Ensuring clear Line Of Sight (LOS) is essential for effective communication in microwave links [1-3]. This is because, microwave signals are known to travel in a straight line. In reality, microwave signals path form an ellipsoidal shape that is described by Fresnel geometry [4-7]. In the Fresnel geometry for LOS links, the signal path are categorised into different Fresnel zones. In that case, microwave communication link designers usually specify the LOS clearance with respect to the Fresnel zones. However, the most important is the first Fresnel zone, where it is believed that over 90% of the signal strength are concentrated [8-10]. While most designers specify their LOS clearance in terms of Fresnel zone 1, others that require high fidelity link specify the LOS clearance in terms of the higher Fresnel zones.
On the contrary, our method reconstructs a 3D point cloud using depth images obtained from several viewpoints by the stereo method. In general, reconstructing the 3D mesh model by the stereo method requires the following five processes: (1) taking depth image, (2) integration of several depth images, (3) polygonal meshing of a point cloud, (4) simplification of meshes, (5) generating texture and mapping it to the 3D mesh. As mentioned above, the computational cost of the stereo method is basically high. The feature of our method is to treat point cloud with the 3D coordinates and the colour information directly without any 3D meshes. So, calculation is reduced drastically because above (3), (4) and (5) processes are not required. Moreover, each depth image can be processed separately. Thus it can be implemented with simple parallel processing. In (Waschbüsch, et al., 2007), a 3D imaging system based on the stereo matching method has been proposed for real-time application.
ers etc. Semiconductor lasers exhibit rates of high repetition ranging from hun- dreds of MHz to almost 1/10 GHz, while they have useful applications in tele- communication and in optical data storage using CD and DVD systems. Some other applications include the optical feedback noise reduction in semiconductor injection lasers and optical timing extraction by injection locking of self-pulsing optical oscillators. The phenomenon of self-pulsation is a result of the nonlinear interaction of the slowly responding amplifying and absorbing media and the fast response of the electric field in lasers driven by a constant pumping power. Actually, the basic mechanism responsible for the generation of these oscilla- tions starts as the laser is turned on and the amplifying medium, the gain, is ex- cited to a sufficiently high level via some type of pumping process. The absorber absorbs the free photons in the laser and thus the intensity of the electric field remains low and the saturation of the gain goes on. As soon as the absorbing medium saturates, the usual laser process starts with a strongly excited gain causing a high electric field intensity and thus truly enhanced output power. During this process both the gain and the absorber return to ground state and the process starts all over again. In semiconductor lasers, this can produce a pulse train with a typical frequency of the order of several GHz. The homoclinic point-to-point connecting orbit arising in the system of interest, can be consi- dered as a mathematical representation of the aforementioned high power self-pulsation. A characteristic of lasers with obvious practical importance is that by changing either the material or the pump power, the qualitative behaviour of the laser beam can change dramatically, that is a large variety of local and global bifurcations can occur.
Being a point-to-point protocol, PPP does not distinguish between client and server operations. For the purposes of this application note, a peer that requires a remote peer to provide authentication and provides an IP address to the remote peer is known as a server. Whereas, a peer that does not require a remote peer to authenticate and accepts an IP address is known as a client.
are the generalization of commuting maps. Jungck (Jungck, 1986) enlarged this concept of weakly commutativity by introducing compatible maps. In (Berinde, 2010), Vasile Berinde obtained coincidence and common fixed point theorems, similar to the one in (Abbas and Jungck, 2008), but for more general class of almost contraction, by restricting the ambient space to the class of usual metric spaces. In (Bakhtin, 1989), Bakhtin introduced b-metric space as a generalization of metric spaces and proved a contraction mapping principle in b-metric space that generalized the famous Banach contraction principle in metric spaces. In 2011, Hussain and Shah (Hussain and Shah, 2011) introduced cone b-metric spaces as a generalization of b-metric spaces and cone metric spaces. Recently, Huang and Xu (Huang and Xu, 2012) have proved some fixed point theorems of contraction mapping without the assumption of normality condition in complete cone b-metric space. Inspired and motivated by a result mentioned on (Berinde, 2010) and using the notion introduced on (Shi and Xu, 2013) and (Huang and Xu, 2012), the purpose of the research is to study existence and uniqueness of coincidence point and common fixed point results for a large class of almost contraction in complete cone b-metric space.
