Enhancing the efficiency of freight transport by using simulation

The role of transport in the economy is twofold. As a sector of economic activity it contributes to a share of national income. On the other hand, improvements in transport infrastructure create room for accelerated economic growth. As a means to support railways as a safe and environmentally friendly transportation mode, the EU legislation has required the opening of domestic railway freight for competition from beginning of year 2007. The importance of railways as a mode of transport has been great in Finland, as a larger share of freight has been carried on rails than in Europe on average. In this thesis it is claimed that the efficiency of goods transport can be enhanced by service specific investments. Furthermore, it is stressed that simulation can and should be used to evaluate the cost-efficiency of transport systems on operational level, as well as to assess transportation infrastructure investments. In all the studied cases notable efficiency improvements were found. For example in distribution, home delivery of groceries can be almost twice as cost efficient as the current practice of visiting the store. The majority of the cases concentrated on railway freight. In timber transportation, the item with the largest annual transport volume in domestic railway freight in Finland, the transportation cost could be reduced most substantially. Also in international timber procurement, the utilization of railway wagons could be improved by combining complementary flows. The efficiency improvements also have positive environmental effects; a large part of road transit could be moved to rails annually. If impacts of freight transport are included in cost-benefit analysis of railway investments, up to 50 % increase in the net benefits of the evaluated alternatives can be experienced, avoiding a possible inbuilt bias in the assessment framework, and thus increasing the efficiency of national investments in transportation infrastructure. Transportation systems are a typical example of complex real world systems that cannot be analysed realistically by analytical methods, whereas simulation allows inclusion of dynamics and the level of detail required. Regarding simulation as a viable tool for assessing the efficiency of transportation systems finds support also in the international survey conducted for railway freight operators; operators use operations research methods widely for planning purposes, while simulation is applied only by the larger operators.

Offdesign operation of kraft recovery boiler

A model to solve heat and mass balances during the offdesign load calculations was created. These equations are complex and nonlinear. The main new ideas used in the created offdesign model of a kraft recovery boiler are the use of heat flows as torn iteration variables instead of the current practice of using the mass flows, vectorizing equation solving, thus speeding up the process, using non dimensional variables for solving the multiple heat transfer surface problem and using a new procedure for calculating pressure losses. Recovery boiler heat and mass balances are reduced to vector form. It is shown that these vectorized equations can be solved virtually without iteration. The iteration speed is enhanced by the use of the derived method of calculating multiple heat transfer surfaces simultaneously. To achieve this quick convergence the heat flows were used as the torn iteration parameters. A new method to handle pressure loss calculations with linearization was presented. This method enabled less time to be spent calculating pressure losses. The derived vector representation of the steam generator was used to calculate offdesign operation parameters for a 3000 tds/d example recovery boiler. The model was used to study recovery boiler part load operation and the effect of the black liquor dry solids increase on recovery boiler dimensioning. Heat flows to surface elements for part load calculations can be closely approximated with a previously defined exponent function. The exponential method can be used for the prediction of fouling in kraft recovery boilers. For similar furnaces the firing of 80 % dry solids liquor produces lower hearth heat release rate than the 65 % dry solids liquor if we fire at constant steam flow. The furnace outlet temperatures show that capacity increase with firing rate increase produces higher loadings than capacity increase with dry solids increase. The economizers, boiler banks and furnaces can be dimensioned smaller if we increase the black liquor dry solids content. The main problem with increased black liquor dry solids content is the decrease in the heat available to superheat. Whenever possible the furnace exit temperature should be increased by decreasing the furnace height. The increase in the furnace exit temperature is usually opposed because of fear of increased corrosion.

