Judul: Characteristics of carbon fluxes and catchment health from Java Major Rivers in Java.
Abstrak: Carbon derived from land, whether from natural or the result of human production and consumption will partially be dissolved by surface flow into the river and flows into the sea. Forms of carbon in the rivers are organic and inorganic in the form of dissolved and particulate matter. Watershed condition has great influenced on the river carbon fluxes. Carbon is very important as energy source for life in coastal waters and for the process of photosynthesis. There has not been extensive research yet on the relationship between the condition of watershed and carbon. Changes in river flow patterns have significant influence on the carbon cycle, particularly the flux of carbon from rivers. With regards to the above issue, this study aims to: a) assess characteristics of carbon flux from rivers in Java; b) identify trends and patterns in hydrological character; and c) identify level of catchment health as indicator of environmental degradation. This research is both exploratory and investigative to obtain facts of phenomena that exist, locate and disclose information in a factual, and compare with other research objects. The research on carbon flux is a kind of basic research conducted to address environmental problems, particularly in explaining state of knowledge of the carbon cycle that is always developing. Concentration of carbon and the dissolved organic carbon yield of rivers in Java is higher compared with the rivers in the world. The average concentration of dissolved organic carbon in Java about 11.15 mg/l, while the rivers in the world of 5.62 mg/l. This is influenced by a large population and watershed conditions that have degraded. Catchment health index shows most of the watersheds in Java are in critical condition. River which flows into the north of Java is in more critical condition than that into the south of Java. This phenomenon is also reflected in the distribution of carbon flux, where the flux of carbon going to the north of Java greater than that to the south. Some of the factors that cause smaller carbon export to the south of Java are among others: lower carbon concentration, river flow, watershed area, population density, and number of industries. The rivers in Java contributes dissolved organic carbon to the sea about 6.58% of the rivers in Indonesia, or about 0.66% of the rivers in the world. Export of carbon to the north of Java Island is greater than that to the south of Java Island. Based on calculations by the method of partial pressure of CO2 (pCO2), the rivers in Java has less than 4259 μatm. pCO2 of rivers in Java is greater than the rivers in the world, as an example of the Yangtze in China 1125 μatm, the Rhine in Europe 1268 μatm, and Amazon 3067 μatm. While the influence of carbon on the quality of river waters in the Java environment is still very difficult to determine. Up to now there has been unknown quality standard for carbon in the waters in the world. Carbon in the river can not be used as an indicator of the watershed health. To overcome
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Judul: Analisis Sebaran Klorofil-a dan Suhu Permukaan Laut Menggunakan Data Satelit Aqua Modis di Laut Jawa
Abstrak: Laut Jawa memiliki potensi sumber daya ikan yang besar. Suhu permukaan laut dan konsentrasi klorofil-a merupakan parameter oseanografi yang dapat mempengaruhi persebaran ikan. Penggunaan parameter ini dapat menganalisis sebaran suhu permukaan laut dan kloofil-a dengan memanfaatan teknologi penginderaan jauh. Tujuan penelitian ini untuk menganalisis sebaran klorofil-a dan suhu permukaan laut menggunakan sensor satelit Aqua Modis di Laut Jawa pada Tahun 2020.Penelitian ini berlokasi di perairan Laut Jawa menggunakan data citra Aqua MODIS bulanan selama tahun 2020. Penentuan nilai konsentrasi klorofil-a dan suhu permukaan laut yang sebelumnya telah diolah menggunakan interpolasi Inverse Distance Weighted (IDW). Analisis sebaran SPL rata-rata bulanan di Laut Jawa dari citra satelit Aqua MODIS tahun 2020 berkisar antara 28.5°C – 30.9°C. Penyebaran SPL di Laut Jawa mengikuti pola angin musim yang terjadi di perairan Indonesia dimana SPL cenderung turun pada musim barat dan timur serta naik pada musim peralihan 1 dan peralihan 2. Konsentrasi klorofil-a berkisar antara 0.54-4 mg/m³. Nilai konsentrasi klorofil-a setiap bulannya berfluktuasi mengikuti musim angin yang sedang berlangsung. Kata kunci: IDW, klorofil-a, Laut Jawa, suhu permukaan laut, The Java Sea has great potential for fish resources. Sea surface temperature and chlorophyll-a concentration are oceanographic parameters that can affect the distribution of fish. The use of this parameter can analyze the distribution of sea surface temperature and chlorophyll-a by utilizing remote sensing technology. The purpose of this study was to analyze the distribution of chlorophyll-a and sea surface temperature using the Aqua Modis satellite sensor in the Java Sea in 2020. This study was located in the waters of the Java Sea using monthly Aqua MODIS image data during 2020. Determination of the value of chlorophyll-a concentration and sea surface temperature which had previously been processed using Inverse Distance Weighted (IDW) interpolation. Analysis of the monthly average SST distribution in the Java Sea from Aqua MODIS satellite imagery in 2020 ranges from 28.5°C – 30.9°C. The distribution of SST in the Java Sea follows the pattern of monsoons that occur in Indonesian waters where SST tends to decrease in the west and east seasons and rises in transitional season 1 and transition 2. The concentration of chlorophyll-a ranges from 0.54-4 mg/m³. The value of the concentration of chlorophyll-a fluctuates every month following the ongoing wind season. Keywords: chlorophyll-a, IDW, Java Sea, sea surface temperature
Keyword: chlorophyll-a, IDW, Java Sea, sea surface temperature

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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