Removal of Base-Line Wander and Power-Line Interference from the ECG by an Efficient FIR Filter with a Reduced Number of Taps

Linear phase filtering is proposed for the removal of baseline wander and power-line frequency components in electrocardiograms. In order to reduce the large number of computations involved in the digital filtering that are necessary, the desired filter spectrum was defined periodically. Making use of the property that the spectrum period is 50 Hz, the spectrum can be realized with a considerably reduced number of impulse response coefficients. This, in combination with the necessary impulse response symmetry, leads to a reduction in the number of multiplications per output sample by a factor of 10. A suitable impulse response is designed with a pass-band ripple of less than 0.5 dB and a high stop-band attenuation. The applicability is demonstrated by applying the filtering to exercise electrocardiograms

Robustness of ToF estimators - an Empirical Evaluation

The performance of ToF estimators for acoustic tone bursts is empirically evaluated. In indoor applications, the observed waveform is likely to be disrupted by multiple echoes. These echoes can cause complex interference patterns. The paper presents the results of a comparison study of the robustness of various ToF estimators against such type of disruptions

An audio FIR-DAC in a BCD process for high power Class-D amplifiers

A 322 coefficient semi-digital FIR-DAC using a 1-bit PWM input signal was designed and implemented in a high voltage, audio power bipolar CMOS DMOS (BCD) process. This facilitates digital input signals for an analog class-D amplifier in BCD. The FIR-DAC performance depends on the ISI-resistant nature of this PWM-signal. An impulse response with only positive coefficients was chosen, because of its resistance to deadzone and mismatch. With a DAC current of 0.5 mA, the dynamic range is 111 dB (A-weighted), with SINAD = 103 dB (A-weighted). The current consumption is 1mA for the analog part and 4.8 mA for the digital part. The power consumption is 29 mW at V/sub dd/ = 5 V and the chip area is 2 mm/sup 2/ including the reference diode that can be shared by more channels

"Een discussie zondr eind"

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Dambo Farming In Zimbabwe: Water Management, Cropping and Soil Potentials for Smallholder Farming in the Wetlands

A conference paper on water management in Africa.Rising population pressures in Africa have caused the agricultural use of wetlands to become increasingly important. Developing large surface irrigation infrastructures, as Asia did during the sixties and seventies, often proves to be too costly for Africa. This makes wetlands, with their relatively good water availability and high soil fertility, an interesting alternative for increasing food production. Wetland use offers economic advantages as well. Farming on wetlands is a labor-intensive process, while surface irrigation is capital- intensive

A survey of algorithms for the single machine total weighted tardiness scheduling problem

AbstractThis paper surveys algorithms for the problem of scheduling jobs on a single machine to minimize total weighted tardiness. Special attention is given to two dynamic programming and four branch and bound algorithms. The dynamic programming algorithms both use the same recursion defined on sets of jobs, but they generate the sets in lexicographic order and cardinality order respectively. Two of the branch and bound algorithms use the quickly computed but possibly rather weak lower bounds obtained from linear and exponential functions of completion times problems. These algorithms rely heavily on dominance rules to restrict the search. The other two branch and bound algorithms use lower bounds obtained from the Lagrangean relaxation of machine capacity constraints and from dynamic programming state-space relaxation. They invest a substantial amount of computation time at each node of the search tree in an attempt to generate tight lower bounds and thereby generate only small search trees. A computational comparison of all these algorithms on problems with up to 50 jobs is given

Wool production in Dohne Merino, Dormer, Merino and South African Mutton Merino lambs

In this study, the wool growth of Dohne Merino, Dormer, Merino and South African Mutton Merino (SAMM) lambs reared on a feedlot diet (10.62 MJ ME/ kg feed, 20.7% crude protein) was monitored from about two months old until the lambs were shorn as yearlings. The 100 cm2 patches on the left sides of the lambs were sheared monthly and the clippings were weighed to determine the wool growth rate. At approximately one year old, the lambs were shorn and the fleeces were weighed. A mid rib fleece sample was also retrieved from each lamb for quality analysis. Merino lambs presented the highest wool growth rates (12.943 g/day) and fleece weights (6.140 kg), whereas Dormer lambs exhibited the lowest values for these traits (8.487 g/day and 3.330 kg, respectively (P <0.05)). The lack of differences between Dohne Merino (9.720 g/day and 4.671 kg) and SAMM (10.553 g/day and 4.158 kg) lambs for these wool growth rate and fleece weight traits was attributed to disparities in live weight (86.8 kg and 105.2 kg, respectively (P <0.05), with heavier SAMM lambs offsetting the expected variations in fleece weight. Wool from Dohne Merino and Merino sheep had the finest fibre diameters (<21 μm), followed by SAMM wool (22–23 μm), with Dormers producing coarse wool (>27 μm). These results could be used as guidelines in sheep production to predict the income contribution of wool from these breeds

Premium lamb production of South African sheep breed types under feedlot conditions

An increasing number of producers opt to finish their lambs in on-farm feedlots. Therefore, detailed production information is required to implement precision finishing of lambs of different genotypes. Precision finishing monitors growth, feed intake and efficiency to optimize management. In this study, feedlot production characteristics of Dohne Merino, Dormer, Dorper, Meatmaster, Merino, Namaqua Afrikaner, and South African Mutton Merino (SAMM) lambs were evaluated. The lambs were reared in a feedlot and fed a diet with 10.41 MJ metabolizable energy (ME)/kg feed and 19.06% crude protein. Feed intake and body weight were recorded weekly from an initial weight of 30 kg until they had the subcutaneous fat cover needed to produce an A2 carcass. Subcutaneous fat was measured on the Longissimus lumborum muscle with an ultrasound scanner. Dorper, Meatmaster and Namaqua Afrikaner had the shortest rearing periods in the feedlot, and were market ready at a lower live weight (P <0.05). As a result, these lambs consumed less feed in the feedlot. Namaqua Afrikaner and Merino lambs were least efficient: 7.08 and 5.63 kg feed/kg gain, respectively. Dohne Merino, Dormer, Dorper, and Meatmaster rams and Dorper ewes were more efficient; approximately 3.58 kg feed/kg gain. Dohne Merino and Dormer rams had the highest growth rates: approximately 465 g/day. The end weights described in this study could be used as an indication for producers of the ideal slaughter weights for breeds of different maturity types.Keywords: average daily gain, fat deposition, feed efficiency, rearing perio