bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of SIAscopy in the triage of suspicious skin tumours
Authors: Sgouros D. , Lallas A. , Julian Y. , Rigopoulos D. , Zalaudek I. , Longo C. , Moscarella E. , Simonetti V. , Argenziano G.
Published: February 2014

Background/purpose

Spectrophotometric Intracutaneous Analysis (SIAscopy) is a non‐invasive, computerized technique for the diagnosis of pigmented skin tumours. The analysis is based on the evaluation of skin chromophores, i.e. melanin, haemoglobin and collagen within the epidermis and papillary dermis. Our aim was to assess the diagnostic validity of SIAscopy in the detection of melanoma and non‐melanoma skin cancers compared to the clinical‐dermoscopic diagnosis and the histopathologic results of the excised lesions.

Methods

In total, 188 lesions of 180 patients were examined by dermoscopy and SIAscopy. A SIAscopy scoring system was first compared with the clinical‐dermoscopic diagnosis and then with the histopathologic diagnosis of the excised lesions.

Results

With respect to the clinical‐dermoscopic evaluation, SIAscopy had sensitivity and specificity values of 85.7% and 65.4% respectively. Of the 188 evaluated lesions, 44 were excised with histopathologic examination revealing 31 malignant tumours, including 18 melanomas. With respect to histopathology SIAscopy had a sensitivity of 83.9%. Seven of the 13 benign excised lesions were scored as malignant by SIAscopy resulting in a specificity of 46.1%.

Conclusion

SIAscopy cannot replace the standard of care in skin cancer diagnosis, which includes clinical and dermoscopic examination. However, considering that the technique does not require specific training and expertise, it might represent an additional, relatively cost‐effective tool to select lesions for referral.
Tumor necrosis factor haplotype diversity in Mestizo and Native populations of Mexico
Authors: Castro‐Martínez X. H. , Leal‐Cortés C. , Flores‐Martínez S. E. , García‐Zapién A. G. , Sánchez‐Corona J. , Portilla‐de Buen E. , Gómez‐Espinel I. , Zamora‐Ginez I. , Pérez‐Fuentes R. , Islas‐Andrade S. , Revilla‐Monsalve C. , Guerrero‐Romero F. , Rodríguez‐Morán M. , Mendoza‐Carrera F.
Published: February 2014

The so‐called tumor necrosis factor (TNF) block includes the TNFA, lymphotoxin alpha and beta (LTA and LTB) genes with single‐nucleotide polymorphisms (SNP) and microsatellites with an allele frequency that exhibits interpopulation variability. To date, no reports have included both SNPs and microsatellites at the TNF block to study Mestizo or Amerindian populations from Mexico. In this study, samples of five Mexican Mestizo populations (Durango, Guadalajara, Monterrey, Puebla, and Tierra Blanca) and four native‐Mexican populations (North Lacandonians, South Lacandonians, Tepehuanos, and Yaquis) were genotyped for two SNPs (LTA+252A>G and TNFA–308G>A) and four microsatellites (TNFa, d, e, and f), to analyze the genetic substructure of the Mexican population. Allele and haplotype frequencies, linkage disequilibrium (LD), and interpopulation genetic relationships were calculated. There was significant LD along almost all of the TNF block but the lowest D′ values were observed for the TNFf–TNFd pair. Mestizos showed higher allele and haplotype diversity than did natives. The genetic differentiation level was reduced among Mestizos; however, a slightly, but significant genetic substructure was observed between northern and southern Mexican Mestizos. Among the Amerindian populations, the genetic differentiation level was significantly elevated, particularly in both North and South Lacandonians. Furthermore, among Southern Lacandonians, inhabitants of Lacanja town were the most differentiated from all the Mexicans analyzed. The data presented here will serve as a reference for further population and epidemiological studies including these TNF polymorphisms in the Mexican population.
Four‐year retention and risk factors for attrition among members of community ART groups in Tete, Mozambique
Authors: Decroo Tom , Koole Olivier , Remartinez Daniel , dos Santos Natacha , Dezembro Sergio , Jofrisse Mariano , Rasschaert Freya , Biot Marc , Laga Marie
Published: February 2014

Objective

Community ART groups (CAG), peer support groups involved in community ART distribution and mutual psychosocial support, were piloted to respond to staggering antiretroviral treatment (ART) attrition in Mozambique. To understand the impact of CAG on long‐term retention, we estimated mortality and lost‐to‐follow‐up (LTFU) rates and assessed predictors for attrition.

Methods

Retrospective cohort study. Kaplan–Meier techniques were used to estimate mortality and LTFU in CAG. Individual‐ and CAG‐level predictors of attrition were assessed using a multivariable Cox proportional hazards model, adjusted for site‐level clustering.

Results

Mortality and LTFU rates among 5729 CAG members were, respectively, 2.1 and 0.1 per 100 person‐years. Retention was 97.7% at 12 months, 96.0% at 24 months, 93.4% at 36 months and 91.8% at 48 months. At individual level, attrition in CAG was significantly associated with immunosuppression when joining a CAG, and being male. At CAG level, attrition was associated with lack of rotational representation at the clinic, lack of a regular CD4 count among fellow members and linkage to a rural or district clinic compared with linkage to a peri‐urban clinic.

Conclusions

Long‐term retention in this community‐based ART model compares favourably with published data on stable ART patients. Nevertheless, to reduce attrition, further efforts need to be made to enrol patients earlier on ART, promote health‐seeking behaviour, especially for men, promote a strong peer dynamic to assure rotational representation at the clinic and regular CD4 follow‐up and reinforce referral of sick patients.
Family 34 glycosyltransferase (GT34) genes and proteins in Pinus radiata (radiata pine) and Pinus taeda (loblolly pine)
Authors: Ade Carsten P. , Bemm Felix , Dickson James M.J. , Walter Christian , Harris Philip J.
Published: February 2014

Using a functional genomics approach, four candidate genes (PtGT34A, PtGT34B, PtGT34C and PtGT34D) were identified in Pinus taeda. These genes encode CAZy family GT34 glycosyltransferases that are involved in the synthesis of cell‐wall xyloglucans and heteromannans. The full‐length coding sequences of three orthologs (PrGT34A, B and C) were isolated from a xylem‐specific cDNA library from the closely related Pinus radiata. PrGT34B is the ortholog of XXT1 and XXT2, the two main xyloglucan (1→6)‐α‐xylosyltransferases in Arabidopsis thaliana. PrGT34C is the ortholog of XXT5 in A. thaliana, which is also involved in the xylosylation of xyloglucans. PrGT34A is an ortholog of a galactosyltransferase from fenugreek (Trigonella foenum‐graecum) that is involved in galactomannan synthesis. Truncated coding sequences of the genes were cloned into plasmid vectors and expressed in a Sf9 insect cell‐culture system. The heterologous proteins were purified, and in vitro assays showed that, when incubated with UDP‐xylose and cellotetraose, cellopentaose or cellohexaose, PrGT34B showed xylosyltransferase activity, and, when incubated with UDP‐galactose and the same cello‐oligosaccharides, PrGT34B showed some galactosyltransferase activity. The ratio of xylosyltransferase to galactosyltransferase activity was 434:1. Hydrolysis of the galactosyltransferase reaction products using galactosidases showed the linkages formed were α‐linkages. Analysis of the products of PrGT34B by MALDI‐TOF MS showed that up to three xylosyl residues were transferred from UDP‐xylose to cellohexaose. The heterologous proteins PrGT34A and PrGT34C showed no detectable enzymatic activity.
How Far Away is an Intangible? Services FDI and Distance
Authors: Davies Ronald B. , Guillin Amélie
Published: February 2014

Foreign direct investment (FDI) in services has grown significantly in recent years. Evidence of spatial relationships in FDI decisions have been provided for goods manufacturing by utilising physical distance‐based measures of trade costs. This paper investigates spatial interactions for services FDI using several distance measures, including physical distance, genetic distance and transport time. Across different measures of distance, the traditional determinants of outbound FDI activity remain valid for services. We also find spatial interdependence for services FDI that is generally supportive of export‐platform FDI.
Evaluation of anti‐Müllerian hormone in a dog with a Sertoli cell tumour
Authors: Ano Hitoshi , Hidaka Yuichi , Katamoto Hiromu
Published: February 2014

Background

Testicular tumours are common in elderly male dogs, and Sertoli cell tumours (SCTs) are among the most common. An increase in blood estradiol concentration is often seen in canine SCTs, but such measurements do not necessarily correlate with the clinical signs.

Case report

A 6‐year‐old male Pembroke Welsh corgi was referred for nonpruritic alopecia. Clinical examination revealed cryptorchidism of the right testicle, and blood tests showed an increased estradiol concentration. The cryptorchid testis was removed by laparotomy, and SCT was diagnosed histologically. An enzyme‐linked immunosorbent assay kit designed to measure human anti‐Müllerian hormone (AMH) revealed a very high preoperative serum AMH concentration, which decreased after surgery. The serum AMH concentrations of two intact healthy control male dogs were lower than that of the dog with the SCT before treatment but higher than those of two healthy castrated male dogs.

Conclusions and clinical importance

Canine serum AMH concentrations, as measured by a human AMH enzyme‐linked immunosorbent assay, may be useful as a marker for canine SCT.
On the role of survivin as a stem cell biomarker of canine hair follicle and related tumours
Authors: Bongiovanni Laura , Di Diodoro Francesca , Della Salda Leonardo , Brachelente Chiara
Published: February 2014

Background

Survivin has been identified as one of the most cancer‐specific molecules, with a dual function of apoptosis inhibitor and orchestrator of cell division.

Hypothesis/Objectives

Based on our recent results obtained during the study of the role of survivin in epithelial‐to‐mesenchymal transition, we investigate its potential role in maintenance of stemness in both the normal canine hair follicle and related tumours.

Methods

We performed a simultaneous evaluation, by immunofluorescence, of the expression of survivin and CK15. CK15 was selected as a marker for epidermal and hair follicle stem cells, based on its ability to identify hair follicle stem cells in the normal hair follicle and in canine follicular tumours. In this study, six cases were selected from the cases of hair follicle tumours evaluated in previous studies, based on the highest immunoreactivity for survivin and CK15. Three samples of healthy canine skin were also included as a normal control.

