Restoration Of Shape Research Articles

DiffusionBAS: Estimating Camera External Orientation Through Diffusion Process

Abstract. Violent forces such as earthquakes or human interaction can damage or demolish objects of cultural heritage. Many architectural masterpieces have survived only in a few photos or drawings. Moreover, often interior decorations of buildings such as stucco or paintings are destroyed by fire. Therefore, an automatic 2D-to-3D reconstruction that can assists architecture historians in process of restoration of original 3D shape of a lost site of culture heritage is required. An automatic in-paint method can assists restoration of partially destroyed stucco and paintings. We present an end-to-end framework that receives a single image of an object and predicts its vector of the exterior orientation parameters. The main objective of a present work is reconstruction of 3D model of a partially destroyed 3D object and it 3D in-painting. As the initial and prerequisite phase of this framework we propose a new generative model for estimation of the exterior orientation parameters for a given input image using a Diffusion model (DiffusionBAS).

The Use of Traditional Medicinal Plants by Postpartum Mothers in Kecamatan Pasie Raya Kabupaten Aceh Jaya

This study aims to identify the use of traditional medicinal plants by the Acehnese community, specifically for postpartum women in Pasie Raya District, Aceh Jaya Regency. The population of this study consists of women who have recently given birth or have previously given birth, as well as herbal medicine practitioners in Pasie Raya District. The sample includes 3 herbalists and 15 postpartum women who are currently using or have previously used postpartum herbal remedies. The research approach is qualitative, with data collection methods including observation, interviews, and documentation, followed by qualitative descriptive analysis. The results show that the Pasie Raya community uses 11 types of traditional medicinal plants for postpartum women, namely noni, jaloh leaves, sembung leaves, papaya leaves, turmeric, nutmeg, betel leaves, cat’s whiskers leaves, red ginger, soursop, and cirik babi leaves. These plants are processed into various forms, such as pills, liquids, pastes, and poultices, to help restore the physical condition of women after childbirth. The benefits felt include the restoration of the abdominal shape, elimination of unpleasant odors, pain reduction, and body tightening, including the genital area. The processing of these plants is done in various ways, such as drying, grinding, straining, and mixing with other ingredients like honey, tamarind water, eucalyptus oil, and lime. The practice of using these medicinal plants is passed down through generations, reflecting the strong cultural values in traditional medicine within the Pasie Raya community. Despite this, there is awareness of the importance of following the proper dosage and usage methods to avoid negative side effects.

Evaluation of Shape and Volume Restoration of Orbit after Reduction of Orbitozygomatic Fractures

