• Title/Summary/Keyword: level-set function

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Facial Boundary Detection using an Active Contour Model (활성 윤곽선 모델을 이용한 얼굴 경계선 추출)

  • Chang Jae Sik;Kim Eun Yi;Kim Hang Joon
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.42 no.1
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    • pp.79-87
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    • 2005
  • This paper presents an active contour model for extracting accurate facial regions in complex environments. In the model, a contour is represented by a zero level set of level function φ, and evolved via level set partial differential equations. Then, unlike general active contours, skin color information that is represented by 2D Gaussian model is used for evolving and slopping a curve, which allows the proposed method to be robust to noise and varying pose. To assess the effectiveness of the proposed method it was tested with several natural scenes, and the results were compared with those of geodesic active contours. Experimental results demonstrate the superior performance of the proposed method.

The Effects of Home Visiting Physical Therapy on the Motor Function, Activity of Daily Living, and Pain for Disabled Veterans (가정방문물리치료가 국가유공자 재가장애인의 운동기능, 일상생활동작 수행 및 통증수준에 미치는 영향)

  • Kwon, Chun-Suk;Kim, Suhn-Yeop;Jang, Hyun-Jeong
    • Journal of the Korean Society of Physical Medicine
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    • v.9 no.2
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    • pp.171-179
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    • 2014
  • PURPOSE: The objectives of this study were to investigate the effects of physical therapy provided at home on the motor function, activity of daily living (ADL), and level of pain in veterans men with disabilities, and to provide the information. METHODS: The participants were 108 patients men with disabilities living in the cities Seoul, Pusan, Daegu, Gwangju and Daejeon; they performed physical therapy at home-provided by physical therapy services- that included therapeutic exercise for 50 minute, 1~2 times a week for 24 weeks. The motor function was measured by using motor assessment scale (MAS) and ADL, the level of pain were recorded both before and after physical therapy. The data form both before and after physical therapy were analyzed by using the paired t-test. All statistical tests in this study were performed with the level of significance set at .05. RESULTS: After 24 weeks of physical therapy, we observed significant improvement in the MAS and ADL scale, as well as significant decrease in the level fo pain in the participants (p<.01). Significant improvement was also observed in the MAS and ADL scale, as well as a decrease in the level of pain among participants with stroke and spinal disease (p<.05). CONCLUSION: The findings of this study show that physical therapy provided at home can lead to an improvement in the motor function as well as improved ADL and pain control; physical therapy also has positive effects in relieving symptoms of veterans with disabilities.

Cognitive Function among the Elderly and Its Correlated Factors (지역사회 재가노인의 인지기능과 관련요인)

  • Min, Hye Sook
    • Korean Journal of Adult Nursing
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    • v.19 no.1
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    • pp.78-88
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    • 2007
  • Purpose: The purpose of this study was to find out the degree of cognitive function among the elderly and to confirm its correlated factors. Methods: The subjects consisted of 392 elderly people over the age 65 who were living in Busan. Data were collected by the interview method, using a structured questionnaire and the K-MMSE scale. Results: The average points of the elderly's cognitive functions measured by K-MMSE were 23.76(${\pm}4.02$). With the cut-off point for cognitive impairment set as 24 points below using K-MMSE scale, 38.8% of the subjects have cognitive impairments. Among the variables related to cognitive functions, literacy showed the highest correlation with cognitive function(${\beta}=.330$, t=7.249, p<.001), followed in order by educational level, age, depression level, attendance of elderly's college, and religious activity. The total explanatory power of these variables is 36%. Conclusion: In order to prevent cognitive impairment among the elderly, elderly people have to maintain social relationships continuously, and expand the social network by participating in the related programs. Some efforts to prevent the occurrence of depression and to stimulate patients' brain activity need to be recommended.

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Assessing the Functional Status of Acute Stroke Patients using ICF Core Set-short Form (단축형 ICF 핵심지표로 측정한 뇌졸중 환자의 기능상태)

  • Kang, Jiyeon;Gong, Ju;Park, Mi-Jin;Lee, Yeo-Won;Kim, Yuri
    • Journal of muscle and joint health
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    • v.20 no.1
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    • pp.22-30
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    • 2013
  • Purpose: The International Classification of Functioning, Disability and Health (ICF) model was proposed by the World Health Organization for enhancing interdisciplinary communication. The purpose of this study was to examine the functional status of acute stroke patients using ICF core sets-short form. Methods: A set of 15 ICF items on functional status was used by nurses for their daily nursing assessment on functional status in 44 acute stroke patients in a university hospital. Results: The highest level of function was "consciousness", while the lowest was "defecation". Compared with functional status on the first day, consciousness, ingestion, language (mental), and defecation functions were significantly improved on the 14th day. However, there was no significant changes in items on activity and participation or environmental functions. Conclusion: These findings suggest that the function-specific nursing interventions for acute stroke patients need to be developed. Future research needs to test the usefulness of ICF items as an measurement tool.

A Statistical Perspective of Neural Networks for Imbalanced Data Problems

  • Oh, Sang-Hoon
    • International Journal of Contents
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    • v.7 no.3
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    • pp.1-5
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    • 2011
  • It has been an interesting challenge to find a good classifier for imbalanced data, since it is pervasive but a difficult problem to solve. However, classifiers developed with the assumption of well-balanced class distributions show poor classification performance for the imbalanced data. Among many approaches to the imbalanced data problems, the algorithmic level approach is attractive because it can be applied to the other approaches such as data level or ensemble approaches. Especially, the error back-propagation algorithm using the target node method, which can change the amount of weight-updating with regards to the target node of each class, attains good performances in the imbalanced data problems. In this paper, we analyze the relationship between two optimal outputs of neural network classifier trained with the target node method. Also, the optimal relationship is compared with those of the other error function methods such as mean-squared error and the n-th order extension of cross-entropy error. The analyses are verified through simulations on a thyroid data set.

