Search

This paper deals with the experimental investigation of hygrothermal behavior of wooden-frame building envelope. The experiment was based on in-situ monitoring of a full size experimental monozone house built at the University of Lorraine. Variations in temperature and relative humidity inside and outside the envelope were logged simultaneously with local meteorological data. Results showed the high coupling between temperature and relative humidity variations within the envelope materials. An overall hygrothermal response of the wall highlighted an interesting hygrothermal dynamic behavior of the envelope which may contribute to mitigate variations of relative humidity inside the building. Nevertheless, relative humidity evolves within a range of values ​​that can lead to mold growth at a certain position which may alter wooden envelope life.

A sender commissions a study to persuade a receiver, but influences the report with some probability. We show that increasing this probability can benefit the receiver and can lead to a discontinuous drop in the sender’s payoffs. We also examine a public-persuasion setting, where we observe the report’s susceptibility to influence restricts the amount of information the sender can provide. To derive our results, we geometrically characterize the sender’s highest equilibrium payoff, which is based on the concave envelope of her capped value function.

Icing is one of the main external environmental factors that causes aircraft to lose control. The flight safety assurance system under icing condition is particularly important. However, most of the systems do not consider the coupling characteristics of aerodynamics and flight dynamics of icing aircraft. This will affect the accuracy of the calculation results. Besides, the icing risk management system helps the pilot to realize the possible dangers in advance and perform correct maneuvers, based on quantitative assessment and visualization methods of flight risk. The envelope protection system realizes flight safety guarantee based on the real-time boundary protection method of key flight parameters. Finally, based on distributed simulation technology, a flight simulator was used as a platform to integrate the icing risk management system and envelope protection system to realize man-in-the-loop simulation. Two fictional but historically motivated icing scenarios are designed to test the system, and the results demonstrate that the icing risk management and protection system would be useful for aviation safety and can also be used for pilot training and reproducing flight accidents to find the causes.

The global population is growing exponentially with a trend of people moving to cities, resulting in rapid growth in the urban built environment. It is critical for urban planners to promote health, comfort, and resiliency in urban areas through integrated solar access requirements within zoning regulations. This paper evaluates the potential for the Solar Envelope Zoning (SEZ) method as a zoning tool in Toronto, Canada. The SEZ method is compared with current zoning regulations and mid-rise buildings guidelines using parametric modelling to establish the solar envelope on a typical building site. The resulting development density and solar radiation incident on adjacent building facades is evaluated. A similar study is performed on a site that is currently proposed for development along one of Toronto’s main avenues. The results show that by redefining solar access requirements to include climate dependent variables, SEZ can provide competitive development density while improving solar access.

In order to have an immediate impact on building energy-related emissions, existing buildings need to be addressed. To inform policy and technical decisions, detailed mathematical models are required which can explore numerous building retrofit solutions and their energy and emissions performance . This paper describes the adaptation of a hybrid statistical and engineering-based model for residential building stock in Canada to analyze community-scale energy retrofits . The modelling domain includes both envelope and mechanical retrofits, as well as district renewable energy systems. This model is then applied to a case study of converting a community of fifty 1980’s vintage single-detached homes to achieve net-zero energy. The case study demonstrated that deep envelope retrofits and fuel switching from natural gas to electric heat pump systems reduce community energy demand by 69%. Saturating available roof area with photovoltaics was able to achieve net-zero balance. By considering net-zero at the community-scale, individual buildings that did not achieve net-zero were offset by net-exporting neighbours. Annual community emissions of the retrofit reduced emissions by 95%. The analysis also highlights the significant impact on electrical infrastructure due to solar generation and energy demand mismatch.

Traditional multiframe Track-Before-Detect (TBD) may incur adverse integration loss resulting from model mismatch in sensor coordinates. Its suboptimal integration strategy may cause target envelope degradation. To address these issues, a pseudo-spectrum-based multiframe TBD in mixed coordinates is proposed firstly. The data search for energy integration is conducted based on an accurate model in the x - y plane while target energy is integrated based on pseudo-spectrum in sensor coordinates. The algorithm performance is improved since the model mismatch is eliminated, and the pseudo-spectrum based integration facilitates well maintained target envelope. The detailed multiframe integration procedure and theoretical target integrated envelope are derived. Secondly, to cope with the unknown target velocity, a velocity filter bank based on pseudo-spectrum in mixed coordinates is proposed. The effect of velocity mismatch on algorithm performance is analyzed and an efficient method for filter bank design is presented. Thirdly, a parameter estimation method using characteristics of integrated envelope is presented for improved target polar position and Cartesian velocity estimation. Finally, numerical results are provided to demonstrate the effectiveness of the proposed method.

Considering the strong nonlinearity of Unmanned Aerial Vehicles (UAVs) resulting from high Angle of Attack (AoA) and fast maneuvering, we present a multi-model predictive control strategy for UAV maneuvering, which has a small amount of online calculation. Firstly, we divide the maneuver envelope of UAV into several sub-regions on the basis of the gap metric theory. A novel algorithm is then developed to determine the ploytopic model for each sub-region. According to this, a Robust Model Predictive Control based on the Idea of Comprehensive optimization (ICE-RMPC) is proposed. The control law is designed offline and optimized online to reduce the computational expense. Then, the ICE-RMPC method is applied to design the controllers of sub-regions. In addition, to guarantee the stability of whole closed-loop system, a multi-model switching control strategy based on guardian maps is put forward. Finally, the tracking performance of proposed control strategy is demonstrated by an illustrative example.

Reducing uplift payments has been a challenging problem for most wholesale markets in the U.S. The main difficulty comes from the discrete decision-making and non- linear objective function in the unit commitment (UC) problem. Recently, the convex hull pricing approach has shown promises to reduce the uplift payments, in which efficient algorithms are available when i) the convex hull description for each unit and ii) the convex envelope for the objective function are available. Following this framework, in this paper, we provide network-flow-based compact extended formulations for each UC considering ramping constraints, different initial statuses, and maximum start-up restrictions. Meanwhile, by using a piece-wise linear approximation of a quadratic cost curve in the objective function, we show that the corresponding piece-wise linear convex envelope converges to the quadratic envelope as the number of pieces increases in the convex hull pricing problem. The final computational experiments on a revised IEEE 118-bus system indicates the effectiveness of the proposed approach. The trade-off between the cost-saving and computational time improvement is also reported as a reference for further usage.

To achieve the stringent three-axis stability performance, a non-contact satellite framework composed of the payload module and bus module is designed and an embedded second-order noise estimator based controller is proposed in this paper. For the payload module, the embedded second-order noise estimator is developed to envelope the nonlinear three-axis coupling terms, and the stringent attitude control is implemented by adopting the non-contact Lorentz actuators. For the bus module, a collision avoidance controller is adopted to maintain the relative motion between the payload module and bus module. The hardware experiments based on air-bearing platform have been conducted to verify the feasibility and effectiveness of the proposed approach, and the results show that the new methods have superior and reliable performance with low computational cost.

Harnessing flexibility from distributed energy resources (DER) to participate in various markets while accounting for relevant technical and commercial constraints is essential for the development of low-carbon grids. However, there is no clear definition or even description of the salient features of aggregated DER flexibility, including its steady-state and dynamic features and how these are impacted by network constraints and market requirements. This paper proposes a comprehensive DER flexibility modelling and characterisation framework that is based on the concept of nodal operating envelope (NOE). In particular, capacity, ramp, duration and cost are identified as key flexibility metrics and associated with different but consistent NOEs describing capability, feasibility, ramp, duration, economic, technical and commercial flexibility features. These NOEs, which conceptually arise from a Venn diagram, can be built via optimal power flow (OPF) analysis, visualised in the active-reactive power space, and used by different stakeholders. Results from a canonical test system and a real distribution system illustrate the value and applicability of the proposed framework to model and characterise provision of flexibility and market services from DER for different use cases.

A load-based testing methodology has recently been developed for laboratory testing of residential cooling equipment with its integrated controls that employs a model to emulate building dynamics and their interaction with equipment controls. This approach is part of a new performance rating standard that utilizes a bin method to estimate a seasonal energy efficiency (CSA EXP-07, 2019; Cheng et al., 2021). However, a “holy grail” for future equipment performance rating is to be able to map equipment performance using load-based testing results and then implement the map as a "model" in building energy simulations to generate seasonal performance ratings that are specific to various building and climate types. With this goal in mind, this paper presents a performance mapping methodology that incorporates a “gray-box” model structure that uses inputs that are consistent with building energy simulation programs (sensible cooling load and equipment inlet conditions) and outputs key performance metrics (total sensible and latent cooling rates, power consumption, and COP). A strategy and a test matrix for training the model with a relatively small number of testing points were established by developing a successive optimization approach to identify the best 12 test conditions to apply for training from a larger set of available data. In order to develop, demonstrate, and validate the modeling and training approach, load-based laboratory testing was set up within psychrometric chambers and testing was performed to generate 39 quasi-steady-state data points over a range of loads and boundary conditions with a test unit operating with its normal integrated controls. The best model trained using the optimal training subset of 12 data points was able to represent the equipment performance across the operating envelope within ± 10 % .

Purpose A harvesting robot is developed as part of kiwifruit industry automation in New Zealand. This kiwifruit harvester is currently not economically viable, as it drops and damages too many kiwifruit in the harvesting task due to the positional inaccuracy of the gripper. This is due to the difficulties in measuring the exact effective dimensions of the gripper from the manipulator. The purpose of this study is to obtain the effective gripper dimensions using kinematic calibration procedures. Design/methodology/approach A setup of a constraint plate with a dial gauge is proposed to acquire the calibration data. The constraint plate is positioned above the robot. The data is obtained by using a dial gauge and a permanent marker. The effective dimensions of the gripper are used as error parameters in the calibration process. Calibration is exercised by minimizing the difference between target positions and measured positions iteratively. Findings The robot with the obtained effective dimensions is tested in the field. It is found that the fruit drops due to positional inaccuracy of the gripper are greatly reduced after calibration. Practical implications The kiwifruit industry in New Zealand is growing rapidly and announced plans in 2017 to double global sales by 2025. This growth will put extra pressure on the labour supply for harvesting. Furthermore, the Covid pandemic and resulting border restrictions have dramatically reduced seasonal imported labour availability. A robotic system is a potential solution to address the labour shortages for harvesting kiwifruit. Originality/value For kiwifruit harvesting, the picking envelope is well above the robot; the experimental data points obtained by placing a constraint plate above the robot are at similar positions to the target positions of kiwifruit. Using this set of data points for calibration yields a good effect of obtaining the effective dimension of the gripper, which reduces the positional inaccuracy as shown in the field test results.

Mechanical rotating components such as bearing and gear are widely used in various industrial occasions. Fault diagnosis of rotating component can guarantee operational reliability and reduce maintenance cost of system. Although many fault diagnosis methods have been developed based on artificial intelligence methods, most of them ignore the existing signal processing knowledge in rotating element fault diagnosis domain. Meanwhile, these methods just assume that working conditions such as load or rotating speed keep constant, which may cause low accuracy once operating condition changes. To address these problems, an enhanced intelligent fault diagnosis method for rotating component is proposed based on multifeature and convolutional neural network (CNN). The vibration signals are first transformed into angular domain by resampling technique. Then, the angular domain signals are converted to obtain corresponding envelope and squared envelope spectrum features, which are fused into red–green–blue color image form to enhance sample features and enlarge differences among various health states. Finally, a CNN is constructed to accomplish fault recognition. Experimental results show that the average diagnosis accuracies of planetary gearbox and rolling element bearing datasets can reach 96.7% and 95.65%, which demonstrate that the multifeature approach is effective in fault diagnosis of rotating components in scenarios with different rotating speeds.

In the energy generation business steam powered turbo-generators still play an important role in electrical power generation all over the world. Every facility using steam turbines considers them as the critical machinery. Such machines should be well-maintained, properly handled, and precisely diagnosed in order to achieve the best performance and safety. The most valued data about the technical health are collected during machine’s shut-downs and run-ups. These data are more than seldom and hard to assess without expert’s knowledge with strong theoretical background and experience. Main novelty of the paper is the automated method for novelty detection of machine’s vibration. Most proposed methods apply to smaller machines with rolling bearings, whereas we propose the method for large machines with sliding bearings, which have much different behavior. The application of the method is support of the plant maintenance staff to evaluate deviations of turbo-sets from a healthy state based on the concept which we called the Operating Envelope. The envelope is created based on the data from a vibration sensor during the transient state. In this paper we consider a single vibration sensor and only the first harmonic amplitude of this signal. To set the acceptance limits within which turbo-set’s dynamic response will be considered as acceptable, we used the cubic spline interpolation coupled with expert judgement. Beyond these limits the state of the turbo-set is considered as unhealthy, so it is an automated fault detection method. In such a case a machine should be a subject to further and deeper diagnostic analysis. The method was validated on the data from the 13K242 type (a 200 MW class turbine) steam turbine. We also proposed a set of parameters to evaluate the severity of malfunction.

