Anonymizing Graphs: Measuring Quality for Clustering

Peer-reviewed

Enseñar a aprender a pensar en los centros educativos, incluso en las actividades de evaluación.= Teaching to learn how to think at schools, even within assessment activities

El auténtico protagonismo de los centros educativostiene que dirigirse a ayudar a pensar a sus alumnos y aenseñarlos a aprender, es decir, el docente tiene queenseñar estrategias de aprendizaje y debe promover elesfuerzo del estudiante para facilitar la construcción deesquemas y el aprendizaje permanente.El profesor debe utilizar cualquier situación deaprendizaje para enseñar dichas estrategias deaprendizaje, incluso en las situaciones de evaluación;por lo tanto, en este trabajo se sugiere que en lasevaluaciones de los alumnos y alumnas se tenga encuenta la metacognición como factor fundamental en elaprendizaje y la enseñanza

Talviaikainen happitilanne eräissä Pohjois-Savon järvissä vuosina 1997-2008

Pohjois-Savossa seurattiin talviaikaista happitilannetta vuosina 1997-2008. Seurannan kohteena oli neljä pienehköä järveä (Iso-Valkeinen, Kevätön, Kolmisoppi ja Vehmasjärvi), jotka ovat erityyppisiä syvyydeltään, rehevyystasoltaan ja humuspitoisuudeltaan. Näiden esimerkkijärvien oli tarkoitus antaa yleisemminkin viitteitä happitilanteen kehityksestä talven aikana. Alkutalven tulosten perusteella annettiin vuosittain tiedote, jossa arvioitiin happikatojen mahdollisuutta kevättalven kuluessa. Yleisöllä oli myös mahdollisuus seurata happi- ja lämpötilatuloksia Pohjois-Savon ympäristökeskuksen verkkopalvelun kautta. Hapenkulutusnopeus oli rehevimmässä seurantajärvessä kaksinkertainen verrattuna karumpiin ja syvyyden myötä ero vain korostui. Pohjanläheisessä vesikerroksessa 1 mg/l:n happipitoisuus kului karuissa järvissä noin kahdessa viikossa ja rehevässä noin kolmessa päivässä. Vuosien välinen vaihtelu oli kuitenkin hyvin suurta. Vaihtelu oli suurta myös karuissa järvissä. Veden jäätymisajankohdalla ja veden lämpötilalla on merkittävä vaikutus siihen, millainen kevättalven happitilanteesta muodostui. Seurantajärvien aineiston perusteella voidaan karkeasti arvioida, että kuukauden viivästyminen jäätymisessä tai vesipatsaan viilentyminen ennen jäätymistä asteen verran kylmemmäksi merkitsevät noin kolmanneksen korkeampaa happipitoisuutta kevättalvella. Vesipatsaan happitilanteen heikentymisen sekä ravinne- ja rautapitoisuuksien välillä todettiin vahvat yhteydet. Kaikkien järvien aineistossa happitilanteen heikkeneminen johti voimakkaimmin alusveden ammoniumtyppi-, kokonaisfosfori- ja rautapitoisuuksien kasvuun. Pitoisuusmuutokset olivat talven aikana suurimmat rehevimmässä kohdejärvessä, Kevättömässä, jossa kokonaisfosforipitoisuudet keskimäärin kymmenkertaistuivat, fosfaattifosforipitoisuudet kasvoivat keskimäärin 20-kertaisiksi ja rautapitoisuudet yli seitsenkertaisiksi.

Instability of a square sheet under symmetric biaxial loading

An early experiment found that a square rubber sheet under symmetric biaxial loading may not remain square. This curious result has been one of the most instructive examples in finite elasticity. Here thermodynamic considerations are used to analyze this instability.

