This paper reports a study on mathematics teachers’ perceptions of the Matura mathematics exam in Croatia. The study focuses on the suitability of mathematics school textbooks for students’ ...preparation for the exams, the complexity of the tasks in the exams, the grading and scoring of the exams, and teachers’ level of satisfaction with student achievement. The study used a convenience sampling method. It was conducted through a questionnaire administered to 308 upper secondary mathematics teachers. The findings showed that teachers do not perceive school textbooks as suitable resources to prepare for the higher level exam. Furthermore, the teachers believe that the test length is not appropriate i.e., the time given to students for the higher level exam is insufficient. On average they are satisfied with their students’ results, but are undecided about the criteria and scoring of the Matura. Vocational school teachers showed more dissatisfaction with the requirements and outcomes of the Matura exam compared to grammar school teachers. The results of this empirical study can be taken as a good starting point for re-assessing the requirements of the Matura exam in mathematics.
U ovom radu predstavljena su mišljenja i stavovi nastavnika matematike o ispitima iz matematike na Državnoj maturi u Hrvatskoj. Cilj rada bio je ispitati mišljenja nastavnika o prikladnosti srednjoškolskih udžbenika matematike za pripremu učenika za ispite državne mature, općim zahtjevima ispita, ocjenjivanju i bodovanju na ispitima te o uspjehu učenika. Istraživanje je provedeno putem upitnika na prigodnom uzorku od 308 nastavnika matematike koji poučavaju u srednjim školama u Hrvatskoj. Rezultati pokazuju da nastavnici matematike školske udžbenike ne smatraju prikladnima za pripremu učenika za ispit više razine. Nastavnici smatraju da je vrijeme predviđeno za ispit više razine nedovoljno. Većinom su zadovoljni rezultatima svojih učenika, no neopredijeljeni su po pitanju kriterija i bodovanja na maturi. Nastavnici strukovnih škola u većoj su mjeri nezadovoljni zahtjevima i postavkama državne mature u odnosu na gimnazijske nastavnike. Rezultati ovog empirijskog istraživanja mogu poslužiti kao polazište za ponovno razmatranje općih zahtjeva državne mature iz matematike nakon više od deset godina nakon njezina uvođenja.
People with severe mental disorders often require special care. Other than institutionalized care, some organizations provide housing options and special care in the form of organized living. Few ...studies provide a detailed description of nutrient intake in this type of care. The aim of this prospective study was to assess nutritional status and adherence to dietary recommendations in both people with mental disorders (beneficiaries) and their caregivers. Across three levels of care, 46 beneficiaries and 19 caregivers participated in the study. The mean intakes of energy (kcal/day) and macro- and micronutrients (g/day) were estimated from a 3-day dietary record and compared with dietary reference values (DRVs) set by the European Food Safety Authority (EFSA). The majority of participants did not meet energy intake recommendations (kcal/day). The contribution of total fat to energy intake (% E) was higher than recommended in both beneficiaries and caregivers with 42.1 ± 4.4% and 38.5 ± 6.5%, respectively. A total of 45.2% of beneficiaries and 61.1% of caregivers had their carbohydrate intake within the recommended range. Fiber intake was well below the recommendations (25 g/day) in all groups. Across all levels of care, lower micronutrient intake for pantothenic acid, biotin, folate, potassium, magnesium, copper, selenium, and iodine was observed. Based on the current results, the development and implementation of nutritional guidelines may be targeted to specific populations and nutrient intakes.
U ovom radu predstavljena su mišljenja i stavovi nastavnika matematike o ispitima iz matematike na Državnoj maturi u Hrvatskoj. Cilj rada bio je ispitati mišljenja nastavnika o prikladnosti ...srednjoškolskih udžbenika matematike za pripremu učenika za ispite državne mature, općim zahtjevima ispita, ocjenjivanju i bodovanju na ispitima te o uspjehu učenika. Istraživanje je provedeno putem upitnika na prigodnom uzorku od 308 nastavnika matematike koji poučavaju u srednjim školama u Hrvatskoj. Rezultati pokazuju da nastavnici matematike školske udžbenike ne smatraju prikladnima za pripremu učenika za ispit više razine. Nastavnici smatraju da je vrijeme predviđeno za ispit više razine nedovoljno. Većinom su zadovoljni rezultatima svojih učenika, no neopredijeljeni su po pitanju kriterija i bodovanja na maturi. Nastavnici strukovnih škola u većoj su mjeri nezadovoljni zahtjevima i postavkama državne mature u odnosu na gimnazijske nastavnike. Rezultati ovog empirijskog istraživanja mogu poslužiti kao polazište za ponovno razmatranje općih zahtjeva državne mature iz matematike nakon više od deset godina nakon njezina uvođenja.
In this paper we present a catalog of 4584 eclipsing binaries observed during the first two years (26 sectors) of the TESS survey. We discuss selection criteria for eclipsing binary candidates, ...detection of hitherto unknown eclipsing systems, determination of the ephemerides, the validation and triage process, and the derivation of heuristic estimates for the ephemerides. Instead of keeping to the widely used discrete classes, we propose a binary star morphology classification based on a dimensionality reduction algorithm. Finally, we present statistical properties of the sample, we qualitatively estimate completeness, and we discuss the results. The work presented here is organized and performed within the TESS Eclipsing Binary Working Group, an open group of professional and citizen scientists; we conclude by describing ongoing work and future goals for the group. The catalog is available from http://tessEBs.villanova.edu and from MAST.
The Kepler space mission is devoted to finding Earth-size planets orbiting other stars in their habitable zones. Its large, 105 deg2 field of view features over 156,000 stars that are observed ...continuously to detect and characterize planet transits. Yet, this high-precision instrument holds great promise for other types of objects as well. Here we present a comprehensive catalog of eclipsing binary stars observed by Kepler in the first 44 days of operation, the data being publicly available through MAST as of 2010 June 15. The catalog contains 1879 unique objects. For each object, we provide its Kepler ID (KID), ephemeris (BJD0, P 0), morphology type, physical parameters (T eff, log g, E(B -- V)), the estimate of third light contamination (crowding), and principal parameters (T 2/T 1, q, fillout factor, and sin i for overcontacts, and T 2/T 1, (R 1 + R 2)/a, esin Delta *w, ecos Delta *w, and sin i for detached binaries). We present statistics based on the determined periods and measure the average occurrence rate of eclipsing binaries to be ~1.2% across the Kepler field. We further discuss the distribution of binaries as a function of galactic latitude and thoroughly explain the application of artificial intelligence to obtain principal parameters in a matter of seconds for the whole sample. The catalog was envisioned to serve as a bridge between the now public Kepler data and the scientific community interested in eclipsing binary stars.
We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise ...Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all of the transiting planets (41 of 42 have an FPP under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than three times the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify six planets with densities above 5 g cm super(-3), suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than ~2 R sub(+ in circle). Larger planets evidently contain a larger fraction of low-density material (H, He, and H sub(2)O).
We report the distribution of planets as a function of planet radius, orbital period, and stellar effective temperature for orbital periods less than 50 days around solar-type (GK) stars. These ...results are based on the 1235 planets (formally "planet candidates") from the Kepler mission that include a nearly complete set of detected planets as small as 2 R. For all planets with orbital periods less than 50 days, we measure occurrence of 0.130 + or - 0.008, 0.023 + or - 0.003, and 0.013 + or - 0.002 planets per star for planets with radii 2-4, 4-8, and 8-32 R, in agreement with Doppler surveys. We fit occurrence as a function of P to a power-law model with an exponential cutoff below a critical period Psub 0. For smaller planets, Psub 0 has larger values, suggesting that the "parking distance" for migrating planets moves outward with decreasing planet size.
On 2011 February 1 the Kepler mission released data for 156,453 stars observed from the beginning of the science observations on 2009 May 2 through September 16. There are 1235 planetary candidates ...with transit-like signatures detected in this period. These are associated with 997 host stars. Distributions of the characteristics of the planetary candidates are separated into five class sizes: 68 candidates of approximately Earth-size (R p < 1.25 R {circled plus}), 288 super-Earth-size (1.25 R {circled plus} <= R p < 2 R {circled plus}), 662 Neptune-size (2 R {circled plus} <= R p < 6 R {circled plus}), 165 Jupiter-size (6 R {circled plus} <= R p < 15 R {circled plus}), and 19 up to twice the size of Jupiter (15 R {circled plus} <= R p < 22 R {circled plus}). In the temperature range appropriate for the habitable zone, 54 candidates are found with sizes ranging from Earth-size to larger than that of Jupiter. Six are less than twice the size of the Earth. Over 74% of the planetary candidates are smaller than Neptune. The observed number versus size distribution of planetary candidates increases to a peak at two to three times the Earth-size and then declines inversely proportional to the area of the candidate. Our current best estimates of the intrinsic frequencies of planetary candidates, after correcting for geometric and sensitivity biases, are 5% for Earth-size candidates, 8% for super-Earth-size candidates, 18% for Neptune-size candidates, 2% for Jupiter-size candidates, and 0.1% for very large candidates; a total of 0.34 candidates per star. Multi-candidate, transiting systems are frequent; 17% of the host stars have multi-candidate systems, and 34% of all the candidates are part of multi-candidate systems.
The Kepler mission was designed to determine the frequency of Earth-sized planets in and near the habitable zone of Sun-like stars. The habitable zone is the region where planetary temperatures are ...suitable for water to exist on a planet's surface. During the first 6 weeks of observations, Kepler monitored 156,000 stars, and five new exoplanets with sizes between 0.37 and 1.6 Jupiter radii and orbital periods from 3.2 to 4.9 days were discovered. The density of the Neptune-sized Kepler-4b is similar to that of Neptune and GJ 436b, even though the irradiation level is 800,000 times higher. Kepler-7b is one of the lowest-density planets (approximately 0.17 gram per cubic centimeter) yet detected. Kepler-5b, -6b, and -8b confirm the existence of planets with densities lower than those predicted for gas giant planets.
PDF
