We show that a limiting bit rate exists for dispersion-managedsoliton systems and it depends only on the dispersion- map conﬁguration. We introduce a new map parameter that determines the minimum input pulse width that can be launched into a dispersion-managedsolitonsystem. We use this parameter to provide simple design rules and ap- proximate analytic expressions for the three input pulse parameters (pulse width, chirp, and energy) for a two-ﬁber- section dispersion map and verify their accuracy numerically. The results conﬁrm the known empirical result that pulse interactions are minimized for a map strength of about 1.6. They also explain why dense dispersion management is needed at high bit rates. Ó 2002 Published by Elsevier Science B.V.
In this work, the performance analysis of solitons transmission in dispersionmanaged DWDM system is studied and it also compares the system with and without soliton parameters with varying these parameters. A soliton is a special form of light pulses that can be transmitted over long distances through fibre which maintains its shape. The Observation through Q factor, BER revealed that transmission has been bested performance for long distance optical communication system because of low Bit Error rate.
The strong harmful inﬂuence of second order dispersion is well known in literature . This was reason for investigating new methods and new technologies that could reduce and undo degrading inﬂuence of second order of dispersion. Some of them are: dispersion shifted ﬁber (DSF), dispersion ﬂattened ﬁber (DFF), dispersion compensating ﬁber (DCF), dispersion-managed optical ﬁber, temporal optical conjugation (TOC), etc. In the optical transmission system with bit rate higher than hundreds of Mb/s, inﬂuence of fourth order dispersion on pulse propagation must not be neglected [2–4]. In some cases it is necessary to investigate the joint inﬂuence of both above mentioned order of dispersion on transmission quality of signal.
At present Soliton pulse compression techniques are more interest because of their simplicity dominance over other techniques. In this manuscript, we consider a system with both nonlinear and dispersion parameter treated as a inhomogeneous. By manipulating various physical parameter such as amplitude and velocity of pulse, we improve the soliton stability during long distance communication channels. We have plotted the femtosecond solitons for the above conditions by controlling the parameter K. If we taken as a low value of K=0.07, Dispersionmanaged solitons are formed as shown in Figure 2(a).After propagation pulse width controlled which is illustrated in the Figure2(b).The effect of erbium doped ions produces phase shift occurs in soliton pulses which makes interaction between two solitons. At initial position two solitons are propagating itself .In figure 2(c) and 2(d) high amplitude signal is considered as a energy reservoir (pump signal) and another signal act as a information signal. During propagation the energy is transferred from pump signal and the information signal gets amplified and stably transmitted over long distance communication.
1 < M < 1.6, (3) It may be useful to plot the graph of the PP (2) versus its argument χ . The graph is illustrated in Figure 1 for three values of M. As the figure shows, the depth of the potential well and amplitude of the soliton increase with increasing Mach number.
We have proposed an interesting concept of the ultra-short soliton pulse generation using microring resonators (MRRs), in which the single and multiple temporal and spatial soliton pulses could be achieved. The balance established between the dispersion and nonlinear lengths of the soliton pulse presents the soliton behavior known as self-phase modulation, which introduces the optical output constant, meaning that the light pulse can be localized coherently within the nano- waveguide. We have demonstrated that a large bandwidth of the arbitrary soliton pulses can be generated and compressed within a microring waveguide. The chaotic signal generation by means of a soliton pulse in the nonlinear MRRs has been presented. Selected light pulse can be localized and used to perform the high capacity of optical communication due to generate ultra-short bandwidth of the pulses. Localized spatial and temporal soliton pulse are useful to generate optical communication signals applicable for wired/wireless networks. As an application, the classical information and security codes can be formed by using the temporal and spatial soliton pulses, respectively.
We have derived the exact topological soliton solutions of the three nonlinear equa- tions. The 1-soliton solution is obtained by solitary wave ansatz method. With the aid of Maple, it is confirmed that the solutions are correct since these solutions satisfy the original equation. To our knowledge, these new solutions have not been reported in former literature. In view of the analysis, we see that the used method is an efficient method of integrability for constructing exact soliton solutions.
