Model based system engineering approach of a lightweight embedded TCP/IP

The use of embedded software is growing very rapidly. Accessing the internet is a necessary service which has large range of applications in many fields. The Internet is based on TCP/IP which is a very important stack. Although TCP/IP is very important there is not a software engineering model describing it. The common method in modeling and describing TCP/IP is RFCs which is not sufficient for software engineer and developers. Therefore there is a need for software engineering approach to help engineers and developers to customize their own web based applications for embedded systems. This research presents a model based system engineering approach of lightweight TCP/IP. The model contains the necessary phases for developing a lightweight TCP/IP for embedded systems. The proposed model is based on SysML as a model based system engineering language

The charged lepton mass matrix and non-zero θ13\theta_{13} with TeV scale New Physics

We provide an explicit structure of the charged lepton mass matrix which is 2-3 symmetric except for a single breaking of this symmetry by the muon mass. We identify a flavor symmetric limit for the mass matrices where the first generation is decoupled from the other two in the charged lepton sector while in the neutrino sector the third generation is decoupled from the first two generations. The leptonic mixing in the symmetric limit can be, among other structures, the bi-maximal (BM) or the tri-bimaximal (TBM) mixing. Symmetry breaking effects are included both in the charged lepton and the neutrino sector to produce corrections to the leptonic mixing and explain the recent $\theta_{13}$ measurements. A model that extends the SM by three right handed neutrinos, an extra Higgs doublet, and two singlet scalars is introduced to generate the leptonic mixing.Comment: 28 pages, 24 figures. arXiv admin note: substantial text overlap with arXiv:1111.307

Heme oxygenase effect on mesenchymal stem cells action on experimental Alzheimer's disease

The objective is to evaluate the effect of heme oxygenase-1 (HO-1) enzyme inducer and inhibitor on Mesenchymal Stem Cells (MSCs) in Alzheimer disease. Materials and Methods: 70 female albino rats were divided equally into 7 groups as follows: group 1: healthy control; group 2: Aluminium chloride induced Alzheimer disease; group 3: induced Alzheimer rats that received intravenous injection of MSCs; group 4: induced Alzheimer rats that received MSCs and HO inducer cobalt protoporphyrin; group 5: induced Alzheimer rats that received MSCs and HO inhibitor zinc protoporphyrin; group 6: induced Alzheimer rats that received HO inducer; group7: induced Alzheimer rats that received HO inhibitor. Brain tissue was collected for HO-1, seladin-1 gene expression by real time polymerase chain reaction, heme oxygenase activity, cholesterol estimation and histopathological examination. Results: MSCs decreased the plaque lesions, heme oxygenase induction with stem cells also decreased plaque lesions however there was hemorrhage in the brain. Both heme oxygenase inducer alone or with stem cells increased seladin-1 expression and decreased cholesterol level. Conclusion: MSCs alone or with HO-1 induction exert a therapeutic effect against the brain lesion in Alzheimer’s disease possibly through decreasing the brain cholesterol level and increasing seladin-1 gene expression

Competing biosecurity and risk rationalities in the Chittagong poultry commodity chain, Bangladesh

This paper anthropologically explores how key actors in the Chittagong live bird trading network perceive biosecurity and risk in relation to avian influenza between production sites, market maker scenes and outlets. They pay attention to the past and the present, rather than the future, downplaying the need for strict risk management, as outbreaks have not been reported frequently for a number of years. This is analysed as ‘temporalities of risk perception regarding biosecurity’, through Black Swan theory, the idea that unexpected events with major effects are often inappropriately rationalized (Taleb in The Black Swan. The impact of the highly improbable, Random House, New York, 2007). This incorporates a sociocultural perspective on risk, emphasizing the contexts in which risk is understood, lived, embodied and experienced. Their risk calculation is explained in terms of social consent, practical intelligibility and convergence of constraints and motivation. The pragmatic and practical orientation towards risk stands in contrast to how risk is calculated in the avian influenza preparedness paradigm. It is argued that disease risk on the ground has become a normalized part of everyday business, as implied in Black Swan theory. Risk which is calculated retrospectively is unlikely to encourage investment in biosecurity and, thereby, points to the danger of unpredictable outlier events

Study of the Effect of Geomembranes on the Interaction between the Soil and Underground Structures

Geomembranes are one of the most widely used insulation materials in various civil engineering applications. Failure due to the slippage between geomembranes and the interfacing soils was detected at some cases. This paper presents the results of a series of laboratory tests carried out to investigate the factors controlling the developed interface stresses strength between the soil and geomembranes. In order to quantify the effect of different commonly used isolation membranes on the behavior and stability of buried concrete structures, laboratory studies by using modified direct shear apparatus is performed and integrated and the reduction in the shear resistance between the soil and different types of isolation geomembranes is determined. Graded sand with well-rounded particles was used in the experimental program. Shear tests were conducted under a normal stress range of about 25-100 kPa. The effect of the geomembranes on the peak and residual interface shear strengths is highlighted. Test’s results indicate development of peak interface shear resistance at a small strain and constant residual interface shear resistance at large strain. It was found that the developed peak and residual interface friction angles between the sand and the geomembranes interfaces ranged from 59 % to 82 % of the corresponding peak and residual interface friction angles between sand and un-protected concrete

A pulse amplitude modulation scheme based on in-line semiconductor optical amplifiers (SOAs) for optical soliton systems

The objective of this work is to simulate a pulse amplitude modulation (PAM) scheme based on in-line semiconductor optical amplifiers for optical soliton systems. The max. power for soliton systems, based on various bits/symbol PAM modulation schemes after a fiber length of 100 km, is simulated and clarified. In addition to the max. Q factor for soliton systems, PAM modulation schemes with various in-line SOA injection currents and a fiber length of 100 km are also simulated and demonstrated in the results. The total electrical power after photo-detectors for soliton systems, based on PAM modulation schemes with various in-line SOA injection currents and a fiber length of 100 km, is also simulated and clarified in the results. The study emphasizes that the higher the SOA injection current, the higher the electrical power and the lower the Q factor that can be achieved in the soliton system

Conventional doped silica/fluoride glass fibers for low loss and minimum dispersion effects

This paper has clarified the conventional silica doped (SiGeO2) and aluminum fluoride (AlF3) fibers for low loss and minimum dispersion effects for upgrading fiber-optic communication systems. The total dispersion with the total losses are modeled for both fibers. Fiber bandwidth and the power received are estimated based on different dopant ratios. The spectral and thermal effects are applied on both fibers. The study assured the negative effects of increasing ambient temperatures and the positive effects of increasing dopant ratios on the performance of the fibers.

Hybrid CPFSK/OQPSK modulation transmission techniques’ performance efficiency with RZ line coding–based fiber systems in passive optical networks

This study shows hybrid continuous-phase frequency shift keying (CPFSK)/optical quadrature-phase shift keying (OQPSK) modulation transmission techniques’ performance efficiency with return-to-zero (RZ) line coding scheme–based fiber systems in passive optical networks. Max. Q factor/min. bit error rate variations versus modulation frequency and fiber length are studied in detail for various bits/symbol, based on hybrid proposed modulation transmission techniques. Also, optical power and received electrical power variations are simulated with fiber-length variations at a specified modulation frequency of 300 GHz. Max. Q Factor, min. BER, max. signal power, and min. noise power variations are based on hybrid modulation techniques for CPFSK/OQPSK of 32 bits/symbol and a modulation frequency of 500 GHz through a fiber length of 30 km