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An accurate State of Charge (SoC) estimation method is one of the most significant and difficult techniques to promote the commercialization of electric vehicles. A novel approach based on second-order sliding mode observer for battery state of charge (SOC) estimation has been proposed. The Thevenin equivalent circuit model is selected to model the li-ion battery and cooperative particle swarm optimization...
China and lots of other countries invested heavily to the Electrical Vehicles (EVs) to reduce the air pollution and save energy. As a result, lots of EV charging stations came out. But this will impact the Power Grid a lot. For example, distribution network circuit overload, voltage drop, loss distribution network increased overload distribution transformers and other issues make the stability decrease...
Smart meter is an essential part of the metering system in electrical vehicle (EV) charging station. In Smart Grid, EVs can work in charging and discharging status. So it is indispensable that smart meter has features of bi-directional metering and communication. This papers proposes a smart metering system (SMS) which is part of the electrical vehicles management system (EVMS). The SMS can bi-directionally...
This paper presents a comparative study of three equivalent circuit models for lithium -ion batteries used in electric vehicles(EVs). Model parameters are all obtained by cooperative particle swarm optimization algorithm on the Dynamic Stress Test data, not the traditional hybrid pulse power characteristic (HPPC) test procedure. A 1372s Federal Urban Driving Schedule test are used to validate and...
With the rapid development of Electric Vehicles (EVs), large-scale charging requirement will heavily impact the existing power grid. So there is an urgent need for coordinating control to avoid it in smart grids. Demand side management reducing charging rate at peak load and rescheduling charging process at appropriate time such as low grid load can be used to solve this issue. This paper proposed...
This paper provide a new method of elevator overspeed measurement. Helium-Neon laser is mounted vertically on the surface of the elevator car. One-dimensional photodiode array(PDA) is installed at the top of the shaft. The laser beam passes through the beam shaping lens for good homogeneity and proper divergence angle. According to the total height of shaft and the divergence angle θ=0.4mrad, the...
The traditional VCSEL has the problem of uneven current injection. In order to solve this problem, we designed a new electrode structure. Then we used ANSYS to simulate the thermal characteristics of VCSEL. The results showed that VCSEL with the new electrode structure had a better cooling effect than the traditional electrode structure.
In this paper, optical and electrical properties of the traditional and intracavity-contacted structures of 980nm VCSELs were simulated in the case of the same epitaxial growth by Crosslight PICS3D. Threshold current of the traditional structure device was 8.76mA and the one of intracavity-contacted structure device was 6.23mA. When operating current was 25 mA, the output power of the traditional...
The application of large-scale Electric Vehicles (EVs) poses a threat to grid stability if charged without control. It needs expansion of the grid capacity and leads to major investment in current grid and capacity-wasting in low-load time. This paper proposes a solution based on two-level Electric Vehicles Charging Management System (EVCMS) to optimal demand side management by means of scheduling...
M&A actions in product differentiation market reflect a transition of social division of labor to division of labor within enterprises. The fundamental cause underlying this transition is the significant difference in efficiency between the two types of division of labor. The triggering mechanism is the end of product differentiation competition based on a highly developed productivity. The determination...
Vertical cavity surface emitting lasers with large aperture were fabricated by using wet oxidation technique at about 420°C, and the device chips were packaged with three different packaging methods. The optical output power and wavelength shift of the devices were compared experimentally. The device bonded with diamond spreader shows the best performance, and 200μm-diameter device produces a room...
We report the fabrication of a novel high-power VCSEL with reticular electrode in this letter. The analysis shows that the reticular electrodes can improve the homogeneity in the injected current and heighten VCSEL optical output power. The high-power reticular electrode VCSELs with 500μm aperture have been made and tested. Testing results show the slope efficiency of 0.75mW/mA, output power of up...
A new device structure is reported to improve performance of vertical cavity surface-emitting lasers (VCSELs). Namely many cylindrical holes (CH) or noncontiguous ring trench (NRT) are etched instead of the conventional ring trench (RT). The mesa with such new structure offers radial bridges for current injection, the connecting Ti-Au metal between ohmic contact and bonding pad does not have to cross...
This paper presents our replacement algorithm named RED for storage caches. RED is exclusive. It can eliminate the duplications between a storage cache and its client cache. RED is high performance. A new criterion Resident Distance is proposed for making an efficient replacement decision instead of Recency and Frequency. Moreover, RED is non-intrusive to a storage client. It does not need to change...
Computational prediction of RNA secondary structure is classical open problem in computational molecular biology. Comparative sequence analysis is the gold standard method when given homologous sequences alignment. The essential of this method is a classification problem: to judge if any two columns of an alignment correspond to a base pair using provided information by alignment. However, all existing...
As the performance gap between disks and processors continues to increase, dozens of cache replacement policies come up to handle the problem. Unfortunately, most of the policies are static. Nimrod Megiddo etc put forward a low overhead adaptive policy called ARC. It outperforms most of the static policies in most situations. But, ARC adapts itself to the workloads by the feedback of the missed pages...
The computational prediction of protein-protein interactions is currently an important issue in biology. In this paper, a K-local hyperplane distance nearest neighbor (HKNN) classifiers with symmetrical encoding scheme is proposed to predict protein-protein interactions. Moreover, a new sample encoding scheme, named symmetrical encoding scheme (SYES), for protein pair is developed by which a single...
Current cache replacement policies mostly work at the block device level. Block level policies try to achieve better hit ratio by balancing the frequently and recently visited pages, however, further improvements can be realized by using file-system metadata. There are two reasons for this. First, sequential access of disk data is more quickly than non-sequential access, that is to say, the cache...
Ever since a long time ago, recency and frequency are not to be sneezed at design of cache management policy. Meanwhile, hit ratio is used to estimate whether a cache replacement policy is good or not. The influence of miss penalty on cache performance is neglected incorrectly. In fact, the cache miss penalty can vary by almost one or two orders of magnitude among different policies because of tremendous...
Multi-level cache hierarchies are very common in today's networked storage environments. Dedicated data servers or file servers are simultaneously accessed by multi-applications of multi-clients. Workload shift results in cache pollution and degrade of hit ratio. Widely used cache policies work well on the case when a single level cache separates the data provider and data consumer, but poorly on...
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