bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trajectory Planning Using the Ferguson Curve Model and Curvature Theory of Ruled Surface
Authors: Ryuh B. S. , Pennock G. R. 
Published: April 2021

Abstract
The trajectory of a robot end-effector is completely described by a ruled surface and a spin angle about the ruling of the ruled surface. In this way the differential properties of motion of the end-effector are obtained from the well-known curvature theory of a ruled surface. The robot can then be programmed so that the end-effector will follow the prescribed trajectory with high accuracy. In the case where the ruled surface can not be described by an explicit analytic function, the ruled surface may be represented by a geometric modeling technique. Since a ruled surface can be expressed in terms of a single parameter, a curve generating technique is used to represent the ruled surface. The technique presented in this paper is the Ferguson curve model which guarantees that the trajectory will pass through all of the set points and will have curvature continuity at each set point. To illustrate the proposed method of robot trajectory planning, a practical example is included in the paper.
Computer-Assisted Generation of the Requirements List in an Automated Methodical Design Procedure
Authors: Hundal M. S. , Byrne J. F. 
Published: April 2021

Abstract
The paper discusses the application of computers in the earliest stage of a design, i.e., preparation of the requirements list. The requirements list helps define a problem in solution-neutral terms. The work presented here is a portion of a program for conceptual design of engineering systems. The computer program uses data bases of task specifications, functions and solutions to generate the solution to a design problem in the form of a block diagram. The program is intended to help in developing new and improving existing products and processes.
Synthesis of Systems From Specifications Containing Orientations and Positions Associated With Flow Variables
Authors: Prabhu D. R. , Taylor D. L. 
Published: April 2021

Abstract
A class of systems can be specified by a set of constant input-output power variables with generalized flow variables having associated orientations and positions. This paper presents a method for generating conceptual parametric designs. A quasi-decoupled approach is taken to solve the problem. A hierarchy of considerations of magnitude, orientation and position transforms is established. Orientation and position transformers are introduced in each domain. A solution to the “vector” problem is obtained by augmenting the “scalar” solution using vector transformers.
Expert System for Design of Industrial Robots — ESDIR
Authors: Tsai M. J. , Wu T. G. , Hong L. 
Published: April 2021

Abstract
A prototype frame base expert system ESDIR (Expert System for Design of Industrial Robot) has been built. For a given specification and application, the design procedure of ESDIR is first to synthesize and evaluate the robot geometry. The synthesis is accomplished by on-line interfacing with external CAD programs written in conventional language. Then the selections of power drive, actuation, and coordination method are recommended. Iterations between design and re-design are needed in ordinary design procedure. This is time consuming and error-prone. ESDIR is one of the efforts toward design automation trying to minimize the cycle time and improve design efficiency.
An Expert System for the Structural Identification and Generalization of Mechanical Devices
Authors: Yan H.-S. , Hwang Y.-W. 
Published: April 2021

Abstract
This paper attempts to use a new conceptual scheme to present an expert system for the structural identification and generalization of mechanical devices. This expert system consists of a knowledge base with frames, rules and procedures, a forward-chaining inference engine, a working memory, and a user interface. The results of this work will be beneficial to the automation of the creative design of mechanical devices.
Computation of Boundary Stresses by Finite Element Post Processing
Authors: Vasilopoulos D. 
Published: April 2021

Abstract
In the displacement formulation of the finite element method, the primary unknowns are the nodal displacements. They are automatically chosen by the computer so that the energy is minimized. Stresses are then obtained by performing numerical differentiation on the displacement field. This leads to poorer accuracy for the stresses. The stresses computed this way are also sensitive to the design of the local mesh in the area where they are computed: different meshes and element types give different results, sometimes widely varying. Moreover, the convergence of the pointwise stress values is far from monotonic. A more refined model will not necessarily improve the result. Apparent convergence of the stress values may be misleading.
In this paper we implement an extraction technique that computes the stress at a boundary point by performing a mathematical postprocessing of the finite element results. The stress is expressed as a weighted average of the displacements on the boundary. This extracted value is less sensitive to the local mesh and it converges much faster than the traditional point-wise stress. Comparative results are presented for a structure of moderate complexity.
Nonlinear Mixed Integer-Discrete-Continuous Programming and its Application to Engineering Design Problems
Authors: Fu J.-F. , Fenton R. G. , Cleghorn W. L. 
Published: April 2021