Abstract Background The appearance of the Orbitozygomatic complex (OZC) fracture terminology is contributed to the fact that a fracture in the lateral side of the midface is not strict to anatomical boundaries, however, it involves the zygoma, maxilla and orbital structures. Orbitozygomatic complex fractures are one of the most commonly encountered injuries of the craniofacial skeleton. The solid zygomatic bone acts as a part of the vertical and horizontal facial buttress, along with the malar eminence, which plays a key role in the determination of facial morphology. It forms a significant portion of the floor and lateral wall of the orbit thus it acts as one of the most common contributors to the orbital integrity, restoration of orbital volume is essential to prevent enophthalmos. Objective Evaluate restoration of orbital shape, volume and globe position in the anterior-posterior plane after reduction of zygomatico-orbital fractures. Methods This Prospective observational study was done from March 2023 to August 2023 at plastic, burn and maxillofacial department in El Demerdash Hospital, Ain Shams University. Eighteen (18) adult patients, complaining of post traumatic orbito-zygomatic fractures requiring operative intervention, were included in this study. Evaluations of orbital shape and differences between orbital volume measurements (damaged orbits compared to intact orbits before and after surgery), orbital volume calculated from area marked by delineating bony landmarks of the orbit interconnected by freehand cursor manually on a series of CT slices in the axial plane, the CT images were exported to the CMF orbital analysis software (adw4.7), where the volume was calculated automatically, Depth: measured from orbital rim to the orbital apex, from outer optic foramen to the middle point of a line passing through lateral and medial orbital rims; width: Maximal horizontal distance from lateral to medial rim and height: measured from superior to inferior margin at their maximum distance perpendicular to orbital width. Results The mean volume of the affected orbit throughout our study showed significant decrease from 24.81 ± 2.04 cm3 before the operation to 23.38 ± 2.22 cm3 after the surgical intervention (P < 0.001), indicating a highly significant difference, where volume has significantly increased on fractured side preoperative in comparison to the sound side (P = 0.016) indicating significant effect of trauma on increasing orbital volume from normal, while no statistical difference was noted (P = 0.75) between orbital volume of fractured side postoperatively 23.38 ± 2.22 cm3 and the sound side 23.24 ± 1.64 cm3, indicating proper reduction and restoration of orbital volume to near normal postoperatively, increased depth (45.46 ± 3.26), width (38 ± 2.94) and height (35.7 ± 2.98) of fractured side preoperatively; this increase was statistically significant, While Depth and width showed more increase than height; values were more statistically significant and return to near normal postoperatively (42.96 ± 2.68), (36 ± 2.88) and (34.23 ± 3.45) respectively; this decrease was still significant statistically except for height where it was non-significant, indicating better restoration of height than depth and width attributed to its lesser increase from the first place, as values of sound side weree (41.64 ± 2.25), (34.56 ± 3.25) and (34.51± 3.52) respectively. Conclusion Our study suggests that the surgical reduction of orbitozygomatic fractures has a significant role in restoration of the orbital shape, volume, and globe positioning in the anterior-posterior plane. And that enophthalmos occurrence is greatly influenced by increase of the bony orbital volume, also it’s affected by other factors for further research. Orbital dimensions were affected by trauma and restored to near normal after reduction but showed no major shape changes of the conical orbit.

Deformation mitigation and twisting moment control in space frames

Over the last five decades, space frames have centered on the modernization of touristic zones in view of architectural attractions. Although attempts to control joint movement and minimize axial force and bending moment in such structures were made sufficiently, twisting moments in space frames have been underestimated so far. In space frames, external load or restoring the misshapen shape may cause twisting in members. We herein developed a robust computational algorithm to reduce the induced torsional moment through shape restoration within a desired limit by changing the length of active bars that are placed in space frames. Applying optimization algorithms like interior-point and Sequential quadratic programming (SQP), a direct correlation was pursued between bar length alteration and twisting in structural members. A numerical model of a single-layer space frame resembling an egg captures the twisting moment in all members, achieving a specified limit. The overall length change of the active members using an iterative process based on a heuristic that considers a threshold on the minimum length change of the active members.

Dual and Multi-Target Cone-Beam X-ray Luminescence Computed Tomography Based on the DeepCB-XLCT Network.

Emerging as a hybrid imaging modality, cone-beam X-ray luminescence computed tomography (CB-XLCT) has been developed using X-ray-excitable nanoparticles. In contrast to conventional bio-optical imaging techniques like bioluminescence tomography (BLT) and fluorescence molecular tomography (FMT), CB-XLCT offers the advantage of greater imaging depth while significantly reducing interference from autofluorescence and background fluorescence, owing to its utilization of X-ray-excited nanoparticles. However, due to the intricate excitation process and extensive light scattering within biological tissues, the inverse problem of CB-XLCT is fundamentally ill-conditioned. An end-to-end three-dimensional deep encoder-decoder network, termed DeepCB-XLCT, is introduced to improve the quality of CB-XLCT reconstructions. This network directly establishes a nonlinear mapping between the distribution of internal X-ray-excitable nanoparticles and the corresponding boundary fluorescent signals. To improve the fidelity of target shape restoration, the structural similarity loss (SSIM) was incorporated into the objective function of the DeepCB-XLCT network. Additionally, a loss term specifically for target regions was introduced to improve the network's emphasis on the areas of interest. As a result, the inaccuracies in reconstruction caused by the simplified linear model used in conventional methods can be effectively minimized by the proposed DeepCB-XLCT method. Numerical simulations, phantom experiments, and in vivo experiments with two targets were performed, revealing that the DeepCB-XLCT network enhances reconstruction accuracy regarding contrast-to-noise ratio and shape similarity when compared to traditional methods. In addition, the findings from the XLCT tomographic images involving three targets demonstrate its potential for multi-target CB-XLCT imaging.