Managerial Careers in the IT Industry: Women in China and in Finland

This research focuses on the career experiences of women managers in the IT industry in China and Finland, two countries with different cultures, policies, size of population, and social and economic structures regarding work-life support and equal opportunities. The object of this research is to present a cross-cultural comparison of women’s career experiences and how women themselves understand and account for their careers. The study explores how the macro and the micro levels of cultural and social processes become manifested in the lives of individual women. The main argument in this thesis is that culture plays a crucial role in making sense of women’s career experiences, although its role should be understood through its interrelationship with other social processes, e.g., institutional relations, social policies, industrial structures and organizations, as well as globalization. The interrelationship of a series of cultural and social processes affects individuals’ attitudes to, and arrangement and organization of, their work and family lives. This thesis consists of two parts. The first part introduces the research topic and discusses the overall results. The second part comprises five research papers. The main research question of the study is: How do cultural and social processes affect the experiences of women managers? Quantitative and qualitative research methods, which include in-depth interviews, Q-methodology, interpretive analysis, and questionnaires, are used in the study. The main theoretical background is culturally sensitive career theory and the theory of individual differences. The results of this study are viewed through a feminist lens. The research methodology applied allows new explorations on how demographic factors, work experiences, lifestyle issues, and organizational cultures can jointly affect women’s managerial careers. The sample group used in the research is 42 women managers working in IT companies in China (21) and Finland (21). The results of the study illustrate the impact of history, tradition, culture, institutional relations, social politics, industry and organizations, and globalization on the careers of women managers. It is claimed that the role of culture – cultural norms within nations and organizations – is of great importance in the relationship of gender and work. Women’s managerial careers are affected by multiple factors (personal, social and cultural) reflecting national and inter-individual differences. The results of the study contribute to research on careers, adding particularly to the literature on gender, work and culture, and offering a complex and holistic perspective for a richer understanding of pluralism and global diversity. The results of the study indicate how old and new career perspectives are evidenced in women managers in the IT industry. The research further contributes to an understanding of women’s managerial careers from a cross-culture perspective. In addition, the study contributes to the literature on culture and extends understanding of Hofstede’s work. Further, most traditional career theories do not perceive the importance of culture in determining an individual’s career experience and this study richens understanding of women managers’ careers and has considerable implications for international human resource management. The results of this study emphasize the need, when discussing women managers’ careers, to understand the ways by which gendering is produced rather than merely examining gender differences. It is argued that the meaning of self-knowledge is critical. Further, the environment where the careers under study develop differs greatly; China and Finland are very different – culturally, historically and socially. The findings of this study should, therefore, be understood as a holistic, specific, and contextually-bound.

Essays on pricing of risk and international linkage of Russian stock market

Last two decades have seen a rapid change in the global economic and financial situation; the economic conditions in many small and large underdeveloped countries started to improve and they became recognized as emerging markets. This led to growth in the amounts of global investments in these countries, partly spurred by expectations of higher returns, favorable risk-return opportunities, and better diversification alternatives to global investors. This process, however, has not been without problems and it has emphasized the need for more information on these markets. In particular, the liberalization of financial markets around the world, globalization of trade and companies, recent formation of economic and regional blocks, and the rapid development of underdeveloped countries during the last two decades have brought a major challenge to the financial world and researchers alike. This doctoral dissertation studies one of the largest emerging markets, namely Russia. The motivation why the Russian equity market is worth investigating includes, among other factors, its sheer size, rapid and robust economic growth since the turn of the millennium, future prospect for international investors, and a number of important major financial reforms implemented since the early 1990s. Another interesting feature of the Russian economy, which gives motivation to study Russian market, is Russia’s 1998 financial crisis, considered as one of the worst crisis in recent times, affecting both developed and developing economies. Therefore, special attention has been paid to Russia’s 1998 financial crisis throughout this dissertation. This thesis covers the period from the birth of the modern Russian financial markets to the present day, Special attention is given to the international linkage and the 1998 financial crisis. This study first identifies the risks associated with Russian market and then deals with their pricing issues. Finally some insights about portfolio construction within Russian market are presented. The first research paper of this dissertation considers the linkage of the Russian equity market to the world equity market by examining the international transmission of the Russia’s 1998 financial crisis utilizing the GARCH-BEKK model proposed by Engle and Kroner. Empirical results shows evidence of direct linkage between the Russian equity market and the world market both in regards of returns and volatility. However, the weakness of the linkage suggests that the Russian equity market was only partially integrated into the world market, even though the contagion can be clearly seen during the time of the crisis period. The second and the third paper, co-authored with Mika Vaihekoski, investigate whether global, local and currency risks are priced in the Russian stock market from a US investors’ point of view. Furthermore, the dynamics of these sources of risk are studied, i.e., whether the prices of the global and local risk factors are constant or time-varying over time. We utilize the multivariate GARCH-M framework of De Santis and Gérard (1998). Similar to them we find price of global market risk to be time-varying. Currency risk also found to be priced and highly time varying in the Russian market. Moreover, our results suggest that the Russian market is partially segmented and local risk is also priced in the market. The model also implies that the biggest impact on the US market risk premium is coming from the world risk component whereas the Russian risk premium is on average caused mostly by the local and currency components. The purpose of the fourth paper is to look at the relationship between the stock and the bond market of Russia. The objective is to examine whether the correlations between two classes of assets are time varying by using multivariate conditional volatility models. The Constant Conditional Correlation model by Bollerslev (1990), the Dynamic Conditional Correlation model by Engle (2002), and an asymmetric version of the Dynamic Conditional Correlation model by Cappiello et al. (2006) are used in the analysis. The empirical results do not support the assumption of constant conditional correlation and there was clear evidence of time varying correlations between the Russian stocks and bond market and both asset markets exhibit positive asymmetries. The implications of the results in this dissertation are useful for both companies and international investors who are interested in investing in Russia. Our results give useful insights to those involved in minimising or managing financial risk exposures, such as, portfolio managers, international investors, risk analysts and financial researchers. When portfolio managers aim to optimize the risk-return relationship, the results indicate that at least in the case of Russia, one should account for the local market as well as currency risk when calculating the key inputs for the optimization. In addition, the pricing of exchange rate risk implies that exchange rate exposure is partly non-diversifiable and investors are compensated for bearing the risk. Likewise, international transmission of stock market volatility can profoundly influence corporate capital budgeting decisions, investors’ investment decisions, and other business cycle variables. Finally, the weak integration of the Russian market and low correlations between Russian stock and bond market offers good opportunities to the international investors to diversify their portfolios.

