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Copyright of Journal of Intelligent Systems: Theory & Applications is the property of Journal of Intelligent Systems: Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article proposes a hybrid control strategy that integrates the merits of both zero-vibration double derivative input shaping control and neuro-adaptive sliding mode control. The approximation ability of the radial basis function neural network is utilized to estimate the unknown dynamics of the gantry crane system. The input shaping control is used to shape the trolley position, velocity, and acceleration references. These reference trajectories are generated as the state trajectories of a closed-loop system obtained by controlling a nominal system model with a sliding mode control constructed based on the nominal model. The shaped trajectories are sent to the proposed neuro-adaptive sliding mode control as references to be tracked. In comparison with the conventional sliding mode control, the proposed control has higher tracking accuracy and robustness to external disturbances, and effectively reduces the sway angle without suffering from the chattering phenomenon. Moreover, the proposed control has a very high insensitivity to parameter uncertainties. The adaptation mechanisms of the radial basis function neural networks are established based on the Lyapunov stability theory. The effectiveness of the proposed controller is verified through some numerical simulations. [ABSTRACT FROM AUTHOR]

In this technical note, a combined discrete-time controller, consisting of a partial feedback linearization controller and a backstepping controller, is proposed to manage the stabilization for a class of underactuated nonlinear mechanical systems. The traditional backstepping control method is impracticable to directly apply it to underactuated systems since they are generally not in the lower triangular form. First, a feedback controller that partially linearizes the underactuated mechanical systems is derived to facilitate the backstepping controller design. In the design, discrete-time system dynamics obtained utilizing the Euler approximation are considered. Afterward, a novel coordinate transformation is introduced for a class of underactuated systems that transform the mathematical model of the partially linearized underactuated mechanical systems into the strict-feedback form. After these steps, the conventional backstepping approach is structured in discrete-time setting. The stability of the closed-loop system dynamics with the proposed combined discrete-time controller is shown utilizing Lyapunov theory. Several computer-based simulations are executed to depict the performance and the applicability of the proposed method on the Cart–Pole system and the Inertia Wheel Pendulum. Moreover, the effectiveness of the proposed nonlinear controller is verified by numerical simulation results in comparison with a discrete-time chattering-free sliding-mode controller. [ABSTRACT FROM AUTHOR]

In this paper, an asymptotically stabilizing, nonlinear flight controller design via immersion and invariance (I&I) approach for a fixed‐wing unmanned aerial vehicle is presented. The objective is to adjust pitch, roll, and yaw angles with the control inputs aileron, elevator, and rudder deflections. The important issues in designing a controller for fixed‐wing unmanned aerial vehicles (UAVs) are to cope with its nonlinear dynamics and to obtain a controller that can deal with various disturbances. Existing linear controllers cannot deal well with the nonlinear dynamics of the UAVs and that can not guarantee stability outside of the considered operating point. On the other hand, widely used nonlinear controllers have some weaknesses. Such as sliding mode controllers are robust to disturbances but suffer from the chattering phenomenon, and the backstepping controllers are not very robust to disturbances. The proposed controller ensures global stability with smooth and precise reference tracking and also yields significant disturbance attenuation without the chattering phenomenon. I&I approach also enables us to directly assign closed‐loop dynamics. Thus, tuning of the proposed controller is straightforward. Most of the other nonlinear methods do not have straightforward tuning of control parameters to assign desired dynamics to a closed‐loop system. The superior performance of the proposed controller is shown via simulations for various disturbances in comparison with the sliding mode controllers; the one with standard control law and the one with modified control law that eliminate the chattering phenomenon. [ABSTRACT FROM AUTHOR]

This paper addresses the attenuation problem of input disturbances in the control of fully actuated mechanical systems in the discrete-time setting. Firstly, a discrete-time disturbance estimator design with immersion and invariance (I&I) approach is presented for the n-degrees of freedom (DOF) fully actuated mechanical systems. Then, a discrete-time combined feedback linearising and backstepping control is established that this controller uses the estimated disturbance information. Global asymptotic stability of the estimator and local asymptotic stability of the entire closed-loop system in an arbitrarily large compact set are shown utilising the Lyapunov stability theory. In order to show the effectiveness of the proposed composite observer-based discrete-time control method, it is applied to the 3-DOF robotic manipulator. Performance of proposed direct discrete-time combined feedback linearising and backstepping controller with discrete-time I&I observer is compared with a direct discrete-time conventional second-order sliding mode controller with another discrete-time nonlinear disturbance observer via simulations. The superior performance of the proposed method is demonstrated with simulation results. [ABSTRACT FROM AUTHOR]

