971 resultados para RDA in Many Metadata Formats
Resumo:
Random effect models have been widely applied in many fields of research. However, models with uncertain design matrices for random effects have been little investigated before. In some applications with such problems, an expectation method has been used for simplicity. This method does not include the extra information of uncertainty in the design matrix is not included. The closed solution for this problem is generally difficult to attain. We therefore propose an two-step algorithm for estimating the parameters, especially the variance components in the model. The implementation is based on Monte Carlo approximation and a Newton-Raphson-based EM algorithm. As an example, a simulated genetics dataset was analyzed. The results showed that the proportion of the total variance explained by the random effects was accurately estimated, which was highly underestimated by the expectation method. By introducing heuristic search and optimization methods, the algorithm can possibly be developed to infer the 'model-based' best design matrix and the corresponding best estimates.
Resumo:
Wholesale trade has an intermediate position between manufacturing and retail in the distributional channel. In modern economies, consumers buy few, if any, products directly from manufacture or producer. Instead, it is a wholesaler, who is in direct contact with producers, buying goods in larger quantities and selling them in smaller quantities to retailers. Traditionally, the main function of a wholesaler has been to push goods along the distributional channel from producer to retailer, or other nonend user. However, the function of wholesalers usually goes beyond the process of the physical distribution of goods. Wholesalers also arrange storage, perform market analyses, promote trade or provide technical support to consumers (Riemers 1998). The existence of wholesalers (and other intermediaries) in the distributional channel is based on the effective and efficient performance of distribution services, that are needed by producers and other members of the supply chain. Producers usually do not enjoy the economies of scale that they have in production, when it comes to providing distributional services (Rosenbloom 2007) and this creates a space for wholesalers or other intermediaries. Even though recent developments in the distributional channel indicate that traditional wholesaling activities now also compete with other supply chain organizations, wholesaling still remains an important activity in many economies (Quinn and Sparks, 2007). In 2010, the Swedish wholesale trade sector consisted of approximately 46.000 firms and generated an annual turnover of 1 300 billion SEK (Företagsstatistiken, Statistics Sweden). In terms of turnover, wholesaling accounts for 20% of the gross domestic product and is thereby the third largest industry. This is behind manufacturing and a composite group of firms in other sectors of the service industry but ahead of retailing. This indicates that the wholesale trade sector is an important part of the Swedish economy. The position of wholesaling is further reinforced when measuring productivity growth. Measured in terms of value added per employee, wholesaling experienced the largest productivity growth of all industries in the Swedish economy during the years 2000 through 2010. The fact that wholesale trade is one of the important parts of a modern economy, and the positive development of the Swedish wholesale trade sector in recent decades, leads to several questions related to industry dynamics. The three topics that will be examined in this thesis are firm entry, firm relocation and firm growth. The main question to be answered by this thesis is what factors influence new firm formation, firm relocation and firm growth in the Swedish wholesale trade sector?
Resumo:
In order for town centres to manage increased competition in retailing, co-operation between stakeholders in a strategic alliance has become more important. A typical set of stakeholders in a strategic alliance for strengthening retailingare retailers, local authorities and property owners. The roles of retailer’sand local authorities’ are well researched. However, the role of property owners is not. The aim of this paper seeks to unfold the role of property owners in a strategic alliance. This is a case study of a medium-sized town in which semi-structured interviews with different stakeholders were conducted. In the chosen town there is a TCM alliance co-operation at work. The above mentioned stakeholders are possible members in an alliance. The case studied shows a fragmented property owner market with no dominant property owner, as it is in many medium-sized towns. Our study shows that many stakeholders look at the role of property owners as crucial for town centre development. However, property owners do not see that they can significantly contribute to or benefit from the development.The main reasons for this opinion are that they consider themselves as not having enough resources or the capability to influence the town development.
