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Abstrak :
X-ray computed tomography (CT) has been playing an important role in current medical practice for diagnostic procedure. Beside its delicate technology, the 'hidden' software of CT image reconstruction has contributed almost half of total cost of a CT-scanner unit. Since Algebraic Reconstruction Technique (ART) is a basic to understand an iterative method of CT image reconstruction algortihm, and since it is difficult to find a clear description of fan beam ART algorithm in university literatures, it is important to develop an own algorithm and to begin a basic systematic research of this iterative method. After a long term of trial and error work, the research had succeded in developing an ART algorithm for third generation CT image reconstruction. By comparing the result of the research with more popular technique like Filtered Back Projection (FBP), the algorithm has been proved applicable to reconstruct a low dimension object matrix (32x32 and 64x64). By the resulted computer program, then basically a simple and low cost third generation CT-scanner can be designed for medical physics or biomedical imaging research. Finding a way of shortening the massive number of iterations process then, will be able to open the possibility of using the software for higher object matrix dimensions.

Abstrak :
Telah dirancang sebuah Sistem untuk mengukur debit minyak yang mengalir di dalam sebuah pipa dengan menggunakan Sistem Electrical Capacitance Tomography (ECT) yang menggunakan teknik rekonstruksi gambar Iterative Linear Back Projection (ILBP). Teknik rekonstruksi gambar Iterative Linear Back Projection dilakukan dengan menggunakan bahasa pemograman MATLAB 7.1. Sistem yang terdiri dari sensor kapasitif dengan 12 elektrode, pengkondisi sinyal analog dan digital, serta komputer dapat menghasilkan data yang sesuai dengan waktu yang sebenarnya. Rekonstruksi gambar yang dihasilkan merupakan bentuk gambar 2 dimensi. Data juga disajikan dalam bentuk film dan gambar per satuan waktu. Teknik ini telah diverifikasi dengan objek sebenarnya dalam percobaan yang lain. ......Has been developed a system to measure oil volume flow rate which flow in a pipe by electrical capacitance tomography (ECT) system with Iterative Linear Back Projection (ILBP) as the image reconstruction techique. Iterative Linear Back Projection (ILBP) image reconstruction technique programmed by MATLAB 7.1 programming language. The system is consist of a capacitive sensor with 12 electrode, analog and digital signal conditioning, and computer which can obtain the data by real time. Image reconstruction obtained in 2D. The data is also showed in a film and image per second. This technique has been verified with the truly object in another experiment.

Abstrak :
Jacobsite nanomagnetic particles with various size can be easily synthesized by using coprecipitation method. Samples are categorized into two synthesis condition, which is nonultrasonic assisted and ultrasonic assisted process. Samples are characterized with various methods to give understanding on their structure. Annealing process gave significant effect on the structure of the particles, thus provides better crystallinity on the annealed samples. The study shows that upon the annealing temperature of 300OC for four hours on nanomagnetic particles synthesized using ultrasonic are in Jacobsite phase; on the other hand we could have pure Jacobsite only by an hour of annealing when we subject the samples to ultrasonic treatment. Nanomagnetic particles size ranging from 4 nm to 16 nm are found after annealing process when samples are synthesized without using ultrasonic treatment. We have also obtained nanomagnetic particles with size ranging from 2 nm to 11 nm after annealing process when the samples are being exposed to ultrasonic treatment.

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Rekonstruksi merupakan bagian penting dari proses pencitrran. Pada sistem pencitraan ultrasonik, untuk menghasilkan citra dilakukan tahap rekonstruksi sinyal akustik A ? Mode menjadi B ? Mode yang merupakan dasar dari sistem pencitraan ultrasonik. Untuk memperoleh hasil yang optimal, sebelum merekonstruksi citra yang sesungguhnya, dilakukan simulasi. Pada skripsi ini, simulasi dilakukan dengan menggunakan software COMSOL34 MULTIPHYSICS dan MATLAB R2007. Dengan menggunakan software COMSOL34 MULTIPHYSICS menerapkan metode elemen hingga dapat diperoleh data berupa sinyal A ? Mode yang selanjutnya sinyal tersebut diolah menggunakan software MATLAB R2007. Software MATLAB R2007 berfungsi untuk menampilkan citra dan menganalisis hasil. Citra yang dihasilkan dipengaruhi oleh beberapa faktor, seperti frekuensi, bandwitdh, lebar transducer, pengaruh mesh COMSOL34 MULTIPHYSICS dan grid transducer pada COMSOL34 MULTIPHYSICS . Semua faktor tersebut berpengaruh kepada resolusi, ketajaman, tingkat kecerahan citra yang dihasilkan.

