• Current Optics and Photonics
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• v.8 no.1
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• pp.1-15
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• 2024

This paper presents a brief introduction to self-interference incoherent digital holography (SIDH). Holography conducted under incoherent light conditions has various advantages over digital holography performed with a conventional coherent light source. We categorize the methods for SIDH, which divides the incident light into two waves and modulates them differently. We also explore various optical concepts and techniques for the implementation and advancement of SIDH. This review presents the system design, performance analysis, and improvement of SIDH, as well as recent applications of SIDH, including optical sectioning and deep-learning-based SIDH.

• Journal of Smart Tourism
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• v.4 no.1
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• pp.19-29
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• 2024

The objective of this article is to create a model of integrated management from the framework modeling of a digital collaborative network supported by knowledge engineering to make heritage site in the Brazil more effective. It is an exploratory and qualitative research with thematic analysis as technique of data analysis from the collaborative network, digital platform, world heritage, and tourism themes. The snowballing approach was chosen, and the mapping and classification of relevant studies was developed with the use of the spreadsheet tool and the Mendeley® software. The results show that the collaborative network model oriented towards strategic objectives should be supported by a digital platform that provides a technological environment that adds functionalities and digital platform services with the integration of knowledge engineering techniques and tools, enabling the discovery and sharing of knowledge in the collaborative network.

• Journal of Information Processing Systems
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• v.13 no.3
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• pp.599-617
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• 2017

Due to the rapid growth and expansion of the Internet, the digital multimedia such as image, audio and video are available for everyone. Anyone can make unauthorized copying for any digital product. Accordingly, the owner of these products cannot protect his ownership. Unfortunately, this situation will restrict any improvement which can be done on the digital media production in the future. Some procedures have been proposed to protect these products such as cryptography and watermarking techniques. Watermarking means embedding a message such as text, the image is called watermark, yet, in a host such as a text, an image, an audio, or a video, it is called a cover. Watermarking can provide and ensure security, data authentication and copyright protection for the digital media. In this paper, a new watermarking method of still image is proposed for the purpose of copyright protection. The procedure of embedding watermark is done in a transform domain. The discrete cosine transform (DCT) is exploited in the proposed method, where the watermark is embedded in the selected coefficients according to several criteria. With this procedure, the deterioration on the image is minimized to achieve high invisibility. Unlike the traditional techniques, in this paper, a new method is suggested for selecting the best blocks of DCT coefficients. After selecting the best DCT coefficients blocks, the best coefficients in the selected blocks are selected as a host in which the watermark bit is embedded. The coefficients selection is done depending on a weighting function method, where this function exploits the values and locations of the selected coefficients for choosing them. The experimental results proved that the proposed method has produced good imperceptibility and robustness for different types of attacks.

• Journal of Information Processing Systems
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• v.14 no.2
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• pp.346-376
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• 2018

Digital forensics is a vital part of almost every criminal investigation given the amount of information available and the opportunities offered by electronic data to investigate and evidence a crime. However, in criminal justice proceedings, these electronic pieces of evidence are often considered with the utmost suspicion and uncertainty, although, on occasions are justifiable. Presently, the use of scientifically unproven forensic techniques are highly criticized in legal proceedings. Nevertheless, the exceedingly distinct and dynamic characteristics of electronic data, in addition to the current legislation and privacy laws remain as challenging aspects for systematically attesting evidence in a court of law. This article presents a comprehensive study to examine the issues that are considered essential to discuss and resolve, for the proper acceptance of evidence based on scientific grounds. Moreover, the article explains the state of forensics in emerging sub-fields of digital technology such as, cloud computing, social media, and the Internet of Things (IoT), and reviewing the challenges which may complicate the process of systematic validation of electronic evidence. The study further explores various solutions previously proposed, by researchers and academics, regarding their appropriateness based on their experimental evaluation. Additionally, this article suggests open research areas, highlighting many of the issues and problems associated with the empirical evaluation of these solutions for immediate attention by researchers and practitioners. Notably, academics must react to these challenges with appropriate emphasis on methodical verification. Therefore, for this purpose, the issues in the experiential validation of practices currently available are reviewed in this study. The review also discusses the struggle involved in demonstrating the reliability and validity of these approaches with contemporary evaluation methods. Furthermore, the development of best practices, reliable tools and the formulation of formal testing methods for digital forensic techniques are highlighted which could be extremely useful and of immense value to improve the trustworthiness of electronic evidence in legal proceedings.

• The Journal of Advanced Prosthodontics
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• v.15 no.1
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• pp.22-32
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• 2023

PURPOSE. Digital technology has enabled improvements in the fitting accuracy of denture bases via milling techniques. The aim of this study was to evaluate the trueness and precision of digital and analog techniques for manufacturing complete dentures (CDs). MATERIALS AND METHODS. Sixty identical CDs were manufactured using different production protocols. Digital and analog technologies were compared using the reference geometric approach, and the Δ-error values of eight areas of interest (AOI) were calculated. For each AOI, a precise number of measurement points was selected according to sensitivity analyses to compare the Δ-error of trueness and precision between the original model and manufactured prosthesis. Three types of statistical analysis were performed: to calculate the intergroup cumulative difference among the three protocols, the intergroup among the AOIs, and the intragroup difference among AOIs. RESULTS. There was a statistically significant difference between the dentures made using the oversize process and injection molding process (P < .001), but no significant difference between the other two manufacturing methods (P = .1227). There was also a statistically significant difference between the dentures made using the monolithic process and the other two processes for all AOIs (P = .0061), but there was no significant difference between the other two processes (P = 1). Within each group, significant differences among the AOIs were observed. CONCLUSION. The monolithic process yielded better results, in terms of accuracy (trueness and precision), than the other groups, although all three processes led to dentures with Δ-error values well within the clinical tolerance limit.

• Journal of The Korean Digital Architecture Interior Association
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• v.13 no.4
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• pp.5-12
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• 2013

Conceptual and technical design designated as digital architecture has been discussed with disorderly meaning as a conception only. Thus, this study aims at verification of development possibility for the digital architecture by analyzing how works of Frank Gehry have effect on nonlinearity of the digital architecture. Nonlinear characteristics appeared on works of Frank Gehry analyzed on the basis of expression techniques and modeling principle are as follows: 1) Initial works show a trend to gradually change and develop from horizontal and vertical linear structure to nonlinear pattern. 2) From a nonlinear modeling principle, initial works appear the primary deformation elements only, while afterwards, they are gradually developing to a pattern to mix the primary and secondary deformation elements as introduction of digital architecture. 3) Through specific cases, Frank Gehry has conducted attempts with various method for nonlinear pattern expression. 4) From the initial works to the latest works, continuity becomes higher and changed to nonlinear pattern. This study is significant from a viewpoint that it has verified development possibility of digital architecture by analyzing nonlinear trend of digital architecture for Frank Gehry and it is required to conduct multilateral researches related to the digital architecture.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1505-1511
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• 2012

Since digital hologram includes an amount of data as can be seen at the process of digitization, it is necessary that the data representing digital hologram is reduced for storing, transmission, and processing. As the efforts that are to handle hologram with a type of digital information have been increased, various methods to compress digital hologram called by fringe pattern are groped. Suitable proposal is encoding of digital hologram. This paper analyzed the properties of digital hologram using tools of frequency transform, assuming that a generated digital hologram is a 2D image by introducing Fresnel Transform. The analysis results of digital hologram to be proposed in this paper are being expected to be used as the core techniques for an encoding of digital hologram.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.295-300
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• 2015

In vocabulary recognition using an HMM model which models the prior distribution for the observation of a discrete probability distribution indicates the advantages of low computational complexity, but relatively low recognition rate. The Bayesian techniques to improve vocabulary recognition model, it is proposed using a convergence of two methods to improve recognition noise-canceling recognition. In this paper, using a convergence of the prior probability method and techniques of Bayesian posterior probability based on HMM remove noise and improves the recognition rate. The result of applying the proposed method, the recognition rate of 97.9% in vocabulary recognition, respectively.

• International Journal of Contents
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• v.16 no.2
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• pp.41-50
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• 2020

This paper presents Reflectance Transformation Imaging (RTI) as a tool to support the study of paintings and authentication. Manufacturing techniques of the artist are reviewed through the comparison between liberal perspectives and digital imaging techniques. In this study, RTI was applied to focus on the detailed textural information of eight paintings by Korean artist Lee Ji-ho. The RTI result visualizes shallow reliefs of brush strokes and different mediums on the surface technically enhanced through imaging filters, and these morphological textures on the surface act as a key factor in understanding the characteristics of the artist. The surface morphology and art criticism work as qualitative indicators to analyze the change of artistic techniques through time, and the usage of different mediums. The results of this study confirm that the RTI technique can be used as an analysis device in the study of paintings.

• Journal of Digital Contents Society
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• v.9 no.2
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• pp.187-192
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• 2008

This study carried out researches on the techniques which are applicable to express sense of depth in the process of producing lofty image contents, and it's verification. Techniques for expression of sense of depth are how to use highlight and shadow, how to use depth of field and lenses, and how to use camera motion, zoom and dolly. For the practical application in all cases, I examine the preference frequency, and most of the pictures that techniques are adapted are selected. As a result we can verify the way of using lenses is the most convenient way in the expression of 'sense of depth'.