Jesper Ole Jensen

On Optimal Multichannel Mean-Squared Error Estimators for Speech Enhancement

In this letter we present discrete Fourier transform (DFT) domain minimum mean-squared error (MMSE) estimators for multichannel noise reduction. The estimators are derived assuming that the clean speech magnitude DFT coefficients are generalized-Gamma distributed. We show that for Gaussian distributed noise DFT coefficients, the optimal filtering approach consists of a concatenation of a minimum variance distortionless response (MVDR) beamformer followed by well-known single-channel MMSE estimators. The multichannel Wiener filter follows as a special case of the presented MSE estimators and is in general suboptimal. For non-Gaussian distributed noise DFT coefficients the resulting spatial filter is in general nonlinear with respect to the noisy microphone signals and cannot be decomposed into an MVDR beamformer and a post-filter.

Analysis of Acoustic Feedback/Echo Cancellation in Multiple-Microphone and Single-Loudspeaker Systems Using a Power Transfer Function Method

In this work, we analyze a general multiple-microphone and single-loudspeaker audio processing system, where a multichannel adaptive system is used to cancel the effect of acoustic feedback/echo, and a beamformer processes the feedback/echo canceled signals. We introduce and derive an accurate approximation of a frequency domain measure - the power transfer function - and show how it can be used to predict the convergence rate, system stability bound and the steady-state behavior of the entire cancellation system across frequency and time. We consider three example adaptive algorithms in the cancellation system: the least mean square, normalized least mean square, and the recursive least squares algorithms. Furthermore, we derive expressions to determine the step size parameter in the adaptive algorithms to achieve a desired system behavior, e.g., convergence rate at a specific frequency. Finally, we compare and discuss the performance of all three adaptive algorithms, and we verify the derived expressions through simulation experiments.

Area-based Initiatives—And Their Work in Bonding, Bridging and Linking Social Capital

Abstract In this article, we provide a conceptual and argumentative framework for studying how Area-based Initiatives (ABIs) can facilitate contact between networks in deprived neighbourhoods and external forms of power (linking social capital). These relations provide the residents and other members of civil society with crucial access to leveraging resources, ideas and information. Although few studies on linking social capital have been carried out in relation to urban regeneration, there is empirical evidence that suggests that it can play a positive role in establishing trust and relations between civil society and a municipality. We set out with a review of how social capital literature has been applied in an urban context, and then demonstrate empirical examples from Denmark of how, in different contexts (village, town and city), ABIs have facilitated processes that generated different forms of social capital (bridging, bonding and linking). The article concludes that ABIs contribute to creating linking social capital, but the extent of the contribution depends on the level of bonding and bridging social capital in the area. We argue that public planners as well as evaluators of the ABIs should increase their awareness about the potentials of an ABI to create linking social capital in deprived neighbourhoods.

Has Social Sustainability Left the Building? the Recent Conceptualization of "Sustainability" in Danish Buildings

Abstract Sustainable buildings have often been niche products, but in recent years a new approach has emerged in Denmark aimed at mainstreaming and normalizing this mode of construction and seeking to attract ordinary Danes through market conditions. The aim is to present an alternative conceptualization of sustainable buildings to the ecocommunities’ vision and to involve traditional building firms in their design and development. From a theoretical perspective, the mainstreaming of sustainable buildings can be seen either as an example of ecological modernization or technological transition. The new conceptualization has implied a narrower approach to sustainability and a lack of social sustainability measures. While earlier paradigms of sustainable buildings emphasized themes such as community building, self-provisioning, local empowerment, and shared facilities, such objectives are largely absent in the new types of sustainable buildings. We question to what extent it is possible to design sustainable settlements without social sustainability. By viewing sustainable buildings as technological configurations, we argue that the multiactor approach, fragmentation of roles, and absent initiatives for social sustainability influence the buildings’ environmental performance and should be important for the next generation of these structures.

Harmonic exponential modeling of transitional speech segments

An extended sinusoidal model for speech signal processing is proposed. In this model, the frequencies of the sinusoidal components are constrained to be harmonically related, but their amplitudes are allowed to vary exponentially with time. Algorithms for model parameter estimation are derived. The proposed model shows considerable objective and subjective improvements in speech segments with transitions, especially in speech onsets, compared to the constant-frequency, constant-amplitude harmonic model. Potential application areas include speech synthesis and multimode speech coding.

