Stability analysis of power system including facts (TCSC) effects by direct method approach

The problem of power system stability including the effects of a flexible alternating current transmission system (FACTS) is approached. First, the controlled series compensation is considered in the machine against infinite bar system and its effects are taken into account by means of construction of a Lyapunov function (LF). This simple system is helpful in order to understand the form the device affects dynamic and transient performance of the power system. After, the multimachine case is considered and it is shown that the single-machine results apply to multimachine systems. An energy-form Lyapunov function is derived for the power system including the FACTS device and it is used to analyse damping and synchronizing effects due to the FACTS device in single-machine as well as in multimachine power systems. © 2005 Elsevier Ltd. All rights reserved.

Electromyographyc evaluation of movements of lower limb in double pulley system equipment: Comparison between gastrocnemius (caput laterale) and gluteus maximus

It was evaluated movements of lower limb in the double pulley system equipment on ten male volunteers during contraction of gastrocnemius (caput laterale ) and gluteus maximus muscles in the following movements: 1) hip extension with extended knee and erect trunk, 2) hip extension with flexed knee and erect trunk, 3) hip extension with flexed knee and erect trunk, 3) hip extension with extended knee and inclined trunk, 5) hip abduction along the midline, 7) hip abduction with extension beyond the midline, 8) adduction with hip flexion beyond the midline, 8) adduction with hip flexion beyond the midline, and 9) adduction with hip extension beyond the midline. Myoelectric signals were taken up by Lec Tec surface electrodes connected to a 6-channel Lynx electromyographic signal amplifier coupled with a computer equipped with a model CAD 10/26 analogue digital conversion board and with a specific software for signal recording and analysis. We observed weak gastrocnemius muscle activity for all movements studied. In the case of gluteus maximus, the most important potentials were observed for movement 2, while for the remaining movements the actions were of reasonable intensity. Compared to gluteus, gastrocnemius was less required for all movements.

Efficient parametric adjustment of fuzzy inference system using unconstrained optimization

This paper presents a new methodology for the adjustment of fuzzy inference systems, which uses technique based on error back-propagation method. The free parameters of the fuzzy inference system, such as its intrinsic parameters of the membership function and the weights of the inference rules, are automatically adjusted. This methodology is interesting, not only for the results presented and obtained through computer simulations, but also for its generality concerning to the kind of fuzzy inference system used. Therefore, this methodology is expandable either to the Mandani architecture or also to that suggested by Takagi-Sugeno. The validation of the presented methodology is accomplished through estimation of time series and by a mathematical modeling problem. More specifically, the Mackey-Glass chaotic time series is used for the validation of the proposed methodology. © Springer-Verlag Berlin Heidelberg 2007.

Radial basis function network applied to the linearization of a voltage controlled oscillator

An analog circuit that implements a radial basis function network is presented. The proposed circuit allows the adjustment of all shape parameters of the radial functions, i.e., amplitude, center and width. The implemented network was applied to the linearization of a nonlinear circuit, a voltage controlled oscillator (VCO). This application can be classified as an open-loop control in which the network plays the role of the controller. Experimental results have proved the linearization capability of the proposed circuit. Its performance can be improved by using a network with more basis functions. Copyright 2007 ACM.

A comparative study of the damping oscillation function of TCSC and UPFC

The main objective of this work is to analyze the ability of FACTS devices like TCSC and UPFC to damp low frequency oscillations and a POD controller is also included. A comparative study of damping effect of those devices IS carried out. The Power Sensitivity Model (PSM) is used to the representation of the electric power system. Sensibility analysis using the residue method shows the best place for the installation of FACTS and the procedure to determine POD parameters. ©2008 IEEE.

Functional and esthetic rehabilitation with In-Ceram alumina and zirconia system: A multidisciplinary approach

The development of all-ceramic systems following metalceramics restorations allowed simulation of natural dentition due to favorable esthetics and resistance. In-Ceram is an alternative when esthetics is primordial as well as resistance required in rehabilitation. However, an ideal smile is associated to not only shape, color, texture and translucency but also harmony with gingival tissue. So, the aim of this study is to report a clinical case based on periodontal and fixed partial dentures principles to perform periodontal plastic surgery followed by esthetic rehabilitation. A female patient, 40-year-old, presented complaint about dental esthetics. After clinical and radiographic exams, metal-ceramics crowns (teeth 11, 12, 13, 21, 22 and 23) were considered unsatisfactory due to marginal leakage, color change in gingival tissue associated to metallic margin, and gummy smile. So, a crown lengthening surgery of anterior teeth was performed followed by rehabilitation of superior teeth with In-Ceram single crowns. Clinical significance: The interaction between periodontics and fixed prosthodontic area is the key of an adequated treatment planning which involves gingival smile to provide function and an esthetic condition in association with an esthetic, resistant and predictable material.

