PENGELOMPOKAN SMA/MA JURUSAN IPA DI PROVINSI ACEH MENGGUNAKAN METODE K-MEANS DAN K-MEDIANS

Penyelenggaran Ujian Nasional (UN) pada tahun 2016 dan 2017 menggunakan 2 cara yaitu Ujian Nasional Kertas dan Pensil (UNKP) dan Ujian Nasional Berbasis Komputer (UNBK). Untuk menggambarkan kondisi pendidikan pada tahun tersebut, akan dilakukan pengelompokan SMA/MA jurusan IPA di Provinsi Aceh berdasarkan nilai UN dan Indeks Integritas Ujian Nasional (IIUN) menggunakan metode K-means dan K-medians clustering. Jumlah SMA/MA jurusan IPA yang akan dikelompokan pada penelitian adalah 610. Penentuan metode terbaik pada penelitian ini menggunakan validitas internal yang terdiri atas connectivity, dunn index, dan silhouette width. Berdasarkan hasil yang telah diperoleh, metode K-means terpilih sebagai metode terbaik dengan jumlah cluster (k) yang terbaik adalah 4 cluster. Penentuan peringkat cluster berdasarkan nilai UN & IIUN pada pengelompokan tahun 2016 berdasarkan statistik rata-rata, median, minimum, dan maksimum. Sementara, untuk tahun 2017 berdasarkan statistik rata-rata, median, minimum, maksimum, dan standar deviasi. Dari tahun 2016 ke tahun 2017, berdasarkan total jumlah anggota cluster disimpulkan bahwa, peringkat 1 dan 2 mengalami penurunan jumlah SMA/MA yaitu, dari 183 menjadi 94 dan dari 148 menjadi 69. Sementara, peringkat 3 dan 4 mengalami peningkatan jumlah SMA/MA yaitu, dari 123 menjadi 133 dan dari 156 menjadi 314. Berdasarkan nilai rerata UN disimpulkan bahwa, peringkat 1 dan 3 mengalami penurunan nilai rerata serta peringkat 2 dan 4 mengalami peningkatan. Sementara nilai IIUN mengalami peningkatan pada semua peringkat dalam cluster. Penurunan jumlah SMA/MA dan rerata UN pada peringkat tinggi yaitu peringkat 1 dan 2 dan peningkatan pada peringkat rendah yaitu peringkat 3 dan 4 tersebut diduga salah satunya disebabkan karena adanya peningkatan jumlah SMA/MA yang melaksanakan UNBK, yaitu dari 49 SMA/MA pada tahun 2016 menjadi 368 SMA/MA pada tahun 2017.Kata kunci: IIUN, K-means clustering, K-medians clustering, UN, UNBK, validasi internal

Relationships between hornblende K-Ar ages, chemical composition and hydrogen isotopes, Connemara, western Ireland: evidence for a massive extinct hydrothermal system

Major element compositional analyses, K-Ar ages, deltaD parts per thousand and delta O-18 parts per thousand values for 30 zoned and unzoned hornblendes from Dalradian amphibolites and metagabbros. mostly in north Connemara are reported. Although the cooling ages are expected from previous U-Pb zircon studies to be c. 475-450 Ma the results obtained are from 556 +/- 6 to 410 +/- 9 Ma with an average of 470 Ma. Fluid movements. probably at 275 +/- 15 degreesC, i.e. much below Ar closure temperature for hornblende. erratically reset the ages, as is shown by a negative correlation of hornblende deltaD and age and a wide scatter of ages even within 2 m. The changes were implemented by deltaD exchange between fluid and hornblendes in which ionic porosity. Z, influenced the loss of Ar and possibly its gain from the fluid to give the excess Ar found in some samples. Z is controlled by hornblende chemical composition. High Mg, Si and Mg/Fe and low Fe, Al, Ti, Na and particularly low K, amphiboles giving low Z values retained Ar more firmly and gained Ar more readily than compositions which had higher Z values, which gave younger ages. These range down to c, 400 Ma. being the age of the intrusion of the Galway Granite suite that initiated the fluid circulation. The scatter of ages is a consequence of incomplete equilibration, mainly because of the slow deltaD exchange rate below 350 degreesC and partly because the fluid permeated erratically in different areas and down cracks of all kinds, promoting irregular Ar movement. The meteoric fluid circulated through Connemara. the Galway Granite and at least some of the contiguous Silurian sediments of the South Mayo trough. These overlying sediments may have contributed to the water circulated in north Connemara which was slightly less negative deltaD than in central Connemara. For hornblende K-Ar ages to be a reliable measure of times of uplift and cooling, they need to be demonstrated to be free from the influence of hot fluids by showing no correlation of age with deltaD

Point-source scalar turbulence

The statistics of a passive scalar randomly emitted from a point source is investigated analytically. Our attention has been focused on the two-point equal-time scalar correlation function. The latter is indeed easily related to the spectrum, a statistical indicator widely used both in experiments and in numerical simulations. The only source of inhomogeneity/anisotropy is in the injection mechanism, the advecting velocity here being statistically homogeneous and isotropic. Our main results can be summarized as follows. 1) For a very large velocity integral scale, a pure scaling behaviour in the distance between the two points emerges only if their separation is much smaller than their distance from the point source. 2) The value we have found for the scaling exponent suggests the existence of a direct cascade, in spite of the fact that here the forcing integral scale is formally set to zero. 3) The combined effect of a finite inertial-range extension and of inhomogeneities causes the emergence of subleading anisotropic corrections to the leading isotropic term, that we have quantified and discussed.Comment: 10 pages, 1 figure, submitted to Journal of Fluid Mechanic

Kauppakohtaisten tekijöiden vaikutukset kantohintoihin Suomessa

TutkimusselosteSeloste artikkelista: Kolis, K., Hiironen, J., Ärölä, E. & Vitikainen, A. 2014. Effects of sale-specific factors on stumpage prices in Finland. Silva Fennica 48(3), article id 1054

K-Ar biotite ages of the coarse-grained granites from the Inada area, Ibaraki Prefecture: Evaluation of suitability for a new K-Ar dating standard

K-Ar ages have been determined on biotite fractions of three coarse-grained granites from the Inada area, Ibaraki Prefecture. Ages are 65.0 +/－ 2.3 Ma for Inada-I, 63.7 +/－ 2.2 Ma for Inada-II and 62.1 +/－ 2.8 Ma for Inada-III. The Inada-II sample is a better candidate than the other two samples as a K-Ar dating standard on the basis of thin section observation and K-Ar dating results. However, a chlorite removal step is necessary to make the new dating standard

Book Review

Reviews of the following books: K. S. SHRADER-FRECHETTE, Risk AND RATIONALITY (U. California Press 1991) [312 pp.] Index of Names, Index of Subjects, Notes. CIP 91-3294; ISBN 0-520-07287-1 (Cloth $39.95); ISBN 0-520-07289-8 (Pbk.$15.95). [2120 Berkeley Way, Berkeley, CA 94720.] W. KIP VisCusi, REFORMING PRODUCTS LIABILITY (Harvard U. Press 1991). [270 pp.] Appendices, bibliography, index, notes. CIP 90-23161, ISBN 0-674-75323-2 (Cloth $39.95). [79 Garden Street Cambridge, MA 02138.

Piano Ensemble, April 26, 1990

This is the concert program of the Piano Ensemble performance on Thursday, April 26, 1990 at 12:00 p.m., at the Boston University Concert Hall, 855 Commonwealth Avenue, Boston, Massachusetts. Works performed were Sonata in D major, K. 448 by Wolfgang Amadeus Mozart, Fantasie in F minor, Op. 103 by Franz Schubert, Ma Mère L'Oye for Four Hands by Maurice Ravel, and Sonate by Francis Poulenc. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund