Judul: Analysis of Factors that Influence Community Consumption Patterns on Water Resources in Bogor City (Case Study: PDAM Tirta Pakuan, Bogor City)
Abstrak: Bertambahnya jumlah penduduk dan tingginya aktivitas ekonomi di Kota Bogor menyebabkan pencemaran air serta meningkatnya kebutuhan terhadap air bersih. Hal ini mengakibatkan masyarakat mengonsumsi sumber air utama PDAM untuk memenuhi kebutuhan air sehari-hari, sehingga masyarakat harus menyisihkan sebagian pendapatannya untuk konsumsi air. Penelitian ini bertujuan untuk (1) menganalisis karakteristik dan pola konsumsi masyarakat terhadap air PDAM Tirta Pakuan Kota Bogor, (2) menganalisis pengeluaran rumah tangga dalam konsumsi air PDAM Tirta Pakuan Kota Bogor, dan (3) mengidentifikasi faktor-faktor yang memengaruhi konsumsi air PDAM Tirta Pakuan Kota Bogor. Metode analisis yang digunakan pada penelitian ini yaitu analisis deskriptif, skala likert, analisis pengeluaran, dan analisis regresi linear berganda. Hasil dari penelitian ini menunjukkan bahwa terdapat tiga sumber air yang digunakan dan membentuk empat pola kombinasi air. Sebagian besar pelanggan PDAM mulai dari R1 hingga R8 memberikan penilaian baik terhadap kualitas, tarif, dan kinerja sumber air PDAM. Proporsi pengeluaran air telah memenuhi prinsip keterjangkauan karena tidak melebihi empat persen dari total pendapatan. Faktor yang memengaruhi masyarakat terhadap jumlah pemakaian air PDAM adalah jumlah anggota keluarga, pendapatan, dan sumber air lain yang dimiliki., Population growth and high economic activity in Bogor City cause water pollution and the increasing demand of clean water. This causes the community to consume water supply from PDAM for their daily water needs, so that the community must set aside a portion of their income for water consumption. The purpose of this research are (1) to analyze the characteristics and patterns of public consumption of PDAM Tirta Pakuan water, (2) to analyze household expenditures in water consumption PDAM Tirta Pakuan, and (3) to identify the factors that influence PDAM Tirta Pakuan water consumption. The analysis methods used are descriptive analysis, likert scale, expenditure analysis, and multiple linear regression analysis. The results of this research show that there are three water sources and form four patterns of water use combination. Most PDAM customers from R1 to R8 give a good perception of the quality, tariff, and performance of PDAM water sources. The proportion of water consumption expenditure has met the principle of affordability because it is not more than four percent of the total household income. The factors that influence the community consumption of PDAM water use are number of family members, income, and other water sources they have.
Keyword: expenditure analysis, likert scale, linear regression, perception, water demand

Judul: Analisis Ekonomi Pemenuhan Kebutuhan Air Bersih Masyarakat Kampung Pulo Geulis, Kota Bogor.
Abstrak: Tingginya aktivitas ekonomi di Kota Bogor menyebabkan terjadinya pencemaran air serta sanitasi yang buruk. Salah satu daerah di Kota Bogor dengan akses air tanah yang sulit dan sanitasi yang buruk adalah Kampung Pulo Geulis. Hal tersebut mengakibatkan masyarakat harus mengalokasikan sebagian pendapatannya untuk menggunakan air PDAM, AMDK, maupun air isi ulang. Tujuan penelitian ini adalah (1) menganalisis pemenuhan kebutuhan air bersih masyarakat Kampung Pulo Geulis, (2) menganalisis alokasi pengeluaran konsumsi air terhadap pendapatan rumah tangga, (3) menganalisis persepsi masyarakat terhadap air bersih dan estimasi nilai willingness to pay (WTP) masyarakat terhadap perbaikan sistem penyediaan air bersih dari PDAM, (4) menganalisis persepsi masyarakat terhadap dampak pencemaran limbah dan perbaikan kualitas lingkungan. Metode analisis data yang digunakan adalah analisis deskriptif, proporsi pengeluaran, dan contingent valuation method (CVM). Hasil penelitian menunjukkan bahwa terdapat empat sumber air yang digunakan masyarakat dan membentuk lima pola kombinasi penggunaan air. Pada umumnya, alokasi pengeluaran konsumsi air bersih masyarakat tergolong rendah karena tidak melebihi empat persen dari total pendapatan rumah tangga. Analisis persepsi terhadap air bersih menunjukkan bahwa kualitas air PDAM lebih rendah dari AMDK dan air isi ulang. Hal ini dapat memengaruhi keinginan masyarakat terhadap perbaikan sistem penyediaan air bersih dari PDAM dengan nilai estimasi rata-rata WTP rumah tangga yang cukup tinggi. Menurut masyarakat, pencemaran limbah berdampak pada timbulnya bau tidak sedap dan tercemarnya air sungai. Program perbaikan kualitas lingkungan yang diinginkan masyarakat adalah program pembuatan tanggul dan pengerukan sampah di sungai.
Keyword: air bersih, alokasi pengeluaran, persepsi masyarakat, willingness to pay

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm