Pattern Matching

An important subtask of the pattern discovery process is pattern matching, where the pattern sought is already known and we want to determine how often and where it occurs in a sequence. In this paper we review the most practical techniques to find patterns of different kinds. We show how regular expressions can be searched for with general techniques, and how simpler patterns can be dealt with more simply and efficiently. We consider exact as well as approximate pattern matching. Also we cover both sequential searching, where the sequence cannot be preprocessed, and indexed searching, where we have a data structure built over the sequence to speed up the search.     

Subjective well‐being: what do adolescents say?

The aim of this paper is to analyse how 10‐ to 15‐year‐old adolescents define their own perceptions of well‐being and the factors influencing it at their age. Ten focus groups were organized, two from each age group. One group for each age included the students with the lowest scores in subjective well‐being (SWB) and the other included those with the highest, according to their responses to previously administered psychometric scales. The views of the participating adolescents were explored by means of a content analysis. In general, the children mentioned both positive and negative elements of participating in defining what constitutes well‐being. According to these children, well‐being is related to both affects and attitudes, relations with family and friends being key factors in it. Differences in the information provided reveal some variations according to age and SWB score. Children scoring lower in SWB tend to refer more to relationships with friends and basic needs covered, whereas those scoring higher tend to refer more to family relationships and not having problems. The results of this research can contribute to both social policy design and appraisal as they provide an in‐depth understanding of how SWB works at these ages.     

Characterizations through reliability measures from weighted distributions

In this paper we obtain general characterizations of probability distributions from relationships between failure rate and mean residual life from the origin distribution and associated weighted distribution. Our characterization properties extend particular results given by Gupta and Keating (1986), Jain et al. (1989) and Asadi (1998). Using the theoretical results we obtain characterizations of some usual distributions. Received: December 7, 1998; revised version: May 10, 2000     

Distorted Lorenz curves: models and comparisons

The economic literature contains many parametric models for the Lorenz curve. A number of these models can be obtained by distorting an original Lorenz curve $L$ by a function $h$ , giving rise to a distorted Lorenz curve ${\widetilde{L}}=h\circ L$ . In this paper, we study, in a unified framework, this family of curves. First, we explore the role of these curves in the context of the axiomatic structure of Aaberge (2001) for orderings on the set of Lorenz curves. Then, we describe some particular models and investigate how changes in the parameters in the baseline Lorenz curve $L$ affect the transformed curve ${\widetilde{L}}$ . Our results are stated in terms of preservation of some stochastic orders between two Lorenz curves when both are distorted by a common function.     

Characterizations and ordering properties based on log-odds functions

In this paper, we obtain some general results on characterizations of probability distributions from relationships between conditional moment, failure rate, and log-odds rate functions. We also study stochastic orders and classes based on the log-odds rate function and some relationships with usual stochastic orderings and classes. Some characterizations and ordering properties are obtained by using weighted distributions.     

Ordering Properties of Systems with Two Dependent Components

The study of systems with dependent components from a reliability point of view is a very important topic. However, the majority of the articles study the case of independent components. In this article, we study how the dependency influences the performance of the system. We extend some comparison results obtained in the case of independent components to the case of two dependent components. We show that the more diverse the exponential parameters of the two components, the stronger (weaker) the parallel (series) system in the stochastic ordering. We apply our general results to some common bivariate models in the reliability theory.     

Kernel density estimation using weighted data ∗

In this paper we compare the kernel density estimators proposed by Bhattacharyya et al. (1988) and Jones (1991) for length biased data, showing the asymptotic normality of the estimators. A method to construct a new estimator is proposed. Moreover, we extend these results to weighted data and we study an estimator for the weight function.     

Satisfied users clubs: family planning acceptors as model agents of the program

The National Population Program in the Philippines has encouraged family planning acceptors to shift from their passive role as recipients of family planning services into an active role as program participants. In the mid 1970s the Commission on Population (Popcom) began setting up satisfied users clubs in various regions of the country with the aid of the Ministry of Social Services and Development (MSSD). Other government institutions like the Ministry of Labor and Employment (MOLE) formed similar family planning groups. So did private agencies participating in the Program. There were indications at that time that community based family planning clubs could help the Program in informing couples about family planning and in motivating them to practice contraception. In 1977 a study conducted by the University of the Philippines Institute of Maternal Clinic found that family planning acceptors in Dumaguete City received social and psychological support from local barrio women's clubs. A 1978 Community Outreach Survey indicated that full time outreach workers (FTOWs) found statisfied users clubs helpful in increasing the number of new acceptors in their areas and in bringing down the number of family planning dropouts. Once a decision to create a club is made, club organizers meet with the barangay captain and his council to get their approval and seek their cooperation in inviting people to join the proposed club. Once the approval is given known family planning users in the community or mothers of reproductive age are invited to attend a community assembly. Of 59 clubs surveyed, only 10 had a formal constitution and bylaws. All clubs elected their officers and conducted monthly meetings which lasted from 2-4 hours. The main selling proposition of the clubs is the involvement of members in nonfamily planning activities like income generating schemes, skills training, nutrition seminars, and immunization of children. 81% of the officers of all 59 clubs were family planning acceptors. The majority of officers had undergone voluntary sterilization. Only 8 of the 59 clubs considered themselves single purpose clubs committed to the promotion of family planning. The other 51 were multipurpose organizations, with both family planning and nonfamily planning activities. In the area of family planning, the club's objectives were to increase family planning acceptors, disseminate family planning information, and maintain current users.