• Current Optics and Photonics
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• 제7권4호
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• pp.387-397
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• 2023

Tooth surface shape error is an important parameter in gear accuracy evaluation. When tooth surface shape error is measured by laser interferometry, the gear interferogram is highly distorted and the gray level distribution is not uniform. Therefore, it is important for gear interferometry to extract the foreground region from the gear interference fringe image directly and accurately. This paper presents an approach for foreground extraction in gear interference images by leveraging the sinusoidal variation characteristics shown by the interference fringes. A gray level mask with an adaptive threshold is established to capture the relevant features, while a local variance evaluation function is employed to analyze the fluctuation state of the interference image and derive a repair mask. By combining these masks, the foreground region is directly extracted. Comparative evaluations using qualitative and quantitative assessment methods are performed to compare the proposed algorithm with both reference results and traditional approaches. The experimental findings reveal a remarkable degree of matching between the algorithm and the reference results. As a result, this method shows great potential for widespread application in the foreground extraction of gear interference images.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제49권3호
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• pp.135-141
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• 2023

Objectives: This study aimed to develop and validate machine learning (ML) models using H₂O-AutoML, an automated ML program, for predicting medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis undergoing tooth extraction or implantation. Patients and Methods: We conducted a retrospective chart review of 340 patients who visited Dankook University Dental Hospital between January 2019 and June 2022 who met the following inclusion criteria: female, age ≥55 years, osteoporosis treated with antiresorptive therapy, and recent dental extraction or implantation. We considered medication administration and duration, demographics, and systemic factors (age and medical history). Local factors, such as surgical method, number of operated teeth, and operation area, were also included. Six algorithms were used to generate the MRONJ prediction model. Results: Gradient boosting demonstrated the best diagnostic accuracy, with an area under the receiver operating characteristic curve (AUC) of 0.8283. Validation with the test dataset yielded a stable AUC of 0.7526. Variable importance analysis identified duration of medication as the most important variable, followed by age, number of teeth operated, and operation site. Conclusion: ML models can help predict MRONJ occurrence in patients with osteoporosis undergoing tooth extraction or implantation based on questionnaire data acquired at the first visit.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권5호
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• pp.461-470
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• 2001

A unhealthy 58-year-old male patient required extraction of left upper second molar due to advanced periodontitis. Lidocaine contained 1 : 100000 epinephrine for left posterior superior alveolar nerve block was administered in the mucobuccal fold above the second molar to be treated at the local private dental clinic. After four hours of posterior superior alveolar block anesthesia, patient feeled double vision and discomfort of eyeball movement. At next day, he complained difficulty of left eyeball movement, vertigo and diplopia. He was referred to our department via local clinic and department of ophthalomology of our hospital. He was treated by medication and eyeball exercise, and then follow up check. The double vision and medial rectus muscle palsy disappeared patially after 2 months of block anesthesia. We described herein an ocular complication of diplopia and inferior rectus muscle palsy after posterior superior alveolar nerve block for extraction of left upper second molar, and review the cause or origin of this case. The autonomic nervous system is presented as the logical basis for the untoward systems of ophthalmologic sign likely to diplopia and inferior rectus muscle palsy, rather then simple circulation of anesthetic solution in the vascular network.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권8호
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• pp.3806-3825
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• 2016

This paper brings out a neoteric frame of reference for visual semantic based 3d video search and retrieval applications. Newfangled 3D retrieval application spotlight on shape analysis like object matching, classification and retrieval not only sticking up entirely with video retrieval. In this ambit, we delve into 3D-CBVR (Content Based Video Retrieval) concept for the first time. For this purpose we intent to hitch on BOVW and Mapreduce in 3D framework. Here, we tried to coalesce shape, color and texture for feature extraction. For this purpose, we have used combination of geometric & topological features for shape and 3D co-occurrence matrix for color and texture. After thriving extraction of local descriptors, TB-PCT (Threshold Based- Predictive Clustering Tree) algorithm is used to generate visual codebook. Further, matching is performed using soft weighting scheme with L₂ distance function. As a final step, retrieved results are ranked according to the Index value and produce results .In order to handle prodigious amount of data and Efficacious retrieval, we have incorporated HDFS in our Intellection. Using 3D video dataset, we fiture the performance of our proposed system which can pan out that the proposed work gives meticulous result and also reduce the time intricacy.

• 한국멀티미디어학회논문지
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• 제18권9호
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• pp.1008-1018
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• 2015

In this paper, we propose a method that constructs a saliency map in which important regions are accurately specified and the colors of the regions are less influenced by the similar surrounding colors. Our method utilizes LBP(Local Binary Pattern) histogram information to compare and analyze texture information of surrounding regions in order to reduce the effect of color information. We extract the saliency of stereoscopic images by integrating a 2D saliency map with depth information of stereoscopic images. We then measure the distance between two different sizes of the LBP histograms that are generated from pixels. The distance we measure is texture difference between the surrounding regions. We then assign a saliency value according to the distance in LBP histogram. To evaluate our experimental results, we measure the F-measure compared to ground-truth by thresholding a saliency map at 0.8. The average F-Measure is 0.65 and our experimental results show improved performance in comparison with existing other saliency map extraction methods.

