Patch antennas on inhomogeneous substrates are analyzed with the stable FEM-FDTD hybrid method [T. Rylander and A. Bondeson, “Stable FEMFDTD hybrid method for Maxwell’s equations,” Comput. Phys. Comm. 125, 75 (2000)] and an analytic propagator technique. For inhomogeneous substrates with a fixed homogenized value of the permittivity, our results conjecture that a decrease of the permittivity in the

In this paper, the problem of calibrating a paper machine dryer section model to measurement data is treated. The model, which is dynamic, nonlinear and of large scale, is implemented in Modelica and Dymola. The purpose of the model is to evaluate, in simulation, new control structures before application to the plant. This approach requires a well calibrated model in order for simulation results t

Technology scaling has caused Negative Bias Temperature Instability (NBTI) to emerge as a major circuit reliability concern. Simultaneously leakage power is becoming a greater fraction of the total power dissipated by logic circuits. As both NBTI and leakage power are highly dependent on vectors applied at the circuit’s inputs, they can be minimized by applying carefully chosen input vectors durin

Det talas även i forskningen om exempelvis “maladaptivt” eller “problematiskt” användande av exempelvis datorspel eller internet. Men de studier som gjorts är rätt ense om att det inte är nätet som är problemet. Datar man så mycket att man inte längre sover, äter eller tar hand om sig själv är det förstås ett bekymmer. Men internet är då en del av symptomen på något annat.

A 1.8-GHz CMOS VCO is presented, employing a monolithic transformer as an inductance with voltage-controlled value. The design was implemented in a standard digital 0.6 μm, 2-metal CMOS process and exhibits a 10% tuning range with a 2.7 V supply voltage and a 9 mA supply current. Phase noise measurements show a worst-case phase noise of about -112 dBc/Hz at 3 MHz offset from the carrier

The present paper reports on two different applications developed at ULUND. Both applications are designed to allow the user to interact with a haptic-auditory virtual environment. Common problems in both applications concern the design of tools for creat

This paper describes one approach to verification of governor response during normal operation. It is based on field tests carried out in four hydro power plants in the Sweden. The experiments were carried out in September 1976 but have not been published internationally until now. Additional analysis and simulations were carried out during the preparation of this paper in July 2002.

The understanding of how forests function with respect to carbon (C) balance and its interaction with the climate system is a fundamental question in climate change research. Another important question is how large the sink for CO2 is in northern forests and how it varies with forest type, management, stand age and with external factors, such as climate variability. According to the Kyoto Protocol