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When a feedback controller is implemented in a networked embedded system, the computations and communications induce delays and jitter, which may destabilize the control loop. The majority of previous work on analysis of control loops with time-varying delays has focused on output (actuation) jitter. In many embedded systems, input (sampling) jitter is also an issue. In this paper, we analyze the

We have implemented a prototype editor for a visual language where the semantics depends on layout. A high-level abstract syntax is defined, where these semantics can be captured without the need for storing concrete graphical coordinates. The model implementation is done in JastAdd, a metacompilation tool based on reference attribute grammars. This gives a modular architecture where the core comp

Abstract in Undetermined The 60 GHz band is very prominsing for high data rate (>1 Gb/s) wireless systems operating at short ranges. However, due to the short wavelengths in this frequency band, the shadowing effects cuased by human bodies and furniture are severe and needs to be modeled properly. In this paper, we present an experimental, measurement-based characterization of the reflection and s

Synthesis of case studies is different from synthesis of purely quantitative studies, for example, in that sampling and analysis in primary studies have been carried out differently, and that primary results are of a different nature. The objective of this research is to identify what challenges should be considered when choosing and using a method for synthesis of case studies. We collected exper

When a mobile station moves along a trajectory, it will see different parts of the same scatterers or scatterer groups during its movement. In this paper, we present a new method to identify such physical clusters of scatterers, and the corresponding groups of multipath components (MPCs) interacting with those clusters, from measurements of channel impulse responses. The method is based on identif

In control theory there exist two convenient representations of a model, which are transfer functions and state-space matrices. However, structure in the transfer functions is not clearly seen in the state-space form, and on the other hand structure in the state-space form is not clearly seen in the transfer functions. The main reason for this is that Laplace transformation destroys most types of

This paper presents new versions of the McEliece PKC that use time-varying convolutional codes. In opposite to the choice of Goppa codes, the proposed construction uses large parts of randomly generated parity-checks, presumably making structured attacks more difficult. The drawback is that we have a small but nonzero probability of not being successful in decoding, in which case we need to ask fo

This paper presents an approach to teaching programming and abstract thinking to young learners using Scala and Kojo. Kojo is an open source IDE for the Scala programming language. The approach is based on Scala APIs for turtle graphics and functional pictures, a process of interactive exploration and discovery, and structured learning material that guides learners. The approach encourages playful

A differential LNA using capacitive shunt feedback is demonstrated in 65nm CMOS. The capacitive shunt feedback structure gives a wideband input matching, S11 <;-17 dB from 500MHz - 1 GHz for low band and S11 <;-20 dB from 1.1 GHz - 2.3GHz for high band. The NF for the complete receiver chain in low band and high band was measured to 3.3 dB and 3.9 dB, respectively. The 1-dB compression point with

The goal of the paper is to present a distributed scheme to resolving a single path routing problem in multidomain networks. The global problem is formulated as a mixed-integer program (MIP) and approached by means of branch-and-price (B&P). Problems associated with a B&P tree nodes are decomposed using the Dantzig-Wolfe method to a set of domain subproblems coordinated by a single master

We consider the problem of providing trusted computing functionality in high availability systems. We consider the case where data is required to be encrypted with a TPM protected key. For redundancy, and to facilitate high availability, the same TPM key is stored in multiple computational units, each one ready to take over if the main unit breaks down. This requires the TPM key to be migratable.

The traditional routing protocols used in wireless mesh networks like AODV are not very efficient since the number of hops to a destination is mainly considered as the routing metric. This may lead to shorter paths; however, the throughput can decrease when traffic is routed through those paths. Various contributions have proposed different metrics or completely different routing algorithms. Never

Spatially coupled regular LDPC code ensembles have outstanding performance with belief propagation decoding and can perform close to the Shannon limit. In this paper we investigate the suitability of coupled regular LDPC code ensembles with respect to rate-flexibility. Regular ensembles with good performance and low complexity exist for a variety of specific code rates. On the other hand it can be

In this paper we evaluate the use of parallel interleavers for user separation in coded IDMA systems. The parallel interleavers have previously been evaluated for uncoded systems, and we here present extended results for the coded case. The new results are important for real systems, as they will most likely use performance enhancing channel coding. The parallel interleavers are designed to remove

The fast correlation attack is a general cryptanalytic attack directed at stream ciphers and is related to the decoding of low-density parity-check (LDPC) codes. In this paper, we improve the message passing algorithm by exploiting the fact that the sum of an arbitrary number of initial state variables, called a fixed point, can be written as the sum of only a few other variables. This will result