Objectives and motivations of small-scale forest owners : theoretical modelling and qualitative assessment

Abstract

The environmental effectiviness of alternative agri-environmental policy reforms : theoretical and empirical analysis

Selostus: Maatalouden ympäristöpolitiikan reformien tehokkuus ravinnepäästöjen vähentämisessä - teoreettinen ja empiirinen analyysi

Theoretical Analysis and Simulations of Vertically Vibrated Granular Materials

The dynamical properties ofshaken granular materials are important in many industrial applications where the shaking is used to mix, segregate and transport them. In this work asystematic, large scale simulation study has been performed to investigate the rheology of dense granular media, in the presence of gas, in a three dimensional vertical cylinder filled with glass balls. The base wall of the cylinder is subjected to sinusoidal oscillation in the vertical direction. The viscoelastic behavior of glass balls during a collision, have been studied experimentally using a modified Newton's Cradle device. By analyzing the results of the measurements, using numerical model based on finite element method, the viscous damping coefficient was determinedfor the glass balls. To obtain detailed information about the interparticle interactions in a shaker, a simplified model for collision between particles of a granular material was proposed. In order to simulate the flow of surrounding gas, a formulation of the equations for fluid flow in a porous medium including particle forces was proposed. These equations are solved with Large Eddy Simulation (LES) technique using a subgrid-model originally proposed for compressible turbulent flows. For a pentagonal prism-shaped container under vertical vibrations, the results show that oscillon type structures were formed. Oscillons are highly localized particle-like excitations of the granular layer. This self-sustaining state was named by analogy with its closest large-scale analogy, the soliton, which was first documented by J.S. Russell in 1834. The results which has been reportedbyBordbar and Zamankhan(2005b)also show that slightly revised fluctuation-dissipation theorem might apply to shaken sand, which appears to be asystem far from equilibrium and could exhibit strong spatial and temporal variations in quantities such as density and local particle velocity. In this light, hydrodynamic type continuum equations were presented for describing the deformation and flow of dense gas-particle mixtures. The constitutive equation used for the stress tensor provides an effective viscosity with a liquid-like character at low shear rates and a gaseous-like behavior at high shear rates. The numerical solutions were obtained for the aforementioned hydrodynamic equations for predicting the flow dynamics ofdense mixture of gas and particles in vertical cylindrical containers. For a heptagonal prism shaped container under vertical vibrations, the model results were found to predict bubbling behavior analogous to those observed experimentally. This bubbling behavior may be explained by the unusual gas pressure distribution found in the bed. In addition, oscillon type structures were found to be formed using a vertically vibrated, pentagonal prism shaped container in agreement with computer simulation results. These observations suggest that the pressure distribution plays a key rolein deformation and flow of dense mixtures of gas and particles under vertical vibrations. The present models provide greater insight toward the explanation of poorly understood hydrodynamic phenomena in the field of granular flows and dense gas-particle mixtures. The models can be generalized to investigate the granular material-container wall interactions which would be an issue of high interests in the industrial applications. By following this approach ideal processing conditions and powder transport can be created in industrial systems.

Theoretical and numerical study of thermomagnetic convection in magnetic fluids

In this thesis, the magnetic field control of convection instabilities and heat and mass transfer processesin magnetic fluids have been investigated by numerical simulations and theoretical considerations. Simulation models based on finite element and finite volume methods have been developed. In addition to standard conservation equations, themagnetic field inside the simulation domain is calculated from Maxwell equations and the necessary terms to take into account for the magnetic body force and magnetic dissipation have been added to the equations governing the fluid motion.Numerical simulations of magnetic fluid convection near the threshold supportedexperimental observations qualitatively. Near the onset of convection the competitive action of thermal and concentration density gradients leads to mostly spatiotemporally chaotic convection with oscillatory and travelling wave regimes, previously observed in binary mixtures and nematic liquid crystals. In many applications of magnetic fluids, the heat and mass transfer processes including the effects of external magnetic fields are of great importance. In addition to magnetic fluids, the concepts and the simulation models used in this study may be applied also to the studies of convective instabilities in ordinary fluids as well as in other binary mixtures and complex fluids.

Theoretical background for market emergence framework : Case: Electricity Distribution Industry

Both the competitive environment and the internal structure of an industrial organization are typically included in the processes which describe the strategic management processes of the firm, but less attention has been paid to the interdependence between these views. Therefore, this research focuses on explaining the particular conditions of an industry change, which lead managers to realign the firm in respect of its environment for generating competitive advantage. The research question that directs the development of the theoretical framework is: Why do firms outsource some of their functions? The three general stages of the analysis are related to the following research topics: (i) understanding forces that shape the industry, (ii) estimating the impacts of transforming customer preferences, rivalry, and changing capability bases on the relevance of existing assets and activities, and emergence of new business models, and (iii) developing optional structures for future value chains and understanding general boundaries for market emergence. The defined research setting contributes to the managerial research questions “Why do firms reorganize their value chains?”, “Why and how are decisions made?” Combining Transaction Cost Economics (TCE) and Resource-Based View (RBV) within an integrated framework makes it possible to evaluate the two dimensions of a company’s resources, namely the strategic value and transferability. The final decision of restructuring will be made based on an analysis of the actual business potential of the outsourcing, where benefits and risks are evaluated. The firm focuses on the risk of opportunism, hold-up problems, pricing, and opportunities to reach a complete contract, and finally on the direct benefits and risks for financial performance. The supplier analyzes the business potential of an activity outside the specific customer, the amount of customer-specific investments, the service provider’s competitive position, abilities to revenue gains in generic segments, and long-term dependence on the customer.

An experimental and theoretical study of multiphase flow in a circulating fluidized bed

A systematic averaging procedure has been derived in order to obtain an integral form of conservation equations for dispersed multiphase flow, especially applicable to fluidized beds. A similar averaging method is applied further to formulate macroscopic integral equations, which can be used in one-dimensional and macroscopic multi dimensional models. Circulating fluid bed hydrodynamics has been studied experimentally and both macroscopic and microscopic flow profiles have been measured in a cold model. As an application of the theory, the one dimensional model has been used to study mass and momentum conservation of gas and solid in a circulating fluid bed. Axial solid mixing has also been modelled by the one dimensional model and mixing parameters have been evaluated.

The concept of solution: Industry’s insights compared to theoretical views

Many manufacturing companies have started to offer complete solutions to their customers’ unique needs due to toughening competition and customer demand. Discourse on this kind of solution business is still developing, hence, there is not an established definition for the concept of solution. The aim of the study is to profoundly identify the concept of solution and to understand how the industry’s current views differ from the theoretical concepts. The describing dimensions are identified from selected 13 theoretical notions, and from responses, that the employees of five different companies have given. The 32 interview transcripts are analyzed with thematic analysis and qualitative content analysis. According to the findings, the concept of solution is characterized by integration, customization, risk-sharing, value co-creation, long-term orientation, and desired outcomes. The industry’s insights differ in terms of them all. The results illustrate, that a solution is a bundle, and the whole solution is customized on some level for a client. A solution supplier needs to be customer-focused, in which value co-creation is only a part. The solution solves the customer’s problem, and improves both the customer’s, and the supplier’s business. Neither long-term focus nor risks-sharing were directly employed to characterize the concept of solution. Differences are mainly due to the different approaches to the definitions and inexperience of the companies.

Comparison of Local Feature Detectors and Descriptors for Visual Object Categorization

Local features are used in many computer vision tasks including visual object categorization, content-based image retrieval and object recognition to mention a few. Local features are points, blobs or regions in images that are extracted using a local feature detector. To make use of extracted local features the localized interest points are described using a local feature descriptor. A descriptor histogram vector is a compact representation of an image and can be used for searching and matching images in databases. In this thesis the performance of local feature detectors and descriptors is evaluated for object class detection task. Features are extracted from image samples belonging to several object classes. Matching features are then searched using random image pairs of a same class. The goal of this thesis is to find out what are the best detector and descriptor methods for such task in terms of detector repeatability and descriptor matching rate.

Applications of graph transformation in tools for domain-specific modeling languages

The use of domain-specific languages (DSLs) has been proposed as an approach to cost-e ectively develop families of software systems in a restricted application domain. Domain-specific languages in combination with the accumulated knowledge and experience of previous implementations, can in turn be used to generate new applications with unique sets of requirements. For this reason, DSLs are considered to be an important approach for software reuse. However, the toolset supporting a particular domain-specific language is also domain-specific and is per definition not reusable. Therefore, creating and maintaining a DSL requires additional resources that could be even larger than the savings associated with using them. As a solution, di erent tool frameworks have been proposed to simplify and reduce the cost of developments of DSLs. Developers of tool support for DSLs need to instantiate, customize or configure the framework for a particular DSL. There are di erent approaches for this. An approach is to use an application programming interface (API) and to extend the basic framework using an imperative programming language. An example of a tools which is based on this approach is Eclipse GEF. Another approach is to configure the framework using declarative languages that are independent of the underlying framework implementation. We believe this second approach can bring important benefits as this brings focus to specifying what should the tool be like instead of writing a program specifying how the tool achieves this functionality. In this thesis we explore this second approach. We use graph transformation as the basic approach to customize a domain-specific modeling (DSM) tool framework. The contributions of this thesis includes a comparison of di erent approaches for defining, representing and interchanging software modeling languages and models and a tool architecture for an open domain-specific modeling framework that e ciently integrates several model transformation components and visual editors. We also present several specific algorithms and tool components for DSM framework. These include an approach for graph query based on region operators and the star operator and an approach for reconciling models and diagrams after executing model transformation programs. We exemplify our approach with two case studies MICAS and EFCO. In these studies we show how our experimental modeling tool framework has been used to define tool environments for domain-specific languages.

