• 전자공학회논문지CI
• /
• 제45권4호
• /
• pp.1-11
• /
• 2008

본 논문에서는 adaboost(adaptive boosting)를 이용한 눈 검출 알고리즘을 제안한다. 또한 기존의 adaboost를 이용한 눈 검출 알고리즘의 문제점으로 지적된, 실제 눈이 아님에도 불구하고, 눈으로 찾는 오검출율(false alarm rate)를 감소시키기 위해 각막 면에 생성되는 조명의 반사광을 모델링을 통해 추정하고 adaboost의 학습과 눈 검출에 사용되는 박스의 최적의 크기를 실험을 통해 결정하였다. 위의 결과로 검출된 눈 영역을 중심으로 일정 영역에 대하여 동공과 홍채 영역을 원형검출기(circular edge detector)를 이용하여 검출하였다. 실험결과 휴대폰으로 취득한 얼굴영상에서 약 99%의 눈 검출 정확도를 나타내었으며 휴대폰 환경에 적용했을 때 처리시간은 1초 내외 소요됨을 알 수 있었다.

• International journal of thyroidology
• /
• 제11권2호
• /
• pp.92-98
• /
• 2018

Intraoperative identification and localization of parathyroid glands are crucial step in preventing postoperative hypocalcemia during thyroid and parathyroid surgery. If there is a method to predict the parathyroid's location rather than detecting and verifying with naked eye, it would make the operator easier to find and identify the parathyroid. Recently, near-infrared light imaging technologies have been introduced in the fields of thyroid and parathyroid surgery to predict the localization of the parathyroid. These are being conducted in two ways: autofluorescence imaging with a unique intrinsic fluorophore in the parathyroid tissues and fluorescence imaging with external fluorescence materials specially absorbed into parathyroid tissues. We are suggest that parathyroid glands can be detected by surgeon with NIR autofluorescence imaging even if they are covered by fibrofatty tissues before they are detected by surgeon's naked eye. These novel techniques are very useful to identify and preserve parathyroid glands during thyroidectomy. In this article, we reviewed the latest papers that describe autofluorescence imaging and exogenous ICG fluorescence imaging of parathyroid glands during thyroid and parathyroid surgery.

• 한국지능시스템학회논문지
• /
• 제19권4호
• /
• pp.478-484
• /
• 2009

음성 인식 기술은 편리한 삶을 추구하는 요즘 추세에 HMI를 위해 매력적인 기술이다. 음성 인식기술에 대한 많은 연구가 진행되고 있으나 여전히 잡음 환경에서의 성능은 취약하다. 이를 해결하기 위해 요즘은 청각 정보 뿐 아니라 시각 정보를 이용하는 시각 음성인식에 대한 연구가 활발히 진행되고 있다. 본 논문에서는 모바일 환경에서의 시각 음성인식을 위한 입술의 탐지 방법을 제안한다. 시각 음성인식을 위해서는 정확한 입술의 탐지가 필요하다. 우리는 입력 영상에서 입술에 비해 보다 찾기 쉬운 눈을 이용하여 눈의 위치를 먼저 탐지한 후 이 정보를 이용하여 대략적인 입술 영상을 구한다. 구해진 입술 영상에 K-means 집단화 알고리듬을 이용하여 영역을 분할하고 분할된 영역들 중 가장 큰 영역을 선택하여 입술의 양 끝점과 중심을 얻는다. 마지막으로, 실험을 통하여 제안된 기법의 성능을 확인하였다.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제3권2호
• /
• pp.178-186
• /
• 2003

Recently, many researchers have been interested in biometric systems such as fingerprint, handwriting, key-stroke patterns and human iris. From the viewpoint of reliability and robustness, iris recognition is the most attractive biometric system. Moreover, the iris recognition system is a comfortable biometric system, since the video image of an eye can be taken at a distance. In this paper, we discuss human iris recognition, which is based on accurate iris localization, robust feature extraction, and Neural Network classification. The iris region is accurately localized in the eye image using a multiresolution active snake model. For the feature representation, the localized iris image is decomposed using wavelet transform based on dyadic Haar wavelet. Experimental results show the usefulness of wavelet transform in comparison to conventional Gabor transform. In addition, we present a new method for setting initial weight vectors in competitive learning. The proposed initialization method yields better accuracy than the conventional method.

• 정신신체의학
• /
• 제15권2호
• /
• pp.73-80
• /
• 2007

지난 여러 해 동안 치매에서 나타나는 안구운동기능부전에 대해 수많은 논문이 발표되었다. 안구운동검사는 뇌의 기능을 평가하는 비침습적인 검사이며, 치매와 연관된 뇌의 이상을 밝혀내는데 유용한 방법이다. 저자는 치매와 연관된 안구운동이상에 대한 지금까지의 여러 연구들을 고찰해 보았다. 알쯔하이머병에서는 신속안구운동의 잠재기가 증가하고 정확도가 감소하며 항신속안구운동의 오류가 증가 한다. 전측두엽 치매 환자에서는 반사성 신속안구운동 억제의 장애와 항신속안구운동 잠재기와 오류 증가 소견이 나타난다. 그리고 헌팅톤병에서는 수의적인 신속안구운동의 시작 지연, 느린 신속안구운동, 항신속안구운동의 오류와 잠재기 증가 소견이 나타난다. 파킨슨병 치매와 루이체 치매 환자에서는 반사성 신속안구운동과 복합성 신속안구운동 실행 장애가 보고되었다. 크로이츠펠트-야콥 병에 관한 연구는 많지 않으며, 안구운동장애는 치매 증상이 명확해진 이후인 질병의 말기에 나타나고, 이차적으로 소뇌와 전정기관을 침범하게 된다고 한다. 진행성 핵상마비에서는 느린 신속안구운동과 측정저하 신속안구운동이 수직방향주시 장애가 오기 이전에 나타나는 경우가 많다. 수의적인 눈꺼풀 운동의 기능부전도 진행성 핵상마비의 특징적인 증상이다. 결론적으로 치매 환자들은 다양한 비정상적인 안구운동장애를 나타내며 이는 피질, 피질하 기능부전과 연관되어 있다. 치매 환자의 안구운동장애에 대한 다음 단계 연구는 치매에서 나타나는 임상적인 증상이 뇌의 어떤 부위 이상 때문에 발생하는지를 좀 더 명확하게 밝히는 것이 될 것이다.

• Journal of the Optical Society of Korea
• /
• 제13권1호
• /
• pp.116-122
• /
• 2009

In this paper, a robust method is developed to locate the irises of both eyes. The method doesn't put any restrictions on the background. The method is based on the AdaBoost algorithm for face and eye candidate points detection. Candidate points are tuned such that two candidate points are exactly in the centers of the irises. Mean crossing function and convolution template are proposed to filter out candidate points and select the iris pair. The advantage of using this kind of hybrid method is that AdaBoost is robust to different illumination conditions and backgrounds. The tuning step improves the precision of iris localization while the convolution filter and mean crossing function reliably filter out candidate points and select the iris pair. The proposed structure is evaluated on three public databases, Bern, Yale and BioID. Extensive experimental results verified the robustness and accuracy of the proposed method. Using the Bern database, the performance of the proposed algorithm is also compared with some of the existing methods.

• International Journal of Automotive Technology
• /
• 제7권3호
• /
• pp.361-367
• /
• 2006

This paper describes a novel stereo vision based localization of free parking site, which recognizes the target position of automatic parking system. Pixel structure classification and feature based stereo matching extract the 3D information of parking site in real time. The pixel structure represents intensity configuration around a pixel and the feature based stereo matching uses step-by-step investigation strategy to reduce computational load. This paper considers only parking site divided by marking, which is generally drawn according to relevant standards. Parking site marking is separated by plane surface constraint and is transformed into bird's eye view, on which template matching is performed to determine the location of parking site. Obstacle depth map, which is generated from the disparity of adjacent vehicles, can be used as the guideline of template matching by limiting search range and orientation. Proposed method using both the obstacle depth map and the bird's eye view of parking site marking increases operation speed and robustness to visual noise by effectively limiting search range.

• 한국임상수의학회지
• /
• 제40권5호
• /
• pp.360-364
• /
• 2023

A 7-year-old castrated male Yorkshire Terrier presented for a palpable mass of the right neck with ophthalmic signs of conjunctival hyperemia and anisocoria with fixed mydriatic pupil of the right eye. Clinical examination findings included the absence of direct and consensual pupillary light reflexes, external and internal ophthalmoplegia, and corneal hypoesthesia with incomplete blinking of the right eye. Magnetic resonance imaging and computed tomography revealed a mass extending from the right cavernous sinus to the orbital fissure with neighboring bone lysis. Cytological examination of fine-needle aspiration samples of the mass revealed a neuroendocrine tumor. The owner declined further diagnosis and did not wish to care for the dog receiving chemotherapy. This study describes the importance of investigating neuro-ophthalmic findings, which might provide clues for the localization of lesions, including tumors, to aid in diagnosis.

• Korean Journal of Radiology
• /
• 제24권3호
• /
• pp.247-258
• /
• 2023

Objective: To localize the neuroanatomical substrate of rapid eye movement sleep behavior disorder (RBD) and to investigate the neuroanatomical locational relationship between RBD and α-synucleinopathy neurodegenerative diseases. Materials and Methods: Using a systematic PubMed search, we identified 19 patients with lesions in different brain regions that caused RBD. First, lesion network mapping was applied to confirm whether the lesion locations causing RBD corresponded to a common brain network. Second, the literature-based RBD lesion network map was validated using neuroimaging findings and locations of brain pathologies at post-mortem in patients with idiopathic RBD (iRBD) who were identified by independent systematic literature search using PubMed. Finally, we assessed the locational relationship between the sites of pathological alterations at the preclinical stage in α-synucleinopathy neurodegenerative diseases and the brain network for RBD. Results: The lesion network mapping showed lesions causing RBD to be localized to a common brain network defined by connectivity to the pons (including the locus coeruleus, dorsal raphe nucleus, central superior nucleus, and ventrolateral periaqueductal gray), regardless of the lesion location. The positive regions in the pons were replicated by the neuroimaging findings in an independent group of patients with iRBD and it coincided with the reported pathological alterations at post-mortem in patients with iRBD. Furthermore, all brain pathological sites at preclinical stages (Braak stages 1-2) in Parkinson's disease (PD) and at brainstem Lewy body disease in dementia with Lewy bodies (DLB) were involved in the brain network identified for RBD. Conclusion: The brain network defined by connectivity to positive pons regions might be the regulatory network loop inducing RBD in humans. In addition, our results suggested that the underlying cause of high phenoconversion rate from iRBD to neurodegenerative α-synucleinopathy might be pathological changes in the preclinical stage of α-synucleinopathy located at the regulatory network loop of RBD.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
• /
• pp.106-109
• /
• 2004

Many reported methods assume that the faces in an image or an image sequence have been identified and localization. Face detection from image is a challenging task because of variability in scale, location, orientation and pose. In this paper, we present an efficient linear discriminant for multi-view face detection. Our approaches are based on linear discriminant. We define training data with fisher linear discriminant to efficient learning method. Face detection is considerably difficult because it will be influenced by poses of human face and changes in illumination. This idea can solve the multi-view and scale face detection problem poses. Quickly and efficiently, which fits for detecting face automatically. In this paper, we extract face using fisher linear discriminant that is hierarchical models invariant pose and background. We estimation the pose in detected face and eye detect. The purpose of this paper is to classify face and non-face and efficient fisher linear discriminant..