Fingerprint Domain Research Articles

The Effect of Annealing on the Soft Magnetic Properties and Microstructure of Fe82Si2B13P1C3 Amorphous Iron Cores.

This research paper investigated the impact of normal annealing (NA) and magnetic field annealing (FA) on the soft magnetic properties and microstructure of Fe82Si2B13P1C3 amorphous alloy iron cores. The annealing process involved various methods of magnetic field application: transverse magnetic field annealing (TFA), longitudinal magnetic field annealing (LFA), transverse magnetic field annealing followed by longitudinal magnetic field annealing (TLFA) and longitudinal magnetic field annealing followed by transverse magnetic field annealing (LTFA). The annealed samples were subjected to testing and analysis using techniques such as differential scanning calorimetry (DSC), transmission electron microscopy (TEM), X-ray diffraction (XRD), magnetic performance testing equipment and magneto-optical Kerr microscopy. The obtained results were then compared with those of commercially produced Fe80Si9B11. Fe82Si2B13P1C3 demonstrated the lowest loss of P1.4T,2kHz = 8.1 W/kg when annealed in a transverse magnetic field at 370 °C, which was 17% lower than that of Fe80Si9B11. When influenced by the longitudinal magnetic field, the magnetization curve tended to become more rectangular, and the coercivity (B3500A/m) of Fe82Si2B13P1C3 reached 1.6 T, which was 0.05 T higher than that of Fe80Si9B11. During the 370 °C annealing process of the Fe82Si2B13P1C3 amorphous iron core, the internal stress in the strip gradually dissipated, and impurity domains such as fingerprint domains disappeared and aligned with the length direction of the strip. Consequently, wide strip domains with low resistance and easy magnetization were formed, thereby reducing the overall loss of the amorphous iron core.

Error rates and proficiency tests in the fingerprint domain: A matter of perspective and conceptualization

The purpose of this work is to critically analyse the aspects connected both with the measurement of error rates and with the design of proficiency tests and collaborative exercises in the fingerprint domain. All from the dual perspective of practitioners and organizers of PT’s/CE’s. A thorough analysis of the types of errors, of the methods to infer them through black-box studies and PT’s/CE’s is carried out, and the limits to the generalization of error rates are described, providing insightful indication on how to design PT’s/CE’s in the fingerprint domain, which are aimed to represent the complexity of casework.

Two molecule force spectroscopy on ligand-receptor interactions.

Many biological processes involve the rupture of multiple ligand-receptors or multivalent ligand-receptors. It is challenging to study the rupture of such parallelly arranged multiple ligand-receptors due to the difficulties in engineering such systems in a well-controlled fashion. Here we report the use of two-molecule force spectroscopy to investigate the rupture of two parallelly arranged monomeric streptavidin (mSA)-biotin complexes. By using SpyCatcher-SpyTag chemistry, we successfully engineered a molecular twin of biotin, in which two biotins are arranged in parallel. By reacting mSA with twin biotin, we constructed parallelly arranged two mSA-biotin complexes for force spectroscopy experiments. The incorporation of single molecule fingerprint domains into our mSA-biotin dimers allowed us to identify and assign the rupture events of the parallelly arranged mSA-biotin complexes without any ambiguity in the two-molecule force spectroscopy experiments. Our results revealed that the rupture force of the parallel dimer mSA-biotin is 172 pN at a pulling speed of 400 nm s-1, which is about 1.6 times of that of single mSA-biotin (105 pN). Furthermore, our findings indicate that the two mSA-biotin behave as non-interacting, independent ligand-receptors. The strategy we demonstrated here can be extended to other ligand-receptors and may open up an avenue toward rigorously testing the theoretic predictions proposed in various models regarding the rupture of multiple parallel ligand-receptors.

Quantifying cation-π interactions in marine adhesive proteins using single-molecule force spectroscopy

In marine adhesives, cation-π interactions play an important role in their liquid-liquid phase separation process and underlying their strong interfacial bonding. However, it remains challenging to study the strength of cation-π interactions at the single-molecule level. Here, we engineer a recombinant chimeric polyprotein containing the mussel foot proteins-5 (MFP5) and a finger print domain GB1 to unambiguiously quantify the strength of cation-π interactions using atomic force microscopy (AFM)-based single-molecule force spectroscopy. Our results show that the formation of intermolecular cation-π interactions can be triggered at elevated salt concentrations, consistent with previous ensemble studies. Individual cation-π interaction ruptures at about 70 pN at a pulling speed of 1.6 μm s−1, comparable to the strength of other non-covalent interactions. The strength of cation-π interactions is weakly dependent on pH, which is in stark contrast with the hydrogen bonding and charge-charge interactions. Moreover, we find that the position of the cation-π bonds are formed randomly along the polyprotein chains. The propensity of forming long range cation-π interactions increases considerably when increasing the pH from 4 to 8, presumably due to the neutralization of the positive changes of MFP5. Our study directly quantifies the mechanical strength of cation-π bonds in the biological relavent settings and reveals key design parameters that may inspire the design of biomimetic strong underwater adhesives.

