Judul: Kajian Metode Penggerombolan Dua Tahap untuk Data yang Mengandung Pencilan
Abstrak: Cluster analysis is often encountered in various studies. Analysis of classical clusters, such as hierarchical clustering method and k-means clustering cannot handle categorical variables or a mixture of numerical and categorical. In addition, the determination of the optimal number of clusters are still dependent on the subjectivity of the researcher and cannot handle very large datasets, which is larger than 500. One approach to addressing this problem is to use a two-step clustering method. The accuracy of the two-step clustering method of predicting the number of clusters generated as well as the classification of cluster membership, especially in the data containing outliers is important to be studied. Outliers in the data containing a small (1%), this method provides more accurate compared with the results of data containing a large outliers (5% or 15%). Scale use of outliers handling in the data containing outliers must be greater than the amount of outliers itself. Two-step clustering method is very accurate in producing a number of clusters associated with the actual number of population clusters that do not contain data outliers, especially in the most variable of type numeric and categorical rest. Clustering villages in Indonesia by a factor of progress and backwardness villages using a two-step clustering method generates optimal cluster 7.
Keyword: two-step clustering method, data outliers, cluster analysis

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: Co-infection of Infectious Myonecrosis Virus (IMNV) and Vibrio harveyi in Pacific White Shrimp (Litopenaeus vannamei)
Abstrak: L. vannamei production in Indonesia was growing intensively. In 2006, IMN (infectious myonecrosis) disease was confirmed spread to Indonesia shrimp farm and declined shrimp production. The study was conducted to investigate effect of dose of V. harveyi on co-infection with IMNV in L. vannamei as well as development of viral infection. Shrimps juvenile were oral infected with IMNV infected shrimps 10 % feeding rate during 3 days and co-infected with 106, 107 and 108 cfu/ml V. harveyi. Mortality rate was 0 % in control and single infection of V. harveyi except 108 cfu/ml treatment. Mortality pattern demonstrated on co-infection was faster and higher than single IMNV infection in 14 days observation. The density of green colony Vibrio in hepatopancreas of co-infected shrimps collected in 2, 4, 6, 8 and 10 days post infection were higher than V. harveyi single infected (significantly in 10 days post infection). There were no difference of IMN disease development between co-infection and IMNV single infection. It was confirmed by visual gross sign appeared, tissue and lymphoid organ histophatology, organ abnormality, and PCR test. In conclusion, IMN disease caused higher and faster mortality on co-infection with V. harveyi, but not affect to IMN disease development.
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