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Popular Abstract in English In the age where there is a great demand of energy, raise in the prices of fossil fuels and increase of environmental concerns because of the greenhouse gas emissions, biogas production through anaerobic digestion, of different organic materials, provides a full or partial solution. There is a large number of cheap substrates as organic waste materials that can be utiliThe anaerobic digestion process results in the production of biogas from a large diversity of organic residues, which can be used as an alternate source of energy generation and for waste management. However, the biogas production technology is not exploited efficiently due to the characteristics of raw materials, poor methane yields, process instability, limited raw materials and lack of knowledg

Background: There is a need for ecient regression testing in most software development organizations. Often the proposed solutions involve automation. However, despite this being a well researched area, research results are rarely applied in industrial practice. Aim: In this paper we aim to bridge the gap between research and practice by providing examples of how evidence-based regression testing

Pattern reconfigurability is a desirable feature of mobile handset antennas, as it enables the antennas to adapt to non-stationary propagation environments. However, it is difficult to vary the radiation pattern of a handset antenna at frequencies below 1 GHz because the entire chassis commonly acts as the main radiator. Hence, designing pattern reconfigurability based on the antenna element (seco

Background. When delivering an embedded product, such as a mobile phone, third party products, like games, are often bundled with it in the form of Java MIDlets. To verify the compatibility be- tween the runtime platform and the MIDlet is a labour-intensive task, if input data should be manually generated for thousands of MIDlets. Aim. In order to make the verification more efficient, we investiga

In this paper we present an algorithm for finding low-weight multiples of polynomials over the binary field using coding theoretic methods. The code defined by the public polynomial is cyclic, allowing an attacker to search for any shift of the sought codeword. Therefore, a code with higher length and dimension is used, having a larger number of low-weight codewords. Additionally, since the degree of

Optimization models related to designing and operating complex systems are mainly focused on some efficiency metrics such as response time, queue length, throughput, and cost. However, in systems which serve many entities there is also a need for respecting fairness: each system entity ought to be provided with an adequate share of the system's services. Still, due to system operations-dependant c

This paper presents a novel memory optimization technique to exploit the analogy between correlation coefficients in MMSE-based channel estimators across multiple standards. The need for coefficient storage for robust MMSE channel estimators is expensive in terms of on-chip memory. Besides, the memory requirements grow linearly by integrating more standards onto one platform. Thus, it becomes inev

We have previously shown how it is possible to lower accident risk levels while at the same time increasing traffic flows with the aid of vehicular ad-hoc networks. In this paper, we extend the online traffic accident risk mitigation sys- tem to include link choice. We develop an algorithm that allows vehicles to choose road links that provide the current maximal utility, based on information rece

Coordinating a software project across distances is challenging. Even without geographical and time zone distances, other distances within a project can cause communication gaps. For example, organisational and cognitive distances between product owners and development-near roles such as developers and testers can lead to weak alignment of the software and the business requirements. Applying good

Despite the widely recognized importance of replications in software engineering, industrial replications in software engineering are still rarely reported. Although the literature provides some evidence about the issues and challenges related to conducting experiments and replications the practitioner's view of the issues and challenges has not been fully explored. This paper reports an industria

Quality requirements complement functional requirements with information on the target quality levels of software functions or emergent system quality aspects. In release planning the allocation of development effort in further investments into product enhancements, new or enhanced functions are competing with quality improvements for limited resources. When setting balanced quality targets for de

Multiple-input multiple-output (MIMO) is a mandatory feature of the Third Generation Partnership Project (3GPP) Long Term Evolution. This work investigates the performance of a low complexity channel estimator for LTE terminals with an emphasis on the 4 × 4 multiple antenna scheme. The presented work extends a promising low-complexity 2 × 2 MIMO channel estimator to the 4 × 4 MIMO case and evaluat

Vehicular networks bring new ways of viewing road traffic management and safety applications. For the first time, it will be possible for vehicles to exchange information and build fine-grained knowledge about the current situation, estimating risks and adapting their driving. Central to these applications is the need to exchange information in a highly dynamic environment, building a view of the

Several researchers have proposed creating after-the-fact structure among software artifacts using trace recovery based on Information Retrieval (IR). Due to significant variation points in previous studies, results are not easily aggregated. Aim. We aim at an overview picture of the outcome of previous evaluations. Method. Based on a systematic mapping study, we perform a synthesis of published r

In this work, we analyze the use of a WiFi network deployed in a large-scale technical university. To this extent, we leverage three weeks of WiFi traffic data logs and characterize the spatio-temporal correlation of the traffic at different granularities (each individual access point, groups of access points, entire network). The spatial correlation of traffic across nearby access points is also