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The flow characteristics and heat transfer mechanism of supercritical pressure CO2 in a bent pipe were studied by the method of numerical simulation. The velocity, temperature, secondary flow, and turbulent kinetic energy distribution of the CO2 under different heating conditions are analyzed. The effects of pipe bend and sharp changes in the thermal properties of CO2 on the flow field and temperature field are discussed and compared. The results show that a narrow high-temperature region appears on the inside wall, where the turbulent kinetic energy is low. Here, the local heat transfer coefficient decreases by 60%, compared with the other areas of the bend. Under the conditions of high heat flux and low mass flux, this narrow region transfers from the inside wall to the outside wall, and a reduction in heat transfer occurred. More specifically, the heat flux increases from 20 to 50 kW·m-2, and the heat transfer coefficient decreases by 35%, while the mass flux decreases from 600 to 400 kg·m-2·s-1, and the heat transfer coefficient decreases by 50%. When the pressure changes from 7.58 MPa to 9.00 MPa, the heat transfer coefficient is maximum of 5% reduction. At higher pressures, the heat transfer coefficient is slightly affected by the pressure. Meanwhile, the secondary flow significantly enhances the convective heat transfer, and the range and intensity increase with the flow development.

This study aims to evaluate the pavement performance of permeable asphalt concrete (PAC) produced with modified recycled coarse aggregate (RCA) based on six types of single modification methods and three types of double modification methods. Firstly, the water absorption, apparent density, and crushing value of the RCA before and after modification were tested. Subsequently, the performance of PAC with these types of modified RCA was investigated, including the optimum asphalt-aggregate ratio, water stability, high-temperature performance, and low-temperature crack. The test results show that the physical properties of RCA were improved to some extent owing to the modification methods adopted, except that the water absorption of RCA-C and RCA-PC increased by 33.5% and 32.6%, respectively, compared with that of RCA. This increase in the water absorption was attributed to the high water absorption of the cement mortar. As a whole, various modification methods have different effects on the road performance of asphalt mixtures, and soaking RCA with slag powder and silane coupling agent was prominent among them. Compared with the PAC with RCA, the Marshall stability, Marshall stability of immersion, residual stability, TSR, dynamic stability and low-temperature tensile strength of PAC with RCA-SLSC were increased by 31.8%, 41.0%, 7.0%, 5.8%, 280.7% and 17.2%, respectively.

An ultra-high performance liquid chromatography system coupled with the Q-Exactive mass spectrometry (UHPLC-QE-MS) approach combined with multivariate statistical analysis was used to investigate the metabolic profiles of the fruits of Lycium barbarum in different geographical origins in China. Several classes of compounds such as sugars, amino acids, organic acids, fatty acids, polyphenols and alkaloid were identified in hydroalcoholic extracts, and ten differential metabolites including amino acids, organic acids and vitamins were identified by multivariate statistical method. It was discussed that the differences between organic acids and amino acids in the samples may be caused by environmental factors such as ultraviolet radiation, soil and altitude. A total of 119 metabolic pathways were involved in the differential metabolites and 17 of them were retained for enrichment analysis. It was found that alanine, aspartate and glutamate metabolism, arginine biosynthesis, glutathione metabolism, glyoxylate and dicarboxylate metabolism, purine metabolism, histidine metabolism and aminoacyl-tRNA biosynthesis were the most important pathways. These findings play an important role in the origin tracing of the Lycium barbarum fruit.

PURPOSE One of the main problems concerning the design of clinical trials in critically ill patients with acute cholecystitis (AC) is the lack of validated, well-established scoring systems to stratify the severity of patient disease states. The aim of this study was to evaluate the performance of the Acute Physiology and Chronic Health Evaluation IV (APACHE IV) scoring system in patients over 65 years with AC. METHODS All patients over 65 years of age admitted to our hospital for treatment of AC in the intensive care unit between January 2013 and January 2019 were retrospectively analyzed. RESULTS A total of 443 consecutive patients with AC were enrolled in this study. As for the patients over 65 years, the survivors had lower APACHE IV scores and lower risk of death than nonsurvivors (P

Objective Cholecystostomy is a palliative treatment for patients unfit to undergo immediate cholecystectomy. Nevertheless, the role of cholecystostomy in the clinical management of such patients remains unclear. The Acute Physiology and Chronic Health Evaluation IV (APACHE IV) scoring system is useful for estimating the hospital mortality of high-risk patients. We evaluated the therapeutic effect of cholecystostomy by the APACHE IV scoring system in patients aged >65 years with acute cholecystitis. Methods In total, 597 patients aged >65 years with acute cholecystitis were retrospectively analyzed using APACHE IV scores. Results The fitness of the APACHE IV score prediction was good, with an area under the receiver operating characteristic curve of 0.894. The chi square independence test indicated that compared with conservative treatment, cholecystostomy may have different effects on mortality for patients whose estimated mortality rate was >10%. Comparison of the estimated mortality of patients before and after cholecystostomy indicated that the estimated mortality was significantly lower after than before puncture, both in the whole patient group and in the group with an estimated mortality of >10%. Conclusion The APACHE IV scoring system showed that cholecystostomy is a safe and effective treatment for elderly high-risk patients with acute cholecystitis.

Thermal barrier coatings (TBCs) have been extensively used in industry to provide thermal fatigue protection. For example, in engine design, TBCs are commonly seen on combustion chamber components of aerospace engines. In this study, Nano Y2O3 partially stabilized zirconia (PYSZ) TBC was applied on the piston to provide thermal fatigue protection for the aluminum alloy piston of natural gas engine, and to improve its high temperature performance and thermal load carrying capacity. This method can eliminate the severe restrictions on the development of the natural gas engine and also can be referenced by other internal combustion engine components. Experiments and simulation analyses were conducted to determine the effects of the Nano PYSZ TBCs on temperature and thermal load distributions. Results showed that the substrate temperature of Nano PYSZ TBCs piston was considerably lower (about 16% or 55 °C lower) than that of the conventional (uncoated) piston, which indicates that TBCs can effectively provide thermal fatigue protection for pistons and reduce thermal damage to pistons. Simultaneously, the top surface temperature of the piston increased about 52% or 179 °C after applying the coatings, which increased the combustion chamber temperature, resulting in an improved the engine thermal efficiency.

Nano ceramic coatings have low thermal conductivity which can provide good heat insulation properties, and therefore they have been widely used in industrial design as thermal barrier coatings (TBCs). In the design of internal combustion engines, TBCs have been used on combustion chamber components to improve engine performance. In this paper, improvement in the working performance of natural gas engines is demonstrated when an aluminum alloy piston is sprayed with a Y2O3 partially stabilized zirconia (PYSZ) ceramic coating. Steady-state thermal analyses were used to determine the effects of the ceramic coating on temperature distributions. Output was compared with results from an uncoated conventional piston using the finite element method. Results show that the temperature at the top surface of coated piston is significantly higher (about 44% or 153 °C higher) than that of the uncoated piston. This higher combustion chamber temperature results in better engine thermal efficiency and lower emissions. Simultaneously, the temperature of the coated piston substrate is much lower (about 12% or 43 °C lower) than that of the uncoated piston. The lower metallic substrate temperature provides better thermal fatigue protection for the piston.

In the petroleum industry, the transport of offshore crude oil via pipelines may suffer damage known as wax precipitation. This reduces the flow capacity of the crude oil, reducing its transport efficiency. Under extreme conditions, this may also result in serious damage to equipment. To help alleviate this problem, the petroleum transport and flow characteristics of offshore waxy crude oil in pipelines are investigated, together with the development of several options to help minimize wax precipitation. This paper reviews the current research status for reducing wax precipitation and enhancing crude oil flow in offshore pipelines. Specifically, reducing the viscosity of waxy crude oil, strengthening the process technology of the pipeline and the related flow mechanisms are each investigated. This paper also identifies and discusses areas of study that require further investigation.

