bluuebunny/crossref_metadata_2025 huggingface dataset:
Permanent Pacemaker Insertion Following Isolated Aortic Valve Replacement before and after the Introduction of TAVI
Authors: KOGAN ALEXANDER , STERNIK LEONID , BEINART ROY , SHALABI AMJAD , GLIKSON MICHAEL , SPIEGELSTEIN DANNY , LEVIN SHANY , RAANANI EHUD
Published: January 2015

Background

Permanent pacemaker (PPM) implantation is required in 3–12% of all patients undergoing surgical aortic valve replacement (AVR). Our aim was to evaluate the contemporary incidence and impact of the introduction of transcatheter aortic valve implantation (TAVI) for PPM insertion after isolated AVR.

Methods

Since 2004, during a 10‐year period, a total of 858 patients underwent isolated AVR at our institution. Forty‐one patients with PPM before operation were excluded from the study and 817 patients were included in the statistical analysis. Of these, 20 patients (2.45%) developed significant conduction disorders, leading to PPM implantation within 120 days postoperatively. Patients were further divided into two groups. Before (Group I: June 2004 to September 2008) and after (Group II: October 2008 to May 2014) the introduction of the TAVI program.

Results

There were 343 patients in Group I and 475 patients in Group II. The incidence of PPM implantation decreased from 3.79% (13 patients) in Group I to 1.47% (seven patients) in Group II (P < 0.001). Risk factors for permanent pacing identified by univariate analysis were: Group I (before introducing TAVI program), pulmonary hypertension, preoperative anemia, age older than 75 years, and previous myocardial infarction. Multivariate analysis identified Group I (before introducing TAVI program; P < 0.005; odds ratio [OR] 15.2, 95% confidence interval [CI] 6.3–19.9) and pulmonary hypertension (P < 0.005; OR 12.5, 95% CI 3.2–18.3) to be significant.

Conclusions

Irreversible atrio‐ventricular block or symptomatic bradycardia requiring PPM implantation is a relatively rare complication. The incidence of PPM implantation after isolated surgical AVR decreased in a contemporary setting after the introduction of the TAVI program.
Expression of a bacterial 3‐dehydroshikimate dehydratase reduces lignin content and improves biomass saccharification efficiency
Authors: Eudes Aymerick , Sathitsuksanoh Noppadon , Baidoo Edward E. K. , George Anthe , Liang Yan , Yang Fan , Singh Seema , Keasling Jay D. , Simmons Blake A. , Loqué Dominique
Published: January 2015

Lignin confers recalcitrance to plant biomass used as feedstocks in agro‐processing industries or as source of renewable sugars for the production of bioproducts. The metabolic steps for the synthesis of lignin building blocks belong to the shikimate and phenylpropanoid pathways. Genetic engineering efforts to reduce lignin content typically employ gene knockout or gene silencing techniques to constitutively repress one of these metabolic pathways. Recently, new strategies have emerged offering better spatiotemporal control of lignin deposition, including the expression of enzymes that interfere with the normal process for cell wall lignification. In this study, we report that expression of a 3‐dehydroshikimate dehydratase (QsuB from Corynebacterium glutamicum) reduces lignin deposition in Arabidopsis cell walls. QsuB was targeted to the plastids to convert 3‐dehydroshikimate – an intermediate of the shikimate pathway – into protocatechuate. Compared to wild‐type plants, lines expressing QsuB contain higher amounts of protocatechuate, p‐coumarate, p‐coumaraldehyde and p‐coumaryl alcohol, and lower amounts of coniferaldehyde, coniferyl alcohol, sinapaldehyde and sinapyl alcohol. 2D‐NMR spectroscopy and pyrolysis‐gas chromatography/mass spectrometry (pyro‐GC/MS) reveal an increase of p‐hydroxyphenyl units and a reduction of guaiacyl units in the lignin of QsuB lines. Size‐exclusion chromatography indicates a lower degree of lignin polymerization in the transgenic lines. Therefore, our data show that the expression of QsuB primarily affects the lignin biosynthetic pathway. Finally, biomass from these lines exhibits more than a twofold improvement in saccharification efficiency. We conclude that the expression of QsuB in plants, in combination with specific promoters, is a promising gain‐of‐function strategy for spatiotemporal reduction of lignin in plant biomass.
Efficacy of hepatic T2* MRI values and serum ferritin concentration in predicting thalassemia major classification for hematopoietic stem cell transplantation
Authors: Hamidieh Amir Ali , Moeininia Fatemeh , Tayebi Sirous , Shamshiri Ahmad Reza , Behfar Maryam , Jalili Mahdi , Alimoghaddam Kamran , Ghavamzadeh Ardeshir
Published: January 2015

