• 대한기계학회논문집A
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• 제20권12호
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• pp.3782-3791
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• 1996

A great deal of effert has been invested in upgrading the performance and the efficiency of mechanical structures. Using experimental modal analysis(EMA) or finite element analysis(FEA) data of mechanical structures, this performance and efficiency can be effectively evaluated. In order to analyze complex structures such as automobiles and aircraft, for the sake of computing efficiency, the dynamic substructuring techniques that allow to predict the dynamic behavior of a structure based on that of the composing structures, are widely used. By llinking a modal model obtained from EMA and an analytical model obtained from FEA, the best conditioned structures can be desinged. In this paper, a new algorithm for structural dynamic modification-SRFSM (substructure response function sensitivity method) is proposed by linking frequency responce function synthesis and response function sensitivity. A mehtod to obtain response function sensitivity using direct derivative of mechanical impedance, is also used.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제9권7호
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• pp.213-220
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• 2020

합성곱 신경망은 합성곱층과 완전연결층으로 구성되어 있다. 합성곱층과 완전연결층의 각 층에서는 비선형 활성함수를 사용하고 있다. 활성함수는 뉴런 간에 신호를 전달할 때 입력신호가 일정 기준 이상이면 신호를 전달하고 기준에 도달하지 못하면 신호를 보내지 않을 수 있는 뉴런의 정보전달 방법을 모사하는 함수이다. 기존의 활성함수는 손실함수와 관계성을 가지고 있지 않아 최적해를 찾아가는 과정이 늦어지는 점을 개선하기 위해 활성함수를 일반화한 민첩한 활성함수를 제안하였다. 민첩한 활성함수의 매개변수는 역전파 과정에서, 매개변수에 대한 손실함수의 1차 미분계수를 이용한 학습과정을 통해 최적의 매개변수를 선택하는 방법으로 손실함수를 감소시킴으로써 심층신경망의 성능을 향상시킬 수 있다. MNIST 분류문제를 통하여 민첩한 활성함수가 기존의 활성함수에 비해 우월한 성능을 가짐을 확인하였다.

• Research in Vestibular Science
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• 제17권4호
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• pp.134-141
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• 2018

Objectives: We aimed to study the role of vestibular input on spatial memory performance in mice that had undergone bilateral surgical labyrinthectomy, semicircular canal (SCC) occlusion and 4G hypergravity exposure. Methods: Twelve to 16 weeks old ICR mice (n=30) were used for the experiment. The experimental group divided into 3 groups. One group had undergone bilateral chemical labyrinthectomy, and the other group had performed SCC occlusion surgery, and the last group was exposed to 4G hypergravity for 2 weeks. The movement of mice was recorded using camera in Y maze which had 3 radial arms (35 cm long, 7 cm high, 10 cm wide). We counted the number of visiting arms and analyzed the information of arm selection using program we developed before and after procedure. Results: The bilateral labyrinthectomy group which semicircular canal and otolithic function was impaired showed low behavioral performance and spacial memory. The semicircular canal occlusion with $CO_2$ laser group which only semicircular canal function was impaired showed no difference in performance activity and spatial memory. However the hypergravity exposure group in which only otolithic function impaired showed spatial memory function was affected but the behavioral performance was spared. The impairment of spatial memory recovered after a few days after exposure in hypergravity group. Conclusions: This spatial memory function was affected by bilateral vestibular loss. Space-related information processing seems to be determined by otolithic organ information rather than semicircular canals. Due to otolithic function impairment, spatial learning was impaired after exposure to gravity changes in animals and this impaired performance was compensated after normal gravity exposure.

• 한국음향학회지
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• 제32권5호
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• pp.415-422
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• 2013

본 논문에서는 경첩 손실 함수를 최소화를 통해서 강인한 이진 오디오 핑거프린팅 방법을 제안하였다. 특히 제안된 방법에서 오디오 핑거프린트는 이진값을 가지므로 핑거프린트 DB 크기를 줄여줄 수 있는 장점이 있다. 일반적으로 특징을 이진화하는 과정에서 핑거프린트의 강인성, 식별성 등 성능의 손실이 불가피하므로 손실을 최소화하는 것이 필요하다. 본 논문에서는 핑거프린팅에서 두 오디오 클립 간의 유사도가 경첩 함수 형태로 주어지는 것에 착안하여 경첩 손실을 최소화하는 방법으로 특징을 이진화하여 핑거프린트를 구하는 방법을 제안한다. 유도된 경첩 손실 함수는 최소 손실 해싱 기법을 통해서 최소화 하였다. 수 천곡 규모의 오디오에 대해서 다양한 변환들에 대한 인식 성능을 실험하였으며, 제안된 경첩 손실 함수 최소화를 통해서 핑거프린트의 식별성과 강인성이 개선됨을 확인하였다.

• 대한한의학원전학회지
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• 제33권2호
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• pp.51-59
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• 2020

Objectives : We would like to study what is the most appropriate "feature" to effectively perform authorship attribution of the text of Traditional East Asian Medicine Methods : The authorship attribution performance of the Support Vector Machine (SVM) was compared by cross validation, depending on whether the function words or content words, single word or collocations, and IDF weights were applied or not, using 'Variorum of the Nanjing' as an experimental Corpus. Results : When using the combination of 'function words/uni-bigram/TF', the performance was best with accuracy of 0.732, and the combination of 'content words/unigram/TFIDF' showed the lowest accuracy of 0.351. Conclusions : This shows the following facts from the authorship attribution of the text of East Asian traditional medicine. First, function words play an important role in comparison to content words. Second, collocations was relatively important in content words, but single words have more important meanings in function words. Third, unlike general text analysis, IDF weighting resulted in worse performance.

