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Requirements communication plays a vital role in development projects in coordinating the customers, the business roles and the software engineers. Communication gaps represent a significant source of project failures and overruns. For example, misunderstood or uncommunicated requirements can lead to software that does not meet the customers’ requirements, and subsequent low number of sales or add
This study investigates the role of below-cloud evaporation and evapotranspiration for the short-term variability of stable isotopes in near-surface water vapor and precipitation associated with central European cold fronts. To this end, a combination of observations with high temporal resolution and numerical sensitivity experiments with the isotope-enabled regional weather prediction model COSMO
Abstract — The proposed time-to-digital converter (TDC) arranges two Vernier gated-ring-oscillator (GRO) branches in a 2-dimension (2-D) fashion. All delay differences between X-axis phases and Y-axis phases (based on 2-D definition) can be used, rather than only the diagonal line. The large latency time inherited from Vernier structure is therefore dramatically reduced. The TDC is implemented in
In this work a 2.2 GHz quadrature receiver front-end suitable for low-power applications is presented. The low-noise amplifier, the mixer and the voltage-controlled oscillator are merged into a single stage, making the circuit capable of extreme current reuse while keeping it still functional at low supply voltage. A careful linear time-variant analysis is proven to be necessary to accurately pred
Large open and closed source organizations like Google, Facebook and Mozilla are migrating their products towards rapid releases. While this allows faster time-to-market and user feedback, it also implies less time for testing and bug fixing. Since initial research results indeed show that rapid releases fix proportionally less reported bugs than traditional releases, this paper investigates the c
Realistic Multiple-Input Multiple-Outout (MIMO) radio channel models are required in order to make fair system comparisons and to design proper signal processing algorithms using this technology. This technical report presents a full parameterization of the COST 2100 MIMO channel model for peer-to-peer communication in the 300 MHz band. Measurements were carried out in a semi-rural and suburban en
An iterative decoding threshold analysis for terminated regular LDPC convolutional (LDPCC) codes is presented. Using density evolution techniques, the convergence behavior of an iterative belief propagation decoder is analyzed for the binary erasure channel and the AWGN channel with binary inputs. It is shown that for a terminated LDPCC code ensemble, the thresholds are better than for correspondi
This paper investigates linear precoding over nonsingular linear channels with additive white Gaussian noise, with lattice-type inputs. The aim is to maximize the minimum distance of the received lattice points, where the precoder is subject to an energy constraint. It is shown that the optimal precoder only produces a finite number of different lattices, namely perfect lattices, at the receiver.
Service discovery is central in pervasive middleware systems, built on top of the communication substrate using the more fundamental mechanisms for device discovery. In mobile pervasive systems devices come and go, and switch network frequently, demanding support for device discovery across heterogeneous networks. We present the design of a device discovery mechanism for the PalCom middleware that
The Bidirectional Efficient Algorithm for Searching code Trees (BEAST), which is an algorithm to efficiently determine the free distance and spectral components of convolutional encoders, is implemented for the Cell Broadband Engine Architecture, efficiently utilizing the underlying hardware. Exhaustive and random searches are carried out, presenting new rate R=1/2 convolutional encoding matrices
Massive MIMO can greatly increase both spectral and transmit-energy efficiency. This is achieved by allowing the number of antennas and RF chains to grow very large. However, the challenges include high system complexity and hardware energy consumption. Here we investigate the possibilities to reduce the required number of RF chains, by performing antenna selection. While this approach is not a ve
Determining requirements process efficiency, and measuring the corresponding monetary impacts, is a challenging but necessary aspect of project management. In this paper, we perform an independent analysis of scoping decisions from a large industrial project with the goal of providing visualizations that facilitate investigations of process efficiency, agility, and the effects of scoping decisions
Software failures in medical devices can lead to catastrophic situations. Therefore is it crucial to handle software related risks when developing medical devices. This paper presents the experiences gained from an ongoing case study with a medical device development organisation. This part of the study focuses on the two first steps of the risk management process, i.e. risk identification and ris
A VCO is implemented in an RF 90 nm CMOS process and covers the frequency range 2.55-4.08 GHz. Drawing 19 mA from 1.2 V, the phase noise at 20 MHz frequency offset from a 3.7 GHz carrier is -156 dBc/Hz, meeting the phase noise requirement for GSM/EDGE and SAW-less WCDMA transmitter after frequency division by 2 or by 4. A second version of the VCO covers an additional 4.90-5.75 GHz range, at the e
Abstract in UndeterminedIn this paper, a number of channel estimation algorithms for iterative receivers are compared for the case of an up-link orthogonal frequency division multiplexing interleave division multiple access (OFDM-IDMA) system. Both pilot based algorithms, used to obtain an initial estimate, as well as semi-blind decision-directed algorithms working as a component of the iterative
Robots operating in real-world settings must manage task variability, environmental uncertainty, and failures during execution. This thesis presents a unified framework for building self-reliant robotic systems by integrating symbolic planning, reinforcement learning, behavior trees (BTs), and vision-language models (VLMs).At the core of the approach is an interpretable policy representation based
