Judul: Analisis Ragam Gabungan Dengan Ragam Tidak  Homogen  (Studi Kasus Percobaan Multilokasi Budidaya Jahe Di Jawa Barat)
Abstrak: Combined analysis of variance has several rigid assumptions. One of them is homogeneity of variance which in many cases is failed to be fulfilled. So there should be a statistical approach to handle this problem. Classical liniear model of data from an experiment assumes the homogeneity of variance. If it is violated then usually the data will be transformed to achieve linearity of the model. But one problem in using transformed data is difficulty in interpreting it. Other approach used for handling this problem is organizing the data into groups based on the similarity of variance. One procedure that uses this kind of approach is Mixed Procedure. The objectives of this research were to distinguish the interaction between the little white ginger expected genotype and its cultivation location and to study the technique of handling heterogeneity of variance in Combined Analysis of Variance. The data used in this research was experiments data of little white ginger produced by researcher of Indon Spices and Medical Crops Research Institute (ISMECRI) Bogor. The experiment was conducted in five location: Sukamulya, Wado, Malangbong, Garut, and Majalengka. The single experiment was accomplished by cultivating seven little white ginger expected genotype. The environmental design was Randomize Complete Block Design with three repetitions and the response was the amount of ginger young plants. Three analysis’ of variance with different covariance matrix conclude significant interaction between location and genotype. Log-likelihood ratio of each model covariance matrix was used to select the best model wich turns out to be the model with revision of location groups. The treatment significance test with the assumption that the variance between locations is not homogeny result greater p-value compared to the treatment significance test with revised estimated variance. This means that the treatment significance test with the assumption that the variance between locations is not homogeny has lesser accuracy level than the treatment significance test with revised estimated variance on the same level of significance. Likewise, the treatment significant test with transformed data has lesser accuracy level than the treatment significance test with revised estimated variance. The appropriate organization of the data into groups on the similarity of variance (proper selection of covariance matrix) can increase accuracy of treatment significance test for cases when the variance is not homogeny.
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Judul: Klasifikasi Genotipe Pada Data Tidak Lengkap  Dengan Pendekatan Model Ammi
Abstrak: Multilocations trials play an important role in plant breeding and agronomic research. Study concerning genotype-environment interaction needed in selection of genotype to be released. AMMI (Additive Main effect and Multiplicative Interaction) is one of statistical technique to analyze data from multilocations trials. The analysis of AMMI is a combining analysis between additive main effect and principal component analysis. The main restriction of using AMMI analysis is balance data. However a multilocations trials give an opportunity of the occurrence of unbalance data become very big. It is intended for every combination of genotype and location have the same number of replication. Therefore, we must estimate the data which do not complete. Incomplete data case, it is needed some data estimation method analysis, at this research employed connected data method and EM-AMMI algorithm to estimate incomplete data. Data which used in this research is obtained from Indon Spices Medicinal Crops Research Institute (ISMECRI) Bogor. It is a secondary data of ginger essential content resulted from multilocations trials, sixteen of genotype ginger which tested at five location in West Java. Simulation result shows that estimation using connected data will obtain smaller MAPE if its followed by two times EM-AMMI algorithm, for the percentage of data lose 10% to 20%. Production of ginger essential content estimated with AMMI2 model can explain 76.09% interaction structure among location and genotype. Seen from stability of genotype, there are 2 stable genotype, that is genotype 3 and 7. Genotype 8, 12, 15 specific at location B; genotype 9, 11, 14, 16 specific at location D and E; and genotype 1, 2, 4, 5, 6, 10 and 13 specific at location A and C.
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Judul: Elektrodeposisi Film Tipis Semikonduktor Cu2ZnSnS4 (CZTS) pada Substrat Kaca ITO
Abstrak: Semiconductor Cu2ZnSnS4 (CZTS) thin film that can be used as absorber layers on solar cell module was made via electrodeposition method. CZTS thin film was electrodeposited on the surface of a silicate glass coated with a thin layer of indium tin oxide (ITO). Deposition process was done using potentiostatic mode at room temperature with a potential of 1.05 V for 30, 45, and 60 minutes, followed with annealing the film at 2 different temperatures, 500 ºC using furnace and 180 ºC using hot plate, both treatments for 45 minutes in N2/H2S atmosphere. The X-ray difractograms were analyzed using Match 2 program and showed that the CZTS thin films had kesterit crystalline structure, with a low percentage of CZTS phase. The thin film also contained secondary phases such as Cu2S, ZnS, and SnS. The obtained CZTS thin films had a thickness between 1.039 and 1.676 μm. Absorption study showed that the band gap energy of CZTS thin films which was annealed using furnace ranged from 1.50 to 1.52 eV, whereas that annealed using the hot plate was not observed. The band gap energy value showed that CZTS thin films can be used as sunlight absorber layers on solar cell. The formation of CZTS crystal film on this investigation was effectively performed using furnace annealing process at a temperature of 500 ºC with deposition time of 45 minutes.
Keyword: Thin film, Electrodeposition, Cu2ZnSnS4