Design Considerations of a Sub-50 {\mu}W Receiver Front-end for Implantable Devices in MedRadio Band

Emerging health-monitor applications, such as information transmission through multi-channel neural implants, image and video communication from inside the body etc., calls for ultra-low active power (<50${\mu}$W) high data-rate, energy-scalable, highly energy-efficient (pJ/bit) radios. Previous literature has strongly focused on low average power duty-cycled radios or low power but low-date radios. In this paper, we investigate power performance trade-off of each front-end component in a conventional radio including active matching, down-conversion and RF/IF amplification and prioritize them based on highest performance/energy metric. The analysis reveals 50${\Omega}$ active matching and RF gain is prohibitive for 50${\mu}$W power-budget. A mixer-first architecture with an N-path mixer and a self-biased inverter based baseband LNA, designed in TSMC 65nm technology show that sub 50${\mu}$W performance can be achieved up to 10Mbps (< 5pJ/b) with OOK modulation.Comment: Accepted to appear on International Conference on VLSI Design 2018 (VLSID

Option-Implied Measures of Equity Risk

Equity risk measured by beta is of great interest to both academics and practitioners. Existing estimates of beta use historical returns. Many studies have found option-implied volatility to be a strong predictor of future realized volatility. We .nd that option-implied volatility and skewness are also good predictors of future realized beta. Motivated by this .nding, we establish a set of assumptions needed to construct a beta estimate from option-implied return moments using equity and index options. This beta can be computed using only option data on a single day. It is therefore potentially able to re.ect sudden changes in the structure of the underlying company. Le risque du marché des actions mesuré selon le coefficient bêta suscite un vif intérêt de la part des universitaires et des praticiens. Les estimations existantes du coefficient bêta utilisent les rendements historiques. De nombreuses études ont démontré que la volatilité implicite du prix des options constitue un indice solide de la volatilité future réalisée. Nous constatons que la volatilité implicite des options et leur caractère asymétrique sont aussi de bons facteurs prévisionnels du bêta futur réalisé. Motivés par ce constat, nous établissons un ensemble d’hypothèses nécessaires pour effectuer une estimation du bêta, à partir des moments de rendement implicite des options, en recourant aux actions et aux options sur indices boursiers. Ce bêta peut être calculé en utilisant seulement les données obtenues sur les options au cours d’une même journée. Il peut donc refléter les changements soudains de la structure de la société sous-jacente.market beta; CAPM; historical; capital budgeting; model-free moments, bêta du marché, MEDAF (modèle d’équilibre des actifs financiers), historique, budgétisation des investissements, moments non paramétriques.

Maximizing Spin Correlations in Top Quark Pair Production at the Tevatron

A comparison is made between the off-diagonal and helicity spin bases for top quark pair production at the FNAL Tevatron. In the off-diagonal basis, 92% of the top quark pairs are in the spin configuration up-down plus down-up, whereas in the helicity basis only 70% are left-right plus right-left. The off-diagonal basis maximizes the spin asymmetry and hence the measured angular correlations between the decay products, which are more than twice as big in this basis as compared to the helicity basis. In addition, for the process q qbar --> t tbar, we give a very simple analytic expression for the matrix element squared which includes all spin correlations between the production and subsequent decay of the top quarks.Comment: 15 pages, revtex. 4 Postscript figures (included

Distribution of hydrogen peroxide and methylhydroperoxide over the Pacific and South Atlantic Oceans

The gas phase hydrogen peroxide and methylhydroperoxide concentrations were measured in the troposphere over the tropical Pacific Ocean as a component of NASA's Global Tropospheric Experiment/Pacific Exploratory Mission-Tropics A field campaign. Flights on two aircraft covered the Pacific from 70°S to 60°N and 110°E to 80°W and South Atlantic from 40°S to 15°N and 45°W to 70°E, and extending from 76 to 13,000 m altitude. H2O2 and CH3OOH have the highest concentrations at a given altitude at the equator and decrease with increasing latitude in both the northern and southern hemispheres. Above 4 km the gradient is substantially reduced for both H2O2 and CH3OOH with latitude, and at altitudes in excess of 8 km there is no latitudinal dependence. H2O2 and CH3OOH exhibit maximum mixing ratios between 1 and 2 km at all latitudes. The mean mixing ratio of H2O2 at the equator was 1600 ± 600 parts per trillion by volume (pptv) decreasing to 500 ± 250 pptv at latitudes greater than 55° north and south between 1 and 2 km altitude. CH3OOH at the equator was 1400 ± 250 pptv, decreasing to 330 ± 200 pptv at high latitudes at altitudes between 1 and 2 km. The concentration of peroxides at high latitudes in the northern hemisphere was generally a factor of 2 higher than at corresponding latitudes in the southern hemisphere. The ratio of H2O2 to CH3OOH was between 1 and 2 from 45°S to 35°N at altitudes below 4 km. Between 5° to 15°N the ratio is less than 1, due to preferential removal of H2O2 in the Intertropical Convergence Zone. Copyright 1999 by the American Geophysical Union

Mutational Heterogeneity in Melanoma: An Inconvenient Truth

Identification of oncogenic BRAF mutations in primary and metastatic melanomas supports a linear model of clonal evolution in cancer. Some mutational studies, however, have failed to identify BRAF mutations in metastatic tumors from patients with BRAFmutant primary melanomas. Using a combination of methods, Riveiro-Falkenbach et al. (2015) assert that technical issues, and not clonal heterogeneity, may explain prior discordant mutational results

Parallel Computing on a PC Cluster

The tremendous advance in computer technology in the past decade has made it possible to achieve the performance of a supercomputer on a very small budget. We have built a multi-CPU cluster of Pentium PC capable of parallel computations using the Message Passing Interface (MPI). We will discuss the configuration, performance, and application of the cluster to our work in physics.Comment: 3 pages, uses Latex and aipproc.cl