Abstract
An algorithm for solving nonlinear programming problems containing integer, discrete and continuous variables is presented. Based on a commonly employed optimization algorithm, penalties on integer and/or discrete violations are imposed on the objective function to force the search to converge onto standard values. Examples are included to illustrate the practical use of this algorithm.
An Object Oriented Data Base and Application Management System for Integrated, Interdisciplinary Mechanical System Simulation
Authors: Dopker B. , Murray P. , Choong F. N. 
Published: April 2021

Abstract
An object oriented data base and application management system for integrated, interdisciplinary mechanical system simulation is developed and implemented; with emphasis on flexible body dynamic simulation, stress history calculation, and fatigue life prediction. The system consists of (1) functional objects that perform a particular analysis task, (2) data objects that store data in the data base, (3) data and object management tools that manage the communication between the different parts of the system, and (4) network communication tools that communicate between different hardware platforms. Functional objects are developed and implemented for the different analysis needs of the system. Such objects (1) hide implementation details, (2) provide easy extendability, and (3) simplify use of the system. Data are organized in terms of objects, object hierarchies, and object attributes. This provides quasi data inheritance and information hiding, which allows for a data base schema that is both robust and extendable.
Hydrodynamic Lubrication of Slider Bearings With Two-Dimensionally Varying Contoured Surfaces and Optimum Design Data
Authors: Bagci C. , McClure C. J. , Rajavenkateswaran S. K. 
Published: April 2021

Abstract
Contoured bearing surfaces forming continuous surface pockets in slider bearings increase the load carrying capacity considerably. Article investigates the effect of two dimensionally contoured surfaces of a few sample shapes on the performance characteristics of hydrodynamic slider bearings. Exponential and trigonometric film shapes are considered. Computer-aided numerical finite difference solution of the two-dimensional Reynolds equation is used via a self mesh generating computer program, which also generates optimum design data including dimensionless load-, flow-, temperature rise-, power loss-, stiffness-, damping, and friction coefficients. Optimum bearings are defined as the maximum load capacity bearings. Optimum design charts are given, where dimensional ratios and powers of exponents are optimized. Lubricant is incompressible with temperature dependent viscosity. The effect of temperature is considered by maintaining energy balance via iterative thermal loop. In comparison to optimum one-dimensional tapered film bearings gains of over 200% in the load capacities of contoured narrow bearings are observed.
Optimum Vibration Suppression of Systems Subjected to Broadband Excitation Frequencies
Authors: Ebrahimi N. D. 
Published: April 2021

Abstract
In previous research, techniques have been devised for vibration abatement of mechanical systems based on fixed excitation frequencies. To remove the dependency and sensitivity of the vibration suppression process from the input frequencies, this paper presents a strategy for vibration reduction when the system is run over a wide range of frequencies. The approach is based on a general discretized mathematical system representation. First, the equations for frequency response of these types of models is reviewed. Next, the vibration control plan is formulated as a nonlinear mathematical programming problem so that the peak response amplitudes of a set of degrees of freedom would be diminished. Finally, a numerical optimization algorithm is employed to solve this nonlinear problem. Results for a number of illustrative examples are then summarized and discussed. These results show that the control strategy is strikingly effective in subsiding the vibration.
Computer Aided Straight Bevel Gearing Design and Parametric Drawing of a Bevel Gear by a Computer
Authors: Kaixiu Y. 
Published: April 2021

