Asymptotic defectiveness of manufacturing plants: an estimate based on process learning curves

The paper describes a method for a preliminary estimation of asymptotic defectiveness of a manufacturing plant based on the prediction of its learning curve estimated during a p-chart setting up. The proposed approach provides process managers with the possibility of estimating the asymptotic variability of the process and the period of revision of p-chart control limits. An application of the method is also provided

Adaptive Background Compensation of Frequency Interleaved DACs with Application to Coherent Optical Transceivers

Digital-to-analog converters (DACs) with bandwidths larger than 70 GHz and sampling rates in excess of 170 GS/s will soon be required in ultra-high speed communication applications such as coherent optical transceivers operating at symbol rates of 140 GBd and beyond. Frequency interleaving has been proposed as a way to break the bandwidth bottleneck in such applications. Splitting the input signal into multiple frequency bands reduces the required bandwidth per interleaved DAC and therefore it enables the synthesis of greater bandwidth signals in the reconstructed output. Elaborate digital signal processing (DSP) is required to seamlessly stitch together the sub-bands and compensate the errors of the analog signal path, which would otherwise severely degrade the performance of the communication system. Adaptive DSP techniques are required to automatically compensate errors caused by process, voltage, and temperature variations in the technology (e.g., CMOS, SiGe, etc.) implementations of the data converters, and therefore ensure high manufacturing yield. These techniques must operate in background mode to avoid interfering with the normal operation of the communication system. This work introduces an adaptive background compensation scheme for frequency interleaved DACs (FI-DACs). The primary application example is a 128 GBd QAM16 coherent optical transceiver. However, the technique is applicable to other types of communication transceivers, and it can be generalized to arbitrary signals, as long as they are stationary or quasi-stationary and have a wideband continuous spectrum. The key elements of the proposed technique are a MIMO equalizer and the backpropagation algorithm. Numerical simulation results for the aforementioned application example show that the signal to noise and distortion ratio (SNDR) of the FI-DAC is boosted by more than 25 dB when the proposed compensation technique is applied in the presence of typical analog mismatches. Furthermore, the optical signal to noise ratio penalty of the optical transceiver is reduced from 6 dB to 0.1 dB.Fil: Galetto, Agustín C.. Fundación Fulgor; ArgentinaFil: Reyes, Benjamín Tomás. Fundación Fulgor; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Morero, Damián Alfonso. Universidad Nacional de Córdoba; ArgentinaFil: Hueda, Mario Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Estudios Avanzados en Ingeniería y Tecnología. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Estudios Avanzados en Ingeniería y Tecnología; Argentin

PTEN deficiency and mutant p53 confer glucose-addiction to thyroid cancer cells: impact of glucose depletion on cell proliferation, cell survival, autophagy and cell migration.

Proliferating cancer cells oxidize glucose through the glycolytic pathway. Since this metabolism is less profitable in terms of ATP production, cancer cells consume large quantity of glucose, and those that experience insufficient blood supply become glucose-addicted. We have analyzed the response to glucose depletion in WRO and FTC133 follicular thyroid cancer cells, which differ in the expression of two key regulators of the glucose metabolism. WRO cells, which express wild type p53 and PTEN, showed a higher rate of cell proliferation and were much less sensitive to glucose-depletion than FTC133 cells, which are PTEN null and express mutant p53. Glucose depletion slowed-down the autophagy flux in FTC133 cells, not in WRO cells. In a wound-healing assay, WRO cells were shown to migrate faster than FTC133 cells. Glucose depletion slowed down the cell migration rate, and these effects were more evident in FTC133 cells. Genetic silencing of either wild-type PTEN or p53 in WRO cells resulted in increased uptake of glucose, whereas the ectopic expression of PTEN in FTC133 cells resulted in diminished glucose uptake. In conclusion, compared to WRO, FTC133 cells were higher glucose up-taker and consumer. These data do not support the general contention that cancer cells lacking PTEN or expressing the mutant p53R273H are more aggressive and prone to better face glucose depletion. We propose that concurrent PTEN deficiency and mutant p53 leads to a glucose-addiction state that renders the cancer cell more sensitive to glucose restriction. The present observation substantiates the view that glucose-restriction may be an adjuvant strategy to combat these tumours

Information-rich quality controls prediction model based on non-destructive analysis for porosity determination of AISI H13 produced by electron beam melting

The number of materials processed via additive manufacturing (AM) technologies has rapidly increased over the past decade. As of these emerging technologies, electron beam powder bed fusion (EB-PBF) process is becoming an enabling technology to manufacture complex-shaped components made of thermal-cracking sensitive materials, such as AISI H13 hot-work tool steel. In this process, a proper combination of process parameters should be employed to produce dense parts. Therefore, one of the first steps in the EB-PBF part production is to perform the process parameter optimization procedure. However, the conventional procedure that includes the image analysis of the cross-section of several as-built samples is time-consuming and costly. Hence, a new model is introduced in this work to find the best combination of EB-PBF process parameters concisely and cost-effectively. A correlation between the surface topography, the internal porosity, and the process parameters is established. The correlation between the internal porosity and the melting process parameters has been described by a high robust model (R-adj(2) = 0.91) as well as the correlation of topography parameters and melting process parameters (R-adj(2) = 0.77-0.96). Finally, a robust and information-rich prediction model for evaluating the internal porosity is proposed (R-adj(2) = 0.95) based on in situ surface topography characterization and process parameters. The information-rich prediction model allows obtaining more robust and representative model, yielding an improvement of about 4% with respect to the process parameter-based model. The model is experimentally validated showing adequate performances, with a RMSE of 2% on the predicted porosity. This result can support process and quality control designers in optimizing resource usage towards zero-defect manufacturing by reducing scraps and waste from destructive quality controls and reworks

Do children with uncomplicated severe acute malnutrition need antibiotics? A systematic review and meta-analysis.

Current (1999) World Health Organization guidelines recommend giving routine antibiotics (AB) for all children with severe acute malnutrition (SAM), even if they have uncomplicated disease with no clinically obvious infections. We examined the evidence behind this recommendation

Design and analysis of fractional factorial experiments from the viewpoint of computational algebraic statistics

We give an expository review of applications of computational algebraic statistics to design and analysis of fractional factorial experiments based on our recent works. For the purpose of design, the techniques of Gr\"obner bases and indicator functions allow us to treat fractional factorial designs without distinction between regular designs and non-regular designs. For the purpose of analysis of data from fractional factorial designs, the techniques of Markov bases allow us to handle discrete observations. Thus the approach of computational algebraic statistics greatly enlarges the scope of fractional factorial designs.Comment: 16 page

Ten policies for pollinators

Earlier this year, the first global thematic assessment from the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) evaluated the state of knowledge about pollinators and pollination (1, 2). It confirmed evidence of large-scale wild pollinator declines in northwest Europe and North America and identified data shortfalls and an urgent need for monitoring elsewhere in the world. With high-level political commitments to support pollinators in the United States (3), the United Kingdom (4), and France (5); encouragement from the Convention on Biological Diversity's (CBD's) scientific advice body (6); and the issue on the agenda for next month's Conference of the Parties to the CBD, we see a chance for global-scale policy change. We extend beyond the IPBES report, which we helped to write, and suggest 10 policies that governments should seriously consider to protect pollinators and secure pollination services. Our suggestions are not the only available responses but are those we consider most likely to succeed, because of synergy with international policy objectives and strategies or formulation of international policy creating opportunities for change. We make these suggestions as independent scientists and not on behalf of IPBES