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The ability of state-of-the-art regional climate models (RCMs) to simulate the trends of intense cyclone activity in the Arctic is assessed based on an ensemble of 13 simulations from 11 models from the Arctic-CORDEX initiative. Some models employ large-scale spectral nudging techniques. Cyclone characteristics simulated by the ensemble in winter and summer are compared with the results from four

This paper presents an injection-locked 65-nm CMOS circuit that upconverts and power amplifies baseband signals to RF. The circuit delivers an RF output power of 28.7 dBm, with a power gain and maximum power added efficiency (PAE) of 20.6 dB and 68.1%, respectively. Both AM–AM-conversion and AM–PM-conversion are low, less than 1 dB and 1°, respectively, resulting in an EVM of 4.7% for Long Term Ev

We present two sensitivity function trade-offs that apply to a class of networks with a string topology. In particular we show that a lower bound on the H-infinity norm and a Bode sensitivity relation hold for an entire family of sensitivity functions associated with growing the network. The trade-offs we identify are a direct consequence of growing the network, and can be used to explain why poor

We consider least-squares approximation of a function of one variable by a continuous, piecewise-linear approximand that has a small number of breakpoints. This problem was notably considered by Bellman who proposed an approximate algorithm based on dynamic programming. Many suboptimal approaches have been suggested, but so far, the only exact methods resort to mixed integer programming with super

This document outlines how to setup and run computations in parallel using Julia on a collection of remote computers, such as computers in a university lab. After the environment has been setup,Only minor modifications to serially executed code is necessary to enable parallel execution.Written for Julia version 1.0

We describe how to utilize the possibility of differentiating through arbitrary Julia codeto perform tasks such as controller optimization. The user specifies a cost function, forexample, the integrated squared error between output and reference, and constraints, suchas a maximum acceptable value of the sensitivity function. Julia performs the integrationand calculates the sensitivities of the cos

Savannas are inherently “disturbed” ecosystems, but the regularly recurring disruptions play such a fundamental ecological role (Scholes and Archer, 1997) that “episodic events” rather than “disturbance” may the more apt terminology. From an atmospheric perspective, fire is the most significant of these episodic events. Fires shape community species composition; tree to grass ratio and nutrient re

This paper describes a method to compute frame size estimates to be used in quasi Worst-Case Transmission Times (qWCTT) for cameras that transmit frames over IP-based communication networks. The precise determination of qWCTT allows us to model the network access scheduling problem as a multiframe problem and to re-use theoretical results for network scheduling. The paper presents a set of experim

An established rule of thumb in the field of traffic light control prescribes that, during periods of higher demand, it is convenient to have longer cycles. This is in order to reduce the fraction of the cycle length when no incoming lanes receive green light. In this paper, we simulate a novel, provably stable, decentralized feedback traffic light control policy with variable cycle length. The pr

Forward–backward and Douglas–Rachford splitting are methods for structured nonsmooth optimization. With the aim to use smooth optimization techniques for nonsmooth problems, the forward–backward and Douglas–Rachford envelopes where recently proposed. Under specific problem assumptions, these envelope functions have favorable smoothness and convexity properties and their stationary points coincide

We consider the problem of finding an event-based sampling scheme that optimizes the trade-off between average sampling rate and control performance in a linear-quadratic-Gaussian (LQG) control problem setting with output feedback. Our analysis is based on a recently presented sampled-data controller structure, which remains LQG-optimal for any choice of sampling scheme. We show that optimization

The morphological transformation of soot particles via condensation of low-volatility materials constitutes a dominant atmospheric process with serious implications for the optical and hygroscopic properties, as well as atmospheric lifetime of the soot. We consider the morphological transformation of soot aggregates under the influence of condensation of vapors of sulfuric acid, and/or limonene oz

Rotational singularities inherent to three different geometric controllers on SE (3) are studied. A new singularity-free method of incrementally generating a reference rotation is proposed, removing a class of singularities without affecting proven stability properties of the closed-loop systems. If satisfying a bound on attitude rate and maximum loop rate in the reference generation, the proposed

We consider temperature stabilization of the phase-reference line at the European Spallation Source, a facility for neutron spallation currently under construction. Based on extensive modeling of the heat dynamics, a prototype model-based control system with associated hardware architecture is developed and experimentally evaluated on a small-scale setup. The results indicate that temperature stab

Big Data Applications (BDAs) manage so much data to require a cluster of machines for computation and storage. Their execution often has temporal constraints, such as deadlines to process the data. BDAs are executed within Big Data Frameworks (BDFs), that provide mechanisms to automatically manage the complexity of the computation distribution. For a BDA to fulfill its deadline when executed in a

Hygroscopicity measurements of secondary organic aerosol (SOA) particles often show inconsistent results between the supersaturated and subsaturated regimes, with higher activity as cloud condensation nucleus (CCN) than indicated by hygroscopic growth. In this study, we have investigated the discrepancy between the two regimes in the Lund University (LU) smog chamber. Various anthropogenic SOA wer

This paper presents a scalable and high-Throughput hybrid computing platform for the real-Time multi-particle based Linac (Linear accelerator) simulation model to be used at the European Spallation Source (ESS). The multi-particle simulation model with non-linear modeling is needed to provide a realistic behavior of the particle beam for reducing the losses at the superconducting structures. The c

This paper presents a cryptographic processor compliant with the security algorithms specified by the 3rd Generation Partnership Project (3GPP) specifications for Long Term Evolution (LTE). The proposed processor has been adapted to the needs of the low end portfolio technologies that compose the Internet of Things (IoT) market, which addresses low-Area, low-cost and low-data rate applications. Th