Background Cholecystostomy offers an alternative method for patients unfit to undergo immediate cholecystectomy. Nevertheless, the role of cholecystostomy in the clinical management of high-risk surgical patients remains unclear. One of the main problems concerning the therapeutic effect in critically ill patients with acute cholecystitis is the lack of validated, well-established scoring systems to stratify the severity of patient disease states. APACHE IV scoring system was useful to estimate the hospital mortality for high-risk patients. We try to evaluate the performance of the APACHE IV scoring system in patients over 65 years of age with acute cholecystitis and the therapeutic effect of percutaneous cholecystostomy. Methods 597 patients over 65 years of age with acute cholecystitis between January 2011 and December 2018 were retrospectively analyzed with the APACHE IV scores. Results Among the 597 patients, 52 successfully underwent cholecystectomy (2 died, 3.85%), 65 underwent percutaneous cholecystostomy (1 died, 1.54%), and 480 received conservative therapy (27 died, 5.63%). The fitness of the APACHE IV score prediction is good with the area under the ROC curve of 0.894. The APACHE IV models were well-calibrated (with the Hosmer-Lemeshow statistic). Using the method of binary regression analysis, for the patients whose estimated mortality rate was more than 10%, cholecystostomy was an important factor for prognosis (P = 0.048). The estimated mortality of PC patients before and after operation was compared, which indicated that the estimated mortality after puncture was significantly decreased, either in the whole patient group (P = 0.004) or in the group with an estimated mortality greater than 10% (P = 0.008). Conclusion The APACHE IV scoring system showed that cholecystostomy was a safe and effective treatment for elderly high-risk patients with acute cholecystitis.

© 2019 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. At present, many modification methods have been proposed to improve the performance of recycled aggregate concrete (RAC). In this study, tests on the compressive strength and damping properties of modified RAC with the addition of different proportions of recycled coarse aggregate (RCA) (0, 50, 100%), rubber powder (10, 15, 20%), steel fibre (5, 7.5, 10%) and fly ash (15, 20, 5%) are carried out. To elucidate the effect of the modification method on the interfacial transition zone (ITZ) performance of RAC, model ITZ specimens are used for push-out tests. The results show that when the replacement rate of RCA reaches 100%, the loss factor of the RAC is 6.0% higher than that of natural aggregate concrete; however, the compressive strength of the RAC decreases by 22.6%. With the addition of 20% rubber powder, the damping capacity of the modified RAC increases by 213.7%, while the compressive strength of the modified RAC decreases by 47.5%. However, with the addition of steel fibre and fly ash, both the compressive strength and loss factor of the RAC specimens increase. With a steel fibre content of 10 wt%, the compressive strength and loss factor of the RAC increase by 21.9% and 15.2%, respectively. With a fly ash content of 25 wt%, the compressive strength and loss factor of the RAC increase by 8.6% and 6.9%, respectively. This demonstrates that steel fibre and fly ash are effective in improving both the damping properties and compressive strength of RAC, and steel fibre is more effective than fly ash. Two methods were used for modification of the RAC: reinforcing the RCA through impregnation with a 0.5% polyvinyl alcohol (PVA) emulsion and nano-SiO2 solution, and strengthening the RAC integrally through the addition of fly ash as an admixture. Both of these techniques can improve the ITZ bond strength between the RAC and new mortar. Replacing 10% of the cement with fly ash in the new mortar is shown to be the best method to improve the ITZ strength.

An absorption refrigeration system (ARS) is an alternative to the conventional mechanical compression system for cold production. This study developed a novel calculation model using the Matlab language for the thermodynamic analysis of ARS. It was found to be reliable in LiCl-H2O and LiBr-H2O ARS simulations and the parametric study was performed in detail. Moreover, two 50 kW water-cooled single effect absorption chillers were simply designed to analyze their off-design behaviors. The results indicate that LiCl-H2O ARS had a higher coefficient of performance (COP) and exergetic efficiency, particularly in the lower generator or higher condenser temperature conditions, but it operated more restrictively due to crystallization. The off-design analyses revealed that the preponderant performance of LiCl-H2O ARS was mainly due to its better solution properties because the temperature of each component was almost the same for both chillers in the operation. The optimum inlet temperature of hot water for LiCl-H2O (83 °C) was lower than that of LiBr-H2O (98 °C). The cooling water inlet temperature should be controlled within 41 °C, otherwise the performances are discounted heavily. The COP and cooling capacity could be improved by increasing the temperature of hot water or chilled water properly, contrary to the exergetic efficiency.

