Gelar Budiman

The performance analysis of multiuser WCDMA systems using D-STBC in Rayleigh fading channel

The development of wireless communication systems is focusing to provide a link with a high capacity and good quality. The multi-hop communication system using relays diversity with a reliable coding is designed to fulfil the above requirements. Using multi-user WCDMA system, this research applies the above multi-hop technique using a relay with Alamouti code which can be defined as Distributed-Space Time Block Code or D-STBC. Therefore it does not need multi antenna but act like MIMO and that is why it is also called virtual MIMO using a cooperative multi-hop system. The simulation results show that the 2×1 virtual MIMO multi hop system performs better than a single hop system. Targeting BER of 10-3, the multi hop system give 12 dB gain compared with a single hop system.

A multicarrier modulation audio watermarking system

Information hiding of data in an audio file is an important thing that the media can be recognized by its ownership. The hidden information would be the important information which describes the copyright of the audio file. In this research, the binary data is inserted or hidden into the audio file by multicarrier modulation technique data hiding. The encoded binary data by convolutional encoding is modulated by multicarrier frequencies before embedding into the host audio. For detecting the error data extraction, CRC bits are inserted into the encoded data. Data hiding capacity with this technique can achieve up to 40 bits per second in file mode with good audio imperceptibility and 100% detection rate without any attack.

Implementation of steganography using LSB with encrypted and compressed text using TEA-LZW on Android

The development of data communications enabling the exchange of information via mobile devices more easily. Security in the exchange of information on mobile devices is very important. One of the weaknesses in steganography is the capacity of data that can be inserted. With compression, the size of the data will be reduced. In this paper, designed a system application on the Android platform with the implementation of LSB steganography and cryptography using TEA to the security of a text message. The size of this text message may be reduced by performing lossless compression technique using LZW method. The advantages of this method is can provide double security and more messages to be inserted, so it is expected be a good way to exchange information data. The system is able to perform the compression process with an average ratio of 67.42 %. Modified TEA algorithm resulting average value of avalanche effect 53.8%. Average result PSNR of stego image 70.44 dB. As well as average MOS values is 4.8.

Feasibility study of strengthening the public–private partnership for tuberculosis case detection in Bandung City, Indonesia

ObjectivePrivate practitioner’s (PPs) collaboration for detection, diagnosis and treatment of tuberculosis (TB) is recommended by the World Health Organization and encouraged by the Indonesian National TB control programme. TB case management by PPs, however, are mostly not in line with current guidelines. Therefore, we developed an intervention package for PPs comprising of TB training, implementation of a mobile phone application for notification of TB cases and a 6-month regular follow-up with PPs. This study aimed to evaluate the feasibility of the intervention package to increase TB case detection and notification rates among PPs in five community health centre areas in Bandung City, Indonesia.ResultsA total of 87 PPs were registered within the study area of whom 17 attended the training and 12 had the mobile phone application successfully installed. The remaining five PPs had phones that did not support the application. During the follow-up period, five PPs registered patients with TB symptoms and cases into the application. A total of 36 patients with TB symptoms were identified and 17 were confirmed TB positive.

Designing secured data using a combination of LZW compression, RSA encryption, and DCT steganography

Information security in mobile phones has become a challenge when large amounts of data exchanged on the Internet. Secure information transfer can be achieved by cryptography and steganography. Cryptography is a tool that provides encryption techniques for secure communication. Steganography is the technique of hiding information by way of the message of the picture, so that in addition to the person addressed, another person will not be aware of the existence of the message. In this study the issues to be discussed is the technique of message encryption with RSA (Rivest Shamir Adleman) method. Messages are encrypted after compressed by LZW (Lempel Ziv Welch) method, so it will reduce the size of the message that will be inserted and increase the capacity of messages that can be inserted. Messages that have been compressed and encrypted, is then hidden by DCT (Discrete Cosine Transform) techniques. With the incorporation of encryption techniques, steganography, and compression, the acquired information is more secure and its capacity is larger. For a 512×512 colored image there are 1536 characters enable for hiding. With LZW the amount of characters hiding will be about twice larger in this research.