Three-dimensional Variation Research Articles

Characterization of Thermal Damage Due to Two-Temperature High-Order Thermal Lagging in a Three-Dimensional Biological Tissue Subjected to a Rectangular Laser Pulse.

The use of lasers and thermal transfers on the skin is fundamental in medical and clinical treatments. In this paper, we constructed and applied bioheat transfer equations in the context of a two-temperature heat conduction model in order to discuss the three-dimensional variation in the temperature of laser-irradiated biological tissue. The amount of thermal damage in the tissue was calculated using the Arrhenius integral. Mathematical difficulties were encountered in applying the equations. As a result, the Laplace and Fourier transform technique was employed, and solutions for the conductive temperature and dynamical temperature were obtained in the Fourier transform domain.

Morphometric approach to 3D soft-tissue craniofacial analysis and classification of ethnicity, sex, and age.

BackgroundThe application of three-dimensional scan models offers a useful resource for studying craniofacial variation. The complex mathematical analysis for facial point acquisition in three-dimensional models has made many craniofacial assessments laborious.MethodThis study investigates three-dimensional (3D) soft-tissue craniofacial variation, with relation to ethnicity, sex and age variables in British and Irish white Europeans. This utilizes a geometric morphometric approach on a subsampled dataset comprising 292 scans, taken from a Liverpool-York Head Model database. Shape variation and analysis of each variable are tested using 20 anchor anatomical landmarks and 480 sliding semi-landmarks.ResultsSignificant ethnicity, sex, and age differences are observed for measurement covering major aspects of the craniofacial shape. The ethnicity shows subtle significant differences compared to sex and age; even though it presents the lowest classification accuracy. The magnitude of dimorphism in sex is revealed in the facial, nasal and crania measurement. Significant shape differences are also seen at each age group, with some distinct dimorphic features present in the age groups.ConclusionsThe patterns of shape variation show that white British individuals have a more rounded head shape, whereas white Irish individuals have a narrower head shape. White British persons also demonstrate higher classification accuracy. Regarding sex patterns, males are relatively larger than females, especially in the mouth and nasal regions. Females presented with higher classification accuracy than males. The differences in the chin, mouth, nose, crania, and forehead emerge from different growth rates between the groups. Classification accuracy is best for children and senior adult age groups.

Morphological variations of the human talus investigated using three-dimensional geometric morphometrics.

The shape of the talus determines the positional and kinematic features of the subtalar, talonavicular, and talocrural joints during walking. Thus, detailed knowledge of the pattern of sexual dimorphism of the human talus may be useful for revealing the pathogenetic mechanism of foot and knee disorders, which are more prevalent in females. The aim of this study was to characterize and visualize the three-dimensional shape variations of the talus in relation to sex and age using geometric morphometrics. Computed tomography images of 56 feet without talar injuries or disorders were used in this study. Thirty-seven anatomical landmarks were identified on a bone model of the talus to calculate principal components (PCs) of shape variations among specimens. PC scores were compared between sexes, and their correlations with age were also investigated. The female talus had a longer neck and narrower head width than the male talus. The superior trochlea was tilted more laterally in the frontal plane in females. Furthermore, the female talar head was more twisted and was more elongated in the dorsoplantar direction. Morphological features of the talus in females could alter the subtalar and talonavicular joint kinematics during walking and could be a structural factor in the pathogenetic mechanism underlying foot and knee disorders. This study contributes to the comprehensive understanding of shape variations in the human talus.

