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1.
The introduction of high spatial and spectral resolution sensors on-board remote-sensing spacecraft has increased, by orders of magnitude, the data rates which need to be sustained on the down-link or cross-link transmission channels. Since these channels are severely limited in capacity, the need arises to perform on-board compression to reduce the volume of data which would need to be down-linked. This paper discusses the development and refinement of a low complexity lossy spectral/spatial compression method which provides high compression ratios at low levels of distortion. The developed techniques uses pixels in adjacent bands to predict the intensity of pixels in the band being compressed via a simple linear prediction model. This prediction method when combined with a low-distortion discrete cosine transform (DCT) block coding method yields performance comparable to block-adaptive Karhunen-Loeve Transform (KLT)-DCT methods without incurring the complexity penalty of the KLT. The methods' performance suffers under misregistration. A fractional-pixel interpolation enhancement to the basic technique significantly improves the performance in the case of misregistered bands  相似文献   
2.
To convey the dynamic information related to traffic conditions in various parts of a city, we propose an environment utilizing the technology of smart phones to provide information anywhere and anytime. Called ";The Interactive Traffic Beat Project,"; it uses a Web-based service to deliver this information to people through their cell phones at the right time so that valuable time can be saved and the chaos on the roads can be managed.  相似文献   
3.
There is a need for developing low cost, easily and abundantly available, yet efficient, adsorbents for the removal of phosphates during the tertiary treatment of wastewaters. The tamarind nut shell activated carbon (TNSAC) prepared on a laboratory scale has been used to evaluate its performance for phosphate adsorption. This paper describes the laboratory production of this adsorbent material in its various forms, and discusses the effects of the TNSAC process variables (the unrinsed and rinsed forms of the TNSAC and the impregnation ratio) on its performance in adsorbing phosphate. The material has been shown to be a good alternative adsorbent. As much as 95% phosphate removal by the unrinsed TNSAC is possible in about 30 min under the test conditions. The phosphate adsorbing capacity is about two times higher for the unrinsed TNSAC in comparison to the rinsed TNSAC. The adsorption rates, however, transit to extremely low rates towards the end when equilibrium conditions could be attained in about 2 h contact time. The phosphate removal mechanics are adsorption and precipitation/ion exchange when unrinsed TNSAC is used, and adsorption alone for the rinsed TNSAC. The maximum phosphate removal is found to take place at an impregnation ratio of 1.0 for both forms of the TNSAC.  相似文献   
4.
The problem of transporting constant-bit-rate (CBR) traffic through a packet network is analyzed. In the system considered, CBR traffic is packetized and packets from several similar sources are multiplexed on a transmission link. The bit streams are recreated at the receiving end by demultiplexing the packets and then playing out the packets of each CBR stream. Traffic fluctuations may cause gaps to appear in the playout process. Their frequency can be reduced by adding a smoothing delay to each stream. The queueing system analyzed has periodic arrivals and deterministic service times. A method of analysis, based on the ballot theorems of Takacs (1967), is presented to provide steady-state delay distributions as well as a transient analysis of the system to predict the statistics of the time for a gap to develop in the CBR stream as a function of the smoothing delay  相似文献   
5.
Forty paediatric cases of A.R.F. (Acute Renal Failure) of various aetiology were included in the study. 60% of patients were less than 4 years of age with male predominance. 80% cases reported to us very late with oligoanuria of more than 24 hours (2-7 days). Diarrhoea, vomiting and fever were other dominant symptoms. Maximum cases were severely anaemic (87.5%) with mean Hb 7.73 +/- 1.9 gm%. 40% cases were of underweight while only one case (2.5%) was of over weight, inspite of volume excess in 40% cases. All 24 cases, who were estimated for serum albumin, found to have marked hypoalbuminemia. Mortality was found to be as high as 65% inspite of effective peritoneal dialysis in all cases. High mortality seems to be due to profound anuria of many days (because of marked delay in reaching the hospital), fever and malnutrition besides other factors as aetiology.  相似文献   
6.
