Threshold Of Human Perception Research Articles

Seismic fragility analysis of human perception in high‐rise buildings subjected to far‐field long‐period earthquake ground motions: A case study for Shanghai tower

AbstractHuman perception in high‐rise buildings during far‐field long‐period earthquake ground motions often induces psychological discomfort, including fear and anxiety. A comprehensive understanding on human perception of seismic events is vital for city planning and emergency management, facilitating effective evacuation plans and minimizing stampede risks. This study addresses a gap by employing the seismic fragility analysis method to delineate how human perception in high‐rise buildings is affected during far‐field long‐period ground motions. The methodology involves several key steps. First, the far‐field long‐period earthquake ground motion was identified by detecting the later‐arriving surface waves, and a series of records were selected from the next generation attenuation (NGA) West‐2 ground motion database of the Pacific Earthquake Engineering Research center. Then, a high‐rise building in Shanghai, China was modeled using ETABS 20. Through the linear‐elastic time history analysis, the structural seismic response at each floor was computed. Furthermore, human perception thresholds to vibration were introduced to assess the degree of human perception at each floor, illustrating the difference of human perception to seismic tremor at different floors. Finally, a novel earthquake intensity measure (IM), namely average response spectrum intensity (ARSI) within the vibration period ranging from 0.1 s to 10 s was introduced to generate seismic fragility curves for human perception. According to the investigation, it was found that the corner frequency and the associated energy ratio are useful indicators to identify the far‐field long‐period earthquake ground motions. The ARSI is an effective parameter to assess human perception to seismic tremor compared to the spectral acceleration at a given fundamental period. The generated seismic fragility analysis can provide a complete and thorough understanding on the probability of people that should be evacuated under different earthquake intensity levels. The probability of human perception at different floors varies along the building height, demonstrating the difficulty to make crowd evacuation plan in practice. This insight is vital for understanding and mitigating seismic concerns in high‐rise buildings, particularly in low‐to‐moderate seismicity regions.

Guidelines to optimise the sensory detection of 2,4,6-trichloroanisole in neutral spirit and whisky

Why was the work done: Guidelines are required to optimise the sensory detection of musty/stale taints in alcoholic spirits caused by 2,4,6-trichloroanisole. Early detection of the taint is necessary as the low sensory threshold can result in significant quality issues and masking the musty/stale off-note through blending is difficult. How was the work done: The standard industry practice for ‘nosing’ is to dilute samples of spirit to 20% ABV to prevent sensory fatigue. It is not known if 20% ABV is the optimal concentration for detecting 2,4,6-trichloroanisole. In this study, the effects of ethanol concentration on the detection of the taint were evaluated using a sensory panel and gas chromatography-mass spectroscopy. The efficacy of nosing versus tasting to detect 2,4,6-trichloroanisole was investigated at different dilutions of distilled spirits. Further, the stability of this off-note at 20% ABV was determined to assess if the taint could be detected by nosing over a working day. Finally, the serving temperature of the sample was assessed in the sensory perception of the taint. What are the main findings: The recommendations to optimise the sensory detection of 2,4,6-trichloroanisole in spirit samples are (i) nose samples at 20% ABV, (ii) as soon as possible after dilution conduct sensory tests and (iii) chill the sample. Why is the work important: The limits of detection for conventional solid phase microextraction with gas chromatography-mass spectroscopy are typically above the threshold of human perception. Therefore, the industry needs to maximise the detection by sensory panellists of contaminated whisky samples to ensure the product does not go to market so as to avoid any reputational damage.

High-speed fluidic processing circuits for dynamic control of haptic and robotic systems.

Fluidic logic circuits simplify system design for soft robotics by eliminating bulky components while enabling operation in a range of hostile environments that are incompatible with electronics but at the expense of limited computational capabilities and response times on the order of seconds. This paper presents a four-terminal fluidic transistor optimized for fast switching times, reduced component count, low unit cost, and high reproducibility to achieve complex fluidic control circuits while maintaining flow rates of liters per minute. A ring oscillator using three fluidic transistors achieves oscillation frequencies up to a kilohertz with full signal propagation, tolerating billions of cycles without failure. Fundamental processor circuits like a full adder and a 3-bit analog-to-digital converter require just seven transistors each. A decode circuit drives a high-resolution soft haptic display with refresh times below the human perception threshold for latency, and an electronics-free control circuit performs closed-loop position control of a pneumatic actuator with disturbance rejection, demonstrating the value across domains.

