How do different densities in a network affect the optimal location of service centers?

The p-median problem is often used to locate p service centers by minimizing their distances to a geographically distributed demand (n). The optimal locations are sensitive to geographical context such as road network and demand points especially when they are asymmetrically distributed in the plane. Most studies focus on evaluating performances of the p-median model when p and n vary. To our knowledge this is not a very well-studied problem when the road network is alternated especially when it is applied in a real world context. The aim in this study is to analyze how the optimal location solutions vary, using the p-median model, when the density in the road network is alternated. The investigation is conducted by the means of a case study in a region in Sweden with an asymmetrically distributed population (15,000 weighted demand points), Dalecarlia. To locate 5 to 50 service centers we use the national transport administrations official road network (NVDB). The road network consists of 1.5 million nodes. To find the optimal location we start with 500 candidate nodes in the network and increase the number of candidate nodes in steps up to 67,000. To find the optimal solution we use a simulated annealing algorithm with adaptive tuning of the temperature. The results show that there is a limited improvement in the optimal solutions when nodes in the road network increase and p is low. When p is high the improvements are larger. The results also show that choice of the best network depends on p. The larger p the larger density of the network is needed. 

MACHINE VISION FOR AUTOMATICVISUAL INSPECTION OF WOODENRAILWAY SLEEPERS USING UNSUPERVISED NEURAL NETWORKS

The motivation for this thesis work is the need for improving reliability of equipment and quality of service to railway passengers as well as a requirement for cost-effective and efficient condition maintenance management for rail transportation. This thesis work develops a fusion of various machine vision analysis methods to achieve high performance in automation of wooden rail track inspection.The condition monitoring in rail transport is done manually by a human operator where people rely on inference systems and assumptions to develop conclusions. The use of conditional monitoring allows maintenance to be scheduled, or other actions to be taken to avoid the consequences of failure, before the failure occurs. Manual or automated condition monitoring of materials in fields of public transportation like railway, aerial navigation, traffic safety, etc, where safety is of prior importance needs non-destructive testing (NDT).In general, wooden railway sleeper inspection is done manually by a human operator, by moving along the rail sleeper and gathering information by visual and sound analysis for examining the presence of cracks. Human inspectors working on lines visually inspect wooden rails to judge the quality of rail sleeper. In this project work the machine vision system is developed based on the manual visual analysis system, which uses digital cameras and image processing software to perform similar manual inspections. As the manual inspection requires much effort and is expected to be error prone sometimes and also appears difficult to discriminate even for a human operator by the frequent changes in inspected material. The machine vision system developed classifies the condition of material by examining individual pixels of images, processing them and attempting to develop conclusions with the assistance of knowledge bases and features.A pattern recognition approach is developed based on the methodological knowledge from manual procedure. The pattern recognition approach for this thesis work was developed and achieved by a non destructive testing method to identify the flaws in manually done condition monitoring of sleepers.In this method, a test vehicle is designed to capture sleeper images similar to visual inspection by human operator and the raw data for pattern recognition approach is provided from the captured images of the wooden sleepers. The data from the NDT method were further processed and appropriate features were extracted.The collection of data by the NDT method is to achieve high accuracy in reliable classification results. A key idea is to use the non supervised classifier based on the features extracted from the method to discriminate the condition of wooden sleepers in to either good or bad. Self organising map is used as classifier for the wooden sleeper classification.In order to achieve greater integration, the data collected by the machine vision system was made to interface with one another by a strategy called fusion. Data fusion was looked in at two different levels namely sensor-level fusion, feature- level fusion. As the goal was to reduce the accuracy of the human error on the rail sleeper classification as good or bad the results obtained by the feature-level fusion compared to that of the results of actual classification were satisfactory.

The concept of e-service from a social interaction perspective

Today’s e-services are complex phenomenon consisting of several different e-services linked together. The e-services are provided by IT systems and presented to customers through user interfaces. Within web design research criteria are laid out for the design of good user interfaces, but one problem is that these analyses are performed without a service focus. This lack of service focus can result in the designed user interfaces providing indistinct service concepts, especially where several e-services are intertwined with each other.In order to design IT system interfaces, we have to be clear about which e-services are provided by the IT system and how these e-services are related to each other. This paper presents a framework for the analysis of user interfaces in terms of focused e-service, service environment and two types of intertwined e-services; related e-services and interrelating e-services. The analyses are exemplified by an Internet based e-marketplace. The paper discusses how the framework can be combined with ordinary web design criteria and how it can be used for e-service development.

‘Being in a womb’ or ‘playing musical chairs’ : the impact of place and space on infant feeding in NICUs

Background: Becoming a parent of a preterm baby requiring neonatal care constitutes an extraordinary life situation in which parenting begins and evolves in a medical and unfamiliar setting. Although there is increasing emphasis within maternity and neonatal care on the influence of place and space upon the experiences of staff and service users, there is a lack of research on how space and place influence relationships and care in the neonatal environment. The aim of this study was to explore, in-depth, the impact of place and space on parents’ experiences and practices related to feeding their preterm babies in Neonatal Intensive Care Units (NICUs) in Sweden and England. Methods: An ethnographic approach was utilised in two NICUs in Sweden and two comparable units in England, UK. Over an eleven month period, a total of 52 mothers, 19 fathers and 102 staff were observed and interviewed. A grounded theory approach was utilised throughout data collection and analysis. Results: The core category of ‘the room as a conveyance for an attuned feeding’ was underpinned by four categories: the level of ‘ownership’ of space and place; the feeling of ‘at-homeness’; the experience of ‘the door or a shield’ against people entering, for privacy, for enabling a focus within, and for regulating socialising and the; ‘window of opportunity’. Findings showed that the construction and design of space and place was strongly influential on the developing parent-infant relationship and for experiencing a sense of connectedness and a shared awareness with the baby during feeding, an attuned feeding. Conclusions: If our proposed model is valid, it is vital that these findings are considered when developing or reconfiguring NICUs so that account is taken of the influences of spatiality upon parent’s experiences. Even without redesign there are measures that may be taken to make a positive difference for parents and their preterm babies.

Learning Grammar : A study of upper secondary level students’ attitudes and beliefs concerning the learning of grammar

The communicative approach to language learning is widely taught in Western education, and yet its predecessor, the grammar-translation method, is still commonly employed in other parts of the world. In Sweden, the increasing popularity of the communicative approach is often justified by the high level of students’ communicative skills (Öhman, 2013). At the same time, students’ written texts and speech contain many grammatical errors (Öhman, 2013). Consequently, being aware of their tendency to produce grammatical errors, some students express beliefs regarding both the explicit and implicit learning of grammar (Sawir, 2005; Boroujeni, 2012). The objective of this thesis is to gain more knowledge regarding students’ beliefs concerning the learning of English grammar at the upper secondary level, in Sweden. With this purpose a survey was conducted in two schools in Sweden, where 49 upper-secondary English students participated. Qualitative and quantitative methods were applied to process the collected data. Despite some difference in the participants’ ages, there were many similarities in their attitudes towards the teaching and learning of grammar. The results show that the participants in both schools believe that only by applying both, explicit and implicit methods, can they obtain a high level of language proficiency. The results of this study can help teachers in planning different activities that enhance the students’ knowledge of grammar.