Inefficient Devices Research Articles

Secure and efficient implementation of facial emotion detection for smart patient monitoring system

BackgroundMachine learning has enabled the automatic detection of facial expressions, which is particularly beneficial in smart monitoring and understanding the mental state of medical and psychological patients. Most algorithms that attain high emotion classification accuracy require extensive computational resources, which either require bulky and inefficient devices or require the sensor data to be processed on cloud servers. However, there is always the risk of privacy invasion, data misuse, and data manipulation when the raw images are transferred to cloud servers for processing facical emotion recognition (FER) data. One possible solution to this problem is to minimize the movement of such private data.MethodsIn this research, we propose an efficient implementation of a convolutional neural network (CNN) based algorithm for on‐device FER on a low‐power field programmable gate array (FPGA) platform. This is done by encoding the CNN weights to approximated signed digits, which reduces the number of partial sums to be computed for multiply‐accumulate (MAC) operations. This is advantageous for portable devices that lack full‐fledged resource‐intensive multipliers.ResultsWe applied our approximation method on MobileNet‐v2 and ResNet18 models, which were pretrained with the FER2013 dataset. Our implementations and simulations reduce the FPGA resource requirement by at least 22% compared to models with integer weight, with negligible loss in classification accuracy.ConclusionsThe outcome of this research will help in the development of secure and low‐power systems for FER and other biomedical applications. The approximation methods used in this research can also be extended to other image‐based biomedical research fields.

Bright Emission at Reverse Bias After Trailing Edge of Driving Pulse in Wide InGaN Quantum Wells

In group‐III‐nitride quantum wells (QWs), a strong piezoelectric field is formed. A built‐in potential from the p–n junction is working in the opposite direction depending on an externally applied voltage. Furthermore, the electric field in the QW can be partially screened by a high charge carrier density. Herein, the influence of these effects on recombination and spectrum for over 10 nm wide InGaN QWs is investigated. The very low overlap of electrons and holes would suggest inefficient devices. However, it is shown that thick QWs can be more effective and reach high optical gain. This can be explained by the screening of the electric field, resulting in a high overlap of excited electron and hole states that enable lasing. Herein, a pulsed electrical excitation scheme is used, where carrier injection at forward bias and predominant recombination at zero or reverse bias are separated in time. The interplay between the piezoelectric field and the built‐in potential on carrier recombination in dependence on an external bias voltage is observed. In particular, a strong increase of the radiative recombination rate after the trailing edge of the driving pulse is observed.

Effects of Magnetic Field on the Performance of Solar Distillers: A Review Study

Due to the rising demand for treated water, the enhancement of potable water yield technologies, such as traditional solar distillers, is a pressing concern. Solar desalination is one of the easiest techniques for producing fresh water from salt water. It has several benefits, not the least. It utilizes free solar energy. Moreover, it is a simple and inexpensive technique compared to other alternatives. They are, nevertheless, relatively inefficient devices. Many studies have been done to boost the daily output of solar stills by using many active strategies to produce a large amount of evaporation and condensation compared to a basic standard type distiller. The magnetic field (MF) is one of the most important and recent techniques affecting the productivity of the solar still due to its positive impact on the water evaporation rate. The primary focus of the current study is to review the effects of magnetic field approaches on the distillate production, performance, and thermal efficiency of several types of solar distillers. Based on previous studies, the magnetic field is responsible for increasing the partial pressure difference between water and glass cover. The change occurs in the hydration shells of the saltwater, which should enhance the evaporation rate and improve the performance of solar still. Besides, the magnetic field significantly reduces the surface tension of salty water, which leads to increased evaporation. Furthermore, the intensity, direction, position, and magnet sizes of magnetic have a strong effect on the rate of water evaporation as well as the rate of heat transfer.

