• 한국레이저가공학회지
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• 제11권1호
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• pp.1-6
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• 2008

We proposed new light guide panel (LGP) fabrication method exploiting laser-processed inner scatterers and surface pattern. The proposed method has achieved LGP performance improvement in both brightness and uniformity. The inner scatterers and surface pattern of grid type were fabricated with a 2nd harmonic Nd:YAG pulse laser engraving system and a $CO_2$ laser scanning system, respectively. In the implementation of LGP, inner scatterers was arranged in accordance with linear or curved pattern with changing density and surface pattern was engraved on the surface of an inner-scatterers embedded LGP. The increase of scatterers' density and the use of surface patterns in both linear and curved pattern provided high luminance and uniformity enhancement. While thecurved pattern incorporated with increased scatterers' density and surface patterns yielded brightness improvement with preserving good uniformity, the linear pattern showed highly localized brightness near the light entrance of the LGP. We can also observe that the uniformity was mainly determined by pattern of inner scatterers, and the brightness was improved by the higher density and the utilization of surface patterns. From the results, the use of laser-processed inner and surface patterns can be a potential alternative for efficient and simple LGP fabrication method.

• 한국의류학회지
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• 제47권1호
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• pp.123-136
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• 2023

To develop smart sportswear capable of measuring biometric data, we created a close-fitting pattern using two- and three-dimensional (2D and 3D, respectively) methods. After 3D virtual fitting, the tightness of each pattern was evaluated using image processing of contact points, mesh deviation, and cross-sectional shapes. In contact-point analysis, the 3D pattern showed high rates of contact with the body (84.6% and 93.1% for shirts and pants, respectively). Compared with the 2D pattern, the 3D pattern demonstrated closer contact at the lower chest, upper arm, and thigh regions, where electrocardiography and electromyography were primarily carried out. The overall average gap was also lower in the 3D pattern (5.27 and 4.66 mm in shirts and pants, respectively). In the underbust, waist, thigh circumference, and mid-thigh circumference, the cross-section distance between clothing and body was showed a statistically significant difference and evenly distributed in the 3D pattern, exhibiting more closeness. The tightness and fit of the 3D smart sportswear sensor pattern were successfully evaluated. We believe that this study is critical, as it facilitates the comparison of different patterns through visualization and digitization through 3D virtual fitting.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1391-1394
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• 1997

This paper proposes a new image processing algorithm to recognize korean documents. It take out the region of text area form input image, then it makes esgmentation of lines, words and characters in the text. A precision segmentation is very important to recognize the input document. The input image has 8-bit gray scaled resolution. Not only the histogram but also brightness dispersion graph are used for segmentation. The result shows a higher accuracy of document recognition.

• 산업경영시스템학회지
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• 제22권50호
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• pp.11-21
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• 1999

In this paper, an algorithm to generate the mounting position and orientation of SMD is proposed. For the proposed algorithm, we used the image captured from PCB and utilized image processing technique. Pre-processing technique, threshold level determination method, divided recognition of the SMD pattern on a PCB, calculating mounting position and orientation are related topics of this research. All of the related topics were reviewed and the results of this research were obtained from applying the algorithm to the real Surface Mounting Machine(model:MCUl/CPM) made by Samsung Electronics Co.

• 한국생산제조학회지
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• 제22권1호
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• pp.77-84
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• 2013

In this paper, we review two-dimensional measuring methods referring to target patterns. The patterns consist of two linearly-repeated patterns or is designed repeatedly in two-dimension. The repeated properties are reflectivity, refractivity, air-gapping distance, capacitance, magnetic reluctance, electrical resistance and sloping gradient, etc. However, the optical methods are generally used for high speed processing and density, and their encoding principles are treated here. In case of two-dimensional pattern, as there is not inherently error between single units encoding the pattern except for the metrology frame errors, the end-effector position of an object accompanying the pattern can be measured with respect of the global frame without via error. Therefore, it is regarded as a substitute for laser interferometer with severe environmental constraints and has been applied to the high-accurate planar actuator.

• 정보처리학회논문지A
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• 제12A권7호
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• pp.589-596
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• 2005

임베디드 소프트웨어는 하드웨어 플랫폼에 탑재하기 전, 소스 코드에 대한 품질을 검증하는 작업이 매우 중요하다. 임베디드 소프트웨어의 코드 품질을 향상시키기 위해서는 분석 및 설계 단계의 모델에 대한 품질과 생성된 코드에 대한 품질이 관리되어야 한다. 본 연구에서는 임베디드 소프트웨어의 소스 코드 품질을 향상시키기 위한 방법으로 Practice Pattern을 제안한다. 이는 모델링 과정이나 코딩 과정에서 개발자를 가이드 하는 절차 패턴으로써, 모델의 품질과 소스 코드 품질을 향상시키는 방법으로 사용될 수 있다. 제시하는 패턴의 적용은 기능의 정확성뿐만 아니라 성능, 모듈화, 재사용성 및 이식성 등과 같은 품질 요소들을 향상시킬 수 있을 것으로 보인다.

