• Review of KIISC
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• v.25 no.6
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• pp.47-52
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• 2015

최근에 모바일 장치 관련 정보 유출과 더불어 유출된 정보를 악용한 범죄가 빈번하게 일어남에 따라 정보호호에 대한 관심과 중요성이 높아지고 있다. 국내 모바일 장치 관련 사용자 수도 해를 거듭할수록 기하급수적으로 증가하고 있는 추세이며, 이에 따른 모바일 장치의 보안에 대한 중요성 역시 대두되고 있다. 그 중에서도 사용자 측의 모바일 잠금 기술인 비밀번호, PIN, 얼굴 인식 등의 기능을 활용하여 사용자 모바일 장치에 대한 암호 보안 기술을 적용하고 있다. 또한 사용자들의 개인정보를 다루는 서비스 이용이 증가함에 따라 모바일 장치 자체의 보안에 대한 안전한 처리 문제, 편리성, 효율성 등을 고려한 문제점이 대두되고 있다. 본 지에서는 사용자 모바일 장치 잠금 관련 동향을 분석하고, 이와 관련된 모바일 장치 잠금 어플리케이션의 한계점에 대해서 살펴본다. 또한 현 모바일 장치 잠금 시스템이 직면하는 보안성과 편의성의 한계점을 보완하기 위한 위치 정보 기반의 모바일 장치 보안 시스템을 제안한다.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.3
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• pp.200-205
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• 2015

An ultra-precise infrared microscope consisting of a high-resolution infrared objective lens and infrared sensors is utilized successfully to obtain location information on the plane and depth of local heat sources causing defects in a semiconductor device. In this study, multi-layer semiconductor chips are analyzed for the positional information of heat sources by using a lock-in infrared microscope. Optimal conditions such as focal position, integration time, current and lock-in frequency for measuring the accurate depth of the heat sources are studied by lock-in thermography. The location indicated by the results of the depth estimate, according to the change in distance between the infrared objective lens and the specimen is analyzed under these optimal conditions.

• Journal of the Korea Convergence Society
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• v.11 no.3
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• pp.45-52
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• 2020

In this study, we propose a new Relative position pattern unlocking solution based on blind interaction, which is a new unlocking method, and compared it with existing unlocking methods to verify usability and security improvement. And verified the practical value of the proposed new unlocking solution. The relative position pattern unlock method is easily remembered than the numeric code method and is worth practical enough to show a degree of learning ease similar to the drawing pattern method. The new method is safer to steal than other two methods. It can be manufactured at a low cost and can also be used by special users such as blind people. Therefore, the practical value is relatively high.

• Journal of the Korean Society for Nondestructive Testing
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• v.27 no.4
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• pp.321-327
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• 2007

In lock-in thermography, a phase difference between the defect area and the healthy area indicates the qualitative location and size of the defect. To accurately estimate these parameters, the shearing-phase technique has been employed which gives the shearing-phase distribution. The shearing-phase distribution has maximum, minimum, and zero points that help determine quantitatively the size and location of the subsurface defect. In experiment, the proposed technique is verified with artificial specimen and these related factors are analyzed.

• Korean Journal of Optics and Photonics
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• v.26 no.6
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• pp.312-317
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• 2015

We investigate the effect of laser-resonator mode size on the output of a Yb:YAG laser that is mode-locked by a semiconductor saturable absorber mirror (SESAM). We demonstrate that the smaller the product of the mode sizes at a SESAM and at a Yb:YAG crystal, the more stable the mode-locked output is. Also, we found numerically that there is a resonator length at which the mode-locked output occurs, regardless of the thermal lens effect of a Yb:YAG.

