PI output feedback control of differential linear repetitive processes

Repetitive processes are characterized by a series of sweeps, termed passes, through a set of dynamics defined over a finite duration known as the pass length. On each pass an output, termed the pass profile, is produced which acts as a forcing function on, and hence contributes to, the dynamics of the next pass profile. This can lead to oscillations which increase in amplitude in the pass-to-pass direction and cannot be controlled by standard control laws. Here we give new results on the design of physically based control laws. These are for the sub-class of so-called differential linear repetitive processes which arise in applications areas such as iterative learning control. They show how a form of proportional-integral (PI) control based only on process outputs can be designed to give stability plus performance and disturbance rejection

Decoupling and iterative approaches to the control of discrete linear repetitive processes

This paper reports new results on the analysis and control of discrete linear repetitive processes which are a distinct class of 2D discrete linear systems of both systems theoretic and applications interest. In particular, we first propose an extension to the basic state-space model to include a coupling term previously neglected but which arises in some applications and then proceed to show how computationally efficient control laws can be designed for this new model

The Durability of a Concrete Sewer Pipeline under Deterioration by Sulphate and Chloride Corrosion

AbstractIn the article an issue of corrosion impact both sulphate and chloride on the reliability index was solved by analytical methods. The pipeline was located in a homogenic soil backfill under communication load. The depth of corrosion penetration was estimated by selection of the maximum length of cracks. As a result of deterioration zone appeared to be a function of time in exploitation according to average environmental concentration which can initialise a percent of chemical and mechanical degradation of concrete. The work shows also the complete analytical way which help to assess the safety level of sewer pipelines what can be introduced to geographic information systems

Age, growth, and reproductive biology, of the winter skate, Leucoraja ocellata, in the western Gulf of Maine

This study describes the age, growth and reproductive biology of the winter skate, Leucoraja ocellata, in the Western Gulf of Maine. Age was estimated by enumerating annular bands within the vertebral centra. Precision of the age estimates was evaluated using the Index of Average Percent Error and the annual nature of growth band formation was documented using marginal increment analyses. Growth was assessed with the use of the von Bertalanffy growth equation. Age and size at maturity was estimated by measuring morphological and histological changes in the reproductive tract and circulating steroid hormone concentrations. Maturity ogives for males predict that 50% maturity occurs at a total length of 730 mm and at 11 years. For females, maturity ogives predict that 50% maturity occurs at a total length of 760 mm and between 11 and 12 years of age. To elucidate the reproductive cycle of the winter skate, plasma concentrations of the sex steroids testosterone (T), 17beta-estradiol (E2), and progesterone (P4) were determined by radio immunoassay and compared to morphological and histological changes occurring in the reproductive tract over a complete reproductive cycle for mature individuals. Overall, when the results of my dissertation are combined, they indicate that the winter skate is a late maturing, slow growing, long lived species, with an apparent succinct reproductive cycle. Like many other elasmobranchs, these characteristics make L. ocellata \u27s populations highly susceptible to exploitation by commercial fisheries

Comparison of teachers’ and vocalists’ awareness of voice functioning, voice emission therapy and physiotherapy

Introduction Voice seems to us inalienable, although the lack of proper voice hygiene can result in that we may be excluded from professional activity for a long time or even completely. Therefore, it was decided to check voice functioning awareness of people who professionally speak or sing. Material and methods The research was based on a survey on a sample of 135 people from the target group. The form consisted of 28 items, including detailed questions about the type and degree of occupational exposure to voice effort, as well as the level of physical activity, occurrence of possible disorders, addiction to stimulants such as cigarettes or alcohol, and questions regarding participation in classes of correct voice emission, awareness of the existence of physiotherapeutic assistance in the field of voice rehabilitation and many others. Results The results presented and discussed in detail include the analysis of answers to questions posed in the survey, as well as the results of the Voice Handicap Index test in the group of teachers and vocalists. Conclusions Significant differences in awareness of voice functioning between teachers and vocalists were noticed. It can be stated that among teachers the deteriorating voice correlates with the increase in age. On the other hand, among vocalists, the level of perceived voice fatigue remains relatively constant while aging. Teachers who participated in the study show significantly less awareness of the principles of proper voice emission and hygiene than vocalists, as demonstrated by the Voice Handicap Index

Kłącze hermeneutyczne, czyli – nie wszystko musi być powiedziane

Recenzja książki Marka Bernackiego Hermeneutyka fenomenu istnienia. Studia o polskiej literaturze współczesnej (Vincenz, Miłosz, Wojtyła, Herbert, Szymborska), ATH, Bielsko-Biała 2010, ss. 39

The reproductive cycle of the thorny skate (Amblyraid radiata) in the western Gulf of Maine

The thorny skate (Amblyraja radiata) is a large species of skate that is endemic to the waters of the western north Atlantic in the Gulf of Maine. Because the biomass of thorny skates has recently declined below threshold levels mandated by the Sustainable Fisheries Act, commercial harvests from this region are prohibited. We have undertaken a comprehensive study to gain insight into the life history of this skate. The present study describes and characterizes the reproductive cycle of female and male thorny skates, based on monthly samples taken off the coast of New Hampshire, from May 2001 to May 2003. Gonadosomatic index (GSI), shell gland weight, follicle size, and egg case formation, were assessed for 48 female skates. In general, these reproductive parameters remained relatively constant throughout most of the year. However, transient but significant increases in shell gland weight and GSI were observed during certain months. Within the cohort of specimens sampled monthly throughout the year, a subset of females always had large preovulatory follicles present in their ovaries. With the exception of June and September specimens, egg cases undergoing various stages of development were observed in the uteri of specimens captured during all other months of the year. For males (n=48), histological stages Ill through VI (SIII-SVI) of spermatogenesis, GSI, and hepatosomatic index (HSI) were examined. Although there appeared to be monthly fluctuations in spermatogenesis, GSI, and HSI, no significant differences were found. The production and maintenance of mature spermatocysts (SVI) within the testes was observed throughout the year. These findings collectively indicate that the thorny skate is reproductively active year round

„Tygodnik Powszechny” Jerzego Turowicza wobec literatury. Medium prawie doskonałe

Jerzy Turowicz’s “Tygodnik Powszechny” and literature. The almost perfect mediumThe subject of the discussion is Jerzy Turowicz’s attitude to the issues of literature (based on queries in the decades when he was the editor-in-chief of “TP”, i.e. in the 1945-1995 half-century). The special position occupied by the journal from Krakow on the map of the communist-era Polish press is stressed. Since its establishment, this journal enjoyed wide and long-time support from the professor communityof the Jagiellonian University, as well as other academies of Krakow. Assorted accounts from poets and prose authors, including Marek Skwarnicki, Jan Józef Szczepański, Jan Twardowski and others, were discussed. Attention was paid to Turowicz’s outstanding merits in discovering and advocating of literary talents (with an example of Father Jan Twardowski and Maria Jarczyńska-Bukowska). Turowicz seldom wrote on poets and poetry, but he continuously monitoredboth domestic and emigrationliterature on this subject. He also had an extraordinary aesthetic sense which allowed him to selecttalented poets as his collaborators, and published authors whose fame wentmuch further than the borders of Poland (cases of Father Karol Wojtyła, Czesław Miłosz, Stanisław Lem and others). Only under Turowicz, Polish literature had such a wide and competent coverage in “TP”. Thanks to this, readers could acquaint themselves with the foremost pens of literary criticism and were becomingthoroughly oriented in the Polish and world’s literature. It seems that since Turowicz’s passing, “Tygodnik Powszechny” has not played such a role in this regard anymore