44 research outputs found
A 200Gb/s PAM-4 Transmitter with Hybrid Sub-Sampling PLL in 28nm CMOS Technology
No full textThis paper presents a complete 200Gb/s PAM-4 transmitter (TX) in 28nm CMOS technology. The transmitter features a hybrid sub-sampling PLL (SSPLL) with a delta-sigma (?S) modulator, clock distribution network with flexible timing control, and data path with a hybrid 5-tap Feed-Forward Equalizer (FFE) and T-coil for bandwidth extension. The prototype chip achieves 4.69 pJ/bit efficiency, 54mV eye height, 0.27UI eye width, and 97% RLM under -6dB channel loss at 50GHz. Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Instrumentatio
An Output Bandwidth Optimized 200-Gb/s PAM-4 100-Gb/s NRZ Transmitter With 5-Tap FFE in 28-nm CMOS
No full textThis article presents a 200-Gb/s pulse amplitude-modulation four-level (PAM-4) and 100-Gb/s non-return-to-zero (NRZ) transmitter (TX) in 28-nm CMOS technology. To achieve the target data rate, the output bandwidth and swing of the proposed TX are optimized by minimizing the output capacitance of the 4:1 multiplexer (MUX) and driver stage with pull-up current sources and adopting a fully reconfigurable 5-tap feed-forward equalizer (FFE). The key circuit includes a segmented 8:4 MUX and 4:1 MUX/driver, a thermal encoder and retimer, and a flexible clock distribution network. Using the layout generated with Berkeley Analog Generator (BAG), the proposed TX achieves an eye opening with >52.9-mV eye height, 0.36 UI eye width, >98% RLM, and 4.63 pJ/b at 200-Gb/s PAM-4 signaling under >6-dB channel loss at 50 GHz, demonstrating the highest data rate achieved using a planar process.Electronic Instrumentatio
A Cryo-CMOS DAC-based 40 Gb/s PAM4 Wireline Transmitter for Quantum Computing Applications
No full textState-of-the-art quantum computers already comprise hundreds of cryogenic quantum bits (qubits), and prototypes with over 10k qubits are currently being developed. Such large-scale systems require local cryogenic electronics for qubit control and readout, leaving the digital controllers for algorithm execution and quantum error correction (QEC) at room temperature due to the limited cryogenic cooling budget. The entire process, including qubit readout, data transmission, QEC, and algorithm execution, should be completed well within the qubit decoherence time, thus requiring a low-power high-speed communication link between the cryogenic quantum processor and classical processor located at room temperature. To this end, this paper presents the first cryo-CMOS high-speed 4-level pulse amplitude modulation (PAM4) wireline transmitter. Thanks to a power-efficient serializing architecture driving a 6-bit digital-to-analog converter (DAC), the 40-nm CMOS chip achieves a data rate of 40 Gb/s PAM4 with an efficiency of 2.46pJ/b and a ratio of level mismatch (RLM) of 97.8% at 4.2 K. While demonstrating an energy efficiency comparable to state-of-the-art transmitters in more advanced CMOS nodes, the extremely wide temperature operating range (4.2 K - 300 K) will enable future large-scale quantum computers.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.QCD/Babaie LabElectronicsElectrical Engineering, Mathematics and Computer ScienceQuantum Circuit Architectures and Technolog
On mutually permutable products of finite groups
No full text[EN] The main purpose of this paper is to study mutually permutable products G = AB in which the subgroups of prime order p and cyclic of order 4 (if p = 2) of the largest normal subgroup of G contained in A boolean AND B are well situated in G. Our results confirm once again the important role of the intersection of the factors in the structural study of mutually permutable products.The first author is supported by the grant MTM2014-54707-C3-1-P from the Ministerio de Economia y Competitividad, Spain, and FEDER, European Union. The first and second authors are supported by Major Projects in Basic Research and Applied Research (Natural Science) of Guangdong Province (2017KZDXM058). The first and third authors are supported by Prometeo/2017/057 of Generalitat (Valencian Community, Spain). The second author is supported by Funds of Guangzhou Science and Technology (No: 201804010088). The fourth author is supported by the project of NSF China (11401597).Ballester-Bolinches, A.; Li, Y.; Pedraza Aguilera, MC.; Su, N. (2018). On mutually permutable products of finite groups. Rendiconti Lincei - Matematica e Applicazioni. 29(4):711-719. https://doi.org/10.4171/RLM/830S71171929