Numerical Modeling of Tidal Current Patterns Using 3-Dimensional MOHID in Balikpapan Bay, Indonesia

HighlightsThe results of the model and observation showed the similarity of the amplitude and phase formedAt the highest tide was in the position above the Sea Mean level and the current velocity was lower than when heading to the tideThere was a difference in the direction of the current when heading towards high tideStratification of the water column in both seasons tended to be classified in well-mixed watersAbstractBalikpapan Bay is significant as a link between the cities within and outside of East Kalimantan by becoming the primary path used for local transportation and distribution of produced goods. The various anthropogenic activities increased liquid wastes and debris, which flowed through channels and rivers along the bay. This study aimed to determine tidal current patterns in Balikpapan Bay and its influence on salinity and temperature distributions. This study applied a baroclinic three-dimensional (3D) hydrodynamic model, employing wind, tides, and density variations, resulting from the differences of temperature and salinity, as the model input. To simulate the tidal current flow, we applied MOHID Water Modeling System, which the tidal current patterns depicted current directions and speeds at the different tidal conditions. During the displacement toward the high tidal condition, the water mass moves northwestward entering the river body, while at the displacement toward the low tidal condition, the water mass moves southeastward, which flows toward the coast and without the bay. The current speed varies at certain tidal conditions. At the highest tidal condition, the surface elevation ranged 1.3 - 1.5 m above mean sea level; the current rate is lower compared to the displacement toward high tidal condition, which ranged from 0.01 - 0.15 m/s. At the lowest tidal condition, the surface elevation reached 1 - 1.2 m below mean sea level, and the weaker flow velocity took place (less than 0.15 m/s). The results also showed that the water mass temperature tends to be higher in the inner part of Balikpapan Bay, the Balikpapan Bay waters profile that is increasingly shallow towards the bay head also causes this area to tend to have a higher temperature. Also, areas located on the inside of the bay tend to get more freshwater input from rivers, so this area has lower salinity while the area located at the mouth of the bay tends to be of higher salinity because it gets a lot of mass input of seawater from the Makassar Strait.

Applying Satellite Data Assimilation to Wind Simulation of Coastal Wind Farms in Guangdong, China

With the development of the wind power industry in China, accurate simulation of near-surface wind plays an important role in wind-resource assessment. Numerical weather prediction (NWP) models have been widely used to simulate the near-surface wind speed. By combining the Weather Research and Forecast (WRF) model with the Three-dimensional variation (3DVar) data assimilation system, our work applied satellite data assimilation to the wind resource assessment tasks of coastal wind farms in Guangdong, China. We compared the simulation results with wind speed observation data from seven wind observation towers in the Guangdong coastal area, and the results showed that satellite data assimilation with the WRF model can significantly reduce the root-mean-square error (RMSE) and improve the index of agreement (IA) and correlation coefficient (R). In different months and at different height layers (10, 50, and 70 m), the Root-Mean-Square Error (RMSE) can be reduced by a range of 0–0.8 m/s from 2.5–4 m/s of the original results, the IA can be increased by a range of 0–0.2 from 0.5–0.8 of the original results, and the R can be increased by a range of 0–0.3 from 0.2–0.7 of the original results. The results of the wind speed Weibull distribution show that, after data assimilation was used, the WRF model was able to simulate the distribution of wind speed more accurately. Based on the numerical simulation, our work proposes a combined wind resource evaluation approach of numerical modeling and data assimilation, which will benefit the wind power assessment of wind farms.

Elastic properties and lattice waves of TiAl

The elastic properties, lattice wave propagation and phonon focusing of TiAl are studied in detail based on Bond matrices model and lattice-dynamical method. The results contain remarkably complex three-dimensional variations in the phonon flux with angular distribution. The feature of elastic waves and phonon distribution is affected by the elastic anisotropy of the lattice. The correspondence between these features and contours of Gaussian curvature on the slowness surface is explored and the phonon topology is discussed about the presence of caustics in the anistropic flux of phonons emanating from a localized phonon distribution. The topology slowness surface gives insights into the mixing of longitudinal and transverse modes and gives the origin of the phonon focusing. The elastic anisotropy not only affects lattice wave propagation but also influences phonon focusing.

