75 resultados para OPEN PROBLEMS IN TOPOLOGY
Resumo:
Polymeric materials have been used in dental applications for decades. Adhesion of polymeric materials to each other and to the tooth substrate is essential to their successful use. The aim of this series of studies was two-folded. First, to improve adhesion of poly(paraphenylene) based rigid rod polymer (RRP) to other dental polymers, and secondly, to evaluate the usability of a new dentin primer system based on RRP fillers. Poly(paraphenylene) based RRP would be a tempting material for dental applications because of its good mechanical properties. To be used in dental applications, reliable adhesion between RRP and other dental polymers is required. In this series of studies, the adhesion of RRP to denture base polymer and the mechanical properties of RRP-denture base polymer-material combination were evaluated. Also adhesion of BisGMA-TEGDMA-resin to RRP was determined. Different surface treatments were tested to improve the adhesion of BisGMA-TEGDMA-resin to RRP. Results were based on three-point bending testing, Vickers surface hardness test and scanning electron microscope analysis (SEM), which showed that no reliable adhesion between RRP and denture base polymer was formed. Addition of RRP filler to denture base polymer increased surface hardness and flexural modulus but flexural strength decreased. Results from the shear bond strength test and SEM revealed that adhesion between resin and RRP was possible to improve by surface treatment with dichloromethane (DCM) based primer and a new kind of adhesive surface can be designed. The current dentin bonding agents have good immediate bond strength, but in long term the bond strength may decrease due to the detrimental effect of water and perhaps by matrix metalloproteinases. This leads to problems in longevity of restorations. Current bonding agents use organic monomers. In this series of studies, RRP filled dentin primer was tested in order to decrease the water sorption of the monomer system of the primers. The properties of new dentin primer system were evaluated in vitro by comparing it to commercial etch and rinse adhesive system. The results from the contact angle measurements and SEM showed that experimental primer with RRP reinforcement provided similar resin infiltration to dentin collagen and formed the resin-dentin interface as the control primer. Microtensile bond strength test and SEM revealed that in short term water storing, RRP increased bond strength and primer with BMEP-monomer (bis[2-(methacryloyloxy)-ethyl]phosphate) and high solvent concentration provided comparable bonding properties to the commercial control primers. In long term water storing, the high solvent-monomer concentration of the experimental primers decreased bond strength. However, in low solvent-monomer concentration groups, the long-term water storing did not decrease the bond strength despite the existence of hydrophilic monomers which were used in the system. These studies demonstrated that new dentin primer system reached the mechanical properties of current traditional etch and rinse adhesive system in short time water storing. Improved properties can be achieved by further modifications of the monomer system. Studies of the adhesion of RRP to other polymers suggest that adhesion between RRP and other dental polymers is possible to obtain by certain surface treatments.
Resumo:
Preference relations, and their modeling, have played a crucial role in both social sciences and applied mathematics. A special category of preference relations is represented by cardinal preference relations, which are nothing other than relations which can also take into account the degree of relation. Preference relations play a pivotal role in most of multi criteria decision making methods and in the operational research. This thesis aims at showing some recent advances in their methodology. Actually, there are a number of open issues in this field and the contributions presented in this thesis can be grouped accordingly. The first issue regards the estimation of a weight vector given a preference relation. A new and efficient algorithm for estimating the priority vector of a reciprocal relation, i.e. a special type of preference relation, is going to be presented. The same section contains the proof that twenty methods already proposed in literature lead to unsatisfactory results as they employ a conflicting constraint in their optimization model. The second area of interest concerns consistency evaluation and it is possibly the kernel of the thesis. This thesis contains the proofs that some indices are equivalent and that therefore, some seemingly different formulae, end up leading to the very same result. Moreover, some numerical simulations are presented. The section ends with some consideration of a new method for fairly evaluating consistency. The third matter regards incomplete relations and how to estimate missing comparisons. This section reports a numerical study of the methods already proposed in literature and analyzes their behavior in different situations. The fourth, and last, topic, proposes a way to deal with group decision making by means of connecting preference relations with social network analysis.
