Judul: Evolution of Jakarta Bay waters based on sediment and foraminifera
Abstrak: Jakarta Bay is located in Special Region of Jakarta Province where the downstream of 13 rivers cut through the whole area of Jakarta. Jakarta Bay is cover approximately 514 km2. Based on the foraminifera characteristic as potential indicator for understanding both the recent and the ancient water environment. The aim of this research is to study vertically and horizontally ecological change that have had occurred in Jakarta Bay. The sampling of sediment samples in Jakarta Bay had been carried out using the Geomarine I. There are 25 collected samples location. The collected samples had been done in 1994 and had been storage in the cold storage in Cirebon. The sediment and microorganism observation and study has been carried out at Paleontology Laboratorium, Geological Technological Faculty of Padjadjaran University. Analitical of submarine core sample were included the description of sediment and indentification of benthic foraminifera. Analitical of Lost On Ignition (LOI) is a method to count organic material content and carbonate content in the sediment sample. The absolute dating for Holocen is based on radioactive (210Pb method) for sediment dating. Factorial Correspondence Analysis is for sediment group analysis and benthic foraminifera by using XLSTAT 2012 software. The result of sediment grain measurement analysis shows that sediment of Jakarta bay is consist of clay fraction (<0.004 mm) and shale (0.063-0.004 mm) based on grain measurement scale of Wenworth (1922). The result of Lost On Ignition analysis shows that carbonate and organic material content in the sediment change from time to time. Carbonate content in the sample is the opposite result with its organic material content. The dating from the core TJ-11 in the sediment layer 20- 22 cm was more than 173 years. Core TJ-21 in the sediment layer 30-32 cm was more 115 years. Core TJ -89 sediment layer less than 30-32 cm, which was more than 136 years. The study on Recent Benthic Foraminifera from the Jakarta Bay consist 177 species included 84 genera. The grouping based on shell: -Subordo Rotaliina was found 87 species included its 52 genera. -Subordo Miliolina was found 65 species included its 17 genera. -Subordo Textulariina was 25 species included its 15 genera. The result on Factorial Correspondence Analysis that the genus of benthic foraminifera with layers of depth shows the distribution pattern which is different in each layer of sample depth. The change of composition foraminifera genus can be seen in each layers has different genus composition. From here, it can be noticed the environment evolution that has been characterised by Benthic Foraminifera.
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Judul: Sebaran Konsentrasi Fosfat (PO4-P) dan Nitrat (NO3-N) sebagai Indikator Kesuburan Perairan di Teluk Jakarta
Abstrak: Teluk Jakarta terletak di pantai utara Pulau Jawa merupakan muara bagi 13 sungai besar di Jakarta, Bogor, Depok, Tangerang, dan Bekasi. Berbagai aktivitas yang melibatkan pemanfaatan perairan baik teluk maupun sungai dapat menyebabkan penurunan kualitas perairan dan pengayaan nutrien. Salah satu akibat pengayaan nutrien yaitu peningkatan nutrien seperti fosfat dan nitrat yang dapat memengaruhi produktivitas perairan. Penelitian ini bertujuan menganalisis sebaran konsentrasi fosfat dan nitrat di Teluk Jakarta secara spasial dan temporal. Pemantauan kualitas air dilakukan antara tahun 2012 hingga 2019 sebanyak delapan kali pengamatan dari 23 stasiun. Penentuan 23 stasiun berdasarkan keterwakilan wilayah Teluk Jakarta. Berdasarkan kandungan fosfat dan nitrat, perairan Teluk Jakarta terrmasuk subur. Pola sebaran spasial fosfat dan nitrat konsentrasinya lebih tinggi di sekitar pantai dan semakin rendah seiring mendekati mulut teluk. Secara temporal, konsentrasi fosfat dan nitrat menunjukkan perbedaan yang signifikan cenderung meningkat dari tahun ke tahun., Jakarta Bay is located on the north coast of Java Island and is the mouth of 13 major rivers in Jakarta, Bogor, Depok, Tangerang, and Bekasi. Various activities that involve the use of waters, both bays and rivers, can cause a decrease in water quality and nutrient enrichment. One result of nutrient enrichment is an increase in nutrients such as phosphate and nitrate which can affect water productivity. This study aims to analyze the spatial and temporal distribution of phosphate and nitrate concentrations in Jakarta Bay. Water quality monitoring was carried out between 2012 and 2019 in eight observations from 23 stations. Map of 23 stations based on the representativeness of the Jakarta Bay area. Based on the content of phosphate and nitrate, the waters of Jakarta Bay are considered fertile. The pattern of spatial distribution of phosphate and nitrate concentrations is higher around the coast and lower as they approach the mouth of the bay. Temporally, the concentrations of phosphate and nitrate showed significant differences which tended to increase from year to year.
Keyword: temporal, Jakarta Bay, nitrate, phosphate, spatial

Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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