Judul: Thermal Comfort by Differences Land Cover around Bogor Botanical Garden Area
Abstrak: Peningkatan jumlah penduduk di Kota Bogor mengakibatkan kebutuhan akan lahan terbangun yang semakin meningkat. Hal ini akan memengaruhi unsur iklim dan kondisi kenyamanan. Penelitian ini bertujuan untuk memperoleh informasi tingkat kenyamanan termal di wilayah sekitar Kebun Raya Bogor secara spasial dan temporal menggunakan pendekatan Universal Thermal Climate Index (UTCI) serta mengidentifikasi pengaruh perubahan tutupan lahan. Nilai UTCI diperoleh dari hasil observasi lapang yaitu dengan melakukan pengukuran data meteorologi dan menganalisis hasil kuisioner di delapan titik lokasi yang merepresentasikan pemukiman, lahan terbangun, jalan dengan vegetasi jarang, jalan bervegetasi rapat, lahan bervegetasi jarang, dan lahan bervegetasi rapat. Hasil yang diperoleh dari penelitian ini menunjukkan rataan nilai UTCI musiman berada pada kategori moderate heat stress hingga very strong heat stress. Tutupan lahan bervegetasi memiliki suhu udara yang lebih rendah dibandingkan tutupan lahan lainnya. Nilai persepsi panas di sekitar wilayah Kebun Raya Bogor dalam kesetaraan suhu °C, menunjukkan nilai dominasi dingin saat UTCI ≤ 30,6 dengan kategori moderate heat stress. Seluruh responden menyatakan panas jika nilai UTCI mencapai ≥ 40,5 dengan kategori UTCI very strong heat stress. Penelitian ini mendapatkah kondisi kawasan di sekitar Kebun Raya Bogor tergolong cukup nyaman dengan skor kenyamanan 0,7. Faktor-faktor yang dapat meningkatkan persepsi panas di sekitar wilayah Kebun Raya Bogor adalah nilai UTCI, durasi di lokasi, preferensi suhu, MET, dan ragam pakaian, sedangkan faktor-faktor yang secara nyata memengaruhi persepsi nyaman adalah nilai UTCI dan preferensi suhu., The increasing number of residents in the city of Bogor has resulted in an increasing need for built-up land. This will affect the climatic elements and comfort conditions. This study aims to obtain information on the level of thermal comfort in the area around the Bogor Botanical Gardens spatially and temporally using the Universal Thermal Climate Index (UTCI) approach and identify the effect of land cover changes. The UTCI value was obtained from the results of field observations, namely by measuring meteorological data and analyzing the results of questionnaires at eight location points representing settlements, built-up land, roads with sparse vegetation, roads with dense vegetation, sparsely vegetated land, and densely vegetated land. The results obtained from this study indicate that the average of seasonal UTCI value is in the category of moderate heat stress to very strong heat stress. Vegetated land cover has a lower air temperature than other land cover. The value of heat perception around the Bogor Botanical Gardens area is equal to temperature °C, indicating the value of cold dominance when UTCI 30.6 in the moderate heat stress category. All respondents stated that it was hot if the UTCI value reached 40.5 with the UTCI category of very strong heat stress. This study found that the condition of the area around the Bogor Botanical Gardens was quite comfortable with a comfort score of 0.7. Factors that can increase the perception of heat around the Bogor Botanical Gardens area are UTCI value, duration in location, temperature preference, MET, and variety of clothing, while the factors that significantly affect comfortable perception are UTCI value and temperature preference.
Keyword: Kebun Raya Bogor, kenyamanan termal, kerapatan vegetasi, tutupan lahan, UTCI

Judul: Identification of Thermoscape Characteristics of Urban Parks, Bogor City
Abstrak: Keberadaan ruang terbuka hijau perkotaan sangat penting bagi terciptanya ruang publik yang dapat mendukung berbagai aktivitas publik warga kota dan menjadi ruang ekologis bagi terciptanya kualitas lingkungan perkotaan yang memadai. Kota Bogor merupakan salah satu kota yang saat ini sedang mengembangkan ruang terbuka hijau berupa taman kota untuk memenuhi kebutuhan ruang publik sebagai sarana berkumpul dan berekreasi. Kenyamanan termal sangat penting dan harus diperhatikan dalam ruang terbuka hijau. Untuk memperoleh kondisi termal suatu lanskap, penelitian ini menggunakan thermal drone. Penelitian ini bertujuan untuk mengidentifikasi karakteristik thermoscape elemen lanskap dan persepsi pengunjung serta hubungan antara keduanya. Hasil thermoscape pada kedua taman kota berbeda karena adanya perbedaan cuaca. Namun, kondisi termal masing-masing elemen lanskap hampir sama di kedua taman. Hardscape di kedua taman tersebut dapat bersuhu >40˚ C, sedangkan vegetasi, terutama pepohonan, dapat bersuhu <20˚ C. Menurut responden, kedua taman tersebut masih dianggap hangat berdasarkan sensasi termalnya. Thermoscape (nilai RIA) dan persepsi responden mempunyai korelasi kuat dan hubungan searah. Selain itu, hasil analisis regresi kedua taman menunjukkan bahwa nilai RIA berpengaruh positif terhadap persepsi responden. Kawasan taman kota yang panas dapat dimodifikasi dengan menyediakan ruang hijau atau perairan yang lebih luas dengan distribusi dan proporsi elemen yang baik sehingga memberikan kenyamanan bagi penggunanya., The existence of urban green open space is very important for the creation of a public space that can support various public activities of urban residents and become an ecological space for the creation of an adequate quality urban environment. Bogor City is one of the cities that is currently developing green open space in the form of an urban park to meet the needs of public space as a means of gathering and recreation. Thermal comfort is very important and must be considered in a green space. To obtain the thermal conditions of a landscape, this research uses a thermal drone. This study aims to identify the thermoscape characteristics of landscape elements and people's perceptions of it and also the correlations between them. The thermoscape results in the two urban parks are different due to differences in weather. However, the thermal conditions of each landscape elements are almost the same in both parks. Hardscapes in both parks can have a temperature of >40˚ C, while vegetation, especially trees, can have a temperature of <20˚ C. According to respondents, both parks are still considered warm based on their thermal sensation. Thermoscape (RIA value) and respondent perception have a strong correlation and a unidirectional relationship. Besides that, the results of the regression analysis for both parks show that the RIA value has a positive effect on respondents' perceptions. Hot urban park areas can be modified by providing wider green space or water with a good distribution and proportion of elements so as to provide comfort for users.
Keyword: elemen lanskap, kenyamanan termal, sensasi termal, thermal drone, thermoscape

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.
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