Digital sensors use biotechnology and information processing technology to strengthen the processing of relevant visual and auditory information, which is helpful to ensure that the receiver can obtain more accurate information, so as to improve the learning effect and reduce the impact on the environment. This paper designs an experiment to explore the role of digital sensors in language audio-visual teaching, which provides a reference for the application of digital sensors in the future. The impulse response function in sensor technology is introduced. The speech time domain envelope and time-varying mouth area of the sensor device are calculated. The auditory attention transfer detection based on line of sight rotation estimation is carried out through the auditory attention decoding fusion technology and the sensor auditory attention conversion detection method. At the same time, the characteristic of sensor heog signal is analyzed. The results show that the algorithm proposed in this paper has good results.

The use of mechanical metamaterials in engineering applications is often limited because of uncertainty regarding their deformation behavior. This uncertainty necessitates large safety factors and assumptions about their behavior to be included in mechanical designs including metamaterials, which detracts from their greatest benefit, viz. their ultralight weight. In this study, a yield envelope was created for both a bending-dominated and a stretching-dominated cellular material topology to improve the understanding of the response of cellular materials under various load types and orientations. Experimental studies revealed that the shear strength of a cellular material is significantly lower than that predicted by Mohr’s criterion, necessitating a modification of the Mohr’s yield criterion for cellular materials. All topologies experienced tension–compression anisotropy and topology orientation anisotropy during loading, with the stretching-dominated topology experiencing the largest anisotropies.

This research consists in diagnosing the hygrothermal imbalance problem inside tourism buildings located at the edge of the Mediterranean Sea. In particular, we study the case of Ben M’Hidi tourism development area in Skikda coastline in Algeria. The southern room of "Royal Tulip" hotel was chosen as object of this study in order to investigate its internal hygrothermal behavior. Our study uses the problem-based approach for generating biomimetic architectural concepts that help to develop a meteorosensitive room’s envelope depending on hygrothermic local conditions. Our proposed biomimetic design was inspired by the hygro-adaptive mechanism of the so-called endemic plant "Silene Amphorina". The focus of this paper is to compare the hygrothermal efficiency of the biomimetic envelope versus the real room’s envelope. For this purpose, hygrothermal simulations were performed using the WUFI Plus® software. Our results show that the biomimetic hygrothermal behavior is more adapted than the real one. It has regulated the ambient temperature and it has reduced the internal humidity rate by around 20% in summer, 23% in mid-season and 35% in winter, which will enhance the internal hygrothermal comfort and ensuring the sustainability of the tourism building. In future works, we will be able to propose meteorosensitive envelope responses based on these results.

Echocardiographic evaluation of mitral valve gradients after percutaneous mitral valve repair is pivotal for decision making and double envelope spectral Doppler is a real challenge in this setting. The case in this E-Challenge presents a hydraulic explanation behind this phenomenon, providing a practical approach when it occurs during the procedure.

PurposeThe two main contributing factors that control the overall buildings’ energy performance are the heating ventilation and air conditioning (HVAC) system and the envelope design. Environmental design guidelines that consider these two factors aim to lower energy consumption. However, they are regional and climate-sensitive. This study aims to investigate how three main buildings’ envelope design variables (orientation, compactness and window to wall ratio) impact the overall building’s energy consumption within Kuwait’s regional and climate conditions.Design/methodology/approachThis study simulate the energy consumption of typically shaped buildings by varying their geometry between a square to a rectangular floor plan. This study analyse the associated energy usage and provide early-stage envelope design guidance specific to the country’s conditions, to make informed decisions towards environmentally conscious buildings.FindingsThe analysed envelope variables have the potential to reduce energy consumption by 40%, and the possibility to reduce HVAC system capacity by 30%. In contrast to the general guidance in literature and standards, the simulation results demonstrate that less compact building forms perform on occasions better than the most compact ones.Originality/valueThe objective of this paper is to quantify the energy consumption rates for buildings located within the Arabian Peninsula, an under-studied region with potentially high interest considering three main envelope design variables. The buildings’ yearly energy consumption patterns are unique and suggest different envelope design considerations, compared to other regions with different climate conditions. This emphasises the importance of regional guidelines for the different factors associated with energy and buildings’ environmental performance.

Recent development in research and practice for curved cross-laminated timber (CLT) opens up novel and interesting possibilities for applications of slender surface-active shell structures in architecture. Such typologies provide advantageous structural behaviour allowing for efficient and lightweight structures while simultaneously determine the envelope and space of a building. The high degree of prefabrication combined with a sustainable and renewable building material makes CLT an ecological and economic solution for future construction. This paper presents the design development and construction of the Urbach Tower for the Remstal Gartenschau 2019: a structure made from high curvature CLT components on a building scale. This research contribution illustrates a sophisticated integrative design to construction process emphasizing computational and structural design, fabrication and detailing for curved timber components in complex spatial structures. The authors further explore the structural potential of self-shaped curved CLT investigating the influence of curvature radius on the load-bearing behaviour of the tower structure. The Urbach Tower translates these technical developments into practice arising at the intersection of digital innovation and scientific research.

The aircraft weight and balance problem (WBP) defined in terms of selecting unit load devices (ULDs) from an available set and allocating them to specified positions in cargo holds. It is critical to aircraft safety as well as operational efficiency and profit. It is an NP‐hard problem combining characteristics of the knapsack problem and generalized assignment problems, as well as complex practical constraints. A mixed integer programming model is constructed to maximize the total payload and minimize the center of gravity (CG) deviation by considering the constraints of positions, weights, balance etc. In contrast to prior studies using a constant delta to limit CG deviation, a new set of CG envelope constraints is proposed based on the variation in actual CG under different statuses and precise describing CG. A linearizing strategy is further designed to simplify the nonlinear CG envelope constraints. The proposed model can be solved using commercial optimization software within a few seconds and maintain the CG within the designated CG envelope in all test instances; in contrast, the other (CG deviation‐based) method may result in flight hazards in some scenarios.

Synthesis of a flight control system for such an aircraft that achieves stable and acceptable performance across a specified flying envelope in the presence of uncertainties represents an attractive and challenging design problem. This study uses the genetic self-tuning PID algorithm to develop an intelligent flight control system for the aerosonde UAV model. To improve the system's transient responses, the gains of the PID controller are improved using a genetic algorithm (GA). Simulink/MATLAB software is used to model and simulate the proposed system. The proposed PID controller integrated with the GA is compared with the classical one. Three simulation scenarios are carried out. In the first scenario, and at normal conditions, the proposed controller performance is better than the classical one. While in the second scenario, identical results are achieved from both controllers. Finally, in the third scenario, the PID controller with GA shows the robustness and durability of the system compared with the classical PID in presence of external wind disturbance. The simulation results prove the system parameters optimization.

