bluuebunny/crossref_metadata_2025 huggingface dataset:
Coupled Multibody Dynamics and Discrete Element Modeling of Vehicle Mobility on Cohesive Granular Terrains
Authors: Wasfy Tamer M. , Wasfy Hatem M. , Peters Jeanne M.
Published: January 2015

Multibody dynamics and the discrete element method (DEM) are integrated into one solver for predicting the dynamic response of ground vehicles which run on wheels and/or tracks on cohesive soft soils (such as mud and snow). Multibody dynamics techniques are used to model the various vehicle components and connect those components using various types of joints and contact surfaces. A penalty technique is used to impose joint and normal contact constraints. An asperity-based friction model is used to model joint and contact friction. A soft cohesive soil material model (that includes normal and tangential inter-particle force models) is presented that can account for soil compressibility, plasticity, fracture, friction, viscosity, cohesive strength and flow. A Cartesian Eulerian grid contact search algorithm is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between the particles and polygonal contact surfaces. The governing equations of motion are solved along with joint/constraint equations using a time-accurate explicit solution procedure. Numerical simulations of a typical vehicle going over a slopped soft soil terrain are presented to demonstrate the integrated solver. The solver can be used in vehicle design optimization.
Logic-Based Evaluation Metrics for Concept Evaluation
Authors: Liu Ang , Wei Wei , Lu Stephen C.-Y.
Published: January 2015

Synthesis is a common activity in engineering design. It is widely recognized to be important to the whole engineering design process in general, and to the early design stages in particular. In the past, however, there remains lack of a set of rigorous metrics to evaluate the effectiveness of performing design synthesis in conceptual design. Based on relevant studies of abductive reasoning in logic, this paper introduces a set of domain-independent design synthesis metric: clarity, feasibility, testability, simplicity, and analogy. For each metrics, the rationale of including it is explained, and a systemic evaluation procedure is prescribed. Individually, each metrics addresses a particular aspect of design synthesis in conceptual design. Collectively, the combined consideration of all metrics as a single vector helps the designer to identify the most promising synthesis outcome, the best design concept, which both satisfies upstream objectives and meets downstream constraints.
Improvement of Product Adaptability by Efficient Module Interactions
Authors: Peng Qingjin , Liu Yunhui , Gu Peihua
Published: January 2015

Adaptable products can meet different functional requirements in the product life cycle by adding or replacing function modules of the products. Product’s architecture builds relationships of functional modules to support feasibility of the adaptable products to be upgraded based on users’ needs. A final adaptable product is formed by the combination of different functional modules. This paper introduces a quantitative measure of product adaptability based on the product architecture, interface complexity and operation ability. Design efficiency of module interactions is introduced to evaluate product adaptability based on the design solution and related operation constraints of interactions. An electric vehicle is improved for the adaptability based on the proposed evaluation method.
Study of Snubbing Mechanism Using Finite Element Method
Authors: Chen Jingming , Pennacchi Paolo , Jiang Dongxiang , Chatterton Steven
Published: January 2015

In the rotating machineries, large vibrations of a blade would result in fatigue crack, which is a great threaten to the safety. Therefore, it is of great importance to reduce the blade vibrations. Snubbing technique is a possible solution to this problem. A tiny gap is left between the shrouds of adjacent blades. While the forced vibration makes the relative displacement between two neighboring blades exceed the gap, the contact happens at the contact face of the shrouds, accompanied with friction and energy dissipation, which restricts the vibration.

In this paper, a simplified model for a set of rotor blades is established, by using finite element method. The contact between the adjacent shrouds is considered. In this way, snubbing phenomenon can occur under forced vibration. Based on the model, modal analysis has been conducted. The 8x rev. frequency has been chosen as the excitation frequency. Under a certain amplitude of sine excitation, the circumferential vibration of the blades has been simulated. The vibration has been analyzed in the time domain. As expected, the blade motion is divided into four different states in one period. They are: non-contact, rebounding, sticky and escaping state. The four states had different mechanical and motion characteristics.

The motion pattern for the set of blades has been also analyzed and the wave spreading along the bladerow has been described. Because of the snubbing mechanism, the waveform was distorted into serrated shape.
Sustainability Assessment of the Injection Molding Process and the Effects of Material Selection
Authors: Roy Utpal , Li Yunpeng
Published: January 2015

This paper discusses the use of the proposed Material Information Model (MIM) [1] in assessing the sustainability of the Injection Molding (IM) process, and clarifies how to use the material information (based on the characteristics of different types of polymers) to quantify the material impacts. The assessment criteria include energy/water consumption and waste (pollution) production during the process and the effects of other materials during production (like the use of additives) that may add to environmental burdens. This paper addresses issues mainly at the IM process level taking the followings into account — pollution and manufacturing cost, energy and water consumption, waste management, operation safety, hazards to the plastic manufacturing personnel and other environmental impacts — to develop requisite process metrics for measuring the sustainability performances of the IM process. The ideas discussed in the paper lead to the development of computational approaches for selecting the “best” process-material combination.
Projection-Based Topology Optimization Using Discrete Object Sets
Authors: Guest James K.
Published: January 2015