Liver biopsy has been performed for many decades for classifying the patients with TM. Meanwhile, using non‐invasive methods such as T2* MRI technique has been recently much more considered to determine the hepatic iron overload. Ninety‐three pediatric HSCT candidates with TM who underwent liver biopsy were included in this study. Hepatic T2* MRI values and serum ferritin concentrations were assessed to investigate and determine the useful method in detection of patients with TM class III whom received different conditioning regimens, in comparison with class I and II. Twenty (21.5%) patients were categorized as class III. Hepatic T2* MRI could detect TM class III patients with 60% sensitivity and 87.67% specificity (LR+: 4.867, accuracy: 81.72%), while predictive feature of ferritin values for distinguishing patients with TM class III was not statistically significant (p‐value >0.01). Combination of T2*MRI with age (T2*‐age) could detect TM class III with 85% sensitivity and 72.6% specificity (LR+: 3.1, accuracy: 75.27%).T2*‐age may be considered as an alternative and non‐invasive method to liver biopsy for differentiation and classification of patients with TM before transplantation.
The LEADER Initiative has been a Victim of Its Own Success. The Decline of the Bottom‐Up Approach in Rural Development Programmes. The Cases of Wales and Andalusia
Authors: Navarro Francisco Antonio , Woods Michael , Cejudo Eugenio
Published: January 2015

The LEADER approach has been at the heart of European rural development policy for the last 20 years, encompassing the principles of bottom‐up endogenous development and community empowerment. Initially delivered through autonomous local action groups (LAGs), since the 2007–2013 programming period, LEADER has been integrated with other measures in broader regional rural development programmes. It has been claimed that these changes have diluted the participatory principles of this programme. We examine the extent and impact of participation in rural development through LEADER, how this has changed over time, and the factors driving changes, through surveys of LAG managers in two case study regions in Spain (Andalusia) and the UK (Wales). The findings show that LAG managers are very positive about the breadth of participation in their own group and its role in decentralising decision‐making, but critical of the structure, operation and management of LEADER in rural development programmes. In particular bureaucracy and the increased influence of regional and local government are perceived to have limited the autonomy of LAGs and to have deterred the participation of marginalised groups. The principles of this initiative are perceived to have been diluted and LEADER appears to have been a victim of its own success.
Firm Profitability and Agglomeration Economies: An Elusive Relationship
Authors: Stavropoulos Spyridon , Skuras Dimitris
Published: January 2015

Recent empirical research has questioned the ability of agglomeration economies to stimulate profitability and healthy financial performance in firms. We devise a cross‐sectional sample of approximately 410,000 firms that were active in all subsectors of the manufacturing industry and that were located across 191 NUTS 2 regions of 15 European Union member states in 2005. For each firm, we calculate two profitability indicators and a labour efficiency indicator. We find that the part of the variance of the profitability and labour efficiency indicators that is attributed to regions is very small. Furthermore, fitted multilevel models show that the quantitative effect of regional specialisation, despite being statistically significant, is very small. The results are robust across more refined geographical scales and subsectors. However, the NUTS 2 level remains the major spatial scale of the design and implementation of European Union regional policy. Our results benefit from the power and safety of a large sample and challenge conventional approaches to agglomeration research and cluster policy.
Port Regionalisation from a Relational Perspective: The Rise of Venlo as Dutch International Logistics Hub
Authors: Raimbault Nicolas , Jacobs Wouter , van Dongen Frank
Published: January 2015

The rise of global supply chain systems and geographical dispersion of related inland logistics centres has led to a new phase in the evolution of port systems, referred to as port regionalisation. While this process largely results from the decisions of shippers and logistics providers, the scope of public policy can also shape it. This includes the strategic capacity of stakeholders to couple not only locally available assets with the needs of global flows, but also to provide meaning through the constitution of symbols, frames and discourses. We propose the application of a relational perspective to port regionalisation, which allows us to analyse how various actors engage strategically in actor‐networks and coalitions across scales to stimulate growth based on logistics. This is accomplished by presenting the rise of Venlo in the Netherlands as an inland logistics hub within the corridor of the port of Rotterdam.
Natural Resource Industries As a Platform for the Development of Knowledge Intensive Industries
Authors: Marin Anabel , Navas‐Alemán Lizbeth , Perez Carlota
Published: January 2015

In the innovation and development literature, natural resources (NR) are generally viewed as a curse for developing nations and NR‐based industries as having little potential to innovate and drive long‐term growth. This has led policy and development experts to opt for strategies to induce a shift in the pattern of specialization towards other sectors. This paper proposes a different approach. By exploring recent evidence from the Argentinean agricultural sector and the mining industry in Chile, it points to the window of opportunity that NR industries offer as a platform to develop knowledge intensive industries with which to support economic development in resource‐endowed countries. The lessons drawn from these findings suggest that development strategies can also promote more innovative knowledge intensive NR‐based industries rather than moving away from them.
Reframing HIV care: putting people at the centre of antiretroviral delivery
Authors: Duncombe Chris , Rosenblum Scott , Hellmann Nicholas , Holmes Charles , Wilkinson Lynne , Biot Marc , Bygrave Helen , Hoos David , Garnett Geoff
Published: January 2015

