Stacked Siamese Neural Network (SSiNN) on Neural Codes for Content-Based Image Retrieval

Content-based image retrieval (CBIR) represents a class of problems that aims at finding relevant images in response to an image-based search query. The CBIR systems use similarity measures or distance metrics between a group of representative features in the query image and those in the image repository. Traditionally, these features were generated by hand, employing image features such as colour, texture, shape, and so on. Due to the fact that these methods do not provide a comprehensive perspective of the images, they cannot be widely utilized in contemporary CBIR systems. This is due to the so-called semantic gap between query intent and system perspective. The most recent advancements in deep learning offer a viable alternative to manually built features, leveraging the representational learning capability of deep neural networks. This paper presents a method of implementing a CBIR system using a multi-stage approach known as classify, differentiate, and retrieve (CDR). The first stage involves using a deep neural network to encode the images. Later, a custom-trained stacked Siamese Neural network (SSiNN) is employed to differentiate the latent space representation of the images obtained from the first stage. The experimental results for the CIFAR-10 dataset were presented, along with an algorithm for applying this strategy to any generic dataset. Experimental outcomes demonstrate that the proposed strategy is superior to the current best practices

Low PAPR STBCs from Complex Partial-Orthogonal Designs (CPODs)

Space-time codes from complex orthogonal designs (CODs) with no zero entries offer low peak to average power ratio (PAPR) and avoid the problem of turning off antennas. But CODs for 2alpha antennas with alpha + 1 complex variables, with no zero entries are not known in the literature for alpha ges 4. In this paper, a method of obtaining no zero entry (NZE) codes, called complex partial-orthogonal designs (CPODs), for 2alpha+1 antennas whenever a certain type of NZE code exists for 2alpha antennas is presented. This is achieved with slight increase in the ML decoding complexity for regular QAM constellations and no increase for other complex constellations. Since NZE CODs have been constructed for 8 antennas our method leads to NZE CPODs for 16 antennas. Moreover, starting from certain NZE CPODs for n antennas, a construction procedure is given to obtain NZE CPODs for 2n antennas. The class of CPODs do not offer full-diversity for all complex constellations. For the NZE CPODs presented in the paper, conditions on the signal sets which will guarantee full-diversity are identified. Simulations results show that bit error performance of our codes under average power constraint is same as that of the CODs and superior to CODs under peak power constraint

Complex Near-Orthogonal Designs with No Zero Entry

Zero entries in Complex Orthogonal Designs (CODs) impede their practical implementation. In this paper, a method of obtaining a No Zero Entry (NZE) code for 2^k+1 antennas whenever a NZE code exists for 2^k antennas is presented. This is achieved with slight increase in the ML decoding complexity for regular QAM constellations and no increase for other complex constellations. Since NZE CODs have been constructed recently for 8 antennas our method leads to NZE codes for 16 antennas. Simulation results show good performance of our new codes compared to the well known constructions for 16 and 32 antennas under peak power constraints

Low PAPR square STBCs from complex partial-orthogonal designs (CPODs)

Space-time codes from complex orthogonal designs (CODs) with no zero entries offer low Peak to Average Power Ratio (PAPR) and avoid the problem of switching off antennas. But square CODs for 2^a antennas with a+1 complex variables, with no zero entries were discovered only for a les 3 and if a+1 = 2^k, for k ges 4. In this paper, a method of obtaining no zero entry (NZE) square designs, called Complex Partial-Orthogonal Designs (CPODs), for 2^a+1 antennas whenever a certain type of NZE code exists for 2a antennas is presented. Then, starting from a so constructed NZE CPOD for n = 2^a+1 antennas, a construction procedure is given to obtain NZE CPODs for 2n antennas, successively. Compared to the CODs, CPODs have slightly more ML decoding complexity for rectangular QAM constellations and the same ML decoding complexity for other complex constellations. Using the recently constructed NZE CODs for 8 antennas our method leads to NZE CPODs for 16 antennas. The class of CPODs do not offer full-diversity for all complex constellations. For the NZE CPODs presented in the paper, conditions on the signal sets which will guarantee full diversity are identified. Simulation results show that bit error performance of our codes is same as that of the CODs under average power constraint and superior to CODs under peak power constraint

Capacity of layered cathode materials for lithium-ion batteries — a theoretical study and experimental evaluation

The theoretical capacity and the vacancy concentration of metal-ion-doped layered compounds such as LiCoO2, LiNiO2, and LiMnO2, acting as cathodes in high-voltage lithium-ion batteries are calculated. The capacity shows strong dependence on valency of the doped metal ion and vacancy concentration. Experimental verification carried out to check the validity of the proposed equation for aluminium substitution into the potential layered materials shows good agreement between the experimental and theoretical capacity values. The vacancy concentration values of doped layered compounds have been found to be high when compared with that of the doped spinel compounds. Keywords: Lithium-ion batteries, Doped compounds, Layered cathodic materials, Theoretical capacity, Vacancy concentratio