bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement of tear production and intraocular pressure in ducks and geese
Authors: Ansari Mood Maneli , Rajaei Seyed Mehdi , Ghazanfari Hashemi Sohail , Williams David L. , Sadjadi Reza 
Published: January 2016

AbstractObjectivesThe purpose of this study was to establish a reference value of tear production and intraocular pressure in clinically normal ducks and geese.Animal StudiedThe study population consisted of forty‐eight ducks (24 males and 24 females) and fifty‐two geese (26 males and 26 females).ProceduresBirds were gently physically restrained in dorsoventral position without any pressure to the head and neck. Tear secretion and intraocular pressure were measured using 5‐mm‐wide Schirmer tear test strips and TonoVet® rebound tonometer, respectively.ResultsOverall mean ± 2SD STT and IOP values of all eyes were 6.2 ± 2.2 mm/min and 10.2 ± 2.2 mmHg, respectively, for the ducks; 5.5 ± 2.6 mm/min and 9.1 ± 2.0 mmHg, respectively, for the geese. There was no statistically significant difference in IOP between left eye and right eye or between males and females in ducks (P = 0.56, P = 0.63) and geese (P = 0.23, P = 0.22). Analysis of variance revealed that there were no significant differences in the STT and IOP between the breeds in ducks (P = 0.49, P = 0.68) and geese (P = 0.14, P = 0.26).ConclusionsResults of this study may be beneficial for the diagnosis and therapeutic monitoring of ducks and geese affected with Keratoconjunctivitis sicca, glaucoma, and uveitis.
The Modal Twist Axis: A Method for Describing the Dynamical Characteristics of Single Track Vehicles
Authors: Doria Alberto , Taraborrelli Luca 
Published: January 2016

Static and dynamic properties of single-track vehicles components (such as frames, front forks and swing-arms) play a fundamental role from the point of view of vehicle stability, which is a key issue of single-track vehicles dynamics and safety. Nowadays, the stability of a vehicle is studied by means of multi-body codes, in which it is possible to implement models of the tires and of the components of the vehicle. Actually, the chassis and the forks of motorcycles are mechanical systems with distributed mass and stiffness properties, but in most simulation codes the elastic properties of the structural elements are modeled with lumped stiffness and damping elements. Very few research has been carried out on the identification of the lumped elements, of their natural frequencies and damping from laboratory tests.
In the first section of the paper, the concept of modal twist axis is proposed to characterize the dynamic deformability of a structural element. The twist axis is defined as the intersection between the un-deformed plane of the structural element and the plane tangent to the free end of the structural element in deformed condition. If the identification of the twist axis is carried out in resonance condition, the modal twist axis is found. A method for measuring the modal twist axis position and orientation is described. It is based on impulse excitation by means of a modally tuned hammer and three accelerometers which are used for defining the deformed plane.
In the second section of the paper, experimental results obtained on two motorcycle frames are shown. In order to know the modal shapes of the components at the measured natural frequencies, modal analysis is carried out. A correlation between the modal twist axis position and the mode of vibration is shown and discussed. In order to study the influence of the constraints on dynamic properties, the frames are tested in two different constraint conditions: rear constrained and front constrained.
The last section of the paper shows the experimental results obtained by applying the proposed method to other motorcycle components, such as a front fork and a frame with the engine.
A Parametric Amplifier for Weak, Low-Frequency Forces
Authors: Dolev Amit , Bucher Izhak 
Published: January 2016

The present work introduces a tunable parametric amplifier (PA) with a hardening, Duffing-type nonlinearity. By introducing a multi-frequency parametric excitation, one is able to achieve both: (i) High amplification of the weak, low-frequency external excitation (ii) Projection of the low frequency on any natural frequency of the system, thus transforming the low frequency excitation to a frequency band where signal levels are considerably higher. Having developed multiple-scales based expressions for the response of such systems, it is demonstrated that (a) The analytical analysis agrees well with numerically obtained simulations. (b) Both the phase, magnitude and spatial projection of this force on any system’s eigenvector can be retrieved by appropriate selection of parameters, with superior signal to noise levels.
Closed form analytic expressions for the sensitivity and gain are derived and analyzed. Additionally, some practical applications envisaged for the proposed method will be outlined.
Solution Space Exploration in Model-Based Realization of Engineered Systems
Authors: Sabeghi Maryam , Smith Warren , Allen Janet K. , Mistree Farrokh 
Published: January 2016

