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  • Author: Krzysztof Kaczmarek x
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Open access

Sylwester Kaczmarek and Krzysztof Nowak

Performance Evaluation of Preemption Algorithms in MPLS Networks

Preemption is a traffic engineering technique in Multiprotocol Switching Networks that enables creation of high priority paths when there is not enough free bandwidth left on the route. Challenging part of any preemption method is to select the best set of paths for removal. Several heuristic methods are available but no wider comparison had been published before. In this paper, we discuss the dilemmas in implementing preemption methods and present the simulation study of well known existing algorithms. Based on the results, we provide recommendations for deployment of preemption for the two most common evaluation criteria: number of preemptions and preempted bandwidth.

Open access

Radosław Włodarczyk, Krzysztof Kaczmarek and Rafał Bargiel

Fifteen years of the Common Snipe (Gallinago gallinago) study at the Jeziorsko reservoir with some notes about weight and moult

The Students's Section from University of Łódź organises ringing camp at the dam reservoir every year. The aim of the camp is wader and duck ringing. One of the most numerous species of bird ringed is the Common Snipe. During 15 years (1989-2003) of studies 4142 individuals of this species were ringed. Age ratio differed among years, but every year young birds represented more that 80% of all ringed individuals. Snipes caught in September caused problems with age identification and that impeded to obtain correct age ratio each year. Analysis of weight of caught birds revealed between-years variation in juvenile birds, adults were excluded from analysis due to small sample size. Throughout the autumn months the increase in mean body mass in young birds was observed. Data about moult suggest that adult birds show two main strategies of primary moult: traditional moult and suspended moult. Both of them are of the same frequency. Tail feathers are moulted by juveniles as well as by adults simultaneously.

Open access

Piotr Minias, Krzysztof Kaczmarek and Tomasz Janiszewski

Creation and development of the subcolony in Cormorant Phalacrocorax carbo sinensis at the Jeziorsko reservoir, Central Poland

The research was conducted at Jeziorsko reservoir (51°73'N, 18°63'E) in Central Poland during the years 2004-2007. In 2005, a small subcolony of Cormorants (41 breeding pairs) was created about 1 km away from the main colony (370 breeding pairs). This year, the mean clutch size in the subcolony was lower than in the main colony and the fraction of small clutches (2-3 eggs) in the subcolony was significantly higher (57.1% vs. 37.1%). Although in 2005 breeding success was unusually low in the main colony, the number of fledglings raised per nest and per successful nest were significantly higher in the main colony in comparison to the subcolony. This followed the higher losses of whole clutches/broods recorded in the subcolony (68.6% vs. 39.5%). In the following year (2006), the number of pairs breeding in the subcolony increased over 4-fold (165 pairs) and was only slightly lower than in the main colony (220 pairs). The values of all breeding parameters recorded in the subcolony were significantly higher than in the previous year and were similar to those in the main colony. In 2007 the number of fledglings raised per successful nest in the subcolony was significantly higher in comparison to the main colony. The obtained results suggest that probably young and inexperienced birds limited by the availability of the nest sites were mainly involved in the creation of the subcolony. The growth of the breeding parameters recorded in consecutive years in the subcolony could be connected with the subsequent movement of higher-quality birds from the main colony and shows the advantages of occasional abandonment of overexploited colony location.

Open access

Radosław Włodarczyk, Tomasz Janiszewski, Krzysztof Kaczmarek, Piotr Minias and Anna Kleszcz

Sexing Common Snipe (Gallinago gallinago) in the Field - is there any Simple Method?

There are a few methods used for sex determination in the Common Snipe. However, all proposed methods are based on data obtained from dead birds. The most important feature is the total length of the outermost tail feather. The performed analysis showed that the vane length was strongly correlated with the total length of this feather. It allowed to predict this measurement having only the vane length. Because the measurement procedure influences the vane length, new ranges of vane length typical for each sex are proposed. However, the analysis of the vane length distribution suggested that there were no two homogenous groups that would represent the two sexes. This supports the prediction that the total feather length should be used rather cautiously as a simple sex trait in the Common Snipe. Also the second trait based on the tail feather colour resulted in overestimation of the proportion of females.

