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Object Watermarking for MPEG-4 Video Protection
Roberto Caldelli,Mauro Barni,Franco Bartolini,Alessandro Piva 에스케이텔레콤 (주) 2002 Telecommunications Review Vol.12 No.5
The MPEG-4 standard is appearing to be very attractive for a large set of applications. In most of them, such as video distribution over mobile and fixed open networks, a copy protection system allowing to control and trace the delivery of multimedia data is required. A new technology useful for copyright protection and media identification is watermarking: a digital code (watermark), bringing information about the copyright owner, is directly embedded into the video signal without degrading its quality. The possibility of the MPEG-4 standard to directly access objects within a video sequence, introduces some new constraints to the classic watermarking process. Further to the classical requirements regarding video watermarking, two features appear to be important in the framework of MPEG-4 applications: first of all, object watermarking should be dealt with, second, the possibility to identify the presence of watermarked objects also after the video sequence has been encoded in another format should be granted. The method proposed in this paper satisfies the two previous requirements by relying on an image watermarking algorithm which embeds the code directly in the video objects. The watermark is inserted by modifying some Discrete Wavelet Transform (DWT) coefficients of the Video Objects extracted from each frame of the video sequence.
Tribst, Joao Paulo Mendes,Dal Piva, Amanda Maria de Oliveira,Borges, Alexandre Luiz Souto,Rodrigues, Vinicius Aneas,Bottino, Marco Antonio,Kleverlaan, Cornelis Johannes The Korean Academy of Prosthodonitics 2020 The Journal of Advanced Prosthodontics Vol.12 No.2
PURPOSE. This study evaluated the influence of prosthesis weight and number of implants on the bone tissue microstrain. MATERIALS AND METHODS. Fifteen (15) fixed full-arch implant-supported prosthesis designs were created using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15, 20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elements formed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior. The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implant interface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along the Z-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria. RESULTS. The prosthesis weight was related to the bone strain. The more implants installed, the less the amount of strain generated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with the largest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce bone remodeling simply due to the prosthesis weight. CONCLUSION. Heavier prostheses under the effect of gravity force are related to more strain being generated around the implants. Installing more implants to support the prosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generate harmful values of peri-implant bone strain.
da Rocha, Daniel Maranha,Tribst, Joao Paulo Mendes,Ausiello, Pietro,Dal Piva, Amanda Maria de Oliveira,Rocha, Milena Cerqueira da,Di Nicolo, Rebeca,Borges, Alexandre Luiz Souto The Korean Academy of Conservative Dentistry 2019 Restorative Dentistry & Endodontics Vol.44 No.3
Objectives: To evaluate the influence of the restorative technique on the mechanical response of endodontically-treated upper premolars with mesio-occluso-distal (MOD) cavity. Materials and Methods: Forty-eight premolars received MOD preparation (4 groups, n = 12) with different restorative techniques: glass ionomer cement + composite resin (the GIC group), a metallic post + composite resin (the MP group), a fiberglass post + composite resin (the FGP group), or no endodontic treatment + restoration with composite resin (the CR group). Cusp strain and load-bearing capacity were evaluated. One-way analysis of variance and the Tukey test were used with ${\alpha}=5%$. Finite element analysis (FEA) was used to calculate displacement and tensile stress for the teeth and restorations. Results: MP showed the highest cusp (p = 0.027) deflection ($24.28{\pm}5.09{\mu}m/{\mu}m$), followed by FGP ($20.61{\pm}5.05{\mu}m/{\mu}m$), CR ($17.62{\pm}7.00{\mu}m/{\mu}m$), and GIC ($17.62{\pm}7.00{\mu}m/{\mu}m$). For load-bearing, CR ($38.89{\pm}3.24N$) showed the highest, followed by GIC ($37.51{\pm}6.69N$), FGP ($29.80{\pm}10.03N$), and MP ($18.41{\pm}4.15N$) (p = 0.001) value. FEA showed similar behavior in the restorations in all groups, while MP showed the highest stress concentration in the tooth and post. Conclusions: There is no mechanical advantage in using intraradicular posts for endodontically-treated premolars requiring MOD restoration. Filling the pulp chamber with GIC and restoring the tooth with only CR showed the most promising results for cusp deflection, failure load, and stress distribution.
