Judul: Kajian Paleoklimatologi dan Perubahan Suhu Global
Abstrak: Global climate change is a change of climate patterns and intensity on a global scale as a result of changes in the energy budget components within the earth system and may be caused by both natural and antrophogenic factors. Studies of climate change requires a long data which may be reconstructed by several methods of paleoclimatology including ice cores, tree ring, coral, and pollen methods. Climate reconstruction using Ice core method requires longer data records compared with the tree ring, coral, and pollen method. The complexity of physical and chemical analysis are major constaints in utilizing ice core and coral method. On the other hand, the unven speard of tree on the earth cause limitations to the information obtained from tree ring and pollen method. Among factors consider important to the global climate change include solar constant, properties of earth surface, and atmospheric chemical compositions of greenhouse gases. Radiative forcing is an index defined by the rate of energy change per unit area of the globe as measured at the top of the atmosphere. Global climate change is indicated by increased of global average surface temperature which according to data records has increased by 0.7oC during the last century. A number of literature suggest the temperature rise was due to anthropogenic factors; however, using simplified energy balance model of the earth-atmosphere system reveals that an increase of solar constant by 1% (which may occur during the last century), while holding other factors unchanged, will result in an average global surface temperature increase of 0.6oC which is fairly close to the value obtained from observations. It must be emphasized that climate is an extremely complex system in which various factors interact with each other in some forms of linear and non-linear feedbacks. Analysis of time series data of Jakarta Observatory which cover a period of 1965-2010 shows a slight increase of average temperature and decrease of average rainfall.
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Judul: Analisis Peningkatan Intensitas Cuaca Ekstrim Di JABOTA (Jakarta, Bogor, Tangerang) Periode 1980 - 2008
Abstrak: Pertumbuhan penduduk mempengaruhi perubahan penggunaan lahan terutama berkurang ruang terbuka hijau. Hal ini mempengaruhi naiknya suhu udara dan meningkatnya cuaca ekstrim. Penelitian di beberapa negara sudah terbukti adanya kenaikan suhu dan cuaca ekstrim sebagai akibat dari perubahan penggunaan lahan seperti Taiwan, Cina dan Jepang. Data yang di gunakan pengamatan cuaca harian stasiun Meteorologi sekitar Jabota kurun waktu antara tahun 1980-2008 dibagi menjadi dua periode (periode 1980-1997 dan 1998- 2008) dan dibandingkan untuk mengetahui peningkatan suhu dan cuaca ekstrim. Data pengamatan udara atas periode tahun 1988-2008 dibagi menjadi dua periode dan dibandingkan untuk mengetahui peningkatan suhu udara atas pada lapisan tertentu. Data cuaca setiap jam antara tahun 2003-2008, stasiun Curug sebagai contoh untuk menganalisis pergeseran waktu kejadian suhu maksimum dan waktu terjadinya badai petir. Hasil analisis menunjukkan adanya peningkatan suhu rata-rata pada periode kedua, meningkatnya frekuensi suhu di atas 34°C, meningkatnya frekuensi curah hujan ekstrim pada bulanbulan tertentu terutama pada bulan di musim hujan dan transisi, meningkatnya frekuensi kejadian badai petir, meningkatnya rata-rata suhu udara atas terutama pada lapisan permukaan hingga 500mb, terjadi pergeseran waktu suhu maksimum pada bulan-bulan tertentu di musim kemarau dan transisi pada dari pukul 13.00 mejadi pukul 14.00 wib dan waktu kejadian badai petir tertinggi antara pukul 15.00-17.00 wib dan pukul 19.00-20.00 wib
Keyword: land us e changes, increase temperature, extreme weather

Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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