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Assembly sequence planning plays a major role in the manufacturing industry. There are still many challenges in the area of assembly planning. One of the significant reasons is the weakness in effective description of assembly knowledge and information. With the purpose of reducing computational complexity, this paper presents a method based on engineering knowledge approach to the assembly sequence planning. The DACG (Directed Assembly Connection Graph) proposed provides an appropriate way to express both geometric information and non-geometric knowledge. In order to increase the assembly planning efficiency, the DACG includes engineering knowledge and semantic in design, manufacturing and assembly fields. Product semantic information model could offer much useful information for designer to finish the assembly (process) design and make right decision in that process. A product assembly planning example is presented to illustrate the effectiveness of the proposed approach. Preliminary experience with the approach indicates the potential to reduce lead times and thereby can help in completing new product launch projects on time. [ABSTRACT FROM AUTHOR]

The flatness measurement of a large 2-D flat work- piece such as a satellite solar panel substrate is a key problem in its manufacturing process. Based on the current measuring methods and the actual engineering project, a new noncontact high-precision, low-cost large 2-D flat workpiece flatness measuring system is developed, in which the techniques of oblique optical triangle measuring structure, virtual measurement datum plane, and error self-correction are adopted. By means of the oblique optical triangle measuring structure that is first proposed, the measuring area and resolution of the measuring system can be greatly increased. Meanwhile, on the basis of the techniques of virtual measurement datum plane and error self-correction, the noncontact high-precision, low-cost flatness measurement can be realized on a nonprecise large metallic platform. Experimental results on the satellite solar panel substrate indicate the correctness and effectiveness of the proposed noncontact flatness-measuring system of the large 2-D flat workpiece. Although the specific application of the satellite solar panel substrate is presented in this paper, the proposed measurement techniques and measuring system could be applied independent of the nature or use of the large 2-D flat workpieces. [ABSTRACT FROM AUTHOR]

This paper presents a circuit design and simulation result for unit circuit and the overall circuit of assembly line structure ADC. Among the unit circuit, the sampling switch of sample holder uses a higher linearity bootstrapped switch, by using the bottom plate sampling to offset the effect of charge injection effect, and by using the capacitance flip type structure to reduce power consumption, designing a high gain and high speed operational trans-conductance amplifier to improve gain and speed. According to the influence of noise, the sampling capacitor is selected, and then the load operational amplifier is determined. Operational amplifier is the core module. Therefore it is very necessary to take design and simulation to it. the common mode level changes of MDAC input signal is smaller, we use the higher current efficiency sleeve type amplifier to save power consumption. In two-phase non overlapping clock circuit, a buffer is added to drive heavy load. Simulating the whole ADC circuit, we can get SNDR=72.3dB,SFDR=84.9dB, and the effective bit is 11.7. [ABSTRACT FROM AUTHOR]

Type I modular polyketide synthases (PKSs) are multi-domain enzymes functioning like assembly lines. Many engineering attempts have been made for the last three decades to replace, delete and insert new functional domains into PKSs to produce novel molecules. However, inserting heterologous domains often destabilize PKSs, causing loss of activity and protein misfolding. To address this challenge, here we develop a fluorescence-based solubility biosensor that can quickly identify engineered PKSs variants with minimal structural disruptions. Using this biosensor, we screen a library of acyltransferase (AT)-exchanged PKS hybrids with randomly assigned domain boundaries, and we identify variants that maintain wild type production levels. We then probe each position in the AT linker region to determine how domain boundaries influence structural integrity and identify a set of optimized domain boundaries. Overall, we have successfully developed an experimentally validated, high-throughput method for making hybrid PKSs that produce novel molecules. Engineering polyketide synthases can be challenging due to the absence of efficient high-throughput methods. Here, the authors used a solubility biosensor to identify stable variants from libraries of modified polyketide synthases. [ABSTRACT FROM AUTHOR]

The modular organization of the type I polyketide synthases (PKSs) would seem propitious for rational engineering of desirable analogous. However, despite decades of efforts, such experiments remain largely inefficient. Here, we combine multiple, state-of-the-art approaches to reprogram the stambomycin PKS by deleting seven internal modules. One system produces the target 37-membered mini-stambomycin metabolites − a reduction in chain length of 14 carbons relative to the 51-membered parental compounds − but also substantial quantities of shunt metabolites. Our data also support an unprecedented off-loading mechanism of such stalled intermediates involving the C-terminal thioesterase domain of the PKS. The mini-stambomycin yields are reduced relative to wild type, likely reflecting the poor tolerance of the modules downstream of the modified interfaces to the non-native substrates. Overall, we identify factors contributing to the productivity of engineered whole assembly lines, but our findings also highlight the need for further research to increase production titers. Genetic engineering of the type I polyketide synthases (PKSs) to produce desirable analogous remains largely inefficient. Here, the authors leverage multiple approaches to delete seven internal modules from the stambomycin PKS and generate 37-membered mini-stambomycin macrolactones. [ABSTRACT FROM AUTHOR]

We present a decision-support framework for speeding up the ramp-up of modular assembly systems by learning from past experience. Bringing an assembly system to the expected level of productivity requires engineers performing mechanical adjustments and changes to the assembly process to improve the performance. This activity is time-consuming, knowledge-intensive and highly dependent on the skills of the engineers. Learning the ramp-up process has shown to be effective for making progress faster. Our approach consists of automatically capturing information about the changes made by an operator dealing with disturbances, relating them to the modular structure of the machine and evaluating the resulting system state by analysing sensor data. The feedback thus obtained on applied adaptations is used to derive recommendations in similar contexts. Recommendations are generated with a variant of the k-nearest neighbour algorithm through searching in a multidimensional space containing previous system states. Applications of the framework include knowledge transfer among operators and machines with overlapping structure and functionality. The application of our method in a case study is discussed. [ABSTRACT FROM AUTHOR]

The theoretical and applied issues of complex analysis and control of economic safety of the developing natural monopolies were considered by the example of a system of oil-trunk pipelines.A general problem of forming an economically safe development program for a natural monopoly was posed, and a heuristic approach to it was proposed. It is based on constructing a system of interrelated simulational and calculational financial-and-economic and balance models, which enables one to analyze and select variants of the system development programs with regard for the interests of all parties: monopoly, state, clients, and allied industries. An example of realization of the proposed procedure was presented. [ABSTRACT FROM AUTHOR]

A case is stated for extending the techniques of assembly line balancing to provide for the parallel operation of identical stations, where this leads to a reduction in idle time. The practical implications of operating with this type of system are discussed, both for the stations themselves and the line as a whole, with reference to various classifications of assembly line, and ways in which balancing can be made to fit into an overall strategy for production line design are touched upon. Two distinct types of computer program have been developed to enable multiple stations to become a recognised feature incorporated into 'heuristic' line balancing, rather than an appendage to be applied ad hoc by industrial engineers when current techniques have proven inadequate. One approach is based on a more sophisticated version of the 'positional weight' method while the other relies on the contrasting philosophy of the 'random generation' method, and a comparison is made of their relative success in solving two assembly line problems, and their potential from an industrial viewpoint. [ABSTRACT FROM AUTHOR]