22 research outputs found
-stable classification of -manifolds with finite fundamental group
We show that two closed, connected -manifolds with finite fundamental groups are -stably homeomorphic if and only if their quadratic -types are stably isomorphic and their Kirby-Siebenmann invariant agrees
Simplified automatic method for measuring the visual field using the perimeter ZERK 1
Background: Currently available perimeters have limited capabilities of performing measurements of the visual field in children. In addition, they do not allow for fully automatic measurement even in adults. The patient in each case (in any type of perimeter) has at his disposal a button which he uses to indicate that he has seen a light stimulus. Such restrictions have been offset in the presented new perimeter ZERK 1. Methods: The paper describes a new type of automated, computerized perimeter designed to test the visual field in children and adults. The new perimeter and proprietary software enable to carry out tests automatically (without the need to press any button). The presented full version of the perimeter has been tested on a head phantom. The next steps will involve clinical trials and a comparison with measurements obtained using other types of perimeters. Results: The perimeter ZERK 1 enables automatic measurement of the visual field in two axes (with a span of 870 mm and a depth of 525 mm) with an accuracy of not less than 1o (95 LEDs on each arm) at a typical position of the patient's head. The measurement can be carried out in two modes: default/typical (lasting about 1 min), and accurate (lasting about 10 min). Compared with available and known types of perimeters, it has an open canopy, proprietary software and cameras tracking the eye movement, automatic control of fixation points, light stimuli with automatically preset light stimulus intensity in the following ranges: 550-700 mcd (red 620-630 nm), 1100-1400 mcd (green 515-530 nm), 200-400 mcd (blue 465-475 nm). Conclusions: The paper presents a new approach to the construction of perimeters based on automatic tracking of the eye movements in response to stimuli. The unique construction of the perimeter and the software allow for its mobile use in the examination of children and bedridden patients
Rules of work and functions of the computer system accounting and information about chemicals in universities - iChem
Odczynniki chemiczne s膮 charakterystyczn膮 grup膮 substancji, stwarzaj膮cych znaczne zagro偶enia w trakcie ich przechowywania, transportu, stosowania i eliminacji. W uczelnianych laboratoriach chemicznych i magazynach zosta艂y zgromadzone du偶e ilo艣ci przeterminowanych, w wielu wypadkach zb臋dnych odczynnik贸w. Jednocze艣nie obserwowana jest tendencja przekazywania do szk贸艂 wy偶szych odczynnik贸w z innych jednostek badawczych, szk贸艂 i podmiot贸w gospodarczych, w celu ich wykorzystania, b膮d藕 eliminacji. Dla spe艂nienia wszelkich wymog贸w w zakresie ochrony 艣rodowiska naturalnego wa偶ne jest opracowanie bezpiecznych procedur, przy prowadzeniu prac zwi膮zanych z porz膮dkowaniem i 艣cis艂膮 ewidencj膮 zmagazynowanych substancji chemicznych [1梅3]. Likwidacja nadmiernych zapas贸w odczynnik贸w zwi膮zana jest z wysokimi kosztami, kt贸re mo偶na obni偶y膰 poprzez wykorzystanie zb臋dnych odczynnik贸w w procesie dydaktycznym, w pracach badawczych lub przez przekazanie innym uczelniom w ramach wymiany. Na przeszkodzie tym dzia艂aniom sta艂 brak sprawnego systemu ewidencji odczynnik贸w i wymiany informacji. System iChem zosta艂 zainstalowany na 25 wydzia艂ach chemicznych polskich uczelni, po przeprowadzeniu cyklu szkole艅 dla uprzednio wytypowanych w poszczeg贸lnych jednostkach administrator贸w. System iChem umo偶liwi艂 na wydzia艂ach chemicznych szk贸艂 wy偶szych sporz膮dzenie jednolitej, pe艂nej ewidencji substancji chemicznych, prowadzenie uproszczonej gospodarki magazynowej oraz udost臋pnienie w skali og贸lnokrajowej informacji o zb臋dnych odczynnikach. Niezwykle cenne okaza艂o si臋 wprowadzenie do systemu iChem baz danych, zawieraj膮cych informacje o w艂a艣ciwo艣ciach odczynnik贸w, w tym obszerne dane dotycz膮ce bezpiecze艅stwa pracy z danymi chemikaliami, wyst臋puj膮cych zagro偶e艅, informacje toksykologiczne, ekologiczne i opis sposobu post臋powania z odpadami. Dla wi臋kszo艣ci substancji chemicznych umieszczonych w bazie dost臋pne s膮 karty bezpiecze艅stwa odczynnik贸w, stanowi膮ce cenne 藕r贸d艂o informacji, obowi膮zuj膮ce prawem [6]. Dane te s膮 szczeg贸lnie istotne w