Perlindungan Rekam Medis Berbasis Robust Watermarking pada Citra Medis Digital Menggunakan Metode DWT-DCT dan Optimasi dengan GA

Jasa layananan telemedis memanfaatkan kemajuan teknologi informasi untuk pertukaran informasi dan pelayanan kesehatan tanpa memperhatikan batas tempat dan waktu. Data medis yang dapat dikirim, ditukar, dan distribusikan untuk memenuhi layanan telemedis harus diikuti dengan sistem keamanan karena kejahatan pencurian data identitas medis semakin meningkat dan membahayakan. Data pasien yang bersifat pribadi dan rahasia dapat dijaga dengan skema watermarking dengan cara menyisipkan rekam medis pasien pada citra medis digitalnya. Hal ini dapat menjamin kerahasiaan dan keamanan pengiriman data serta menjaga integritas dan hak milik citra medis digitalnya. Pada penelitian ini diusulkan skema watermarking menggunakan penggabungan metode DWT-DCT serta optimasi dengan GA untuk mencapai nilai robustness dan imperceptibility yang lebih baik. Parameter yang dioptimasi adalah subband DWT, subband DCT, dan scale factor penyisipan. Skema watermarking yang diusulkan dibandingkan dengan skema watermarking satu metode (DWT) dan penggabungan metode (DWT-DCT) tanpa algoritma optimasi. Dari hasil pengujian tanpa serangan, skema watermarking yang diusulkan lebih baik hingga 13,28 dB untuk nilai PSNR, dan 0,21 poin untuk nilai NCC. Pada pengujian menggunakan serangan, skema watermarking yang diusulkan dapat dikatakan baik untuk beberapa nilai serangan

Development of variable voltage variable frequency drive system for induction motor speed control

This project describes the development of a Variable Voltage Variable Frequency (VVVF) system that controls the speed of Induction Motor (IM) at specific speed. Texas Instrument C2000 Microcontroller (TMS320F28335) has been used in this project as the interface between the control design with the IM. The Texas Instrument microcontroller has been combined with the MATLAB/Simulink and the VVVF system as the communication interface for processing the speed control system. The combination between power electronic circuits and microcontroller along with variable voltage variable frequency (VVVF) technique is able to control the target speed of IM. The target value of VVVF is implemented inside Lookup table and has been combined with the Proportional Integral (PI) speed control that generates the signal into the sinusoidal pulse width modulation (SPWM) for inverter operation. The SPWM signal is produced from the microcontroller with the instruction from MATLAB/Simulink, where the controller performs the output of the motor speed. The PI speed control receives the output of a closed loop feedback system from the motor speed and the error signal is reduced to achieve the value of desired speed reference. In the conclusion, the VVVF closed loop system is very useful to control the desired speed of motor at different variable voltage and variable frequency value. As collected for the results, its show, the VVVF with PI speed control can achieve the actual speed for the IM at 1297rpm and 1499rpm when the reference speeds have been set at 1300rpm and 1500rpm respectively. At the end it can be concluded that the VVVF combined with microcontroller have created an ecosystem for speed control that have achieved the objectives

A comparison of discrete cosine transform and discrete wavelet transform algorithm in watermarking against common attacks

Digital watermarking is a technique to embed additional data to digital images, audios and videos without affecting the quality of the original image. Watermark can be extracted for ownership verification or authentication. Currently, there is no comparison documented done between Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT). In this report, the DCT watermarking algorithms and DWT watermarking algorithms were compared based on robustness and imperceptibility criteria. With DCT, the watermark bits were embedded into the mid-band coefficients of the DCT in the cover image where the DWT algorithm was embedded the watermark bits into the horizontal and vertical sub-bands of DWT in the cover image. Experimental results had shown that the watermark is robust to geometric attacks and removal attacks. DCT and DWT are compared with regard to peak signal to noise ratio (PSNR), Mean Square Error (MSE) and Normalized Correlation (NC). The PSNR value of the watermarked Lena image in DWT is 47, higher than the DCT which is 44. The Normalized Correlation (NC) also had clarified that the extracted watermark in DWT 0.9964 is greater than the extracted watermark in DCT 0.2057. Thus, the results had indicated that the DWT gives better image quality than DCT

Research on digital image watermark encryption based on hyperchaos

The digital watermarking technique embeds meaningful information into one or more watermark images hidden in one image, in which it is known as a secret carrier. It is difficult for a hacker to extract or remove any hidden watermark from an image, and especially to crack so called digital watermark. The combination of digital watermarking technique and traditional image encryption technique is able to greatly improve anti-hacking capability, which suggests it is a good method for keeping the integrity of the original image. The research works contained in this thesis include: (1)A literature review the hyperchaotic watermarking technique is relatively more advantageous, and becomes the main subject in this programme. (2)The theoretical foundation of watermarking technologies, including the human visual system (HVS), the colour space transform, discrete wavelet transform (DWT), the main watermark embedding algorithms, and the mainstream methods for improving watermark robustness and for evaluating watermark embedding performance. (3) The devised hyperchaotic scrambling technique it has been applied to colour image watermark that helps to improve the image encryption and anti-cracking capabilities. The experiments in this research prove the robustness and some other advantages of the invented technique. This thesis focuses on combining the chaotic scrambling and wavelet watermark embedding to achieve a hyperchaotic digital watermark to encrypt digital products, with the human visual system (HVS) and other factors taken into account. This research is of significant importance and has industrial application value