• Proceedings of the Korean Society of Computer Information Conference
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• 2010.07a
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• pp.421-423
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• 2010

본 논문에서는 ART2 알고리즘을 이용하여 잠금 상태에서 스마트폰의 어플리케이션을 쉽고 빠르게 구동하기 위한 방법을 제안한다. 자신이 원하는 그림과 설치되어 있는 어플리케이션과의 대응 테이블을 만들기 위하여 학습 어플리케이션을 실행한다. 학습 어플리케이션의 동작 순서는 어플리케이션 실행 후 화면 하단에서 빠른 실행을 하고자 하는 어플리케이션을 선택하고 좌측상단에 위치하고 있는 입력 부분에 그림을 그린 후, 학습 버튼을 클릭한다. 그려진 그림의 배경은 0으로 그림은 1로 변환하고 ART2의 입력으로 사용할 수 있도록 일정한 크기로 정규화한다. 정규화 된 데이터를 팽창 연산을 통하여 학습에 용이하도록 최외각 픽셀을 확장하여 ART2의 입력 데이터로 적용한다. 학습이 끝난 후, 잠금 상태에서 액정 윗부분에 학습된 것과 같은 모양의 그림을 그리면 해당 어플리케이션이 실행된다. 제안된 방법은 기존의 방식인 잠금 해제 후, 어플리케이션을 탐색하고, 해당 어플리케이션을 실행하는 3 단계로 된 방식을 1 단계로 줄이기 때문에 원하는 어플리케이션을 실행하는데 시간이 적게 소요되는 장점이 있다.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.2
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• pp.91-97
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• 2010

This paper proposes method to evaluate the location and size of the internal defects of metallic specimens by the shearing phase lock-in infrared thermography. Until now, infrared thermography test for metal specimen of STS304 and Cu-Zn were conducted to find the best test conditions. However, In unspecified situation of the form and existence of defects, there was a disadvantage to takes a long time for finding the optimal experimental conditions. The defect detection and evaluation was performed at 60 MHz signal using lock-in and shearing-phase method under limited heating conditions. By shearing-phase distribution method, Defects for the maximum, minimum and zero points were quantitatively detected at the size and location of the subsurface. As results, application of the proposed technique was verified for STS304 and Cu7-Zn3 with artificial defect and factors affected defect evaluation were searched and analyzed.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.2
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• pp.104-109
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• 2010

Lap joint friction stir welding(LFSW) is an relatively new solid state joining process. A6061-T6 aluminium alloy has gathered wide acceptance in the fabrication of light weight structures requiring a high strength to weight ratio and good corrosion resistance. Test methods used in this paper, lock-in thermography, a phase difference between the defect area and the healthy area indicates the qualitative location and size of the defect. In this paper, the defects detected from the thermal image of mechanical properties for weld were evaluated and compared by the lock-in infrared thermography technique.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.10
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• pp.1228-1233
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• 2019

Recently, a variety of algorithms using encryption technology have been adopted as methods of unlocking smartphone. It is advancing toward the direction to solve the unlocking problem through human biometrics technology, which has already succeeded in commercializing. These include finger print recognition, face recognition, and iris recognition. In this study, the evaluation items are five algorithms, including finger print recognition, face recognition, iris recognition, pattern recognition, and password input method. Based on the algorithms adopted, the AHP (analytic hierarchy process) technique was used to calculate the preferred priorities for smartphone users. Finger print recognition ( .400) was the top priority for smartphone users. Next, pattern recognition ( .237) was placed in the second priority for smartphone users. Therefore, based on the results of the analysis, the limitations of the study and theoretical implications are suggested.

• The Research Journal of the Costume Culture
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• v.10 no.2
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• pp.178-185
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• 2002

The purpose of this study was to measure distribution of clothing pressure on breast in brassiere according to body shape and motion, and the position of hook-and-eye on brassiere, and to get basic data for comfortable brassiere design. Clothing pressure was measured from 8 female subjects under wearing trials in climatic chamber. When brassiere was tied together with inner or outer hook-and-eye, clothing pressure under the condition were 10.2 and 9.6 gf/cm², respectively. With the degree between main body and arms increased from 0° to 45° and 90°to the front, clothing pressure decreased from 10.2 to 9.6 gf/cm², and then increased to 10.4 gf/cm² When the decree was increased from 45° to 70° to the flank, the pressure increased from 9.3 to 10.6 gf/cm². Fat body shape recorded 10.8 gf/cm², and lean body shape recorded 9.5 gf/cm² of clothing pressure by wearing brassiere. Clothing pressures of brassiere were 7.8g gf/cm² in front, 9.5 gf/cm² in side, 12.8 gf/cm² in the back side. Therefore, clothing pressure of brassiere was influenced to the greater extent by body shape and measuring points on human body than by the position of hook-and-eye and body motion.