The Experts below are selected from a list of 21 Experts worldwide ranked by ideXlab platform
Mieczyslaw Siemiatkowski - One of the best experts on this subject based on the ideXlab platform.
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machining process sequencing and machine assignment in generative feature based capp for mill turn parts
Journal of Manufacturing Systems, 2018Co-Authors: Mariusz Deja, Mieczyslaw SiemiatkowskiAbstract:Abstract Process selection and sequencing, as one of the most complex issues when evaluated from a mathematical point of view and crucial in CAPP, still attract research attention. For the current trend of intelligent manufacturing, machining features (MFs) are the information carriers for workpiece geometry and topology representation. They are basically derived from CAD models and are used by Downstream Engineering applications. A feature-based reasoning approach for generating machining sequences in terms of part setups and the assignment of machine alternatives is presented. The approach suggested in this research assumes a heavy reliance on a data input model incorporating functional requirements for parts and in particular GD&T references. An extended feature taxonomy corresponding to the needs of the rational process plan selection for the addressed category of part types is proposed. It is meant to be applicable to machining of both rotational and prismatic features using machines of various configurations. The developed taxonomy is based on the working directions for MFs and includes the identification of their location with respect to datum references. The developed taxonomy that involves feature tolerance relationships is at the core of the information data model utilised by the original algorithm which was aimed at generic process sequencing for the definite category of mechanical parts. Through the developed algorithm, adequate process alternatives can be generated by adaptive setup merging on a single machine or across multiple available machines under consideration of their respective process capabilities. The approach has been validated through an illustrative case study using a sample mill-turn part of considerable complexity.
Danielle Tullmanercek - One of the best experts on this subject based on the ideXlab platform.
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self assembling shell proteins pdua and pduj have essential and redundant roles in bacterial microcompartment assembly
bioRxiv, 2020Co-Authors: Nolan W Kennedy, Svetlana P Ikonomova, Henry W Raeder, Danielle TullmanercekAbstract:Protein self-assembly is a common and essential biological phenomenon, and bacterial microcompartments present a promising model system to study this process. Bacterial microcompartments are large, protein-based organelles which natively carry out processes important for carbon fixation in cyanobacteria and the survival of enteric bacteria. These structures are increasingly popular with biological engineers due to their potential utility as nanobioreactors or drug delivery vehicles. However, the limited understanding of the assembly mechanism of these bacterial microcompartments hinders efforts to repurpose them for non-native functions. Here, we comprehensively investigate proteins involved in the assembly of the 1,2-propanediol utilization bacterial microcompartment from Salmonella enterica serovar Typhimurium LT2, one of the most widely studied microcompartment systems. We first demonstrate that two shell proteins, PduA and PduJ, have a high propensity for self-assembly upon overexpression, and we provide a novel method for self-assembly quantification. Using genomic knock-outs and knock-ins, we systematically show that these two proteins play an essential and redundant role in bacterial microcompartment assembly that cannot be compensated by other shell proteins. At least one of the two proteins PduA and PduJ must be present for the bacterial microcompartment shell to assemble. We also demonstrate that assembly-deficient variants of these proteins are unable to rescue microcompartment formation, highlighting the importance of this assembly property. Our work provides insight into the assembly mechanism of these bacterial organelles and will aid Downstream Engineering efforts.
Stefan Hasinger - One of the best experts on this subject based on the ideXlab platform.
