On properties of modified degree six chordal rings network

Chordal rings are circulant graphs and have deserved significant attention in the last decade. Chordal rings were used to build interconnection networks for distributed and parallel systems. There are many of publications analyzing their networks properties. In this paper, we present the main properties of the latest method of chordal rings called Modified Chordal Rings Degree Six (CHRm6). The properties are connectivity, Hamiltonian cycle and asymmetry. We prove some lemmas and theorems for every property. All of these properties are useful for further works especially in developing a routing scheme

Tuchola County Broadband Network (TCBN)

Abstract In the paper the designing project (plan) of Tuchola City broadband IP optical network has been presented. The extended version of network plan constitute technical part of network Feasibility Study, that it is expected to be implemented in Tuchola and be financed from European Regional Development Funds. The network plan presented in the paper contains both topological structure of fiber optic network as well as the active equipment for the network. In the project described in the paper it has been suggested to use Modular Cable System - MCS for passive infrastructure and Metro Ethernet technology for active equipment. The presented solution provides low cost of construction (CAPEX), ease of implementation of the network and low operating cost (OPEX). Moreover the parameters of installed Metro Ethernet switches in the network guarantee the scalability of the network for at least 10 years.</jats:p

IMPLEMENTATION OF CHORDAL RING NETWORK TOPOLOGY TO ENHANCE THE PERFORMANCE OF WIRELESS BROADBAND NETWORK

The expansion of networks involved higher jump on the users utilizing the networks resources, which may require extra higher bandwidth. Due to the development of technology especially those folded under the Internet of Things (IoT), the new demand of higher data rate is been witnesses among the users. In order to feed the demand of users with high data rate, broadband networks are required where high data rate can be ensured for each user. Broadband networks can be established using optical network that carries the data through wide broadband. Areas such as rural and forests sides which are witnessing plenty of natural obstacles such as mountains, trees, seas, etc. are forming big challenge for propagating a cable (wire) or optical network. Due to the limitations of the wire network, World Interoperability for Microwave Access (WiMAX) technology has been introduced as substitution for the broadband network. Such kind of alternative can be deployed through any geographical area without concerning on the wire paths. WiMAX preserved large coverage area and hence it may not suffer from the signal hand-off as in the case of another wireless network. In this project, Chordal Ring network topology is implemented to enhance the performance of wireless broadband network. With different routing protocols such as Destination Sequenced Distance Vector Protocol (DSDV) and Ad hoc On Demand Distance Vector (AODV), the network performance was examined for various Chordal Ring degree (e.g. fourth degree and fifth degree). Performance metrics such as number of transmitted packets, number of received packers, delivered packet rate (PDR), total number of drop packers (DP) and average queuing delay (been measured). Finally, the obtained results had been shown that fifth-degree Chordal Ring network is outperforming through DSDV routing protoco

Calculation of the longitudinal aerodynamic characteristics of STOL aircraft with externally-blown jet-augmented flaps

A theoretical investigation was made to develop methods for predicting the longitudinal aerodynamic characteristics of externally-blown, jet-augmented wing-flap combinations. A potential flow analysis was used to develop two models: a wing-flap lifting surface model and a high-bypass-ratio turbofan engine wake model. Use of these two models in sequence provides for calculation of the wing-flap load distribution including the influence of the engine wake. The method can accommodate multiple engines per wing panel and part-span flaps but is limited to the case where the flow and geometry of the configuration are symmetric about a vertical plane containing the wing root chord. Comparisons of predicted and measured lift and pitching moment on unswept and swept wings with one and two engines per panel and with various flap deflection angles indicate satisfactory prediction of lift and moment for flap deflections up to 30 to 40 degrees. At higher flap angles with and without power, the method begins to overpredict lift, due probably to the appearance of flow separation on the flaps

Intermediate-term results of a nonresectional dynamic repair technique in 662 patients with mitral valve prolapse and mitral regurgitation

ObjectiveA nonresectional technique has been developed for repair of mitral leaflet prolapse causing mitral regurgitation. Polytetrafluoroethylene chordae are used for correction of edge misalignment of the prolapsed mitral leaflet. New chordal length is adjusted during progressive left ventricular inflation to systolic pressure. Annular sizing is determined dynamically after leaflet edge alignment is accomplished to produce an optimal zone of predefined leaflet apposition. The aim of this study was to document the 8- to 10-year durability of this nonresectional approach.MethodsFrom 1983 through 2008, 1121 consecutive patients had mitral valve repair on one service. Of these, 662 had repair of mitral leaflet prolapse. From 1983 until 1998, standard quadratic leaflet resection/plication was used in 72 (11.1%) patients, similar but smaller resection in 93 (14.1%) patients, and then smaller resection and polytetrafluoroethylene chordae in 24 (3.7%) patients. All received Puig–Massana fully flexible rings (Shiley, Inc, Irvine, Calif). After 1998, no leaflet resections or valve replacements have been performed regardless of leaflet size in 566 consecutive patients. Of the 662 patients, the mean age was 62.6 ± 14.1 years, and 424 (64.1%) patients were male. Coronary artery disease was present in 147 (22.2%) patients and 33 (5.0%) had prior coronary artery bypass. Leaflets corrected were as follows: anterior, 152 (23.0%) patients; posterior, 427 (64.5%); and both, 83 (12.5%) Common pathologic characteristics of prolapsing valves were as follows: myxomatous, 332 (50.2%) patients, degenerative, 83 (12.5%), ischemic, 31 (4.7%), and rheumatic, 29 (4.4%).ResultsPerioperative mortality was 2.9% (19/662) overall and 0.49% (2/414) for isolated repair. Freedom from reoperation at 10 years (Kaplan–Meier) was 90.1% and freedom from significant mitral regurgitation (echocardiography) was 93.9%.ConclusionsThis study confirms that mitral regurgitation from mitral leaflet prolapse can be repaired in all cases by a nonresectional technique provided that accurate dynamic evaluation of chordal length and annular sizing is achieved. The intermediate-term results are durable

The Smallest Particles in Saturn's A and C Rings

Radio occultations of Saturn's main rings by spacecraft suggest a power law particle size-distribution down to sizes of the order of 1 cm (Marouf et al., 1983), (Zebker et al., 1985). The lack of optical depth variations between ultraviolet and near-IR wavelengths indicate a lack of micron-sized particles. Between these two regimes, the particle-size distribution is largely unknown. A cutoff where the particle-size distribution turns over must exist, but the position and shape of it is not clear from existing studies. Using a series of solar occultations performed by the VIMS instrument on-board Cassini in the near-infrared, we are able to measure light forward scattered by particles in the A and C rings. With a model of diffraction by ring particles, and the previous radio work as a constraint on the slope of the particle size distribution, we estimate the minimum particle size using a truncated power-law size distribution. The C Ring shows a minimum particle size of $4.1^{+3.8}_{-1.3}$ mm, with an assumed power law index of q=3.1 and a maximum particle size of 10 m. The A Ring signal shows a similar level of scattered flux, but modeling is complicated by the presence of self-gravity wakes and higher optical depths. If q<3, our A Ring model requires a minimum particle size below one millimeter (< 0.34 mm for an assumed q=2.75, or $0.56^{+0.35}_{-0.16}$ mm for a steeper q=2.9) to be consistent with VIMS observations. These results might seem to contradict previous optical(Dones et al., 1993) and infrared (French and Nicholson, 2000) work, which implied that there were few particles in the A Ring smaller than 1 cm. But, because of the shallow power law, relatively little optical depth (between 0.03 and 0.16 in extinction, or 0.015 - 0.08 in absorption) is provided by these particles.Comment: 47 pages, 16 figures, 3 Table