Reflection Model Research Articles

Measurement of the Void Size Between Wall Tiles and Concrete Through Nondestructive Inspection Using Electromagnetic Waves

The separation of tiles from buildings degrades the aesthetic appeal of buildings and may result in structural failure. Therefore, tiles should be inspected periodically. However, manual inspections are expensive and require qualified experts. In this study, voids corresponding to tile separation were detected in a concrete specimen using nondestructive inspection based on electromagnetic wave detection. Furthermore, wave reflection models of healthy and defective tiles were created, and the effects of the void plane size on the reflection of defective tiles were considered. The correlation between the void plane size and the reflection intensity difference integral value was verified through multilayer scanning using these models. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Teaching and Learning of Attitudes, Ethics and Communication using the AETCOM Module in India

The National Medical Council of India has introduced AETCOM in its new CBME curriculum to focus on learning in the affective domain. Learning in the affective domain was hitherto relegated to the hidden curriculum, poses unique challenges, and requires use of additional teaching-learning [TL] methods that are not routinely used. Most medical college faculty members are unfamiliar with these methods. Case vignettes, video clips, book review, mock ethics meetings, field visits, story-telling (patients /caregivers / doctors), standardized patients, feedback from alumni/seniors, guest lectures, ward rounds with ethical checklists, news-paper clippings, assignments and projects, student seminars/debates and role plays are some methods that can be used to improve learning in the affective domain. Any of the teaching learning methods for affective domain listed above should be followed by reflection using Boyd’s triangular reflection model (What happened? So what? and Now what?). Teaching attitudes, communication and ethics cannot be done in isolation. It must be integrated into routine patient care and other everyday experiences that medical students are exposed to.

Three-Dimensional Division of Visible Light Communication Irradiation Area

In this article, we divide the irradiated area of visible light communication (VLC) into three parts, according to the influence of diffuse reflection, the irradiance half angle at the source and the communication distance on VLC. We present a volume ratio method to quantitatively analyze each divided part. In this work, based on the Lambertian reflection model of the VLC system in line-of-sight channels, five factors affecting the VLC performance are compared and discussed. A VLC system of a single white-light-emitting diode in a 10 m line-of-sight channel indoors is designed by using the intensity modulation and direct detection technique, and a three-dimensional model of the irradiated area is established.By comparing the distribution of the bit error rate (BER) of the optical signal at different lampshade heights, the volume ratio method is used to calculate the volume percentage of the three irradiated areas. The experimental results show that area II with a volume ratio greater than 50% is the best signal receiving area when compared with areas I and III, having a volume ratio in the range 20∼30%.

Development of 3D surface reconstruction by the images triad based on the Lambertian reflection model

A method for reconstructing the surface of an object using on a series of images based on the Lambertian model of light reflection is proposed. The original images are obtained by the method of photography under natural lighting. The model parameters are determined by changing the position of the light source using additional shading and the stable position of the receiver. The series contains a triad of images obtained from different directions of illumination and a shaded image of the surface of the reconstruction object. In the first stage, the derived surfaces of the reconstruction object are reconstructed. The next step is the accumulation of derivatives and determination of the surface height of the reconstruction object. To simplify the complexity of the practical implementation of the 3D-reconstruction a pyramid layout is chosen. The photography of the triad of images of the pyramid is done before noon, at noon and in the afternoon. The information about the triad and the shadowed image of the pyramid surface enters the processing system, where the directions of the photograph lighting are first determined. The parameters of the lighting directions are determined based on data on the height of the Sun at its upper culmination on the day and the time of the photo shoot. The procedure for determining the elevation of the Sun on a particular day of the year has been implemented. Calculated lighting direction data and image information using the Lambertian model of light reflection are reconstructed into horizontal and vertical derivatives. As a result of the discrete accumulation of derivatives, the pyramid surface is reconstructed.

