bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of an outpatient protocol in the treatment of canine parvoviral enteritis
Authors: Venn Emilee C. , Preisner Karolina , Boscan Pedro L. , Twedt David C. , Sullivan Lauren A.
Published: December 2016

Objective

To compare 2 treatment protocols (standard in‐hospital versus modified outpatient) in affecting the duration of treatment or survival of dogs with parvoviral enteritis.

Design

Prospective, randomized study.

Setting

University teaching hospital.

Animals

Client‐owned dogs with naturally acquired parvovirus were randomized to receive either an inpatient (n = 20) or outpatient (n = 20) treatment protocol.

Interventions

Both groups received intravenous (IV) fluid resuscitation and correction of hypoglycemia at hospital admission. Following stabilization, basic inpatient interventions included administration of IV fluids, administration of cefoxitin (22 mg/kg IV q 8 h), and maropitant (1 mg/kg IV q 24 h). Basic outpatient interventions (provided in‐hospital) included administration of subcutaneous (SC) fluid (30 mL/kg q 6 h), administration of maropitant (1 mg/kg SC q 24 h) and cefovecin (8 mg/kg SC once). Using daily electrolyte and glucose evaluations, dextrose and potassium supplementation was provided intravenously (inpatients) or orally (outpatients) as indicated. Rescue criteria were used in both groups for analgesia and nausea. All dogs were syringe fed a commercial canine convalescence diet (1 mL/kg PO q 6 h) until voluntary appetite returned.

Measurements and Main Results

Protocol success, defined as survival to hospital discharge, was 90% (18/20) for the inpatient group compared to 80% (16/20) for the outpatient group (P = 0.66). There was no difference detected in duration of hospitalization for inpatient dogs (4.6 ± 2 days) versus outpatient dogs (3.8 ± 1.8 days, P = 0.20). Metabolic disturbances were frequent in the outpatient group, with 50% of dogs requiring dextrose supplementation and 60% of dogs requiring potassium supplementation.

Conclusions

An outpatient protocol may be a reasonable alternative for dogs that cannot receive standard in‐hospital treatment for parvoviral enteritis. Diligent supportive care and monitoring are still required to optimize treatment of dogs with parvoviral enteritis in an outpatient setting.
Seroprevalence and Risk Factors for Leptospira Seropositivity in Beef Cattle, Sheep and Deer Farmers in New Zealand
Authors: Sanhueza J. M. , Heuer C. , Wilson P. R. , Benschop J. , Collins‐Emerson J. M.
Published: December 2016

Leptospirosis is a global zoonosis that in New Zealand affects primarily people occupationally exposed to livestock. The objective of this study was to estimate the seroprevalence of five Leptospira serovars in farmers working on cattle, sheep and deer farms that had the serological status of animals previously assessed and to identify risk factors for farmer seropositivity. A total of 178 farmers from 127 properties participated in the study. Blood samples were tested using the microscopic agglutination test (MAT) for the presence of antibodies to Leptospira. Samples with a MAT titre ≥48 were considered seropositive. Using Bayesian statistical analysis, the median seroprevalence of Leptospira, all serovars combined, was estimated to be 6.6% (95% probability interval (PI) 3.6–10.9%). Risk factors associated with seropositivity were assisting deer or cattle calving, farming deer, having ≥25% of flat terrain and high abundance of wild deer on farm, while high possum abundance on farm was negatively associated with seropositivity. No association was observed between farmer serostatus and previously recorded livestock serology. Leptospira seropositivity was associated with influenza‐like illness of farmers (RR = 1.7; 95% PI 1.0–2.5). Assuming a causal relationship, this suggested an annual risk of 1.3% (95% PI 0.0–3.0%) of influenza‐like illnesses due to Leptospira infection in the population of farmers. The association between seropositivity and disease can be used to estimate the public health burden of leptospirosis in New Zealand. Identifying and understanding risk factors for Leptospira seropositivity can inform preventive measures, hence contributing to the reduction of leptospirosis incidence in farmers.
Reservoir‐Driven Heterogeneous Distribution of Recorded Human Puumala virus Cases in South‐West Germany
Authors: Drewes S. , Turni H. , Rosenfeld U. M. , Obiegala A. , Straková P. , Imholt C. , Glatthaar E. , Dressel K. , Pfeffer M. , Jacob J. , Wagner‐Wiening C. , Ulrich R. G.
Published: December 2016

