Hexagonal Network Model Research Articles

Energy Efficient Key Management Scheme using Modified Blom’s Scheme in Wireless Sensor Network

Objectives: To compute a new secret common key pair value consuming less energy, time and storage. Methods/Statistical analysis: Finding of effective energy efficient key management scheme is still a challenging task. To produce effective key management system, Hexagonal cluster based routing protocol (HCRP) is proposed with modified Hadamard matrix as a public matrix that is obtained from the balance factor using AVL tree applied in each cluster head in the hexagonal network model where each vertex is considered as cluster head. Public matrix and secret matrix are used for finding common key pair value. Findings: The newly designed public matrix is beneficial to obtain the common key value. Result shows that proposed HCRP protocol consumes less packet ratio with minimum data rate. The work is implemented using NS2 simulator considering various factors like packet drops, computation time, energy consumption and storage overhead. Application/Improvements: The proposed key management scheme is an efficient one and can be used as a security measure for the computational field.

Analytical Tractability of Hexagonal Network Model With Random User Location

Explicit derivation of interferences in hexagonal wireless networks has been widely considered intractable and requires extensive computations with system level simulations. In this paper, we fundamentally tackle this problem and explicitly evaluate the downlink Interference-to-Signal Ratio (ISR) for any mobile location $m$ in a hexagonal wireless network, whether composed of omni-directional or tri-sectorized sites. The explicit formula of ISR is a very convergent series on $m$ and involves the use of Gauss hypergeometric and Hurwitz Riemann zeta functions. Besides, we establish simple identities that well approximate this convergent series and turn out quite useful compared to other approximations in literature. The derived expression of ISR is easily extended to any frequency reuse pattern. Moreover, it is also exploited in the derivation of an explicit form of SINR distribution for any arbitrary distribution of mobile user locations, reflecting the spatial traffic density in the network. Knowing explicitly about interferences and SINR distribution is very useful information in capacity and coverage planning of wireless cellular networks and particularly for macro-cells' layer that forms almost a regular point pattern.

Analysis of Hexagonal Network Based on Cellular Automation

With reference to the traditional two dimensional cellular automata network model, we design a kind of hexagonal network model with reconfigurable boundary. By simulating, we have achieved a series of experiments based on the model of the network packet exchange .Then we draw that the node load under congestion phase state is with characteristics of white noise and 1/f noise by computing the power spectrum density. And the results reveal the fact that, the hexagonal one gains more efficient network transmission capacity than the square one, and it is more applicable for the behavioral modeling study on the large-scale network.

Mechanical interactions between collagen and proteoglycans: implications for the stability of lung tissue.

Collagen and elastin are thought to dominate the elasticity of the connective tissue including lung parenchyma. The glycosaminoglycans on the proteoglycans may also play a role because osmolarity of interstitial fluid can alter the repulsive forces on the negatively charged glycosaminoglycans, allowing them to collapse or inflate, which can affect the stretching and folding pattern of the fibers. Hence, we hypothesized that the elasticity of lung tissue arises primarily from 1) the topology of the collagen-elastin network and 2) the mechanical interaction between proteoglycans and fibers. We measured the quasi-static, uniaxial stress-strain curves of lung tissue sheets in hypotonic, normal, and hypertonic solutions. We found that the stress-strain curve was sensitive to osmolarity, but this sensitivity decreased after proteoglycan digestion. Images of immunofluorescently labeled collagen networks showed that the fibers follow the alveolar walls that form a hexagonal-like structure. Despite the large heterogeneity, the aspect ratio of the hexagons at 30% uniaxial strain increased linearly with osmolarity. We developed a two-dimensional hexagonal network model of the alveolar structure incorporating the mechanical properties of the collagen-elastin fibers and their interaction with proteoglycans. The model accounted for the stress-strain curves observed under all experimental conditions. The model also predicted how aspect ratio changed with osmolarity and strain, which allowed us to estimate the Young's modulus of a single alveolar wall and a collagen fiber. We therefore identify a novel and important role for the proteoglycans: they stabilize the collagen-elastin network of connective tissues and contribute to lung elasticity and alveolar stability at low to medium lung volumes.

Numerical simulation of capillary-induced flow in a powder-embedded porous matrix

Capillary-induced fluid motions in an isotropic powder-embedded porous matrix are studied by the Monte-Carlo simulation method. The concept of random walk and a two-block hexagonal network model are employed to accomplish the simulation procedures. The pressure field, intrinsically representing the internal collision effects among fluid particles, is correlated by the Laplace equation and can facilitate the determination of the pressure-orienteddisplacing strength, Γ, of the random walk. Also, a set of normalized random numbers on the interval (0, 1) is used to modify the displacing strength for ‘chance’ variation. Simulated conditions are selected to coincide with the practical capillary-wick debinding process in metal powder injection molding. The numerical results agree well with the theoretical and experimental ones in the literature. This shows that capillary fingering in the wicking material tends to lift the potential of the local suction malfunction of the leading front. Methods that shorten the length of the liquid column in the wick will reduce the debinding time.