347 research outputs found

    Fuzzy Determination of Target Shifting Time and Torque Control of Shifting Phase for Dry Dual Clutch Transmission

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    Based on the independently developed five-speed dry dual clutch transmission (DDCT), the paper proposes the torque coordinating control strategy between engine and two clutches, which obtains engine speed and clutch transferred torque in the shifting process, adequately reflecting the driver intention and improving the shifting quality. Five-degree-of-freedom (DOF) shifting dynamics model of DDCT with single intermediate shaft is firstly established according to its physical characteristics. Then the quantitative control objectives of the shifting process are presented. The fuzzy decision of shifting time and the model-based torque coordinating control strategy are proposed and also verified by simulating under different driving intentions in up-/downshifting processes with the DCT model established on the MATLAB/Simulink. Simulation results validate that the shifting control algorithm proposed in this paper can not only meet the shifting quality requirements, but also adapt to the various shifting intentions, having a strong robustness

    Transitional fossil earwigs - a missing link in Dermaptera evolution

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    <p>Abstract</p> <p>Background</p> <p>The Dermaptera belongs to a group of winged insects of uncertain relationship within Polyneoptera, which has expanded anal region and adds numerous anal veins in the hind wing. Evolutional history and origin of Dermaptera have been in contention.</p> <p>Results</p> <p>In this paper, we report two new fossil earwigs in a new family of Bellodermatidae fam. nov. The fossils were collected from the Jiulongshan Formation (Middle Jurassic) in Inner Mongolia, northeast China. This new family, characterized by an unexpected combination of primitive and derived characters, is bridging the missing link between suborders of Archidermaptera and Eodermaptera. Phylogenetic analyses support the new family to be a new clade at the base of previously defined Eodermaptera and to be a stem group of (Eodermaptera+Neodermaptera).</p> <p>Conclusion</p> <p>Evolutional history and origin of Dermaptera have been in contention, with dramatically different viewpoints by contemporary authors. It is suggested that the oldest Dermaptera might possibly be traced back to the Late Triassic-Early Jurassic and they had divided into Archidermaptera and (Eodermaptera+Neodermaptera) in the Middle Jurassic.</p

    Multi-Objective Optimization for a Dual-Flux-Modulator Coaxial Magnetic Gear with Double-Layer Permanent Magnet Inner Rotor

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    Kystes de dinoflagellés et paléoenvironnement quaternaire dans la région Izu-Bonin, Nord-Ouest Pacifique (ODP Leg 125, site 782A et Leg 126, site 791B)

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    Cinquante espèces de kystes de dinoflagellés dont deux nouvelles, ont été recensées dans les sédiments de sondages réalisés dans la région Izu-Bonin au sud du Japon. Toutes ces espèces, qui entrent dans la composition des assemblages, ont une signification paléoenvironnementale. La représentation relative de deux groupes d’espèces qui ont été définis à partir de la localisation de leur centre de dispersion dans les latitudes tempérées à équatoriales d’une part, tempérées à subpolaires d’autre part, révèlent les changements cycliques de température des eaux de surface depuis environ 1,79 Ma. Ces résultats, associés aux données sédimentologiques, ont permis d’aborder les changements de l’environnement dans la région Izu-Bonin, au nord-ouest du Pacifique. Les taux de carbonates sont plus élevés dans les sédiments attribués aux périodes tempérées à tendance froide que dans les sédiments attribués aux périodes tempérées à tendance chaude. Par rapport à la ride externe dominant la fosse (site 782B), l’axe du rift intra-arc (791A) est caractérisé par un taux de sédimentation plus élevé, dû à l’abondance de matériel volcanique, et une forte représentation de pollen de conifères. Ces particularités suggèrent un effet possible de l’activité volcanique sur la composition du contenu palynologique après 1 Ma dans l’axe du rift. De plus, un déplacement du courant Kuroshio après 0,46 Ma, en entraînant un enrichissement en sels nutritifs des eaux de surface, aurait provoqué une différenciation de la représentation des espèces du genre Impagidinium dans les sédiments du bassin intra-arc par rapport au bord externe.Fifty species of dinoflagellate cysts, among them two new species, have been identified in oceanic sediments of the Izu-Bonin region, south of Japan. All these species have a paleoenvironmental significance. The Quaternary climatic oscillation and environment evolution in the NW Pacific have been demonstrated by the variation of dinoflagellate cyst assemblages and the contents pollen grains in the arc sediments of the Izu-Bonin region. The variation of species ratios: temperate-warm to temperate-cold dinoflagellate cysts reveals the cyclic temperature changes of sea surface waters. The data are used to reconstruct the climatic evolution since 1,79 Ma ago. The results of the present study and a consideration of relevant sedimentological factors allow us to draw the following conclusions concerning the environment of the Izu-Bonin region. It appears that the carbonate concentration in sediments was higher in the temperate-cold than in the temperate-warm phases. In comparison with the ridge of outer arc, the axial region of the inner arc rift is characterized by greater proportion of volcaniclastic materials as well as a higher sedimentation rate and the palynological contents by high percentages of coniferous pollen. These particularity suggest a possible effect of the volcanic activity on the palynological contents in the intra-arc basin since 1 Ma ago. Thus the axial region of the inner arc has maintained outside of the influence of warm current Kuroshio since 0.46 Ma ago; this is reflected by the very high abundance of Impagidinium patulum to Impagidinium aculeatum

    Dynamic Sparse No Training: Training-Free Fine-tuning for Sparse LLMs

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    The ever-increasing large language models (LLMs), though opening a potential path for the upcoming artificial general intelligence, sadly drops a daunting obstacle on the way towards their on-device deployment. As one of the most well-established pre-LLMs approaches in reducing model complexity, network pruning appears to lag behind in the era of LLMs, due mostly to its costly fine-tuning (or re-training) necessity under the massive volumes of model parameter and training data. To close this industry-academia gap, we introduce Dynamic Sparse No Training (DSnoT), a training-free fine-tuning approach that slightly updates sparse LLMs without the expensive backpropagation and any weight updates. Inspired by the Dynamic Sparse Training, DSnoT minimizes the reconstruction error between the dense and sparse LLMs, in the fashion of performing iterative weight pruning-and-growing on top of sparse LLMs. To accomplish this purpose, DSnoT particularly takes into account the anticipated reduction in reconstruction error for pruning and growing, as well as the variance w.r.t. different input data for growing each weight. This practice can be executed efficiently in linear time since its obviates the need of backpropagation for fine-tuning LLMs. Extensive experiments on LLaMA-V1/V2, Vicuna, and OPT across various benchmarks demonstrate the effectiveness of DSnoT in enhancing the performance of sparse LLMs, especially at high sparsity levels. For instance, DSnoT is able to outperform the state-of-the-art Wanda by 26.79 perplexity at 70% sparsity with LLaMA-7B. Our paper offers fresh insights into how to fine-tune sparse LLMs in an efficient training-free manner and open new venues to scale the great potential of sparsity to LLMs. Codes are available at https://github.com/zyxxmu/DSnoT.Comment: Published as a conference paper at ICLR 202

    Performance of AC-LGAD strip sensor designed for the DarkSHINE experiment

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    AC-coupled Low Gain Avalanche Detector (AC-LGAD) is a new precise detector technology developed in recent years. Based on the standard Low Gain Avalanche Detector (LGAD) technology, AC-LGAD sensors can provide excellent timing performance and spatial resolution. This paper presents the design and performance of several prototype AC-LGAD strip sensors for the DarkSHINE tracking system, as well as the electrical characteristics and spatial resolution of the prototype sensors from two batches of wafers with different n+n^+ dose.The range of spatial resolutions of 6.5μm\mathrm{\mu m} ∼\sim 8.2μm\mathrm{\mu m} and 8.8μm\mathrm{\mu m} ∼\sim 12.3μm\mathrm{\mu m} are achieved by the AC-LGAD sensors with 100μm\mu m pitch size.Comment: 10 pages, 12 figure
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