• 제목/요약/키워드: Beats

검색결과 221건 처리시간 0.032초

Feeding the Larvae of the Sea Urchin Strongylocentrotus intermedius on a Red-Tide Dinoflagellate Cochlodinium polykrikoides

  • Lee, Chang-Hoon
    • 한국양식학회지
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    • 제15권2호
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    • pp.79-86
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    • 2002
  • This study is the first attempt to understand the feeding physiology of a sea-urchin larva on a red-tide dinoflagellate. Fifteen day old larvae of S. intermedius capture C. polykrikoides cells by localized reversal of ciliary beats. No failure to transporte the algal cells from theciliated band to mouth and no rejection at the mouth suggest that C. polykrikoides has no feeding deterrence to S. intermedius larvae. The trend obtained for the clearance rate of S. intermedius larvae is similar to that of other sea urchin larvae. Thus, the clearance rate decreased as the algal concentration increased. Maximum clearance rate of S. intermedius on C. polykrikoides was 17.7 $\mu l$/larva/hr. Ingestion rate rapidly increased at lower algal concentrations and saturated at higher concentrations. There was no inhibition in ingestion rate at the highest prey concentration of ca. 3000 cells/ml. Maximum ingestion rate of S. intermedius on C. polykrikoides was 131 ngC/larva/d, which is higher than that reported for the larvae of the mussel Mytilus gal-lotrovincialis, but lower than that of the ciliate Strombidinopsis sp. The grazing rate, calculated by combining the field data on algal abundances with experimental data on ingestion rate, suggests that due to its low abundance, sea urchin Iarva has no significant grazing impact on C. polykrikoides population.

A Pacemaker AutoSense Algorithm with Dual Thresholds

  • Kim, Jung-Kuk;Huh, Woong
    • 대한의용생체공학회:의공학회지
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    • 제23권6호
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    • pp.477-484
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    • 2002
  • A pacemaker autosense algorithm with dual thresholds. one for noise or tachyarrhythmia detection (noise threshold, NT) and the other for intrinsic beat detection (sensing threshold. ST), was developed to improve the sensing performance in single pass VDD electrograms. unipolar electrograms, or atrial fibrillation detection. When a deflection in an electrogram exceeds the NT (defined as 50% of 57), the autosense algorithm with dual thresholds checks if the deflection also exceeds the ST. If it does, the autosense algorithm calculates the signal to noise ratio (SNR) of the deflection to the highest deflection detected by NT but lower than ST during the last cardiac cycle. If the SNR 2, the autosense algorithm declares an intrinsic beat detection and calculates the next ST based on the three most recent intrinsic peaks. If the SNR $\geq$2, the autosense algorithm checks the number of deflections detected by NT during the last cardiac cycle in order to determine if it is a noise detection or tachyarrhythmia detection. Usually the autosense algorithm tries to set the 57 at 37.5% of the average of the three intrinsic beats, although it changes the percentage according to event classifications. The autosense algorithm was tested through computer simulation of atrial electrograms from 5 patients obtained during EP study, to simulate a worst sensing situation. The result showed that the ST levels for autosense algorithm tracked the electrogram amplitudes properly, providing more noise immunity whenever necessary. Also, the autosense algorithm with dual thresholds achieved sensing performance as good as the conventional fixed sensitivity method that was optimized retrospectively.

Concomitant Right Ventricular Outflow Tract Cryoablation during Pulmonary Valve Replacement in a Patient with Tetralogy of Fallot

  • Shin, Hong Ju;Song, Seunghwan;Shin, Yu Rim;Park, Han Ki;Park, Young Hwan
    • Journal of Chest Surgery
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    • 제50권1호
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    • pp.41-43
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    • 2017
  • A 38-year-old female patient with a history of tetralogy of Fallot repair at 10 years of age underwent pulmonary valve replacement with a mechanical prosthesis, tricuspid annuloplasty, and right ventricular outflow tract cryoablation due to pulmonary regurgitation, tricuspid regurgitation, and multiple premature ventricular contractions with sustained ventricular tachycardia. After surgery, she had an uneventful postoperative course with arrhythmia monitoring. She was discharged without incident, and a follow-up Holter examination showed a decrease in the number of ventricular ectopic beats from 702 to 41.

Multi-objective Optimization Model with AHP Decision-making for Cloud Service Composition

  • Liu, Li;Zhang, Miao
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제9권9호
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    • pp.3293-3311
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    • 2015
  • Cloud services are required to be composed as a single service to fulfill the workflow applications. Service composition in Cloud raises new challenges caused by the diversity of users with different QoS requirements and vague preferences, as well as the development of cloud computing having geographically distributed characteristics. So the selection of the best service composition is a complex problem and it faces trade-off among various QoS criteria. In this paper, we propose a Cloud service composition approach based on evolutionary algorithms, i.e., NSGA-II and MOPSO. We utilize the combination of multi-objective evolutionary approaches and Decision-Making method (AHP) to solve Cloud service composition optimization problem. The weights generated from AHP are applied to the Crowding Distance calculations of the above two evolutionary algorithms. Our algorithm beats single-objective algorithms on the optimization ability. And compared with general multi-objective algorithms, it is able to precisely capture the users' preferences. The results of the simulation also show that our approach can achieve a better scalability.

