This paper deals with the size of the random walk property of Colombia's output in two periods 1925-1994 and 1950-1994. GDP and GDPPC were both found to be integrated of order one a result which is ...very well known. The sequences are highly persistent, specially in the period 1950-1994. The forecast error when an innovation of 1 percent enters into the economy is about 1.5 percent in the very long run, when GDP is considered. The response is about 1.3 percent in the case of GDPPC, which seems to give support to the idea that population growth is a source of nonstationarity in some macroeconomic aggregates. For the larger sample(1925-1994) persistence is less. This result could cast some doubt on the method of estimation of GDP for the period 1925-1950. Finally, evidence of nonlinearity is found only in Hodrick- Prescott filtered variables dated between 1925 and 1994. This leaves open the question about whether the HP filter introduces nonlinearity in the hight frequency variable that it generates.
In the article the history and the actual state of the system of professional higher education (PHE) in Russia is examined. The analysis of recent tendencies of the sector is presented, and its life ...cycle is investigated. The necessity as well as the possibility of the approximation of key parameters of the higher education system are proved using the logistic function. A specific situation emerged in 1991–2009, characterized by a saturating avalanche-like process. It included mass demand of the Russian population for higher education, low cost of educational service, lowering of the market entrance barriers for new educational institutions. The education law of 1992 played the role of catalyst in these processes. The model of quantity of students is constructed; the conditions, which define the level and dynamics of the key indicators of PHE are examined. Authors formulated and substantiated their position in relation to the planned trends of PHE restructure.
A Heuristic Chaotic Neural Network: Candidate Model for Perception Ahmadlou, M.; Mamashli, F.; Golpayegani, M.
2008 First International Conference on Complexity and Intelligence of the Artificial and Natural Complex Systems. Medical Applications of the Complex Systems. Biomedical Computing,
2008-Nov.
Conference Proceeding
In this paper a new Chaotic Neural Network (CNN) have been made. This network contains desired number of interacting units and each one has its own chaotic dynamic and strange attractor caused by ...creating convex hull among output units. Having a special interaction characteristic, the model is able to create enormous different chaotic behaviors. Lyapunov Exponent and phase space plane criteria have been used for demonstrating discrimination between behaviors. Making use of convex hull for trapping generated outputs of each unit in subsequent iteration, its folding characteristic and stretching property of logistic function, emerging of arbitrary number of various strange attractors have been accomplished. Therefore, based on desired criterion, this network is able to assign each strange attractor to each sensory input. In other words the network has the ability of being a candidate for modeling perception.
A sort of annealing particle swarm optimization algorithm based on logistic function is proposed to deal with the problem of shipboard power system network reconfiguration. In this algorithm, part of ...the particle swarm is annealed based on the character of the logistic function. This method can solve the problem of local minimum of the standard particle swarm optimization algorithm effectively. The efficiency of the algorithm is improved; at the same time the computation time is well controlled. Shipboard power system network reconfiguration tests show that better service restoration can be provided by this method, which possesses strong convergence capability.
Early respiratory mechanics have been reported to predict outcome in newborns with respiratory failure. However, it remains unknown whether measurements of pulmonary function add significantly to the ...predictive value of more readily available variables The present study was designed to answer this question. Passive respiratory system mechanics were measured by an airway occlusion technique in 104 ventilator-dependent premature infants between 6 and 48 hours of life and corrected for infant size. A ventilation index FiO2 x mean airway pressure (MAP) was calculated at the time of pulmonary function testing. Poor outcome was defined as death from respiratory failure or need for supplemental oxygen at 28 days. Stepwise logistic function regression examined whether ventilation index and respiratory mechanics added predictive power over and above birthweight. Five infants died, and 45 patients required supplemental oxygen at 28 days. Birthweight was a strong predictor and would have entered the logistic model first in any case. Ventilation index added significantly to the predictive model (P = 0.038). Respiratory system conductance (P = 0.15) and compliance (P = 0.93) entered on the third and last step, respectively. We conclude that in premature infants with respiratory failure, birthweight is a strong predictor of outcome. Early ventilator requirements but not respiratory system mechanics, add significantly to this predictive model.
In order to evaluate the characteristic of performance ability which has to do with stability of performance in track and field, one-parameter logistic function was utilized to describe the ...achievement probability curve based upon the assumption that athletic performance distributes as normal during such a short period that the ability could not be assumed to change. A parameter of logistic function was used as random variable denoting characteristic of performance ability, because it determines the maximal slope of logistic function and the distribution range of records. About 95% of samples showed successful application of the function. Logistic function parameter; athletic performance characteristic, was different among the athletes and did not show any relationship with records. This is why this parameter is effective for evaluation of one aspect of performance ability.
Extract: Often the estimation of agricultural production technologies in less developed countries is achieved by dividing the sample arbitrarily into "small" and "large" farms and estimating a ...separate production function for each group. This is equivalent to including an appropriate dummy variable in a single regression on the whole sample. A modification of this approach is to replace the dummy variable (a step-function) by either a cumulative normal or logistic function. The parameters of such a "generalized dummy variable" convey valuable information on whether a small-large categorization is appropriate and, if so, where the division should be made
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Using some special models, this study tries to quantify the size of underground economy in Romania. The exposition plan includes: 1) Models based on direct approaches; 2) Models based on indirect ...approaches; 3) A generalised model for the allocation of time; 4) A model based on May’s logistic; 5) Conclusions.
A mathematical model which accounts for the non-linear response of both the camera and film in computer-aided quantitative autoradiography is derived. This model and the algorithm to fit the data for ...radioactive standards by a non-linear least-squares procedure to this model are described. The usefulness of this technique is demonstrated by employing it to analyze a set of 14C-labeled brain paste standards which were exposed to Ultrofilm in such a way that the full response range of the film was used. This technique can be readily implemented on most commercially available image analysis systems and is compatible with most types of video cameras.
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