• 대한두개안면성형외과학회지
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• 제25권3호
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• pp.133-140
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• 2024

Background: The medial canthal region features a complex three-dimensional and internal anatomical structure. When reconstructing a defect in this area, it is crucial to consider both functional and aesthetic aspects, which presents significant challenges. Generally, local flaps are preferred for reconstruction; however, skin grafts can be used when local flaps are not feasible. Therefore, we conducted a comparative analysis of surgical outcomes skin grafts when local flaps were not feasible, to determine which surgical method is more effective for medial canthal region reconstruction. Methods: Twenty-five patients who underwent medial canthal region reconstruction using skin grafts or local flaps from 2002 to 2021 were enrolled. Patient information was obtained from medical records. Five plastic surgeons evaluated the surgical outcomes based on general appearance, color, contour, and symmetry. Results: Skin grafts were used in eight patients and local flaps were used in 13. Combined reconstructions were employed in four cases. Minor complications arose in four cases but improved with conservative treatment. No major complications were reported. Recurrence of the skin cancer was noted in two cases. All categories showed higher scores for the local flap compared to both skin graft and combined reconstruction; however, the differences were not statistically significant respectively. Conclusion: The choice of appropriate surgical methods for reconstructing defects in the medial canthal region depends on various factors, including the patient's overall health, the size and depth of the defect, and the degree of involvement of surrounding structures. When a local flap is not feasible, a skin graft may provide favorable surgical outcomes. Therefore, a skin graft can serve as a viable alternative for reconstructing the medial canthal region.

• 스마트미디어저널
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• 제11권11호
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• pp.92-98
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• 2022

섬유산업에서 생산된 직물의 결함을 식별하는 것은 품질관리를 위한 핵심적인 절차이다. 본 연구는 직물의 이미지를 분석하여 결함을 검출하는 모델을 만들고자 하였다. 연구에 사용된 모델은 딥러닝 기반의 VGGNet 과 ResNet이었고, 두 모델의 결함 검출 성능을 비교하여 평가하였다. 정확도는 VGGNet 모델이 0.859, ResNet 모델이 0.893으로 ResNet 모델의 정확도가 더 높은 결과를 보여주었다. 추가적으로 딥러닝 모델이 직물의 이미지 내에서 결함으로 인식한 부분의 위치를 알아보기 위하여 XAI(eXplainable Artificial Intelligence)기법인 Grad-CAM 알고리즘을 사용하여 모델의 관심영역을 도출하였다. 그 결과 딥러닝 모델이 직물의 결함으로 인식한 부분이 육안으로도 실제 결함이 있는 것으로 확인되었다. 본 연구의 결과는 직물의 결함 검출에 있어서 딥러닝 기반의 인공지능을 활용함으로써 섬유의 생산과정에서 발생하는 시간과 비용을 줄일 수 있을 것으로 기대된다.

• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.415-419
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• 2008

Detecting and correcting defects on LCD glasses early in the manufacturing process becomes important for panel makers to reduce the manufacturing costs and to improve productivity. Many attempts have been made and were successfully applied to detect and identify simple defects such as scratches, dents, and foreign objects on glasses. However, it is still difficult to robustly detect low-contrast defect region, called Mura or blemish area on glasses. Typically, these defect areas are roughly defined as relatively large, several millimeters of diameter, and relatively dark and/or bright region of low Signal-to-Noise Ratio (SNR) against background of low-frequency signal. The aim of this article is to present a robust algorithm to segment these blemish defects. Early 90's, a highly robust estimator, known as the Model-Fitting (MF) estimator was developed by X. Zhuang et. al. and have been successfully used in many computer vision application. Compared to the conventional Least-Square (LS) estimator the MF estimator can successfully estimate model parameters from a dataset of contaminated Gaussian mixture. Such a noise model is defined as a regular white Gaussian noise model with probability $1-\varepsilon$ plus an outlier process with probability $varepsilon$. In the sense of robust estimation, the blemish defect in images can be considered as being a group of outliers in the process of estimating image background model parameters. The algorithm developed in this paper uses a modified MF estimator to robustly estimate the background model and as a by-product to segment the blemish defects, the outliers.

• Journal of Welding and Joining
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• 제6권1호
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• pp.21-27
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• 1988

This paper describes weldability of dissimilar metal plates with YAG laser for the use of a small-size electronic spring parts. Effects of welding conditions, combination of plates, thickness of upper plate are examined in relation to welding strength and microstructure of welded region. The obtained results are summarized as follows. Welding defects such as cavity and crack showed a tendency to easily occur in the case where 1) pulse duration is short, 2) laser power is high, 3) PBS plate with high thermal diffusivity is used for lower plate. Among these defects, the occurrence of cavity cased a drop of welding strength. This results from the reduction of welding area between upper and lower plates. In SK-5/SUS304 plates (thickness: 0.2/0.4mm/, welding strength was the highest in welding conditions: laser power is 30J/pulse, pulse duration 9ms, amount of defocus +2mm.

