Judul: Pollution Load of Upstream Citarum  River in Cirasea Watershed at Bandung Regency
Abstrak: Sungai Citarum termasuk salah satu sungai yang tercemar berat di Indonesia, akibat besarnya beban pencemaran, khususnya banyaknya pabrik tekstil yang ada di hulu sungainya. Sub DAS Cirasea merupakan salah satu sub DAS yang terdapat di hulu Sungai Citarum. Penelitian ini bertujuan menganalisis status kualitas air, besarnya beban pencemaran, dan total beban pencemaran Sungai Citarum bagian hulu pada sub DAS Cirasea. Kondisi kualitas air dianalisis dengan membandingkan hasil pengukuran pemantauan dengan baku mutu kualis air kelas I. Perhitungan beban pencemaran dihitung dengan metode rapid assesment. Hasil analisis menunjukkan bahwa kondisi kualitas air Sungai Citarum hulu pada sub DAS Cirasea relatif masih baik. Terdapat beberapa parameter yang melebihi baku mutu yaitu TSS, nitrit, BOD, dan COD. Sumber pencemar yang menyumbang beban pencemaran terbesar yaitu industri. Total beban pencemaran di sub DAS Cirasea yaitu BOD sebesar 121.922,64 ton/bulan, COD 248.978,29 ton/bulan, dan TSS 60.830,48 ton/bulan. Pengaruh beban pencemaran terhadap kualitas air menyebabkan peningkatan parameter BOD 0,004-0,01 mg/liter, COD 0,008-0,02 mg/liter, dan 0,002-0,005 TSS mg/liter.
Keyword: Beban pencemaran, kualitas air, sungai cirasea

Judul: Water Quality and Pollution Load in Ciwidey Sub-Watershed
Abstrak: Sungai Ciwidey merupakan salah satu hulu Sungai Citarum yang berada di wilayah Kabupaten Bandung. Pertumbuhan penduduk dan penggunaan lahan di Sub-DAS Ciwidey menyebabkan perubahan pada parameter kualitas air Sungai Ciwidey, terutama di bagian hilirnya. Penelitian ini bertujuan menganalisis kualitas air, besarnya beban pencemaran, total beban pencemaran dan pengaruhnya terhadap kualitas air di Sub-DAS Ciwidey. Analisis hasil pemantauan kualitas air Sungai Ciwidey dibandingkan dengan baku mutu kelas I. Besarnya beban pencemaran dihitung menggunakan metode rapid assessment. Analisis kualitas air menunjukkan pencemaran bahan organik dengan indikasi tingginya nilai biological oxygen demand (BOD), chemical oxygen demand (COD), dan fecal coliform. Parameter lain yang melebihi baku mutu adalah total suspended solid (TSS), total fosfat, besi (Fe), mangan (Mn), seng (Zn), dan detergen total. Beban pencemaran terbesar berasal dari kegiatan industri. Total beban pencemaran sebesar BOD 70,9672 ton/bulan; COD 116,6503 ton/bulan; TSS 45,3445 ton/bulan; total nitrate (TN) 0,0387 ton/bulan; dan total phosphate (TP) 0,0172 ton/bulan. Konsentrasi beban pencemar terbesar terhadap debit air terjadi pada bulan Agustus dan terkecil pada bulan Januari., Ciwidey River is one of the headwaters of the Citarum River in Bandung Regency area. Population growth and land use in Ciwidey Sub-watershed have caused changes in the water quality parameters of the Ciwidey River, especially in the downstream part. This research aims to analyze water quality, the magnitude of the pollution load, total pollution load and its effect on water quality in the Ciwidey Sub-watershed. Analysis of the results of monitoring water quality of Ciwidey River compared to class I quality standards. Meanwhile, pollution load was calculated using rapid assessment method. Water quality analysis shows organic material pollution with indicate by high biological oxygen demand (BOD), chemical oxygen demand COD and fecal coliform values. Other parameters that exceed quality standards are total suspended solid (TSS), total phosphate, iron (Fe), manganese (Mn), zinc (Zn), and total detergent. The largest pollution load comes from industrial factories with BOD 70,9672 tons/month; COD 116,6503 tons/month; TSS 45,3445 tons/month; total nitrate (TN) 0,0387 tons/month; and total phosphate (TP) 0,0172 tons/month. The largest concentration of pollutant loads to water discharge occurs in August and the smallest in January.
Keyword: baku mutu, limbah, pencemaran air

Judul: The Exploration of Discrete Logarithm over Finite Field GF(3m)
Abstrak: The security of many public~key algorithms is based on the problem of finding discrete logarithms. The generalized discrete logarithm problem is the following: given a finite cyclic group G of order n, a generator a of G, and an element fl E G, find the integer x, 0 ~ x ~ n - 1, such that 0: = fl. Algorithm for discrete logarithm problem focused on Menezes et al. (1997) that consist of exhaustive search algorithm, the baby-step giant-step algorithm, Pollard's rho algorithm, Pohlig-Hellman algorithm, and index-calculus algorithm. These algorithms are explorated to be used in discrete logarithm problem over finite field GF(3m ). The exploration also produces some algorithms, i.e. naif negative algorithm, baby-step mother-step algorithm, baby-step mother free-step algorithm, and baby-step free-step algorithm. All algorithms implemented using Maple 11. The Pohlig-Hellman and baby-step giant-step algorithms are efficient enough to be used in discrete logarithm problem over finite field GF(3m ) for m < 20.
Keyword: