bluuebunny/crossref_metadata_2025 huggingface dataset:
Anreizeffekte und Angebotsinduzierung im Rahmen der Riester-Rente: Eine empirische Analyse geschlechts- und sozialisationsbedingter Unterschiede
Authors: Pfarr Christian , Schneider Udo
Published: February 2011

In 2001, the voluntary Riester pension scheme was implemented in Germany. Financial subsidies should provide incentives to increase private pension savings. In this paper, we hypothesize that these publicly subsidized savings are mainly driven by the incentives of child benefits and that supplier induced demand is an important factor. Using data from the Socio-economic Panel we analyze the key determinants in the choice of a Riester-pension. We find a higher probability to sign a Riester contract for those with higher income, higher education and children. Furthermore, we show that a contact with an insurance agent in the previous year is a major factor for the possession of a Riesterpension. Separate estimations regarding gender and socialization confirm our hypothesis of heterogeneous determinants.
Effect of Sintering Temperature on Microstructure and Electric Properties of 0.95(K0.5Na0.5)NbO3–0.05Li(Nb0.5Sb0.5)O3with Copper Oxide Sintering Aid
Authors: Zhao Yongjie , Zhao Yuzhen , Huang Rongxia , Liu Rongzheng , Zhou Heping
Published: February 2011

The 0.95(K0.5Na0.5NbO3)–0.05Li(Nb0.5Sb0.5)O3 doped with 0.8 mol% copper oxide (CuO) lead‐free piezoelectric ceramics were synthesized by conventional solid‐state reaction route. The introduction of CuO could significantly improve the sinterability of 0.95(K0.5Na0.5NbO3)–0.05Li(Nb0.5Sb0.5)O3 ceramics. The grain size of the specimen was considerably decreased due to the formation of a large amount of liquid phase when the sintering temperature exceeded 960°C. The piezoelectric constant (d33), planar electromechanical coupling (kp), and dielectric constant (

) values increased with increasing relative density and grain size. The improved piezoelectric and dielectric properties of d33=207 pC/N, kp=44%, tan δ=0.0137, Qm=320, and

=340 can be obtained for specimens sintered at 960°C for 2 h.
Spark Plasma Sintering of Barium Zirconate Titanate/Carbon Nanotube Composites with Colossal Dielectric Constant and Low Dielectric Loss
Authors: Wu Yong Jun , Su Shao Hua , Cheng Ji Peng , Chen Xiang Ming
Published: February 2011

Ba(Zr0.2Ti0.8)O3/carbon nanotube composites were prepared by spark plasma sintering and characterized by SEM and dielectric spectrometer. The composites exhibit colossal dielectric constant up to several 105with relatively low dielectric loss over a wide temperature range from 250 to 400 K. For composite with 0.025 wt% CNTs, the dielectric constant and dielectric loss at 50°C and 1 kHz were 6.1 × 105and 0.074, respectively. The high dielectric constant can be explained by the Maxwell–Wagner polarization originating from the CNTs and Ba(Zr0.2Ti0.8)O3interfaces and microcapacitance microstructure.
The Effects of BN Addition on the Mechanical Properties of Porous Si3N4/BN Ceramics Prepared Via Nitridation of Silicon Powder
Authors: Yao Dongxu , Zeng Yu‐Ping , Zuo Kai‐Hui , Jiang Dongliang
Published: February 2011

Porous Si3N4/BN ceramics were prepared via nitridation of silicon powder, with Si and BN as starting powder, Y2O3as sintering additive. After nitridation and sintering at 1680°C, porous Si3N4/BN ceramics with a porosity of 47%–51% and a flexural strength of 170–90 MPa were obtained. Compared with pure porous Si3N4ceramics, the grains of porous Si3N4/BN ceramics were finer, the aspect ratio of β‐Si3N4grains was higher, and the pore size was decreased, which can be attributed to grain‐boundary pinning due to BN dispersions. The relatively high flexural strength was obtained with 5% BN addition. The porous Si3N4/BN ceramics also showed low shrinkage and machinable properties.
Arteriovenous Access Closure in Hemodialysis Patients With Refractory Heart Failure: A Single Center Experience
Authors: Kurita Noriaki , Mise Naobumi , Tanaka Shinji , Tanaka Mototsugu , Sai Keiko , Nishi Takahiro , Miura Sumio , Kigawa Ikutaro , Miyairi Takeshi , Sugimoto Tokuichiro
Published: February 2011

