• 한국멀티미디어학회논문지
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• 제8권11호
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• pp.1510-1519
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• 2005

본 논문에서는 1차 인쇄물을 스캔한 영상에서는 워터마크를 검출하여 저작권 증명이 가능하고, 불법적인 도용을 의미하는 2차 인쇄물을 스캔한 영상에서는 워터마크가 검출되지 않도록 하여 위조 방지가 가능한 디지털 워터마킹 방법을 제안한다. 제안한 알고리즘은 화소값의 왜곡과 기하학적 왜곡에 강인하기 위하여 LPM(Log-Polar Map) 변환과 DFT(Discrete Fourier Transform) 변환을 사용한다. LPM 변환과정 에서 최대 표본반지름을 선택하여 워터마크 검출성능과 화질을 개선할 수 있었다. 또한 프린트-스캔 처리의 특성을 분석한 후, 프린트-스캔 처리가 DFT의 고주파 밴드에서 왜곡이 커진다는 점을 이용하여, 1차 인쇄물에서는 워터마크가 살아남고 2차 인쇄물에서는 워터마크가 깨어지는 주파수 밴드를 실험적으로 선택하여 워터마크를 삽입하였다. 실험 결과, 1차 인쇄물을 스캔한 영상에서는 유사도가 평균 6.13으로 임계 값 4.0 이상 검출되어 원본 증명이 가능하였고, 2차 인쇄물을 스캔한 영상에서는 유사도가 임계값 4.0 이하인 평균 2.76을 나타내어서 위조 영상임을 확인할 수 있었다.

• 한국멀티미디어학회논문지
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• 제21권8호
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• pp.1021-1026
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• 2018

3D SCAN enables easy human body measurement via a digital method in the process of film costume production which used to be done manually. Software-oriented computer graphic, which integrates 3D SCAN data in the process of manual film costume production, can induce quick and diverse design outcomes. While, 3D PRINT, which integrates computer graphic data in the process of manual film costume production, can automate the process of special costume production using a digital method. Integration of 3D Scan + Computer Graphic + 3D Print using integrated platforms for tailored costume production as developed in this study allows significant reduction of costume production period and costs. It also allows efficient integration of costume production outcomes in various industries related with OSMU contents in particular. In other words, using it, we can create a new business market that integrates multiple areas of film content, drama content and game content.

• Journal of Electrical Engineering and Technology
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• 제8권3호
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• pp.633-637
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• 2013

A wide range of applications for Foot Print Recognition System is discussed in this paper. The whole concept works under the principle that foot print is a parameter associated with biometrics that is very common as well as distinct. Its foremost application is at the government hospitals in the under developed and third world nations where there aren't the best of facilities. This system can be applied in the maternity ward of the hospitals for the identification or differentiation of the infants. Till date there has been no specialized system adopted for this purpose. The Foot Print Recognition System will overcome all the defects of any biometrics when applied here. Since the child will be very delicate for an iris scan and it will not be able to open its eyes wide or to correctly place its finger print on the sensor since the hands of a new born infant will be closed for a while. The Foot Print Recognition system can also be implemented in temples where there are cases of theft often reported. This can be used to grant access to the karpagraham of the deity by authorized users alone. These 2 applications of FPRS are discussed in this paper.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제12권5호
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• pp.229-236
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• 2023

3D 출력된 의료용 임플란트(implant) 부품은 보통 표면에 결함이 발생되므로, 출력 후 표면을 검사하는 과정이 필요하다. 자동화된 표면 검사를 수행하기 위해서는 임플란트를 3D 스캔하여 점군(point cloud)과 같은 스캔 모델로 복원하는 방법이 효과적이다. 스캔 모델을 구성할 때, 임플란트는 일반적인 3D 출력 제조 부품과 다른 특성들을 가지므로, 임플란트의 형태와 재료의 특성에 대한 고려가 필요하다. 본 논문에서는 의료용 임플란트 부품의 한 종류인 금속 bone-plate의 3D 출력물에 대해 스캔 모델로 복원하는 방법을 제안한다. 다각도의 시점에서 3D 스캔을 수행하여 다수의 부분 스캔 데이터를 생성한 뒤, 이들에 대해 정렬(alignment)과 정합(merging)을 수행하여 스캔 모델로 복원한다. 또한, 실험을 통해 스캔 모델로 복원하는 과정을 보인다.

