274 research outputs found
A Comparative Study of Thermo-Mechanical Fatigue Performance of Different Grades of SiMo Nodular Cast Iron
No full textThis thesis is a comparative study of the Thermo-Mechanical Fatigue (TMF) performance of different grades of SiMo nodular cast iron for heavy-duty diesel engine exhaust gas manifold applications. The TMF performance of the current SiMo variant used to manufacture exhaust manifolds - SiMo 5.10 (C-3.25Si-4.45Mo-0.76), is compared with that of the variants SiMo 4.05 (C-3.22Si-4.66Mo-0.56) and SiMoNi (C-3.3Si-4.5Mo-1Ni-1.3) by performing three out-of-phase (OP) TMF test series under partial constraint conditions. A benchmark TMF test series in the temperature range: 50 ˚C to 550 ˚C with a hold time of 30 s at 550 ˚C showed that SiMo 5.10 had relatively better performance due to development of lower mechanical crack driving forces compared to other variants. However, a long holding time of 600 s at 550 ˚C saw a larger decrease of average TMF lifetimes for SiMo 5.10 than that of SiMo 4.05 despite similar crack driving forces. An investigation of the stress relaxation during TMF of the two variants showed that the SiMo 4.05 performs better during long hold time due to better stress relaxation properties. The SiMoNi variant which is very brittle at low temperatures was found to fail by a fracture by overloading mechanism taking over quite early in the fatigue cycle; which is confirmed by examination of the fracture surfaces and numerical estimations. This also explained the low lifetimes and scatter in previously performed TMF tests under total constraint conditions. The TMF test series performed in the temperature range: 150 ˚C to 550 ˚C with a hold time of 30 s at 550 ˚C found that a heat-treatment seemed to reduce the TMF performance of the SiMo 5.10 variant. Metallographic investigations and hardness measurements of as-cast and heat-treated materials revealed that the distribution of the Mo-rich phase from the grain boundary regions into the matrix due to an annealing heat-treatment seemed to affect the TMF performance.Materials Science and Engineerin
Book Reviews: Cochlear Implants in Children: Ethics and Choices; Title: Ethics in Mental Health and Deafness
No full textTitle: Cochlear Implants in Children: Ethics and Choices
Authors: John B. Christiansen & Irene W. Leigh
Publisher: Gallaudet University Press, 2002
Cost: 65.00, hardcover
ISBN: 1-56368-120-X
Reviewer: Simo Vehma
Symbol Error Rate for Nonblind Adaptive Equalizers Applicable for the SIMO and FGn Case
No full textA nonzero residual intersymbol interference (ISI) causes the symbol error rate (SER) to increase where the achievable SER may not answer any more on the system's requirements. Recently, a closed-form approximated expression was derived by the same author for the residual ISI obtained by nonblind adaptive equalizers for the single-input single-output (SISO) case. Up to now, there does not exist a closed-form expression for the residual ISI obtained by nonblind adaptive equalizers for the single-input multiple-output (SIMO) case. Furthermore, there does not exist a closed-form expression for the SER valid for the SISO or SIMO case that takes into account the residual ISI obtained by nonblind adaptive equalizers and is valid for fractional Gaussian noise (fGn) input where the Hurst exponent is in the region of 0.5 ≤ < 1. In this paper, we derive a closed-form approximated expression for the residual ISI obtained by nonblind adaptive equalizers for the SIMO case (where SISO is a special case of SIMO), valid for fGn input where the Hurst exponent is in the region of 0.5 ≤ < 1. Based on this new expression for the residual ISI, a closed-form approximated expression is obtained for the SER valid for the SIMO and fGn case
Minéraux détritiques paramagnétiques (argiles) controllant le signal de susceptibilité magnétique et détection de minéraux ferromagnétiques détritiques au cours du Danien et du Sélandien (Carrière de Loubieng, France)
No full textTemporal Parallelization of Inference in Hidden Markov Models
