• 수산해양기술연구
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• 제52권1호
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• pp.42-47
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• 2016

This study was conducted to investigate visual threshold of nigro (Cichlasoma nigrofasciatum) on white LED light. The visual threshold was obtained by analyzing electrocardiogram (ECG) of the nigro. 5 individuals (body weight: 15.62~45.49 g; TL: 8.9~12.4 cm) were trained for lights by an electric stimulus. And then the heart rate (beats/10s) before and after switching on the light were compared. Light intensity range was from 0.00 to 226.4 lux. Average heart rate was 10.36 beats/10s in the normal condition. When the fish perceived the light, the heart rate was decreased. Visual threshold of the fish was 2.59 lux.

• 한국컴퓨터정보학회논문지
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• 제22권5호
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• pp.65-72
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• 2017

Premature Ventricular Contraction(PVC) arrhythmia is most common abnormal-heart rhythm that may increase mortal risk of a cardiac patient. Thus, it is very important issue to identify the specular portraits of PVC pattern especially from the patient. In this paper, we propose a new method to extract the characteristics of PVC pattern by applying K-means machine learning algorithm on Heart Rate Variability depicted in Poinecare plot. For the quantitative analysis to distinguish the trend of cluster patterns between normal sinus rhythm and PVC beat, the Euclidean distance measure was sought between the clusters. Experimental simulations on MIT-BIH arrhythmia database draw the fact that the distance measure on the cluster is valid for differentiating the pattern-traits of PVC beats. Therefore, we proposed a method that can offer the simple remedy to identify the attributes of PVC beats in terms of K-means clusters especially in the long-period Electrocardiogram(ECG).

• 한국멀티미디어학회논문지
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• 제21권11호
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• pp.1317-1326
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• 2018

A common treatment for tinnitus rehabilitation is to use a device called a sound generator to continuously supplying the sound stimuli. The devices usually provides a sound called white noise, or pink noise, which are common in nature. In this paper, we developed a mobile system for tinnitus diagnostics and therapy using Android mobile applications. The first step for tinnitus diagnostics is detecting an exact tinnitus frequency of the patients, therefore we provide a bark scale tinnitus detection algorithm for fast and accurate diagnostics. Also, the system can provide various stimuli sounds including white noise, pink noise, brown noise, nature sounds, and binaural beats. Also we provides the therapeutic functions through questionnaires to solve existing problems of the patients.

• 디지털콘텐츠학회 논문지
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• 제17권6호
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• pp.449-459
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• 2016

본 논문에서는 기존의 인공신경망을 이용한 자동작곡 방법에서 발생한 세 가지 문제점을 개선하는 새로운 방법을 제안한다. 첫 번째 문제는 인공신경망이 출력한 곡의 박자를 음악이론에 맞도록 후처리 하는 것에서 모든 경우를 처리하지 못하여 발생한 문제이다. 두 번째 문제는 음표를 학습하는 인공신경망에 음표와 구분되는 큰 값으로 쉼표를 같이 학습하다보니 음표공간이 왜곡되어 발생하는 문제이다. 마지막 문제는 새로운 곡 작곡 시 사용자가 작곡해서 넣어준 초기 멜로디와 박자가 인공신경망이 출력하는 나머지 멜로디와 박자와 어울리지 못하여 발생하는 문제이다. 본 논문에서는 이러한 문제를 해결하기 위하여 개선된 박자 후처리 알고리즘과 초기 멜로디 처리 방법을 제안하였으며 쉼표용 인공신경망을 새로이 도입하였다. 실험결과 새로 제안한 방법이 기존의 방법에서 발생한 세 가지 문제점을 모두 해결하는 것으로 판명되었다.

• Physical Therapy Rehabilitation Science
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• 제6권3호
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• pp.146-151
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• 2017

Objective: The purpose of this study was to investigate the effects rhythmic and non-rhythmic aerobic exercises on depression and balance of healthy elderly people. Design: Randomized controled trial. Methods: Nineteen older subjects were randomly divided into 2 groups for rhythmic and non-rhythmic aerobic exercises. Both aerobic exercises consisted of functional movements such as turning in opposite directions, and running in place, the exercise consisted of movements that could activate balance. The rhythmic training group initially used music with 8 beats, and then later progressed to 16 beats. Additionally, we adjusted the pace of the music using songs from 125 beats per minute (bpm) to 160 bpm. Both groups were exercised for 50 minutes a day, twice a week, for a total of 8 weeks. We measured the condition of the patients before the intervention, and after 8 weeks of intervention. The Beck depression inventory (BDI) was used to measure the degree of depression. The Berg balance scale (BBS) was used to measure static and dynamic balance ability. We measured the subject's subjective balance confidence using the fall efficacy scale (FES). Results: Both groups showed significant improvement in BDI, BBS, and FES (p<0.05). The rhythmic aerobic exercise group showed a significant improvement only in the BBS change values compared to the non-rhythmic group (p<0.05). Conclusions: According to this study, both rhythmic and non-rhythmic aerobic exercises resulted in significant improvement in the degree of depression and balance ability of the elderly. The rhythmic aerobic exercise was more effective for dynamic balance ability.

• 한국전문물리치료학회지
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• 제10권3호
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• pp.81-90
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• 2003

This study was conducted to assess the effects of the gait training method in incomplete spinal cord injured persons using an auto-walking machine. Persons with incomplete spinal cord injury level C or D on the American Spinal Injury Association impairment scale participated for eight weeks in an auto-walking training program. The gait training program was carried out for 15 minutes, three times per day for 8 weeks with an auto-walking machine. The foot rests of the auto-walking machine can be moved forward, downward, backward and upward to make the gait pattern with fixed on crank. The patient's body weight is supported by a harness during waking training. We evaluated the gait speed, physiologic cost index, motor score of lower extremities and the WISCI (walking index for spinal cord injury) level before the training and after the forth and eighth week of walking training. 1. The mean gait speed was significantly increased from .22 m/s at pre-training to .28 m/s after 4 weeks of training and .31 m/s after 8 weeks of training (p=.004). 2. The mean physiologic cost index was decreased from 4.6 beats/min at pre-training to 3.0 beats/min after 4 weeks and 2.0 beats/min after 8 weeks of training, but it was not statistically significant (p=.140). 3. The mean motor score of lower extrernities was significantly increased from 29.8 to 35.8 after 8 weeks of training (p=.043). 4. The mean WISCI level was significantly increased from level 10 to level 19 after 8 weeks of training (p=.007). The results of this study suggest that the gait training program using the auto-walking machine increased the gait speed, muscle strength and galt pattern (WISCI level) in persons with incomplete spinal cord injury. A large, controlled study of this technique is warranted.

• Environmental Analysis Health and Toxicology
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• 제25권2호
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• pp.145-151
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• 2010

Perfluorinated chemicals (PFCs) is a kinds of persistent organic pollutants, and have the potential toxicity of which is causing great concern. In this study, we employed Oryzias latipes embryos to investigate the developmental toxicity of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA)s compound using flowthrow system for 14 day. O. latipes embryos were exposed to solvent control, 20, 40 and 80 mg/L of PFOS and 62.5, 130, 260 mg/L of PFOA respectively. After exposure, hatchability, mortality, total length and heart beats were examined. Hatching rates were reduced approximately 27% in the 80 mg/L PFOS-treated group and 17% in the 62.5, 130 mg/L PFOA-treated groups. Heart beats in the PFOS-treated groups were reduced at 7 day but, PFOA-treated groups were increased heart beats. 80 mg/L PFOS treated group showed significant reduction in growth (total length) level to 90% of control. But PFOA did not showed significant effect on growth. In the 14 days $LC_{50}$ of PFOS and PFOA was 22.74 mg/L and 173 mg/L, respectively. The overall results indicated that the early stage of O. latipes might be a reliable model for the testing of developmental toxicity to perfluorinated chemicals.