Aluminium alloys in internal combustion (IC) engines may suffer from heat damage. Such heat damage can be mitigated using thermal barrier coatings (TBCs). In this study, the TBC Nano yttria partially stabilized zirconia (PYSZ) is applied as an aggregated powder to an aluminum alloy piston using an atmospheric plasma spray (APS) method. The preparation and application of the Nano PYSZ aggregated powder are critical to its effectiveness as a TBC. IC engine bench experiments were undertaken to provide a baseline against which the effectiveness of the TBC could be judged. The microstructure of the Nano PYSZ aggregated powder and thermal barrier coatings were examined using three instruments: scanning electron microscopy (SEM), field emission scanning electron microscopy (FESEM) and X-ray powder diffraction (XRD). Results from this study show that the Nano PYSZ ceramic TBCs, applied to the aluminum alloy piston using a plasma spraying technique, (a) has a high quality Nano-structure, (b) can effectively resist the thermal shock of high temperature gas in the cylinder and (c) maintains both stable macro characteristics and micro structure during the working cycle of the IC engine. The thermal insulation properties of TBCs were also examined. The thermal analyses describe the distribution of temperature across both the piston and the aluminum alloy substrate. Results desmonstrate the effectiveness of the TBCs in reducing the temperature of the aluminium alloy substrate at the top of piston. One benefit is that the piston can operate effectively at higher temperatures. Specifically, as the thickness of ceramic coating increased from 0.1 mm to 1.4 mm, the maximum temperature of the pistons coated with the TBCs increased from 399 °C to 665 °C. The maximum temperature of the aluminum alloy substrates simultaneously decreased from 336 °C to 241 °C. This study clearly demonstrates the excellent thermal insulation properties of the TBCs and shows that the thermal insulation performance can be significantly enhanced by increasing the thickness of the ceramic layer.

2-D MUSIC method has been presented to jointly estimate range and DOA of narrowband near field signals. However, this approach is impractical on enormous application situations such as underwater source detection. Sparsity-based IAA are able to work well with few snapshots (even one). Two-dimensional version of IAA is proposed to estimate 2-D range and bearing information of narrowband near-field sources with few snapshots. In the case that snapshots are abundant, both 2-D MUSIC and 2-D IAA do well in estimating range and DOA. However, when it comes to a few snapshots, 2-D IAA performs much better than 2-D MUSIC. Computer simulation results by MATLAB validate the efficacy of 2-D IAA algorithm with few snapshots.

The QuPARA Risk Analysis Framework is an analytical framework implemented using MapReduce and designed to answer a wide variety of complex risk analysis queries on massive portfolios of catastrophic risk contracts. In this paper, we present data structure improvements that greatly accelerate QuPARA's computation of Exceedance Probability (EP) curves with secondary uncertainty.

Alzheimer's disease (AD) is pathologically characterized by deposition of β-amyloid (Aβ) peptides, which closely correlates with the balance of nerve growth factor (NGF)-related TrkA/p75NTR signaling. (−)-Epigallocatechin-3-gallate (EGCG) is used for prevention and treatment of many neurodegenerative diseases, including AD. However, whether the neuroprotective effects of EGCG treatment were via modulating the balance of TrkA/p75NTR signaling was still unknown. In this study, we found that EGCG treatment (2 mg · kg –1 · day –1) dramatically ameliorated the cognitive impairments, reduced the overexpressions of Aβ(1–40) and amyloid precursor protein (APP), and inhibited the neuronal apoptosis in the APP/PS1 mice. Interestingly, the EGCG treatment enhanced the relative expression level of NGF by increasing the NGF/proNGF ratio in the APP/PS1 mice. Moreover, after EGCG treatment, TrkA signaling was activated by increasing the phosphorylation of TrkA following the increased phosphorylation of c-Raf, ERK1/2, and cAMP response element-binding protein (CREB), simultaneously the p75NTR signaling was significantly inhibited by decreasing the p75ICD expression, JNK2 phosphorylation, and cleaved-caspase 3 expression, so that the Aβ deposits and neuronal apoptosis in the hippocampus were inhibited.