• 한국산학기술학회논문지
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• 제10권1호
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• pp.128-134
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• 2009

홍채인식은 홍채의 무의 패턴 정보를 이용하여 동일인 여부를 판별하는 생체인식 기술이다. 최근 들어 홍채 정보를 이용하여 출입통제, 정보보안등의 분야에 많이 활용되고 있다. 하지만 홍채 특징 추출 시 복잡한 연산을 수행한다. 이로 인하여 실시간 홍채인식을 위해서는 고사양의 하드웨어가 수반된다. 본 논문에서는 저사양의 임베디드 환경에 적합한 국부적 그래디언트 히스토그램을 이용한 홍채 특징 추출 방법을 사용하여 임베디드 시스템을 구현하였다. 실험에서 기존의 홍채 특징 추출 방식과 비교하여 특징 추출 속도는 더 빠르면서 대등한 성능을 보여주는 것을 확인 할 수 있으며, 회전에도 강인한 특성을 보였다.

• 반도체디스플레이기술학회지
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• 제15권2호
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• pp.61-65
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• 2016

Facial feature detection is a fundamental function in the field of computer vision such as security, bio-metrics, 3D modeling, and face recognition. There are many algorithms for the function, active shape model is one of the most popular local texture models. This paper addresses issues related to face detection, and implements an efficient extraction algorithm for extracting the facial feature points to use on iOS platform. In this paper, we extend the original ASM algorithm to improve its performance by four modifications. First, to detect a face and to initialize the shape model, we apply a face detection API provided from iOS CoreImage framework. Second, we construct a weighted local structure model for landmarks to utilize the edge points of the face contour. Third, we build a modified model definition and fitting more landmarks than the classical ASM. And last, we extend and build two-dimensional profile model for detecting faces within input images. The proposed algorithm is evaluated on experimental test set containing over 500 face images, and found to successfully extract facial feature points, clearly outperforming the original ASM.

• 한국인터넷방송통신학회논문지
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• 제11권1호
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• pp.185-191
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• 2011

최근들어 영상보안 시스템에 관한 관심이 높아지고 있다. 영상으로부터 객체를 검출하고, 객체가 사람인지를 판별하며, 인식하는 기술이 다방면으로 활용되고 있다. 따라서 본 논문에서는 이러한 객체를 검색하기 위한 적응적인 방법을 제안하며, 이를 위하여 지역적 컨텍스트 기반의 얼굴 특징 검출 방법을 제안한다. 가보 번치를 이용하여 검출하는 이와 함께 베이지안 검출 방법을 이용한 특징점 보정에 따른 특징 검색 방법을 설명한다. 전체적인 시스템은 영상에서 오브젝트 영역을 검색하고, 지역적 컨텍스트 기반의 얼굴 검출, 특징 추출 방법을 적용하여 시스템의 성능을 높인다.

• Environmental Engineering Research
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• 제24권1호
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• pp.137-143
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• 2019

In this study, extraction, clean-up and instrumental analytical conditions were optimized for identifying and quantifying methyl-, chloromethylbenzi-, octyl- isothiazolinone (MIT, CMIT, BIT, OIT) and 3-iodo-2-propynyl butyl carbamate (IPBC), widely used biocidal active ingredients in human hygiene consumer products. Accuracy of the developed ultrasonic assisted extraction method followed by HPLC/MS analysis for four isothiazolinones and IPBC ranged between 60.4% and 113% in various types of consumer product samples. Method detection limits ranged 0.011-0.034 mg/kg for wet wipes, 0.57-1.5 mg/kg for liquid detergent and 0.58-1.6 mg/kg for powder detergent. Wet wipes, powder and liquid detergents collected from local market in Korea were analyzed to demonstrate the applicability of the developed method. Even after the regulation of those compounds in wet wipes, CMIT, MIT and IPBC were still frequently detected from complementary wet wipes without brand labels which were distributed to customers at local retail shops and restaurants. The maximum observed concentrations of MIT and CMIT found in those complementary wet wipes were 70.2 mg/kg and 11.3 mg/kg, respectively.

• 한국정보전자통신기술학회논문지
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• 제14권3호
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• pp.208-214
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• 2021

최근 많은 지능형 보안 시나리오 및 범죄수사에서는 사진이 아닌 얼굴 영상과 다수의 정면 사진과의 매칭을 요구한다. 기존의 얼굴 인식 시스템은 이러한 요구를 충분히 충족시킬 수 없다. 본 논문에서는 동일 인물의 스케치와 사진 간의 양식 차이를 줄임으로써, 이질적 얼굴 인식 시스템의 성능을 향상시키는 알고리즘을 제안한다. 제안하는 알고리즘은 텍스처 기술자들(그레이 레벨 동시 발생 행렬, 멀티스케일 지역 이진 패턴)을 통하여 영상의 텍스처 특징들을 각각 추출하고, 이를 바탕으로 고유특징 정규화 및 추출기법을 통해 변환 행렬을 생성하게 된다. 이렇게 생성된 벡터들 간 계산된 스코어 값은 스코어 정규화 방식들을 통하여 최종적으로 스케치 영상의 신원을 인식하게 된다.