Vertical and Horizontal Profiles of Particulate Matter and Black Carbon Near Elevated Highways Based on Unmanned Aerial Vehicle Monitoring

Highways passing through cities cause additional pollution inside the city. However, most of the current studies are using ground-based monitoring technologies, which make it difficult to capture the dispersion patterns of pollutants near elevated highways or transportation interchanges. The purpose of this study is to discover short-term three-dimensional variations in traffic-related pollutants based on unmanned aerial vehicles. The monitoring locations are at suburban elevated highway and transportation interchanges. The monitoring parameters include the particle number concentration (PN), particle mass concentration (PM), and black carbon (BC). The vertical profiles showed that most air pollutants increased significantly with the height of the elevated highways. Compared with the ground level, PNs increased by 54%–248% and BC increased by 201%. The decline rate of particle concentrations decreased with the increase of height and remained stable after 120 m. Furthermore, the R2 heatmap for regressions between each altitude showed that the linear relationship between 0–120 m was higher than that of other altitudes. In horizontal profiles, PNs spread to 100 m and then began to decline, BC began to decay rapidly after 50 m, but PMs varied less. After crossing another highway, PNs increased by 69–289%, PMs by 7–28%, and BC by 101%. Furthermore, the formation of new particles was observed at both locations as PN3 increased with distance within 100 m from the highway. This paper fills in the void of three-dimensional in situ monitoring near elevated highways, and can help develop and refine a three-dimensional traffic-related air pollution dispersion model and assess the impacts of transportation facilities on the urban environment.

Mapping the response of volumetric soil water content to an intense rainfall event at the field scale using GPR

Ground-penetrating radar (GPR) is a convenient tool for volumetric soil water content (VSWC) estimation in hydrological and agricultural studies. Although case studies have been widely carried out, little attention has been paid to subsoil moisture estimates. In this research, we investigated three-dimensional soil moisture variation down to a depth of 1 m and the effect of rainfall events on spatial soil moisture dynamics. GPR surveying lines were conducted both before and after a heavy rainfall event to map the VSWC. Soil sampling and time domain reflectometry (TDR) probe data at different depths (20, 40, 60, 80, and 100 cm) were acquired. Our results demonstrated that there was a significant correlation between the dielectric constants and VSWCs at all depths. The established relationships for the different depth ranges had a low VSWC discrepancy when the dielectric constants ranged from 10 to 15. The effective range of each variogram was larger than 20 m, except for that of the 0–100 cm VSWC map after rainfall. In addition, the validation diagrams using corrected TDR values demonstrated relatively reliable VSWC maps. Approximately 89% of the variation in VSWC could be explained by the dielectric constants in the depth range of 0–40 cm, and VSWC predictions at this soil depth outperformed those at other depth ranges, with an overall RMSE of 0.027 m3 m−3 and R2 of 0.725. Furthermore, we also monitored the effect of precipitation on the accuracy of the VSWC prediction on shallow surfaces. Our study shows that three-dimensional soil moisture dynamics can be accurately estimated at the field scale by integrating GPR interpretation and spatial extrapolation methods.

Selection Method of Test Pulse Width and Amplitude to Avoid Self-heating Effect of Power Devices

The objective of this study was to address the deviation of electrical parameters, which is caused by the self-temperature rise effect of power devices in electrical testing processes. The pulse width and amplitude of the device test were considered as the research object. The three-dimensional variation of the power, junction temperature, and pulse width of semiconductor power devices were investigated using the principle of electrical temperature measurement, and the three-dimensional variation surfaces of the power, junction temperature, and pulse width were established. A method for selecting the pulse width and amplitude of the test to avoid the self-temperature rise of the power device is proposed. This method uses cutting projection to obtain the characteristic curve of the pulse width and power change, and selects an appropriate two-dimensional region of the pulse width and power to avoid the self-temperature rise of the power device. Moreover, the proposed method can be used as a reference when selecting a pulse test method.

Forecasting extreme precipitation event over Munsiyari (Uttarakhand) using 3DVAR data assimilation in mesoscale model

A localized extreme precipitation event occurred over Munsiyari (Uttarakhand, India) on 2nd July 2018 causing flash floods, landslides and damage to the hydropower project. A preliminary study has been carried out by using Weather Research and Forecasting (WRF) model with three-dimensional variation data assimilation technique (3DVAR) to examine the feasibility of the model to predict the localized phenomena. Sensitivity experiments were carried out with two different microphysics in the model. Results show that P3 1-category plus double moment cloud water microphysics scheme with 3DVAR in WRF simulates the quantity of precipitation closer to the observed precipitation over Munsiyari. The vertical velocity and relative humidity were also simulated well during 3DVAR data assimilation as compared to without data assimilation over study region.