The delivery of HIV care in the initial rapid scale‐up of HIV care and treatment was based on existing clinic‐based models, which are common in highly resourced settings and largely undifferentiated for individual needs. A new framework for treatment based on variable intensities of care tailored to the specific needs of different groups of individuals across the cascade of care is proposed here. Service intensity is characterised by four delivery components: (i) types of services delivered, (ii) location of service delivery, (iii) provider of health services and (iv) frequency of health services. How these components are developed into a service delivery framework will vary across countries and populations, with the intention being to improve acceptability and care outcomes. The goal of getting more people on treatment before they become ill will necessitate innovative models of delivering both testing and care. As HIV programmes expand treatment eligibility, many people entering care will not be ‘patients’ but healthy, active and productive members of society . To take the framework to scale, it will be important to: (i) define which individuals can be served by an alternative delivery framework; (ii) strengthen health systems that support decentralisation, integration and task shifting; (iii) make the supply chain more robust; and (iv) invest in data systems for patient tracking and for programme monitoring and evaluation.
Thick and Thin Borders in theEuropeanUnion: How Deep Internal Integration is Within Countries, and How Shallow Between Them
Authors: Gallego Nuria , Llano Carlos
Published: January 2015

The existence of large border effects is one of the main puzzles of international macroeconomics. The seminal paper byMcCallum found that trade between any twoCanadian provinces was (on average) 22 times greater than trade between anyCanadian province and anyUSstate. Although various authors have estimated internal and external border effects for the wholeEuropeanUnion and some specificEuropean countries, none has done so in the manner thatMcCallum's seminal paper, stymied by lack of data on region‐to‐region international trade flows. This study uses a novel data set that captures intra and international truck shipments betweenSpanish regions and regions in sevenEuropean countries during the period 2004–11. It computes internal and external border effects, offering novel results for aggregate flows and the importing countries, and estimates several specifications of the gravity equation, so as to tackle such issues as the multilateral resistance term, heteroscedasticity, and zero flows and non‐linear relation between trade and distance. The paper also adds a detailed analysis on the external border effect for eachSpanish exporting region and each of the sevenEuropean countries considered. By means of this analysis, we shed new light on therelative integrationbetween regions of these seven countries andSpanish exporting regions. Finally, we conduct an extrapolation exercise, computing the ‘trade potentials’ that would be expected in a fully integratedEurope and estimating how long full integration would take to achieve between eachSpanish exporting region and eachEuropean importing country. To this regard, two alternative scenarios are considered: one using the growth rates of theSpanish exports before the crisis (2001–08) and other considering the post‐crisis growth rates (2011–13).
State and Extended Disturbance Observer for Sliding Mode Control of Mismatched Uncertain Systems
Authors: Ginoya Divyesh , Shendge P. D. , Phadke S. B.
Published: January 2015

In this paper, a state and extended disturbance observer (DO) is designed for mismatched uncertain systems. Apart from system states and disturbances, the proposed observer estimates the derivatives of the disturbances and thereby improves the accuracy of estimation of disturbances as well as the states. No knowledge of bounds of disturbances or their derivatives is assumed. An observer–controller combination for a sliding mode controller that requires the estimates of the derivatives of disturbances is described, and the ultimate boundedness of the overall system is proved. The proposed observer is illustrated by simulation of a numerical example and a rotary hydraulic actuator. The proposed observer–controller combination is validated on a serial flexible joint manipulator in laboratory.
From Crease Pattern to Product: Considerations to Engineering Origami-Adapted Designs
Authors: Francis Kevin C. , Rupert Levi T. , Lang Robert J. , Morgan David C. , Magleby Spencer P. , Howell Larry L.
Published: January 2015

Origami art provides possible inspiration for products that require extreme portability, stowability, and deployability. Origami-based design represents a possible source of innovative configurations for engineered products, which could meet challenging design situations. However, a fundamental gap exists between paper-based origami art and engineered products. This work proposes a basic terminology for origami-based design, and presents areas of consideration for cases where the final engineering design is directly related to a crease pattern. The considerations are applied after the crease pattern has been selected for a given application. Four areas of consideration are discussed: 1) rigid-foldability 2) crease characterization 3) material properties and dimensions and 4) manufacturing.