Arteriovenous dialysis access may impose a burden on the cardiac system. The objective of this study is to examine the usefulness of access closure in hemodialysis patients with refractory heart failure and to identify possible factors associated with symptomatic improvements. The study population comprised 33 hemodialysis patients with symptomatic heart failure (New York Heart Association [NYHA] class ≥II), who underwent arteriovenous access closure (30 fistulas and three grafts) between 1991 and 2008. In all patients, heart failure was refractory to all possible medical and surgical treatments, and persisted after optimal dry weight control. First, short‐term changes in hemodynamics, clinical symptoms and echocardiographic morphology were examined. Second, clinical and echocardiographic parameters were compared between responders (N = 23), who demonstrated NYHA class improvement after access closure, and non‐responders (N = 10). After access closure, systolic blood pressure rose and the heart rate decreased significantly. Body weight and echocardiographic parameters did not change significantly. Twenty‐three patients (70%) demonstrated NYHA class improvement and were designated as responders. In responders, the duration from access creation to closure was significantly shorter and fewer had ischemic heart disease, compared with non‐responders. Access flow, cardiac output and ejection fraction were comparable between the two groups. Although the five‐year survival was 20.2% in all patients, responders showed better early survival than non‐responders. Arteriovenous access closure improved clinical symptoms in 70% of patients with refractory heart failure. This improvement was especially likely to be achieved in patients without ischemic heart disease and those who developed heart failure within a relatively short time after access creation.
Prostatic cavitary lesions containing urine in dogs
Authors: Bokemeyer J. , Peppler C. , Thiel C. , Failing K. , Kramer M. , Gerwing M.
Published: February 2011

Objectives: The purpose of this retrospective study was to determine the proportion of urine‐containing prostatic cavitary lesions (“urinary cysts”) in dogs and to describe their clinical management.

Methods: The study included dogs with clinically relevant prostatic‐retention cyst/abscess (n=87) treated initially by percutaneous ultrasound‐guided drainage of the prostatic cavity. Based on a prostatic fluid:serum creatinine ratio, the study population was divided into two groups: group 1 (n=16) with and group 2 (n=71) without evidence of urine within the lesion. Medical records of both the groups were reviewed.

Results: Cavitary lesions containing urine were observed in 16 of the 87 dogs (18·4%; group 1). In 10 (62·5%) of the group 1 dogs, abdominal surgery was recommended, because of recurrent filling during follow‐up. In group 2, abdominal surgery was recommended in only 11 of 71 cases (15·5%).

ClinicalSignificance: In dogs, 18·4% (95% confidence interval, 10·9 to 28·1%) of the prostatic cavitary lesions contain urine. Measurement of creatinine within the prostatic cavity fluid is a helpful tool in diagnosing a presurgical intra‐prostatic urethral fistulation, and these dogs tend to require a more aggressive surgical therapy than percutaneous drainage alone.
Temporo‐mandibular joint condylectomy and its effect over occlusion in cats: cadaveric study
Authors: El‐Warrak A. O. , Ferrer G. A. , Lanthier T. , Loureiro Silva B. , El‐Warrak L. O.
Published: February 2011

Objective: To determine the effect of unilateral condylectomy on dental occlusion in cats.

Methods: Twelve feline cadaver heads were randomly submitted to either a right or left unilateral condylectomy of the temporo‐mandibular joint. The distance between the mandibular and maxillary canine tooth was measured before (B0) and after the unilateral condylectomy (P0). A right or left latero‐‐lateral standardised force (4 N) was applied to the mandibular mentus area before and after the surgical procedure. These measurements were analysed with a linear model for repeated measures.

Results: The comparative analysis between pre‐ and postsurgical values indicated no significant variation in teeth displacement following condylectomy between B0 and P0 measurements. Statistically significant differences were detected after either left or right condylectomy with respect to all measurements after application of the standardised forces. Occlusion changes are significant when comparing bites before and after surgery.

Clinical Significance: Unilateral condylectomy causes a significant increase in latero‐lateral amplitude of jaw movement which might clinically affect feline dental occlusion. Clinical studies are required to determine the effect of unilateral condylectomies on mastication and dental occlusion in feline patients.
Diabetes type 2 self‐management among Thai Muslim women
Authors: Lundberg Pranee C , Thrakul Supunnee
Published: February 2011

lundberg pc & thrakul s (2011) Journal of Nursing and Healthcare of Chronic Illness 3, 52–60 Diabetes type 2 self‐management among Thai Muslim women

Aim.  To explore and describe Thai Muslim women’s self‐management of diabetes type 2.

Background.  The importance of diabetes self‐management is well recognised. However, research on diabetes self‐management in Thailand is limited, and no such research related to Muslim patients with diabetes type 2 has been found.

Methods.  An explorative qualitative study using ethnography was conducted. The ethnographic method was based on qualitative interview and participant observation carried out in 2008. Orem’s self‐care deficit nursing theory provided the theoretical framework. Purposive convenience sampling was used, and twenty‐nine women aged 40–80 years participated.

Results.  Four themes of self‐management among Thai Muslim women with diabetes type 2 emerged, viz., daily life practices (dietary management, exercise, use of medicine, see doctor to follow‐up, self‐monitoring of blood sugar and use of herbal remedies), impact of the illness (feeling psychological burden of diabetes and struggling to control the disease), everyday life as before (maintaining religious practices and learning to live with the disease) and family support.

Conclusion.  The Thai Muslim women suffered from a partial self‐care deficit. The results underline the importance of taking religious traditions into account in the care, offering health education that helps patients cope with their disease, involving family members who can reinforce information given to patients, and increasing self‐management power and capability of patients.

