The Different Shades of Infinite Session Types

Many type systems include infinite types. In session type systems, infinite types are important because they specify communication protocols that are unbounded in time. Usually infinite session types are introduced as simple finite-state expressions rec X.T or by nonparametric equational definitions X .= T. Alternatively, some systems of label- or value-dependent session types go beyond simple recursive types. However, leaving dependent types aside, there is a much richer world of infinite session types, ranging through various forms of parametric equational definitions, to arbitrary infinite types in a coinductively defined space. We study infinite session types across a spectrum of shades of grey on the way to the bright light of general infinite types. We identify four points on the spectrum, characterised by different styles of equational definitions, and show that they form a strict hierarchy by establishing bidirectional correspondences with classes of automata: finite-state, 1- counter, pushdown and 2-counter. This allows us to establish decidability and undecidability results for type formation, type equivalence and duality in each class of types. We also consider previous work on context-free session types (and extend it to higher-order) and nested session types, and locate them on our spectrum of infinite types

2015/16 seasonal vaccine effectiveness against hospitalisation with influenza a(H1N1)pdm09 and B among elderly people in Europe: Results from the I-MOVE+ project

We conducted a multicentre test-negative caseâ\u80\u93control study in 27 hospitals of 11 European countries to measure 2015/16 influenza vaccine effectiveness (IVE) against hospitalised influenza A(H1N1)pdm09 and B among people aged â\u89¥ 65 years. Patients swabbed within 7 days after onset of symptoms compatible with severe acute respiratory infection were included. Information on demographics, vaccination and underlying conditions was collected. Using logistic regression, we measured IVE adjusted for potential confounders. We included 355 influenza A(H1N1)pdm09 cases, 110 influenza B cases, and 1,274 controls. Adjusted IVE against influenza A(H1N1)pdm09 was 42% (95% confidence interval (CI): 22 to 57). It was 59% (95% CI: 23 to 78), 48% (95% CI: 5 to 71), 43% (95% CI: 8 to 65) and 39% (95% CI: 7 to 60) in patients with diabetes mellitus, cancer, lung and heart disease, respectively. Adjusted IVE against influenza B was 52% (95% CI: 24 to 70). It was 62% (95% CI: 5 to 85), 60% (95% CI: 18 to 80) and 36% (95% CI: -23 to 67) in patients with diabetes mellitus, lung and heart disease, respectively. 2015/16 IVE estimates against hospitalised influenza in elderly people was moderate against influenza A(H1N1)pdm09 and B, including among those with diabetes mellitus, cancer, lung or heart diseases

0.12 µm GATE LENGTH In0.52Al0.48As/In0.53Ga0.47As HEMTs on transferred substrate

New In0.52Al0.48As/In0.53Ga0.47As transferred-substrate high electron mobility transistors (TS-HEMTs) have been successfully fabricated on 2 inch Silicon substrate with 0.12 µm T-shaped gate length. These new TS-HEMTs exhibit typical drain currents of 450 mA/mm and extrinsic transconductance up to 770 mS/mm. An extrinsic current cutoff frequency fT of 185 GHz is obtained. That result is the first reported for In0.52Al0.48As/In0.53Ga0.47As TS-HEMTs on Silicon substrate

Computer aided design in wastewater treatment

SIGLEAvailable from British Library Lending Division - LD:D55300/85 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A Monolithic Visible, Infrared and Terahertz 2D Detector

A monolithic multispectral detector for imaging in the visible (VIS), infrared (IR) and terahertz (THz) ranges has been designed for operation at room temperature. This sensor is composed of a CMOS readout integrated circuit (ROIC) housing visible photodiodes and of IR and THz microbolometer pixels processed above the CMOS wafer. Without package- and system-level issues, targeted individual pixel sensitivities are respectively an 80dB dynamic range for VIS photodiodes, a NETD=50mK @f/1 for IR and a THz NEP smaller than 10pW. Prototyping chips will be integrated in tri-spectral imaging and THz spectroscopy demonstration system

A 160x160-pixel Image Sensor for Multispectral Visible, Infrared and Terahertz Detection

This paper describes the development and characterization of a 160×160-pixels image sensor for the simultaneous detection of visible, infrared and terahertz spectra. The monolithic imager is realized by means of post-processing of CMOS wafers housing the readout integrated circuit (ROIC). Visible pixels are implemented as conventional photodiodes in the ROIC, which contains also the addressing and processing electronics for the infrared and terahertz bands. Infrared and terahertz detectors are based on micro-bolometers and realized during the post-processing fabrication steps. A standard 0.35μm 2P4M CMOS wafer lot has been fabricated and processed, and single imagers characterized for the three spectral bands. Successful operation has been verified at 50 fps, with more than 100 dB dynamic range in the visible region, a NETD of 60mK in the infrared, and a 63pW NEP for the terahertz, with a total power consumption of 173 mW

0.12 µm GATE LENGTH In 0.52 Al 0.48 As/In 0.53 Ga 0.47 As HEMTs ON TRANSFERRED SUBSTRATE

ABSTRAC

Effect of temperature on the optical properties of GaAsSbN/GaAs single quantum wells grown by molecular-beam epitaxy

GaAsSbN/GaAs strained-layer single quantum wells grown on a GaAs substrate by molecular-beam epitaxy with different N concentrations were studied using the photoluminescence (PL) technique in the temperature range from 9 to 296 K. A strong redshift in optical transition energies induced by a small increase in N concentration has been observed in the PL spectra. This effect can be explained by the interaction between a narrow resonant band formed by the N-localized states and the conduction band of the host semiconductor. Excitonic transitions in the quantum wells show a successive red/blue/redshift with increasing temperature in the 2-100 K range. The activation energies of nonradiative channels responsible for a strong thermal quenching are deduced from an Arrhenius plot of the integrated PL intensity. (C) 2003 American Institute of Physics