Results

A partial co‐localization of the molecules was observed in normal hair follicles, as well as in trichoepitheliomas and trichoblastomas. In particular, a different co‐expression was observed in relationship to the hair follicle cycle stage.

Conclusions and clinical importance

These findings suggest that survivin could play an important role in the maintenance of the hair follicle cycle as well as in tumour initiation and maintenance of cancer stem cells.
The Effects of Trailing Edge Thickness on the Losses of Ultrahigh Lift Low Pressure Turbine Blades
Authors: Zhou Chao , Hodson Howard , Himmel Christoph
Published: February 2014

Experimental, numerical and analytical methods were used to investigate the effects of the blade trailing edge thickness on the profile loss of ultrahigh-lift low-pressure turbine blades. Two cascades, the T106C and the T2, were studied. The loss obtained based on the data at the blade trailing edge plane and the plane 0.3 Chord downstream of the trailing edge agree with each other for T106C blade with and without upstream wakes at different Reynolds numbers. The blade profile losses were broken down as the suction surface boundary loss, the pressure side boundary loss and the mixing loss downstream of the trailing edge for six Reynolds numbers. Trailing edge thicknesses varying from 1.4% to 4.7% pitch were investigated at a Reynolds number of 210,000. It was found that the flow distributions across the passage at the trailing edge planes were highly nonuniform. In particular, and as a result, the trailing edge base pressure was higher than the mixed-out static pressure, so the contribution of the base pressure to the mixing loss downstream of the trailing edge plane was to reduce the loss. When the trailing edge thickness increases, there are three main effects: (1) the area with high base pressure region increases, which tends to reduce the downstream mixing loss; (2) the base pressure reduces, which tends to increase the loss; and (3) the flow diffusion downstream of the trailing edge, which tends to increase the loss. The overall result is the combined effect. For the T106C cascade, increasing the trailing edge thickness from 1.9% pitch to 2.8% pitch has a small effect on the loss. Further increasing the trailing edge thickness increases the loss. The T2 blade has a higher lift than the T106C blade, so the effects of the base pressure in reducing the mixing loss downstream of the trailing edge is more evident. The experimental results show that the profile loss first decreases and then increases as the trailing edge thickness increases. CFD, using the transition k-ω SST model and the k-ω SST model, provides good predictions of the aerodynamic performance. It was used to study the cases with trailing edge thicknesses of 1.4% pitch and 2.9% pitch. The profile loss is almost the same for these two trailing edge thickness. The results show that it is possible to use thicker blade trailing edges in low pressure turbines without aerodynamic penalty. This can lead to benefits in terms of mechanical integrity and manufacturing cost reductions.
An Efficient Methodology for the Reliability Analysis of Corroding Pipelines
Authors: Zhang Shenwei , Zhou Wenxing
Published: February 2014

This paper describes an efficient methodology that utilizes the first order reliability method (FORM) and system reliability approaches to evaluate the time-dependent failure probabilities of a pressurized pipeline at a single active corrosion defect considering three different failure modes, i.e., small leak, large leak, and rupture. The criteria for distinguishing small leak, large leak, and rupture at a given corrosion defect are established based on the information in the literature. The wedge integral and probability weighting factor methods are used to evaluate the probabilities of small leak and burst, whereas the conditional reliability index method is used to evaluate the probabilities of large leak and rupture. Two numerical examples are used to illustrate the accuracy, efficiency and robustness of the proposed methodology. The proposed methodology can be used to facilitate reliability-based corrosion management programs for energy pipelines.
Electrohydrodynamic Microfabricated Ionic Wind Pumps for Thermal Management Applications
Authors: Ongkodjojo Ong Andojo , Abramson Alexis R. , Tien Norman C.
Published: February 2014

This work demonstrates an innovative microfabricated air-cooling technology that employs an electrohydrodynamic (EHD) corona discharge (i.e., ionic wind pump) for electronics cooling applications. A single, microfabricated ionic wind pump element consists of two parallel collecting electrodes between which a single emitting tip is positioned. A grid structure on the collector electrodes can enhance the overall heat-transfer coefficient and facilitate an IC compatible batch process. The optimized devices studied exhibit an overall device area of 5.4 mm × 3.6 mm, an emitter-to-collector gap of ∼0.5 mm, and an emitter curvature radius of ∼12.5 μm. The manufacturing process developed for the device uses glass wafers, a single mask-based photolithography process, and a low-cost copper-based electroplating process. Various design configurations were explored and modeled computationally to investigate their influence on the cooling phenomenon. The single devices provide a high heat-transfer coefficient of up to ∼3200 W/m2 K and a coefficient of performance (COP) of up to ∼47. The COP was obtained by dividing the heat removal enhancement, ΔQ by the power consumed by the ionic wind pump device. A maximum applied voltage of 1.9 kV, which is equivalent to approximately 38 mW of power input, is required for operation, which is significantly lower than the power required for the previously reported devices. Furthermore, the microfabricated single device exhibits a flexible and small form factor, no noise generation, high efficiency, large heat removal over a small dimension and at low power, and high reliability (no moving parts); these are characteristics required by the semiconductor industry for next generation thermal management solutions.
Assessment and Characterization of Volcanic Ash Threat to Gas Turbine Engine Performance
Authors: Davison Craig R. , Rutke Timothy A.
Published: February 2014