Modern reinsurance companies hold portfolios consisting of thousands of reinsurance contracts covering millions of individually insured locations. To ensure capital adequacy and for fine-grained financial planning, these companies carry out large-scale Monte Carlo simulations to estimate the probabilities that the losses incurred due to catastrophic events such as hurricanes, earthquakes, etc. exceed certain critical values. This is a computationally intensive process that requires the use of parallelism to answer risk queries over a portfolio in a timely manner. We present a system that uses the MapReduce framework to evaluate risk analysis queries on industrial-scale portfolios efficiently. In contrast to existing production systems, this system is designed to support arbitrary ad hoc queries an analyst may pose while achieving a performance that is very close to that of highly optimized production systems, which often only support evaluating a limited set of risk metrics. For example, a full portfolio risk analysis run consisting of a 1,000,000-trial simulation, with 1,000 events per trial, and 3,200 risk transfer contracts can be completed on a 16-node Hadoop cluster in just over 20 min. MapReduce is an easy-to-use parallel programming framework that offers the flexibility required to develop the type of system we describe. The key to nearly matching the performance of highly optimized production systems was to judiciously choose which parts of our system should depart from the classical MapReduce model and use a combination of advanced features offered by Apache Hadoop with carefully engineered data structure implementations to eliminate performance bottlenecks while not sacrificing the flexibility of our system.

A "dumbbell-shaped" stir bar was proposed to prevent the friction loss of coating during the stirring process, and thus prolonged the lifetime of stir bars. The effects of the coating components, including polydimethylsiloxane (PDMS), beta-cyclodextrin (beta-CD) and divinylbenzene (DVB) were investigated according to an orthogonal experimental design, using three polycyclic aromatic hydrocarbons (PAHs) and four polycyclic aromatic sulfur heterocycles (PASHs) as model analytes. Four kinds of stir bars coated with PDMS, PDMS/beta-CD, PDMS/DVB and PDMS/beta-CD/DVB were prepared and their extraction efficiencies for the target compounds were compared. It was demonstrated that PDMS/beta-CD/DVB-coated stir bar showed the best affinity to the studied compounds. The preparation reproducibility of PDMS/beta-CD/DVB-coated stir bar ranged from 3.2% to 15.2% (n = 6) in one batch, and 5.2% to 13.4% (n = 6) among batches. The "dumbbell-shaped" stir bar could be used for about 40 times, which were 10 extractions more than a normal stir bar. The prepared PDMS/beta-CD/DVB-coated "dumbbell-shaped" stir bar was used for stir bar sorptive extraction (SBSE) of PAHs and PASHs and the desorbed solution was introduced into HPLC-UV for subsequent analysis. The limits of detection of the proposed method for seven target analytes ranged from 0.007 to 0.103 microg L(-1), the relative standard deviations were in the range of 6.3-12.9% (n = 6, c = 40 microg L(-1)), and the enrichment factors were 19-86. The proposed method was successfully applied to the analysis of seven target analytes in lake water and soil samples.

Rare earth (RE) elements inhering in low toxicity have been widely used in biomedicine. The RE elements can also improve the hot workability, corrosion resistance and mechanical properties of stainless steels. However, the antibacterial mechanisms of the RE elements are still under discussion and the antibacterial property of RE-bearing stainless steels has not yet been investigated or reported so far. In this paper several Ce-bearing stainless steels were prepared, the microstructure of the steels was examined, and the antibacterial property of Ce-bearing stainless steels was investigated. It was found that Ce-rich zones were precipitated in the Ce-bearing stainless steels and the volume fraction of the Ce-rich zones increased with increasing Ce content. The Ce-bearing stainless steels showed excellent antibacterial property when the amount of Ce added was above a critical value. Compared to the conventional Cu-bearing antibacterial stainless steels, the Ce-bearing stainless steels investigated presently exhibited good antibacterial ability without any thermal aging treatment. The antibacterial mechanism of Ce-bearing stainless steels is also discussed.

Measuring document relatedness using unsupervised co-occurrence based word relatedness methods is a processing-time and memory consuming task. This paper introduces the application of compact data structures for efficient computation of word relatedness based on corpus statistics. The data structure is used to efficiently lookup: (1) the corpus statistics for the Common Word Relatedness Approach, (2) the pairwise word relatedness for the Algorithm Specific Word Relatedness Approach. These two approaches significantly accelerate the processing time of word relatedness methods and reduce the space cost of storing co-occurrence statistics in memory, making text mining tasks like classification and clustering based on word relatedness practical.

Finding pair wise document relatedness plays an important role in a variety of Natural Language Processing problems. Google Trigram Method (GTM) is one of the corpus-based unsupervised method that can be used to capture word relatedness and document relatedness. It has been shown that it is possible to apply GTM to construct high quality document relatedness applications. However, there are challenges in implementing GTM for pair-wise document relatedness computation on a large volume of document set given its high computational complexity. This paper presents time and space efficient methods for the computation of pair-wise document relatedness using GTM. In order to improve the performance algorithmic engineering, data structure enhancement, and parallel computing methods are applied. Two parallel methods are discussed in this paper: shared memory multicore implementation and distributed memory Hadoop implementation. Both parallel methods provide an order of magnitude improvement in accelerating the pair-wise document relatedness computation using GTM.

In this paper, the existence of our country city of Roof garden landscape design problems are discussed through the analysis of plant, configuration principle in designing Roof garden, expounds the Countermeasures of plant configuration of modern city landscape design of the Roof garden, has the instruction significance to the city living environment construction of good. Building roof space has unique environmental features, which determines the Roof garden plant must have a happy light, heat resistance, cold resistance, wind proof, dust-proof, anti pollution, is not strict, strong vitality, positive, slow growth, good maintenance, shallow root or root system developed features of the soil requirements.

yzmzzsf@163.com KEYWORDS: graphic form, city square, landscape design ABSTRACT. Plane constitution principle can be applied in the design of city square, different Plaza has different properties, which determine the landscape of city square design scale and design style, the square of the scale and design style, but also directly affect the ground paving material, shape and color pattern scale. Follow the principle of visual aesthetics, embodying the beauty square shape, inspire users pleasant feeling, to explore the aesthetic features of landscape art from multiple angles of plane composition. The scale of city square design Scale design objective is to need to meet people's physiological and mental activities, in the city square landscape, people and transport is the use of the body, therefore, we consider in scale, should not only consider the visitors with all kinds of transport tool motion space size, also according to the actual environmental function and the use of the environment style and other factors to the different arrangements of the scale, to meet people's psychological needs. Square design of large scale can be designed into a gentle wave pattern of the urban space, full of change. Landscape design of small scale the lovely and lively, color floor full of rhythm. The design of scale should be conformed to the principle of human body engineering. In the actual design of the basic motion in space, not only to meet people and the traffic tools, but also consider the people's psychological scale, narrow space makes people feel cramped and crowded, spacious space makes people feel open and empty. Comparison of different scales also can let a person produce or atmospheric open or different psychological kind of natural feeling, pleasant scale can enhance the overall performance of environmental effect. In addition, different material texture and color application for people will produce different visual scale; scale relation should be reasonable use and material texture, color, pattern and other factors to adapt. Such as large scale square landscape generally use the color uniform texture, simple form; contrary to some small scale relation square landscape can use a variety of texture and different combinations of colures, thus enriching the square space level and change.

The design and fabrication of a micromechanical capacitive membrane microwave switching device is described. The switching element consists of a thin metallic membrane, which has two states, actuated or unactuated, depending on the applied bias. A microwave signal is switched on and off when the membrane is switched between the two states. These switches have a switching on speed of less than 6 /spl mu/s and a switching off speed of less than 4 /spl mu/s. The switching voltage is about 50 V. The switches have a bowtie shape and showed low insertion loss of 0.14 dB at 20 GHz and 0.25 dB at 35 GHz, and isolation of 24 dB at 20 GHz and 35 dB at 35 GHz. These devices offer the potential for building a new generation of low-loss high-linearity microwave circuits for a variety of phased antenna arrays for radar and communications applications.

