Remote Configurations Research Articles

Impact of space utilization and work time flexibility on energy performance of office buildings

This study investigates the impact of different space utilization on energy use intensity, heating load, cooling load, and thermal comfort of occupants using a combination of empirical data gathering and simulation-based studies. The increasing worldwide preoccupation with energy consumption and environmental sustainability has led to increased attention on optimizing interior spaces to mitigate total energy demand. The considered case study for conducting this research was the Norwegian living lab namely Zero Emission Building (ZEB) Flexible Lab in Trondheim, Norway. In this study, 10 different scenarios of occupancy schedules based on flexible arrangements from standard workweeks to extensive remote work configurations were designed and analyzed using IDA ICE 5.0. The findings demonstrate significant reductions in energy use across scenarios with increased teleworking and compressed work weeks. The remote scenario achieved the most significant decrease in Energy Use Intensity (EUI), with a reduction of 46 % compared to the base case. Similarly, the implementation of flexible hours and remote working in scenarios resulted in a reduction of electric heating demand by up to 23 %, underscoring the potential of occupancy-based strategies in enhancing building energy efficiency. However, uncomfortable hours increased by 59 % in the 2-day remote working scenario compared to the base case, demonstrating the need to consider climate conditions when implementing remote work. The research offers valuable insights into the complex connections between flexible arrangements and energy efficiency, considering many elements such as occupancy schedule and use dynamics. This article offers a comprehensive analysis that may give architects, building managers, and policymakers valuable insights. This study contributes to the developing sustainable architecture by emphasizing the impact of dynamic occupancy on the energy performance of office buildings.

Flow–acoustic resonance mechanism in tandem deep cavities coupled with acoustic eigenmodes in turbulent shear layers

This study presents the interplay of flow and acoustics within tandem deep cavities, focusing on the resonance mechanism occurring between turbulent shear layers and acoustic eigenmodes. The arrangement inside the tandem deep cavities includes both close and remote configurations. A combined fully coupled and decoupled aeroacoustic simulation strategy was devised. Employing an advanced high-order spectral/hp element method in conjunction with implicit large eddy simulation, the nonlinear compressible Navier–Stokes equations were solved to acquire internal flow–acoustic resonant field. In parallel, the linearized Navier–Stokes equations were tackled to determine coherent shear layer perturbations with external acoustic forcing. Based on acoustic measurements, the mainstream Reynolds number approaches approximately $R{e_{in}} = {O}({10^5})$ , where we identified the presence of frequency lock-in and a resonance range. Aeroacoustic noise sources were examined by implementing spectral proper orthogonal decomposition to decompose the pressure fields into hydrodynamic and acoustic components. As feedback intensified, the flow characteristics by the acoustic forcing effect and the flow-interactive effect were categorized according to the development of concurrent turbulent shear layers. Subsequently, the alternating and synchronous behaviours of concurrent shear layers resonated with the out-of-phase and in-phase acoustic eigenmodes were identified, and the corresponding large-scale counter-rotating vortex pairs and co-rotating vortex structures at the cavity entrances were extracted. The acoustic power generated by the Coriolis force was calculated using Howe's vortex-sound analogy, and the aeroacoustic energy transfer mechanism between large-scale shear layer vortices with acoustic eigenmodes was further explored. Finally, a linear response of coherent perturbations of the concurrent shear layers by external acoustic forcing was established. The amplification of flow in the streamwise direction toward the main duct led to the formation of coherent vortex structures, accompanied by separation bubbles into the main duct.

Exploring multimodal approaches for writing centres in remote and in-person configurations

Writing centres have had to adapt to many challenges, including the move to online learning during the Covid-19 pandemic. In South Africa this move was complexified by differential access to digital environments and contextual issues such as lack of electricity and rolling blackouts. Writing centres also need to consider the increasing massification of higher education and ways of harnessing diverse resources to enrich communication. This paper explores writing centre approaches to research and pedagogy within a social justice agenda, including combining an academic literacies approach with a multimodal social semiotic approach. It also investigates innovative approaches to teaching writing in diverse and multilingual contexts, including expanding the repertoire of resources used in writing consultations. It argues that the explicit utilisation of a range of modes can enhance writing production and enable writers to actively explore different modes for constructing meaning. The paper reflects on developing inclusive multimodal writing centre materials. It then explores the changing function of modes in online and face-to-face consultations (postpandemic lockdowns), including talk as mode, silence as mode, visual modes, and the use of time. The aim is to interrogate our academic practices concerning the diverse languages and various forms of communication that students possess, whether in virtual or physical learning environments.

Quantifying Efficiency of Remote Excitation for Surface-Enhanced Raman Spectroscopy in Molecular Junctions.

Surface-enhanced Raman spectroscopy (SERS) is enabled by local surface plasmon resonances (LSPRs) in metallic nanogaps. When SERS is excited by direct illumination of the nanogap, the background heating of the lattice and electrons can prevent further manipulation of the molecules. To overcome this issue, we report SERS in electromigrated gold molecular junctions excited remotely: surface plasmon polaritons (SPPs) are excited at nearby gratings, propagate to the junction, and couple to the local nanogap plasmon modes. Like direct excitation, remote excitation of the nanogap can generate both SERS emission and an open-circuit photovoltage (OCPV). We compare the SERS intensity and the OCPV in both direct and remote illumination configurations. SERS spectra obtained by remote excitation are much more stable than those obtained through direct excitation when the photon count rates are comparable. By statistical analysis of 33 devices, the coupling efficiency of remote excitation is calculated to be around 10%, consistent with the simulated energy flow.

Improvement of double-layer phosphor structure WLEDS in color homogeneity and luminous flux

The concept of the analysis is to put a CaAl2O4:Mn2+ green phosphor layer on top of the YAG:Ce3+ yellow phosphor layer. After that, find the added CaAl2O4:Mn2+ concentration appropriate for the highest luminous flux (LF) and color homogeneity (CH). In this analysis, five equivalent WLEDs were applied but with distinct color temperatures, including 5600 K - 8500 K. The findings showed that CaAl2O4:Mn2+ brings great benefits to increase not only the luminous flux but also the color homogeneity. Especially, the higher the CaAl2O4:Mn2+ concentration, the more the luminous flux released by WLEDs, owing to the risen content of the light of green in WLEDs. Nevertheless, as the CaAl2O4:Mn2+ concentration raised significantly, a small reduction in the color rendering metric (CRI) and color quality scale (CQS) occurred. This is supported by simulation and calculation according to the theory of Monte Carlo. The paper results are the crucial contribution to the manufacture of WLEDs with better optical performance and color homogeneity of remote phosphor configurations.

(Invited) Organic Semiconductor, Receptor Material and Circuit Design for Organic Electronic Vapor Sensors and Biosensors

We will present our recent results on the design of semiconducting material, gate structures, and stabilizing and amplifying circuits for detection of volatile analytes in the atmosphere and proteins in aqueous solution. Besides our natural interest in designing materials that respond more strongly to analytes of interest than to likely interferents, we also emphasize the use of chemical and electronic amplification methods to increase the ratio of the desired responses to the drift (signal/noise ratio). Printable materials, especially polymers, are emphasized for the responsive layers. The use of multiple sensing elements, typically field-effect transistors (FETs), to create patterns of responses increases the selectivity of the information, either by narrowing the classes of compounds providing the responses, distinguishing time-dependent from dose-dependent responses, and/or increasing the ratio of analyte responses to environmental drifts. As a specific example, using pairs of FETs, in series or in parallel, allows device drifts to be substantially canceled while analyte responses are maintained and even reinforced. This strategy has led to significant improvements in the use of polymer-based FETs to detect pollutant gases such as nitrogen dioxide and ammonia. To increase the stability of systems used to detect analytes in solution, we sometimes separate the sensing surface from the output device in an arrangement known as a remote gate. We show that the output device may be an organic-based or a silicon-based transistor, and can respond to electrochemical potential changes at the sensing surface arising from a variety of chemical interactions. This type of configuration was applied to the understanding of vapor sensors and the effect of receptor polarity on the detection of brain injury biomarker proteins. New details about the mechanisms for sensor responses to analytes can be obtained from remote gate configurations, including connection of interfacial voltages and charge densities in responsive polymer semiconductors.

