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71.
'Software defined radio' (SDR) is a technology that will appear in future generations of mobile phones, i.e. following the third-generation mobile phone technology that is currently being defined and developed. Early versions of 'pragmatic' SDR will allow the terminal to be reconfigured at any level of its protocol stack. Ultimately, the 'pure' SDR technology will allow a mobile phone or terminal to have its air interface software configured or reconfigured by other software (or software parameters) that have been downloaded to the terminal, e.g. over the air, or from a remote server via the Internet and one's personal computer (PC). A number of security issues arise with downloaded code that implements the air interface functions, and these may not be obvious simply from looking at the way PC software is updated on-line today. This paper starts with an outline of the code that allows a mobile phone to operate over a particular air interface. This sets the baseline for a discussion of the security issues surrounding the change of this code from one that is fixed and downloaded once only, to code that is reconfigurable during the life of a product.  相似文献   
72.
Announcement     
Samples of nine different fruits grown in Oyo State of Nigeria were obtained from different market locations within Ibadan Municipality and analysed for their vitamin C content. Sweet orange was found to contain the highest amount of vitamin C (56·0 mg100 g edible portion) whilst sweet banana variety II contained the lowest amount (9·4 mg100 g edible portion). Lime, grapefruit, pawpaw and ‘agbalumo’ were found to contain considerable amounts of vitamin C, having 46·5, 47·0, 43·2 and 48·0 mg100 g respectively. Consumption of these fruits would thus meet the nutritional requirement for vitamin C in this part of Nigeria. It is also recommended that sweet orange, agbalumo, grapefruit, lime and pawpaw, found to contain considerable amounts of vitamin C, should be processed either at home or factory level to make them available to the people all year round.  相似文献   
73.
74.
In the development of a novel freeze-drying technique in a fluidized bed at atmospheric pressure, a parallel study was undertaken using a conventional vacuum equipment. Two kinetically distinct phases were observed during freeze drying of representative Pood samples:

(1) a period during which the rate of drying was constant and (2) a second period during which the drying rate sufferedcontinual reduction. This paper focused attention on the primary drying period which corresponded with the kinetics of sublimation of pure  相似文献   
75.
76.
测定钠中杂质的手动阻塞计的研究   总被引:1,自引:1,他引:0  
文章介绍了测定钠中杂质浓度的手动阻塞计的原理、装置和实验结果。为了减少测量误差,我们研究了影响准确测定阻塞温度的因素,并且找到了减少测量误差的办法。在同样的杂质饱和温度下,该阻塞计测得的高、低阻塞温度所对应的杂质浓度差是很接近的。对氧其差值为1.03ppm;对氢为0.0763ppm。  相似文献   
77.
Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 14–15, February, 1989.  相似文献   
78.
The usefulness of selected PCR-protocols for the detection of Salmonella in 117 samples of animal origin (17 raw minced meat, 27 raw chicken meat, 8 raw sausages, and 25 egg samples, as well as 18 poultry faecal, and caecal swabs samples) and DNA-fingerprinting typing is shown. To establish an accurate PCR-procedure for Salmonella detection the following parameters were evaluated: two pre-PCR concentration procedures, centrifugation and immunomagnetic separation (IMS) using Dynabeads anti- Salmonella; the specificity and sensitivity of 10 sets of primers; and different conditions of the amplification reaction. In light of the results obtained from the use of PCR-based procedures alone or in combination with conventional methods, the following findings can be underlined: First, IMS is more efficient than centrifugation in the recovery of Salmonella. Second, the selected IMS/PCR-detection protocol is less time-consuming (45 h) than the IMS/culture procedure (90 h), and a good concordance between them was found when the Kappa coefficient was calculated (0·87). Third, PCR-ribotyping technique showed a very low discrimination power, being able to differentiate only three profiles. Fourth, RAPD technique using specific primers supports previous works in which it was proposed as a simple and useful tool for discriminating isolates between and within serotypes. Fifth, The efficiency, rapidity, and flexibility of the PCR-protocols applied were high, and they can be performed using two PCR-programs and the same basic equipment.  相似文献   
79.
This study empirically examined the organisational learning effects of the nonfinancial performance information provided by management accounting information systems (MAISs) under advanced manufacturing technology (AMT). In this study, a target costing system and the frequent and quick reporting of information were considered the facilitators of learning. First, we examined the relationships between AMT level and the amount of nonfinancial performance information produced by MAISs. The empirical results showed that there are significant positive relationships between the level of AMT and nonfinancial performance information. With a systems approach, we also proved the impact of the relationships among AMT levels, nonfinancial performance information and learning facilitators on the organisational performance of a firm. The results of our research suggest that under a high level of AMT, for the provision of information to result in an increase of performance through organisational learning, a target costing system must be introduced and a large amount of information should be provided frequently and quickly. The results of this study also showed that although AMT level may be low, fairly well-arranged facilitators and a moderately large amount of information may be necessary for the improvement of performance. In conclusion, effective organisational learning depends on the provision of relevant information as well as efficient learning support mechanisms.  相似文献   
80.
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