Symmetric pollen mitosis I and suppression of pollen mitosis II prevent pollen development in Brachiaria jubata (Gramineae)

Microsporogenesis and pollen development were analyzed in a tetraploid (2n = 4x = 36) accession of the forage grass Brachiaria jubata (BRA 007820) from the Embrapa Beef Cattle Brachiaria collection that showed partial male sterility. Microsporocytes and pollen grains were prepared by squashing and staining with 0.5% propionic carmine. The meiotic process was typical of polyploids, with precocious chromosome migration to the poles and laggards in both meiosis I and II, resulting in tetrads with micronuclei in some microspores. After callose dissolution, microspores were released into the anther locule and appeared to be normal. Although each microspore initiated its differentiation into a pollen grain, in 11.1% of them nucleus polarization was not observed, i.e., pollen mitosis I was symmetric and the typical hemispherical cell plate was not detected. After a central cytokinesis, two equal-sized cells showing equal chromatin condensation and the same nuclear shape and size were formed. Generative cells and vegetative cells could not be distinguished. These cells did not undergo the second pollen mitosis and after completion of pollen wall synthesis each gave rise to a sterile and uninucleate pollen grain. The frequency of abnormal pollen mitosis varied among flowers and also among inflorescences. All plants were equally affected. The absence of fertile sperm cells in a considerable amount of pollen grains in this accession of B. jubata may compromise its use in breeding and could explain, at least in part, why seed production is low when compared with the amount of flowers per raceme.

Distortion and internal warping torsion of a double symmetric hollow section

This thesis is made in cooperation with Laboratory of Steel Structures and the steel company SSAB. Maximization of the benefits of high-strength steel usually requires the usage of thin wall thicknesses. This means the failures related to buckling, distortion and warping stand out. One must be aware of these phenomena to design thin-walled structures stressed with forces such as torsional loading. It is also important to take into account small stress ranges when evaluating the accurate fatigue strength of structures. The objective of this thesis is to clarify the theory of the uniform and non-uniform torsion. This paper focuses on warping due to the non-uniform torsion in double symmetric box girder and structural hollow section. The arisen stress states are explained and researched using the finite element method. Another research target is the distortion in double symmetric box girder due to torsion, and the restraining effect of transverse diaphragms at the load end. Multiple transverse diaphragms are used to study more efficient restraining against warping and distortion than a common one end plate structure.

Comorbidity of psychiatric disorders and symmetric distal polyneuropathy among type II diabetic outpatients

The objective of the present study was to establish the frequency of psychiatric comorbidity in a sample of diabetic patients with symmetric distal polyneuropathy (SDPN). Sixty-five patients with type 2 diabetes mellitus were selected consecutively to participate in the study at Instituto Estadual de Diabetes e Endocrinologia. All patients were submitted to a complete clinical and psychiatric evaluation, including the Portuguese version of the structured clinical interview for DSM-IV, the Beck Depression Inventory, the Neuropathy Symptom Score, and Neuropathy Disability Score. SDPN was identified in 22 subjects (33.8%). Patients with and without SDPN did not differ significantly regarding sociodemographic characteristics. However, a trend toward a worse glycemic control was found in patients with SDPN in comparison to patients without SDPN (HbA1c = 8.43 ± 1.97 vs 7.48 ± 1.95; P = 0.08). Patients with SDPN exhibited axis I psychiatric disorders significantly more often than those without SDPN (especially anxiety disorders, in general (81.8 vs 60.0%; P = 0.01), and major depression - current episode, in particular (18.2 vs 7.7%; P = 0.04)). The severity of the depressive symptoms correlated positively with the severity of SDPN symptoms (r = 0.38; P = 0.006), but not with the severity of SDPN signs (r = 0.07; P = 0.56). In conclusion, the presence of SDPN seems to be associated with a trend toward glycemic control. The diagnosis of SDPN in diabetic subjects seems also to be associated with relevant psychiatric comorbidity, including anxiety and current mood disorders.

Modelling Cutting States in Rough Turning of 34CrNiMo6 Steel

Rough turning is an important form of manufacturing cylinder-symmetric parts. Thus far, increasing the level of automation in rough turning has included process monitoring methods or adaptive turning control methods that aim to keep the process conditions constant. However, in order to improve process safety, quality and efficiency, an adaptive turning control should be transformed into an intelligent machining system optimizing cutting values to match process conditions or to actively seek to improve process conditions. In this study, primary and secondary chatter and chip formation are studied to understand how to measure the effect of these phenomena to the process conditions and how to avoid undesired cutting conditions. The concept of cutting state is used to address the combination of these phenomena and the current use of the power capacity of the lathe. The measures to the phenomena are not developed based on physical measures, but instead, the severity of the measures is modelled against expert opinion. Based on the concept of cutting state, an expert system style fuzzy control system capable of optimizing the cutting process was created. Important aspects of the system include the capability to adapt to several cutting phenomena appearing at once, even if the said phenomena would potentially require conflicting control action.

