Simultaneous Confidence Intervals for the Parameters of Pareto Distribution under Progressive Censoring

In this article, we consider the progressive Type II right censored sample from Pareto distribution. We introduce a new approach for constructing the simultaneous confidence interval of the unknown parameters of this distribution under progressive censoring. A Monte Carlo study is also presented for illustration. It is shown that this confidence region has a smaller area than that introduced by Ku? and Kaya (2007 Ku? , C. , Kaya , M. F. ( 2007 ). Estimation for the parameters of the Pareto distribution under progressive censoring . Commun. Statist. Theor. Meth. 36 : 1359 – 1365 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]).     

The urban market of Açaí fruit (Euterpe oleracea Mart.) and rural land use change: Ethnographic insights into the role of price and land tenure constraining agricultural choices in the Amazon estuary

This paper examines the recent development of the açaí fruit economy in regional Amazonian urban markets (as a staple food) and more recently among national and international consumers (as a fashion food) and the consequences for agroforestry intensification by Caboclo communities in the Amazon estuary. The paper is based on long-term ethnographic research and field experiments; the açaí fruit economy is discussed from agricultural, social, and economic perspectives; attention is given to its historical development, the structure of açaí fruit production, its agents, the relationship among themselves and the urban market. Decadal price performance is presented for açaí fruit and açaí transportation costs and compared to major agropastoral products for the Eastern Amazon region. Dominant views about the economic rationality of rural producers' decision-making are discussed. Açaí fruit has performed as well as and in some cases surpassed most agro-pastoral products of the Northern region. Economic returns for producers reflect linkages between price signals from urban markets, harvesting decision, and land tenure condition of the producer. Urban markets for the fruit is expanding and bringing new participants to the açaí fruit economy further conditioning the ability of rural producers to take advantage of external markets for forest products. Discussion of factors conditioning agricultural development and integration between urban and rural areas conclude the article.     

Designing an ergonomics backpack for student aged 7-9 with user centred design approach

Researches explored that backpacks are the most common means of carrying school supplies for students. Carrying heavy backpacks causes a wide range of disorders such as musculoskeletal disorders and postural malfunction. User Centered Design has proven its suitability to produce high efficient products with the most adaptability to consumer demands. This approach combined with consideration of normal standards and ergonomics features, with the recognition of children's needs and requirements, has been used in this research to prepare an initial design of a backpack. After that, its prototype was manufactured. The backpack was tested by 120 elementary students in three steps of form, ergonomics and load sense. A redesign was performed that has applied the results of the test run. Results showed that this new backpack can considerably reduce the effective loads on the shoulders, back and neck.     

Reliability of a soccer player based on the bivariate Rayleigh distribution with right censored and ignorable missing data

In this paper, we study the performance of a soccer player based on analysing an incomplete data set. To achieve this aim, we fit the bivariate Rayleigh distribution to the soccer dataset by the maximum likelihood method. In this way, the missing data and right censoring problems, that usually happen in such studies, are considered. Our aim is to inference about the performance of a soccer player by considering the stress and strength components. The first goal of the player of interest in a match is assumed as the stress component and the second goal of the match is assumed as the strength component. We propose some methods to overcome incomplete data problem and we use these methods to inference about the performance of a soccer player.     

Conditional Maximum Likelihood and Interval Estimation for Two Weibull Populations under Joint Type-II Progressive Censoring

Comparative lifetime experiments are important when the object of a study is to determine the relative merits of two competing duration of life products. This study considers the interval estimation for two Weibull populations when joint Type-II progressive censoring is implemented. We obtain the conditional maximum likelihood estimators of the two Weibull parameters under this scheme. Moreover, simultaneous approximate confidence region based on the asymptotic normality of the maximum likelihood estimators are also discussed and compared with two Bootstrap confidence regions. We consider the behavior of probability of failure structure with different schemes. A simulation study is performed and an illustrative example is also given.