A robust and efficient fingerprint image restoration method based on a phase-field model

In this study, we present a robust and efficient fingerprint image restoration algorithm using the nonlocal Cahn–Hilliard (CH) equation, which was proposed for modeling the microphase separation of diblock copolymers. We take a small local region embedding the damaged domain and solve the nonlocal CH equation to restore the fingerprint image. A Gauss–Seidel type iterative method, which is efficient and simple to implement, is used. The proposed method has the advantage in that the pixel values in the damaged fingerprint domain can be obtained using the image information from the outside of the damaged fingerprint region. Fingerprint restoration based on adjacent pixel information can ensure the accuracy of the fingerprint information with a low computational cost. Computational experiments demonstrated the superior performance of the proposed fingerprint restoration algorithm.

Engineering the Uniform Lying Helical Structure in Chiral Nematic Liquid Crystals: From Morphology Transition to Dimension Control

Chiral nematic liquid crystals (CLCs), with a unique helix structure, have attracted immense recognition over the last few decades owing to the abundant presence in natural phenomena and their diverse applications. However, the optical properties of CLC are usually hindered by the abundance of the so-called fingerprint domains. Up to now, studies have worked on controlling the in-plane orientation of the lying helix through surface rubbing and external stimuli. It remains challenging to achieve a steady and uniform lying helical structure. Here, by varying the surface anchoring strength, a uniform lying helical structure with long-range order is achieved as thermodynamically stable state without any external support. Poly (6-(4-methoxy-azobenzene-4’-oxy) hexyl methacrylate) (PMMAZO)—a liquid crystalline polymer—is deposited onto the silicon substrate to fine-tune the surface anchoring. By changing the grafting density of PMMAZO, both pitch size and morphology of the lying helical structure can be controlled. As the grafting density increases, the enhanced titled deformation of helical structure suppresses the pitch size of CLC at the same cell thickness; as the cell thickness increases, the morphology transition from long-range order stripes to small fingerprint domains is facilitated.

Analysis of Magneto-Optical Hysteresis Loops of Amorphous and Surface-Crystalline Fe-Based Ribbons.

Three Fe-based ribbon-type samples prepared by a conventional planar flow casting process are studied from the viewpoint of the amorphous Fe80Si4B16 and partially surface crystallized Fe80Si10B10, and Fe80.5Nb6.9B12.6, microstructures. Surface magnetic properties are investigated by magneto-optical Kerr microscopy, allowing the measurement of a local hysteresis loop from a selected area on the ribbon surface, and simultaneously, a domain structure corresponding to a definite point at the loop. For an amorphous sample, the changes in the slopes of hysteresis loops are related either to the size of the selected surface area, from which the loop is measured, or to the type, width, and movement of magnetic domains through this area. In the first case, the resizing of the area simulates an effect of changing the diameter of the incident laser beam on the magneto-optical properties of the ribbon. In the latter case, the observed wide-curved and fingerprint domains are responsible for markedly different shapes of the hysteresis loops at lower magnetic fields. If the surface is crystallized, the magnetic properties are more homogenous, showing typical one-jump magnetization reversal with less dependence on the size of the surface area. The magneto-optical experiments are completed by transmission electron microscopy and magnetic force microscopy.

End-to-End Automated Latent Fingerprint Identification With Improved DCNN-FFT Enhancement.

