Statistical inference for type I multiply left-censored samples from Weibull distribution

Left-censored data with one or more detection limits occur frequently in many application areas. In this paper, the computational procedure for calculation of maximum likelihood estimates of the parameters for type I multiply left-censored data from underlying Weibull distribution is suggested and used considering various numbers of detection limits. The expected Fisher information matrix is analytically determined and its performance is compared with sample (observed) Fisher information matrix using simulations. Simulations are focused primarily on the properties of estimators for small sample sizes. Real data illustration is included.Во многих областях науки часто встречаются задачи с цензурированными слева данными с одной или несколькими границами обнаружения. В данной работе предложена процедура для вычисления оценок максимальной правдоподобности параметров многократного цензурирования слева типа I для распределения Вейбулла с учетом разного числа границ обнаружения. Ожидаемая информационная матрица Фишера определена аналитически и ее вид сравнен с выборочной (наблюдаемой) информационной матрицей Фишера. Моделирование основано, главным образом, на свойствах оценок выборок малых размеров. Примеры проиллюстрированы на реальных данных.У багатьох галузях науки часто зустрічаються задачі з цензурованими зліва даними з однією або кількома межами виявлення. У цій роботі запропоновано процедуру для обчислення оцінок максимальної правдоподібності параметрів багаторазового цензурування зліва типу I з розподілу Вейбулла з урахуванням різної кількості меж виявлення. Очікувану інформаційну матрицю Фішера визначено аналітично та її вигляд порівняно з вибірковою (спостережуваною) інформаційною матрицею Фішера. Моделювання здебільшого ґрунтується на властивостях оцінок вибірок малих розмірів. Приклади проілюстровано на реальних даних

Development and acceptability of the Person-centred Observation and Reflection Tool (PORT) for supporting staff and practice development in dementia care services

Background Observational tools can support understanding of the complex needs of older people with dementia and aid delivery of person-centred care. However, existing tools are complex and resource intensive to use. Aim To develop and evaluate the acceptability and feasibility of a low-resource, observational tool to support staff reflection and practice development. Method Intervention development of the Person-Centred Observation and Reflection Tool (PORT) and acceptability and feasibility study, using surveys and focus groups in the UK, Norway and Spain. Findings PORT was reported as easy, accessible and acceptable to use. Observation was identified as powerful for individual staff development and provided an evidence-based source for underpinning individualised care planning. Potential time challenges associated with implementation were identified. Conclusion Initial evaluation indicates PORT is an acceptable and feasible tool for use in health and social care settings for older people. Further research is needed on implementation models and impacts of use

Aubin property and uniqueness of solutions in cone constrained optimization

We discuss conditions for the Aubin property of solutions to perturbed cone constrained programs, by using and refining results given in Klatte-Kummer "Nonsmooth Equations in Optimization", Kluwer, 2002. In particular, we show that constraint nondegeneracy and hence uniqueness of the multiplier is necessary for the Aubin property of the critical point map. Moreover, we give conditions under which the critical point map has the Aubin property if and only if it is locally single-valued and Lipschitz

Investigation of the properties of powdermetallurgical and ceramic materials Final report

In the frame of the BMFT Project the application potential of the Emanation Thermal Analysis (ETA) in the characterization of powder metallurgical and ceramic materials was demonstrated. This method can be advantageously used for obtaining information about the surface area and morphology changes of the materials, under 'in-situ' conditions of their thermal treatment. The radon atoms (incorporated into the samples before their investigation) were used as tthe universal probe of surface area and nanoporosity changes, the size of radon atoms being 0.38 nm. The thermal behaviours of WC-Co based hardmetal samples differing in the WC grain size and the content of Co, were investigated by the ETA. A new insight in the solid state and solid-liquid interactions occurring during thermal treatment of the Ti-Al intermetallic samples was obtained by the ETA. (orig.)SIGLEAvailable from TIB Hannover: F95B1212+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman