Comparative Study on the Performance of TCP-Freeze and TCP-Newreno Over Divert Failure Routing Protocol

Many enhancements have been proposed to address TCP throughput issues over wireless links. In this project, we will study the performance of the standard TCP over TCP Freeze with Divert Route Failure Protocol as the routing mechanism. This study is aimed for the purpose of further improvement in related services provided by TCP over the wireless links. Such enhancements are needed due to the high transmission error rates in wireless links

Numerical Treatment for Special Type of Mixed Linear Delay Volterra Integro-Differential Equations

The idea of research is a representation of the nonlinear pseudo-random generators using state-space equations that is not based on the usual description as shift register synthesis but in terms of matrices. Different types of nonlinear pseudo-random generators with their algorithms have been applied in order to investigate the output pseudo-random sequences. Moreover, two examples are given for conciliated the results of this representation

Computer Modeling Using The Finite-Difference Time-Domain (FDTD) Method for Electromagnetic Wave Propagation

The Finite-Difference Time-Domain (FDTD) technique is a numerical analysis modeling method to find the solutions of the partial derivatives in Maxwell’s equations to electromagnetic problems. In FDTD the electrical and magnetic fields components staggered in time and space by a method developed by Yee. The approximation of the solutions can be found using a set of updated equations. In every simulation that utilizes the FDTD method, the factors of time and memory size are the two significant considerations. This study focused on reducing the computation time, as the time required to time-march the components of the electrical and magnetic fields at each of the FDTD problem cells is computationally expensive. Based on the findings of this study, the issue of time can be solved by parallelizing the code. Since the structures of the FDTD field\u27s components are independent, the algorithm of the FDTD can be divided into small tasks that can be executed concurrently. Two approaches were taken to parallelize the one- and two-dimensional FDTD code: The Compute Unified Device Architecture (CUDA) approach and Open Computing Language (OpenCL) approach. The serial FDTD C code was implemented and accelerated using CUDA. The result of the comparison between the serial and parallel algorithms (C, CUDA, MATLAB) showed a speed-up of 505 speed factor with the GPU-GPU method and 5 speedup factor with the CPU-GPU method. This was the case for a one-dimensional space problem. The FDTD code was implemented and executed with the OpenCL (Open Computing Language) software as well. The OpenCL software is important since it is open-source and freely available. In contrast to CUDA, which only supports NVIDIA and enabled GPUs, the code written in OpenCL isportable and can be executed on any parallel processing platforms such as CPUs, GPUs, DSPs, FPGAs, and others. Total time\u27s Speedup of 22X has been recorded with OpenCL (PCL) with respect to CPU-C, with 10000 iterations and a 150000 cells grid size

The Attachment of the Neighbor and the Accusative Objection in the Holy Qur'an - a Semantic Grammatical Study

This research aims to comprehensively monitor the cases of attachment (the neighbor, the traitor, and the adverb) in the Holy Qur'an, exclude the unproblematic attachments as an abbreviation of the research material, present the abstaining attachments as a sign in the views of the commentators by analyzing them grammatically and semantically, and to determine the grammatical attachments of the neighbor and the drawer that are authenticated by the sayings of the grammarians, abstaining semantically while providing valid alternatives.This research is based on a comprehensive monitoring of the cases of attachment of the two types of semi-sentence (the neighbor, the traitor and the adverb) in the Noble Qur'an, and then excludes the unresolved attachments as a shortcut to the subject of the research. The accusative and the adverb which are authenticated by the sayings of grammarians by refraining from semantics, while providing valid alternatives for them. Keywords: neighbor and drawer, semi-sentence - Attached, - semantic block, - the meanin