Facilities management innovation in public-private collaborations: Danish ESCO projects

Purpose – The purpose of this article is to investigate how facilities management (FM) units navigate Energy Service Company (ESCO) collaborations, here defined as examples of public collaborative innovation within the context of FM. The driving motivation is to inform and inspire internal FM units of local institutions on how to navigate and manage collaboration of different, intra- and inter-organisational actors throughout ESCO projects. Design/methodology/approach – A deductive research methodology was applied based on the first ten ESCO projects in Danish municipalities between 2008 and 2012. Findings – A model of FM roles in FM public innovation is proposed. The internal FM unit coordinates between clients and end users by acting as translator and demonstrator and collaborates with the ESCO company to implement the energy renovation (FM processor). Research limitations/implications – The data were collected from a limited sample of ESCO collaborations in Denmark. Future research should thus investig...

Low delay moving-horizon multiple-description audio coding forwireless hearing aids

In this work, we construct a novel scheme for efficient perceptual coding of audio for robust communication between encoders and wireless hearing aids. To limit the physical size of the hearing aids and to reduce power consumption and thereby increase the lifetime expectancy of the batteries, the hearing aids are constrained to be of low complexity. We therefore provide an asymmetric strategy where most of the computational load is placed at the encoding side. We make use of multiple-description coding. This combats possible erasures on the wireless link between the encoder and the hearing aids without introducing significant delay. Furthermore, we employ psychoacoustically optimized noise-shaping quantizers based on the moving-horizon principle, which exploits a finite prediction horizon.

Sustainable Built Environment Conference 2016 in Hamburg : Strategies, Stakeholders, Success factors, 7th - 11th March 2016 ; Conference Proceedings

Citation for published version (APA): Jensen, J. O., Gram-Hanssen, K., & Friis, F. (2016). Local initiatives for motivating Danish house-owners for energy improvements. In Sustainable Built Environment Conference 2016 in Hamburg : Strategies, Stakeholders, Success factors, 7th 11th March 2016 ; Conference Proceedings (1 ed., pp. 826-835). Hamburg: ZEBAU, Hamburg. https://doi.org/10.5445/IR/1000051699This paper considers two linked architectural projects designed and delivered by the author. The first considered the challenges associated with designing and building a energy efficient prefabricated dwelling in just six days, using predominately locally sourced, organic, ‘compostable’ materials whilst creating no waste on site. 5 million viewers a night on UK TV saw this program. However, frustrated by the lack of credible communication of the challenges associated with this project that the medium of TV provided, the author was keen to re-build this project on campus at the University of Brighton where he taught, so that he could involve students in all aspects of the process, thus sharing the learning experience and proving that ‘live’ construction projects could be a useful pedagogic tool. This paper considers why the design emphasis of the second project went from ‘locking carbon’ and zero waste on site, to constructing with waste and proving “that there is no such thing as waste just stuff in the wrong place”. http://arts.brighton.ac.uk/business-and-community/wastehouse

Local initiatives for motivating Danish house-owners for energy improvements

Citation for published version (APA): Jensen, J. O., Gram-Hanssen, K., & Friis, F. (2016). Local initiatives for motivating Danish house-owners for energy improvements. In Sustainable Built Environment Conference 2016 in Hamburg : Strategies, Stakeholders, Success factors, 7th 11th March 2016 ; Conference Proceedings (1 ed., pp. 826-835). Hamburg: ZEBAU, Hamburg. https://doi.org/10.5445/IR/1000051699This paper considers two linked architectural projects designed and delivered by the author. The first considered the challenges associated with designing and building a energy efficient prefabricated dwelling in just six days, using predominately locally sourced, organic, ‘compostable’ materials whilst creating no waste on site. 5 million viewers a night on UK TV saw this program. However, frustrated by the lack of credible communication of the challenges associated with this project that the medium of TV provided, the author was keen to re-build this project on campus at the University of Brighton where he taught, so that he could involve students in all aspects of the process, thus sharing the learning experience and proving that ‘live’ construction projects could be a useful pedagogic tool. This paper considers why the design emphasis of the second project went from ‘locking carbon’ and zero waste on site, to constructing with waste and proving “that there is no such thing as waste just stuff in the wrong place”. http://arts.brighton.ac.uk/business-and-community/wastehouse