4,843 research outputs found
Порівняльно-правові дослідження засад професійної діяльності працівників НЦБ Інтерполу в Україні
Vårt huvudsyfte har varit att utvärdera huruvida några för gymnasieungdomar tidigare kända begrepp i ämnet matematik kvalitetsmässigt förändras i olika lärandesituationer över tid. I styrdokumenten för gymnasieskolan definieras begreppet kunskap med hjälp av de fyra f:en: Fakta, kunskap som information; Förståelse, att begripa kunskap; Färdighet, kunskapens praktiska sida; Förtrogenhet, kunskap som bedömning. Vi har använt oss huvudsakligen av kvalitativ metod och teknik eftersom vi ville se vilka uppfattningar som avser begreppet ekvation som eleverna hade med sig från tidigare utbildning och hur dessa uppfattningar förändrades över tid. Den kvalitativa metoden är lämplig just för detta ändamål när vi i förväg inte vet vilka svar eleverna kommer att delge oss. Vi har använt oss av tre olika metoder för att få svar på våra frågeställningar nämligen enkät, intervju och utvärdering. Under hösten 2003 genomförde vi två olika undervisningsserier i två parallella klasser på gymnasiet. Med den ena gruppen har vi bedrivit utomhuspedagogik och den andra har undervisats på traditionellt sätt. Grupperna har mött samma problemtyper men arbetat med dem på två helt olika sätt. Det slutliga resultatet visar att majoriteten av eleverna i utegruppen ser tillämpningsmöjligheter utanför skolans värld med ekvationer emedan elever i innegruppen inte gör det utan ser ekvationer som något relaterat till skolmatematiken. Vår tolkning är att utegruppen nått en högre förtrogenhet med begreppet vi undersökt. Vår slutsats är att utomhuspedagogik kan vara en framkomlig väg att lära matematik
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Transition Probabilities Of Astrophysical Interest In The Niobium Ions Nb+ And Nb2+
Aims. We attempt to derive accurate transition probabilities for astrophysically interesting spectral lines of Nb II and Nb III and determine the niobium abundance in the Sun and metal-poor stars rich in neutron-capture elements. Methods. We used the time-resolved laser-induced fluorescence technique to measure radiative lifetimes in Nb II. Branching fractions were measured from spectra recorded using Fourier transform spectroscopy. The radiative lifetimes and the branching fractions were combined yielding transition probabilities. In addition, we calculated lifetimes and transition probablities in Nb II and Nb III using a relativistic Hartree-Fock method that includes core polarization. Abundances of the sun and five metal-poor stars were derived using synthetic spectra calculated with the MOOG code, including hyperfine broadening of the lines. Results. We present laboratory measurements of 17 radiative lifetimes in Nb II. By combining these lifetimes with branching fractions for lines depopulating the levels, we derive the transition probabilities of 107 Nb II lines from 4d(3)5p configuration in the wavelength region 2240-4700 angstrom. For the first time, we present theoretical transition probabilities of 76 Nb III transitions with wavelengths in the range 1430-3140 angstrom. The derived solar photospheric niobium abundance log epsilon(circle dot) = 1.44 +/- 0.06 is in agreement with the meteoritic value. The stellar Nb/Eu abundance ratio determined for five metal-poor stars confirms that the r-process is a dominant production method for the n-capture elements in these stars.Integrated Initiative of Infrastructure RII3-CT-2003-506350Swedish Research CouncilKnut and Alice Wallenberg FoundationBelgian FRS-FNRSFRIAUS National Science Foundation AST-0607708, AST-0908978Astronom
Experimental and theoretical lifetimes and transition probabilities in Sb I
We present experimental atomic lifetimes for 12 levels in Sb I, out of which
seven are reported for the first time. The levels belong to the 5p(P)6s
P, P and 5p(P)5d P, F and F terms. The
lifetimes were measured using time-resolved laser-induced fluorescence. In
addition, we report new calculations of transition probabilities in Sb I using
a Multiconfigurational Dirac-Hartree-Fock method. The physical model being
tested through comparisons between theoretical and experimental lifetimes for
5d and 6s levels. The lifetimes of the 5d F levels (19.5,
7.8 and 54 ns, respectively) depend strongly on the -value. This is
explained by different degrees of level mixing for the different levels in the
F term.Comment: 10 page
Fairway: A Way to Build Fair ML Software
Machine learning software is increasingly being used to make decisions that
affect people's lives. But sometimes, the core part of this software (the
learned model), behaves in a biased manner that gives undue advantages to a
specific group of people (where those groups are determined by sex, race,
etc.). This "algorithmic discrimination" in the AI software systems has become
a matter of serious concern in the machine learning and software engineering
community. There have been works done to find "algorithmic bias" or "ethical
bias" in the software system. Once the bias is detected in the AI software
system, the mitigation of bias is extremely important. In this work, we
a)explain how ground-truth bias in training data affects machine learning model
fairness and how to find that bias in AI software,b)propose a
methodFairwaywhich combines pre-processing and in-processing approach to remove
ethical bias from training data and trained model. Our results show that we can
find bias and mitigate bias in a learned model, without much damaging the
predictive performance of that model. We propose that (1) test-ing for bias and
(2) bias mitigation should be a routine part of the machine learning software
development life cycle. Fairway offers much support for these two purposes.Comment: ESEC/FSE'20: The 28th ACM Joint European Software Engineering
Conference and Symposium on the Foundations of Software Engineerin
Ovariectomized rats as a model of postmenopausal osteoarthritis: validation and application
We aimed to assess the effect of ovariectomy on cartilage turnover and degradation, to evaluate whether ovariectomized (OVX) rats could form an experimental model of postmenopausal osteoarthritis. The effect of ovariectomy on cartilage was studied using two cohorts of female Sprague–Dawley rats, aged 5 and 7 months. In a third cohort, the effect of exogenous estrogen and a selective estrogen receptor modulator was analyzed. Knee joints were assessed by histological analysis of the articular cartilage after 9 weeks. Cartilage turnover was measured in urine by an immunoassay specific for collagen type II degradation products (CTX-II), and bone resorption was quantified in serum using an assay for bone collagen type I fragments (CTX-I). Surface erosion in the cartilage of the knee was more severe in OVX rats than in sham-operated animals, particularly in the 7-month-old cohort (P = 0.008). Ovariectomy also significant increased CTX-I and CTX-II. Both the absolute levels of CTX-II and the relative changes from baseline seen at week 4 correlated strongly with the severity of cartilage surface erosion at termination (r = 0.74, P < 0.01). Both estrogen and the selective estrogen receptor modulator inhibited the ovariectomy-induced acceleration of cartilage and bone turnover and significantly suppressed cartilage degradation and erosion seen in vehicle-treated OVX rats. The study indicates that estrogen deficiency accelerates cartilage turnover and increases cartilage surface erosion. OVX rats provide a useful experimental model for the evaluation of the chondroprotective effects of estrogens and estrogen-like substances and the model may be an in vivo representation of osteoarthritis in postmenopausal women
Polarization in Hadronic \Lambda Hyperon Production and Chiral-Odd Twist-3 Distribution
Polarization of the \Lambda hyperon produced with a large transverse momentum
in the unpolarized nucleon-nucleon collision is analyzed in the framework of
QCD factorization. We focus on the mechanism in which the soft-gluon component
of the chiral-odd spin-independent twist-3 quark distribution E_F(x,x) becomes
a source of the polarized quark fragmenting into the polarized \Lambda. Our
simple model estimate for this contribution indicates that it gives rise to a
significant \Lambda polarization at large x_F. This is in parallel with the
observation that the soft gluon pole mechanism gives rise to a large single
transverse spin asymmetry in the pion production at x_F\to 1.Comment: 10 pages in LaTex + 5 figures in PS files. Phys. Rev. D in press.
Title changed and some discussions adde
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