Preoperative upper limb lymphatic function in breast cancer surgery

Objective: To describe the preoperative upper limb lymphoscintigraphic pattern in women with breast cancer. Methods: Thirty-seven patients undergoing lymphoscintigraphy within 30 days of surgery were investigated. Lymphoscintigraphic studies of 37 upper limbs ipsilateral to surgery and 32 contralateral upper limbs were performed. The examination protocol consisted in obtaining static images of the upper limb in semi-flexion after 10 minutes, and 1 and 2 hours after subcutaneous injection of 1 mCi (37 MBq) of Tc-99m-dextran in the dorsum of the hand. The velocity of axillary lymph node visualization (I, visible at 10 minutes; II, 1 hour; III, 2 hours; and IV, invisible) and degree (intensity) of nodal uptake (a, marked; b, moderate; c,mild; and d, absent) were analyzed. Results: Optimal lymphatic functional pattern (Ia) was observed in four (11%) patients, in the ipsilateral upper limb, and six (19%), in the contralateral upper limb. Worse condition was observed in three (8%) patients (IVd) in the ipsilateral upper limb and two (6%) patients in the contralateral upper limb. The remaining patients showed intermediate states of velocity and uptake intensity. Conclusion: This study found relevant changes in preoperative lymphoscintigraphy, demonstrating preexisting functional differences in the lymphatic system. © 2011 Elsevier Editora Ltda.

Preoperative upper limb lymphatic function in breast cancer surgery.

To describe the preoperative upper limb lymphoscintigraphic pattern in women with breast cancer. Thirty-seven patients undergoing lymphoscintigraphy within 30 days of surgery were investigated. Lymphoscintigraphic studies of 37 upper limbs ipsilateral to surgery and 32 contralateral upper limbs were performed. The examination protocol consisted in obtaining static images of the upper limb in semi-flexion after 10 minutes, and 1 and 2 hours after subcutaneous injection of 1 mCi (37 MBq) of Tc-99m-dextran in the dorsum of the hand. The velocity of axillary lymph node visualization (I, visible at 10 minutes; II, 1 hour; III, 2 hours; and IV, invisible) and degree (intensity) of nodal uptake (a, marked; b, moderate; c,mild; and d, absent) were analyzed. Optimal lymphatic functional pattern (Ia) was observed in four (11%) patients, in the ipsilateral upper limb, and six (19%), in the contralateral upper limb. Worse condition was observed in three (8%) patients (IVd) in the ipsilateral upper limb and two (6%) patients in the contralateral upper limb. The remaining patients showed intermediate states of velocity and uptake intensity. This study found relevant changes in preoperative lymphoscintigraphy, demonstrating preexisting functional differences in the lymphatic system.

Productivity characteristics of endive as a function of spacing

Endive (Cichorium intybus) is one of the vegetables least studied in Brazil with respect to the behavior of the most commercialized cultivars, but it is known that the number of plants per area is one of the factors that most influences the productivity of various crops. Thus, the objective of this work was to evaluate the behavior of endive using four spacings between rows and five spacings between plants, in the region of Jaboticabal-SP. The experiment was conducted in the field in the period of August 12, 2008 to November 6, 2008, in the experimental area of the Sector of Vegetable Crops and Aromatic-Medicinal Plants, Department of Crop Sciences, School of Agricultural and Veterinary Sciences - UNESP-FCAV. The experimental design utilized was a randomized block design with a 4 × 5 factorial scheme, i.e., four spacings between rows (0.15, 0.20, 0.25 and 0.30 m) and five spacings between plants (0.10, 0.15, 0.20, 0.25 and 0.30 m), with three repetitions. The endive cultivar studied was 'Pão-de-Acucar', obtained from the company Tecnoseed. Seedlings were established utilizing the sowing system in 200-cell Styrofoam trays containing the substrate Plantmax Vegetables® HA. The seedlings were transplanted at 37 days after planting. After harvesting, the following characteristics were determined: height (cm), diameter of the plant in rows (cm), diameter of the plant in between rows (cm), number of leaves, fresh weight (g) and total estimated productivity (t/ha). There were no interactions between the factors studied. Based on the data, we conclude that spacings of 0.15 m between rows and of 0.15 m between plants produce plants of higher quality and with greater productivity.

A semi-automatic method for indirect orientation of aerial images using ground control lines extracted from airborne laser scanner data

This paper presents a method for indirect orientation of aerial images using ground control lines extracted from airborne Laser system (ALS) data. This data integration strategy has shown good potential in the automation of photogrammetric tasks, including the indirect orientation of images. The most important characteristic of the proposed approach is that the exterior orientation parameters (EOP) of a single or multiple images can be automatically computed with a space resection procedure from data derived from different sensors. The suggested method works as follows. Firstly, the straight lines are automatically extracted in the digital aerial image (s) and in the intensity image derived from an ALS data-set (S). Then, correspondence between s and S is automatically determined. A line-based coplanarity model that establishes the relationship between straight lines in the object and in the image space is used to estimate the EOP with the iterated extended Kalman filtering (IEKF). Implementation and testing of the method have employed data from different sensors. Experiments were conducted to assess the proposed method and the results obtained showed that the estimation of the EOP is function of ALS positional accuracy.