LCD Reflection Model for Simulation of Automotive and Mobile Displays under Daylight Condition

LCD Reflection Model for Simulation of Automotive and Mobile Displays under Daylight Condition

Critical reflections on an interprofessional collaboration to develop domestic violence curriculum in an undergraduate dentistry program

ABSTRACT There is growing recognition of the critical need to incorporate Domestic Violence (DV) curriculum into dentistry degrees. Interprofessional collaboration between Social Work, DV sector and Dentistry developed and delivered the Dentistry and Domestic Violence – Recognise, Respond and Refer (DDV-RRR) program within an undergraduate dentistry degree in Australia. This article presents our critical reflections on the collaboration, development and delivery of this program. Selected questions from Fook’s critical reflection model were utilised to guide the reflection process. Key learnings from this process include acknowledging inherent challenges, power and barriers in collaborative projects; importance of interprofessional collaboration for best practice; and the importance of interpersonal/professional relationships for forming and maintaining interprofessional collaborations. We share the learnings from our critical reflections as an example of how interprofessional collaboration enhances the development and delivery of DV curriculum in one undergraduate dentistry course.

Histological and Morphometric Analysis of the Effects of Methyl Methacrylate compounds on the Skin of Adult Male Albino Rats: a model for Reflection on Occupational Hazards

Histological and Morphometric Analysis of the Effects of Methyl Methacrylate compounds on the Skin of Adult Male Albino Rats: a model for Reflection on Occupational Hazards

Development of a hardened THz energy meter for use on the kilojoule-scale, short-pulse OMEGA EP laser.

A highly adaptable and robust terahertz (THz) energy meter is designed and implemented to detect energetic THz pulses from high-intensity (>1018 W/cm2) laser-plasma interactions on the OMEGA EP. THz radiation from the laser driven target is detected by a shielded pyrometer. A second identical pyrometer is used for background subtraction. The detector can be configured to detect THz pulses in the 1mm to 30μm (0.3- to 10-THz) range and pulse energies from joules to microjoules via changes in filtration, aperture size, and position. Additional polarization selective filtration can also be used to determine the THz pulse polarization. The design incorporates significant radiation and electromagnetic pulse shielding to survive and operate within the OMEGA EP radiation environment. We describe the design, operational principle, calibration, and testing of the THz energy meter. The pyrometers were calibrated using a benchtop laser and show linear sensitivity to up to 1000 nJ of absorbed energy. The initial results from four OMEGA EP THz experiments detected up to ∼15μJ at the detector, which can correspond to hundreds of mJ depending on THz emission and reflection models.

Improved spectral reflectance model of oil films on seawater based on two-beam interference theory.

The theoretical properties of electromagnetic transmission and radiation of light are combined with the propagation law of light in a uniform medium and the Fresnel formula to provide an improved two-beam interference model for simulating oil spills. This model enables the study of spectral reflectance under different thicknesses and different illumination angles. Through observation and analysis of simulation results, it is found that light waves reflected at the interface of water and oil films and of oil films and air oscillate due to interference. In order to overcome this problem, solar irradiance is simulated and multiplied with the reflection model to obtain the outgoing illuminance values at different wavelengths, which are convoluted with the slit function of the hyperspectral camera. The processed results are compared with incoming illuminance values to obtain new simulation results. In addition, based on portable hyperspectral imagery and imported xenon lamp light sources and other experimental equipment, indoor simulated oil spill experiments were conducted. By comparing and analyzing the results of these simulations, the accuracy of the improved model was further improved, demonstrating the feasibility and utility of the model in studying oil spills at water surfaces.

Using process-oriented groups reflections with health care providers to improve childbirth care in the Democratic Republic of Congo – An implementation study

ObjectiveThe ability to systematically reflect on care during labour and birth needs to be developed among health care providers. This study investigates the experiences of health care providers who have participated in process-oriented group reflections. The activity of group reflections was one of the three pillars of a training intervention seeking to implement evidence-based care routines during labour and birth that could contribute to reduced mortality and improved maternal and newborn health in the Democratic Republic of Congo (DRC). MethodsUsing a qualitative approach, we interviewed 131 health care providers, in focus groups (n = 19) and individually (n = 2). Analysis of transcribed interviews was conducted using qualitative content analysis according to Elo and Kyngäs. ResultsGroup reflections added essential knowledge to the other components of the three-pillar training intervention. Through sharing and analysing care situations health care providers got increased self-awareness, tools to achieve structured and safe care routines, and to practice teamworking. ConclusionUsing a structured model of process-oriented group reflection for health care providers on care during labour and birth proved to be a vital aspect of the training intervention, as it added knowledge to the skills gained through theoretical and simulation-based education. The three-pillar training intervention improved care routines that supported healthy births and management of complications. We recommend that structured and secure group reflections be included in similar training activities in the DRC and elsewhere, and assessed in further studies.

