• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1993년도 추계학술대회
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• pp.93-95
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• 1993

• 농촌계획
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• 제9권2호
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• pp.29-37
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• 2003

The objectives of this study are to develop an agricultural drought evaluation model based on administrative boundaries and to assist the effective drought-related decision-making of local governments. The model which was named ADEM(Administrative Drought Evaluation Model for Paddies) is designed to simulate daily water balance between available water quantities from various agricultural water facilities such as reservoirs, wells, pump stations, etc. and water requirements in paddies. And in order to numerically describe the agricultural drought severity, two indices were defined; One is ADFP(Agricultural Drought Frequency for Paddies) which is calculated with a frequency analysis of monthly water deficit, and the other is ADIP(Agricultural Drought Index for Paddies) with a scale of $-4.2{\sim}+4.2$. The developed model was applied to Yeoju district and showed good correspondence with the historical records of drought.

• 대한의용생체공학회:의공학회지
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• 제27권2호
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• pp.78-82
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• 2006

The ventricular assist device(VAD) helps to reduce the overload against the patient's native heart(NH). The pulsatile VAD pumps out the ventricular blood to the aorta with pulsatile flow. If the VAD pulsates simultaneously with the NH, the ventricle of the NH could confronts abnormally elevated aortic pressure, and this could deteriorate the ventricle rather than assist to recover it. Thus counterpulsation algorithms to avoid copulsation have been adopted by many VADs, but these methods utilize electrocardiography or arterial pressure signals, which may have difficulties to acquire consistently for a long period. In this study, the copulsation estimation algorithm for the counterpulsation is developed using the VAD outlet pressure signal. The VAD outlet pressure signal is good to maintain for a long time and the sensor part could be integrated to the VAD as a built-in module. From the VAD outlet pressure signal and its pump rate information calculated with Fast Fourier Transform, pulse peaks by the VAD and the NH were extracted and the next copulsation time at which the VAD and the NH would pulsate simultaneously was estimated. This estimation algorithm was implemented by using PC MATLAB software and tested for various pump rate conditions with mock circulation system. For each condition, the copulsation time was estimated successfully. Consequently, the results showed the possibility to use the outlet cannula pressure signal in the copulsation estimation.

• 한국미생물·생명공학회지
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• 제32권3호
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• pp.265-270
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• 2004

하수 중계펌프장에서 발생되는 악취를 효율적으로 저감할 수 있는 기술로 4가지 기술(활성탄 흡착법, 약액세정법, 지렁이 분변로를 이용한 탈취법, 바이오필터법)의 탈취 효율과 경제성을 조사하였다. PU 바이오필터와 활성탄 흡착법의 평균탈취 효율은 98% 이상이었으나, 지렁이 분변토 바이오필터와 약액세정법은 60-80%의 탈취율을 보였다. PU 바이오필터 탈취 성능은 악취가스의 체류시간이 4-36초에서 체류시간과 무관하게 약 98-99%로 매우 안정적이었고, 최대 탈취능은 으로 평가되었다. $1.6${\times}$10^{ 7}$ $OUm^{-3}$$h^{-1}$ PU 바이오필터와 활성탄 흡착법의 탈취비용을 조사하였다. 악취 강도가 증가함에 따라 활성탄 흡탁법의 운전비는 선형적으로 증가하였지만 바이오필터법은 약간 증가하였다. 바이오필터의 초기 시설비의 비용이 활성탄 흡탁법의 2배 이상이었지만 운전비가 활성탄 보다 아주 저렴한 것으로 평가되었다. 결론적으로 탈취효율과 경제성이 우수한 생물여과법이 가장 유망한 기술로 평가되었다.

• 대한의용생체공학회:의공학회지
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• 제38권4호
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• pp.168-174
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• 2017

To improve and downsize the KIOM-Pulse Analysis System(KIOM-PAS), which has been traditionally used in clinical trials, a miniaturized PAS(M-PAS) with a pneumatic pump has been developed. M-PAS is composed of a measurement module and an arm-mounting module, on which an arm can be placed. The measurement module is equipped with a pressing component and sensor, which is a wearable wristband. The arm-mounting module includes a pneumatic motor, data acquisition board and valves. In addition, the measurement module is divided into a fixing module of band type for attachment to a pulsation site and a sensing module, which includes a sensor and a tube. The fixing module and sensing module are constructed independently, and the detachable fastening method improves the posture convenience of the subject during measurement. M-PAS has been reduced to 1/6 the size of KIOM-PAS, and the measurement time is shortened by 22%. Using a simulator, the difference between the waveforms measured by the two devices exhibited a high degree of similarity of within 3.65%. M-PAS represents improvements in size and convenience compared with KIOM-PAS, and it is expected to be widely used in clinics in the future because it improves the attachment method of the fixing module.

• 대한의용생체공학회:의공학회지
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• 제23권2호
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• pp.131-137
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• 2002

이동 작동기형 인공 심장의 원격 모니터링을 위한 시스템을 설계, 구현하였다 동물 실험이나 환자에의 임상 실험 후 인공 심장 동작 상황에 대한 원격 모니터링은 필수적이다. 본 논문에서는 담당자가 환자로부터 멀리 떨어진 곳에 있을 때에도 인터넷을 통해 간편하게 인공 심장의 동작 상황과 혈류역학 정보를 확인할 수 있는 시스템을 제안하여 그 성능을 확인하였다. 기존의 시스템과 쉽게 연결하여 사용할 수 있도록. 또 쉬운 관리와 기능 향상을 위하여 COM(Component Object Model) 기술 기반의 콤포넌트 모듈로 데이터 전송 부분을 구현하였고. 범용의 브라우저를 이용하여 인터넷에 연결, 확인토록 자바 애플릿을 이용하여 실행되도록 하였다. 또한 정해진 룰에 따라 판단하여 인공 심장의 이상 동작시 관리자에게 알려주도록 하였다. 구현된 시스템을 1개월 이상 생존하는 동물에 적용하여 본 결과 아무런 문제없이 정상 동작함을 확인하였다.