Development of Comfort Feeling Structure in Indoor Environments Using Hybrid Neuralnetworks (하이브리드 신경망을 이용한 실내(室內) 쾌적감성(快適感性)모형 개발)

  • Jeon, Yong-Ung;Jo, Am
    • Journal of the Ergonomics Society of Korea
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    • v.20 no.2
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    • pp.29-46
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    • 2001
  • This study is about the modeling of comfort feeling structure in indoor environments. To represent the degree of practical comfort feeling level in an environment, we measured elements of human sense and resultant elements of comfort feeling such as coziness, refreshment, and freshness with physical values(temperature, illumination, noise. etc.). The relationships of elements of human sense and elements of comfort feeling were formulated as a fuzzy model. And a hybrid-neural network with three layers were designed where obtained from fuzzy membership function values of the elements of human sense were used as inputs, and given as fuzzy membership function values of resultant elements of comfort feeling were used as outputs. Both kinds of fuzzy membership function values were obtained from physical values. The network was trained by measured data set. The proposed hybrid-neural network were tested and proposed a more realistic model of comfort feeling structure in indoor environments.

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Development of Quality Information Control Technique using Fuzzy Theory (퍼지이론을 이용한 품질 정보 관리기법 개발에 관한 연구)

  • 김경환;하성도
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.524-528
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    • 1996
  • Quality information is known to have the characteristic of continuous distribution in many manufacturing processes. It is difficult to describe the process condition by classifying the distribution into discrete ranges which is based on the set concept. Fuzzy control chart has been developed for the control of linguistic data but it still utilizes the dichotomous notion of classical set theory. In this paper, the fuzzy sampling method is studied in order to manage the ambiguous data properly and incorporated for generating fuzzy control chart. The method is based on the fuzzy set concept and considered to be appropriate for the realization of a complete fuzzy control chart. The fuzzy control chart was compared with the conventional generalized p-chart in the sensitivity for quality distribution and robustiness against the noise. The fuzzy control chart with the fuzzy sampling method showed better characteristics.

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Photovoltaic System Allocation Using Discrete Particle Swarm Optimization with Multi-level Quantization

  • Song, Hwa-Chang;Diolata, Ryan;Joo, Young-Hoon
    • Journal of Electrical Engineering and Technology
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    • v.4 no.2
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    • pp.185-193
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    • 2009
  • This paper presents a methodology for photovoltaic (PV) system allocation in distribution systems using a discrete particle swarm optimization (DPSO). The PV allocation problem is in the category of mixed integer nonlinear programming and its formulation may include multi-valued dis-crete variables. Thus, the PSO requires a scheme to deal with multi-valued discrete variables. This paper introduces a novel multi-level quantization scheme using a sigmoid function for discrete particle swarm optimization. The technique is employed to a standard PSO architecture; the same velocity update equation as in continuous versions of PSO is used but the particle's positions are updated in an alternative manner. The set of multi-level quantization is defined as integer multiples of powers-of-two terms to efficiently approximate the sigmoid function in transforming a particle's position into discrete values. A comparison with a genetic algorithm (GA) is performed to verify the quality of the solutions obtained.

Market Segmentation With Price-Dependent Quality Evaluation in Denim Jeans Market ; Based on Conjoin analysis and mixture model (청바지제품 세분시장 내 가격-품질 평가집단 추출에 관한 연구: 결합분석과 mixture model를 이용하여)

  • 곽영식;이진화
    • Journal of the Korean Society of Clothing and Textiles
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    • v.26 no.11
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    • pp.1605-1614
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    • 2002
  • The purpose of this study was to identify the consumers who use the level of price as the indicator of the product quality. In order to implement the purpose of this study, Jeans market had been segmented by the mixture regression model, and price response function was calibrated for each segment. Based on the types of price response function, segments were allocated into one of two groups; the group using the level of price as the quality indicator or the group not using the level of price as that. Then, characteristics of both groups were compared in terms of product attributes and demographic variables. Data were co]looted from the sample of the 23o undergraduate and graduate students in Seoul. For the data analysis, mixture regression model, conjoint analysis, and t-test were used. As a result, jeans market was divided into 5 segments. Segment 1,2,3 were allocated into the group not using the level of price as the quality indicator while segment 4,5 were done into the other group. Significant differences existed between two groups in product attributes, not in demographic variables. Mixture model and conjoint analysis were proved to be an effective set of tools in market segmentation.

The Effects of Computer - based Attention Program on Cognition and Executive Function in Elderly with Vascular Dementia (컴퓨터 주의집중 프로그램이 혈관성 치매노인의 인지, 실행기능에 미치는 영향)

  • Lee, Hyojeong;Hwang, Kyoungok
    • Journal of The Korean Society of Integrative Medicine
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    • v.2 no.2
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    • pp.13-20
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    • 2014
  • Purpose : The purpose of this study was to evaluate the influence of cognition and executive function by computer - based attention program in vascular dementia. Method : The subjects of this study, old man diagnosed with vascular dementia, 12 patients were picked up, who were agreed with this research and were having hospital care for 4 weeks at nursing care centers. Computer-based attention program was applied to vascular dementia. Cognitive function measured by a K-MMSE and executive function measured by ACL. The SPSS Ver. 18.0 statistical program was used for data processing. The significance level for statistical inspection was set as 0.05. Result : In comparison of cognitive function was not significantly correlated in the pre and post test and executive function was significantly correlated in the pre and post test. Conclusion : Therefore, the computer-based attention program is useful to improve the cognitive and executive function in elderly with vascular dementia.