Human foot traffic in urban environments provides essential information for city planners to manage the urban resources and urban residents to plan their activities. Compared to camera or mobile-based solutions, seismic sensors detect human footstep signals with fewer privacy concerns. However, seismic sensors often record signals generated from multiple sources, particularly in an urban outdoor environment. In this article, we monitor people’s running activities during COVID-19 pandemic with a seismic sensor in a park in Singapore. We compare the spectra of natural and urban events in the recorded seismic data. For each 3 s seismic data, we define hierarchical screening criteria to identify footsteps based on the spectrum of the signal and its envelope. We derive the cadence of each runner by detecting the primary frequency of the footstep signals. The resulting algorithm achieves higher accuracy and higher temporal resolution for weak and overlapping signals compared to existing methods. Runner statistics based on four-month long seismic data show that urban running activities have clear daily and weekly cycles. Lockdown measures to mitigate COVID-19 pandemic promoted running activities, particularly over the weekends. Cadence statistics show that morning runners have higher cadence on average.

In plays which deal with individual and collective pain, it is primarily the omnipresence of a trivial body which is disturbing. That of a performer, author and director of creations which are close to the performance. This envelope of flesh and blood that has become unbearable, has suffered exhaustion and self mutilation and secretes repugnant substances all over the boards. A tool or a medium of this aesthetic violence, this impulsive animalistic body can follow either a spiritual or sacred path. As a figure of martyr or redemption, the body is given, sacrificed in a ritual with every performance. The Atra Bilis company presents to us a highly political drama where the body reveals our relationship with Society and concretizes our refusal of established conventions.

Purpose Listeners shift their listening strategies between lower level acoustic information and higher level semantic information to prioritize maximum speech intelligibility in challenging listening conditions. Although increasing task demands via acoustic degradation modulates lexical-semantic processing, the neural mechanisms underlying different listening strategies are unclear. The current study examined the extent to which encoding of lower level acoustic cues is modulated by task demand and associations with lexical-semantic processes. Method Electroencephalography was acquired while participants listened to sentences in the presence of four-talker babble that contained either higher or lower probability final words. Task difficulty was modulated by time available to process responses. Cortical tracking of speech—neural correlates of acoustic temporal envelope processing—were estimated using temporal response functions. Results Task difficulty did not affect cortical tracking of temporal envelope of speech under challenging listening conditions. Neural indices of lexical-semantic processing (N400 amplitudes) were larger with increased task difficulty. No correlations were observed between the cortical tracking of temporal envelope of speech and lexical-semantic processes, even after controlling for the effect of individualized signal-to-noise ratios. Conclusions Cortical tracking of the temporal envelope of speech and semantic processing are differentially influenced by task difficulty. While increased task demands modulated higher level semantic processing, cortical tracking of the temporal envelope of speech may be influenced by task difficulty primarily when the demand is manipulated in terms of acoustic properties of the stimulus, consistent with an emerging perspective in speech perception.

Sensitivities for Stochastic Optimization

A growing attention has been paid to building envelope features for achieving lower energy consumption especially in large office buildings and hot climate zones, since these features and their variables are affecting energy consumption widely and with different sensitivity. Therefore, this paper conducts simulation-based comparative analyses between main envelope features with their internal variables; the selected features for this study are building geometry ratios, orientations and common envelope finishing materials (FMs). Two applications have been conducted (comparing cases with either a same or different building volumes), and more than 500 cases/simulations have been conducted and studied in total. Accordingly, sensitive features and variables have been determined to enrich design decisions for different cases, along with best variables' integrations that achieve best energy consumption through the proposed applications and cases. Cubic office buildings in Egypt have been used to demonstrate the study, and energy simulations have been achieved using eQuest (DOE-2). Results show that lower height with wider roof achieves best energy consumption if building volume is fixed via comparisons, and vice versa. Gravel and galvanized steel represent best studied roof and walls' FMs, while roofing shingles is the worst one. If building volume is varied via comparisons, horizontal dimensions are the most sensitive feature that affects energy consumption per m2, while FMs and height represent lowest sensitivity among studied features. Ranking of cases, features, variables along with sensitive features in details have been analyzed and discussed through the paper.

This paper introduces a new, preliminary physical ergonomics model for spacecraft cabin and cockpit architecture and for control systems layout conceptualization. The research was executed during a year-long collaboration between the Florida Institute of Technology's Human Spaceflight Laboratory and Embry-Riddle Aeronautical University's Spacesuit Utilization of Innovative Technology Laboratory. It focused on physical ergonomics using an adjustable intravehicular activity Terra Spacesuit manufactured by Final Frontier Design (FFD). The main goal of this laboratory research was to generate an FFD spacesuit specific reference model of reach envelope. The model provides concrete numerical data about potential spaceflight participants' or astronauts' upper body motion, which can be used to improve spacecraft interior design. The reach envelope was mapped using an IR motion tracking system in unsuited, suited unpressurized, and suited pressurized configurations. The resulting model is presented as a geometric area accessible to all test subjects participating in this research. Although this experimental model is based on training spacesuit hardware and operated under lower (1.5 psid) than usual (3.5 psid) operating pressure, it demonstrates the physical ergonomic limitations of wearing an Intra Vehicular Activity pressurized suit. This model further helps spacecraft cabin, flight deck or cockpit architects to identify the optimum internal layout of the vehicle, placement of the control and display components. Control function activation during specific phases of the spaceflight may require either unpressurized or pressurized spacesuit operations. The accessibility of the control input systems is the primary factor in their placement inside the cockpit. More importantly, the vehicle controls, system input devices, and displays should be not only within reach, but also within an executable/operational position and configuration, or work envelope.

The MAP approach provides a way to analyze the steady-state handling behavior of road/race cars. It is completely general, in the sense that is can be employed for any real car, and for any mathematical model as well. Two concepts play a central role in MAP: the achievable region, that is the totality of the achievable trim conditions for a given vehicle, and the level (handling) curves inside the achievable region, to highlight the vehicle peculiar features. The envelope of level curves is often a good practical way to obtain the achievable regions.

Increasing traffic and speeds on passenger rail lines, and a short season for maintenance work, have motivated the industry to find new methods to assess the condition of existing infrastructure and determine where upgrades are required. In this study, acceleration data from the car body and axle boxes of a revenue car over 92 km of a Canadian passenger rail route in Ontario were collected for two purposes: first, to apply weighted filtering method according to ISO 2631-1997 standard as a technique to determine the locations which highly impact the ride quality and to investigate the effect of type of track features and speed on the ride quality; second, a new analytical method called the envelope of acceleration was applied to use the recorded accelerations to evaluate the alignment and surface roughness along the track. Since the alignment and surface roughness values are always positive and are calculated over a specified length (e.g. 9.5 m, 18.9 m, 38 m) an envelope technique was employed which uses spline interpolations over local maxima of the absolute magnitude of accelerations at every separated n samples corresponding to best fit with track roughness. The regression analysis between the envelope of accelerations and alignment and surface roughness presented a meaningful correlation and showed the applied method is a promising analytical technique to indicate rough sections of the track. The limitations to the application of envelope of acceleration are also discussed.