Relevance to clinical practice.  When caring for Thai Muslim women with diabetes type 2, health care professionals should stimulate their patients to adopt a powerful strategy for modifying their daily life behaviour, and they should be aware of the existence of certain problematic behaviour of their patients. It is also important that they understand the roles of cultural background, religious tradition and family as parts of the basis for educational strategies aimed at helping patients successfully integrate disease management into their lives.
An Integrated Model of Designing
Authors: Srinivasan V. , Chakrabarti Amaresh
Published: February 2011

Current design models and frameworks describe various overlapping fragments of designing. However, little effort exists in consolidating these fragments into an integrated model. We propose a model of designing that integrates product and process facets of designing by combining activities, outcomes, requirements, and solutions. Validation of the model using video protocols of design sessions demonstrates that all the constructs are used naturally by designers but often not to the expected level, which hinders the variety and resulting novelty of the concepts developed in these sessions. To resolve this, a prescriptive framework for supporting design for variety and novelty is proposed and plans for its implementation are created.
Transformation Design Theory: A Meta-Analogical Framework
Authors: Weaver Jason , Wood Kristin , Crawford Richard , Jensen Dan
Published: February 2011

Electromechanical products and systems are often designed to transform or reconfigure between two or more states. Each state is customized to fulfill a specific set of functions, and the transformation between these multiple states allows for greater functionality and the elimination of many trade-offs between conflicting needs. Empirical examination of existing transforming systems and their similarities has led to a foundational transformation design theory, with meta-analogies and guidelines that explain how transformation processes occur, when they are useful, and how the designer can ensure their maximum benefit. The foundation of these principles and guidelines forms a meta-analogical framework for designing transformers and transformational systems. This paper presents a history of the development of transformational design theory, including the relationship of the research to case-based reasoning in other fields. Ideation methods are presented that specifically exploit the meta-analogies, i.e., categories of transformers. An example design problem is considered to illustrate the potential utility of this design-by-analogy approach.
Impact of Flow Force to the Constant Flow Characteristic of Load Sensing Pump
Authors: Ma Chong , Kong Xiaowu
Published: February 2011

Aiming at studying the impact of steady-state flow force to YL-56 load sensing pump and how to reduce the effects of flow force on control valve spool, the factors of steady-state flow force were analyzed using CFD software FLUENT, and virtual prototype of load sensing pump was developed to study its characteristics. Compared with the effect of using position-controlled proportional solenoid to drive the throttle valve in simulation, the use of force-controlled proportional solenoid could suppress the impact of steady-state flow force much better, and the problem that the output flow increased when load pressure rose was solved. The experiment test results indicate that using force-controlled proportional solenoid in throttle valve can decrease the impact of steady-state flow force quite well.
Stability of the Consensus of a Group of Second Order Agents With Time Delayed Communications
Authors: Cepeda-Gomez Rudy , Olgac Nejat
Published: February 2011

This study addresses the consensus problem and its stability for a group of agents with second order dynamics and feedback time delays. It is assumed that all the agents in the group communicate with the same number of agents, and that the time delay incurred remains constant and the same for all the interagent communication channels. A decentralized control structure of PD type is proposed to create consensus in the position and velocity of the agents. Contribution of the paper is in the peculiar construction of the system characteristic equation owing to the proposed control law, which is exploited to effectively execute the stability analysis in the delay space. A complete stability picture is obtained taking into account the variations in both the control parameters and the communication delay. Case studies and simulations results are presented to verify the analytical derivations.
A Physically-Based, Control-Oriented Diesel Particulate Filter (DPF) Model for the Applications of NO/NO2 Ratio Estimation Using a NOx Sensor
Authors: Hsieh Ming-Feng , Wang Junmin
Published: February 2011

This paper presents a physically-based, control-oriented Diesel particulate filter (DPF) model for the purposes of NO and NO2 concentration estimations in Diesel engine aftertreatment systems. The presence of NO2 in exhaust gas plays an important role in selective catalytic reduction (SCR) NOx reduction efficiency. However, current NOx cannot differentiate NO and NO2 from the total NOx concentration. A model which can be used to estimate NO and NO2concentrations in exhaust gas flowing into the SCR catalyst is thus necessary. Current aftertreatment systems for light-, medium-, and heavy-duty Diesel engines generally include Diesel oxidation catalyst (DOC), DPF, and SCR. The DPF related NO/NO2 dynamics was investigated in this study, and a control-oriented model was developed and validated with experimental data.
The Reverse Sigmoid Ca-PTH Relationship is Not Symmetrical
Authors: Shrestha Rajiv P. , Schmitt Claus P. , Hollot Christopher V. , Chipkin Stuart R. , Chait Yossi
Published: February 2011

We present a new, two-pool, linear, time-varying model to describe the short term dynamics of the Ca-PTH axis. We use an asymmetrical reverse sigmoid PTH secretion rate function in the model. This results in an asymmetrical reverse sigmoid relationship between plasma Ca++ and plasma parathyroid hormone (PTH) concentrations (Ca-PTH relationship). In the first validation of this kind, with parameters estimated separately based on each subject’s hypocalcemic clamp test data, we successfully test the model’s ability to predict the same subject’s induced hypercalcemic clamp test responses. We then show that the conventional symmetrical reverse sigmoid Ca-PTH relationship is deficient.
Automating ICSI With Rotationally Oscillating Drill (Ros-Drill©) Using Visual Feedback
Authors: Diaz Jhon , Olgac Nejat , Karzar Jeddi Mehdi , Fan Tai-Hsi
Published: February 2011

