Power system restoration has attracted more attention and made great progress recently. Research progress of the power system restoration from 2006 to 2016 is reviewed in this paper, including black-start, network reconfiguration and load restoration. Some emerging methods and key techniques are also discussed in the context of the integration of variable renewable energy and development of the smart grid. There is a long way to go to achieve automatic self-healing in bulk power systems because of its extreme complexity. However, rapidly developing artificial intelligence technology will eventually enable the step-by-step dynamic decision-making based on the situation awareness of supervisory control and data acquisition systems(SCADA) and wide area measurement systems(WAMS) in the near future.
Background Little is known about the role of dual angiotensin Ⅱ forming pathways during heart failure. In the present study, the changes of chymase and angiotensin converting enzyme （ACE） expressions in the failing hearts of hamsters were analysed. Methods Heart failure was induced by ligation of left anterior descending branch of the coronary artery. Chymase, ACE and angiotensin Ⅱ type 1 receptor （AT1R） mRNA levels were analysed by reverse transcription polymerase chain reaction （RT-PCR）. The activities of chymase and ACE were determined by radioimmunoassay （RIA）. Myocardial collagen fibre analysis was performed under optical microscope. Results Left ventricular systolic pressure （LVSP） and maximum left ventricular developed pressure increase rate （ dp/dtmax, mmHg/s） gradually moved lower at 2, 3,4 and 8 weeks after operation. On the other hand, left ventricular end-diastolic pressure （LVEDP） increased gradually after operation. Compared with the control group （3.55±0. 06, 4.79±0.70）, the heart weight/body weight ratio in operation group had increased significantly at 4 weeks and 8 weeks （4. 28±0. 43, 6. 17±0.73） （P 〈0. 01 ）. Collagen staining showed that the quantity of myocardial collagen fibre increased significantly in the operation group. RT-PCR showed that the chymase mRNA level in the operation group was consistently greater than that in the control group. ATIR mRNA level was also increased significantly at 3 weeks and 4 weeks, both being 1.3 times that of the control group （ P〈0.01 ）, whereas ACE mRNA level was not changed. Higher activity of chymase was detected in operation group, being 4, 8, 13 and 19 times that of the control group at 2, 3, 4 and 8 weeks （P〈0.01 ）, respectively. ACE activity was also significantly higher at the same time, being 7, 10, 10 and 3.5 times that of the control（P〈0.01）. Angiotensin Ⅱ （Ang Ⅱ） level in operation group increased significantly, being 2.5, 2.7, 3.5 and 2 times that of the control group a
The proper orthogonal decomposition （POD） is a model reduction technique for the simulation Of physical processes governed by partial differential equations （e.g., fluid flows）. It has been successfully used in the reduced-order modeling of complex systems. In this paper, the applications of the POD method are extended, i.e., the POD method is applied to a classical finite difference （FD） scheme for the non-stationary Stokes equation with a real practical applied background. A reduced FD scheme is established with lower dimensions and sufficiently high accuracy, and the error estimates are provided between the reduced and the classical FD solutions. Some numerical examples illustrate that the numerical results are consistent with theoretical conclusions. Moreover, it is shown that the reduced FD scheme based on the POD method is feasible and efficient in solving the FD scheme for the non-stationary Stokes equation.
In this paper,we investigate on the problem of energy-efficient traffic grooming under sliding scheduled traffic model for IP over WDM optical networks,so as to minimize the total energy consumption of the core network.We present a two-layer auxiliary graph model and propose a new energyefficient traffic grooming heuristic named Two-Dimension Green Traffic Grooming(TDGTG) algorithm,which takes both space and time factors into consideration for network energy efficiency.We compare our proposed TDGTG algorithm with the previous traffic grooming algorithms for scheduled traffic model in terms of total energy consumption and blocking probability.The simulation results in three typical carrier topologies show the efficiency of our proposed TDGTD algorithm.
In this paper, the in-house multifunction solver naoe-FOAM-SJTU is applied to study the resistance and wave-making performance of a high-speed catamaran sailing at different velocity in calm water. The volume of fluid（VOF） method is used to capture the free interface and the finite volume method（FVM） is adopted as the discretization scheme. The hull model is fixed with initial trim and sinkage. The numerical results of the presented paper agree very well with the measurement data of model test. Wave making and vortex field are well simulated to analyze the hydrodynamic performance of a catamaran.
We show that Bogoliubov＇s quasiparticle in superfluid 3He-B undergoes the Zitterbewegung, as a free relativistic Dirac＇s electron does. The expectation value of position, as well as spin, of the quasiparticle is obtained and compared with that of the Dirac＇s electron, In particular, the Zitterbewegung of Bogoliubov＇s quasiparticle has a frequency approximately 105 lower than that of an electron, rendering a more promising experimented observation.
