2,609 research outputs found
Interrelationships between human capital and social capital in small and medium sized firms: The effect of age and sector of activity
This study explores the interconnection between human factors and social factors and analyses the relations influenced by the specific activity and age of firms. A statistical approach is implemented which applies factor analysis techniques, based on a sample of small and medium sized firms from four sectors of activity which are between four and fifteen years old, and are split into three time periods. It is found that there are interconnected groups of human capital and social capital factors, although a sizeable proportion of the literature conceptually separates these factors and deals with them individually. It is also ascertained that this relationship is influenced by the field of activity and the age of the firms.Entrepreneurship, Factor analysis, Human capital, Management, Social capital
Generalized Metropolis dynamics with a generalized master equation: An approach for time-independent and time-dependent Monte Carlo simulations of generalized spin systems
The extension of Boltzmann-Gibbs thermostatistics, proposed by Tsallis,
introduces an additional parameter to the inverse temperature .
Here, we show that a previously introduced generalized Metropolis dynamics to
evolve spin models is not local and does not obey the detailed energy balance.
In this dynamics, locality is only retrieved for , which corresponds to
the standard Metropolis algorithm. Non-locality implies in very time consuming
computer calculations, since the energy of the whole system must be
reevaluated, when a single spin is flipped. To circumvent this costly
calculation, we propose a generalized master equation, which gives rise to a
local generalized Metropolis dynamics that obeys the detailed energy balance.
To compare the different critical values obtained with other generalized
dynamics, we perform Monte Carlo simulations in equilibrium for Ising model. By
using the short time non-equilibrium numerical simulations, we also calculate
for this model: the critical temperature, the static and dynamical critical
exponents as function of . Even for , we show that suitable time
evolving power laws can be found for each initial condition. Our numerical
experiments corroborate the literature results, when we use non-local dynamics,
showing that short time parameter determination works also in this case.
However, the dynamics governed by the new master equation leads to different
results for critical temperatures and also the critical exponents affecting
universality classes. We further propose a simple algorithm to optimize
modeling the time evolution with a power law considering in a log-log plot two
successive refinements.Comment: 10 pages, 5 figures and 5 table
Environmental indicators applied to reality of Eco-Industrial Park (EIP)
Part of:
Seliger, Günther (Ed.): Innovative solutions : proceedings / 11th Global Conference on Sustainable Manufacturing, Berlin, Germany, 23rd - 25th September, 2013. - Berlin: Universitätsverlag der TU Berlin, 2013. - ISBN 978-3-7983-2609-5 (online). - http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-40276. - pp. 84-89.The Eco-Industrial Parks (EIP - Eco-Industrial Park) emerged as a new model of spatial organization for industrial arrangements. An important feature for an EIP is the adoption of the concept of industrial symbiosis (IS), in which companies reuse waste to reach a closed system, reducing environmental impact. The article describes an analysis of the environmental indicators used in EIPs through a systematic literature review (RBS). Results indicated that there are proposals to evaluate the waste stream and the symbiosis of an EIP through detailed indicators, which capture the need in a particular moment of time. The paper describes, compares and analyzes these proposals. As a result, it was shown that they have limitations described and exemplified in the text
Sustainable uses and method for water treatment plant sludges
Part of:
Seliger, Günther (Ed.): Innovative solutions : proceedings / 11th Global Conference on Sustainable Manufacturing, Berlin, Germany, 23rd - 25th September, 2013. - Berlin: Universitätsverlag der TU Berlin, 2013. - ISBN 978-3-7983-2609-5 (online). - http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-40276. - pp. 120–124.Once Water Treatment Plant (WTP) for public supply is considered as an industry, it uses water as a source, chemicals and physics and biologic steps to treat the water and, obviously, generate waste, which is called as sludge. Most of these WTPs in Brazil use surface water as a source and a conventional complete cycle treatment type. The WTPs sludges are found mainly in clarifiers and backwash water filter. Unfortunately, most of Brazilian WTPs launches its sludge directly into water resources, without previous treatment, violating management practices and the Brazilian legislation. A solution for this sludge is to remove its water and after that, recycle the water removed and use the dried sludge in other activities, for example in ceramic production, in non-structural buildings and even to generate energy. This paper presents a natural and sustainable technology to dewater clarifiers WTPs’ sludge and discusses possible uses for this processed waste
