Filtyp
Open Source Software (OSS) ecosystems have reshaped the ways how software-intensive firms develop products and deliver value to customers. However, firms still need support for strategic product planning in terms of what to develop internally and what to share as OSS. Existing models accurately capture commoditization in software business, but lack operational support to decide what contribution s
Reference Attribute Grammars (RAGs) is a declarative executable formalism used for constructing compilers and related tools. Existing implementations support concurrent evaluation only with global evaluation locks. This may lead to long latencies in interactive tools, where interactive and background threads query attributes concurrently.We present lock-free algorithms for concurrent attribute ev
An adaptive uplink detection scheme for a Massive MIMO (MaMi) base station serving up to 16 users is presented. Considering user distribution in a cell, selective matched filtering (MF) is proposed for non-interference limited users and a Cholesky decomposition (CD) based zero-forcing (ZF) detector is implemented for the remaining users. Channel conditions such as coherence bandwidth are exploited
Advanced combustion concepts like partially premixed combustion (PPC) are sensitive to inlet gas conditions especially inlet temperature. To estimate the combustion parameters like ignition delay on a cycle-to-cycle basis, both complementary filter and extended Kalman filter were designed to estimate the inlet temperature, and the ignition delay was calculated with properly estimated temperature.
Graphical user interface (GUI) development is generally complicated, time-consuming, and requires programming knowledge. In the context of the internet of things, this work focuses on producing an efficient development approach that also supports non-experts. We introduce a novel "inverted" development approach that does not require program code to be written - a step towards supporting end-user d
The contribution of forest harvesting to base cation losses and soil acidification has increased in recent years in Sweden, as the demand for bioenergy has increased and the sulphur deposition has decreased. Thus, new policy tools are required to evaluate the progress of the recovery from acidification, and as a basis for forest management recommendations. In this study we introduce and test a con
Reference Attribute Grammars (RAGs) is a declarative executable formalism used for constructing compilers and related tools. Existing implementations support concurrent evaluation only with global evaluation locks. This may lead to long latencies in interactive tools, where interactive and background threads query attributes concurrently.We present lock-free algorithms for concurrent attribute eva
Student engagement is an important factor when it comes to the learning process. Students who do not feel engaged in their studies risk surface learning, are more likely to fail their exams and might even drop out of their education. The teaching community has tried different methods in order to increase student engagement. One of them is the Contributing Student Pedagogy (CSP), where students con
The role of computer science and IT in Swedish schools has varied throughout the years. In fall 2014, the Swedish government gave the National Agency for Education (Skolverket) the task of preparing a proposal for K–9 education on how to better address the competences required in a digitalized society. In June 2016, Skolverket handed over a proposal introducing digital competence and programming a
Complex systems often integrate domain-specific languages to let users customize the behavior. Developing tooling for such languages is typically time-consuming and error-prone. We present Jatte, a tool intended to simplify this development. Jatte works as a generic tree editor for an abstract syntax, but uses aspects and attribute grammars to support powerful modular ways of tuning both the proje
Context: The increased use of Open Source Software (OSS) affects how software-intensive product development organizations (SIPDO) innovate and compete, moving them towards Open Innovation (OI). Specifically, software engineering tools have the potential for OI, but require better understanding regarding what to develop internally and what to acquire from outside the organization, and how to cooper
The first measured results for massive multiple-input, multiple-output (MIMO) performance in a line-of-sight (LOS) scenario with moderate mobility are presented, with 8 users served by a 100 antenna base Station (BS) at 3.7 GHz. When such a large number of channels dynamically change, the inherent propagation and processing delay has a critical relationship with the rate of change, as the use of o
We consider the over-fitting problem for multinomial probabilistic Latent Semantic Analysis (pLSA) in collaborative filtering, using a regularization approach. For big data applications, the computational complexity is at a premium and we, therefore, consider a maximum a posteriori approach based on conjugate priors that ensure that complexity of each step remains the same as compared to the un-re
Two smartphone applications were developed with the aim of harvesting insights of vulnerable road user accidents. The apps require a backend database with software tools for generating and managing questionnaires, etc. Such a system was developed using a MySQL database where a user-friendly platform has been developed in CakePHP. The backend system has been successfully developed and been used to
Background. Continuous experimentation (CE) has recently emerged as an established industry practice and as a research subject. Our aim is to study the application of CE and A/B testing in various industrial contexts. Objective. We wanted to investigate whether CE is used in different sectors of industry, by how it is reported in academic studies. We also wanted to explore the main topics research
The Internet of Things (IoT) paradigm brings an opportunity for advanced Demand Response (DR) solutions. It enables visibility and control on the various appliances that may consume, store or generate energy within a home. It has been shown that a centralized control on the appliances of a set of households leads to efficient DR mechanisms; unfortunately, such solutions raise privacy and scalabili
This paper deals with noise suppression in multichannel measurements, using a certain signal model but without assuming stationarity of the signals involved. This enables application to signals whose spectral characteristics are time-variable. The novelty consists of an algorithm for obtaining an approximation of the Wiener filter for each channel. The filters are computed using the Weyl transform
Modern transportation requires advanced powertrain systems to reduce the production of greenhouse gas CO2. Partially premixed combustion (PPC) is one of the most promising methods to achieve low emission and low fuel consumption of internal combustion engines. The present paper evaluated the effects of the calibration parameters on the efficiency and emissions of a multi-cylinder engine using PPC