Automatic Latent Fingerprint Identification Systems (AFIS) are most widely used by forensic experts in law enforcement and criminal investigations. One of the critical steps used in automatic latent fingerprint matching is to automatically extract reliable minutiae from fingerprint images. Hence, minutiae extraction is considered to be a very important step in AFIS. The performance of such systems relies heavily on the quality of the input fingerprint images. Most of the state-of-the-art AFIS failed to produce good matching results due to poor ridge patterns and the presence of background noise. To ensure the robustness of fingerprint matching against low quality latent fingerprint images, it is essential to include a good fingerprint enhancement algorithm before minutiae extraction and matching. In this paper, we have proposed an end-to-end fingerprint matching system to automatically enhance, extract minutiae, and produce matching results. To achieve this, we have proposed a method to automatically enhance the poor-quality fingerprint images using the “Automated Deep Convolutional Neural Network (DCNN)” and “Fast Fourier Transform (FFT)” filters. The Deep Convolutional Neural Network (DCNN) produces a frequency enhanced map from fingerprint domain knowledge. We propose an “FFT Enhancement” algorithm to enhance and extract the ridges from the frequency enhanced map. Minutiae from the enhanced ridges are automatically extracted using a proposed “Automated Latent Minutiae Extractor (ALME)”. Based on the extracted minutiae, the fingerprints are automatically aligned, and a matching score is calculated using a proposed “Frequency Enhanced Minutiae Matcher (FEMM)” algorithm. Experiments are conducted on FVC2002, FVC2004, and NIST SD27 latent fingerprint databases. The minutiae extraction results show significant improvement in precision, recall, and F1 scores. We obtained the highest Rank-1 identification rate of 100% for FVC2002/2004 and 84.5% for NIST SD27 fingerprint databases. The matching results reveal that the proposed system outperforms state-of-the-art systems.

Learning a Fixed-Length Fingerprint Representation.

We present DeepPrint, a deep network, which learns to extract fixed-length fingerprint representations of only 200 bytes. DeepPrint incorporates fingerprint domain knowledge, including alignment and minutiae detection, into the deep network architecture to maximize the discriminative power of its representation. The compact, DeepPrint representation has several advantages over the prevailing variable length minutiae representation which (i) requires computationally expensive graph matching techniques, (ii) is difficult to secure using strong encryption schemes (e.g., homomorphic encryption), and (iii) has low discriminative power in poor quality fingerprints where minutiae extraction is unreliable. We benchmark DeepPrint against two top performing COTS SDKs (Verifinger and Innovatrics) from the NIST and FVC evaluations. Coupled with a re-ranking scheme, the DeepPrint rank-1 search accuracy on the NIST SD4 dataset against a gallery of 1.1 million fingerprints is comparable to the top COTS matcher, but it is significantly faster (DeepPrint: 98.80% in 0.3 seconds vs. COTS A: 98.85% in 27 seconds). To the best of our knowledge, the DeepPrint representation is the most compact and discriminative fixed-length fingerprint representation reported in the academic literature.

Facilitation of the ongoing development of fingerprint subject matter expertise

ABSTRACTAlthough considerable expertise exists in the fingerprint domain, there are opportunities for improvements to be made regarding the development and maintenance of expertise, and in the reliable application of scientific methods and principles. Here, we propose a framework for the facilitation of ongoing development of fingerprint subject matter expertise in order to improve reliability and minimize errors. We describe two essential elements to support ongoing development: scientific leadership and continued education. Furthermore, we recommend that examiners should be exposed to opportunities for practice and feedback on the full myriad of tasks that they engage in (e.g. comparisons, report writing, court presentations, and evaluation of the latest scientific developments). These elements and the rationale behind them are discussed here in detail.

The 2016 ENFSI Fingerprint Working Group testing programme

In 2016, the Fingerprint Working Group (EFP-WG) of the European Network of Forensic Science Institutes (ENFSI), officially established an advisory group with the task of organising proficiency tests (PTs), as well as collaborative exercises (CEs) as a way of raising standards within the fingerprint profession.This article will provide an overview of the Visualisation collaborative exercise and the Comparison proficiency test, which were carried out in 2016. Both the exercise and the test were organised and co-funded by the Prevention of and Fight against Crime Programme of the European Union [1–3], Direct Grant “Towards the Vision for European Forensic Science 2020 (TVEFS-2020)” HOME/2013/ISEC/MO/ENFSI/4000005962, work package T3 “Proficiency Tests and Collaborative Exercises for the Fingerprint Domain”. The characteristics of the testing programme are summarised, followed by an overview of the knowledge that has been gained, including lessons learnt.

Magnetic Domain Patterns in Bilayered Ribbons Studied by Magnetic Force Microscopy and Magneto-Optical Kerr Microscopy.

The magnetic domain patterns of amorphous bilayered FeSiB/FeNbSiB and FeNbCuSiB/CoSiB ribbons are observed and analysed using the magneto-optical Kerr microscopy (MOKM) and magnetic force microscopy (MFM). Both microscopic techniques are highly sensitive to the sample surface; possibility of Kerr microscopy to visualize the domains separately in both layers is achieved by focusing the laser spot on the ribbon cross section. Wide curved domains as well as fine fingerprint domains were detected at the surface of ribbons due to presence of local stresses coming from the preparation process. With respect to high lateral resolution of MFM and its out-of-plane magnetization sensitivity, the perpendicularly magnetized crossed stripe domain patterns can be selected as well. Coiling of the ribbons on the half-round-end sample holder is often used to induce and control the magnetic anisotropy of these alloys. Changes in the magnetic domain structure at the outer-coiled surface and its dependence on the sign of magnetostriction coefficient are discussed in detail. Finally, the MFM images in the presence of external in-plane magnetic field up to ±40 kA/m are shown.

Biasing effects of receptor-ligand complexes on protein-unfolding statistics.

Protein receptor-ligand pairs are increasingly used as specific molecular handles in single-molecule protein-unfolding experiments. Further, known marker domains, also referred to as fingerprints, provide unique unfolding signatures to identify specific single-molecule interactions, when receptor-ligand pairs themselves are investigated. We show here that in cases where there is an overlap between the probability distribution associated with fingerprint domain unfolding and that associated with receptor-ligand dissociation, the experimentally measured force distributions are mutually biased. This biasing effect masks the true parameters of the underlying free energy landscape. To address this, we present a model-free theoretical framework that corrects for the biasing effect caused by such overlapping distributions.

Design and modelling of dispersion-engineered rib waveguide for ultra broadband mid-infrared supercontinuum generation

We report a dispersion-engineered As2Se3 chalcogenide glass rib waveguide structure for ultra broadband mid-infrared supercontinuum generation across molecular ‘fingerprint region’. The proposed rib waveguide structure offers non-linear coefficient as high as 18,250 W−1 km−1 at 2.5 μm. Supercontinuum spectrum spanning 2–15 μm, which not only covers the both atmospheric transparent windows (3–5 μm and 8–13 μm) in the mid-infrared domain but also covers the important molecular ‘fingerprint domain’, is obtained using only 4 mm-long rib waveguide structure. To the best of our knowledge, such broadband mid-infrared supercontinuum spectrum in As2Se3-based chalcogenide waveguide geometry is reported for the first time. The proposed design of rib waveguide has potential for robust, integrated and low-cost supercontinuum sources in various applications including frequency comb generation, chemical sensing, food quality control and early cancer diagnostics.

Single-molecule force spectroscopy on polyproteins and receptor–ligand complexes: The current toolbox

Single-molecule force spectroscopy sheds light onto the free energy landscapes governing protein folding and molecular recognition. Since only a single molecule or single molecular complex is probed at any given point in time, the technique is capable of identifying low-probability conformations within a large ensemble of possibilities. It furthermore allows choosing certain unbinding pathways through careful selection of the points at which the force acts on the protein or molecular complex. This review focuses on recent innovations in construct design, site-specific bioconjugation, measurement techniques, instrumental advances, and data analysis methods for improving workflow, throughput, and data yield of AFM-based single-molecule force spectroscopy experiments. Current trends that we highlight include customized fingerprint domains, peptide tags for site-specific covalent surface attachment, and polyproteins that are formed through mechanostable receptor-ligand interactions. Recent methods to improve measurement stability, signal-to-noise ratio, and force precision are presented, and theoretical considerations, analysis methods, and algorithms for analyzing large numbers of force-extension curves are further discussed. The various innovations identified here will serve as a starting point to researchers in the field looking for opportunities to push the limits of the technique further.