Some Actual Problems of Magnetic Filters With Magnetized Packed Beds and Comparative Analysis of Filter Performances

In this article, the filter performance characteristics of magnetic filters obtained by different physical models were compared. Performance models for magnetic filters were chosen based on the balance of forces and momentum that act on the captured particle, and on the collision efficiency of the particle with the filter matrix. The filter performance characteristics of the filtration systems are evaluated based on the magnitude of the external magnetic field, the rate of filtration, the variation of matrix element sizes, and captured particles. Three-dimensional variations of these characteristics were investigated. The experimental data from the literature for the different working conditions were used for comparing various models. The effect of filtration velocity and size variation of the captured particles on the magnetic filter performance over a wide range were evaluated using different models. As a result, a practical mathematical model with the exponential change of the system parameters was found to offer more possibilities to determine the magnetic filter performance. It was proposed that it is possible to determine whether the obtained filter performance models are valid either by making appropriate experiments or using the data in the literature as reference values.

Metameric variation of upper molars in hominoids and its implications for the diversification of molar morphogenesis

Metameric variation of molar size is in part associated with the dietary adaptations of mammals and results from slight alterations of developmental processes. Humans and great apes exhibit conspicuous variation in tooth morphology both between taxa and across tooth types. However, the manner in which metameric variation in molars emerged among apes and humans via evolutionary alterations in developmental processes remains largely unknown. In this study, we compare the enamel-dentine junction of the upper molars of humans—which closely correlates with morphology of the outer enamel surface and is less affected by wear—with that of the other extant hominoids: chimpanzees, bonobos, gorillas, orangutans, and gibbons. We used the morphometric mapping method to quantify and visualize three-dimensional morphological variation, and applied multivariate statistical analyses. Results revealed the following: 1) extant hominoids other than humans share a common pattern of metameric variation characterized by a largely linear change in morphospace; this indicates a relatively simple graded change in metameric molar shape; 2) intertaxon morphological differences become less distinct from the mesial to distal molars; and 3) humans diverge from the extant ape pattern in exhibiting a distinct metameric shape change trajectory in the morphospace. The graded shape change and lower intertaxon resolution from the mesial to distal molars are consistent with the concept of a ‘key’ tooth. The common metameric pattern observed among the extant nonhuman hominoids indicates that developmental patterns underlying metameric variation were largely conserved during ape evolution. Furthermore, the human-specific metameric pattern suggests considerable developmental modifications in the human lineage.

A New Multigrid 3D-VAR Optimization Method for Bottom Friction Using HF Radar Current Observation

This paper proposes a new method for data assimilation of the surface radial current observed by High Frequency ground wave radar and optimization of the bottom friction coefficient. In this method, the shallow water wave equation is introduced into the cost function of the multigrid three-dimensional variation data assimilation method as the weak constraint term, the surface current and the bottom friction coefficient are defined as the analytical variables, and the high spatiotemporal resolution surface radial flow observed by the high-frequency ground wave radar is used to optimize the surface current and bottom friction coefficient. This method can effectively consider the spatiotemporal correlation of radar data and extract multiscale information from surface radial flow data from long waves to short waves. Introducing the shallow water wave equation into the cost function as a weak constraint condition can adjust both the momentum and mass fields simultaneously to obtain more reasonable analysis information. The optimized bottom friction coefficient is introduced into the regional ocean numerical model to carry out numerical experiments. The test results show that the bottom friction coefficient obtained by this method can effectively improve the accuracy of the numerical simulation of sea surface height in the offshore area and reduce the simulation error.

Three-Dimensional Morphological Variations of the Human Calcaneus Investigated Using Geometric Morphometrics.