No full textFunding Information: Manuscript received February 10, 2021; revised June 4, 2021 and July 26, 2021; accepted August 4, 2021. Date of publication August 12, 2021; date of current version September 3, 2021. The associate editor coordinating the review of this manuscript and approving it for publication was Dr. N. Dobigeon. This work was supported by Academy of Finland. (Corresponding author: Syeda Sakira Hassan.) Syeda Sakira Hassan and Simo Särkkä are with the Department of Electrical Engineering and Automation, Aalto University, 02150 Espoo, Finland (e-mail: [email protected]; [email protected]). Publisher Copyright: © 1991-2012 IEEE.This paper presents algorithms for the parallelization of inference in hidden Markov models (HMMs). In particular, we propose a parallel forward-backward type of filtering and smoothing algorithm as well as a parallel Viterbi-type maximum-a-posteriori (MAP) algorithm. We define associative elements and operators to pose these inference problems as all-prefix-sums computations and parallelize them using the parallel-scan algorithm. The advantage of the proposed algorithms is that they are computationally efficient in HMM inference problems with long time horizons. We empirically compare the performance of the proposed methods to classical methods on a highly parallel graphics processing unit (GPU).Peer reviewe
Estimating baking temperatures in a Roman pottery kiln by rock magnetic properties: implications of thermochemical alteration on archaeointensity determinations
No full textOnko eläimillä oikeuksia? : Eläinkoelainsäädännön kehitys ja nykytila
No full textThe use of animals in scientific experiments tends to arouse strong emotional reactions among the general public, the most essential concern being the pain and suffering they cause. It is felt that suffering inflicted on other beings, including animals, is not morally acceptable. Is the function of a researcher who uses animals morally acceptable and beneficial for humans and animals? May such a researcher him/herself decide what animal experiments he/she can perform or should some outsider have the right to decide what kind of experiments a researcher can or cannot perform?
The research material comprises the legislation of Finland and that of some member and non-member states of the European Union, together with European Union directives and pertinent preparatory parliamentary documents. The author has likewise studied the vast literature on animal rights, both pro and contra writings and opinions. The opinions of philosophers on the moral and legal rights of animals are markedly conflicting. Some strongly support the existence of rights, while others totally refute such an opinion, claiming that the question is only of the moral principles of man himself which imply that animals must be treated in a human manner. Speaking of animal rights only tends to muddle ideas on the one hand in philosophical considerations and in legal analyses on the other.
The development of legislation in Finland and some other member states of the European Union has in principle been similar. In Finland, the positive laws on animal experiments nowadays comply with the EU directive 86/609/EEC. However, there are marked differences between member states in respect of the way they have in practice implemented the principles of the EU directive. No essential alterations have in practice been discernible in the actual performance of animal experiments during the decades when legislation has been developed in different countries. Self-regulation within the scientific community has been markedly more effectual than legislative procedures. Legal regulation has nevertheless clearly influenced the quality of breeding and life conditions of experimental laboratory animals, cages for example being nowadays larger than hitherto.
EU parliament and council have now accepted in September 2010 a new directive on animal experiments which must be implemented in the national legislations by January 1, 2013.Eläinten käyttö tieteellisissä kokeissa on omiaan herättämään voimakkaita tunteita ja kannanottoja suuren yleisön keskuudessa. Keskeisin huolenaihe on kokeiden aiheuttama kipu ja tuska. Kärsimysten aiheuttamista toiselle yksilölle, mukaan luettuna eläimet, pidetään moraalisesti tuomittavana. Onko koe-eläimiä käyttävän tutkijan toiminta moraalisesti hyväksyttävää ja ihmis- ja eläinkunnan kannalta hyödyllistä? Voiko tutkija itse päättää, millainen eläinkoe on tarpeellinen ja hyödyllinen, vai onko joillekin muille ulkopuolisille annettava oikeus päättää, mitä eläinkokeita tutkija saa tehdä ja mitä hän ei saa tehdä?