Endemic regions for Puumala virus (PUUV) are located in the most affected federal state Baden‐Wuerttemberg, South‐West Germany, where high numbers of notified human hantavirus disease cases have been occurring for a long time. The distribution of human cases in Baden‐Wuerttemberg is, however, heterogeneous, with a high number of cases recorded during 2012 in four districts (H districts) but a low number or even no cases recorded in four other districts (L districts). Bank vole monitoring during 2012, following a beech (Fagus sylvatica) mast year, resulted in the trapping of 499 bank voles, the host of PUUV. Analyses indicated PUUV prevalences of 7–50% (serological) and 1.8–27.5% (molecular) in seven of eight districts, but an absence of PUUV in one L district. The PUUV prevalence differed significantly between bank voles in H and L districts. In the following year 2013, 161 bank voles were trapped, with reduced bank vole abundance in almost all investigated districts except one. In 2013, no PUUV infections were detected in voles from seven of eight districts. In conclusion, the linear modelling approach indicated that the heterogeneous distribution of human PUUV cases in South‐West Germany was caused by different factors including the abundance of PUUV RNA‐positive bank voles, as well as by the interaction of beech mast and the proportional coverage of beech and oak (Quercus spec.) forest per district. These results can aid developing local public health risk management measures and early warning models.
Development of SNTA Code System for SCWR Core Steady-State Analysis
Authors: Wang Lianjie , Zhao Wenbo , Yang Ping , Ma Yongqiang , Lu Di
Published: December 2016

A coupled neutronics/thermal-hydraulics (N/T) three-dimensional code system SNTA is developed for supercritical water-cooled reactor (SCWR) core steady-state analysis by modular coupling the improved neutronics nodal methodological code and SCWR thermal-hydraulic subchannel code. The appropriate outer iteration coupling method and self-adaptive relaxation factor are proposed for enhancing convergence, stability, and efficiency of coupled N/T calculation. The steady-state analysis for the CSR1000 core is applied to verify SNTA. The results calculated by SNTA agreed well with those by CASIR and SRAC. SNTA is more efficient than CASIR and SRAC, where the neutronics modules are based on the finite-difference method. The numeric results show that SNTA can be applied to SCWR core steady-state analysis and core concept design.
Collapse Criterion for the CANDU 6 Calandria Vault Floor During a Severe Accident
Authors: David Robert
Published: December 2016

The thickness at which the calandria vault floor in a generic CANDU 6 nuclear reactor may collapse while undergoing molten core–concrete interaction (MCCI) was studied using an approximate analytical model and a finite-element model. It was confirmed that the collapse criterion of 0.45 m floor thickness that is currently used in severe accident analyses is adequate. The estimated timing of collapse is subject to uncertainty of several hours.
Novel Tribological Behavior of Hybrid MWCNTs/MLNGPs as an Additive on Lithium Grease
Authors: Ashour M. E. , Osman T. A. , Khattab A. , Elshalakny A. B.
Published: December 2016

The goal of this paper is to investigate tribological characteristics of nanographene platelets and hybridized nanocomposite of multiwalled carbon nanotubes (MWCNTs)/multilayer nanographene platelets (MLNGPs)/lithium based-grease. Characterization is done through high resolution transmission electron microscopy (TEM) and X-ray diffraction. While grease properties were tested using Falex four-ball testing machine. Scanning electron microscopy (SEM) and energy dispersive X-ray diffraction (EDX) were utilized to characterize the lubrication mechanism and the worn surface. The results showed that 1% of MLNGPs is the optimum concentration. Wear scar diameter (WSD) was reduced by 66%, friction coefficient was reduced by 91%, while maximum nonseizer load was increased by 90 kg over ordinary lithium grease. Hybrid MWCNTs\MLNGPs were studied, and the optimum ratio of MLNGPs to MWCNTs was found to be 4:1.
Comparative Dynamic Control of SynRM Servodrive Continuously Variable Transmission System Using Blend Amend Recurrent Gegenbauer-Functional-Expansions Neural Network Control and Altered Artificial Bee Colony Optimization
Authors: Lin Chih-Hong
Published: December 2016

In comparison control performance with more complex and nonlinear control methods, the classical linear controller is poor because of the nonlinear uncertainty action that the continuously variable transmission (CVT) system is operated by the synchronous reluctance motor (SynRM). Owing to good learning skill online, a blend amended recurrent Gegenbauer-functional-expansions neural network (NN) control system was developed to return to the nonlinear uncertainties behavior. The blend amended recurrent Gegenbauer-functional-expansions NN control system can fulfill overseer control, amended recurrent Gegenbauer-functional-expansions NN control with an adaptive dharma, and recompensed control with a reckoned dharma. In addition, according to the Lyapunov stability theorem, the adaptive dharma in the amended recurrent Gegenbauer-functional-expansions NN and the reckoned dharma of the recompensed controller are established. Furthermore, an altered artificial bee colony optimization (ABCO) yields two varied learning rates for two parameters to find two optimal values, which helped improve convergence. Finally, the experimental results with various comparisons are demonstrated to confirm that the proposed control system can result in better control performance.
Dropwise Condensation on/in High Roughness Structures
Authors: Cai Steve Q. , Bhunia Avijit
Published: December 2016

