Interfacial chemical bonding-mediated ionic resistive switching.

In this paper, we present a unique resistive switching (RS) mechanism study of Pt/TiO2/Pt cell, one of the most widely studied RS system, by focusing on the role of interfacial bonding at the active TiO2-Pt interface, as opposed to a physico-chemical change within the RS film. This study was enabled by the use of a non-conventional scanning probe-based setup. The nanoscale cell is formed by bringing a Pt/TiO2-coated atomic force microscope tip into contact with a flat substrate coated with Pt. The study reveals that electrical resistance and interfacial bonding status are highly coupled together. An oxygen-mediated chemical bonding at the active interface between TiO2 and Pt is a necessary condition for a non-polar low-resistance state, and a reset switching process disconnects the chemical bonding. Bipolar switching mode did not involve the chemical bonding. The nature of chemical bonding at the TiO2-metal interface is further studied by density functional theory calculations

Optimal QoE Scheduling in MPEG-DASH Video Streaming

DASH is a popular technology for video streaming over the Internet. However, the quality of experience (QoE), a measure of humans’ perceived satisfaction of the quality of these streamed videos, is their subjective opinion, which is difficult to evaluate. Previous studies only considered network-based indices and focused on them to provide smooth video playback instead of improving the true QoE experienced by humans. In this study, we designed a series of click density experiments to verify whether different resolutions could affect the QoE for different video scenes. We observed that, in a single video segment, different scenes with the same resolution could affect the viewer’s QoE differently. It is true that the user’s satisfaction as a result of watching high-resolution video segments is always greater than that when watching low-resolution video segments of the same scenes. However, the most important observation is that low-resolution video segments yield higher viewing QoE gain in slow motion scenes than in fast motion scenes. Thus, the inclusion of more high-resolution segments in the fast motion scenes and more low-resolution segments in the slow motion scenes would be expected to maximize the user’s viewing QoE. In this study, to evaluate the user’s true experience, we convert the viewing QoE into a satisfaction quality score, termed the Q-score, for scenes with different resolutions in each video segment. Additionally, we developed an optimal segment assignment (OSA) algorithm for Q-score optimization in environments characterized by a constrained network bandwidth. Our experimental results show that application of the OSA algorithm to the playback schedule significantly improved users’ viewing satisfaction

CasNet: Investigating Channel Robustness for Speech Separation

Recording channel mismatch between training and testing conditions has been shown to be a serious problem for speech separation. This situation greatly reduces the separation performance, and cannot meet the requirement of daily use. In this study, inheriting the use of our previously constructed TAT-2mix corpus, we address the channel mismatch problem by proposing a channel-aware audio separation network (CasNet), a deep learning framework for end-to-end time-domain speech separation. CasNet is implemented on top of TasNet. Channel embedding (characterizing channel information in a mixture of multiple utterances) generated by Channel Encoder is introduced into the separation module by the FiLM technique. Through two training strategies, we explore two roles that channel embedding may play: 1) a real-life noise disturbance, making the model more robust, or 2) a guide, instructing the separation model to retain the desired channel information. Experimental results on TAT-2mix show that CasNet trained with both training strategies outperforms the TasNet baseline, which does not use channel embeddings.Comment: Submitted to ICASSP 202

Green tea extract supplementation ameliorates CCl4-induced hepatic oxidative stress, fibrosis, and acute-phase protein expression in rat

Background/PurposeWe evaluated the long-term effects of green tea extract (GTE) supplementation on oxidative stress, biliary acute phase protein expression, and liver function in CCl4-induced chronic liver injury.MethodsWe evaluated the antioxidant activity of GTE in comparison with those of vitamin C, vitamin E, and β-carotene in vitro by using an ultrasensitive chemiluminescence analyzer. Chronic liver injury was induced by intraperitoneally administering carbon tetrachloride (CCl4) (1mL/kg body weight, twice weekly) to female Wistar rats for 8 weeks. The effects of low (4mg/kg body weight per day) and high (20mg/kg body weight per day) doses of intragastric GTE on CCl4-induced liver dysfunction and fibrosis were examined by measuring the bile and blood reactive oxygen species levels and biochemical parameters by using Western blot and two-dimensional polyacrylamide gel electrophoresis techniques.ResultsGTE has greater scavenging activity against O2–, H2O2, and Hypochlorous acid (HOCl) in vitro than vitamin C, vitamin E, and β-carotene do. In vivo, CCl4 markedly increased bile and blood reactive oxygen species production, lipid accumulation, number of infiltrated leukocytes, fibrosis, hepatic hydroxyproline content, and plasma alanine aminotransferase and aspartate aminotransferase activities, and reduced plasma albumin levels. Two-dimensional polyacrylamide gel electrophoresis revealed that CCl4 increased the acute-phase expression of six biliary proteins and decreased hepatic B-cell lymphoma 2 (Bcl-2), catalase, and CuZn superoxide dismutase protein expression. GTE supplementation attenuated CCl4-enhanced oxidative stress, levels of biochemical parameters, pathology, and acute-phase protein secretion, and preserved antioxidant/antiapoptotic protein expression.ConclusionGTE supplementation attenuates CCl4-induced hepatic oxidative stress, fibrosis, acute phase protein excretion, and hepatic dysfunction via the antioxidant and antiapoptotic defense mechanisms

Archaeobotanical evidence of plant cultivation from the Sanbaopi site in south-western Taiwan during the Late Neolithic and Metal Age

Despite decades of lively debate about Taiwan’s role in the spread of early agriculture, crops and cultivation practices to the Indo-Pacific region, there is little archaeobotanical data from the island. Here we present the first directly dated and systematically analysed macrobotanical records from Taiwan obtained by flotation at the archaeological site Sanbaopi 5 (23°07′03′′N, 120°15′32′′E), representing the Dahu (1400 BCE–100 CE) and Niaosong (100–1400 CE) culture periods. The results suggest that Middle Dahu (900–100 BCE) communities in the study area practiced rainfed crop cultivation with mainly foxtail (Setaria italica) and broomcorn (Panicum miliaceum) millet and rice (Oryza sativa). Pulses (Vigna angularis, Glycine soja/max) were also part of the subsistence of local farmers and used as supplementary food and/or green manure. The archaeobotanical record together with archaeological site data for prehistoric China substantiates evidence that the Dahu culture originates in the Lower Yellow River region and migrated to Taiwan along the East China Sea coast. The emergence of the Dahu culture coincided with the spread of mixed millet-rice farming to the Korean Peninsula and Japan and was possibly related to enhanced economic and political expansion of the Shang and Western Zhou dynasties and the long-term weakening of summer monsoon precipitation. Pigeon pea (Cajanus cajan) and mung bean (V. radiata var. radiata) assemblages from the sixth century CE Niaosong period highlight the influx of goods, crops, knowledge and people from South and Southeast Asia via southern routes in the context of enhanced exchange across the South China Sea region

Comparative analysis for datadriven temporal filters obtained via principal component analysis (PCA) and linear discriminant analysis (LDA) in speech recognition

Abstract The Linear Discriminant Analysis (LDA) has been widely used to derive the data-driven temporal filtering of speech feature vectors. In this paper, we proposed that the Principal Component Analysis (PCA) can also be used in the optimization process just as LDA to obtain the temporal filters, and detailed comparative analysis between these two approaches are presented and discussed. It's found that the PCA-derived temporal filters significantly improve the recognition performance of the original MFCC features as LDA-derived filters do. Also, while PCA/LDA filters are combined with the conventional temporal filters, RASTA or CMS, the recognition performance will be further improved regardless the training and testing environments are matched or mismatched, compressed or noise corrupted