Absolute Values Of Variables Research Articles

Динамика прокатки сварных швов

Представлены результаты исследований переходных процессов и нагрузок в межклетевых промежутках при холодной непрерывной прокатке полос со сварными соединениями. Применена разработанная ранее и адаптированная к 5-клетевому стану математическая модель и компьютерная программа заполнения полосой непрерывной группы клетей, записанная в абсолютных значениях переменных. Рассмотрены два вида возмущений, действующих со стороны шва: его утолщение на 0,1-0,2 мм длиной до 20 мм и превышение сопротивления деформации на 10-20 % по сравнению с стыкуемыми полосами. При входе утолщенного шва в клеть № 1 происходит кратковременное снижение (ослабление) заднего натяжения до 0,6 начального значения между клетями № 1 и 2. Действие шва в следующих клетях существенно ослабляется ввиду трансформации его формы. Более динамичный случай наступает при увеличенном сопротивлении деформации участка шва: формируются рывки переднего и заднего натяжений до 1,5-2,2 установившегося значения, увеличивается их зависимость от скорости прокатки. В обоих случаях на шве остаются отпечатки вертикальных колебаний клетей, шов становится разнотолщинным. Непосредственно после шва наблюдается утонение («пережим») полосы на 0,07 мм, что способствует нежелательной концентрации продольных напряжений.

Modified HS conjugate gradient method for solving generalized absolute value equations

We investigate a kind of generalized equations involving absolute values of variables as |A|x-|B||x|=b, where A in R^{ntimes n} is a symmetric matrix, B in R^{ntimes n} is a diagonal matrix, and bin R^{n}. A sufficient condition for unique solvability of the proposed generalized absolute value equations is also given. By utilizing an equivalence relation to the unconstrained optimization problem, we propose a modified HS conjugate gradient method to solve the transformed unconstrained optimization problem. Only under mild conditions, the global convergence of the given method is also established. Finally, the numerical results show the efficiency of the proposed method.

Changing seasonality of the Baltic Sea

Abstract. Changes in the phenology of physical and ecological variables associated with climate change are likely to have significant effect on many aspects of the Baltic ecosystem. We apply a set of phenological indicators to multiple environmental variables measured by satellite sensors for 17–36 years to detect possible changes in the seasonality in the Baltic Sea environment. We detect significant temporal changes, such as earlier start of the summer season and prolongation of the productive season, in several variables ranging from basic physical drivers to ecological status indicators. While increasing trends in the absolute values of variables like sea-surface temperature (SST), diffuse attenuation of light (Ked490) and satellite-detected chlorophyll concentration (CHL) are detectable, the corresponding changes in their seasonal cycles are more dramatic. For example, the cumulative sum of 30 000 W m−2 of surface incoming shortwave irradiance (SIS) was reached 23 days earlier in 2014 compared to the beginning of the time series in 1983. The period of the year with SST of at least 17 °C has almost doubled (from 29 days in 1982 to 56 days in 2014), and the period with Ked490 over 0.4 m−1 has increased from about 60 days in 1998 to 240 days in 2013 – i.e., quadrupled. The period with satellite-estimated CHL of at least 3 mg m−3 has doubled from approximately 110 days in 1998 to 220 days in 2013. While the timing of both the phytoplankton spring and summer blooms have advanced, the annual CHL maximum that in the 1980s corresponded to the spring diatom bloom in May has now shifted to the summer cyanobacteria bloom in July.