One of the most advanced and most commonly used technique in the dispersion compensation methods is FBG. FBG is a piece of optical fiber with the periodic variation of refractive index along the fiber axis. This phase grating acts like a band rejection filter reflecting wavelengths that satisfy the Bragg condition and transmitting the other wavelengths. The reflected wavelength changes with grating period. Thus, FBG is very simple and low cost filter for wavelength selection that improves the quality and reduces the costs in optical networks . The equation relating the grating periodicity, Bragg wavelength and effective refractive index of the transmission medium is given by:
Rapid development and investigation about gap soliton in Fiber Bragg Grating (FBG) have brought wide applications and devices in the optical fiber communication field. FBG that based on the Kerr-non-linearity is the outstanding device for studying nonlinear phenomena (Senthilnathan and Porsezian, 2003). Recently, there are many researches in designing nonlinear ﬁber Bragg gratings with a low reﬂectivity, that allows us to obtain compressed pulses with a very low wing intensity (Amir Rosenthal and Moshe Horowitz, 2006). Shapira and Horowitz (2009) have developed a model to study nonlinear pulse propagation in a FBG written. The ﬁrst experimental observation of nonlinear propagation effects in FBG, resulting in nonlinear optical pulse compression and soliton propagation (Benjamin and Slusher, 1996).
The dissolution improvement of ibuprofen from drug- poloxamer-407 solid dispersion might be due to surface active property (lowering of surface tension between drug and solvent), critical micellar concentration of the polymer and improvement of wetting characteristics of the drug (Newa et al. 2007; Zhang et al. 2009). From the figure 1, it is clearly seen that as the poloxamer concentration was increased, percent release of the drug was also found to be increased accordingly.
Nowadays pulsatile drug delivery systems are gaining importance in various disease conditions specifically in diabetes where dose is required at different time intervals. Among these systems, multi-particulate systems (e.g. pellets) offer various advantages over single unit which include no risk of dose dumping, flexibility of blending units with different release patterns, as well as short and reproducible gastric residence time26. Multiparticulate systems consists pellets of different release profile which can be of any type like time dependent, pH dependent, micro flora activated system as discussed in the previous sections. Site and time specific oral drug delivery have recently been of great interest in pharmaceutical field to achieve improved therapeutic efficacy. Gastro retentive drug delivery system is an approach to prolong gastric residence time, thereby targeting site specific drug release in upper gastrointestinal (GI) tract. Floating drug delivery system (FDDS) and bioadhesive drug delivery are widely used techniques for gastro retention. Low density porous
of parabolic cross-slope shape is obtained. It generalizes the Carrier-Greenspan transformation that is currently used for the long wave runup on a plane beach of constant slope. It is theoretically shown that the runup height in the channel whose cross-slope shape is parabolic is larger than that of simple shaped cross-slope (Sect. 2). Numerical simulations of solitary wave runup on an inclined beach with parabolic cross-slope shape are performed in the framework of the 3- D Reynolds Averaged Navier-Stokes system (Sect. 3). De- tailed characteristics of the wave processes (water displace- ment, velocity field, turbulent kinetic energy and energy dis- sipation) are analyzed and compared. Results of 3-D com- putations are compared, particularly with the experimental data of Zelt (1986) reproduced in 2-D simulations by Ozkan- Haller and Kirby (1997), and analytical formulas for soliton runup.
Proof. Let M be an arbitrary state of G, and α be a neg- ative external M -alternating path from some v ∈ Ext(G) to a principal vertex z of the root R of F. Furthermore, let γ be an M -alternating cycle in C. Since C is accessible through z, we can fix a soliton c-trail β with respect to M such that β starts out from v and c(β) = γ. We can as- sume, without loss of generality, that R = C. For, we need to rule out the only possible scenario that is incompatible with this assumption, namely when R is a single mandatory edge e = (z, w). Since in this case there are two-way mem- bers of the family F (e.g. C), there exists an M -alternating R-ear (loop) ² around w. The loop ² gives rise to a soliton l-trail δ = αe², which, by Lemma 4.2, cannot co-exist with β .
Vendor Managed Inventory simply means the vendor (the Manufacturer) manages the inventory of the distributor. The manufacturer receives electronic messages, usually via EDI, from the distributor. These messages tell the manufacturer various bits of information such as what the distributor has sold and what they have currently in inventory. The manufacturer reviews this information and decides when it is appropriate to generate a Purchase Order. The basic principle of VMI is that the vendor, or supplier, becomes responsible for managing the inventory at the customer’s site. In contrast to buyers who often manage a broad portfolio of purchased items, suppliers are usually responsible for a more limited range of products of which they have more specific knowledge, and therefore should be better in forecasting and managing the flow of their products through to the end consumer. Making the supplier responsible for replenishment should result in inventory and logistics costs being reduced throughout the total supply chain.