• 정보처리학회논문지B
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• 제15B권4호
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• pp.307-314
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• 2008

본 논문에서는 이미지의 선에 대하여 워터마크 정보를 삽입 및 추출하는 기술을 제안한다. 기존의 워터마킹 기술이 이미지의 픽셀 밝기값을 이용하는 것과 달리 제안된 알고리즘은 이미지의 곡선들을 B-스프라인 곡선으로 모델화하여 B-스프라인 제어점을 추출하고 이를 주파수 영역으로 변환하여 워터마크를 삽입한다. 제어점에 Delaunay 삼각화를 적용하여 메시를 생성하고, 메시-스펙트럼 분석을 통하여 주파수 영역의 메시-스펙트럼 계수를 계산한다. 워터마크는 이 계수의 중간 주파수 성분에 스프레드 스펙트럼 방식으로 삽입한다. 워터마크가 삽입된 계수를 메시-스펙트럼 역변환을 통하여 제어점을 계산하고 이를 통하여 워터마크가 삽입된 B-스프라인 곡선을 재구성할 수 있다. 삽입된 워터마크는 원본 선 이미지를 사용하여 검출이 이루어진다. 먼저 대상 선 이미지를 B-스프라인 모델화하고 곡선의 굴곡점을 이용하여 원본 선 이미지와 동기화를 수행한다. 동기화된 이미지에서 워터마크 삽입과정과 같이 메시-스펙트럼 계수를 추출하고 원본 메시-스펙트럼 계수와의 차이값을 계산하여 워터마크를 추출한다. 마지막으로 랜덤 워터마크와 추정된 워터마크의 상관 계수를 계산하여 삽입된 워터마크를 확인할 수 있다. 실험을 통하여 제안된 워터마킹 알고리즘이 기존 알고리즘보다 기하학적 공격과 프린트-스캔 공격에 강인함을 보였다.

• Journal of Korean Dental Science
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• 제17권1호
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• pp.1-13
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• 2024

With the advances of digital scanning technology in dentistry, the interests in facial scanning in orthodontics have increased. There are many different manufacturers of facial scanners marketing to the dental practice. How do you know which one will work best for you? What questions should you be asking? We suggest a clinical guideline which may help you make an informed decision when choosing facial scanners. The characteristics of 7 facial scanners were discussed in this article. Here are some considerations for choosing a facial scanner. *Accuracy: For facial scanners to be of real value, having an appropriate camera resolution is necessary to achieve more accurate facial image representation. For orthodontic application, the scanner must create an accurate representation of an entire face. *Ease of Use: Scanner-related issues that impact their ease of use include type of light; scan type; scan time; file type generated by the scanner; unit size and foot print; and acceptance of scans by third-party providers. *Cost: Most of the expenses associated with facial scanning involve the fixed cost of purchase and maintenance. Other expenses include technical support, warranty costs, transmission fees, and supply costs. This article suggests a clinical guideline to make the right choice for facial scanner in orthodontics.

• Interaction and multiscale mechanics
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• 제3권2호
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• pp.173-191
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• 2010

Damage detection plays a very important role to the maintenance of bridge structures. Traditional damage detection methods are usually based on structural dynamic properties, which are acquired from pre-installed sensors on the bridge. This is not only time-consuming and costly, but also suffers from poor sensitivity to damage if only natural frequencies and mode shapes are concerned in a noisy environment. Recently, the idea of using the dynamic responses of a passing vehicle shows a convenient and economical way for damage detection of bridge structures. Inspired by this new idea and the well-established tap test in the field of non-destructive testing, this paper proposes a new method for obtaining the damage information through the acceleration of a passing vehicle enhanced by a tapping device. Since no finger-print is required of the intact structure, this method can be easily implemented in practice. The logistics of this method is illustrated by a vehicle-bridge interaction model, along with the sensitivity analysis presented in detail. The validity of the method is proved by some numerical examples, and remarks are given concerning the potential implementation of the method as well as the directions for future research.

• 대한치과의사협회지
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• 제58권11호
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• pp.700-712
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• 2020

The conventional mouthguard fabrication process consists of elastomeric impression taking and followed gypsum model making is now into intraoral scanning and direct mouthguard 3D printing with an additive manufacturing process. Also, dental professionals can get various diagnostic data collection such as facial scans, cone-beam CT, jaw motion tracking, and intraoral scan data to superimpose them for making virtual patient datasets. To print mouthguards, dental CAD software allows dental professionals to design mouthguards with ease. This article shows how to make 3D printed mouthguard step by step.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.332-334
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• 2009

This thesis puts forward a suggestion of measuring inner crack and center segregation in steel processing by using scanner and image processing with sulfur printer. This is a system to scan according to the program, to choose the size of the specimen and to press the 'Measurement' button, come to a check result, to send the result to the server, and to save the data and check the measurement result in web. To sum up, there are three points in this system.

• 산업기술연구
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• 제34권
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• pp.33-37
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• 2014

The current companion animal registration system is based on implanting microchip into animal body. Thus, the maintenance cost is high, and it may cause dangerous effect on the animal health. Moreover, it is very inconvenient in utilizing the information. This paper presents a pet registration and information providing system based on QR code for low cost and convenience in field application. The owner can simply register pet information on the web server, print the QR code and attach it to the pet. Any person can scan the QR code by smart phone, identify the information, and call the owner directly.