The Minimum Description Length Principle and Model Selection in Spectropolarimetry

It is shown that the two-part Minimum Description Length Principle can be used to discriminate among different models that can explain a given observed dataset. The description length is chosen to be the sum of the lengths of the message needed to encode the model plus the message needed to encode the data when the model is applied to the dataset. It is verified that the proposed principle can efficiently distinguish the model that correctly fits the observations while avoiding over-fitting. The capabilities of this criterion are shown in two simple problems for the analysis of observed spectropolarimetric signals. The first is the de-noising of observations with the aid of the PCA technique. The second is the selection of the optimal number of parameters in LTE inversions. We propose this criterion as a quantitative approach for distinguising the most plausible model among a set of proposed models. This quantity is very easy to implement as an additional output on the existing inversion codes.Comment: Accepted for publication in the Astrophysical Journa

”Heitäppä yks kompiainen — joku viisas mies joskus”:lukioikäisten oululaisten käsityksiä Oulun murteen sanoista

Tiivistelmä. Olen kandidaatintutkielmassani tutkinut lukioikäisten oululaisten käsityksiä Oulun murteen sanoista. Tutkin, kuinka hyvin oululaisnuoret tunnistavat Oulun murteelle tyypillisiä sanoja sekä millaisia merkityksiä he niille antavat. Tutkielmassani selvitän myös käyttävätkö nuoret itse näitä murresanoja ja ovatko he kuulleet tai nähneet jonkun toisen käyttävän niitä. Olen kerännyt aineistoni sähköisellä kyselylomakkeella, jolla kysyin merkitystä 14 Oulun murteen sanalle. Kyselyni sisälsi ruotsalaisperäisiä lainasanoja, stereotyyppisiä oululaisia murresanoja sekä satunnaisesti valitsemiani Oulun murteen sanoja. Analysoin vastauksia sisällönanalyysin keinoin. Aineistoni koostuu vähintään 15 vuotta täyttäneiden lukiolaisten tuottamista kyselylomakevastauksista. Vastauksia on yhteensä 49. Olen luokitellut aineistoni sanat ensiksi kolmeen ryhmään sen perusteella, miten informantit olivat ne tunnistaneet. Kolme ryhmää ovat sana tunnistettu, sana tunnistettu osittain ja sanaa ei tunnistettu. Ryhmien perusteella olen jakanut sanat edelleen kolmeen luokkaan sen perusteella, kuinka hyvin informantit ovat ne tunnistaneet. Luokat ovat hyvin tunnistetut sanat, melko hyvin tunnistetut sanat ja heikosti tunnistetut sanat. Tutkimustulosteni mukaan lukioikäiset oululaisnuoret tunnistavat hyvin vain harvoja murresanoja. Aineistoni murresanoista miltei puolet oli tunnistettu heikosti. Tutkimustuloksissa oli myös nähtävissä selkeää kahtia jakautumista: useat sanat oli tunnistettu joko hyvin tai ei ollenkaan. Sanojen tunnistamisen ja käyttämisen välillä on tutkimustuloksissani huomioitavissa selkeä yhteys. Suurin osa hyvin ja melko hyvin tunnistetuista sanoista ovat myös aineistoni käytetyimpiä sanoja. Informanttini ilmoittivat kuitenkin käyttävänsä vain harvoja aineistoni sanoja itse. Aineistoni neljästätoista sanasta seitsemän sanan käyttäjien määrä oli alle 10 %. Tutkimustulosteni mukaan puolet aineistoni sanoista ovat siis lukioikäisillä oululaisnuorilla erittäin vähäisessä käytössä

Mutual Information of Population Codes and Distance Measures in Probability Space

We studied the mutual information between a stimulus and a large system consisting of stochastic, statistically independent elements that respond to a stimulus. The Mutual Information (MI) of the system saturates exponentially with system size. A theory of the rate of saturation of the MI is developed. We show that this rate is controlled by a distance function between the response probabilities induced by different stimuli. This function, which we term the {\it Confusion Distance} between two probabilities, is related to the Renyi $\alpha$-Information.Comment: 11 pages, 3 figures, accepted to PR

Textiles as Material Gestalt: Cloth as a Catalyst in the Co-designing Process

Textiles is the common language within Emotional Fit, a collaborative research project investigating a person-centred, sustainable approach to fashion for an ageing female demographic (55+). Through the co-designing of a collection of research tools, textiles have acted as a material gestalt for exploring our research participants' identities by tracing their embodied knowledge of fashionable dress. The methodology merges Interpretative Phenomenological Analysis, co-design and a simultaneous approach to textile and garment design. Based on an enhanced understanding of our participants textile preferences, particular fabric qualities have catalysed silhouettes, through live draping and geometric pattern cutting to accommodate multiple body shapes and customisation. Printedtextiles have also been digitally crafted in response to the contours of the garment and body and personal narratives of wear. Sensorial and tactile interactions have informed the engineering and scaling of patterns within zero-waste volumes. The article considers the functional and aesthetic role of textiles

PAC-Bayesian Bounds for Randomized Empirical Risk Minimizers

The aim of this paper is to generalize the PAC-Bayesian theorems proved by Catoni in the classification setting to more general problems of statistical inference. We show how to control the deviations of the risk of randomized estimators. A particular attention is paid to randomized estimators drawn in a small neighborhood of classical estimators, whose study leads to control the risk of the latter. These results allow to bound the risk of very general estimation procedures, as well as to perform model selection

Correction to: Maternal complications in twin pregnancies in Finland during 1987–2014 : a retrospective study

An amendment to this paper has been published and can be accessed via the original article

One-year unsupervised individualized exercise training intervention enhances cardiorespiratory fitness but not muscle deoxygenation or glycemic control in adults with type 1 diabetes

Adaptations to long-term exercise training in type 1 diabetes are sparsely studied. We examined the effects of a 1-year individualized training intervention on cardiorespiratory fitness, exercise-induced active muscle deoxygenation, and glycemic control in adults with and without type 1 diabetes. Eight men with type 1 diabetes (T1D) and 8 healthy men (CON) matched for age, anthropometry, and peak pulmonary O-2 uptake, completed a 1-year individualized training intervention in an unsupervised real-world setting. Before and after the intervention, the subjects performed a maximal incremental cycling test, during which alveolar gas exchange (volume turbine and mass spectrometry) and relative concentration changes in active leg muscle deoxygenated (Delta[HHb]) and total (Delta[tHb]) hemoglobin (near-infrared spectroscopy) were monitored. Peak O-2 pulse, reflecting peak stroke volume, was calculated (peak pulmonary O-2 uptake/peak heart rate). Glycemic control (glycosylated hemoglobin A(1c) (HbA(1c))) was evaluated. Both T1D and CON averagely performed 1 resistance-training and 3-4 endurance-training sessions per week (similar to 1 h/session at similar to moderate intensity). Training increased peak pulmonary O-2 uptake in T1D (p = 0.004) and CON (p = 0.045) (group x time p = 0.677). Peak O-2 pulse also rose in T1D (p = 0.032) and CON (p = 0.018) (group x time p = 0.880). Training increased leg Delta[HHb] at peak exercise in CON (p = 0.039) but not in T1D (group x time p = 0.052), while no changes in leg Delta[tHb] at any work rate were observed in either group (p > 0.05). HbA(1c) retained unchanged in T1D (from 58 +/- 10 to 59 +/- 11 mmol/mol, p = 0.609). In conclusion, 1-year adherence to exercise training enhanced cardiorespiratory fitness similarly in T1D and CON but had no effect on active muscle deoxygenation or glycemic control in T1D.Peer reviewe

Correction to: Perinatal outcomes in Finnish twins : a retrospective study

An amendment to this paper has been published and can be accessed via the original article

Perinatal outcome of dichorionic and monochorionic-diamniotic Finnish twins : a historical cohort study

Introduction Although the perinatal mortality of monochorionic twins has been reported to be higher, the role of chorionicity is debated and data from Finland are still lacking. To examine the effect of chorionicity on the main outcome measures, perinatal and neonatal mortality and neonatal morbidity of Finnish twins, a comprehensive population-based historical cohort study was performed at Helsinki University Hospitals. Material and methods All 1034 dichorionic and monochorionic-diamniotic twin pregnancies managed at Helsinki University Hospital area during 2006, 2010, 2014 and 2018 were collected from patient databases. Information on chorionicity was retrieved from ultrasound reports and all relevant clinical information from patient records. Differences in perinatal and neonatal mortality and neonatal morbidity were analyzed by performing group comparisons between the twins and chorionicity. The role of chorionicity was also assessed in logistic regression analyses. Results There were 1034 dichorionic-diamniotic (DCDA, n = 789, 76.3%, 95% confidence interval [CI] 73.6-78.9) and monochorionic-diamniotic (MCDA, n = 245, 23.7%, 95% CI 21.4-26.0) twin pregnancies during the studied years. Most (n = 580, 56.1%, 95% CI 52.8-59.2) twins were born at term, but 151 (61.6%, 95% CI 55.8-67.3) of MCDA twins were preterm and had lower birthweight and Apgar scores and higher risk of death of one twin. Perinatal and neonatal mortality did not differ between twins A and B, but the immediate outcome of twin B was worse, with lower arterial pH and Apgar scores and increased need of neonatal intensive care unit treatment. Conclusions Chorionicity contributes to the perinatal and neonatal outcome in favor of dichorionic twins. This disadvantage of MCDA twinning is likely explained by earlier gestational age at birth and inequal placental sharing. Irrespective of chorionicity, twin B faces more complications.Peer reviewe