Resumo:
The English language is widely used throughout the world and has become a core subject in many countries, especially for students in the upper elementary classroom. While textbooks have been the preferred EFL teaching method for a long time, this belief has seemingly changed within the last few years. Therefore, this study looks at what prior research says about the use of authentic texts in the EFL upper elementary classroom with an aim to answer research questions on how teachers can work with authentic texts, what the potential benefits of using authentic texts are and what teachers and students say about the use of authentic texts in the EFL classroom. While this thesis is written from a Swedish perspective, it is recognized that many countries teach EFL. Therefore, international results have also been taken into consideration and seven previous research studies have been analyzed in order to gain a better understanding of the use of authentic texts in the EFL classroom. Results indicate that the use of authentic texts is beneficial in teaching EFL. However, many teachers are still reluctant to use these, mainly because of time constraints and the belief that such texts are too difficult for their students. Since these findings are mainly focused on areas outside of Sweden, additional research is needed before conclusions can be drawn on the use of authentic texts in the Swedish upper elementary EFL classroom.
Resumo:
The aim of this literature review is to investigate which strategies teachers use to motivate pupils to communicate orally in English. The literature review also investigates how these teacher strategies affect pupils. The methodology used for this investigation is a systematic literature review. Various databases have been used when searching for literature. Scientific articles and theses have been searched for. They have also been read and analyzed before they have become a part of this review. The results indicate that some teachers feel insecure when speaking English. Therefore Swedish is spoken in many language classrooms. Teachers speaking in front of the class is the traditional way of teaching, and it does not seem to be a strategy who influences pupils positively. If teachers speak the target language among pupils they often get more motivated and focused pupils who feel comfortable speaking English. Young pupils are fast learners. By exposing them to the English language in early ages they receive great opportunities to learn a foreign language and strengthen their self-confidence. Drama, songs and rhymes are preferable strategies to use when teaching young learners. What position teachers decide to take in the classroom is also a significant element when teaching foreign languages.
Resumo:
Young people now spend a longer and longer period of their lives at school then ever before. Not always because that they want to, but because society has nothing else to offer. The situation in many schools may also, in different aspects, be seen as highly problematic. Andersson (2001) has, for example, found in a large longitudinal study - The Life Project – that schools seem to be adapted to the needs of only a minority of the students - around 30%. On the other hand school is badly adjusted to the requirements of another 30 %. This group of students often find school meaningless, uninteresting and boring. For these students school is mostly a waste of time. In such circumstances, it seems natural that society has a responsibility to offer young people a meaningful time at school, both here and now and to prepare them for a future live as adults, not only as a part of the work force.As a part of departure I briefly describe the model that Antonovsky has developed and try to use it in a school context instead. I have here, of course, no possibility to make a deeper analysis of a complex problem such as this.In Antonovsky’s spirit, using a salutogenic perspective, instead of asking ourselves why do pupils fail or perhaps also not like being at school we have to ask, instead: What it is that makes pupils successful? From this background the purpose of this paper is to discuss some aspects of how pupils may use different strategies to handle their school situation in a proper way.
Resumo:
This paper seeks to describe and discuss the impact of inspections of schools in Sweden. It outlines the political context, based on New Public Management (NPM) theory, according to what role the Schools Inspectorate is supposed to play in order to govern and control. Attention is also devoted, referring an on-going case study, to how inspections influence head teachers and their leadership in their everyday work. Reports from the Schools inspectorate are public. This forces both politicians and head teachers to take measures. In this case, the head teachers perceived that the inspection reports confirmed what they already knew, but it also gave them an alibi and a tool to push their teachers to take part in everyday school development work. During the first year after the inspection the head teachers mainly strived to adjust formal deficiencies in local steering documents. However, some of the deviations reported from the Schools inspectorate are regarding pedagogical problems that are complicated and difficult to handle. As interventions in many cases will show up much later the results are, for example as increased goal fulfilment, in this case, still an open question. Nevertheless, it seems obvious that the Schools Inspectorate must be seen as a result of the governing philosophy that denotes New Public Management NPM).
