. Besides the decreasing of the response time, the offloading mechanisms may reduce the energy consumption of mobile devices. In the paper, we focused on the analysis of the energy consumption of mobile devices that use fog computing infrastructure to increase the overall system performance and to improve the battery life. We consider a three-layer computing architecture, which consists of the mobile device itself, a fog node, and a remote cloud. The tasks are processed locally or offloaded according to the threshold-based offloading criterion. We have formulated an optimization problem that minimizes the energy consumption under the constraints on the average response time and the probability that the response time is lower than a certain threshold. We also provide the numerical solution to the optimization problem and discuss the numerical results.

scholarly journals The Impact of the Treatment Method of Root Crops on Micro flora during their Storage

2019 ◽  
Vol 9 (1) ◽  
pp. 4273-4278
Keyword(s):  
Magnetic Induction ◽  
Treatment Time ◽  
Low Frequency ◽  
Treatment Method ◽  
Integrated Treatment ◽  
Low Frequencies ◽  
Anaerobic Microorganisms ◽  
Root Crops ◽  
Different Temperatures ◽  
The Impact

The study aims at determining the effect of the treatment method of root crops before storage, as well as storage parameters, on the dynamics of their microflora, namely, the quantity of bacterial microflora, mesophilic aerobic and optionally anaerobic microorganisms (MAaOAM), as well as molds. When storing garden carrot at t = +(2±1) °C (during 56 days), the amount of bacterial microflora of the samples subjected to integrated treatment decreased by 2.5 times by the end of storage; the number of mold fungi decreased twice compared to the control. When storing garden carrot at t = +(25±1) °C (for 21 days) the amount of bacterial microflora in the samples treated by electromagnetic fields of extremely low frequencies (with the following parameters: frequency – 28 Hz, the treatment time – 5 min, the magnetic induction – 12 mTl), and by Vitaplan biologic preparation (at the concentration of 106 CFU/g, and in the amount of 2.5 ml/kg), decreased by 2.1 times, while the number of mold fungi reduced by 1.5 times. When storing garden beet at t = +(2±1) °C for 56 days, the amount of bacterial microflora of samples, subjected to integrated treatment for 5 min at a frequency of 15, 24, and 30 Hz, and magnetic induction of 9 mTl, as well as treatment with Bactofit biological preparation (at the concentration of 106 CFU/g in amount of 2.5 ml/kg), decreased by 1.5 times compared to the control, while the number of mold fungi decreased by 2.3 times. When storing garden beet at t = +(25±1) °C (for 21 days), the quantity of bacterial microflora of samples, subjected to integrated treatment, was by 2.8 times lower compared to the control, while the number of mold fungi reduced by 1.8 times. It has been revealed that the integrated treatment of root crops with biopreparations and extremely low frequency (ELF) electric and magnetic fields (EMF) more effectively inhibits the development of pathogenic microflora compared to treatment only with biopreparations or treatment only by ELF-EMF. Significant retardation of growth rates was revealed in both bacterial and fungal pathogenic microflora during storage of root crops at different temperatures.

scholarly journals Neutral stability curves of low-frequency Görtler flow generated by free-stream vortical disturbances

2018 ◽  
Vol 845 ◽  
Author(s):  
Samuele Viaro ◽  
Pierre Ricco
Keyword(s):  
Vortex Flow ◽  
Free Stream ◽  
Low Frequency ◽  
Neutral Stability ◽  
Flow Conditions ◽  
Low Frequencies ◽  
Transition Prediction ◽  
Neutral Curves ◽  
The Impact ◽  
Inviscid Instability

The neutral curves of the boundary layer Görtler-vortex flow generated by free-stream disturbances, i.e., curves that distinguish the perturbation flow conditions of growth and decay, are computed through a receptivity study for different Görtler numbers, wavelengths, and low frequencies of the free-stream disturbance. The perturbations are defined as Klebanoff modes or strong and weak Görtler vortices, depending on their growth rate. The critical Görtler number below which the inviscid instability due to the curvature never occurs is obtained and the conditions for which only Klebanoff modes exist are thus revealed. A streamwise-dependent receptivity coefficient is defined and we discuss the impact of the receptivity on the $N$-factor approach for transition prediction.

Noise induced hearing loss in low frequencies in employees in a hospital microbiology department

2021 ◽  
Vol 7 (5) ◽  
pp. 861
Author(s):  
Konstantina Chrysouli ◽  
Dimitrios Kikidis
Keyword(s):  
Hearing Loss ◽  
Low Frequency ◽  
Control Group ◽  
Frequency Noise ◽  
Noise Induced Hearing Loss ◽  
Low Frequency Noise ◽  
Low Frequencies ◽  
History Of ◽  
Laboratory Workers ◽  
The Impact