SODL-IR-FISTA: sparse online dictionary learning with iterative reduction FISTA for cone-beam X-ray luminescence computed tomography.

Cone beam X-ray luminescence computed tomography (CB-XLCT) is an emerging imaging technique with potential for early 3D tumor detection. However, the reconstruction challenge due to low light absorption and high scattering in tissues makes it a difficult inverse problem. In this study, the online dictionary learning (ODL) method, combined with iterative reduction FISTA (IR-FISTA), has been utilized to achieve high-quality reconstruction. Our method integrates IR-FISTA for efficient and accurate sparse coding, followed by an online stochastic approximation for dictionary updates, effectively capturing the sparse features inherent to the problem. Additionally, a re-sparse step is introduced to enhance the sparsity of the solution, making it better suited for CB-XLCT reconstruction. Numerical simulations and in vivo experiments were conducted to assess the performance of the method. The SODL-IR-FISTA achieved the smallest location error of 0.325 mm in in vivo experiments, which is 58% and 45% of the IVTCG-L 1 (0.562 mm) and OMP-L 0 (0.721 mm), respectively. Additionally, it has the highest DICE similarity coefficient, which is 0.748. The results demonstrate that our approach outperforms traditional methods in terms of localization precision, shape restoration, robustness, and practicality in live subjects.

Functional and Radiological Outcome after Internal Fixation of Intra-articular Calcaneal Fractures.

Calcaneal fractures are rare injuries constituting 2% of all fractures. Fractures of calcaneum correspond to nearly 60-75% of the tarsal bone fractures. The calcaneum is the most commonly fractured tarsal bone 90% occur in males between 21 and 45 years of age. The calcaneal fracture may be extra-articular (sparing the subtalar joint) and intra-articular involving the subtalar joint. Intra-articular fractures account for approximately 75% of calcaneal fractures and have been associated with poor functional outcomes. In this study, we aim to assess the functional outcome of internal fixation in displaced intra-articular calcaneal fractures. A prospective interventional study was conducted on patients with only intra-articular calcaneal fractures admitted to Chettinad Hospital and Research Institute, Kelambakkam during the period from May 1, 2022, to February 29, 2024, and a total of 32 patients were considered. The functional outcome was assessed by the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle Hindfoot Scoring System. The average age of the patients in our study was 39 years of which all were male. Fall from height is the most common mode of injury. The right calcaneum is more commonly involved than the left. The mean duration of hospital stay was around 10 days. The fracture classification was based on the sanders and Essex-Lopresti classification of which 17 patients were sanders type 3 and 13 patients were sanders type 2 and 1 patient was sanders type 4. The mean time for radiological union is 12 weeks. The Bohler's angle and Gissane's angle preoperatively 16.16 ± 8.87 and 121.48 ± 7.47 restored to near normal values after fixation 27.77 ± 6.02 and 113.485 ± 44, respectively. Heel height and heel width restored to near normal values of (pre-operative heel height - 24.74 ± 3.71 and heel width - 39.97 ± 4.11 and post-operative heel height - 31.55 ± 3.38 and heel width - 34.0 ± 3.1), respectively. The most common complications were wound-related complications (superficial wound infection - 9.7%, deep wound infection - 3.2%, and wound margin necrosis and wound dehiscence 6.4%) and the most common late complications were complex regional pain syndrome - 9.7% and subfibular lateral impingement with peroneal tendinitis - 6.5%. AOFAS grading of functional outcome had shown good to excellent results in 83.8% (26 patients) of the cases. The mean AOFAS score was 83.39 in our study. The present study shows that open reduction and internal fixation give superior radiographic results as shown by the restoration of Bohler's and Gissane's angle and height and width of the calcaneus to near normal values, indicating anatomical restoration of calcaneal shape. The functional outcome by AOFAS score showed good to excellent results in most of the patients with minimal wound complications.