Resumo:
Understanding the genetic basis of traits involved in adaptation is a major challenge in evolutionary biology but remains poorly understood. Here, we use genome-wide association mapping using a custom 50 k single nucleotide polymorphism (SNP) array in a natural population of collared flycatchers to examine the genetic basis of clutch size, an important life-history trait in many animal species. We found evidence for an association on chromosome 18 where one SNP significant at the genome-wide level explained 3.9% of the phenotypic variance. We also detected two suggestive quantitative trait loci (QTLs) on chromosomes 9 and 26. Fitness differences among genotypes were generally weak and not significant, although there was some indication of a sex-by-genotype interaction for lifetime reproductive success at the suggestive QTL on chromosome 26. This implies that sexual antagonism may play a role in maintaining genetic variation at this QTL. Our findings provide candidate regions for a classic avian life-history trait that will be useful for future studies examining the molecular and cellular function of, as well as evolutionary mechanisms operating at, these loci.
Resumo:
A number of recent works have introduced statistical methods for detecting genetic loci that affect phenotypic variability, which we refer to as variability-controlling quantitative trait loci (vQTL). These are genetic variants whose allelic state predicts how much phenotype values will vary about their expected means. Such loci are of great potential interest in both human and non-human genetic studies, one reason being that a detected vQTL could represent a previously undetected interaction with other genes or environmental factors. The simultaneous publication of these new methods in different journals has in many cases precluded opportunity for comparison. We survey some of these methods, the respective trade-offs they imply, and the connections between them. The methods fall into three main groups: classical non-parametric, fully parametric, and semi-parametric two-stage approximations. Choosing between alternatives involves balancing the need for robustness, flexibility, and speed. For each method, we identify important assumptions and limitations, including those of practical importance, such as their scope for including covariates and random effects. We show in simulations that both parametric methods and their semi-parametric approximations can give elevated false positive rates when they ignore mean-variance relationships intrinsic to the data generation process. We conclude that choice of method depends on the trait distribution, the need to include non-genetic covariates, and the population size and structure, coupled with a critical evaluation of how these fit with the assumptions of the statistical model.
Resumo:
Reindeer herding in Sweden is a form of pastoralism practised by the indigenous Sami population. The economy is mainly based on meat production. Herd size is generally regulated by harvest in order not to overuse grazing ranges and keep a productive herd. Nonetheless, herd growth and room for harvest is currently small in many areas. Negative herd growth and low harvest rate were observed in one of two herds in a reindeer herding community in Central Sweden. The herds (A and B) used the same ranges from April until the autumn gathering in October-December, but were separated on different ranges over winter. Analyses of capture-recapture for 723 adult female reindeer over five years (2007-2012) revealed high annual losses (7.1% and 18.4%, for herd A and B respectively). A continuing decline in the total reindeer number in herd B demonstrated an inability to maintain the herd size in spite of a very small harvest. An estimated breakpoint for when herd size cannot be kept stable confirmed that the observed female mortality rate in herd B represented a state of herd collapse. Lower calving success in herd B compared to A indicated differences in winter foraging conditions. However, we found only minor differences in animal body condition between the herds in autumn. We found no evidence that a lower autumn body mass generally increased the risk for a female of dying from one autumn to the next. We conclude that the prime driver of the on-going collapse of herd B is not high animal density or poor body condition. Accidents or disease seem unlikely as major causes of mortality. Predation, primarily by lynx and wolverine, appears to be the most plausible reason for the high female mortality and state of collapse in the studied reindeer herding community.
Resumo:
Determining the provenance of data, i.e. the process that led to that data, is vital in many disciplines. For example, in science, the process that produced a given result must be demonstrably rigorous for the result to be deemed reliable. A provenance system supports applications in recording adequate documentation about process executions to answer queries regarding provenance, and provides functionality to perform those queries. Several provenance systems are being developed, but all focus on systems in which the components are textitreactive, for example Web Services that act on the basis of a request, job submission system, etc. This limitation means that questions regarding the motives of autonomous actors, or textitagents, in such systems remain unanswerable in the general case. Such questions include: who was ultimately responsible for a given effect, what was their reason for initiating the process and does the effect of a process match what was intended to occur by those initiating the process? In this paper, we address this limitation by integrating two solutions: a generic, re-usable framework for representing the provenance of data in service-oriented architectures and a model for describing the goal-oriented delegation and engagement of agents in multi-agent systems. Using these solutions, we present algorithms to answer common questions regarding responsibility and success of a process and evaluate the approach with a simulated healthcare example.