Measuring The Evolving Internet Ecosystem With Exchange Points

The Internet ecosystem comprising of thousands of Autonomous Systems (ASes) now include Internet eXchange Points (IXPs) as another critical component in the infrastructure. Peering plays a significant part in driving the economic growth of ASes and is contributing to a variety of structural changes in the Internet. IXPs are a primary component of this peering ecosystem and are playing an increasing role not only in the topology evolution of the Internet but also inter-domain path routing. In this dissertation we study and analyze the overall affects of peering and IXP infrastructure on the Internet. We observe IXP peering is enabling a quicker flattening of the Internet topology and leading to over-utilization of popular inter-AS links. Indiscriminate peering at these locations is leading to higher endto-end path latencies for ASes peering at an exchange point, an effect magnified at the most popular worldwide IXPs. We first study the effects of recently discovered IXP links on the inter-AS routes using graph based approaches and find that it points towards the changing and flattening landscape in the evolution of the Internet’s topology. We then study more IXP effects by using measurements to investigate the networks benefits of peering. We propose and implement a measurement framework which identifies default paths through IXPs and compares them with alternate paths isolating the IXP hop. Our system is running and recording default and alternate path latencies and made publicly available. We model the probability of an alternate path performing better than a default path through an IXP iii by identifying the underlying factors influencing the end-to end path latency. Our firstof-its-kind modeling study, which uses a combination of statistical and machine learning approaches, shows that path latencies depend on the popularity of the particular IXP, the size of the provider ASes of the networks peering at common locations and the relative position of the IXP hop along the path. An in-depth comparison of end-to-end path latencies reveal a significant percentage of alternate paths outperforming the default route through an IXP. This characteristic of higher path latencies is magnified in the popular continental exchanges as measured by us in a case study looking at the largest regional IXPs. We continue by studying another effect of peering which has numerous applications in overlay routing, Triangle Inequality Violations (TIVs). These TIVs in the Internet delay space are created due to peering and we compare their essential characteristics with overlay paths such as detour routes. They are identified and analyzed from existing measurement datasets but on a scale not carried out earlier. This implementation exhibits the effectiveness of GPUs in analyzing big data sets while the TIVs studied show that the a set of common inter-AS links create these TIVs. This result provides a new insight about the development of TIVs by analyzing a very large data set using GPGPUs. Overall our work presents numerous insights into the inner workings of the Internet’s peering ecosystem. Our measurements show the effects of exchange points on the evolving Internet and exhibits their importance to Internet routing

Pakistan: Prospects for Private Capital Flows and Financial Sector Development

In less than a decade after the debt crisis of 1982, developing countries have experienced a surge of capital inflows in recent years. This trend became more pronounced in the 1990s resulting in overall balance of payments surpluses and accumulation of reserves. Total private capital inflows to developing countries exceeded $173 billion in 1994, compared to annual average inflows of$34 billion during 1983–90 [World Bank (1995)]. Although the characteristics of capital inflows in this episode are different than in the period prior to the last debt crisis, nevertheless concerns about macroeconomic stability, loss in competitiveness, financial sector vulnerability and excessive borrowing remain the same. While the rise in inflows during 1991–93 was supported in part by low interest rates and weak economic activity in industrial countries, improved economic policies and prospects in most recipient countries also played an important role. The larger share in inflows of those countries that achieved greater progress in economic reforms, is evidence of the importance of recipient country policies. During this period, the composition of private flows to developing countries also became more diversified. Foreign direct investment (FDI) accounted for 45 percent of total equity inflows in 1994, with debt accounting for 32 percent and portfolio flows accounting for the remaining 23 percent

Zero-tillage Technology and Farm Profits: A Case Study of Wheat Growers in the Rice Zone of Punjab

The rice-wheat cropping zone of Punjab is the main producer of high-valued and fine quality basmati rice in Pakistan. The rice produced in this area is famous for its grain length and aromatic characteristics. Being an important export item, rice contributes significantly to the national foreign exchange earnings. Wheat is the other major crop of the rice-wheat system and being the staple food is central to national agricultural policies. Rice is grown on a vast area in this zone during Kharif mostly followed by wheat in the Rabi season. Studies have shown that a large gap exists between the potential and yields actually realised by the wheat growers of the area [Byerlee, et al. (1984); Hobbs (1985) and Sheikh, et al. (2000)]. Farmers’ practices regarding land preparation for paddy, wheat planting time, and other conflicts endogenous to the rice-wheat based cropping system were identified as the major factors limiting wheat yield in the area. The flooded and puddled soils that are well suited for paddy production as compared to well-drained conditions required for wheat is such an example of the system conflicts. The farmers in the rice-wheat zone of the Punjab predominantly grow basmati varieties, which are late maturing as compared to coarse varieties of rice. Therefore, paddy harvest is generally delayed at most of the farms in this zone. The late paddy harvest coupled with poor soil structure and loose plant residues create problems for preparation of a good seedbed and planting of wheat often gets late [Byerlee, et al. (1984)]. The farmers also had to resort to the broadcast method for wheat sowing which results in poor and patchy plant stands.

Three-Dimensional Graph Drawing Procedures for Functions of Two and Several Variables

Many functions depend on more than one independent variable. For instance, the volume of a right circular cylinder is a function of its radius and its height, so it is a function V(r, h) of two variables r and h. Real valued functions of several independent real variables are defined similarly to functions in the single-variable case. In this article, we define functions of more than one independent variable and discuss ways to graph them. But their graph is impossible in the two-dimensional system and the MATLAB program is the language that guarantees computer implementation at a high level in mathematics, easily presenting calculations, images, graphs, and writing programs in its environment. For achieving this goal, we first explained the plot3 procedure in the three-dimensional coordinate system to draw the graph of two dependent subordinates on the MATLAB program environment, followed by the surf procedure as well as the mesh procedure. Then we explained the procedures mentioned in the polar coordinates. We have provided examples to better understand each procedure

Evaluating Multicore Algorithms on the Unified Memory Model

One of the challenges to achieving good performance on multicore architectures is the effective utilization of the underlying memory hierarchy. While this is an issue for single-core architectures, it is a critical problem for multicore chips. In this paper, we formulate the unified multicore model (UMM) to help understand the fundamental limits on cache performance on these architectures. The UMM seamlessly handles different types of multiple-core processors with varying degrees of cache sharing at different levels. We demonstrate that our model can be used to study a variety of multicore architectures on a variety of applications. In particular, we use it to analyze an option pricing problem using the trinomial model and develop an algorithm for it that has near-optimal memory traffic between cache levels. We have implemented the algorithm on a two Quad-Core Intel Xeon 5310 1.6 GHz processors (8 cores). It achieves a peak performance of 19.5 GFLOPs, which is 38% of the theoretical peak of the multicore system. We demonstrate that our algorithm outperforms compiler-optimized and auto-parallelized code by a factor of up to 7.5

Parallel spatial direct numerical simulations on the Intel iPSC/860 hypercube

The implementation and performance of a parallel spatial direct numerical simulation (PSDNS) approach on the Intel iPSC/860 hypercube is documented. The direct numerical simulation approach is used to compute spatially evolving disturbances associated with the laminar-to-turbulent transition in boundary-layer flows. The feasibility of using the PSDNS on the hypercube to perform transition studies is examined. The results indicate that the direct numerical simulation approach can effectively be parallelized on a distributed-memory parallel machine. By increasing the number of processors nearly ideal linear speedups are achieved with nonoptimized routines; slower than linear speedups are achieved with optimized (machine dependent library) routines. This slower than linear speedup results because the Fast Fourier Transform (FFT) routine dominates the computational cost and because the routine indicates less than ideal speedups. However with the machine-dependent routines the total computational cost decreases by a factor of 4 to 5 compared with standard FORTRAN routines. The computational cost increases linearly with spanwise wall-normal and streamwise grid refinements. The hypercube with 32 processors was estimated to require approximately twice the amount of Cray supercomputer single processor time to complete a comparable simulation; however it is estimated that a subgrid-scale model which reduces the required number of grid points and becomes a large-eddy simulation (PSLES) would reduce the computational cost and memory requirements by a factor of 10 over the PSDNS. This PSLES implementation would enable transition simulations on the hypercube at a reasonable computational cost