Dynamic diffraction of thermal neutrons in crystals with continuous deformation field

The purpose of the work is to consider the basics of the formation of a diffraction wave field of thermal neutrons in the case of Laue transmission geometry of a limited beam of neutrons in the crystal, taking into account the peculiarities of the interaction of thermal neutrons with a continuously and slowly changing deformation field of the crystal net. The conditions of both diffraction blurring and diffraction contraction (focusing) up to the practical restoration of the original shape of the packet will be studied.An integral form for determining the quasi-amplitudes of diffracted waves within the framework of the original spatially inhomogeneous beams is formulated, based on the constructed functions of the influence of a point source of thermal neutron waves for crystals with a continues deformation field. It has been shown that neutron focusing is effective, which is revealed by a smaller half-width of the focal spot, an increase in the resolving power of the energy spectrum and focusing efficiency.

Radiographic assessment of the quality of post and core restorations performed by general dental practitioners in Saudi Arabia

BackgroundDentists utilize various techniques and materials for post and core restoration of endodontically treated teeth, which remains a noteworthy health concern and can be addressed through interdisciplinary strategies to enhance outcomes. Therefore, this study aimed to evaluate the technical quality of the residual gutta-percha (GP) and posts by analysing the periapical radiographs of endodontically restored teeth. MethodsA total of 594 periapical digital radiographs were evaluated for tooth type, post material, post shape, design, diameter, length, residual GP, GP length, GP tapering, GP homogeneity, and final restoration. Frequency distribution and cross-tabulation of the variables were performed. ResultsMaxillary molars had the highest frequency of restorations, including posts, accounting for 27.4 %, followed by maxillary premolars (25.4 %) and maxillary anterior teeth (19.2 %). The prefabricated metallic posts were most commonly used (81.0 %), among these, 50.4 % were screwed posts. Tapered posts were the most commonly used (65.6 %). The percentage of posts with an acceptable length was 58.2 %. The most commonly used posts exhibited a width of one-third of the root diameter, accounting for 87.0 %. Suitable GP lengths were observed in 61.1 % of the restorations, and 62.8 % demonstrated adequate GP homogeneity. The findings of this study revealed that crown restoration accounted for 42.6 % of the studied sample. ConclusionsThe technical quality of the remaining GP after restoration was comparable to that of previous epidemiological investigations. However, the technical quality of the post was deemed suboptimal.

The Incremental Clinical Benefit of Adding Layers of Complexity to the Planning and Execution of Adult Spinal Deformity Corrective Surgery.

For patients with surgical adult spinal deformity (ASD), our understanding of alignment has evolved, especially in the last 20 years. Determination of optimal restoration of alignment and spinal shape has been increasingly studied, yet the assessment of how these alignment schematics have incrementally added benefit to outcomes remains to be evaluated. Patients with ASD with baseline and 2-year were included, classified by 4 alignment measures: Scoliosis Research Society (SRS)-Schwab, Age-Adjusted, Roussouly, and Global Alignment and Proportion (GAP). The incremental benefits of alignment schemas were assessed in chronological order as our understanding of optimal alignment progressed. Alignment was considered improved from baseline based on SRS-Schwab 0 or decrease in severity, Age-Adjusted ideal match, Roussouly current (based on sacral slope) matching theoretical (pelvic incidence-based), and decrease in proportion. Patients separated into 4 first improving in SRS-Schwab at 2-year, second Schwab improvement and matching Age-Adjusted, third two prior with Roussouly, and fourth improvement in all four. Comparison was accomplished with means comparison tests and χ 2 analyses. Sevenhundredthirty-two. patients met inclusion. SRS-Schwab BL: pelvic incidence-lumbar lordosis mismatch (++:32.9%), sagittal vertical axis (++: 23%), pelvic tilt (++:24.6%). 640 (87.4%) met criteria for first, 517 (70.6%) second, 176 (24%) third, and 55 (7.5%) fourth. The addition of Roussouly (third) resulted in lower rates of mechanical complications and proximal junctional kyphosis (48.3%) and higher rates of meeting minimal clinically important difference (MCID) for physical component summary and SRS-Mental ( P < .05) compared with the second. Fourth compared with the third had higher rates of MCID for ODI (44.2% vs third: 28.3%, P = .011) and SRS-Appearance (70.6% vs 44.8%, P < .001). Mechanical complications and proximal junctional kyphosis were lower with the addition of Roussouly ( P = .024), while the addition of GAP had higher rates of meeting MCID for SRS-22 Appearance ( P = .002) and Oswestry Disability Index ( P = .085). Our evaluation of the incremental benefit that alignment schemas have provided in ASD corrective surgery suggests that the addition of Roussouly provided the greatest reduction in mechanical complications, while the incorporation of GAP provided the most significant improvement in patient-reported outcomes.

