bluuebunny/crossref_metadata_2025 huggingface dataset:
An overview of only child family mental health in China
Authors: KUO‐TAITAO
Published: March 2014

This author reviewed most of the recent literature and research including three major studies in Shanghai, Changsha and Beijing as well as the authors' studies, including the 4 and 6 year follow‐up studies in Nanjing. Most of the research undertaken in the USA and other Western countries and in China challenges the negative view of the only child described as ‘selfish', ‘lonely’ or ‘maladjusted'. The results showed no significant differences between the only child and the child with siblings, in terms of the prevalence of behavior problems except that certain items needed attention. In 4 and 6 year follow‐up studies the developmental impact of being an only child or being a child without sibling was found to be different. However, the difference was not at a clinical level, but in behavior patterns or traits which clearly revealed many variables that were ‘functional’ in nature and related to child rearing. The data from these studies reflected only the comparison between groups of only children versus children with siblings. As individuals, behavior problems dominated in only a few children without siblings.
Clinical characteristics of hyperglycemic crises in patients without a history of diabetes
Authors: Chou Willy , Chung Min‐Hsien , Wang Hsien‐Yi , Chen Jiann‐Hwa , Chen Wei‐Lung , Guo How‐Ran , Lin Hung‐Jung , Su Shih‐Bin , Huang Chien‐Cheng , Hsu Chien‐Chin
Published: March 2014

Aims/Introduction

Hyperglycemic crises without a history of diabetes have not been well studied. We compared the clinical characteristics of patients with and without a history of diabetes, and evaluated the glycated hemoglobin levels.

Materials and Methods

Consecutive adult patients (aged >18 years) visiting the emergency department (ED) between January 2004 and December 2010 were enrolled if they met the criteria for a hyperglycemic crisis. Patients were separated into those without and those with a history of diabetes. The 30‐day mortality was the primary end‐point.

Results

We enrolled 295 patients who made 330 visits to the ED. Patients without a history of diabetes made up 24.5% (81/330) of the hyperglycemic crises. Patients without a history of diabetes were more prone than patients with a history of diabetes to be younger and male, and to have better consciousness and renal function, more significant diabetic signs and symptoms (e.g., thirst, polydipsia, polyuria and bodyweight loss), higher blood sugar, and less opportunity of infection and mortality. Most of the patients (93.8%, 76/81) had glycated hemoglobin of ≥6.5%.

Conclusions

The present study delineates the clinical characteristics of patients with hyperglycemic crises, but without a history of diabetes. Most patients had glycated hemoglobin ≥6.5%, which raises the argument of using this biomarker for routine screening of diabetes.
When Women Support the Patriarchal Family: The Dynamics of Marriage in a Gécamines Mining Camp (Katanga Province, DR Congo)
Authors: Rubbers Benjamin
Published: March 2014

Based on ethnographic research among the ex‐Gécamines workers of Panda (Likasi, DR Congo), this article studies the dynamics of the spousal relationship in a post‐industrial context that has been long characterized by paternalism. The results of this research suggest that, though men and women living in this mining community talk about their spousal relationships by invoking the ideal of Christian marriage promoted during the colonial period, in practice such relationships faced important changes following Congolese independence in 1960. The nationalization and subsequent dramatic decline of Gécamines caused changes which directly affected three central dimensions of the colonial family model, namely monogamy, the ideal of domesticity, and male authority. If men and women continue to reference this model, it is because, in times of growing poverty, it allows spouses to remind one another of their respective duties as docile housewives and responsible husbands, and to command respect as virtuous Christian families in the local community.
Importance of HCV genotype 1 subtypes for drug resistance and response to therapy
Authors: Wyles D. L. , Gutierrez J. A.
Published: March 2014

The treatment for patients infected with hepatitis C virus (HCV) genotype 1 has undergone major changes with the availability of direct‐acting antivirals. Triple therapy, containing telaprevir or boceprevir, first‐wave NS3 protease inhibitors, in combination with peginterferon and ribavirin, improved rates of sustained virologic response compared with peginterferon and ribavirin alone in patients with HCV genotype 1. However, the development of drug‐resistant variants is a concern. In patients treated with telaprevir or boceprevir, different patterns of resistance are observed for the two major HCV genotype 1 subtypes, 1a and 1b. Genotype 1b is associated with a lower rate of resistant variant selection and better response to triple therapy compared with genotype 1a. Similar subtype‐specific patterns have been observed for investigational direct‐acting antivirals, including second‐wave NS3 protease inhibitors, NS5A inhibitors and non‐nucleoside NS5B inhibitors. This review explores resistance to approved and investigational direct‐acting antivirals for the treatment of HCV, focusing on the differences between genotype 1a and genotype 1b. Finally, given the importance of HCV genotype 1 subtype on resistance and treatment outcomes, clinicians must also be aware of the tests currently available for genotype subtyping and their limitations.
“Playing the Numbers Game”: Evidence‐based Advocacy and the Technocratic Narrowing of the Safe Motherhood Initiative
Authors: Storeng Katerini T. , Béhague Dominique P.
Published: March 2014