Retrofitting existing buildings to reduce electrical energy consumption and greenhouse gas emission in Nigerian food and beverage industries

Food and Beverage industry is one of the fastest growing manufacturing industries in Nigeria with its attendant carbon emission. In this paper, retrofitting (one of the demand side management (DSM) techniques) is adopted as a strategy to reducing energy consumption and the associated greenhouse gas emission of three selected food and beverages industries in Nigeria. This is achieved by carrying out a walk through energy audit on the selected industries with the aim of reducing their carbon footprint by reducing the electrical energy consumption pattern. Retrofitting exercise involves identification of energy-inefficient electrical equipment within the industry and thereafter replacing them with available identical device but with better energy efficiency. The investment cost for adopting energy efficient technology and its corresponding payback period are estimated. Recommendations for policy documents were proposed based on the study. The energy audit reveals that electric motor, lighting points (lamps) and computer system constitute electrical load that are inefficiently operated within the selected industries. Applying DSM by retrofitting on these components of electrical load reduces the overall electrical energy consumption of the industry by 17%, 20% and 14% for industries A, B and C, respectively. An estimated reduction in CO2 emission of 159,471.2 kg, 139,598.7 kg and 186,696.4 kg is achieved for industries A, B and C, respectively, using the DSM. This paper is useful as it provides scientific information on the need to retrofit inefficient devices in Nigeria industries.

A 96-well high-throughput, rapid-screening platform of extracellular electron transfer in microbial fuel cells

Microbial extracellular electron transfer (EET) stimulates a plethora of intellectual concepts leading to potential applications that offer environmentally sustainable advances in the fields of biofuels, wastewater treatment, bioremediation, desalination, and biosensing. Despite its vast potential and remarkable research efforts to date, bacterial electrogenicity is arguably the most underdeveloped technology used to confront the aforementioned challenges. Severe limitations are placed in the intrinsic energy and electron transfer processes of naturally occurring microorganisms. Significant boosts in this technology can be achieved with the growth of synthetic biology tools that manipulate microbial electron transfer pathways and improve their electrogenic potential. In particular, electrogenic Pseudomonas aeruginosa has been studied with the utility of its complete genome being sequenced coupled with well-established techniques for genetic manipulation. To optimize power density production, a high-throughput, rapid and highly sensitive test array for measuring the electrogenicity of hundreds of genetically engineered P. aeruginosa mutants is needed. This task is not trivial, as the accurate and parallel quantitative measurements of bacterial electrogenicity require long measurement times (~tens of days), continuous introduction of organic fuels (~tends of milliliters), architecturally complex and often inefficient devices, and labor-intensive operation. The overall objective of this work was to enable rapid (<30 min), sensitive (>100-fold improvement), and high-throughput (>96 wells) characterization of bacterial electrogenicity from a single 5 μL culture suspension. This project used paper as a substratum that inherently produces favorable conditions for easy, rapid, and sensitive control of an electrogenic microbial suspension. From 95 isogenic P. aeruginosa mutant, an hmgA mutant generated the highest power density (39 μW/cm2), which is higher than that of wild-type P. aeruginosa and even the strongly electrogenic organism, Shewanella oneidensis (25 μW/cm2). In summary, this work will serve as a springboard for the development of novel paradigms for genetic networks that will help develop mutations or over-expression and synthetic biology constructs to identify genes in P. aeruginosa and other organisms that enhance electrogenic performance in microbial fuel cells (MFCs).

The environmental impacts of preparation for reuse: A case study of WEEE reuse in Germany

Abstract According to the European waste management hierarchy, preparation for reuse (PfR) is preferable to recycling. From an environmental point of view, reuse is beneficial, if the impacts that arise during a certain usage duration of a reused product are smaller than those of a new product. If this is not the case, reuse is not beneficial to recycling. This study explores potential benefits of PfR compared to other waste management options for four white goods (washing machine, refrigerator, range, freezer) and four small electric devices (PC, printer, monitor, laptop) by the use of Life Cycle Assessment. These eight devices account for 68% by weight of all the collected waste electrical and electronic equipment (WEEE) in Germany. The results show, that the assumption that reuse is preferable to recycling does not apply to every case. Especially the impact categories of global warming, water consumption and cumulative energy demand are strongly dominated by the use phase of white goods, therefore a reuse of inefficient devices should be avoided. The results show that a reuse of products with an European energy efficiency rating of D and C is not recommended for any of the analyzed products. For small electric devices, the use phase is less dominant in comparison to the production, therefore reuse leads to significant saving potentials in almost all impact categories. A comparison of energy efficiency classes allows for product-specific decisions, whereas the assessment approach based on average devices yields for generalizable recommendations. Therefore, the results support environmentally conscious consumer decisions about the acquisition of a new versus a second-hand product and enable End-of-Life decision making in terms of the separation of reusable devices at collection points.

Integrating sustainability analysis with sectoral exergy analysis: A case study of rural residential sector of Bangladesh

To achieve sustainable development in all stages of society the participation of rural communities is essential. Rural communities are known to employ energy inefficient devices which lead to major energy depletion and this has a negative impact on sustainability. Exergy and sustainability analyses can be applied to highlight the relation between energy utilization and sustainability. Keeping this in mind, the current study focuses on the integration of conventional sectoral exergy analysis and sustainability analysis. Based on forecasted data between 2010 and 2050, a case study of Bangladesh's rural residential sector is investigated in terms of energy, exergy, and sustainability analyses. The energy efficiencies of this sector are found to vary between 18.96% and 31.53% while exergy efficiencies vary between 4.86% and 8.42%. Several exergetic sustainability indicators such as depletion number, sustainability index, environmental effect factor, waste exergy ratio, environmental destruction coefficient, environmental destruction index, and environmental benign index are used to highlight the sustainability of this sector. From the sustainability analysis, it is found that 95% of the fuel is depleted from this sector and it contributes to lower sustainability index of 1.05. Waste exergy ratio from biomass varies between 0.75 and 0.93. This sector has the highest environmental destruction index of 39.10 and lowest environmental benign index of 0.03. Efficient use of biomass resources, replacing old biomass stoves and developing energy policies using exergy can improve the sustainability of this sector.

Impacts of household sources on air pollution at village and regional scales in India

Abstract. Approximately 3 billion people worldwide cook with solid fuels, such as wood, charcoal, and agricultural residues. These fuels, also used for residential heating, are often combusted in inefficient devices, producing carbonaceous emissions. Between 2.6 and 3.8 million premature deaths occur as a result of exposure to fine particulate matter from the resulting household air pollution (Health Effects Institute, 2018a; World Health Organization, 2018). Household air pollution also contributes to ambient air pollution; the magnitude of this contribution is uncertain. Here, we simulate the distribution of the two major health-damaging outdoor air pollutants (PM2.5 and O3) using state-of-the-science emissions databases and atmospheric chemical transport models to estimate the impact of household combustion on ambient air quality in India. The present study focuses on New Delhi and the SOMAARTH Demographic, Development, and Environmental Surveillance Site (DDESS) in the Palwal District of Haryana, located about 80 km south of New Delhi. The DDESS covers an approximate population of 200 000 within 52 villages. The emissions inventory used in the present study was prepared based on a national inventory in India (Sharma et al., 2015, 2016), an updated residential sector inventory prepared at the University of Illinois, updated cookstove emissions factors from Fleming et al. (2018b), and PM2.5 speciation from cooking fires from Jayarathne et al. (2018). Simulation of regional air quality was carried out using the US Environmental Protection Agency Community Multiscale Air Quality modeling system (CMAQ) in conjunction with the Weather Research and Forecasting modeling system (WRF) to simulate the meteorological inputs for CMAQ, and the global chemical transport model GEOS-Chem to generate concentrations on the boundary of the computational domain. Comparisons between observed and simulated O3 and PM2.5 levels are carried out to assess overall airborne levels and to estimate the contribution of household cooking emissions. Observed and predicted ozone levels over New Delhi during September 2015, December 2015, and September 2016 routinely exceeded the 8 h Indian standard of 100 µg m−3, and, on occasion, exceeded 180 µg m−3. PM2.5 levels are predicted over the SOMAARTH headquarters (September 2015 and September 2016), Bajada Pahari (a village in the surveillance site; September 2015, December 2015, and September 2016), and New Delhi (September 2015, December 2015, and September 2016). The predicted fractional impact of residential emissions on anthropogenic PM2.5 levels varies from about 0.27 in SOMAARTH HQ and Bajada Pahari to about 0.10 in New Delhi. The predicted secondary organic portion of PM2.5 produced by household emissions ranges from 16 % to 80 %. Predicted levels of secondary organic PM2.5 during the periods studied at the four locations averaged about 30 µg m−3, representing approximately 30 % and 20 % of total PM2.5 levels in the rural and urban stations, respectively.

Diseño de un Sistema Inteligente y Compacto de Iluminación

La luz es un factor ambiental muy influyente en la calidad de vida y el rendimiento de las personas. Por esta razón es necesario crear e implementar tecnologías que ayuden a mantener ambientes sanos, en términos de iluminación, para los usuarios. Si a esto sumamos la gran cantidad de energía eléctrica que se desperdicia por malos hábitos de consumo y por el uso de dispositivos anticuados e ineficientes, resulta evidente la importancia del presente trabajo, el cual propone el diseño de una lámpara compacta y versátil que reemplace fácilmente a los focos tradicionales con ventajas como un control automático para el encendido y apagado en función del movimiento registrado en la habitación, un control automático de nivel de iluminación para mantener niveles óptimos en todo momento y regulación del tono de la luz de acuerdo a la habitación y a la hora del día. Para lograr lo anteriormente mencionado se utilizó tecnología LED, un microcontrolador y sensores que junto con técnicas de control gobiernan el comportamiento de la lámpara. Se establecieron varios parámetros de funcionamiento como nivel de iluminación y tono de la luz emitida los cuales se cumplieron dentro de ciertas condiciones operativas.

Review and perspective on ultrafast wavelength-size electro-optic modulators

As electronic device feature sizes scale-down, the power consumed due to onchip communications as compared to computations will increase dramatically; likewise, the available bandwidth per computational operation will continue to decrease. Integrated photonics can offer savings in power and potential increase in bandwidth for onchip networks. Classical diffraction-limited photonics currently utilized in photonic integrated circuits (PIC) is characterized by bulky and inefficient devices compared to their electronic counterparts due to weak light–matter interactions (LMI). Performance critical for the PIC is electro-optic modulators (EOM), whose performances depend inherently on enhancing LMIs. Current EOMs based on diffraction-limited optical modes often deploy ring resonators and are consequently bulky, photon-lifetime modulation limited, and power inefficient due to large electrical capacitances and thermal tuning requirements. In contrast, wavelength-scale EOMs are potentially able to surpass fundamental restrictions set by classical (i.e. diffraction-limited) devices via (a) high-index modulating materials, (b) nonresonant field and density-of-states enhancements such as found in metal optics, and (c) synergistic onchip integration schemes. This manuscript discusses challenges, opportunities, and early demonstrations of nanophotonic EOMs attempting to address this LMI challenge, and early benchmarks suggest that nanophotonic building blocks allow for densely integrated high-performance photonic integrated circuits.

Analysis of Household Electricity Consumption Patterns and Economy of Water Heating Shifting and Saving Bulbs

Analysis of Household Electricity Consumption Patterns and Economy of Water Heating Shifting and Saving BulbsThis article analyses household electricity consumption based on an object in Estonia. Energy consumption of workday and holiday by loads (including high and low tariff energy consumption) is discussed. The final part describes the evaluation of profitability of common investments of consumption shifting and replacing inefficient devices with more efficient ones. Additionally it describes shifting problems and shifting equipment profitability in real-time tariff system.

