982 resultados para Methodological problems


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Children’s pain symptoms and sleep problems are among the most common health complaints. They distract children from activities, decrease the quality of life, contribute to a significant economic burden, and have shown continuity into adulthood. The main aims of this thesis were to investigate long-term changes in the prevalence of pain symptoms and sleep problems among Finnish school-aged children, and the later mental health of those who in childhood experience pain. Prevalence, co-occurrence, and associated psychosocial factors of pain symptoms and sleep problems were also assessed. In study I, prevalence changes in eight-year-old children’s pain symptoms and sleep problems were investigated in three cross-sectional population-based samples (years 1989: n=1038, 1999: n=1035, and 2005: n=1030). In study II, cross-sectional associations between pain symptoms, sleep problems, and psychosocial factors were assessed among 13-18-year-old adolescents (n=2476). In studies III and IV, associations between pain symptoms at age eight (n=6017), and register-based data on antidepressant use and severe suicidality by age 24, were examined in a nationwide birth cohort. Pain symptoms and sleep problems were common and often co-occurred. A considerable number of children’s pain symptoms remained unrecognized by the parents. The prevalence of pain symptoms, sleep problems, and multiple concurrent symptoms approximately doubled from 1989 to 2005. Psychiatric difficulties or demographic factors did not explain the increase. Psychosocial factors that were associated with pain, sleep problems, and a higher number of symptoms, were female sex, psychological difficulties, emotional symptoms, smoking, victimization, and feeling not cared about by teachers. In longitudinal analyses, the child’s own report of headache, and to a smaller degree the parental report of the child’s abdominal pain predicted later antidepressant use. Parental report of the child’s abdominal pain predicted severe suicidality among males. If one of the symptoms is present, health care professionals should inquire about other symptoms as well. Questions should be directed to the children, not only to their parents. Inquiring about psychiatric difficulties, substance use, victimization, and relations with teachers should be included as a part of the assessment. Further studies are needed to clarify the reasons that underlie the increased prevalence rates, and the factors that may increase or decrease the risk for later mental health problems among pain-suffering children.

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Statistical analyses of measurements that can be described by statistical models are of essence in astronomy and in scientific inquiry in general. The sensitivity of such analyses, modelling approaches, and the consequent predictions, is sometimes highly dependent on the exact techniques applied, and improvements therein can result in significantly better understanding of the observed system of interest. Particularly, optimising the sensitivity of statistical techniques in detecting the faint signatures of low-mass planets orbiting the nearby stars is, together with improvements in instrumentation, essential in estimating the properties of the population of such planets, and in the race to detect Earth-analogs, i.e. planets that could support liquid water and, perhaps, life on their surfaces. We review the developments in Bayesian statistical techniques applicable to detections planets orbiting nearby stars and astronomical data analysis problems in general. We also discuss these techniques and demonstrate their usefulness by using various examples and detailed descriptions of the respective mathematics involved. We demonstrate the practical aspects of Bayesian statistical techniques by describing several algorithms and numerical techniques, as well as theoretical constructions, in the estimation of model parameters and in hypothesis testing. We also apply these algorithms to Doppler measurements of nearby stars to show how they can be used in practice to obtain as much information from the noisy data as possible. Bayesian statistical techniques are powerful tools in analysing and interpreting noisy data and should be preferred in practice whenever computational limitations are not too restrictive.

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By coupling the Boundary Element Method (BEM) and the Finite Element Method (FEM) an algorithm that combines the advantages of both numerical processes is developed. The main aim of the work concerns the time domain analysis of general three-dimensional wave propagation problems in elastic media. In addition, mathematical and numerical aspects of the related BE-, FE- and BE/FE-formulations are discussed. The coupling algorithm allows investigations of elastodynamic problems with a BE- and a FE-subdomain. In order to observe the performance of the coupling algorithm two problems are solved and their results compared to other numerical solutions.

