Automated formulation of optimisation models for steel beam structures

Over 70% of the total costs of an end product are consequences of decisions that are made during the design process. A search for optimal cross-sections will often have only a marginal effect on the amount of material used if the geometry of a structure is fixed and if the cross-sectional characteristics of its elements are property designed by conventional methods. In recent years, optimalgeometry has become a central area of research in the automated design of structures. It is generally accepted that no single optimisation algorithm is suitable for all engineering design problems. An appropriate algorithm, therefore, mustbe selected individually for each optimisation situation. Modelling is the mosttime consuming phase in the optimisation of steel and metal structures. In thisresearch, the goal was to develop a method and computer program, which reduces the modelling and optimisation time for structural design. The program needed anoptimisation algorithm that is suitable for various engineering design problems. Because Finite Element modelling is commonly used in the design of steel and metal structures, the interaction between a finite element tool and optimisation tool needed a practical solution. The developed method and computer programs were tested with standard optimisation tests and practical design optimisation cases. Three generations of computer programs are developed. The programs combine anoptimisation problem modelling tool and FE-modelling program using three alternate methdos. The modelling and optimisation was demonstrated in the design of a new boom construction and steel structures of flat and ridge roofs. This thesis demonstrates that the most time consuming modelling time is significantly reduced. Modelling errors are reduced and the results are more reliable. A new selection rule for the evolution algorithm, which eliminates the need for constraint weight factors is tested with optimisation cases of the steel structures that include hundreds of constraints. It is seen that the tested algorithm can be used nearly as a black box without parameter settings and penalty factors of the constraints.

Optimal beef cattle management under agricultural policy reforms in Finland

Selostus: Politiikkamuutosten vaikutus lihanautojen optimaaliseen ruokintaan ja teurastuksen ajoitukseen

Accounting system for activity standard costs formulation in ERP environment

Toiminnanohjausjärjestelmän implementointi ja sen mukanaan tuomat muutokset tuotekustannuslaskentaan asettavat haasteita yritykselle. Metallitoimialalla toimivassa yrityksessä on havaittu samat haasteet implementoitaessa SAP R/3 toiminnanohjausjärjestelmää ja sen tuotekustannuslaskentatoiminnallisuutta. SAP R/3 tuotekustannuslogiikka tarvitsee tietoa järjestelmän ulkopuolelta, minkä huomioimatta jättäminen vaikuttaa suoraan laskentatarkkuuteen. Diplomityössä kehitetään sekä standardoitu prosessi että laskentajärjestelmä, joiden avulla pystytään laskemaan tarvittavat niin toimintokustannukset eri teräspalvelukeskuksen kuormituspisteille kuin kustannustenvyörytysarvot. Lasketut arvot muodostavat tarvittavat tekijät SAP R/3 tuotekustannuslaskennan master dataan. Tavoitteena on edesauttaa läpinäkyvän kustannustiedon muodostumista. Diplomityö pohjautuu ns. vesiputousmalliin (SDLC). Ensin tunnistetaan reunaehdot ympäristöstä, jossa tuotekustannuslaskenta toteutetaan. Tämä asettaa joustamattomia komponentteja kehitettävälle laskentajärjestelmälle. Joustavat komponentit sen sijaan antavat vapautta laskentajärjestelmälle. Yhdistämällä joustamattomat ja joustavat komponentit saavutetaan järjestelmä, jolla voidaan täydentää SAP R/3 tuotekustannuslaskennan puutteellisuutta.

