Judul: Analisis Atenuasi Noise Koheren dan Acak pada Data Seismik  di Perairan Aru
Abstrak: Data seismik selalu terdiri dari sinyal utama yang diinginkan dan komponen noise. Noise tersebut menjadi salah satu permasalahan, karena bisa membuat hasil interpretasi penampang seismik menjadi tidak akurat. Oleh karena itu mengatenuasi noise koheren dan acak menjadi bagian yang sangat penting untuk meningkatkan resolusi sehingga interpretasi data menjadi akurat. Penelitian ini menggunakan dua metode utama untuk mengatenuasi noise, yakni metode koheren filter dan metode koheren denoising. Metode koheren filter memiliki hasil akhir yang memuaskan, dengan target utama untuk menghilangkan swell noise dan berhasil dengan hasil yang signifikan. Metode koheren denoising disisi lain juga memiliki hasil akhir yang memuaskan, noise yang menjadi target adalah noise koheren linear dan berhasil dengan hasil yang cukup signifikan. Perbedaan target noise pada kedua metode terjadi karena memiliki konsep proses yang cukup berbeda, metode koheren filter menerapkan pembobotan koherensi pada trace sedangkan metode koheren denoising menerapkan filter spasial pada trace yang keduanya sama-sama dilakukan pada domain frekuensi., Seismic data always consists of the desired main signal and a noise component. This noise can be a problem, because noise can make the interpretation of the seismic section inaccurate. Therefore attenuating coherent and random noise is a very important part of increasing the resolution so that data interpretation becomes accurate. This study uses two main methods to attenuate noise, namely the coherent filter method and the coherent denoising method. The coherent filter method has a satisfactory final result, with the main objective of removing swell noise and succeeding with significant results. The coherent denoising method, on the other hand, also has a satisfactory final result. The target noise is linear coherent noise and it works with significant results. The difference in target noise in the two methods occurs because they have quite different process concepts, the coherent filter method applies coherence weighting to the trace, while the coherent denoising method applies a spatial filter to the trace, both of which are carried out in the frequency domain.
Keyword: Coherent Denoising, Coherent Filter, Coherency Weighting, Random and  Coherent Noise, Spatial Filter

Judul: Application of Bandpass Filter Method on Single Channel 2D Seismic data in Krakatoa Waters
Abstrak: Seismic menjadi salah satu metode yang menggunakan akustik kelautan untuk mengetahui struktur di bawah permukaan laut. Penampang seismik hasil akuisisi data biasanya terdapat noise yang merupakan gelombang atau sinyal yang tidak dikehendaki dan harus dibuang dari data utama. Untuk mengidentifikasi noise pada data seismic tersebut, dalam penelitian ini digunakan fungsi FFT atau Fast Fourier Transform. Penelitian ini bertujuan untuk memisahkan sinyal akustik objek dan noise pada data seismic dengan menggunakan fungsi FFT dan metode Bandpass Filter pada data Seismic Single Channel 2D di Perairan Krakatau. Akuisisi data seismic yang digunakan pada penelitian ini menggunakan peralatan single-channel high resolution seismic berupa EG&G Multi Electrode Sparker dan hidrofon 16 elemen merek EG&G sebagai receiver. Pengolahan data seismic dalam bentuk *segy pada penelitian ini menggunakan perangkat lunak Seisee dan Matlab. Frekuensi tepi optimal pada penelitian ini berkisar antara 7 Hz hingga 29 Hz, dan frekuensi 2400 Hz untuk tepi atas. Frekuensi cut-off optimal bergantung pada nilai frekuensi pada tiap Trace dengan nilai frekuensi cut-off bawah menggunakan frekuensi pada kisaran 200 Hz hingga 400 Hz dan nilai frekuensi cut-off atas menggunakan frekuensi 1500 Hz. Kata kunci: Bandpass Filter, FFT, Frekuensi, Noise, Seismic., Seismic is one method that uses marine acoustics to determine the structure below the sea surface. Seismic cross-sections resulting from data acquisition usually contain noise which is an unwanted wave or signal and must be removed from the main data. To identify noise in the Seismic data, this study used the FFT function or Fast Fourier Transform. This study aims to separate the object’s acoustic signal and noise in Seismic data by using the FFT function and Bandpass Filter method onSingle Channel 2D Seismic data in Krakatau waters. Seismic data acquisition used in this study used a single-channel high resolution Seismic form of EG&G Multi Electrode Sparker brand EG&G as receiver. Seismic data processing in the form of *segy in this study used Seisee and Matlab software. The optimal edge frequency in this study ranges from 7 Hz to 29 Hz, and the frequency is 2400 Hz for the top edge. The optimal cut-off frequency depends on the frequency value in each Trace with the lower cut-off frequency value using a frequency in the range of 200 Hz to 400 Hz and the upper cut-off frequency value using a frequency of 1500 Hz.
Keyword: Bandpass Filter, FFT, Frequency, Noise, Seismic

Judul: Biology and ecology of the buffalo fly, haematobia exigua de meijere (diptera:muscidae)
Abstrak: The life history of the buffalo fly was observed at room temperature of 27°-29.5°C and at a relative humidity of 48-68 percent. The eggs hatched after 17-22 hours, with an average of 18 hours. First instar larvae measured 1.25 + 0.16 mm long and 0.27 + 0.037 mm wide. reach the second larval stage. It took 6-12 hours to the second instar larvae measured 2.676 +0.187 mm long and 0.353 +0.028 mm wide. The second instar took about 12-24 hours to reach the third larval stage. The third instar measured 6.833 + 0.189 mm long and 0.919 + 0.051 mm wide. It took about 2-3 days for the third instar to become pupae. Duration of the pupal stage was about 5-7 days before the adults emerged. Under laboratory condition, the buffalo fly completed its life cycle in 9.5 to 10.5 days, whereas under field condition it took 9-14 days with an average of 10.5 days. The growth ratio which was based on the measurements of the cephalo-pharyngeal skeleton of each instar was 1.797. The preoviposition period was 8-12 days and mating usually occurred on the 6th or 7th day. The longevity of the male was 29 days, whereas it was 32 days in the female. The range of egg production under laboratory condition was between 20-139 per female fly. The belly and hind legs of the carabao were the most preferred habitat either during cloudy and cool dry or shiny and warm day. When the weather was clear and the carabao was in the shade, the flies tended to be more distributed particularly on the shoulder, dewlap, back and horns. The carabaos had relatively fewer Musca sp. and Stomoxys calcitrans than cattle; never the less carabaos had a higher infestation of buffalo fly than cattle. Oviposition occured either during the day or night but the buffalo flies were more active during the night than in the day time. The effect of various lengths of exposure time of manure in relation to the oviposition was profound. observed, the maximum number of the buffalo flies was occurred when the dung was exposed for 30 minutes. With increasing time of exposure the number and variety of insects also increase. It was evident that Sepsidae and psychodidae were the most dominant insects emerging from the dung. The number of buffalo flies also increased with increasing
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