Transfer Technique Research Articles

Classification in Early Fire Detection Using Multi-Sensor Nodes-A Transfer Learning Approach.

Effective early fire detection is crucial for preventing damage to people and buildings, especially in fire-prone historic structures. However, due to the infrequent occurrence of fire events throughout a building's lifespan, real-world data for training models are often sparse. In this study, we applied feature representation transfer and instance transfer in the context of early fire detection using multi-sensor nodes. The goal was to investigate whether training data from a small-scale setup (source domain) can be used to identify various incipient fire scenarios in their early stages within a full-scale test room (target domain). In a first step, we employed Linear Discriminant Analysis (LDA) to create a new feature space solely based on the source domain data and predicted four different fire types (smoldering wood, smoldering cotton, smoldering cable and candle fire) in the target domain with a classification rate up to 69% and a Cohen's Kappa of 0.58. Notably, lower classification performance was observed for sensor node positions close to the wall in the full-scale test room. In a second experiment, we applied the TrAdaBoost algorithm as a common instance transfer technique to adapt the model to the target domain, assuming that sparse information from the target domain is available. Boosting the data from 1% to 30% was utilized for individual sensor node positions in the target domain to adapt the model to the target domain. We found that additional boosting improved the classification performance (average classification rate of 73% and an average Cohen's Kappa of 0.63). However, it was noted that excessively boosting the data could lead to overfitting to a specific sensor node position in the target domain, resulting in a reduction in the overall classification performance.

Paraffin-Enabled Superlattice Customization for a Photostimulated Gradient-Responsive Artificial Reflex Arc.

The development of photostimulated-motion artificial reflex arcs - a neural circuit inspired by light-driven motion reflexes - holds significant promises for advancements in robotic perception, navigation, and motion control. However, the fabrication of such systems, especially those that accommodate multiple actions and exhibit gradient responses, remains challenging. Here, a gradient-responsive photostimulated-motion artificial reflex arc is developed by integrating a programmable and tunable photoreceptor based on folded MoS2 at different twist angles. The twisted folded bilayer MoS2 used as photoreceptors can be customized via the transfer technique using patternable paraffin, where the twist angle and fold-line could be controlled. The photoluminescence (PL) intensity is 3.7 times higher at a twist angle of 29° compared to that at 0°, showing a monotonically decreasing indirect bandgap. Through tunable interlayer carrier transport, photoreceptors fabricated using folded bilayer MoS2 at different twist angles demonstrate gradient response time, enabling the photostimulated-motion artificial reflex arc for multiaction responses. They are transformed to digital command flow and studied via machine learning to control the gestures of a robotic hand, showing a prototype of photostimulated gradient-responsive artificial reflex arcs for the first time. This work provides a unique idea for developing intelligent soft robots and next-generation human-computer interfaces.

A Review of Techniques and Bio-Heat Transfer Models Supporting Infrared Thermal Imaging for Diagnosis of Malignancy

The present review aims to analyze the application of infrared thermal imaging, aided by bio-heat models, as a tool for the diagnosis of skin and breast cancers. The state of the art of the related technical procedures, bio-heat transfer modeling, and thermogram post-processing methods is comprehensively reviewed. Once the thermal signatures of different malignant diseases are described, the updated thermographic techniques (steady-state and dynamic) used for cancer diagnosis are discussed in detail, along with the recommended best practices to ensure the most significant thermal contrast observable between the cancerous and healthy tissues. Regarding the dynamic techniques, particular emphasis is placed on innovative methods, such as lock-in thermography, thermal wave imaging, and rotational breast thermography. Forward and inverse modeling techniques for the bio-heat transfer in skin and breast tissues, supporting the thermographic examination and providing accurate data for training artificial intelligence (AI) algorithms, are reported with a special focus on real breast geometry-based 3D models. In terms of inverse techniques, different data processing algorithms to retrieve thermophysical parameters and growth features of tumor lesions are mentioned. Post-processing of infrared images is also described, citing both conventional processing procedures and applications of AI algorithms for tumor detection.