George Box a British mathematician and professor of statistics wrote that “essentially, all models are wrong, but some are useful.” In keeping with George Box’s observation we suggest that in the model-based realization of complex systems, the decision maker must be able to work constructively with decision models of varying fidelity, completeness and accuracy in order to make defendable decisions under uncertainty. The models, and the search algorithms that use these models, will never be perfect and the inherent inaccuracy and incompleteness of analysis models and solvers manifest as uncertainties in the projected outcomes. Therefore, a significant and desirable step in any model-based application is to find stable and robust solutions in which variation of the (input) variables and parameters within manageable tolerances has the minimum effect on delivering favorable, system performance. In this paper we present a method for visualizing and exploring the solution space using the compromise Decision Support Problem (cDSP) as a decision model to aid a decision maker in finding these stable and robust solutions.
The efficacy of the method is illustrated using the design of a shell and tube heat exchanger as an example. The method is generalizable to other decision constructs. Our emphasis is on the method rather than the results per se.
Relaxation Length Review and Time Constant Analysis for Agile Tire Dynamics Control
Authors: Vantsevich Vladimir V. , Gray Jeremy P. 
Published: January 2016

For military all-terrain vehicles, there is a need to radically increase tactical and operational mobility through new modalities by fundamentally improving vehicle terrain control. By characterizing the tire relaxation length and time constants for lateral and longitudinal dynamic changes, mobility control can be enhanced to accommodate agile tire dynamics.
This paper analyzes the transient period of the tire reaction force development process, which is characterized by the relaxation length, for the purpose of agile tire dynamics control as a pre-emptive, fast and exact response of a tire to dynamic changes of its interaction with terrain. In this regards, a comprehensive literature review was undertaken and the tire relaxation length was analyzed for different types of vehicles and their operational velocities. The time relaxation constants, which are derived from the relaxation length, are determined and analyzed based on the data gathered in technical literature. Based on the analysis, reference magnitudes of the time relaxation constants are proposed to be used in agile tire dynamics control algorithm and hardware developments of military all-terrain vehicles.
Digital Design of Crack Patterns With Natural Impressions on Pottery
Authors: Shimizu Kaoru , Aoyama Hideki 
Published: January 2016

With the rapid development in production technology, it is becoming increasingly difficult to identify high-quality industrial products. Thus, appearance design is considered an important factor for deciding quality. There is increasing burden on the designer to develop a design that matches the preferences of a large number of consumers. For this reason, it is imperative to develop a system that can efficiently generate numerous patterns at the early stages of the design process. One of the patterns preferred by many customers is that with a natural impression. Therefore, an approach to derive a pattern exhibiting a natural impression, based on natural phenomena, is considered to be suitable for obtaining designs preferred by a large number of users, and it is believed to be a support tool to designers.
The purpose of this study is to develop a system capable of obtaining a pattern design exhibiting a natural impression by quantifying natural phenomena. This paper focuses on crack formation, a natural phenomenon, which can be seen on pottery surfaces. Based on the mechanism of formation of real cracks, a method for generating crack patterns via a mechanical process is developed, and design generation by a basic system is performed.
The fractal dimensions of the generated crack patterns are calculated by fractal analysis, and the effectiveness of the patterns is quantitatively verified based on fractal dimensions from the viewpoint of naturalness.
Dual Residual for Distributed Augmented Lagrangian Coordination Based on Optimality Conditions
Authors: Xu Meng , Fadel Georges , Wiecek Margaret M. 
Published: January 2016

Augmented Lagrangian Coordination (ALC) is one of the more popular coordination strategies for decomposition based optimization. It employs the augmented Lagrangian relaxation approach and has shown great improvements in terms of efficiency and solution accuracy when compared to other methods addressing the same type of problem. Additionally, by offering two variants: the centralized ALC in which an artificial master problem in the upper level is created to coordinate all the sub-problems in the lower level, and the distributed ALC in which coordination can be performed directly between sub-problems without a master problem, ALC provides more flexibility than other methods. However, the initial setting and the update strategy of the penalty weights in ALC still significantly affect its performance and thus are worth further research.
For centralized ALC, the non-monotone weight update strategy based on the theory of dual residual has shown very good improvements over the traditional monotone update, in which the penalty weights can either increase or decrease. In this paper, we extend the research on the dual residual in centralized ALC to the distributed ALC. Through applying the Karush-Kuhn-Tucker (KKT) optimality conditions to the All-In-One (AIO) and decomposed problems, the necessary conditions for the decomposed solution to be optimal are derived, which leads to the definition of primal and dual residuals in distributed ALC. A new non-monotone weight based on both residuals is then proposed, by which all AIO KKT conditions are guaranteed after decomposition. Numerical tests are conducted on two mathematical problems and one engineering problem and the performances of the new update are compared to those of the traditional update. The results show that our proposed methods improve the process efficiency, accuracy, and robustness for distributed ALC.
Towards a Methodology for Multidisciplinary Design Optimization of Haptic Devices
Authors: Sun Xuan , Andersson Kjell , Sellgren Ulf 
Published: January 2016

