Metaanin muodostumisen mallintaminen kaatopaikalla

Methane-rich landfill gas is generated when biodegradable organic wastes disposed of in landfills decompose under anaerobic conditions. Methane is a significant greenhouse gas, and landfills are its major source in Finland. Methane production in landfill depends on many factors such as the composition of waste and landfill conditions, and it can vary a lot temporally and spatially. Methane generation from waste can be estimated with various models. In this thesis three spreadsheet applications, a reaction equation and a triangular model for estimating the gas generation were introduced. The spreadsheet models introduced are IPCC Waste Model (2006), Metaanilaskentamalli by Jouko Petäjä of Finnish Environment Institute and LandGEM (3.02) of U.S. Environmental Protection Agency. All these are based on the first order decay (FOD) method. Gas recovery methods and gas emission measurements were also examined. Vertical wells and horizontal trenches are the most commonly used gas collection systems. Emission measurements chamber method, tracer method, soil core and isotope measurements, micrometeorological mass-balance and eddy covariance methods and gas measuring FID-technology were discussed. Methane production at Ämmässuo landfill of HSY Helsinki Region Environmental Services Authority was estimated with methane generation models and the results were compared with the volumes of collected gas. All spreadsheet models underestimated the methane generation at some point. LandGEM with default parameters and Metaanilaskentamalli with modified parameters corresponded best with the gas recovery numbers. Reason for the differences between evaluated and collected volumes could be e.g. that the parameter values of the degradable organic carbon (DOC) and the fraction of decomposable degradable organic carbon (DOCf) do not represent the real values well enough. Notable uncertainty is associated with the modelling results and model parameters. However, no simple explanation for the discovered differences can be given within this thesis.

Image analysis for assessing broiler breeder behavior response to thermal environment

The research proposes a methodology for assessing broiler breeder response to changes in rearing thermal environment. The continuous video recording of a flock analyzed may offer compelling evidences of thermal comfort, as well as other indications of welfare. An algorithm for classifying specific broiler breeder behavior was developed. Videos were recorded over three boxes where 30 breeders were reared. The boxes were mounted inside an environmental chamber were ambient temperature varied from cold to hot. Digital images were processed based on the number of pixels, according to their light intensity variation and binary contrast allowing a sequence of behaviors related to welfare. The system used the default of x, y coordinates, where x represents the horizontal distance from the top left of the work area to the point P, and y is the vertical distance. The video images were observed, and a grid was developed for identifying the area the birds stayed and the time they spent at that place. The sequence was analyzed frame by frame confronting the data with specific adopted thermal neutral rearing standards. The grid mask overlapped the real bird image. The resulting image allows the visualization of clusters, as birds in flock behave in certain patterns. An algorithm indicating the breeder response to thermal environment was developed.

Eurojärjestelmän vakuudet kotimaisten markkinoiden näkökulmasta

Tutkimus kohdistuu Eurojärjestelmän vakuuksien tarkasteluun teoreetti-sesta näkökulmasta. Tutkimus perustuu Eurojärjestelmän sääntelyyn ja kansalliseen lainsäädäntöön, joiden yhteensovittaminen Euroalueella on luonut omanlaisensa järjestelmän. Eurojärjestelmän vakuushallinnan kehikko on monipuolinen tarkastelun kohde ja tutkimuksen mukaan kotimaisen markkinan yhteensovittaminen sekä arvostaminen ovat onnistuneet toistaiseksi, mutta tulevaisuudessa on näkyvissä haasteita. Toisaalta tutkimuksen mukaan käynnissä oleva taloudellinen tilanne on ajanut Eurojärjestelmän uusien ongelmien eteen, joiden keskuksessa ovat Eurojärjestelmän saatavien turvaaminen jokaisessa mahdollisessa tilanteessa. Tämä on haaste jonka Eurojärjestelmä on ottanut huomioon teoriassa ja vakuushallinnan riskienhallintakehikko kehittyy jatkuvasti. Kotimaisten velkainstrumenttien kohdalla ei ole vastaanvanlaista monipuolisuutta, kuin muualla Eurojärjestelmässä.

