Comparing Basal Area Diameter Distributions Estimated by Tree Species and for the Entire Stock in a Mixed Stand

Summary

Degree of previous cutting in explaining the differences in diameter distributions between mature managed and natural Norway spruce forests

Abstract

Height distributions of Scots pine sapling stands affected by retained tree and edge stand competition

Abstract

Calibrating predicted tree diameter distributions in Catalonia, Spain

Abstract

Potassium channel KCNH2 K897T polymorphism and cardiac repolarization during exercise test: The Finnish Cardiovascular Study.

Scand J Clin Lab Invest. 2007 Aug 1;:1-11 [Epub ahead of print]

Channel Partner Program Benchmark

Tämän diplomityön tavoitteena on vertailla maailmanlaajuisen sähköalan yhtiön kanavapartneriohjelmaa yhtiön kilpailijoiden vastaaviin ohjelmiin, sekä laatia yhtiön käyttöön konkreettinen työkalu kanavapartneriohjelmien vertailua varten. Tavoitteena on myös tutkimuksessa kerätyn tiedon perusteella selvittää yhtiön kanavapartneriohjelman vahvuudet ja heikkoudet. Tässä diplomityössä tutkimusongelmaa on ensin tarkasteltu kirjallisuuden valossa, keskittyen kirjallisuuteen kilpailijavertailusta sekä jakelukanavista. Kilpailijavertailu, benchmark,on kuvattu tässä yhteydessä osana laadunhallintaa, painottaen yleisesti käytössä olevaa Campin 10 askeleen kilpailijavertailuprosessia. Tässä tutkimuksessa tarkasteltavat jakelukanavateoriat on jaoteltu kahteen osaan; jakelukanavan rakennetta käsitteleviin teorioihin sekä jakelukanavan hallintaa käsitteleviin teorioihin. Ensin mainitussa keskitytään lähinnä jakelukanavamalleihin ja -tyyppeihin, ja toisessa lähemmin partneri -käsitteeseen; kumppanuuteen, kanavapartnereihin ja kanavapartneriohjelmiin. Tavoitteena oli kerätä mahdollisimman tarkkaa ja ajankohtaista tietoa tutkimuksen kohteena olevien kilpailijayritysten kanavapartneriohjelmista. Tämä osoittautui varsin haastavaksi tehtäväksi. Tarpeeksi tietoa saatiin kuitenkin kerättyä sekä kirjallisuudesta että tehdyn kyselyn avulla, mikä mahdollisti alkuperäisenä tavoitteena olleen kilpailijavertailun sekä sen pohjalta tehdyt analyysit.

Minimum error contrast enhancement

Contrast enhancement is an image processing technique where the objective is to preprocess the image so that relevant information can be either seen or further processed more reliably. These techniques are typically applied when the image itself or the device used for image reproduction provides poor visibility and distinguishability of different regions of interest inthe image. In most studies, the emphasis is on the visualization of image data,but this human observer biased goal often results to images which are not optimal for automated processing. The main contribution of this study is to express the contrast enhancement as a mapping from N-channel image data to 1-channel gray-level image, and to devise a projection method which results to an image with minimal error to the correct contrast image. The projection, the minimum-error contrast image, possess the optimal contrast between the regions of interest in the image. The method is based on estimation of the probability density distributions of the region values, and it employs Bayesian inference to establish the minimum error projection.

Ash Particle Erosion on Steam Boiler Convective Section

In this study, equations for the calculation of erosion wear caused by ash particles on convective heat exchanger tubes of steam boilers are presented. Anew, three-dimensional test arrangement was used in the testing of the erosion wear of convective heat exchanger tubes of steam boilers. When using the sleeve-method, three different tube materials and three tube constructions could be tested. New results were obtained from the analyses. The main mechanisms of erosionwear phenomena and erosion wear as a function of collision conditions and material properties have been studied. Properties of fossil fuels have also been presented. When burning solid fuels, such as pulverized coal and peat in steam boilers, most of the ash is entrained by the flue gas in the furnace. In bubbling andcirculating fluidized bed boilers, particle concentration in the flue gas is high because of bed material entrained in the flue gas. Hard particles, such as sharp edged quartz crystals, cause erosion wear when colliding on convective heat exchanger tubes and on the rear wall of the steam boiler. The most important ways to reduce erosion wear in steam boilers is to keep the velocity of the flue gas moderate and prevent channelling of the ash flow in a certain part of the cross section of the flue gas channel, especially near the back wall. One can do this by constructing the boiler with the following components. Screen plates can beused to make the velocity and ash flow distributions more even at the cross-section of the channel. Shield plates and plate type constructions in superheaters can also be used. Erosion testing was conducted with three types of tube constructions: a one tube row, an inline tube bank with six tube rows, and a staggered tube bank with six tube rows. Three flow velocities and two particle concentrations were used in the tests, which were carried out at room temperature. Three particle materials were used: quartz, coal ash and peat ash particles. Mass loss, diameter loss and wall thickness loss measurements of the test sleeves were taken. Erosion wear as a function of flow conditions, tube material and tube construction was analyzed by single-variable linear regression analysis. In developing the erosion wear calculation equations, multi-variable linear regression analysis was used. In the staggered tube bank, erosion wear had a maximum value in a tube row 2 and a local maximum in row 5. In rows 3, 4 and 6, the erosion rate was low. On the other hand, in the in-line tube bank the minimum erosion rate occurred in tube row 2 and in further rows the erosion had an increasing value, so that in a six row tube bank, the maximum value occurred in row 6.

Implementation of Customer Relationship Management system to support channel partners

Työn tavoitteena oli selvittää, kokevatko matkapuhelinalalla toimivat kanavapartnerit heitä varten suunnitellun asiakassuhdehallintajärjestelmän lisäarvopalveluna vaiko eivät. Työ toteutettiin asiakastyytyväisyystutkimuksen avulla, jossa mitattiin erilaisten partnereiden asennetta palvelua kohtaan. Työn tuloksena ilmeni, että palvelussa olevan informaation määrällä ei ollut suurta vaikutusta asiakkaiden tyytyväisyyteen. Syyt ovat pikemminkin yleisissä asenteissa vastaavia palveluja kohtaan.

On Option Price Information Content and Extraction of Implied Probability Distributions

In this study we used market settlement prices of European call options on stock index futures to extract implied probability distribution function (PDF). The method used produces a PDF of returns of an underlying asset at expiration date from implied volatility smile. With this method, the assumption of lognormal distribution (Black-Scholes model) is tested. The market view of the asset price dynamics can then be used for various purposes (hedging, speculation). We used the so called smoothing approach for implied PDF extraction presented by Shimko (1993). In our analysis we obtained implied volatility smiles from index futures markets (S&P 500 and DAX indices) and standardized them. The method introduced by Breeden and Litzenberger (1978) was then used on PDF extraction. The results show significant deviations from the assumption of lognormal returns for S&P500 options while DAX options mostly fit the lognormal distribution. A deviant subjective view of PDF can be used to form a strategy as discussed in the last section.