198 research outputs found
Development of a time-to-digital converter ASIC for the upgrade of the ATLAS Monitored Drift Tube detector
The upgrade of the ATLAS muon spectrometer for high-luminosity LHC requires
new trigger and readout electronics for the various elements of the detector.
We present the design of a time-to-digital converter (TDC) ASIC prototype for
the ATLAS Monitored Drift Tube (MDT) detector. The chip was fabricated in a
GlobalFoundries 130 nm CMOS technology. Studies indicate that its timing and
power consumption characteristics meet the design specifications, with a timing
bin variation of 40 ps for all 48 channels with a power consumption of about
6.5 mW per channel.Comment: 9 pages, 12 figure
Prospects of Searching for Type Ia Supernovae with 2.5-m Wide Field Survey Telescope
Type Ia Supernovae (SNe Ia) are the thermonuclear explosion of a
carbon-oxygen white dwarf (WD) and are well-known as a distance indicator.
However, it is still unclear how WDs increase their mass near the Chandrasekhar
limit and how the thermonuclear runaway happens. The observational clues
associated with these open questions, such as the photometric data within hours
to days since the explosion, are scarce. Thus, an essential way is to discover
SNe Ia at specific epochs with optimal surveys. The 2.5-m Wide Field Survey
Telescope (WFST) is an upcoming survey facility deployed in western China. In
this paper, we assess the detecability of SNe Ia with mock observations of
WFST. Followed by the volumetric rate, we generate a spectral series of SNe Ia
based on a data-based model and introduce the line-of-sight extinction to
calculate the brightness from the observer. By comparing with the detection
limit of WFST, which is affected by the observing conditions, we can count the
number of SNe Ia discovered by mock WFST observations. We expect that WFST can
find more than pre-maximum SNe Ia within one-year running. In
particular, WFST could discover about 45 bright SNe Ia, 99 early-phase SNe Ia,
or well-observed SNe Ia with the hypothesized Wide, Deep, or
Medium mode, respectively, suggesting WFST will be an influential facility in
time-domain astronomy.Comment: Accepted by Univers
Impact of soda tax on beverage price, sale, purchase, and consumption in the US: a systematic review and meta-analysis of natural experiments
BackgroundAs a primary source of added sugars in the US diet, sugar-sweetened beverage (SSB) consumption is presumed to contribute to obesity prevalence and poor oral health. We systematically synthesized and quantified evidence from US-based natural experiments concerning the impact of SSB taxes on beverage prices, sales, purchases, and consumption.MethodsA keyword and reference search was performed in PubMed, Web of Science, Cochrane Library, Scopus, and EconLit from the inception of an electronic bibliographic database to Oct 31, 2022. Meta-analysis was conducted to estimate the pooled effect of soda taxes on SSB consumption, prices, passthrough rate, and purchases.ResultsTwenty-six natural experiments, all adopting a difference-in-differences approach, were included. Studies assessed soda taxes in Berkeley, Oakland, and San Francisco in California, Philadelphia in Pennsylvania, Boulder in Colorado, Seattle in Washington, and Cook County in Illinois. Tax rates ranged from 1 to 2 ¢/oz. The imposition of the soda tax was associated with a 1.06 ¢/oz. (95% confidence interval [CI] = 0.90, 1.22) increase in SSB prices and a 27.3% (95% CI = 19.3, 35.4%) decrease in SSB purchases. The soda tax passthrough rate was 79.7% (95% CI = 65.8, 93.6%). A 1 ¢/oz. increase in soda tax rate was associated with increased prices of SSBs by 0.84 ¢/oz (95% CI = 0.33, 1.35).ConclusionSoda taxes could be effective policy leverage to nudge people toward purchasing and consuming fewer SSBs. Future research should examine evidence-based classifications of SSBs, targeted use of revenues generated by taxes to reduce health and income disparities, and the feasibility of redesigning the soda tax to improve efficiency
Application of Parallel Compution on Numerical Simulation for the Fluid Flow Field of Fan
Abstract-In this paper, Numerical simulation and analysis was conducted on the flow field of axial fan by FLUENT software and the solved speeds of serial and parallel solver has been compared, and the effect of different number of nodes on the speed of parallel computation was discussed. The results showed that the convergence time used with the parallel solver is reduced by nearly 40% than that of the serial solver; with the increase of the number of nodes in parallel computation, the time required for convergence first decreased and then increased. The convergence time is the least when it is 6 nodes. On this basis, three-dimensional time average N-S equation was solved by the parallel algorithm, and the flow field of axial fan was simulated. The results show that when air flows through the impeller, vortex flow is generated at the rear of wheel, and the flow resistance increase; The "C" type distribution of pressure gradient is formed at leaf blade surface which can better improve the air distribution in the channel
Relation-Aware Diffusion Model for Controllable Poster Layout Generation
Poster layout is a crucial aspect of poster design. Prior methods primarily
focus on the correlation between visual content and graphic elements. However,
a pleasant layout should also consider the relationship between visual and
textual contents and the relationship between elements. In this study, we
introduce a relation-aware diffusion model for poster layout generation that
incorporates these two relationships in the generation process. Firstly, we
devise a visual-textual relation-aware module that aligns the visual and
textual representations across modalities, thereby enhancing the layout's
efficacy in conveying textual information. Subsequently, we propose a geometry
relation-aware module that learns the geometry relationship between elements by
comprehensively considering contextual information. Additionally, the proposed
method can generate diverse layouts based on user constraints. To advance
research in this field, we have constructed a poster layout dataset named
CGL-Dataset V2. Our proposed method outperforms state-of-the-art methods on
CGL-Dataset V2. The data and code will be available at
https://github.com/liuan0803/RADM.Comment: accepted by CIKM 202
Investigation of short-circuit failure mechanisms of SiC MOSFETs by varying DC bus voltage
In this study, the experimental evaluation and numerical analysis of short-circuit mechanisms of 1200 V SiC planar and trench MOSFETs were conducted at various DC bus voltages from 400 to 800 V. Investigation of the impact of DC bus voltage on short-circuit capability yielded results that are extremely useful for many existing power electronics applications. Three failure mechanisms were identified in this study: thermal runaway, MOS channel current following device turn-off, and rupture of the gate oxide layer (gate oxide layer damage). The SiC MOSFETs experienced lattice temperatures exceeding 1000 K during the short-circuit transient; as Si insulated gate bipolar transistors (IGBTs) are not typically subject to such temperatures, the MOSFETs experienced distinct failure modes, and the mode experienced was significantly influenced by the DC bus voltage. In conclusion, suggestions regarding the SiC MOSFET design and operation methods that would enhance device robustness are proposed
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