Based on an ethnography of the international Safe Motherhood Initiative (SMI), this article charts the rise of evidence‐based advocacy (EBA), a term global‐level maternal health advocates have used to indicate the use of scientific evidence to bolster the SMI's authority in the global health arena. EBA represents a shift in the SMI's priorities and tactics over the past two decades, from a call to promote poor women's health on the grounds of feminism and social justice (entailing broad‐scale action) to the enumeration of much more narrowly defined practices to avert maternal deaths whose outcomes and cost effectiveness can be measured and evaluated. Though linked to the growth of an audit‐ and business‐oriented ethos, we draw from anthropological theory of global forms to argue that EBA—or “playing the numbers game”—profoundly affects nearly every facet of evidence production, bringing about ambivalent reactions and a contested technocratic narrowing of the SMI's policy agenda.
“Lungisa”—Weaving Relationships and Social Space to Restore Health in Rural KwaZulu Natal
Authors: Wickström Anette
Published: March 2014

Many Zulu people who live in big cities in South Africa return to their rural homestead when they fall ill. Although the health care offered in rural areas is not efficient, people wish to connect to their family and ancestors. My aim is to explore acts of lungisa (“to put in order”) and what they say about health, agency, and the circumstances under which people live. Returning home means weaving oneself firmly within a web of relationships that are located in material things and places. Healing involves imperfect strategies used to better connect bodies, relationships, and places. I theorize the acts of returning using Adriana Cavarero's concept of weaving together and argue that people produce space and relationships over time to exert some control over a life lived under political and economic circumstances that have created separation. Six months of ethnographic fieldwork make up the material for my analysis.
A Retrospective Study of Propranolol Therapy in 635 Infants with Infantile Hemangioma
Authors: Luo Yongqi , Zeng Yinghong , Zhou Bin , Tang Jianping
Published: March 2014

Six hundred thirty‐five patients underwent oral propranolol treatment for infantile hemangioma. The efficacy rate was 91.2% and 162 of the patients recovered completely. No significant adverse effects were observed and the overall incidence of adverse effects was 2.1%.
Effects of pre‐ and post‐treatment with ethephon on gum formation of peach gummosis caused by Lasiodiplodia theobromae
Authors: Li Z. , Zhu W. , Fan Y.‐C. , Ye J.‐L. , Li G.‐H.
Published: March 2014

Peach gummosis, caused by Botryosphaeria spp. fungi, is the process of gum accumulation and exudation in plants. Ethephon (2‐chloroethylphosphonic acid) has profound effects on plants, including enhanced production of secondary metabolites and regulation of plant diseases. This study investigates the effects of application of ethephon before and after inoculation with Lasiodiplodia theobromae on gum formation. Gum formation was promoted by ethephon treatment prior to pathogen inoculation, but inhibited by ethephon applied after the pathogen. The inhibitory effect was counteracted by 1‐methylcyclopropane, which is an ethylene signal inhibitor. 1‐methylcyclopropane also promoted gum formation. Exposure of three isolates of Botryosphaeria to ethephon inhibited mycelial growth. Both treatment methods increased the sugar content at 12 and 24 h post‐inoculation (hpi). However, the sucrose, glucose and fructose contents were significantly higher in shoots with ethephon post‐treatment (application of ethephon after the pathogen inoculation) than those in shoots with ethephon pre‐treatment (application of ethephon prior to pathogen inoculation) at 48 and 72 hpi. The expression of two putative senescence‐related genes, SEN2 and SEN4, were significantly enhanced in pre‐ and post‐treated shoots with ethephon at 24, 48 and 72 hpi. Ethephon application also up‐regulated expression of the pathogenesis‐related protein PR4 while down‐regulating PR1a and PR10. The results show that ethephon has a dual function in regulating gum formation by affecting both the peach shoots and the pathogen.
Public Value and the Integrative Mind: How Multiple Sectors Can Collaborate in City Building
Authors: Fisher Thomas
Published: March 2014

Creating the public realm in an era of constrained resources demands a level of cooperation among multiple sectors rarely seen before and a recognition that the boundaries between what we have considered “public” and “private” have become porous and blurred. A number of recent projects on either side of the Mississippi River near downtown Minneapolis show what this means in terms of delivering public value much greater than any one sector could produce on its own.
Seasonal Variations in Seminal Plasma Proteins of Buffalo
Authors: Sharma L , Pandey V , Nigam R , Singh P , Saxena A , Swain DK
Published: March 2014