ICSI (Intra-Cytoplasmic Sperm Injection) has attracted research interest from both biological and engineering groups. This technique is used to create genetically identical offsprings of many different species (mice, rats, cattle et al.). We focus on a relatively recent technology for ICSI, called Ros-Drill© (Rotationally Oscillating Drill). In this paper, we present a procedure to automate a critical part of the ICSI operation: initiation of the rotational oscillation phase. (The visual feedback is on the real-time visual monitoring of the tip of the injection pipette. First, the real-time feature extraction in visual feedback is explained). The proposed algorithm which does this is split up into two parts: off-line and on-line. In the off-line part a proper thresholding grey level is determined. In the on-line part a realtime algorithm tracks the tip of the injecting pipette. A predetermined, species-specific penetration depth is used to initiate the rotational oscillation action of the drill. This real-time visual feedback control is compared with an earlier curvature-based analysis. Algorithmic stages as well as the outcomes from the concept validation tests are presented.
A State Machine Controller for the Autonomous Guidance of a Trained Canine
Authors: Britt Winard , Lyles William , Bevly David M.
Published: February 2011

This work demonstrates the autonomous command of a trained search canine to multiple waypoints using a novel state machine control algorithm. A hardware system is utilized in order to interface with the Global Position Satellite (GPS) system and with a tone and vibration generator for the purpose of accurately navigating and commanding the canine. An operational control algorithm for autonomous guidance of the canine is described in detail. Empirical results of an autonomously commanded canine are demonstrated with an 73% mission success rate for simple paths and a 62% mission success rate for complex paths. This work demonstrates a novel way to expand the capabilities of canines in a wide variety of missions, including search and detection.
Robust Region-Tracking for Multi-Agent Systems Using Sliding Mode Control
Authors: Bacon Mark , Olgac Nejat
Published: February 2011

Control of autonomous agent swarms is studied for targeted flocking exercises. The desired decentralized control also requires robustness against modeling uncertainties and bounded unknown forces. In this analysis, we consider the task of robustly driving multiple agents to a moving ‘target region’, as repulsive interactions help spread out the agents. An unconventional form of sliding mode control is implemented to provide the robust attraction towards the region’s center. For robustness a ‘boundary layer’ is conceived, which corresponds to the desired target region. The attraction is intentionally softened inside this target region, allowing agents to create a final formation utilizing their repulsion forces. Examples are given for moving circular and elliptical regions which illustrate the effectiveness of the proposed strategy.
Control Oriented Modeling and Nonlinear Model Predictive Control of Advanced SI Engine System
Authors: Lee Tae-Kyung , Filipi Zoran S.
Published: February 2011

Control oriented model (COM) using crank-angle resolved flame propagation simulation and nonlinear model predictive control (NMPC) methodology for the purpose of transient control of HDOF engines are proposed in this paper. The nonlinear nature of the combustion process has been a challenge in building a reliable COM and engine simulation. Artificial neural networks (ANNs) are subsequently trained on the data generated with a quasi-D combustion model to create fast surrogate combustion models. System dynamics are augmented by manifold and actuator dynamics models. Then, NMPC for an internal combustion (IC) engine with a dual-independent variable valve timing (VVT) system is designed to achieve fast torque responses, to eliminate exhaust emissions penalty, and to track the optimal actuator response closely. The NMPC significantly improves engine dynamics and minimizes excursions of in-cylinder variables under highly transient operation. Dead-beat like control is achieved with selected prediction horizon and control horizon in the NMPC.
Investigations of Natural Frequencies and Vibration Mode Shapes for a Post-Buckled Beam With Different Attached Masses
Authors: Cette Pascaline , Sneller Adam J. , Mann Brian P.
Published: February 2011

This paper considers the theoretical response of a base-excited post-buckled beam. A mass that can be varied was attached to the midspan of the clamped-clamped beam. The theoretical model for the post-buckled beam was first investigated by applying the extended Hamilton principle to obtain a partial differential equation for beam motion carrying a central mass. This equation was used to analyze the behavior of the pre- and post-buckled natural frequencies in terms of the axial load. The first three buckled configurations were then examined, and plots showing the pre- and post-buckled modal frequencies were constructed. It was found that the addition of a central mass to the beam significantly lowered its first natural frequency, while the second frequency was relatively unaffected. A set of experiments were performed and it was shown that adding a mass on the beam increased the occurrence of snap through behavior. This nonlinear behavior produced large displacements and chaotic behavior.
Brain Limbic System Based Robust Control for Lane Change Maneuver
Authors: Kim Changwon , Langari Reza
Published: February 2011

