• Journal of Korea Society of Industrial Information Systems
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• v.22 no.4
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• pp.1-9
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• 2017

In this Paper, Double Encryption Technology Based on Phase-Shifting Digital Holography and Digital Watermarking is Proposed. For the Purpose, we First Set a Logo Image to be used for Digital Watermark and Design a Binary Phase Computer Generated Hologram for this Logo Image using an Iterative Algorithm. And Random Generated Binary Phase Mask to be set as a Watermark and Key Image is Obtained through XOR Operation between Binary Phase CGH and Random Binary Phase Mask. Object Image is Phase Modulated to be a Constant Amplitude and Multiplied with Binary Phase Mask to Generate Object Wave. This Object Wave can be said to be a First Encrypted Image Having a Pattern Similar to the Noise Including the Watermark Information. Finally, we Interfere the First Encrypted Image with Reference Wave using 2-step PSDH and get a Good Visible Interference Pattern to be Called Second Encrypted Image. The Decryption Process is Proceeded with Fresnel Transform and Inverse Process of First Encryption Process After Appropriate Arithmetic Operation with Two Encrypted Images. The Proposed Encryption and Decryption Process is Confirmed through the Computer Simulations.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.249-250
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• 2006

In this paper, hardware design and implementation of digital controller for the High Precision Digital Power Supply (HPDPS) based on Digital Signal Processor (DSP) and Field Programmable Gate Array (FPGA) is presented. Developed digital controller is composed of high resolution Digital Pulse Width Modulation (DPWM) and high resolution analog to digital converter circuit with anti-aliasing filter. And Digital Signal Processor (DSP) has the capability of a few micro-second calculation time for one feedback loop. 32-bit DSP and DPWM with 150[ps] step resolution is used to implement the HPDPS. Also 18-bit 2 mega sample per second ADC board is adopted for the developed digital controller. Also, hardware structure of the developed digital controller and experimental results of the first prototype board for HPDPS is described.

• Educational Technology International
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• v.16 no.1
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• pp.58-83
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• 2015

Digital textbooks draw attention as a new format of educational material, using the advantages of information technology; this innovative learning tool requires consideration as a part of successful and effective learning. The main purpose of the article is to investigate the mediating role of self-regulation between digital literacy and learning outcomes (academic performance and learning motivation) when using digital textbooks as a learning tool in Middle School English. Both descriptive and regression analysis were used as data analyses methods. The main findings of this study were as follows: first, digital literacy and self-regulation significantly predicted academic performance and learning motivation; second, self-regulation fully mediated between digital literacy and academic performance; third, self-regulation partially mediated between digital literacy and learning motivation. The research results proved the effects of digital literacy and self-regulation on the learning outcomes and mediating role of self-regulation between digital literacy and learning outcomes. These results help to design and implement effective lessons when using a digital textbook in Middle school English.

• The Research Journal of the Costume Culture
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• v.29 no.3
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• pp.422-436
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• 2021

The fashion industry analyzes the value of its essence with ecological design and is expressed as an innovative sculpture using digital technology. Accordingly, this study explores ecological images and digital technologies, categorizes types and derives their meanings through analysis of ecological images shown in modern digital fashion. A literature survey was conducted on ecological images and digital technology as a theoretical background. To analyze the expression type and internal meanings of ecological images, designs with ecological formability were selected and analyzed from related journals, books, and internet sites. The finding are as follows: The expression type was first identified as organic curved garment silhouettes of a non-material liquid with digital retouching. Second, ecological fashion design includes structural shape that applies the silhouette of an organism and patterning of the ecosystem. Third, ecosystems consist of interactions between components of an ecosystem that appear in the interactive type. Accordingly, the internal meanings of ecological images in modern digital fashion are: first, digital fashion can encircle the inherent concepts of nature as organic collections of individuals; second, digital ecological images emphasize a sense of community with coexistence and harmony, playing a complementary role; and finally, the images express perceptual features by providing people with transcendent experiences. This study is significant as it analyzes new formative features based on ecological systems in the digital fashion environment, establishes an aesthetic system through internal meanings, and enhances awareness of human-natural relationships.

• Journal of Information Technology Applications and Management
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• v.28 no.5
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• pp.17-39
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• 2021

Indonesia's industrial application of digital technology is growing fast, especially in the application of mobile technology. About 1,700 digital startups are sprouting. PT Aplikasi Karya Anak Bangsa is one of those digital startups founded in 2010. This company is widely known, especially in Southeast Asia, for its products and services called 'Gojek' which was launched initially in 2015. Gojek began as a ride-hailing mobile-based application that later evolved into a Super App providing more than 20 different services in one single mobile application. After becoming Indonesian first unicorn company in 2016, Gojek now has become the first decacorn company in Indonesia, worth more than USD 10 billion since 2019. This paper aims to analyzes the technology industry in Indonesia and analyzes Gojek's background and history, its competitive status, and critical success factors. As a conclusion, we provide some advices for future development of Gojek in Indonesia and other countries in Southeast Asia's market. The advices include rebranding its overseas presence and the use of consistent brand identity across countries.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1159-1169
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• 2013

EQM Model Digital transponder applying the Korean's own designing and manufacturing technology has gone through a series of trials and errors during the development. In particular, lack of thermal designs expedience for the vacuum causes variety of errors in designing, assembling transponder and setting up the test at the first thermal vacuum test (TVAC). Since the first TVAC test could not accomplished its aims successfully, so the second TVAC should be performed as make up test with revised Digital transponder. In this paper, the defects that identified in the first TVAC are analyzed and applied solutions and its results at the second TVAC are presented. Using the lessons from the first and second TVAC, we will be able to make more reliable digital transponders in the next phase of project. In addition it also be useful as a reference when we design another satellite payloads.

