Judul: Implementasi dan Analisis Video Watermarking Menggunakan Discrete Cosine Transform dan Logika Fuzzy Berdasarkan Human Visual System
Abstrak: Nowadays, usage of digital data format has become more popular, because digital data is easier to distribute. Unfortunately, it makes easier to pirate it. Watermarking is a technique of information hiding in a specific media. This research is to implement and analyze video watermarking using Discrete Cosine Transform and fuzzy logic based on Human Visual System. Discrete cosine transform is a compression technique used to transform digital image and digital signal. Discrete cosine transform separates each data byte into two groups, namely high-frequency (DC) coefficient and low frequency (AC) coefficients. DC coefficient is used to insert a watermark. Fuzzy logic is an appropriate way to map an input space into an output space. Human Visual System is a method of image compression techniques, which is based on human visual characteristics. Human Visual System is used to calculate the sensitivity of the luminance and texture sensitivity. Fuzzy logic is used to determine the amount of insertion on each DC coefficient. The result of the experiment showed that the execution time for insertion is longer than the execution time for extraction. Moreover, the watermarked video has a Mean Structural Similarity of 0.934. This is a relatively good result. The whole watermarked message is always successfully extracted with 100% similarity. Also, the test result confirmed that the watermark video is invulnerable to cutting and adding attack. It is proven by the undamaged watermark message.
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Judul: Implementasi Audio Watermarking Menggunakan Metode DWT-SVD dengan Teks sebagai Watermark
Abstrak: The growth of data and network communication technologies has made digital data, such as audio, easier to be distributed illegally. Therefore, copyright protection becomes an important issue. Digital audio watermarking has been proposed as one of the possible solutions. It is a process of information insertion and extraction to and from an audio file without influencing the audio quality. Digital audio watermarking has been developed in several domains, such as time domain, frequency domain, and spatial domain. In this research, the audio watermarking has been implemented using DWT-SVD method that combines the frequency and spatial domain. This method works by combining the virtue of mathematical transform: the discrete wavelet transform (DWT) and singular value decomposition (SVD). Perceptibility and robustness of this method were analyzed using variance of watermark intensity and several attacks. It was found that the watermarked audio has good perceptibility at low watermark intensity of 0.1 to 0.3. Furthermore, the watermarked audio was found to be robust to some attacks namely amplify, invert, low pass filtering, high pass filtering, and resampling attacks at higher watermark intensity. Thus, this research proved the trade-off between perceptibility and robustness in digital audio watermarking.
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Judul: Lejeuneaceae Subfamily Ptychanthoideae (Hepaticae) in  West Java
Abstrak: Subfamily Ptychanthoideae of the family Lejeuneaceae (Hepaticae) in West Java is still poorly known. Publications on this subfamily are out of dated and written in the 19th or early of 20th century. The last taxonomic treatment of Ptychanthoideae of West Java was in 1933, many species names have changed since then. Studies on Ptychanthoideae of West Java are urgently needed. Studies on the Ptychanthoideae were based on the specimens collected from West Java. A total number of 361 of specimens deposited in the Herbarium Bogoriense (BO), Herbarium Biotrop (BIOT), Gottingen Herbarium (GOET) and Bangi Herbarium (UKMB) were examined, those are old and several recent specimens collected in West Java. Recent collections were made from Telaga Warna, Ciater, Gunung Halimun Salak National Park, Cibodas Botanical Garden, Bodogol Education Center and Conservation (Gunung Gede Pangrango National Park), University of Indonesia Campus Depok, including several collections from Banten Province. Twenty four species of Lejeuneaceae subfamily Ptychanthoideae are known from West Java, belonging to 8 genera namely Acrolejeunea (Spruce) Schiffn. (2 species), Archilejeunea (Spruce) Schiffn. (1 species), Lopholejeunea (Spruce) Schiffn. (10 species), Mastigolejeunea (Spruce) Schiffn. (3 species), Ptychanthus Nees (1 species), Schiffneriolejeunea Verd. (1 species), Spruceanthus Verd. (2 species) and Thysananthus Lindenb. (4 species). Two new records of Ptychanthoideae: Mastigolejeunea indica Steph. and Thysananthus minor Verdoorn are reported for Java. A determination key to the species is presented including their descriptions and illustrations.
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