SenGlove—A Modular Wearable Device to Measure Kinematic Parameters of The Human Hand

For technical or medical applications, the knowledge of the exact kinematics of the human hand is key to utilizing its capability of handling and manipulating objects and communicating with other humans or machines. The optimal relationship between the number of measurement parameters, measurement accuracy, as well as complexity, usability and cost of the measuring systems is hard to find. Biomechanic assumptions, the concepts of a biomechatronic system and the mechatronic design process, as well as commercially available components, are used to develop a sensorized glove. The proposed wearable introduced in this paper can measure 14 of 15 angular values of a simplified hand model. Additionally, five contact pressure values at the fingertips and inertial data of the whole hand with six degrees of freedom are gathered. Due to the modular design and a hand size examination based on anthropometric parameters, the concept of the wearable is applicable to a large variety of hand sizes and adaptable to different use cases. Validations show a combined root-mean-square error of 0.99° to 2.38° for the measurement of all joint angles on one finger, surpassing the human perception threshold and the current state-of-the-art in science and technology for comparable systems.

Measuring interaction forces in surgical telemanipulation using conventional instruments

AbstractMinimally invasive surgery (MIS) has been an essential tool in the surgical sector for many years due to its crucial advantages compared to open surgery. To overcome remaining limitations, teleoperated MIS experienced a strong emergence. However, the widespread usage of such systems is hindered by the enormous financial hurdle. The use of standard components and conventional tools for teleoperated MIS can facilitate integration into existing hospital workflows and can be a cost-efficient and versatile approach for research purposes. To compensate for the lack of haptic feedback, some teleoperation setups inherit a sensor system allowing them to record interaction forces and display them at the user interface. In research and in commercially available systems, different positions for the sensor can be found. In this paper, mechanical interfaces for the guidance and actuation of non-wristed and wristed standard instruments are presented. Furthermore, a method for the extracorporeal measurement of interaction forces is presented, characterized, and discussed. The overall mean relative error of the magnitude of the interaction force is 9.4%, while the overall mean absolute error of the force vector is 14.4 $^{\circ }$ , both below the respective human differential perception threshold. The presented measurement method is a simple, yet sufficiently accurate approach to measure interaction forces in surgical telemanipulation.

Wagner's Furious Host

Wagner's Furious Host

Evaluation of human perception thresholds of transient vibrations for the assessment of building vibration

Vibrations in low-rise buildings in the frequency range from a few hertz to tens of hertz are caused by external sources, such as road traffic, and could induce annoyance in occupants if their magnitude is in excess of human perception levels. Although there have been several different standardised metrics to evaluate human responses to such vibrations, no common metric has been accepted worldwide. In the present study, laboratory experiments were conducted to determine human perception thresholds of transient vibrations similar to building vibrations. The thresholds were evaluated by three methods based on running r.m.s. acceleration with different integration methods and frequency weightings and by the fourth power vibration dose method. The metrics based on the Vibration Level used in Japan and the Vibration Dose Value in the international standard were better than the other methods for the evaluation of perception of the input vibrations used in the experiments. The evaluation of threshold of transient vibrations was also investigated with short-time average acceleration by optimising the integration time and time constant for averaging. The optimised integration time and time constant appeared to be dependent on the frequency and waveform of transient vibration.

Development and Evaluation of a Threshold-Based Motion Cueing Algorithm

In this paper, a motion cueing algorithm (MCA) without a frequency divider is proposed, which aims to reproduce the longitudinal reference acceleration as far as possible via tilt coordination. Using a second-order rate limit, the human perception thresholds can directly be taken into account when parameterizing the MCA. The washout is compensated by tilt coordination and means of feedback from the translational acceleration. The proposed MCA is compared with the classical washout algorithm and the compensation MCA based on selected qualitative metrics and their workspace demand. In addition, a subjective study on the evaluation of the MCA was conducted. The results show that even high washout rates are not noticeable by the test subjects. Overall, the MCA was rated as very good.

