Workload characterization of JVM languages

Originally developed with a single language in mind, the JVM is now targeted by numerous programming languages—its automatic memory management, just‐in‐time compilation, and adaptive optimizations—making it an attractive execution platform. However, the garbage collector, the just‐in‐time compiler, and other optimizations and heuristics were designed primarily with the performance of Java programs in mind. Consequently, many of the languages targeting the JVM, and especially the dynamically typed languages, are suffering from performance problems that cannot be simply solved at the JVM side. In this article, we aim to contribute to the understanding of the character of the workloads imposed on the JVM by both dynamically typed and statically typed JVM languages. To this end, we introduce a new set of dynamic metrics for workload characterization, along with an easy‐to‐use toolchain to collect the metrics. We apply the toolchain to applications written in six JVM languages (Java, Scala, Clojure, Jython, JRuby, and JavaScript) and discuss the findings. Given the recently identified importance of inlining for the performance of Scala programs, we also analyze the inlining behavior of the HotSpot JVM when executing bytecode originating from different JVM languages. As a result, we identify several traits in the non‐Java workloads that represent potential opportunities for optimization. © 2015 The Authors. Software: Practice and Experience Published by John Wiley & Sons Ltd.     

Impacts of Climate Variables on Residential Water Consumption in the Czech Republic

The paper investigates whether there is a statistically significant impact of short-term climate variables (specifically air temperature and rainfall) on residential water consumption at two selected case sites in the Czech Republic. The analysis is based on a unique time series of daily data from 2004–2009. The statistical methods used are CART methodology and a decomposition of these time series based on a locally weighted regression method. Apart from the data analysis results, the investigation raises several methodological questions regarding the use of daily data and the scope of analysis based on such data sets.     

Preliminary investigation of factors determining self-organised structures preparation in polymer layers

Factors determining creation of self-organized structures, Bénar–Marangoni cells, during the process of solvent evaporation from the polymer solution and formation of polymer film were studied. Examined parameters were temperature, temperature gradient, rate of drying, height of a liquid layer, area for film preparation, viscosity, molecular weight distribution, etc. A special apparatus, micro condensation drying system, was engineered for this study. As a model system, hydroxyethyl cellulose aqueous solution was used for its excellent film-forming ability and the tendency to self-aggregation. Experimental results, presented in a wide spectrum of self-organized patterns, show the complexity of the problem and the crucial role of molecular weight distribution of the polymer in the fixation of organized structures under highly non-equilibrium conditions.     

Estimation of the effective conjugation length of oligo-p-phenylenes from specific refractive index increments of solutions

Summary An unusually strong molecular weight dependence of the specific refractive index increment which has been reported for solutions of oligomers (M < 10³) of p-2-methyl phenylene is attributed to the exaltation of polarizability of phenylene units. The saturation length is estimated to be l _s≅ 6 phenylene units. Received: 3 November 1997/Revised version: 20 April 1998/Accepted: 22 April 1998     

Reactive phenylbenzimidazole UV absorbers and their application to cellulose textiles

New types of reactive UV absorbers for applications to cellulose textiles have been prepared. These substances are condensation products of sulfobenzimidazolaniline, cyanuric chloride, and aminophenyl‐(2‐sulfethoxy)‐sulfone. They were applied to bleached, unbleached, as well as dyed cellulose textiles with the aim to increase the protection effect of these textiles against UV radiation. All the tested textiles showed a marked increase in the UV protection factor (UPF). The effects of the UV absorbers tested neither interfere with the function of fluorescent brighteners (FBs) nor affect the hue of the used dyestuffs. They exhibit synergistic effect in the protection effectiveness against UV radiation: the UV absorbers used together with dyestuffs and FBs have a higher UPF factor than is the sum of UPF contributions of the individual components. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Levels of eight trace elements in edible mushrooms from a rural area

Eight trace elements were determined using ICP–MS in 78 fruiting body samples of 22 edible mushroom species. The mushrooms were collected from four sites in a rural area, unpolluted by human activity. Median values (dry matter) were as follows: Arsenic (As) 1.45?mg?kg^–1, barium (Ba) 1.41?mg?kg^–1, cobalt (Co) 0.28?mg?kg^–1, copper (Cu) 47.0?mg?kg^–1, rubidium (Rb) 130?mg?kg^–1, silver (Ag) 2.95?mg?kg^–1, thallium (Tl) 0.02?mg?kg^–1 and vanadium (V) 0.25?mg?kg^–1. Higher trace element accumulation was observed in samples of Macrolepiota procera, Macrolepiota rhacodes, Lycoperdon perlatum, Lycoperdon gigantea and Xerocomus chrysenteron for As and Cu, and in samples of Cantharellus cibarius and of genera Boletus and Suillus for Rb.     

Mechanical,Hygric, and Thermal Properties of Cement-Based Composite with Hybrid Fiber Reinforcement Subjected to High Temperatures

The tensile strength, bending strength, water vapor diffusion resistance factor, gas permeability, thermal conductivity, specific heat capacity, and linear thermal expansion coefficient of a cement-based composite with hybrid PVA-fiber reinforcement are determined as functions of thermal pre-treatment, the loading temperatures being 600 °C, 800 °C, and 1000 °C. The experimental results show that the most important changes in all studied parameters occur between the unloaded state and the loading temperature of 600 °C and then between 800 °C and 1000 °C. Although seemingly high, these changes are still small as compared to many other cement-based composites. The positive effect of using PVA fibers for the high-temperature behavior of the studied composite can be seen mainly in their ability to prevent thermal spalling which is a serious deterioration effect for cement-based composites.     

Stereometric Analysis of Effects of Heat Stressing on Micromorphology of Si Single Crystals

Silicon - The purpose of this work is study of silicon single crystal wafer thermal stability in correlation with three-dimensional (3D) surface characterization using atomic force microscopy...     

A special instrument for exact control of self-organized structures preparation in polymer layers

Special micro-condensation drying system (MCDS) was constructed for precise preparation of self-organized polymeric layers by casting from solutions and dispersions at highly non-equilibrium conditions. There were respected the needs for exact regulation of temperature, temperature gradient and rate of solvent evaporation, vibration damping, dust-free design and wide variability in process parameters settings as well. MCDS allows to study a broad spectrum of effects determining creation of self-organized structures during the evaporation of solvent from the polymer solution (e.g. Rayleigh–Bénard or Bénard–Marangoni cells). As a model system for MCDS functionality testing aqueous solution of hydroxyethyl-cellulose was chosen, with respect to its excellent film-forming properties and the self-organization ability. All of this is observable in high number of cell patterns, originating according to the process parameters, in the given polymer-solution system.