Networking lessons in delivering ‘Software as a Service’—part I

This is a two‐part paper. In part I, we describe the origins of Software as a Service (SaaS) and its value proposition to Corporate IT, Service Providers, Independent Software Vendors, and End Users. In part II, we examine the networking lessons learned in researching, building, and running a SaaS service. Copyright © 2002 John Wiley & Sons, Ltd.     

Self‐Compensation in Transparent Conducting F‐Doped SnO2

The factors limiting the conductivity of fluorine‐doped tin dioxide (FTO) produced via atmospheric pressure chemical vapor deposition are investigated. Modeling of the transport properties indicates that the measured Hall effect mobilities are far below the theoretical ionized impurity scattering limit. Significant compensation of donors by acceptors is present with a compensation ratio of 0.5, indicating that for every two donors there is approximately one acceptor. Hybrid density functional theory calculations of defect and impurity formation energies indicate the most probable acceptor‐type defects. The fluorine interstitial defect has the lowest formation energy in the degenerate regime of FTO. Fluorine interstitials act as singly charged acceptors at the high Fermi levels corresponding to degenerately n‐type films. X‐ray photoemission spectroscopy of the fluorine impurities is consistent with the presence of substitutional F_O donors and interstitial F_i in a roughly 2:1 ratio in agreement with the compensation ratio indicated by the transport modeling. Quantitative analysis through Hall effect, X‐ray photoemission spectroscopy, and calibrated secondary ion mass spectrometry further supports the presence of compensating fluorine‐related defects.     

Using Data Contention in Dual-ported Memories for Security Applications

Field Programmable Gate Arrays (FPGA) provide the invaluable feature of dynamic hardware reconfiguration by loading configuration bit files. However, this flexibility also opens up the threat of theft of Intellectual Property (IP) since these configuration files can be easily extracted and cloned. In this context, the ability to bind an application configuration to a specific device is an important step to prevent product counterfeiting. Furthermore, such a technology can also enable advanced business models such as device-specific feature activation. In this work, we present a new technique to generate entropy on FPGA device—based on data contention in the hardware circuitry. For this entropy, we use the output of intentionally generated write collisions in synchronous dual-ported block RAMs (BRAM). We show that the parts of this output generated by such write collisions can be either probabilistic but also deterministic and device-specific. The characteristics of such an entropy source can be used for a large variety of security applications, such as chip identification and device authentication. In addition to that, we also propose a solution to efficiently create cryptographic keys on-chip at runtime. As a last contribution, we eventually present a strategy how to transform this entropy source into a circuit for True Random Number Generation (TRNG).     

3D-FE-Analysis of CT-specimens including viscoplastic material behavior and nonlocal damage

In order to describe the time-dependent inelastic behavior of steel structures up to failure, a material model is developed within the framework of thermodynamics considering viscoplastic material behavior, isotropic hardening, softening, and isotropic ductile damage. Since softening and damage lead to localization of deformations, the model is extended by a non-local implicit gradient formulation. An additional gradient equation is formulated for the local damage variable in order to achieve results independent of the finite-element discretization. The approach is verified by 3D-structural analysis of CT-specimens.     

Applying heat integration total site based pinch technology to a large industrial area in Japan to further improve performance of highly efficient process plants

“Area-wide pinch technology” which consists of R-curve analysis and Site Source Sink Profile (SSSP) analysis, was applied to Kashima industrial area, one of the biggest heavy chemical complexes in Japan. This case study demonstrates that despite the very high efficiency of the individual sites in the complex, there is a huge amount of energy saving potential through energy sharing among the various sites. In addition it was found that appropriate use of the available pinch technology tools and techniques allows an industrial area of enormous scale and complexity to be analysed conveniently. This has resulted in practical area-wide energy saving projects being proposed and implemented.     

350／700筒式钢球磨煤机端盖的形状优化设计

运用形状优化的数值方法,对350/700筒式钢球磨煤机的端盖进行了以降低应力集中,使其最大有效应力极小化为目标的几何形状优化设计。优化结果表明,若对球磨机端盖上锥形部分的锥角及锥部与中空轴的过渡圆角半径进行合理变动,可使端盖上的应力分布得到改善,最大应力下降幅度可达21.7％。     

Exploratory data analysis using set operations and ordinal mapping

Exploratory data analysis requires the ability to issue ad hoc queries to filter and summarise data sets. As the sizes of health data sets grow, traditional methods of processing data have difficulty in providing acceptable response times for such queries. An alternative method is described which combines complete vertical partitioning of data with set operations on ordinal mappings (SOOM). An initial implementation of the technique provides significantly better performance than a conventional SQL database on typical exploratory data analysis queries. The use of parallel, distributed computation to further increase the performance of the technique appears to be feasible.     

Estimating average growth trajectories in shape-space using kernel smoothing

In this paper, we show how a dense surface point distribution model of the human face can be computed and demonstrate the usefulness of the high-dimensional shape-space for expressing the shape changes associated with growth and aging. We show how average growth trajectories for the human face can be computed in the absence of longitudinal data by using kernel smoothing across a population. A training set of three-dimensional surface scans of 199 male and 201 female subjects of between 0 and 50 years of age is used to build the model.     

Der Einfluss von Struktur des Laserimpulses auf die Temperaturverteilung und Wärmespannungen des elastischen Halbraumes

The approximate method for the determination of temperature and stress distributions in an elastic half-space heated by laser impulse on its boundary is derived. The method is based on the solutions for two cases of laser time structure: uniform and linear as well as approximate finite functions. The numerical results are presented for the laser impulses applied in engineering practice.