• Journal of Preventive Medicine and Public Health
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• 제39권6호
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• pp.485-492
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• 2006

Objectives : To measure the distribution of electrocardiographic ST segment depression, and evaluate its relationships with cardiovascular risk factors based on the cross-sectional studies within a rural Korean community Methods : This study analyzed 1,343 persons, over 40 years old, who participated in a baseline survey during 2002-2005; the exclusion criteria included: a past history of myocardial infarction and angina pectoris, and specific conduction abnormalities. A Standard 12 leads ECG was recorded using an FCP-2101 (Fukuda Denshi Co.). The ST segment depression was retrospectively measured by a physician, according to the Minnesota code classification. Results : ST segment depression was found in 3.6 and 6.4% of male and female participants, respectively. After adjusting for age, gender, smoking, physical activity and obesity differences, high blood pressure showed significant relations with ST depression in females (male ORs=2.67, 95% CI=0.85-8.50; female ORs=2.62, 95% CI=1.29-5.32) Conclusions : As an ischemic ECG sign, ST depression was related to hypertension in female participants. This relationship remained significant, even after cases with left ventricular hypertrophy were removed.

• Journal of Information Processing Systems
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• 제14권5호
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• pp.1176-1194
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• 2018

The object classification using the images' contents is a big challenge in computer vision. The superpixels' information can be used to detect and classify objects in an image based on locations. In this paper, we proposed a methodology to detect and classify the image's pixels' locations using enhanced bag of words (BOW). It calculates the initial positions of each segment of an image using superpixels and then ranks it according to the region score. Further, this information is used to extract local and global features using a hybrid approach of Scale Invariant Feature Transform (SIFT) and GIST, respectively. To enhance the classification accuracy, the feature fusion technique is applied to combine local and global features vectors through weight parameter. The support vector machine classifier is a supervised algorithm is used for classification in order to analyze the proposed methodology. The Pascal Visual Object Classes Challenge 2007 (VOC2007) dataset is used in the experiment to test the results. The proposed approach gave the results in high-quality class for independent objects' locations with a mean average best overlap (MABO) of 0.833 at 1,500 locations resulting in a better detection rate. The results are compared with previous approaches and it is proved that it gave the better classification results for the non-rigid classes.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.283-284
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• 2006

In this paper, we propose a novel segmentation and classification method using texture features for the document image. First, we extract the local entropy and then segment the document image to separate the background and the foreground using the Otsu's method. Finally, we classify the segmented regions into each component using PCA(principle component analysis) algorithm based on the texture features that are extracted from the co-occurrence matrix for the entropy image. The entropy-based segmentation is robust to not only noise and the change of light, but also skew and rotation. Texture features are not restricted from any form of the document image and have a superior discrimination for each component. In addition, PCA algorithm used for the classifier can classify the components more robustly than neural network.

• 한국정보과학회논문지:소프트웨어및응용
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• 제35권11호
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• pp.692-700
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• 2008

일부 음악 장르 분류에 관한 기존 연구에서는 특징 추출을 위한 구간 선택 시 사람이 직접 곡의 주요 구간을 지정하는 방법을 사용하였다. 이러한 방법은 분류 성능이 좋은 반면 수작업으로 인한 부담으로 새롭게 등록되는 음악들에 대해 지속적으로 적용하기가 곤란하다. 수작업 없이 음악 특징을 추출하기 위해 최근 음악 장르 분류와 관련된 연구에서는 자동으로 추출구간을 선정하는 방법을 사용하고 있지만 이러한 연구의 대부분이 고정된 구간 (예, 30초 이후의 30초 구간)에서 특징을 추출하는 관계로 분류의 정확도가 떨어지는 문제점을 갖고 있다. 본 논문에서는 이러한 문제점을 해결하기 위해 곡 전체 구간에 대하여 반복구간들을 파악하고 이들의 위치와 에너지를 고려하여 곡을 대표할 수 있는 단일 대표구간을 선정한 후, 대표구간으로 부터 특징을 추출하여 장르 분류시스템에 적용하는 방법을 제안하였다. 실험 결과, 기존 고정구간을 사용한 방법에 비해 괄목할 만한 성능 향상을 얻을 수 있었다.

• 한국정보통신학회논문지
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• 제23권12호
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• pp.1542-1550
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• 2019

부정맥 분류를 위한 기존 연구들은 분류의 정확성을 높이기 위해 신경회로망(Artificial Neural Network), 퍼지(Fuzzy), 기계학습(Machine Learning) 등을 이용한 방법이 연구되어 왔다. 특히 딥러닝은 신경회로망의 문제인 은닉층 개수의 한계를 해결함으로 인해 오류 역전파 알고리즘을 이용한 부정맥 분류에 가장 많이 사용되고 있다. 딥러닝 모델을 심전도 신호에 적용하기 위해서는 적절한 모델선택과 파라미터를 최적에 가깝게 선택할 필요가 있다. 본 연구에서는 심실 조기 수축 비트 검출을 위한 딥러닝 기반의 최적 파라미터 검출 방법을 제안한다. 이를 위해 먼저 잡음을 제거한 ECG신호에서 R파를 검출하고 QRS와 RR간격 세그먼트를 추출하였다. 이후 딥러닝을 통한 지도학습 방법으로 가중치를 학습시키고 검증데이터로 모델을 평가하였다. 제안된 방법의 타당성 평가를 위해 MIT-BIH 부정맥 데이터베이스를 통해 각 파라미터에 따른 딥러닝 모델로 훈련 및 검증 정확도를 확인하였다. 성능 평가 결과 R파의 평균 검출 성능은 99.77%, PVC는 97.84의 평균 분류율을 나타내었다.