• 대한의용생체공학회:의공학회지
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• 제18권4호
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• pp.389-396
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• 1997

본 논문에서는 뇌파측정기에서 발생하는 전기적 잡음을 제거하기 위하여 뇌파 측정시 발생하는 안구운동, PVC 룰러 펌프 잡음등을 포함하는 전기적 잡음에 대하여 기술하였다. 적응 디지틀 필터는 이러한 뇌파 측정 잡음을 제거하는 효과적인 방법이다. 그러나 일반적인 적응 디지틀 필터는 뇌파신호의 일부주파수 성분에 영향을 주게되므로 자동 뇌파 처리에는 부적합하다. 그러므로 본 고에서 이러한 뇌파잡음을 제거하기 위하여 제안한 방법은 일반적인 적응디지틀 필터의 참조채널을 사용하지 않으며, EOG 잡음을 제거하기 위하여 선형예측기와 고정차수 FIR 필터를 연결하였으며, 펌프잡음을 제거하기 위하여 선형예측기와 잡음 제거기를 연결함으로써 실현하였다. 또한 시뮬레이션을 통한 결과는 잡음제거 능력의 관점에서 제안한 방법의 성능을 분석하였으며, 결과적으로 약 20dB의 잡음제거 성능을 보였다.

• 대한의용생체공학회:의공학회지
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• 제21권4호
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• pp.353-362
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• 2000

축류형 혈액펌프에서 발생하는 용혈이 이 펌프의 성공여부를 결정짓는 주요한 요인의 하나이다. 지금까지는 용혈을 알아내기 위해서는 in-vitro 적인 실험에 의하여 용혈량을 추정하였으나, 수치유체해석에 의한 용혈량의 추정이 가능하다고 생각된다. 따라서, 본 연구에서는 다양한 형태의 임펠러에 대하여, 난류모델은 k-$\varepsilon$모델을 사용하여 3차원 수치유체역학 해석을 시도하였다. 수치유체해석에 있어서는 펌프 유입측에 입자를 흘려 넣어 이 입자가 매일 10ms마다 받는 난류에너지를 구하여 전단응력으로 환산하였다. 해석결과 전단응력은 주로 임펠러의 후방에서 나타나는 것을 알 수 있었다. 수치유체해석결과의 신뢰성을 확인하기 위하여 임펠러의 in-vitro 실험에 의한 용혈시험 결과를 비교하였으나, 양자 사이에 상관도는 높은 것을 알 수 있었다. 상기한바와 같이 유체 해석에 의한 용혈 예측은 물론 용혈이 발생하는 주요 부위의 예측이 가능함을 시사하고 있어, 축류형 혈액펌프 개발시 용혈 특성 개선을 위한 설계도구로써의 유용함을 확인하였다.

• 한국농공학회논문집
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• 제61권4호
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• pp.87-96
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• 2019

The objective of this study was to develop a general inundation modeling technique considering the effect of drainage delay in the paddy field districts. In most studies, farmland inundation simulations have been conducted using previously developed watershed models. However, the water cycle in the paddy fields has a different structure from that of the general watershed, and the effect of the drainage delay should be considered. In this study, the drainage delay algorithm was developed using water balance equation, and the inundation modeling was performed for inundation-prone paddy fields located near Doowol stream. As a result, the depth of inundation was 43.1 cm and 45.2 cm, respectively, due to the 100-year and 200-year frequency rainfall. With the operation of drainage pump ($0.1m^3/s$), inundation depths decreased by 5.8 cm and 6.0 cm, respectively, and inundation time reduced by 20 hours and 21 hours, respectively for the 100-year and 200-year frequency rainfall. The result showed that the general inundation modeling technique developed in this study could reflect the effect of drainage delay due to the rise of external water level and the flooding reduction effect by operation of drainage pump. The results of this study are expected to be useful to establish measures for damage caused by farmland inundation.

• 한국물환경학회지
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• 제36권6호
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• pp.535-545
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• 2020

This study aims to conserve and monitor energy use in public sewage treatment plants by utilizing data from the SCADA system and by controlling the aeration rate required for maintaining effluent water quality. Power consumption in the sewage treatment process was predicted using the equipment's uptime, efficiency, and inherent power consumption. The predicted energy consumption was calibrated by measured data. Additionally, energy efficiency indicators were proposed based on statistical data for energy use, capacity, and effluent quality. In one case study, a sewage treatment plant operated via the SBR process used ~30% of energy consumed in maintaining the bioreactors and treated water tanks (included decanting pump and cleaning systems). Energy consumption analysis with the K-ECO Tool-kit was conducted for unit processing. The results showed that about 58.7% of total energy consumed was used in the preliminary and biological treatment rotating equipment such as the blower and pump. In addition, the energy consumption rate was higher to the order of 19.2% in the phosphorus removal process, 16.0% during sludge treatment, and 6.1% during disinfection and discharge. In terms of equipment energy usage, feeding and decanting pumps accounted for 40% of total energy consumed following 27% for blowers. By controlling the aeration rate based on the proposed feedback control system, the DO concentration was reduced by 56% compared pre-controls and the aeration amount decreased by 28%. The overall power consumption of the plant was reduced by 6% via aeration control.