Restoration Temperature Control through Glass Transition Temperature Modulation of Shape Memory Polymer for Thermally Switchable Adhesive.

Shape memory polymers (SMPs) undergo changes between arbitrary shapes and programmed shapes upon exposure to specific stimulus, allowing them to restore their original shape. All kinds of external stimuli have a threshold to change the shape of the SMP. Especially, for the thermal type SMP, the critical temperature for shape restoration is typically near the glass transition temperature (Tg). In this study, the controllability of the restoration temperature is analyzed by adjusting the Tg of the polymer using Norland Optical Adhesive 63, which can be cured with UV irradiation. By varying the ambient temperature from 20 to 120°C during UV exposure, Tg changes ranging from 35.84 to 50.50°C are obtained, with corresponding changes in restoration temperature. As a practical application, a thermal-activated SMP dry adhesive is developed with programmable Tg and switchable adhesion. The fabricated SMP dry adhesive exhibited strong adhesion to substrates with various surface roughness. Additionally, the shape memory effect allowed for easy detachment through shape recovery, and different adhesive performances at different temperatures are achieved by programming various Tg values. Moreover, the simple manufacturing process of the SMP dry adhesive is confirmed to be suitable for continuous fabrication processes based on roll-to-roll methods.

Oncoplastic Breast Conservation for Central Tumors: Definition, Classification, and the Analysis of Single Institution Experience.

Tumors in the central part of the breast are usually considered more aggressive and technically difficult, which limits breast conservation. The definition of central tumors from a surgical point of view, classification of the techniques for partial breast reconstruction, and conceptual algorithm of choice based on tumor and breast characteristics are proposed, along with the estimation of surgical and oncological safety. This is a retrospective analysis of the single-institution experience, with a focus on the decision-making process for choosing the oncoplastic breast-conserving surgery technique. To evaluate the safety of breast conservation for central tumors, a comparative analysis of early surgical complications and oncological long-term results of treatment in patients with central breast tumor location and other breast tumor locations was performed. A total of 940 lumpectomies were performed in 926 patients during 15 years. The central breast tumor location group included 128 patients with 130 lumpectomies (13.8%), and the other breast tumor locations group included 798 patients with 810 lumpectomies (86.2%). We did not find any significant differences in the rate of early surgical complications and involved margins, local and systemic recurrence rates, time to progression, or overall survival between the groups. Oncoplastic breast-conserving surgery is a safe procedure for the treatment of central tumors. In our opinion, the proposed classification of partial breast reconstruction techniques and an algorithm of their choice allow for effective restoration of the breast shape and volume according to the parameters of the tumor, breast, surgeon, and patient preferences.

The role of forensic odontology and dental anthropology:An approach to forensic issues

Dental treatment essential to justice Action, review of evidence, appropriate evaluation and presentation of dental examination results. Most involve the use of teeth and oral samples for identification in a legal context. Dental anthropology, on the other hand, provides information such as characteristics of teeth, tooth morphology, size and shape changes, restoration, disease, tooth loss, wear pattern, dentistry, color and teeth. Dental records are also useful for comparing teeth; this can help determine a person's age, gender, race or ethnicity, personality and occupation, all of which can take on meaning on their own. The dental profession plays an important role as well as the responsibility to maintain accurate dental records to provide the necessary information to assist in the identification of victims. This article provides an overview of how forensic odontology and dental anthropology play an important role in identifying individuals and finding ways to resolve legal issues.