• PNF and Movement
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• 제18권2호
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• pp.159-172
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• 2020

Purpose: The study sought to determine whether goal achievement, performance, satisfaction, activities of daily living, and gross motor function in children with spastic cerebral palsy are positive affected by goal-oriented functional task training. Methods: In a single case study, two 7-year-old girls diagnosed with spastic cerebral palsy were given functional task training based on individualized goals for 24 60-minute sessions over a period of 6 months. The individualized goals reflected the needs of both children and parents. The Canadian occupational performance measure (COPM) and the goal attainment scale (GAS) were used to measure goal performance and satisfaction before and after intervention. Independence of activities of daily living before and after intervention were assessed using the functional independence measure for children (Wee-FIM). And change of gross motor function were assessed using gross motor function measure (GMFM). Results: Clinically significant changes were observed in COPM and GAS, as well as positive changes in independence of gross motor function and activities of daily living. Conclusion: The findings indicate that goal-oriented functional task training addresses the needs of children with spastic cerebral palsy, which increases treatment satisfaction and has a positive effect on independent activities and participation in daily life.

• PNF and Movement
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• 제18권3호
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• pp.445-452
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• 2020

Purpose: The purpose of this study was to evaluate the analysis of the association between upper extremity function and the Wolf Motor Function Test (WMFT) for chronic hemiparetic stroke patients and investigate the evidence of the WMFT as a clinical tool of upper extremity function in individuals with chronic hemiparetic stroke. Methods: This study applied an observational, cross-sectional design in outpatients at three local rehabilitation units in Seoul. Forty-nine individuals who had a diagnosis of first stroke participated in this study. All participants were analyzed for four clinical measures, including the Box and Block Test (BBT), the WMFT, grip strength, and the Canadian Occupational Performance Measure (COPM). Results: Upon analysis, a significant relationship was found between the WMFT scores and BBT scores as well as the grip strength. The WMFT score was statistically and positively associated with the COPM satisfaction score; however, it was not related to the COPM performance score. Conclusion: The results of this study suggest that the WMFT is positively related to simple tasks, such as hand muscle strength and manual dexterity. However, the WMFT does not have a relationship with complex tasks, which are measured by COPM performance abilities.

• The Journal of Korean Physical Therapy
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• 제34권5호
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• pp.248-254
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• 2022

Purpose: This study was undertaken to identify the effect of amateur wind musical performance and choir activity on pulmonary function, and to determine the usefulness as a respiration training program by measuring the pulmonary functions of subjects. Methods: A total of 90 subjects (wind instrument players group=30, choir members group=30, control group=30) participated in the experiment. Pulmonary function test (FVC, FEV₁, FEV₁/FVC ratio, MVV, SVC, PEF, FEF 25-75%, IRV, ERV) was conducted using a spirometer (CardioTouch 3000S, Bionet, Seoul, Republic of Korea). Each factor was measured 3 times to meet the American Thoracic Society criteria, and the highest value was used in the analysis. Results: Comparing pulmonary function between the amateur wind instrument players (WP), amateur choir members (CH), and control (CG) groups revealed significant differences in FEV₁, FVC, FEV₁/FVC, and ERV (p<0.05). Highest values were obtained in the WP group. Significant differences were obtained for various factors in the multiple regression analysis of practice year (PY), practice time per week (PTPW), and exercise time per week (ETPW): FEV₁ and FVC in PY, FEV₁/FVC in PTPW, and FEV₁/FVC, MVV, PEF, and FEF (25-75%) in ETPW. Conclusion: Amateur wind instrument performance effectively improves lung function and is useful as a breathing training program for preventing debilitation and improving respiratory function.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1694-1700
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• 2004

In this paper, we propose the AWLS/MFT (Adaptive Weighed Least Squares/ Modulation Function Technique) devised by A. E. Pearson et al. for the transfer function estimation of a modal system and investigate the performance of several algorithms, the Gram matrix method, a Luenberger Observer (LO), Least Squares (LS), and Recursive Least Squares (RLS), for the estimation of initial conditions. With the benefit of the Modulation Function Technique (MFT), we can separate the estimation problem into two phases: the transfer function parameters are estimated in the first phase, and the initial conditions are estimated in the second phase. The LO method produces excellent IC estimates in the noise free case, but the other three methods show better performance in the noisy case. Finally, we compared our result with the Prony based method. In the noisy case, the AWLS and one of the three methods - Gram matrix, LS, and RLS- show better performance in the output Signal to Error Ratio (SER) aspect than the Prony based method under the same simulation conditions.

• International journal of advanced smart convergence
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• 제6권4호
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• pp.73-79
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• 2017

The Convolutional Neural Network (CNN) has shown an excellent performance in computer vision task. Applications of CNN include image classification, object detection in images, autonomous driving, etc. This paper will evaluate the performance of CNN model with ReLU and SELU as activation function. The evaluation will be performed on four different choices of hyperparameter which are initialization method, network configuration, optimization technique, and regularization. We did experiment on each choice of hyperparameter and show how it influences the network convergence and test accuracy. In this experiment, we also discover performance improvement when using SELU as activation function over ReLU.