• Journal of Korean Neurosurgical Society
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• 제64권1호
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• pp.69-77
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• 2021

Objective : Classification systems for cervical ossification of the posterior longitudinal ligament (OPLL) have traditionally focused on the morphological characteristics of ossification. Although the classification describes many clinical features associated with the shape of the ossification, including the concept of spondylosis seems necessary because of the similarity in age distribution. Methods : Patients diagnosed with OPLL who presented with increase signal intensity (ISI) on magnetic resonance imaging were surgically treated in our department. The patients were divided into two groups (pure versus degenerative) according to the presence of disc degeneration. Results : Of 141 patients enrolled in this study, more than half (61%) were classified into the degenerative group. The pure group showed a profound male predominance, early presentation of myelopathy, and a different predilection for ISI compared to the degenerative group. The mean canal compromise ratio (CC) of the ISI was 47% in the degenerative group versus 61% in the pure group (p<0.0000). On the contrary, the global and segment motions were significantly larger in the degenerative group (p<0.0000 and p=0.003, respectively). The canal diameters and global angles did not differ between groups. Conclusion : Classifying cervical OPLL based on the presence of combined disc degeneration is beneficial for understanding the disorder's behavior. CC appears to be the main factor in the development of myelopathy in the pure group, whereas additional dynamic factors appear to affect its development in the degenerative group.

• 보건행정학회지
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• 제12권2호
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• pp.1-22
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• 2002

Since the early 1980s scholars have applied latent structure and other type of finite mixture models from various academic fields. Although the merits of finite mixture model are well documented, the attempt to apply the mixture model to medical service has been relatively rare. The researchers aim to try to fill this gap by introducing finite mixture model and segmenting inpatients DB from one general hospital. In section 2 finite mixture models are compared with clustering, chi-square analysis, and discriminant analysis based on Wedel and Kamakura(2000)'s segmentation methodology schemata. The mixture model shows the optimal segments number and fuzzy classification for each observation by EM(expectation-maximization algorism). The finite mixture model is to unfix the sample, to Identify the groups, and to estimate the parameters of the density function underlying the observed data within each group. In section 3 and 4 we illustrate results of segmenting 4510 patients data including menial and ratio scales. And then, we show AHP can be identify the attractiveness of each segment, in which the decision maker can select the best target segment.

• 한국통신학회논문지
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• 제18권5호
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• pp.757-772
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• 1993

본 논문에서는 영상 이해를 위한 지식 베이스 시스템에 있어서 핵심적 기능을 수행하게 되는 저급 지식원과 중급 지식원의 추출에 관한 것으로 화소 영역에 적용되는 저급 처리 과정으로 영역 분할 처리과정, 방향 영상 변환과정, 형태 정보 추출 과정, 영역 특징량 추출과정으로 구성되며 중급 처리 과정으로 특징 베이스 분류, 기하학적 토큰 관계성, 인지적 조직과 집단화 과정으로 구성되어 있다.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.28-35
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• 2003

Quaternary faults found around the Ulsan Fault System can be divided into 4 types based on the fault outcrop features : Type I fault cuts basements and Quaternary deposits of which remain on both hangwall and footwall. Type II fault is developed only in Quaternary deposit. Type III fault has inclined unconformity after Quaternary faulting. Type IV fault is common type around the Ulsan fault system and has horizontal unconformity surface after cutting earlier Quaternary deposit. After erosion, later Quaternary deposit overlays on both old deposit and basement. The Ulsan Fault System consists of three segments at large scale from north to south based on the lineament rank and shape, Quaternary fault location, and slip rate. The segment boundaries are identified by the existence of the two intervals which show no lineaments and Quaternary faults. But, if detail fault parameters could be obtained and used in segmentation, it can be divided into more than three segments.

• The Journal of Korean Physical Therapy
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• 제15권1호
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• pp.155-170
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• 2003

Lumbar segmental instability is considered to represent a significant sub-group within the chronic low back pain population. This condition has a unique clinical presentation that displays its symptoms and movement dysfunction within the neutral zone of the motion segment. The loosening of the motion segment secondary to injury and associated dysfunction of the local muscle system renders it biomechanically vulnerable in the neutral zone. There in evidence of muscle dysfunction related to the control of the movement system. There is a clear link between reduced proprioceptive input, altered slow motor unit recruitment and the development of chronic pain states. Dysfunction in the global and local muscle systems in presented to support the development of a system of classification of muscle function and development of dysfunction related to musculoskeletal pain. The global muscles control range of movement and alignment, and evidence of dysfunction is presented in terms of imbalance in recruitment and length between the global stability muscles and the global mobility muscles. The local stability muscles demonstrate evidence of failure of aeequate segmental control in terms of allowing excessive uncontrolled translation or specific loss of cross-sectional area at the site of pathology Motor recruitment deficits present as altered timing and patterns of recruitment. The evidence of local and global dysfunction allows the development of an integrated model of movement dysfunction. The clinical diagnosis of this chronic low back pain condition is based on the report of pain and the observation of movement dysfunction within the neutral zone and the associated finding of excessive intervertebral motion at the symptomatic level. Four different clinical patterns are described based on the directional nature of the injury and the manifestation of the patient's symptoms and motor dysfunction. A specific stabilizing exercise intervention based on a motor learning model in proposed and evidence for the efficacy of the approach provided.