Stochastic simulation techniques are used for portfolio risk analysis. Risk portfolios may consist of thousands of reinsurance contracts covering millions of insured locations. To quantify risk each portfolio must be evaluated in up to a million simulation trials, each capturing a different possible sequence of catastrophic events over the course of a contractual year. In this paper, we explore the design of a flexible framework for portfolio risk analysis that facilitates answering a rich variety of catastrophic risk queries. Rather than aggregating simulation data in order to produce a small set of high-level risk metrics efficiently (as is often done in production risk management systems), the focus here is on allowing the user to pose queries on unaggregated or partially aggregated data. The goal is to provide a flexible framework that can be used by analysts to answer a wide variety of unanticipated but natural ad hoc queries. Such detailed queries can help actuaries or underwriters to better understand the multiple dimensions (e.g., spatial correlation, seasonality, peril features, construction features, and financial terms) that can impact portfolio risk. We implemented a prototype system, called QuPARA (Query-Driven Large-Scale Portfolio Aggregate Risk Analysis), using Hadoop, which is Apache's implementation of the MapReduce paradigm. This allows the user to take advantage of large parallel compute servers in order to answer ad hoc risk analysis queries efficiently even on very large data sets typically encountered in practice. We describe the design and implementation of QuPARA and present experimental results that demonstrate its feasibility. A full portfolio risk analysis run consisting of a 1,000,000 trial simulation, with 1,000 events per trial, and 3,200 risk transfer contracts can be completed on a 16-node Hadoop cluster in just over 20 minutes., 9 pages, IEEE International Conference on Big Data (BigData), Santa Clara, USA, 2013

Monte Carlo simulations employed for the analysis of portfolios of catastrophic risk process large volumes of data. Often times these simulations are not performed in real-time scenarios as they are slow and consume large data. Such simulations can benefit from a framework that exploits parallelism for addressing the computational challenge and facilitates a distributed file system for addressing the data challenge. To this end, the Apache Hadoop framework is chosen for the simulation reported in this paper so that the computational challenge can be tackled using the MapReduce model and the data challenge can be addressed using the Hadoop Distributed File System. A parallel algorithm for the analysis of aggregate risk is proposed and implemented using the MapReduce model in this paper. An evaluation of the performance of the algorithm indicates that the Hadoop MapReduce model offers a framework for processing large data in aggregate risk analysis. A simulation of aggregate risk employing 100,000 trials with 1000 catastrophic events per trial on a typical exposure set and contract structure is performed on multiple worker nodes in less than 6 minutes. The result indicates the scope and feasibility of MapReduce for tackling the computational and data challenge in the analysis of aggregate risk for real-time use., ScienceCloud 2013 at HPDC 2013, New York, USA

There are two methods evaluating the energy utilization system: energy balance analysis and exergy analysis. Energy balance analysis is to study the amount of energy conversion, transmission, utilization and losses, and also to determine the energy efficiency of a system or device. Nevertheless, exergy analysis is to judge the quality of different energies, such as high quality energy and low grade energy, to make full use of it and avoid wasting. In this paper, the simulation of working process on a middle-speed diesel engine is performed. With this simulation, the energy utilization is evaluated by the above-mentioned two methods.

Background Alzheimer’s disease (AD), an age-related neurodegenerative disorder, is the predominant form of dementia in the elderly, clinically characterized by cognitive impairment and pathologically characterized by extracellular senile plaques largely composed of b-amyloid (Ab) peptide. The overburden of b-amyloid (Ab )d eposition in AD is associated with peroxidation which plays an important role in neuronal dysfunction. APP/PS1 double transgenic mice, which display significant learning and memory impairments and the typical pathological changes such as numerous Ab deposition, are ideal model to mimic the symptoms of AD. (-)-Epigallocatechin-3-gallate (EGCG) is the most abundant polyphenolic constituent in green tea, which has ironchelating, anti-inflammatory, antioxidant and anticancer activities. However, it remains unclear whether EGCG improves learning and memory impairments by attenuating peroxidation in APP/PS1 double transgenic mice. Therefore, we evaluated the relationships between the ameliorated memory dysfunctions and the inhibited peroxidative levels in APP/PS1 transgenic mice after EGCG treatment. Methods APP/PS1 mice at the age of 9 months, randomly distributed into EGCG-treated APP/PS1 group (EGCG group) or APP/PS1 group, and age-matched wild-type mice (C57 BL/6J, WT group) were assigned as aging control. Mice were intragastrically administered EGCG (2 mg/ kg) or vehicle (distilled water) once daily for 4 weeks. Memory function was evaluated in Morris Water Maze (MWM) and passive avoidance test (PAT). The contents of malondialdehyde (MDA), and the activities of total superoxide dismutase (t-SOD) and glutathione peroxidase (GSH-Px) in hippocampus were examined using lipid preoxidation MDA assay kit, total superoxide dismutase assay kit with WST-1, and total glutathione peroxidase assay kit, respectively. The protein expression of inducible nitric-oxide synthase (iNOS) in the hippocampus was measured by Western blot. Results In PAT, the shorter latency and the increased error time to enter the dark compartment of APP/PS1 group were found compared with WT group (P

In this paper, the energy balance analysis of diesel engine system is introduced, and a medium-speed diesel engine was used as a research object to build simulation models. The correctness of model was verified by comparing simulation data to experimental result. The energy balance on thermodynamic cycle is analyzed by combining the results of simulation data and theoretical analysis to evaluate the energy efficiency of this diesel engine. Factors of energy efficiency are pointed out by theoretical analysis, and the result of the research on effects caused by changes of parameters is been used to pointing out the path of improving the energy efficiency of diesel engines.

With the rapid development of the integration of the world economy, the two deltas, that is, the Yangtze River Delta and the Pearl River Delta have developed fastest and are the strongest and the most dynamic areas. The economic development of the two areas plays a most important role in the all-around development of China's economy. The paper introduces factor analysis and clustering analysis of multivariate statistical analysis to appraise the development status of the above two regions' economy, finds out the reason why the economic development is different in different clusters.

According to the deep knowledge of the electronic device structure to build the original diagnosis tree, and classify the domain knowledge on the basis of the tree nodes. The experts can evaluate the tree nodes by certain indicators, using fuzzy group Multi-attribute Decision-making method, complying with the rule that the greater the vulnerability C the higher the priority, to gain the priority. Building the diagnosis tree of the electronic devices which control the missile launch and making the trapezoidal fuzzy number M to be fuzzy membership function, defining the criteria for each membership function, calculating the degree of vulnerability C of each node and sorting by size, to gain the priority diagnosis tree. This expert system is smarter than the reasoning strategy of the traditional expert system, searching the entire Knowledge Base for each diagnosis is not necessary, can just search the rule base of the highest priority node. Diagnostic efficiency is increased and the matching rules are more flexible.

Taken geomagnetism vector as benchmark, magnetism sensor can be used to measure the rotation angle of projectile body and the angle appraised in equipment simulation training system. For the geomagnetism can be effected by environment factor, the measure error can be compensated with hardware design and software compensation separately. By analyzing the turntable data and measure data in training system, it is show that the application of magnetism sensor in angle measurement is feasible, and its precision can meet the requirement with error compensation.

Electronic equipment analog circuit has high failure rate, factors cause failure are fuzzy, fault diagnosis is complex. This method use Multisim circuit simulation software for band-pass filter circuit simulation and analysis, setting the soft and hard failures to obtain simulation results. Using the largest amount of fault information diagnosis method to seek the greatest amount of fault informative feature groups and determine the failure source. This method of fault diagnosis provides a reference for the measured data.

Ant colony algorithm (ACA) is a heuristic search algorithm to solve combinational optimization problems whose selection strategy has direct relations with the information content of the routes which is indefinite. Based on comparison of several improved algorithms, improved ACA based on comentropy is proposed in the paper. By controlling comentropy figure, route selection and the probability of local random mutation perturbation can be controlled to achieve adaptive adjustment. The superiority of the improved algorithm is proved by experimental data.

'This letter details the construction and performance of metal membrane radio frequency MEMS switches at microwave and millimeter-wave frequencies. These shunt switches possess a movable metal membrane which pulls down onto a metal/dielectric sandwich to form a capacitive switch. These switches exhibit low loss (

The micro mirror supported by torsional beams is fabricated by the SCREAM process. The frame and the supporting beams consist of a single crystal silicon (SCS) core, coated by SiO/sub 2/ and Al. The mirror is twisted or moved out of plane by applying bias between the mirror and the substrate. In order to understand the reliability of the mirror-beam system, we study the failure mechanism of a single crystal silicon bar subjected to torsion and bending. The result implies that the failure strength of SCS increases by about two orders of magnitude as the size is reduced to the /spl mu/m scale-the scale used to support micro mirrors. It thus follows that the beams can sustain very large deformations before failure.