Role of references in international industrial marketing : a theory-building case study about supplier’s processes of utilizing references

Scientific studies regarding specifically references do not seem to exist. However, the utilization of references is an important practice for many companies involved in industrial marketing. The purpose of the study is to increase the understanding about the utilization of references in international industrial marketing in order to contribute to the development of a theory of reference behavior. Specifically, the modes of reference usage in industry, the factors affecting a supplier's reference behavior, and the question how references are actually utilized, are explored in the study. Due to the explorative nature of the study, a research design was followed where theory and empirical studies alternated. An Exploratory Framework was developed to guide a pilot case study that resulted in Framework 1. Results of the pilot study guided an expanded literature review that was used to develop first a Structural Framework and a Process Framework which were combined in Framework 2. Then, the second empirical phase of the case study was conducted in the same (pilot) case company. In this phase, Decision Systems Analysis (DSA) was used as the analysis method. The DSA procedure consists of three interviewing waves: initial interviews, reinterviews, and validating interviews. Four reference decision processes were identified, described and analyzed in the form of flowchart descriptions. The flowchart descriptions were used to explore new constructs and to develop new propositions to develop Framework 2 further. The quality of the study was ascertained by many actions in both empirical parts of the study. The construct validity of the study was ascertained by using multiple sources of evidence and by asking the key informant to review the pilot case report. The DSA method itself includes procedures assuring validity. Because of the choice to conduct a single case study, external validity was not even pursued. High reliability was pursued through detailed documentation and thorough reporting of evidence. It was concluded that the core of the concept of reference is a customer relationship regardless of the concrete forms a reference might take in its utilization. Depending on various contingencies, references might have various tasks inside the four roles of increasing 1) efficiency of sales and sales management, 2) efficiency of the business, 3) effectiveness of marketing activities, and 4) effectiveness in establishing, maintaining and enhancing customer relationships. Thus, references have not only external but internal tasks as well. A supplier's reference behavior might be affected by many hierarchical conditions. Additionally, the empirical study showed that the supplier can utilize its references as a continuous, all pervasive decision making process through various practices. The process includes both individual and unstructured decision making subprocesses. The proposed concept of reference can be used to guide a reference policy recommendable for companies for which the utilization of references is important. The significance of the study is threefold: proposing the concept of reference, developing a framework of a supplier's reference behavior and its short term process of utilizing references, and conceptual structuring of an unstructured and in industrial marketing important phenomenon to four roles.

Electrochemical Characterisation of Filter Media Properties and Their Exploitation in Enhanced Filtration

Streaming potential measurements for the surface charge characterisation of different filter media types and materials were used. The equipment was developed further so that measurements could be taken along the surfaces, and so that tubular membranes could also be measured. The streaming potential proved to be a very useful tool in the charge analysis of both clean and fouled filter media. Adsorption and fouling could be studied, as could flux, as functions of time. A module to determine the membrane potential was also constructed. The results collected from the experiments conducted with these devices were used in the study of the theory of streaming potential as an electrokinetic phenomenon. Several correction factors, which are derived to take into account the surface conductance and the electrokinetic flow in very narrow capillaries, were tested in practice. The surface materials were studied using FTIR and the results compared with those from the streaming potentials. FTIR analysis was also found to be a useful tool in the characterisation of filters, as well as in the fouling studies. Upon examination of the recorded spectra from different depths in a sample it was possible to determine the adsorption sites. The influence of an external electric field on the cross flow microflltration of a binary protein system was investigated using a membrane electroflltration apparatus. The results showed that a significant improvement could be achieved in membrane filtration by using the measured electrochemical properties to help adjust the process conditions.

