392 research outputs found

    An Approximate Dynamic Programming Approach to Vehicle Platooning Coordination in Networks

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    Platooning connected and autonomous vehicles (CAVs) provide significant benefits in terms of traffic efficiency and fuel economy. However, most existing platooning systems assume the availability of pre-determined plans, which is not feasible in real-time scenarios. In this paper, we address this issue in time-dependent networks by formulating a Markov decision process at each junction, aiming to minimize travel time and fuel consumption. Initially, we analyze coordinated platooning without routing to explore the cooperation among controllers on an identical path. We propose two novel approaches based on approximate dynamic programming, offering suboptimal control in the context of a stochastic finite horizon problem. The results demonstrate the superiority of the approximation in the policy space. Furthermore, we investigate platooning in a network setting, where speed profiles and routes are determined simultaneously. To simplify the problem, we decouple the action space by prioritizing routing decisions based on travel time estimation. We subsequently employ the aforementioned policy approximation to determine speed profiles, considering essential parameters such as travel times. Our simulation results in SUMO indicate that our method yields better performance than conventional approaches, leading to potential travel cost savings of up to 40%. Additionally, we evaluate the resilience of our approach in dynamically changing networks, affirming its ability to maintain efficient platooning operations

    Dual Identity and Multiple Tasks: Contemporary Chinese Party Mediaā€™s Involvement in Political Communication

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    Alongside the reform and opening-up policies in China since 1978, there has been a transformation of Chinaā€™s governmental functions and of its media system.Ā While adapting to the complex political process towards democratization, theĀ Chinese Communist Party media have further expanded their dual identity asĀ both organizational communicator and mass communicator, and are involvedĀ in Chinese political communication in a variety of ways. To improve the roleĀ of internal organizational communication, the Party media have extended theirĀ sphere of activity from traditional Internal Reference (xinwen neican ę–°é—»å†…å‚) toĀ Online Public Opinion Monitoring (yuqing jiance 舆ꃅē›‘굋) and Media ThinkĀ Tank Consultation (meiti zhiku åŖ’体ę™ŗåŗ“). As leaders in Chinaā€™s market-orientedĀ media reform and tech-driven media integration, the Chinese Party media haveĀ remained dominant and privileged agents in Chinaā€™s mass media system, andĀ active participants in social political communication in a number of ways, fromĀ traditional policy publicity, to media supervision and timely external opinionĀ guiding

    An advanced general dominant eigenvalue method of accelerating successive substitution during ļ¬‚ash calculation for compositional reservoir model

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    The efļ¬ciency and accuracy of phase equilibrium calculations are essential in compositional reservoir models. Usually, a signiļ¬cant part of the computational effort in compositional reservoir simulations is spent on phase equilibrium calculations. The nonlinear nature of phase equilibrium calculations requires an iterative solution procedure. Although the successive substitution method (SSM) is robust and simple to implement, it suffers from slow convergence, especially near the critical point of the mixture. The general dominant eigenvalue method (GDEM) has been widely used to accelerate SSM, but its stability and efļ¬ciency deteriorate as the temperature and pressure approach the critical point. This paper proposes a modiļ¬ed form of GDEM to improve its performance in the near-critical region. The modiļ¬cations have two aspects. First, the liquid phase fraction in the mixture is added as a variable when performing GDEM acceleration, improving both stability and efļ¬ciency. The second modiļ¬cation is a post-calibration step imposed to replace the conventional criterion, which is applied before triggering GDEM. With the help of the post-calibration step, the stability of the modiļ¬ed GDEM is ensured, and more importantly, the calculation efļ¬ciency can be improved. Numerical tests of three hydrocarbon mixtures, including different numbers of components, show that the stability of the modiļ¬ed GDEM is almost the same as SSM and that its calculation efļ¬ciency is much higher than SSM and the conventional GDEM.Cited as: Wang, X., Wei, D., Wang, X., Zhao, X., Li, J., Noetinger, B. An advanced general dominant eigenvalue method of accelerating successive substitution during ļ¬‚ash calculation for compositional reservoir model. Advances in Geo-Energy Research, 2022, 6(3): 241-251. https://doi.org/10.46690/ager.2022.03.0

    Passively Q-switched erbium-doped fiber laser using evanescent field interaction with gold-nanosphere based saturable absorber

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    We demonstrate an all-fiber passively Q-switched erbiumdoped fiber laser (EDFL) using a gold-nanosphere (GNS) based saturable absorber (SA) with evanescent field interaction. Using the interaction of evanescent field for fabricating SAs, long nonlinear interaction length of evanescent wave and GNSs can be achieved. The GNSs are synthesized from mixing solution of chloroauricacid (HAuCl4) and sodium citrate by the heating effects of the microfiber's evanescent field radiation. The proposed passively Q-switched EDFL could give output pulses at 1562 nm with pulse width of 1.78 Ī¼s, a repetition rate of 58.1 kHz, a pulse energy of 133 nJ and a output power of 7.7 mWwhen pumped by a 980 nm laser diode of 237 mW