We look to expand the reach of continuum topology optimization to include the design of ‘structures’ that gain functionality or are specifically manufactured from discrete, non-overlapping objects. While significant advancements have been made in restricting the geometric properties of topology-optimized structures, including restricting the minimum and maximum length scale of features, continuum topology optimization is still largely limited to monolithic structures. A wide variety of structures and materials, however, gain their stiffness or functionality from discrete objects, such as fiber-reinforced composites. This work examines a recently developed method for optimizing the distribution of discrete objects (2d inclusions) across a design domain and extends the approach to variable shape and variable sized objects that must be selected from a designer-defined set. This essentially enables simultaneous optimization of object sizes, shapes, and/or locations within the projection framework, without need for additional constraints. As in traditional topology optimization, gradient-based optimizers are used with sensitivity information estimated via the adjoint method, solved using finite element analysis. The algorithm is demonstrated on benchmark problems in structural design for the case where the objects are stiff inclusions embedded in a compliant matrix material.
A Case Study of Modeling and Simulation for Manufacturing, Installation, and Maintenance of Solar Power Systems
Authors: Irudayaraj Prashanth , Liu Yitao , Zhou Feng , Jiao Roger J. , Goodman Joseph N.
Published: January 2015

Solar power systems are becoming increasingly popular due to the fact that solar power can offer time and money saving solutions for off-grid and grid-connected homes, cabins, and businesses with clean and affordable energy. However, there are still significant opportunities to reduce the cost of solar power systems by optimizing system design. We employ system modeling and simulation methods to compare a commercial rooftop solar system with a new concept for the same application, namely Mega Module system. In order to accomplish this, a solar power system’s lifecycle is divided into three phases, namely manufacturing, installation, and maintenance. Specifically, a SysML-based conceptual model was first constructed, based on which, Arena simulation models were built for three phases of the two systems. Then, we performed input analysis on data collected onsite for the two systems, and output analysis of the theoretical seconds/watt of all three phases based on reasonable assumptions. The results of the simulation study indicate that although it increases the manufacturing time, the Mega Module system saves a significant amount of time in the installation phase and a relatively small amount of time in the maintenance phase, and thus can be more cost-effective in the long term. The case study further demonstrates the feasibility and potential to reduce costs of product-service systems by quick installation and optimization using system modeling and simulation methods.
Considering Design Prohibitions in Product Line Optimization
Authors: Foster Garrett , Ferguson Scott
Published: January 2015

To be competitive in today’s market, firms need to offer a variety of products that appeal to a diverse set of customer needs. Product line optimization provides a simple method to design for this challenge. Using a heterogeneous customer preference model allows the optimization to better explore the diversity in the market. The optimization should also consider aesthetic, engineering, manufacturing, and marketing constraints to ensure the feasibility of the final solution. However, as more constraints are added the difficulty of the optimization increases. There is an opportunity to reduce the difficulty of the optimization by allowing the heterogeneous customer preference model to handle a subset of these constraints termed design prohibitions. Design prohibitions include component incompatibility and dependency. This paper investigates whether design prohibitions should be handled solely in the heterogeneous customer preference model, solely in the optimization formulation, or in both. The effects of including design prohibitions in the creation of a hierarchical Bayes mixed logit model and a genetic algorithm based product line optimization are explored using a bicycle case study.
A Dynamic Service-Oriented Distributed Computing Framework for Evaluation of Computationally Expensive Black-Box Analyses
Authors: Cheng George H. , Qi Chao , Wang G. Gary
Published: January 2015

A practical, flexible, versatile, and heterogeneous distributed computing framework is presented that simplifies the creation of small-scale local distributed computing networks for the execution of computationally expensive black-box analyses. The framework is called the Dynamic Service-oriented Optimization Computing Framework (DSOCF), and is designed to parallelize black-box computation to speed up optimization runs. It is developed in Java and leverages the Apache River project, which is a dynamic Service-Oriented Architecture (SOA). A roulette-based real-time load balancing algorithm is implemented that supports multiple users and balances against task priorities, which is superior to the rigid pre-set wall clock limits commonly seen in grid computing. The framework accounts for constraints on resources and incorporates a credit-based system to ensure fair usage and access to computing resources. Experimental testing results are shown to demonstrate the effectiveness of the framework.
A Global High Dimensional Metamodeling Approach With the Ability of Using Non-Uniform Sampling
Authors: Hajikolaei Kambiz Haji , Wang G. Gary
Published: January 2015

In engineering design, spending excessive amount of time on physical experiments or expensive simulations makes the design costly and lengthy. This issue exacerbates when the design problem has a large number of inputs, or of high dimension. High Dimensional Model Representation (HDMR) is one powerful method in approximating high dimensional, expensive, black-box (HEB) problems. One existing HDMR implementation, Random Sampling HDMR (RS-HDMR), can build a HDMR model from random sample points with a linear combination of basis functions. The most critical issue in RS-HDMR is that calculating the coefficients for the basis functions includes integrals that are approximated by Monte Carlo summations, which are error prone with limited samples and especially with non-uniform sampling. In this paper, a new approach based on Principal Component Analysis (PCA), called PCA-HDMR, is proposed for finding the coefficients that provide the best linear combination of the bases with minimum error and without using any integral. Benchmark problems are modeled using the method and the results are compared with RS-HDMR results. With both uniform and non-uniform sampling, PCA-HDMR built more accurate models than RS-HDMR for a given set of sample points.
On the Direct Static Problem of a Planar Rigid Body Suspended From Two Cables
Authors: Dion-Gauvin Pascal , Gosselin Clément
Published: January 2015

This paper presents a general solution to the direct static problem of a planar body suspended from two cables. First, the conditions for static equilibrium are stated and a mathematical formulation of the problem is derived. A twelfth degree univariate polynomial is then obtained using the resultant of two intermediate polynomials. It is shown that up to twelve real solutions can be obtained, thereby confirming that the polynomial is of minimal degree. Since the condition used in the derivation is necessary but not sufficient, the roots must be tested a posteriori for validity. Simple mathematical conditions are provided that allow such a verification. Finally, two examples are provided to illustrate the results and highlight the importance of the proposed root validation procedure.
Piezoelectric Leaf Generator for Wind Energy Harvest
Authors: Zhang Guitao , Chen Vincent , Xu Weihe , Galos Richard , Zhou Liang , Shi Yong
Published: January 2015

In this paper, a piezoelectric leaf generator for harvesting wind energy was proposed, fabricated and tested. The leaf generator had a bimorph cantilever structure, with Su-8 as the protective supporting layer, and aligned lead zirconate titanate (PZT) nanofibers as the active layer. Interdigitated electrodes were sputtered on top of the aligned PZT nanofibers to collect the generated charge. After fabrication of the leaf generator, it was tested in a wind tunnel with different wind incident angles and wind speeds. The maximum voltage output of the leaf generator was 820 mV when the wind speed was 17 m/s. The developed leaf generator does not need further bonding to the vibration source, which make it much easier for real applications. In addition, benefited from unique material properties of the PZT nanofiber such as flexible, robust, and high piezoelectric coupling ability, the leaf generator is promising for a high efficiency wind energy harvest.
Numerical Simulation of Laminar Flow Heat Transfer Enhancement Using Surface Modification
Authors: Paranjape Abhijit S. , Maniar Ninad C. , Pandya Deval A. , Dennis Brian H.
Published: January 2015

Heat transfer augmentation techniques have gained great importance in different engineering applications to deal with thermal management issues. In this work, a numerical investigation was carried out to see the effects of a modified surface on the heat transfer enhancement compared to a smooth surface. In the first case, spherical dimple arrays were applied to the surface. The effects were observed for dimples on the bottom wall of a channel for a laminar airflow. The effects of a 21×7 staggered array and a 19×4 inline array on the bottom wall were investigated. In the second case, the heat exchange enhancement in a rectangular channel using longitudinal vortex generators (LVG) for a laminar flow was considered. In both cases, a 3D steady viscous computational fluid dynamics package with an unstructured grid was used to compute the flow and temperature field. The heat transfer characteristics were studied as a function of the Reynolds number based on the hydraulic diameter of the channel. The heat transfer was quantified by computing the surface averaged Nusselt number. The pressure drop and flow characteristics were also calculated. The Nusselt number was compared with that of a smooth channel without surface modification to assess the level of heat transfer enhancement.
Single Cell Battery Charger for Portable Electronic Devices in Developing Countries
Authors: Johnson Nathan G. , Granato Michael
Published: January 2015

Many household electronic devices — flashlights, stereos, radios — require AA, AAA, C, and D size batteries. These batteries are often disposable in remote areas of the world that lack access to grid electricity. In parts of the globe, disposable batteries can account for over 50% of household energy expenditures and amount to 25 or more batteries disposed of per person per year. This amounts to more than 25,000 batteries annually for a village of 1000 people. Solutions to this problem can address economic and environmental concerns. Replacing disposable batteries with rechargeable batteries maintained by a local entrepreneur is one business-driven method to reduce environmental waste and household energy expenditures. This study evaluates technical options for providing rechargeable batteries to a decentralized population, and introduces a prototype portable charging kit that addresses the techno-economic requirements of charging batteries, delivering batteries at a reasonable cost to consumers, providing a profit margin for local entrepreneurs, and allowing for portability during travel between villages or refugee camps. The unit includes a solar PV power source, a lead-acid battery for intermediate energy storage, a battery charger equipped with single cell batteries, a charge controller to manage power flow, and a protective suitcase to house the equipment.
An Improved L1 Based Algorithm for Standardized Planar Datum Establishment
Authors: Shakarji Craig M. , Srinivasan Vijay
Published: January 2015

This paper has two major goals. First, we present an algorithm for establishing planar datums suitable for a default in tolerancing standards. The algorithm is based on a constrained minimization search based on the L1 (L1) norm after forming a convex surface from the original surface or sampled points. We prove that the problem reduces to a simple minimization search between the convex surface and its centroid. The data points in the discrete case do not need to have any corresponding weights provided with them, as appropriate weighting is part of the algorithm itself, thereby making the algorithm largely insensitive to nonuniformly sampled data points. Terse Mathematica code is included for the reader. The code is sufficient for constrained and unconstrained planar fitting as well as a 3-2-1 datum reference frame generation. The second goal of this paper is to compare this new method with several other possible means for establishing datum planes, ultimately showing several appealing characteristics of the proposed algorithm. Since both the ISO and ASME standardization efforts are actively working to establish datum plane definitions, the timing of such a study is opportune.
Primary Resonance of MEMS/NEMS Circular Plate Biosensors
Authors: Caruntu Dumitru I. , Oyervides Reynaldo
Published: January 2015

This investigation deals with M/NEMS circular plates under electrostatic actuation. Such structures can be used as resonator sensors for medicine and biology applications such as virus, bacteria or DNA detection. The system consists of a clamped circular plate over a ground. The actuation of the plate is done through an AC voltage whose frequency is near half natural frequency of the plate. This produces a primary resonance to be used afterwards for sensing purposes. It is showed that a saddle-node bifurcation occurs. The effects of damping, voltage, Casimir, and van der Waals forces are predicted.
Nonlinear Characteristics for Rotatable Magnetically Coupling Piezoelectric Energy Harvesters
Authors: Cao Junyi , Zhou Shengxi , Inman Daniel J.
Published: January 2015

This paper investigates the nonlinear dynamic characteristics of a magnetically coupled piezoelectric energy harvesters under low frequency excitation, where the angle of external magnetic field is adjustable. The nonlinear dynamic equation with the identified nonlinear magnetic force is derived to describe the electromechanical interaction of variable inclination angle harvesters. The effect of excitation amplitude and frequency on dynamic behavior is proposed by using the phase trajectory and bifurcation diagram. The numerical analysis shows that a rotatable magnetically coupling energy harvesting system exhibits rich nonlinear characteristics with the change of external magnet inclination angle. The nonlinear route to and from large amplitude high energy motion can be clearly observed. It is demonstrated numerically and experimentally that lumped parameters equations with an identified polynomials for magnetic force could adequately describe the characteristics of nonlinear energy harvester. The rotating magnetically coupled energy harvester possesses the usable frequency bandwidth over a wide range of low frequency excitation by adjusting the angular orientation.
Reducing Resonant Vibrations of Adjacent Base Isolation Systems Using Connected Control Method
Authors: Botelho Rui M. , Christenson Richard E.
Published: January 2015

The connected control method (CCM) is a vibration control strategy that uses damping devices between adjacent dynamic systems to impart dissipative forces upon one another for mitigating their fundamental resonant vibrations. CCM was originally conceived for civil applications to mitigate the resonant vibrations of adjacent high-rise buildings from seismic and wind excitations. This paper examines CCM as a potential vibration control strategy for mechanical applications, particularly for the case of adjacent base isolation systems. These systems typically have lightly damped fundamental resonant frequencies to provide effective isolation at the higher frequencies. The conventional approach to reduce the vibrations of these fundamental resonances is to add damping to the isolators, but at the expense of degraded isolation. For cases when the two or more base isolation systems are adjacent to each other, it is possible to apply CCM to mitigate their fundamental resonant vibrations by interconnecting them with damping devices. This paper first reviews the basic theory of CCM for adjacent one degree of freedom (DOF) mass-spring systems connected by a viscous damper, followed by analytical modeling and optimization of adjacent 6-DOF mass-spring systems connected by viscous dampers. In addition, experimental results using simplified base isolation systems connected by Taylor Devices viscous dampers are also presented to demonstrate the effectiveness of CCM. Results show that CCM can effectively reduce the resonant vibrations of adjacent base isolation systems without degrading the isolation effectiveness as long as their fundamental resonances are sufficiently separated.
Use Scenario to Implement an Innovative Service: Teledermatology
Authors: Duong Tu Anh , Farel Romain , Le Cardinal Julie
Published: January 2015

Teledermatology is an application of telemedicine i.e. clinical healthcare using IT-technologies, for skin disorders. This innovative system is consider as a potential answer to the decrease number of physicians, their unequal density, and to shorten the lead time and the time to schedule a visit. Despite its indisputable medical interest and a mature technology, teledermatology struggles to demonstrate the benefit of its large-scale deployment to decision makers. Considering Teledermatology as a technological or organizational innovation, to improve the conventional care process delivery and not as an independent healthcare delivery may be a key issue. Using conventional care activity modeling, we will in this paper take the example of skin cancer management to generate the possible observed scenarios and their possible occurrence in >65 year old population. Then using time and cost as process indicators, we will measure and evaluate the impact of a teledermatology process on the conventional care process. Numerical data will be gathered by two experimental studies.
Effect of Diamond-Like-Carbon Coating on 3D Surface Roughness
Authors: Mordo Sergio , Popravko Valery , Barari Ahmad
Published: January 2015