Spectral Analysis of Symmetric and Anti-Symmetric Pairwise Kernels

This work investigates theoretical properties of symmetric and anti-symmetric kernels. First chapters give an overview of the theory of kernels used in supervised machine learning. Central focus is on the regularized least squares algorithm, which is motivated as a problem of function reconstruction through an abstract inverse problem. Brief review of reproducing kernel Hilbert spaces shows how kernels define an implicit hypothesis space with multiple equivalent characterizations and how this space may be modified by incorporating prior knowledge. Mathematical results of the abstract inverse problem, in particular spectral properties, pseudoinverse and regularization are recollected and then specialized to kernels. Symmetric and anti-symmetric kernels are applied in relation learning problems which incorporate prior knowledge that the relation is symmetric or anti-symmetric, respectively. Theoretical properties of these kernels are proved in a draft this thesis is based on and comprehensively referenced here. These proofs show that these kernels can be guaranteed to learn only symmetric or anti-symmetric relations, and they can learn any relations relative to the original kernel modified to learn only symmetric or anti-symmetric parts. Further results prove spectral properties of these kernels, central result being a simple inequality for the the trace of the estimator, also called the effective dimension. This quantity is used in learning bounds to guarantee smaller variance.

Effect of loading type on the fatigue strength of symmetric and asymmetric welded joints made of ultra high strength steel

In this study, finite element analyses and experimental tests are carried out in order to investigate the effect of loading type and symmetry on the fatigue strength of three different non-load carrying welded joints. The current codes and recommendations do not give explicit instructions how to consider degree of bending in loading and the effect of symmetry in the fatigue assessment of welded joints. The fatigue assessment is done by using effective notch stress method and linear elastic fracture mechanics. Transverse attachment and cover plate joints are analyzed by using 2D plane strain element models in FEMAP/NxNastran and Franc2D software and longitudinal gusset case is analyzed by using solid element models in Abaqus and Abaqus/XFEM software. By means of the evaluated effective notch stress range and stress intensity factor range, the nominal fatigue strength is assessed. Experimental tests consist of the fatigue tests of transverse attachment joints with total amount of 12 specimens. In the tests, the effect of both loading type and symmetry on the fatigue strength is studied. Finite element analyses showed that the fatigue strength of asymmetric joint is higher in tensile loading and the fatigue strength of symmetric joint is higher in bending loading in terms of nominal and hot spot stress methods. Linear elastic fracture mechanics indicated that bending reduces stress intensity factors when the crack size is relatively large since the normal stress decreases at the crack tip due to the stress gradient. Under tensile loading, experimental tests corresponded with finite element analyzes. Still, the fatigue tested joints subjected to bending showed the bending increased the fatigue strength of non-load carrying welded joints and the fatigue test results did not fully agree with the fatigue assessment. According to the results, it can be concluded that in tensile loading, the symmetry of joint distinctly affects on the fatigue strength. The fatigue life assessment of bending loaded joints is challenging since it depends on whether the crack initiation or propagation is predominant.

Coriolis effects in symmetric top spectra /

The "x-y Coriolis Coupling Theory" as presented by Dilauro and Mills (1966) is reformulated and extended to the determination of Raman intensities. Theoretical Raman and Infrared spectra are computed in order to understand the effects due to this coupling in both types of spectra. Both the Infrared and Raman spectra obtained indicate very real effects due to Coriolis coupling. In some of the cases chosen the computed spectra are grossly different from the normal spectra where coupling is absent. Such large effects can greatly impede the interpretation of experimental results. Theoretical spectra therefore aids in the interpretation of experimental results, as is clearly demonstrated in the results of this work.