Some qualitative behaviors of stationary solutions for the 2-D Lengyel-Epstein system are considered from the local bifurcation viewpoint in this paper. First, local bifurcation branches of hexagonal stationary soluti...Some qualitative behaviors of stationary solutions for the 2-D Lengyel-Epstein system are considered from the local bifurcation viewpoint in this paper. First, local bifurcation branches of hexagonal stationary solutions are constructed in the special case when the habitat domain is a rectangle. Next, the type of the bifurcation diagram near the bifurcation points is discussed.展开更多
The hollow hexagonal pattern involved in surface discharges is firstly investigated in a？dielectric barrier discharge system. The spatiotemporal structures of the pattern are studied using an intensified charge-coupl...The hollow hexagonal pattern involved in surface discharges is firstly investigated in a？dielectric barrier discharge system. The spatiotemporal structures of the pattern are studied using an intensified charge-coupled device and photomultiplier. Instantaneous images taken by an intensified charge-coupled device and optical correlation measurements show that the surface discharges are induced by volume discharges. The optical signals indicate that the discharge filaments constituting the hexagonal frame discharge randomly at the first current pulse or the second pulse, once？or twice. There is no？interleaving of several sub-lattices, which indicates that the ‘memory＇ effect is no longer in force due to surface discharges. By using the emission spectrum method, both the molecule vibration temperature？and electron density of the surface discharges are larger than that of the volume discharges.展开更多
In this paper,we propose a novel adjustable multiple cross-hexagonal search(AMCHS) algorithm for fast block motion estimation. It employs adjustable multiple cross search patterns(AMCSP) in the first step and then use...In this paper,we propose a novel adjustable multiple cross-hexagonal search(AMCHS) algorithm for fast block motion estimation. It employs adjustable multiple cross search patterns(AMCSP) in the first step and then uses half-way-skip and half-way-stop technique to determine whether to employ two hexagonal search patterns(HSPs) subsequently. The AMCSP can be used to find small motion vectors efficiently while the HSPs can be used to find large ones accurately to ensure prediction quality. Simulation results showed that our proposed AMCHS achieves faster search speed,and provides better distortion performance than other popular fast search algorithms,such as CDS and CDHS.展开更多
Channel estimation in coherent OFDM by inserting pilot-symbols into two-dimensional time- frequency lattice is a promising candidate for improving channel transmission capacity in future wireless communication systems...Channel estimation in coherent OFDM by inserting pilot-symbols into two-dimensional time- frequency lattice is a promising candidate for improving channel transmission capacity in future wireless communication systems. This paper proposes a new Cartesian mathematical concept of the Hexagonal Pilot Pattern, Hexagonal Pilot with Virtual and Rectangular Pilot Pattern. The main focus of this work is to compare between the two pilots and by virtue of simulation conclusion which of the two pilots yields a better performance.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.11761063 61872227)
文摘Some qualitative behaviors of stationary solutions for the 2-D Lengyel-Epstein system are considered from the local bifurcation viewpoint in this paper. First, local bifurcation branches of hexagonal stationary solutions are constructed in the special case when the habitat domain is a rectangle. Next, the type of the bifurcation diagram near the bifurcation points is discussed.
基金supported by National Natural Science Foundation of China(Nos.11375051 and 11505044)Key Basic Research Project in the application basic research plan of Hebei Province(No.15961105D)the Research Foundation of Education Bureau of Hebei Province,China(No.LJRC011)
文摘The hollow hexagonal pattern involved in surface discharges is firstly investigated in a？dielectric barrier discharge system. The spatiotemporal structures of the pattern are studied using an intensified charge-coupled device and photomultiplier. Instantaneous images taken by an intensified charge-coupled device and optical correlation measurements show that the surface discharges are induced by volume discharges. The optical signals indicate that the discharge filaments constituting the hexagonal frame discharge randomly at the first current pulse or the second pulse, once？or twice. There is no？interleaving of several sub-lattices, which indicates that the ‘memory＇ effect is no longer in force due to surface discharges. By using the emission spectrum method, both the molecule vibration temperature？and electron density of the surface discharges are larger than that of the volume discharges.
文摘In this paper,we propose a novel adjustable multiple cross-hexagonal search(AMCHS) algorithm for fast block motion estimation. It employs adjustable multiple cross search patterns(AMCSP) in the first step and then uses half-way-skip and half-way-stop technique to determine whether to employ two hexagonal search patterns(HSPs) subsequently. The AMCSP can be used to find small motion vectors efficiently while the HSPs can be used to find large ones accurately to ensure prediction quality. Simulation results showed that our proposed AMCHS achieves faster search speed,and provides better distortion performance than other popular fast search algorithms,such as CDS and CDHS.
文摘Channel estimation in coherent OFDM by inserting pilot-symbols into two-dimensional time- frequency lattice is a promising candidate for improving channel transmission capacity in future wireless communication systems. This paper proposes a new Cartesian mathematical concept of the Hexagonal Pilot Pattern, Hexagonal Pilot with Virtual and Rectangular Pilot Pattern. The main focus of this work is to compare between the two pilots and by virtue of simulation conclusion which of the two pilots yields a better performance.