Several methods have been developed in biomedical signal processing to extract the envelope and features of electromyography (EMG) signals and predict human motion. Also, efforts were made to use this information to improve the interaction of a human body and artificial protheses. The main operations here are envelope acquiring, artifacts filtering, estimate smoothing, EMG value standardizing, feature classifying, and motion recognizing. In this paper, we employ EMG data to extract the envelope with a highest Gaussianity using the rectified signal, where we deal with the absolute EMG signals so that all values become positive. First, we remove artifacts from EMG data by using filters such as the Kalman filter (KF), H1 filter, unbiased finite impulse response (UFIR) filter, and the cKF, cH1 filter, and cUFIR filter modified for colored measurement noise. Next, we standardize the EMG envelope and improve the Gaussianity. Finally, we extract the EMG signal features to provide an accurate prediction.

All convex polygons whose envelopes of all area or perimeter-bisecting lines, their area or perimeter-bisecting deltoids, are tri-cusped and tri-concave-out (segment-free) closed curves were classified by the authors in a recent article. The present paper computes the area of each envelope as a fraction of the area of its corresponding polygon, thereby generalizing the formulas obtained for triangles by a group of students led by John Conway for the area-bisecting deltoid, and by the authors for the perimeter-bisecting deltoid.

The Mach number, angle of attack and altitude of operation for an interceptor vary widely during the course of its trajectory. As a result, the interceptor Center of Pressure (CP) locations move significantly around a given Center of Gravity (CG) location at these operating conditions. This results in an inevitable variation in aerodynamic static stability leading to stable and unstable operating regions. In order to ensure good speed of response during the interceptor homing phase, lesser static stability is desirable. Hence the requirement to handle aerodynamic instability at some other operating conditions in the interceptor envelope become inevitable. Since flexibility has a strong bearing on autopilot design, it becomes necessary to control unstable operating points in the presence of flexibility modes. Despite the static stability variation, aerodynamic design can control the level of maximum instability of the configuration. Hence the maximum static instability the autopilot can handle has to be specified for aerodynamic configuration design. This paper brings out the limitations of autopilot design in controlling an unstable interceptor with low bending mode frequencies in terms of maximum instability the autopilot design can handle, which serves as an important input for aerodynamic design.

Despite the significant contribution of hearing assistive devices, medications, and surgery to restoring auditory periphery, a large number of people with hearing loss still struggle with understanding speech. This leads many studies on speech perception to move towards the central auditory functions by looking at associated brain activities using macroscopic recording tools such as electroencephalography (EEG). Up until a few years ago, however, limitation has been given to the brain scientists who attempted to investigate speech perception mechanisms using the EEG. In particular, short duration of speech segments has inevitably been used to elicit auditory evoked potential, even though they were too brief to be considered as speech. Today, however, advance in neural engineering and better understanding of neural mechanism have better facilitated brain scientists to perform studies with running stream of continuous speech and expand the scope of EEG studies to include comprehension of more realistic speech envelope. The purpose of this study is to review literatures on neural tracking to speech envelope to discuss it in Audiology perspective. This review article consists of seven subjects including introduction, neural tracking theories, neural tracking measure, signal processing & analysis, literature review on neural tracking associated with hearing loss, application of neural tracking to audiology, and conclusion. We noted that neural tracking has potential to be used in clinical sets to objectively evaluate speech comprehension for people with hearing loss in the future.

This text explores the birth of the science of ecology relating to the landscape architecture discipline and, through the lens of circular economy and recycling, urban agriculture and its most recent experiments concerning vertical farms. Agriculture, which has always been an integral part of the urban landscape, plays an ecological, social, cultural and aesthetic role in the sustainable growth of contemporary cities. With the development of vertical farms and new production technologies, urban agriculture is increasingly evolving towards new architectural experiments. In its final part, the text describes a building envelope, a patent developed by APS spin-off UNIRC, for vertical farms to be organised in unfinished buildings.

Textile electrodes are an alternative to conventional silver-chloride electrodes in wearable systems. Their easy integration in garments and comfort provided to the user make them an interesting development of textile engineering. The potential of such electrodes to allow more unobtrusive data collection in health and sports context may enable the development of biosensing garments to be used in biomechanics. However, proper validation of the recorded signals is paramount, and few studies have yet presented consistent methodologies for textile-based electromyographic recordings. This study presents the validation of the electrical and morphological properties of electromyographic signals recorded with textile electrode, in comparison to conventional silver-chloride electrodes. Results indicate that both sets of electrodes have identical signal-to-noise ratios, but with distinct impedance frequency responses. Electromyographic envelope morphologies are also identical, although textile electrodes usually have lower amplitudes., Los electrodos textiles son una alternativa a los electrodos de cloruro de plata convencionales en los sistemas portátiles. Su fácil integración en las vestimentas y la comodidad que brinda al usuario las convierten en un interesante desarrollo de la ingeniería textil. El potencial de tales electrodos para permitir una recopilación de datos más discreta en el contexto de la salud y el deporte puede permitir el desarrollo de vestimentas biosensibles para su uso en biomecánica. Sin embargo, la validación adecuada de los señales registradas es primordial y pocos estudios han presentado metodologías consistentes para registros electromiográficos basados en textiles. Este estudio presenta la validación de las propiedades eléctricas y morfológicas de señales electromiográficas registradas con electrodo textil, en comparación con electrodos convencionales de cloruro de plata. Los resultados indican que ambos los electrodos tienen relaciones señal-ruido idénticas, pero con una respuesta de frecuencia de impedancia distinta. La morfología de la envoltura electromiográfica también se identifica entre electrodos, aunque generalmente de menor amplitud en el electrodo textil., Eléctrodos têxteis são uma alternativa aos convencionais eléctrodos de cloreto de prata em sistemas vestiveis. A sua fácil integração em vestuário e o conforto que providenciam tornam-nos um interessante desenvolvimento da engenharia têxtil. O potencial destes eléctrodos para permitir a discreta recolha de dados em contexto de saúde e desporto poderá permitir o desenvolvimento de vestuário biossensivel com aplicação em biomecânica. No entanto, uma adequada validação dos sinais registados é fundamental, e poucos estudos apresentaram metodologias consistentes para registos electromiográficos baseados em elétrodos têxteis. Este estudo apresenta a validação das propriedades eléctricas e morfológicas de sinais electromiográficos registados com eléctrodos têxteis, em comparação com os convencionais eléctrodos de cloreto de prata. Os resultados indicam que ambos os eléctrodos apresentam razões sinal-ruído identicos, mas com uma resposta em frequência de impedância distincta. A morfologia do envelope electromiográfico é também identifca entre electrodos, ainda que geralmente de menor amplitude no eléctrodo têxtil.

Electrocardiography (ECG) signals play an important role in the cardiac disorder diagnosis and arrhythmia detection since they reflect all the electrical activities of the heart and include information about heart function and heart conditions. Due to the subtle alterations in the amplitude, duration and morphology of the ECG, the development of computer-based intelligent system in the arrhythmia diagnosis field is attractive in terms of the amount of data and the importance of the data it contains for the classification of heartbeats from different types of arrhythmias. In the present study we propose a novel technique for the automatic detection of cardiac arrhythmia with one-lead ECG signals based upon variational mode decomposition (VMD), Shannon energy envelope, phase space reconstruction (PSR) and deterministic learning theory. First, VMD is employed to decompose the ECG signals into different intrinsic modes, in which the first four intrinsic modes contain the majority of the ECG signals’ energy and are considered to be the predominant intrinsic modes. Second, Shannon energy is used to extract the characteristic envelope of predominant intrinsic modes. Third, phase space of the Shannon energy envelope (SEE) is reconstructed, in which properties associated with the nonlinear ECG characteristics are preserved. Three-dimensional (3D) phase space reconstruction (PSR) together with Euclidean distance (ED) has been utilized to derive features, which demonstrate significant difference in ECG system dynamics between normal versus abnormal individual heartbeats. Fourth, neural networks are then used to model, identify and classify ECG system dynamics between normal (healthy) and arrhythmic ECG signals based on deterministic learning theory. Finally, experiments are carried out on the MIT-BIH arrhythmia database to verify the effectiveness of the proposed method, in which 626 ECG signal fragments for one lead (MLII) from 28 persons of five classes of heartbeats were extracted. These five classes are normal sinus rhythm (NSR), premature ventricular contraction (PVC), paced beat (PB), left bundle branch block (LBBB), and right bundle branch block (RBBB). By using the 10-fold cross-validation style, the achieved average classification accuracy is reported to be 98.72 $$\%$$ . Experimental results verify the effectiveness of the proposed method and indicate that it has the potential to serve as a candidate for the automatic detection of myocardial dysfunction in the clinical application.

Uncertainty is an essential property of rock mechanics and engineering, which is of great significance to excavation, design, and control of rock engineering. In this study, an innovative framework of the reliability-based design was developed for the rock tunnel under uncertainty. The convergence-confinement method is used to characterize the interaction mechanism between the support structure and surrounding rock mass. Artificial bee colony (ABC) was adopted to solve the optimization problem in the reliability-based design. The probabilistic properties of rock strength and failure envelope were obtained based on the triaxial compression test data using the Bayesian method. The reliability of the tunnel and support structure was evaluated based on the abovementioned probabilistic properties of rock strength using the reliability analysis method. A circular tunnel was used to illustrate the developed framework, and the procedure was presented in detail. The time of rockbolt installed, the thickness of the shotcrete, length of rockbolt, circumferential space, and longitudinal space of rockbolt were determined and met the constraints of reliability index. Results show that the developed framework can consider the uncertainty for support design in the tunnel. It provides a good and promising way to support design considering the uncertainty of test data using the reliability-based design.

Compliant, nonrigid parts are widely used in many industries today. Existing variation simulation analysis on the manufacturing part focuses on orientation and position deviation with part shape errors being largely omitted. This is a valid approach for the rigid part, but it is unrealistic and can be problematic for the compliant part. In this study, a new methodology has been introduced to compliant assembly early phase design to generate various probable variated manufacturing parts that conform to predefined tolerance specification or meet the certain industrial requirement. The proposed method is based upon the novel idea of a parametric space envelope, a purpose-designed variation tool constructed from parametric curves. Variation of embedded manufacturing part is linked to and controlled by a compact set of envelope’s boundary control points. Part variation instances are generated by simulating the control points’ movement in a systematic and efficient way. Importantly, simulated variations can be visualized in 3-D virtual space to provide user insight into part variation. The proposed methodology can help identify assembly high-risk regions, select proper fixtures, guide assembly engineering changes, and optimize assembly operations. An industrial case study on a deformable vehicle door hinge plate is presented to illustrate the methodology. Note to Practitioners —This article is motivated by two acute problems encountered in geometric variation simulation analysis for compliant parts in the early design stage. First, form errors of the nonrigid part are not fully captured in existing methods. Second, variation visualization can significantly enhance understanding of the geometric variation effects, but it is difficult to achieve under existing approaches. Inspired by the idea of a parametric space envelope, this article proposes a new methodology by building a variation tool to aid the task. Under the proposal, the geometric variation of the compliant part is indirectly modeled through the constructed variation tool. This indirect modeling enables capturing intrapart interactions that are the major source of the inaccuracy of existing methods. The simulated geometric variation can be visualized through the variation tool. In addition, the developed method does not rely on historical manufacturing experience. This can be valuable for early stage designer when such production information is not available or expensive to get. Furthermore, the proposed method can be integrated into existing computer-aided design (CAD), computer-aided manufacturing (CAM), and computer-aided engineering (CAE) systems to improve overall design quality and reduce reliance on multiple physical prototyping.

Objectives To model the cost-effectiveness of the TYRX Absorbable Antibacterial Envelope when used in patients at increased risk of cardiac implantable electronic device (CIED) infection in the context of 3 European healthcare systems: Germany, Italy, and England. Methods A decision tree model with a lifetime horizon was populated using data from the Worldwide Randomized Antibiotic Envelope Infection Prevention Trial, a large multicenter randomized controlled trial. Use of the antibacterial envelope adjunctive to standard of care was compared to standard of care infection prevention alone. Patients in the model were divided into subgroups based on presence of factors known to increase infection risk. Results The antibacterial envelope had the most favorable cost-effectiveness profile when patients had previously experienced CIED infection, had a history of immunosuppressive therapy, or had a Prevention of Arrhythmia Device Infection Trial (PADIT) score indicating high risk of infection (scores ≥6) at cost-effectiveness thresholds of €50 000 in Germany (assumed in the absence of an official threshold), €40 000 in Italy, and £30 000 in England. Probabilistic sensitivity analysis indicated that the antibacterial envelope was likely to be cost-effective in patients with other risk factors (including replacement of high power CIEDs, generator replacement with lead modification, and PADIT scores indicating intermediate risk of infection) when used with some device types and in some countries. Conclusions The absorbable antibacterial envelope was associated with cost-effectiveness ratios below European benchmarks in selected patients at increased risk of infection, suggesting the envelope provides value for European healthcare systems by reducing CIED infections.

The problem of determining feasible maneuver envelope in multi-unmanned aerial vehicle (multi-UAV) formations is considered. In the leader–follower framework, an analysis is carried out relating th...