    CDSD: Chinese Dysarthria Speech Database

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    We present the Chinese Dysarthria Speech Database (CDSD) as a valuable resource for dysarthria research. This database comprises speech data from 24 participants with dysarthria. Among these participants, one recorded an additional 10 hours of speech data, while each recorded one hour, resulting in 34 hours of speech material. To accommodate participants with varying cognitive levels, our text pool primarily consists of content from the AISHELL-1 dataset and speeches by primary and secondary school students. When participants read these texts, they must use a mobile device or the ZOOM F8n multi-track field recorder to record their speeches. In this paper, we elucidate the data collection and annotation processes and present an approach for establishing a baseline for dysarthric speech recognition. Furthermore, we conducted a speaker-dependent dysarthric speech recognition experiment using an additional 10 hours of speech data from one of our participants. Our research findings indicate that, through extensive data-driven model training, fine-tuning limited quantities of specific individual data yields commendable results in speaker-dependent dysarthric speech recognition. However, we observe significant variations in recognition results among different dysarthric speakers. These insights provide valuable reference points for speaker-dependent dysarthric speech recognition.Comment: 9 pages, 3 figure

    Cr3_3X4_4 (X=Se, Te) monolayers as new platform to realize robust spin filter, spin diode and spin valve

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    Two-dimensional ferromagnetic (FM) half-metals are promising candidates for advanced spintronic devices with small-size and high-capacity. Motivated by recent report on controlling synthesis of FM Cr3_3Te4_4 nanosheet, herein, to explore the potential application in spintronics, we designed spintronic devices based on Cr3_3X4_4 (X=Se, Te) monolayers and investigated their spin transport properties. We found that Cr3_3Te4_4 monolayer based device shows spin filtering and dual spin diode effect when applying bias voltage, while Cr3_3S4_4 monolayer is an excellent platform to realize a spin valve. The different transport properties are primarily ascribed to the semiconducting spin channel, which is close to and away from the Fermi level in Cr3_3Te4_4 and Cr3_3Se4_4 monolayers, respectively. Interestingly, the current in monolayer Cr3_3Se4_4 based device also displays a negative differential resistance effect (NDRE) and a high magnetoresistance ratio (up to 2*103^3). Moreover, we found thermally induced spin filtering effect and NDRE in Cr3_3Se4_4 junction when applying temperature gradient instead of bias voltage. These theoretical findings highlight the potential of Cr3_3X4_4 (X=Se, Te) monolayers in spintronic applications and put forward realistic materials to realize nanosale spintronic device

    Targeted next-generation sequencing of dedifferentiated chondrosarcoma in the skull base reveals combined TP53 and PTEN mutations with increased proliferation index, an implication for pathogenesis

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    Dedifferentiated chondrosarcoma (DDCS) is a rare disease with a dismal prognosis. DDCS consists of two morphologically distinct components: the cartilaginous and noncartilaginous components. Whether the two components originate from the same progenitor cells has been controversial. Recurrent DDCS commonly displays increased proliferation compared with the primary tumor. However, there is no conclusive explanation for this mechanism. In this paper, we present two DDCSs in the sellar region. Patient 1 exclusively exhibited a noncartilaginous component with a TP53 frameshift mutation in the pathological specimens from the first surgery. The tumor recurred after radiation therapy with an exceedingly increased proliferation index. Targeted next-generation sequencing (NGS) revealed the presence of both a TP53 mutation and a PTEN deletion in the cartilaginous and the noncartilaginous components of the recurrent tumor. Fluorescence in situ hybridization and immunostaining confirmed reduced DNA copy number and protein levels of the PTEN gene as a result of the PTEN deletion. Patient 2 exhibited both cartilaginous and noncartilaginous components in the surgical specimens. Targeted NGS of cells from both components showed neither TP53 nor PTEN mutations, making Patient 2 a naĆÆve TP53 and PTEN control for comparison. In conclusion, additional PTEN loss in the background of the TP53 mutation could be the cause of increased proliferation capacity in the recurrent tumor

    Heterosis-related genes under different planting densities in maize

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    Heterosis and increasing planting density have contributed to improving maize grain yield (GY) for several decades. As planting densities increase, the GY per plot also increases whereas the contribution of heterosis to GY decreases. There are trade-offs between heterosis and planting density, and the transcriptional characterization of heterosis may explain the mechanism involved. In this study, 48 transcriptome libraries were sequenced from four inbred Chinese maize lines and their F1 hybrids. They were planted at densities of 45,000 plants/ha and 67,500 plants/ha. Maternal-effect differentially expressed genes (DEGs) played important roles in processes related to photosynthesis and carbohydrate biosynthesis and metabolism. Paternal-effect DEGs participated in abiotic/biotic stress response and plant hormone production under high planting density. Weighted gene co-expression network analysis revealed that high planting-density induced heterosis-related genes regulating abiotic/biotic stress response, plant hormone biosynthesis, and ubiquitin-mediated proteolysis but repressed other genes regulating energy formation. Under high planting density, maternal genes were mainly enriched in the photosynthesis reaction center, while paternal genes were mostly concentrated in the peripheral antenna system. Four important genes were identified in maize heterosis and high planting density, all with functions in photosynthesis, starch biosynthesis, auxin metabolism, gene silencing, and RNA interference

    Neoadjuvant Therapy of Pancreatic Cancer: The Emerging Paradigm?

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140013/1/onco0192-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/140013/2/onco0192.pd
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