87,305 research outputs found
Maximally selected chi-square statistics and binary splits of nominal variables
No full textWe address the problem of maximally selected chi-square statistics in the case of a binary Y variable and a nominal X variable with several categories. The distribution of the maximally selected chi-square statistic has already been derived when the best cutpoint is chosen from a continuous or an ordinal X, but not when the best split is chosen from a nominal X. In this paper, we derive the exact distribution of the maximally selected chi-square statistic in this case using a combinatorial approach. Applications of the derived distribution to variable selection and hypothesis testing are discussed based on simulations. As an illustration, our method is applied to a pregnancy and birth data set
Maximally selected chi-square statistics for at least ordinal scaled variables
No full textThe association between a binary variable Y and a variable X with an at least ordinal measurement scale might be examined by selecting a cutpoint in the range of X and then performing an association test for the obtained 2x2 contingency table using the chi-square statistic. The distribution of the maximally selected chi-square statistic (i.e. the maximal chi-square statistic over all possible cutpoints) under the null-hypothesis of no association between X and Y is different from the known chi-square distribution. In the last decades, this topic has been extensively studied for continuous X variables, but not for non-continuous variables with an at least ordinal measurement scale (which include e.g. classical ordinal or discretized continuous variables). In this paper, we suggest an exact method to determine the distribution of maximally selected chi-square statistics in this context. This novel approach can be seen as a method to measure the association between a binary variable and variables with an at least ordinal scale of different types (ordinal, discretized continuous, etc). As an illustration, this method is applied to a new data set describing pregnancy and birth for 811 babies
Traces and shards of self-injury: Strange accounting with “Author X”
No full textIn this strange account autoethnography, three or four authors explore their lived experiences with self-injury. Strange accounting is both a post-modern style of text, and a method for keeping identities concealed when risks and secrets are in play. Author X, a post-modern place-keeper for an anonymous author who may or may not have contributed to this manuscript, introduces a new dimension and layer of concealment. With Author X in-play and under erasure, the reader will never be sure if there were three or four authors on this manuscript. Through strange accounting, a post-structuralist/postmodernist frame will be applied to understanding the self-injury experience. We frame self-injury as a social practice and, for some, an everyday norm, while remaining acutely aware of the stigma surrounding the topic of self-injury. Each of us, coupled with Author X, provide the others cover to trace stories of self-injury through the literature, our flesh, and our lives
Jenny Chi: Drawings
No full textThis portfolio of selected drawings captures the romantic realism of Jenny Chi\u27s artwork.
YOUNG ARTEMIS 26 x 19 inches Red Chalk
EDWARD 13 x 9.5 inches Red Chalk
MARISSA 26 x 19 inches Red Chalk
GRACE 20 x 16 inches Charcoal
MOMENT 30 x 20 inches Charcoalhttps://thekeep.eiu.edu/artdept_facportfolios/1003/thumbnail.jp
Jenny Chi: Landscape Paintings
No full textThis portfolio highlights the romantic realism of Jenny Chi\u27s landscape paintings. Included in the selection are:
TUSCAN LANDSCAPE 15 x 26 inches Oil on Linen
ITALIAN LANDSCAPE I 4 x 9 inches Oil on Linen
ITALIAN LANDSCAPE II 8 x 5 inches Oil on Linenhttps://thekeep.eiu.edu/artdept_facportfolios/1001/thumbnail.jp
Jenny Chi: Figurative Paintings
No full textThis portfolio highlights the romantic realism of Jenny Chi\u27s figurative paintings. Included in the selection are:
SELENE AND ENDYMION 32 x 52 inches Oil on Linen
HELOISE AND ABELARD 40 x 52 inches Oil on Linen
ST. LUKE 30 x 30 inches Oil on Linen
ZEUS 40 x 26 inches Oil on Linen
ARIADNE ABANDONED 36 x 28 inches Oil on Linenhttps://thekeep.eiu.edu/artdept_facportfolios/1000/thumbnail.jp
Jenny Chi: Still Life Paintings
No full textThis portfolio contains selected works of the still life paintings of Jenny Chi, in the style of romantic realism:
ARTE MUSICA II 42 x 30 inches Oil on Linen
SILENT WORDS 15x 18 inches Oil on Linen
GOLDEN APPLE 8 x 10 inches Oil on Linen
PERSEPHONE\u27S FEAST 11 x 16 inches Oil on Linen
BROKEN D 24 x 32 inches Oil on Linenhttps://thekeep.eiu.edu/artdept_facportfolios/1002/thumbnail.jp
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Observation of e(+)e(-) -> phi chi(c1) and phi chi(c2) at root s=4.600 GeV
No full textUsing a data sample collected with the BESIII detector operating at the BEPCII storage ring at a center-of-mass energy of root s = 4.600 GeV, we search for the production of e(+)e(-) -> phi chi(c0,1,2). A search is also performed for the charmonium-like state X(4140) in the radiative transition e(+)e(-) -> gamma X(4140) with X(4140) subsequently decaying into phi J/psi The processes e(+)e(-) -> phi chi(c1) and phi chi(c2) are observed for the first time, each with a statistical significance of more than 10 sigma, and the Born cross sections are measured to be (4.2(-1.0)(+1.7) +/- 0.3) and (6.7(-1.7)(+3.4) +/- 0.5) pb, respectively, where the first uncertainties are statistical and the second systematic. No significant signals are observed for e(+)e(-) -> phi chi(c0) and e(+)e(-) -> gamma X(4140) and upper limits on the Born cross sections at 90% C. L. are provided at root s = 4.600 GeV
Search for X(3872) -> pi(0)chi(c0) and X(3872) -> pi pi chi(c0) at BESIII
No full textUsing 9.9 fb(-1) of e(+)e(-) collision data collected by the BESIII detector at center-of-mass energies between 4.15 and 4.30 GeV, we search for the processes e(+)e(-) -> gamma(X)(3872) with X(3872) -> pi(0)chi(c0) and X(3872) -> pi pi chi(c0). We set upper limits (at 90% C.L.) of B(X(3872)->pi(0)chi(c0))/B(X(3872) -> pi(+)pi(-) J/psi) < 3.6, B(X(3872) -> pi(+)pi(-)chi(c0))/B(X(3872) -> pi(+)pi(-) J/psi) < 0.56, and B(X(3872) -> pi(+)pi(-)chi(c0))/B(X(3872) -> pi(+)pi(-) J/psi) < 1.7. Combined with the BESIII measurement of X(3872) -> pi(0)chi(c1), we also set an upper limit of B(X(3872)->pi(0)chi(c0))/B(X(3872) -> pi(0)chi(c1) < 4.5.For complete list of authors see http://dx.doi.org/10.1103/PhysRevD.105.072009</p
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