Abstrak :
Pencitraan volumetric berdasarkan prinsip electrical capacitance tomography (ECT), dinamakan electrical capacitance volume tomography (ECVT), telah dikembangkan dalam penelitian ini. Teknik yang digunakan berawal dari pengukuran kapasitan diseluruh geometri benda volumetrik tiga dimensi yang diliputi sensor kapasitan. Pengembangan ini memungkinkan real-time pencitraan volume bergerak ( 4 D ). Pengembangan dari teknik pencitraan ECVT meliputi 3-D desain sensor untuk mendapatkan citra yang optimal dan teknik rekonstruksi pencitaraan volum. Teknik rekonstruksi gambar dimodifikasi oleh algoritma 3-D matrik sensitivitas. Distribusi sensitivitas sangat mempengaruhi citra yang dihasilkan. penelitian ini telah dilakukan dengan simulasi dan komputasi medan listrik pada software COMSOL Multiphysics yang berdasarkan metode element terbatas dan dihitung dalam MATLAB 2007b serta di ujicobakan melalui alat.

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A dynamic volume imaging based on the principle of electrical capacitance tomography (ECT), namely, electrical capacitance volume tomography (ECVT), has been developed in this research. The technique generates, from the measured capacitance, a whole volumetric image of the region enclosed by the geometrically three-dimensional capacitance sensor. This development enables a real-time, 3-D imaging of a moving object or a real-time volume imaging (4-D) to be realized. The development of the ECVT imaging technique primarily encloses the 3-D capacitance sensor design to get the optimum image and image volume reconstruction technique. The image reconstruction technique is modified by introducing into the algorithm a 3-D sensitivity matrix. The Distribution of sensitivity affects the produced image. The research is done with the simulation system and computational electric field in COMSOL Multiphysics software that is based in a finite element method and calculated in MATLAB 2007b and is examined with hardware.

Abstrak :
Keretakan yang dialami suatu tabung perlu diketahui sedini mungkin untuk menghindari adanya ledakan akibat tekanan operasional tabung yang tinggi. Gelombang mekanik ultrasonik yang dipancarkan pada logam tabung akan mengalami efek atenuasi yang disebabkan oleh peristiwa refleksi dari adanya perbedaan impedansi akustik. Perbedaan impedansi akustik yang disebabkan oleh keretakan akan merefleksikan gelombang mekanik ultrasonik hingga mampu mengurangi besarnya intensitas gelombang ultrasonik yang diterima. Untuk itu telah dilakukan simulasi dari sistem aplikasi ultrasonik yang dapat diaplikasikan untuk mendeteksi keretakan pada logam tabung CNG. Simulasi dilakukan dengan menggunakan software COMSOL Multiphysics v3.4 yang berbasis metode elemen-hingga. Sistem disimulasikan dengan mengirim gelombang pulsa ultrasonik 5 MHz dari suatu angle-beam transduser 70 derajat kemudian akan diterima dengan transduser yang berbeda. Analisa penelitian dilakukan dengan membandingkan intensitas sinyal gelombang ultrasonik yang diterima dengan kondisi yang berbeda yaitu tidak ada retak, retak dengan berbagai variasi kedalamannya, retak dengan berbagai orientasi sudut dan posisi relatif transduser terhadap suatu keretakan. A crack in a high pressure tube must be identified immediately to avoid highly damaging explosion caused by pressure. Ultrasonic mechanic wave that transmits in metal will experience an attenuation effect caused by reflection when encounters obstacles with different acoustic impedance. The difference of the acoustic impedance of the crack will cause reflection of the ultrasonic wave and reduce the intensity of the transmitted ultrasonic wave. As a result, a measurement of the transmitted wave using an ultrasonic application system can be used to detect a crack in CNG metal tube. A simulation is done using COMSOL Multiphysics v3.4 software that is based on a finite element method. A crack system is simulated by sending 5 MHZ ultrasonic pulse wave from 70-degree angle-beam transducer, and then the pulse is received using a different transducer. The analysis is done along with a comparison of the received ultrasonic wave signal in different conditions, such as no crack, cracks with various depths, cracks with different angle orientations, and transducer with different positions relative to the crack.

