Optimization heuristic solutions, how good can they be? : With empirical applications in location problems

Combinatorial optimization problems, are one of the most important types of problems in operational research. Heuristic and metaheuristics algorithms are widely applied to find a good solution. However, a common problem is that these algorithms do not guarantee that the solution will coincide with the optimum and, hence, many solutions to real world OR-problems are afflicted with an uncertainty about the quality of the solution. The main aim of this thesis is to investigate the usability of statistical bounds to evaluate the quality of heuristic solutions applied to large combinatorial problems. The contributions of this thesis are both methodological and empirical. From a methodological point of view, the usefulness of statistical bounds on p-median problems is thoroughly investigated. The statistical bounds have good performance in providing informative quality assessment under appropriate parameter settings. Also, they outperform the commonly used Lagrangian bounds. It is demonstrated that the statistical bounds are shown to be comparable with the deterministic bounds in quadratic assignment problems. As to empirical research, environment pollution has become a worldwide problem, and transportation can cause a great amount of pollution. A new method for calculating and comparing the CO2-emissions of online and brick-and-mortar retailing is proposed. It leads to the conclusion that online retailing has significantly lesser CO2-emissions. Another problem is that the Swedish regional division is under revision and the border effect to public service accessibility is concerned of both residents and politicians. After analysis, it is shown that borders hinder the optimal location of public services and consequently the highest achievable economic and social utility may not be attained.

Är variation i STFI-tjocklek ett bra mått på kartongs bulighet? : Are variation in STFI-thickness a good measure of uneven surface, bumpiness, on cardboard?

This degree project aim to evaluate if variations of the STFI thickness can be used to assess bumpiness on cardboard. During the project cardboard samples were measured using Bendtsen, PPS, a L&W formation tester, OptiTopo, Ambertec formation, the STFI thickness tester and a visual comparison. The different methods were then compared to see if there is any correlations between them. The results showed that the visual comparison and OptiTopo correlates. The STFI thickness tester shows however no correlation with the OptiTopo and visual comparison, thus aren't suitable measuring bumpiness.

Speak Good English Movement in Singapore : Reactions in Social and Traditional Media

The first Speak Good English Movement, SGEM, took place in 2000, and has been organized annually ever since. Speaking a “standard” form of English is considered to bring increased personal power. However, the SGEM wants the Singaporeans to use “standard” English in their private life as well. A decade after the beginning of the campaign, a Speak Good Singlish Movement was started. Based on studies of language and identity, it is understandable why some Singaporeans might feel the SGEM threatens their identity. However, the reactions towards the campaign are mainly positive. For the purposes of this analysis, Twitter messages, Facebook pages, and newspaper articles from The Straits Times were collected. The SGEM has hailed both direct and indirect praise and criticism in both social and traditional media: Five newspaper articles praise the campaign while five criticize it; the results are nine and seven respectively for social media. This thesis looks at reactions towards the SGEM in both social and traditional media, analyzes how these reactions might relate to the ideas of the power of language, its variety and the relation of language and identity.

Produktion, skador och grenegenskaper hos 10-årig tall i ett kombinerat förbands- och avkommeförsök : Volume production, damages and branch properties in a 10-year old combined spacing and progeny trial of Scots pine

A Scots pine (Pinus sylvestris) progeny trial was established in 1990, in the southwestern part of Sweden. The offspring was from 30 plus trees. The trial is located on abandoned agricultural land and has a single tree block design with a variation in spacing. The trial has been damaged by voles. At a tree age of ten years, growth, damages and branch properties were estimated. An analysis of variance on height, diameter and stem volume shows significant difference between spacing and progenies as well as interactions between these factors. As indicated by a better annual height increment and fewer and thinner branches at each whorl the densest spacing has the highest potential to produce quality logs.There were also differences between progenies in growth and quality traits. Some progenies combined good growth and branch characters with low mortality, straight stems and few damages. Other progenies had superior volume production.