Controlled Preparation of High Quality Bubble-Free and Uniform Conducting Interfaces of Vertical van der Waals Heterostructures of Arrays.

Sharp and clean interfaces of van der Waals (vdW) heterostructures are highly demanded in two-dimensional (2D) materials-based devices. However, current assembly methods usually cause interfacial bubbles and wrinkles, hindering carrier interlayer transport. The preparation of a large-scale vdW heterostructure with a bubble-free interface is still a challenge. Although many efforts have been made to eliminate bubbles, the evolution processes of the interfacial bubbles are rarely studied. Here, the interface bubble formation and evolution of the transferred 2D materials and their vdW heterostructure are systemically studied by the atomic force microscopy (AFM) technique and high-resolution surface current mapping. A thermal annealing procedure is developed to reduce the number of bubbles and to improve the quality of interfaces. In addition, influences of the interface residues and nanosteps on bubble evolution are also discussed. Further, we develop the polystyrene (PS)-mediated polydimethylsiloxane (PDMS) transfer technique to realize the high-quality transfer of heterostructure arrays. Finally, high-resolution surface current mapping results confirm that we can now produce highly uniform electrical conduction interfaces of heterojunctions. This study provides guidance for assembling high quality interfaces and paves the way for production of bubble-free heterostructure-based electronic devices with high performance and good uniformity.

Advancing glenohumeral dysplasia treatment in brachial plexus birth injury: the end-to-side spinal accessory to suprascapular nerve transfer technique

PurposeBrachial plexus birth injury (BPBI) is a common injury with the spectrum of disease prognosis ranging from spontaneous recovery to lifelong debilitating disability. A common sequela of BPBI is glenohumeral dysplasia (GHD) which, if not addressed early on, can lead to shoulder dysfunction as the child matures. However, there are no clear criteria for when to employ various surgical procedures for the correction of GHD.MethodsWe describe our approach to correcting GDH in infants with BPBIs using a reverse end-to-side (ETS) transfer from the spinal accessory to the suprascapular nerve. This technique is employed in infants that present with GHD with poor external rotation (ER) function who would not necessitate a complete end-to-end transfer and are still too young for a tendon transfer. In this study, we present our outcomes in seven patients.ResultsAt presentation, all patients had persistent weakness of the upper trunk and functional limitations of the shoulder. Point-of-care ultrasounds confirmed GHD in each case. Five patients were male, and two patients were female, with a mean age of 3.3 months age (4 days–7 months) at presentation. Surgery was performed on average at 5.8 months of age (3–8.6 months). All seven patients treated with a reverse ETS approach had full recovery of ER according to active movement scores at the latest follow-up. Additionally, ultrasounds at the latest follow-up showed a complete resolution of GHD.ConclusionIn infants with BPBI and evidence of GHD with poor ER, end-to-end nerve transfers, which initially downgrade function, or tendon transfers, that are not age-appropriate for the patient, are not recommended. Instead, we report seven successful cases of infants who underwent ETS spinal accessory to suprascapular nerve transfer for the treatment of GHD following BPBI.

Preparation and characterization of nanocellulose acetate and acrylate polymer composite membrane

Abstract In the present study, a nanocellulose acetate and acrylate polymer composite membrane was formed by the phase transfer technique. The physical and mechanical properties, water flux, and desalination performance of the achieved composite membrane were investigated. When 3 % (w/w) acrylate polymer, 10 % acetylated nanocellulose, and 0.3 % mass fraction of TiO2 were used for the formation of the membrane, the obtained product could reach a tensile strength of 1.97 N/mm2 and a pure water flux of 51 L/(m2 h). Moreover, the composite membrane achieved a desalination rate of 92.4 %. Thus, the obtained composite membrane could meet the performance requirements for the treatment of industrial wastewater.

GaAs Mid-IR Electrically Tunable Metasurfaces.