Novel recursive formula for removing damping distortion effect on bridge mode shape restoration using a two-axle scanning vehicle

Mode shapes recovered for bridges are often distorted by bridge damping when using the vehicle scanning method (VSM). To remedy such an effect, a novel recursive formula utilizing the spatial correlation between the front and rear contact points of a two-axle scanning vehicle is theoretically established. For a bridge subjected to a two-axle moving test vehicle, the dynamic response of the system is first derived in closed form. The vehicle-bridge contact response is used as a substitute for the vehicle response in signal processing, since it is free of the masking effect posed by vehicle frequencies. Using either the Hilbert transform (HT) or wavelet transform (WT), instantaneous amplitudes are extracted for the component response of the bridge of concern. Further, recursive formula that accounts for the spatial correlation between the two contact points is established to recover the undistorted bridge mode shapes. The following are the conclusions: (1) The distortion effect of damping on bridge mode shapes can be effectively removed by the recursive formula against various factors; (2) the WT is more effective in recovering undistorted bridge mode shapes than the HT; and (3) the proposed formula works well for restoring the mode shapes of bridges with rough pavement, by adding an accompanying truck during the vehicle scanning.

Precise tooth design using deep learning-based templates

ObjectivesIn prosthodontic procedures, traditional computer-aided design (CAD) is often time-consuming and lacks accuracy in shape restoration. In this study, we combined implicit template and deep learning (DL) to construct a precise neural network for personalized tooth defect restoration. MethodsNinety models of right maxillary central incisor (80 for training, 10 for validation) were collected. A DL model named ToothDIT was trained to establish an implicit template and a neural network capable of predicting unique identifications. In the validation stage, teeth in validation set were processed into corner, incisive, and medium defects. The defective teeth were inputted into ToothDIT to predict the unique identification, which actuated the deformation of the implicit template to generate the highly customized template (DIT) for the target tooth. Morphological restorations were executed with templates from template shape library (TSL), average tooth template (ATT), and DIT in Exocad (GmbH, Germany). RMSestimate, width, length, aspect ratio, incisal edge curvature, incisive end retraction, and guiding inclination were introduced to assess the restorative accuracy. Statistical analysis was conducted using two-way ANOVA and paired t-test for overall and detailed differences. ResultsDIT displayed significantly smaller RMSestimate than TSL and ATT. In 2D detailed analysis, DIT exhibited significantly less deviations from the natural teeth compared to TSL and ATT. ConclusionThe proposed DL model successfully reconstructed the morphology of anterior teeth with various degrees of defects and achieved satisfactory accuracy. This approach provides a more reliable reference for prostheses design, resulting in enhanced accuracy in morphological restoration. Clinical significanceThis DL model holds promise in assisting dentists and technicians in obtaining morphology templates that closely resemble the original shape of the defective teeth. These customized templates serve as a foundation for enhancing the efficiency and precision of digital restorative design for defective teeth.

Microscopic Electric Rotary Grinding of Plaques Combined with Graft Repair in the Management of Peyronie's Disease.

Peyronie's Disease (PD) is clinically characterized by the development of localized fibrous plaques, primarily on the tunica albuginea, especially on the dorsal area of the penis. These plaques are the hallmark feature of this condition, resulting in penile curvature, deformity, and painful erections for affected individuals. Although various nonsurgical treatment options exist, their overall effectiveness is limited. As a result, surgical intervention has become the ultimate choice for patients with severe penile curvature deformities and associated erectile dysfunction. Our research team has successfully employed a combined approach involving microscopic electric rotary grinding of the fibrous plaques and the use of tunica vaginalis or bovine pericardium as graft materials for the repairing of the defects of tunica albuginea in the treatment of PD. This approach has consistently yielded highly satisfactory results regarding the restoration of penile shape, with excellent cosmetic results and significantly improved sexual satisfaction. This protocol aims to present a comprehensive surgical management strategy utilizing electric rotary grinding of the plaques and repairing the defects of tunica albuginea by using the tunica vaginalis, which represents an optimal surgical strategy for treating PD.

