Search results

A method based on hollow fiber liquid phase microextraction (HF-LPME) for analysis of pinic acid and pinonic acid was developed and for the first time successfully applied to ambient aerosol samples. In this method, the aerosol samples were dissolved in 0.05M H(2)SO(4) and the solution was extracted using three-phase HF-LPME where donor phase was 0.1M (NH(4))(2)CO(3). Different parameters like typ

QR decomposition (QRD) is used to solve least squares (LS) problems for a wide range of applications. However, traditional QR decomposition methods, such as Gram-Schmidt (GS), require high computational complexity and non-linear operations to achieve high throughput, limiting their usage on resource-limited platforms. To enable efficient LS computation on embedded systems for real-time application

Context The popularity of the open source software development in the last decade, has brought about an increased interest from the industry on how to use open source components, participate in the open source community, build business models around this type of software development, and learn more about open source development methodologies. There is a need to understand the results of research i

This paper treats the feasibility to use only the sign bit of the in-phase and quadrature components when estimating time and frequency in OFDM systems. Using only the sign bit is shown to result in a frequency dependent bias, which can be easily compensated. The approach is evaluated for LTE and DVB-H, where the estimation is performed using the cyclic prefix, and for WLAN 802.11g, where the estim

We propose new M-algorithm BCJR (M-BCJR) algorithms for low-complexity turbo equalization and apply them to severe intersymbol interference (ISI) introduced by faster than Nyquist signaling. These reduced-search detectors are evaluated in simple detection over the ISI channel and in iterative decoding of coded FTN transmissions. In the second case, accurate log likelihood ratios are essential and

This paper discusses compact node-link formulations for MPLS fast reroute optimal single path layout. We propose mathematical formulations for MPLS fast reroute local protection mechanisms. In fact, we compare one-to-one (also called detour) local protection and many-to-one (also called facility backup) local protection mechanisms with respect to minimized maximum link utilization. The optimal res

Project retrospectives can be powerful tools for project teams to collectively identify communication gaps and practices to improve for future projects. However, even if project members take the time for a retrospective, it can be hard to correctly remember and jointly discuss past events in a constructive way. Fact-based timelines that visualize a project's events offer a possible solution.

Efficient and realistic mm-wave channel models are of vital importance for the development of novel mm-wave wireless technologies. Though many of the current 60 GHz channel models are based on the useful concept of multi-path clusters, only a limited number of 60 GHz channel measurements have been reported in the literature for this purpose. Therefore, there is still a need for further measurement

Optimal data detection of a linear channel can always be implemented through the Viterbi algorithm (VA). However, in many cases of interest the memory of the channel prohibits application of the VA. A popular and conceptually simple method in this case, studied since the early 70s, is to first filter the received signal in order to shorten the memory of the channel, and then to apply a VA that ope

As new systems and applications are introduced for next-generation wireless systems, the propagation channels in which they operate need to be characterized. This paper discusses propagation channels for four types of next-generation systems: (i) distributed Multiple-Input Multiple-Output (MIMO) and Cooperative MultiPoint (CoMP), systems, which require the characterization of correlation between c

This paper presents class-D CMOS oscillators capable of an excellent phase noise performance from a very low power supply voltage. Starting from the recognition of the time-variant nature of the class-D LC tank, accurate expressions of the oscillation frequency, oscillation amplitude, current consumption, phase noise, and figure-of-merit (FoM) have been derived. Compared with the commonly used cla

We review the recent progress in dynamical and statistical downscaling approaches for west African precipitation and perform a regional climate model (RCM) intercomparison using the novel multi-model RCM data set from the Ensembles-based Predictions of Climate Changes and Their Impacts (ENSEMBLES) and African Monsoon Multidisciplinary Analyses (AMMA) projects. Present RCMs have distinct systematic

Consider the communication system model y = HFx+n, where H and F are the channel and precoder matrices, x is a vector of data symbols drawn from some lattice-type constellation, such as M-QAM, n is an additive white Gaussian noise vector and y is the received vector. It is assumed that both the transmitter and the receiver have perfect knowledge of the channel matrix H and that the transmitted sig

The performance of continuous time deltasigma modulators is limited by their large sensitivity to feedback pulse-width variations caused by clock jitter in their feedback DACs. To mitigate that effect, a dual switched- capacitor-resistor feedback DAC technique is proposed. The architecture has the additional benefit of reducing the typically high switched-capacitor-resistor DAC output peak current

Open innovation is an emerging innovation paradigm that can greatly accelerate technical knowledge innovation in software companies. The increasing importance and density of software in today’s products and services puts extensive pressure on excelling the discovery, description and execution of innovation. Despite that, software engineering literature lacks methods, tools and frameworks for full

Context: In large software organizations with a product line development approach, system test planning and scope selection is a complex task. Due to repeated testing: across different testing levels, over time (test for regression) as well as of different variants, the risk of redundant testing is large as well as the risk of overlooking important tests, hidden by the huge amount of possible test

Like many engineering programs in Europe, the final part of most Swedish software engineering programs is a longer project in which the students write a Master's thesis. These projects are often conducted in cooperation between a university and industry, and the students often have two supervisors, one at the university and one in industry. In particular, the Bologna Process that is currently unde

The COST 2100 channel model is a geometry based stochastic channel model (GSCM) for multiple-input multiple-output (MIMO) simulations. This paper presents parameterization and validation of the channel model for peer-to-peer communication in the 300 MHz band. Measurements were carried out in outdoor environments for both line-of-sight (LOS) and non line-of-sight (NLOS) scenarios. The COST 2100 cha