In this work, we explore III-V based metal-semiconductor-metal structures for tunable metasurfaces. We use an epitaxial transfer technique to transfer a III-V thin film directly on metallic surfaces, realizing III-V metal-semiconductor-metal (MSM) structures without heavily doped semiconductors as substitutes for metal layers. The device platform consists of gold metal layers with a p-i-n GaAs junction. The target resonance wavelength can be tuned by modifying the geometry of the top metal grating on the GaAs, while systematic resonance tunability has been shown through the modulation of various carrier concentration injections in the mid-IR range. Electrically tunable metasurfaces with multilevel biasing can serve as a fundamental building block for electrically tunable metasurfaces. We believe that our demonstration can contribute to understanding the optical tuning of III-V under various biased conditions, inducing changes in metasurfaces.

Factors influencing ovum pick-up technique results in cattle

The Ovum Pick-Up (OPU) technique, which is used in in vitro embryo production (IVP) to retrieve immature oocytes from live donor animals, is one of the most important biotechnological procedures used in cattle breeding. The most important advantage of this technology is that it allows for the reproducible retrieval of immature oocytes from living donor animals. It is particularly useful in dairy cattle breeding to address infertility issues and boost the production of superior animals with high genetic value. The OPU technique offers several advantages, including its applicability to cows ranging from six-month-old calves to the first three months of pregnancy, its effectiveness in animals with genital tract infection or acyclic cattle, and its ability to yield a higher number of embryos within the same period compared to the Multiple Ovulation and Embryo Transfer (MOET) technique. Understanding and improving the technical and biological factors influencing the OPU procedure is necessary to increase and optimize donor animal use in IVP and the number of quality oocytes obtained. This review aims to examine the specifics of the OPU approach and the factors influencing its performance in light of contemporary literature, as well as to propose fresh ideas to researchers.

Comparison of Umbilical Cord Mesenchymal Stem Cells and Fibroblasts as Donor Nuclei for Handmade Cloning in Sheep Using a Single-Cell Transcriptome.

Oocytes are efficient at reprogramming terminally differentiated cells to a totipotent state. Nuclear transfer techniques can exploit this property to produce cloned animals. However, the overall efficiency is low. The use of umbilical cord mesenchymal stem cells (UC-MSCs) as donor nuclei may increase blastocyst rates, but the exact reasons for this remain unexplored. A single-cell transcriptomic approach was used to map the transcriptome profiles of eight-cell embryos that were in vitro-fertilized and handmade-cloned using umbilical cord mesenchymal stem cells and fibroblasts as nuclear donors. Differences were examined at the chromatin level, the level of differentially expressed genes, the level of histone modifications and the level of DNA methylation. This research provides critical information regarding the use of UC-MSCs as a preferred donor nucleus for nuclear transfer techniques. It also offers unique insights into the mechanism of cellular reprogramming.

Research on image style transfer based on deep learning

In many fields, image style transfer has been a popular topic. It also has a long history; the earliest examples date back to the previous century. A number of style transfer techniques are currently flourishing, from manual modeling to the use of neural networks. Image style transfer methods is improving and taking less time. This paper is separated into two main categories to analyze based on picture iteration and model iteration - and summarizes the various techniques of image style transfer based on deep learning in accordance with the timeline. This paper introduces maximum mean difference, Markov random field, and deep image analogy in picture iteration-based image style transfer. In terms of model iteration-based image style migration, this paper introduces generative models and image reconstruction decoders. Finally, the paper presents some recommendations and outlook on the future.

Resolving taphonomic and preparation biases in silicified faunas through paired acid residues and X-ray microscopy.

