30 resultados para Difficult times


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Rakennusteollisuuden prosessit ovat vielä usein paperipohjaisia, mikä aiheuttaa työmaiden luonteesta johtuen tiedon hajaantumista, hidastaa tiedon siirtymistä ja vaikeuttaa tiedon käsittelyä. Työmaiden väliaikaisilla konttoreilla tiedon määrä voi nousta hallitsemattoman suureksi, mikä haittaa ja hidastaa työnjohdon päätöksentekoa. Käyttämällä sähköisiä työkaluja tiedon keräämistä, keskittämistä ja siirtoa voidaan tehostaa. Projektin tavoitteeksi otettiin teollisuuden laadunvalvonnan tarkastusprosessin tehostaminen ajallisesti käyttämällä tarkastustyöhön sähköistä tarkastuspöytäkirjaa. Tätä varten suunniteltiin sähköinen tarkastusjärjestelmä, joka koostuu kolmesta erillisestä osasta: Tarkastajan mukana kulkeva mobiililaite, jolle tallennetaan suoraan tarkastuksen laatutietoa, palvelinkone avustamaan tiedonsiirrossa ja –varastoinnissa sekä työpöytäsovellus työnjohdon tarpeisiin. Järjestelmää testattiin sähköalan asennuksia tekevässä yrityksessä osana yrityksen normaalia tarkastustyötä. Verrattuna paperiseen pöytäkirjaan sähköinen tarkastusjärjestelmä nopeutti prosessia moninkertaisesti. Nopeustesteissä havaittiin kuitenkin, että valittu tiedon synkronointikirjasto oli järjestelmän tarpeisiin liian hidas. Järjestelmä saavutti sille asetetut tavoitteet tehostamalla prosessia ajallisesti, mutta järjestelmässä on vielä osa-alueita, jotka tarvitsevat jatkokehittämistä.

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Kirjallisuustyössä tutkittiin tehostetun hapetuksen menetelmiä (engl. Advanced Oxidation Processes, AOPs) kloorifenolien käsittelyssä. Tutkittava aine valittiin US EPA:n (United States Environmental Protection Agency) ympäristölle haitallisten aineiden listalta. Työssä tutkitut AOP-menetelmät olivat otsonointi kasvatetussa pH:ssa, O3/H2O2-prosessi, fotolyyttinen otsonointi (O3/UV), H2O2/UV-prosessi ja Fenton-prosessi (H2O2+Fe2+). AOP-käsittelyssä OH-radikaalien oletetaan pääosin aiheuttavan epäpuhtauksien hapettumisen. Kirjallisuustyössä tutkittiin OH-radikaaleihin vaikuttavien parametrien, kuten pH:n, lämpötilan sekä hapettimien ja hapetettavan aineen konsentraatioiden vaikutusta kloorifenolien hapetusprosessissa. Työn tarkoituksena oli selvittää tehokkain AOP-käsittely kloorifenoleja sisältävien jätevesien käsittelylle. AOP-käsittelyjen tehokkuutta verrattiin hajoamisnopeusvakioiden, puoliintumisaikojen sekä hapettimen kemikaalikulutuksen ja kustannuksen perusteella. Fenton-prosessin ja otsonoinnin pH:ssa 9 todettiin olevan tehokkaimpia menetelmiä kloorifenolien hapetuksessa. Fenton-prosessin hapetusnopeus oli tehokkaampaa 4-CP:n ja 2,4-DCP:n hapetuksessa, kun taas otsonointi pH:ssa 9 hapetti nopeammin 2,3,4,6-TeCP:n ja 2,4,6-TCP:n. Kustannustehokkuuden perusteella Fenton-prosessi oli otsonointia tehokkaampi. Parhaan menetelmän valinta kloorifenoleiden poistamiseksi oli vaikeaa, sillä useissa tutkimuksissa oli tutkittu vain yhtä menetelmää. Lisäksi eri tutkimuksissa käytetyt prosessiolosuhteet olivat erilaiset, joka hankaloitti tutkimusten vertailua. Lopullinen AOP-menetelmän valinta tulisikin suorittaa vasta laboratoriotutkimusten jälkeen.

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Deep cannulation is a prerequisite for successful endoscopic retrograde cholangiopancreatography (ERCP) procedures. Of the biliary procedures, stenting is one of the most common. This study was carried out to investigate current and controversial issues regarding biliary cannulation and stenting. The double guidewire (DGW) technique was studied to analyze its safety and feasibility in biliary cannulation as a single procedure and as a part of the novel three-step cannulation protocol. Female gender was evaluated in regard to difficult cannulation. The use of an angled and a straight tipped guidewire in biliary cannulation was studied in a prospective, randomized trial. Additionally, the patency of the novel antireflux plastic biliary stent was compared to the patency of the conventional plastic biliary stent in a prospective, randomized setting. The DGW method seems safe and feasible as an alternative cannulation technique in biliary cannulation. Female gender was not associated significantly with difficult biliary cannulation in our study, although the cannulation times seemed to be longer and the alternative cannulation techniques seemed to be needed more often in females than males. According to the results of this thesis, an angled tipped guidewire may facilitate biliary cannulation. In controversy to the previous result presented in the literature, the antireflux plastic biliary stent tested herein should not be used, as the patency of the stent was significantly shorter compared to the conventional plastic stent.

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Previous research on productivity is often associated with manufacturing or uses manufacturing definitions of productivity. Marketing research on services has not been satisfied with the manufacturing definitions. No universal definition for service productivity exists. The lack of a universal definition highlights the complexity entailed in the concept of productivity. The objective of this study was to investigate service productivity in situations, where traditional ways are in some cases even not possible or are not enough. In one definition of the productivity of service organisations there is the efficiency of the organisation on the input side and on the output side the customers’ perceived quality or value-in-use. To learn about value-in-use, many methods have been developed. A common practice is to make customer opinion surveys in the form of customer questionnaires and interviews. However, customers cannot always be asked directly, for example, because of impaired cognitive abilities. Such cases include the elderly and children. Furthermore, customer opinion surveys are time consuming. In addition, customers do not always know what kind of services they would benefit from. For the empirical part of the study, a business area was identified where traditional ways of measuring value-in-use are difficult or in some cases even not possible. This business area is safety telephone services. These services are most often used by the elderly. The way to define value-in-use here was to assess how well the services offered met customer expectations. Comparing the services customers asked for and the services provided to them indicated whether customer expectations were met. This study showed that customers had their ideas concerning the contents of the services but many times the services provided did not meet these expectations. Organisational efficiency aspirations can decrease customers’ value-in-use. This study found a solution, in which increasing organisational efficiency would go hand-in-hand with increasing customers’ value-in-use; the result being that the organisations’ needs and the service users’ expectations were in line. Value creation for customers produced organisational efficiency and thus increased productivity. In this study, customer expectations were observed by means of wellness technology. With the help of modern technology, customer expectations can be followed quickly and easily and customers can co-create with the organisation. This type of an approach could be useful even in the development of other services for other ages and in different contexts. If a service organisation decreases the number of personnel and, at the same time, tries to offer services to the same or a larger clientele, customers easily notice the change, which is often negative. To avoid harmful decrease in value-in-use, limitations to the aspiration of efficiency should be implemented – one of such is that the organisation is required to meet certain quality standards defined by experts. The aim is to secure that, as a result of efficiency aspirations in the organisation, the quality of the service offerings does not diminish below mutually agreed standards. Traditionally, when productivity in services has been estimated, organisational efficiency has not been combined with both customer expectations and an expert assessment of quality. This study contributes with novel thinking entitled ‘Relationship Management of the Elderly’. This study handles productivity, expert defined quality and value-in-use in an organisational context, which is practically untouched in previous research studies.

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Global illumination algorithms are at the center of realistic image synthesis and account for non-trivial light transport and occlusion within scenes, such as indirect illumination, ambient occlusion, and environment lighting. Their computationally most difficult part is determining light source visibility at each visible scene point. Height fields, on the other hand, constitute an important special case of geometry and are mainly used to describe certain types of objects such as terrains and to map detailed geometry onto object surfaces. The geometry of an entire scene can also be approximated by treating the distance values of its camera projection as a screen-space height field. In order to shadow height fields from environment lights a horizon map is usually used to occlude incident light. We reduce the per-receiver time complexity of generating the horizon map on N N height fields from O(N) of the previous work to O(1) by using an algorithm that incrementally traverses the height field and reuses the information already gathered along the path of traversal. We also propose an accurate method to integrate the incident light within the limits given by the horizon map. Indirect illumination in height fields requires information about which other points are visible to each height field point. We present an algorithm to determine this intervisibility in a time complexity that matches the space complexity of the produced visibility information, which is in contrast to previous methods which scale in the height field size. As a result the amount of computation is reduced by two orders of magnitude in common use cases. Screen-space ambient obscurance methods approximate ambient obscurance from the depth bu er geometry and have been widely adopted by contemporary real-time applications. They work by sampling the screen-space geometry around each receiver point but have been previously limited to near- field effects because sampling a large radius quickly exceeds the render time budget. We present an algorithm that reduces the quadratic per-pixel complexity of previous methods to a linear complexity by line sweeping over the depth bu er and maintaining an internal representation of the processed geometry from which occluders can be efficiently queried. Another algorithm is presented to determine ambient obscurance from the entire depth bu er at each screen pixel. The algorithm scans the depth bu er in a quick pre-pass and locates important features in it, which are then used to evaluate the ambient obscurance integral accurately. We also propose an evaluation of the integral such that results within a few percent of the ray traced screen-space reference are obtained at real-time render times.