This paper presents the application of a novel intelligent control strategy for lane change maneuvers in highway environment. The lateral dynamics of a vehicle with and without wind disturbance are derived and utilized to implement a neuromophic controller based on the brain limbic system. To show the robustness of the proposed controller, several disturbance conditions including wind, uncertainty in the cornering stiffness, and changes in the vehicle mass, are investigated. To demonstrate the performance of the suggested strategy, the simulation results of the proposed method were compared with the human driver model based control scheme, which has been discussed in the literature. The simulation results demonstrate the superiority of the proposed controller in energy efficiency, driving comfort, and robustness.
On the Dynamic Stability and Agility of Aggressive Vehicle Maneuvers: A Pendulum-Turn Maneuver Example
Authors: Li Jingliang , Yi Jingang , Liu Zhaodu , Lu Jianbo
Published: February 2011

We present a dynamic stability and agility study of a pendulum-turn aggressive vehicle maneuver. Instead of optimizing the controlled inputs to mimic the human performance profile during a pendulum-turn agile maneuver, we focus on studying the stability regions and agility performance of the vehicle motion using professional racing car driver testing data. A hybrid physical/dynamic tire/road friction model is used to capture the dynamic friction force characteristics in analysis and simulation and to compare with testing data. We also introduce the use of vehicle lateral jerk information as the agility metric to compare vehicle maneuvering performance. The analysis and testing results show that during the pendulum-turn maneuvers, the professional driver operates the vehicle outside the stable regions of the vehicle dynamics to achieve superior agility performance than that under a typical human driver model. Comparison results with a typical human driver model also show that the racing car driver outperforms in both the traveling time and the newly defined agility metric. Designing a control strategy for autonomous pendulum-turn-like safe vehicle agile maneuvers is ongoing work.
Application of Sliding Mode Control to Swarms Under Conflict
Authors: Cepeda-Gomez Rudy , Olgac Nejat , Sierra Daniel A.
Published: February 2011

A robustizing Sliding Mode Control (SMC) strategy is implemented on two competing multi-agent swarms, called pursuers and evaders. Newtonian dynamic models are considered, which include drag forces as well as the inter-agent attraction/repulsion forces. The proposed control achieves the stability and the capture of the evaders by the pursuers despite the uncertainties in the evader behavior. The group pursuit is conceived in two phases: the approach phase during which the two swarms act like two individuals; and the assigned pursuit phase when each pursuer is assigned to an evader. Furthermore, we take into account a turning action for the evaders, which adds to their agility. This property is considered as a part of the uncertainty in the dynamics. The control parameters are separately studied to assess their influences on the pursuit.
Distributed Constrained Attitude and Position Control Using Graph Laplacians
Authors: Okoloko Innocent , Kim Yoonsoo
Published: February 2011

We present a graph theoretic and optimization based method for attitude and position consensus of a team of communicating vehicles navigating in three dimensional space. Coordinated control of such vehicles has applications in planetary scale mobile sensor networks, and multiple vehicle navigation in general. Using the Laplacian matrix of the communication graph, and attitude quaternions, a synthesis of the optimal stochastic matrix that drives the attitudes to consensus, is done, by solving a constrained semidefinite program. This novel methodology attempts to extend quadratically constrained attitude control (Q-CAC), to the consensus framework. The solutions obtained are used to realize coordinated rendezvous, and formation acquisition, in the presence of static and dynamic obstacles.
Tracking Control of Flexible Ball Screw Drives With Runout Effect Compensation
Authors: Sepasi Mohammad , Sassani Farrokh , Nagamune Ryozo
Published: February 2011

Most machine tools rely on precision ball screw drives to accurately position the workpiece relative to the tool. In terms of the performance of such machines, tracking is one of the most important aspects that significantly affects the machining outcomes. Minimizing tracking errors of a flexible ball screw drive in the presence of runout phenomenon is explained in this paper. To achieve small tracking errors, the flexibility and runout are modeled by a linear parameter varying system. Based on the derived model, gain scheduling tracking controllers with parameter-dependent Lyapunov functions are designed. The efficiency of the designed controllers in minimizing the tracking error, as well as the importance of the runout modeling, is demonstrated on a ball screw drive experimental setup.
Control-Oriented Dynamic Models for In-Cylinder Conditions of Multi-Cylinder Diesel Engines
Authors: Yan Fengjun , Wang Junmin
Published: February 2011

This paper presents control-oriented models, describing the dynamics of the in-cylinder conditions (ICCs) at intake valve closing (IVC), for multi-cylinder Diesel engines. Such models are based on multi-cylinder Diesel engines equipped with dual-loop exhaust gas recirculation (EGR) systems. As the thermodynamic boundary conditions for Diesel engine combustion, ICCs at IVC play critical roles for controlling combustion, particularly advanced combustion modes whose sensitivities to ICCs are very high. Grounded in physical principles, control-oriented ICC dynamic models were developed to describe the multi-cylinder characteristic and the coupling effects among the ICC quantities (i.e. in-cylinder gas mass, gas temperature, and oxygen fraction at IVC). The effectiveness of the developed control-oriented model was validated by comparing with a high-fidelity, 1-D computational, GT-Power engine model.
Observer-Based Estimation of Diesel Engine Aftertreatment System NO and NO2 Concentrations
Authors: Hsieh Ming-Feng , Wang Junmin
Published: February 2011

This paper presents an observer design for Diesel engine aftertreatment system NO and NO2 concentrations estimations. NO and NO2 have different reaction characteristics within SCR systems. Current production NOx sensors cannot differentiate NO and NO2. Such an observer thus can be used by selective catalytic reduction (SCR) system control and diagnosis purposes. Diesel oxidation catalyst (DOC) and Diesel particulate filter (DPF) were considered as the catalysts which can affect NO/NO2 fraction of the exhaust gas upstream of the SCR. The observer was designed based on an experimentally-validated control-oriented dynamic model which can accurately represent the NO and NO2 dynamics from engine-out, through DOC, and to DPF. Stability of the observer was theoretically proved through a Lyapunov analysis assisted by insight into the system characteristics. The effectiveness of the observer was shown by comparing the estimated NO and NO2 concentrations with the measured ones by a Horiba emissions measurement system.
A Rollout Control Algorithm for Discrete-Time Stochastic Systems
Authors: Malikopoulos Andreas A.
Published: February 2011

The growing demand for making autonomous intelligent systems that can learn how to improve their performance while interacting with their environment has induced significant research on computational cognitive models. Computational intelligence, or rationality, can be achieved by modeling a system and the interaction with its environment through actions, perceptions, and associated costs. A widely adopted paradigm for modeling this interaction is the controlled Markov chain. In this context, the problem is formulated as a sequential decision-making process in which an intelligent system has to select those control actions in several time steps to achieve long-term goals. This paper presents a rollout control algorithm that aims to build an online decision-making mechanism for a controlled Markov chain. The algorithm yields a lookahead suboptimal control policy. Under certain conditions, a theoretical bound on its performance can be established.
Controlling the Position of Magnetic Particles Using Adaptive Q-Parameterization
Authors: Pickel Jason G. , Cole Daniel G.
Published: February 2011

Controlling the position of magnetic particles with magnetic traps for single molecule manipulation is difficult due to the complexity of the instrument. Currently, users are spending an immense amount of time designing compensators to satisfy their experimental conditions, yielding them minimal time to concentrate on their experiment. This paper discusses using adaptive Q-parametrized compensator methods to control the position of the particle. Incorporating adaptive control methods into the magnetic trap design can eliminate this issue by adjusting the controller parameters to ensure the performance of the instrument meets specific requirements. The adaptive Q-parametrized compensator structure has been incorporated into the design of the magnetic trap, resulting in the displacement of the particle being stabilized and the effects of the Brownian disturbances being reduced as the number of filter weight coefficients are increased.
A Momentum-Based Algorithm for Identifying the Inertia Properties of a Human Body: A Preliminary Study
Authors: Lu Qi , Ma Ou
Published: February 2011

The body segment parameters (BSP) of a human body are critical information for modeling, simulating, and understanding human dynamics. The determination of BSPs of human bodies has received increasing attention in biomechanics, sport science, ergonomics, rehabilitation and other fields. This paper presents a momentum-based identification algorithm for dynamically estimating the BSPs of a human body. The human body is modeled as a multibody dynamical system, and the momentum equation of the system can be derived by applying the principle of impulse and momentum. It is possible to formulate the momentum equations corresponding to a set of experiment tests into a linear regression form with respect to the unknown BSPs, which then can be solved using the least square method or other methods. The momentum-based algorithm requires inputting position, velocity, and external force data only. Since acceleration and all the internal force data is not needed, the algorithm is less demanding on measurements and is also less sensitive to measurement errors. As a result, it is practically more appealing than the algorithms depending on the equations of motion. The paper presents the momentum-based inertia identification algorithm along with a simulation study of the algorithm using a simplified trunk-leg model representing a main portion of a human body.
Model Based Control of a Diesel Engine
Authors: Jammoussi H. , Franchek M. A. , Grigoriadis K. , Books M.
Published: February 2011

Proposed in this paper is an automated framework for calibration of diesel engine governors. The process involves two basic parts, online engine model identification followed by governor gain design. A previously developed Instrumental Variable 3 Step Algorithm for closed loop system identification is used to estimate the engine model. The identified model is then used in two different governor calibration approaches. The first approach employs a typical governor structure involving acceleration feedback. It will be shown that this governor structure reduces to a classical two degree-of-freedom design. The second approach is based on a procedure in which a desired open-loop transfer function (target transfer function) is shaped such that the same performance specifications as for the first design are satisfied. The control design methods are applied for an off-highway diesel engine with a disengaged transmission. In-field data collected from the engine operating closed-loop is used to identify a model for the open-loop system and the controller gains are then determined. The loop shaping method is then applied to the identified model to design a feedback controller and a prefilter. The efficacy of both loops in terms of tracking performance and noise rejection has been demonstrated through a time domain simulation of both closed-loop step responses.
A Simple Design Approach for Excitation Controller and Power System Stabilizer
Authors: Fusco G. , Russo M.
Published: February 2011