High-Performance InP-Based Mid-IR Quantum Cascade Lasers

Quantum cascade lasers (QCLs) were once considered as inefficient devices, as the wall-plug efficiency (WPE) was merely a few percent at room temperature. But this situation has changed in the past few years, as dramatic enhancements to the output power and WPE have been made for InP-based mid-IR QCLs. Room temperature continuous-wave (CW) output power as high as 2.8 W and WPE as high as 15% have now been demonstrated for individual devices. Along with the fundamental exploration of refining the design and improving the material quality, a consistent determination of important device performance parameters allows for strategically addressing each component that can be improved potentially. In this paper, we present quantitative experimental evidence backing up the strategies we have adopted to improve the WPE for QCLs with room temperature CW operation.

PRIVATE WATER STORAGE TANKS: EVALUATING THEIR INEFFICIENCIES

Private water storage tanks are often considered as very inefficient devices than can only be justified in systems that suffer frequent water service interruptions. This paper presents the results obtained after studying four different aspects of this question: the effect of this kind of tanks on water losses, unaccounted for water, time modulation curve and energy losses (other implications, such as those related to water quality deterioration, remain out of the scope of the study). Conclusions for each particular point will turn uneven, specially highlighting the effect on the meter global error and unregistered water. In any case, all four points, as well as several additional issues to be considered, are described and evaluated.

Energy technology portfolio analysis: an example of lighting for residential sector

Lighting is one of the most important and high quality uses of electricity. Recent advances in lighting technologies have made it possible to use the precious electrical energy more efficiently. Even though efficient lighting devices are available in abundance, their performance in terms of penetrating the market is rather dismal. The main reasons for this are the high initial purchase costs, uncertainties in returns and the tendency of consumers to use high discount rates in investing in energy efficient devices. Therefore, there is a need to develop a portfolio of both inefficient and efficient lighting devices for better market penetration of the latter one, since total elimination of the use of inefficient devices is impossible. Further, it is interesting to study whether the energy efficient alternatives are attractive investments vis-à-vis common stock options. This paper analyses the economics of such an issue before developing an optimal portfolio of these alternatives for a typical household in Karnataka State, India. A mixed integer programming model has been developed, and a comparison of returns is made. The results show that the optimal lighting portfolio provides a far higher return at a lower risk compared to the stock market. Overall results indicate a substantial savings both in terms of energy and peak demand.

Women, energy and sustainable development

Sustainable development is an equitable, empowering, environmentally sound, economically viable process of growth. Energy is the key indicator of sustainable development. About 74% of the population of India live in rural areas. 80% of their energy needs are derived from biomass. About 92% of this energy is consumed in cooking activity. Women play a major role in biofuel management. Rural women's perspective in sustainable development is therefore critical. Declining biofuel resources, poor quality of the available biofuels and inefficient devices have pushed women into greater hardships. This paper examines the role of rural women in biomass management. The energy resources that rural women use, the strategy that the government and other organisations have adopted to alleviate rural energy problems and how these strategies have benefited women and improved their quality of life, the importance of incorporating the concept of “gender and development” in alternative energy strategies to achieve the objectives of sustainable development are discussed in this paper.

A Simulation Model for Heat Pump Dryer Plants for Fruits and Roots.