The growing demand for dependable manufacturing techniques has sped up research into condition monitoring and fault diagnosis of critical motor parts. On the other hand, in modern industry, machine maintenance is becoming increasingly necessary. An insufficient maintenance strategy can result in unnecessarily high downtime or accidental machine failure, resulting in significant financial and even human life losses. Downtime and repair costs rise as a result of failure. Furthermore, developing an online condition monitoring method may be one solution to come up for the problem. Early detection of faults is very vital since they grow quickly and can cause further problems to the motor. This paper proposes an effective strategy for the classification of broken rotor bars (BRBs) for induction motors (IMs) that uses a new approach based on Artificial Neural Network (ANN) and stator current envelope. The stator current envelope is extracted using the cubic spline interpolation process. This is based on the idea that the amplitude-modulated motor current signal can be revealed using the motor current envelope. The stator current envelope is used to select seven features, which will be used as input for the neural network. Five IM conditions were experimentally used in this study, including a part of BRB, 1 BRB, 2 BRBs and 3 BRBs. The new feature extraction and selection approach achieves a higher level of accuracy than the conventional method for motor fault classification, according to the experimental results. Indeed, the results are impressive, and it is capable of detecting the exact number of broken rotor bars under full load conditions, Растущий спрос на надежные технологии производства ускорил исследования в области мониторинга состояния и диагностики неисправностей критически важных деталей двигателя. С другой стороны, в современной промышленности все более необходимым становится техническое обслуживание машин. Недостаточная стратегия технического обслуживания может привести к неоправданно длительному простою или аварийному выходу машины из строя, что приведет к значительным финансовым и даже человеческим потерям. В результате неисправности увеличиваются простои и затраты на ремонт. Поэтому, одним из решений этой проблемы может быть разработка метода онлайн-мониторинга состояния. Раннее обнаружение неисправностей имеет большое значение, поскольку их количество быстро растет, что может вызвать дополнительные проблемы с двигателем. В данной статье предлагается эффективная стратегия классификации обрывов стержней ротора (ОСР) асинхронных двигателей (АД) с использованием нового подхода, основанного на искусственной нейронной сети (ИНС) и огибающей тока статора. Огибающая тока статора извлекается с помощью процесса интерполяции кубическими сплайнами. Он основан на идее, что с помощью огибающей тока двигателя можно выявить амплитудно-модулированный сигнал тока двигателя. Огибающая тока статора используется для выбора семи признаков, которые будут использоваться в качестве входных данных для нейронной сети. В исследовании экспериментально использованы пять состояний АД, которые включают обрыв части стержня ротора, обрыв 1 стержня ротора, обрыв 2 стержней ротора и обрыв 3 стержней ротора. Согласно результатам эксперимента, новый подход к выделению и выбору признаков обеспечивает более высокий уровень точности, чем обычный метод классификации неисправностей двигателя. Результаты действительно впечатляют, он способен определять точное количество обрывов стержней ротора в условиях полной нагрузки, Зростаючий попит на надійні технології виробництва прискорив дослідження в області моніторингу стану та діагностики несправностей критично важливих деталей двигуна. З іншого боку, в сучасній промисловості все більш необхідним стає технічне обслуговування машин. Недостатня стратегія технічного обслуговування може призвести до невиправдано тривалого простою або аварійного виходу машини з ладу, що призведе до значних фінансових і навіть людських втрат. В результаті несправності збільшуються простої і витрати на ремонт. Тому, одним з рішень цієї проблеми може бути розробка методу онлайн-моніторингу стану. Раннє виявлення несправностей має велике значення, оскільки їхня кількість швидко зростає, що може викликати додаткові проблеми з двигуном. У даній статті пропонується ефективна стратегія класифікації обривів стрижнів ротора (ОСР) асинхронних двигунів (АД) з використанням нового підходу, заснованого на штучній нейронній мережі (ШНМ) і обвідній струму статора. Обвідна струму статора вилучається за допомогою процесу інтерполяції кубічними сплайнами. Він заснований на ідеї, що за допомогою обвідної струму двигуна можна виявити амплітудно-модульований сигнал струму двигуна. Обвідна струму статора використовується для вибору семи ознак, які будуть використовуватися в якості вхідних даних для нейронної мережі. У дослідженні експериментально використані п'ять станів АД, які включають обрив частини стрижня ротора, обрив 1 стрижня ротора, обрив 2 стрижнів ротора і обрив 3 стрижнів ротора. Згідно з результатами експерименту, новий підхід до виділення і вибору ознак забезпечує більш високий рівень точності, ніж звичайний метод класифікації несправностей двигуна. Результати дійсно вражають, він здатний визначати точну кількість обривів стрижнів ротора в умовах повного навантаження

Purpose This paper aims to optimize the mass of a tethered aerostat to achieve optimum hull volume, and fins to generate aerodynamic lift to reduce the blow-by. Design/methodology/approach The design code of aerostat involving structure, aerostatics, aerodynamics and stability has been developed using MATLAB®. The design code is used to obtain the baseline configuration for a tactical aerostat mission by using the statistical values of the hull fineness ratio and the fin parameters of in-service aerostats. The effect of the design variables that include the hull fineness ratio, fin area and fin position on the aerostat mass and blow-by is determined through sensitivity analysis. The aerostat is optimized with an objective function of minimization of mass for the bounded values of design variables and taking blow-by limit as a constraint. Findings This study reveals that the simultaneous optimization of the aerostat hull fineness ratio, fin area and fin position results in an improvement in the design. The aerostat design with optimum values of these parameters helps in a reduction in its size and mass without compromising the blow-by limits. Research limitations/implications This study has been conducted by keeping the hull shape constant by selecting standard National Physics Laboratory envelope shape. The aerodynamic model used in the design code is based on empirical relationships that can be improved in future studies that can use high fidelity aerodynamic models using CFD based surrogate models. Originality/value The previous studies on optimization of aerostats are limited to hull envelope shape only, whereas this paper presents the optimization of the hull and fin together. The optimized configuration obtained has a reduced mass and can operate within the specified blow-by limits.

Student performance in classrooms is related to the indoor environmental quality. High air change rates are necessary to secure an acceptable level of indoor air quality and provide fresh air, which require large amounts of energy and technical installations. Mostly, mechanically supplied air is partially mixed with the return air. In warm climates, the capacity for natural ventilation is not fully exploited in modern buildings. During periods of acceptable outdoor temperatures, buildings need to adapt and employ available free renewable resources, such as wind. In this context, the building form, orientation, and envelope openings are crucial to enable an increased air change rate, user satisfaction, and energy savings. Owing to the difficulty of providing cross-ventilation in buildings with double-loaded corridors, single-sided ventilation is the most common approach. This study investigates the methods to improve the wind-driven air exchange of classrooms in warm climates, where naturally ventilated corridors help increase air movement. This study examines the potential of a set of alternatives within the context of a generic model regarding the pressure distribution, thermal sensation, air velocity, and air change rate. The study suggests that no single opening scenario can be applied to all façades at any time. Each façade requires special treatment. Decisions on natural ventilation need to be made during the early design stages for each façade. It was found that with the aid of low-tech modifications, remarkable increases in air change rates, in some cases up to 14.5 times that of the typical single-sided ventilation case, could be achieved.

