Depolarized Holography with Polarization-multiplexing Metasurface

The evolution of computer-generated holography (CGH) algorithms has prompted significant improvements in the performances of holographic displays. Nonetheless, they start to encounter a limited degree of freedom in CGH optimization and physical constraints stemming from the coherent nature of holograms. To surpass the physical limitations, we consider polarization as a new degree of freedom by utilizing a novel optical platform called metasurface. Polarization-multiplexing metasurfaces enable incoherent-like behavior in holographic displays due to the mutual incoherence of orthogonal polarization states. We leverage this unique characteristic of a metasurface by integrating it into a holographic display and exploiting polarization diversity to bring an additional degree of freedom for CGH algorithms. To minimize the speckle noise while maximizing the image quality, we devise a fully differentiable optimization pipeline by taking into account the metasurface proxy model, thereby jointly optimizing spatial light modulator phase patterns and geometric parameters of metasurface nanostructures. We evaluate the metasurface-enabled depolarized holography through simulations and experiments, demonstrating its ability to reduce speckle noise and enhance image quality.Comment: 15 pages, 13 figures, to be published in SIGGRAPH Asia 202

An Empirical Examination of Consumer Behavior for Search and Experience Goods in Sentiment Analysis

With the explosive increase of user-generated content such as product reviews and social media, sentiment analysis has emerged as an area of interest. Sentiment analysis is a useful method to analyze product reviews, and product feature extraction is an important task in sentiment analysis, during which one identifies features of products from reviews. Product features are categorized by product type, such as search goods or experience goods, and their characteristics are totally different. Thus, we examine whether the classification performance differs by product type. The findings show that the optimal threshold varies by product type, and simply decreasing the threshold to cover many features does not guarantee improvement of the classification performance

Constant-round Dynamic Group Key Exchange from RLWE Assumption

In this paper, we propose a novel lattice-based group key exchange protocol with dynamic membership. Our protocol is constructed by generalizing Dutta-Barua protocol to RLWE setting, inspired by Apon et al.’s recent paper in PQCrypto 2019. We describe our (static) group key exchange protocol from Apon et al.’s paper by modifying its third round and computation step. Then, we present both authenticated and dynamic group key exchange protocol with Join and Leave algorithms. The number of rounds for authenticated group key exchange remains the same as unauthenticated one. Our protocol also supports the scalable property so that the number of rounds does not change depending on the number of group participants. By assuming the hardness of RLWE assumption and unforgeability of digital signatures, we give a full security proof for (un-)authenticated (dynamic) group key exchange protocols

A Review System Based On Product Features In A Mobile Environment

With the rapid growth of the mobile commerce, firms have been trying to get their online channels optimized for the mobile devices. However, many contents on online shopping sites are still focused on a desktop PC environment. Especially, consumer reviews are difficult to browse and grasp via a mobile device. Usually, it is not helpful to simply reduce the size of fonts or photos to fit to mobile devices without a fundamental transformation of the review presentation. In this study, we suggest a feature-based summarization process of consumer reviews in mobile environment. Further, we illustrate an implementation of the process by applying opinion mining techniques to product reviews crawled from a major shopping site in Korean. Finally, a plan for a controlled laboratory experiment is proposed to validate the effectiveness of the suggested review framework in this study

SUPER MULTI-VIEW NEAR-EYE DISPLAY WITH LED ARRAY AND WAVEGUIDE ILLUMINATION MODULE

A near-eye display includes an array of light sources, a reflective spatial light modulator (SLM) synchronized with the array of light sources and configured to modulate and reflect incident light beams to generate images, display optics configured to project the images generated by the reflective SLM to a user’s eye, and a waveguide between the display optics and the reflective SLM, where the waveguide is configured to guide light beams emitted by the array of light sources and direct the light beams towards the reflective SLM to illuminate the reflective SL

A study of the impact of secondary organisms on physiology of Moorella thermoacetica

The isolation and cultivation method of microorganisms has been explored to study morphology, physiology, genetics, and pathogenicity of organisms in detail. Pure cultured microorganisms provide us informative knowledge on the physiology of organisms but it has some limits in the examination of interactions of microorganisms with their microbial community. Coculture study has strong merits in that it helps us understand interactions between microorganisms and predict the phenotypic changes that might occur during the cultivation. The physiology of Moorella thermoacetica was examined when it was cocultured with six secondary organisms : Geobacter sulfurreducens, Thermotoga maritima, Clostridium ljungdhalii, Sporomusa ovata, Methanosarcina barkeri, and Methanococcus maripaludis. M. thermoacetica growth was enhanced only with supplementation of G. sulfurreducens cells. To interpret the cause of the amplified growth of M. thermoacetica, different components of G. sulfurreducens were examined. The metabolites were analyzed by mass spectrometer in order to find the compound responsible for the growth advantage of M. thermoacetica. From LCMS analysis, total 138 compounds were detected as metabolites of M. thermoacetica. The genetic profiles of M. thermoacetica and M. thermoacetica with filtered G. sulfurreducens media were analyzed. Detection of plasmid pJIR418 in Cmr transformants of M. thermoacetica was also performed by PCR after the extraction of plasmid. Single compound or genes responsible for the stimulation of growth of M. thermoacetica were unable to be identified. When M. thermoacetica was supplemented with G. sulfurreducens, the biomass was doubled but the hydrogen production was decreased. RNA sequencing result shows no significant change in hydrogenase activity between two samples, which indicates M. thermoacetica produces hydrogen and consumes hydrogen for respiration as well. The genes identified for the respiration, however, were not up-regulated with the supplementation of G. sulfurreducens. The results indicate that the secondary organisms have an impact on the proteomics or fluxomics level of M. thermoacetic