• Title/Summary/Keyword: defects

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Automated classification of display defects based on imaging colorimeter measurements

  • Kostal, Hubert;Pedeville, Gary;Rykowski, Ronald;Skelly, Sean
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1261-1264
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    • 2009
  • The use of imaging colorimeter systems and associated analytical software to assess display brightness and color uniformity, contrast, and to identify defects is well established. In this paper we describe recent work to extend these methods to classify defects based on human visual perception.

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The Effects of the Difference of Ultrasonic Damped Rate on the Judgment of Defects (초음파 감쇠율의 차가 결함판정에 주는 영향)

  • Namkoong Chai-Kwan
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.14 no.4
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    • pp.1-6
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    • 2005
  • In this study, on automatic ultrasonic testing system is used to detect defects of flawtest specimen. We study the effects of the difference of ultrasonic damped rate of the different materials on the judgment of defects. The results indicate that the difference of sensitivity compensating quantity is 2dB, and the judgment is correct over $90\%$ when a specimen is judged as a defect when it exceeds third grade.

Positron Annihilation Study of Vacancy Type Defects in Ti, Si, and BaSrFBr:Eu

  • Lee, Chong Yong
    • Applied Science and Convergence Technology
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    • v.25 no.5
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    • pp.85-87
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    • 2016
  • Coincidence Doppler broadening and positron lifetime methods in positron annihilation spectroscopy has been used to analyze defect structures in metal, semiconductor and polycrystal, respectively. The S parameter and the lifetime (${\tau}$) value show that the defects were strongly related with vacancies. A positive relationship existed between the scanning electron microscope (SEM) images and the positron annihilation spectroscopy (PAS). According to the SEM images and PAS results, measurements of the defects with PAS indicate that it was more affected by the defect than the purity.

Development of Highly Accurate Inspection System for Cylindrical Aluminum Casts with Microscopic Defects

  • Shinji, Ohyama;Hong, Keum-Shik
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.35.3-35
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    • 2001
  • Developed is an optical auto-inspection system to detect some microscopic defects on the Inside surface of the hydraulic automobile brakes at the production line. A small cylindrical detection module with a solid laser source at its center has two rings of optical fibers to separately collect light reflected and scattered from the defects on the surface. The cylindrical brake part rotates with respect to the detection module that will move parallel to the rotational axis of the cylinder. Thus, the optical module can scan the whole inside surface area. The automatic detection of the defects is to compare the intensity distributions ...

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Various Methods of Reconstruction in Nasal Defect (코 결손 부위에 따른 다양한 재건)

  • Kim, Seok Kwun;Yang, Jin Il;Kwon, Yong Seok;Lee, Keun Cheol
    • Archives of Craniofacial Surgery
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    • v.11 no.1
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    • pp.13-18
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    • 2010
  • Purpose: Nasal defect can be caused by excision of tumor, trauma, inflammation from foreign body reaction. Nose is located in the middle of face and protruded, reconstruction should be done in harmony with size, shape, color, and textures. We report various methods of nasal reconstruction using local flaps. Methods: From March 1998 to July 2008, 36 patients were operated to reconstruct the nasal defects. Causes of the nasal defects were tumor (18 cases), trauma (11 cases), inflammation from foreign body reaction (5 cases) and congenital malformation (2 cases). The sites of the defects were ala (22 cases), nasal tip (8 cases) and dorsum (6 cases). The thickness of the defects was skin only (5 cases), dermis and cartilagenous layer (7 cases) and full-thickness (24 cases). According to the sites and thickness of the defects, various local flaps were used. Most of alar defects were covered by nasolabial flaps or bilobed flaps and the majority of dorsal and tip defects were covered by paramedian forehead flaps. Small defects below $0.25 cm^2$ were covered with composite graft or full-thickness skin graft. Results: The follow-up period was 14 months. Partial flap necrosis was observed in a case, and one case of infection was reported, it was improved by wound revision and antibiotics. Nasal reconstruction with various local flaps could provide satisfactory results in terms of color and texture match. Conclusion: The important factors of nasal reconstruction are the shape of reconstructed nose, color, and texture. Nasolabial flap is appropriate method for alar or columellar reconstruction and nasolabial island flap is suitable for tip defect. The defect located lateral wall could be reconstructed with bilobed flap for natural color and texture. Skin graft should be considered when the defect could not afford to be covered by adjacent local flap. And entire nasal defect or large defect could be reconstructed by paramedian forehead flap.

Arterial or venous free flaps for volar tissue defects of the proximal interphalangeal joint: A comparison of surgical outcomes

  • Choi, Min Suk;Roh, Si Young;Koh, Sung Hoon;Kim, Jin Soo;Lee, Dong Chul;Lee, Kyung Jin;Hong, Min Ki
    • Archives of Plastic Surgery
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    • v.47 no.5
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    • pp.451-459
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    • 2020
  • Background For volar soft tissue defects of the proximal interphalangeal (PIP) joint, free flaps are technically challenging, but have more esthetic and functional advantages than local or distant flaps. In this study, we compared the long-term surgical outcomes of arterial (hypothenar, thenar, or second toe plantar) and venous free flaps for volar defects of the PIP joint. Methods This was a single-center retrospective review of free flap coverage of volar defects between the distal interphalangeal and metacarpophalangeal joint from July 2010 to August 2019. Patients with severe crush injuries (degloving, tendon or bone defects, or comminuted/intra-articular fractures), thumb injuries, multiple-joint and finger injuries, dorsal soft tissue defects, and defects >6 cm in length were excluded from the study, as were those lost to follow-up within 6 months. Thirteen patients received arterial (hypothenar, thenar, or second toe plantar) free flaps and 12 received venous free flaps. Patients' age, follow-up period, PIP joint active range of motion (ROM), extension lag, grip-strength ratio of the injured to the uninjured hand, and Quick Disabilities of Arm, Shoulder & Hand (QuickDASH) score were compared between the groups. Results Arterial free flaps showed significantly higher PIP joint active ROM (P=0.043) and lower extension lag (P =0.035) than venous free flaps. The differences in flexion, grip strength, and QuickDASH scores were not statistically significant. Conclusions The surgical outcomes of arterial free flaps were superior to those of venous free flaps for volar defects of the PIP joint.

Analysis on Characteristics of Defects before Inspection for Apartment Use (공동주택 사용검사 전 하자 특성 분석)

  • Lee, Sang-Hyo;Han, Man-Cheon;Kim, Jae-Jun;Lee, Jeong-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.5
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    • pp.167-178
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    • 2020
  • The purpose of this paper is to establish a defect classification system for defects before inspection and to derive the pattern and characteristics of defects before inspection by examining about 3,110 defect items for 133 apartment buildings. The study analysis revealed a relatively high rate of defects before inspection that occurred in finishing work. Second, defects occurred such as cracking of external wall, which is a very important defect. However, defects before inspection were relatively rare on the external wall. Finally, defects before inspection occurred during waterproofing in the common area or garage. It is necessary to establish a reasonable basis or countermeasure to resolve differences between stakeholders as various issues may arise in the course of a dispute, as a result of identifying the details of defects within the top 20 of the defectives.

Inspection Algorithm for Double-Cut Defect of Motor Shaft (모터 샤프트 이중컷 불량 검사 알고리즘)

  • Hwang, Myun Joong;Chung, Seong Youb
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.2
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    • pp.335-341
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    • 2017
  • This paper proposes an image-processing algorithm for inspecting double-cut defects in the motor shaft manufacturing process. The algorithm consists of extracting the outline using the brightness of the image, obtaining a binarized boundary graph using the extracted outline, and determining the defects from the graph. Defects in which two cut surfaces are separated are considered type 1 defects, and those in which two cut surfaces are connected are defined as type 2 defects. In an actual manufacturing process, 112 good samples and 44 defective samples (34 type 1 defects and 10 type 2 defects) were collected and used to verify the algorithm. The samples were judged with 100% accuracy for both type 1 and type 2 defects. The algorithm will be used in the field after securing reliability for various samples.

Detectability of Ektaspeed Plus Film, Digitized and Digora Images for Artificial Periapical Bone Lesions (Ektaspeed Plus 방사선사진, 간접 디지털 영상 및 Digora 영상의 치근단 병소의 판독능 비교)

  • Cho Bong-Hae;Nah Kyung-Soo;Lee Hee-Joo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.28 no.2
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    • pp.461-470
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    • 1998
  • The comparative detectability of the artificial periapical defects among Ektaspeed Plus film. digitized and digora images was evaluated. The artifical defects were made in the cancellous bone and cancellous-cortical junction with the size of 1.0×0.8mm², 1.4×1.1mm² and 2.8×2.2mm². The defects in cancellous-cortical junction extended into cortical bone with the depth of 0, 0.5 and 1.0 mm. The results were as follows : 1. In junctional defects Ektaspeed Plus film for 2.8×12.2mm² defect showed the highest detectability. But significant difference were only found between Ektaspeed Plus films and digitized images (p<0.05). 2. Almost all defects within cacellous bone were not detected except a few digitized and Digora images for the size of 2.8×2.2mm². Digora images for them showed significant differences with Ektaspeed Plus films and digitized images (p<0.05). 3. The sensitinity of all imaging modalities were 0.9 or 1.0 in junctional defects for the size of 1.4×2.2mm² and 2.8×2.2mm². For cancellous defects, Digora image showed the highest sensitivity of 0.6 for the size of 2.8×2.2mm². 4. Significant differences for change of exposure time were found in most group of Ektaspeed Plus films and digitized images (p<0.05) . But there was no significant differences in Digora images for cacellous defects.

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Development of Defects Detecting System for Corrugated Board, Mill Application, and Changes of Production Defects Ratio (골판지 불량 검색 시스템 개발, 현장적용과 생산 불량률 변화)

  • Jeong, Jin-Mo;Min, Kyung-Eun;Kim, Mun-Sung;Park, Jong-Moon
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.40 no.2
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    • pp.37-42
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    • 2008
  • Defects of corrugated board were limiting factors to the corrugated industry's growth. On-line detecting systems of defects are beneficial to increase profits of the corrugated board companies by reducing base paper consumption, increasing process reliability, and increasing productivity. By replacing naked eye inspection of defects to a defects detecting system, continuous inspection without fatigue may guarantee final products quality. The system was developed, which was consisted of line scan CCD camera, lens, illuminating parts, high speed image processor, software, various input parts, and output parts. First installation location of the system was at before fluting process after base paper unwinding, and surface of liner board was inspected by the system. Second installation location was after fluting process and combining process for liner board. Production loss includes ragged appearance of edge, irregular flute shape, wrong combination of flute, score cracking, defects in base paper, and flute cracking. The production loss was analyzed before and after the system installation at a commercial domestic mill. The production loss ratio was defined as a production loss weight per total production weight. The production loss ratio before the installation was decreased a lot from 1.28%(during 3 months before installation) to 0.76%(during 12 months after the first installation) and to 0.25%(during 6 months after the second installation).