Judul: The Analysis if Rainfall Effect on Carbon Monoxide (CO) and
Nitrogen Oxide (NOx) Concentrations in the Puncak Bogor Area
Abstrak: Karbon monoksida (CO) dan Nitrogen Oksida (NOx) merupakan polutan yang sangat berbahaya bagi kesehatan manusia. Fluktuasi konsentrasi CO dan NOx tidak hanya dipengaruhi oleh aktivitas antropogenik tetapi faktor meteorologi seperti curah hujan. Penelitian ini bertujuan menganalisis pengaruh curah hujan terhadap konsentrasi CO dan NOx, dengan studi kasus Puncak Bogor tahun 2019. Data yang digunakan berupa data sekunder curah hujan dan konsentrasi CO dan NOx diperoleh dari BMKG Citeko bekerjasama dengan NIES Jepang. Analisis yang dilakukan adalah analisis data bulanan, harian, dan per menit. Hasil analisis data bulanan, curah hujan berpengaruh signifikan terhadap penurunan konsentrasi CO (r = -0,725; p-value, Carbon monoxide (CO) and Nitrogen Oxide (NOx) were pollutants that were very dangerous for human health. Fluctuations in CO and NOx concentrations are not only influenced by anthropogenic activities but meteorological factors such as rainfall. This research aims to analyze the effect of rainfall on CO and NOx concentrations, with a case study in Puncak Bogor in 2019. The data used in this study were rainfall, and CO and NOx concentrations secondary data obtained from BMKG Citeko in collaboration with NIES Japan. The data were analyzed in different time interval such as monthly, daily and minute. The results of monthly data analysis showed that rainfall has a significant effect on reducing CO concentrations (r = -0.725; p-value < 0.05), in contrast there was no significant effect on NOx concentrations (r = -0.531; p-value > 0.05). The results of daily data analysis showed that rainfall has an effect on reducing CO and NOx concentrations with a low level of correlation (r CO = -0.16 and r NOx = -0.17). The results of analysis of data per minute in certain periods of the wet month and dry season showed that rainfall has a significant effect on reducing CO and NOx concentrations, especially in the wet season. On the other hand, in the dry season, rainfall had a less significant effect on reducing CO and NOx concentrations. Based on analysis over the same time period, the average concentrations of CO and NOx were smaller when rain occurred than there were no rain occured. This showed that rainfall has an effect on reducing the concentration of CO and NOx pollutants in the Puncak Bogor area.
Keyword: curah hujan, Kualitas Udara, karbon monoksida, nitrogen oksida

Judul: Analysis of NO2, CO Concentrations and Meteorological Factors in Puncak Bogor during the Covid-19 Pandemic
Abstrak: Analisis pencemaran udara yang berkaitan dengan kebijakan atau peraturan selama pandemi covid-19 di wilayah rural belum banyak dilakukan. Kajian pencemaran udara di wilayah Puncak Bogor selama tahun terdampak pandemi bertujuan untuk membandingkan pengaruh faktor pembatasan aktivitas, berupa jumlah kendaraan yang melintasi pintu Tol Gadog selama pandemi covid-19 dan pengaruh faktor meteorologi terhadap fluktuasi konsentrasi NO2 dan CO di wilayah Puncak Bogor. Data yang digunakan adalah konsentrasi NO2 dan CO, curah hujan, suhu udara, kelembapan, arah dan kecepatan angin, di sekitar lokasi Cibeureum (Puncak) serta data jumlah kendaraan yang menuju Puncak Bogor melalui pintu Tol Gadog. Hasil analisis menunjukkan jumlah kendaraan menurun pada awal pembatasan aktivitas masyarakat dan diikuti dengan penurunan konsentrasi harian NO2 dan CO, namun hanya pada masa awal pembatasan saja. Peningkatan polutan pada periode PPKM darurat berkaitan dengan pengaruh bulan kering. Konsentrasi NO2 dan CO berbanding terbalik dengan kelembapan, kecepatan angin, dan curah hujan, tetapi cenderung berbanding lurus dengan suhu dan jumlah kendaraan. Nilai R2 antara NO2, CO dan faktor meteorologi lebih besar (< 40%) dibandingkan dengan nilai R2 antara NO2, CO dan jumlah kendaraan (< 20%) sebelum PSBB dan saat PSBB. Saat PPKM nilai R2 antara NO2, CO dan faktor meteorologi juga lebih besar (< 70%) dibandingkan dengan nilai R2 antara NO2, CO dan jumlah kendaraan (< 20%). Hal ini menunjukkan bahwa konsentrasi NO2 dan CO di sekitar pemantauan Cibeureum (Puncak) lebih besar dipengaruhi oleh faktor meteorologi daripada pembatasan aktivitas masyarakat (PSBB dan PPKM) di Puncak Bogor., The analysis of air pollution related to policies or regulations during the covid-19 pandemic in rural areas has not been widely carried out. The study of air pollution in Puncak Bogor area during the year affected by the pandemic aims to compare the effect of Large-scale Social Restrictions, (PSBB and PPKM) during the covid-19 pandemic and meteorological factors on concentrations fluctuations of NO2 and CO. The data used are NO2 and CO concentrations, rainfall, air temperature, humidity, wind direction and speed at Cibereum (Puncak) location. PSBB data are represented by the number of vehicles going to Puncak Bogor at the Gadog Toll Gate. The results of the analysis showed that the number of vehicles decreased at the beginning of PSBB and was followed by a decrease in daily concentrations of NO2 and CO, only at during the initial period of restriction. The increase of pollutants concentrations in the emergency PPKM period are also influenced by dry season. NO2 and CO concentrations are inversely proportional to humidity, wind speed, and rainfall, but tend to be directly proportional to temperature and number of vehicles. The R2 value between NO2, CO and rainfall is greater (<40%) compared to the R2 value between NO2, CO and the number of vehicles (<20%) before PSBB and during PSBB. During PPKM, R2 value between NO2, CO and meteorological factors was also greater (<70%) compared to the R2 value between NO2, CO and the number of vehicles (<20%). This shows that the concentration of NO2 and CO around the monitoring Cibeureum (Puncak) is more influenced by meteorological factors than restrictions on community activities (PSBB and PPKM) in Puncak, Bogor.
Keyword: activity restrictions, CO, covid-19 pandemic, meteorological factors, NO2

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