A discrete-time backstepping controller with an active disturbance attenuation property for the Inverted-Pendulum system is constructed in this paper. The main purpose of this study is to show that Immersion and Invariance (I & I) approach can be used to design a nonlinear observer for disturbance estimation and demonstrate its effectiveness considering a nonlinear system with an unstable equilibrium point, namely Inverted-Pendulum system, by utilizing the estimated values in backstepping control design. All designs are directly performed in discrete-time domain to obtain directly implementable observer and controller in discrete processors with superior performance compared to emulators. The Inverted-Pendulum system is not in strict feedback form therefore backstepping procedure cannot be directly applied. In order to enable backstepping construction, firstly a partial feedback linearization is performed and afterwards a novel discrete-time coordinate transformation is proposed. Prior to the construction of partial feedback linearizing and backstepping controller, a nonlinear disturbance estimator design is proposed with Immersion and Invariance approach. The estimated disturbance values used in the partial feedback linearization and construction of the backstepping controller. The global asymptotic stability of the estimator and local asymptotic stability of overall closed loop system are proved in the sense of Lyapunov. Performance of proposed direct discrete-time backstepping control with discrete I & I observer is compared with a backstepping sliding mode controller with another nonlinear disturbance observer (NDO) by simulations. [ABSTRACT FROM AUTHOR]

Summary: In this paper, discrete‐time adaptive control of linearly parameterized fully actuated Port‐controlled Hamiltonian systems with parameter uncertainties in energy function is considered. A discrete‐time adaptive interconnection and damping assignment passivity‐based control (IDA‐PBC) method, utilizing the immersion and invariance (I&I) approach, for the considered uncertain Hamiltonian system, is presented. A discrete‐time parameter estimator based on the immersion and invariance approach is derived to obtain an automatic tuning mechanism for the IDA‐PBC controller. The stability analysis for the estimator and the closed‐loop system is done using the Lyapunov theory. The proposed method is applied to two fully actuated physical systems and its performance is tested by simulations. Simulation results show that the proposed I&I‐based adaptive IDA‐PBC controller successfully preserves the performance of the IDA‐PBC controller designed with true parameters under a large amount of uncertainty. [ABSTRACT FROM AUTHOR]