Contents

The study was designed to evaluate the influence of season on semen characteristics and seminal plasma protein profile of buffalo bull semen. Thirty‐six ejaculates were collected in three seasons (winter, summer and rainy) from six adult Bhadawari bulls, and semen characteristics were evaluated immediately after collection. The seminal plasma was harvested by centrifugation and protein profiling, and percentage protein fractions were analysed by SDS‐PAGE. The significant effect of season was observed on ejaculate volume, sperm concentration, progressive motility, percentage live spermatozoa, hypo‐osmotic swelling test (HOST) and acrosomal integrity. The electrophoretogram of seminal plasma proteins revealed 20 protein bands in winter, 23 bands in rainy and 25 bands in summer seasons, illustrating the significant effect of seasons on seminal plasma proteins. Among these protein bands, 18 bands were observed common in semen samples of all three seasons while protein bands of 46, 55, 58, 144 and 160 kDa were found in rainy and summer seasons. The protein bands of 48 and 60 kDa were observed only in winter season, whereas 184 and 200 kDa were reported in summer season only. The protein fractions (protein%) of common protein bands observed in three seasons revealed a significant effect of season on protein bands of 24.5, 66, 70, 72, 84 and 86 kDa. From the study, it was pertinent that bull seminal plasma contains specific proteins in particular season, which may be associated with some of the semen characteristics, and these proteins could be used as markers of the semen quality of buffalo bulls.
Modeling Deoxyribose Nucleic Acid as an Elastic Rod Inlaid With Fibrils
Authors: Chen Bin , Dong Chenling
Published: March 2014

A classical view of the double-stranded deoxyribose nucleic acid (DNA) as an isotropic elastic rod fails to explain its high flexibility manifested in the formation of sharp loops that are essential in gene regulation and DNA storage. Since the basic structure of DNA can be divided into the external highly polar backbone and the internal hydrophobic bases, here we model DNA as an elastic rod inlaid with fibrils. If the fibrils are much stiffer than the rod, we find that the persistence length of short DNA can be much smaller than that of long DNA with an adapted shear lag analysis. Consequently, the cyclization rate for short DNA is found to be much higher than the previous prediction of the worm-like chain model, which is interestingly in consistency with experiments. Our analysis suggests that the bending of short DNAs can be facilitated if there exists a specific structural heterogeneity.
Coupling Analysis of Liquid Sloshing and Structural Vibration Using General Software
Authors: Zhu C. F. , Tang G. A. , Zhang M. Y.
Published: March 2014

In this paper, a convenient modal analysis method for the linear coupled vibration of a container that is partially filled with a fluid is introduced. This problem is important for various reasons, such as stability analysis. The fluid-structure interactions in an elastic tank with an incompressible liquid are assumed to produce small vibrations. Reduced symmetric finite element equations of the system are acquired according to the component mode synthesis method. Considering that the liquid satisfies the same governing equation as steady heat conduction, general programs can be used to calculate the mass matrix and stiffness matrix of the coupled system. Then, modal analysis of the liquid container using general software, e.g., MSC Nastran, that ensures accuracy and stableness in the process, is applied to demonstrate that this method can determine the modal frequency in a fluid-structure coupled system.
Enhancement of Long Bone Fracture Healing by Local Soft Tissue Compression1
Authors: Chisena Ernest C. , Rastegar Jahangir S. , Chisena Robert S.
Published: March 2014

Endochondral fracture healing, the process in which callus bridges a fracture, can be enhanced using a brace with a deforming element. This deforming element acts to locally increase pressure at the fracture site. In this paper, we describe a bracing device, which has the capability of controlling blood flow in targeted regions of an extremity. Controlling the blood flow around a fracture site induces a mechanism that enhances fracture healing. We hypothesize that, since local oxygen tension is lowered by means of controlling the blood flow at the fracture site, fracture healing is accelerated and bony union is more likely. Using the results of several previous studies, we will show that increased mechanical pressure in the soft tissues over the fracture site enhances fracture healing.
Instantaneous Screws of Weight-Bearing Knee: What Can the Screws Tell Us About the Knee Motion
Authors: Wolf Alon
Published: March 2014

There are several ways to represent a given object's motion in a 3D space having 6DOF i.e., three translations and three rotations. Some of the methods that are used are mathematical and do not provide any geometrical insight into the nature of the motion. Screw theory is a mathematical, while at the same time, geometrical method in which the 6DOF motion of an object can be represented. We describe the 6DOF motion of a weight-bearing knee by its screw parameters, that are extracted from 3D Optical Reflective motion capture data. The screw parameters which describe the transformation of the shank with respect to the thigh in each two successive frames, is represented as the instantaneous screw axis of the motion given in its Plücker line coordinate, along with its corresponding pitch and intensity values. Moreover, the Striction curve associated with the motion provides geometrical insight into the nature of the motion and its repeatability. We describe the theoretical background and demonstrate what the screw can tell us about the motion of healthy subjects' knee.
Biomechanical Measurements of Stiffness and Strength for Five Types of Whole Human and Artificial Humeri
Authors: Aziz Mina S. R. , Nicayenzi Bruce , Crookshank Meghan C. , Bougherara Habiba , Schemitsch Emil H. , Zdero Radovan
Published: March 2014

The human humerus is the third largest longbone and experiences 2–3% of all fractures. Yet, almost no data exist on its intact biomechanical properties, thus preventing researchers from obtaining a full understanding of humerus behavior during injury and after being repaired with fracture plates and nails. The aim of this experimental study was to compare the biomechanical stiffness and strength of “gold standard” fresh-frozen humeri to a variety of humerus models. A series of five types of intact whole humeri were obtained: human fresh-frozen (n = 19); human embalmed (n = 18); human dried (n = 15); artificial “normal” (n = 12); and artificial “osteoporotic” (n = 12). Humeri were tested under “real world” clinical loading modes for shear stiffness, torsional stiffness, cantilever bending stiffness, and cantilever bending strength. After removing geometric effects, fresh-frozen results were 585.8 ± 181.5 N/mm2 (normalized shear stiffness); 3.1 ± 1.1 N/(mm2 deg) (normalized torsional stiffness); 850.8 ± 347.9 N/mm2 (normalized cantilever stiffness); and 8.3 ± 2.7 N/mm2 (normalized cantilever strength). Compared to fresh-frozen values, statistical equivalence (p ≥ 0.05) was obtained for all four test modes (embalmed humeri), 1 of 4 test modes (dried humeri), 1 of 4 test modes (artificial “normal” humeri), and 1 of 4 test modes (artificial “osteoporotic” humeri). Age and bone mineral density versus experimental results had Pearson linear correlations ranging from R = −0.57 to 0.80. About 77% of human humeri failed via a transverse or oblique distal shaft fracture, whilst 88% of artificial humeri failed with a mixed transverse + oblique fracture. To date, this is the most comprehensive study on the biomechanics of intact human and artificial humeri and can assist researchers to choose an alternate humerus model that can substitute for fresh-frozen humeri.
Effect of Calibration Error on Bone Tracking Accuracy With Fluoroscopy
Authors: Tersi Luca , Stagni Rita
Published: March 2014

Model-based 3D-fluoroscopy can quantify joint kinematics with 1 mm and 1 deg accuracy level. A calibration based on the acquisition of devices of known geometry is usually applied to size the system. This study aimed at quantifying the sensitivity of the fluoroscopic pose estimation accuracy specifically to errors in the calibration process, excluding other sources of error. X-ray focus calibration error was quantified for different calibration setups, and its propagation to the pose estimation was characterized in-silico. Focus reference position influenced the calibration error dispersion, while calibration cage pose affected its bias. In the worst-case scenario, the estimation error of the principal point and of the focus distance was lower than 1 mm and 2 mm, respectively. The consequent estimation of joint angles was scarcely influenced by calibration errors. A linear trend was highlighted for joint translations, with a sensitivity proportional to the distance between the model and the image plane, resulting in a submillimeter error for realistic calibration errors. The biased component of the error is compensated when computing relative joint kinematics between two segments.
Observer Based Fault Detection and Identification in Differential Algebraic Equations
Authors: Scott Jason R. , Campbell Stephen L.
Published: March 2014

Fault detection and identification (FDI) are important tasks in most modern industrial and mechanical systems and processes. Many of these systems are most naturally modeled by differential algebraic equations. One approach to FDI is based on the use of observers and filters to detect and identify faults. The method presented here uses the least squares completion to compute an ODE that contains the solution of the DAE and applies the observer directly to this ODE. Robustness with respect to disturbances is also addressed by a frequency filtering technique.
A Linear Matrix Inequality Solution to the Input Covariance Constraint Control Problem
Authors: White Andrew , Zhu Guoming , Choi Jongeun
Published: March 2014

In this paper, the input covariance constraint (ICC) control problem is solved by a convex optimization with linear matrix inequality (LMI) constraints. The ICC control problem is an optimal control problem that is concerned with finding the best output performance possible subject to multiple constraints on the input covariance matrices. The contribution of this paper is the characterization of the control synthesis LMIs used to solve the ICC control problem. To demonstrate the effectiveness of the proposed approach a numerical example is solved with the control synthesis LMIs. Both discrete and continuous-time problems are considered.
Research on an Approximate Model Based Virtual Calibration Method With DoE and Optimization Algorithm for Transmission Control Unit
Authors: Wu Guangqiang , Sun Lu , Zhu Sheng , Zhang Kuankuan
Published: March 2014

In order to solve the problems arising from the manual calibration method in the developing process of vehicle automatic transmission control unit (TCU), known as time-consuming, heavy workload, high cost and over-dependence on subjective experience, this article researches on a virtual calibration method based on an approximate model to obtain optimal parameters for TCU. The neural network approximate model is established from the test data chosen with the method of DoE (Design of Experiment). The virtual calibration method is then conducted through Optimal Latin Hypercube Design (OLHD) and multi-island genetic algorithm (MIGA) to search the optimal parameters. By comparing the new calibration method with original manual one on the condition of gear 1 up to gear 2, the result shows that the new method can increase the efficiency significantly.
A Feed Forward Neural Network for Solving the Inverse Kinetics of Non-Constant Curvature Soft Manipulators Driven by Cables
Authors: Giorelli Michele , Renda Federico , Ferri Gabriele , Laschi Cecilia
Published: March 2014