Two diverse examples are used to illustrate these areas of consideration: design for a backpack shell, and design of a shroud for an adjustable C-Arm x-ray device.
Multi-Objective Design Optimization of the Leg Mechanism for a Piping Inspection Robot
Authors: Henry Renaud , Chablat Damien , Porez Mathieu , Boyer Frédéric , Kanaan Daniel
Published: January 2015

This paper addresses the dimensional synthesis of an adaptive mechanism of contact points ie a leg mechanism of a piping inspection robot operating in an irradiated area as a nuclear power plant. This studied mechanism is the leading part of the robot sub-system responsible of the locomotion. Firstly, three architectures are chosen from the literature and their properties are described. Then, a method using a multi-objective optimization is proposed to determine the best architecture and the optimal geometric parameters of a leg taking into account environmental and design constraints. In this context, the objective functions are the minimization of the mechanism size and the maximization of the transmission force factor. Representations of the Pareto front versus the objective functions and the design parameters are given. Finally, the CAD model of several solutions located on the Pareto front are presented and discussed.
An Immersed Boundary Method for Calculating the Relative Viscosity of a Suspension of Rigid Particles
Authors: Daghooghi Mohsen , Borazjani Iman
Published: January 2015

In this paper, we provide a numerical framework to calculate the relative viscosity of a suspension of rigid particles. A high-resolution background grid is used to solve the flow around the particles. In order to generate infinite number of particles in the suspension, a particle is placed in the center of a cubic cell and periodic boundary conditions are imposed in two directions. The flow around the particle is solved using the second-order accurate curvilinear immersed boundary (CURVIB) method [1]. The particle is discretized with triangular elements, and is treated as a sharp interface immersed boundary by reconstructing the velocities on the fluid nodes adjacent to interface using a quadratic interpolation method. Hydrodynamic torque on the particle has been calculated, to solve the equation of motion for the particle and obtain its angular velocity. Finally, relative viscosity of the suspension has been calculated based on two different methods: (1) the rate of the energy consumption and (2) bulk stress-bulk strain method. The framework has been validated by simulating a suspension of spheres, and comparing the numerical results with the corresponding analytical ones. Very good agreement has been observed between the analytical and the calculated relative viscosities using both methods. This framework is then used to model a suspension with arbitrary complex particles, which demonstrates the effect of shape on the effective viscosity.
Hand Gesture Based Intuitive CAD Interface
Authors: Huang Jinmiao , Rai Rahul
Published: January 2015

A key objective of gesture based computer aided design (CAD) interface is to enable humans to manipulate 3D models in virtual environments in a manner similar to how such objects are manipulated in real-life. In this paper, we outline the development of a novel real-time gesture based conceptual computer aided design tool which enables intuitive hand gesture based interaction with a given design interface. Recognized hand gestures along with hand position information are converted into commands for rotating, scaling, and translating 3D models. In the presented system, gestures are identified based solely on the depth information obtained via inexpensive depth sensing cameras (SoftKinetics DepthSense 311). Since the gesture recognition system is entirely based on using depth images, the developed system is robust and insensitive to variations in lighting conditions, hand color, and background noise. The difference between the input hand shape and the nearest neighboring point in the database is employed as the criterion to recognize different gestures. Extensive experiments with a design interface are also presented to demonstrate the accuracy, robustness, and effectiveness of the presented system.
A Generic Approach to Modeling Geometry of Un-Deformed Chip by Mathematical Representing Envelopes of Swept Cutter in Five-Axis CNC Milling
Authors: Chang Zhiyong , Chen Zezhong C. , Zhao Jie , Zhang Dinghua
Published: January 2015

To pursue high performance 5-axis CNC milling in industry, it is crucial to simulate each specific mill process in high fidelity beforehand, which should model the machined surfaces and predict the cutting forces in the process planning. However, the kernel technique, representation of the un-deformed chip geometry removed by cutter in 5-axis milling, is far from mature. Aiming to solve the problem, this paper presents a generic approach to representing un-deformed chip geometry mathematically in 5-axis CNC milling. The unique features of this research are: (1) the machine tool kinematics chain is investigated and a 5-axis CNC interpolation algorithm is adopted to establish the tool kinematics model, and (2) the closed-form equation of the un-deformed chip geometry representation is derived based on the machined shape being the envelope of a group of ellipses. This approach can model a machined surface with high accuracy and efficiently, and can be used to evaluate the machine surface quality and machining parameters. It can greatly promote the technique of high performance 5-axis CNC milling.
Twice-Running-Speed Resonances of a Paper Machine Tube Roll Supported by Spherical Roller Bearings: Analysis and Comparison With Experiments
Authors: Heikkinen Janne , Ghalamchi Behnam , Sopanen Jussi , Mikkola Aki
Published: January 2015