Companies that coat their products with DLC often have strict surface roughness goals. This research investigates the surface roughness properties of uncoated and DLC coated specimens in an effort to know what uncoated surface roughness is needed to obtain a certain DLC coated surface roughness. Therefore, a model describing the relationship between uncoated and DLC coated surface roughness is needed. If this relationship can be estimated, the cost of surface finishing can be minimized by avoiding any unnecessary processes. A total of 7 specimens were tested before and after coating process with a non-contact surface roughness measurement microscope. Mathematical relationships are found between the DLC coated surface roughness and uncoated surface roughness. An experimental methodology was described for applying the findings to other coating methods and materials as the mathematical relationships found in this study are specific to the coating process and materials used.
Dynamic Simulation of Human Gait Using a Combination of Model Predictive and PID Control
Authors: Sun Jinming , Voglewede Philip A.
Published: January 2015

Human gait studies have not been applied frequently to the prediction of the performance of medical devices such as prostheses and orthoses. The reason is most biomechanics simulations require experimental data such as muscle activity or joint moment information a priori. In addition, biomechanical models are normally too complicated to be adjusted and these simulations normally take a long period of time to be performed which makes testing of various possibilities time consuming; therefore they are not suitable for prediction purpose. The objective of this research is to develop a control oriented human gait model that is able to predict the performance of prostheses and orthoses before they are experimentally tested. This model is composed of two parts. The first part is a seven link nine degree-of-freedom (DOF) plant to represent the forward dynamics of human gait. The second part is a control system which is a combination of Model Predictive Control (MPC) and Proportional-Integral-Derivative (PID) control. The purpose of this control system is to simulate the central nervous system (CNS). This model is sufficiently simple that it can be simulated and adjusted in a reasonable time, while still representing the essential principles of human gait.
Precessional Motions of a Chain of Coupled Gyrostats in a Central Newtonian Force Field
Authors: Chebanov Dmitriy
Published: January 2015

This paper studies the problem of the motion of a classical model of modern analytical multibody dynamics — a chain of gyrostats coupled by ideal spherical joints. The chain moves about a fixed point in a central Newtonian force field. The paper develops the equations of chain’s motion and then establishes and analyzes the conditions for existence of some classes of precessional motions of the chain, under the assumption that the barycenter of each gyrostat is located on the line connecting the points where it is attached to other gyrostats. The findings of the paper extend corresponding results in the dynamics of a single gyrostat to a case of the multibody chain as well as generalize some of the known properties of precessional motions in the dynamics of many bodies.
Micro-Scale Friction Model for Elastomers Considering Temperature Dependent Criterion for Wave Length Limit and Contribution of Adhesive Friction
Authors: Afrasiabi Erfan , Braghin Francesco , Maggioni Massimiliano , Sabbioni Edoardo
Published: January 2015

Existing friction laws for rubber like materials are tuned on available experimental data. Once their parameters are identified, a sensitivity analysis is carried out in order to check their extrapolation and prediction capabilities. It is seen that, although several fiction laws at micro scale are available in the literature, neither one is able to correctly predict the friction law at macro scale for all the tire working conditions. In the present paper a thorough review of the most advanced local friction models, i.e. Persson and Kluppel models, is carried out. Persson’s model is then integrated with a limiting criterion and an adhesive contribution is added to improve the prediction of the friction law at macro scale.
Preliminary Study in Parallel Simulation of Equation-Based System-Level Physical Models
Authors: Zhao Yan , Chen Liping , Ding Jianwan , Zhao Jianjun
Published: January 2015

As the maximum speed for processors seems to have reached its peak, parallelization becomes an important way to speed up the simulation. This paper discusses the problems of parallelizing the task graphs that represent the system-level physical models at the equation level. The methods for estimating the runtimes of the equation solving tasks are presented. There is a focus on an interactive tool which is designed to parallelize the task graph semi-automatically and to generate the parallel simulation code automatically. For further research, this tool can be used to test the automatic parallelizing algorithms. Several example models are parallelized. The parallel programs are generated and experimented. The final results suggest that parallelization at the equation level is effective and better performances are supposed to be found in bigger systems.
A Novel Flow Diverter for Direct Treatment of Cerebral Aneurysms
Authors: Ma Jiayao , Peach Thomas , You Zhong , Rizkallah Rafik R. , Byrne James
Published: January 2015

A summary of the manufacturing, in-silico and in-vivo testing of a laser cut cerebral flow-diverting stent (FDS) prototype is presented. The predicted flow-reduction achieved by both variants of the FDS design compares favorably with current commercially available designs. FDS design II is implanted into a swine aneurysm model to validate both the flow-diverting capability and a lack of adverse biological reaction.
Vortex Generation in Two Intracranial Aneurysms
Authors: Asgharzadeh Hafez , Borazjani Iman , Xiang Jianping , Meng Hui
Published: January 2015