Abstract
A multiple objective function optimization design of straight bevel gearing with an advanced optimization method is described. The main parameters and geometric dimensions obtained with this algorithm are made use of to make computer parametric drawing of bevel gear in accordance with gear structure and by adopting currently high-level FORAUT interface software and the U. S.-made AUTOCAD autoplotting package, thus organically combining mechanical design calculation with the drawing of graphs.
The said program is applicable to the optimization design of straight bevel gearing with arbitrary shaft angles and different pressure angles (α = 14.5°, 20°, 22.5°, 25°) to obtain ideal optimization parameters or engagement parameters, geometrical parameters and strength performance parameters and plot the correspnnding part working diagram.
The results of application show that the system proposed is feasible, the algorithm explicit, the program operation reliable, convenient and flexible.
Determination of the Workspace of 6-DOF Parallel Manipulators
Authors: Gosselin C. 
Published: April 2021

Abstract
This paper presents an algorithm for the determination of the workspace of parallel manipulators. The method described here, which is based on geometrical properties of the workspace, leads to a simple graphical representation of the regions of the three-dimensional Cartesian space that are attainable by the manipulator with a given orientation of the platform. Moreover, the volume of the workspace can be easily computed by performing an integration on its boundary, which is obtained from the algorithm. Examples are included to illustrate the application of the method to a six-degree-of-freedom fully-parallel manipulator.
Climatically driven instability of marine methane hydrate along a canyon-incised continental margin
Authors: Davies Richard J. , Maqueda Miguel Ángel Morales , Li Ang , Ireland Mark 
Published: April 2021

AbstractEstablishing how past climate change affected the stability of marine methane hydrate is important for our understanding of the impact of a future warmer world. As oceans shallow toward continental margins, the base of the hydrate stability zone also shallows, and this delineates the feather edge of marine methane hydrate. It is in these rarely documented settings that the base of the hydrate stability zone intersects the seabed and hydrate can crop out where it is close to being unstable and most susceptible to dissociation due to ocean warming. We show evidence for a seismically defined outcrop zone intersecting canyons on a canyon-incised margin offshore of Mauritania. We propose that climatic, and hence ocean, warming since the Last Glacial Maximum as well as lateral canyon migration, cutting, and filling caused multiple shifts of the hydrate stability field, and therefore hydrate instability and likely methane release into the ocean. This is particularly significant because the outcrop zone is longer on canyon-incised margins than on less bathymetrically complex submarine slopes. We propose considerably more hydrate will dissociate in these settings during future ocean warming, releasing methane into the world’s oceans.
Telemedicine in oculoplastic and adnexal surgery: clinicians’ perspectives in the UK
Authors: Kang Swan , Raja Laxmi , Sim Dawn A , Thomas Peter B M , Ezra Daniel G 
Published: April 2021

Background/AimsThe COVID-19 has facilitated a paradigm shift in the sphere of ophthalmic telemedicine: its utility is no longer limited to providing care to remote regions, rather it is expeditiously being adopted as the new standard of care. The aim of our paper is to explore the current attitudes of oculoplastic surgeons towards telemedicine and its utility in the present landscape and its prospects in the future.MethodsA 39-item questionnaire was distributed to consultant oculoplastic surgeons practising across the UK and anonymised responses were collected and analysed.ResultsThe COVID-19 pandemic has allowed rapid implementation of telemedicine services in oculoplastic departments across the UK with 86.6% of the respondents incorporating telemedicine into the routine clinical practice. Clinicians reported a statistically significant increase in utility of telemedicine, confidence in using telemedicine and quality of infrastructure available to employ telemedicine following the COVID-19 outbreak. The greatest utility of telemedicine is in triaging, postoperative assessment and eyelid lesion assessment. Main barriers to implementation of telemedicine included difficulties in conducting clinical examinations, lack of administrative support and poor access to digital technologies for patients. Overall, most clinicians were satisfied with the impact of telemedicine services and almost all experts foresee themselves continuing to use telemedicine in the future.ConclusionsTelemedicine has become an integral part of the oculoplastic service delivery since the COVID-19 pandemic its use is likely to continue. Further development of digital infrastructure and improvement of clinical examination capabilities are required to enable its wider adoption.
Qualitative study: patients’ enduring concerns about discussing internet use in general practice consultations
Authors: Cuteanu Anita , Seguin Maureen , Ziebland Sue , Pope Catherine , Leydon Geraldine , Barnes Rebecca , Murray Elizabeth , Atherton Helen , Stevenson Fiona 
Published: April 2021