Poly(ethylene oxide) (PEO) star polymers were prepared by anionic polymerization of methacryloyl chloride and glyceryl trimethacrylate with sec‐butyllithium in cyclohexane. The ensuing polymers were grafted with poly(ethylene glycol) of molecular weight 400. The final product was washed with methylene chloride and analyzed with infrared spectroscopy, differential scanning calorimetry, and thermogravimetry. Star polymers of PEO were also prepared by anionic polymerization of glycidol with sec‐butyllithium in cyclohexane. The initiator was chosen so as to yield a polymer of 10,000 molecular weight. The resulting polymers were analyzed by nuclear magnetic resonance, infrared spectroscopy, and thermogravimetry. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 322–327, 2003  相似文献   
7.
A 7-Mb BiCMOS ECL (emitter coupled logic) SRAM was fabricated in a 0.8 μm BiCMOS process. An improved buffer with a high-level output of nearly VCC is adopted to eliminate the DC current in the level converter circuit, and the PMOS transistor has a wide operating margin in the level converter. The configurable bit organization is realized by using a sense-amplifier switch circuit with no access degradation. A wired-OR demultiplexer for the ×1 output, having the same critical path as the ×4 output circuit, allows for the same access time between the two modes. The ×1 or ×4 mode is electrically selected by the external signal. A simplified programming redundancy technology, shift redundancy, is utilized. Address programming is performed by cutting only one fuse in the shift redundancy. The RAM operates at the ECL-10K level with an access time of 7 ns. and the power dissipation at 50 MHz is 600 mW for the × mode  相似文献   
8.
9.
The pharmacokinetics and dose proportionality of fexofenadine, a new non-sedating antihistamine, and its enantiomers were characterized after single and multiple-dose administration of its hydrochloride salt. A total of 24 healthy male volunteers (31 +/- 8 years) received oral doses of 20, 60, 120 and 240 mg fexofenadine HCl in a randomized, complete four-period cross-over design. Subjects received a single oral dose on day 1, and multiple oral doses every 12 h on day 3 through the morning on day 7. Treatments were separated by a 14-day washout period. Serial blood and urine samples were collected for up to 48 h following the first and last doses of fexofenadine HCl. Fexofenadine and its R(+) and S(-) enantiomers were analysed in plasma and urine by validated HPLC methods. Fexofenadine pharmacokinetics were linear across the 20-120 mg dose range, but a small disproportionate increase in area under the plasma concentration-time curve (AUC) (< 25%) was observed following the 240 mg dose. Single-dose pharmacokinetics of fexofenadine were predictive of steady-state pharmacokinetics. Urinary elimination of fexofenadine played a minor role (10%) in the disposition of this drug. A 63:37 steady-state ratio of R(+) and S(-) fexofenadine was observed in plasma. This ratio was essentially constant across time and dose. R(+) and S(-) fexofenadine were eliminated into urine in equal rates and quantities. All doses of fexofenadine HCl were well tolerated after single and multiple-dose administration.  相似文献   
10.
Attempts were made to find out the nature and cause of a widespread sugarcane chlorosis in a cane growing area. Soils from chlorotic and nonchlorotic fields did not differ markedly in pH, CaCO3, electrical conductivity, organic C, and soil test P, Zn, Cu, and Mn levels, but the chlorotic field soils had relatively more NH4OAc-extractable K and less clay and DTPA-extractable Fe. Chlorotic and green leaf blades contained about the same concentration of P, S, Mg, Fe, Zn, Cu, and Mo, but the former leaf blades had more K and less Ca and HCl soluble Fe than the green ones. Green leaves of plants that seemed to have naturally recovered in chlorotic fields were higher in Mn. A foliage spray with 2.5% FeSO4.7H2O solution resulted in greening of leaves and a field experiment showed marked crop response to Fe and some response to Mn. The results thus suggest that the chlorosis is due to a lime-induced Fe-deficiency with the possibility of some role of Mn in Fe nutrition in calcareous soil conditions.Deceased 22 September 1988  相似文献   
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