Ultrafine grinding of FGD and phosphogypsum with an attrition bead mill and a jet mill : optimisation and modelling of grinding and mill comparison

Fine powders of minerals are used commonly in the paper and paint industry, and for ceramics. Research for utilizing of different waste materials in these applications is environmentally important. In this work, the ultrafine grinding of two waste gypsum materials, namely FGD (Flue Gas Desulphurisation) gypsum and phosphogypsum from a phosphoric acid plant, with the attrition bead mill and with the jet mill has been studied. The ' objective of this research was to test the suitability of the attrition bead mill and of the jet mill to produce gypsum powders with a particle size of a few microns. The grinding conditions were optimised by studying the influences of different operational grinding parameters on the grinding rate and on the energy consumption of the process in order to achieve a product fineness such as that required in the paper industry with as low energy consumption as possible. Based on experimental results, the most influential parameters in the attrition grinding were found to be the bead size, the stirrer type, and the stirring speed. The best conditions, based on the product fineness and specific energy consumption of grinding, for the attrition grinding process is to grind the material with small grinding beads and a high rotational speed of the stirrer. Also, by using some suitable grinding additive, a finer product is achieved with a lower energy consumption. In jet mill grinding the most influential parameters were the feed rate, the volumetric flow rate of the grinding air, and the height of the internal classification tube. The optimised condition for the jet is to grind with a small feed rate and with a large rate of volumetric flow rate of grinding air when the inside tube is low. The finer product with a larger rate of production was achieved with the attrition bead mill than with the jet mill, thus the attrition grinding is better for the ultrafine grinding of gypsum than the jet grinding. Finally the suitability of the population balance model for simulation of grinding processes has been studied with different S , B , and C functions. A new S function for the modelling of an attrition mill and a new C function for the modelling of a jet mill were developed. The suitability of the selected models with the developed grinding functions was tested by curve fitting the particle size distributions of the grinding products and then comparing the fitted size distributions to the measured particle sizes. According to the simulation results, the models are suitable for the estimation and simulation of the studied grinding processes.

Inter organizational learning within and by innovation networks

The thesis deals with the phenomenon of learning between organizations in innovation networks that develop new products, services or processes. Inter organizational learning is studied especially at the level of the network. The role of the network can be seen as twofold: either the network is a context for inter organizational learning, if the learner is something else than the network (organization, group, individual), or the network itself is the learner. Innovations are regarded as a primary source of competitiveness and renewal in organizations. Networking has become increasingly common particularly because of the possibility to extend the resource base of the organization through partnerships and to concentrate on core competencies. Especially in innovation activities, networks provide the possibility to answer the complex needs of the customers faster and to share the costs and risks of the development work. Networked innovation activities are often organized in practice as distributed virtual teams, either within one organization or as cross organizational co operation. The role of technology is considered in the research mainly as an enabling tool for collaboration and learning. Learning has been recognized as one important collaborative process in networks or as a motivation for networking. It is even more important in the innovation context as an enabler of renewal, since the essence of the innovation process is creating new knowledge, processes, products and services. The thesis aims at providing enhanced understanding about the inter organizational learning phenomenon in and by innovation networks, especially concentrating on the network level. The perspectives used in the research are the theoretical viewpoints and concepts, challenges, and solutions for learning. The methods used in the study are literature reviews and empirical research carried out with semi structured interviews analyzed with qualitative content analysis. The empirical research concentrates on two different areas, firstly on the theoretical approaches to learning that are relevant to innovation networks, secondly on learning in virtual innovation teams. As a result, the research identifies insights and implications for learning in innovation networks from several viewpoints on organizational learning. Using multiple perspectives allows drawing a many sided picture of the learning phenomenon that is valuable because of the versatility and complexity of situations and challenges of learning in the context of innovation and networks. The research results also show some of the challenges of learning and possible solutions for supporting especially network level learning.

Haja-asutusalueiden sähkönjakelujärjestelmien kehittäminen – erityisesti 1000 V jakelujännitteen käyttömahdollisuudet

Yhteiskunnan riippuvuus sähköstä on lisääntynyt voimakkaasti viime vuosikymmenien aikana. Sähkönjakelussa esiintyneet lyhyet ja pitkät keskeytykset ovat osoittaneet yhteiskunnan haavoittuvuuden ja yhteiskunta kestää entistä vähemmän sähkönjakelussa tapahtuvia häiriöitä. Keskeytyksistä aiheutuneiden haittojen arvostus on kasvanut ja tämä on luonut taloudelliset perusteet sähkön laatua parantaville investoinneille. Haja-asutusalueiden keskijänniteverkon johdot on rakennettu avojohtoina ja siten ne ovat alttiita sääolosuhteista johtuville myrsky- ja lumikuormavaurioille. Ilmastomuutoksen ennustetaan lisäävän tuulisuutta ja siten ongelmat sähkönjakelussa mahdollisesti lisääntyvät. Taajamissa käytetään enemmän kaapeleita ja johtolähdöt ovat lyhyitä, joten myrskyistä aiheutuvia keskeytyksiä on vähemmän kuin haja-asutusalueella. Olemassa olevat jakeluverkot ovat käytössä vielä vuosikymmeniä, joten uuden tekniikan kehittämisen rinnalla on kehitettävä myös olemassa olevaa jakeluverkkoa ja sen ylläpitoa. Ylläpidon tavoitteena on käyttövarmuuden parantamisen lisäksi huolehtia siitä, että jakeluverkkoihin sitoutunut omaisuus säilyttää arvonsa mahdollisimman hyvin pitoajan loppuun saakka. Jakeluverkkoihin investoitiin paljon 1950–70-luvuilla. Tältä ajalta on yhä käytössä puupylväitä, joiden ikääntymisen takia korvausinvestointien tarve kasvaa. Hyvänä puolena tässä on että käyttövarmuuden parantamiseksi olemassa olevaa jakeluverkkoa ei tarvitse uusia ennenaikaisesti. Tutkimuksessa päähuomio on haja-asutusalueiden 20 kV keskijänniteverkon kehittämisessä, sillä yli 90 % asiakkaiden kokemista keskeytyksistä johtuu keskijänniteverkon vioista. Erityisesti johtorakenteisiin ja johtojen sijoittamiseen on kiinnitettävä huomiota. Käyttövarmuuden lisäksi jakeluverkkojen kehittämistä ohjaavia tekijöitä ovat taloudellisuus, ympäristön huomioiminen, viranomaisvalvonta sekä asiakkaiden ja omistajien odotukset. Haja-asutusalueilla taloudelliset haasteet ovat suuret vakituisen väestön vähenemisen ja mahdollisesti sähköntarpeen pienenemisen takia. Taloudellisuus korostuu ja riskit kasvavat, kun tuottojen määrä supistuu tarvittaviin jakeluverkon investointeihin ja ylläpitokustannuksiin verrattuna. Ristiriitaa aiheuttaa se, että asiakkaat odottavat sähkönjakelulta parempaa luotettavuutta, mutta paremmasta sähkönlaadusta ei olla valmiita maksamaan juurikaan nykyistä enempää. Jakeluverkkojen kehittämistä voi hidastaa myös viranomaisvalvonta, jos tuottoja ei voida lisätä investointien lisätarpeiden suhteessa. Tutkimuksessa on analysoitu yleisellä tasolla kaapeloinnin lisäämistä, korkeiden pylväiden käyttämistä, leveitä johtokatuja, edullisten ja yksinkertaisten sähköasemien rakentamista haja-asutusalueille ja automaatioasemien lisäämistä keskijänniteverkon solmupisteisiin. Erityisesti tutkimuksessa on analysoitu uutena tekniikkana 1000 V jännitteen käyttömahdollisuutta jakeluverkkojen kehittämisessä. Sähköjohtojen siirtäminen teiden varsiin parantaa käyttövarmuutta, vaikka johdot rakennetaan samalla tekniikalla kuin olemassa olevat johdot. Hajaasutusalueille rakennettavilla sähköasemilla pitkät syöttöjohdot voidaan jakaa pienemmiksi syöttöalueiksi, jolloin keskeytyksistä aiheutuvat haitat koskettavat kerrallaan pienempää asiakasmäärää. Samaan tulokseen päästään oikein sijoitetuilla ja toteutetuilla automaatioasemilla. Tutkimuksen mukaan lupaavaksi tekniikaksi jakeluverkkojen kehittämisessä on osoittautumassa 1000 V jänniteportaan ottaminen 400 V pienjännitteen lisäksi. 1000 V verkoilla voidaan korvata häiriöherkkiä 20 kV keskijänniteverkon lyhyitä, alle viiden kilometrin pituisia haarajohtoja ja haarajohtojen jatkeita, missä siirrettävät tehot ovat pieniä. Uudessa jakelujärjestelmässä sähkö tuodaan 1000 V jännitteellä lähelle asiakasta, jossa jännite muunnetaan normaaliksi asiakkaille soveltuvaksi 400/230 V jännitteeksi. Edullisuus perustuu siihen, että rakentamisessa käytetään samoja pienjännitejohtoja kuin asiakkaille menevässä 400 V pienjänniteverkossa. 1000 V jakelutekniikassa sekä investointikustannukset että ylläpitokustannukset ovat pienemmät kuin perinteisessä 20 kV ilmajohtotekniikassa. 1000 V johdot säästävät maisemaa, sillä ne eivät tarvitse leveää johtokatua kuten 20 kV keskijännitejohdot. 1000 V verkkojen käyttö soveltuukin erityisesti vapaa-ajanasuntojen sähköistykseen herkissä ranta- ja järvimaisemissa. 1000 V verkot mahdollistavat kaapeliauraamisen lisäämisen ja näin voidaan vähentää ympäristöä haittaavien kyllästettyjen pylväiden käyttöä. 1000 V jakeluverkkojen osalta tutkimustyön tuloksia on sovellettu suomalaisessa Suur-Savon Sähkö Oy:ssä. Käytännön kokemuksia 1000 V jakelujärjestelmästä on useista kymmenistä kohteista. Tutkimustulokset osoittavat, ettei keskijänniteverkon maakaapelointi hajaasutusalueilla ole taloudellisesti kannattavaa nykyisillä keskeytyksistä aiheutuvilla haitta-arvoilla, mutta jos keskeytyskustannusten arvostus kasvaa, tulee kaapelointi kannattavaksi monissa paikoissa. Myös myrskyisyyden ja myrskyistä aiheutuvien jakelukeskeytysten lisääntyminen tekisi kaapeloinnista kannattavan. Tulevaisuudessa jakeluverkkojen rakentaminen on entistä monimuotoisempi tehtävä, jossa taloudellisuuden ja käyttövarmuuden lisäksi on huomioitava asiakkaat, omistajat, viranomaiset ja ympäristö. Tutkimusta jakelutekniikan kehittämiseksi tarvitaan edelleen. Tulevaisuuden osalta haja-asutusalueiden jakeluverkkojen kehittämiseen liittyy paljon epävarmuuksia. Hajautetun kiinteistökohtaisen sähköntuotannon lisääntyminen voi tehdä jakeluverkoista nykyistä tarpeettomampia, mutta esimerkiksi liikenteen sähköistyminen voi kasvattaa jakeluverkkojen merkitystä. Tästä syystä jakeluverkkojen rakentamisessa tarvitaan joustavuutta, jotta tarvittaessa voidaan helposti sopeutua erilaisiin kehityssuuntiin.

Mahdollisuudet pakkausten hiilijalanjäljen pienentämiseen. Case: kuituvalos

Ilmastonmuutoksen myötä tuotteiden hiilijalanjälkien laskeminen on yleistynyt. Tässä työssä perehdytään pakkausten aiheuttamiin kasvihuonekaasupäästöihin niiden elinkaaren aikana. Työssä lasketaan hiilijalanjälki myymäläpakkaukselle, joka on valmistettu kuituvaloksesta. Vertailua varten lasketaan hiilijalanjälki paisutetusta polystyreenistä valmistetulle pakkaukselle samassa käyttötarkoituksessa. Tavoitteena on selvittää, miten pakkausten kasvihuonekaasutaseet eroavat toisistaan, ja mitkä elinkaaren aikaiset vaiheet muodostavat merkittävimmät päästöt. Työssä käytetään PAS 2050 -ohjeistusta hiilijalanjäljen laskentaan. Laskennassa on huomioitu suorien ja epäsuorien päästöjen lisäksi myös vältetyt päästöt. Tulosten mukaan materiaalien välisen paremmuuden ratkaisee käytetty jätteenkäsittelytapa. Mikäli kuituvalos kierrätetään, on sen hiilijalanjälki paisutettua polystyreeniä (EPS) pienempi. Tarkastellut jätteenkäsittelytavat EPS:lle olivat kaatopaikkasijoitus ja energiahyötykäyttö. Mikäli kuituvalos kompostoidaan tai käytetään hyödyksi energiana, on sen hiilijalanjälki suurempi kuin EPS:n. Kuituvaloksella selkeästi merkittävimmäksi kasvihuonekaasujen aiheuttajaksi osoittautui pakkauksen valmistusvaihe. EPS:llä merkittäviä vaiheita olivat raaka-aineen tuotanto ja kuljetukset. Tulokset antavat kuvan materiaalien ilmastonmuutospotentiaalista, mutta on huomioitava, ettei hiilijalanjälkitarkastelussa huomioida muita pakkausten ympäristövaikutuksia niiden elinkaaren ajalta.

Rakennettu muutos. Esiselvitys Etelä-Karjalan alueellisen toimintakyvyn ylläpitämisestä talouslaman ja teollisuuden rakennemuutoksen paineessa.