Paired petrography and acid maceration has shown that preferential silicification of shelly faunas can bias recovery based on taxon and body size. Here, silicified fossils from the Upper Ordovician Edinburg Formation, Strasburg Junction, Virginia, USA, were analyzed using X-ray tomographic microscopy (μCT) in conjunction with recovered residues from acid maceration of the same materials to further examine sources of potential bias. Results reveal that very small (<~1 mm) fossils are poorly resolved in μCT when scanning at lower resolutions (~30 µm), underestimating abundance of taxa including ostracods and bryozoans. Acid maceration, meanwhile, fails to recover poorly silicified fossils prone to disarticulation and/or fragmentation during digestion. Tests for patterns of breakage, however, indicate no significant size or taxonomic bias during extraction. Comparisons of individual fossils from 3-D fossil renders and maceration residues reveal patterns of fragmentation that are taxon-specific and allow the differentiation of biostratinomic and preparational breakage. Multivariate ordinations and cluster analyses of μCT and residue data in general produce concordant results but indicate that the variation in taxonomic composition of our samples is compromised by the resolvability of small size classes in μCT imaging, limiting the utility of this method for addressing paleoecological questions in these specific samples. We suggest that comparability of results will depend strongly on the sample size, taphonomic history, textural, and compositional characteristics of the samples in question, as well as μCT scan parameters. Additionally, applying these methods to different deposits will test the general applicability of the conclusions drawn on the relative strengths and weaknesses of the methods.

Dual-Level Knowledge Distillation via Knowledge Alignment and Correlation.

Knowledge distillation (KD) has become a widely used technique for model compression and knowledge transfer. We find that the standard KD method performs the knowledge alignment on an individual sample indirectly via class prototypes and neglects the structural knowledge between different samples, namely, knowledge correlation. Although recent contrastive learning-based distillation methods can be decomposed into knowledge alignment and correlation, their correlation objectives undesirably push apart representations of samples from the same class, leading to inferior distillation results. To improve the distillation performance, in this work, we propose a novel knowledge correlation objective and introduce the dual-level knowledge distillation (DLKD), which explicitly combines knowledge alignment and correlation together instead of using one single contrastive objective. We show that both knowledge alignment and correlation are necessary to improve the distillation performance. In particular, knowledge correlation can serve as an effective regularization to learn generalized representations. The proposed DLKD is task-agnostic and model-agnostic, and enables effective knowledge transfer from supervised or self-supervised pretrained teachers to students. Experiments show that DLKD outperforms other state-of-the-art methods on a large number of experimental settings including: 1) pretraining strategies; 2) network architectures; 3) datasets; and 4) tasks.

Flow characteristics in a semi-confined circular-pipe impinging jet

The impinging jet is a complex heat and mass transfer technique that involves several process variables, such as the jet Reynolds number, impingement distance, and jet configuration. In this study, the flow characteristics of a semi-confined circular-pipe impinging jet over different Reynolds numbers and impingement distances were experimentally investigated using a two-dimensional particle image velocimetry technique. The confinement was achieved by positioning a plate parallel to the impinging plate at the nozzle exit. The time-averaged velocity field exhibited a recirculation structure that gradually shifted downstream with increasing Reynolds numbers or impingement distances. Notably, at H/d = 2, this downstream shift of the structure was accompanied by an increase in the vortex intensity. Moreover, the confined plate induced alterations in the overall flow pattern within the confined region, significantly reducing the wall jet decay rate compared with both unconfined and confined radial wall jets for H/d ≥ 3. Conversely, the confinement did not affect the expansion of the wall jet. Unlike the free (unconfined) impinging jets, the semi-confined circular-pipe impinging jet did not exhibit self-similar behavior in the conventional outer-scaled coordinates, particularly concerning the turbulence intensity and Reynolds shear stress. Finally, self-similarity in the time-averaged velocity and various turbulence parameters was achieved using the parameter scale proposed in this study, thereby obtaining the corresponding scaling laws in the wall jet region. Our study results can deepen the current understanding of the flow characteristics of semi-confined circular-pipe impinging jets and are significant for optimizing the performance and efficiency of compact electronic packaging equipment.

Functional and morphological evaluation of the trapezius muscle after spinal accessory nerve transfer to brachial plexus nerves.

The main innervation of the trapezius muscle is provided by the spinal accessory nerve. Several studies describe the contributions of cervical plexus roots to the trapezius muscle innervation, either directly or through connections with the spinal accessory nerve. There is no adequate understanding of how the trapezius muscle is affected after using the spinal accessory nerve in nerve transfer procedures with the usual technique, preserving at least 1 branch for the upper trapezius. We evaluated 20 patients with sequelae of traumatic brachial plexus injury who underwent surgical procedures for brachial plexus repair or free muscle transfer, which included the spinal accessory nerve transfer technique and were followed for a minimum of 1 year. The three portions trapezius muscle were evaluated by physical examination, magnetic resonance imaging (analysis of fatty degeneration) and electromyography. In all evaluation methods, the middle and lower portions of the trapezius muscle showed more significant morphological and/or functional impairment than the upper portion, in most cases. There was a statistically significant difference in all the complementary exams results, between the affected side (with sacrifice of the nerve) versus the normal side, in the middle and lower portions of the trapezius muscle. Physical examination alone is not sufficient to determine the residual functionality of the trapezius muscle. Magnetic resonance imaging and electromyography are useful tools to assess both morphological involvement of the trapezius muscle and nerve conduction impairment of the trapezius muscle, respectively. The results suggest that the middle and lower portions of the trapezius muscle are affected by previous SAN transfer and should be considered with caution for further muscle transfer procedures.

A Comprehensive Review of Evaluating Donor Site Morbidity and Scar Outcomes in Skin Transfer Techniques.

This comprehensive review delves into the intricacies of donor site morbidity and scar outcomes in skin transfer techniques central to the field of reconstructive surgery. The review synthesizes existing literature to illuminate the multifaceted factors influencing outcomes by surveying a broad spectrum of grafting methods, from traditional autografts to cutting-edge tissue engineering approaches. Key findings underscore the complex interplay of graft characteristics, surgical techniques, and patient-specific variables. The implications for clinical practice advocate for a nuanced, patient-centered approach, incorporating emerging minimally invasive procedures and adjuvant therapies. The review concludes with recommendations for future research, emphasizing the importance of longitudinal studies, comparative analyses, patient-reported outcomes, advanced imaging techniques, and exploration of tissue engineering innovations. This synthesis advances our understanding of donor site morbidity and scar outcomes. It provides a roadmap for refining clinical protocols, ultimately enhancing the delicate balance between therapeutic efficacy and patient well-being in reconstructive surgery.

Weighted fair energy transfer in a UAV network: A multi-agent deep reinforcement learning approach

Flying Energy Sources (FESs) have been proven highly effective in transferring energy to battery-powered Unmanned Aerial Vehicles (UAVs). Such wireless transfer techniques in the literature were able to extend the flight duration of UAVs; however, they overlooked the fair distribution of energy among UAVs, which is of utmost importance for supporting diverse application demands. In this work, we quantify the urgency level of a UAV following its application responsibility, energy charging, and drainage rates and develop a framework for optimal energy transfer from FESs to UAVs in a weighted-fair way. Even though the developed framework can promote a highly balanced and fair energy distribution, its computation cannot always be done in polynomial time. Alternatively, to achieve a real-time solution, we further develop a Multi-Agent Deep Deterministic Policy Gradient (MADDPG) algorithm, namely AERIAL, to effectively model the complex interactions and dependencies among the UAVs and FESs and improve the wireless energy transfer process. The AERIAL system is implemented in the OpenAI Gym simulator platform and its performances have been compared with the state-of-the-art approaches. As high as improvements of 25.2% in fairness and 19.4% in average energy level demonstrated by the AERIAL system prove its effectiveness.

Investigating ultra-low frequency emissions and total electron content anomalies as earthquake precursors in Sumatra (2019–2020)

Ultra-low frequency (ULF) emissions and total electron content (TEC) anomalies are potential earthquake precursors for short-term earthquake prediction. This study comprehensively examines ULF emissions and TEC anomalies associated with the Sumatra earthquakes spanning 2019–2020. Precursor ULF emissions are identified through the polarization power ratio calculations involving Z-component and H-component geomagnetic data, meticulously recorded by the Magnetik Acquisition Data System (MAGDAS). Employing the Single Station Function Transfer technique, ULF anomalies directed toward the epicenter of earthquakes are recognized as reliable precursors. Among the 29 earthquakes scrutinized, 25 were heralded by ULF emissions acting as precursors. Among these, 15 instances solely exhibited ULF emissions, unaccompanied by TEC anomalies, while the remaining ten were linked to TEC anomalies. The investigation of TEC anomalies employs advanced autocorrelation techniques rooted in the analysis of correlation coefficient deviations. TEC anomalies are meticulously acquired from the observations of the Sumatran GPS Array (SuGAr) stations. Furthermore, this study illuminates a positive correlation (R = 0.65) between the lead time of ULF emissions and TEC anomalies. Moreover, the frequency of ULF emissions and TEC anomalies also showcases a direct relationship with earthquake magnitude. Heightened frequencies of ULF emissions and TEC anomalies as earthquake precursors correspond to more significant magnitudes in ensuing earthquakes. The outcomes of this research significantly augment the understanding of employing ULF emissions and TEC anomalies as effective earthquake precursors in the context of Sumatra.

