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Intelligent transport information systems (TIS) are one of the most rapidly emerging applications of wireless vehicular communications using DSRC/WAVE technology. A core function in a TIS is the estimation of traffic density using beacons transmitted by individual vehicles, subsequently used for purposes such as traffic light control or incident detection. In this paper, we conduct an in-depth stu

In this paper we present a new class of MAC protocols for wireless LANs based on sharing of transmission intentions. We develop an example protocol implementation based on distributed, co-operative scheduling of data frames. Sched- ules are non-binding, requiring minimal negotiation between nodes. The protocol is implemented on top of standard 802.11 so that backwards compatibility with legacy nod

The trend within fluid industry is towards continuous production, leading to an increasing demand for new and improved methods that allow real-time monitoring of quality parameters and fast process control. The consistency and viscosity can be described by fluid rheology and are frequently used as quality control parameters. Rheological properties can be correlated with product microstructure, the

Concepts of cognitive radio are yet in an early stage of development. They aim at improving the efficiency of spectrum utilization by exploiting locally and temporally vacant parts of the spectrum. When hierarchical spectrum access is considered, secondary users are authorized to use spectrum white spaces on a non-interfering basis, where minimal impact on the primary systems has to be ensured. GF

We study the well known linear consensus algorithm by means of a LQ-type performance cost. We want to understand how the communication topology influences this algorithm. In order to do this, we recall the analogy between Markov Chains and electrical resistive networks. By exploiting this analogy, we are able to rewrite the performance cost as the average effective resistance on a suitable network

We analyze the convergence behavior of iteratively decoded coupled LDPC codes from a complexity point of view. It can be observed that the thresholds of coupled regular LDPC codes approach capacity as the node degrees and the number L of coupled blocks tend to infinity. The absence of degree two variable nodes in these capacity achieving ensembles implies for any fixed L a doubly exponential decre

We investigate the CCN activity of freshly emitted biomass burning particles and their hygroscopic growth at a relative humidity (RH) of 85%. The particles were produced in the Mainz combustion laboratory by controlled burning of various wood types. The water uptake at sub- and supersaturations is parameterized by the hygroscopicity parameter, κ (c.f. Petters and Kreidenweis, 2007). For the wood b

Road safety is one of the most important emerging applications envisioned for Vehicular Ad hoc Networks (VANETs). Generally, such applications involve the broadcast of safety messages, consisting of beacons transmitting vehicles' state (e.g. position and velocity) with a regular period, as well as emergency messages warning about unexpected critical events. From the perspective of safety, the appl

A novel code construction based on spatially coupled low-density parity-check (SC-LDPC) code chains is presented. The proposed code ensembles are described by graphs in which individual SC-LDPC code chains of various lengths serve as edges. We demonstrate that connecting several appropriately chosen SC-LDPC code chains results in improved iterative decoding thresholds compared to those of a single

We studied the behavior of an iterative receiver using protograph based LDPC codes (PG-LDPCC) in an UWB short range communication system. An EXIT-Chart-Analysis is applied by means of density evolution of protographs. We show that AWGN-optimized protograph ensembles perform also well on frequency-flat UWB channels, outperform rate-compatible punctured convolutional codes (RCPC), but degrade with i

Network re-optimization is a process that must be triggered periodically in order to improve the inefficient resource allocation of online routing heuristics due to the uncertainty of online lightpath demand arrivals and departures. Network re-optimization involves two tasks: a) finding new lightpaths for a (sub)set of current demands, i.e. rerouting, and b) migrating the current traffic to the ne

As average packet sizes in wireless networks shrink and data rates increase, the fundamental CSMA mechanism in the 802.11 protocol family is put under stress. With the emerg- ing 802.11ax standard, the carrier sensing mechanism is low- ering the efficiency of the protocol to the level of random access (ALOHA), and as future-generation 802.11 standards emerge, CSMA-based protocols will fall below t

Abstract in UndeterminedRoot cause analysis (RCA) is a structured investigation of a problem to detect the causes that need to be prevented. We applied ARCA, an RCA method, to target problems of four medium-sized software companies and collected 648 causes of software engineering problems. Thereafter, we applied grounded theory to the causes to study their types and related process areas. We detec

The cluster power is an important parameter for cluster-based wireless channel models. This paper addresses modeling and estimation of the cluster power for wireless channels. A novel way of estimating the cluster decay and cluster fading, where the effects of the noise floor is taken into account, is presented. Due to the noise floor present in the measurement, only a limited number of clusters a

This paper presents the main features of the TURNUS co-exploration environment, an unified design space exploration framework suitable for heterogeneous parallel systems designed using an high level dataflow representation. The main functions of this tool are illustrated through the analysis of a video decoder implemented in the RVC-CAL dataflow language.

Vehicular traffic density is a key factor in determining the behaviour of radio overlapping and thus impacts performance of data and safety message communication in Vehicular Ad hoc Networks (VANETs). In this paper, we propose a novel density model for urban traffic systems and employ this model for the purpose of spatial-temporal analysis of radio overlapping. To model traffic density, we conside

Families of asymptotically regular LDPC block code ensembles can be formed by terminating (J, K)-regular protograph-based LDPC convolutional codes. By varying the termination length, we obtain a large selection of LDPC block code ensembles with varying code rates, minimum distance that grows linearly with block length, and capacity approaching iterative decoding thresholds, despite the fact that t