Background. Mitochondrial uncoupling proteins (UCP) 1, 2 and 3 are members of the anion carrier protein family located in the inner mitochondrial membrane. There are various controversial reports on UCP genotypes and obesity in adults and children. This study aims to investigate the link between mostly studied UCP polymorphisms (UCP1-3826A/G, UCP2 Insertion/Deletion (Ins/Del) polymorphism of exon 8, and UCP3-55C/T Polymorphisms) and obesity in Turkish children. Furthermore, the relationships of UCP polymorphisms are also analyzed within the scope of metabolic parameters of obese children. Methods. Molecular screening of the UCP1, UCP2, and UCP3 gene polymorphisms was carried out in 189 children aged 6 to 18 years, 102 of who had exogenous obesity (54 girls) and 87 of whom were healthy controls (48 girls). In the obese group, fasting lipids, glucose and insulin levels were measured. In 60 obese children, an oral glucose tolerance test (OGTT) was performed with 0, 30, 60, 90 and 120 minutes of sampling for plasma glucose and insulin levels. Results. The frequency of UCP polymorphisms was similar in obese and non-obese children. In obese children, fasting lipids, glucose and insulin levels were not different among the UCP 1, 2 and 3 genotypes. While no relationship was found between the UCP 1 and 3 genotypes and glucose/insulin levels during OGTT, carriers of the Insertion allele with UCP2 Ins/Del polymorphism had significantly higher 30-minute insulin levels (p=0.018). Conclusions. Polymorphisms of the UCP1-3826A/G, UCP2 Ins/Del, and UCP3-55C/T are not associated with obesity and related pathologies in Turkish children. However, the presence of the Ins allele of the UCP2 gene has been found to have an unfavorable influence on early insulin excursion after glucose loading. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Surgery & Medicine (JOSAM) is the property of Journal of Surgery & Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: The aim of this study was to analyze maternal and neonatal interleukin 6 (IL-6) (-174 G/C) polymorphism and to determine effect on preterm birth and neonatal morbidity.Study Design: One hundred and sixty-four mothers (100 term births, 64 preterm births) and 183 newborn infants who were 100 healthy term and 83 preterm babies followed in newborn intensive care units were evaluated. PCR-RFLP was performed for IL-6 (-174 G/C) genotyping.Results: The rate of GG genotype in mothers of term and preterm infants were 54% (n = 54/100), 75% (n = 48/64), respectively (p > .05) and the rate of GC + CC genotype was 46% (n = 46/100) and 25% (n = 16/64) in mothers giving term and preterm birth (PTB), respectively (p < .05). Additionally, the rate of GG genotype was 65% (n = 65/100) and 81.9% (n = 68/83) in term infants and preterm infants, respectively. GC + CC genotype was 35% (n = 35/100) in term infants and 18.1% (n = 15/83) in preterm infants (p < .05). The effect of IL-6 (-174) GC + CC genotype on PTB was statistically significant.Conclusion: The IL-6 174 G/C gene polymorphism was significantly different between mothers who were giving to term and preterm birth. The presence of polymorphism is protective against preterm birth and was not associated with neonatal outcome. [ABSTRACT FROM AUTHOR]

Glial cell-derived neurotrophic factor and other neurotrophins have important role in the development of mental disorders. Here, we aimed to assess the effects of Single nucleotide polymorphisms at potentially regulated regions of GDNF on severity and functionality of bipolar disorder and GDNF serum levels in bipolar disorder patients and healthy volunteers. Severity and functionality of bipolar disorder were evaluated using the Clinical Global Impression and Global Assessment of Functioning scales in sixty-six bipolar disorder patients. The GDNF serum levels obtained from bipolar disorder patients and healthy volunteers who had been already reported SNPs information by our group. GAF scales were lower and GDNF serum levels were higher in Bipolar disorder patients with T/A genotype at 5:37812784 and 5:37812782 compared to patients with T/T genotype. There were significant difference in severity and functionality scores, but not in GDNF serum levels, between patients with G/G and G/A genotype of rs62360370 G > A SNP.rs2075680 C > A and rs79669773 T > C SNPs had no effect on bipolar disorder severity and functionality scores and GDNF serum levels. The results suggest that some SNPs of GDNF have potential association with severity and functionality of bipolar disorder. In addition, except two SNPs, none of GDNF SNPs had association with GDNF serum levels. [ABSTRACT FROM AUTHOR]

The discrete-time robust disturbance attenuation problem for the n-degrees of freedom (dof) mechanical systems with uncertain energy function is considered in this paper. First, it is shown in the continuous time-setting that the robust control problem of n-dof mechanical systems can be reduced to a disturbance attenuation problem when a specific type of control rule is used. Afterwards, the robust disturbance attenuation problem is formulised as a special disturbance attenuation problem. Then, the discrete-time counterpart of this problem characterised by means of L2 gain is given. Finally, a solution of the problem via direct-discrete-time design is presented as a sufficient condition. The proposed discrete-time design utilizes discrete gradient of the energy function of considered system. Therefore, a new method is also proposed using the quadratic approximation lemma to construct discrete gradients for general energy functions. The proposed direct-discrete-time design method is used to solve the robust disturbance attenuation problem for the double pendulum system. Simulation results are given for the discrete gradient obtained with the method presented in this paper. Note that the solution presented here for the robust disturbance attenuation problem give an explicit algebraic condition on the design parameter, whereas solution of the same problem requires solving a Hamilton-Jacobi-Isaacs partial differential inequality in general nonlinear systems. [ABSTRACT FROM AUTHOR]