• 비파괴검사학회지
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• 제25권6호
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• pp.459-466
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• 2005

The scanning laser source (SLS) technique has been proposed recently as an effective way to investigate small surface-breaking defects, By monitoring the amplitude and frequency changes of the ultrasound generated as the SLS scans over a defect, the SLS technique has provided enhanced signal-to-noise performance compared to the traditional pitch-catch or pulse-echo ultrasonic methods, An extension of the SLS approach to map defects in microdevices is proposed by bringing both the generator and the receiver to the near-field scattering region of the defects, To facilitate near-field ultrasound measurement, silicon microcantilever probes are fabricated using microfabrication technique and their acoustical characteristics are investigated, Then, both the laser-generated ultrasonic source and the microcantilever probe are used to monitor near-field scattering by a surface-breaking defect.

• Asian-Australasian Journal of Animal Sciences
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• 제24권8호
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• pp.1053-1059
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• 2011

The objective of this study was to assess the teratogenic and embryotoxic effects of clomiphene citrate in mice. The pregnant mice were administered a single dose of clomiphene citrate at different concentrations i.e 1.0, 2.0, 4.0 and 6.0 ${\mu}g/g$ BW on day 8 of gestation. Fetuses recovered on day 18 of gestation were analyzed on morphological, morphometric and histological basis. Morphological observations showed defects like open eyelids, anophthalmia, fore and hindlimb micromelia, meromelia, amelia, sacral hygroma, hydrocephaly, hemorrhagic spots, kyphosis and clubbed feet. Morphometric analysis indicated a significant (p<0.001) reduction in fetal body weight, crown rump length, head circumference, eye circumference, forelimb and hindlimb lengths and tail size against controls. The histological observations showed brain defects like hydrocephaly, enlarged ventricles and undifferentiated neuroglial cells in cerebellum. Cleft palate, underdeveloped pharynx and atrophy of jaw muscles were the common anatomical defects of pharyngeal region. It is concluded that the concentrations of clomiphene citrate used during the present study proved teratogenic in mice fetuses.

• 한국정밀공학회지
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• 제28권5호
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• pp.606-613
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• 2011

In this paper, patterns of laser scattering and detection of micro defects have been investigated based on Rayleigh criterion for silicon wafer in solar cell. Also, a new laser scattering mechanism is designed using characteristics of light scattering against silicon wafer surfaces. Its parameters are to be optimally selected to obtain effective and featured patterns of laser scattering. The optimal parametric ranges of laser scattering are determined using the mean intensity of laser scattering. Scattering patterns of micro defects are investigated at the extracted parameter region. Among a lot of pattern features, both maximum connected area and number of connected component in patterns of laser scattering are regarded as the important information for detecting micro defects. Their usefulness is verified in the experiment.

• 반도체디스플레이기술학회지
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• 제10권1호
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• pp.113-118
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• 2011

This paper proposes computer visual inspection algorithms for PCB defects which are found in a manufacturing process. The proposed method can detect open circuit and short circuit on bare PCB without using any reference images. It performs adaptive threshold processing for the ROI (Region of Interest) of a target image, median filtering to remove noises, and then analyzes connected components of the binary image. In this paper, the connected components of circuit pattern are defined as 6 types. The proposed method classifies the connected components of the target image into 6 types, and determines an unclassified component as a defect of the circuit. The analysis of the original target image detects open circuits, while the analysis of the complement image finds short circuits. The machine vision inspection system is implemented using C language in an embedded Linux system for a high-speed real-time image processing. Experiment results show that the proposed algorithms are quite successful.

• Journal of Chest Surgery
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• 제46권2호
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• pp.135-137
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• 2013

An atrial septal defect is the most common type of congenital heart disease among adults. Surgical repair or percutaneous closure of the defect is the treatment options. Even though percutaneous closure seems to be less risky than surgical repair, it may result in fatal complications like device embolism, cardiac perforation and tamponade. Herein we report a case of the embolism of a device into the pulmonary artery after one hour of percutaneous closure in which the embolized device was surgically removed and the defect was closed with a pericardial patch.

• 제어로봇시스템학회논문지
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• 제2권1호
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• pp.26-34
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• 1996

One of the challenging tasks in visual inspection using CCD camera is to identify surface defects in an image with complex textured backgeound. In microscopic view, the surface of real objects shows regular or random textured patterns. In this paper, we present a visual inspection algorithm to extract abnormal surface defects in an image with textured background. The algorithm uses the space and frequency information at the same time by introducing the Dominant Frequency Map(DFM) which can describe the frequency characteristics of every small local region of an input image. We demonstrate the feasibility and effectiveness of the method through a series of real experiments for a 14" TV CRT mold. The method successfully identifies a variety of infinitesimal defects, whose size is larger than $50\mu\textrm{m}$, of the mold. The experimental results show that the DFM based method is less sensitive to the environmental changes, such as illumination and defocusing, than conventional vision techniques.ques.