ObjectivesTo examine patients’ accounts of their use of the internet before seeing a general practitioner (GP) using thematic analysis of semistructured interviews.DesignQualitative semistructured interview study with transcripts analysed thematically.SettingPrimary care patients consulting with 10 GPs working at 7 GP practices of varying sizes and at a range of locations around London and the Southeast of England.Participants28 adult patients: 16 women and 12 men ranging in age from 18 to 75 from a range of self-defined ethnic backgrounds. Participants were selected based on instances when the patients reported having used the internet before the consultation, when patients referred to the internet in the consultation or when the physician used the internet or made reference to it during the consultation.ResultsPatients report that they can find health information online that they believe is reliable and helpful for both themselves and their GP. However, they report uncertainty about how to share internet-based findings and reluctance to disclose their efforts at researching health issues online for fear of appearing disrespectful or interfering with the flow of the consultation.ConclusionsDespite the democratisation of access to information about health due via the internet, patients continue to experience their use of the internet for health information as a sensitive and potentially problematic topic. The onus may well be on GPs to raise the likelihood (without judgement) that patients will have looked things up before consulting and invite them to talk about what they found.
Association of traumatic brain injury severity and time to definitive care in three low-middle-income European countries
Authors: Peek-Asa Corinne , Coman Madalina Adina , Zorn Alison , Chikhladze Nino , Cebanu Serghei , Tadevosyan Artashes , Hamann Cara J 
Published: April 2021

BackgroundLow-middle-income countries experience among the highest rates of traumatic brain injury in the world. Much of this burden may be preventable with faster intervention, including reducing the time to definitive care. This study examines the relationship between traumatic brain injury severity and time to definitive care in major trauma hospitals in three low-middle-income countries.MethodsA prospective traumatic brain injury registry was implemented in six trauma hospitals in Armenia, Georgia and the Republic of Moldova for 6 months in 2019. Brain injury severity was measured using the Glasgow Coma Scale (GCS) at admission. Time to definitive care was the time from injury until arrival at the hospital. Cox proportionate hazards models predicted time to care by severity, controlling for age, sex, mechanism, mode of transportation, location of injury and country.ResultsAmong 1135 patients, 749 (66.0%) were paediatric and 386 (34.0%) were adults. Falls and road traffic were the most common mechanisms. A higher proportion of adult (23.6%) than paediatric (5.4%) patients had GCS scores indicating moderate (GCS 9–11) or severe injury (GCS 0–8) (p<0.001). Less severe injury was associated with shorter times to care, while more severe injury was associated with longer times to care (HR=1.05, 95% CI 1.01 to 1.09). Age interacted with time to care, with paediatric cases receiving faster care.ConclusionsImplementation of standard triage and transport protocols may reduce mortality and improve outcomes from traumatic brain injury, and trauma systems should focus on the most severe injuries.
Genetic burden linked to founder effects in Saguenay–Lac-Saint-Jean illustrates the importance of genetic screening test availability
Authors: Bchetnia Mbarka , Bouchard Luigi , Mathieu Jean , Campeau Philippe M , Morin Charles , Brisson Diane , Laberge Anne-Marie , Vézina Hélène , Gaudet Daniel , Laprise Catherine 
Published: April 2021