Nonequilibrium scaling explorations on a 2D Z(5)-symmetric model
We have investigated the dynamic critical behavior of the two-dimensional
Z(5)-symmetric spin model by using short-time Monte Carlo (MC) simulations. We
have obtained estimates of some critical points in its rich phase diagram and
included, among the usual critical lines the study of first-order (weak)
transition by looking into the order-disorder phase transition. Besides, we
also investigated the soft-disorder phase transition by considering empiric
methods. A study of the behavior of along the self-dual critical
line has been performed and special attention has been devoted to the critical
bifurcation point, or FZ (Fateev-Zamolodchikov) point. Firstly, by using a
refinement method and taking into account simulations out-of-equilibrium, we
were able to localize parameters of this point. In a second part of our study,
we turned our attention to the behavior of the model at the early stage of its
time evolution in order to find the dynamic critical exponent z as well as the
static critical exponents and of the FZ-point on square
lattices. The values of the static critical exponents and parameters are in
good agreement with the exact results, and the dynamic critical exponent
very close of the 4-state Potts model ().Comment: 11 pages, 7 figure
Analysis of the reflex response time of the patellar stabilizer muscles in individuals with patellofemoral pain syndrome
OBJETIVO: Avaliar o tempo de resposta reflexa (TRR) dos músculos vasto medial oblíquo (VMO), vasto lateral oblíquo (VLO) e vasto lateral longo (VLL) em indivíduos clinicamente saudáveis e portadores de síndrome da dor patelofemural (SDPF). MÉTODOS: Foram avaliadas 12 mulheres clinicamente saudáveis e 12 mulheres com SDPF. Os registros eletromiográficos foram obtidos por eletrodos ativos simples conectados a um eletromiógrafo, acionados por um sensor externo fixado sobre a porção média do ligamento da patela a partir de sua percussão. A análise do TRR foi realizada por meio da medida do tempo zero ao pico da resposta elétrica dos músculos VMO, VLO e VLL, em segundos, para ambos os grupos. A análise estatística empregada foi o teste de análise de variância (ANOVA, p< 0,05) e teste Tukey post hoc (p< 0,05) para comparação entre os músculos, e o teste t de Student (p< 0,05) para a comparação entre os grupos. RESULTADOS: Ambos os grupos apresentaram um TRR menor para o músculo VMO, quando comparado aos músculos VLO e VLL; entretanto, não se observou diferença significativa entre os músculos VLO e VLL. Na comparação do TRR entre os grupos, não se observou diferença significativa. CONCLUSÕES: De acordo com esses resultados, pode-se sugerir que o TRR das porções do músculo quadríceps não diferencia indivíduos com SDFP dos indivíduos clinicamente saudáveis, sendo que o VMO apresenta um TRR menor em relação ao VLO e VLL para ambos os grupos.OBJECTIVE: To investigate the reflex response time (RRT) of the vastus medialis obliquus (VMO), vastus lateralis obliquus (VLO) and vastus lateralis longus (VLL) muscles in clinically healthy individuals and subjects with patellofemoral pain syndrome (PPS). METHODS: Twelve clinically health women and twelve women with PPS were evaluated. Electromyography (EMG) records were obtained using active electrodes connected to an electromyograph that was activated by an external sensor attached to the medial portion of the patella ligament, by means of percussion. The RRT was analyzed by measuring the time, in seconds, between zero and peak electrical response of the VMO, VLO and VLL muscles, for both groups. The statistical analysis consisted of analysis of variance (ANOVA, p< 0.05) and the Tukey post-hoc test (p< 0.05) to compare the response between muscles, and Student's t test (p< 0.05) to compare the response between groups. RESULTS: Both groups presented lower RRT for the VMO muscle than for the VLO and VLL muscles. However, no significant difference was seen between the VLO and VLL muscles. There was no significant difference in RRT between the groups. CONCLUSIONS: According to these results, it can be suggested that the RRTs in the different portions of the quadriceps muscle do not distinguish between subjects with PPS and clinically healthy individuals. The RRT for the VMO muscle was lower than the RRT for the VLO and VLL muscles, for both groups
A new look at the 2D Ising model from exact partition function zeros for large lattice sizes
A general numerical method is presented to locate the partition function
zeros in the complex beta plane for large lattice sizes. We apply this method
to the 2D Ising model and results are reported for square lattice sizes up tp
L=64. We also propose an alternative method to evaluate corrections to scaling
which relies only on the leading zeros. This method is illustrated with our
data.Comment: 9 pages, Latex, 3 figures. To appear in Int. J. Mod. Phys.
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