Scheduling of guarded command based models

Formal methods provide a means of reasoning about computer programs in order to prove correctness criteria. One subtype of formal methods is based on the weakest precondition predicate transformer semantics and uses guarded commands as the basic modelling construct. Examples of such formalisms are Action Systems and Event-B. Guarded commands can intuitively be understood as actions that may be triggered when an associated guard condition holds. Guarded commands whose guards hold are nondeterministically chosen for execution, but no further control flow is present by default. Such a modelling approach is convenient for proving correctness, and the Refinement Calculus allows for a stepwise development method. It also has a parallel interpretation facilitating development of concurrent software, and it is suitable for describing event-driven scenarios. However, for many application areas, the execution paradigm traditionally used comprises more explicit control flow, which constitutes an obstacle for using the above mentioned formal methods. In this thesis, we study how guarded command based modelling approaches can be conveniently and efficiently scheduled in different scenarios. We first focus on the modelling of trust for transactions in a social networking setting. Due to the event-based nature of the scenario, the use of guarded commands turns out to be relatively straightforward. We continue by studying modelling of concurrent software, with particular focus on compute-intensive scenarios. We go from theoretical considerations to the feasibility of implementation by evaluating the performance and scalability of executing a case study model in parallel using automatic scheduling performed by a dedicated scheduler. Finally, we propose a more explicit and non-centralised approach in which the flow of each task is controlled by a schedule of its own. The schedules are expressed in a dedicated scheduling language, and patterns assist the developer in proving correctness of the scheduled model with respect to the original one.

Beta and debt premium for a Finnish distribution company

Suomessa sähkönjakelu on säännelty monopoli. Energiamarkkinavirasto tuottaa ohjeistuksen sekä mallin yritysten ansaintamahdollisuuksille. Karkeasti sanottuna tulomalli on sijoitetun pääoman ja pääoman painotetun kustannuksen tulo. Pääoman painotettu kustannus koostuu useista parametreista kuten beta ja vieraan pääoman riskipreemio. Näiden parametrien taso ja määrittämisajankohta perustuvat subjektiivisiin näkemyksiin, kun objektiivista parametrien määrittämismenetelmää tulisi käyttää. Nykyiset beta ja vieraan pääoman riskipreemio perustuvat energiamarkkinaviraston ja asiantuntijoiden lausuntoihin. Aihealuetta on tutkittu erittäin vähän, mikä johtunee pääasiassa siitä, ettei ole olemassa listautuneita puhtaita jakeluverkkoyhtiöitä. Betan nykytaso on 0.529 ja vieraan pääoman riskipreemio on 1.0 %. Tässä pro gradu –työssä määritetään markkinaperusteisesti betan ja vieraan pääoman riskipreemion nykytaso. Tässä työssä esiteltävä määrittämismalli perustuu puhtaasti markkinadataan eikä sen soveltamisessa käytetä subjektiivisia mielipiteitä. Markkinaehtoisia tietoja käyttäen betan pitäisi olla tasolla 0.525 ja vieraan pääoman riskipreemion tasolla 1.34 %. Nämä luvut, mikäli ne otettaisiin käyttöön, vaikuttaisivat suoraan ja positiivisesti jakeluverkkoyhtiöiden sallittuun tuottoon Suomessa.

Determinants of credit risk in secured loans – Evidence from the auto loan industry

The purpose of this study is to examine attributes which have explanation power to the probability of default or serious overdue in secured auto loans. Another goal is to find out differences between defaulted loans and loans which have had payment difficulties but survived without defaulting. 19 independent variables used in this study reflect information available at the time of credit decision. These variables were tested with logistic regression and backward elimination procedure. The data includes 8931 auto loans from a Finnish finance company. 1118 of the contracts were taken by company customers and 7813 by private customers. 130 of the loans defaulted and 584 had serious payment problems but did not default. The maturities of those loans were from one month to 60 months and they have ended during year 2011. The LTV (loan-to-value) variable was ranked as the most significant explainer because of its strong positive relationship with probability of payment difficulties. Another important explainer in this study was the credit rating variable which got a negative relationship with payment problems. Also maturity and car age performed well having both a positive relationship with the probability of payment problems. When compared default and serious overdue situations, the most significant differences were found in the roles of LTV, Maturity and Gender variables.