Benign metastasizing leiomyoma

Benign metastasizing leiomyoma (BML) is a rare condition, affecting predominantly reproductive-age females with uterine leiomyomata and is most often associated with multiple benign-appearing smooth muscle tumors in lungs. We report herein a case of a 38-year-old woman who presented with multiple uterine fibroids for which hysterectomy was carried out on her. Postoperatively, she developed left-sided pleural effusion. Computed chest tomography (CT) scan revealed multiple nodules in both lungs and pleurae. Histopathology of one of the pleura-based nodules revealed a neoplasm composed of interlacing fascicles of spindle cells with uniform nuclei. The tumor cells were positive for alpha-smooth muscle actin and negative for CD34 immunohistochemical stain

gpusvcalibration: A R Package for Fast Stochastic Volatility Model Calibration Using GPUs

In this paper we describe the gpusvcalibration R package for accelerating stochastic volatility model calibration on GPUs. The package is designed for use with existing CRAN packages for optimization such as DEOptim and nloptr. Stochastic volatility models are used extensively across the capital markets for pricing and risk management of exchange traded financial options. However, there are many challenges to calibration, including comparative assessment of the robustness of different models and optimization routines. For example, we observe that when fitted to sub-minute level midmarket quotes, models require frequent calibration every few minutes and the quality of the fit is routine sensitive. The R statistical software environment is popular with quantitative analysts in the financial industry partly because it facilitates application design space exploration. However, a typical R based implementation of a stochastic volatility model calibration on a CPU does not meet the performance requirements for sub-minute level trading, i.e. mid to high frequency trading.We identified the most computationally intensive part of the calibration process in R and off-loaded that to the GPU.We created a map-reduce interface to the computationally intensive kernel so that it can be easily integrated in a variety of R based calibration codes using our package. We demonstrate that the new R based implementation using our package is comparable in performance to aC=C++ GPU based calibration code

Impact of Information and Communication Technology Investment to Achieve Excellence in Banking Services Quality: An Analytical Study of the Views of a Sample of Workers in a Number of Government and Private Banks in the Province of Dohuk Iraqi Kurdista

The research discussed the information and communication technology investment in the pursuit of excellence in the provision of banking services with high quality in the banks of the province of Dohuk and their impact in facilitating the task that lies upon themselves to implement the plans and programs of development and improve the quality of services provided to beneficiaries , the importance of the research is triggering  from the banks as a service organization specializes in the package production of banking and financial services, which is one of the main pillars to achieve the proper construction of banks, And the banking sector considered to be one   of the most important economic sectors and the most sensitive and vulnerable to revolution communications and information that contributed to its progress and prosperity, especially in recent decades, which is  used networks and connected computers with each other for banks  development  to apply to high technology systems which  will exchange data and access to the Legal banking business  based on the pillars of sophisticated electronic, Moreover, banks constantly sought to achieve a high quality of services, especially in light of growing competition in this sector by identifying the requirements of customers and work to meet the various strategies of marketing, because the quality is the price of entering the market and excellence which does not achieved only through the possession of these banks to sophisticated technology. And thus achieve access to quality services in banks and these services cannot achieve its goals unless its production and presentation were in a distinct level of quality, hence the importance of the subject technology investment in the provision of quality services in banks including banks of Dohuk province. So research aims to follow up the strengths and weaknesses in the implementation of programs in the province of Dohuk banksDepending on the foregoing and the importance of excellence in the provision of services under the efficient use of information technology and communications, the current research seeks to determine the impact of information and communication technology in the pursuit of excellence in the provision of services in the light of the analysis of data collected by Form questionnaire distributed to a sample of (47) as director of Sections the number of people from government and private banks in the province of Dohuk, right down to display a set of conclusions, as well as providing the necessary recommendations and proposals in this area