INCREASING LEARNING OUTCOMES AND ACTIVITY OF CLASS V STUDENTS UPT SD NEGERI BINANGUN 01 THROUGH THE IMPLEMENTATION OF PROBLEM BASED LEARNING ON FACTORS NUMBERS FOR THE ACADEMIC YEAR 2022/2023

This study aims to determine the improvement of student learning outcomes and activeness by applying the Problem Based Learning (PBL) model. The teacher conveys the objectives, main points of learning, conducts group discussions, exercises questions, provides learning motivation and conclusions on the subject of fractional mathematics for class V UPT SD Negeri Binangun 01. This research is CAR (classroom action research) which contains 2 cycles. Each cycle is carried out once in a meeting. Each cycle begins with the stages of action planning, implementing the Problem Based Learning (PBL) model of action and reflection. The method of data collection is done by means of observation. Data analysis was carried out by comparing the test results in pre-cycle 1 and cycle 2 with descriptive techniques. The data obtained are presented naturally and then analyzed descriptively to get an overview of the facts. To measure student achievement using the class average value on the evaluation results of each cycle. The results showed that the achievement and learning activities of the fifth grade students of UPT SD Negeri Binangun 01 in learning mathematics had increased, this was indicated by the results of observations and results of English learning achievement tests. With these results, it is concluded that the application of the problem based learning model can increase the activity and learning outcomes of fifth grade students at UPT SD Negeri Binangun 01

Photophysics of β-Ga2O3: Phonon polaritons, exciton polaritons, free-carrier absorption, and band-edge absorption

Monoclinic gallium oxide (β-Ga2O3) has attracted much attention from the fields of optoelectronic and electronic devices owing to the properties of wide bandgap, great breakdown field strength, as well as the economic advantages of low-cost growth of large-size single crystals. Here, the basic photophysical properties including absorption (free-carrier absorption and band-edge absorption) and reflection (phonon polaritons and exciton polaritons) of differently doped β-Ga2O3 with diverse carrier concentrations are studied in detail. The unpolarized reflection spectra of differently doped β-Ga2O3 crystals are well fitted based on the non-polarized reflection model. Besides, according to analysis, the longitudinal–transverse splitting energy of β-Ga2O3 direct excitons is estimated to be as high as 100 meV, reflecting the strong interaction between light and excitons. It is hoped that this work can provide beneficial reference for a comprehensive understanding on the spectral physical characteristics of β-Ga2O3, so as to deepen and expand the basic recognition of this material in the aspect of photophysical properties.

Microwave absorption and bandwidth study of Y2Co17 rare earth soft magnetic alloy with easy-plane anisotropy

The easy-plane anisotropy of the Y2Co17 rare earth soft magnetic alloy has high saturation magnetization and operating frequency, and good impedance matching. Therefore, it is expected to become a kind of high-performance microwave absorbing material. In this paper, Y2Co17 alloy was prepared by a reduction-diffusion method, and its micropowder was prepared as polyurethane (PU) based composite absorbing materials (Y2Co17/PU composites). The microwave properties of composites with different volume fractions were calculated. The composites showed outstanding absorption characteristics in the range of 20–30 vol%, and the minimum reflection loss (RL) was less than −50 dB. When the volume fraction was 25%, the effective absorption bandwidth could cover the X-band at a thickness of 1.5 mm, and the Ku-band at a thickness of 1.08 mm. The absorption mechanism was analyzed by the interface reflection model. The RL absorption peak bandwidth mechanism was discussed by using the amplitude relation and calculating the effective absorption bandwidth at different thicknesses. The effective absorption bandwidth values were in good agreement with the theoretical expectation.