Performance of children with learning difficulties in fine motor function and handwriting

This study aimed to compare and characterize the fine, sensory and perceptive function performance and handwriting quality between students with learning difficulties and students with good academic performance. Methods: This study comprised 192 students from 2nd to 4th grades, both genders, whose ages ranged from 7 to 11 years old. The students were distributed into: GI, GII, GIII and GIV, comprising 96 students with learning difficulties, and groups GV, GVI, GVII, GVIII comprising 96 students with good academic performance. The students were submitted to evaluation of fine motor, sensorial and perception functions and handwriting evaluation under dictation. Results: The results showed that the students with learning difficulties, from 1st to 3rd grade, had lower performance on tests of fine motor, sensory and perceptive function, when compared to the students with good academic performance in the same grade; the students from 4th grade, both groups, did not show changes on fine motor, sensory and perceptive function; and only the students of GII showed dysgraphia. Conclusions: the results presented in this study suggest that the qualitative aspects of fine motor, sensory and perceptive skills reflect the integrity and maturity of central nervous system and can probably play an important role in early diagnosis of development disorders and consequently prevent academic disorders such as handwriting performance.

AMMONIUM AND NITRATE IN SOIL AND RATOON SUGARCANE GROWN IN FUNCTION OF NITROGEN ON OXISOL

After harvest, sugarcane residues left on the soil surface can alter nitrogen (N) dynamics in the plant-soil system. In Oxisols, the nitrogen fertilizer applied had its effects on the levels of ammonium and nitrate in the soil, N concentration in the plant leaves, and on the growth and productivity of second ratoon plants. The N rates tested were of 0, 60, 120, 180, and 240 kg ha-1. Each treatment was replicated four times. Four months after the experiment was started, ammonium and nitrate concentration in the soil, N levels in plant leaves, and plant growth were evaluated. Productivity was evaluated 11 months after the experiment was set. By increasing the content of mineral N in soil, plant growth variables reflected differences in the production of stems; however, it did not affect foliar N. The use of leaf analysis was not important to assess the nutritional status of nitrogen in the ratoon sugarcane. Nitrogen concentration in soil was affected by nitrogen fertilization, but not the N content in leaves. The rate of 138 kg N ha-1enabled greater production of sugarcane stalks (140 t ha-1). © 2013 Copyright Taylor and Francis Group, LLC.

Role of the range of the dipole function in the classical dynamics of molecular dissociation

The dissociation dynamics of heteronuclear diatomic molecules induced by infrared laser pulses is investigated within the framework of the classical driven Morse oscillator. The interaction between the molecule and the laser field described in the dipole formulation is given by the product of a time-dependent external field with a position-dependent permanent dipole function. The effects of changing the spatial range of the dipole function in the classical dissociation dynamics of large ensembles of trajectories are studied. Numerical calculations have been performed for distinct amplitudes and carrier frequencies of the external pulses and also for ensembles with different initial energies. It is found that there exist a set of values of the dipole range for which the dissociation probability can be completely suppressed. The dependence of the dissociation on the dipole range is explained through the examination of the Fourier series coefficients of the dipole function in the angle variable of the free system. In particular, the suppression of dissociation corresponds to dipole ranges for which the Fourier coefficients associated with nonlinear resonances are null and the chaotic region in the phase space is reduced to thin layers. In this context, it is shown that the suppression of dissociation of heteronuclear molecules for certain frequencies of the external field is a consequence of the finite range of the corresponding permanent dipole. © 2013 American Physical Society.

Optical properties of the MoO3-TiO2 particulate system and its use as a ceramic pigment

Mo-doped TiO2 powders were prepared using a dry mixture of TiO2 and MoO3 oxides with several compositions, followed by a calcination step at several temperatures. The resulting oxide system develops yellow and green tones. The XRD patterns showed only traces of MoO 3; however, EDS results, combined with TG/DTA data, confirmed the presence of molybdenum ions, suggesting that the changes in optical properties of the oxide system is due to the incorporation of Mo ions into the TiO 2 matrix, substituting Ti+4 with Mo+6 ions. The band gap decreased with increasing of MoO3 content; on the other hand, the band gap reached a maximum value at about 850°C to 910°C when plotted as a function of the calcination temperature. The glazes produced showed that the oxide system under study is a potential material for use as abinary ceramic pigment. Copyright © 2013 Taylor & Francis Group, LLC.

Approximation of hyperbolic tangent activation function using hybrid methods

Artificial Neural Networks are widely used in various applications in engineering, as such solutions of nonlinear problems. The implementation of this technique in reconfigurable devices is a great challenge to researchers by several factors, such as floating point precision, nonlinear activation function, performance and area used in FPGA. The contribution of this work is the approximation of a nonlinear function used in ANN, the popular hyperbolic tangent activation function. The system architecture is composed of several scenarios that provide a tradeoff of performance, precision and area used in FPGA. The results are compared in different scenarios and with current literature on error analysis, area and system performance. © 2013 IEEE.