Design of haptic devices requires trade-off between many conflicting requirements, such as high stiffness, large workspace, small inertia, low actuator force/torque, and a small size of the device. With the traditional design and optimization process, it is difficult to effectively fulfill the system requirements by separately treating the different discipline domains. To solve this problem and to avoid sub-optimization, this work proposes a design methodology, based on Multidisciplinary Design Optimization (MDO) methods and tools, for design optimization of six degree-of-freedom (DOF) haptic devices for medical applications, e.g. simulators for surgeon and dentist training or for remote surgery.
The proposed model-based and simulation-driven methodology aims to enable different disciplines and subsystems to be included in the haptic device optimization process by using a robust model architecture that integrates discipline-specific models in an optimization framework and thus enables automation of design activities in the concept and detail design phase. Because of the multi-criteria character of the performance requirements, multi-objective optimization is included as part of the proposed methodology. Because of the high-level requirements on haptic devices for medical applications in combination with a complex structure, models such as CAD (Computer Aided Design), CAE (Computer Aided Engineering), and kinematic models are considered to be integrated in the optimization process and presenting a systems view to the design engineers. An integration tool for MDO is used as framework to manage, integrate, and execute the optimization process.
A case study of a 6-DOF haptic device based on a TAU structure is used to illustrate the proposed methodology. With this specific case, a Multi-objective Genetic Algorithm (MOGA) with an initial population based on a pseudo random SOBOL sequence and Monte Carlo samplings is used for the optimization.
The Skateboard Speed Wobble
Authors: Rosatello Marco , Dion Jean-Luc , Renaud Franck , Garibaldi Luigi 
Published: January 2016

The speed wobble is a phenomenon in nonlinear dynamics that can occur in many vehicles such as bicycles, motorbikes, skateboards and airplanes nose landing gear. The dynamic instability affects the steerable wheels of a vehicle and can lead to the loss of control. While for bikes, motorbikes and airplanes the dynamics and causes of the wobble are well known and the literature fully describes the subject, for the skateboard the literature is very poor and there is no paper which investigates this type of instability.
In order to do that, the skateboard equations of motion were obtained through Lagrange formalism and Lagrange multipliers method was used to solve the non-holonomic constraints. A parametric stability study was carried out on the linearized equations of motion and the influence of different skateboard parameters was investigated.
The main discovery is that the wobble doesn’t strictly depend on skateboard configuration, but the human control characteristics are predominant in the vehicle dynamics.
The Effect of Credit Definition and Aggregation Strategies on Multi-Objective Hyper-Heuristics
Authors: Hitomi Nozomi , Selva Daniel 
Published: January 2016

Heuristics and meta-heuristics are often used to solve complex real-world problems such as the non-linear, non-convex, and multi-objective combinatorial optimization problems that regularly appear in system design and architecture. Unfortunately, the performance of a specific heuristic is largely dependent on the specific problem at hand. Moreover, a heuristic’s performance can vary throughout the optimization process. Hyper-heuristics is one approach that can maintain relatively good performance over the course of an optimization process and across a variety of problems without parameter retuning or major modifications. Given a set of domain-specific and domain-independent heuristics, a hyper-heuristic adapts its search strategy over time by selecting the most promising heuristics to use at a given point.
A hyper-heuristic must have: 1) a credit assignment strategy to rank the heuristics by their likelihood of producing improving solutions; and 2) a heuristic selection strategy based on the credits assigned to each heuristic. The literature contains many examples of hyper-heuristics with effective credit assignment and heuristic selection strategies for single-objective optimization problems. In multi-objective optimization problems, however, defining credit is less straightforward because there are often competing objectives. Therefore, there is a need to define and assign credit so that heuristics are rewarded for finding solutions with good trades between the objectives.
This paper studies, for the first time, different combinations of credit definition, credit aggregation, and heuristic selection strategies. Credit definitions are based on different applications of the notion of Pareto dominance, namely: A1) dominance of the offspring with respect to the parent solutions; A2) ability to produce non-dominated solutions with respect to the entire population; A3) Pareto ranking with respect to the entire population. Two different credit aggregation strategies for assigning credit are also examined. A heuristic will receive credit for: B1) only the solutions it created in the current iteration or B2) all solutions it created that are in the current population. Different heuristic selection strategies are considered including: C1) probability matching; C2) dynamic multi-armed bandit; and C3) Hyper-GA.
Thus, we conduct an experiment with three factors: credit definition (A1, A2, A3), credit aggregation (B1, B2), and heuristic selection (C1, C2, C3) and conduct a full factorial experiment. Performance is measured by hyper-volume of the last population. All algorithms are tested on a design problem for a climate monitoring satellite constellation instead of classical benchmarking problems to apply domain-specific heuristics within the hyper-heuristic.
Local Analysis of Closed-Loop Linkages: Mobility, Singularities, and Shakiness
Authors: Müller Andreas 
Published: January 2016

