Dynamic and Super-Personalized Media Ecosystem Driven by Generative AI: Unpredictable Plays Never Repeating The Same

This paper introduces a media service model that exploits artificial intelligence (AI) video generators at the receive end. This proposal deviates from the traditional multimedia ecosystem, completely relying on in-house production, by shifting part of the content creation onto the receiver. We bring a semantic process into the framework, allowing the distribution network to provide service elements that prompt the content generator, rather than distributing encoded data of fully finished programs. The service elements include fine-tailored text descriptions, lightweight image data of some objects, or application programming interfaces, comprehensively referred to as semantic sources, and the user terminal translates the received semantic data into video frames. Empowered by the random nature of generative AI, the users could then experience super-personalized services accordingly. The proposed idea incorporates the situations in which the user receives different service providers' element packages; a sequence of packages over time, or multiple packages at the same time. Given promised in-context coherence and content integrity, the combinatory dynamics will amplify the service diversity, allowing the users to always chance upon new experiences. This work particularly aims at short-form videos and advertisements, which the users would easily feel fatigued by seeing the same frame sequence every time. In those use cases, the content provider's role will be recast as scripting semantic sources, transformed from a thorough producer. Overall, this work explores a new form of media ecosystem facilitated by receiver-embedded generative models, featuring both random content dynamics and enhanced delivery efficiency simultaneously.Comment: 13 pages, 7 figure

Guided cracking of electrodes by stretching prism-patterned membrane electrode assemblies for high-performance fuel cells

Guided cracks were successfully generated in an electrode using the concentrated surface stress of a prism-patterned Nafion membrane. An electrode with guided cracks was formed by stretching the catalyst-coated Nafion membrane. The morphological features of the stretched membrane electrode assembly (MEA) were investigated with respect to variation in the prism pattern dimension (prism pitches of 20 μm and 50 μm) and applied strain (S ≈ 0.5 and 1.0). The behaviour of water on the surface of the cracked electrode was examined using environmental scanning electron microscopy. Guided cracks in the electrode layer were shown to be efficient water reservoirs and liquid water passages. The MEAs with and without guided cracks were incorporated into fuel cells, and electrochemical measurements were conducted. As expected, all MEAs with guided cracks exhibited better performance than conventional MEAs, mainly because of the improved water transport. © 2018 The Author(s)1

Origami-Based Flexible and Simple Tubular Polymer Electrolyte Membrane Fuel Cell Stack

© 2021 American Chemical Society.Flexible energy devices are essential for future small and flexible devices, and there are many challenges to create deformable energy devices. In this study, we developed a lightweight and flexible passive air-breathing polymer electrolyte membrane fuel cell (PEMFC) stack with a flexible 3D structure using a straw-like tubular design. This stack is lighter than a conventional PEMFC stack because it contains a smaller number of components. By applying a conical design, the device was easily assembled with the units connected in series using banded-type connections (i.e., without clamps or fixing parts). Moreover, for the first time, a conical reverse truss origami design was applied to the tubular PEMFC, which enabled 3D movement and reduced the volume of the PEMFC. The flexible tubular PEMFC is expected to be an energy source for small devices and can be used to replace wires or external fuel pipelines in devices that require mechanical movement.11Nsciescopu

Characterization and Modeling of UHF Wireless Channel in Terrestrial SFN Environments: Urban Fading Profiles

[EN] This paper proposes several realistic fading channel models to describe the signal distortions that arise in single frequency network (SFN) environments. The proposed models characterize ultra-high frequency (UHF) wireless channels based on measurements from operating networks in metropolitan areas. In this paper, the unique features of SFN transmission are identified compared to the conventional, single antenna transmission channels. The impacts of urban propagation, tower configuration, and mobile and terrain effects are considered based on the tapped delay line structure. The proposed models can provide a useful reference to facilitate the SFN system design, network planning, verification, and receiver performance test. Free MATLAB source code of the fading simulator is available at https://github.com/ETRI-KMOU/FadingChannelSimulatorThis work was supported by the Institute of Information and Communications Technology Planning and Evaluation (IITP) Grant funded by the Korea Government (MSIT, Development of Convergence Transmission and Technology for 5G and ATSC 3.0 Networks) under Grant 2020-0-00846. This work was partially presented at IEEE BMSB in 2022 [DOI: 10.1109/BMSB55706.2022.9828617].Ahn, S.; Kim, J.; Ahn, S.; Kwon, S.; Jeon, S.; Gomez-Barquero, D.; Angueira, P.... (2022). Characterization and Modeling of UHF Wireless Channel in Terrestrial SFN Environments: Urban Fading Profiles. IEEE Transactions on Broadcasting (Online). 68(4):803-818. https://doi.org/10.1109/TBC.2022.321038280381868