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Denna avhandling handlar om metoder för att hitta begränsningar för det asymptotiska beteendet hos en förväntad uthoppstid från ett område omkring en xpunkt för processer som har normalfördelad störning. I huvudsak behandlas olika typer av autoregressiva processer. Fyra olika metoder används. En metod som använder principen för stora avvikelser samt en metod som jämför uthoppstiden med en återkomsttid ger övre begränsningar för den förväntade uthoppstiden. En martingalmetod och en metod för normalfördelade stokastiska variabler ger undre begränsningar. Metoderna har alla både förtjänster och nackdelar. Genom att kombinera de olika metoderna får man de bästa resultaten. Vi får fram gränsvärdet för det asymptotiska beteendet hos en uthoppstid för den multivariata autoregressiva processen, samt motsvarande gränsvärde för den univariata autoregressiva processen av ordning n.

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Interest towards working capital management increased among practitioners and researchers because the financial crisis of 2008 caused the deterioration of the general financial situation. The importance of managing working capital effectively increased dramatically during the financial crisis. On one hand, companies highlighted the importance of working capital management as part of short-term financial management to overcome funding difficulties. On the other hand, in academia, it has been highlighted the need to analyze working capital management from a wider perspective namely from the value chain perspective. Previously, academic articles mostly discussed working capital management from a company-centered perspective. The objective of this thesis was to put working capital management in a wider and more academic perspective and present case studies of the value chains of industries as instrumental in theoretical contributions and practical contributions as complementary to theoretical contributions and conclusions. The principal assumption of this thesis is that selffinancing of value chains can be established through effective working capital management. Thus, the thesis introduces the financial value chain analysis method which is employed in the empirical studies. The effectiveness of working capital management of the value chains is studied through the cycle time of working capital. The financial value chain analysis method employed in this study is designed for considering value chain level phenomena. This method provides a holistic picture of the value chain through financial figures. It extends the value chain analysis to the industry level. Working capital management is studied by the cash conversion cycle that measures the length (days) of time a company has funds tied up in working capital, starting from the payment of purchases to the supplier and ending when remittance of sales is received from the customers. The working capital management practices employed in the automotive, pulp and paper and information and communication technology industries have been studied in this research project. Additionally, the Finnish pharmaceutical industry is studied to obtain a deeper understanding of the working capital management of the value chain. The results indicate that the cycle time of working capital is constant in the value chain context over time. The cash conversion cycle of automotive, pulp and paper, and ICT industries are on average 70, 60 and 40 days, respectively. The difference is mainly a consequence of the different cycle time of inventories. The financial crisis of 2008 affected the working capital management of the industries similarly. Both the cycle time of accounts receivable and accounts payable increased between 2008 and 2009. The results suggest that the companies of the automotive, pulp and paper and ICT value chains were not able to self-finance. Results do not indicate the improvement of value chains position in regard to working capital management either. The findings suggest that companies operating in the Finnish pharmaceutical industry are interested in developing their own working capital management, but collaboration with the value chain partners is not considered interesting. Competition no longer occurs between individual companies, but between value chains. Therefore the financial value chain analysis method introduced in this thesis has the potential to support value chains in improving their competitiveness.

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Fertilizer plant’s process waters contain high concentrations of nitrogen compounds, such as ammonium and nitrate. Phosphorus and fluorine, which originate from phosphoric acid and rock phosphate (apatite) used in fertilizer production, are also present. Phosphorus and nitrogen are the primary nutrients causing eutrophication of surface waters. At fertilizer plant process waters are held in closed internal circulation. In a scrubber system process waters are used for washing exhaust gases from fertilizer reactors and dry gases from granulation drums as well as for cooling down the fertilizer slurry in neutralization reactor. Solids in process waters are separated in an inclined plate settler by gravitational sedimentation. However, the operation of inclined plate settler has been inadequate. The aim of this thesis was to intensify the operation of inclined plate settler and thus the solids separation e.g. through coagulation and/or flocculation process. Chemical precipitation was studied to reduce the amount of dissolved species in process waters. Specific interest was in precipitation of nitrogen, phosphorus, and fluorine containing specimens. Amounts of phosphorus and fluorine were reduced significantly by chemical precipitation. When compared to earlier studies, annual chemical costs were almost eight times lower. Instead, nitrogen compounds are readily dissolved in water, thus being difficult to remove by precipitation. Possible alternative techniques for nitrogen removal are adsorption, ion exchange, and reverse osmosis. Settling velocities of pH adjusted and flocculated process waters were sufficient for the operation of inclined plate settler. Design principles of inclined plate settler are also presented. In continuation studies, flow conditions in inclined plate settler should be modelled with computational fluid dynamics and suitability of adsorbents, ion exchange resins, and membranes should be studied in laboratory scale tests.

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The construction of offshore structures, equipment and devices requires a high level of mechanical reliability in terms of strength, toughness and ductility. One major site for mechanical failure, the weld joint region, needs particularly careful examination, and weld joint quality has become a major focus of research in recent times. Underwater welding carried out offshore faces specific challenges affecting the mechanical reliability of constructions completed underwater. The focus of this thesis is on improvement of weld quality of underwater welding using control theory. This research work identifies ways of optimizing the welding process parameters of flux cored arc welding (FCAW) during underwater welding so as to achieve desired weld bead geometry when welding in a water environment. The weld bead geometry has no known linear relationship with the welding process parameters, which makes it difficult to determine a satisfactory weld quality. However, good weld bead geometry is achievable by controlling the welding process parameters. The doctoral dissertation comprises two sections. The first part introduces the topic of the research, discusses the mechanisms of underwater welding and examines the effect of the water environment on the weld quality of wet welding. The second part comprises four research papers examining different aspects of underwater wet welding and its control and optimization. Issues considered include the effects of welding process parameters on weld bead geometry, optimization of FCAW process parameters, and design of a control system for the purpose of achieving a desired bead geometry that can ensure a high level of mechanical reliability in welded joints of offshore structures. Artificial neural network systems and a fuzzy logic controller, which are incorporated in the control system design, and a hybrid of fuzzy and PID controllers are the major control dynamics used. This study contributes to knowledge of possible solutions for achieving similar high weld quality in underwater wet welding as found with welding in air. The study shows that carefully selected steels with very low carbon equivalent and proper control of the welding process parameters are essential in achieving good weld quality. The study provides a platform for further research in underwater welding. It promotes increased awareness of the need to improve the quality of underwater welding for offshore industries and thus minimize the risk of structural defects resulting from poor weld quality.

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Teräsvalimon toimitusprosessissa toimitusvarmuus on tärkeä tuotannon tunnusluku. Valimotuotannossa olevien lukuisten muuttujien vuoksi tuotannonsuunnittelu ja läpivirtauksen hallinta on haasteellista. Tuotteiden, valumateriaalien ja näiden yhdistelmien suuri yhtäaikainen määrä tuotannossa vaikeuttaa tuotannon ennustettavuutta sekä vaikuttaa läpivirtaukseen ja toimitusvarmuuteen. Lisäksi tuotannon eri työvaiheissa ilmenevät kapeikot rajoittavat läpivirtausta ja kasvattavat läpimenoaikoja. Kapeikkoja voidaan hyödyntää tuotannonohjauksessa jos kapeikot ovat selkeästi havaittavissa. Kapasiteetin siirtäminen ei-kapeikosta kapeikkoon lisää tuotannon läpivirtausta. Pelkkä kapeikkojen hallinta ei paranna toimitusvarmuutta jos keskeneräisen tuotannon määrä on suuri ja järjestys väärä. Tuotannon työkuormien visuaalisuuden parantaminen kaikilla työvaiheilla antaa mahdollisuuksia ohjata tuotantoa tehokkaammin. Kandidaatintyössä on tarkasteltu teräsvalimon valmistusprosessia ja selvitetty tuotannon eri vaiheissa ilmeneviä kapeikkoja. Selvitystyössä hyödynnettiin TOC-analyysiä. Keskeneräisen tuotannon määrää mitattiin useilla otannoilla eri työvaiheiden kohdalla. Tuloksia analysoimalla löydettiin tuotannon ongelmakohdat ja niihin tarvittavat kehitystoimenpiteet.

