A view on the internal consistency of linear source identification for I.C. engine exhaust noise prediction

[EN] Considerable efforts have been devoted to the development of predictive models that, from a certain set of data related to an engine, and making use of an adequate representation of the effect of the silencing elements, provide an estimate of the exhaust noise emitted. Such models should allow for the consideration of the engine and its interaction with the exhaust system. This is properly achieved by gas-dynamic models, which are becoming the standard, but linear models solved in the frequency domain and representing the engine as a linear time-invariant source may still play a role in exhaust system design, as the engine is treated as a black box. Such a representation is very attractive for engine manufacturers, since it gives the possibility to provide data on the engine without any possibility to trace back to its real characteristics. In order to provide additional criteria for the suitability of the application of a linear time-invariant representation to an engine exhaust, in this paper a multi-load method has been used to extract source characteristics from gas-dynamic simulation results. The details of the method, in which the resulting over-determined system is solved by fitting the values of the source parameters in a least-squares sense, are described, and different approaches are used in order to check the internal consistency of the source representation: the identification of pressure and velocity sources, and the application of the least-squares criterion to the modulus or to the real and imaginary parts separately. In particular, eight different determinations of the source impedance are obtained and, considering the application of the formalism to an engine exhaust, the differences observed provide a suitable criterion for the evaluation of the suitability of the representation and of the particular set of loads chosen.Macian Martinez, V.; Torregrosa Huguet, AJ.; Broatch, A.; Niven, P.; Amphlett, S. (2013). A view on the internal consistency of linear source identification for I.C. engine exhaust noise prediction. Mathematical and Computer Modelling. 57(7-8):1867-1875. doi:10.1016/j.mcm.2011.12.018S18671875577-

Medication and suicide risk in schizophrenia: A nested case-control study

Introduction: Patients with schizophrenia are at increased risk of suicide, but data from controlled studies of pharmacotherapy in relation to suicide risk is limited. Aim: To explore suicide risk in schizophrenia in relation to medication with antipsychotics, antidepressants, and lithium. Methods: Of all patients with a first clinical discharge diagnosis of schizophrenia or schizoaffective disorder in Stockholm County between 1984 and 2000 (n=4000), patients who died by suicide within five years from diagnosis were defined as cases (n=84; 54% male). Individually matched controls were identified from the same population. Information on prescribed medication was retrieved from psychiatric records in a blinded way. Adjusted odds ratios [OR] of the association between medication and suicide were calculated by conditional logistic regression. Results: Lower suicide risk was found in patients who had been prescribed a second generation antipsychotic (clozapine, olanzapine, risperidone, or ziprasidone; 12 cases and 20 controls): OR 0.29 (95% confidence interval [CI], 0.09-0.97). When the 6 cases and 8 controls who had been prescribed clozapine were excluded, the OR was 0.23 (95% CI 0.06-0.89). No significant association was observed between suicide and prescription of any antipsychotic, depot injection antipsychotics, antidepressants, SSRI, or lithium. Conclusions: Lower suicide risk for patients who had been prescribed second generation antipsychotics may be related to a pharmacological effect of these drugs, to differences in adherence, or to differences in other patient characteristics associated with lower suicide risk. © 2013 Elsevier B.V