Rigorous solution to second harmonic generation considering transmission and reflection of light at air–crystal interface

Considering the transmission and reflection of TE-polarized pump light at the air–crystal interface, the second harmonic generation (SHG) in a lithium niobate (LN) crystal is investigated theoretically and systematically in this work. In previous studies, the theoretical analyses of reflection and transmission of incident wave in the process of nonlinear frequency conversion were not considered in LN crystal on account of the complicated calculations. First, we establish a physical picture describing that a beam of light in TE mode transports in the LN crystal considering transmission and reflection at the crystal surface and generates nonlinear second-order optical polarization in crystal. Then we analytically derive the reflection coefficient and transmission coefficient of pump light by using the dispersion relationships and electromagnetic boundary conditions. We construct the nonlinear coupled wave equations, derive and present the small signal approximation solution and the general large signal solution exactly. Under the transmission model and reflection model, we find that the conversion efficiency of the second-harmonic wave is obviously dependent on transmission coefficient and other general physical quantities such as the length of LN crystal and the amplitude of pump light. Our analytical theory and formulation can act as an accurate tool for the quantitative evaluation of the SHG energy conversion efficiency in an LN crystal under practical situations, and it can practically be used to treat other more complicated and general nonlinear optics problems.

Deep learning-based remote-photoplethysmography measurement from short-time facial video

Objective. Efficient non-contact heart rate (HR) measurement from facial video has received much attention in health monitoring. Past methods relied on prior knowledge and an unproven hypothesis to extract remote photoplethysmography (rPPG) signals, e.g. manually designed regions of interest (ROIs) and the skin reflection model. Approach. This paper presents a short-time end to end HR estimation framework based on facial features and temporal relationships of video frames. In the proposed method, a deep 3D multi-scale network with cross-layer residual structure is designed to construct an autoencoder and extract robust rPPG features. Then, a spatial-temporal fusion mechanism is proposed to help the network focus on features related to rPPG signals. Both shallow and fused 3D spatial-temporal features are distilled to suppress redundant information in the complex environment. Finally, a data augmentation strategy is presented to solve the problem of uneven distribution of HR in existing datasets. Main results. The experimental results on four face-rPPG datasets show that our method overperforms the state-of-the-art methods and requires fewer video frames. Compared with the previous best results, the proposed method improves the root mean square error (RMSE) by 5.9%, 3.4% and 21.4% on the OBF dataset (intra-test), COHFACE dataset (intra-test) and UBFC dataset (cross-test), respectively. Significance. Our method achieves good results on diverse datasets (i.e. highly compressed video, low-resolution and illumination variation), demonstrating that our method can extract stable rPPG signals in short time.

A Study of Projection-Based Attentive Spatial–Temporal Map for Remote Photoplethysmography Measurement

The photoplethysmography (PPG) signal contains various information that is related to CVD (cardiovascular disease). The remote PPG (rPPG) is a method that can measure a PPG signal using a face image taken with a camera, without a PPG device. Deep learning-based rPPG methods can be classified into three main categories. First, there is a 3D CNN approach that uses a facial image video as input, which focuses on the spatio-temporal changes in the facial video. The second approach is a method that uses a spatio-temporal map (STMap), and the video image is pre-processed using the point where it is easier to analyze changes in blood flow in time order. The last approach uses a preprocessing model with a dichromatic reflection model. This study proposed the concept of an axis projection network (APNET) that complements the drawbacks, in which the 3D CNN method requires significant memory; the STMap method requires a preprocessing method; and the dyschromatic reflection model (DRM) method does not learn long-term temporal characteristics. We also showed that the proposed APNET effectively reduced the network memory size, and that the low-frequency signal was observed in the inferred PPG signal, suggesting that it can provide meaningful results to the study when developing the rPPG algorithm.

