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In a micro ring of a superconductor with a spin-triplet equal-spin pairing state, a fluxoid, a combined object of magnetic flux and circulating supercurrent, can penetrate as half-integer multiples of the flux quantum. A candidate material to investigate such half-quantum fluxoids is Sr$_\mathsf{2}$RuO$_\mathsf{4}$. We fabricated Sr$_\mathsf{2}$RuO$_\mathsf{4}$ micro rings using single crystals and measured their resistance behavior under magnetic fields controlled with a three-axes vector magnet. Proper Little-Parks oscillations in the magnetovoltage as a function of an axially applied field, associated with fluxoid quantization are clearly observed, for the first time using bulk single crystalline superconductors. We then performed magnetovoltage measurements with additional in-plane magnetic fields. By carefully analyzing both the voltages $V_+$ ($V_-$) measured at positive (negative) current, we find that, above an in-plane threshold field of about 10 mT, the magnetovoltage maxima convert to minima. We interpret this behavior as the peak splitting expected for the half-quantum fluxoid states., Comment: 16 pages, 15 figures

This study examined teacher and peer assessment of English language oral presentation skills in Japanese classrooms. Twelve graduate university students' oral class presentations were assessed by a teacher and four peers. After presentations were rated, teachers calculated the evaluations, and classmates shared their opinions on the top three presenters. The teacher gave summary comments on all presenters. The Many-Facet Rasch Measurement Model was used to investigate three areas (student ability, item difficulty, and rater severity). This analysis provided information on the relationship between the three facets (raters, students, and items); rater severity and fit statistic; student ability and fit statistic; item difficulty and fit statistic; and functioning of rating categories. Results suggest that the test can be improved by examining the fit statistics (misfit items) statistically and by having discussions with raters or students when they are misfitting. The study indicates that peer assessment can successfully motivate students to improve their presentations, students can be reliable peer raters, and the Rasch model can yield considerable significant data on several factors involved in presentation assessment (student academic adequacy, item difficulty, rater severity, and ability of students to adjust socially). (Contains 11 tables.) (SM)

The Rasch Model is an item response theory, one parameter model developed that states that the probability of a correct response on a test is a function of the difficulty of the item and the ability of the candidate. Item banking is useful for language testing. The Rasch Model provides estimates of item difficulties that are meaningful, irrespective of the ability level tested. This paper focuses mainly on how the model can contribute to the feasibility of item banking in terms of language testing. The present research deals mainly with the following basic aspects of item banking: calibration of items for storage; the measurement of student abilities; and the advantages and limitations of item banking. Item characteristics can be determined either by traditional item statistics (Classical Test Theory) or a newer method of estimating item statistics called Item Response Theory. In this paper, Item Response Theory is used for dealing with item characteristics. The sample data for the research in this paper were taken from a multiple choice test that consisted of 10 items and was given to 105 students. It is concluded that Item Response Theory facilitates item banking by allowing all of the items to be calibrated and positioned on the same latent continuum by means of a common metric, and allows additional items to be added subsequently without the need to locate and retest the original sample of examinees. Furthermore, an item bank permits the construction of tests of known reliability and validity based on appropriate selection of item subsets from the bank without further need for trial in the field. (Contains 12 references.) (KFT)

The Rasch Model is an item response theory, one parameter model developed that states that the probability of a correct response is a function of the difficulty of the item and the ability of the candidate. Item banking is useful for language testing. The Rasch Model provides estimates of item difficulties that are meaningful, irrespective of ability level tested. Application of a many-faceted Rasch measurement model is one of the current issues in the language testing area. This paper explores what the Rasch model tells us in analyzing the multifaceted data of assessment in presentation classes, and focuses more specifically on the possible ways of constructing item banks for oral presentation classes so that teachers will know how difficult a set of test items is for the student-raters and how well those items can distinguish between the better and the poor students. This paper explores several areas of importance with respect to assessment, specifically, what the many-faceted Rasch Measurement Model tells us about the following factors: the relationship among the three facets of assessment (students, items, raters); rater severity/leniency; and students' ability. All of these questions are answered with extensive empirical basis for judgment. (KFT)

In this paper, we present an expanding disc model to derive polarization properties of the Crab nebula. The distribution function of the plasma and the energy density of the magnetic field are prescribed as function of the distance from the pulsar by using the model by Kennel and Coroniti (1984) with $\sigma = 0.003$, where $\sigma$ is the ratio of Poynting flux to the kinetic energy flux in the bulk motion just before the termination shock. Unlike previous models, we introduce disordered magnetic field, which is parameterized by the fractional energy density of the disordered component. Flow dynamics is not solved. The mean field is toroidal. Averaged polarization degree over the disc is obtained as a function of inclination angle and fractional energy density of the disordered magnetic field. It is found for the Crab that the disordered component has about 60 percent of the magnetic field energy. This value is also supported by the facts that the disc appears not `lip-shape' but as `rings' in the intensity map as was observed, and that the highest polarization degree of $\sim 40$ percent is reproduced for rings, being consistent with the observation. We suggest that because the disordered field contributes rather pressure than tension, the pinch force may be over-estimated in previous relativistic magnetohydrodynamic simulations. Disruption of the toroidal magnetic field with alternating direction, which is proposed by Lyubarski (2003), may actually takes place. The relativistic flow speed, which is indicated by the front-back contrast, can be detected in asymmetry in distributions of the position angle and depolarization., Comment: 7 pages, 8 figures, accepted for publication in MNRAS