Minimization of the blocking time of the unreliable Geo/G_D/1 queueing system

In this paper we study the blocking time of an unreliable single-server queueing system $Geo/G_D/1$. The service can be interrupted upon explicit or implicit breakdowns. For the successful finish of the service we use a special service discipline dividing the pure service time $X$ (assumed to be a random variable with known distribution) in subintervals with deterministically selected time-points $0=t_0<t_1<dots <t_k< t_{k+1}; t_k < X le t_{k+1},$ and making a copy at the end of each subinterval (if no breakdowns occur during it) we derive the probability generating function of the blocking time of the server by a customer. As an application, we consider an unreliable system Geo/D/1 and the results is that the expected blocking time is minimized when the time-points t_0,t_1,... are equidistant. We determine the optimal number of copies and the length of the corresponding interval between two consecutive copies

Intraoperative colonoscopy - Indications and advantages

The introduction of colonoscopy as a routine method in the diagnostic and treatment practice is a new stage in coloproctology. As we know, the number of paraneoplastic diseases and multicentral forms of cancer increases. Based on the existence of determinate number of preoperative colonoscopical unexamined patients, we began the application of intraoperative "peranal colonoscopy". With the method of intraoperative colonoscopy were examined 25 patients. From them 19 were men and 6 women at the age of 31 to 65 years. In 25 examined patients we discovered 9 with undiagnosed preoperatively polyps over the stenosing tumor process. Knowing the opportunities of the intraoperative colonoscopy and based on our experience we propose that this method could be applied in urgent operative interventions of colon and rectum with un known source of haemorrhage. Intraoperative colonoscopy is a valuable diagnostic method in the surgeon's hands and its appropriate application to selected patients helps us having the correct operative behaviour

THE EFFECT OF APPLYING WITH IMMUNOCYTOPHYTE ON THE CONTENT AND CHEMICAL COMPOSITION OF THE ESSENTIAL OIL FROM COMMON BASIL OF ‘TRAKIA’ CULTIVAR

The aim of the study was to establish the effect of the leaf treatments with Immunocytophyte on the content, yield and chemical composition of the essential oil distilled from dry leaf and stems biomass and flower spikes of common basil, ‘Trakia’ cultivar. The experiment was carried out in the period 2007-2009 on the Training-and-Experimental fields of the Agricultural University – Plovdiv, set by the block plot design in four replications, the plot size being 20 m2. The following variants were studied: 1) Control; 2) 0.5 tablet per 50 m2, 3) 1 tablet per 50 m2, 4) 1.5 tablet per 50 m2, applied three times during the vegetation period before flowering of the second-order branches after basic fertilization with 16 kg/da of nitrogen (applied three times) and irrigation to 80-100% of water holding capacity. The results showed that the application of Immunocytophyte had a negative effect on the essential oil content. Nevertheless, higher essential oil yields were obtained in the treated variants thanks to the higher yield of dry matter. The major components of the essential oil distilled from dry leaf and stem biomass and flower spikes are linalool, limonene, methyl chavicol and methyl cinnamate

Example for Risk Estimation of Fault Appearance under the Place of Designed Skyscraper in Sofia

There was an interesting discussion during the designing stage of one of the future skyscrapers in Sofia – is the soil basement reliable enough if it is true the hypotheses for a fold under the construction place? The substantial geotechnical report doesn’t give answers to this question but the geological profiles suggest to us about an appearance of fold. Topographic and historical specifics of the area are supporting the same unsuitable idea. The additional geophysics investigations clearly establish a lack of fold displacements under the place during the Quaternary period. The zone has high seism and an individual seismic ratio is calculated and presented. The geophysics and geologic profiles are compared too. According the summary estimation there is not active fold under the construction place in spite of obvious existing conditions. Dynamic soil protection caused by the deep pile foundation is estimated

Investigation on the Effect of Application of Monopolar Electrocoagulation for Endoscopic Haemostasis in Bleeding Peptic Ulcers

The authors investigate the effect of application of monopolar electrocoagulation for endoscopic haemostasis in bleeding peptic ulcers. In group of 30 randomly selected patients with acute bleeding from gastroduodenal ulcers, classified after Forrest by Wirtz we apply endoscopic electrocoagulation. The authors reveal that the method of monopolar high-frequent diathermal coagulation in present days is not appropriate for the purposes of endoscopic haemostasis in acute bleeding from gastroduodenal ulcers

Geotechnical Preconditions for Skyscrapers Construction in Bulgaria and Seismic Risk Aspect

Parallel to the economic development of Bulgaria in the last nine – ten years there is a rapid raise in construction as well. This increase has been a good precondition for invest in some very high buildings with application of the newest technological achievements. These buildings are situated in the centrums of the largest Bulgarian cities: Sofia, Plovdiv, Varna and Bourgas. The Paper describes the geotechnical preconditions for construction of this type of buildings from seismic risk aspect. These preconditions are divided in four groups: geological, urban, technological and economical. The paper renders an account of the preconditions which are very different in the four cities. Varna and Bourgas have more or less similar conditions because they are situated on the Black Sea coast. The seismic risk for these two cities is relatively smaller. However, the wind pressure from the sea is strong. The geologist profiles of the quaternary period under Sofia are very variegated and the rock basement is to 400m of the depth. Plovdiv is a typical example for the risk of sand liquefaction combined with hay degree of seismic risk. Specific soils around Bourgas are peat and silt clay. Analyzed are the possibilities for application of combined raft – pile foundation, and are chosen and presented different technologies for deep excavation\u27s protection with respect to the geological conditions and the seismic risk. Urban and economical peculiarities of these ancient Bulgarian cities present difficult problems contradictions the aspiration for skyscraper construction

An intuitionistic fuzzy component based appoach for identifying web usage patterns

An intuitionistic fuzzy component based appoach fo

Direct Ascription of Missing Categorical Values in Survey Research Data

The complete datasets are a prerequisite for sustainable analyses, robust an- alytics and unbiased interpretation of results. Missing values in a survey occur when no data value is stored for the variable in an observation. Missing data can have a significant effect on the conclusions that can be drawn from the data. Direct ascription is the process of replacing missing data with predicted values. The aim of this work is to describe an approach to direct ascription of missing categorical values in survey research data based both on the assumption that values in a data set are missing at random and on the implementation of the correspondence analysis

Treatment recommendations for multimodality management of rectal cancer with a foc us on radiotherapy indications

Colorectal cancer (CRC) is one of the most commonly diagnosed cancer in Europe and US A and one of the leading causes of cancer death worldwide with 30% of all CRCs diagnosed in the rectum. Numerous published trials prove that the treatment of rectal cancer requires multidisciplinary approach. In this article the treatment recommendations for rectal cancer with an emphasis on radiotherapy (RT) application are defined