Resumo:
The aim of the study was to create and evaluate an intervention programme for Tanzanian children from a low-income area who are at risk of reading and writing difficulties. The learning difficulties, including reading and writing difficulties, are likely to be behind many of the common school problems in Tanzania, but they are not well understood, and research is needed. The design of the study included an identification and intervention phase with follow-up. A group based dynamic assessment approach was used in identifying children at risk of difficulties in reading and writing. The same approach was used in the intervention. The study was a randomized experiment with one experimental and two control groups. For the experimental and the control groups, a total of 96 (46 girls and 50 boys) children from grade one were screened out of 301 children from two schools in a low income urban area of Dar-es-Salaam. One third of the children, the experimental group, participated in an intensive training programme in literacy skills for five weeks, six hours per week, aimed at promoting reading and writing ability, while the children in the control groups had a mathematics and art programme. Follow-up was performed five months after the intervention. The intervention programme and the tests were based on the Zambian BASAT (Basic Skill Assessment Tool, Ketonen & Mulenga, 2003), but the content was drawn from the Kiswahili school curriculum in Tanzania. The main components of the training and testing programme were the same, only differing in content. The training process was different from traditional training in Tanzanian schools in that principles of teaching and training in dynamic assessment were followed. Feedback was the cornerstone of the training and the focus was on supporting the children in exploring knowledge and strategies in performing the tasks. The experimental group improved significantly more (p = .000) than the control groups during the intervention from pre-test to follow-up (repeated measures ANOVA). No differences between the control groups were noticed. The effect was significant on all the measures: phonological awareness, reading skills, writing skills and overall literacy skills. A transfer effect on school marks in Kiswahili and English was found. Following a discussion of the results, suggestions for further research and adaptation of the programme are presented.
Resumo:
Open innovation is becoming increasingly popular in academic literature and in business life, but even if people heard about it, they might not understand what it really is, they may over-estimate it thinking that it is savior or underestimate it, concentrating on limitations and risks. Current work sheds light on most important concepts of open innovation theory. Goal of current research is to offer business processes improvement for both inbound and outbound modes in case company. It is relevant as open innovation proved to affect firms‘ performance in general case and in case company, and Nokia planned to develop open innovation implementation since 2008 but still competitors succeed in it more, therefore analysis of current situation with open innovation in Nokia and recommendations how to improve it are topical. Case study method was used to answer the question ―How open innovation processes can be improved?‖. 11 in-depth interviews with Nokia senior managers and independent consultants were used to reach the goal of the thesis, as well as secondary sources. Results of current work are as-is and to-be models (process models of today and best practices models) of several open innovation modes, and recommendation for case company, which will be presented to company representatives and checked for practical applicability.
Resumo:
The target of the thesis is to improve product profitability control in continuous IT-services. Accurate product cost accounting and correctly allocated revenues are a necessity for good product profitability control. The focus of the study is on costs and revenues that are not traced directly to services. The thesis is focused on revenue allocations as revenue allocation methods have not been used in the case company before. In order to achieve the target revenue allocation methods, which improve the product profitability accounting and control, are presented. The research methods used in the thesis are literature review and empirical case study. The research approach is constructive. The theoretical part is composed of literature and articles that create a base for the empirical part. Internal interviews describe the current situation in the company and based on it development actions are planned. The part of the empirical case study is seen mostly in the limitations as the research is limited to concern only one department in the company. Problems in the revenue tracing are caused by customer specific services and lack of service definitions because of which the revenues are not traced correctly. Methods to allocate revenues are presented in the thesis and stand-alone revenue allocation method is the most suitable one because it is fair and it can be modified. Approximate product profitability analysis is done in the thesis and the results of it indicate that some services are profitable and some unprofitable.
Resumo:
IT service catalog is an increasingly important issue as many IT organizations have been realizing it as a central communication and visualization tool to bridge the gap between IT and the business. This study reviews relevant literature on IT service catalog and related issues on IT services delivery. Furthermore, the study shows how IT service catalog can enhance IT effectiveness as well as provide more benefits when integrating with Configuration Management Database. In order to analyze whether IT service catalog is needed to be implemented in a Pan-Nordic Insurance Company, this study also investigates the current IT services delivery of a case study. The findings of the study show the problems in the current situation of IT services delivery in the case. The characteristics of IT service catalog are recommended in order to help with the mentioned flaws.
Resumo:
The intellectual property (IP) environment in China is still very immature. There are several problems in legal, political, economic, social-cultural, competitive and labor environment which have hindered IP legal enforcement. Under such circumstances, IP misappropriation is a major concern especially for foreign small and medium-sized enterprises (SMEs) doing business in China. These circumstances require foreign companies, no matter whether they are multinational corporations (MNCs) or SMEs and have own manufacturing in China or not, to take strong IP actions. Therefore, the purpose of this study is to discuss how IP can be protected in China in the case of outsourcing and in the case of own manufacturing. The comparison will consider the process of outsourcing and own manufacturing consisting two stages: preparation stage and operation stage. In order to clarify the conceptual arguments, two illustrative case studies were studied. The case data bases on two semi-structured interviews of the managing directors, field notes and archival data. The findings propose that attention in IP protection should be given to following issues: integrating IP strategy into the company’s business strategy, protecting the most critical knowledge, regarding IP steps as a whole in the protection mechanism and making IP strategy as proactive as possible. The major difference between outsourcing and own manufacturing in IP protection is in the operation stage. Besides, the findings also provide managerial advice on IP protection, e.g. foreign managers should be prepared for IP risks in China, they should establish an own IP protection mechanism which matches the company’s situation and they should consider IP protection as an on-going process.
Resumo:
Alcohol consumption during pregnancy can potentially affect the developing fetus in devastating ways, leading to a range of physical, neurological, and behavioral alterations most accurately termed Fetal Alcohol Spectrum Disorders (FASD). Despite the fact that it is a preventable disorder, prenatal alcohol exposure today constitutes a leading cause of intellectual disability in the Western world. In Western countries where prevalence studies have been performed the rates of FASD exceed, for example, autism spectrum disorders, Down’s syndrome and cerebral palsy. In addition to the direct effects of alcohol, children and adolescents with FASD are often exposed to a double burden in life, as their neurological sequelae are accompanied by adverse living surroundings exposing them to further environmental risk. However, children with FASD today remain remarkably underdiagnosed by the health care system. This thesis forms part of a larger multinational research project, The Collaborative Initiative on Fetal Alcohol Spectrum Disorders (the CIFASD), initiated by the National Institute of Alcohol Abuse and Alcoholism (NIAAA) in the U.S.A. The general aim of the present thesis was to examine a cohort of children and adolescents growing up with fetal alcohol-related damage in Finland. The thesis consists of five studies with a broad focus on diagnosis, cognition, behavior, adaptation and brain metabolic alterations in children and adolescents with FASD. The participants consisted of four different groups: one group with histories of prenatal exposure to alcohol, the FASD group; one IQ matched contrast group mostly consisting of children with specific learning disorder (SLD); and two typically-developing control groups (CON1 and CON2). Participants were identified through medical records, random sampling from the Finnish national population registry and email alerts to students. Importantly, the participants in the present studies comprise a group of very carefully clinically characterized children with FASD as the studies were performed in close collaboration with leading experts in the field (Prof. Edward Riley and Prof. Sarah Mattson, Center for Behavioral Teratology, San Diego State University, U.S.A; Prof. Eugene Hoyme, Sanford School of Medicine, University of South Dakota, U.S.A.). In the present thesis, the revised Institute of Medicine diagnostic criteria for FASD were tested on a Finnish population and found to be a reliable tool for differentiating among the subgroups of FASD. A weighted dysmorphology scoring system proved to be a valuable additional adjunct in quantification of growth deficits and dysmorphic features in children with FASD (Study 1). The purpose of Study 2 was to clarify the relationship between alcohol-related dysmorphic features and general cognitive capacity. Results showed a significant correlation between dysmorphic features and cognitive capacity, suggesting that children with more severe growth deficiency and dysmorphic features have more cognitive limitations. This association was, however, only moderate, indicating that physical markers and cognitive capacity not always go hand in hand in individuals with FASD. Behavioral problems in the FASD group proved substantial compared to the typically developing control group. In Study 3 risk and protective factors associated with behavioral problems in the FASD group were explored further focusing on diagnostic and environmental factors. Two groups with elevated risks for behavioral problems emerged: length of time spent in residential care and a low dysmorphology score proved to be the most pervasive risk factor for behavioral problems. The results underscore the clinical importance of appropriate services and care for less visibly alcohol affected children and highlight the need to attend to children with FASD being raised in institutions. With their