Three-dimensional numerical simulations, using the sharp-interface immersed boundary method, are carried out to investigate the effect of aneurysm shape on the hemodynamics of intracranial aneurysm. In our previous work [1] only a single geometry of an aneurysm was tested, but here two three-dimensional geometries are tested by reconstruction from three-dimensional rotational angiography of a human subject [2]. The results support our previous hypothesis [1], i.e., when the vortex formation time scale at the parent artery is smaller than the transportation time scale across the aneurysm neck, the flow aneurysm dome is dominated by a dynamic, unsteady vortex formation.
Body Shape and Size Modelling Using Regression Analysis and Neural Network Prediction
Authors: Vaughan Neil , Dubey Venketesh N. , Wee Michael Y. K. , Isaacs Richard
Published: January 2015

The aim of this research is to build a patient-specific virtual body shape model for patients of various Body Mass Index (BMI) and body shape. This will enable simulated epidural procedure on patients of various body characteristics, to increase trainee skill, reduce injuries and litigation costs.

Regression analysis (RA) and artificial neural networks (ANN) were implemented to accurately calculate body shape in a data-driven approach. Epidural simulator software was developed containing a screen to enter patient characteristics. When the patient BMI is adjusted, the modelled body shape and tissue layer thickness updates allowing patient specific simulation. The model uses anthropometric measurements as input: body mass, height, age, gender and body shape.

The developed model enables a virtual representation of any actual patient to be built based on their measured parameters for epidural rehearsal prior to in-vivo procedure.
Examination of Factors Influencing Intramedullary Reaming Into Femurs
Authors: Yerrabolu Santosh Rohit , Mollendorf Joseph C. , Baier Robert E. , Ehrensberger Mark T.
Published: January 2015

This preliminary study explores material surface chemistry modifications to optimize intramedullary (IM) reaming into femurs. Understanding and quantifying the effects of surface chemistry will allow beneficial new material choices. M2 standard High Speed Steel Straight Shank Straight Fluke chucking reamers of 5/32” or ∼4mm diameter were reamed into RenShape®-BM5460 (bone analogs) blocks for the investigation. Sterilizations (Steam Autoclave and Radio Frequency Glow Discharge Treatment) and low friction coatings (Octadecyltrichlorosilane or ODS and 3-Hepta-fluoropropyl-methyl-dichloro-silane or 3-HEPT) were the surface modifications so far pursued in this study. The effects due to the presence of possible transfer films from bone analogs during reaming on cutting efficacies have been investigated on a custom made Orthopaedic Rotational Cutter Analysis System (ORCAS) test system. The results preliminarily suggest a transfer film from the bone analog resulting in reduction of peak loads and peak toques through repeated use. The low-friction coatings have induced lower peak loads and comparable peak torques, suggesting a corollary between low friction coatings and lower surgical efforts required.
MAPK feedback encodes a switch and timer for tunable stress adaptation in yeast
Authors: English Justin G. , Shellhammer James P. , Malahe Michael , McCarter Patrick C. , Elston Timothy C. , Dohlman Henrik G.
Published: January 2015

Positive and negative feedback converts the switchlike activation of the yeast osmotic stress response into graded adaptation.
Annotation of human cancers with EGFR signaling–associated protein complexes using proximity ligation assays
Authors: Smith Matthew A. , Hall Richard , Fisher Kate , Haake Scott M. , Khalil Farah , Schabath Matthew B. , Vuaroqueaux Vincent , Fiebig Heinz-Herbert , Altiok Soner , Chen Yian Ann , Haura Eric B.
Published: January 2015

A method for detecting receptor tyrosine kinase signaling in patient tumor samples may improve diagnosis and therapy.
Innate Immunity Induced by Plasmodium Liver Infection Inhibits Malaria Reinfections
Authors: Liehl Peter , Meireles Patrícia , Albuquerque Inês S. , Pinkevych Mykola , Baptista Fernanda , Mota Maria M. , Davenport Miles P. , Prudêncio Miguel
Published: January 2015

Following transmission through a mosquito bite to the mammalian host,Plasmodiumparasites first invade and replicate inside hepatocytes before infecting erythrocytes and causing malaria. The mechanisms limitingPlasmodiumreinfections in humans living in regions of malaria endemicity have mainly been explored by studying the resistance induced by the blood stage of infection. However, epidemiologic studies have suggested that in high-transmission areas, preerythrocytic stages also activate host resistance to reinfection. This, along with the recent discovery that liver infections trigger a specific and effective type I interferon (IFN) response, prompted us to hypothesize that this pre-erythrocyte-stage-induced resistance is linked to liver innate immunity. Here, we combined experimental approaches and mathematical modeling to recapitulate field studies and understand the molecular basis behind such resistance. We present a newly established mouse reinfection model and demonstrate that rodent malaria liver-stage infection inhibits reinfection. This protection relies on the activation of innate immunity and involves the type I IFN response and the antimicrobial cytokine gamma IFN (IFN-γ). Importantly, mathematical simulations indicate that the predictions based on our experimental murine reinfection model fit available epidemiological data. Overall, our study revealed that liver-stage-induced innate immunity may contribute to the preerythrocytic resistance observed in humans in regions of malaria hyperendemicity.
Clinical values of FDG PET in polymyositis and dermatomyositis syndromes: imaging of skeletal muscle inflammation
Authors: Tateyama Maki , Fujihara Kazuo , Misu Tatsuro , Arai Akira , Kaneta Tomohiro , Aoki Masashi
Published: January 2015