Water droplets on bio-mimicked hierarchical roughness exhibit superhydrophobic properties, such as large contact angles, minor dynamic hysteresis, and high mobility. Vapor condensation on such superhydrophobic surface enables rapid condensate removal and surface cleaning, thereby significantly enhancing the heat transfer coefficient. In this paper, research attention is given to dropwise condensation on/in specially designed one-tier and hierarchical roughness structures. Utilizing a normal optical tomographic system composed of a Sensi-Cam and a Nikon microscope, close-up visualization is conducted to characterize small condensate droplets, in size of a few micrometers, between structural units of roughness. Experimental snapshots show that, within the one-tier roughness, condensate droplets tend to stick to surrounding structures. Low mobility of these droplets extends their residence time, and therefore increases their average diameter. In comparison, surface energy of the hierarchical structure is significantly reduced. As a result, small condensate droplets behave nonsticky to their surroundings, which enable rapid drain of the droplets and accomplish self-cleaning of the structure. Because of high mobility, the droplet average diameter in the two-tier structure is smaller than those in the one-tire roughness. Condensation sites reach the maximum in the middle of the structure where dew point of moisture is reached. Less condensation droplets on both the top and bottom of the roughness are blamed to the unsaturated moisture and the reduced humidity, respectively.
Direct Integration Method for Time-Delayed Control of Second-Order Dynamic Systems
Authors: Wen Zhijie , Ding Ye , Liu Pinkuan , Ding Han
Published: December 2016

A direct integration method (DIM) for time-delayed control (TDC) is proposed in this research. For a second-order dynamic system with time-delayed controllers, a Volterra integral equation of the second kind is used instead of a state derivative equation. With the proposed DIM where matrix exponentials are avoided, semi-analytical representation of the Floquet transition matrix for stability analysis can be derived, the stability region on the parametric space comprising control variables can also be plotted. Within this stability region, optimal control variables are subsequently obtained using a multilevel conjugate gradient optimization method. Further simulation examples demonstrated the superiority of the proposed DIM in terms of computational efficiency and accuracy, as well as the effectiveness of the optimization-based controller design approach.
Effects of Damköhler Number on Methane/Oxygen Tubular Combustion Diluted by N2 and CO2
Authors: Shi Baolu , Chu Qingzhao , Chen Run
Published: December 2016

To fundamentally elucidate the mixing and its effects on the characteristics of methane/oxygen flame in a rapidly mixed tubular flame burner, experiments were conducted under various oxygen mole fractions and flow rates. Two inert gases of nitrogen and carbon dioxide were used, respectively. The inert gas was added to both the oxidizer and fuel slits to maintain the oxidizer/fuel injection velocity ratio near unity. Based on flow visualization, the mixing process around injection slits and that in the axial downstream were discussed. The Damköhler number (Da1), defined as the ratio of molecular mixing time to reaction time, was selected as a parameter to quantitatively examine the criterion for the establishment of tubular flame from low to ultrahigh oxygen mole fractions (0.21–0.86). The mixing around slit exit determined the tubular flame establishment. Due to a flow time between two neighboring injection slits of fuel and oxidizer, part of the fuel was mixed in the downstream swirling flow, resulting in luminous helical structures. Hence, the Damköhler number (Da2), defined as the flow to the reaction time ratio, was examined. Detailed observations indicated that when Da2 was smaller than unity, the flame was uniform in luminosity, whereas the flame was nonuniform when Da2 ≥ 1. The value of Da2 was about 1.5 times as Da1; however, they correspond to different mixing zones and Da2 can be more easily calculated. The differences in flame stability between N2 and CO2 diluted combustion were also studied.
Traumatic Brain Injury Caused by +Gz Acceleration
Authors: Shafiee Abbas , Ahmadian Mohammad Taghi , Hoviattalab Maryam
Published: December 2016

Traumatic brain injury (TBI) has long been known as one of the most anonymous reasons for death around the world. This phenomenon has been under study for many years and yet it remains a question due to physiological, geometrical and computational complexity. Although the modeling facilities for soft tissue have improved, the precise CT-imaging of human head has revealed novel details of the brain, skull and meninges. In this study a 3D human head including the brain, skull, and meninges is modeled using CT-scan and MRI data of a 30-year old human. This model is named “Sharif University of Technology Head Trauma Model (SUTHTM)”. By validating SUTHTM, the model is then used to study the effect of +Gz acceleration on the human brain. Damage threshold based on loss of consciousness in terms of acceleration and time duration is developed using Maximum Brain Pressure criteria. Results revealed that the Max. Brain Pressure ≥3.1 are representation of loss of consciousness. 3D domains for the loss of consciousness are based on Max. Brain Pressure is developed.
Understanding the Impact of Expertise on Design Outcome: An Approach Based on Concept Inventories and Item Response Theory
Authors: Shergadwala Murtuza , Kannan Karthik N. , Panchal Jitesh H.
Published: December 2016