Optimal Mechanical PulpingProcesses for Eucalyptus, Acacia and Birch

Tässä diplomityössä tutkittiin ja vertailtiin eukalyptuksen, akaasian ja koivun kemimekaanista kuiduttamista ja valkaisua. Yleensä näitä puulajeja käytetään sellun keittoon. Puulajit eroavat toisistaan kasvupaikan ja kuiturakenteen osalta. Eukalyptus ja akaasia ovat niin sanottuja trooppisia lehtipuita, kun taas koivu kasvaa pohjoisilla vyöhykkeillä. Koivulla on kookkaimmat kuidut ja akaasialla pienimmät kuidut. Myös näiden lajien putkilot eroavat toisistaan. Koivun putkilot ovat pitkiä ja kapeita, kun taas eukalyptuksen ja akaasian putkilot ovat lyhyitä ja leveitä. Prosessiksi valittiin kaksivaiheinen APMP-prosessi. Koeajot tehtiinKeskuslaboratorio Oy:ssä. Massoille asetettiin seuraavat tavoitteet: freeness 150-200 ml ja vaaleus 80 %ISO. Eukalyptukselle ja koivulle tehtiin kaksi erilaista impregnointisarjaa, mutta akaasialle vain yksi. Jauhatuksen viimeisessä vaiheessa kokeiltiin myös jauhinvalkaisua. Jauhatuksen energiankulutus oli korkea varsinkin eukalyptuksella ja akaasialla. Jotta energiankulutus saataisiin pienemmäksi, tulisi käyttää enemmän lipeää, mutta se johtaa alkalitummumiseen. Lopuksi massat valkaistiin laboratoriossa. Eukalyptus ja koivu pystyttiin valkaisemaan vaaleuteen 80 %ISO, mutta eukalyptuksen valkaisu vaati enemmän peroksidia kuin koivun valkaisu. Akaasian lähtövaaleus oli niin alhainen, ettei siinä päästy tavoitevaaleuteen. Eukalyptuksella on parempi valonsironta ja paremmat lujuusominaisuudet kuin koivulla. Kemimekaanista massaa voidaan käyttää hienopaperissa parantamassa jäykkyyttä, bulkkia ja valonsirontaa, mutta usein ongelmana on alhainen vaaleus ja huono vaaleuden pysyvyys. Kemimekaanista massaa voidaankäyttää missä tahansa mekaanisissa painopapereissa. Mekaanisissa painopapereissa kemimekaanisella lehtipuumassalla voidaan korvata mekaanista havupuumassaa. Akaasia on niin tummaa, ettei sitä voida käyttää korkeavaaleuksisiin papereihin. Eukalyptus ja koivu ovat vaaleampia ja helpompia valkaista kuin akaasia, mutta myös niillä on niin huono vaaleudenpysyvyys että käyttö hienopapereissa on rajoittunutta. Mekaanisille eukalyptus ja koivumassoille hienopaperia parempi käyttökohde on mekaaniset painopaperit, kuten MWC-paperi.

In Search of Corporate Renewal: How to Benefit from Corporate Venturing?

Despite the rapid change in today's business environment there are relatively few studies about corporate renewal. This study aims for its part at filling that research gap by studying the concepts of strategy, corporate renewal, innovation and corporate venturing. Its purpose is to enhance our understanding of how established companies operating in dynamic and global environment can benefit from their corporate venturing activities. The theoretical part approaches the research problem in corporate and venture levels. Firstly, it focuses on mapping the determinants of strategy and suggests using industry, location, resources, knowledge, structure and culture, market, technology and business model to assess the environment and using these determinants to optimize speed and magnitude of change.Secondly, it concludes that the choice of innovation strategy is dependent on the type and dimensions of innovation and suggests assessing market, technology, business model as well as novelty and complexity related to each of them for choosing an optimal context for developing innovations further. Thirdly, it directsattention on processes through which corporate renewal takes place. On corporate level these processes are identified as strategy formulation, strategy formation and strategy implementation. On the venture level the renewal processes are identified as learning, leveraging and nesting. The theoretical contribution of this study, the framework of strategic corporate venturing, joins corporate and venture level management issues together and concludes that strategy processes and linking processes are the mechanism through which continuous corporate renewaltakes place. The framework of strategic corporate venturing proposed by this study is a new way to illustrate the role of corporate venturing as a purposefullybuilt, different view of a company's business environment. The empirical part extended the framework by enhancing our understanding of the link between corporate renewal and corporate venturing in its real life environment in three Finnish companies: Metso, Nokia and TeliaSonera. Characterizing companies' environmentwith the determinants of strategy identified in this study provided a structured way to analyze their competitive position and renewal challenges that they arefacing. More importantly the case studies confirmed that a link between corporate renewal and corporate venturing exists and found out that the link is not as straight forward as indicated by the theory. Furthermore, the case studies enhanced the framework by indicating a sequence according to which the processes work. Firstly, the induced strategy processes strategy formulation and strategy implementation set the scene for corporate venturing context and management processes and leave strategy formation for the venture. Only after that can strategies formed by ventures come back to the corporate level - and if found viable in the corporate level be formalized through formulation and implementation. With the help of the framework of strategic corporate venturing the link between corporaterenewal and corporate venturing can be found and managed. The suggested response to the continuous need for change is continuous renewal i.e. institutionalizing corporate renewal in the strategy processes of the company. As far as benefiting from venturing is concerned the answer lies in deliberately managing venturing in a context different to the mainstream businesses and establishing efficientlinking processes to exploit the renewal potential of individual ventures.