Strategic communication : practice, ideology and dissonance

This dissertation approaches the manifestations of ideology in U.S. Strategic Communication. The discussion approaches Strategic Communication by relating it to the Enlightenment narratives and suggesting these narratives maintain similar social and political functions. This dissertation aims to address the key contents and mechanisms of Strategic Communication by covering the perspectives of (i) communication as leadership as well as (ii) communication as discourse , i.e. practice and contents. Throughout the empirical part of the dissertation, the communication theoretical discussion is supported by a methodological framework that bridges Critical Discourse Analysis (CDA) and functional language theory. According to the principles of CDA, Strategic Communication is treated as ideological, hegemonic discourse that impacts social order. The primary method of analysis is transitivity analysis, which is concerned with how language and its patterns construe reality. This analysis is complemented with a discussion on the rituals of production and interpretation, which can be treated as visual extensions of textual transitivity. The concept of agency is the key object of analysis. From the perspective of leadership, Strategic Communication is essentially a leadership model through which the organization defines itself, its aims and legitimacy. This dissertation arrives to the conclusion that Strategic Communication is used not only as a concept for managing Public Relations and information operations. It is an esse ntial asset in the inter-organization management of its members. The current developments indicate that the concept is developing towards even heavier measures of control. From the perspective of language and discourse, the key narratives of Strategic Communication are advocated with the intrinsic values of democracy and technological progress as the prerequisites of ethics and justice. The transitivity patterns reveal highly polarized agency. The agency of the Self is typically outsourced to technology. Further, the transitivity pa tterns demonstrate how the effects-centric paradigm of warfare has created a lexicon that is ideologically exclusive. It has led to the development of two mutually exclusive sets of vocabulary, where the desc riptions of legitimate ac tion exclude Others by default. These ideological discourses have become naturalized in the official vocabulary of strategic planning and le adership. Finally, the analysis of the images of the captures and deaths of Saddam Hussein, Osama bin Laden and Muammar Gaddafi bring the discussion back to the themes of the Enlightenment by demonstrating how democracy is framed to serve political purposes. The images of democracy are essentially images of violence. Contrary to the official, instrumental and humanitari an narratives of Strategic Communication, it is the grammar of expressive, violent rituals that serve as the instrument of unity.

Pankkien nykysääntelyn vaikutukset pk-yritysten rahoitukseen : empiirinen tutkimus konkurssiriskin ja vakuuden vaikutuksista luotonantopäätökseen

Pankkialan sääntely on viime vuosina lisääntynyt. Pankkisääntelyn keskeisimpänä ohjenuorana toimiva Basel-sääntelykehikko asettaa pankeille minipääomavaatimuksia, joiden tarkoituksena on säilyttää pankkitoiminta terveellä pohjalla ja parantaa pankkien tappionsietokykyä. Sääntelyn varjopuolena on kuitenkin pankkien vakavaraisuuden nostamisesta seuraava luotonleikkaus, joka vaikuttaisi kohdistuvan terävimmin pieniin ja keskisuuriin yrityksiin – yrityksiin, jotka rahoittavat valtaosan toiminnastaan velkarahalla. Pelkkä yleinen luotonannon vähentäminen ei kuitenkaan suoraan selitä, miksi juuri pk-yritykset ovat leikkausten kohteena, sillä luotonannon vähentyessä lainattavan potin jakaminen pienempiin osiin – pienemmiksi luotoiksi – saa rahat riittämään useammalle, jolloin myös pankin luottosalkku on hajautetumpi. On siten oltava jokin muu syy, miksi lähtökohtaisesti pienempiä luottoja hakevat pk-yritykset eivät saa pankkilainaa. Tutkielmassa tarkastellaan pankkien nykysääntelyn vaikutusta pk-yritysten lainansaantiin. Basel-säännöstön asettamat minipääomavaatimukset vaikuttavat pankkien luotonmyöntöpäätöksiin luotolle laskettavan riskipainon kautta. Riskipainoon vaikuttaa kaksi ulkoista tekijää, vastapuolen konkurssin todennäköisyys (Probability of Default, PD) sekä luotolle myönnettävä vakuus. Tutkielmassa luodaan malli pk-yrityksen konkurssiriskin estimoimiseksi logistisella regressioanalyysillä. Malli luodaan, jotta tutkielmaan kerätyn aineiston yrityksien riskiprofiileja olisi mahdollista tarkastella. Aineistoon on kerätty Voitto + -tietokannasta 116 yrityksen tilinpäätökset sekä tunnusluvut, joiden pohjalta konkurssiriskiä tutkitaan, ja vakuudeksi riittävän omaisuuden määrää tarkastellaan. Riskipainon määräytymistä tarkastellaan kahdeksan aineistosta valitun esimerkkiyrityksen avulla ja koko aineiston pohjalta luodaan katsaus varsinaissuomalaisten pk-yritysten luotonsaantimahdollisuuksiin. Basel-säännöstö vaikuttaa kannustavan pankkeja turvattuun luotonantoon, jolloin lainan vakuuden merkitys korostuu. Tutkielmassa luodun konkurssiriskin estimointimallin perusteella aineiston yrityksille itse konkurssiriski ei näyttäisi olevan suuri ongelma lainaa haettaessa: noin 70 % yrityksistä oli selkeästi vielä luottokelpoisia. Sen sijaan krooninen vakuuden puute vaikuttaisi suurimmalta syyltä negatiiviseen luotonmyöntöpäätökseen. Aineiston yrityksistä vain yhdellä oli riittävästi vakuudeksi kelpaavaa omaisuutta kattamaan esimerkkilaskelmissa käytetyn 100 000 €:n lainapääoman; valtaosalla yrityksistä vakuusmassaa oli taseessa alle 10 000 €. Koska Basel-sääntely asettaa korkeat riskipainot vakuudettomille luotoille, ja riskipaino kasvattaa suoraan pankissa pidettäviä pääomareservejä, pk-yritysten luototus aiheuttaa pankeille ylimääräisiä kustannuksia. Näin on löydetty osaltaan yksi selitys juuri pk-yrityksiin kohdistuviin luotonleikkauksiin.