Research on expertise in design has focused primarily on understanding expert-novice differences. Although it is well established that experts perform better than novices, there is a lack of formal methods to quantify the potential impact of expertise on the quality of design outcomes. The research question addressed in this paper is: How can the impact of expertise on the quality of design solutions be quantified? Quantifying such impacts can be of particular importance in product development, recruitment processes and design competitions. We utilize an approach based on Item Response Theory (IRT) and Concept Inventories (CI) for expertise quantification. We then investigate and validate the impact of expertise on solution quality through a behavioral experiment involving a track design problem. The results highlight the usefulness of the proposed approach and provide a functional relationship between expertise and solution quality. We also observe behavioral differences between participants with varying scores on a test taken in the behavioral experiment. The proposed approach could be used in the future work to quantify learning.
Dynamic Spatial Context Computation for Time-Varying Process Scenarios
Authors: Horváth Imre , Li Yongzhe , Rusák Zoltán , Van Der Vegte Wilhelm Frederik , Zhang Guangjun
Published: December 2016

There are many real life processes whose smart control requires processing context information. Though the issue of processing varying context information has been addressed in the literature, domain independent solutions that can support reasoning and decision making according to time-varying process scenarios in multiple application fields are scarce. This paper proposes a method for dynamic context computation concerning spatial and attributive information. Context is interpreted as a body of information dynamically created by a pattern of entities and relationships over a history of situations. Time is conceived as a causative force capable of changing situations, and acting on people and objects. The invariant and variant spatial information is captured by a two-dimensional spatial feature representation matrix. The time-dependent changes in the context information are computed based on a dynamic context information management hyper-matrix. This humble but powerful representation lends itself to a quasi-real time computing and is able to provide information about foreseeable happenings over multiple situations. The paper uses the practical case of evacuation of a building in fire both as an explorative case for conceptualization of the functionality of the computational mechanism and as a demonstrative and testing application. Our intention is to use the dynamic context computation mechanism as a kernel component of a reasoning platform for informing cyber physical systems.
Highly Compressible Origami Bellows for Harsh Environments
Authors: Butler Jared , Morgan Jessica , Pehrson Nathan , Tolman Kyler , Bateman Terri , Magleby Spencer P. , Howell Larry L.
Published: December 2016

The design and testing of a highly compressible origami bellows for harsh environments is described. Several origami patterns are evaluated and the Kresling fold pattern was customized to constraints and selected for use in the bellows design. Origami bellows were prototyped in five different materials and tested in fatigue, thermal cycling, ablation, and radiation. Tested bellows show good fatigue life exceeding 100,000 cycles for some materials and resilience to potential harsh environmental conditions such as thermal cycling, abrasion, and high radiation. The bellows can be designed to fit within a given inner and outer diameter and stroke length depending on the design requirements. The origami bellows shows promise for space application and as an adequate replacement for current metal bellows due to its high compressibility and low mass.
Additive Manufacturing of Subject-Specific Spine Model for In-Vitro Intrathecal Drug Delivery Study
Authors: Lu Lu , Tangen Kevin , Gabor Theodore , Pan Yayue , Linninger Andreas , Purandare Neil
Published: December 2016

Intrathecal (IT) drug delivery is a preferred treatment for chronic pain, brain cancers and spasticity. However, the application of IT drug delivery treatment is still limited by the large patient-to-patient variations and numerous kinds of rare genetic diseases. A fast, relatively cheap and subject-specific in-vitro method to study the drug bio-dispersion mechanism and optimize the intrathecal drug therapies for individual patients is in great need. In this study, we will investigate the model design and additive manufacturing process for producing a subject-specific spine model, which will simulate the interaction of the real human spine with cerebrospinal fluid (CSF). Research issues including watertight 3D printable model construction and 3D printing of anatomical accurate, physiological functional spine models are discussed in this paper. A pipeline of additive manufacturing in-vitro subject-specific models for study of cerebrospinal fluid and drug transport in spine is presented.
The Effects of Subsonic Airflow on the Nonlinear Vibration Properties of a Composite Laminated Plate
Authors: Meng Ling-Chang , Li Feng-Ming , Zhang Wei
Published: December 2016

The nonlinear aeroelasticity of an orthotropic composite laminated plate subjected to axial subsonic airflow and transverse harmonic excitation is investigated. Considering the von Karman’s large deformation, the partial differential equation of motion of the structural system is established using the Hamilton’s principle and reduced into a system of ordinary differential equations through Galerkin’s method. The aerodynamic pressure induced by the transverse motion of the plate is derived from the linear potential flow theory. For the structural system, the Melnikov’s method and numerical simulations are adopted to investigate the influence of the flow velocity on the chaotic motion of the plate for a given external harmonic excitation. The results show that when the flow velocity increases, the plate will be unstable, and the chaotic motion of the laminated plate will happen.
The Application of Geometric Constraint Programming to the Design of Stephenson III Dwell Linkages
Authors: Mirth John A.
Published: December 2016