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It is well known that the numerical solutions of incompressible viscous flows are of great importance in Fluid Dynamics. The graphics output capabilities of their computational codes have revolutionized the communication of ideas to the non-specialist public. In general those codes include, in their hydrodynamic features, the visualization of flow streamlines - essentially a form of contour plot showing the line patterns of the flow - and the magnitudes and orientations of their velocity vectors. However, the standard finite element formulation to compute streamlines suffers from the disadvantage of requiring the determination of boundary integrals, leading to cumbersome implementations at the construction of the finite element code. In this article, we introduce an efficient way - via an alternative variational formulation - to determine the streamlines for fluid flows, which does not need the computation of contour integrals. In order to illustrate the good performance of the alternative formulation proposed, we capture the streamlines of three viscous models: Stokes, Navier-Stokes and Viscoelastic flows.

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Products developed at industries, institutes and research centers are expected to have high level of quality and performance, having a minimum waste, which require efficient and robust tools to numerically simulate stringent project conditions with great reliability. In this context, Computational Fluid Dynamics (CFD) plays an important role and the present work shows two numerical algorithms that are used in the CFD community to solve the Euler and Navier-Stokes equations applied to typical aerospace and aeronautical problems. Particularly, unstructured discretization of the spatial domain has gained special attention by the international community due to its ease in discretizing complex spatial domains. This work has the main objective of illustrating some advantages and disadvantages of numerical algorithms using structured and unstructured spatial discretization of the flow governing equations. Numerical methods include a finite volume formulation and the Euler and Navier-Stokes equations are applied to solve a transonic nozzle problem, a low supersonic airfoil problem and a hypersonic inlet problem. In a structured context, these problems are solved using MacCormack’s implicit algorithm with Steger and Warming’s flux vector splitting technique, while, in an unstructured context, Jameson and Mavriplis’ explicit algorithm is used. Convergence acceleration is obtained using a spatially variable time stepping procedure.

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In this work, we present the solution of a class of linear inverse heat conduction problems for the estimation of unknown heat source terms, with no prior information of the functional forms of timewise and spatial dependence of the source strength, using the conjugate gradient method with an adjoint problem. After describing the mathematical formulation of a general direct problem and the procedure for the solution of the inverse problem, we show applications to three transient heat transfer problems: a one-dimensional cylindrical problem; a two-dimensional cylindrical problem; and a one-dimensional problem with two plates.

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In this work it is presented a systematic procedure for constructing the solution of a large class of nonlinear conduction heat transfer problems through the minimization of quadratic functionals like the ones usually employed for linear descriptions. The proposed procedure gives rise to an efficient and easy way for carrying out numerical simulations of nonlinear heat transfer problems by means of finite elements. To illustrate the procedure a particular problem is simulated by means of a finite element approximation.

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The goals of the study were to describe patients’ perceptions of care after experiencing seclusion/restraint and their quality of life. The goal was moreover to identify methodological challenges related to studies from the perspective of coerced patients. The study was conducted in three phases between September 2008 and April 2012. In the first phase, the instrument Secluded/ Restrained Patients’ Perception of their Treatment (SR-PPT) was developed and validated in Japan in cooperation with a Finnish research group (n = 56). Additional data were collected over one year from secluded/restrained patients using the instrument (n = 90). In the second phase, data were collected during the discharge process (n = 264). In the third phase, data were collected from electronic databases. Methodological and ethical issues were reviewed (n = 32) using systematic review method. Patients perceived that co-operation with the staff was poor; patients’ opinions were not taken into account, treatment targets collated and treatment methods were seen in different ways. Patients also felt that their concerns were not well enough understood. However, patients received getting nurses’ time. In particular, seclusion/restraint was considered unnecessary. The patients felt that they benefited from the isolation in treating their problems more than they needed it, even if the benefit was seen to be minor. Patients treated on forensic wards rated their treatment and care significantly lower than in general units. During hospitalization secluded/restrained patients evaluated their quality of life, however, better than did non-secluded/restrained patients. However, no conclusion is drawn to the effect that the better quality of life assessment is attributable to the seclusion/restraint because patients’ treatment period after the isolation was long and because of many other factors, as rehabilitation, medication, diagnostic differences, and adaptation. According to the systematic mixed studies review variation between study designs was found to be a methodological challenge. This makes comparison of the results more difficult. A research ethical weakness is conceded as regards descriptions of the ethical review process (44 %) and informed consent (32 %). It can be concluded that patients in psychiatric hospital care and having a voice as an equal expert require special attention to clinical nursing, decision-making and service planning. Patients and their family members will be consulted in plans of preventive and alternative methods for seclusion and restraint. The study supports the theory that in ethical decision-making situations account should be taken of medical indications, in addition to the patients’ preferences, the effect of treatment on quality of life, and this depends on other factors. The connection between treatment decisions and a patient’s quality of life should be evaluated more structurally in practice. Changing treatment culture towards patients’ involvement will support daily life in nursing and service planning taking into account improvements in patients’ quality of life.

