Orthogonal subspace projection (OSP) is a versatile hyperspectral imaging technique which has shown great potential in dimensionality reduction, target detection, spectral unmixing, etc. However, due ...to its inherent requirement of prior target knowledge, OSP has not been explored in anomaly detection. This article takes advantage of an unsupervised OSP-based algorithm, automatic target generation process (ATGP), and a recently developed OSP-go decomposition (OSP-GoDec) along with data sphering (DS) to make OSP applicable to anomaly detection. Its idea is to implement ATGP on the background (BKG) and target subspaces constructed from the low-rank matrix L and sparse matrix S generated by OSP-GoDec to derive an OSP-based anomaly detector (OSP-AD). In particular, OSP-AD also includes DS to remove BKG interference from the target subspace so as to enhance anomaly detection. Surprisingly, operating data samples on different constructions of the BKG subspace and the target subspace yields various versions of OSP-AD. Experiments show that given an appropriate construction of the BKG subspace and the target subspace, OSP-AD can be shown to outperform existing anomaly detectors including Reed-Xiaoli anomaly detector and collaborative representation-based anomaly detector (CRD).
This paper develops a new Neyman-Pearson detection approach, to be called band-specified virtual dimensionality (BSVD), to estimating the number of bands required by band selection (BS), ...<inline-formula> <tex-math notation="LaTeX">n_{\mathrm {BS}} </tex-math></inline-formula>, as well as finding desired bands at the same time. Its idea is derived from target-specified virtual dimensionality (TSVD) where targets under hypotheses as signal sources in TSVD are replaced with bands as signal sources and the test statistics derived for a Neyman-Pearson detector (NPD) is signal-to-noise ratio (SNR) that is used to derive orthogonal subspace projection (OSP) approach for hyperspectral image classification and dimensionality reduction. Accordingly, the resulting virtual dimensionality is referred to as OSP-based BSVD. Several benefits resulting from BSVD cannot be offered by the traditional BS methods. One is its direct approach to dealing with <inline-formula> <tex-math notation="LaTeX">n_{\mathrm {BS}} </tex-math></inline-formula>. Another is no-search strategy needed for finding optimal bands. Instead, it uses NPD to determine and rank desired bands for band prioritization. Most importantly, it determines <inline-formula> <tex-math notation="LaTeX">n_{\mathrm {BS}} </tex-math></inline-formula> and finds desired bands simultaneously and progressively.
We consider the Hamiltonian reduction and canonical quantization of a massive AdS2 superparticle realized on the coset SO(1,1). The phase space of the massive superparticle is represented as a ...coadjoint orbit of a timelike element of . This orbit has a well defined symplectic structure and the symmetry is realized as the Poisson bracket algebra of the Noether charges. We then construct canonical coordinates given by one bosonic and one fermionic oscillator, whose quantization leads to the Holstein-Primakoff type realization of . We also perform a similar analysis and discuss new features and inconsistencies in the massless case.
An orthogonal basis of weight vectors for a class of infinite-dimensional representations of the orthosymplectic Lie superalgebra is introduced. These representations are particular lowest weight ...representations V(p), with a lowest weight of the form , p being a positive integer. Explicit expressions for the transformation of the basis under the action of algebra generators are found. Since the relations of algebra generators correspond to the defining relations of m pairs of parafermion operators and n pairs of paraboson operators with relative parafermion relations, the parastatistics Fock space of order p is also explicitly constructed. Furthermore, the representations V(p) are shown to have interesting characters in terms of supersymmetric Schur functions, and a simple character formula is also obtained.
