In this paper we give a new definition of the classical contact elements of a smooth manifold M as ideals of its ring of smooth functions: they are the kernels of Weil’s near points. Ehresmann’s jets of cross-sections of a fibre bundle are obtained as a particular case. The tangent space at a point of a manifold of contact elements of M is shown to be a quotient of a space of derivations from the same ringC∞(M) into certain finite-dimensional local algebras. The prolongation of an ideal of functions from a Weil
bundle to another one is the same ideal, when its functions take values into certain Weil algebras; following the same idea vector fields are prolonged, without any considerations about local one-parameter groups. As a consequence, we give an algebraic definition of Kuranishi’s fundamental identification on Weil bundles, and study their affine structures, as a generalization of the classical results on spaces of jets of cross-sections.
A new genus, Weketrema, is erected in the family Lecithasteridae for the species hitherto known as Lecithophyllum hawaiiense. Weketrema hawaiiense (Yamaguti, 1970) comb. n. is redescribed from Scolopsis bilineatus (Bloch) (Perciformes: Nemipteridae) from Lizard Island and Heron Island, Queensland, Plectorhinchus gibbosus (Lacepède) (Perciformes: Haemulidae) from Heron Island and Cheilodactylus nigripes Richardson (Perciformes: Cheilodactylidae) and Latridopsis forsteri (Castelnau) (Perciformes: Latridae) from Stanley, northern Tasmania. The new genus is distinguished from related members of the family Lecithasteridae by its complete lack of a sinus-sac. Although placed in the subfamily Lecithasterinae pro tem, its true subfamily position is not entirely clear. Comment is made on its unusual distribution, both in terms of zoogeography and hosts.
Correct detection of input and output parameters of a welding process is significant for successful development of an automated welding operation. In welding process literature, we observe that output parameters are predicted according to given input parameters. As a new approach to previous efforts, this paper presents a new modeling approach on prediction and classification of welding parameters. 3 different models are developed on a critical welding process based on Artificial Neural Networks (ANNs) which are (i) Output parameter prediction, (ii) Input parameter prediction (reverse application of output prediction model) and (iii) Classification of products. In this study, firstly we use Pareto Analysis for determining uncontrollable input parameters of the welding process based on expert views. With the help of these analysis, 9 uncontrollable parameters are determined among 22 potential parameters. Then, the welding process of ammunition is modeled as a multi-input multi-output process with 9 input and 3 output parameters. 1st model predicts the values of output parameters according to given input values. 2nd model predicts the values of correct input parameter combination for a defect-free weld operation and 3rd model is used to classify the products whether defected or defect-free. 3rd model is also used for validation of results obtained by 1st and 2nd models. A high level of performance is attained by all the methods tested in this study. In addition, the product is a strategic ammunition in the armed forces inventory which is manufactured in a limited number of countries in the world. Before application of this study, the welding process of the product could not be carried out in a systematic way. The process was conducted by trialand- error approach by changing input parameter values at each operation. This caused a lot of costs. With the help of this study, best parameter combination is found, tested, validated with ANNs and operation costs are minimized by 30%.
Osobní pohoda a její vybrané souvislosti u souboru zdravotních sester
Cíle. Článek je zaměřen na problematiku osobní pohody (well-being), jež tvoří jednu z nejvýznamnějších složek kvality života. Studie je zaměřena na empirický výzkum osobní pohody a životní spokojenosti u souboru českých zdravotních sester. Soubor a metody. Ve studii byl vyšetřen soubor 337 zdravotních sester (průměrný věk 34 let) baterií českých verzí dotazníků (Satisfaction with Life Scale; Anamnesis questionnaire; Social Readjustment Rating Scale; seznam stresujících událostí a způsobů zvládání stresu). Hypotézy. Nejvýznamnějšími stresory jsou pro zdravotní sestry přepracování, únava a nízká úroveň finančního hodnocení. Většina souboru zdravotních sester vykáže vysokou úroveň skóru životních událostí. Podstata vlivu stresorů na náš soubor zdravotních sester je spojena s vlivem jejich věku a úrovně životních událostí. Statistická analýza. Postupně jsme použili postupů korelační, faktorové a regresní analýzy. Výsledky. Výsledky přinesly rozsáhlý soupis stresorů, jež jsou chápány v profesi zdravotní sestry jako významné. Byly zjištěny stresory pocházející z oblasti interpersonálních vztahů, neadekvátního finančního hodnocení, pracovního přetížení a důsledků, zvl. únavy. Pokud jde o výsledky, týkající se skóru životních událostí, více než polovina souboru (55,5%) vykázala nerizikovou dynamiku života (do 150 bodů při hodnocení za posledních 12 měsíců), avšak 16,2% sester vykazovalo výsledek v rozpětí od 150 do 199 bodů, 19,2% sester rozpětí od 200 do 299 bodů, což reprezentuje již vysokou úroveň zatížení, a 9,1% vyšetřeného souboru zdravotních sester vykazovalo úroveň této životní dynamiky dokonce v oblasti nad 300 bodů. Výsledky dalších statistických analýz ukázaly, že sledovaný soubor zdravotních sester je vystaven nadměrné zátěži, vyplývající jak z distribuce stresorů, spojených s jejich pracovní náplní, tak z hlediska vzájemných vztahů mezi vlivem stresorů, věku a životních událostí. Omezení studie. Výsledky studie jsou omezeny rozsahem vyšetřeného souboru zdravotních sester, jeho demografickými charakteristikami, jakož i možnostmi použitých metod. and Objectives. The presented paper is focused on the issue of well-being, which is considered as one of the most important sources of the quality of life. The concept of well-being is understood as the combination of feeling good and functioning effectively, and paper is related to the specific features of the sense of personal well-being and satisfaction with life in a sample of Czech nurses, the largest group in health care that is active in all aspects of the health care system.
Sample and setting. A sample of 337 (mostly) Czech nurses (average age 34 years) has been surveyed with a set of questionnaires (Satisfaction with Life Scale, Anamnesis questionnaire; Social Readjustment Rating Scale; a list of stressful items and ways of coping with stress).
Research questions and hypotheses. It was supposed that the most important stressors for nurses are overburdening, tiredness and low level of financial compensation. The majority of the sample of nurses will show the high-risk level of life events score. The substance of the influence of stressors on our sample of nurses is connected with the influence of age and life events.
Statistical analysis. Correlation analysis, factor, and regression analysis were employed. Results. Results show a considerably wide scope of stressors that were considered important by our sample of nurses. Stressors from the area of interpersonal relationships, inadequate financial assessment, large work load (or more precisely overburdening) and tiredness connected with it were discovered. As for the results dealing with the sphere of life events, it is obvious that more than one half of the studied sample (55.5 %) show non-risk dynamics of life, filled by life events within the frame of the evaluated period of twelve months and with a resulting score up to 150 points, but 16.2 % nurses fall into the range from 150 – 199 pofints, 19.2 % into the range from 200 – 299 points, which is a very high level, showing the demanding level of lie dynamics of almost one fifth of the studied sample, and 9.1 % of nurses shows the level of this dynamics even in the range over 300 points. The results of further statistical procedures (factor and regression analyses) showed that nurses within our sample are extremely demanding, both from the point of view of the distribution of stressors that are connected with their work, and from the point of view of mutual relations between the influence of stressors, age and life events.
Study limitations. The results of the study are restricted by the scope of the studied sample, its demographic features, but also by the methods used.
In this paper, we consider the interaction between a rigid body and an incompressible, homogeneous, viscous fluid. This fluid-solid system is assumed to fill the whole space $\Bbb R^d$, $d=2$ or $3$. The equations for the fluid are the classical Navier-Stokes equations whereas the motion of the rigid body is governed by the standard conservation laws of linear and angular momentum. The time variation of the fluid domain (due to the motion of the rigid body) is not known {\it a priori}, so we deal with a free boundary value problem. \endgraf We improve the known results by proving a complete wellposedness result: our main result yields a local in time existence and uniqueness of strong solutions for $d=2$ or $3$. Moreover, we prove that the solution is global in time for $d=2$ and also for $d=3$ if the data are small enough.