The mobility of a linkage is determined by the constraints imposed on its members. The constraints define the configuration space (c-space) variety as the geometric entity in which the finite mobility of a linkage is encoded. The instantaneous motions are determined by the constraints, rather than by the c-space geometry. Shaky linkages are prominent examples that exhibit a higher instantaneous than finite DOF even in regular configurations. Inextricably connected to the mobility are kinematic singularities that are reflected in a change of the instantaneous DOF. The local analysis of a linkage, aiming at determining the instantaneous and finite mobility in a given configuration, hence needs to consider the c-space geometry as well as the constraint system.
A method for the local analysis is presented based on a higher-order local approximation of the c-space adopting the concept of the tangent cone to a variety. The latter is the best local approximation of the c-space in a general configuration. It thus allows for investigating the mobility in regular as well as singular configurations. Therewith the c-space is locally represented as an algebraic variety whose degree is the necessary approximation order. In regular configurations the tangent cone is the tangent space. The method is generally applicable and computationally simple. It allows for a classification of linkages as overconstrained and underconstrained, and to identify singularities.
Visual Performance Maps for Human Choice in Hybrid Electric Vehicle’s In-Wheel Motors: Part II — Operation, Maintenance, and Refreshment Criteria
Authors: Lee Hoon , Ashok Pradeepkumar , Tesar Delbert 
Published: January 2016

Part I of this paper demonstrated how different human choices affect the selection of all basic components of a Hybrid Electric Vehicles (HEV) equipped with four-independent In-Wheel Motors (IWM) based on detailed human needs structured by visual performance maps to guide the customer in terms of purchase criteria: cost, weight, power, acceleration, gradeability, braking, handling, ride comfort, efficiency, and durability.
This Part II discusses ten operation criteria: cornering force margin, roll angle, sideslip angle, lateral acceleration, slip angle, yaw rate, acceleration force margin, braking force margin, pitch angle, and travel range. These visual performance maps show the effects of HEV weight on acceleration, braking, and cornering maneuvers under various road conditions (i.e., dry asphalt, wet asphalt, snowy or icy road) which are evaluated and compared based on the implementation of a nonlinear 14 DOF full-vehicle model based on ride (7 DOF), handling (3 DOF), tire (4 DOF), slip ratio, slip angle, and the tire magic formula. In addition, this paper demonstrates how different human choices affect the HEV’s expected performance. Lastly, maintenance and refreshment criteria are presented and explained.
In Vivo In Situ Experimentation Projects by Innovative Cleantech Start-Ups in Paris
Authors: Bekhradi Alborz , Yannou Bernard , Cluzel François , Chabbert Frédérique , Farel Romain 
Published: January 2016

Cities play an essential role in facilitating and supporting the real-world experimentations (for instance in public spaces with real users) of innovative products and services in the field of clean technologies. In this respect, the City of Paris has implemented an experimentation mechanism to help innovative start-ups improving their solutions and robustifying their business models in a multi-stakeholder eco-system. Nonetheless, a primary investigation demonstrated that the efficiency of these in vivo in situ experimentations have means of being improved.
To deal with this issue, the current paper proposes a critical review and a characterization of the existing projects related to clean technology and sustainability themes. A study over 25 experimentation projects results in identifying matches and mismatches between the expectations and the obtained results of tests by innovative start-ups. We have statistically demonstrated that the most important purpose of running experimentation projects by start-ups is to test and build a relevant “stakeholders network” around their businesses. Furthermore, we have assessed the influence of these experimentations on the design of innovative products.
Experimental and Numerical Investigation of Automotive Aerodynamics Using DrivAer Model
Authors: Miao Lu , Mack Steffen , Indinger Thomas 
Published: January 2016

The use of experimental and numerical investigation to predict the aerodynamic characteristics of road vehicles is a standard practice in automotive design and development. Fundamental research has been often conducted on generic models with limited applicability to realistic cars. The DrivAer model developed in TU München possesses more representative car features. To encourage the use of the DrivAer model in independent research work, the experimental results and some numerical results were published.
In this paper, a new developed wind tunnel setup of the DrivAer model was introduced. A new suspension system was designed in such a way that drag and lift force could be measured whilst the wheels are rolling on the moving ground without wheel struts (In this paper we call it wheels-on setup). The more close-truth experimental results of different rear end configurations were obtained. The lift force of the total model was firstly obtained. Additionally, the influences of the wheel struts and top sting were studied.
Numerical investigation for performing finite-volume-based Reynolds-averaged Navier-Stokes (RANS) for the prediction of aerodynamic forces of passenger vehicles developed was presented, using the open-source CFD toolbox OpenFOAM®.
Validation of the predictions was done on the basis of detailed comparisons to experimental wind tunnel data, both of the basic body (wheelhouse covered and without wheels) and the new wheels-on model. Results of drag coefficient were found to compare favourably to the experiments.