The solution of the inverse kinetics problem of soft manipulators is essential to generate paths in the task space to perform grasping operations. To address this issue, researchers have proposed different iterative methods based on Jacobian matrix. However, although these methods guarantee a good degree of accuracy, they suffer from singularities, long-term convergence, parametric uncertainties and high computational cost. To overcome intrinsic problems of iterative algorithms, we propose here a neural network learning of the inverse kinetics of a soft manipulator. To our best knowledge, this represents the first attempt in this direction. A preliminary work on the feasibility of the neural network solution has been proposed for a conical shape manipulator driven by cables. After the training, a feed-forward neural network (FNN) is able to represent the relation between the manipulator tip position and the forces applied to the cables. The results show that a desired tip position can be achieved quickly with a degree of accuracy of 0.73% relative average error with respect to total length of arm.
Nonlinear Compensation for High Performance Feedback Systems With Actuator Imperfections
Authors: Mock Cameron L. , Hamilton Zachary T. , Carruthers Dustin , O’Brien John F.
Published: March 2014

Measures to reduce control performance for greater robustness (e.g. reduced bandwidth, shallow loop roll-off) must be enhanced if the plant or actuators are known to have nonlinear characteristics that cause variations in loop transmission. Common causes of these nonlinear behaviors are actuator saturation and friction/stiction in the moving parts of mechanical systems. Systems with these characteristics that also have stringent closed loop performance requirements present the control designer with an extremely challenging problem. A design method for these systems is presented that combines very aggressive Nyquist-stable linear control to provide large negative feedback with nonlinear feedback to compensate for the effects of multiple nonlinearities in the loop that threaten stability and performance. The efficacy of this approach is experimentally verified on a parallel kinematic mechanism with multiple uncertain nonlinearities used for vibration suppression.
Exploiting Image Moments for Aerial Manipulation Control
Authors: Mebarki Rafik , Lippiello Vincenzo , Siciliano Bruno
Published: March 2014

This paper proposes a new visual servo control scheme that endows flying manipulators with the capability of positioning with respect to visual targets. A camera attached to the UAV provides real-time images of the scene. We consider the approaching part of an aerial assembling task, where the manipulator carries a structure to be plugged into the visual target. In order to augment the system capabilities regarding the 3D interaction with the target, we propose to use image moments. The developed controller generates desired velocities to both the UAV and the manipulator, simultaneously. While taking into account the under-actuation specific to rotary-wing vehicles, it makes use of the system redundancy to realize potential sub-tasks. The joints limits avoidance is also guaranteed. The presented developments are validated by means of computer simulations.
Proportional Nonlinear Systems: A Liable Class for Global Exponential State-Feedback Stabilization
Authors: Carravetta Francesco
Published: March 2014

We introduce, through an analysis overall restricted, for the sake of simplicity, in two-dimensions, the class of proportional systems, a nice subclass of the ΣΠ-algebraic nonlinear systems that we formerly introduced in another paper as a sort of ‘non-linear paradigm’ linking nonlinear to bilinear systems. Also we define a decomposition, which every ΣΠ-algebraic system undergoes, into the cascade of a driver, medial and final bilinear subsystem, having the same input-output behavior as the original. We show that a systematic way for global feedback stabilization can be developed for the class of proportional systems, leading to the global feedback exponential stabilization of the medial part under some ‘natural’ condition of non singularity. We show in an example the capability of the proposed method to achieving global feedback stabilization for the original system as well.
Bandwidth Allocation of Networked Control Systems With Exponential Approximation
Authors: Dong Jiawei , Kim Won-jong
Published: March 2014

This paper investigates bandwidth allocation of networked control systems (NCSs) with nonlinear-programming techniques. The bandwidth utilization (BU) is defined in terms of sampling frequency. An exponential approximation is formulated to describe system performance versus the sampling frequencies. The optimal sampling frequencies are obtained by solving the approximation with Karush-Kuhn-Tucker (KKT) conditions. Simulation and experimental results verify the effectiveness of the proposed approximation. The exponential approximation can minimize the BU so that the plants can be scheduled along with the system PIFs being optimized.
UDE-Based Robust Control for a Class of Non-Affine Nonlinear Systems
Authors: Ren Beibei , Zhong Qing-Chang
Published: March 2014

In this paper, the UDE (uncertainty and disturbance estimator) based robust control is investigated for a class of non-affine nonlinear systems in a normal form. Control system design for non-affine nonlinear systems is one of the most difficult problems due to the lack of mathematical tools. This is also true even for the exact known non-affine systems because of the difficulty in explicitly constructing the control law. It is shown that the proposed UDE-based robust control strategy leads to a stable system. The most important features of the approach are that (i) by adding and subtracting the control term u, the original non-affine form is transformed into a semi-affine form, which not only simplifies the control design procedure, but also avoids the singularity problem of the controller; (ii) the employment of UDE makes the estimation of the lumped uncertain term which is a function of control input, states and disturbances possible, rather than states alone; and (iii) it does not require any knowledge (e.g., bounds) about the uncertainties and disturbances, except the information about the bandwidth, during the design process. The stability of the closed-loop system is established. Effectiveness of the proposed approach is demonstrated through application to the hard disk driver control problem.
BMI Based Robust Optimal Control Synthesis via Sensitivity Minimization
Authors: Tulpule Punit J. , Kelkar Atul G.
Published: March 2014