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design and Engineering process integration through a multiple view intermediate modeller in a distributed object oriented system environment
Computer-aided Design, 1998Co-Authors: Teresa De Martino, Bianca Falcidieno, Stefan HasingerAbstract:Abstract Feature-based modelling is the emerging technology to integrate design and Engineering activities. It enriches product data representation with semantic information, that allows more efficient and direct communication between Engineering processes. Nevertheless, major industrial problems arise from the fact that the communication between these processes is still not based on sharing the same information within a computer-internal product model. The lack of industrial product data exchange between various CAD/CAE applications is owing to the fact that there are diverse data formats and standards, giving rise to conversion problems. The ISO standard STEP provides a unique, comprehensive technology to solve most of the industrial problems in data exchange. However, it still does not provide all the resources needed to achieve a high-level, semantic data communication between Engineering processes. In this article, we propose a solution to link the design process (CAD) with Downstream Engineering processes (CAE) based on an integrated feature-based modelling approach that supports both design-by-features and feature recognition. Integration is thereby achieved through a homogeneous, multiple view feature-based representation of the part model, called intermediate model, which is shared among the various applications. A distributed, object-oriented feature-based system architecture is described. Herein, the intermediate modeller server acts as a service provider to network-based distributed applications. These share the intermediate model and are able to extract their specific view from the semantic data of the product. A prototype implementation of the integrated feature-based modelling kernel and its integration into the distributed environment is also outlined.
Mariusz Deja - One of the best experts on this subject based on the ideXlab platform.
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machining process sequencing and machine assignment in generative feature based capp for mill turn parts
Journal of Manufacturing Systems, 2018Co-Authors: Mariusz Deja, Mieczyslaw SiemiatkowskiAbstract:Abstract Process selection and sequencing, as one of the most complex issues when evaluated from a mathematical point of view and crucial in CAPP, still attract research attention. For the current trend of intelligent manufacturing, machining features (MFs) are the information carriers for workpiece geometry and topology representation. They are basically derived from CAD models and are used by Downstream Engineering applications. A feature-based reasoning approach for generating machining sequences in terms of part setups and the assignment of machine alternatives is presented. The approach suggested in this research assumes a heavy reliance on a data input model incorporating functional requirements for parts and in particular GD&T references. An extended feature taxonomy corresponding to the needs of the rational process plan selection for the addressed category of part types is proposed. It is meant to be applicable to machining of both rotational and prismatic features using machines of various configurations. The developed taxonomy is based on the working directions for MFs and includes the identification of their location with respect to datum references. The developed taxonomy that involves feature tolerance relationships is at the core of the information data model utilised by the original algorithm which was aimed at generic process sequencing for the definite category of mechanical parts. Through the developed algorithm, adequate process alternatives can be generated by adaptive setup merging on a single machine or across multiple available machines under consideration of their respective process capabilities. The approach has been validated through an illustrative case study using a sample mill-turn part of considerable complexity.
Nolan W Kennedy - One of the best experts on this subject based on the ideXlab platform.
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self assembling shell proteins pdua and pduj have essential and redundant roles in bacterial microcompartment assembly
bioRxiv, 2020Co-Authors: Nolan W Kennedy, Svetlana P Ikonomova, Henry W Raeder, Danielle TullmanercekAbstract:Protein self-assembly is a common and essential biological phenomenon, and bacterial microcompartments present a promising model system to study this process. Bacterial microcompartments are large, protein-based organelles which natively carry out processes important for carbon fixation in cyanobacteria and the survival of enteric bacteria. These structures are increasingly popular with biological engineers due to their potential utility as nanobioreactors or drug delivery vehicles. However, the limited understanding of the assembly mechanism of these bacterial microcompartments hinders efforts to repurpose them for non-native functions. Here, we comprehensively investigate proteins involved in the assembly of the 1,2-propanediol utilization bacterial microcompartment from Salmonella enterica serovar Typhimurium LT2, one of the most widely studied microcompartment systems. We first demonstrate that two shell proteins, PduA and PduJ, have a high propensity for self-assembly upon overexpression, and we provide a novel method for self-assembly quantification. Using genomic knock-outs and knock-ins, we systematically show that these two proteins play an essential and redundant role in bacterial microcompartment assembly that cannot be compensated by other shell proteins. At least one of the two proteins PduA and PduJ must be present for the bacterial microcompartment shell to assemble. We also demonstrate that assembly-deficient variants of these proteins are unable to rescue microcompartment formation, highlighting the importance of this assembly property. Our work provides insight into the assembly mechanism of these bacterial organelles and will aid Downstream Engineering efforts.