Judul: Model dinamik pengelolaan daerah aliran sungai (watershed) dalam upaya penyediaan air yang berkelanjutan di Semenanjung Leitimor Pulau Ambon,
Abstrak: Landcover changes from forest to other uses will impact the hydrological sistem, and result in the availability of water in the watershed Semenajung Leitimor Ambon Island. Population growth in the city of Ambon will be proportional to the demand for land and water requirements. The purpose of this study was (i). Analyzing changes in land cover in the watershed Leitimor Peninsula, (ii) to analyze the discharge mainstay at Peninsula Watershed Leitimor, (iii) to analyze the need for water in the peninsula Leitimor and (iv) Designing watershed management model for supporting sustainable water resources ecologically, economically and sosial Leitimor Peninsula. Analysis using digital image analysis, SWAT analysis, Multidimensional Scale (MDS) dynamic models (Stella) and descriptive analysis. The results showed that there have been changes in watershed landcover in Ambon; SWAT models can describe the characteristics of the watershed with an average water availability at the fifth annual tie at 395.6 million m3; catchment water demand in the fifth over of the production of water services company; multidimensional sustainability status of 50.97% is quite sustainable management model is best RHL activities and expansion of agriculture with agroforestry sistems, and stakeholders a role in watershed management is the Forum DAS and forest farmer groups.
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Judul: Alternative of optimum land management for water resources sustainability in Ambon Island
Abstrak: Land degradation on the upper stream area in Ambon island has reduced the water resources discharge and fresh water availability significantly to the people. For Ambon city in particular, fresh water capacity provided by PDAM, the local government fresh water company, can serve only 19,14% of total households. Fresh water discharge reduction is attributable to the change in forest land use to agriculture and settlement at the upper stream area. In order to solve the problem of fresh water resources in Ambon island, Batugantung watershed had been chosen as a representative of critical watershed in Ambon island for this research with the objectives as follows : 1) to evaluate the effect of a change of land use towards watershed hydrology characteristic (distribution and water yield) in Ambon island; 2) Determine erosion rate at each land unit and income of existing “dusun” farming at Batugantung watershed; and 3) to determine alternative optimum land management in order to reduce the rate of soil erosion, incline of land productivity and farmer income, as well as to protect and conserve water resource in Ambon island.
Keyword: water yield, erosion rate, forest area, fresh water potency, land degradation

Judul: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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