This paper revisits the sensitivity minimization approach with new formulation and synthesis methodology. The new robust control synthesis approach is presented here with a numerical example of an application to a header height control of combine harvester machine. The proposed synthesis methodology is compared with the H∞ control design by comparing the performance of controllers designed using both techniques. The results indicate that the proposed methodology provides a viable alternative for robust controller synthesis and can even be better in robust performance in many cases.
Lumped-Parameter Modeling of an Automotive Air Conditioning System for Energy Optimization and Management
Authors: Zhang Quansheng , Canova Marcello
Published: March 2014

The air conditioning (A/C) system is the largest ancillary load in passenger cars, with significant impact on fuel economy. In order to reduce the energy consumption of A/C systems, model-based optimization and optimal control design tools can be effectively applied to design of a supervisory energy management strategy. Significant challenges however lie in the design of a system model that is accurate enough to represent the nonlinear behavior of the system, yet sufficiently simple to enable the use of model-based control design methods.

This paper presents a low-order, energy-based model of an automotive A/C system that is able to predict the dynamics of the evaporator and condenser pressures and the compressor power consumption during typical thermostatic (on/off) operations. A characterization of the mass and energy transport in the heat exchangers is obtained using a lumped-parameter approximation, leading to a model with reasonable accuracy but greatly reduced complexity, hence for supervisory control design. The model was validated against experimental data obtained on a test vehicle, allowing one to evaluate the accuracy in predicting the pressure states and the power consumption.
An Application of the Autogyro Theory to Airborne Wind Energy Extraction
Authors: Rimkus Sigitas , Das Tuhin
Published: March 2014

Auto-rotation or autogyro is a well-known phenomenon where a rotor in a wind field generates significant lift while the wind induces considerable aerodynamic torque on the rotor. The principle has been studied extensively for applications in aviation. However, with recent works indicating immense, persistent, and pervasive, available wind energy at high altitudes, the principle of autogyro could potentially be exploited for energy harvesting. In this paper, we carry out a preliminary investigation on the viability of using autogyros for energy extraction. We mainly focus on one of the earliest documented works on modeling of autogyro and extend its use to explore energy harvesting. The model is based on blade element theory. We provide simulation results of the concept. Although the results are encouraging, there are various practical aspects that need to be investigated to build confidence on this approach of energy harvesting. This work aims to build a framework upon which more comprehensive research can be conducted.
A Human Motion Capture System Based on Inertial Sensing and a Complementary Filter
Authors: Kanjanapas Kan , Wang Yizhou , Zhang Wenlong , Whittingham Lauren , Tomizuka Masayoshi
Published: March 2014

A human motion capture system is becoming one of the most useful tools in rehabilitation application because it can record and reconstruct a patient’s motion accurately for motion analysis. In this paper, a human motion capture system is proposed based on inertial sensing. A microprocessor is implemented on-board to obtain raw sensing data from the inertial measurement unit (IMU), and transmit the raw data to the central processing unit. To reject noise in the accelerometer, drift in the gyroscope, and magnetic distortion in the magnetometer, a time-varying complementary filter (TVCF) is implemented in the central processing unit to provide accurate attitude estimation. A forward kinematic model of the human arm is developed to create an animation for patients and physical therapists. Performance of the hardware and filtering algorithm is verified by experimental results.
Development of Energy Management Strategies for Heavy Mobile Machinery
Authors: Lajunen Antti
Published: March 2014

This paper introduces a method for developing energy management strategies (EMS) for task-oriented heavy mobile machinery. The case application is a hybrid underground mining loader but the method is also used for a diesel-electric and electric loader. Depending on the optimization target, the sequence for optimal power-split between the engine-generator (gen-set) and battery is defined. The minimization of the energy consumption and maximization of the operating efficiency are used as the optimization targets. The developed method is based on dynamic programming simulations which generate the optimal power-split for the evaluation of the control parameters. The simulation results showed that there are no significant differences between the two optimization targets in terms of the control sequence of the hybrid loader. The major difference was observed in the battery charging power which was much lower in the case of the minimization of the energy consumption.
Backward-Euler Discretization of Second-Order Sliding Mode Control and Super-Twisting Observer for Accurate Position Control
Authors: Xiong Xiaogang , Kikuuwe Ryo , Yamamoto Motoji
Published: March 2014

This paper introduces an accurate position control algorithm based on Backward-Euler discretization of a second-order sliding mode control (SOSMC) and the super-twisting observer (STO). This position control algorithm does not produce numerical chattering, which has been known to be a major drawback of explicit implementation of SOSMC and STO. It is more accurate than the conventional PID control that is also free of chattering. In contrast to conventional Backward-Euler discretization schemes of SOSMC and STO, the presented discretization method does not require any special solvers for computation. The accuracy and implementation of this algorithm are illustrated by simulations.
Determining Human Control Intent Using Inverse LQR Solutions
Authors: Priess M. Cody , Choi Jongeun , Radcliffe Clark
Published: March 2014

In this paper, we have developed a method for determining the control intention in human subjects during a prescribed motion task. Our method is based on the solution to the inverse LQR problem, which can be stated as: does a given controller K describe the solution to a time-invariant LQR problem, and if so, what weights Q and R produce K as the optimal solution? We describe an efficient Linear Matrix Inequality (LMI) method for determining a solution to the general case of this inverse LQR problem when both the weighting matrices Q and R are unknown. Additionally, we propose a gradient-based, least-squares minimization method that can be applied to approximate a solution in cases when the LMIs are infeasible. We develop a model for an upright seated-balance task which will be suitable for identification of human control intent once experimental data is available.
Active Vibration Control of Resonant Systems via Multivariable Modified Positive Position Feedback
Authors: Omidi Ehsan , Mahmoodi S. Nima
Published: March 2014

One of the predominant difficulties in the theory of distributed structure control systems comes from the fact that these resonant structures have a large number of active modes in the working band-width. Among the different methods for vibration control, Positive Position Feedback (PPF) is of interest, which uses piezoelectric actuation to overcome the vibration as a collocated controller. Modified Positive Position Feedback (MPPF) is later presented by adding a first-order damping compensator to the conventional second-order compensator, to have a better performance for steady-state and transient disturbances. In this paper, Multivariable Modified Positive Position Feedback (MMPPF) is presented to suppress the unwanted resonant vibrations in the structure. This approach benefits the advantages of MPPF, while it controls larger number vibration modes. An optimization method is introduced, consisting of a cost function that is minimized in the area of the stability of the system. LQR problem is also used to optimize the controller performance by optimized gain selection. It is shown that the LQR-optimized MMPPF controller provides vibration suppression in more efficiently manner.
Fine Structure of Pareto Front of Multi-Objective Optimal Feedback Control Design
Authors: Naranjani Yousef , Sardahi Yousef , Sun Jian-Qiao , Hernandez Carlos , Schuetze Oliver
Published: March 2014

Recently, we have proposed the simple cell mapping method (SCM) for global solutionsof multi-objective optimization problems (MOPs). We have applied the SCM method to the multi-objective optimal time domain design of PID control gains for linear systems to simultaneously minimize the overshoot, peak time and integrated absolute tracking error of the closed-loop step response. The SCM method can efficiently obtain the Pareto set and Pareto front globally, which represent the optimal control gains and performance measures, respectively. The Pareto set and Pareto front contain a complete set of control designs with various compromises in the tracking performance, and give the system designer a much wider range of choices and flexibility. Furthermore, we have discovered a fine structure of the Pareto front of the MOP solution, which was notseen before in the literature. In this paper, we further examine the implication of the fine structure with regard to the vibration control design and expected performance of the controller, and compare our findings with the dominant method in MOP studies, i.e. the genetic algorithm.
Iterative-Control-Based High-Speed Direct Mask Fabrication via Ultrasonic-Vibration-Assisted Mechanical Plowing
Authors: Wang Zhihua , Zou Qingze
Published: March 2014

Mechanical indentation and plowing is one of the most widely used methods in probe-based nanolithography. Compared to other probe-based nanolithography techniques such as the Dip-pen and the milliped, mechanical plowing is not restrictive to conductive materials and/or soft materials. However, like other probe-based nanolithgraphy techniques, the low-throughput has hindered the implementation of this technique in practices. The fabrication throughput, although can be increased via parallel-probe, is ultimately limited by the tracking precision of the probe relative to the sample during the plowing process. In this paper, a new iterative learning control technique is proposed and utilized to account for the adverse effects encountered in high-speed, large-range mechanical plowing nanolithography, including the hysteresis, the vibrational dynamics, and the cross-axis dynamics-coupling effects. Moreover, vertical (normal) ultrasonic vibration of the cantilever is introduced during the fabrication process to improve the fabrication quality. This approach is implemented to directly fabricate patterns on a mask with a tungsten layer deposited on a silicon dioxide substrate. The experimental results demonstrated that a relatively large-size pattern of four grooves (20 μm in length) can be fabricated at a high-speed of ∼5 mm/sec, with the line width and line depth at ∼95 nm and 2 nm, respectively. A fine pattern of the word ‘NANO’ is also achieved at the speed of ∼5 mm/sec. Such a high-speed direct lithography of mask with nanoscale line width and depth points the use of mechanical-plowing technique in strategic-important applications such as mask lithography for semiconductor industry.
Optimal Gait Design for Systems With Drift on SO(3)
Authors: Travers Matthew , Choset Howie
Published: March 2014

Geckos that jump, cats that fall, and satellites that are inertially controlled fundamentally locomote in the same way. These systems are bodies in free flight that actively reorientate under the influence of conservation of angular momentum. We refer to such bodies as inertial systems. This work presents a novel control method for inertial systems with drift that combines geometric methods and computational control. In previous work, which focused on inertial systems starting from rest, a set of visual tools was developed that readily allowed on to design gaits. A key insight of this work was deriving coordinates, called minimum perturbation coordinates, which allowed the visual tools to be applied to the design of a wide range of motions. This paper draws upon the same insight to show that it is possible to approximately analyze the kinematic and dynamic contributions to net motion independently. This approach is novel because it uses geometric tools to support computational reduction in automatic gait generation on three-dimensional spaces.
A Random Matrix Approach to Manipulator Jacobian
Authors: Sovizi Javad , Alamdari Aliakbar , Krovi Venkat N.
Published: March 2014