Objectives

[18F] Fluorodeoxyglucose positron emission tomography (FDG PET), a standard tool for evaluating malignancies, can also detect inflammatory lesions. However, its usefulness in evaluating muscle lesions in polymyositis and dermatomyositis syndromes (PM/DM) has not been established.

Methods

33 patients with PM/DM who had undergone FDG PET were retrospectively analysed. FDG uptake was visually evaluated (visually identified FDG uptake, vFDG) in 16 regions of the body using mediastinum blood vessels as a positivity criterion. We also calculated the maximum standardised uptake value (SUVmax) in all four limbs of the patients with PM/DM as well as in 22 patients with amyotrophic lateral sclerosis (ALS) with similar disabilities. In 24 patients with PM/DM, MRI and FDG PET findings were compared.

Results

vFDG was observed in multiple muscle lesions with varying distributions in two-thirds of the patients with PM/DM, with most lesions being symmetrical. The number of vFDG-positive regions strongly correlated with the mean SUVmax in all four limbs (p<0.0001). Histological grades of biopsied muscles correlated with both the mean SUVmax and number of vFDG-positive regions. Serum creatine kinase levels were higher in patients with more than two vFDG-positive regions than in those with two or less regions (p<0.05). While the inflamed muscles showed diffused, patchy or marginal signal abnormalities on MRI, FDG uptake was most prominent inside the muscles. Compared with ALS, the mean SUVmax was significantly higher in the patients with PM/DM (p<0.0001) and showed a striking correlation in the bilateral muscles, reflecting symmetrical muscle involvement in PM/DM.

Conclusions

The visual assessment of FDG uptake as well as calculation of SUV enabled us to comprehensively evaluate skeletal muscle. This method can improve clinical practices and provide insights into pathomechanisms of PM/DM.
Epigenetics in idiopathic pulmonary fibrosis
Authors: Tzouvelekis Argyrios , Kaminski Naftali
Published: January 2015

Idiopathic pulmonary fibrosis (IPF) is a lethal chronic lung disorder with no effective treatment and a prognosis worse than that of lung cancer. Despite extensive research efforts, its etiology and pathogenesis still remain largely unknown. Current experimental evidence has shifted the disease paradigm from chronic inflammation towards the premise of abnormal epithelial wound repair in response to repeated epigenetic injurious stimuli in genetically predisposed individuals. Epigenetics is defined as the study of heritable changes in gene function by factors other than an individual’s DNA sequence, providing valuable information regarding adaption of genes to environmental changes. Although cancer is the most studied disease with relevance to epigenetic modifications, recent data support the idea that epigenomic alterations may lead to variable disease phenotypes, including fibroproliferative lung disorders such as IPF. This review article summarizes the latest experimental and translational epigenetic studies in the research field of chronic lung disorders, mainly focusing on IPF, highlights current methodology limitations, and underlines future directions and perspectives.
Conceptual hydrogeological model for a landfill in a floodplain environment: case study of the JV Industries and Fairway Landfill, Shxwhá:y Village First Nation, Chilliwack, B.C.
Authors: Romano Connie , Sacré Jillian , Pflug Siege , Sam Murray
Published: January 2015

The characteristics of floodplains of major rivers are of interest to many shoreline communities due to issues related to flooding, water demand, and land use. Studies of the hydrogeological conditions within these environments can improve our understanding of these settings. The case study of the JV Industries and Fairway Landfill, located within the floodplain of the Fraser River, highlights the complex groundwater flow dynamics in such an environment. In particular, the study examined the potential for substantial changes to both groundwater flow and groundwater quality during or immediately following the spring freshet due to the presence of permeable, extensive, and hydraulically well-connected floodplain deposits. During spring and early summer, groundwater flow across the landfill is controlled primarily by the Fraser River freshet and the direction of flow varies spatially across the site. During the winter, groundwater flow is controlled primarily by regional topography and is directed to the southwest towards the nearest topographic depression, the remnant Coco-oppelo Slough. In the intervening months, the flow directions are transitional between the winter and spring – early summer flow patterns. The changes in the groundwater flow patterns were inferred to temporally affect the groundwater quality downgradient of the landfill.
Three-body decay of B0→D¯*(2007) 0π+π−
Authors: Mohammadi Behnam , Mehraban Hossein
Published: January 2015

We investigate the [Formula: see text] decay using Dalitz plot analysis. There are two tree diagrams for this decay mode in the factorization approach: the transition matrix element is factorized into a B0 → π+π− form factor multiplied by [Formula: see text] decay constant; and a [Formula: see text] form factor multiplied by a π+ decay constant. In this research we evaluate the matrix elements of the vector and axial vector currents between the B0 and [Formula: see text] meson states by using the B*+ pole. The contributions of intermediate resonances, such as f0(980), f0(1370), f0(1500) and ρ(770), ρ(1450), ρ(1700), have been taken into account. According to the QCD factorization approach and using Dalitz plot analysis, we calculate the branching ratio of [Formula: see text] decay and obtain 3.81 ± 1.31 × 10−4 and 7.49 ± 2.71 × 10−4 at the μ = mb and 2mb scales, respectively, whereas the experimental result is (6.20 ± 2.20) × 10−4.
STABILITY ANALYSIS IN PATIENTS WITH NEUROLOGICAL AND MUSCULOSKELETAL DISORDERS USING LINEAR AND NON-LINEAR APPROACHES
Authors: KARIMI MOHAMMAD , SADEGHISANI MEISSAM , OMAR ABDUL HAFIDZ HAJI , KOUCHAKI EHSAN , MIRAHMADI MINA , FATOYE FRANCIS
Published: January 2015

Standing stability is controlled by musculoskeletal and neurological systems. Various methods have been used to evaluate the performance of subjects during standing including linear and non-linear methods. It is not clear which method has more sensitivity to represent the stability of subjects with various musculoskeletal disorders. Therefore, the aim of this study was to investigate the stability of the subjects with various musculoskeletal disorders by use of linear and non-linear methods. About 65 subjects including, normal and those with flatfoot, Parkinson and Perthes were recruited into this study. A Kistler forceplate was used to evaluate the stability. The difference between the linear (center of pressure excursion, velocity and path length) and non-linear (approximate entropy) parameters were evaluated using the independent t-test. The mean values of stability parameters (linear and non-linear) of flat arch subjects were more than that of normal subjects. Although there was no difference between linear stability parameters of normal and those with Parkinson disease, their mean value of non-linear parameter was less than that of normal subject (p-< 0.05). The results of stability analysis based on both linear and non-linear approaches showed that the subjects with Perthes disease were more unstable than normal subjects. It seems that non-linear method is more sensitive to represent the difference between stability of subjects with flatfoot, Parkinson and Perthes. However, if a combination of various parameters, based on linear method, is used to measure stability, the difference between stability can be enhanced. Depending on the disease condition increasing and decreasing the value of approximate entropy represent the unstability situations.
A THREE LAYER MODEL FOR THE THERMAL IMPEDANCE OF THE HUMAN SKIN: MODELING AND EXPERIMENTAL MEASUREMENTS
Authors: STRA̧KOWSKA MARIA , DE MEY GILBERT , WIȨCEK BOGUSŁAW , STRZELECKI MICHAŁ
Published: January 2015

In this paper a dynamic three layer model for the heat transfer in the human skin is presented. The model is solved in the Laplace domain using the phasor notation. In order to compare the theoretical model with experimental results, a transient heating was carried out and the time dependent skin temperature was recorded with a thermographic camera. The transient temperature could be fitted very well to an analytical function, which could easily be transformed into the Laplace domain allowing an easy comparison between the model and the experimental results. The aim of the research is to evaluate the skin thermal parameters for all layers including the blood perfusion.
Two mod-p Johnson filtrations
Authors: Cooper James
Published: January 2015

We consider two mod-p central series of the free group given by Stallings and Zassenhaus. Applying these series to definitions of Dennis Johnson's filtration of the mapping class group, we obtain two mod-p Johnson filtrations. Further, we adapt the definition of the Johnson homomorphisms to obtain mod-p Johnson homomorphisms.

We calculate the image of the first of these homomorphisms. We give generators for the kernels of these homomorphisms as well. We restrict the range of our mod-p Johnson homomorphisms using work of Morita. We finally prove the announced result of Perron that a rational homology 3-sphere may be given as a Heegaard splitting with gluing map coming from certain members of our mod-p Johnson filtrations.
A Feasibility Study of a Noncontact Torque Sensor with Multiple Hall Sensors
Authors: Lee Kyungshik , Cho Chongdu
Published: January 2015

The feasibility of a noncontact sensor is investigated. This type of sensor can potentially be used for torque measurement in a speed-variable power transmission system. Torque can be read by examining the phase difference between two induction signals from respective magnetic sensors that detect the magnetic field intensity of permanent magnets mounted on the surface of a shaft in rotation. A real-time measuring algorithm that includes filtering and calibration is adopted to measure the torque magnitude. It is shown that this new torque sensor can perform well under rotation speeds ranging from 300 rpm to 500 rpm. As an interim report rather than a complete development, this work demonstrates the feasibility of noncontact torque measurement by monitoring a magnetic field. The result shows an error of less than 2% within the full test range, which is a sufficient competitive performance for commercial sensors. The price is very low compared to competitors in the marketplace, and the device does not require special handling of the shaft of the surface.