Judul: Anatomical Structure and Fiber Quality Analysis of Mangium Wood from Three Different Generations. Supervised
Abstrak: Struktur anatomi dan mutu serat kayu mangium (Acacia mangium) dari tiga generasi (F0, F1 dan F2) hasil kegiatan pemuliaan pohon perlu diteliti karena kegiatan tersebut sedikit banyak akan mempengaruhi sifat dan karakteristik kayu yang dihasilkan. Penelitian ini bertujuan untuk mengkaji struktur anatomi dan mutu serat kayu mangium hasil kegiatan pemuliaan antar tiga generasi yang berbeda. Bahan yang digunakan adalah kayu mangium tiga generasi dari tegakan mangium umur 10 tahun hasil kegiatan pemuliaan pohon. Struktur anatomi dianalisis secara makro- dan mikroskopis mengikuti prosedur standar baku, sedangkan kelas mutu seratnya dievaluasi berdasarkan panjang serat dan nilai turunan dimensi serat. Hasil penelitian menunjukkan struktur anatomi dan mutu serat kayu mangium yang diteliti secara keseluruhan tidak berbeda antar ketiganya, kecuali dalam hal ukuran dan proporsi beberapa sel penyusunnya. Serat kayu ketiga generasi masuk dalam Kelas Mutu II. Kegiatan pemuliaan pohon mengakibatkan porsi teras dan kekuatan kayu berkurang, kayu menjadi lebih porous, serat semakin panjang namun tebal dindingnya semakin tipis., The anatomical structure and fiber quality of mangium (Acacia mangium) wood from three generations (F0, F1 and F2) as a result of breeding activities need to be investigated because the treatment applied could affect the characteristics and properties of wood produced. This study aims to examine the anatomical structure and fiber quality of A. mangium wood resulting from tree breeding/tree improvement activities among three different generations. The material used is three generations of mangium wood from a 10-year-old breeding stand. Anatomical structures were analyzed macro- and microscopically following standard procedures, while the fiber quality class was evaluated based on fiber length and fiber dimension derivative values. The results showed that the overall anatomical structure and fiber quality of the studied mangium wood did not differ among the three, except for the size and proportion of some of the constituent cells. Wood fibers from all generations are categorized as Quality Class II. Tree breeding activities result in a reduction in the portion of the heartwood and the strength of the wood. The wood becomes more porous, the fiber becomes longer but the wall thickness becomes thinner.
Keyword: Acacia mangium, anatomical structure, breeding program, fiber dimensions, three generations

Judul: Keawetan Alami Tiga Generasi Kayu Mangium (Acacia mangium Willd.) Hasil Kegiatan Pemuliaan Pohon
Abstrak: Pengembangan hutan tanaman, termasuk Hutan Tanaman Industri, selama ini belum mampu memenuhi kebutuhan bahan baku industri perkayuan di dalam negeri. Untuk mengatasi hal tersebut, Balai Besar Pengujian Standar Instrumen Kehutanan (BBPSIK), Yogyakarta melakukan kegiatan pemuliaan pohon mangium untuk meningkatkan laju pertumbuhannya. Penelitian ini bertujuan untuk menganalisis keawetan alami tiga generasi kayu mangium hasil kegiatan pemuliaan pohon yaitu F0 (generasi pertama), F1 (generasi kedua) dan F2 (generasi ketiga) yang berumur 10 tahun dan mengidentifikasi jenis rayap penyerangnya. Pohon sampel berasal dari plot ukur permanen milik BBPSIK. Pengujian keawetan alami dilakukan di lapangan berdasarkan ASTM D 1758-06. Hasil penelitian menunjukkan keawetan alami ketiga generasi kayu mangium relatif sama meski F2 cenderung lebih baik dari F1 dan F0. Kelas awet ketiga generasi kayu mangium tersebut masih sama dengan kelas awet kayu mangium pada umumnya. Hal tersebut membuktikan teknik/metode pemuliaan pohon yang diaplikasikan tidak mengubah kualitas kayunya meski laju pertumbuhan pohon cenderung meningkat. Jenis rayap tanah yang menyerang adalah Macrotermes gilvus kasta prajurit mayor dan minor., The development of plantation forests, including Industrial Plantation Forests, has not been able to meet the demand for the domestic timber industries. To overcome this, the Center for Standard Testing of Forestry Instruments (BBPSIK), Yogyakarta has been carried out mangium tree breeding programs to increase the growth rate of the tree. This research aims to analyze the natural durability of three generations of mangium wood resulting from tree breeding activities, namely F0 (1 st generation), F1 (2 nd generation) and F2 (3 rd generation) which are 10 years old as well as to identify the termite species. The sample trees come from permanent plots belonging to BBPSIK. Natural durability testing is carried out in the field based on ASTM D 1758-06. The results show that natural durability of F0, F1 and F2 is similar even though the F2 tends to be better than F1 and F0. Durability class of all mangium woods studied was still the same as durability class of mangium wood in general. This proves that tree breeding techniques/methods applied do not change the natural durability of the wood even though the growth rate of the trees increased well. The subterranean termites species that attacked the wood samples are major and minor soldier castes of Macrotermes gilvus.
Keyword: arboretum, mangium, natural durability, tree breeding, subterranean termites

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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