Multiple volcanoes erupt yearly propelling volcanic ash into the atmosphere and creating an aviation hazard. The plinian eruption type is most likely to create a significant aviation hazard. Plinian eruptions can eject large quantities of fine ash up to an altitude of 50,000 m (164,000 ft). While large airborne particles rapidly fall, smaller particles at reduced concentrations drift for days to weeks as they gradually descend and deposit on the ground. Very small particles, less than 1 μm, can remain aloft for years. An average of three aircraft encounters with volcanic ash was reported every year between 1973 and 2003. Of these, eight resulted in some loss of engine power, including a complete shutdown of all four engines on a Boeing 747. However, no crashes have been attributed to volcanic ash. The major forms of engine damage caused by volcanic ash are: (1) deposition of ash on turbine nozzles and blades due to glassification (2) erosion of compressor and turbine blades (3) carbon deposits on fuel nozzles. The combination of these effects can push the engine to surge and flame out. If a flame out occurs, engine restart may be possible. Less serious engine damage can also occur. In most cases the major damage will require an engine overhaul long before the minor damage becomes an operational issue, but under some conditions no sign of volcanic ash is evident and the turbine cooling system blockage could go unnoticed until an engine inspection is performed. Several organizations provide aircrew procedures to respond to encounters with a volcanic ash cloud. If a volcanic ash encounter is suspected, then an engine inspection, including borescope, should be performed with particular attention given to the turbine cooling system.
Effect of Cetane Improver on Autoignition Characteristics of Low Cetane Sasol IPK Using Ignition Quality Tester1
Authors: Zheng Ziliang , Badawy Tamer , Henein Naeim , Sattler Eric , Johnson Nicholas
Published: February 2014

This paper investigates the effect of a cetane improver on the autoignition characteristics of Sasol IPK in the combustion chamber of the ignition quality tester (IQT). The fuel tested was Sasol IPK with a derived cetane number (DCN) of 31, treated with different percentages of Lubrizol 8090 cetane improver ranging from 0.1 to 0.4%. Tests were conducted under steady state conditions at a constant charging pressure of 21 bar. The charge air temperature before fuel injection varied from 778 to 848 K. Accordingly, all the tests were conducted under a constant charge density. The rate of heat release was calculated and analyzed in detail, particularly during the autoignition period. In addition, the physical and chemical delay periods were determined by comparing the results of two tests. The first was conducted with fuel injection into air according to ASTM standards where combustion occurred. In the second test, the fuel was injected into the chamber charged with nitrogen. The physical delay is defined as the period of time from start of injection (SOI) to point of inflection (POI), and the chemical delay is defined as the period of time from POI to start of combustion (SOC). Both the physical and chemical delay periods were determined under different charge temperatures. The cetane improver was found to have an effect only on the chemical ID period. In addition, the effect of the cetane improver on the apparent activation energy of the global combustion reactions was determined. The results showed a linear drop in the apparent activation energy with the increase in the percentage of the cetane improver. Moreover, the low temperature (LT) regimes were investigated and found to be presented in base fuel, as well as cetane improver treated fuels.
Modeling of Thermomagnetic Phenomena in Active Magnetocaloric Regenerators
Authors: Trevizoli Paulo V. , Barbosa Jader R. , Tura Armando , Arnold Daniel , Rowe Andrew
Published: February 2014

The active magnetic regenerator (AMR) consists of a porous matrix heat exchanger whose solid phase is a magnetocaloric material (solid refrigerant) that undergoes a reversible magnetic entropy change when subjected to a changing magnetic field. The cooling capacity of the cycle is proportional to the mass of solid refrigerant, operating frequency, volumetric displacement of the heat transfer fluid and regenerator effectiveness. AMRs can be modeled via a porous media approach and a model has been developed in this work to simulate the time-dependent fluid flow and heat transfer processes in the regenerator matrix. Gadolinium (Gd) is usually adopted as a reference material for magnetic cooling at near room temperature and its magnetic temperature change and physical properties were accounted for through a combination of experimental data and the Weiss-Debye-Sommerfeld (WDS) theory. In this paper, the interaction of the applied magnetic field waveform with the heat transfer fluid displacement profile and the influence of demagnetizing effects on the AMR performance are investigated numerically. The numerical model is evaluated against experimental data for a regenerator containing spherical Gd particles.
Flow in the Simplified Draft Tube of a Francis Turbine Operating at Partial Load—Part I: Simulation of the Vortex Rope
Authors: Foroutan Hosein , Yavuzkurt Savas
Published: February 2014

