Interactive Feature Recognition Using Multi-Processor Methods

Author(s):  
William C. Regli ◽  
Satyandra K. Gupta ◽  
Dana S. Nau

Abstract The availability of low-cost computational power is enabling development of increasingly sophisticated CAD software. Automation of design and manufacturing activities poses many difficult computational problems. Design is an interactive process and speed is a critical factor in systems that enable designers to explore and experiment with alternative ideas. As more downstream manufacturing activities are considered during the design phase, computational costs become problematic. Achieving interactivity requires a sophisticated allocation of computational resources in order to perform realistic design analyses and generate feedback in real time. This paper presents our initial efforts to use distributed algorithms to recognize machining features from solid models of parts with large numbers of features and many geometric and topological entities. Our goal is to outline how significant improvements in computation time can be obtained using existing hardware and software tools. An implementation of our approach is discussed.

2021 ◽  
Vol 9 (6) ◽  
pp. 624
Author(s):  
Antonino Cirello ◽  
Tommaso Ingrassia ◽  
Antonio Mancuso ◽  
Vincenzo Nigrelli ◽  
Davide Tumino

The process of designing a sail can be a challenging task because of the difficulties in predicting the real aerodynamic performance. This is especially true in the case of downwind sails, where the evaluation of the real shapes and aerodynamic forces can be very complex because of turbulent and detached flows and the high-deformable behavior of structures. Of course, numerical methods are very useful and reliable tools to investigate sail performances, and their use, also as a result of the exponential growth of computational resources at a very low cost, is spreading more and more, even in not highly competitive fields. This paper presents a new methodology to support sail designers in evaluating and optimizing downwind sail performance and manufacturing. A new weakly coupled fluid–structure interaction (FSI) procedure has been developed to study downwind sails. The proposed method is parametric and automated and allows for investigating multiple kinds of sails under different sailing conditions. The study of a gennaker of a small sailing yacht is presented as a case study. Based on the numerical results obtained, an analytical formulation for calculating the sail corner loads has been also proposed. The novel proposed methodology could represent a promising approach to allow for the widespread and effective use of numerical methods in the design and manufacturing of yacht sails.


Genes ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Zaid Al-Ars ◽  
Saiyi Wang ◽  
Hamid Mushtaq

The rapid proliferation of low-cost RNA-seq data has resulted in a growing interest in RNA analysis techniques for various applications, ranging from identifying genotype–phenotype relationships to validating discoveries of other analysis results. However, many practical applications in this field are limited by the available computational resources and associated long computing time needed to perform the analysis. GATK has a popular best practices pipeline specifically designed for variant calling RNA-seq analysis. Some tools in this pipeline are not optimized to scale the analysis to multiple processors or compute nodes efficiently, thereby limiting their ability to process large datasets. In this paper, we present SparkRA, an Apache Spark based pipeline to efficiently scale up the GATK RNA-seq variant calling pipeline on multiple cores in one node or in a large cluster. On a single node with 20 hyper-threaded cores, the original pipeline runs for more than 5 h to process a dataset of 32 GB. In contrast, SparkRA is able to reduce the overall computation time of the pipeline on the same single node by about 4×, reducing the computation time down to 1.3 h. On a cluster with 16 nodes (each with eight single-threaded cores), SparkRA is able to further reduce this computation time by 7.7× compared to a single node. Compared to other scalable state-of-the-art solutions, SparkRA is 1.2× faster while achieving the same accuracy of the results.


Author(s):  
Hiroshi Sakurai ◽  
Chia-Wei Chin

Abstract In design and manufacturing, cavity features, such as holes and pockets, and protrusion features, such as bosses and ribs are commonly used. In this work, cavity and protrusion in a solid object were defined with the volumes enclosed by the faces of the object and their extensions. These definitions of cavity and protrusion match our intuitive notions of cavity and protrusion better than the commonly used definitions that consider the convexity and concavity of edges. Together with an algorithm called “spatial decomposition and composition”, the definitions provide a method to find cavities and protrusions in solid models. By applying graph matching commonly used in feature recognition to the volumes of cavity and protrusion, all the features in a solid model can be recognized whether they intersect or not.


Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1178 ◽  
Author(s):  
Jorge Prada ◽  
Christina Cordes ◽  
Carsten Harms ◽  
Walter Lang

This contribution outlines the design and manufacturing of a microfluidic device implemented as a biosensor for retrieval and detection of bacteria RNA. The device is fully made of Cyclo-Olefin Copolymer (COC), which features low auto-fluorescence, biocompatibility and manufacturability by hot-embossing. The RNA retrieval was carried on after bacteria heat-lysis by an on-chip micro-heater, whose function was characterized at different working parameters. Carbon resistive temperature sensors were tested, characterized and printed on the biochip sealing film to monitor the heating process. Off-chip and on-chip processed RNA were hybridized with capture probes on the reaction chamber surface and identification was achieved by detection of fluorescence tags. The application of the mentioned techniques and materials proved to allow the development of low-cost, disposable albeit multi-functional microfluidic system, performing heating, temperature sensing and chemical reaction processes in the same device. By proving its effectiveness, this device contributes a reference to show the integration potential of fully thermoplastic devices in biosensor systems.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Jian Zhang ◽  
Jingjing Zhang ◽  
Feng He ◽  
Yijun Chen ◽  
Jiawei Zhu ◽  
...  