Uudella vuosituhannella vauhtia saanut suomalaisen metsäteollisuuden muodonmuutos on yksi eteläkarjalaisen keskustelun ykkösaiheista. Naapurimaakunnassa Kymenlaaksossa suuret konsernit ovat jo sulkeneet kokonaisia tehtaita ja metsäteollisuuden rakennemuutoksen vaiku-tukset ovat näkyneet täydessä mitassa. Etelä-Karjalassa tapahtumia on seurattu läheltä eikä niiden jatkoksi ole ollut halua liittyä. Etelä-Karjalan lähtökohtia rakennemuutokseen voi avata ja taustoittaa tarkastelemalla rakennemuutoksen kokonaiskuvaa. Vaikka rakennemuutos on yllättänyt monet metsäteollisuusalueet voimallaan, rakenteellisia muutoksia on koettu ennenkin. Yhteiskunnalliset ja taloudelliset rakenteet hakevatkin muotoaan jatkuvasti. Globaalissa toimintaympäristössä muutoksen tahti on kuitenkin kiihtynyt, mikä on puolestaan tuonut uusia alueellisia haasteita erityisesti jos elinkeinorakenne nojaa vahvasti yhteen teollisuuden alaan tai toimijaan. Alueellisina vahvuuksina pidetyt klusterit ovatkin vaarassa muodostua myös riskitekijöiksi, jotka voivat estää uusia innovaatioita ja jarruttaa tarpeettomasti rakenteellista uudistumista. Suomi ei ole tässä suhteessa ainoa: teollisuuskaupungit ympäri läntisen maailman ovat kohdanneet uudistumispaineita, jotka ovat siirtäneet elinkeinorakennetta perinteisestä teollisuudesta kohti palvelu- ja tietointensiivisiä aloja. Toiset kaupungit ovat onnistuneet muuttumaan joustavasti omilla ehdoillaan, toiset ovat heränneet rakenteelliseen uudistumiseen vasta kriisin kautta. Monet perinteiset eurooppalaiset teollisuudenalat, kuten tekstiili-, hiili- ja autoteollisuus ovat kokeneet kovia alasajoja, mutta niiden raunioilta on lähtenyt kasvamaan myös uutta osaamista, kuten kulttuuriprofiloitumista sekä ympäristö- ja ICT-osaamista. Alueelliset lähtökohdat rakennemuutokseen määrittyvät pitkälti nykyisen osaamis- ja yhteistyörakenteen mukaan, jotka Etelä-Karjalassa ovat monelta osin sidoksissa metsäteollisuuteen. Metsäteollisuus on supistuksista ja muista rakennemuutoksen merkeistä huolimatta vielä maakunnassa vahvasti läsnä – niin fyysisesti kuin henkisestikin. UPM ja Stora Enso ovat Etelä-Karjalan suurimmat yksityiset työllistäjät ja molemmilla on tuotantolaitosten lisäksi alueella myös omat tutkimuslaitoksensa. Yhteistyö Lappeenrannan teknillisen yliopiston kanssa on tiivistä yliopiston kouluttaessa alalle merkittävän määrän uusia osaajia. Metsäklusteriin on sidottu myös monet muut toimijat kuten Etelä-Karjalan ammattikorkeakoulu, alueen oma Metsäteollisuusinstituutti, maakunnasta käsin hallinnoitava Uusiutuva metsäteollisuus -klusteri, sekä laaja alihankinta- ja palveluverkosto. Rakennemuutoksen haasteisiin on Etelä-Karjalassa ja myös valtakunnan tasolla vastattu käynnistämällä hankkeita, jotka pyrkivät lisäämään metsäteollisuuden kannattavuutta kehittämällä yhä älykkäämpiä metsäteollisuustuotteita. Metsäteollisuuden ohella Etelä-Karjalan vahvoina osaamisalueina ja tärkeinä investointikohteina pidetään ympäristö- ja energia-alaa sekä Venäjä-osaamista. Myös palvelualaan sekä alueen matkailuun on investoitu vahvasti viime vuosina. Kokemukset äkillisistä rakennemuutoksista muualla Suomessa ovat osoittaneet, että kriisitilanteessa eri toimijat kokoontuvat laajasti yhteen tekemään töitä tilanteen kääntämiseksi positiiviseksi. Nämä verkostot rakentuvat luontevasti ja nopealla aikataululla äkillisen kriisin uhatessa alueellisen elinvoiman säilymistä. Vaikka kriisivalmiuden rakentaminen on olennainen osa rakennemuutoksen valmistautumista myös Etelä-Karjalassa, vielä suurempi merkitys on ennakoimisella ja muutoksen aktiivisella rakentamisella. Ennakointiin kuuluu laaja katsantokanta ja valmistautuminen myös kipeisiin skenaarioihin. Metsäteollisuusmaakunnan on myös uskallettava katsoa rakennemuutosta myös muuten kuin metsäteollisuuden silmin, sillä rakennemuutoksen vaikutusalue ei rajaudu vain metsäklusteriin. Kriisitilanne onkin alueelle aina myös mahdollisuus kehittymiseen ja vanhojen rakenteiden uudelleenarviointiin. Mikäli hyvin vauhtiin päässyt metsäteollisuuden uudistumissuunnitelma ei kanna tai se jättää Etelä-Karjalaan vain hyvin pienen, entistä erikoistuneemman metsäteollisuussektorin, varalla on hyvä olla uusia suunnitelmia, rakenteita sekä jo kasvuun alkuun päässeitä tulevaisuuden aloja. Elinkeinorakennetta tulee arvioida myös laajemmin; onko klusteriajattelu jo aikansa elänyt yhä lyhentyvien elinkaarien myötä ja pitäisikö veturiyritysten sijaan osaamista hajauttaa joustavampaan ja monipuolisempaan muotoon? Miten rakennemuutokseen tulisi ylipäätään suhtautua? Onko rakennemuutoksen estäminen ja lieventäminen ainoat toimintamallit vai voisiko rakennemuutosta jopa olla edullisempaa jouduttaa?

On the effects of welding parameters on weld quality of plasma arc keyhole welding of structural steels

The possibility and the usefulness of applying plasma keyhole welding to structural steels with different compositions and material thicknesses, and in various welding positions has been examinated. Single pass butt welding with I groove in flat, horizontal vertical and vertical positions and root welding with V , Y and U grooves of thick plate material in flat position have been studied and the welds with high quality has been obtained. The technological conditions for successful welding are presented. The single and interactive effects of welding parameters on weld quality, especially on surface weld defects, geometrical form errors, internal defects and mechanical properties (strength, ductility, impact toughness, hardness and bendability) of weld joint, are presented. Welding parameter combinations providing the best quality welds are also presented.

Knapsack sets for cryptography

The basic goal of this study is to extend old and propose new ways to generate knapsack sets suitable for use in public key cryptography. The knapsack problem and its cryptographic use are reviewed in the introductory chapter. Terminology is based on common cryptographic vocabulary. For example, solving the knapsack problem (which is here a subset sum problem) is termed decipherment. Chapter 1 also reviews the most famous knapsack cryptosystem, the Merkle Hellman system. It is based on a superincreasing knapsack and uses modular multiplication as a trapdoor transformation. The insecurity caused by these two properties exemplifies the two general categories of attacks against knapsack systems. These categories provide the motivation for Chapters 2 and 4. Chapter 2 discusses the density of a knapsack and the dangers of having a low density. Chapter 3 interrupts for a while the more abstract treatment by showing examples of small injective knapsacks and extrapolating conjectures on some characteristics of knapsacks of larger size, especially their density and number. The most common trapdoor technique, modular multiplication, is likely to cause insecurity, but as argued in Chapter 4, it is difficult to find any other simple trapdoor techniques. This discussion also provides a basis for the introduction of various categories of non injectivity in Chapter 5. Besides general ideas of non injectivity of knapsack systems, Chapter 5 introduces and evaluates several ways to construct such systems, most notably the "exceptional blocks" in superincreasing knapsacks and the usage of "too small" a modulus in the modular multiplication as a trapdoor technique. The author believes that non injectivity is the most promising direction for development of knapsack cryptosystema. Chapter 6 modifies two well known knapsack schemes, the Merkle Hellman multiplicative trapdoor knapsack and the Graham Shamir knapsack. The main interest is in aspects other than non injectivity, although that is also exploited. In the end of the chapter, constructions proposed by Desmedt et. al. are presented to serve as a comparison for the developments of the subsequent three chapters. Chapter 7 provides a general framework for the iterative construction of injective knapsacks from smaller knapsacks, together with a simple example, the "three elements" system. In Chapters 8 and 9 the general framework is put into practice in two different ways. Modularly injective small knapsacks are used in Chapter 9 to construct a large knapsack, which is called the congruential knapsack. The addends of a subset sum can be found by decrementing the sum iteratively by using each of the small knapsacks and their moduli in turn. The construction is also generalized to the non injective case, which can lead to especially good results in the density, without complicating the deciphering process too much. Chapter 9 presents three related ways to realize the general framework of Chapter 7. The main idea is to join iteratively small knapsacks, each element of which would satisfy the superincreasing condition. As a whole, none of these systems need become superincreasing, though the development of density is not better than that. The new knapsack systems are injective but they can be deciphered with the same searching method as the non injective knapsacks with the "exceptional blocks" in Chapter 5. The final Chapter 10 first reviews the Chor Rivest knapsack system, which has withstood all cryptanalytic attacks. A couple of modifications to the use of this system are presented in order to further increase the security or make the construction easier. The latter goal is attempted by reducing the size of the Chor Rivest knapsack embedded in the modified system. '