Retraction: Specific Transfection of Inflamed Brain by Macrophages: A New Therapeutic Strategy for Neurodegenerative Diseases (PLoS ONE (2013) 8:4 (e61852) DOI: 10.1371/journal.pone.0061852)
No full textFollowing publication of this article [1, 2] an investigation by the University of North Carolina at Chapel Hill concluded that research misconduct occurred. Specifically, the investigation found falsification of research results as follows: In the corrected version of Figure 3B [2], the research results in the first panel (i.c. PBS followed by i.v. injection of PBS) originated from an unrelated experiment. In Figure 3B [1, 2], the research results in the third panel from the left (i.c. 6-OHDA followed by i.v. injection of PBS) originated from an unrelated experiment. In light of the concerns about the reliability and integrity of the reported results the PLOS ONE Editors retract this article. The corresponding author EVB responded but did not confirm agreement nor disagreement with the editorial decision, and indicated that the wrong data were included in the article in error. EVB stands by the article’s findings and apologizes for the issues with the published article. MJH, YZ, EBH, VM, SA, ZH, PS, SDH, NLK, RLM, HEG, and AVK agreed with the retraction. MJH, EBH, RLM, HEG, and AVK apologize for the issues with the published article. MJH, RLM, and HEG stand by the article’s findings. At the time of retraction of [1], the Correction [2] was republished to amend the author list
Decoupling and prices: determinant of dairy farmers’ choices? A model to analyse impacts of the 2003 CAP reform
No full textThe reform of European Common Agricultural Policy (CAP) in 2003 has resulted in substantial changes to the attribution of subsidies to dairy farmers. Moreover, dairy farmers are in also facing an unprecedented situation on the markets with the soaring prices of agricultural raw materials: they sell their products at a higher price (milk, meat and cereals), but must also cope with the increasing prices of concentrates. In this paper1, we discuss cross effects, on the productive strategy of French dairy farms, of the Luxemburg Agreement and the prices variations. A model based on mathematical programming has been privileged to determine how dairy farmers might re-evaluate their systems to identify optimal production plan. While respecting the principle of agent rationality (maximization of profit), the model incorporates the economic risk related to the volatility of the inputs and outputs prices. Thus the model maximises the expected utility of the income while taking into account a set of constraints: regulatory, structural, zootechnical, agronomic and environmental. The model is applied to four types of dairy farms to cope with the diversity of production systems in the west of France (“grazier” type, “semi intensive” type, “milk + cereals” type and “milk + young bulls” type). The model is used to produce quantitative estimations and support reflection through the simulation of the setting up of the Single payment scheme. The sensitivity of the results is discussed by taking into account several options of prices for cereals and livestock products. These may have a strong influence on the structure of the diet and, therefore, on the level of intensification of the forage area. The results show that the implementation of the CAP reform encourages farmers to substitute a part of corn silage by grass in the diet. However, the rising price of agricultural production encourages, on the contrary, farmers to intensify their system in order to free up land for growing cereals. We also observe that a decrease of the young bulls fattening activity to develop cereal crops is also economically profitable.dairy farm, single payment, price variation, Agricultural and Food Policy, Livestock Production/Industries,
DNA Glycosylases Involved in Base Excision Repair May Be Associated with Cancer Risk in BRCA1 and BRCA2 Mutation Carriers.