The methodology of the study has been established by applying the model of the Radio Communications Sector of the International Telecommunications Union (ITU-R) to evaluate and predict the performance degradations particularly due to rain attenuation . Thus several locations in Malaysia have been selected for the study namely Ipoh, Alor Setar, Kuantan and Kota Bahru.
The main purpose of this research to help people know many things about microwave antenna use in communication system. Microwaves are widely used for point-to-point communications because their small wavelength allows conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other, as lower frequency radio waves do. Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a bandwidth 30 times that of all the rest of the radio spectrum below it.
The map (Figure 1) will help you determine if you are in a predominantly sandy soil area where driven-point well installation is more likely. However, sandy soils alone will not guarantee successful installation of a driven-point well. If the water table is deep, it may not be physically possible to drive the well point deep enough to reach it. Large boulders or layers of tightly compacted soil like clay or “hardpan” may be encountered that effectively stop the driving process. Further, though clay can hold a lot of water, the clay particles are too closely packed to allow water to fl ow through it into a well. Depth to the water table is another very important consideration when installing a driven-point well. Although 1-1/4” diameter well pipe can be used when the water table is less than about 20’ below the ground surface,
We have constructed a simple point particle model of lightly bound skyrmions which almost flawlessly reproduces the results of numerical field theoretic energy minimization for charges 1 to 8. The only exception is charge 6. Here, the point particle model predicts minimizers with shapes, in order of ascending energy, octahedron, bowtie and pyramid-plus-one, whereas full field simulations find that the correct order is bowtie, octohedron, pyramid-plus-one, albeit with the first two of these very close to degenerate. Alongside this minor blemish one should set some unexpected successes: the point particle model predicted previously unknown energy minimizers at charges 5, 7 and 8, all of which corresponded to local energy minimizers of the field theory with correct energy ordering. This includes the (so far) lowest energy skyrmion at charge 7. The point particle model makes a simple prediction for the inertia tensors of lightly bound skyrmions which, with only two free parameters, fits the field theoretic data for the global minimizers with 1 ≤ B ≤ 8 to within 10%. In judging this, one should bear in mind that an inertia tensor is not a single number, but rather (after accounting for symmetries) 15 independent numbers, so we are actually fitting 120 independent quantities here.
Quoting these authors (pp. 63–64), “measurements [of electromagnetism] are taken at sites falling on a regular grid, as shown in [Figure 1], where the sites are one meter apart in both the vertical and horizontal directions. . . . Electromagnetism is expected to be fairly constant across the field, but an existing metal pole affects the measuring device so that the constant pattern in the field is not observable. It is in this sense that we consider the metal pole to be a point source. . . . Electromagnetism appears to be a function only of distance to the point source, and because the contours are approximately circular, there is no apparent need for rotating or rescaling the axes.”
In the first alternative, label skip contains any event not declared as a symbol. It is represented by a self-loop in an automaton. Transitions to the f ail state (0) are added for each declared symbol not present in the pattern at that particular state. We will refer to this alternative as the implicit fail model. The second alter- native adds those symbols to label skip for a particular state. Transitions to the f ail state only contain those symbols explicitly excluded using a negation opera- tor (¬). We will refer to this alternative as the explicit fail model. The explicit fail model corresponds in syntax to extended regular expressions (ERE). Automata created for the same pattern in both models are not equivalent, however. Com- bining them with the pattern instantiation mechanism described earlier, both models become an alternative for matching events on traces. Both alternatives, however, have their advantages and disadvantages. They will be explained by putting both models side-by-side using simple examples.
The model is based upon a Bayesian approach with user specified prior distributions for all parameters, while empir- ical data are used for deriving posterior distributions. There are many ways to parameterize the model, however, and in this paper we present only one of these. The basic princi- ples behind the algorithms we have used and the following calculations remain independent of this particular parameter- ization. Another freedom of the model is the choice of prior distributions, where, when faced with an unresolved situa- tion, one may revert to flat priors. This, however, gives less information and subsequently may lead to less precision in the estimates.