• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.48-50
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• 2006

In this paper, we propose a method to minimize the baseline wandering that make hard to detect R wave in ECG. This method uses a different signal between ECG and ascending slope tracing waves to minimize the baseline wandering. When the slope of ECG signal maintains the value or falls, the ascending slope tracing wave fellows ECG signal directly, and this wave holds that value of ECG signal when the slope begins to rises in a certain time(=hold time). After this hold time, this wave traces ECG signal again. To evaluate this minimizing method for baseline wandering, the experiments are carried out with 5 ECG data in the database of MIT/BIH. R waves in the proposed different signal are detected by using descending slope trace waves and compared with the annotation file. The results show that the proposed method Is sure to minimize the baseline wandering in ECG.

• Advances in pediatric surgery
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• 제14권2호
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• pp.183-188
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• 2008

Wandering spleen is very rare condition in children characterized by migration of the spleen from its normal position due to laxity or absence of the supporting splenic ligaments. We experienced a case of splenic infarction due to torsion of a wandering spleen in a 6-year-old boy who presented with fever, vomiting, and abdominal pain of 2 day's duration. On physical examination, there was severe tenderness in the left upper quadrant of the abdomen. The plain abdominal radiograph showed marked colonic gaseous distension. Contrast-enhanced abdominal computed tomography scan showed decreased density of spleen in the normal position, consistent with infarction. At emergency laparotomy, a wandering spleen twisted $360^{\circ}$ on its pedicle was found. Despite splenic detorsion, blood flow could not be restored. Splenectomy was therefore performed. The child was discharged 7 days after surgery without any complications.

• 재활간호학회지
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• 제16권1호
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• pp.9-17
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• 2013

Purpose: This study was to evaluate the effects of aromatherapy and foot reflex massage on emotion, sleep disturbance and wandering behavior in older adults with dementia. Methods: This is a quasi-experimental study with a non-equivalent control group. A total of 39 participants were divided into two groups. Aromatherapy and foot reflex massage was administrated to experimental group (N=19). There was no treatment for the control group (N=20). Data were analyzed using the SPSS/Win 18.0 program. Results: Experimental group showed significant differences in emotion, sleep disturbance and wandering behavior in comparison to the control group. Conclusion: The results showed that aromatherapy and foot reflex massage program was effective on emotion, sleep and decreasing a wandering behavior in older adults with dementia. This research suggests that aromatherapy and foot reflex massage could be recommended as a nursing intervention for enhancing quality of life in older adults with dementia.

• 한국정보통신학회논문지
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• 제5권7호
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• pp.1287-1294
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• 2001

심전도는 파형의 크기가 수 ㎷정도로 아주 작은 생체신호로서, 계측할 때 발생되는 잡음으로 인하여 해석하는데 어려움을 준다[1]. 깨끗한 파형을 얻기 위해서는 심전도 신호에 포함되어 있는 전원 잡음, 기저선 변동, 근 잡음을 제거해야 된다. 심전계에서 심전도 신호를 기록하는데 있어서 가장 큰 문제를 야기하는 부분이 기저선 변동인데 전극을 부착한 부위의 근육수축과 호흡의 리듬에 따라서 발생하게 된다. 그러한 기저선은 상하로 심하게 불규칙한 변동을 하면서 흔들리게 되어 심전도 신호를 진단하는데 어려움이 있으므로 기저선 변동을 제거하는 부분이 매우 중요하다. 본 연구에서는 실시간으로 신호처리 할 수 있는 디지털 필터를 구현함으로써 기저선 변동을 제거하는 시스템을 설계하여 환자의 심장질환을 분석하는데 응용할 수 있도록 하였다.

• 한국도로학회논문집
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• 제19권5호
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• pp.89-96
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• 2017

PURPOSES: This study aims to develop a rational procedure for estimating the pavement roughness index considering vehicle wandering. METHODS : The location analysis of the passing vehicle in the lane was performed by approximately 1.2 million vehicles for verification of the wandering distribution. According to verification result, the distribution follows the normal distribution pattern. The probability density function was estimated using each lane's wandering distribution model. Then the procedure for applying a weighted value into the lane profile was conducted using this function. RESULTS : The modified index, MRIw, with consideration towards applying the wandering weighted value application was computed then compared with MRI. It was found that the Coefficient of Variation for distribution of lateral roughness index in the lane was high in the case of a large difference between each index (i.e., MRIw and MRI) observed. CONCLUSIONS : This result confirms that the new procedure with consideration of the weight factor can successfully improve the lane representative characteristics of the roughness index.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 춘계종합학술대회
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• pp.512-515
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• 2001

