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171.
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We propose a new metaphor for the visualization of prefixes propagation in the Internet. Such a metaphor is based on the concept of topographic map and allows to put in evidence the relative importance of the Internet Service Providers (ISPs) involved in the routing of the prefix. Based on the new metaphor we propose an algorithm for computing layouts and experiment with such algorithm on a test suite taken from the real Internet. The paper extends the visualization approach of the BGPlay service, which is an Internet routing monitoring tool widely used by ISP operators  相似文献   
173.
Output-Sensitive Reporting of Disjoint Paths   总被引:1,自引:0,他引:1  
A k -path query on a graph consists of computing k vertex-disjoint paths between two given vertices of the graph, whenever they exist. In this paper we study the problem of performing k -path queries, with , in a graph G with n vertices. We denote with the total length of the reported paths. For , we present an optimal data structure for G that uses O(n) space and executes k -path queries in output-sensitive time. For triconnected planar graphs, our results make use of a new combinatorial structure that plays the same role as bipolar (st ) orientations for biconnected planar graphs. This combinatorial structure also yields an alternative construction of convex grid drawings of triconnected planar graphs. Received August 24, 1996; revised April 8, 1997.  相似文献   
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Vegetables are rich sources of the biologically active compounds which have beneficial effects in prevention of some diseases and certain types of cancer. From the point of view of protection and health, the objective of this paper was to optimize food content in order to obtain a functional food. In order to improve the nutritive and protective properties of the product, the beetroot and carrot juices enriched with brewer’s yeast autolysate were subjected to lactic-acid fermentation with Lactobacillus acidophilus NCDO1748.  相似文献   
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Ash from the coal gasification process contains a broad spectrum of elements which through leaching (gasifier ash leachates) may enter into the environment. The health effect of such leachates i.e. complex mixtures of inorganic elements is insufficiently known. We investigated the effect of gasifier ash leachates in a chronic-(9-month) and in a three-generation reproduction study. The leachates were prepared weekly by water extraction of ash from a Lurgi coal gasification plant in Yugoslavia, and given to experimental animals instead of drinking water. In the chronic experiment exposed animals showed no changes in mortality rate, haematological findings, concentration of Fe, Zn, Mn in kidneys, liver, testicles and femur, as well as in femur composition and morphometry, gross pathology and organ histology. In the reproduction study the number of pregnancies, weight and number of newborns, and concentration of Fe, Zn, Mn in carcasses of sucklings were the same in control and experimental animals.  相似文献   
179.
The authors report their experience with 463 tension free hernioplasty procedures for inguinal and femoral hernias. The surgical technique included the insertion of both a polypropylene plug and a polypropylene mesh, and was carried out mostly in local anesthesia (84.2%) using bupivacaine 0.25% for ileoinguinal and ileohypogastric blockage and mepivacaine 0.5% for local infiltration. There was no major intraoperative complication; local postoperative complications were rare (10%) and easily managed; postoperative pain was frequently observed (66%), though mild and transient; resumption of working activity occurred within a month in 96.6% of cases; there were only 3 post-operative recurrences (respectively, at 1, 6 and 12 months). The authors conclude that the tension free hernioplasty is a simple, rapid, low-cost and effective technique, easily performed under local anesthesia.  相似文献   
180.
An ultrasound-assisted liquefaction as a pretreatment for bioethanol production by simultaneous saccharification and fermentation (SSF) of corn meal using Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system was studied. Ultrasound pretreatment (at a frequency of 40 kHz) was performed at different sonication times and temperatures, before addition of liquefying enzyme. An optimal duration of the treatment of 5 min and sonication temperature of 60 °C were selected, taking into account glucose concentration after the liquefaction step. Under the optimum conditions an increase of glucose concentration of 6.82% over untreated control sample was achieved. Furthermore, the SSF process kinetics was assessed and determined, and the effect of ultrasound pretreatment on an increase of ethanol productivity was investigated. The obtained results indicated that the ultrasound pretreatment could increase the ethanol concentration by 11.15% (compared to the control sample) as well as other significant process parameters. In this case, the maximum ethanol concentration of 9.67% w/w (which corresponded to percentage of the theoretical ethanol yield of 88.96%) was achieved after 32 h of the SSF process. A comparison of scanning electron micrographs of the ultrasound-pretreated and untreated samples of corn meal suspensions showed that the ultrasound stimulated degradation of starch granules and release of glucose, and thereby accelerated the starch hydrolysis due to the cavitation and acoustic streaming caused by the ultrasonic action.  相似文献   
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