On Generating Prime Numbers Efficiently

The prime numbers can be considered as the building blocks of natural numbers, having innumerable applications in number theory and cryptography. There exist multiple different sieving algorithms for the generation of prime numbers. In this thesis, an elementary modular result is utilized to construct an analytically useful generator function and its inverse function. The functions are used to generate a (log)log-linear time complexity prime sieving algorithm which is further optimized to be of linear time complexity. The constructed algorithms and their operation are studied and the linear implementations in JS, Python and C++ are compared to other prime sieves.Alkulukuja voidaan pitää luonnollisten lukujen rakennuspalikoina joilla on lukemattomia sovelluksia lukuteoriassa ja kryptografiassa. Alkulukujen luomiseen on olemassa useita erilaisia seulonta-algoritmeja. Tässä opinnäytetyössä käytetään modulaarista perustulosta analyyttisesti hyödyllisten kehitysfunktion ja sen käänteisfunktion luomiseen. Funktioiden avulla luodaan aikakompleksisuudeltaan (log)log-lineaarinen alkulukuseula, joka optimoidaan lineaariseksi. Rakennettuja algoritmeja ja niiden toimintaa tarkastellaan ja lineaarista implementaatiota JS, Python ja C++ ohjelmointikielillä verrataan toisiin alkulukuseuloihin

Waltarista turhia tärkeilemättä tai teoretisoimatta

Kirja-arvostelu: Panu Rajala: Unio Mystica. Mika Waltarin elämä ja teokset.Helsinki: WSOY, 200

”Meidän ja teidän välillä suuri juopa”: Köyhät ja rikkaat Pentti Haanpään romaanissa Isännät ja isäntien varjot

”The wide gap between us and you”. The Poor and the Rich in Pentti Haanpää’s Novel Isännät ja isäntien varjot (Masters and Masters’ Shadows) The novel Isännät ja isäntien varjot (1935) by Pentti Haanpää contains a significant amount of allusions to the Bible. This fact has been taken note of in earlier study, and the novel has been proved to have as its intertexts a few very well known Old Testament stories: The story of Esau and Jacob, the story of the journey to the Promised Land, The book of Job and a few others. This article shows that one interesting intertext has not been discovered in earlier studies: The story of a rich man, poor Lazarus and Abraham in Luke’s gospel (Luke 16: 19—31). Perceived intertext arranges and at the same time enriches in a new way the thematic field of the novel. Through the intertext the gap between the rich and the poor becomes even more noticeable. At the same time, the social criticism in the novel appears sharper than ever. The connection with the story in Luke’s gospel deepens also the existential level of the novel as the messages from another world or another reality troubles the hero of the novel. In the world of the novel, justice does not win, but it gives a hint that in the invisible world even the poor can gain justice

Association of CHA2DS2-VASc Score with Long-Term Incidence of New-Onset Atrial Fibrillation and Ischemic Stroke after Myocardial Infarction

The CHA2DS2-VASc score is a reliable tool used to estimate the risk of ischemic stroke (IS) in patients with atrial fibrillation (AF). Few tools exist for the prediction of new-onset AF (NOAF) after myocardial infarction (MI) and its relation to IS. We studied the usefulness of CHA2DS2-VASc in predicting NOAF and IS in a long-term follow-up after MI. Consecutive MI patients without baseline AF (n = 70,922; mean age: 68.2 years), discharged from 20 hospitals in Finland during 2005-2018, were retrospectively studied using national registries. The outcomes of interest after discharge were NOAF- and IS-assessed with competing risk analyses at one and ten years. The median follow-up was 4.2 years. The median baseline CHA2DS2-VASc score was 3 (IQR 2-5). The likelihood of both NOAF and NOAF-related IS increased stepwise with this score at one and ten years (all p 2DS2-VASc scores ≥6 points. The cumulative incidence of IS was 15.2% in patients with NOAF vs. 6.2% in patients without AF at 10 years after MI (adj. sHR 2.12; CI 1.98-2.28; p p 2DS2-VASc score is a simple tool used to estimate the long-term risk of NOAF and IS after MI in patients without baseline AF. Coronary bypass surgery is associated with an increased NOAF incidence after MI.</p

Helsingin Kotimainen kirjallisuus: Perinteitä ja uusia haasteita

Kotimaisen kirjallisuuden oppiaine Helsingin yliopistossa on saanut alkunsa Werner Söderhjelmiä varten vuonna 1913 perustetusta kotimaisen ja yleisen kirjallisuushistorian professorin virasta. Se jaettiin kahtia vuonna 1924, jolloin suomenkielisen professuurin sai Viljo Tarkiainen ja ruotsinkielisen Gunnar Castrén. Kun yleinen kirjallisuus ja kotimainen erkanivat vuonna 1968, syntyi kotimaisen kirjallisuuden laitos, joka ehti toimia itsenäisenä tasan 30 vuotta. Nykyään kotimainen kirjallisuus kuuluu oppiaineena suureen suomen kielen, suomalaisugrilaisten ja pohjoismaisten kielten ja kirjallisuuksien laitokseen, jota leikillisesti myös Norsuksi kutsutaan

Oxidation of SO2 by stabilized Criegee intermediate (sCI) radicals as a crucial source for atmospheric sulfuric acid concentrations

The effect of increased reaction rates of stabilized Criegee intermediates (sCIs) with SO2 to produce sulfuric acid is investigated using data from two different locations, SMEAR II, Hyytiälä, Finland, and Hohenpeissenberg, Germany. Results from MALTE, a zero-dimensional model, show that using previous values for the rate coefficients of sCI + SO2, the model underestimates gas phase H2SO4 by up to a factor of two when compared to measurements. Using the rate coefficients recently calculated by Mauldin et al. (2012) increases sulfuric acid by 30–40%. Increasing the rate coefficient for formaldehyde oxide (CH2OO) with SO2 according to the values recommended by Welz et al. (2012) increases the H2SO4 yield by 3–6%. Taken together, these increases lead to the conclusion that, depending on their concentrations, the reaction of stabilized Criegee intermediates with SO2 could contribute as much as 33–46% to atmospheric sulfuric acid gas phase concentrations at ground level. Using the SMEAR II data, results from SOSA, a one-dimensional model, show that the contribution from sCI reactions to sulfuric acid production is most important in the canopy, where the concentrations of organic compounds are the highest, but can have significant effects on sulfuric acid concentrations up to 100 m. The recent findings that the reaction of sCI + SO2 is much faster than previously thought together with these results show that the inclusion of this new oxidation mechanism could be crucial in regional as well as global models.Peer reviewe