Abstrak :
Seismic Interpretation is a part of exploration project to get depth structure map, also to find an interesting structure with hidrocarbon prospect. Located in Kalimantan with the main object is Basin X. 2D seismic data, borehole checkshot, well logs, and some geological data such as geological map and regional stratigraphy are the main database. In this study, depth conversion is performed by using layering cake method with two layering strategies. Starting with seismic horizon and fault picking, then mapping the time structure map based on two-way time. The depth conversion can be done after the value of k, Vo and Vinterval are inverted from checkshot. After make velocity modelling for Vo and Vinterval, used it with DT formula, then the result would be considered the fisrst depth structure map. Callibrated it with log data would gain residual depth, the residual modelling will give correction to the depth structure map, that would be considered as the final depth structure map. HC prospect and structure of interest are analyzed using this depth structure map, and found two structures with HC prospect.

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Munculnya keabnormalan pada tubuh manusia perlu diketahui sedini mungkin untuk mempercepat proses terapi dan mempertinggi kesempatan sembuh. Informasi penting tentang anatomik fungsional jaringan tubuh, sebagai hadirnya kanker atau jaringan abnormal pada tubuh dapat diperoleh menggunakan karakterisasi parameter fisika pancaran ultrasonik pada jaringan tubuh seperti intensitas. Karakter sinyal akustik untuk mendeteksi jaringan abnormal diukur menggunakan metode pulsa. Pada penelitian ini, karakterisasi sinyal akustik diperoleh dengan simulasi menggunakan software Comsol Multiphysics 3.4 dan eksperimen menggunakan ultrasonik. Uji kasus secara simulasi dilakukan untuk mencari parameter optimal dalam diagnosis dengan impedansi akustik dan ukuran jaringan abnormal yang berbeda. Hasilnya menunjukkan ada perbedaan echo antara jaringan normal dan jaringan abnormal. Hubungan intensitas echo berbanding lurus dengan impedansi akustik jaringan abnormal dan ukuran jaringan abnormal. Noise yang terdapat pada sinyal dapat direduksi menggunakan wavelet.

Abstrak :
Seismic inversion is used to make geological subsurface model in terms acoustic impedance. Seismic and well data is used as input on inversion process. Having both the data need to be integrated with geostatistic because they have different scale so more consistent geological model is made. The project area is Boonsville Field in Texas, US. This process is made with open-source software called Delivery which does model-based inversion with Bayesian approach. The result is acoustic impedance cross section which presented sand at Boonsville Filed. An attempt to image human body arm using Electrical Capacitance Volume Tomography (ECVT) system has been done. We used reconstruction method as Linear Back Projection (LBP), Landweber Equation (Iterative Linear Back Projection, ILBP) and Neural Network Multi-criterion Optimization image Reconstruction technique (NN-MOIRT) algorithms. The results from image reconstruction showed a possibility of human arm imaging with different image reconstruction. NN-MOIRT algorithm method results performed better image compared to LBP and ILBP methods. Image reconstruction process was conducted using MATLAB R2007b software.

Abstrak :
Metode artificial neural network digunakan dalam penghitungan nilai kapasitansi pada problem maju dari sistem ECVT untuk proses rekonstruksi semi non linear. Nilai kapasitansi hasil prediksi neural network didapatkan dari input distribusi permitivitas yang menunjukkan hasil citra yang diinginkan. Metode training neural network yang digunakan adalah training backpropagation. Pasangan input dan output data training didapatkan dari hasil simulasi menggunakan software COMSOL Multiphysics 3.4 yang kemudian ditraining menggunakan software Toolbox Neural Network pada Matlab R2007b. Hasil rekonstruksi citra semi nonlinear dibandingkan dengan hasil rekonstruksi linear.

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Methods of artificial neural network used in the calculation value of capacitance in the forward problem of the system for the semi non-linear reconstruction of ECVT. Capacitance value of neural network predicted results obtained from the input distribution of permitivitty results indicate that the desired image. Training method used by neural network is backpropagation training. Pair input and output data obtained from the training results of the simulation using COMSOL Multiphysics 3.4 software, which then use the software Neural Network Toolbox in Matlab R2007b to train neural network. Results semi nonlinear image reconstruction compared with the results of the linear reconstruction.