Structural modification of electrode for anion exchange membrane fuel cell by controlling ionomer dispersion

An appropriate electrode microstructure design should be necessary to achieve high-performance anion exchange membrane fuel cells (AEMFCs). In general, the electrodes are fabricated from catalyst slurries which contain self-assembled agglomerates of catalyst particles with ionomer dispersed in a solvent. Therefore, solvent nature greatly affects the microstructure of the electrode, such as the pore structure and the formation of triple-phase boundaries for electrochemical reactions. Here, we investigate the influence of solvent on the microstructure of I2 ionomer-based electrode and its performance using three alcohol-based solvents (ethanol, 2-propanol, and 2-methyl-2-propanol [tBuOH)) with different dielectric constants and similar boiling points. Various physical and electrochemical characterization confirmed that the electrode pore structure changes significantly depending on the type of solvent while the electrochemically active surface area hardly changes. Furthermore, the efect of the three electrodes with different pore structures on AEMFC performance is observed for anode and cathode, respectively. It is demonstrated that the porous electrode with large pores is more advantageous in performance than a dense electrode at both the anode and the cathode for AEMFC. Consequently, the membrane electrode assembly with porous tBuOH-based electrodes exhibits more than 40% higher performance (1.32 W cm(-2)) than dense ethanol-based electrodes (0.94 W cm(-2)).11Nsciescopu

The impact of the catalyst layer structure on the performance of anion exchange membrane fuel cell

© 2021Intrinsic water imbalance in AEMFC complicates the mass transport phenomena in the electrodes and causes performance loss. Because an AEMFC electrode is a complex multi-component system composed of agglomerates of carbon-supported catalyst bound to ionomer, balancing these components is critical for better water management. Herein, we clarify the influence of the three electrode parameters (ionomer content, active material loading, and active material to carbon ratio) on AEMFC performance using commercial AEM and AEI (FAA-3–50 membrane and FAA-3 ionomer) with standard precious metal catalysts (PtRu/C and Pt/C). The influence of the electrode parameters of each electrode (anode and cathode) was investigated individually. Physical and electrochemical measurements revealed that the cell performance was highly dependent on each electrode parameter for both electrodes, and it was confirmed that the supply of water by back-diffusion rather than oxygen at the cathode, as well as water flooding at the anode, limited the performance of the AEMFC. In particular, we demonstrate commercial material-based AEMFC with specific power over 3 W mgPGM−1 with low PGM loading (0.2 mgPGM cm−2) by adjusting the anode and cathode electrode parameters.11Nsciescopu

Renal-Adenocarcinoma-Associated Erythrocytosis in a Cat

A 9-year-old spayed female domestic shorthair cat was referred for erythrocytosis. Even after the correction of dehydration, blood analyses showed that there had been no improvement. An abdominal ultrasonography and computed tomography identified the presence of a mass on the left kidney. Measurement of serum erythropoietin (EPO) showed higher concentration than the reference interval. These findings suggested a direct association of the erythrocytosis with excessive EPO production. The cat underwent nephrectomy of the affected (left) kidney. Subsequent histopathology was consistent with a diagnosis of renal adenocarcinoma. Following the nephrectomy, serum EPO concentrations decreased gradually, and the erythrocytosis resolved 15 days postoperatively. This case describes the diagnosis and treatment of secondary inappropriate erythrocytosis in a cat with renal adenocarcinoma

Gold nanoparticle formation via x-ray radiolysis investigated with time-resolved x-ray liquidography

© 2020 by the authors. We report the generation of gold nanoparticles (AuNPs) from the aqueous solution of chloro(2,2′,2′′-terpyridine)gold(III) ion ([Au(tpy)Cl]2+ ) through X-ray radiolysis and optical excitation at a synchrotron. The original purpose of the experiment was to investigate the photoinduced structural changes of [Au(tpy)Cl]2+ upon 400 nm excitation using time-resolved X-ray liquidography (TRXL). Initially, the TRXL data did not show any signal that would suggest structural changes of the solute molecule, but after an induction time, the TRXL data started to show sharp peaks and valleys. In the early phase, AuNPs with two types of morphology, dendrites, and spheres, were formed by the reducing action of hydrated electrons generated by the X-ray radiolysis of water, thereby allowing the detection of TRXL data due to the laser-induced lattice expansion and relaxation of AuNPs. Along with the lattice expansion, the dendritic and spherical AuNPs were transformed into smaller, raspberry-shaped AuNPs of a relatively uniform size via ablation by the optical femtosecond laser pulse used for the TRXL experiment. Density functional theory calculations confirm that the reduction potential of the metal complex relative to the hydration potential of X-ray-generated electrons determines the facile AuNP formation observed for [Au(tpy)Cl]2+11sciescopu