No full textSingle Nucleotide Polymorphisms (SNPs) in genes involved in the DNA Base Excision Repair (BER) pathway could be
associated with cancer risk in carriers of mutations in the high-penetrance susceptibility genes BRCA1 and BRCA2, given the relation of synthetic lethality that exists between one of the components of the BER pathway, PARP1 (poly ADP ribose
polymerase), and both BRCA1 and BRCA2. In the present study, we have performed a comprehensive analysis of 18 genes involved in BER using a tagging SNP approach in a large series of BRCA1 and BRCA2 mutation carriers. 144 SNPs were analyzed in a two stage study involving 23,463 carriers from the CIMBA consortium (the Consortium of Investigators of Modifiers of BRCA1 and BRCA2). Eleven SNPs showed evidence of association with breast and/or ovarian cancer at p,0.05 in the combined analysis. Four of the five genes for which strongest evidence of association was observed were DNA glycosylases. The strongest evidence was for rs1466785 in the NEIL2 (endonuclease VIII-like 2) gene (HR: 1.09, 95% CI (1.03– 1.16), p = 2.761023) for association with breast cancer risk in BRCA2 mutation carriers, and rs2304277 in the OGG1 (8-guanine DNA glycosylase) gene, with ovarian cancer risk in BRCA1 mutation carriers (HR: 1.12 95%CI: 1.03–1.21,
p = 4.861023). DNA glycosylases involved in the first steps of the BER pathway may be associated with cancer risk in BRCA1/ 2 mutation carriers and should be more comprehensively studied
Performance evaluation of the CWI BRDF-fitting method under cloud-contaminated conditions: A numerical experiment using PROSAIL
No full textRemote retrieval of Normalized Difference Vegetation Index (NDVI) over the Earth’s surface is a critical component of monitoring the surface processes of our planet. NDVI is a widely used and useful indicator of vegetation health and quantity however its retrieval using satellite data is hindered by the frequent presence of clouds in the Earth’s atmosphere. Zeng et al. (2016) developed a novel technique that estimates a surface's Bidirectional Reflectance Distribution Function (BRDF) with a RossLiMaignan (RLM) BRDF model from a set of observations. This method, the ChangingWeight Iterative (CWI) method, uses iterative a posteriori estimation of observation errors to reduce the impact of cloud-contaminated measurements in the sample. Its performance was compared to two conventional methods, ordinaryleast squares (OLS) and LiGao BRDF-fitting. The three different BRDFfitting methods were compared in a numerical experiment. 6,000 surface types covering a broad range of surface types were modeled using the canopy radiative transfer model PROSAIL. For each surface, sets of pseudo-observations of the surface’s red and NIR band reflectance were generated using realistic suntarget view geometries from the MODIS and MERSI satellite sensors. The effects of cloudcontamination were simulated by adding different numbers of cloudcontaminated observation to the sample, with varying degrees of contamination. The RLM BRDF model was fitted to these samples using the three different methods to estimate the BRDF model parameters. These were subsequently used to calculate a NDVI composite value. Each method’s estimate was compared to a reference value generated by PROSAIL. Results for the 6,000 surfaces confirmed that the CWI method is more noiseresistant than OLS and LiGao in situations with many observations (i.e. a large sample), and resulted in estimates that more closely matched the reference value from PROSAIL, compared to the conventional LiGao and OLS methods. In scenarios of lowcloud contamination, all three methods failed to detect and significantly suppress the impact of noisy observations, which was expected from existing literature. For a largesized sample of 13 pseudoobservations studied for the validation site Mongu, Zambia, the CWI method was observed to have a very accurate performance, for up to 5 contaminated observations in the sample. With smaller sized samples of 8 and 10 for two other validation sites, it was found that the RMSE of the CWI method would suddenly increase approximately tenfold when the number of contaminated observations increased beyond 2 and 3, respectively. After these ’tipping points’, the LiGao method was more accurate and outperformed CWI. The CWI method therefore performed promisingly when given a large enough sample size, and in these cases it was more accurate than the conventional Li-Gao and OLS methods. However, when it fails to correctly identify noisy observations, its accuracy could decrease suddenly, which should be taken into consideration for operational use. Since the results of the experiment were averaged over 6,000 different sampling points of the PROSAIL model's parameter space, it is suggested that the conclusions apply to a wide range of surface types found all over the Earth.Geoscience and Remote Sensin
A fractional Gehring lemma, with applications to nonlocal equations
No full textTo Carlo Sbordone on his 65th birthday.This paper reports the content of a talk given by the second-named author at the Accademia dei Lincei on November 26, 2013.International audienceWe describe a fractional version of the classical Gehring lemma. As a consequence, new self-improving regularity properties of solutions to integrodifferential equations emerge