• 정보처리학회논문지B
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• 제12B권3호
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• pp.283-290
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• 2005

워터마킹에서 영상의 평행이동, 회전, 크기변환 왜곡에 기인한 워터마크 삽입 위치와 추출 위치의 불일치는 해결해야 하는 문제이다. 본 논문에서는 복구패턴 정합을 통한 영상동기화를 이용함으로써 기하학적 왜곡에 강인한 워터마킹 방법을 제안한다. 제안하는 방법은 복구패턴을 정의하여 워터마크가 삽입된 영상에 복구패턴을 삽입 배포한다. 그리고 배포된 영상으로부터 복구패턴을 추출하여 삽입한 복구패턴과 비교함으로써 기하학적 왜곡 여부를 확인한다 기하학적 왜곡이 발생하였다면 왜곡된 만큼 역변환을 함으로써 워터마크 삽입 위치와 추출 위치를 동기화 한다. 제안한 방법의 성능을 평가하기 위하여 이동, 회전, 스케일링 공격에 대한 실험결과를 보인다.

• Tribology and Lubricants
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• 제39권4호
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• pp.148-153
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• 2023

Laser surface dimple patterning is a method of laser surface texturing to reduce lubrication sliding friction. The dimple pattern improves friction properties by reserving lubricant and trapping worn particles. This surface texturing technology can reduce coefficients of friction and extend the service life by applying a uniform load to the surface of the material. This study investigates the friction properties using PMMA, a highly compatible polymer material, as a specimen. We observe the friction properties of untextured specimens by processing specimens with dimple pattern densities of 5 and 10 on the surface area using laser. Dimple pattern density affects the coefficient of friction. We present the following friction property results using a pin-on-disc sliding friction test under saline lubrication. The coefficients of friction for the dimple patterned specimens are lower than those for the untextured specimens. As the normal load and sliding speed increase, the coefficients of friction of the dimple pattern specimens decrease differently from those of the untextured specimens. The specimen with a dimple pattern density of 5 at a normal load of 24.5 N and a sliding speed of 0.22 m/s has the best friction properties. Notably, different friction properties are exhibited depending on the dimple pattern densities.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제5권12호
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• pp.623-634
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• 2016

현존하는 빈발 패턴 마이닝 방법은 대부분 시간 효율성을 목표로 하고, 물리적 메모리 사용에 매우 의존적이다. 하지만 빅데이터 시대가 도래함에 따라 실제 세상의 데이터베이스는 급속도로 증가하고 있으며, 그에 따라 기존의 방법으로 현실적인 거대한 양의 데이터를 마이닝하기에 물리적 메모리 공간이 부족한 실정이다. 이러한 문제를 해결하기 위해, 빈발 패턴 마이닝의 메모리 의존성을 줄이기 위한 보조저장장치 기반의 연구들이 진행되었으나, 메모리 기반의 방법들에 비해 처리 시간이 너무 많이 소비된다는 한계가 있었다. 따라서 확장성을 가지며, 기존의 디스크 기반의 방법들에 비해 시간효율성을 높인 새로운 빈발 패턴 마이닝이 필요하게 되었다. 본 논문에서는 빅데이터로부터 빈도 아이템 집합들을 마이닝하기 위해 메모리와 디스크를 함께 사용하는 스택 기반의 새로운 접근법인 PPFP 알고리즘을 제안하였다. PPFP는 빈발 패턴 마이닝 접근법 중 가장 인기 있고 효율적인 접근법 중 하나인 FP-growth를 기반으로 하고 있다. PPFP 마이닝 방법은 다음과 같이 두 단계로 진행된다. (1) IFP-tree 구축: FP-tree를 생성한 후, 새로운 인덱스 번호 부여 방법으로 FP-tree의 각 노드에 인덱스 번호를 부여하고, 이 인덱스 번호가 부여된 FP-tree(IFP-tree)를 테이블로 변환하여(IFP-table) 디스크에 저장한다. (2) PPFP 알고리즘을 이용한 빈발 패턴 마이닝: 스택 기반의 PUSH-POP 방식으로 패턴을 확장시켜 나가며 빈발 패턴을 마이닝한다. 이러한 방식을 통해 메모리 기반의 방법에 비해 반복적으로 많은 시간이 소모되는 연산에 매우 적은 양의 메모리를 활용하여 확장성과 함께 시간효율성 또한 향상시킬 수 있었다. 그리고 기존의 연구 방법들과 비교 실험을 통해 새로운 알고리즘의 성능을 증명하였다.

• E2M - 전기 전자와 첨단 소재
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• 제8권5호
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• pp.551-557
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• 1995

For the observation of treeing, a visual measurement with an optical microscope has been used to explain breakdown mechanism in high-voltage systems. The conventional directed visual method of tree aging observation is difficult to measure in short time processing, and it is impossible to analyze on tree degradation area, progressed direction, tree pattern, etc. By using an image processing technique, the tree features which appear immediately after the tree initiation as well as changes in the configuration of the tree can be easily measured and observed than using the conventional visual methods. In this paper, we have developed a tree observating system by using image processing for tree growth, degradation area and other treeing progress. As an experimental result, it can be concluded that the image processing method is a more effective alternative than directed visual observation method. As a matter of fact, it is possible to record the image of tree propagation immediately after its first appearance and explain the characteristics of tree growth froth the computer processing image.