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The Arctic region becoming very active area of the industrial developments since it may contain approximately 15-25% of the hydrocarbon and other valuable natural resources which are in great demand nowadays. Harsh operation conditions make the Arctic region difficult to access due to low temperatures which can drop below -50 °C in winter and various additional loads. As a result, newer and modified metallic materials are implemented which can cause certain problems in welding them properly. Steel is still the most widely used material in the Arctic regions due to high mechanical properties, cheapness and manufacturability. Moreover, with recent steel manufacturing development it is possible to make up to 1100 MPa yield strength microalloyed high strength steel which can be operated at temperatures -60 °C possessing reasonable weldability, ductility and suitable impact toughness which is the most crucial property for the Arctic usability. For many years, the arc welding was the most dominant joining method of the metallic materials. Recently, other joining methods are successfully implemented into welding manufacturing due to growing industrial demands and one of them is the laser-arc hybrid welding. The laser-arc hybrid welding successfully combines the advantages and eliminates the disadvantages of the both joining methods therefore produce less distortions, reduce the need of edge preparation, generates narrower heat-affected zone, and increase welding speed or productivity significantly. Moreover, due to easy implementation of the filler wire, accordingly the mechanical properties of the joints can be manipulated in order to produce suitable quality. Moreover, with laser-arc hybrid welding it is possible to achieve matching weld metal compared to the base material even with the low alloying welding wires without excessive softening of the HAZ in the high strength steels. As a result, the laser-arc welding methods can be the most desired and dominating welding technology nowadays, and which is already operating in automotive and shipbuilding industries with a great success. However, in the future it can be extended to offshore, pipe-laying, and heavy equipment industries for arctic environment. CO2 and Nd:YAG laser sources in combination with gas metal arc source have been used widely in the past two decades. Recently, the fiber laser sources offered high power outputs with excellent beam quality, very high electrical efficiency, low maintenance expenses, and higher mobility due to fiber optics. As a result, fiber laser-arc hybrid process offers even more extended advantages and applications. However, the information about fiber or disk laser-arc hybrid welding is very limited. The objectives of the Master’s thesis are concentrated on the study of fiber laser-MAG hybrid welding parameters in order to understand resulting mechanical properties and quality of the welds. In this work only ferrous materials are reviewed. The qualitative methodological approach has been used to achieve the objectives. This study demonstrates that laser-arc hybrid welding is suitable for welding of many types, thicknesses and strength of steels with acceptable mechanical properties along very high productivity. New developments of the fiber laser-arc hybrid process offers extended capabilities over CO2 laser combined with the arc. This work can be used as guideline in hybrid welding technology with comprehensive study the effect of welding parameter on joint quality.