Modulation instability and collision dynamics of solitons in birefringence optical fibers

In this paper, we investigate soliton modulation instability and collision dynamics in the birefringence optical fibers. Soliton transmission in the picosecond or femtosecond range in optical fibers is described by the coupled hybrid nonlinear Schrödinger equations. We focus on the modulation instability of the plane wave solutions and the gain spectrum under different parameters. The three-soliton solutions are used to analyze soliton collisions, and the asymptotic analysis is provided to reveal the properties of soliton collisions. The elastic and inelastic collisions of three-soliton are presented, and there exists the possibility of shape restoration of one or two solitons during the three-soliton inelastic collisions. The relevant results provide not only a new perspective for the realization of optical logic gates, but also theoretical value for the experimental observation of soliton collisions.

Research on sector scanning imaging technology of EMAT for through-hole defects in aluminium plates

ABSTRACT To overcome the drawbacks of traditional electromagnetic acoustic transducers (EMATs) that depend on mechanical scanning, adding to both cost and complexity, this study introduces a sector scanning imaging method utilizing Electromagnetic Ultrasonic Shear Vertical (SV) waves. A simulation model for EMAT was developed, optimizing through variable frequency and unidirectional line focusing coils. The simulation revealed that a novel composite magnetic structure significantly enhanced the magnetic flux density to 1.318 T, a 159.44% increase over conventional magnets, leading to a 102.08% rise in ultrasonic signal intensity and a marked improvement in the signal-to-noise ratio. By converting echo signal time data into spatial coordinates, the technology enables high-resolution defect imaging. The variable frequency-EMAT (VF-EMAT) technique accurately identified defects, with minor discrepancies from actual defect centers, showcasing its precision. The unidirectional line focusing-EMAT (ULF-EMAT) method further improved defect detection accuracy and shape restoration. However, the technique’s reliance on the main-pulse limits its ability to detect near-surface defects, suggesting an avenue for future research.

Adaptive neural network controller for the rotating SMA actuator

In this research, we present a new data-driven Adaptive Neural Network (ANN) controller designed for a unique arc-shaped Shape Memory Alloy (SMA) actuator. The actuator generates rotational motion through two-dimensional shape restoration, which is significantly different from traditional linear SMA actuators. The SMA in an arc-shaped pattern tries to recover its original shape when heated, ultimately leading to rotational motion. Due to complexity in SMA motion, it is difficult to apply conventional empirical modeling methods in this research. Given this modelling difficulty, a model-based control approach may not be promising. Thus, a data-driven ANN is adopted here to control the SMA actuator without relying on precise modelling. This controller adeptly learns the actuator's dynamic behavior in real-time, fine-tuning its neural network weights to ensure optimal control. To validate its efficacy, we compare performance of the ANN controller with that of the traditional Proportional-Integral-Derivative (PID) and sliding mode controllers across two reference inputs (sinusoidal and square) under four different disturbance scenarios (input-output, output-only, input-only, and no disturbance). Our experimental results show the ANN controller can provide similar or slightly better performance in terms of tracking accuracy and disturbance rejection without rigorous parameter or gain tuning compared to traditional controllers. Our results verify advanced learning capabilities of the ANN controller and its potential in control of the SMA actuator.

Methodology of generation of CFD meshes and 4D shape reconstruction of coronary arteries from patient-specific dynamic CT

Due to the difficulties in retrieving both the time-dependent shapes of the vessels and the generation of numerical meshes for such cases, most of the simulations of blood flow in the cardiac arteries use static geometry. The article describes a methodology for generating a sequence of time-dependent 3D shapes based on images of different resolutions and qualities acquired from ECG-gated coronary artery CT angiography. The precision of the shape restoration method has been validated using an independent technique. The original proposed approach also generates for each of the retrieved vessel shapes a numerical mesh of the same topology (connectivity matrix), greatly simplifying the CFD blood flow simulations. This feature is of significant importance in practical CFD simulations, as it gives the possibility of using the mesh-morphing utility, minimizing the computation time and the need of interpolation between boundary meshes at subsequent time instants. The developed technique can be applied to generate numerical meshes in arteries and other organs whose shapes change over time. It is applicable to medical images produced by other than angio-CT modalities.