Judul: Penerapan Metodetwo Step Cluster Dalam  Analisis Gerombol  (Studi Kasus : Data Potensi Desa Sensus Ekonomi 2003 Wilayah Jawa Barat)
Abstrak: Clustering is a process of grouping objects based on similarities . Some problems in cluster analysis are the different scale of measurement, large data sets and unspecified number of cluster. One approach to handle this problems is by using Two Step cluster method. The purpose of this research is to applicate Two Step cluster method by clustering villages residing in West Java. The result of Two Step cluster method are pre-cluster which early yielded at first phase counted eight clusters and optimal cluster which yielded at second phase counted three clusters. Members in first cluster are objects which is extreme outliers and cannot be grouped into other clusters. Villages which include into second clusters have rural characteristic. The village has wide farm, many agriculture households, but also has underdeveloped field of industries and also information and communications. So that, to improve village potency for this cluster, the variables which still have low growth level has to be increased. The third cluster has the characteristic of urban status. Village in this cluster has the closest distance to downtown, developed enough in the field of industry, information and communications, but still have the highest number for unemployment citizens.
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Judul: Penerapan Metode Dua Tahap Dalam Penggerombolan Data Berskala Campuran (Studi Kasus: Potensi Desa di Provinsi Jawa Barat pada Tahun 2011)
Abstrak: Umumnya metode penggerombolan mengasumsikan data memiliki skala numerik saja atau kategorik saja. Namun pada kenyataan, sering didapatkan data berskala campuran, yaitu memiliki skala kategorik dan juga numerik. Jenis data berskala campuran apabila diterapkan metode penggerombolan klasik menjadi kurang efektif. Salah satu alternatif yang dapat digunakan dalam penanganan data berskala campuran, yaitu dengan pendekatan metode dua tahap. Pendekatan ini merupakan analisis gerombol dua tahap untuk menggerombolkan data yang memiliki peubah campuran. Tahapan dalam pendekatan ini ialah mengubah peubah kategorik menjadi peubah numerik sehingga penerapan analisis gerombol berskala numerik dapat diterapkan. Berdasarkan hasil pengerombolan pada data Podes 2011 wilayah Jawa Barat dihasilkan 2 gerombol sebagai gerombol akhir, yaitu gerombol perkotaan dan gerombol perdesaan. Peubah yang menjadi ciri pada gerombol perkotaan ialah Peubah Jumlah Penduduk, Kepadatan Penduduk, dan Peubah Jumlah Minimarket. Sedangkan peubah yang menjadi ciri pada gerombol perdesaan ialah Peubah Sumber Penghasilan Utama berupa pertanian, tidak adanya pertokoan atau Peubah Pertokoan, dan tidak adanya Bank Umum atau Peubah Bank Umum.
Keyword: clutering analysis, mixed scale data, two-step method

Judul: Hydroxyapatite-Chitosan Composite Coating on Stainless Steel 316 to Improve Corrosion Resistance
Abstrak: Metals that were used in bone implantation should have good corrosion resistance that were not easily corroded when implanted into the body. Metal corrosion resistance of stainless steel 316 can be enhanced through the metal coating by hydroxyapatite-chitosan composite with composition ratio of hydroxyapatite (gram) and chitosan 3% (mL) 0.2:0, 0.2:0.1, 0.2:0.5, 0.2:1.0, and 0.2:1.5. Besides improving the corrosion resistance of metal, the presence of chitosan also maintain the position of hydroxyapatite on metal surfaces. Corrosion resistance increases with increasing amount of chitosan added and the best composition of hydroxyapatite-chitosan composite was 0.2:1.0.
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