Daniel Maranha da Rocha,João Paulo Mendes Tribst,Pietro Ausiello,Amanda Maria de Oliveira Dal Piva,Milena Cerqueira da Rocha,Rebeca Di Nicoló,Alexandre Luiz Souto Borges 대한치과보존학회 2019 Restorative Dentistry & Endodontics Vol.44 No.3
Objectives: To evaluate the influence of the restorative technique on the mechanical response of endodontically-treated upper premolars with mesio-occluso-distal (MOD) cavity. Materials and Methods: Forty-eight premolars received MOD preparation (4 groups, n = 12) with different restorative techniques: glass ionomer cement + composite resin (the GIC group), a metallic post + composite resin (the MP group), a fiberglass post + composite resin (the FGP group), or no endodontic treatment + restoration with composite resin (the CR group). Cusp strain and load-bearing capacity were evaluated. One-way analysis of variance and the Tukey test were used with α = 5%. Finite element analysis (FEA) was used to calculate displacement and tensile stress for the teeth and restorations. Results: MP showed the highest cusp (p = 0.027) deflection (24.28 ± 5.09 µm/µm), followed by FGP (20.61 ± 5.05 µm/µm), CR (17.72 ± 6.32 µm/µm), and GIC (17.62 ± 7.00 µm/µm). For load-bearing, CR (38.89 ± 3.24 N) showed the highest, followed by GIC (37.51 ± 6.69 N), FGP (29.80 ± 10.03 N), and MP (18.41 ± 4.15 N) (p = 0.001) value. FEA showed similar behavior in the restorations in all groups, while MP showed the highest stress concentration in the tooth and post. Conclusions: There is no mechanical advantage in using intraradicular posts for endodontically-treated premolars requiring MOD restoration. Filling the pulp chamber with GIC and restoring the tooth with only CR showed the most promising results for cusp deflection, failure load, and stress distribution.
Park, Hyun Jung,Oh, Sung,Vinod, Nagarajan,Ji, Seongmi,Noh, Han Byul,Koo, Jung Mo,Lee, Su Hyeong,Kim, Sei Chang,Lee, Ki-Sung,Choi, Chang Won,Piva, Terrence MDPI 2016 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.17 No.11
<P>Acellular bacterial ghosts (BGs) are empty non-living bacterial cell envelopes, commonly generated by controlled expression of the cloned lysis gene <I>E</I> of bacteriophage PhiX174. In this study, <I>Vibrio parahaemolyticus</I> ghosts (VPGs) were generated by chemically-induced lysis and the method is based on minimum inhibitory concentration (MIC) of sodium hydroxide (NaOH), acetic acid, boric acid, citric acid, maleic acid, hydrochloric acid, and sulfuric acid. The MIC values of the respective chemicals were 3.125, 6.25, <50.0, 25.0, 6.25, 1.56, and 0.781 mg/mL. Except for boric acid, the lysis efficiency reached more than 99.99% at 5 min after treatment of all chemicals. Among those chemicals, NaOH-induced VPGs appeared completely DNA-free, which was confirmed by quantitative real-time PCR. Besides, lipopolysaccharides (LPS) extracted from the NaOH-induced VPGs showed no distinctive band on SDS-PAGE gel after silver staining. On the other hand, LPS extracted from wild-type bacterial cells, as well as the organic acids-induced VPGs showed triple major bands and LPS extracted from the inorganic acids-induced VPGs showed double bands. It suggests that some surface structures in LPS of the NaOH-induced VPGs may be lost, weakened, or modified by the MIC of NaOH. Nevertheless, <I>Limulus amoebocyte</I> lysate assay revealed that there is no significant difference in endotoxic activity between the NaOH-induced VPGs and wild-type bacterial cells. Macrophages exposed to the NaOH-induced VPGs at 0.5 × 10<SUP>6</SUP> CFU/mL showed cell viability of 97.9%, however, the MIC of NaOH did not reduce the cytotoxic effect of wild-type bacterial cells. Like <I>Escherichia coli</I> LPS, the NaOH-induced VPGs are an excellent activator of pro-inflammatory cytokines (IL-1β and iNOS), anti-inflammatory cytokine (IL-10), and dual activities (IL-6) in the stimulated macrophage cells. On the other hand, the induction of TNF-α mRNA was remarkable in the macrophages exposed with wild-type cells. Scanning electron microscopy showed the formation of trans-membrane lysis tunnel structures in the NaOH-induced VPGs. SDS-PAGE and agarose gel electrophoresis also confirmed that cytoplasmic proteins and genomic DNA released from the VPGs to culture medium through the lysis tunnel structures. Taken together, all these data indicate that the NaOH-induced VPGs show the potency of a safe, economical, and effective inactivated bacterial vaccine candidate.</P>