PurposeA broad area of interest to our group is to understand the consequences of the “cue profile” (a measure of how well a listener can utilize audible temporal and/or spectral cues for listening scenarios in which a subset of cues is distorted. The study goal was to determine if listeners whose cue profile indicated that they primarily used temporal cues for recognition would respond differently to speech-envelope distortion than listeners who utilized both spectral and temporal cues.MethodTwenty-five adults with sensorineural hearing loss participated in the study. The listener's cue profile was measured by analyzing identification patterns for a set of synthetic syllables in which envelope rise time and formant transitions were varied. A linear discriminant analysis quantified the relative contributions of spectral and temporal cues to identification patterns. Low-context sentences in noise were processed with time compression, wide-dynamic range compression, or a combination of time compression and wide-dynamic range compression to create a range of speech-envelope distortions. An acoustic metric, a modified version of the Spectral Correlation Index, was calculated to quantify envelope distortion.ResultsA binomial generalized linear mixed-effects model indicated that envelope distortion, the cue profile, the interaction between envelope distortion and the cue profile, and the pure-tone average were significant predictors of sentence recognition.ConclusionsThe listeners with good perception of spectro-temporal contrasts were more resilient to the detrimental effects of envelope compression than listeners who used temporal cues to a greater extent. The cue profile may provide information about individual listening that can direct choice of hearing aid parameters, especially those parameters that affect the speech envelope.

Hobbing is one of the crucial gear manufacturing processes with high precision and high efficiency. In order to improve the accuracy of hobbing and hob relief grinding, more precise grinding wheels are demanded for relief grinding in the production of gear hobs. In this paper, a new and accurate mathematical method for calculating the axial profile of grinding wheel based on the corresponding gear hob to be ground is proposed. Considering that most researches have been conducted to focus on the optimization of hob geometric feature and only can be applied to a specific type of hand of helix and rake angle of gear hobs. The method in this paper can be served as a general algorithm for generating axial profile of grinding wheels on the basis of the spatial envelope theory, the principle of coordinate system transformation, and studies on normal profile of single-tooth. The accuracy of grinding hobs is based on applying the approach in practical manufacturing. Taking two typical different kinds of pre-grinding gear hobs as examples for calculation and experiment, the results of tooth profile errors strengthen the position that the validity and feasibility of this method, it can be employed for gear hob design and grinding processing.

Precision grinding is the key process to meet the heavy demands of large-aperture aspherical optical elements in the fields of laser nuclear fusion devices, large-aperture astronomical telescopes and high-resolution space cameras. In this study, the arc envelope grinding process of large-aperture aspherical optics was investigated using the CM1500 precision grinding machine with a maximum machinable diameter of Φ1500 mm. The analytical form error models of aspherical workpiece induced by wheel setting errors were established for both parallel grinding and cross grinding. Result show that the form error is much more sensitive to the wheel setting error along the feed direction than that along the lateral direction. It is a bilinear function of the feed-direction wheel setting error and the distance to optical axis. Based on the above analysis, a method to determine the wheel setting error is proposed. The grinding tests were then performed with the wheel accurately aligned. By using a newly proposed partial error compensation method with an appropriate compensation factor, a form error of 3.4 µm PV for a Φ400 mm elliptical K9 glass surface was achieved.

This article demonstrates how network analysis of qualitative content can be used to build on traditional research approaches to confirm and expand prior findings and to point to fruitful directions for future research. Drawing on mixed methods research on policies and practices that improve access to study abroad at U.S. higher education institutions, we demonstrate how network analysis, namely, quadratic assignment procedure and community detection, of qualitative content codes can enhance the explanatory power and generalizability of previous research. Our use of network analysis contributes an empirical example that validates, challenges, and deepens conversations surrounding network analysis in mixed methods research, all while pushing the envelope on how and when qualitative and quantitative data can and should be integrated.

Ethical journalism repudiates the practice of brown envelope solicitation or the acceptance of any form of gifts that might influence news sourcing, production and publication. The authors of the present study therefore revisited their earlier inquiry (2014) on brown envelope journalism practice in Kuwait to determine if the situation has changed or relatively remained the same. Results from the present study mirror the findings in the previous inquiry in the conceptualization of ethics by journalists in Kuwait, the use of part-time journalists in the country, the lack of measures by editors and supervisors to stamp out this form of journalism and discipline erring reporters, and the journalists’ view that it was up to individual reporters to accept or reject brown envelopes in the course of duty. The authors contend that primary responsibility to curtail this behaviour falls on editors and supervisors in media houses as well as the journalists themselves and their association. Survey and interview instruments were used in this study.

Northern building envelopes must provide efficient indoor-outdoor connections based on photobiological-psychological needs of occupants for positive relationships with the sub-Arctic nature, particularly daylighting and day/night cycles. Envelope configurations of Northern Canada’s buildings have not yet considered such requirements. Potentials of adaptive systems are also still limited. This research develops a fundamental model of adaptive multi-skin envelopes for sub-Arctic buildings based on main biophilic and photobiological indicators which characterize efficient indoor-outdoor connections. Biophilic indicators characterize the state of connections among occupants and outdoors which could stimulate biological-psychological responses. Photobiological indicators determine human-centric lighting adaptation scenarios for hourly lighting qualities and sufficient darkness in relation to local day/night cycles and daylighting. Biophilic performance of the proposed envelope was evaluated through 18 numerical models in terms of impacts of window and shading sizes on occupants’ field of views. Photobiological lighting performance was evaluated by experimental methods using 23 physical models at 1:10 scale. Surface characteristics of dynamic shading panels, including color, reflectance, orientation, and inclination, were studied for potential photobiological impacts in terms of melanopic/photopic ratios and color temperatures. Results show that the proposed envelope could (i) offer acceptable direct visual connections with the outdoor nature through efficient window sizes for biophilia, and (ii) modify daylighting qualities to address hourly/seasonal photobiological needs of sub-Arctic occupants. Challenges of the proposed envelope to implement under sub-Arctic climatic conditions are underlined especially in terms of energy issues. The research outcomes help architects and decision-makers to improve occupants’ wellbeing and healthy buildings in sub-Arctic climates.