Cartilage Tissue Engineering For Rhinoplasty

Nasal surgery (rhinoplasty) has evolved considerably since its origins in Egypt around 1600BCE, yet modern reconstruction still relies on grafts harvested from autologous rib cartilage. Rib cartilage is an excellent graft material, but chest donor site morbidity can be a significant problem. The aim of this thesis was to create a patient specific cartilage surgical product using autologous stem cells that would provide surgeons with an effective alternative to rib cartilage. Adipose-derived stem cells (ADSCs) and cartilage-derived stem/precursor cells (CSPCs) were used in this thesis as they can be harvested through minimally invasive procedures and their chondrogenic potential already widely established. Using a novel tissue clearing protocol for whole mount imaging, primary experiments confirmed the ability of both cell types to self-organize and generate cartilage-like extracellular matrix (ECM) in 3D spheroids. Three different methods of engineering cartilage in 3D were investigated. Firstly, a clinically approved collagen matrix was used as a scaffold and seeded with cells. Immunocytochemistry and histological staining demonstrated cartilage like ECM on the scaffold surface in preference to deeper regions. The collagen matrix proved too be tight and constrictive on cell expansion. Secondly, a 3D bioprinter was used to print cells mixed with cellulose/alginate “bioink” hydrogels. This bioink failed to demonstrate cartilage like ECM in static culture and in a chick embryo chorioallantoic membrane (CAM) model. Lastly, a cell laden fibrin hydrogel was “sandwiched” between 2 layers of polycaprolactone (PCL) sheets to provide mechanical support and grafted onto CAM. Histological analysis of cell laden fibrin confirmed regions of chondrogenesis by positive staining of collagen and glycosaminoglycans. In conclusion, the results provide further understanding of how these cells respond to different 3D environments and the effect on chondrogenesis. Combining 3D bioprinting with a sandwich design may be an effective future approach to product development

The Impact of Transmission Range Over Node Density in Vehicular Ad Hoc Network (Vanet) With Obstruction of Road Infrastructure

Vehicular ad hoc networks have the characteristic to of experiencing rapid change of network topology and mobility. Importantly, vehicular networks are required to deal with different network densities in order to provide efficient routing and data dissemination. These are some of the main characteristic that can affect the performance of the network immensely. The main issue that became the driving factor in implementing this project is the need to fill these gaps of understanding the behavioral of vehicular network performance when they are restrained by certain network condition which in this case, dealing with an obstruction of road infrastructure with varying transmission range and node density. In order to understand this problem, we identify the objectives of this project to integrate SUMO/MOVE (a vehicular traffic generator) into NS-2 to simulate a realistic vehicular ad hoc network environment and to study the performance of the network when the being conditioned into varying settings of transmission range and node density. In this project, we evaluate the network performance of VANETs in a highway environment using SUMO traffic simulator and network simulator, NS-2 which specifically focusing at the toll booths by studying the effect of varying transmission range over node density. From the simulation results, we found out that the smaller transmission range will produce less throughput, higher end to end delay and also higher normalized routing load. Particularly in vehicular ad hoc network, a constant or a fixed transmission range is not efficient enough in maintaining the connectivity in the network. This is due to the unpredictable of traffic conditions in the network. In addition to this, by dynamically changing the transmission range according to its need, will offer the advantage of power saving and increase capacity

