Judul: Penentuan Karakteristik Akifer dan Potensi Airbumi di Jakarta
Abstrak: Groundwater is one of the water resources used for domestic and industrial water uses, particularly in Jakarta region. Excessive extraction of groundwater has caused groundwater depletion and land subsidance. This study aimed to determine the characteristics of aquifer and groundwater potential of the Jakarta region based on available geologic logs and well data, including pumping test data. Analysis of geological log indicated that Jakarta region had several layers of confined aquifer namely aquifer 20 – 30 m below ground and another aquifer 50 – 170 m below the ground surface. Analysis result of the pumping test data from 14 production wells in Jakarta region indicated transmisivity value ranged from 5 to 522.8 m2/days, while the values of hydraulic conductivity of the aquifer system in Jakarta region ranged from 0.62 to 58.09 m/day. Hydraulic conductivity values indicated that the rock types of aquifer in Jakarta region were dominated by fine sands and clay. From the aquifer characteristic, potential groundwater in Jakarta region ranged from 5 to 522.8 m3/day/ meter aquifer. Groundwater potential of each well in Jakarta region was still not fully utilized due to improper pumping construction in positioning the well –screen-, where was not installed properly on aquifer layers but on clay layers, so the well efficiency become low with the consequences of high operation costs.
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Judul: Potensi Cadangan Airbumi dan Efisiensi Sumur Produksi di Wilayah DKI Jakarta
Abstrak: improvement of human needs for clean water in the fulfillment of basic needs, and the needs in various major sectors such as industry, offices, hotels and so on are now increasing. Water needs not only rely from Water Supply Company but also rely on the quantity of groundwater. This problem is very common in large cities one of Jakarta. It is known that the population of Jakarta which increased to reach 9.6 million in 2010 will increase the need for clean water is sourced from airbumi will be even greater. The purpose of this study to estimate reserves of groundwater in Jakarta area as well as analyzing the efficiency of production wells in Jakarta as a solution to meet the needs of the population to clean water by taking into account the sustainability of the resource of groundwater. Estimation potential reserves of groundwater analyzed based on geological logdata interpretation of well production in some areas in Jakarta. Total reserves of groundwater at various layers of the aquifer in eight production wells in Jakarta by assuming an area of 1 km2 transects on each well STK, STT, SBA, SPG, SSW, SSS, SSG, and the SSO in a row of 88.510 m3; 16.200 m3; 40.090 m3; 398.200 m3; 19.911 m3; 66.300 m3; 22.499,5 m3; 29.120 m3. Analysis of the efficiency of production wells in Jakarta area using recovery test method determines the values of skin effect on each well. It is known that seven of eight production wells are wells analyzed STK, STT, SBA, SSW, SSS, SSG, SSO has a negative value of skin effect while SPG well have a positive value of skin effect with a value of 0.19. Skin effect positive on the well stating that the pumping wells in good condition or the filter is not clogged wells.
Keyword: Bogor Agricultural University (IPB), recovery test, Theiss methods, Cooper-Jacob methods, drawdown test, aquifer

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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