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Vaikka liiketoimintatiedon hallintaa sekä johdon päätöksentekoa on tutkittu laajasti, näiden kahden käsitteen yhteisvaikutuksesta on olemassa hyvin rajallinen määrä tutkimustietoa. Tulevaisuudessa aiheen tärkeys korostuu, sillä olemassa olevan datan määrä kasvaa jatkuvasti. Yritykset tarvitsevat jatkossa yhä enemmän kyvykkyyksiä sekä resursseja, jotta sekä strukturoitua että strukturoimatonta tietoa voidaan hyödyntää lähteestä riippumatta. Nykyiset Business Intelligence -ratkaisut mahdollistavat tehokkaan liiketoimintatiedon hallinnan osana johdon päätöksentekoa. Aiemman kirjallisuuden pohjalta, tutkimuksen empiirinen osuus tunnistaa liiketoimintatiedon hyödyntämiseen liittyviä tekijöitä, jotka joko tukevat tai rajoittavat johdon päätöksentekoprosessia. Tutkimuksen teoreettinen osuus johdattaa lukijan tutkimusaiheeseen kirjallisuuskatsauksen avulla. Keskeisimmät tutkimukseen liittyvät käsitteet, kuten Business Intelligence ja johdon päätöksenteko, esitetään relevantin kirjallisuuden avulla – tämän lisäksi myös dataan liittyvät käsitteet analysoidaan tarkasti. Tutkimuksen empiirinen osuus rakentuu tutkimusteorian pohjalta. Tutkimuksen empiirisessä osuudessa paneudutaan tutkimusteemoihin käytännön esimerkein: kolmen tapaustutkimuksen avulla tutkitaan sekä kuvataan toisistaan irrallisia tapauksia. Jokainen tapaus kuvataan sekä analysoidaan teoriaan perustuvien väitteiden avulla – nämä väitteet ovat perusedellytyksiä menestyksekkäälle liiketoimintatiedon hyödyntämiseen perustuvalle päätöksenteolle. Tapaustutkimusten avulla alkuperäistä tutkimusongelmaa voidaan analysoida tarkasti huomioiden jo olemassa oleva tutkimustieto. Analyysin tulosten avulla myös yksittäisiä rajoitteita sekä mahdollistavia tekijöitä voidaan analysoida. Tulokset osoittavat, että rajoitteilla on vahvasti negatiivinen vaikutus päätöksentekoprosessin onnistumiseen. Toisaalta yritysjohto on tietoinen liiketoimintatiedon hallintaan liittyvistä positiivisista seurauksista, vaikka kaikkia mahdollisuuksia ei olisikaan hyödynnetty. Tutkimuksen merkittävin tulos esittelee viitekehyksen, jonka puitteissa johdon päätöksentekoprosesseja voidaan arvioida sekä analysoida. Despite the fact that the literature on Business Intelligence and managerial decision-making is extensive, relatively little effort has been made to research the relationship between them. This particular field of study has become important since the amount of data in the world is growing every second. Companies require capabilities and resources in order to utilize structured data and unstructured data from internal and external data sources. However, the present Business Intelligence technologies enable managers to utilize data effectively in decision-making. Based on the prior literature, the empirical part of the thesis identifies the enablers and constraints in computer-aided managerial decision-making process. In this thesis, the theoretical part provides a preliminary understanding about the research area through a literature review. The key concepts such as Business Intelligence and managerial decision-making are explored by reviewing the relevant literature. Additionally, different data sources as well as data forms are analyzed in further detail. All key concepts are taken into account when the empirical part is carried out. The empirical part obtains an understanding of the real world situation when it comes to the themes that were covered in the theoretical part. Three selected case companies are analyzed through those statements, which are considered as critical prerequisites for successful computer-aided managerial decision-making. The case study analysis, which is a part of the empirical part, enables the researcher to examine the relationship between Business Intelligence and managerial decision-making. Based on the findings of the case study analysis, the researcher identifies the enablers and constraints through the case study interviews. The findings indicate that the constraints have a highly negative influence on the decision-making process. In addition, the managers are aware of the positive implications that Business Intelligence has for decision-making, but all possibilities are not yet utilized. As a main result of this study, a data-driven framework for managerial decision-making is introduced. This framework can be used when the managerial decision-making processes are evaluated and analyzed.

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Objective of the study The aim of this study is to understand the institutional implications in Abenomics in a spatial context, the contemporary economic reform taking place in Japan, which is to finally end over two decades of economic malaise. For theoretical perspective of choice, this study explores a synthesis of institutionalism as the main approach, complemented by economies of agglomeration in spatial economics, or New Economic Geography (NEG). The outcomes include a narrative with implications for future research, as well as possible future implications for the economy of Japan, itself. The narrative seeks to depict the dialogue between public discourse and governmental communication in order to create a picture of how this phenomenon is being socially constructed. This is done by studying the official communications by the Cabinet along with public media commentary on respective topics. The reform is studied with reference to historical socio-cultural, economic evolution of Japan, which in turn, is explored through a literature review. This is to assess the unique institutional characteristics of Japan pertinent to reform. Research method This is a social and exploratory qualitative study – an institutional narrative case study. The methodological approach was kept practical: in addition to literature review, a narrative, thematic content analysis with structural emphasis was used to construct the contemporary narrative based on the Cabinet communication. This was combined with practical analytic tools borrowed from critical discourse analysis, which were utilized to assess the implicit intertextual agenda within sources. Findings What appears to characterize the discourse is status quo bias that comes in multiple forms. The bias is also coded in the institutions surrounding the reform, wherein stakeholders have vested interests in protecting the current state of affairs. This correlates with uncertainty avoidance characteristic to Japan. Japan heeds the international criticism to deregulate on a rhetorical level, but consistent with history, the Cabinet solutions appear increasingly bureaucratic. Hence, the imposed western information-age paradigm of liberal cluster agglomeration seems ill-suited to Japan which lacks risk takers and a felicitous entrepreneur culture. The Japanese, however, possess vast innovative potential ascribed to some institutional practices and traits, but restrained by others. The derived conclusion is to study the successful intrapreneur cases in Japanese institutional setting as a potential benchmark for Japan specific cluster agglomeration, and a solution to its structural problems impeding growth.

