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: Perbandingan teknik watermarking berbasis SVD, DCT-SVD, dan SVD-DCT pada video digital
Abstrak: With the advantages of digital video processing, digital video can be manipulated and distributed illegally by irresponsible parties. Such actions are detrimental to owners of digital video and violate the copyright of the digital video. One solution to overcome this problem is to apply the watermarking technique in digital video. Watermarking techniques can be performed in spatial domain, frequency domain and hybrid domain. In the spatial domain, one of the watermarking techniques can be performed using Singular Value Decomposition (SVD) as proposed by Liu-Tan. In the frequency domain, one of the watermarking techniques can be performed using Discrete Cosine Transform (DCT). In the hybrid domain, one of the watermarking technique can be done by combining SVD with DCT. In this paper, the author tries to apply the watermarking technique proposed by Liu-Tan on digital video in spatial domain and hybrid domain. There are two methods in the domain of hybrid that will be proposed, namely the transformation of DCT-SVD and SVD-DCT transformation. Three watermarking technique compared based on the PSNR value of the insertion, insertion time, the correlation value from extraction, extraction time, and the robustness. Attacks carried out in this study is the attack noise, filtering attack, attack rotations, and cropping attacks. The results showed that the watermarking technique proposed by Liu-Tan is applied to the hybrid domain would increase the value of PSNR and correlation values, but vulnerable to some attacks. In the hybrid domain, the transformation of SVD-DCT is better than DCT-SVD transformation.
Keyword: Watermarking, Digital video, SVD Transform, DCT Transform, Bogor Agricultural University, Institut Pertanian Bogor, IPB

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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