Color formulation in maxillofacial elastomer by genetic algorithm

This work proposed to develop a portable, accessible, and objective solution for the reproduction of colors in medical-grade silicone elastomer by means of genetic algorithm and smartphones. The smartphones' application for color recipe prediction followed the two-constant Kubelka-Munk theory with corrections of internal and external reflection by Duntley, Saunderson and Richmond. The calculation of the composition of the mixture of pigments (n = 9) and flocking (n = 11) was performed by applying the genetic algorithm. Then, an intuitive application was developed for clinical use. The user sets the thickness and weight of the prosthesis and chooses a background option. The results screen displays the top five formulations generated by the genetic algorithm and their respective estimated color differences based on the CIELAB (ΔΕ) system under two illuminants (average sunlight and incandescent light). Simulations of color formulation were carried out and the estimated means of color difference were below the thresholds accepted clinically (ΔΕ < 3), but above the threshold of human visual perception for incandescent light (ΔΕ ≥ 1.1). So, different modifications on the algorithm were tested and the mean color difference was significantly improved (ΔΕ < 1.1). Though the mean value under average sunlight increased, it remained under the perceptive threshold. The methodology showed encouraging results and points out the potential use of smartphones to assist the clinician during the color formulation and to reduce costs.

Feel-Good Requirements: Neurophysiological and Psychological Design Criteria of Affective Touch for (Assistive) Robots.

Previous research has shown the value of the sense of embodiment, i.e., being able to integrate objects into one's bodily self-representation, and its connection to (assistive) robotics. Especially, tactile interfaces seem essential to integrate assistive robots into one's body model. Beyond functional feedback, such as tactile force sensing, the human sense of touch comprises specialized nerves for affective signals, which transmit positive sensations during slow and low-force tactile stimulations. Since these signals are extremely relevant for body experience as well as social and emotional contacts but scarcely considered in recent assistive devices, this review provides a requirement analysis to consider affective touch in engineering design. By analyzing quantitative and qualitative information from engineering, cognitive psychology, and neuroscienctific research, requirements are gathered and structured. The resulting requirements comprise technical data such as desired motion or force/torque patterns and an evaluation of potential stimulation modalities as well as their relations to overall user experience, e.g., pleasantness and realism of the sensations. This review systematically considers the very specific characteristics of affective touch and the corresponding parts of the neural system to define design goals and criteria. Based on the analysis, design recommendations for interfaces mediating affective touch are derived. This includes a consideration of biological principles and human perception thresholds which are complemented by an analysis of technical possibilities. Finally, we outline which psychological factors can be satisfied by the mediation of affective touch to increase acceptance of assistive devices and outline demands for further research and development.

Construction of Ultrasonic Tactile Force Feedback Model in Teleoperation Robot System.

The ultrasonic phased array as an emerging interactive tool is increasingly used for aerial tactile interaction. However, there is almost no method to achieve remote variable force feedback through the ultrasonic phased array as far as we know. This article presents a force tactile feedback method for teleoperating robot systems that tracks the five fingers and forms a focus on the fingertips. First, the perceived size of the focus depends on the input parameters. The influence of the parameters on the physical output pressure intensity was obtained through physical test experiments. Then, the absolute threshold and difference threshold of human perception were studied through psychophysical experimental methods. Finally, the input parameters were selected according to the experimental results. According to the collected data, the construction of the force regression model was completed, and different parameters were mapped to the perceived intensity. The contact force generated in the actual operation is fed back to the haptic system, and the constructed model automatically adjusts the control parameters to ensure that the user’s hand presents a sensory output corresponding to the intensity change. The entire force feedback system is evaluated, and results show that the system shows good perceptual quality.