This paper proposes a simple design procedure to solve the problem of controlling generator transient stability following large disturbances in power systems. A state-feedback excitation controller and power system stabilizer are designed to guarantee robustness against uncertainty in the system parameters. These controllers ensure satisfactory swing damping and quick decay of the voltage regulation error over a wide range of operating conditions. The controller performance is evaluated in a case study in which a three-phase short-circuit fault near the generator terminals in a four-bus power system is simulated.
Intelligent Real Time Data Interpretation of Rocket Test Data to Identify Sudden Transitions
Authors: Mahajan Ajay , Oesch Christopher , Figueroa Fernando
Published: February 2011

Integrated Systems Health Monitoring (ISHM) is an implementation of monitoring strategies for complex systems whereby avoiding catastrophic failure, extending life and leading to improved asset management. An ISHM generally encompasses intelligence at many levels and sub-systems including sensors, actuators, devices, etc., but this paper focuses on only smart sensors. Wavelet analysis is used to enhance previous work done in this area. The major advantage provided by adding wavelet analysis is the ability to detect sudden transitions as well as obtaining the frequency content using a much smaller data set then that required by the traditional Fourier transform method. Historically, sudden transitions were detected by visual methods or by offline analysis of the data. The algorithms presented in this paper provide an opportunity to automatically detect sudden transitions as well as many additional data anomalies, and provide improved data-correction and sensor health diagnostic abilities. The developed algorithms have been tested on actual rocket test data provided by NASA’s Stennis Space Center.
Reliability Investigation of Tissue Resonator Indenter Device
Authors: Jia Ming , Zu Jean W. , Hariri Alireza
Published: February 2011

Knowledge of tissue mechanical properties is widely required by medical applications, such as disease diagnostics, surgery operation, simulation, planning, and training. A new portable device, called Tissue Resonator Indenter Device (TRID), has been developed for measurement of regional viscoelastic properties of soft tissues at the Bio-instrument and Biomechanics Lab of the University of Toronto. As a device for soft tissue properties in-vivo measurements, the reliability of TRID is crucial. This paper presents TRID’s working principle and the experimental study of TRID’s reliability with respect to inter-reliability, intra-reliability, and the indenter misalignment effect as well. The experimental results show that TRID is a reliable device for in-vivo measurements of soft tissue mechanical properties.
Hardware-in-the-Loop Simulation of Robust Gain-Scheduling Control of Port-Fuel-Injection Processes
Authors: White Andrew , Zhu Guoming , Choi Jongeun
Published: February 2011

In this paper, an event-based sampled discrete-time linear system representing a port-fuel-injection process based on wall-wetting dynamics is obtained and formulated as a linear parameter varying (LPV) system. The system parameters used in the engine fuel system model are engine speed, temperature, and load. These system parameters can be measured in real-time through physical or virtual sensors. A gain-scheduling controller for the obtained LPV system is then designed based on the numerically efficient convex optimization or linear matrix inequality (LMI) technique. To demonstrate the feasibility of implementing the gain-scheduling controller, a hardware-in-the-loop (HIL) simulation is performed using a mixed mean-value and crank-based engine model. The HIL results show the effectiveness and implementability of the proposed scheme.
Modelling a Single-Wheel Testbed for Planetary Rover Applications
Authors: Irani Rishad A. , Bauer Robert J. , Warkentin Andrew
Published: February 2011

This paper presents a dynamic model for a smooth wheel travelling through loose sandy soil. Many models that are used for such wheel-soil interactions are typically static or quasi-static models. The new model builds upon these widely-used models by adding the dynamic effect of the soil deformation. The new model is validated using experiments that were carried on a new single wheel testbed which was constructed at Dalhousie University. During experiments with a smooth wheel it was noticed that the track of the wheel had repeatable ridges. Moreover, it was noticed that the corresponding torque and force data also had oscillations in it with the periods of the harmonic coinciding with the ridges in the sand left by the track of the wheel.
Application of Real-Time Image Distortion Compensation to a Firearm Simulation Environment
Authors: Priess M. Cody , Radcliffe Clark , Choi Jongeun
Published: February 2011

Pointing tasks frequently require highly accurate tracking of the user’s point of aim. An example is tracking the aim of a user within a video game environment, or calculating the orientation of a mobile robot using data from an onboard camera. Many current methods for tracking user aim are not very accurate, and only capable of tracking relative motions of the pointer. Recognizing this, a system for interacting with a visually projected firearm target practice simulation is presented. An invisible laser is mounted on a training firearm and pointed at a video projection screen. The location of the laser dot on the projector screen is tracked by a camera. Several non-parametric error correction techniques are used to compensate for the distortion of the resulting image in real time and allow for accurate tracking of the dot location. Several targets are generated, and the user engages them by aiming along the standard weapon sights and pulling the trigger. The accuracy of system is evaluated by aiming the weapon at several points not used in the error correction process, and averaging the error between the calculated and actual aimpoints at these locations. This metric shows that the system produces an average normalized error of 0.0013 across the projected field, which corresponds to an aiming error of 3.4 inches at 100 yards.
The Role of Traffic Flow Preview for Planning Fuel Optimal Vehicle Velocity
Authors: Asadi Behrang , Zhang Chen , Vahidi Ardalan
Published: February 2011