Imperfections in a rotor-bearing system may cause undesirable subcritical resonances occurring when the rotating speed of the rotor is a fraction of the natural frequency of the system. These resonances arise partly from rotor imperfections and partly from bearing imperfections. This study demonstrates that the subcritical twice-running-speed vibrations originating from bearing waviness may be investigated by combining a simplified rotor model with a detailed bearing model, using a finite element method. The rotor-bearing system under investigation is a roller test rig consisting of the tube roll of a paper machine supported by spherical roller bearings. The bearing waviness from the second to the fourth orders is emulated as accurately as possible in the finite element model. This is achieved by measuring the waviness of the real bearings and then incorporating the measurement results into a simulation model. The tube roll of the test rig is modeled as a symmetric tube, neglecting the effects of the uneven mass and stiffness distribution of the roll. The contact between the rotor and the bearings is described using nonlinear Hertzian contact theory. The subcritical responses of the system are studied by means of time integration, and the results are converted into the frequency domain using fast Fourier transformation. The results of the analysis are compared with the measurement results for the subcritical responses of the roll. The agreement between the simulation and experimental results of the studied system can be observed even though rotor imperfections are not considered.
Evaluation of Micro-EDM Milling Performance Using Pulse Discrimination
Authors: Modica F. , Guadagno G. , Marrocco V. , Fassi I.
Published: January 2015

In this paper, the pulse discrimination of gap voltage and discharge current waveforms occurring during micro-EDM milling of micro-channels is analyzed in relation to process parameters variation and machining performance. The pulse classification algorithm discriminates voltage and current waveforms into four defined pulse types: short, arc, delayed and normal. The micro-channels are manufactured in hardened steel using an energy level corresponding to the finishing regime and varying pulse width, frequency, gain and gap. The analysis shows that when the erosion process is stable, normal discharges are predominant. Delayed and short pulses are very sporadic. A major number of arcs can be detected when the gap is decreased and gain increased, i.e. erosion speed and feed rate are increased and affect in particular tool wear. Also the increase of the pulse width has an effect on tool wear, though the percentage of the arcs remains small. On the contrary, material removal rate does not seem to be apparently related to the percentage of arcs as the process parameters are varied, since these values are spread in a constant range for all parameter combinations. The evaluation of the depth errors does not provide any significant insights about the erosion process in relation to the considered process parameters.
Stress-Constrained Thermo-Elastic Topology Optimization: A Topological Sensitivity Approach
Authors: Deng Shiguang , Suresh Krishnan , Joo James
Published: January 2015

The focus of this paper is on thermo-elastic topology optimization where the structure is subject to both mechanical and thermal loads. Such problems are of significant importance, for example, in the aircraft industry where structures subject to aerodynamic forces and thermal-gradients must be optimized.

A popular strategy for solving such problems is Solid Isotropic Material with Penalization (SIMP) where pseudo-densities serve as optimization parameters. Yet another strategy is the Rational Approximation of Material Properties (RAMP) that overcomes some of the deficiencies of SIMP. Both methods fundamentally rely on parameterization of the material properties as a function of the pseudo-densities.

Here we consider an alternate level-set approach that relies on the concept of topological sensitivity. The advantages of the proposed method over SIMP and RAMP are: (1) ad hoc material parameterization is not required (2) the stresses are well-defined at all points within the evolving topology and (3) the underlying stiffness matrices are always well-conditioned. The proposed method is illustrated through numerical experiments.
Topology Preserving Digitization of Physical Prototypes Using Deformable Subdivision Models
Authors: Arisoy Erhan Batuhan , Kara Levent Burak
Published: January 2015

Physical prototyping is an important stage of product design where designers have a chance to physically evaluate and alter digitally created surfaces. In these scenarios, designers generate a digital model, manufacture and alter the prototype as needed, and redigitize the prototype through scanning. Despite the variety of reverse engineering tools, redigitizing the prototypes into forms amenable to further digital editing remains a challenge. This is because current digitization methods cannot take advantage of the key elements of the original digital model such as the wireframe topology and surface flows. This paper presents a new reverse engineering method that augments conventional digitization with the knowledge of the original digital model’s curve topology to enhance iterative shape design activities. Our algorithm takes as input a curve network topology forming a subdivision control cage and a 3D scan of the physically modified prototype. To facilitate the digital capture of the physical modifications, our algorithm performs a series of registration, correspondence and deformation calculations to compute the new configuration of the initial control cage. The key advantage of the proposed technique is the preservation of the edge flows and initial topology while transferring surface modifications from prototypes. Our studies show that the proposed technique can be particularly useful for bridging the gap between physical and digital modeling in the early stages of product design.
Random Matrix Based Input Shaping Control of Uncertain Parallel Manipulators
Authors: Sovizi Javad , Alamdari Aliakbar , Narayanan Madusudanan Sathia , Krovi Venkat
Published: January 2015

Input shaping control techniques have proven to be very effective in improving performance and lowering actuation requirements for Linear Time-Invariant (LTI) systems. However, deployments tend to be very sensitive to variation of the system natural frequencies and damping ratios. This limits the application of input shaping schemes in the nonlinear systems (e.g., robotic manipulators) or systems with uncertain parameters. The main focus of this paper is to address the parametric uncertainty in the system and the design of an input shaping control based upon the estimated parameters. The variations induced by system non-linearity are tackled by the method of the linearization. The uncertainty is characterized by treating the linearized system mass matrix as a random matrix. This provides the probability density function of the eigenvalues of the underdamped system that are then used to design the input shaping control for the uncertain system. We believe that such a characterization (and desensitization to production variability) is especially important for successful deployment of newer generations of 3D printed robotic systems. This is verified via a Monte Carlo simulation — the statistics of the percent residual vibration verifies the superiority of the input shaping control scheme based on the estimated parameter values (compared to the one based on the nominal parameters).
Integrated Part Classification for Product Cost and Complexity Reduction
Authors: Nagiligari Babu K. , Shah Jimish , Sha Zhenghui , Thirugnanam Sathishkumar , Jain Anurag , Panchal Jitesh
Published: January 2015

The manufacturing industry is moving towards a truly global arena. Organizations are adopting the philosophy of “design anywhere, manufacture anywhere, and sell anywhere”. Global operations with local focus have become the core of an organization’s strategy. Organizations are trying to have a vast product portfolio with mass customization to meet the customers’ increasing demand for personalized products. While expanding the product portfolio and bringing new products to the market the aspect of product sustenance across its life cycle is often missed out. With regulatory standards becoming more stringent, product maintenance and retirement are becoming challenging and costly. The aspect of “circular economy” is extending the life of the product and individual parts beyond the traditional end of life with re-fabrication, reconditioning and recycling of parts. The part-level detailing is becoming very important at the design stage. This provides huge growth opportunities for organizations, but comes with challenges of increased complexity, variety and cost.

One of the potential ways to address the challenges listed above is the availability and maintenance of part-level information and dynamic traceability across the lifecycle, enriched with cross functional inputs. This is important for business decision making during product portfolio planning and product design in both proactive and reactive scenarios. Based on the authors’ industry experience across multiple product development organizations, it is evident that there is limited awareness of the potential of classification and its impact beyond basic part search and reuse. In this paper, we discuss the need for an integrated, cross-functional model and a common database for part information management. We present an agent-based simulation to show the benefits of such an integrated modeling strategy. In the process, the approach has the potential to also bring configurability of the product till the end of life. Configurability is from the aspect of making a product that will perform to meet customer needs along with delivering profit for business and being compliant with various regulatory norms.
An Overconstrained Eight-Bar Linkage and its Associated Fulleroid-Like Deployable Platonic Mechanisms
Authors: Wei Guowu , Dai Jian S.
Published: January 2015

This paper for the first time presents an overconstrained spatial eight-bar linkage and its application to the synthesis of a group of Fulleroid-like deployable Platonic mechanisms. Structure of the proposed eight-bar linkage is introduced, and constrain and mobility of the linkage are revealed based on screw theory. Then by integrating the proposed eight-bar linkage into Platonic polyhedron bases, synthesis of a group of Fulleroid-like deployable Platonic mechanism is carried out and illustrated by the synthesis and construction of a Fulleroid-like deployable tetrahedral mechanism. Further, mobility of the Fulleroid-like deployable Platonic mechanisms is formulated via constraint matrices by following Kirchhoff’s circulation law for mechanical networks and kinematics of the mechanisms is presented with numerical simulations illustrating the intrinsic kinematic properties of the group of Fulleroid-like deployable Platonic mechanisms. Ultimately, a prototype of the Fulleroid-like deployable hexahedral mechanism is fabricated and tested verifying mobility and kinematic characteristics of the proposed deployable polyhedral mechanisms. This paper thus presents a novel overconstrained spatial eight-bar linkage and a new geometrically intuitive method for synthesizing Fulleroid-like regular deployable polyhedral mechanisms.
Deployable Prismatic Structures With Origami Patterns
Authors: Liu Sicong , Lv Weilin , Chen Yan , Lu Guoxing
Published: January 2015

In order to find the general condition of the rigid origami pattern for the deployable prismatic structures, the kinematic model is proposed based on the mobile assemblies of spherical 4R linkages. The kinematic and geometric compatibility conditions of the mobile assemblies are derived. Two groups of 2n-side deployable prismatic structures are obtained. When n=2, one of them is with kite-shape intersection, while the other is with parallelgram. The variations of the unit are discussed. The straight and curvy multilayer prisms are built by changing the dihedral angles between the intersecting planes. The general design method for the 2n-side multilayer deployable prismatic structures is proposed with the geometric condition of the origami patterns. All the deployable structures constructed with this method can be deployed and folded along the central axis of the prisms with single degree of freedom, which makes the structures have wide engineering applications.
Kinematic Performance Analysis for Hexapod Mobile Robot Using Parallel Mechanism
Authors: Pan Yang , Gao Feng
Published: January 2015