The shape of the calcaneus determines the mechanical interaction of the foot with the ground during the heel-strike in human walking. Detailed knowledge of the pattern of sexual dimorphism of the human calcaneus could help to clarify the pathogenetic mechanism of foot and knee disorders, which are more prevalent in females. Therefore, the aim of this study was to characterize and visualize the three-dimensional shape variations of the calcaneus in relation to sex and age using geometric morphometrics. Computed tomography images of 56 feet without subtalar injuries or disorders were used in this study. Thirty-seven anatomical landmarks were identified on the bone model of the calcaneus to calculate principal components (PCs) of shape variations among specimens. The PC scores were compared between males and females, and their correlations with age were also analyzed. The female calcaneus was longer in length and shorter in height than that of males. The medial process of the calcaneal tuberosity in females was more inferiorly projected and the tuberosity was shifted more laterally. Also, the calcaneus was wider and the sustentaculum tali thickened with aging. Female structural features of the calcaneus alter the kinematics of the foot during walking and could be a structural factor in foot and knee disorders. This study contributes to a comprehensive understanding of shape variations in the human calcaneus. Clin. Anat., 33:751-758, 2020. © 2019 Wiley Periodicals, Inc.

Current-Driven Dynamics of Magnetic Hopfions.

Topological magnetic textures have attracted considerable interest since they exhibit new properties and might be useful in information technology. Magnetic hopfions are three-dimensional (3D) spatial variations in the magnetization with a nontrivial Hopf index. We find that, in ferromagnetic materials, two types of hopfions, Bloch-type and Néel-type hopfions, can be excited as metastable states in the presence of bulk and interfacial Dzyaloshinskii-Moriya interactions, respectively. We further investigate how hopfions can be driven by currents via spin-transfer torques (STTs) and spin-Hall torques (SHTs). Distinct from 2D ferromagnetic skyrmions, hopfions have a vanishing gyrovector. Consequently, there are no undesirable Hall effects. Néel-type hopfions move along the current direction via both STT and SHT, while Bloch-type hopfions move either transverse to the current direction via SHT or parallel to the current direction via STT. Our findings open the door to utilizing hopfions as information carriers.

Three-dimensional measurement of a thermal lens in K9 glass using a Mach-Zehnder interferometer.

Three-dimensional and time-dependent thermal lens distribution was measured in K9 glass by a Mach-Zehnder interferometer in this paper. The thermal lens was introduced by focusing a millisecond pulse laser into the glass, and the phase information was extracted by Fourier analysis. The specific internal three-dimensional refractive index variation (RIV) was then deduced from phase maps by an inverse Abel algorithm. It is demonstrated that the stress-induced birefringence would lead to negative RIV, which is contrary to results of temperature increment. The method proposed herein would provide a novel idea for measurement of thermal lenses.

Three-dimensional shape variation and sexual dimorphism of the face, nose, and mouth of Japanese individuals

Three-dimensional (3D) shape variations of the face and facial parts in Japanese adults were examined to collect basic data to be used for facial comparison in forensics. In total, 1000 3D facial scans (500 males, 500 females) of Japanese individuals were re-meshed into anatomically homologous shape models and analyzed by principal component analysis (PCA) after Procrustes superimposition. Facial parts (the nose and the mouth) were segmented from homologous face models and analyzed by PCA, too. Among all kinds of objects (the face, the nose, and the mouth), the most predominant shape variation represented by the first principal component (PC1) was the height–width proportion. The second largest variation (PC2) in the face and the nose was depth; for the mouth, it was the relative protrusion of the upper and lower lips. We interpreted predominant shape variations represented by the first five principal components (PCs) in each object. Asymmetric shape variations were observed within these PCs for the nose and the mouth.Sexual dimorphism of the face and the facial parts was also examined by testing the significance of sex-linked differences in PC scores. A significant difference was found between males and females for many PCs. Sexual dimorphism was examined also by emphasizing the shape difference between average male and female faces.Our results revealed predominant 3D shape variations and sexual dimorphism of the face and facial parts. The results may be informative for performing facial comparison in police investigations, an increasingly used technique.