Skicklig läs- och skrivundervisning i åk 1-3 : Om lärares möjligheter och hinder

This study focuses on teachers’ opportunities and obstacles to perform skillful reading and writing instruction. It’s about the ability to accurately identify where students are in their reading and writing process and to help them develop good reading skills. It is also about the ability to recognize signs of difficulties that students may have in their written language development and to know what efforts are needed to help them advance their reading and writing skills. The research is based on teachers’ own statements and survey responses on the external conditions for teaching and on their approach, attitudes and knowledge in reading and writing. The empirical material consists of interviews, surveys and test data. The interview study was conducted with eight teachers. The questionnaire was answered by 249 teachers, while the knowledge test was conducted of 269 teachers and 31 special education teachers. Many of the teachers in this study have lack knowledge in the structure of language and common Swedish spelling rules. Furthermore, it appears that a large part of them are unaccustomed to explaining, in detail, students’ reading development and find it difficult to systematically describe the aspects of daily literacy instruction. The overall picture is that many teachers teach without having tools to reflect on how their education really affects students’ reading and writing. These shortcomings make it difficult to conduct effective literacy instruction. Once students have learned to decode or if they have reading difficulties, many teachers seem to one-sidedly focus on getting students to read more. The consequence could be that those who would need to practice more on the technical basic of reading or comprehension strategies are left without support. Lack of variety and individuality in fluency and comprehension training can challenge the students’ reading and writing development. The teachers in the study, who have the old junior school teacher and elementary teacher education, have the highest amount of knowledge of reading and writing (the test). Good education can provide student teachers with professional skills that they may develop further in their careers. Knowledge of the meaning of phonological and phonemic awareness as well as knowledge of how to count phonemes seem to be important for knowledge of reading and writing (the test). Knowledge of basic reading processes can be obtained by systematic and structured work with students’ linguistic development, and through continuous dialogues with experienced colleagues on how and why questions. This is one important way to work also in teacher training. When essential professional skills are established in the teacher education, in practice students will obtain the school’s learning goals.

Formal caregivers' perceptions of quality of care for older people : associating factors

Background: Despite the growing number of studies concerning quality of care for older people, there is a lack of studies depicting factors associated with good quality of care from the formal caregivers' perspective. The aim was to describe formal caregivers' perceptions of quality of care for older people in the community and explore factors associated with these perceptions. In total, 70 nursing assistants, 163 enrolled nurses and 198 registered nurses from 14 communities in central Sweden participated in the study. They filled out the following questionnaires: a modified version of Quality from the Patient's Perspective, Creative Climate Questionnaire, Stress of Conscience Questionnaire, items regarding education and competence, Health Index and Sense of coherence questionnaire. The overall response rate was 57 % (n = 431). Results: In the perceived reality of quality of care respondents assessed the highest mean value in the dimension medical-technical competence and physical technical conditions and lower values in the dimensions; identity-oriented approach, socio-cultural atmosphere and in the context specific dimension. The caregivers estimated their competence and health rather high, had lower average values in sense of coherence and organizational climate and low values in stress of conscience. Conculsions: The PR of quality of care were estimated higher among NA/ENs compared to RNs. Occupation, organizational climate and stress of conscience were factors associated with quality of care that explained 42 % of the variance. Competence, general health and sense of coherence were not significantly associated to quality of care. The mentioned factors explaining quality of care might be intertwined and showed that formal caregivers' working conditions are of great importance for quality of care.

Informal sanctions and conditional cooperation: : A natural experiment on voluntary contributions to a public good.

In a natural experiment, this paper studies the impact of an informal sanctioning mechanism on individuals’ voluntary contribution to a public good. Cross-country skiers’ actual cash contributions in two ski resorts, one with and one without an informal sanctioning system, are used. I find the contributing share to be higher in the informal sanctioning system (79 percent) than in the non-sanctioning system (36 percent). Previous studies in one-shot public good situations have found an increasing conditional contribution (CC) function, i.e. the relationship between expected average contributions of other group members and the individual’s own contribution. In contrast, the present results suggest that the CC-function in the non-sanctioning system is non-increasing at high perceived levels of others’ contribution. This relationship deserves further testing in lab.