Vol. 49 No. 2 (2017)

Indigo leaves (Indigofera tinctoria L.) are utilized as a source of batik dye in Java and Madura islands, Indonesia. Batik makers from the islands collect indigo leaves from wild plants. Continuous collection of wild plants from their natural habitat may decrease their diversity. The present research was conducted to analyze the genetic diversity and population structure of I. tinctoria L. from Java and Madura. 55 indigo accessions were collected from 10 locations in Java and Madura. The indigo DNA was extracted and amplified using 15 ISSR primers. A total of 123 bands showed 50-90%…

The Citarum River is a nationally strategic river located near Bandung, the capital city of West Java Province. The feasibility of using magnetic methods for monitoring pollution level is currently being tested in the river. Due to its location in a volcanic area, the sediments from the river are expected to be highly magnetic. In this study, sand and boulder samples from Balekambang, a relatively pristine upstream area of the river, were subjected to magnetic and geochemical characterizations to establish the baseline for unpolluted sediments. Such baseline is important for future magnetic…

The Holt-Winters method is a well-known forecasting method used in time-series analysis to forecast future data when a trend and seasonal pattern is detected. There are two variations, i.e. the additive and the multiplicative method. Prior study by Vercher, et al. in [1] has shown that choosing the initial conditions is very important in exponential smoothing models, including the Holt-Winters method. Accurate estimates of initial conditions can result in better forecasting results. In this research, we propose new estimation rules for initial conditions for the Holt-Winters multiplicative…

For GSTAR models, the least squares estimation method is commonly used since errors are assumed be uncorrelated. However, this method is not appropriate when errors are correlated, either in time or spatially. For these cases, the generalized least squares (GLS) method can be applied. GLS is more powerful since it has an error parameter that can act as a controller of the model to produce an efficient estimator. In this study, R Software was used to estimate GSTAR parameters. The resulted model was applied to real data, i.e. the monthly tea production of five plantations in West Java,…

Let G be a connected graph with vertex set V(G) and W={w1, w2,..., wm} ⊆ V(G). A representation of a vertex v ∈ V(G) with respect to W is an ordered m-tuple r(v|W)=(d(v,w1),d(v,w2),...,d(v,wm)) where d(v,w) is the distance between vertices v and w. The set W is called a resolving set for G if every vertex of G has a distinct representation with respect to W. A resolving set containing a minimum number of vertices is called a basis for G. The metric dimension of G, denoted by dim (G), is the number of vertices in a basis of G. In general, the comb product and the corona product are…

In vitro regeneration of foxtail millet (Setaria italica (L.) Beauv.) was done using basal shoot explants of 10-day old seedlings. Explants were cultured in MS basal medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D), kinetin, 6-benzylaminopurine (BAP) and 1.5 ppm NiSO4. Shoot multiplication and root induction were done in Murashige and Skoog (MS) basal media. Plantlets were then acclimatized in rice husk charcoal, cocopeat, or mixed media. Results showed that MS basal medium containing 0.5 ppm kinetin, 2 ppm BAP, and 0.1 ppm 2,4-D was the optimal medium for shoot induction, in…

Our purpose in this article is to characterize the properties of C-Γ-hyperideals in ordered Γ-semihypergroups. As an application of the results of this paper, the corresponding results of ordered semihypergroups can also be obtained by moderate modification.