A vehicle’s untimely arrival at a local traffic wave with lots of stops and goes increases its fuel use. This paper proposes predictive planning of the vehicle velocity for reducing the velocity transients in upcoming traffic waves. Macroscopic evolution of traffic pattern along the vehicle route is first estimated by combining a traffic flow model. The fuel optimal velocity trajectory is calculated by solving an optimal control problem with the spatiotemporally varying constraint imposed by the traffic. Preliminary simulation results indicate the potential for improvement in fuel economy with a little compromise on travel time.
Reduction of an Electrochemistry-Based Li-Ion Battery Health Degradation Model via Constraint Linearization and Pade´ Approximation
Authors: Forman Joel C. , Bashash Saeid , Stein Jeffrey , Fathy Hosam
Published: February 2011

This paper examines an electrochemistry-based model of health degradation via anode-side resistive film formation in Lithium-ion batteries. The paper makes this model more tractable and conducive to control design by making two main contributions to the literature. First, we adaptively solve the model’s algebraic constraints using quasi-linearization. This improves the model’s execution speed compared to solving the constraints via optimization. Second, we reduce the model’s order by deriving a family of analytic Pade´ approximations to the model’s spherical diffusion equations. The paper carefully compares these Pade´ approximations to other published methods for reducing spherical diffusion equations. Finally, the paper concludes with simulations of battery degradation that highlight the significant impact of the proposed model reduction approach on the battery model’s overall accuracy and simulation speed.
Battery-Health Conscious Power Management for Plug-In Hybrid Electric Vehicles via Stochastic Control
Authors: Moura Scott J. , Stein Jeffrey L. , Fathy Hosam K.
Published: February 2011

This paper investigates power management algorithms that optimally manage lithium-ion battery pack health, in terms of anode-side film growth, for plug-in hybrid electric vehicles (PHEVs). Specifically, we integrate a reduced electrochemical model of solid electrolyte interface (SEI) film formation into a stochastic dynamic programming formulation of the PHEV power management problem. This makes it possible to optimally trade off energy consumption cost versus battery health. A careful analysis of the resulting Pareto-optimal set of power management solutions provides two important insights into the tradeoffs between battery health and energy consumption cost in PHEVs. First, optimal power management solutions that minimize energy consumption cost tend to ration battery charge, while the solutions that minimize battery health degradation tend to deplete charge aggressively. Second, solutions that balance the needs for minimum energy cost and maximum battery health tend to aggressively deplete battery charge at high states of charge (SOCs), then blend engine and battery power at lower SOCs. These results provide insight into the fundamental tradeoffs between battery health and energy cost in PHEV power management.
A Thrust-Vectored Submersible for Animal Behavior Research: Design and Proof of Concept
Authors: Kopman Vladislav , Cavaliere Nicholas , Porfiri Maurizio
Published: February 2011

In this paper, we present the design and proof of concept of a streamlined, low-cost, and smooth-hulled underwater vehicle (MASUV-1). MASUV-1 utilizes an ad-hoc designed multi-directional thrust-vectoring system for steering and an entirely enclosed propulsion system, allowing for safe operation in the vicinity of marine mammals. Tests of the vehicle in a still water environment show high maneuverability at speeds comparable with similar torpedo-type class underwater vehicles.
Scheduled Feedforward Control of Superheat Through Hardware-in-the-Loop Load Emulation
Authors: Otten Richard , Alleyne Andrew G.
Published: February 2011

Variable speed refrigeration systems have the potential for improved energy savings compared to conventional on-off systems. A single-input-single-output (SISO) control structure does not adequately regulate control parameters due to strong coupling inherent to the vapor compression cycle (VCC). With the use of an electronic expansion valve (EEV) a feedforward control configuration may be implemented to remove the effects of compressor speed changes on evaporator superheat, thus allowing better regulation during transients. Due to the nonlinearity of the VCC a scheduled feedforward compensator is proposed to effectively reject a compressor disturbance over the wide range of operating conditions typically experienced by variable speed systems. The proposed control structure allows superheat regulation at a low level without risking compressor damage, therefore helping maximize system efficiency. This paper presents experimental results obtained through load emulation. This is a novel approach which performs a task similar to the automotive dynamometer, where various size loads and environmental conditions may be placed on a VCC through an on-line experimental simulation.
Measurement of Uncoupled Lateral Carcass Deflections With a Wireless Piezoelectric Sensor and Estimation of Tire Road Friction Coefficient
Authors: Erdogan Gurkan , Alexander Lee , Rajamani Rajesh
Published: February 2011

A new tire-road friction coefficient estimation approach based on lateral carcass deflection measurements is proposed. The unique design of the developed wireless piezoelectric sensor decouples lateral carcass deformations from radial and tangential carcass deformations. The estimation of the tire-road friction coefficient depends on the estimation of the slip angle and the lateral tire force. The tire slip angle is estimated as the slope of the lateral deflection curve at the leading edge of the contact patch. The lateral tire force is obtained by using a parabolic relationship with the lateral deflections in the contact patch. The estimated slip angle and lateral force are then plugged into a tire brush model to estimate the tire-road friction coefficient. A specially constructed tire test-rig is used to experimentally evaluate the performance of the tire sensor and the developed approach. Experimental results show that the proposed tire-road friction coefficient estimation approach is quite promising.