Numerical simulations and analysis of the vortex rope formation in a simplified draft tube of a model Francis turbine are carried out in this paper, which is the first part of a two-paper series. The emphasis of this part is on the simulation and investigation of flow using different turbulence closure models. Two part-load operating conditions with same head and different flow rates (91% and 70% of the best efficiency point (BEP) flow rate) are considered. Steady and unsteady simulations are carried out for axisymmetric and three-dimensional grid in a simplified axisymmetric geometry, and results are compared with experimental data. It is seen that steady simulations with Reynolds-averaged Navier–Stokes (RANS) models cannot resolve the vortex rope and give identical symmetric results for both the axisymmetric and three-dimensional flow geometries. These RANS simulations underpredict the axial velocity (by at least 14%) and turbulent kinetic energy (by at least 40%) near the center of the draft tube, even quite close to the design condition. Moving farther from the design point, models fail in predicting the correct levels of the axial velocity in the draft tube. Unsteady simulations are performed using unsteady RANS (URANS) and detached eddy simulation (DES) turbulence closure approaches. URANS models cannot capture the self-induced unsteadiness of the vortex rope and give steady solutions while DES model gives sufficient unsteady results. Using the proper unsteady model, i.e., DES, the overall shape of the vortex rope is correctly predicted and the calculated vortex rope frequency differs only 6% from experimental data. It is confirmed that the vortex rope is formed due to the roll-up of the shear layer at the interface between the low-velocity inner region created by the wake of the crown cone and highly swirling outer flow.
Manufacture of Optimized Face-Hobbed Spiral Bevel Gears on Computer Numerical Control Hypoid Generator
Authors: Simon Vilmos V.
Published: February 2014

In this study, a method is proposed for the advanced manufacture of face-hobbed spiral bevel gears on CNC hypoid generators with optimized tooth surface geometry. An optimization methodology is applied to systematically define optimal head-cutter geometry and machine tool settings to introduce optimal tooth modifications. The goal of the optimization is to simultaneously minimize tooth contact pressures and angular displacement error of the driven gear (the transmission error). The optimization is based on machine tool setting variation on the cradle-type generator conducted by optimal polynomial functions. An algorithm is developed for the execution of motions on the CNC hypoid generator using the relations on the cradle-type machine. Effectiveness of the method was demonstrated by using a face-hobbed spiral bevel gear example. Significant reductions in the maximum tooth contact pressure and in the transmission errors were obtained.
A Novel Structure of a Less Invasive Forceps to Realize Linear Clamping for Endoscopic Surgery
Authors: Zhao Ruzhen , Zhao Shuang , Sang Yuanjun , Luo Yun
Published: February 2014

Safety is always a commonly concerned issue during the development of minimally invasive surgery for more than 30 yr. For the absence of force feedback in conventional forceps, excessive pressure may be applied on tissues leading to unexpected injury. In this paper, a gear-rack endoscopic forceps structure embedded with a shape memory alloy (SMA) is proposed to solve this problem. The gear-rack jaws structure enables a linear relation between clamping pressure and handling force which makes the estimating clamping force easier for a surgeon. The SMA wire is embedded to control the clamping pressure at a certain value which is necessary and sufficient for tissue clamping. In this way, the forceps with these two features could make surgery much safer. A prototype is designed to demonstrate the concept.
Design and Preliminary Testing of a Pneumatic Muscle-Actuated Transfemoral Prosthesis
Authors: Wu Molei , Driver Tad , Wu Sai-Kit , Shen Xiangrong
Published: February 2014

Providing powered joint actuation is a major focus of research in the lower-limb prosthesis area. The capability of actively powering the joints enables the prosthesis to meet the energetic requirements of locomotion, and thus provide higher performance in restoring the lost lower-limb functions in comparison with traditional passive prostheses. In this paper, a powered transfemoral (above-knee) prosthesis is presented, in which the knee and ankle are powered with pneumatic muscle actuators. A new variable-radius pulley-based mechanism is utilized, which enables the free adjustment of actuation torque curve to better match the desired torque curve as dictated by the locomotive requirements. Additionally, a spring-return mechanism is also incorporated, which replaces the muscle actuator in the “weak” (less torque-demanding) direction with a set of mechanical springs. With this mechanism, both knee and ankle joints can be powered while maintaining a compact profile of the prosthesis. The design details are presented, and the prosthesis is able to provide sufficient torque for an 85 kg user in various locomotion modes. A prototype of the prosthesis has been fabricated and tested, with the preliminary results indicating that this prosthesis is able to provide a walking gait similar to that of a healthy person.
A New Solution for CAE Process Automation and Customization: LMS Virtual.Lab Composer
Authors: Conti Giancarlo , De Cuyper Joris
Published: February 2014

Automation and customization capabilities are becoming one of the most important trends for CAE industry, allowing to fulfill some important needs like improving productivity, increasing value-added time and establishing best practices. The state of the art to meet these requirements is the usage of dedicated applications, also called “verticals”, which enable end-users to save time by automating repetitive tasks, as well as to capture best practices and to manage complex processes with simple, user-friendly interfaces. Within the LMS CAE development suite Virtual.Lab one could already create MS Visual Basic scripts and stand-alone executables, by either programming or macro journaling, where different expertise levels of VB programming were required depending on the complexity of the desired application.