background of early biological and psychological impairment compounded with less opportunity for a close and continuous caregiver relationship, such children seem to run an especially great risk of adverse life outcomes. Study 4 focused on adaptive abilities such as communication, daily living skills and social skills, in other words skills that are important for gradually enabling an independent life, maintain social relationships and allow the individual to become integrated into society. The results showed that adaptive abilities of children and adolescents growing up with FASD were significantly compromised compared to both typically-developing peers and IQ-matched children with SLD. Clearly different adaptive profiles were revealed where the FASD group performed worse than the SLD group, who in turn performed worse than the CON1 group. Importantly, the SLD group outperformed the FASD group on adaptive behavior in spite of comparable cognitive levels. This is the first study to compare adaptive abilities in a group of children and adolescents with FASD relative to both a contrast group of IQ-matched children with SLD and to a group of typically-developing peers. Finally, in Study 5, through magnetic resonance spectroscopic imaging (MRS) evidence of longstanding neurochemical alterations were observed in adolescents and young adults with FASD related to alcohol exposure in utero 14-20 years earlier. Neurochemical alterations were seen in several brain areas: in frontal and parietal cortices, corpus callosum, thalamus and frontal white matter areas as well as in the cerebellar dentate nucleus. The findings are compatible with neuropsychological findings in FASD. Glial cells seemed to be more affected than neurons. In conclusion, more societal efforts and resources should be focused on recognizing and diagnosing FASD, and supporting subgroups with elevated risk of poor outcome. Without adequate intervention children and adolescents with FASD run a great risk of marginalization and social maladjustment, costly not only to society but also to the lives of the many young people with FASD.
Resumo:
Foot health is a part of overall health in every age group and its importance increases during ageing. Health care professionals are in a vital position for preventing foot health problems, and identifying and caring them in older people. Despite the rather high number of studies conducted in the field of foot health in older people, reliable and valid nurse-administered foot health assessment instruments seem to be lacking. By identifying foot health in older people, it is possible to develop nursing interventions to enhance safe, independent living at home. The purpose of this three-phase study was to develop an instrument to assess the level of foot health in older people and evaluate foot care practices from the perspective of older people themselves and nurses in home care. The ultimate goal is to prevent foot health problems by increasing the attention paid to older people’s feet and recognizing those foot health problems which need further care; thus not focus on different foot health problems. The study was conducted in different phases and contexts. In phase 1, a descriptive design with a literature review from the Medline (R) and CINAHL databases to explore foot health in older people and nurses’ role in foot health care and pre-post design intervention study in nursing home with nursing staff (n=16) and older residents (n=43) were conducted. In phase 2, a descriptive and explorative study design was employed to develop an instrument for assessing foot health in older people (N=651, n=309, response rate 47%) and explore the psychometrics of the instrument. The data were collected from sheltered housing and home care settings. Finally, in phase 3, descriptive and explorative as well as cross-sectional correlational survey designs were used to assess foot health and evaluate the foot self-care activities of older people (N=651, n=309, response rate 47%) and to describe foot care knowledge and caring activities of nurses (N=651, n=322, response rate 50%) in home care in Finland. To achieve this, the Foot Health Assessment Instrument (FHAI) developed in phase 2 was used; at the same time, this large sample also was used for the psychometric evaluation of the FHAI. The data analysis methods used in this study were content analysis, descriptive and inferential statistics including factor and multivariate analysis. Many long-term diseases can manifest in feet. Therefore, the FHAI, developed in this study consisted of items relating to skin and nail health, foot structure and foot pain. The FHAI demonstrated acceptable preliminary psychometric properties. A great deal of different foot health problems in older people were found of which edema, dry skin, thickened and discoloured toenails and hallux valgus were the most prevalent foot health problems. Moreover, many older people had difficulties in performing foot self-care. Nurses’ knowledge of foot care was insufficient and revealed a need for more information and continuing education in matters relating to foot care in older people. Instead, nurses’ foot care activities were mainly adequate, though the findings indicate the need for updating foot care activities to correspond with the evidence found in the field of foot care. Practical implications are presented for nursing practice, education and administration. In future, research should focus on developing interventions for older people and nurses to promote foot health in older people and to prevent foot health problems, as well as for further development of the FHAI.
Resumo:
When modeling machines in their natural working environment collisions become a very important feature in terms of simulation accuracy. By expanding the simulation to include the operation environment, the need for a general collision model that is able to handle a wide variety of cases has become central in the development of simulation environments. With the addition of the operating environment the challenges for the collision modeling method also change. More simultaneous contacts with more objects occur in more complicated situations. This means that the real-time requirement becomes more difficult to meet. Common problems in current collision modeling methods include for example dependency on the geometry shape or mesh density, calculation need increasing exponentially in respect to the number of contacts, the lack of a proper friction model and failures due to certain configurations like closed kinematic loops. All these problems mean that the current modeling methods will fail in certain situations. A method that would not fail in any situation is not very realistic but improvements can be made over the current methods.
Resumo:
The purpose of this study is to determine what are the key barriers hampering ESCO service business success in Finland. Research approach for this study is qualitative. Data was collected using Delphi method with two questionnaire rounds. Internet based tool was applied in carrying out questionnaires. Respondents of the questionnaires were ESCO service experts and researchers, and people working for ESCO service providers. Characteristics of ESCO service and ESCO project implementation are analyzed by using transaction costs theory of service business. In terms of ESCO service in Finland, uncertainty and asset specificity are relevant dimensions of TCE. General uncertainty in world’s economy hinders demand for ESCO service, and asset specificity of ESCO contracts induces slight problems for project financiers. Also bounded rationalism and opportunism are present in Finnish ESCO business. The most significant barriers of success of ESCO service in Finland are problems in legislative and political frameworks, and in customers’ investment processes. ESCO service providers should move more strongly towards service dominant business logic and improve understanding of customer needs. Political barriers are unsuitable procurement processes, unclear and unpredictable laws, and lack of compelling factors in subsidy system. Investment process hurdles are caused by customers’ lack of interest to change course of action. These are things in which ESCOs can have influence in.
Resumo:
Open data refers to publishing data on the web in machine-readable formats for public access. Using open data, innovative applications can be developed to facilitate people‟s lives. In this thesis, based on the open data cases (discussed in the literature review), Open Data Lappeenranta is suggested, which publishes open data related to opening hours of shops and stores in Lappeenranta City. To prove the possibility of creating Open Data Lappeenranta, the implementation of an open data system is presented in this thesis, which publishes specific data related to shops and stores (including their opening hours) on the web in standard format (JSON). The published open data is used to develop web and mobile applications to demonstrate the benefits of open data in practice. Also, the open data system provides manual and automatic interfaces which make it possible for shops and stores to maintain their own data in the system. Finally in this thesis, the completed version of Open Data Lappeenranta is proposed, which publishes open data related to other fields and businesses in Lappeenranta beyond only stores‟ data.
Resumo:
Dental caries and dental fear and anxiety (DFA) are common interrelated problems but so far little is known about these problems in Estonia. The aim was to study dental health in relation to DFA, some fear-related factors, and to study the effect of a caries prevention program in children of fearful mothers. Dental health and DFA were assessed in two Estonian [2-4-year-olds (n=472) and 8-10-year-olds (n=344)], and the effect of some medical conditions on DFA in one Finnish child group [3-year-olds (n=148)]. 120 mother-child-pairs participated in the xylitol-based prevention program. Dental health was examined using the WHO or the ICDAS criteria and expressed as dmft/DMFT-indices. The modified children’s fear survey schedule dental subscale (MCFSS-DS) was used to assess DFA of schoolchildren, one single question to assess parental DFA, and the Corah’s dental anxiety scale (DAS) to assess DFA of mothers in the prevention study. Dentine caries was diagnosed in 42% of the 2-4-year-old and in 93% of the 8-10-year-old Estonian children. DFA of 8-10-year-olds (17%) was associated with experience of dental treatment, and maternal and paternal DFA. Dental apprehension at 9 years of age was associated with frequent exposure to invasive medical care. The xylitol-based prevention was successful irrespective of poor dental hygiene habits and maternal severe DFA. In conclusion, experience of operative dental treatment and DFA of Estonian children were closely associated. Invasive medical care and parental DFA were also linked to children’s DFA. Habitual use of xylitol by mothers was effective in preventing caries even in children of severely fearful mothers.