Individual Differences Offer Insight Into Clinical Recommendations for Directional and Remote Microphone Technology Use in Children.

Purpose This study sought to evaluate the effects of common hearing aid microphone technologies on speech recognition and listening effort, and to evaluate potential predictive factors related to microphone benefits for school-age children with hearing loss in a realistic listening situation. Method Children (n = 17, ages 10-17 years) with bilateral, sensorineural hearing loss were fitted with hearing aids set to include three programs: omnidirectional, adaptive directional, and omnidirectional + remote microphone. Children completed a dual-task paradigm in a moderately reverberant room. The primary task included monosyllabic word recognition, with target speech presented at 60 dB A from 0° (front) or 180° (back) azimuth. The secondary task was a "go/no-go," visual shape-recognition task. Multitalker babble noise created a +5 dB SNR. Children were evaluated in two speaker conditions (front, back) using all three hearing aid programs. The remote microphone transmitter remained at the front speaker throughout testing. Speech recognition performance was calculated from the primary task while listening effort was measured as response time during the secondary task. Results Speech presented from the back significantly increased listening effort and caused a reduction in speech perception when directional and remote microphones were used. Considerable variability was found in pattern of benefit across microphones and source location. Clinical measures did not predict benefit patterns with directional or remote microphones; however, child age and performance with omnidirectional microphones did. Conclusions When compared to a traditional omnidirectional setting, the directional and remote microphone configurations evaluated in this study have the potential to provide benefit for some children and increase difficulty for others when used in dynamic environments. A child's performance with omnidirectional hearing aids could be used to better inform clinical recommendations for these technologies.

Building superior lighting properties for WLEDs utilizing two-layered remote phosphor configurations

Abstract The remote phosphor structure produces higher luminous flux but delivers poorer color quality than the conformal or in-cup phosphor structure. To eliminate this weakness, researchers have attempted to improve the chromatic properties of remote phosphor package. This study tends to enhance lighting features for WLEDs including color quality and luminous flux in general or color rendering index (CRI) and color quality scale (CQS) in particular by applying dual-layer remote phosphor structure. In the simulation section, we utilize two identical LEDs that only differ in correlated color temperature values which are 6600 K and 7700 K. The study offers an idea of placing a yellow-green phosphor layer SrBaSiO4:Eu2+ or a red phosphor layer SrwFxByOz:Eu2+,Sm2+ on the yellow phosphor layer YAG:Ce3+ and then modifying the concentrations of SrwFxByOz:Eu2+,Sm2+ and SrBaSiO4:Eu2+ to the suitable values to improve the color quality and lumen output of WLEDs. The results show that red phosphor layer SrwFxByOz:Eu2+,Sm2+ has a significant influence on CRI and CQS improvement. Particularly, the increase of SrwFxByOz:Eu2+,Sm2+ concentration leads to increased CRI and CQS because the red light component increases in WLEDs. On the other hand, the green phosphor layer SrBaSiO4:Eu2+ only brings benefit to the luminous flux. However, the WLEDs’ luminous flux and color quality drop sharply, when SrwFxByOz:Eu2+,Sm2+ and SrBaSiO4:Eu2+ concentrations rise extremely, which is verified based on the Mie-scattering theory and the Lambert-Beer law. In short, the article provides general knowledge and primary information for the production of higher-quality WLEDs.

