Judul: Identifikasi kenyamanan termal bangunan: studi kasus kampus IPB Baranangsiang dan Darmaga Bogor
Abstrak: Housing development, well planned or not well planned, has changed the view of city and thermal environment. Many researchers claim that the worse quality of thermal environment is proportional to physical development of cities. Physical developments in urban areas have caused various environmental problems, one of them is the change in quality of thermal environment, become hotter than surrounding areas or natural areas. The purpose of this research is to identify the thermal comfort either in campus classrooms Darmaga or Baranangsiang IPB, Bogor. The method used is directly observational data in classrooms and campus. Index PMV (Predicted Mean Vote), using the boundary Effective Temperature (TE), THI (Temperature Humidity Index), and the last method is respondent test. The results of PMV ((Predicted Mean Vote) in lecture hall of campus IPB Baranangsiang and Darmaga are thermally neutral to slightly warm, though actually the lecture hall in campus IPB Darmaga is warmer. Temperature effective which is resulted in the both of lecture halls are comfortable warm conditions. In addition, for respondents test, the thermal impression in IPB campus of Baranangsiang prefers to choose the slightly warm conditions, but for a lecture hall in campus of IPB Darmaga is more dominated by warm and slightly warm conditions. The questionnaire has been appropiated to the range of PMV index. So, the lecture halls that have been studied in both of campus can be concluded as slightly warm condition, because the thermal impressions felt by the respondents are also in the range of neutral to slightly. The value of THI for both of campus environment is in the range of moderate or neutral.
Keyword: Kenyamanan, Termal, Iklim bangunan, Indeks PMV, Temperatur efektif, THI, Bogor Agricultural University, Institut Pertanian Bogor, IPB

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: Algoritme LLL dan Aplikasinya dalam Pembongkaran Sistemkripto Knapsack Merkle-Hellman
Abstrak: LLL algorithm is an algorithm that can be used to determine an approximation of the shortest vector in a lattice. Size reduction algorithm is an important step of LLL algorithm. The LLL algorithm can be applied in many elds. This paper shows how LLL algorithm can be used in breaking one of the famous cryptosystem, namely the Merkle-Hellman knapsack cryptosystem. Merkle-Hellman knapsack cryptosystem is an asymmetric cryptosystem using the subset sum problem as the support of security. Subset sum problem can be transformed into the problem of determining shortest vector in a lattice, so that LLL algorithm can also be used to solve the subset sum problem. Since the subset sum problem can be easily solved by applying LLL algorithm, then the Merkle-Hellman knapsack cryptosystem can also be easily be destructed.
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