• 한국운동역학회지
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• 제16권4호
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• pp.61-71
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• 2006

The purpose of this study was to compare kinematic characteristics on the limbs at 3 different walking speed during the energy and the normal walking. Eight subjects performed energy walking and normal walking at the slow speed(65 beats/min), the normal speed(115beats/min), the fast speed(160 beats/min). The 3-d angle was calculated by vector projected with least squares solution with three-dimensional cinematography(Motion Analysis corporation). The range of motion was calculated on the trunk, shoulder, elbow, hip, knee joint. The results showed that stride length was no difference of the two walking pattern. The duration of support phase was also no difference of the two walking pattern. The range of motion of shoulder joint significantly increased in the sagittal and frontal planes, and the range of motion of elbow joint significantly increased as the energy walking. The range of motion of hip joint had no significant difference in the any planes in changing of walking speed. But the most remarkable difference of the two walking patterns revealed at the trunk. The range of flexion/extension angle had significant increasing $2.36^{\circ}$ at normal speed, and the range of the right/left flexion angle had significant increasing below $4^{\circ}$ at the 3 walking speed, and The range of rotation angle had significant increasing $7.35^{\circ}$, $9.22^{\circ}$, respectively at the normal and slow speed. But there was no significant difference of range of motion at the hip and knee joints between energy walking and normal walking.

• 대한의용생체공학회:의공학회지
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• 제25권2호
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• pp.129-135
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• 2004

재택건강관리 시스템은 주로 정상인들로부터 빈번하게 측정한 생체신호의 실시간 처리과정을 필요로 한다. 본 논문에서는 이러한 환경에서 측정되는 심전도 신호에서 DRS를 검출하기 위한 단순화된 알고리즘과 검출된 QRS의 정상과 비정상 여부만을 분류하는 알고리즘에 대하여 기술한다. 기존에 사용되고 있는 실시간 QRS 검출 알고리즘을 세분화하여 단순화된 QRS 검출 알고리즘을 제안함으로서 저가형 소형 단말기에서도 사용이 가능하도록 하였다. 또한 검출된 QRS들로부터 QRS 폭, R-R 간격, DRS 형태변수를 추출하여 QRS의 정상과 비정상을 판단하는 알고리즘을 개발하였다. 단순화된 QRS 검출기의 성능과 정상과 비정상의 분류성능은 각각 약 99%와 96%로 나타났다. 본 논문에서 제안된 QRS 검출과 분류를 위한 알고리즘들은 복잡한 신호처리 과정이 필요치 않으므로 재택건강관리 시스템에서의 실시간 심전도처리에 사용될 수 있을 것이다

• 한국정보통신학회논문지
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• 제26권1호
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• pp.30-40
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• 2022

심전도 신호는 개인에 따라 형태와 특징이 다양하므로, 하나의 신경망으로는 분류하기가 어렵다. 주어진 데이터를 직접적으로 분류하는 것은 어려우나, 대응되는 정상 데이터가 있을 경우, 이를 비교하여 정상 및 비정상을 분류하는 것은 상대적으로 쉽고 정확하다. 본 논문에서는 템플릿 군을 이용하여 대표정상심박 정보를 획득하고, 이를 입력 심박에 결합함으로써 심박을 분류한다. 결합된 심박을 영상화한 후, 학습 및 분류를 진행하여, 하나의 신경망으로도 다양한 레코드의 비정상심박을 검출이 가능하였다. 특히, GoogLeNet, ResNet, DarkNet 등 다양한 신경망에 대해서도 비교학습 기법을 적용한 결과, 모두 우수한 검출성능을 가졌으며, GoogLeNet의 경우 99.72%의 민감도로, 실험에 사용된 신경망 중 가장 우수한 성능을 가졌음을 확인하였다.