Stephenson III linkages provide a means to create an approximate dwell mechanism without the use of cams. The dwell cycle is created by first choosing or designing a four-bar linkage that contains a coupler path with a near circular segment. An external dyad is attached to the coupler point such that the center of the floating link of the dyad coincides with the center of the circular portion of the coupler curve. This connection produces a dwell in the external dyad as the four-bar linkage traverses the circular portion of the coupler curve. This paper demonstrates how the necessary conditions for a dwell linkage can be obtained with the use of Geometric Constraint Programming (GCP). The construction process is initiated by using GCP techniques to develop a four-bar linkage with a minimum of four path points that lie on a prescribed arc. This part of the problem also uses GCP to apply additional constraints to the four-bar linkage. These include the application of appropriate link dimensions to achieve a Grashof linkage with a crank input, and the specification of the required crank rotation angle during the dwell cycle of the mechanism. Once the four-bar is defined, an external dyad is attached to the coupler link of the four-bar to produce the specified dwell characteristics. The dwell dyad may include for its output either a rotational link whose range of angular travel is defined, or a sliding link whose range of linear motion is defined. GCP techniques are used to enforce a specified range of motion for the output dyad through the use of an instant center construction to define the limits of travel of the four-bar coupler curve relative to the dwell ground pivot. If the dwell dyad is designed for angular displacements, the construction is completed by using GCP to define the desired angular displacement of the dwell link, resulting in the specification of the link length and ground pivot location. If the dwell dyad is a linear (slider) output, the final part of the GCP construction is used to define the desired length of linear travel, which results in the complete specification of the slider path and angle. The GCP techniques are presented with the development of an example, with sample results presented for a dwell mechanism with a rotational dwell cycle, and also for a dwell mechanism with a linear (slider) dwell output. The example demonstrates the ability of GCP methods to use standard solid-modeling software to obtain Stephenson III linkages with dwells that deviate from the dwell position by less than 0.1% of total motion.
Optimization Algorithm Comparison for In-Plane Flexible Ring Tire Model Parameter Identification
Authors: Li Bin , Yang Xiaobo , Yang James , Zhang Yunqing , Ma Zeyu
Published: December 2016

The parameter values used in a tire model directly determine the prediction accuracy of the model. Poorly identified parameters lead to incorrect prediction of tire performances. The optimization algorithm used for parameter identification has a huge impact on the quality of the identified parameters for a tire model. In this paper, four different optimization algorithms in MATLAB, including local optimization algorithms (fminsearchcon and patternsearch) and global optimization algorithms (particleswarm and GA-genetic algorithm), are applied to identify the parameters of a newly proposed in-plane flexible ring tire model based on one cleat experiment results, respectively. Their performances are compared in terms of the prediction accuracy, efficiency and some other aspects. After the comparison, the most suitable optimization algorithm for tire model parameter identification is obtained. Finally, the parameters that are identified based on the set of parameters from the most suitable algorithm are used to predict the other cleat test conditions to further validate the tire model.
Multi-Objective Optimization of Human Gait With a Discomfort Function
Authors: Kwon Hyun-Jung , Chung Hyun-Joon , Xiang Yujiang
Published: December 2016

The objective of this study was to develop a discomfort function for including a high DOF upper body model during walking. A multi-objective optimization (MOO) method was formulated by minimizing dynamic effort and the discomfort function simultaneously. The discomfort function is defined as the sum of the squares of deviation of joint angles from their neutral angle positions. The dynamic effort is the sum of the joint torque squared. To investigate the efficacy of the proposed MOO method, backward walking simulation was conducted. By minimizing both dynamic effort and the discomfort function, a 3D whole body model with a high DOF upper body for walking was demonstrated successfully.
Design of Compliant Universal Joint With Linear Stiffness
Authors: Xie Yan , Pan Bo , Pei Xu , Yu Jingjun
Published: December 2016

This paper mainly presents a novel compliant universal joint with linear stiffness (CUJ-LS). This new type of architecture can maintain the linear stiffness while realizing two rotational DOFs. And the planar topology ensures that the rotation axis remains through the center of the moving platform, thus deducing the moment of inertia. According to the Freedom and Constrain Topology (FACT) theory, this paper firstly proposes a topological structure of the compliant universal joint. Then the stiffness model is established by the Beam Constraint Model (BCM) and the condition of achieving linear stiffness is derived: λ = 0.1273/0.8727. By introducing the intermediate platforms, the linear stiffness in two directions of rotation is realized. Finally, FEA method is implemented to verify and analyze the rotation performances of this compliant universal joint. Verified characteristics provide conditions for the applications of compliant universal joint in laser communication, antenna pointing, infrared tracking and aiming, laser processing, precision measurement and other fields which require high-speed, high-acceleration and high precision characteristics.
Prediction of Cutting Forces of Solid End Mills With Differential Helix Angles: A Numerical Approach
Authors: Westermann Hans-Henrik , Thorenz Benjamin , Müller Robert , Steinhilper Rolf
Published: December 2016

Solid end mills with multi-section cutting edges and variable helix angles are available for application. New types of solid end mills for low energy consumption have recently been developed. These so-called Low Power Cutting (LPC)-Tools are characterized by differential helix angles.

Compared to solid end mills with variable helix angles, the new differential helix angles change their pitch continuously over the cutting edge length. Due to this fact the cutting conditions are not in a constant state during the revolution of the cutting tool. Existing mathematical approaches for the calculation of cutting forces only consider constant helix angles in milling operations.

This paper describes an approach for the prediction of cutting forces for differential helix angles. The developed mathematical model is based on geometrical considerations. Due to a continuously changing pitch over the cutting edge length a numerical approach for the mathematical model is chosen.
The Comparison of Four Pressure-Thermal Models of Oil Film Bearing With the Non-Newtonian and Temperature-Viscosity Effects
Authors: Liang Feng , Xu Quanyong , Lan Xudong , Zhou Ming
Published: December 2016

The thermohydrodynamic analysis of oil film bearing is essential for high speed oil film bearing. The temperature field is coupled with the pressure field. The numerical model can be built or chosen according to the complexity of the objects and requirement of the accuracy. In this paper, four pressure-thermal (P-T) models are proposed, which are zero-dimensional temperature field coupled with Reynolds equation (0D P-T model), two-dimensional temperature field coupled with Reynolds equation (2D P-T model), two-dimensional temperature with third dimensional correction coupled with Dawson equation (2sD P-T model), three-dimensional temperature field coupled with Dawson equation (3D P-T model). The non-Newtonian and temperature-viscosity effects of the lubrication oil are considered in all the four models. Two types of cylindrical journal bearing, the bearing with/without axial grooves, are applied for the simulation. All the simulated cases are compared with the solutions of the CFX. The results show that the 0D P-T model fails to predict the behavior of high speed bearing; The 2D and 2sD P-T model have an acceptable accuracy to predict the performance of the bearing without grooves, but are not able to simulate the P-T field of the bearing with grooves because of the under-developed thermal boundary layer; The 2sD P-T model shows a great improvement when calculating the pressure field compared with the 2D P-T model; the 3D P-T model coincides well with the CFX at any condition. The comparison of these four models provides a reference to help designer choose a proper numerical model for a certain project.
A Single Universal Construction Rule for the Structural Synthesis of Mechanisms
Authors: Hahn Elad , Shai Offer
Published: December 2016

In the field of structural synthesis of mechanisms several synthesis methods have been developed using different approaches. One of the more interesting approaches was that of bottom-up construction via the combination of modular structural groups, known as Assur groups. This approach is combined with new graph representations of mechanisms taken from rigidity theory, capable of representing all the different types of planar and spatial mechanisms. With the strong mathematical base of rigidity theory, a new synthesis method is proposed based on Assur groups, which are reformulated in terms of graph theory and renamed Assur Graphs. Using a single universal construction rule, Assur Graphs of different types and of any number of links are constructed, creating a complete set of building blocks for the synthesis of feasible mechanisms. As its name implies, the single universal construction is applicable for mechanisms of all types of joints and links, for planar or spatial motion.
Construction of Baranov Trusses Using a Single Universal Construction Rule
Authors: Hahn Elad , Shai Offer
Published: December 2016

The kinematic structure of Baranov trusses has been widely studied in the field of mechanism theory. Baranov trusses are seen as the fundamental planar linkages which are a basis for all other planar linkages. As such, they have been used for synthesis of mechanisms as well as their analysis. However, up until now only a limited number Baranov trusses are known and cataloged. In this paper, a method is proposed for generation of Baranov trusses using a new graph representation suitable for linkages of the sort. This method, named the Universal construction rule, is capable of generating a complete set of all feasible Baranov trusses with any number of links. The method has been proven using a mathematical basis from rigidity theory. It is based on the correspondence between Baranov trusses and Assur groups, which are reformulated in terms of graph theory to be known as Assur graphs.
Model-Based Hazard an Propagation Assessment of Product Changes
Authors: Roth Michael , Gantenbein Felix
Published: December 2016

The current markets are characterized by an increasing demand for individual products, increasing product complexity and stricter safety regulations. This results in large hazard and safety analysis efforts for each individual product variant. One possible solution to reduce these efforts is the automation of analyses and a preliminary assessment of individual changes.

Therefore, several approaches are published to e.g. model safety aspects or evaluate change propagations. However, the approaches fail to directly establish the connection between product changes and safety aspects by a common model.

This paper develops a method to identify and assess the potential hazard impact of product changes through a common static model. It builds on a graph-based product model and graph-rewriting. From the state of the art, suitable methods tools and principles are identified and evaluated. Based on this, requirements are derived. The capabilities of existing methods are assessed and the most suitable ones adapted and integrated to the method to assess the potential hazard impact of product changes (MBHPA).

The MBHPA reduces the complexity by providing two independent interconnected analyses. To evaluate the product changes, a static propagation analysis is provided. It uses defined graph-rewriting patterns to trace propagations and extract a propagation tree. The affected components in a second step can then be evaluated on their hazard potential. Again graph-rewriting patterns are applied to identify the connected hazards which are visualized in a hazard potential portfolio.

