Presents a microphone array system for use in handsfree mobile telephone equipment. The array is based on a fast and efficient “on-site” and “self-calibration” scheme. The performance in suppressing the interior car cabin noise and the far-end speech is approximately 17 dB, respectively, while maintaining the near-end speaker level. The near-end signal is almost undistorted. The performance of two

In the application of adaptive antenna arrays to wireless communications, a known pilot signal sequence may be used for estimating the array response at the beginning of each data frame. This pilot sequence is usually very short and conventional training methods which estimate the array response, based solely on this training sequence, may incur large estimation errors. In this paper, we propose a

A novel adaptive beamformer employing recursively updated soft constraints for acoustic speech enhancement is proposed. The beamformer operates in a subband structure to allow time-frequency operation for each channel. As such, the processing can be viewed as a combination of weighted spatial and temporal filters. The major benefit of this recursive soft constrained beamformer is that it allows th

This paper introduces a new subband adaptive space constrained beamforming structure for use in hands-free speech enhancement applications. The scheme incorporates a space constrained source model and voice activity information through the integration of a voice activity detector (VAD). The VAD information is used to estimate noise covariance information during non-speech periods and to optimally

This paper presents a new constrained subband beamforming algorithm to enhance speech signals generated by a moving source in a noisy environment. The beamformer is based on the principle of a soft constraint defined for a specified region corresponding to a known source location. The soft constraint secures the spatial-temporal passage of the desired source signal in the adaptive update of the be

While national figures of land availability are used to justify accepting large-scale land investors, not very much is known about the local level realities of land availability. By combining remotely sensed data with fieldwork, system dynamics modelling and qualitative research methods, we examine local level realities of land use and availability in the Malen Chiefdom of Southern Sierra Leone. H

For low-rank Frobenius-norm approximations of matrices with non-negative entries, it is shown that the Lagrange dual is computable by semi-definite programming. Under certain assumptions the duality gap is zero. Even when the duality gap is non-zero, several new insights are provided.

In this paper it is suggested that leadership, at least in some types of organiza tions, can be conceptualized as social integrative action. Such action is seen as a synthesis of institutional and human relations-oriented leadership. A case study of a computer consultancy company, a professional service adhocracy, supports this argument. This paper also argues for viewing leadership as an expressi

This work presents a Scheimpflug lidar system which was employed for atmospheric aerosol monitoring in southern Sweden. Atmospheric aerosol fluctuation was observed around rush-hour. The extinction coefficient over 6 km was retrieved, i.e., 0.15 km-1, by employing the slop-method during the time when the atmosphere was relatively homogenous. The measurements successfully demonstrate the potential

The thesis discusses the licensing system of the Creative Commons from the perspective of the theory of the commons mostly as formulated by Elinor Ostrom. The work starts by describing the concepts and theory of common pool resources and regime of the commons for production and distribution of these resources. The main characteristics for successful traditional commons – efficiency, equity and sus

This paper introduces a new constrained adaptive subband beamformer algorithm for speech enhancement in acoustic telecommunication systems. The solution relies on a pre-calculated source covariance matrix and recursive estimates of background noise- and handsfree signal covariance matrices. The constraint acts as an eye-opening in a vicinity of the near-field location of the source and degradation

A novel adaptive beamformer employing recursively updated soft constraints for acoustic speech enhancement is proposed. The beamformer operates in a subband structure to allow a time-frequency operation for each channel. Consequently, the processing performed can be viewed as a combined weighted spatial,frequency and temporal filter. The major benefit of the new recursive soft constrained beamformer

The paper discusses various representations of collective decisional skill which are useful in the evaluation of decision structures. The recursion formulas we give here and the use of the concepts of majority deficiency as well as majority and unanimity games present expedient approaches in analyzing collective competence. Using the simple majority system as benchmark, applications to certain hie

The previous investigation showed the usefulness of a two-degree-of-freedom configuration. Such a controller can also be designed using pole placement. An adaptive controller based on this concept is developed and applied to the problem with good results. Particular features, like selection of model structure, design parameters and excitation, are also discussed.

Laminar burning velocities of acetic acid + air flames at 1 atm and initial gas temperatures of 338 K, 348 K, and 358 K were determined using the heat flux method. Measurements were performed in non-stretched flames, stabilized on a perforated plate burner at adiabatic conditions. Due to experimental problems related to the corrosiveness of acetic acid towards the burner material, the uncertainty

This report presents a new, one-pot, facile, selective and green method for methoxycarbonylation of alcohols and synthesis of five- and six-membered cyclic carbonates from corresponding alcohols with dimethyl carbonate (DMC) in the presence of molecular sieves without any additional solvent and catalyst. Syntheses of bifunctional structures comprising a six-membered cyclic carbonate with allyl eth