An Open Source, DDI-based Curation System for Social Science Data

Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

DSpace-CRIS tutorial

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Online peer to peer lending: clustering borrowers using self-organizing maps

The purpose of this thesis is to find out whether all the peer to peer lenders are unworthy of credit and also if there are single qualities or combinations of qualities that determine the probability of default of a person or group of people. Distinguishing qualities are searched with self-organizing maps (SOM). Qualities and groups of people found by the self-organizing map are then compared to the average. The comparison is carried out by looking how big proportion of borrowers meeting the criteria is two months or more behind with their payments. Research data used is collected by an Estonian peer to peer lending company during the years of 2011-2014. Data consists of peer to peer borrowers and information gathered from them.

Reflexivity in sovereign debt markets

Finanssi-instrumentin hinta määräytyy sen fundamenttitekijöiden perusteella, eikä päinvastoin. Tämä tutkimus osoittaa, että myös instrumentin hinta voi vaikuttaa fundamenttitekijöihin. Yhteys havainnollistetaan tapaustukimuksella Kreikan velkakriisistä. Hinnan ja fundamenttien välistä yhteyttä arvioidaan ja käänteisen kausaliteetin olemassaolo testataan. Tulokset tukevat ajatusta, jonka mukaan tarvitsemme dynaamisempia valuaatiomenetelmiä, jotka ottavat huomioon myös mahdolliset itseään vahvistavat hintakierteet.

Effect of scanner acoustic background noise on strict resting-state fMRI

Functional MRI (fMRI) resting-state experiments are aimed at identifying brain networks that support basal brain function. Although most investigators consider a ‘resting-state’ fMRI experiment with no specific external stimulation, subjects are unavoidably under heavy acoustic noise produced by the equipment. In the present study, we evaluated the influence of auditory input on the resting-state networks (RSNs). Twenty-two healthy subjects were scanned using two similar echo-planar imaging sequences in the same 3T MRI scanner: a default pulse sequence and a reduced “silent” pulse sequence. Experimental sessions consisted of two consecutive 7-min runs with noise conditions (default or silent) counterbalanced across subjects. A self-organizing group independent component analysis was applied to fMRI data in order to recognize the RSNs. The insula, left middle frontal gyrus and right precentral and left inferior parietal lobules showed significant differences in the voxel-wise comparison between RSNs depending on noise condition. In the presence of low-level noise, these areas Granger-cause oscillations in RSNs with cognitive implications (dorsal attention and entorhinal), while during high noise acquisition, these connectivities are reduced or inverted. Applying low noise MR acquisitions in research may allow the detection of subtle differences of the RSNs, with implications in experimental planning for resting-state studies, data analysis, and ergonomic factors.