Suggested Method for Encryption and Hiding ‎Image using LCG and LSB

من أجل الحفاظ على سريّةِ البياناتِ مِنْ المجالات المهمةِ جداً في تطبيقاتِ الحاسوبِ، عمل العديد مِنْ الباحثين في مجال الإخفاءِ والتشفيرِ لذا في هذا البحثِ نحن نَعْملُ على الجَمْع بين الطريقين، حيث أنَّ البيانات السرّية هي مشُفّرةَ بإستعمال طريقة مقترحة، ثمّ يتم تُشفيّرُ الغطاءَ (الصورة المنتظمة) بواسطة خوارزميةِ LCG (الذي يُولّدُ سلسلة  من الأعدادِ العشوائيةِ) لتَوليد الغطاءِ المشفّرِ (صورة غير منتظمة)، بعد ذلك نحن نَخفي البياناتَ المشفّرةَ في الغطاءِ المشفّرِ بالإعتِماد على تقنيةِ LSB ، ثمّ تحوّلُ الصورةَ غير المنتظمة الى صورةِ منتظمةِ، وبذلك نحْصلُ على بياناتِ مخفيةِ في مواقعِ عشوائيةِ في صورةِ الغطاءَ، هذه الطريقةِ تمتاز بالمرونةِ حيث بامكاننا إخفاء أنواعِ مختلفةِ من البياناتِ السرّيةِ في أنواعِ مختلفةِ مِنْ وسائط النقل، وتمتاز أيظا بالمتانة حيث أنَّ البياناتِ السرية تَكُونُ مخفيةَ في مواقعِ عشوائيةِ وهذا ما يميّزُ الخوارزميةَ المُقتَرَحةَ، حيث أظهرت النَتائِجَ أمنية عالية، وذلك لأن البياناتَ السرية تكون مخفية داخل الصورةِ المشفّرةِ ثمّ تُحوّلُ إلى الصورةِ المنتظمةِ الأصليةِ، ولتوضيحِ الخوارزميةِ المُقتَرَحةِ تم تطبيقها على صورة رقمية ذات التدرج الرماديِ و بأستحدام لغة ماتلاب مع إستعمال مقاييس الكفاءةِ PSNR   و MSE   لقياس كفاءة الطريقة المقترحةMaintaining the confidentiality of the data of the very important areas in computer applications , Where many researchers work in the fields of concealment and encryption . So in this research we are working on the combining of the two methods , where confidential data is encrypted by using  a proposed method , Then the cover is encrypted (regular image) by LCG algorithm (which generates a series of random numbers) to generate the encrypted cover (irregular image) , After that ,we hide the encrypted data in encrypted cover by depending on the LSB technique, then we convert the irregular image into regular image and thereby getting  hidden data in random locations in the  cover image  , This method is characterized by flexibility in terms of the possibility of hiding the different  types of confidential data in different types of media , and durability as that data be hidden in random locations and this  what distinguishes the proposed algorithm , and the results showed high security, because the data is hidden in random locations in encrypted image then convert to the original regular image For clarification of the proposed algorithm , it has been applied on a digital image of the gray type using MATLAB language  by using the efficiency scales PSNR and MS

Boolean Routing on High Degree Chordal Ring Networks

Over the past twenty-five years, the telecommunication field has evolved rapidly. Telephone and computer networks, now nearly ubiquitous, provide access to voice, data and video services throughout the world. As networking technologies evolve and proliferate, researchers develop new traffic routing strategies. The problem of routing in a distributed system has been investigated and issues concerning Boolean routing schemes have been considered. All compact routing techniques minimise time and space complexity. A good routing algorithm optimises the time and space complexity and a routing algorithm that has O(1) time complexity and O(log n) space complexity for high degree chordal ring has been found. A Boolean Routing Scheme (BRS) has been applied on ring topology and regular chordal ring of degree three. It was found that the regular chordal ring of degree three can be represented geometrically. the regular chordal ring of degree three has been categorised into two categories; the first is the regular chordal ring of degree three that satisfies the following formula n mod 4 = 0 and the second other is n mod 4≠0, where n is the number of nodes that the graph contains. A BRS that requires O(log n) bits of storage at each node, O(1) time complexity to compute a shortest path to any destination for the regular chordal ring of degree three and Ө(log n) bits of storage at each node. O(1) time complexity to compute a shortest path to any destination for the ring topologies has been shown. The BRS has been applied on chordal ring of degree six. it has been found that the chordal ring of degree six can be represented geometrically and the representation would be in three dimensions (in the space). Very little is known about routing on high degree chordal rings. A BRS that requires O(log n) bits of storage at each node ,and 0(1) time complexity to compute a shortest path to any destination for the chordal ring of degree six topologyhas been shown. The chordal ring 0(27;9;3) has been considered as a case to apply BRS

Investigating Different Coding Environments for Simplified Reservoir Characterization Models

Reservoir characterization is one of the most important tasks that determines the recovery plan for a specific reservoir. This process incorporates a significant amount of data acquisition and processing to finally develop an acceptable model that matches the production history and can forecast the future production behavior. The model also should be able to adapt to changes along the way: adding or removing producers or injectors, changing the injection pattern, recompletions and converting wells are all examples of possible changes that are common in the oil and gas industry. Usually these changes are modeled by running field-scale simulations and providing the model with the daily data from the field to keep the model up to date and to reduce prediction errors