Run-time adaptation of a reconfigurable mobile UMTS receiver

UMTS receivers are mobile devices, which should have a low energy consumption and operates in a frequently changing environment. The idea of this paper is to adapt the amount of signal processing for the reception within an UMTS mobile to this changing environment. In this way the amount of signal processing can be decreased for a good channel to decrease the energy consumption and for a bad channel the signal processing can be increased to guarantee a minimum Quality of Service for the signal. Due to space limitation, this paper only describes the approach. For full details see [1]

Run-time Mapping of Applications to a Heterogeneous SoC

This paper presents an iterative hierarchical approach to map an application to a parallel heterogeneous SoC architecture at run-time. The application is modeled as a set of communicating processes. The optimization objective is to minimize the energy consumption of the SoC, while still providing the required Quality of Service. This approach is flexible, scalable and the performance looks promisin

BER estimation for wireless links using BPSK/QPSK modulation

This paper introduces a method that computes an estimation of the bit error rate (BER) based on the RAKE receiver soft output only. For this method no knowledge is needed about the channel characteristics nor the precise external conditions. Simulations show that the mean error of the estimation is below 2%, with only a small variance. Also an estimation of the BER for a different spreading factor or a different number of RAKE finger can be made. Implementation issues for a practical use of the method are discussed

Energy-efficient wireless communication for mobile multimedia terminals

This paper presents a control system that adapts a WCDMA receiver at run-time to minimize the energy consumption while providing an adequate Quality of Service (QoS). The adaptation is done at run-time, because of the dynamic environment of a mobile receiver. Simulations show that run-time adaptation to the environment decreases the energy consumption of a receiver and also improves other QoS parameters, such as a higher throughput and a lower frame error rate

Modelling the impact of the ‘Fast Track’ land reform policy on Zimbabwe’s maize sector

This paper attempts to analyze the impacts of the ‘fast track’ land reform policy on maize production in Zimbabwe through the construction of a partial equilibrium model that depicts what could have happened if no further policy shifts had taken place after 2000. The resimulated baseline model was used to make projections based on the various trends of exogenous variables in 2000. This means that the model generated an artificial data set based on what the maize market would have looked like under a set of the pre-2000 existent policy conditions. The ‘fast track’ land reform policy was thus assessed based on the performance of the baseline model using a range of “what if” assumptions. Commercial area harvested was 39 % less than what could have been harvested in 2001, and declining by negative 80.57 % in 2007. Results showed total maize production was 61.85 % and 43.88 % less than what could have been produced in the 2002 and 2005 droughts, respectively. This may imply that droughts would have been less severe if the ‘fast track’ land reform was not implemented. Therefore, the ‘fast track’ land reform had a negative effect on maize production. Thus, the econometric model system developed provided a basis through which the effects of the FTLRP on the maize market may be analyzed and understood.‘fast track’ land reform programme, partial equilibrium model, maize, Zimbabwe, Crop Production/Industries, Land Economics/Use,

Theory of strong localization effects of light in disordered loss or gain media

We present a systematical theory for the interplay of strong localization effects and absorption or gain of classical waves in 3-dimensional, disordered dielectrics. The theory is based on the selfconsistent Cooperon resummation, implementing the effects of energy conservation and its absorptive or emissive corrections by an exact, generalized Ward identity. Substantial renormalizations are found, depending on whether the absorption/gain occurs in the scatterers or in the background medium. We find a finite, gain-induced correlation volume which may be significantly smaller than the scale set by the scattering mean free path, even if there are no truly localized modes. Possible consequences for coherent feedback in random lasers as well as the possibility of oscillatory in time behavior induced by sufficiently strong gain are discussed.Comment: Published versio

Impact of Electrostatic Forces in Contact Mode Scanning Force Microscopy

In this $\ll$ contribution we address the question to what extent surface charges affect contact-mode scanning force microscopy measurements. % We therefore designed samples where we could generate localized electric field distributions near the surface as and when required. % We performed a series of experiments where we varied the load of the tip, the stiffness of the cantilever and the hardness of the sample surface. % It turned out that only for soft cantilevers could an electrostatic interaction between tip and surface charges be detected, irrespective of the surface properties, i.\,e. basically regardless its hardness. % We explain these results through a model based on the alteration of the tip-sample potential by the additional electric field between charged tip and surface charges

Soft output bit error rate estimation for WCDMA

This paper introduces a method that computes an estimation of the bit error rate (BER) based on the RAKE receiver soft output only. For this method no knowledge is needed about the channel characteristics nor the precise external conditions. Simulations show that the mean error of the estimation is below 2%, with only a small variance. Implementation issues for a practical use of the method are discussed

Attitudes and acceptance of South African urban consumers towards genetically modified white maize

The introduction of genetically modified (GM) food products to food markets around the world, has led to considerable controversy. In many cases consumer attitudes and perceptions of GM food products were revealed as fears, concern for, and avoidance of the new technology. The importance of GM foods in South Africa is increasing, even though the GM Food debate lags behind many other (often more developed) parts of the world. This paper investigates the knowledge, attitudes and acceptance of urban South African white-grain maize consumers regarding GM maize. Conjoint- and cluster analysis were used to develop clusters/market segments among the urban consumers of white maize. A range of additional questions was used to develop profiles of the identified market segments. These aspects covered demographics, GM knowledge aspects as well as GM attitude aspects. Four distinct clusters/market segments were identified with specific characteristics: "Anti-GM, Brand aware" cluster (35% of valid responses), "Brand unaware, Farmer sympathetic" cluster (20%), "GM consumer benefit, Brand aware" cluster (25%) and the "Brand aware, Pro-GM" cluster (20%). The most significant differences between the clusters were based on the consumers' attitudes towards GM food products.Consumer/Household Economics,