Traditional kinematic analysis of manipulators, built upon a deterministic articulated kinematic modeling often proves inadequate to capture uncertainties affecting the performance of the real robotic systems. While a probabilistic framework is necessary to characterize the system response variability, the random variable/vector based approaches are unable to effectively and efficiently characterize the system response uncertainties. Hence in this paper, we propose a random matrix formulation for the Jacobian matrix of a robotic system. It facilitates characterization of the uncertainty model using limited system information in addition to taking into account the structural inter-dependencies and kinematic complexity of the manipulator. The random Jacobian matrix is modeled such that it adopts a symmetric positive definite random perturbation matrix. The maximum entropy principle permits characterization of this perturbation matrix in the form of a Wishart distribution with specific parameters. Comparing to the random variable/vector based schemes, the benefits now include: incorporating the kinematic configuration and complexity in the probabilistic formulation, achieving the uncertainty model using limited system information (mean and dispersion parameter), and realizing a faster simulation process. A case study of a 6R serial manipulator (PUMA 560) is presented to highlight the critical aspects of the process. A Monte Carlo analysis is performed to capture the deviations of distal path from the desired trajectory and the statistical analysis on the realizations of the end effector position and orientation shows how the uncertainty propagates throughout the system.
Theoretical Development and Experimental Validation of an Adaptive Controller for Tremor Suppression at Musculoskeletal Level
Authors: Taheri Behzad , Case David , Richer Edmond
Published: March 2014

Tremor is a rhythmical and involuntary oscillatory movement of a body part. Mechanical loading via wearable exoskeletons is a non-invasive tremor suppression alternative to medical treatments. In this approach, the challenge is attenuating the tremor without affecting the patient’s intentional motion. An adaptive tremor suppression algorithm was designed to estimate and restrict motion within the tremor frequency band. An experimental setup was designed and developed to simulate the dynamics of a human arm joint with intentional and tremorous motion. The required orthotic suppressive force was applied via a pneumatic cylinder. The algorithm was implemented with a real-time controller and experimental results show tracking of the tremor frequency and a 97% reduction of tremor amplitude at the fundamental frequency.
Maximizing Wind Farm Energy Capture via Nested-Loop Extremum Seeking Control
Authors: Yang Zhongzhou , Li Yaoyu , Seem John E.
Published: March 2014

This paper proposes a novel control approach for optimizing wind farm energy capture with a nested-loop scheme of extremum seeking control (ESC). Similar to Bellman’s Principle of Optimality, it has been shown in earlier work that the axial induction factors of individual wind turbines can be optimized from downstream to upstream units in a sequential manner, i.e. the turbine operation can be optimized based on the power of the immediate turbine and its downstream units. In this study, this scheme is illustrated for wind turbine array with variable-speed turbines for which torque gain is controlled to vary axial induction factors. The proposed nested-loop ESC is demonstrated with a 3-turbine wind farm using the SimWindFarm simulation platform. Simulation under smooth and turbulent winds show the effectiveness of the proposed scheme. Analysis shows that the optimal torque gain of each turbine in a cascade of turbines is invariant with wind speed if the wind direction does not change, which is supported by simulation results for smooth wind inputs. As changes of upstream turbine operation affects the downstream turbines with significant delays due to wind propagation, a cross-covariance based delay estimate is proposed as adaptive phase compensation between the dither and demodulation signals.
An Open-Circuit-Voltage Model of Lithium-Ion Batteries for Effective Incremental Capacity Analysis
Authors: Weng Caihao , Sun Jing , Peng Huei
Published: March 2014

Open-Circuit-Voltage (OCV) is an essential part of battery models for state-of-charge (SOC) estimation. In this paper, we propose a new parametric OCV model, which considers the staging phenomenon during the lithium intercalation/deintercalation process. Results show that the new parametric model improves SOC estimation accuracy compared to other existing OCV models. Moreover, the model is shown to be suitable and effective for battery state-of-health monitoring. In particular, the new OCV model can be used for incremental capacity analysis (ICA), which reveals important information on the cell behavior associated with its electrochemical properties and aging status.
Novel Design of a Passive Variable Stiffness Joint Mechanism: Inspiration From Biomechanics of Hand Joints
Authors: Kuo Pei-Hsin , Deshpande Ashish D.
Published: March 2014

Passive variable stiffness at the human hand joints is shown to be critical for achieving stable and dexterous grasping and manipulation. Our long-term goal is to implement it in robotic hand joints. We introduce a novel design, using linear springs and non-circular cam, for a variable stiffness joint mechanism that mimics the passive stiffness characteristics of human hand joints. We present a methodology based on the principle of virtual work for synthesizing the cam shape in the joint. Key innovations of our design are a) human-like joint stiffness profile, b) large joint range of motion, and c) modular arrangement for varying torque range. We have built a prototype for validating our approach and the experimental results demonstrate that the proposed joint mechanism fulfills the design goals of our study.