A new solution, called LMS Virtual.Lab Composer, takes it even further: it dramatically improves the development process of verticals by providing dedicated MS Visual Basic controls which allow non-expert users to easily build dedicated applications without need of any extensive programming knowledge. Two examples of verticals created with Virtual.Lab Composer for different multi-body technology based applications are shown in this paper: LMS Driving Dynamics for vehicle’s driving dynamic assessment and a tool for engine mount suspension design.
Synthesis of Planar Mechanisms for Pick and Place Tasks With Guiding Locations
Authors: Larochelle Pierre
Published: February 2014

A novel dimensional synthesis technique for solving the mixed exact and approximate motion synthesis problem for planar RR kinematic chains is presented. The methodology uses an analytic representation of the planar RR dyads rigid body constraint equation in combination with an algebraic geometry formulation of the exact synthesis for three prescribed locations to yield designs that exactly reach the prescribed pick & place locations while approximating an arbitrary number of guiding locations. The result is a dimensional synthesis technique for mixed exact and approximate motion generation for planar RR dyads. A solution dyad may be directly implemented as a 2R open chain or two solution dyads may be combined to form a planar 4R closed chain; also known as a planar four-bar mechanism. The synthesis algorithm utilizes only algebraic geometry and does not require the use of a numerical optimization algorithm or a metric on planar displacements. Two implementations of the synthesis algorithm are presented; computational and graphical construction. Moreover, the kinematic inversion of the algorithm is also included. An example that demonstrates the synthesis technique is included.
Manufacturability Analysis and Design Feedback System Developed Using Semantic Framework
Authors: Rangarajan Arvind , Radhakrishnan Pradeep , Moitra Abha , Crapo Andrew , Robinson Dean
Published: February 2014

Early manufacturability feedback is critical for reducing product cost and lead-time. This paper describes a new architecture and platform for authoring and applying manufacturability rules for design. The key step is to define a domain-specific ontology by creating a higher-level semantic language that describes design and manufacturing concepts relevant to specific manufacturing processes. This language has two primary uses; express design in the context of manufacturing and relate manufacturing constraints on design as declarative rules. OWL and Jena (a reasoning engine) are used in the background to reason about specific designs and provide manufacturability feedback in a client-server model. The use of Semantic Web technology makes it easier to augment manufacturability feedback with a query system for the designer that utilizes the same rule knowledge base to answer what-if scenarios. This is implemented using SPARQL and using the CAD design context and so enhances the user experience. This novel approach makes it easier for the domain experts to write or verify rules and the designers to validate concepts before changing the CAD model. This helps in maintaining the independence between the CAD platform and core enterprise knowledge. A pilot study in the sheet metal domain is implemented to demonstrate the steps necessary for complete early manufacturability analysis software and highlights the benefits of this approach.
The Evaluation of a Virtual-Aided Design Engineering Review (VADER) System for Automated Knowledge Capture and Reuse
Authors: Sung Raymond C. W. , Ritchie James M. , Lim Theodore , Sivanathan Aparajithan , Chantler Mike J.
Published: February 2014

Conducting knowledge capture and embedding it into a products’ through lifecycle remains a key issue in engineering industries; particularly with regard to rationale associated knowledge emanating during formal design reviews. Manual, and often interruptive, methods with associated costly overheads, exacerbate the already time consuming process. As well as these disadvantages, manual methods can potentially capture the wrong data due to human error or not fully-capturing all the pertinent information and associated relationships. Consequently, industries are seeking automated engineering knowledge capture and rationale that adds value to product and processes, potentially reaping the benefits of time and cost. Previous work by the authors proved how user-logging in virtual environments aid unobtrusive capture of engineering knowledge and rationale in design tasks.

This paper advances the work further through a Virtual Aided Design Engineering Review (VADER) system developed to automatically and unobtrusively capture both multimodal human-computer and human-human interactivity during design reviews via the synchronous time-phased logging of software interactions, product models, audio, video and input devices. By processing the captured data review reports and records can be automatically generated as well as allowing fast knowledge retrieval. The backbone of VADER is a multimodal device and data fusion architecture to capture and synchronise structured and unstructured data in realtime. Visualisation is through a 3D virtual environment. In addition to allowing engineers to visualise and annotate 3D design models, the system provides a timeline interface to search and visualise the captured decisions from a design review.

The VADER system has been put through its initial industrial trial and reported herein. Objective and subjective analysis indicate the VADER system is intuitive to use and can lead to savings in both time and cost with regard to project reviews.
Dealing With the Combinatorial Explosion of the Morphological Matrix in a “Manual Engineering Design” Context
Authors: Motte Damien , Bjärnemo Robert
Published: February 2014

The morphological matrix is an important element of the engineering design methodology and is present in many textbooks. This method originally aimed at generating an exhaustive set of solutions for a given problem, by decomposing it into subproblems, finding solutions to each subproblem, and combining them. One issue associated with the morphological matrix has been the necessity to deal with the combinatorial explosions of solutions, especially at the conceptual design phase, when the still fuzzy nature of the design problem precludes the use of automated search for an optimal solution by means of specific algorithms (the “manual engineering design” context), apart from a few exceptions. Several heuristics based on the reduction of the number of combinations are investigated, and their efficiency is assessed. It is showed that the often-recommended compatibility matrix heuristic is the least efficient and can result in overlooking potentially interesting combinations. In fact all heuristics, even combined, generally fail to decrease the number of combinations to a level that can be handled by the designers, unless the original number of combinations is low. However, if one abandons the principle of an exhaustive investigation of the combinations in order to find the “best” solution, it can be showed statistically that the probability of ending up with a “good” concept among a very large number of combinations can be attained. Moreover, it is showed that the number of combinations one is willing to investigate also can contribute to increase this probability. Moreover the experience gained from the first round of investigation can serve as a guide to choose and assess other combinations. Based on those results, some recommendations for using the morphological matrix with all the different heuristics are given. Moreover, this paper discusses and relativizes the importance of the combinatorial explosion issue of morphological matrix compared with some other advantages and shortcomings of the method.
Second Order Accuracy Finite Difference Methods for Fractional Diffusion Equations
Authors: Takeuchi Yuki , Suda Reiji
Published: February 2014

Finite difference methods for fractional differential equation are ever proposed. However, precise error orders have not been analyzed for the methods higher than first order accuracy. This paper proposes a few finite difference methods for fractional diffusion equations and shows our methods have second order accuracy under the conditions that the solution functions have higher order than second order at boundaries. In addition, we show that the accuracy may decrease in the case that the solution functions have lower order than second order at boundaries when we use second order accuracy scheme. In this paper, we treat schemes based on Grunwald-Letnikov definition and apply them to three kinds of fractional diffusion equations using Riemann-Liouville derivative operator including time-fractional diffusion equation, space-fractional diffusion equation and time-space-fractional diffusion equation. Finally, we show the simulation results which indicate that our methods are stable and have successfully second order accuracy under the assumed conditions.
Pole-Axis Based Singularity Analysis of Spherical Mechanisms
Authors: Di Gregorio Raffaele
Published: February 2014

Instantaneous kinematics of complex multi-loop mechanisms is modeled by linear and homogeneous mappings whose coefficient matrices have also important static meanings. As a consequence, the analysis of these models is a mandatory step, during design, that can be implemented by using the superposition principle. Here, spherical mechanisms are considered. Their general instantaneous-kinematics model is written by exploiting the properties of the instantaneous pole axes and the superposition principle. Then, this general model is analyzed to deduce an exhaustive analytic and geometric technique for identifying all the singular configurations of these mechanisms.
Vertical-Plane Dynamics of Power-Augmented-Ram Vehicle
Authors: Matveev Konstantin I.
Published: February 2014

Power-augmented-ram vehicles represent novel air-assisted marine craft that can be used for high-speed amphibious transportation of heavy cargo. These vehicles rely on combined hydrodynamic and aerodynamic support that is also augmented by front air-based propulsors. Dynamic models for these craft in the presence of wind gusts and surface waves are needed for confident design of these vehicles, including motion control systems. This study addresses 3-DOF vertical-plane dynamics. The models for unsteady forces are based on the aerodynamic extreme-ground-effect theory and hydrodynamic added-mass strip theory. Modeling of the vehicle motions are carried out for cases of head and following wind gusts and waves of low and high amplitudes. Simulation results can be used for determining amplitudes of the vehicle responses, peak accelerations, and forward speed degradation.
Sustainable Design Education Through a Self-Directed Online System
Authors: Faludi Jeremy , Menter Adam
Published: February 2014

Sustainable design and engineering is an important topic, yet it is under-represented in educational institutions; moreover, it must be taught to practicing professionals, not just students. A free online system has been created to address both problems at once, providing educational materials for educators and also providing a self-paced program for professionals or students to earn a certificate in sustainable design. Called the Autodesk Sustainability Workshop, it is a collection of video tutorials and supporting materials (PDF reference guides, slide decks, quizzes, and other resources) that can be used either by individuals themselves or by educators (either in schools or the workplace) to learn principles and practical skills related to green design, mechanical engineering, and building science. Its dozens of video tutorials span the range from introduction to fundamental principles in sustainability, to specific operation of analytical software tools such as FEA and energy modeling. All videos are on focused topics and of short duration (typically 3–6 minutes) so they can be inserted into curricula as educators see fit, not forcing a full curriculum structure. For self-guided learners, or educators who desire a full curriculum, an interactive structure provides quizzes along with the learning resources; upon successful completion, they lead up to a certificate in green design. Currently there is only one certificate, in basic building science; future releases will expand the certificate program to sustainable product design as well, since many of the learning resources are on these topics. For content not covered by the certificate program, the website’s information architecture suggests a multi-threaded approach to learning sustainable design. As three-quarters of a million people around the world have already viewed content from the site, this self-directed online learning system is proposed to be a highly scalable method of providing sustainable design and engineering education.
Dynamics of Assembled Structures: Taking Into Account the Surface Defects in Interfaces
Authors: Peyret Nicolas , Chevallier Gaël , Dion Jean-Luc
Published: February 2014

In structural dynamics, the prediction of damping remains the biggest challenge. This paper deals with the energy losses caused by micro-slip in a nominally planar interface of a structure. This paper proposes an analytical and experimental study of flexural vibrations of a clamped-clamped beam with innovative position of the interfaces.

The objective of this test bench is to characterize the global rheology of the interface. The proposed model aims to characterize this rheology based on local settings of the interface.

First, the test bench is described and the choice of the position of the interface is justified. The experimental bench and the dynamic behavior of this structure are presented. We propose to illustrate the mechanism of energy losses by micro-slip by making a comparison between the behavior of a “monolithic” beam and a sectioned beam.

Secondly, a modeling of the interface taking into account the surface defect is presented. The energy dissipated by friction in the interface is calculated during a loading cycle. This leads to a computation of the dissipated energy and thus to a nonlinear loss factor.

Finally, we confront the loss factor calculated analytically and the measured one.
Interactive and On-Line Learning System for Assembly Task Motion Planning
Authors: Yan Yu , Poirson Emilie , Bennis Fouad
Published: February 2014

This paper presents a novel interactive motion planning system for assembly/disassembly operations. Our system consists of three layers: interaction layer, learning layer and motion library layer. In interaction layer, user’s manipulation in difficult scenario is liberated by relaxing collision constraints. The resulting path is retracted and connected by random retraction method and BiRRT algorithm. A motion path which successfully passed through the narrow passage or information of geometrical interference in failed case is returned to user. In learning layer, motion primitives corresponding to prior similar scenario are selected by scenario comparison which is based on medial axis, and then transformed to generate new motions. Significant improvement for motion planning of non-convex object in challenging scenarios with narrow passages is obtained by interactive process. The introduction of learning mechanism can reduce global planning time and obtain experiential knowledge.
Experimental Study of Torsional-Bending Coupled Vibration of a Rotor System With a Bladed Disk
Authors: Kudo Takeshi , Shiohata Koki , Matsushita Osami , Fujiwara Hiroyuki , Okabe Akira , Sakurai Shigeo
Published: February 2014

An experimental investigation was conducted to confirm the bending-torsion coupled vibration of a rotor system with a bladed disk.

For a rotor with relatively long blades such as in the latest low-pressure steam turbines, coupled vibration with shaft torsional vibration represents the bladed disk natural frequency of a nodal diameter (k) of zero (umbrella mode). Today this well-known behavior is reflected in the design of steam turbine rotor systems to prevent the blade vibration resonance due to torque excitation caused by the electric power grid, a standard for which is proposed by ISO 22266-1.

The bending-torsion coupled resonance of rotor systems occurs, however, under specific conditions due to rotor unbalance. When the rotor’s rotational speed (Ω) is equal to the sum/difference of the bending natural frequency (ωb) and torsional natural frequency (ωθ), namely, Ω = ωθ ± ωb, there is coupled resonance, which was experimentally observed with a rotor with a relatively simplified shape.

In this study, the test apparatus for a flexible rotor system equipped with a shrouded bladed disk driven by an electric motor was constructed to confirm the vibration characteristics, by envisioning the bending-torsion coupled resonance as applied to actual rotor systems of turbo machinery. A radial active magnetic bearing (AMB) was employed to support the rotor by controlling bearing stiffness and damping, and applying lateral directional excitation of forward and backward whirl to the rotor. A servomotor was also equipped at the end of the rotor system to excite the torsional vibration.

The resonance of a bladed disk with nodal diameter (k) of zero, which was coupled with the rotor’s torsional vibration, was observed under the above condition (Ω = ωθ − ωb) through AMB excitation of the rotor’s bending natural frequency. Conversely, the torsional excitation caused by the servomotor was confirmed as causing the coupled resonance of rotor bending vibration.
Testing the Basis for an Automated Design-by-Analogy Tool Through Comparison to Expert Thinking
Authors: Fu Katherine , Chan Joel , Schunn Christian , Cagan Jonathan , Kotovsky Kenneth
Published: February 2014

Our prior work presented a method for computationally structuring patent databases as a basis for an automated design-by-analogy tool. In order to examine the validity and sensibility of the prior work as the basis for a design tool, its output is compared in detail to expert designers’ mental models of the domain being structured, i.e., a set of 45 patents and their inter-relationships. The comparison sought first to gauge the intuitiveness and sensibility of the computational method of structuring to human minds, and further to ascertain whether any differences between the method’s and the experts’ structures indicate potentially novel or surprising ways of approaching the space of patents, or indicate that the output was nonsensical, invalid or needing modification in order to be useable. The results indicate that, when compared to expert thinking, the computationally generated structure is sensible in its clustering of patents and in its organization of these clusters into a structure or space. The results also suggest that the computationally-generated structure represents a version of the patent space upon which experts can find common ground and consensus — making it likely to be intuitive and accessible to a broad cohort of designers. Thus, the prior work which presented a computational method for structuring design databases has been found to offer a resource-efficient way of usefully representing the space that is sensible to expert designers, while still preserving an element of surprise and unexpectedness, making it promising as the basis for a computational design-by-analogy inspiration tool.