Experiência de treinamento com Nintendo Wii sobre a funcionalidade, equilíbrio e qualidade de vida de idosas

O objetivo desse relato de experiência foi analisar a funcionalidade, equilíbrio e qualidade de vida em duas idosas não institucionalizadas, após serem submetidas a um protocolo de treinamento em Realidade Virtual composto por nove sessões com duração de 50 minutos cada e frequência de três vezes por semana. Para tanto, utilizou-se os jogos do software Wii Fit, bem como o acessório Balance Board do console Nintendo Wii, a partir de um programa de treinamento elaborado fundamentado em diretrizes gerais de agência de saúde, tais como o Colégio Americano de Medicina do Esporte (ASCM). A avaliação da funcionalidade foi realizada com o uso dos Testes de Aptidão Física para Idosos (TAFI), o equilíbrio foi avaliado com a Escala de Berg e a qualidade de vida foi mensurada com o questionário SF-36. Os resultados apontaram melhora nos valores absolutos de todos os testes analisados, permitindo concluir acerca do potencial do programa de treinamento elaborado para a melhora da independência funcional de idosos. Esperamos que este estudo auxilie pesquisadores a dar continuidade à pesquisa e às ações envolvendo o uso do Nintendo Wii como ferramenta assistiva a idosos.

A branch-and-bound method for absolute value programs

In recent years, the absolute value equation (AVE) has attracted growing attention. The absolute value program (AVP) is an extension of AVE, which contains absolute values of variables in its objective function and constraints. In this article, we propose an algorithm for the AVP, which is based on the branch-and-bound method. In the branching procedure, we generate two subproblems by restricting the sign of a variable to be nonnegative or nonpositive. In the bounding procedure, we utilize the duality results for AVP. Furthermore, we carry out numerical experiments for nonconvex multi-facility location problems to show the validity of the proposed algorithm.

The atmospheric boundary layer in the CSIRO global climate model: simulations versus observations

A 5-year simulation of the atmospheric boundary layer in the CSIRO global climate model (GCM) is compared with detailed boundary-layer observations at six locations, two over the ocean and four over land. Field observations, in the form of surface fluxes and vertical profiles of wind, temperature and humidity, are generally available for each hour over periods of one month or more in a single year. GCM simulations are for specific months corresponding to the field observations, for each of five years. At three of the four land sites (two in Australia, one in south-eastern France), modelled rainfall was close to the observed climatological values, but was significantly in deficit at the fourth (Kansas, USA). Observed rainfall during the field expeditions was close to climatology at all four sites. At the Kansas site, modelled screen temperatures (Tsc), diurnal temperature amplitude and sensible heat flux (H) were significantly higher than observed, with modelled evaporation (E) much lower. At the other three land sites, there is excellent correspondence between the diurnal amplitude and phase and absolute values of each variable (Tsc, H, E). Mean monthly vertical profiles for specific times of the day show strong similarities: over land and ocean in vertical shape and absolute values of variables, and in the mixed-layer and nocturnal-inversion depths (over land) and the height of the elevated inversion or height of the cloud layer (over the sea). Of special interest is the presence climatologically of early morning humidity inversions related to dewfall and of nocturnal low-level jets; such features are found in the GCM simulations. The observed day-to-day variability in vertical structure is captured well in the model for most sites, including, over a whole month, the temperature range at all levels in the boundary layer, and the mix of shallow and deep mixed layers. Weaknesses or unrealistic structure include the following, (a) unrealistic model mixed-layer temperature profiles over land in clear skies, related to use of a simple local first-order turbulence closure, (b) a tendency to overpredict cloud liquid water near the surface.

Symmetrie und Symmetriebrechung in den Naturwissenschaften, insbesondere der Physik

The absolute values of variables that are modified by symmetry transformations of the laws of nature are unobservable. Symmetries imply conservation laws. Symmetric laws of nature are not inconsistent with asymmetric phenomena since in addition to the laws initial conditions are required to fix the phenomena. Symmetry in the mean as well as explizit and spontaneous symmetry breaking are described. Unified theories such as Newton's mechanics, Maxwell's electrodynamics or the standard model of elementary particle physics have a larger domain of applicability and thus a higher symmetry than the individuel laws they unite in a modified form. According to E. P. Wigner, the relation of the symmetries of the laws of nature to these laws is the same as the relation of the laws to the phenomena. Known and supposed symmetries therefore may help in the search for more general laws of nature than are presently known. Symmetrie und Unbeobachtbarkeit