Tutkimusaineistona on käytetty Suomen eläinsuojelulakeja ja asetuksia, eläinkoelakia ja sen käsittelyn eduskunta-asiakirjoja, Euroopan unionin jäsenvaltioiden eläinkokeita koskevia lakeja ja asetuksia, Euroopan unionin ja neuvoston direktiivejä ja asetuksia sekä niiden valmisteluasiakirjoja. Kirjoittaja on myös tutustunut laajaan ns. eläinten oikeuksia käsittelevään kirjallisuuteen, eläinten oikeuksia puolustaviin kannanottoihin ja niiden vastakirjoituksiin. Eri filosofien käsitykset eläinten moraalisista ja legaalisista oikeuksista ovat vastakkaiset. Toisten mukaan ne ovat olemassa. Toiset ovat sitä mieltä, että kyse on pelkästään ihmisen omista moraalisista käsityksistä, jotka velvoittavat kohtelemaan eläimiä humaanilla tavalla. Eläinten oikeuksista puhuminen sekoittaa käsitteitä, joita käytetään toisaalla filosofisissa pohdiskeluissa ja toisaalla oikeustieteellisissä analyyseissä.
Eläinkoelainsäädäntö on kehittynyt Suomessa ja muissa Euroopan unionin jäsenvaltioissa samansuuntaisesti. Suomessa lakien ja asetusten määräykset ovat nykyään hyvin voimassa olevan eläinkoetoimintaa koskevan EU:n direktiivin 86/609/ETY mukaiset. Kuitenkin Euroopan unionin jäsenvaltioiden välillä on huomattavia eroja siinä, miten ne ovat käytännössä toteuttaneet tämän direktiivin määräyksiä. Olennaisia muutoksia itse eläinkokeiden suorittamisessa ei ole tapahtunut niiden vuosikymmenien aikana, jolloin eläinkoelainsäädäntöä on kehitetty eri maissa. Tiedeyhteisön itsesäätely on ollut ratkaisevasti merkityksellisempää kuin lainsäädännölliset toimenpiteet. Eläinkokeita koskevat lait ja asetukset koe-eläinten kasvatusolosuhteista, kuten kasvatushäkkien koosta ja koe-eläinten yleisestä ylläpidosta, ovat parantaneet koe-eläinten elinoloja.
EU:n parlamentti ja neuvosto ovat nyt hyväksyneet syyskuussa 2010 uuden eläinkoedirektiivin, mikä on implementoitava kansallisiin lainsäädäntöihin 1.1.2013 mennessä.ei saavutettav
On the performance of subspace SIMO blind channel identification methods
No full textChannel Identification is an important part of wireless communication systems. Radio-Frequency (RF) signals are subject to reflection, refraction, and diffraction, attenuation, and other effects, that result in a distorted signal at a receiver, particularly over what are known as frequency-selective channels. Traditionally, such distortion is estimated using a ``training sequence" which is a known reference signal used to estimate, and then correct for, the distortion. However, use of training sequences is not always possible, for example in military applications where the source signal is not known, or in broadcast environments where there is a high cost of transmitting a signal. One potential solution is to estimate the channel blindly, that is, without knowledge of the transmitted signal. Blind Channel Identification (BCI) and Equalization has been a extensive topic of research since at least 1975. One strategy in Blind Channel Identification is to use the structure of the received signals in a Single Input Multiple Output (SIMO) system to estimate the channel. Research has occurred on a number of methods that exploit this in the past several decades. The subspace methods form the channel estimate in terms of a one-dimensional subspace constructed using the estimated second-order statistics of the received signals. Additionally, the use of sparsity in signal estimation has been a topic of interest as well, and has recently been used in certain cases to improve the robustness of the subspace methods in a number of works. In this thesis, the Cross-Relations and Noise-Subspace methods, both of which are SIMO BCI methods, as well as their sparse variant, are examined for a deterministic channel. The expected Normalized Projection Misalignment (NPM) is analytically approximated for all considered methods. In addition, it is compared to simulation results for a random source signal and several measured RF channels from earlier literature. Finally, the sensitivity of the sparse variant of the subspace methods as a function of the regularization parameter is studied using simulation for a set of measured RF channels from earlier literature.M.S.Includes bibliographical referencesby Kareem Y. Bonn
The influence and mechanisms involving daf-16 and tol-1 on Bifidobacterium infantis-induced prolongevity and behavior of Caenorhabditis elegans
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