Work for your happiness - Theoretical and empirical study defining and measuring happiness at work

There are vast changes in the work environment, and the traditional rules and management methods might not be suitable for today’s employees anymore. The meaning of work is also changing due to the younger and higher educated generations entering the markets. Old customs need to be re-validated and new approaches should be taken into use. This paper strongly emphasizes the importance of happiness research and happiness at work. The values towards the meaning of work are changing; people demand happiness and quality from all aspects of their lives. The aim of this study is to define happiness - especially at work - and to explain how it can be measured and what kind of results achieved. I also want to find out how the contents of work and the working environment might enhance happiness. The correlation between education and happiness is discussed and examined. I am aware that the findings and theories are concentrating mainly on Western Countries and highlighting the values and work-environments of those societies. The main aim of the empirical study is to find out if there are connections between happiness and work in data collected by World Value Survey in 2005, and if the profession has effects on happiness. Other factors such as the correlation of age, sex, education and income are examined too. I also want to find out what kind of values people have towards work and how these affect the happiness levels. The focus is on two nations: Finland (N=1014) and Italy (N=1012). I have also taken the global comparison within, that is all 54 countries (N=66,566) included in the 5th wave (during the years 2005 -2008) of the World Value Survey. The results suggest that people are generally happy around the world; happiness decreasing with the age, the educated being happier than the uneducated and the employed happier than the unemployed. People working in neat “white collar” jobs are more likely happier than those working in factories or outdoors. Money makes us happier, until certain level is reached. Work is important to people and the importance of work adds happiness. Work is also highly appreciated, but there are more happy people among those who do not appreciate work that highly. Safety matters the most when looking for a job, and there are more happy people among those who have selected the importance of work as the first choice when looking for a job, than among those to whom an income is the most important aspect. People are more likely happy when the quality of work is high, that is when their job consists of creative and cognitive tasks and when they have a feeling of independence.

The Finnish it industries in transition. Defining and Measuring the Finnish Software Product and IT Services Industries by Applying Theoretical Frameworks

The starting point of this study is that the prevailing way to consider the Finnish IT industries and industry information often results in a limited and even skewed picture of the sector. The purpose of the study is to contribute and increase knowledge and understanding of the status, structure and evolution of the Finnish IT industries as well as the Finnish IT vendor field and competition. The focus is on software product and IT services industries which form a crucial part of all ICT industries. This study examines the Finnish IT sector from production (supply) as well as market (demand) perspective. The study is based on empirical information from multiple sources. Three research questions were formulated for the study. The first concerns the status of the Finnish IT industries considered by applying theoretical frameworks. The second research question targets at the basis for the future evolution of the Finnish IT industries and, finally, the third at the ability of the available definitions and indicators to describe the Finnish IT industries and IT markets. Major structural changes like technological changes and related innovations, globalization and new business models are drivers of the evolution of the IT industries. The findings of this study emphasize the significant role of IT services in the Finnish IT sector and in connection to that the ability to combine IT service skills, competences and practices with high level software skills also in the future. According to the study the Finnish IT enterprises and their customers have become increasingly dependent on global ecosystems and platforms, applications and IT services provided by global vendors. As a result, more IT decisions are made outside Finland. In addition, IT companies are facing new competition from other than IT industries bringing into market new substitutes. To respond to the new competition, IT firms seek growth by expanding beyond their traditional markets.. The changing global division of labor accentuates the need for accurate information of the IT sector but, at the same time, also makes it increasingly challenging to acquire the information needed. One of the main contributions of this study is to provide frameworks for describing the Finnish IT sector and its evolution. These frameworks help combine empirical information from various sources and make it easier to concretize the structures, volumes, relationships and interaction of both, the production and market side of the Finnish IT industry. Some frameworks provide tools to analyze the vendor field, competition and the basis for the future evolution of the IT industries. The observations of the study support the argument that static industry definitions and related classifications do not serve the information needs in dynamic industries, such as the IT industries. One of the main messages of this study is to emphasize the importance of understanding the definitions and starting points of different information sources. Simultaneously, in the structure and evolution of Finnish IT industries the number of employees has become a more valid and reliable measure than the revenue based indicators.