In order to classify partial entanglement of multi-partite states, it is natural to consider the convex hulls, intersections and differences of basic convex cones obtained from partially separable ...states with respect to partitions of systems. In this paper, we consider convex cones consisting of -shaped three qubit states arising in this way. The class of -shaped states includes important classes like Greenberger-Horne-Zeilinger diagonal states. We find all the extreme rays of those convex cones to exhibit corresponding partially separable states. We also give characterizations for those cones which give rise to necessary criteria in terms of diagonal and anti-diagonal entries for general three qubit states.
The present study with 248 German teachers examined the conceptual separability of six dimensions of teachers’ self-concept (pedagogical skills, subject content knowledge, consulting, innovation, ...media use, diagnostics) and three emotions (enjoyment, anger, anxiety) as well as relations of these constructs. Results showed that all self-concepts and emotions were clearly separable from each other. All six self-concepts were positively related to enjoyment and negatively related to anxiety and anger. However, regression analysis revealed that only self-concept of pedagogical skills was positively linked to enjoyment and negatively linked to anger, while only self-concept of subject content knowledge was negatively linked to anxiety.
•Teachers' self-concepts are multifaceted.•Teachers' self-concepts are differentially related to specific emotions.•Only self-concept of pedagogical skills is positively linked to enjoyment.•Only self-concept of pedagogical skills is negatively linked to anger.•Only self-concept of subject content knowledge is negatively linked to anxiety.
Attribute reduction is one of the most important preprocessing steps in machine learning and data mining. As a key step of attribute reduction, attribute evaluation directly affects classification ...performance, search time, and stopping criterion. The existing evaluation functions are greatly dependent on the relationship between objects, which makes its computational time and space more costly. To solve this problem, we propose a novel separability-based evaluation function and reduction method by using the relationship between objects and decision categories directly. The degree of aggregation (DA) of intraclass objects and the degree of dispersion (DD) of between-class objects are first defined to measure the significance of an attribute subset. Then, the separability of attribute subsets is defined by DA and DD in fuzzy decision systems, and we design a sequentially forward selection based on the separability (SFSS) algorithm to select attributes. Furthermore, a postpruning strategy is introduced to prevent overfitting and determine a termination parameter. Finally, the SFSS algorithm is compared with some typical reduction algorithms using some public datasets from UCI and ELVIRA Biomedical repositories. The interpretability of SFSS is directly presented by the performance on MNIST handwritten digits. The experimental comparisons show that SFSS is fast and robust, which has higher classification accuracy and compression ratio, with extremely low computational time.
We show that the class of C-hereditarily conjugacy separable groups is closed under taking arbitrary graph products whenever the class C is an extension closed variety of finite groups. As a ...consequence we show that the class of C-conjugacy separable groups is closed under taking arbitrary graph products. In particular, we show that right angled Coxeter groups are hereditarily conjugacy separable and 2-hereditarily conjugacy separable, and we show that infinitely generated right angled Artin groups are hereditarily conjugacy separable and p-hereditarily conjugacy separable for every prime number p.
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Uniform Bi2MoO6 nanosheets were grown in a high dispersed fashion on electrospun BiFeO3 nanofibers via a solvothermal technique. The loading amount of Bi2MoO6 in the Bi2MoO6/BiFeO3 ...heterojunction nanofibers could be controlled by adjusting the precursor concentrations in the solvothermal process. The XPS analysis, energy band position calculation and trapping experiments all proved that the Bi2MoO6/BiFeO3 heterojunction is a Z-scheme heterojunction. The Z-scheme Bi2MoO6/BiFeO3 heterojunction had a much higher photocatalytic activity in the visible-light photodegradation of Rhodamine B (RhB) and tetracycline hydrochloride (TC) than pure BiFeO3 nanofibers or pure Bi2MoO6 nanosheets. The enhanced photocatalytic activity was attributed to the formation of Z-scheme Bi2MoO6/BiFeO3 heterojunctions, which could be beneficial to the separation of photogenerated electron-hole pairs. Moreover, the Bi2MoO6/BiFeO3 heterojunction nanofibers could be easily separated under an external magnetic field via the ferromagnetic BiFeO3. After several cycles, the photocatalytic activity of the Bi2MoO6/BiFeO3 heterojunction no longer significantly decreased suggesting that the Bi2MoO6/BiFeO3 heterojunction is stable. These Z-scheme Bi2MoO6/BiFeO3 heterojunction nanofibers with highly visible-light photocatalytic activity, excellent chemical stability and magnetic separability could be useful in many practical applications.
In this paper, we construct a separable reversible data hiding scheme for encrypted JPEG bitstreams. Our proposed scheme is constructed via a reserving-room-before-encryption manner, that is, the ...original JPEG bitstream is modified with small distortion so that the content owner can reserve enough space for future data embedding and then the modified JPEG bitstream is encrypted. To do that, our key observation is that the least significant bits of the two-bit appended values in the JPEG bitstream is a biased bitstream. Thus we design a new lossless compression algorithm for biased bitstreams with better compression ratio than the binary arithmetic coding method to fulfill the above task for pre-reserving space. With this room-reserving technique, the encrypted JPEG bitstream can be generated and the data embedding in this encrypted bitstream can be done easily by the data hider. Finally, the receiver is able to extract the embedded data and recovers the original JPEG bitstream independently.
•A separable reversible data hiding scheme for encrypted JPEG bitstreams is proposed.•The encryption method keeps the JPEG file structure unchanged.•A new lossless compression algorithm for biased bitstreams is proposed.•The proposed scheme is constructed via a reserving-room-before-encryption manner.
Abstract
We study separability in arbitrary multipartite quantum systems based on principal base matrices. Necessary conditions are presented for different kinds of separable states. These conditions ...can give a complete classification of multipartite quantum states. While the usual Bloch representation of a density matrix uses three types of generators, the representation with principal base matrices has one uniform type of generator which simplifies computation. In this paper, we take advantage of this simplicity to derive useful and operational criteria to detect multipartite separability. We first obtain criteria on detecting
1
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3
separable,
2
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2
separable,
1
−
1
−
2
separable and fully separable four-partite quantum states. We then study
k
-separability for multipartite quantum states in arbitrary dimensions. Detailed examples are given to show that our criteria are able to detect more entanglement states than some existing criteria.
In this work, we present a study about the non-separability of degrees of freedom (DoF) of light in mixed modes, which emulates entangled mixed states. We explore bipartite spin–orbit modes and, by ...adding path DoF to spin–orbit modes, we propose an optical circuit to prepare tripartite non-separable mixed modes that extend the scenario of the classical-quantum analogy of non-separable modes. By using Machine Learning it was possible to show that we can characterize non-separability unambiguously with partial tomography measurements only on Sz basis, which is a remarkable advantage for higher dimension modes avoiding many tomographic measurements.
•Separability verification of mixed modes by partial tomography and machine learning.•Linear optical circuit for tripartite non-separable mixed optical modes preparation.•Linear optical circuit for tomography of tripartite mixed optical modes.•Emulation of entangled tripartite mixed states with intense laser beam.
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