Switching of heating and cooling modes using thermal radiation films

We study emissivity (ε)-dependent radiative heat transfer phenomena in remote and contact configurations. To demonstrate the emissivity-dependent radiative heating mode in a remote configuration, we fabricated miniature greenhouses covered with low (0.34)- and high-ε (0.86) polyethylene films and monitored temperatures on the floors, insides, and covers of the greenhouses during 24 h. The high-ε greenhouse yielded a 9-°C increase in floor temperature relative to the low-ε greenhouse at a one-sun solar irradiance because the high-ε film effectively trapped floor radiation. In contrast, the cover temperature remained lower in the high-ε greenhouse due to intensified radiation released from the high-ε film. This self-cooling effect was more evident when an emissive film was in physical contact with an object. While bare copper heated up to 55 °C, a high-ε film coated copper substrate was kept cooler by 4 and 2 °C compared with the bare and low-ε film coated copper samples, respectively.

(Invited) Organic Semiconductor, Receptor Material and Circuit Design for Organic Electronic Vapor Sensors and Biosensors

We will present our recent results on the design of semiconducting material, dielectric receptor matrices, and stabilizing and amplifying circuit structures for detection of volatile analytes in the atmosphere and proteins in aqueous solution. Besides our natural interest in designing materials that respond more strongly to analytes of interest than to likely interferents, we also emphasize the use of chemical and electronic amplification methods to increase the ratio of the desired responses to the drift (signal/noise ratio). Printable materials, especially polymers, are emphasized for the responsive layers. The use of multiple sensing elements, typically field-effect transistors (FETs), to create patterns of responses increases the selectivity of the information, either by narrowing the classes of compounds providing the responses, distinguishing time-dependent from dose-dependent responses, and/or increasing the ratio of analyte responses to environmental drifts. As a specific example, using pairs of FETs, in series or in parallel, allows device drifts to be substantially canceled while analyte responses are maintained and even reinforced. This strategy has led to significant improvements in the use of polymer-based FETs to detect pollutant gases such as nitrogen dioxide and ammonia. To increase the stability of systems used to detect analytes in solution, we sometimes separate the sensing surface from the output device in an arrangement known as a remote gate. We show that the output device may be an organic-based or a silicon-based transistor, and can respond to electrochemical potential changes at the sensing surface arising from a variety of chemical interactions. This type of configuration was applied to the understanding of vapor sensors and the effect of receptor polarity on the detection of brain injury biomarker proteins. New details about the mechanisms for sensor responses to analytes can be obtained from remote gate configurations, including connection of interfacial voltages and charge densities in responsive polymer semiconductors.

The usage of dual-layer remote phosphor configurations in enhancing color quality and luminous flux of WLEDs

Among conformal phosphor structure, in-cup phosphor structure, and remote phosphor structure, while in term of attaining the highest luminous flux, remote phosphor structure is the most ideal one, it seems to be that this structure results in the lowest-quality of color. Therefore, it is necessary in conducting experiments to surmount this disadvantage and make a possibility in enhancing the color quality of WLEDs with remote phosphor structure. In this research, with the ability of advancing the color rendering index (CRI) and color quality (CQS) for WLEDs, a dual-layer remote phosphor structure was considered as a suggestion. The experiments in this study used three kinds of WLEDs with the similar structures but different color temperatures varying at 5600 K, 7000 K, and 8500 K. The objectives of this paper is proposing a solution to obtain the highest color quality by placing a yellow-green emitting SrBaSiO4:Eu2+ phosphor layer or a red-emitting SrwFxByOz:Eu2+,Sm2+ phosphor layer on the YAG:Ce3+ phosphor layer and then choosing the most appropriate value of SrwFxByOz:Eu2+,Sm2+ concentration. The experimental results which are satisfied expectations of researchers indicated that SrwFxByOz:Eu2+,Sm2+ has enforced its role in managing to raise the CRI and CQS. Particularly, the greater concentration of SrwFxByOz:Eu2+,Sm2+ leads to the higher the CRI and CQS, since the red light component in WLEDs increased. Besides, the quality of luminous flux is in a tight connection with the SrBaSiO4:Eu2+ phosphor layer. Whereas, according to the Mie scattering theory and the Lambert-Beer law, if the concentration of SrwFxByOz:Eu2+,Sm2+ and SrBaSiO4:Eu2+ becomes redundant, the luminous flux and color quality will take a deep dive. Briefly, the results from this article has largely contributed to fabricating high-quality WLEDs.