Choice of Optimal MembraneProcesses for Economical Treatment of Paper Machine Clear Filtrate

In this thesis membrane filtration of paper machnie clear filtrate was studied. The aim of the study was to find membrane processes which are able to produce economically water of sufficient purity from paper machine white water or its saveall clarified fractions for reuse in the paper machnie short circulation. Factors affecting membrane fouling in this application were also studied. The thesis gives an overview af experiments done on a laboratory and a pilot scale with several different membranes and membrane modules. The results were judged by the obtained flux, the fouling tendency and the permeate quality assessed with various chemical analyses. It was shown that membrane modules which used a turbulence promotor of some kind gave the highest fluexes. However, the results showed that the greater the reduction in the concentration polarisation layer caused by increased turbulence in the module, the smaller the reductions in measured substances. Out of the micro-, ultra- and nanofiltration membranes tested, only nanofiltration memebranes produced permeate whose quality was very close to that of the chemically treated raw water used as fresh water in most paper mills today and which should thus be well suited for reuse as shower water both in the wire and press section. It was also shown that a one stage nanofiltration process was more effective than processes in which micro- or ultrafiltration was used as pretreatment for nanofiltration. It was generally observed that acidic pH, high organic matter content, the presence of multivalent ions, hydrophobic membrane material and high membrane cutoff increased the fouling tendency of the membranes.

Studies on integrating kinematic design method with mechanical systems simulation techniques