홀터 심전계는 휴대용 소형 심전도 기록기로서 신체에 부착한 후 일상생활을 계속하면서 심장의 운동 및 전위변화를 기록, 분석하여 심장질환의 유무를 판단하는데 유용하게 쓸 수 있으므로 연구가 활발하게 진행되고 있다. 깨끗한 심전도를 얻기 위해서는 심전도(ECG) 신호에 섞여있는 60Hz 전원 잡음, 기저선 변동, 근 잡음을 제거해야 된다. 홀터 심전계에서 심전도 신호를 기록하는데 있어서 가장 큰 문제를 야기하는 부문이 기저선 변동인데 전극을 부착한 부위의 근육수축과 호흡의 리듬에 따라서 발생하게된다. 그러한 기저선은 상하로 심하게 불규칙한 변동을 하면서 흔들리게 되어 심전도 신호를 진단하는데 어려움이 있으므로 기저선 변동을 제거하는 부분이 매우 중요하다. 본 연구에서는 아날로그 단에서 기저선 변동을 안정화하고 실시간으로 신호 처리할 수 있는 디지털 필터를 구현함으로써 기저선 변동을 제거하는 시스템을 설계하여 환자의 심장질환을 분석하는데 응용할 수 있도록 하였다.

• 공학교육연구
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• 제20권5호
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• pp.23-33
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• 2017

It is examined that how flipped learning and mind-wandering affect an idea generation task. For the purpose, the participants in the idea generation task are divided into two groups to learn SIT(Systematic Inventive Thinking) and BCC(Business Creativity Codes) as idea generating tools in advance. One group learned the tools in a classroom, and the other group through an online education program. The creativity level of an idea is evaluated in the dimensions of originality, practicality, and realizability. The creativity levels of the ideas from the two groups are not statistically different in all the three creativity dimensions. To examine the effect of mind-wandering, another group generated ideas two hours a day in four days instead of eight hours in one day. The creativity levels of the ideas from the third group are higher in the dimensions of originality and practicality. This shows that the effectiveness of flipped learning is not so different from the face-to-face learning in a classroom, and mind-wandering has a positive effect in the learning.

• 한국도로학회논문집
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• 제10권3호
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• pp.79-86
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• 2008

차량의 동적하중이 도로상에 작용하는 위치를 계측하기 위한 원더링 계측용 사선센서의 적정 설치각도를 제안하였다. 이를 위해서 테이프스위치 센서를 이용하여 원더링 계측용 장비를 개발하였고, 개발된 장비와 실험차량을 이용하여 평가용 자료를 수집하였다. 수집자료 분석 결과, 사선센서의 설치각도가 커질수록 원더링 수집자료의 오차가 감소하였고, 이러한 오차의 감소는 통계적으로도 의미가 있는 것으로 분석되었다. 그러나 사선센서를 $30^{\circ}$ 이상으로 설치할 경우, 탠덤축의 제원상의 이유로 인해 오류자료가 수집되는 것을 확인할 수 있었다. 따라서 본 연구에서는 국내 차량제원 등을 종합하여 원더링 계측용 사선센서의 적정 설치각도를 $20^{\circ}{\sim}25^{\circ}$로 제안하였다.

• 대한의용생체공학회:의공학회지
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• 제16권4호
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• pp.517-524
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• 1995

This paper is a study on the design of the cascade adaptive filter (CAF) for baseline wandering elimination in order to enhance the performance of the detection of ST segments in ECG. The CAF using Least Mean Square (LMS) algorithm consists of two filters. The primary adaptive filter which has the cutoff frequency of 0.3Hz eliminates the baseline wandering in raw ECG The secondary adaptive filter removes the remnant baseline wandering which is not eliminated by the primary adaptive filter. The performance of the CAF was compared with the standard filter, the recursive filter, and the adaptive impulse correlated filter (AICF). As a result, the CAF showed a lower signal distortion than the standard filter and the AICF. Also, the CAF showed a better perf'ormance in noise elimination than the standard filter and the recursive filter. In conclusion, considering the characteristics of the noise elimination and the signal distortion, the CAF shows a better performance in the removal of the baseline wandering than the other three Otters and suggests the high performance in the detection of ST segment.

• Wind and Structures
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• 제33권6호
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• pp.447-462
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• 2021

High spatial and temporal surface pressure measurements were carried out in the state-of-the-art tornado simulator, the Wind Engineering, Energy and Environment (WindEEE) Dome, to explore the characteristics of stationary and translating tornado-like vortices (TLV) for a wide range of swirl ratios (S=0.21 to 1.03). The translational speed of the TLV and the surface roughness were varied to examine their effects on tornado ground pressures, wandering, and vortex structure. It was found that wandering is more pronounced at low swirl ratios and has a substantial effect on the peak pressure magnitude for stationary TLV (error percentage ≤ 35%). A new method for removing wandering was proposed which is applicable for a wide range of swirl ratios. For translating TLV, the near-surface part lagged behind the top of the vortex, resulting in a tilt of the tornado vertical axis at higher translating speeds. Also, a veering motion of the tornado base towards the left of the direction of the translation was observed. Wandering was less pronounced for higher translation speeds. Increasing the surface roughness caused an analogous effect as lowering the swirl ratio.