Proton-Assisted Assembly of Colloidal Nanoparticles into Wafer-Scale Monolayers in Seconds.

Underwater adhesion processes in nature promise controllable assembly of functional nanoparticles for industrial mass production; However, their artificial strategies have faced challenges to uniformly transfer nanoparticles into a monolayer, particularly those below 100nm in size, over large areas. Here a scalable "one-shot" self-limiting nanoparticle transfer technique is presented, enabling the efficient transport of nanoparticles from water in microscopic volumes to an entire 2-inch wafer in a remarkably short time of 10 seconds to reach near-maximal surface coverage (≈40%) in a 2D mono-layered fashion. Employing proton engineering in electrostatic assembly accelerates the diffusion of nanoparticles (over 50 µm2/s), resulting in a hundredfold faster coating speed than the previously reported results in the literature. This charge-sensitive process further enables "pick-and-place" nanoparticle patterning at the wafer scale, with large flexibility in surface materials, including flexible metal oxides and 3D-printed polymers. As a result, the fabrication of wafer-scale disordered plasmonic metasurfaces in seconds is successfully demonstrated. These metasurfaces exhibit consistent resonating colors across diverse material and geometrical platforms, showcasing their potential for applications in full-color painting and optical encryption devices.

Strain-restricted transfer of ferromagnetic electrodes for constructing reproducibly superior-quality spintronic devices

Spintronic device is the fundamental platform for spin-related academic and practical studies. However, conventional techniques with energetic deposition or boorish transfer of ferromagnetic metal inevitably introduce uncontrollable damage and undesired contamination in various spin-transport-channel materials, leading to partially attenuated and widely distributed spintronic device performances. These issues will eventually confuse the conclusions of academic studies and limit the practical applications of spintronics. Here we propose a polymer-assistant strain-restricted transfer technique that allows perfectly transferring the pre-patterned ferromagnetic electrodes onto channel materials without any damage and change on the properties of magnetism, interface, and channel. This technique is found productive for pursuing superior-quality spintronic devices with high controllability and reproducibility. It can also apply to various-kind (organic, inorganic, organic-inorganic hybrid, or carbon-based) and diverse-morphology (smooth, rough, even discontinuous) channel materials. This technique can be very useful for reliable device construction and will facilitate the technological transition of spintronic study.

One-Step Non-Contact Additive LIFT Printing of Silver Interconnectors for Flexible Printed Circuits

The single-pass one-step method for printing conductive silver tracks on a glass surface, using the laser-induced forward transfer (LIFT) technique, was proposed, providing a unique opportunity for high-throughput printing of surface micro- and nanostructures with high electrical conductivity and positioning accuracy. This method was developed via our multi-parametric research, resulting in the selection of the optimal material, laser irradiation, and transfer conditions. Optical, scanning and transmission electron, and atomic force microscopy methods, as well as X-ray diffraction, were used to characterize the surface structure and phase state of the printed structures, while energy-dispersive X-ray and X-ray photoelectron microscopy were employed for their chemical microanalysis. Depending on the laser irradiation parameters, the specific electrical conductivity of the printed tracks varied from 0.18 to 83 kS/cm, approaching that of donor magnetron-sputtered films. This single-pass one-step method significantly facilitates fast, large-scale, on-demand local laser printing of metallic (sub)microcomponents of microelectronic devices.