Soviet-Polish relations, 1919-1921

The Polish-Soviet War of 1919-1921 was a direct consequence of the ideological objectives pursued by the belligerents. Ideology shaped the political agenda and the diametrically opposed war aims of both states, and was implemented through the foreign policy, diplomatic negotiation and military engagements pursued. This proved to be the principal obstacle to the establishment of cordial relations. As western democracy and Russian Marxism battled it out, war was inevitable. Externally, the Paris Peace Conference provided the necessary conditions for the resumption of traditional Russian-Polish hostilities, whilst the Allied States consistently demonstrated their absolute inability to directly influence either the development, or outcome, of the conflict. Redressing the balance of historiography, this thesis includes a greater examination of the conflict from the perspective of the Soviet regime. This firmly controlled the Russian decision-making process. By charting the war, it becomes clear that both states deliberately pursued a dual offensive: traditional diplomatic negotiation and military campaign as conditions dictated. However, in addition, Soviet Russia developed a unique and innovative, revolutionary, agit-prop, diplomatic medium. This enabled adept Soviet diplomats to win the majority of diplomatic battles during the conflict, although often negotiating from a militarily weak position. Nevertheless, the regime ultimately failed in its objective: to ignite socialist revolution in western Europe. The mistaken Soviet decision in July 1920 to cross the ethnographic border to forcefully sovietise Poland, in opposition to Marxist doctrine, irreversibly altered the complexion of the war and proved its pivotal turning point. This culminated politically with the short-lived establishment of the Provisional Revolutionary Committee in Białystok, and militarily, with the decisive defeat of the Red Army at the Battle of Warsaw. It is now certain that the Red Army offensive into Poland in July 1920 aimed not only at the sovietisation of Poland, but at spreading the socialist revolution to Western Europe and overthrowing the Versailles settlement. The European revolutionary upsurge had largely extinguished during the previous year and in August 1920, Communist ideology ultimately failed to inspire the vast majority of the Polish population. Thus, by utilising the Soviet military to secure its war aims, Lenin and the Politburo inadvertently signed the death-warrant of socialist revolution in Poland at the beginning of the twentieth century.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Assigning roles to DNA regulatory motifs using comparative genomics

Motivation: Transcription factors (TFs) are crucial during the lifetime of the cell. Their functional roles are defined by the genes they regulate. Uncovering these roles not only sheds light on the TF at hand but puts it into the context of the complete regulatory network

Journal Staff

This paper discusses the effect of high level multi-tone acoustic excitation on the acoustic properties of perforates. It is based on a large experimental study of the nonlinear properties of these types of samples without mean grazing or bias flow. Compared to previously published results the present investigation concentrates on the effect of multiple harmonics. It is known from previous studies that high level acoustic excitation at one frequency will change the acoustic impedance of perforates at other frequencies, thereby changing the boundary condition seen by the acoustic waves. This effect could be used to change the impedance boundary conditions and for instance increase the absorption. It could obviously also pose a problem for the correct modelling of sound transmission through ducts lined with such impedance surfaces. Experimental results are compared to a quasi-stationary model. The effect of the combination of frequency components and phase in the excitation signal is studied.QC 20131030</p

Leaping and dancing with digitality : Exploring human-smartphone-entanglements in classrooms

This chapter explores digitality as part of young people’s everyday lives in the Arctic. It is based on two ethnographic studies situated in the political context of the “digital leap”, the governmental and curricular emphasis on digitality in education in Finland. With the more formal “digital leap”, informal engagements and attachments with digitality intertwine, in which students’ own smartphones play an increasingly significant role. The analyses use the notion of entanglement (Barad) to examine how primary school and upper secondary school students emerge in their situated and specific encounters with smartphones in school. The starting points of things, bodies, affect, time and space open up insights to connectivity between young people’s digital activities and global economic networks as well as to the multidirectionality between humans and technologies: while the students access their digital devices, the digitalities also access their users. We suggest that this wilder form of “digital leap” requires reconsidering materiality, affect, and instability of space and time.Peer reviewe

On the importance of sluggish state memory for learning long term dependency

The vanishing gradients problem inherent in Simple Recurrent Networks (SRN) trained with back-propagation, has led to a significant shift towards the use of Long Short-term Memory (LSTM) and Echo State Networks (ESN), which overcome this problem through either second order error-carousel schemes or different learning algorithms respectively. This paper re-opens the case for SRN-based approaches, by considering a variant, the Multi-recurrent Network (MRN). We show that memory units embedded within its architecture can ameliorate against the vanishing gradient problem, by providing variable sensitivity to recent and more historic information through layer- and self-recurrent links with varied weights, to form a so-called sluggish state-based memory. We demonstrate that an MRN, optimised with noise injection, is able to learn the long term dependency within a complex grammar induction task, significantly outperforming the SRN, NARX and ESN. Analysis of the internal representations of the networks, reveals that sluggish state-based representations of the MRN are best able to latch on to critical temporal dependencies spanning variable time delays, to maintain distinct and stable representations of all underlying grammar states. Surprisingly, the ESN was unable to fully learn the dependency problem, suggesting the major shift towards this class of models may be premature

STAR: predicting recombination sites from amino acid sequence

BACKGROUND: Designing novel proteins with site-directed recombination has enormous prospects. By locating effective recombination sites for swapping sequence parts, the probability that hybrid sequences have the desired properties is increased dramatically. The prohibitive requirements for applying current tools led us to investigate machine learning to assist in finding useful recombination sites from amino acid sequence alone. RESULTS: We present STAR, Site Targeted Amino acid Recombination predictor, which produces a score indicating the structural disruption caused by recombination, for each position in an amino acid sequence. Example predictions contrasted with those of alternative tools, illustrate STAR'S utility to assist in determining useful recombination sites. Overall, the correlation coefficient between the output of the experimentally validated protein design algorithm SCHEMA and the prediction of STAR is very high (0.89). CONCLUSION: STAR allows the user to explore useful recombination sites in amino acid sequences with unknown structure and unknown evolutionary origin. The predictor service is available from

Periprosthetic DXA after total hip arthroplasty with short vs. ultra-short custom-made femoral stems

Background and purpose Dual-energy X-ray absorptiometry (DXA) analysis of the 7 periprosthetic Gruen zones is the most commonly used protocol to evaluate bone remodeling after the implantation of conventional femoral stems. We assessed the value of DXA after cementless primary total hip arthroplasty (THA) by comparing the effect of progressive shortening of the stem of two femoral implants on periprosthetic bone remodeling using a specifically developed protocol of analysis with 5 periprosthetic regions of interest (ROIs)

Association of Mediterranean diet with survival after breast cancer diagnosis in women from nine European countries: results from the EPIC cohort study

BACKGROUND: The Mediterranean diet has been associated with lower risk of breast cancer (BC) but evidence from prospective studies on the role of Mediterranean diet on BC survival remains sparse and conflicting. We aimed to investigate whether adherence to Mediterranean diet prior to diagnosis is associated with overall and BC-specific mortality. METHODS: A total of 13,270 incident breast cancer cases were identified from an initial sample of 318,686 women in 9 countries from the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Adherence to Mediterranean diet was estimated through the adapted relative Mediterranean diet (arMED), a 16-point score that includes 8 key components of the Mediterranean diet and excludes alcohol. The degree of adherence to arMED was classified as low (score 0-5), medium (score 6-8), and high (score 9-16). Multivariable Cox proportional hazards models were used to analyze the association between the arMED score and overall mortality, and Fine-Gray competing risks models were applied for BC-specific mortality. RESULTS: After a mean follow-up of 8.6 years from diagnosis, 2340 women died, including 1475 from breast cancer. Among all BC survivors, low compared to medium adherence to arMED score was associated with a 13% higher risk of all-cause mortality (HR 1.13, 95%CI 1.01-1.26). High compared to medium adherence to arMED showed a non-statistically significant association (HR 0.94; 95% CI 0.84-1.05). With no statistically significant departures from linearity, on a continuous scale, a 3-unit increase in the arMED score was associated with an 8% reduced risk of overall mortality (HR3-unit 0.92, 95% CI: 0.87-0.97). This result sustained when restricted to postmenopausal women and was stronger among metastatic BC cases (HR3-unit 0.81, 95% CI: 0.72-0.91). CONCLUSIONS: Consuming a Mediterranean diet before BC diagnosis may improve long-term prognosis, particularly after menopause and in cases of metastatic breast cancer. Well-designed dietary interventions are needed to confirm these findings and define specific dietary recommendations