WRF-3DVAR Radiance Data Assimilation Impact for Convective Rain Prediction on Jakarta

Weather Research and Forecasting (WRF) is an open source numerical weather prediction model, but one of the main problems is the inaccuracy of initial condition that impacts the accuracy of weather predictions. Techniques that can be used to improve initial condition is to assimilate satellite radiance data using Three-Dimensional Variation (3DVAR) method. The Global Forecast System (GFS) data were used as initial conditions which were assimilated with several radiance data such as from AMSU-A sensors, MHS sensors, and ATMS sensors. The purpose of this study was to compare the effect of data assimilation on the initial condition model and the rainfall prediction for convective precipitation on February 24, 2016 in Jakarta. The results showed there is a clear flow of moisture to the northern part of Jabodetabek area that cause the model captured a high relative humidity which results in the heavy rain. The result of the study obtained different rainfall prediction between non-assimilation model and assimilation model. In general, both models have underestimated rainfall, but satellite radiance data assimilation is better able to describe the convective rain patterns and has better accuracy on the convective rainfall accumulation per hour.

Exploratory study of the three-dimensional morphological variation of the jaw associated to teeth loss

PurposeThe aim of this study is to evaluate the morphological variability in mandibles with different types of edentulism, comparing the use of traditional morphometrics and tridimensional geometric morphometrics. MethodsTraditional morphometrics and geometric morphometrics (GM) exploratory analysis, by principal components (PCs) and PC scores, were performed on a sample of 24 cadaveric hemi mandibles. A digital reconstruction of 3D surfaces of each specimen was obtained by CT scans segmentation. The mandibles were divided in three groups: full dentition (G1), partial edentition (G2) and total edentition (G3). The results of the two methods were compared in relation to the morphological variability determined with each method. ResultsBoth methods were consistent in terms of morphological variability between the defined groups. The main shape variations observed were a decrease in mandibular body height, a widening of the cross sectional morphology on the symphysis, a shorten-narrowed Ramus and a deeper sigmoid notch, in the partially or totally edentition groups, compared to the full dentition group. DiscussionThe general patterns of morphological variations associated with edentulism that have been reported in literature could be visualized with GM method, which had not been previously used for this purpose. The GM methods could offer a more detailed definition of shape variations, which is critical in a clinical context. Moreover, GM allowed defining configurations of mean morphologies and an image library with different types of morphological variations.

Accelerating cardiac diffusion tensor imaging combining local low-rank and 3D TV constraint.

Diffusion tensor magnetic resonance imaging (DT-MRI, or DTI) is a promising technique for invasively probing biological tissue structures. However, DTI is known to suffer from much longer acquisition time with respect to conventional MRI and the problem is worsened when dealing with in vivo acquisitions. Therefore, faster DTI for both ex vivo and in vivo scans is highly desired. This paper proposes a new compressed sensing (CS) reconstruction method that employs local low-rank (LLR) model and three-dimensional (3D) total variation (TV) constraint to reconstruct cardiac diffusion-weighted (DW) images from highly undersampled k-space data. The LLR model takes the set of DW images corresponding to different diffusion gradient directions as a 3D image volume and decomposes the latter into overlapping 3D blocks. Then, the 3D blocks are stacked as two-dimensional (2D) matrix. Finally, low-rank property is applied to each block matrix and the 3D TV constraint to the 3D image volume. The underlying constrained optimization problem is finally solved using the first-order fast method. The proposed method is evaluated on real ex vivo cardiac DTI data as a prerequisite to in vivo cardiac DTI applications. The results on real human ex vivo cardiac DTI images demonstrate that the proposed method exhibits lower reconstruction errors for DTI indices, including fractional anisotropy (FA), mean diffusivities (MD), transverse angle (TA), and helix angle (HA), compared to existing CS-based DTI image reconstruction techniques. The proposed method provides better reconstruction quality and more accurate DTI indices in comparison with the state-of-the-art CS-based DW image reconstruction methods.