The MBHPA is implemented and evaluated with the industrial case of an automated coffee machine. The evaluation underlines that the MBHPA successfully identifies possible propagations and their effect on hazards from a static perspective. It helps to improve safety awareness and traceability and reduces the required experience.
Bioinspired Materials Design: An Assessment of Methods to Improve a Text Mining Algorithm for Identifying Biological Material Structural Design Principles
Authors: Tsenn Joanna , Linsey Julie S. , McAdams Daniel A.
Published: December 2016

Natural materials are able to achieve a wide range and combination of properties through the arrangement of the material’s components. These biological materials are often more effective and better suited to their function than engineered materials, even with the use of a limited set of components. By mimicking a biological material’s component arrangement, or structure, man-made bioinspired materials can achieve improved properties as well. While considerable research has been conducted on biological materials, identifying the beneficial structural design principles can be time-intensive for a materials designer. Previously, a text mining algorithm and tool were developed to quickly extract passages describing property-specific structural design principles from a corpus of materials journals. Although the tool identified over 90% of the principles (recall), many irrelevant passages were returned as well with approximately 32% of the passages being useful (precision). This paper discusses approaches to refine the program in order to improve precision. The text classification techniques of machine learning classifiers, statistical features, and part-of-speech analyses, are evaluated for effectiveness in sorting passages into relevant and irrelevant classes. Manual identification of patterns in the returned passages is also employed to create a rule-based method, resulting in an updated algorithm. An evaluation comparing the revised algorithm to the previously developed algorithm is completed using a new set of journal articles. Although the revised algorithm’s recall was reduced to 80%, the precision increased to 45% and the number of returned passages was reduced by 22%, allowing a materials designer to more quickly identify potentially useful structures. The paper concludes with suggestions to improve the program’s usefulness and scope for future work.
Analysis of Architectural Complexity for Product Family and Platform
Authors: Kim Gwang , Kwon Yunjung , Suh Eun Suk , Ahn Jaemyung
Published: December 2016

A product family is a set of products that are derived from common sets of parts, interfaces, and processes, known as the product platform. To reduce development time and procurement and operating costs of product platform based variants, the product platform can be designed after consideration of several characteristic, such as modularity, flexibility, sustainability and complexity. In this paper, the product platform is viewed from the perspective of system architecting. The architectural complexities of both the platform and its variants, which together constitute a product family, can be quantitatively assessed using a specifically tailored metric. This will aid system architects in designing product platforms and resulting product variants with an emphasis on reducing complexity. Architectural complexity management is demonstrated through a case study of a train bogie platform.
A Comprehensive Investigation of Ensembles of Gaussian-Based and Gradient-Based Transformed Reliability Analyses: When and How to Use Them
Authors: Lin Po Ting , Lu Wei-Hao , Lin Shu-Ping
Published: December 2016

In the past few years, researchers have begun to investigate the existence of arbitrary uncertainties in the design optimization problems. Most traditional reliability-based design optimization (RBDO) methods transform the design space to the standard normal space for reliability analysis but may not work well when the random variables are arbitrarily distributed. It is because that the transformation to the standard normal space cannot be determined or the distribution type is unknown. The methods of Ensemble of Gaussian-based Reliability Analyses (EoGRA) and Ensemble of Gradient-based Transformed Reliability Analyses (EGTRA) have been developed to estimate the joint probability density function using the ensemble of kernel functions. EoGRA performs a series of Gaussian-based kernel reliability analyses and merged them together to compute the reliability of the design point. EGTRA transforms the design space to the single-variate design space toward the constraint gradient, where the kernel reliability analyses become much less costly. In this paper, a series of comprehensive investigations were performed to study the similarities and differences between EoGRA and EGTRA. The results showed that EGTRA performs accurate and effective reliability analyses for both linear and nonlinear problems. When the constraints are highly nonlinear, EGTRA may have little problem but still can be effective in terms of starting from deterministic optimal points. On the other hands, the sensitivity analyses of EoGRA may be ineffective when the random distribution is completely inside the feasible space or infeasible space. However, EoGRA can find acceptable design points when starting from deterministic optimal points. Moreover, EoGRA is capable of delivering estimated failure probability of each constraint during the optimization processes, which may be convenient for some applications.
Structural Design and Forming Method of Single-Curved Surface Structure Based on Miura-Origami
Authors: Wang Hairui , Guo Chunfang , Li Yujie , Liu Yahua , Wang Minjie , You Zhong , Zhao Danyang
Published: December 2016

With the advantage of high adaptability, Miura-origami structure with curvature shows various engineering applications such as a sandwich between two stiff facings with curvature requirements and structural support to form a circular tube. In this research, a forming method of polymer circular tube with single-curved surface origami expressed by five parameters was established and its corresponding theory was solved considering forming rationality in actual manufacturing. The components of circular tube were fabricated by the vacuum forming process and then spliced together. We conducted numerical simulation to analyze the structural performance of the tube with five parameters and shown that these parameters have a great influence on energy absorbed performance. Finally, a male mold of a part with Arc Miura-origami structure was designed and fabricated. The parts with Arc Miura-origami were manufactured using vacuum forming process and then spliced and bonded together into a two-layer tube. This research may provide a method to design and fabricate Miura-origami structure with high efficiency and quality.
FEM-BEM Modeling and Experimental Verification of the Vibro-Acoustic Behaviour of a Section of Aircraft Fuselage
Authors: Koukounian Viken N. , Mechefske Chris K.
Published: December 2016

