Judul: Analisis Perubahan Kualitas Udara Akibat Kebijakan Pembatasan Sosial Berskala Besar (PSBB) di Kota Bogor
Abstrak: Pencemaran udara merupakan salah satu indikator kualitas lingkungan. Pandemi COVID-19 di Indonesia terjadi pada Februari 2020, sehingga Kota Bogor menerapkan Kebijakan Pembatasan Sosial Skala Besar (PSBB). Tujuan penelitian ini adalah menganalisis perubahan kualitas udara yang terjadi di Kota Bogor akibat Kebijakan Pembatasan Sosial Skala Besar (PSBB) berdasarkan nilai ISPU. Data konsentrasi parameter ISPU Kota Yogyakarta dan Kabupaten Bantul digunakan sebagai data pembanding tambahan. Konsentrasi kelima parameter Indeks Standar Pencemar Udara (ISPU) berfluktuasi dari tahun 2015-2020. Nilai ISPU sebelum kebijakan Pembatasan Sosial Berskala Besar (PSBB) Kota Bogor, Kota Yogyakarta, dan Kabupaten Bantul berturut-turut yakni 59, 74, 87. Sedangkan nilai ISPU sesudah kebijakan Pembatasan Sosial Berskala Besar (PSBB) yakni 58, 36, 64. Kebijakan Pembatasan Sosial Skala Besar (PSBB) memberikan dampak positif terhadap peningkatan kualitas udara Kota Bogor, Kota Yogyakarta, dan Kabupaten Bantul.
Keyword: air quality, air quality index, Bogor municipality, large-scale social restriction policies

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: Algorithm Construction of HLI Hash Function
Abstrak: Cryptography is a study of mathematical techniques related to aspects of information security regarding on confidentiality, data integrity, entity authentication, and data origin authentication. Data integrity is a service, which is associated with the conversion of data carried out by unauthorized parties. To maintain data integrity, one can use hash functions. An hash function is a computationally efficient function to map an arbitrary length bitstring to a fixed length bitstring called as hash value. The use of hash function in maintaining the information integrity and authentication is in digital signatures, virus protection, and software distribution. Illustration of the hash function in the integrity and authentication of information that is emailed as follow. The sender sends the information and hash value to the recipient. If the hash value of the information is equal to the hash value that is sent by the sender, then information has not been changed. Otherwise the information has been changed. An hash function has two properties, one way and collision resistance. An hash function is called one way if it is computationally infeasible to find any input such that when given any hash value . Meanwhile an hash function is called collision resistant if it is computationally infeasible to find any two inputs where such that . The purpose of this study is to construct a HLI hash function algorithm, to analyze the speed and security of the hash functions as a results of construction. Furthermore, it is to compare it with SWIFFT. Hash function is constructed based on the result of algebraic operations on modular polynomial ringwith . Modular polynomial ring noted as is a set of all polynomials of degree at most with coefficients in . can be represented as a set of integer vector of modulo in dimension . So, it is simple to implement in a computer. In vector operations, is lattice . Furthermore, alattice that is defined from certain polynomial ring is called ideal lattice. HLI hash function is consists of addition and multiplication algorithm in the ring. Addition algorithm consists of sumation operations of modulo and multiplication consists of multiplication operations of modulo . Generally, algorithm of HLI hash function consists of multiplication operations of modulo and addition operations of modulo . However, if the input is binary number then multiplication algorithm only consists of multiplication operation of modulo , so algorithm of HLI hash function consists of multiplication operations of modulo and addtion operations of modulo . An hash function is secured if it has two properties, i.e., one way and collision resistance. HLI hash function hash is one way, it is following the proof of Micciancio. It is has collision resistant because of polynomial is irreducible over and monic. Moreover, it is proved that for every unit vector , the vector is small vector. If the input of hash function is a binary number then HLI hash function only involves addition operations of modulo . So the time that used almost same with SWIFFT. The excellence of HLI hash function is the key size smaller than SWIFFT. This effect on
Keyword: hash function, modular polynomial ring, lattice