Judul: Uji Robust T2-Hotelling dengan Menggunakan Penduga Minimum Covariance Determinant
Abstrak: Hotelling’s T2 statistic is a good statistic for inference about the mean of a multivariate normal population. In Hotelling’s T2 statistic, approximation with Bonferroni confidence intervals provides shorter interval than T2 confidence intervals. Therefore, to find the mean of a multivariate normal population, simultaneous t-intervals based on the Bonferroni method is often applied. However, hypothesis test and confidence intervals based on T2 statistic can be significantly affected by outliers in a set of multivariate normal data. Therefore, to find a good estimator for the mean of a multivariate normal population, the Minimum Covariance Determinant (MCD) estimator is used. To increase the efficiency of the MCD estimator, this test statistic is applied using the reweighted MCD which gives weights to the mean and covariance based on the robust of the observations.
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Judul: Centrality test for Non-Normal And Skewed Population
Abstrak: The t modified 2 test is more robust than t test for skewed popnlation. This test tolerate the population skewness from -1.2 to 1.2 sample size is reather than 25. The sign test robust to the populated skewed population, but the value of the estimated always close to the size of the tcst. Wilcoxon test is not robust to the population skewness. This test is more suittalble for Symmetric population
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Judul: Leaf morphology and Anatomy Characters of Some Sansevieria Species
Abstrak: Penelitian ini bertujuan untuk mengkaji karakter morfologi dan anatomi daun pada lima spesies tumbuhan Sansevieria. Berdasarkan pengamatan karakter morfologi, dijumpai variasi morfologi daun meliputi ukuran panjang, lebar dan tebal daun serta pola warna pada daun ke lima spesies Sansevieria. S. sufruticosa memiliki daun berbentuk silindris berwarna hijau, dengan ujung daun berduri merah kecoklatan. S. masoniana congo memiliki daun berbentuk jorong, warna hijau tua, dengan tepi daun berwarna merah. S. samurai dwarf memiliki daun berwarna hijau dengan permukaan cekung membentuk saluran. S. trifasciata gold flame memiliki daun berbentuk lanset, tebal berwarna hijau tua bergaris hijau muda dengan tepi daun berwarna kuning, sedangkan S. kirkii brown memiliki daun berbentuk lanset, berwarna coklat dengan bercak putih, permukaannya bergelombang. Pada ke lima spesies Sansevieria daun dilapisi selapis epidermis berbentuk poligonal dengan 4 hingga 6 sisi yang berdinding tipis, kecuali spesies S. samurai dwarf sel epidermis berdinding tebal merata. Stomata dijumpai pada kedua permukaan daun, terdapat lebih banyak pada permukaan bawah daun (abaksial). S. masoniana congo memiliki stomata berukuran (panjang x lebar) terbesar, sedangkan S. kirkii brown memiliki stomata terkecil. S. masoniana congo memiliki kerapatan stomata terkecil dengan indeks stomata terbesar, sebaliknya S. sufruticosa memiliki kerapatan stomata terbesar dengan indeks stomata terkecil. Diantara kelima spesies yang diteliti, daun S. masoniana congo memiliki kutikula yang paling tebal sebaliknya S. trifasciata gold flame memiliki kutikula paling tipis., This research aims to describe leaf morphology and anatomy characters of five Sansevieria species. Based on the morphology characters, there are some variation in the length, width, thickness and leaf color pattern. S. sufruticosa has green cylindrical leaf, with auburn thorny leaf tip. S. masoniana congo has elliptical leaf, dark green with red stripe on the leaf margins. S. samurai dwarf has green leaf blade with concave surface forms thick wide channel. S. trifasciata gold flame has thick lanceolate leaf, light green striped dark green with yellow stripe in the leaf margin, while S. kirkii brown has white spotted brown lanceolate leaf with wavy surface. Sansevieria was leaf covered with a layer of epidermis. Epidermal cells are polygonal in shape with four to six thin wall sides, except S. samurai dwarf with thick cell wall. Stomata were found on both leaf sides, more stomata present on the lower epidermis than the upper epidermis. S. masoniana congo has the biggest (length x width) stomata, while S. kirkii brown has the smallest stomata. S. masoniana congo has the lowest stomatal density with the highest stomatal index, whereas S. sufruticosa has the highest stomatal density with the lowest stomatal index. Among all species, S. masoniana congo leaf has the thickest cuticula while S. trifasciata gold flame has the thinnest. Key words: Leaf anatomy, leaf morphology, Sansevieria, stomata
Keyword: Anatomi daun, morfologi daun, Sansevieria, stomata