Evaluating In-Vehicle Sound and Vibration during Incursions on Sinusoidal Rumble Strips

Rumble strips (RS) are a countermeasure used to reduce roadway-departure crashes by providing audible and haptic alerts to the driver when a vehicle is departing the roadway. This study evaluated the feasibility of using sinusoidal RS as a substitute for more traditional rounded RS. A van, a passenger car, and a heavy vehicle were equipped with sound and vibration sensors to measure the interior noise and haptic feedback of each RS design. A set of typical conditions (with interior climate control fan and radio turned on) were also tested. Data from 75 RS strikes were analyzed. Experimental results demonstrated that the rounded RS doubled interior noise for the passenger car and van (11.3 dBA, 10.0 dBA) but the sinusoidal RS also generated a clearly noticeable interior alert for the passenger car and van (5.8 dBA, 4.6 dBA). The haptic alert provided an increase over the human perception threshold of vibration for all vehicles. The sinusoidal RS interior alert was detectable and within the acceptable range, but not clearly noticeable (5 dBA) when the climate control and radio were active. Alert levels for the rounded RS were &gt;10 dBA, doubling the amount of interior noise for all ambient factor groups (11.2–14.4 dBA).

Podcast: Songs of the Arches (with Helicopters)

Utah’s famous bridges and spires hum with a deep, earthly music, just below the threshold of human perception.

Speckle reduction in laser projection based on a rotating ball lens

A speckle reduction method based on a rotating ball lens is proposed and assessed. The fast rotation of the ball lens results in angle diversity and thus reduced speckle. Furthermore, the same experiment is performed with different motor voltages, shooting distances, and laser driving currents. Efficient speckle reduction was achieved by applying our method to a complete laser projection system, resulting in a lower speckle contrast than the human speckle perception threshold of 4%. Additionally, a novel standardised speckle measurement method based on human eye characteristics was developed to evaluate the speckle contrast. The proposed method can increase opportunities for practical speckle measurement applications.

Route guidance ranking procedures with human perception consideration for personalized public transport service

The use of smartphone applications (apps) to acquire real time and readily available journey planning information is becoming instinctive behavior by public transport (PT) users. Through the apps, a passenger not only seeks a path from origin to destination, but a satisfactory path that caters to the passenger’s preferences at the desired time of travel. Essentially, apps attempt to provide a means of personalized PT service. As the implications of the Covid-19 pandemic take form and infiltrate human and environmental interactions, passenger preference personalization will likely include avoiding risks of infection or contagious contact. The personal preferences are enabled by multiple attributes associated with alternative PT routes. For instance, preferences can be connected to attributes of time, cost, and convenience.This work establishes a personalized PT service, as an adjustment to current design frameworks, by integrating user app experience with operators’ data sources and operations modeling. The work proceeds to focus on its key component: the personalized route guidance methodology. In addition to using the existing shortest path or k-weighted shortest path method, this study develops a novel, lexicographical shortest path method, considering a just noticeable difference (JND). The method adopts lexicographical ordering to capture passenger preferences for different PT attributes following Ernst Weber’s law of human perception threshold. However, a direct application of Weber’s law violates the axiom of transitivity required for an implementable algorithm, and thus, a revised method is developed with proven algorithms for ranking different paths. The differences between the three route-guidance methods and the effects of the JND perception threshold on the order of the alternative PT routes are demonstrated with an example.The developments were examined in a case study by simulation on the Copenhagen PT network. The results show that using the JND method reduces the value/cost of the most important attributes. Identical robust results are attained when JND parameters are not specified and default values are used. The latter may apply for the future with a mixture of specified and default preference input values. Finally, the computation time indicates a favorable potential for real-life applications. It is believed that the consideration of human threshold perception will encourage decision makers to establish new criteria to comply with this.

Electrospun nanofibers versus drop casting films for designing an electronic tongue: comparison of performance for monitoring geosmin and 2‐methylisoborneol in water samples

Geosmin (GSM) and 2‐Methylisoborneol (MIB) are substances commonly found in river water and arise due to eutrophication process. Such contaminants affect the organoleptic properties of water, hampering its consumption, and use in beverage industries. As the human perception threshold for these compounds is low, the devices aimed at their detection must be sensitive enough to detect concentrations as low as a few nanogram per liter in order to guarantee the water quality parameters. Due to the experimental simplicity, fast analysis, portability, and capability for on‐site analysis, the use of electronic tongues and electronic noses employing hybrid and composite materials are potential for GSM and MIB determination. In this work, two distinct electronic tongues were applied in the electrical determination of GSM and MIB in pure and river water. The difference between them consisted in the type of polymer processing used in the fabrication of sensing units. The thin films deposited onto gold IDEs were based on polyamide 6, polypirrole, and polyaniline, but fabricated by drop‐casting and electrospinning. The differences in the electronic tongue performances were correlated to the distinct morphologies of the sensitive layers. Both devices were able to discriminate pure water from solutions tainted with GSM and MIB in concentration as low as 25 ng L−1, with high data correlation and a good reproducibility.