obecnym okresie przystosowywania laboratori贸w badawczych i dydaktycznych do standard贸w obowi膮zuj膮cych w Unii Europejskiej. Informacje o w艂a艣ciwo艣ciach odczynnik贸w, w tym r贸wnie偶 dotycz膮ce bezpiecze艅stwa pracy z odczynnikami i obszerne dane zawarte w kartach substancji niebezpiecznych, s膮 u偶ytecznym narz臋dziem dla zapewnienia bezpiecze艅stwa przy planowania bada艅 naukowych i w prowadzeniu zaj臋膰 dydaktycznych oraz mog膮 stanowi膰 pomoc w likwidacji danych substancji chemicznych w strumieniu odpad贸w. Cz臋艣膰 informacyjna bazy dotycz膮ca zagro偶e艅 w pracy z odczynnikami, udost臋pniona pracownikom oraz studentom, jest wykorzystywana przy opracowywaniu instrukcji bezpiecznej pracy w laboratoriach chemicznych oraz sposob贸w zagospodarowania odpad贸w. Z przedstawionej charakterystyki systemu iChem wynika, 偶e mo偶e stanowi膰 on przydatne narz臋dzie nie tylko dla wydzia艂贸w chemicznych szk贸艂 wy偶szych, lecz r贸wnie偶 dla innych wydzia艂贸w i instytut贸w badawczych, wyposa偶onych w laboratoria chemiczne oraz dla szk贸艂 艣rednich o profilu chemicznym.System iChem gave for faculties of chemistry in Poland an opportunity to prepare one, full and consolidated registry of chemicals and to provide simplified magazine management. It made also simple and available an exchange of information about spare reagents. Very important property of the system is a possibility of creating the unified database of reagents', including physical and chemical properties and a lot of data about safety, threats and toxicological properties. The database is very easy to maintain and modify so it's still growing, because the users are continually updating it. All users can insert new data to the database on their own iChem server. The data is then gathered and analysed on a special server called "Centrala". When it gets a positive acknowledgement, it's then send to all other iChem servers as an update to the properties database. This technique automatically incorporates the work of a lot of people to maintain and update one unified properties database, what gives it the ability to be as big and precise as it's possible. The safety cards (which are now needed by the Polish law) are included for most reagents and are the valuable source of information. These cards are particularly important as Polish laboratories are trying to adapt research and education to the EU standards. Information about reagents, especially these concerned with safe handling with reagents, and wide information included in dangerous reagents cards are very useful tool for ensure safety in scientific research and students' laboratories, and can be helpful in developing process of destruction of chemical wastes. As for now iChem system was accustomed in 25 chemistry faculties in Poland and its database of reagents properties consists of over 8000 elements. The system is a kind of magazine management system but it's expanded with several important and unique properties: possibility of exchanging information about spare reagents among all iChem servers, predefined, very big and still growing database of reagents, a lot of additional information about safety. Moreover it works with a common Internet browser, so no special software is needed on the user side. This property made it accessible for students and therefore the system database may be easily used by them as a valuable source of information during their own work
Pupil Size as a Biometric Trait
We investigate the possibility of using pupil size as a discriminating feature for eye-based soft biometrics. In experiments carried out in different sessions in two consecutive years, 25 subjects were asked to simply watch the center of a plus sign displayed in the middle of a blank screen. Four primary attributes were exploited, namely left and right pupil sizes and ratio and difference of left and right pupil sizes. Fifteen descriptive statistics were used for each primary attribute, plus two further measures, which produced a total of 62 features. Bayes, Neural Network, Support Vector Machine and Random Forest classifiers were employed to analyze both all the features and selected subsets. The Identification task showed higher classification accuracies (0.6194梅70.7187) with the selected features, while the Verification task exhibited almost comparable performances (~ 0.97) in the two cases for accuracy, and an increase in sensitivity and a decrease in specificity with the selected features