17,566 research outputs found

    An Intelligent Auxiliary Vacuum Brake System

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    The purpose of this paper focuses on designing an intelligent, compact, reliable, and robust auxiliary vacuum brake system (VBS) with Kalman filter and self-diagnosis scheme. All of the circuit elements in the designed system are integrated into one programmable system-on-chip (PSoC) with entire computational algorithms implemented by software. In this system, three main goals are achieved: (a) Kalman filter and hysteresis controller algorithms are employed within PSoC chip by software to surpass the noises and disturbances from hostile surrounding in a vehicle. (b) Self-diagnosis scheme is employed to identify any breakdown element of the auxiliary vacuum brake system. (c) Power MOSFET is utilized to implement PWM pump control and compared with relay control. More accurate vacuum pressure control has been accomplished as well as power energy saving. In the end, a prototype has been built and tested to confirm all of the performances claimed above

    A preliminary study to investigate the expressive syntactic ability of normal speakers

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    Grammatical problem was one of the most prominent characteristics of speech in persons with aphasia (Gordon, 2006) and progressive aphasic syndromes (Knibb, Woollams, Hodges, & Patterson, 2009). Measures used to investigate the grammatical deficits on the discourse performance of persons with aphasia could be roughly classified into to two categories, one related to the level of lexicon, the other concerned with the level of syntax. Most of the measures belonged to the former category used words to analysis the variation on the speech performance, such as correct information units (CIUs; Nicholas & Brookshire, 1993), type token ratio (TTR); while the measures applied in studies related to the syntactic ability was more varied. Such as proportion of sentences well formed, auxiliary scores, proportion of verbs inflected, proportion of obligatory determiners in quantitative production analysis (QPA) (Gordon, 2006), and the mean length of the syntactic units, the proportion of syntactic units suggested by Lind, Kristoffersen, Moen, and Simonsen (2009). However, the measures used to depict the syntactic ability of a person was separated, could not provide a profile to reveal a pattern of syntactic ability in a consecutive picture. In order to develop a syntactic scoring system that can capture the changes in the characteristics of narrative speech, we adopted the concept from studies in child language development (Hsu, 2003) and widen the category to encompass the imperfect parts in natural speech. The applicability of this scoring system was firstly tested by the normal population in order to examine if the range of the scope is suitable for reflecting the expressive syntactic ability of a normal speaker

    The Complexity of Distributed Edge Coloring with Small Palettes

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    The complexity of distributed edge coloring depends heavily on the palette size as a function of the maximum degree Δ\Delta. In this paper we explore the complexity of edge coloring in the LOCAL model in different palette size regimes. 1. We simplify the \emph{round elimination} technique of Brandt et al. and prove that (2Δ2)(2\Delta-2)-edge coloring requires Ω(logΔlogn)\Omega(\log_\Delta \log n) time w.h.p. and Ω(logΔn)\Omega(\log_\Delta n) time deterministically, even on trees. The simplified technique is based on two ideas: the notion of an irregular running time and some general observations that transform weak lower bounds into stronger ones. 2. We give a randomized edge coloring algorithm that can use palette sizes as small as Δ+O~(Δ)\Delta + \tilde{O}(\sqrt{\Delta}), which is a natural barrier for randomized approaches. The running time of the algorithm is at most O(logΔTLLL)O(\log\Delta \cdot T_{LLL}), where TLLLT_{LLL} is the complexity of a permissive version of the constructive Lovasz local lemma. 3. We develop a new distributed Lovasz local lemma algorithm for tree-structured dependency graphs, which leads to a (1+ϵ)Δ(1+\epsilon)\Delta-edge coloring algorithm for trees running in O(loglogn)O(\log\log n) time. This algorithm arises from two new results: a deterministic O(logn)O(\log n)-time LLL algorithm for tree-structured instances, and a randomized O(loglogn)O(\log\log n)-time graph shattering method for breaking the dependency graph into independent O(logn)O(\log n)-size LLL instances. 4. A natural approach to computing (Δ+1)(\Delta+1)-edge colorings (Vizing's theorem) is to extend partial colorings by iteratively re-coloring parts of the graph. We prove that this approach may be viable, but in the worst case requires recoloring subgraphs of diameter Ω(Δlogn)\Omega(\Delta\log n). This stands in contrast to distributed algorithms for Brooks' theorem, which exploit the existence of O(logΔn)O(\log_\Delta n)-length augmenting paths

    The Complexity of Distributed Approximation of Packing and Covering Integer Linear Programs

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    In this paper, we present a low-diameter decomposition algorithm in the LOCAL model of distributed computing that succeeds with probability 11/poly(n)1 - 1/poly(n). Specifically, we show how to compute an (ϵ,O(lognϵ))\left(\epsilon, O\left(\frac{\log n}{\epsilon}\right)\right) low-diameter decomposition in O(log3(1/ϵ)lognϵ)O\left(\frac{\log^3(1/\epsilon)\log n}{\epsilon}\right) round Further developing our techniques, we show new distributed algorithms for approximating general packing and covering integer linear programs in the LOCAL model. For packing problems, our algorithm finds an (1ϵ)(1-\epsilon)-approximate solution in O(log3(1/ϵ)lognϵ)O\left(\frac{\log^3 (1/\epsilon) \log n}{\epsilon}\right) rounds with probability 11/poly(n)1 - 1/poly(n). For covering problems, our algorithm finds an (1+ϵ)(1+\epsilon)-approximate solution in O((loglogn+log(1/ϵ))3lognϵ)O\left(\frac{\left(\log \log n + \log (1/\epsilon)\right)^3 \log n}{\epsilon}\right) rounds with probability 11/poly(n)1 - 1/poly(n). These results improve upon the previous O(log3nϵ)O\left(\frac{\log^3 n}{\epsilon}\right)-round algorithm by Ghaffari, Kuhn, and Maus [STOC 2017] which is based on network decompositions. Our algorithms are near-optimal for many fundamental combinatorial graph optimization problems in the LOCAL model, such as minimum vertex cover and minimum dominating set, as their (1±ϵ)(1\pm \epsilon)-approximate solutions require Ω(lognϵ)\Omega\left(\frac{\log n}{\epsilon}\right) rounds to compute.Comment: To appear in PODC 202
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