A Super-Resolution Altitude Measurement Technology for VHF Radar Based on Synthetic Steering Vector and Model Matching

As radar is a kind of measuring device, the altitude measuring accuracy is a quite important core tactical indicator. In engineering practice, the altitude measuring accuracy deteriorates significantly in low elevation range, especially for low frequency radar such as VHF radar. This urgent problem to be solved is what we focus on in this article. After building a multipath reflection model, a method of altitude super-resolution measurement based on synthetic steering vector and model matching is proposed. Then some simulation analysis is finished, and some validation experiments are carried out on a practical VHF radar prototype. The results of theoretical simulation and prototype experiments show obviously improved altitude measuring performance compared with traditional measuring methods, verifying the correctness and engineering feasibility of the super-resolution altitude measurement technology proposed in this article. This study should have certain practical guiding significance for the theoretical and application research of related fields.

The Methodological Implications of the Buddhist Model of Study, Reflection, and Cultivation

This paper discusses aspects of the Buddhist concept of threefold wisdom and their implications on methodology for Buddhist studies, especially the academic study of Buddhist philosophy. The first part of the paper discusses aspects of threefold wisdom as presented in Indian and Tibetan Buddhist sources, arguing that threefold wisdom is not simply a presentation of mental cultivation and philosophical practice, but that it also proposes what can be called a practical hermeneutic, that is, a method to maximize a reader’s understanding of Buddhist scriptures and their full implication. Second, we consider how certain methods of studying Buddhist thought, especially those that deal with philosophical engagement with Buddhist thought, should be adapted to include the dimension of Buddhist philosophy that is exemplified by threefold wisdom. More particularly, Buddhist philosophy’s perspective on what a successful reading method consists of, which is exemplified by the practical hermeneutic described by threefold wisdom, should be included as part of what scholars pay attention to when studying Buddhist philosophy. Thus, only will the conditions for an open dialogue between Buddhism and other philosophical traditions be sufficiently present for such a dialogue to take place in a fruitful way.

Intelligent network planning tool for location optimization of unmanned aerial vehicle base stations using geographical images

Nowadays, automated and intelligent solutions are required by different services and applications to satisfy current industrial necessities. Internet of things/robotic devices have been found useful in the collection and processing of data for pattern recognition, analyzing and anticipating incident information, optimization, and provision of better and timely decision-making to enable network providers to measure the quality of services, thereby ensuring efficiency. Telecommunication systems need reliable and fast internet networks for connected devices and other business activities; thus, technologies are being explored to determine efficient ways of planning and installing base stations. Recently, possibilities of deploying unmanned aerial vehicles (UAVs) as base stations had been investigated. Although successes have been recorded, not much work has been done on network planning tools for location optimization of UAV base stations (UAV-BS) in 5G and beyond networks to the best of our knowledge. In this paper, an intelligent network planning tool (iNPT) for location optimization of UAV-BS has been developed with different channel models and network planning parameters. The developed tool has resources to suggest a better positioning of the UAV-BS using the simulated annealing meta-heuristic to optimize their locations. The tool also includes a battery management interface that can calculate the battery dissipation with reference to the received and transmitted power of the UAV-BS and display the estimated time of flight for the UAV-BS. Geographical information, such as the height of a specific region, obtained from a map is considered in the simulations. The results obtained using the COST231-Hata, Hata path loss, log distance, and two-ray ground reflection models have been presented in this paper. Based on the experimental results, the developed simulator can be useful in network planning tasks to improve coverage areas using UAV-BSs. In addition, the proposed tool has a friendly interface that provides geographical images, and the BSs and UAVs optimized locations.

Эффект «волновода» при распространении сверхширокополосных сигналов в помещении

“Waveguide” effect that occurs by indoor propagation of ultrawideband signals is shown. The effect exhibits itself in the absence of interference factor of signal dissipation at any distance. Unlike outdoor propagation, the signal attenuation in multipath indoor environment is similar to free space. The effect occurs due to reflections of the incident wave from paired opposite surfaces, e.g., floor – ceiling, parallel walls. As a result, the distance range of indoor ultrawideband communications is essentially higher than outdoors. The effect is simulated in a three-ray reflection model.