Improvement of Color Quality and Luminous Flux of WLEDs with Dual-Layer Remote Phosphor Configurations

In comparison with the conformal phosphor or in-cup phosphor structure, remote phosphor structure has a superior luminous flux whereas its color quality is inferior to the others’. Due to this drawback, it is essential to conduct experiments to find the solution for the improvement of the color quality of WLEDs using remote phosphor structure. In this study, a dual-layer remote phosphor structure that is capable of enhancing the Color Rendering Index (CRI) and Color Quality Scale (CQS) for WLEDs was proposed. Three kinds of WLEDs with the similar structures but different color temperatures varying at 5600 K, 7000 K, and 8500 K are used in this article. The mission of this paper is to place a yellow-green emitting SrBaSiO4:Eu2+ phosphor layer or a red-emitting SrwFxByOz:Eu2+,Sm2+ phosphor layer on the YAG:Ce3+ phosphor layer and then select the most appropriate value of SrwFxByOz:Eu2+,Sm2+ concentration to get the greatest color quality. Experimental results were exactly as expected since SrwFxByOz:Eu2+,Sm2+ really succeeded in increasing CRI and CQS. Specifically, the larger the SrwFxByOz:Eu2+,Sm2+ concentration, the higher the CRI and CQS, resulting from the increase of the red light component in WLEDs. Meanwhile, the quality degree of luminous flux depends tightly on the SrBaSiO4:Eu2+ phosphor layer. However, if the SrwFxByOz:Eu2+,Sm2+ and SrBaSiO4:Eu2+ concentration exceeds, the luminous flux and color quality will have a tendency to drop off thanks to the theory of Mie scattering and the Lambert-Beer law. The result of this paper is a valuable reference in the production of high-quality WLEDs.

A Comparison of Techniques for Sign Language Alphabet Recognition Using Armband Wearables

Recent research has shown that reliable recognition of sign language words and phrases using user-friendly and noninvasive armbands is feasible and desirable. This work provides an analysis and implementation of including fingerspelling recognition (FR) in such systems, which is a much harder problem due to lack of distinctive hand movements. A novel algorithm called DyFAV (Dynamic Feature Selection and Voting) is proposed for this purpose that exploits the fact that fingerspelling has a finite corpus (26 alphabets for the American Sign Language (ASL)). Detailed analysis of the algorithm used as well as comparisons with other traditional machine-learning algorithms is provided. The system uses an independent multiple-agent voting approach to identify letters with high accuracy. The independent voting of the agents ensures that the algorithm is highly parallelizable and thus recognition times can be kept low to suit real-time mobile applications. A thorough explanation and analysis is presented on results obtained on the ASL alphabet corpus for nine people with limited training. An average recognition accuracy of 95.36% is reported and compared with recognition results from other machine-learning techniques. This result is extended by including six additional validation users with data collected under similar settings as the previous dataset. Furthermore, a feature selection schema using a subset of the sensors is proposed and the results are evaluated. The mobile, noninvasive, and real-time nature of the technology is demonstrated by evaluating performance on various types of Android phones and remote server configurations. A brief discussion of the user interface is provided along with guidelines for best practices.

Influence of remote earth and impulse polarity on earthing systems by field measurement

There has been a vast vacuum in the literature on the importance of the location of remote earth carried out during impulse test on grounding systems using field measurements. Some published work show that the remote earth is installed surrounding the electrode under tests, whilst some have used separate remote earth, away from it. This work studies the impact of return electrode location on transient behaviour of the earthing electrode. The electrode under test is a single rod. Two types of remote earth configurations are used, a circular electrode with multiple rods surrounding the single rod, and one that is 80 m away from it. Impulse tests are conducted under both impulse polarities. Voltage and current traces are captured for a single rod, using two different types of remote earth configurations, with the impulse resistance measured as well. It has been established that the arrangement of the remote earth poses no influence on the test results. That said, higher oscillations of current traces and higher resistance values have been observed in negative impulse in comparison with positive impulse polarities.