<p class="abstract">Noise induced hearing loss (NIHL) is regarded as a serious problem and one of the most recorded occupational disorders in Europe and in the rest of the world and amounts to between 7% and 21% of the hearing loss. Aim of this study is to explore the development and the prevalence of low frequency noise-induced hearing loss (NIHL) in a hospital, especially in microbiology laboratory workers. Generally it is known that 4 KHz is the main NIHL frequency. Despite current theories, our study suggests for the first time the impact of low frequency noise in hearing loss among laboratory workers. According to the results, the population examined, namely the employees at the Microbiology Department of the Hospital, showed lower hearing levels compared to the control group, who had no history of occupational exposure to noise. There are many other studies which suggest that prolonged exposures to high noise levels have negative physiological and psychological effects on workers. The finding of the correlation of noise frequency with the frequency of the generated hearing loss is involved in the controversy about the pathophysiology of noise effect.</p>

scholarly journals Two Designs of Automatic Embedded System Energy Consumption Measuring Platforms Using GPIO

2020 ◽  
Vol 10 (14) ◽  
pp. 4866
Author(s):  
Huanjie Wu ◽  
Chun Chen ◽  
Kai Weng
Keyword(s):  
Energy Consumption ◽  
Embedded System ◽  
Critical Evaluation ◽  
General Purpose ◽  
Thermal Design ◽  
Battery Life ◽  
Time Integral ◽  
Consumption Data ◽  
Test Sets ◽  
The Impact

Energy consumption is a critical evaluation index of embedded systems, and it has impacts on battery-life, thermal design, as well as device security and reliability. Since energy is the time integral of power, power consumption should be considered, along with the impact of “time”; thus, we propose two designs of automatic energy consumption measuring platforms utilizing General Purpose Input/Output (GPIO). Using these designs, we developed software and introduced auxiliary hardware for solutions with better timing and synchronization. A series of test sets were designed to verify our designs’ capabilities and accuracy levels. Both of our designs showed an accuracy similar to that of traditional measuring methods, which can satisfy the needs of different occasions. In addition, our designs provide real-time energy consumption data, as well as unattended automated measurements.

Assessment of the Noise Generated by Wind Turbines at Low Frequencies

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Martino Marini ◽  
Roberto Baccoli ◽  
Costantino C. Mastino ◽  
Antonino Di Bella ◽  
Carlo Bernardini ◽  
...  
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Low Frequency ◽  
Frequency Noise ◽  
Computational Tools ◽  
Low Frequencies ◽  
Special Concern ◽  
Assessment Procedures ◽  
The Impact ◽  
Noise Production

The noise production from wind turbines (WT) and its propagation into the surrounding environment have an impact on the receptors (RC) that have to be accurately predicted within the environmental impact assessment. The low-frequency noise (LFN) is of special concern for it is typical of wind systems and it involves specific computational issues. The purpose of this study is to apply and compare the assessment procedures currently used in different European countries for the prediction of LFN produced by wind turbines, with reference to a specific case. The results of the calculations for a planned wind farm in northern Sardinia, Italy, obtained by the available computational tools and with the help of the presented predictive models are presented and discussed. It can be deduced from this that the impact due to the low frequencies noise generated by wind turbines in the vicinity of sensitive receptors is negligible in terms of generated sound pressure levels (SPLs), even though further investigations on such a topic are needed.

Effect of Pore Morphology on the Electrochemical Properties of Electric Double Layer Carbon Cryogel Supercapacitors

2007 ◽  
Vol 1056 ◽  
Author(s):  
Betzaida Batalla Garcia ◽  
Aaron M. Feaver ◽  
Richard Champion ◽  
Qifeng Zhang ◽  
Tim T. Fister ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Electrochemical Impedance ◽  
Porous Electrode ◽  
Low Frequency ◽  
Frequency Range ◽  
Low Frequencies ◽  
Diffusion Dynamics ◽  
Pore Size Distributions ◽  
Complex Capacitance ◽  
The Impact

ABSTRACTIn this study a group of resorcinol-formaldehyde carbon cryogels (CC) have been processed chemically, via catalysis and activation, to obtain varied nanostructures and pore size distributions. To understand the relation between structure and electrochemical properties the capacitor can be studied as a dielectric system composed of a porous electrode and the electrolyte (Tetraethylammonium tetrafluoroborate in propylene carbonate). Using Electrochemical impedance spectroscopy (EIS) the complex capacitance and power are used to study the behavior of the system below the relaxation frequency fo (φ = −45°). Therefore, the relaxation of the capacitor system at the low frequency range, f < fo, may be used as a measure of pore/electrolyte interaction. The approach here proposed also allows for a direct experimental characterization of the capacitance and power at low frequencies where small pores are likely to affect the diffusion dynamics of the electrolyte molecules. The results suggest a correlation between the occurrence of small micropores and that of high power losses that are related to the resistive element produced at the low frequency range. Moreover, the impact of the micropore structure upon the supercapacitor's performance is apparent in its capacitance and energy as well. In addition to the complex power and capacitance other measurements including BET Nitrogen sorption, cyclic voltammetry, galvanic cycling and X-Ray Raman Scattering were used to characterize the samples and support these results.

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