Pricing in Infrastructure Clouds – An Analytical and Empirical Examination

With the increasing maturity of the cloud computing market, specifically in the Infrastructure as a Service (IaaS) domain, adequate pricing of services has become a crucial success factor for providers. In this work, we take a threefold approach to examine the current situation concerning pricing in the IaaS market. Based on an initial literature review, we find that pay-as-you-go pricing is perceived as the dominant scheme by the scientific community. Based on this notion, we discuss other pricing schemes with respect to their advantages, disadvantages, and challenges for a cloud provider. These results are complemented by an empirical study, in which we identify pay-as-you-go and subscription pricing as the dominant options that are practically applied in the IaaS market today

Heat Exchanger Design in Mobile Machines

This paper examines the model-based design of thermal systems in mobile machines with a focus on heat exchanger design. An industry project is described in which the vapor compression cycle for the air-conditioning system was modeled using the software SimulationX. By modeling heat exchanger sections separately, multiple flow arrangements could be tested without the need for physical prototypes. The paper presents this work in the context of the full model-based design process including extensions for hardware in the loop (HiL) testing of control units and operator training using virtual machines

Contrast Sensitivity and Night Driving in Older People: Quantifying the Relationship Between Visual Acuity, Contrast Sensitivity, and Hazard Detection Distance in a Night-Time Driving Simulator

Purpose(i) To assess how well contrast sensitivity (CS) predicts night-time hazard detection distance (a key component of night driving ability), in normally sighted older drivers, relative to a conventional measure of high contrast visual acuity (VA); (ii) To evaluate whether CS can be accurately quantified within a night driving simulator.Materials and MethodsParticipants were 15 (five female) ophthalmologically healthy adults, aged 55–81 years. CS was measured in a driving simulator using Landolt Cs, presented under static or dynamic driving conditions, and with or without glare. In the dynamic driving conditions, the participant was asked to simultaneously maintain a (virtual) speed of 60 km/h on a country road. In the with glare conditions, two calibrated LED arrays, moved by cable robots, simulated the trajectories and luminance characteristics of the (low beam) headlights of an approaching car. For comparison, CS was also measured clinically (with and without glare) using a Optovist I instrument (Vistec Inc., Olching, Germany). Visual acuity (VA) thresholds were also assessed at high and low contrast using the Freiburg Visual Acuity Test (FrACT) under photopic conditions. As a measure of driving performance, median hazard detection distance (MHDD) was computed, in meters, across three kinds of simulated obstacles of varying contrast.ResultsContrast sensitivity and low contrast VA were both significantly associated with driving performance (both P < 0.01), whereas conventional high contrast acuity was not (P = 0.10). There was good correlation (P < 0.01) between CS measured in the driving simulator and a conventional clinical instrument (Optovist I). As expected, CS was shown to decrease in the presence of glare, in dynamic driving conditions, and as a function of age (all P < 0.01).ConclusionContrast sensitivity and low contrast VA predict night-time hazard detection ability in a manner that conventional high contrast VA does not. Either may therefore provide a useful metric for assessing fitness to drive at night, particularly in older individuals. CS measurements can be made within a driving simulator, and the data are in good agreement with conventional clinical methods (Optovist I)

Электропривод скипового подъемника

В работе был разработан и спроектирован электропривод главного скипового подъёмника доменной печи на основе устройства преобразования тока SIMOREG- К. В ходе проектирования были рассчитаны параметры силовой цепи привода, произведён расчёт регулировочных характеристик преобразователя, параметров оптимальной настройки и логарифмических амплитудно-частотных и фазочастотных характеристик электропривода. Также был произведён расчёт переходных характеристик регулируемого электропривода методом математического моделирования и определены показатели качества, которые полностью удовлетворяют требованиям технического задания.The electric drive of the main skip hoist of the blast furnace was designed and designed on the basis of the SIMOREG-K current conversion device. During the design, the parameters of the drive power circuit were calculated, the converter adjusting characteristics, the optimum tuning parameters and the logarithmic amplitude-frequency and phase-frequency characteristics of the drive were calculated. The calculation of the transient characteristics of the regulated electric drive by the method of mathematical modeling was also carried out, and quality indicators were determined that fully satisfy the requirements of the technical assignment

How should novelty be valued in science?

<p>Box plot analysis of serum concentrations of sRAGE (A), esRAGE (B), S100A9 (C) and HMGB1 (D) in patients with CTEPH (n = 26) and controls (n = 33). Independent Student’s t-test was used to compare groups. <i>RAGE</i> receptor for advanced glycation endproducts, <i>sRAGE</i> soluble RAGE, <i>esRAGE</i> endogenous secretory RAGE, <i>S100A9</i> member of S100 family of Ca+ binding proteins, <i>HMGB1</i> high mobility group box1, <i>CTEPH</i> chronic thromboembolic pulmonary hypertension.</p

An interdisciplinary approach to data management

Many scientific issues involve interdisciplinary approaches that demand scientists with diverse skills and research fields. For the design and fabrication of new materials, this is especially true since new materials with macroscopically observable properties must be proposed based on changes at the molecular level. Research projects of this kind pose particular challenges for efficient execution and documentation, as research data management (RDM) tools usually fit very well to a specific research area, but cannot provide solutions for interdisciplinary topics. In order to guarantee consistent research and its documentation across disciplines, different tools, which may be used in several groups, must be used cooperatively. In the context of the Science Data Center MoMaF, among other things, strategies are being developed to enable research data management across scales. The RDM tools used for this are Chemotion and Kadi4Mat. The systems cover research at the molecular level (chemotion ELN) as well as simulation activities on the meso- and macroscopic scale (Kadi4Mat), and will be extended within the Science Data Center to enable cooperative use of the systems for work across scales. A first use case shows how Chemotion ELN can be used to document necessary parameters at the molecular level, in order to then be able to manage simulations of phase separation processes on their basis in a further step with the help of Kadi4Mat. For this purpose, the procedure and documentation method of already completed projects were first analysed in order to be able to propose a concept for future processes. Chemotion ELN is used in the presented procedure to document molecular descriptions, the performance of polymerization reactions and their outcome, as well as the properties obtained experimentally and from the literature. Kadi4Mat manages and transfers the parameters from the molecular description as input for mesoscopic simulations that describe the phase separation process in a time-dependent manner. Finally, by applying analysis tools on the time-dependent data via Kadi4Mat, macroscopic properties can be derived across scales as a function of the molecular composition