ABSTRACT Dryer design requires food properties, drying rate and mass-heat transfer coefficients. These values change continuously during drying due to changes in food fractions, particularly the water fraction. The high energy demand and costs allied to inefficient devices, creates a great need for new processing equipment. Along these guide-lines, several heat pump drying research projects were established at the Norwegian University of Science and Technology. The heat pump dryer provides high quality final product as its drying conditions can be controlled. Its efficiency and non-polluting operation come from closed air-refrigerant circuits and from its ability to fully recover the latent heat of moist air as it exits the drying chamber. Most of the above features are quite the opposite of the conventional dryer characteristics. Several experiments were made on heat pump drying of fruits and roots at temperatures from -22.5 to 40°C to obtain data and correlations on thermophysical properties, specific enthalpy and rehydration. Also, tests were done on drying rate, moisture content, drying constant, effective mass diffusivity and heat and mass transfer equations. The next important phase is the development of a simulation model to predict the performance and characteristics of the heat pump dryer plant. The objectives of the present work are to develop and lo test a heat pump dryer simulation model. The simulation provides results on the characteristics of both plant and components which are integrated by heat and mass transfer equations. The program has menus with click-on icons, input and output pop-up dialogue boxes. The usual commands such as, file-open, file-save, edit-delete are available in this program simply called Hpdryer. The model contains moist air psychrometric. natural and conventional refrigerant property libraries. Ammonia is a time-tested, self-alarming and natural refrigerant. It has been used extensively in the past, and it has better thermodynamic and transport properties than halocarbons. Safety is easily attained by design and its restrictive standards have helped increase its use in several countries. There are 36 ammonia installations in Norway and in the United Kingdom, including a drying plant. Ammonia has zero Odp, zero Gwp and the recent R&D has led to viable small-sale heat pump plants. Ammonia and dichlarodifluoromethane refrigerants were used in the test cases simulated by Hpdryer madel.

Are residual stenoses after excimer laser angioplasty and coronary atherectomy due to inefficient or small devices? comparison with balloon angioplasty

Objectives. The purpose of this study was to determine whether residual stenoses after excimer laser angioplasty and atherectomy were due to inefficient tissue ablation/removal or to undersized devices.BackgroundSignificant residual stenoses are commonly observed after use of laser and atherectomy devices. It is not known whether these residual stenoses are due to inefficient or undersized devices,Methods. To determine the relative contribution of these factors, the minimal lumen diameter, percent diameter stenosis and normal reference diameter were measured immediately before and after coronary interventions in 696 lesions, including transluminal extraction atherectomy, high speed mechanical rotational atherectomy, excimer laser angioplasty and conventional balloon angioplasty, The ratio of the diameter of the device to the normal reference diameter (D/A, a measure of device sizing) and the ratio of the residual lumen diameter after use of the device to the device diameter (RLD/D, a measure of the efficiency of lumen enlargement) were calculated.Results. Baseline diameter stenoses were similar for all interventions. The percent diameter stenosis were greater immediately after extraction atherectomy (60 ± 21%), rotational atherectomy (54 ± 23%) and excimer laser angioplasty (61 ± 18%) compared with balloon angioplasty (26 ± 12%, p < 0.001). The DA ratio was smaller after extraction atherectomy (0.63 ± 0.14), rotational atherectomy (0.59 ± 0.17) and excimer laser angioplasty (0.51 ±0.11) compared with balloon angioplasty (1.05 ± 0.13, p < 0.001). The RLD/D ratio was similar after extraction atherectomy (0.73 ±0.24) and balloon angioplasty (0.71 ±0.11) but was greater after rotational athereetomy (0.92 ± 0.16, p < 0.001) and excimer laser angioplasty (0.85 ± 0.30, p < 0.01) compared with balloon angioplasty.Conclusions. Residual stenoses after extraction atherectomy, rotational atherectomy and excimer laser angioplasty were more severe than after balloon angioplasty but were due to undersized devices (low DA ratio), not to inefficient devices (low RLD/D ratio). Rotational atherectomy and excimer laser angioplasty were more efficient (higher RLD/D) than balloon angiopiasty, whereas extraction atherectomy and balloon angioplasty were similar.

The Antipoverty Effectiveness of In-Kind Transfers

In recording its poverty statistics, the U.S. Census Bureau ignores the impact of in-kind transfers on the extent of poverty. In this paper, we estimate that when in-kind food, housing, and medical care transfers are counted and measured at their cash-equivalent value, and when Census income is adjusted for underreporting, federal taxes, and intrahousehold income-sharing, the 1972 poverty count and the poverty gap are halved. In addition, we find that in-kind transfers are relatively inefficient devices for reducing income poverty, delivering only about 31 cents of anitpoverty effect per dollar of program cost.