Orthogonal subspace projection (OSP) has found many applications in hyperspectral data exploitation. Its effectiveness and usefulness result from implementation of two stage processes, i.e., ...annihilation of undesired signal sources by an OSP via inverting a matrix in the first stage followed by a matched filter to extract the desired signal source in the second stage. This paper presents a theory of recursive OSP (ROSP) for hyperspectral imaging, which performs OSP recursively without inverting undesired signature matrices. This ROSP opens up many new dimensions in extending OSP. First of all, ROSP allows OSP to implement varying signatures via a recursive equation without reinverting undesired signature matrices. Second, ROSP can be further used to derive an unsupervised ROSP (UROSP) OSP, which allows OSP to find a growing number of unknown signal sources recursively while simultaneously determining a desired number of signal sources. As a result, the commonly used automatic target generation process (ATGP) can be extended to a recursive ATGP, which can be considered as a special case of UROSP. Third, for practical applications, UROSP can be also extended in two differ ent fashions to causal process and progressive process, which give rise to causal UROSP and progressive UROSP, respectively, both of which can be easily realized in hardware implementation. Finally, UROSP provides a feasible stopping rule via a recently developed UROSP-specified virtual dimensionality.
The orthogonal subspace projection (OSP) approach has received considerable interest in hyperspectral data exploitation recently. It has been shown to be a versatile technique for a wide range of ...applications. Unfortunately, insights into its design rationale have not been investigated and have yet to be explored. This work conducts a comprehensive study and analysis on the OSP from several signal processing perspectives and further discusses in depth how to effectively operate the OSP using different levels of a priori target knowledge for target detection and classification. Additionally, it looks into various assumptions made in the OSP and analyzes filters with different forms, some of which turn out to be well-known and popular target detectors and classifiers. It also shows how the OSP is related to the well-known least-squares-based linear spectral mixture analysis and how the OSP takes advantage of Gaussian noise to arrive at the Gaussian maximum-likelihood detector/estimator and likelihood ratio test. Extensive experiments are also included in this paper to simulate various scenarios to illustrate the utility of the OSP operating under various assumptions and different degrees of target knowledge.
Certification of graduates of the Faculty of Medicine 2 of the National Medical University (NMU) in pediatric disciplines was conducted by the Department of Pediatrics 2 at the objective structured ...practical (clinical) exam 2 (OSP(C)E-2) station “Initial and resuscitation care to a newborn child” on the basis of the Educational and Scientific Center of Medical Simulations of the NMU. The methodology that we introduced in 2022 in the Medical Education journal was presented and approved at the methodical meeting of the heads of departments of pediatrics of higher education institutions of Ukraine during the Sidelnikov readings. The data of an anonymous survey of graduates demonstrated that most respondents (93.4 % of domestic and 91.9 % of foreign ones) were satisfied with the volume of the station and its practical orientation. The students noted that during preparation to exam, this particular model of the station allows them to master, when using mannequins, manipulations according to the algorithm of initial and resuscitation care to a newborn child, which can be useful under various circumstances in wartime conditions. Out of 338 students of the Faculty of Medicine 2, 303 (89.6 %) passed the OSP(C)E-2 exam with an “excellent” grade, 32 (9.4 %) with a “good” grade, and 3 (0.9 %) with a “satisfactory” grade. The issue of optimality and adequacy of assessing only the skills in initial and resuscitation care to a newborn child at the OSP(C)E-2 exam remained debatable among teachers. This corresponds to the opinion of 8.1 % of domestic and 6.6 % of foreign students who believe that for perfection and objectivity of pediatric skills assessment, it would be desirable to introduce one more pediatric station for the OSP(C)E-2 exam with the involvement of a virtual a patient of a different age. Experience of certification in pediatric disciplines of higher education graduates majoring in 222 “medicine” specialty at the Bogomolets National Medical University, both teachers and students, testified to its effectiveness and objectivity in assessing the special competencies of graduates in providing resuscitation care to a newborn child.
Display omitted
•OsP2 nanoparticles anchored on N,P-doped carbon as new catalyst is synthesized.•The interaction between OsP2 nanoparticles and carbon is good to the catalysis.•Hydrogen evolution ...reaction proceeds by Volmer-Heyrovsky mechanism in acid media.•This new electrocatalyst exhibits excellent HER activity at all PH values.
Exploring hydrogen evolution reaction (HER) catalysts with high activity over the wide range of pH (0–14) is of great significance, but extremely challenging. Noble-metal phosphides are newly developed electrocatalysts that can function well at all pH values. Despite the pivotal role Os compounds have played in the progress of catalytic chemistry, its phosphides have never been demonstrated to mediate the HER. Herein, we report a new OsP2-based electrocatalyst that consists of fine OsP2 nanoparticles (NPs) dispersed over N,P co-doped carbon film (OsP2@NPC) using a combination of template and pyrolysis methods. Impressively, this novel OsP2@NPC exhibits improved HER activity compared with Os@NPC, with small overpotentials of 38, 54, and 70 mV at 10 mA cm−2 and Tafel slopes of 40, 82, and 67 mV dec−1, and better stability than commercial Pt/C in 0.5 M H2SO4, 1.0 M phosphate buffer solution, and 1.0 M KOH, respectively. The experimental and computational results indicate that both the unique structure of the porous interconnected network and the interaction between OsP2 NPs and NPC contribute to the robust activity. Meanwhile, the ∼40 mV dec−1 Tafel slope in 0.5 M H2SO4 and the density functional theory (DFT) calculations suggest the predominant Volmer-Heyrovsky mechanism for the OsP2-catalyzed HER, with electrochemical desorption of hydrogen as the rate-limiting step. This new electrocatalyst is expected to enlarge the growing family of transition metal phosphides for the HER.
Low-rank and sparsity-matrix decomposition (LRaSMD) has received considerable interests lately. One of effective methods for LRaSMD is called go decomposition (GoDec), which finds low-rank and sparse ...matrices iteratively subject to the predetermined low-rank matrix order <inline-formula> <tex-math notation="LaTeX">m </tex-math></inline-formula> and sparsity cardinality <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula>. This article presents an orthogonal subspace-projection (OSP) version of GoDec to be called OSP-GoDec, which implements GoDec in an iterative process by a sequence of OSPs to find desired low-rank and sparse matrices. In order to resolve the issues of empirically determining <inline-formula> <tex-math notation="LaTeX">p = m+ j </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula>, the well-known virtual dimensionality (VD) is used to estimate <inline-formula> <tex-math notation="LaTeX">p </tex-math></inline-formula> in conjunction with the Kuybeda et al. developed minimax-singular value decomposition (MX-SVD) in the maximum orthogonal complement algorithm (MOCA) to estimate <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula>. Consequently, LRaSMD can be realized by implementing OSP-GoDec using <inline-formula> <tex-math notation="LaTeX">p </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula> determined by VD and MX-SVD, respectively. Its application to anomaly detection demonstrates that the proposed OSP-GoDec coupled with VD and MX-SVD performs very effectively and better than the commonly used LRaSMD-based anomaly detectors.
With the development of over-the-top (OTT) services, the demand for content is increasing, and you can easily and conveniently acquire various content in the online environment. As a result, ...copyrighted content can be easily copied and distributed, resulting in serious copyright infringement. Some special forms of online service providers (OSP) use filtering-based technologies to protect copyrights, but illegal uploaders use methods that bypass traditional filters. Uploading with a title that bypasses the filter cannot use a similar search method to detect illegal content. In this paper, we propose a technique for profiling the Heavy Uploader by normalizing the bypassed content title and efficiently detecting illegal content. First, the word is extracted from the normalized title and converted into a bit-array to detect illegal works. This Bloom Filter method has a characteristic that there are false positives but no false negatives. The false positive rate has a trade-off relationship with processing performance. As the false positive rate increases, the processing performance increases, and when the false positive rate decreases, the processing performance increases. We increased the detection rate by directly comparing the word to the result of increasing the false positive rate of the Bloom Filter. The processing time was also as fast as when the false positive rate was increased. Afterwards, we create a function that includes information about overall piracy and identify clustering-based heavy uploaders. Analyze the behavior of heavy uploaders to find the first uploader and detect the source site.
PDF