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In today’s world because of the rapid advancement in the field of technology and business, the requirements are not clear, and they are changing continuously in the development process. Due to those changes in the requirements the software development becomes very difficult. Use of traditional software development methods such as waterfall method is not a good option, as the traditional software development methods are not flexible to requirements and the software can be late and over budget. For developing high quality software that satisfies the customer, the organizations can use software development methods, such as agile methods which are flexible to change requirements at any stage in the development process. The agile methods are iterative and incremental methods that can accelerate the delivery of the initial business values through the continuous planning and feedback, and there is close communication between the customer and developers. The main purpose of the current thesis is to find out the problems in traditional software development and to show how agile methods reduced those problems in software development. The study also focuses the different success factors of agile methods, the success rate of agile projects and comparison between traditional and agile software development.

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Cross-sector collaboration and partnerships have become an emerging and desired strategy in addressing huge social and environmental challenges. Despite its popularity, cross-sector collaboration management has proven to be very challenging. Even though cross-sector collaboration and partnership management have been widely studied and discussed in recent years, their effectiveness as well as their ability to create value with respect to the problems they address has remained very challenging. There is little or no evidence of their ability to create value. Regarding all these challenges, this study aims to explore how to manage cross-sector collaborations and partnerships to be able to improve their effectiveness and to create more value for all partners involved in collaboration as well as for customers. The thesis is divided into two parts. The first part comprises an overview of relevant literature (including strategic management, value networks and value creation theories), followed by presenting the results of the whole thesis and the contribution made by the study. The second part consists of six research publications, including both quantitative and qualitative studies. The chosen research strategy is triangulation, as the study includes four types of triangulation: (1) theoretical triangulation, (2) methodological triangulation, (3) data triangulation and (4) researcher triangulation. Two publications represent conceptual development, which are based on secondary data research. One publication is a quantitative study, carried out through a survey. The other three publications represent qualitative studies, based on case studies, where data was collected through interviews and workshops, with participation of managers from all three sectors: public, private and the third (nonprofit). The study consolidates the field of “strategic management of value networks,” which is proposed to be applied in the context of cross-sector collaboration and partnerships, with the aim of increasing their effectiveness and the process of value creation. Furthermore, the study proposes a first definition for the strategic management of value networks. The study also proposes and develops two strategy tools that are recommended to be used for the strategic management of value networks in cross-sector collaboration and partnerships. Taking a step forward, the study implements the strategy tools in practice, aiming to show and to demonstrate how new value can be created by using the developed strategy tools for the strategic management of value networks. This study makes four main contributions. (1) First, it brings a theoretical contribution by providing new insights and consolidating the field of strategic management of value networks, also proposing a first definition for the strategic management of value networks. (2) Second, the study makes a methodical contribution by proposing and developing two strategy tools for value networks of cross-sector collaboration: (a) value network mapping, a method that allows us to assess the current and the potential value network and (b) the Value Network Scorecard, a method of performance measurement and performance prediction in cross-sector collaboration. (3) Third, the study has managerial implications, offering new solutions and empirical evidence on how to increase the effectiveness of cross-sector collaboration and also allow managers to understand how new value can be created in cross-sector partnerships and how to get the full potential of collaboration. (4) And fourth, the study also has practical implications, allowing managers to understand how to use in practice the strategy tools developed in this study, providing discussions on the limitations regarding the proposed tools as well as general limitations involved in the study.