Resumo:
Wood contains only a very small amount of lipophilic extractives, commonly known as wood pitch. The pitch is known to cause severe problems in papermaking processes. The amount of pitch in process waters can be decreased by seasoning of the raw material prior to pulping, pulp washing, removal of pitch by flotation, adsorption of pitch onto various mineral surfaces, and retention of pitch to the fibre material by cationic polymers. The aim of this study was to determine the influence of pH on some of the methods used for pitch control. Experiments were performed using laboratory-made wood pitch emulsions with varying pH, salt concentration, hemicellulose concentration and pitch composition. These emulsions were used to study the phase distribution of resin and fatty acids, the colloidal stability of pitch with and without steric stabilisation by galactoglucomannans, and the interactions between wood pitch and mineral particles. Purification of unbleached and peroxidebleached mill process water was performed by froth flotation in combination with a foaming agent. The distribution of resin and fatty acids (RFAs) between colloidal pitch droplets and the water phase was very dependent on pH. At pH 3, almost all of the RFAs were attached to the pitch droplets, while increasing the pH led to increasing concentration of dissolved RFAs in the water phase. The presence of salt shifted the release of RFAs towards higher pH, while lower ratio of neutral pitch in the emulsion resulted in release of RFAs at lower pH. It was also seen that the dissolution and adsorption of RFAs at sudden pHchanges takes place very quickly. Colloidal pitch was more stable against electrolyte-induced aggregation at higher pH, due to its higher anionic charge. The concentration of cationic polymers needed to aggregate colloidal pitch also increased with increasing pH. The surface characteristics of solid particles, such as amount of charged groups, were very important for understanding their interactions with colloidal wood pitch. Water-soluble galactoglucomannans stabilised the colloidal pitch sterically against aggregation, but could not completely prevent interactions between wood pitch and hydrophilic particles. Froth flotation of unbleached and peroxidebleached process water showed that the pitch could be removed more effectively and selectively at low pH, compared to at neutral pH. The pitch was removed more effectively, using lower concentrations of foaming agent, from peroxide-bleached water than from unbleached water. The results show that pH has a major impact on various pulping and papermaking processes. It determines the anionic charge of the colloidal pitch and the solubility of certain pitch components. Because of this, the pH influences the effectiveness of pitch retention and removal of pitch. The results indicate that pitch problems could be diminished by acknowledging the importance of pH in various papermaking processes.
Resumo:
Wind power is a low-carbon energy production form that reduces the dependence of society on fossil fuels. Finland has adopted wind energy production into its climate change mitigation policy, and that has lead to changes in legislation, guidelines, regional wind power areas allocation and establishing a feed-in tariff. Wind power production has indeed boosted in Finland after two decades of relatively slow growth, for instance from 2010 to 2011 wind energy production increased with 64 %, but there is still a long way to the national goal of 6 TWh by 2020. This thesis introduces a GIS-based decision-support methodology for the preliminary identification of suitable areas for wind energy production including estimation of their level of risk. The goal of this study was to define the least risky places for wind energy development within Kemiönsaari municipality in Southwest Finland. Spatial multicriteria decision analysis (SMCDA) has been used for searching suitable wind power areas along with many other location-allocation problems. SMCDA scrutinizes complex ill-structured decision problems in GIS environment using constraints and evaluation criteria, which are aggregated using weighted linear combination (WLC). Weights for the evaluation criteria were acquired using analytic hierarchy process (AHP) with nine expert interviews. Subsequently, feasible alternatives were ranked in order to provide a recommendation and finally, a sensitivity analysis was conducted for the determination of recommendation robustness. The first study aim was to scrutinize the suitability and necessity of existing data for this SMCDA study. Most of the available data sets were of sufficient resolution and quality. Input data necessity was evaluated qualitatively for each data set based on e.g. constraint coverage and attribute weights. Attribute quality was estimated mainly qualitatively by attribute comprehensiveness, operationality, measurability, completeness, decomposability, minimality and redundancy. The most significant quality issue was redundancy as interdependencies are not tolerated by WLC and AHP does not include measures to detect them. The third aim was to define the least risky areas for wind power development within the study area. The two highest ranking areas were Nordanå-Lövböle and Påvalsby followed by Helgeboda, Degerdal, Pungböle, Björkboda, and Östanå-Labböle. The fourth aim was to assess the recommendation reliability, and the top-ranking two areas proved robust whereas the other ones were more sensitive.