Joko Sampurno

Automated analysis of image mammogram for breast cancer diagnosis

Medical imaging help doctors in diagnosing and detecting diseases that attack the inside of the body without surgery. Mammogram image is a medical image of the inner breast imaging. Diagnosis of breast cancer needs to be done in detail and as soon as possible for determination of next medical treatment. The aim of this work is to increase the objectivity of clinical diagnostic by using fractal analysis. This study applies fractal method based on 2D Fourier analysis to determine the density of normal and abnormal and applying the segmentation technique based on K-Means clustering algorithm to image abnormal for determine the boundary of the organ and calculate the area of organ segmentation results. The results show fractal method based on 2D Fourier analysis can be used to distinguish between the normal and abnormal breast and segmentation techniques with K-Means Clustering algorithm is able to generate the boundaries of normal and abnormal tissue organs, so area of the abnormal tissue can be determined.

IDENTIFIKASI SEBARAN ANOMALI MAGNETIK DI PERAIRAN KABUPATEN SAMBAS KALIMANTAN BARAT DENGAN MENGGUNAKAN METODE GEOMAGNET

Telah dilakukan penelitian sebaran anomali magnetik di perairan Kabupaten Sambas. Metode yang digunakan adalah metode geomagnet. Pengambilan data dilakukan sebanyak 33 lintasan. Data yang diperoleh berupa distribusi medan magnet total. Data ini kemudian dikoreksi dengan koreksi IGRF dan t ie-line levelling untuk mendapatkan distribusi medan magnet lokal. Dari distribusi intensitas medan magnet lokal didapatkan 4 zona anomali. Pada tiap zona anomali dibuat lintasan satu dimensi untuk mendapatkan struktur bawah permukaan dengan metode inversi (lintasan AB, CD, EF, dan GH). Anomali magnetik pada lintasan AB, lintasan EF, dan lintasan GH diduga disebabkan oleh mineral magnetit dengan nilai suseptibilitas antara 1,2 s.d 19,2. Anomali magnetik pada lintasan CD dengan nilai suseptibilitas 0,3 s.d 3,5 diduga disebabkan oleh mineral ilmenit. Nilai korelasi antara data observasi dan data kalkulasi untuk semua lintasan berkisar 0,98 s.d 0,99. The distribution of magnetic anomalies in Sambas Sea has been investigated using the Magnetic method. The raw data, which acquired, have been corrected using IGRF data and tie-line leveling to obtain the local magnetic field distribution. Then, from the corrected data obtained four anomalous zones. Next, a slice that lying on the anomalous zones (line AB, CD, EF, and GH) was made to obtain the subsurface structures which obtain using inversion method. The results show that the presence of magnetic anomalies at the lines AB, EF and GH (with susceptibility values between 1.2 to 19.2) due to the magnetite rock at the subsurface. Moreover, The presence of magnetic anomalies at the line CD (with susceptibility values of 0.3 to 3.5) is caused by ilmenite rock. The correlation coefficients between the observation data and calculated data for all lines are between 0.98 to 0.99.

Pemodelan Variasi Nilai Percepatan Gravitasi di Daerah Khatulistiwa dengan Menggunakan Metode Gauss-Newton

Telah dilakukan penelitian tentang pemodelan variasi nilai percepatan gravitasi yang bertujuan untuk memberikan gambaran variasi nilai percepatan gravitasi terhadap waktu di daerah khatulistiwa dengan menggunakan metode Gauss-Newton. Dengan menggunakan data dari percobaan bandul sederhana di daerah pengamatan yang terletak pada koordinat 0°03¢30,61²LS dan 109°20¢44,09²BT, dihasilkan periodesitas data variasi nilai percepatan gravitasi sebesar 15 hari, yang merupakan setengah dari periodesitas data jarak bumi-bulan dan fase bulan. Korelasi antara variasi nilai percepatan gravitasi dengan jarak bumi-bulan sebesar 0,38. Korelasi antara variasi nilai percepatan gravitasi dengan fase bulan sebesar 0,11. Variasi nilai percepatan gravitasi hasil pengamatan dibuat model berupa sebuah persamaan dari fungsi deret Fourier orde 8, yang bergantung terhadap waktu.

Fractal analysis of microstructure of peat soil

This study discusses fractal analysis on the microscopic structure of the peat soil. The main objective is to investigate the distribution of pores in the rock samples. The results of fractal analysis using the Minkowski-Bouligand method indicates that the SEM images of microscopic structures of peat soil behave as a fractal with dimension value 1.8965. These values confirm that the distribution of pores in the peat soil is very irregular at the microscale levels.