Walking robots have been studied a lot over last several decades due to their good adaptability in different complex environments. The walking robot in this paper is designed for the research on emergency rescue missions in nuclear plants. Unlike other mobile robots, it apply parallel mechanism for its legs. This paper mainly focus on the kinematic performance of the parallel leg mechanism. Section 2 gives a brief introduction of our robot and the kinematic model. Then section 3 analyze the workspace of the leg tip. After that the payload and velocity capability are discussed respectively and it turns out that the mechanism has very good payload performance but the velocity is relatively low. Next the isotropic characteristic is studied in the whole workspace. Then the experiments indicate that the robot can successfully finish walking and manipulating tasks.
A Natural User Interface for Immersive Design Review
Authors: MacAllister Anastacia , Winer Eliot , Yeh Tsung-Pin , Seal Daniel , Degenhardt Grant
Published: January 2015

As markets demand engineered products faster, waiting on the cyclical design processes of the past is not an option. Instead, industry is turning to concurrent design and interdisciplinary teams. When these teams collaborate, engineering CAD tools play a vital role in conceptualizing and validating designs. These tools require significant user investment to master, due to challenging interfaces and an overabundance of features. These challenges often prohibit team members from using these tools for exploring alternatives. This paper presents a method allowing users to interact with a design using intuitive gestures and head tracking, all while keeping the model in a CAD format. Specifically, Siemens’ Teamcenter® Lifecycle Visualization Mockup (Mockup) was used to display the design geometry while modifications were made through a set of gestures captured by a Microsoft Kinect™ in real time. This proof of concept program allowed a user to rotate the scene, activate Mockup’s immersive menu, move the immersive wand, and manipulate the view based on head position. The result is an immersive user-friendly low cost platform for interdisciplinary design review.
Global Optimization With Quantum Walk Enhanced Grover Search
Authors: Wang Yan
Published: January 2015

One of the significant breakthroughs in quantum computation is Grover’s algorithm for unsorted database search. Recently, the applications of Grover’s algorithm to solve global optimization problems have been demonstrated, where unknown optimum solutions are found by iteratively improving the threshold value for the selective phase shift operator in Grover rotation. In this paper, a hybrid approach that combines continuous-time quantum walks with Grover search is proposed. By taking advantage of quantum tunneling effect, local barriers are overcome and better threshold values can be found at the early stage of search process. The new algorithm based on the formalism is demonstrated with benchmark examples of global optimization. The results between the new algorithm and the Grover search method are also compared.
Estimation of Light Commercial Vehicles Dynamics by Results of Road Tests and Simulation
Authors: Tumasov Anton , Groshev Anatoly , Musarsky Roman , Konikova Galina , Trusov Yury , Kostin Sergey
Published: January 2015

The chassis of light commercial vehicle (LCV) could be used for creating a wide range of vehicles modifications with the similar base (chassis), but really different performance in wide range of maneuvers. The differences could be explained by variety of design parameters. It means that the design of LCV modifications needs some effective approach that will provide an engineer by necessary data that could help to estimate the performance of new vehicles in particular active safety characteristics. This paper presents the combination of experimental and simulation methods that could be used for estimation of LCV active safety characteristics (first of all cornering stability). The experimental method of estimation of cornering stability is shown that is based on regulations of the Russian Standard GOST R 52302-2004 that presuppose different types of testing: static rollover and dynamic maneuvering on a road (line changing and running into the corner). The multi-body simulation method with using of MSC.ADAMS/CAR software was also used in a study. The approval of developed LCV multi-body model was made on a basis of good correlation between simulation results and experimental data. The relationship between LCVs design parameters (axle load distribution, height of the center of gravity, vertical and angular suspension stiffness) and active safety characteristics are received.
Design Optimization of a Warehousing Cable-Based Robot
Authors: Torres-Mendez Sergio , Khajepour Amir
Published: January 2015

The optimal architecture of a cable-based robot for warehousing applications is the main topic of this paper. This study is limited to two types of redundant planar symmetrical configurations with crossed and non-crossed cables. The design problem is divided in two main stages. First, the feasible workspace is optimized for a maximum size and rectangular-type shape of each of the redundant planar architectures. A set of four parameters is selected to fully define the geometry of the mobile platform and the location of its anchor points. In the second design stage, an optimized spatial architecture is obtained for a maximum stiffness by selecting a new set of six parameters which defines the transversal anchor points on both the mobile and static platforms. Based on these optimal parameters, a prototype is fully modeled and built for further experimentation.
Documentation in Progress: Challenges With Representing Design Process Online
Authors: Tseng Tiffany , Yang Maria , Ruthmann Stephen
Published: January 2015

Web-based documentation platforms afford lightweight and visually rich mechanisms for designers to share documentation online, yet present challenges regarding representation, particularly for collaborative teams. This paper highlights some of these issues through a descriptive case study based on the use of a new web-based social media tool for documenting the development of design projects called Build in Progress. Undergraduate students worked in teams to design musical construction kits and documented their process using Build in Progress over the course of three weeks. We examined students’ project pages to determine trends with how students visually represented their design process, and we gathered students’ experiences using the platform through surveys and interviews with select project teams. We found that groups developed their own representations of their design process via tree structures afforded by Build in Progress that present the simultaneous development of distinct elements of their projects and highlight the contributions of each student on the team. The interviews revealed differences between how internal and external documentation are presented and contrasting approaches to creating narrative and instructional documentation based on the intended audience. In particular, we found that students interpreted the tool as one used to help others recreate their design, which led to the omission of several parts of their design process, including experimentation and mistakes. These results suggest the need to further develop tools to support reflection on process rather than product.
Control of a Shape Memory Alloy Based Self-Folding Sheet
Authors: Halbert Tyler , Moghadas Peyman , Malak Richard , Hartl Darren
Published: January 2015

The practice of achieving engineering functionality through folding and fold-like operations — known as origami engineering — is receiving increased attention in the research community. Self-folding systems are of particular interest due to their potential to operate (semi-) autonomously in applications across a wide range of length scales. In recent work, we created a reconfigurable self-folding sheet using shape memory alloy (SMA) layers to achieve fold-like behavior. The prior work was devoted to modeling, simulation, and experimentation with the sheet. No attempt had been made to control the sheet. This paper extends our prior work to include feedback control of the self-folding sheet. In particular, the goal is to perform fold control — the use of feedback control to ensure the sheet achieves a desired folded configuration.

Control of SMA material is difficult due to its hysteretic nature. This application involves a laminate material with embedded SMA wires, which further complicates control due to the interaction of the wires with each layer of the sheet. We explore two feedback control methods, On/Off and PID, using a simulation framework for controller evaluation. In the interest of computational efficiency, we introduce a new model for sheet behavior based on classical laminate theory. This allows for a significant reduction in computational cost compared to the finite element models we used in prior work with only a modest tradeoff in terms of accuracy. Our results show that both control methods are capable of performing fold control, but that the On/Off controller is superior in terms of energy requirements.
A System Uncertainty Propagation Approach With Model Uncertainty Quantification in Multidisciplinary Design
Authors: Jiang Zhen , Li Wei , Apley Daniel W. , Chen Wei
Published: January 2015

The performance of a multidisciplinary system is inevitably affected by various sources of uncertainties, usually categorized as aleatory (e.g. input variability) or epistemic (e.g. model uncertainty) uncertainty. In the framework of design under uncertainty, all sources of uncertainties should be aggregated to assess the uncertainty of system quantities of interest (QOIs). In a multidisciplinary design system, uncertainty propagation refers to the analysis that quantifies the overall uncertainty of system QOIs resulting from all sources of aleatory and epistemic uncertainty originating in the individual disciplines. However, due to the complexity of multidisciplinary simulation, especially the coupling relationships between individual disciplines, many uncertainty propagation approaches in the existing literature only consider aleatory uncertainty and ignore the impact of epistemic uncertainty. In this paper, we address the issue of efficient uncertainty quantification of system QOIs considering both aleatory and epistemic uncertainties. We propose a spatial-random-process (SRP) based multidisciplinary uncertainty analysis (MUA) method that, subsequent to SRP-based disciplinary model uncertainty quantification, fully utilizes the structure of SRP emulators and leads to compact analytical formulas for assessing statistical moments of uncertain QOIs. The proposed method is applied to a benchmark electronics packaging problem. To demonstrate the effectiveness of the method, the estimated low-order statistical moments of the QOIs are compared to the results from Monte Carlo simulations.
Ramp Forecasting Performance From Improved Short-Term Wind Power Forecasting
Authors: Zhang Jie , Florita Anthony , Hodge Bri-Mathias , Freedman Jeffrey
Published: January 2015

The variable and uncertain nature of wind generation presents a new concern to power system operators. One of the biggest concerns associated with integrating a large amount of wind power into the grid is the ability to handle large ramps in wind power output. Large ramps can significantly influence system economics and reliability, on which power system operators place primary emphasis. The Wind Forecasting Improvement Project (WFIP) was performed to improve wind power forecasts and determine the value of these improvements to grid operators. This paper evaluates the performance of improved short-term wind power ramp forecasting. The study is performed for the Electric Reliability Council of Texas (ERCOT) by comparing the experimental WFIP forecast to the current short-term wind power forecast (STWPF). Four types of significant wind power ramps are employed in the study; these are based on the power change magnitude, direction, and duration. The swinging door algorithm is adopted to extract ramp events from actual and forecasted wind power time series. The results show that the experimental short-term wind power forecasts improve the accuracy of the wind power ramp forecasting, especially during the summer.