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Tämän diplomityön tavoitteena oli selvittää hyödyttääkö Stora Enso Metsää tietojärjestelmien siirto perinteisistä konesalipalveluista pilvipalveluihin. Stora Enso Metsällä on paljon erilaisia suunnitteluun liittyviä eräajoja. Joitakin niistä ajetaan vain muutamia kertoja vuodessa kuten tehtaiden puuntarve, toisia muutaman kerran kuussa kuten kuljetusten malliajot tai muutaman kerran viikossa ajettava korjuun suunnittelu. Niissä tapauksissa palvelimet voidaan käynnistää erikseen ja käyttää niitä vain silloin, kun niitä oikeasti tarvitaan. Työn lopputuloksena havaittiin, että pilvipalveluiden käyttöönotto tuo kustannussäästöjä ja palveluiden hallintaan joustavuutta. Itsepalveluna toteutettuna palvelimia voidaan hallinnoida joustavasti kustannusten säästämiseksi. Pilvipalveluilla voidaan nopeuttaa projektien läpimenoa ja kohdentaa käyttökatkot tarkemmin koska siihen ei välttämättä tarvita toimittajan työtä lainkaan. Loppujen lopuksi asiakkaan on erittäin vaikea tietää kuinka paljon kustannuksia on jaettu eri tavalla eri palvelujen välillä.

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Beat-sukupolvi, opiskelijoiden poliittinen aktiivisuus ja hipit olivat tunnettuja ilmiöitä Yhdysvalloissa 1950- ja 1960-luvuilla. Ilmiöillä oli paljon yhteistä ja ne vaikuttivat toisiinsa merkittävästi. Tätä yhteyttä ei aina tuoda esiin. Tämä tutkielma tuo esiin sen, miten The New York Times kirjoitti ilmiöistä. Tutkimus kertoo myös, miten The New York Times yhdistää ilmiöt keskenään. Sen lisäksi tulee esiin The New York Timesin näkemys ilmiöiden taustoista suhteessa nuorisokulttuuriin. Tutkimuksen kohteena on The New York Timesin lehtiartikkeleita vuosilta 1952-1969. Tutkimuksen pääkysymykset ovat: Miten The New York Times suhtautui beat-sukupolveen ja nuorisokulttuurin muutokseen? Miten The New York Times suhtautui yliopisto-opiskelijoihin ja heidän suhteeseensa nuorisokulttuurin muutokseen sekä miten The New York Times näkee hippien muuttavan yhteiskuntaa? Ensimmäistä pääkysymystä tarkastelen kahden alakysymyksen kautta: Miten beat-sukupolven synty esitetään The New York Timesissa, ja toisaalta millaisen kuvan The New York Times antaa beat-sukupolven vaikutuksesta nuorisoon? Toista pääkysymystä käsittelen kysymällä: Miten The New York Times näki nuorten poliittisen vaikuttavuuden nousun ja miten lehti suhtautui ajanjakson yliopistomellakoihin?. Kolmannessa luvussa tarkastelen pääkysymystä kysymällä: Keitä hipit olivat, ja olivatko hipit poliittisesti aktiivisia vai ei? Tutkimuksesta selviää, että The New York Times pyrkii kuvaamaan ilmiöitä mahdollisimman objektiivisesti. Lehti antaa ilmiöitä kuvatessa asioihin hyvin perehtyneiden henkilöiden esittää ilmiö. Sen jälkeen lehti antaa lukijoiden ja muiden asiantuntijoiden kommentoida. The New York Times näkee näiden ilmiöiden yhteyden ja se tulee voimakkaasti esille laajoissa artikkeleissa. Lyhyemmissä uutisissa yhteyttä ei aina näe, ja terminologia on yleistävämpi, tekstin eri tarkoitusperän takia. Kaiken kaikkiaan The New York Times tuo esiin mahdollisimman vähän moralisoivaa kuvaa ilmiöistä ja tuo esiin niiden keskinäisiä suhteita. Tuloksista näkee, että The New York Times on arvoiltaan vapaamielinen lehti, joka uutisoi, näiden aiheiden perusteella, kattavasti koko Yhdysvaltoja koskevista tapahtumista.

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Presentation at the seminar "Publishers and Funders for OA in Finland", Helsinki, May 24, 2016