Evaluation of a Wearable Hand Kinesthetic Feedback System for Virtual Reality: Psychophysical and User Experience Evaluation

Most of the wearable hand kinesthetic (force) feedback systems have only been evaluated from a physical perspective, i.e., motion measurement, force transmission, system stability, etc. However, by taking this approach, we cannot gather sufficient data to evaluate the performance of wearable kinesthetic feedback systems as haptic devices. In this paper, we evaluated the wearable hand kinesthetic feedback system developed in our laboratory from psychophysical and user experience (UX) perspectives. We designed the experiments considering the characteristics of our wearable hand system. For psychophysical evaluation, ten subjects participated in force detection, discrimination, and identification experiments. The force detection threshold of our system was better than those of the commercialized haptic systems, and discrimination threshold was similar with the human perception threshold. In the identification experiment, the subjects could distinguish the size and shape of virtual objects over 2.5 levels. For UX evaluation, 15 subjects answered a questionnaire after conducting a task using our wearable hand system in laboratory environment. The UX results verified that the subjects were satisfied with our system by giving a score of 5.87 out of 7 points. It also concluded that our system can provide a good VR experience to users by achieving over 5.5 points in ease of use, learnability, and utilitarian value.

Personalized public transport mobility service: a journey ranking approach for route guidance

Abstract The use of smartphone applications (apps) to acquire real time and readily available journey planning information is becoming an instinctive behavior of public transport (PT) users. Through the apps, a traveler not only seeks a path from origin to destination, but also a satisfactory path that caters to the traveler’s preferences at the requested time of travel. In other words, to strive for a personalized PT service. The personal preferences are naturally enabled because of the existence of multiple attributes associated with alternative PT routes. For instance, preferences can be connected to attributes of time, cost and convenience. Initially this work establishes an adjusted design framework, to those existed nowadays, for a personalized PT service by integrating users’ experiences using apps with operators’ data sources and operations modeling. The work then focuses on its key component, namely the personalized route guidance methodology. In addition to using the classic shortest path method, two developments are suggested: a k-weighted shortest path method and a novel lexicographical shortest path method with a just noticeable difference (JND) consideration. The latter adopts lexicographical ordering to capture traveler preferences over different PT attributes following Ernst Weber’s law of human perception threshold. However, Weber’s law violates the axiom of transitivity required for an implementable algorithm, and thus a revised method is developed with correctness proven algorithms for ranking different paths. A small example is used as an explanatory device to illustrate the differences between the three route-guidance methods and to demonstrate the effects of the JND perception threshold on the order of the alternative PT routes. A simulation study was conducted using the Copenhagen PT network. The results show that the average reduction of the value of the most important PT traveler’s attribute is 12.3% for the k-weighted shortest path method, and 13.4% for the lexicographical JND-based shortest path method in comparison with the classical shortest path method. The computation time indicates favorable potential for real life applications.

Vibration isolation for world-class performance spaces, Part I: A brief history

World-class performance spaces are typically located in central urban areas, often surrounded by sources of groundborne noise such as subways and streetcar lines or sources of structureborne noise within the building itself which, if not addressed, can be disruptive to the performances inside the buildings. The advent of digital recording within performance spaces has also been a major motivation for reducing background noise, often to levels below the threshold of human perception. The history and development of vibration isolation incorporated into such spaces will be discussed.

Memory reactivation improves visual perception.

Human perception thresholds can improve through learning. Here we report findings challenging the fundamental 'practice makes perfect' basis of procedural learning theory, showing that brief reactivations of encoded visual memories are sufficient to improve perceptual discrimination thresholds. Learning was comparable to standard practice-induced learning and was not due to short training per se, nor to an epiphenomenon of primed retrieval enhancement. The results demonstrate that basic perceptual functions can be substantially improved by memory reactivation, supporting a new account of perceptual learning dynamics.