This study compared superoxide dismutase (SOD) and catalase (CAT) alleles in 97 consecutive children and adolescents with migraine to 96 healthy children and adolescents. Isolated genomic DNA was used as a template for SOD1 (35 A/C), SOD2 16 C/T, and CAT2 [(–262 C/T) and (–21 A/T)] allele genotyping. The SOD2 16 C/T genotype and C allele frequency differed significantly between controls and migraine (P = .047; P = .038). CAT –21 AA genotype and A allele frequency were significantly higher in both migraine with aura patients (P = .013; P = .004) and migraine without aura patients (P = .003; P = .001) compared to controls. To our knowledge, this is the first demonstration of differences in SOD and CAT genotypes between pediatric migraine patients and age-matched controls. Further studies on the functional implications of these genetic variants on neural antioxidant capacity and the use of antioxidant modulators for migraine treatment are warranted. [ABSTRACT FROM AUTHOR]

The disturbance attenuation and robust disturbance attenuation problems for Hamiltonian systems in the discrete-time setting are considered and some new results are presented. The new results are derived utilizing the recently presented dissipativity equality obtained by adding the dissipation rate function to the classical dissipativity inequality. A selection of the dissipation rate function yields new results. These results include a condition on the dissipation structure of the system to achieve the desired disturbance attenuation level and gives direct construction of optimal control laws for any desired disturbance attenuation level. The results remove the need to solve Hamilton-Jacobi-Isaacs inequalities. [ABSTRACT FROM AUTHOR]

Objective: In this study, we aimed to investigate the association of W64R polymorphism of the β3-adrenergic receptor gene (β-3AR) with childhood obesity and related pathologies. Methods: β-3AR gene W64R genotyping was carried out in 251 children aged 6-18 years. Of these subjects, 130 were obese (62 boys) and 121 were normal-weight (53 boys). In the obese group, fasting lipids, glucose and insulin levels were measured. Oral glucose tolerance test (OGTT) was performed in 75 of the obese patients. Results: The frequency of W64R genotype was similar in obese and nonobese children. In obese children, relative body mass index, waist-to-hip ratio, serum lipid, glucose and insulin levels, as well as homeostasis model assessment of insulin resistance (HOMA-IR) scores were not different between Arg allele carriers (W64R and R64R) and noncarriers (W64W). In 75 obese children, OGTT results showed that Arg allele carriers had significantly higher 30-minute glucose levels (p=0.027). Conclusion: W64R polymorphism of the β-3AR gene is not associated with obesity and waist-to-hip ratio in Turkish children. Although there were no relationships between the genotypes and lipid, glucose/insulin levels or HOMA-IR, the presence of W64R variant seemed to have an unfavorable influence on early glucose excursion after glucose loading. [ABSTRACT FROM AUTHOR]

There is no information about the role of transforming growth factor–beta 1 (TGF-β1) in the pathogenesis of pediatric migraine. This study included 100 consecutive children and adolescents in whom migraine was diagnosed and 88 healthy children and adolescents. The isolated genomic DNA was used as a template for TGFβ-1 (–800G/A, –509C/T, 869T/C [codon 10] and 915G/C [codon 25]) genotyping. The allelic frequency of 509C/T was significantly different between control and migraine without aura patients (P = .04). Codon 10 C/T genotypic and C10 C allelic frequency of TGF-β1 polymorphisms were significantly higher in migraine and migraine without aura patients versus healthy controls (P = .00; P = .00). To our knowledge, this is the first report dealing with the relationship between TGF-β1 genotype and migraine in the pediatric age group. Further studies related to this subject are needed, along with a search for new therapeutic agents with anti-inflammatory properties. [ABSTRACT FROM AUTHOR]

The precise positioning control problem of the payload and the reduction of sway oscillations in the gantry crane systems are considered in this study. The passivity based control (PBC) technique is used to solve the considered problems. The control laws which are responsible for the energy shaping and damping injection, are derived by direct discrete-time PBC design method. Besides, this work is carried out on a laboratory type gantry crane system which is constructed such that it has exactly the same properties with the considered original crane system but in the ratio of 1/20. In the experiment system, servo drivers are used as the actuators and a programmable logic controller (PLC) is used as control unit. The real-time experiments are done using the control laws derived in this study and the results are presented to illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]