The Saguenay–Lac-Saint-Jean (SLSJ) region located in the province of Quebec was settled in the 19th century by pioneers issued from successive migration waves starting in France in the 17th century and continuing within Quebec until the beginning of the 20th century. The genetic structure of the SLSJ population is considered to be the product of a triple founder effect and is characterised by a higher prevalence of some rare genetic diseases. Several studies were performed to elucidate the historical, demographic and genetic background of current SLSJ inhabitants to assess the origins of these rare disorders and their distribution in the population. Thanks to the development of new sequencing technologies, the genes and the variants responsible for the most prevalent conditions were identified. Combined with other resources such as the BALSAC population database, identifying the causal genes and the pathogenic variants allowed to assess the impacts of some of these founder mutations on the population health and to design precision medicine public health strategies based on carrier testing. Furthermore, it stimulated the establishment of many public programmes.We report here a review and an update of a subset of inherited disorders and founder mutations in the SLSJ region. Data were collected from published scientific sources. This work expands the knowledge about the current frequencies of these rare disorders, the frequencies of other rare genetic diseases in this population, the relevance of the carrier tests offered to the population, as well as the current available treatments and research about future therapeutic avenues for these inherited disorders.
Endovascular therapy with or without intravenous thrombolysis in acute stroke with tandem occlusion
Authors: Anadani Mohammad , Marnat Gaultier , Consoli Arturo , Papanagiotou Panagiotis , Nogueira Raul G , Spiotta Alejandro M , Bourcier Romain , Kyheng Maeva , Labreuche Julien , Siddiqui Adnan H , Ribo Marc , de Havenon Adam , Fischer Urs , Sibon Igor , Dargazanli Cyril , Arquizan Caroline , Cognard Christophe , Olivot Jean Marc , Anxionnat René , Audibert Gérard , Mazighi Mikael , Blanc Raphael , Lapergue Bertrand , Richard Sébastien , Gory Benjamin ,   TITAN (Thrombectomy In TANdem lesions) Investigators
Published: April 2021

BackgroundEndovascular therapy (EVT) is effective and safe in patients with tandem occlusion. The benefit of intravenous thrombolysis (IVT) prior to EVT in acute tandem occlusion is debatable.ObjectiveTo compare EVT alone with EVT plus IVT in patients with acute ischemic stroke due to anterior circulation tandem occlusions.MethodsThis is an individual patient pooled analysis of the Thrombectomy In TANdem lesions (TITAN) and Endovascular Treatment in Ischemic Stroke (ETIS) Registries. Patients were divided into two groups based on prior IVT treatment: (1) IVT+ group, which included patients who received IVT prior to EVT, (2) IVT− group, which included patients who did not receive IVT prior to EVT. Propensity score (inverse probability of treatment weighting (IPTW)) was used to reduce baseline between-group differences. The primary outcome was favorable outcome—that is, modified Rankin Scale (mRS) score 0 to 2 at 90 days.ResultsOverall, 602 consecutive patients with an acute stroke with tandem occlusion were included (380 and 222 in the bridging therapy and EVT alone groups, respectively). Onset to imaging time was shorter in the IVT+ group (median 103 vs 140 min). In contrast, imaging to puncture time was longer in the IVT+ group (median 107 vs 91 min). In IPTW analysis, the IVT+ group had higher odds of favorable outcome, excellent outcome (90-day mRS score 0–1), and successful reperfusion (modified Thrombolysis in Cerebral Infarction score 2b/3 at the end of EVT). There was no difference in the risk of significant hemorrhagic complications between groups. In secondary analysis of patients treated with acute cervical internal carotid artery stenting, bridging therapy was associated with higher odds of favorable outcome and lower odds of mortality at 90 days.ConclusionsOur results suggest that bridging therapy in patients with acute ischemic stroke due to anterior tandem occlusion is safe and may improve functional outcome, even in the setting of acute cervical internal carotid artery stenting during EVT.