The aerodynamics of an aircraft in flight impose significant stresses upon the structure. Specifically, the mechanics of fluid flow are highly turbulent and, the layer around the aircraft, is referred to the turbulent boundary layer (TBL). The TBL incites a gradient of pressure fluctuations across the fuselage skin resulting in its vibration, and in turn, the generation of noise inside the passenger cabin. The investigation herein proposes a hybrid FEM-BEM modeling technique to predict the aforementioned vibro-acoustic response and an experimental methodology to verify the results (following ASTM and ANSI international testing standards). The described expectations required construction of an acoustic facility consisting of a reverberation chamber and a semi-anechoic room, the development of DAQ software using LabVIEW, an assembly of DAQ hardware using National Instruments products, and the post-processing of test data using Microsoft Excel. The principal quantity of interest is transmission loss (though insertion loss, absorption and other metrics are also calculated). Two panels (0.04in (40thou) and 0.09in (90thou) in thickness) were simulated and tested (0.01in = 1thou). The calculated error of the proposed methodology is within a maximum of 5dB, with an average of 1dB. Ongoing work is investigating complex constructions and the use of damping materials.
A State-Behavior-Function Based Approach for Functional Modeling of Multi-State Systems and its Application
Authors: Chen Yong , Zhao Meng , Huang Jian
Published: December 2016

As a critical task of conceptual design, function modeling is regarded as a design activity aimed at establishing the functional model(s) of a technical system. Existing functional modeling approaches usually employ a static diagram to represent the functional structure of a technical system, which, on one hand, cannot allow a system engineer to explicitly represent a system that has multiple states, and on the other hand, cannot effectively support system state analysis. Therefore, this paper proposes a state-behavior-function-based approach for achieving the function modeling of multi-state systems to address the above issues. It first introduces the state-behavior-function-based models for representing an object (i.e., a component or a system). Hereby, a state of an object refers to the internal configuration of the object, a behavior represents the state (i.e., configuration) change of the objet, and a function denotes the intended action that the object exerts on one or multiple flows in the environment of the object. This research then proposes an object-based approach for simulating the functional processes in a multi-state system. With this approach, each component of a system is treated as an active object (rather than a static block node in the functional diagram), which can be in different states and can interact with other components or subsystems through the input and output flows. A prototype system is then developed, which cannot only be used for function modeling, but also can be employed for system state simulation. The function modeling of a washing machine and its system state simulation has been employed to illustrate the proposed approach.
Kinematic Analysis of Conventional and Multi-Mode Spatial Mechanisms Using Dual Quaternions
Authors: Kong Xianwen
Published: December 2016

Although kinematic analysis of conventional mechanisms is a well-documented fundamental issue in mechanisms and robotics, the emerging reconfigurable mechanisms and robots (or mechanisms and robots with multiple operation modes) require re-examining this fundamental issue. Recent advances in mathematics, especially algebraic geometry and numerical algebraic geometry, make it possible to develop an efficient method for the kinematic analysis of not only conventional mechanisms and robots but also reconfigurable mechanisms and robots. This paper first presents a method for setting up a set of kinematic loop equations for mechanisms using dual quaternions. Using this approach, a set of kinematic loop equations of a spatial mechanism is composed of six equations. The effectiveness of the proposed kinematic loop equations is then demonstrated by deriving the explicit input-output equations of a line symmetric 1-DOF (degree-of-freedom) 7R single-loop spatial mechanism, the re-configuration analysis of a novel multi-mode 1-DOF 7R spatial mechanism. In the former case, an explicit input-output equation of degree 8 is derived. In the latter case, it is found that the 7R multi-mode mechanism has three motion modes, including a planar 4R mode, an orthogonal Bricard 6R mode, and a plane symmetric 6R mode. Unlike the 7R multi-mode mechanisms in the literature, the 7R multi-mode mechanism presented in this paper does not have a 7R mode in which all the seven R joints can move simultaneously.
Wearable On-Demand Oxygen Therapy
Authors: Hebbale Chandan , Fu Katherine
Published: December 2016

Oxygen concentration devices currently on the market have many shortcomings. They are bulky and difficult to carry. They alter a patient’s outward image with a visual mark of disability. They do not change oxygen delivery in any way to adjust to the patient’s health. They also lack indicators to help the patient decide when to begin or end a therapy session. Some patient’s decide not to take oxygen therapy as a result of these shortcomings. Those that use these devices may receive over oxygenation or under oxygenation due to the mentioned pitfalls. Any of the shortcomings described can be life threatening to the patient.

The present innovation is a proposed system for oxygen delivery that adjusts flowrate based on the patient health and requires no user input to begin or end a therapy session. This paper presents a unique wearable device design for delivering oxygen in a pressure based concentration system.