Open access

Piotr Minias, Krzysztof Kaczmarek, Radosław Włodarczyk and Tomasz Janiszewski

Pattern of Post-Juvenile Moult in Common Snipe (Gallinago Gallinago) and Its Implications for Ageing of the Species

External ageing of Common Snipe (Gallinago gallinago) still engenders considerable problems. To improve precision of age determination on the basis of plumage characteristics a scheme of post-juvenile moult was investigated in approximately 1200 first-year Common Snipes caught during autumn migration in central Poland. Post-juvenile moult was commenced from body feathers followed by moult of rectrices, lesser/median wing coverts and tertials. Moult sequence showed high inter-individual variability and was started in rectrices (36.9%), wing coverts (25.3%), tertials (8.4%) or simultaneously in several of these tracts of feathers (29.4%). Moult of rectrices was finished before completion of moult of wing coverts and tertials. Moult of tertials finished as the last from all age-indicative tracts of feathers. Consequently, tertials were suggested as the most useful for ageing of first-year Common Snipes in an advanced stage of moult. There was no case of moult of the outermost tertial in first-year birds. The second tertial from distal side of wing was moulted as the last one within this tract of feathers and thereby should be of special interest during plumage examination.

Open access

Jan Przybyłek, Krzysztof Dragon and Piotr Michał Jan Kaczmarek

Abstract

River bank filtration (RBF) is a system that enriches groundwater resources by induced infiltration of river water to an aquifer. Problematic during operation of RBF systems is the deterioration of infiltration effectiveness caused by river bed clogging. This situation was observed in the Krajkowo well field which supplies fresh water to the city of Poznań (Poland) during and after the long hydrological drought between the years 1989 and 1992. The present note discusses results of specific hydrogeological research which included drilling of a net of boreholes to a depth of 10 m below river bottom (for sediment sampling as well as for hydrogeological measurements), analyses of grain size distribution and relative density studies. The results obtained have allowed the recognition of the origin of the clogging processes, as well as the documentation of the clogged parts of the river bottom designated for unclogging activities.

Open access

Aleksander Kaczmarek, Krzysztof Przybyszewski, Dorota Rutkowska and Honorata Sosnowska

Abstract

The aim of this paper is to check whether mathematical competences influence some manifestations of bounded rationality. A special example of bounded rationality called “framing effect” is dealt with to analyze empirically the thesis that mathematical competences and cognitive effort may reduce the framing effect. Two kinds of cognitive effort: probabilistic and deductive are analysed. Experiments were conducted using samples of Polish students, both mathematically and business oriented. As an example of a framing situation an example called “Asian disease”, (the first analyzed and the most popular example of the framing effect), is considered. The thesis that a mathematical background may diminish the occurrence of the framing effect was partly confirmed.

Open access

Mateusz Ściborski, Włodzimierz Meissner, Robert Krupa, Radosław Włodarczyk, Krzysztof Kaczmarek, Rafał Bargiel, Adam Wojciechowski, Aleksandra Raniczkowska, Radosław Kozik and Juliusz Pietrasik

Fieldwork results of wader research stations working in Poland in 2002-2003

Open access

Dorota Konopacka, Urszula Kaczmarek, Aneta Matulska, Anna Wawrzyńczak, Dorota Kruczyńska and Krzysztof P. Rutkowski

Abstract

The aim of the study was to compare the sensory quality of scab resistant ‘Topaz’ apples grown in certified organic orchards (ECO) with those grown in orchards managed within integrated method (IP), and to determine their potential processing suitability. Fruits were harvested in five certificated IP and ECO orchards at the optimum ripeness stage and stored for two months in normal atmosphere at 1 ºC. Apple quality was assessed one day after cold storage and after 7 days of storage at the temperature 18 ºC to simulate shelf life. The results of taste and flavour sensory assessment did not explicitly demonstrate the effect of the orchard management system on the overall eating quality. Although the fruits from the organic orchards were perceived as less sweet and sourer, the management system did not influence the overall eating quality. There was no effect of the growing technology on quality traits connected with aroma and overall texture assessment. Regarding appearance evaluation, fruits from organic orchards were characterized by a higher variation in shape and size, and more frequently than in the case of IP apples had blemishes, scars and rust, which negatively affected their attractiveness. Analysis of the chemical composition of fruits indicates that apples from organic orchards are characterized on average by higher titratable acidity and higher soluble solids content than apples from IP orchards, which could favour their potential application as the additive regulating acidity and shaping the desirable sensory traits of processed organic products.

Open access

Szymon Bzoma, Włodzimierz Meissner, Tomasz Janiszewski, Magdalena Wybraniec, Magdalena Remisiewicz, Robert Krupa, Radosław Kozik, Krzysztof Kaczmarek, Anna Kleszcz, Piotr Minias, Radosław Włodarczyk, Krzysztof Lukoszek and Adam Wojciechowski

Fieldwork Results of Wader Research Stations Working in Poland in 2006-2008