• Imaging Science in Dentistry
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• v.46 no.3
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• pp.179-184
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• 2016

Purpose: In the present study, we coined the term 'alveolar dome' and aimed to demonstrate the prevalence of alveolar domes through digital periapical radiographs. Materials and Methods: This study examined 800 digital periapical radiographs in regard to the presence of alveolar domes. The periapical radiographs were acquired by a digital system using a photostimulable phosphor (PSP) plate. The ${\chi}^2$ test, with a significance level of 5%, was used to compare the prevalence of alveolar domes in the maxillary posterior teeth and, considering the same teeth, to verify the difference in the prevalence of dome-shaped phenomena between the roots. Results: The prevalence of alveolar domes present in the first pre-molars was statistically lower as compared to the other maxillary posterior teeth (p<0.05). No statistically significant difference was observed in the prevalence of alveolar domes between the maxillary first and second molars. Considering the maxillary first and second molars, it was observed that the palatal root presented a lower prevalence of alveolar domes when compared to the distobuccal and mesiobuccal roots (p<0.05). Conclusion: The present study coined the term 'alveolar dome', referring to the anatomical projection of the root into the floor of the maxillary sinus. The maxillary first and second molars presented a greater prevalence of alveolar domes, especially in the buccal roots, followed by the third molars and second pre-molars. Although the periapical radiograph is a two-dimensional method, it can provide dentists with the auxiliary information necessary to identify alveolar domes, thus improving diagnosis, planning, and treatment.

• The korean journal of orthodontics
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• v.46 no.3
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• pp.171-179
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• 2016

Objective: The primary aim of the study was to generate new prediction equations for the estimation of maxillary and mandibular canine and premolar widths based on mandibular incisors and first permanent molar widths. Methods: A total of 2,340 calculations (768 based on the sum of mandibular incisor and first permanent molar widths, and 1,572 based on the maxillary and mandibular canine and premolar widths) were performed, and a digital stereomicroscope was used to derive the the digital models and measurements. Mesiodistal widths of maxillary and mandibular teeth were measured via scanned digital models. Results: There was a strong positive correlation between the estimation of maxillary (r = 0.85994, $r^2=0.7395$) and mandibular (r = 0.8708, $r^2=0.7582$) canine and premolar widths. The intraclass correlation coefficients were statistically significant, and the coefficients were in the strong correlation range, with an average of 0.9. Linear regression analysis was used to establish prediction equations. Prediction equations were developed to estimate maxillary arches based on $Y=15.746+0.602{\times}sum$ of mandibular incisors and mandibular first permanent molar widths (sum of mandibular incisors [SMI] + molars), $Y=18.224+0.540{\times}(SMI+molars)$, and $Y=16.186+0.586{\times}(SMI+molars)$ for both genders, and to estimate mandibular arches the parameters used were $Y=16.391+0.564{\times}(SMI+molars)$, $Y=14.444+0.609{\times}(SMI+molars)$, and $Y=19.915+0.481{\times}(SMI+molars)$. Conclusions: These formulas will be helpful for orthodontic diagnosis and clinical treatment planning during the mixed dentition stage.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.3
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• pp.273-281
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• 2001

Digital subtraction radiography may be one of the most precise and noninvasive methods for assessing subtle density changes in peri-implant bone, providing additional diagnostic information on implant tissue integration in overall maintenance. The aims of this study were to evaluate density changes after first, second surgery of dental implant and to measure the amount of marginal bone loss 9 months after second surgery using digital subtraction radiography. Bone change around 30 screw-shaped implants in 16 patients were assessed on radiographs. 17 Branemark implants of 3.75mm in diameter(Nobel Biocare, Goteborg, Sweden), 2 Branemark implants of 5.0mm in diameter, 11 $Replace^{TM}$ implants of 4.3mm in diameter(Nobel Biocare, Goteborg, Sweden) were used. To standardize the projection geometry of serial radiographs of implants, customized bite block was fabricated using XCP film holder(Rinn Corporation, Elgin, IL.) with polyether impression material of Impregum(ESPE, Germany) and direct digital image was obtained. Qualitative and quantitative changes on radiographs were measured with Emago software(The Oral Diagnostic System, Amsterdam, Netherlands). The results were as follows: 1. The peri-implant bone density of 69.2% implants did not change and the peri-implant bone density of 30.8% implants decreased after 3 months following first surgery. 2. The crestal bone density of 53.9% implants decreased first 3 months after second surgery. The crestal bone density of 58.8% implants increased 9 months after second surgery. No density change was observed around the midportion of the implants after second surgery, 3. The amount of marginal bone loss between different kinds of implants showed no statistically significant differences (p>0.05). 4. More than 90% of total marginal bone loss recorded in a 9-month period occurred during the first 3 months.

• The KIPS Transactions:PartB
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• v.13B no.2 s.105
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• pp.83-88
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• 2006

Digital image processing algorithm was proposed to measure the area inside of an object image using angle-distance graph used to analyze the pattern of an object in the digital image processing techniques. The first angle-distance graph is generated from a point inside of an object area. The second angle-distance graphs are generated for the areas missed in the first graph by extracting the positions with large gradient in the first angle-distance graph. The order of the graph increases according to the complexity of an object pattern. Size of the area inside of an object boundary is measured by integrating square of distance multiplied by angle for each area from the hierarchical angie-distance graphs.