AbstractExploring low-cost and earth-abundant oxygen reduction reaction (ORR) electrocatalyst is essential for fuel cells and metal–air batteries. Among them, non-metal nanocarbon with multiple advantages of low cost, abundance, high conductivity, good durability, and competitive activity has attracted intense interest in recent years. The enhanced ORR activities of the nanocarbons are normally thought to originate from heteroatom (e.g., N, B, P, or S) doping or various induced defects. However, in practice, carbon-based materials usually contain both dopants and defects. In this regard, in terms of the co-engineering of heteroatom doping and defect inducing, we present an overview of recent advances in developing non-metal carbon-based electrocatalysts for the ORR. The characteristics, ORR performance, and the related mechanism of these functionalized nanocarbons by heteroatom doping, defect inducing, and in particular their synergistic promotion effect are emphatically analyzed and discussed. Finally, the current issues and perspectives in developing carbon-based electrocatalysts from both of heteroatom doping and defect engineering are proposed. This review will be beneficial for the rational design and manufacturing of highly efficient carbon-based materials for electrocatalysis.


2012 ◽  
Vol 548 ◽  
pp. 254-257 ◽  
Author(s):  
Yan He ◽  
Bai Ling Huang ◽  
Yong Lai Zhang ◽  
Li Gang Niu

In this paper, a simple and facile technique for manufacturing glass-based microfluidic chips was developed. Instead of using expensive dry etching technology, the standard UV lithography and wet chemical etching technique was used to fabricate microchannels on a K9 glass substrate. The fabrication process of microfluidic chip including vacuum evaporation, annealing, lithography, and BHF (HF-NH4F-H2O) wet etching were investigated. Through series experiments, we found that anneal was the critical factor for chip quality. As a representative example, a microfluidic channel with 20 m of depth, and 80 m of width was successfully prepared, and the channel surfaces are quite smooth. These results present a simple, low cost, flexible and easy way to fabricate glass-based microfluidic chips.


2021 ◽  
Vol 11 (5) ◽  
pp. 2326
Author(s):  
Claudio Favi ◽  
Roberto Garziera ◽  
Federico Campi

Welding is a consolidated technology used to manufacture/assemble large products and structures. Currently, welding design issues are tackled downstream of the 3D modeling, lacking concurrent development of design and manufacturing engineering activities. This study aims to define a method to formalize welding knowledge that can be reused as a base for the development of an engineering design platform, applying design for assembly method to assure product manufacturability and welding operations (design for welding (DFW)). The method of ontology (rule-based system) is used to translate tacit knowledge into explicit knowledge, while geometrical feature recognition with parametric modeling is adopted to couple geometrical information with the identification of welding issues. Results show how, within the design phase, manufacturing issues related to the welding operations can be identified and fixed. Two metal structures (a jack adapter of a heavy-duty prop and a lateral frame of a bracket structure) fabricated with arc welding processes were used as case studies and the following benefits were highlighted: (i) anticipation of welding issues related to the product geometry and (ii) reduction of effort and time required for the design review. In conclusion, this research moves forward toward the direction of concurrent engineering, closing the gap between design and manufacturing.


Author(s):  
Mohsen Rezayat

Abstract An integral part of implementing parallel product and process designs is simulation through numerical analysis. This simulation-driven design requires discretization of the 3D part in an appropriate manner. If the part is thin or has thin sections (e.g., plastic parts), then an analysis model with reduced dimensionality may be more accurate and economical than a standard 3D model. In addition, substantial simplification of some details in the design geometry may be beneficial and desirable in the analysis model. Unfortunately, the majority of CAD systems do not provide the means for abstraction of appropriate analysis models. In this paper we present a new approach, based on midsurface abstraction, which holds significant promise in simplifying simulation-driven design. The method is user-friendly because very little interaction is required to guide the software in its automatic creation of the desired analysis model. It is also robust because it handles typical parts with complex and interacting features. Application of the method for feature recognition and abstraction is also briefly discussed.


2021 ◽  
Author(s):  
Sarah Ovink

Latino/a enrollments at U.S. colleges are rapidly increasing. However, Latinos/as remain underrepresented at four-year universities, and college completion rates and household earnings lag other groups’. Yet, little theoretical attention has been paid to the processes that drive these trends, or to what happens when students not traditionally expected to attend college begin to enroll in large numbers. Longitudinal interviews with 50 Latino/a college aspirants in the San Francisco East Bay Area reveal near-universal college enrollment among these mostly low-income youth, despite significant barriers. East Bay Latino/a youth draw on a set of interrelated logics (economic, regional, family/group, college-for-all) supporting their enrollment, because they conclude that higher education is necessary for socioeconomic mobility. In contrast to the predictions of status attainment and rational choice models, these rationally optimistic college aspirants largely ignore known risks, instead focusing on anticipated gains. Given a postrecession environment featuring increasing costs and uncertain employment, this approach led many to enroll in low-cost, less supportive two-year institutions, resulting in long and winding pathways for some. Results suggest that without structural supports, access to college fails to meaningfully redress stratification processes in higher education and the postrecession economy that significantly shape possibilities for mobility.


2011 ◽  
Vol 133 (1) ◽  
Author(s):  
P. Zhang ◽  
R. Du

Pressure vessel is widely used in many engineering areas. How to achieve a perfect combination of excellent performance and low cost in the design and manufacturing of a pressure vessel is, therefore, very important. Instead of a single cylinder, a multicell pressure vessel with a Kelvin structure is proposed in this paper. It is found that such structure offers not only improved safety but also extra storage capacity. This may lead to a type of pressure vessel suitable for stringent applications, even without employing costly materials.


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