Theultimate goal of any research in the mechanism/kinematic/design area may be called predictive design, ie the optimisation of mechanism proportions in the design stage without requiring extensive life and wear testing. This is an ambitious goal and can be realised through development and refinement of numerical (computational) technology in order to facilitate the design analysis and optimisation of complex mechanisms, mechanical components and systems. As a part of the systematic design methodology this thesis concentrates on kinematic synthesis (kinematic design and analysis) methods in the mechanism synthesis process. The main task of kinematic design is to find all possible solutions in the form of structural parameters to accomplish the desired requirements of motion. Main formulations of kinematic design can be broadly divided to exact synthesis and approximate synthesis formulations. The exact synthesis formulation is based in solving n linear or nonlinear equations in n variables and the solutions for the problem areget by adopting closed form classical or modern algebraic solution methods or using numerical solution methods based on the polynomial continuation or homotopy. The approximate synthesis formulations is based on minimising the approximation error by direct optimisation The main drawbacks of exact synthesis formulationare: (ia) limitations of number of design specifications and (iia) failure in handling design constraints- especially inequality constraints. The main drawbacks of approximate synthesis formulations are: (ib) it is difficult to choose a proper initial linkage and (iib) it is hard to find more than one solution. Recentformulations in solving the approximate synthesis problem adopts polynomial continuation providing several solutions, but it can not handle inequality const-raints. Based on the practical design needs the mixed exact-approximate position synthesis with two exact and an unlimited number of approximate positions has also been developed. The solutions space is presented as a ground pivot map but thepole between the exact positions cannot be selected as a ground pivot. In this thesis the exact synthesis problem of planar mechanism is solved by generating all possible solutions for the optimisation process ¿ including solutions in positive dimensional solution sets - within inequality constraints of structural parameters. Through the literature research it is first shown that the algebraic and numerical solution methods ¿ used in the research area of computational kinematics ¿ are capable of solving non-parametric algebraic systems of n equations inn variables and cannot handle the singularities associated with positive-dimensional solution sets. In this thesis the problem of positive-dimensional solutionsets is solved adopting the main principles from mathematical research area of algebraic geometry in solving parametric ( in the mathematical sense that all parameter values are considered ¿ including the degenerate cases ¿ for which the system is solvable ) algebraic systems of n equations and at least n+1 variables.Adopting the developed solution method in solving the dyadic equations in direct polynomial form in two- to three-precision-points it has been algebraically proved and numerically demonstrated that the map of the ground pivots is ambiguousand that the singularities associated with positive-dimensional solution sets can be solved. The positive-dimensional solution sets associated with the poles might contain physically meaningful solutions in the form of optimal defectfree mechanisms. Traditionally the mechanism optimisation of hydraulically driven boommechanisms is done at early state of the design process. This will result in optimal component design rather than optimal system level design. Modern mechanismoptimisation at system level demands integration of kinematic design methods with mechanical system simulation techniques. In this thesis a new kinematic design method for hydraulically driven boom mechanism is developed and integrated in mechanical system simulation techniques. The developed kinematic design method is based on the combinations of two-precision-point formulation and on optimisation ( with mathematical programming techniques or adopting optimisation methods based on probability and statistics ) of substructures using calculated criteria from the system level response of multidegree-of-freedom mechanisms. Eg. by adopting the mixed exact-approximate position synthesis in direct optimisation (using mathematical programming techniques) with two exact positions and an unlimitednumber of approximate positions the drawbacks of (ia)-(iib) has been cancelled.The design principles of the developed method are based on the design-tree -approach of the mechanical systems and the design method ¿ in principle ¿ is capable of capturing the interrelationship between kinematic and dynamic synthesis simultaneously when the developed kinematic design method is integrated with the mechanical system simulation techniques.

Dynamic analysis of belt-drives using the absolute nodal coordinate formulation

Belt-drive systems have been and still are the most commonly used power transmission form in various applications of different scale and use. The peculiar features of the dynamics of the belt-drives include highly nonlinear deformation,large rigid body motion, a dynamical contact through a dry friction interface between the belt and pulleys with sticking and slipping zones, cyclic tension of the belt during the operation and creeping of the belt against the pulleys. The life of the belt-drive is critically related on these features, and therefore, amodel which can be used to study the correlations between the initial values and the responses of the belt-drives is a valuable source of information for the development process of the belt-drives. Traditionally, the finite element models of the belt-drives consist of a large number of elements thatmay lead to computational inefficiency. In this research, the beneficial features of the absolute nodal coordinate formulation are utilized in the modeling of the belt-drives in order to fulfill the following requirements for the successful and efficient analysis of the belt-drive systems: the exact modeling of the rigid body inertia during an arbitrary rigid body motion, the consideration of theeffect of the shear deformation, the exact description of the highly nonlinear deformations and a simple and realistic description of the contact. The use of distributed contact forces and high order beam and plate elements based on the absolute nodal coordinate formulation are applied to the modeling of the belt-drives in two- and three-dimensional cases. According to the numerical results, a realistic behavior of the belt-drives can be obtained with a significantly smaller number of elements and degrees of freedom in comparison to the previously published finite element models of belt-drives. The results of theexamples demonstrate the functionality and suitability of the absolute nodal coordinate formulation for the computationally efficient and realistic modeling ofbelt-drives. This study also introduces an approach to avoid the problems related to the use of the continuum mechanics approach in the definition of elastic forces on the absolute nodal coordinate formulation. This approach is applied to a new computationally efficient two-dimensional shear deformable beam element based on the absolute nodal coordinate formulation. The proposed beam element uses a linear displacement field neglecting higher-order terms and a reduced number of nodal coordinates, which leads to fewer degrees of freedom in a finite element.