Replication Timing and Pediatric Leukemia

Abstract 4609Abnormal temporal control of replication (“replication timing”) is a universal hallmark of cancer, but the significance of this relationship is not understood. During normal development, changes in replication timing are regulated in defined chromosomal units (“replication domains”) of 400–800 kb, with late replication generally associated with stable gene silencing. We have performed genome-wide replication timing mapping on pediatric acute leukemias and identified patterns of replication-timing mis-regulation (“leukemia fingerprints”) in common across multiple types of pediatric leukemia (“multi-lineage fingerprints”), as well as those linked to specific subtypes of acute leukemia and patient-specific fingerprints. Most of the mis-regulated regions are not associated with copy number variation or translocations and correspond to many of the same domains whose replication timing is regulated during normal development. The existence of multi-lineage fingerprints suggests an early origin of their mis-regulation while type-specific and patient-specific fingerprints suggest that mis-regulation continues to occur downstream of the initiating event. Our hypothesis is that there exists an hierarchy of replication-timing mis-regulation, initiating with frozen vestiges of normal hematopoiesis that are inappropriately maintained, followed by additional changes that evolve as the tumor differentiates. These changes may then affect the ability of downstream lineages to activate or silence genes. Since chromatin is assembled at the replication fork, and different types of chromatin are assembled at different times during S phase, changes in replication timing likely contribute to domain-wide changes in chromatin structure, similar to those observed in long range epigenetic silencing (LRES). In fact, we find that genes within leukemia fingerprint domains are significantly enriched for those transcribed during hematopoiesis and/or mis-regulated in cancers. Replication timing is an exceptionally stable epigenetic property that is not easily disturbed by loss or mis-expression of single master regulators of cell fate and is not directly related to transcription, but rather to the stability of gene silencing. Hence, events occurring early in hematopoiesis could have profound effects on the activation of transcriptional programs in downstream lineages. Elucidating the genesis and genealogy of leukemia-specific replication timing fingerprints and their relationship to transcriptional control will be fundamental to understanding their link to the development of acute leukemias. Disclosures:No relevant conflicts of interest to declare.

Origin of the giant electro-optic Kerr effect in La-doped 75PMN-25PT transparent ceramics

Transparent ceramics of La-doped Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) x/75/25 are prepared, and the ferroelectric domains, dielectric, and ferroelectric properties of x/75/25 are investigated. A double hysteresis loop and small fingerprint domains with uniform distribution observed for 3/75/25 indicate an intermediate ferroelectric state. The dielectric behavior under dc bias and the evolution of the hysteresis loop with increasing electric field for 3/75/25 indicate an electric field-induced phase transition, and it is proposed that the unstable intermediate ferroelectric state which would experience obvious field-induced phase transition is the origin of the giant electro-optic Kerr effect observed in La-doped PMN-PT 3/75/25.

An Evaluation Of Fingerprint Security Using Noninvertible Biohash

Biometric analysis for identifying verification is becoming a widespread reality. It is a very challenging and tedious task to develop a biometric template protection scheme which is anonymous, revocable and noninvertible while maintaining decent performance. Cancellable biometrics is one of the best methods used to resolve this problem. In this paper, a new method called as BioHashing which follows the technique of cancellable biometrics in the fingerprint domain is proposed. This proposed method does not require the re-alignment of fingerprints as all the minutiae are translated into a pre-defined two dimensional space based on a reference minutia. After that, the proposed Biohashing method is used to enforce the one-way property (non-invertibility) of the biometric template. The proposed approach is very much resistant to minor translation error and rotation distortion. An Equal Error Rates (EER) of less than 1% is achieved in this approach and performance of the approach is also significant.

Surface magnetic properties and domains observation in as-quenched and annealed FeNbB ribbons

The longitudinal magneto-optical Kerr effect (MOKE) combined with the magneto-optical microscopy is used to investigate the surface magnetic anisotropy and the domain behavior in as-quenched (AQ) and strain-annealed (SA) FeNbB ribbons. X-ray diffraction, conversion electron Mössbauer spectroscopy (CEMS), and scanning electron microscopy (SEM) confirmed the existence of approximately 1.3 μ m thick magnetically harder layer on the ribbon air side, consisting of crystallites embedded in an amorphous matrix. The underneath bulk phase is amorphous and magnetically soft. Residual anisotropies and the domain patterns (wide in-plane domains with 180 ∘ walls and narrow fingerprint domains) corresponding to amorphous phase are mainly caused by the internal stresses originating from the rapid quenching process. In the surface crystalline phase they are gradually overlapped by strip domains with magnetization directions almost perpendicular to the ribbon axis. The anisotropy changes caused by additional annealing and straining of the samples are shown and discussed in detail.

A multiscale directional operator and morphological tools for reconnecting broken ridges in fingerprint images

In this paper, we introduce a multiscale operator which, together with some morphological tools, can be used to reconnect broken components of fingerprint images. This operator, which can be applied to both binary and gray-scale pictures, extracts the orientation field of an image by taking into account information parameters of sets of pixels in a given neighborhood and located in different directions. It has proved to be very robust to noise and outperforms the gradient- and directional mask-based methods, generally used for orientation field definition. Although we illustrate its application in the fingerprint domain, the approach described here can be easily extended to images whose components exhibit well-defined directional information.