Colour gamut enhancement with remote light conversion mechanism

The backlight unit spectrum of liquid crystal displays (LCD) directly affects the colour gamut. With the invention of GaN based blue light emitting diodes (LED), phosphors and quantum dots (QD) have gained considerable scientific interest due to their broad range of applications especially in lighting and display technologies. These phosphors and QDs are used to convert the blue light of the LEDs into white in general lighting. On the other hand, in display systems, they are used to generate red and green bands. There are different application methods such as on-chip and remote configurations. In this study, we concentrate on remote phosphor and QD backlight configurations where the light conversion is done away from the chips. In our display designs, we used GaN based blue LED lateral chips as an excitation source, on the other hand, light conversion layers were placed in backlight units as a thin film for the emission of green and red bands. The mixing ratios of these composite layers were arranged to match the emission spectrum of the blue LEDs and the light conversion layer to the colour filters of the LCD, so that the green, blue, and red bands efficiently widens the colour space. The results were also compared with the on-chip phosphor arrangements.

(Invited) Spectrally Narrow Quantum Dots and Red Phosphor in White LEDs for Display Applications

The total available market size for high color gamut in display applications including TVs, smart phones, and tablets is rapidly growing and expected to exceed $1 billion by 2020. It is highly desirable to use quantum dots (QD), with narrow emission line widths, and narrow band red phosphors (e.g., SLA) materials to achieve high color gamut. An on-chip converter application is preferred over remote configurations because this provides lower cost and lower complexity for LED use in all sizes of displays. We discuss development of on-chip QD LEDs and narrow band phosphor LED solutions for display applications.

Optical enhancement of phosphor-converted wLEDs using glass beads

YAG:Ce3+ is a yellow-source compound commonly used in phosphor conversion layers for direct coating or remote phosphor configurations in LED illumination. This material, however, suffers from a high correlated color temperature, and low color-rendering index due to its deficiency in the red spectrum. In this study, glass beads (GB) with an average particle diameter of 10 μm were introduced to the conversion layer of a YAG:Ce3+ particulate-filled polydimethylsiloxane matrix composite structure and found to improve the optical features of the resulting composite.

Special issue on Big Data Security and Intelligent Data in Clouds (BDS‐IDC)

Special issue on Big Data Security and Intelligent Data in Clouds (<scp>BDS‐IDC</scp>)

Adaptive human detection approach using FPGA‐based parallel architecture in reconfigurable hardware

SummaryCurrently, the rapid increment of human detections has been changing people's daily life, However, the implementation is still facing the challenges caused by the restrictions of power and hardware. The computation process results in a heavy workload even though prior researches had made efforts to reduce the complexity. We focus on this issue and propose a new approach that employs the binarization‐based optimization algorithm to simplify the computation processes. Our approach is designed to minimize the necessary calculations and memory space. Moreover, we have developed the field‐programmable gate array‐based parallel architecture to apply partial dynamic reconfiguration, which enables the remote configurations for the number of processing units. An experimental evaluation is completed in order to examine our proposed approach. According to our experimental results, the detection precision can reach a miss rate less than 1.97% and a false positive rate of 1%. The energy cost is also reduced up to 36% comparing with the prior methods. Copyright © 2016 John Wiley &amp; Sons, Ltd.

Sweetie: Lightweight Web Authoring Environment

We have developed Simple Web Editor Utilities (Sweetie), a simple lightweight web editor that is suitable for collaborative website authoring. In general, a syntax-highlighting editor helps learners notice mistakes. However, most computer systems in classrooms prohibit installing software. This may reduce the usability and efficiency of the exercise. To solve these issues, we have developed a web editor application that provides syntax highlighting, auto-indent and quick file/image upload functions. We have examined Sweetie in lectures using both local and remote server configurations. We have confirmed that Sweetie can reduce the problems associated with web authoring, particularly for novice learners.