It is natural to wonder whether some of this improvement occurred due to a general improvement in inventory management effectiveness across all retailers. For example, it is well known that sales volume increases lead to improved economies of scale in inventory management and thus to improved inventory turnover. However, during this period, sales for Category 1 declined while Category 2 increased, and total unit sales remained relatively flat. As further evidence, Figure 6 compares the annual inventory turnover of the retailers who participated in the VMI system during 1996 to 1998 to those who did not. Despite the vendor’s goal of having the VMI retailers increase their service levels, which in turn requires more inventory, the non-VMI retailers still had lower inventory turnovers in both categories during this same time period. (Service levels at non-VMI retailers were not available.) This implies that the non-VMI retailers did not achieve significant inventory efficiency improvements for these two product categories during this same time period because they lacked the support from the improved system. Thus, we can infer that the VMI system allowed these two multidivision companies to improve service levels significantly at all their retail chains, with only a modest increase in inventory investment and a substantial improvement in the efficiency of the inventory management system. The corresponding inventory dollar savings are substantial, partic- ularly if a VMI system were rolled-out to achieve similar savings for other product lines at these companies.
105 fs. N.B: The maximum height of the crest, as well as it’s lengths along the Z-axis are very sensitive on initial conditions such as temporal and frequency separation between the interacting pulses. For example a little larger wavelengths difference would make the crest’s peak spike-like typical for soliton’s elastic collisions . While slightly smaller wavelength separation would make the crest longer lasting over Z, but with height less pro- nounced. For the example above delicate initial condi- tions were specially provided to observe a fusion process in PCF. We demonstrated next, how such conditions could be met in a real-life process of supercontinuum generation resultant from the fission of high intensity higher order soliton injected in PCF. The mechanism of acceleration of trailing soliton by dispersive waves radi- ated from preceding one was recently demonstrated  and further explored in all-optical manipulating of soli- tons by means of dispersive waves .
Fibre losses lead to soliton broadening. This problem of loss is overcome by periodic amplification along the propagation line. The amplifiers will restore the soliton energy to its initial value after propagating to a certain distance. However the same peak power launched, does not give a required balance between nonlinearity and dispersion over the entire span. This introduces to the concept of average soliton where the soliton power is increased by a factor of G ln G G 1 , G is the gain of the amplifier which compensates for the losses of the fibre segment so that the average power in one amplification period coincides with the power of a fundamental soliton in the absence of fibre losses.
Modern soliton theory is widely applied in many natural sciences [1-4] such as chemistry, biology, mathematics, communication, and particularly in almost all branches of physics like fluid dynamics, plasma physics, field the- ory, optics, and condensed matter physics, etc. [5-8]. In order to find new exact solutions of nonlinear equations, much methods have been proposed, such as the Lie group method of infinitesimal transformations, the non- classical Lie group method, the Clarkson and Kruskal direct method (CK) [9,10], the conditional similarity re- duction method [11-13] and the improved mapping ap- proach, etc. [14-23].
Intracellular capacitive effect of microstructure. Microstructure contains a dense meshwork of cytoskeletal structures made up of neutrally charged macromolecules assembled from amino-acids using infor- mation encoded in genes in a polypeptide chain linked by peptide bonds. At random orientations, the arrange- ment of charges in some macromolecules are static when no electric field is present, but in the presence of an electric field, macromolecules become polarized and separate by orienting the dipole moments of polar molecules resulting in the formation of permanent dipoles which attract surface charge densities (so-called bound charge densities) causing a displacement of charge. These bounded charges produce intracellular capacitive effects that can contribute to ionic current flow arising from the dispersion (fluctuation) of bound charge by affecting the voltage created by charge flow of molecular ions in the intracellular fluid.
We propose a novel system of a broadband source generation using a common soliton pulse (i.e. with center wavelength at 1.55 m) propagating within a nonlinear microring and nanoring resonators system. A system consists of a micro ring resonator system incorporating an add/drop filter, whereas the large bandwidth sig- nals can be generated, stored and regenerated within the system. By using the appropriate parameters relating to the practical device such as micro ring radii, coupling coefficients, linear and nonlinear refractive index, we found that the obtained multi soliton pulses have shown the potential of application for dense wavelength division application, whereas the different center wavelengths of the soliton bands can be obtained via the add/drop filter, which can be used to increase the channel capacity in communication network.