자동 조기심실수축 탐지를 위한 최소 퍼지소속함수의 추출 (Minimum Fuzzy Membership Function Extraction for Automatic Premature Ventricular Contraction Detection)

  • 임준식
    • 인터넷정보학회논문지
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    • 제8권1호
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    • pp.125-132
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    • 2007
  • 본 논문은 가중 퍼지소속함수 기반 신경망(neural network with weighted fuzzy membership functions, NEWFM)을 이용하여 심전도(ECG) 신호로부터 조기심실수축(premature vedtricular contractions, PVC)을 자동 탐지하는 방안을 제시하고 있다. NEWFM은 MIT-BIH 데이터베이스의 부정맥 심전도를 웨이블릿 변환(wavelet transform, WT)한 계수로부터 학습하여 정상 파형과 PVC 파형을 구분한다. 비중복면적 분산 측정법을 적용하여 중요도가 가장 높은 웨이블릿 변환의 d3과 d4의 8개 계수를 추출하였다. 이들 특징입력을 3개의 실험군에 사용하여 각각 99.80%, 99.21%, 98.78%의 신뢰성 있는 전체분류율을 나타내었고, 이는 각 실험군에 대한 특징입력의 종속성이 적음을 보여준다. 추출된 8개 계수의 ECG 신호 구간과 퍼지소속함수를 제시함으로써 특징입력에 대한 명시적인 해석을 가능하게 하였다.

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칠정(七情)과 사기(四氣)에 대한 비교 연구 (Comparative Study on Seven Emotions and Four Energies)

  • 최성욱;강정수
    • 동의생리병리학회지
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    • 제19권3호
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    • pp.596-599
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    • 2005
  • Human health is affected by not only physical conditions but also mental and social well-being. Changes of human emotions show up as gestures, facial expressions and sweating. Human emotions are affected by such automatic nerve system functions as blood pressure, blood circulation speed, heart beats, pupillary reflex, fluid transfusion, muscular contraction and digestive organs, all of which influence the holistic diseases. The Oriental Medicine sees from a perspective of unity of divinity and men that human life activities are united in terms of their physical and mental functions. From such a perspective, human Five Organs are linked with Five Mental(五神) and Seven Emotions(七情), while they are affected by each other, influencing the life activities both directly and indirectly. Based on Confucianism, Sa-Sang Theory argues that human emotions can be categorized into four energy states and therefore, that human diseases and physiological conditions there of may be determined differently depending on the Four Energies(四氣). There seems to be some common points between Sa-Sang Theory and the conventional Oriental Medicine in that human emotions affect individuals' health conditions, so there seems to be much room for mutual complementation.

Vegetative Endocarditis and Thrombus Formation Associated with Escherichia coli in a Thoroughbred Horse

  • Yang, Hyoung-Seok;Kim, Jin-Young;Han, Jeong-Hee;Kim, Jae-Hoon
    • 한국임상수의학회지
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    • 제34권3호
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    • pp.213-217
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    • 2017
  • A 1-year and 8-month-old male, thoroughbred horse showed fever ($39.8^{\circ}C$), cardiac murmur, tachycardia up to 80 beats/min, anorexia, depression and lameness for about 2 months. The dead horse was referred to pathology laboratory at the College of Veterinary Medicine in Jeju National University. At necropsy, Severe protruding multiple rough cauliflower-like yellowish red nodules ranged $5{\sim}6{\times}2{\sim}3cm$ in size were attached on the mitral valve of the left heart. A yellowish red long stick-shaped thrombus $15{\times}3.5{\times}1.5cm$ in size was also present inside the right ventricle. Multifocal infarcts were scattered in the myocardium and renal cortex. Histopathologic examination revealed that morphologic diagnosis were vegetative endocarditis, thrombus in right ventricle, infarcts in myocardium and kidney, pulmonary congestion and edema, and splenic congestion. The isolated bacteria from vegetative lesions and thrombus were confirmed as Escherichia (E.) coli based on the bacterial culture and VITEK 2 system. Based on the gross and histopathologic features, and bacterial test, this case was diagnosed as vegetative endocarditis with thrombus formation associated by E. coli in a thoroughbred horse.

단일채널 복부 심전도를 통한 태아 심전도 분리 (A Study on the Separation of Fetal ECG from a Single Channel Abdominal ECG)

  • 박광리;이경중;이전
    • 대한전기학회논문지:시스템및제어부문D
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    • 제54권3호
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    • pp.198-205
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    • 2005
  • In this paper, we proposed a new algorithm for the separation of fetal ECG from single channel abdominal ECG. The algorithm consists of a stage of demixing vector calculation for initial signal and a stage of fetal beat detection for the rest of signal. The demixing vector was obtained by applying independent component analysis technique to projected signals into time-frequency domain. For the test of this algorithm, simulation signals, De Lathauwer's data and some measured data, which was acquired from 8 healthy volunteers whose pregnant periods ranged from 22 weeks to 35 weeks and whose ages from 27 to 37, were used. For each data, the accuracy of fetal beat detection was $100\%$ and with the location of fetal beats, fetal heart rate variability and morphology could be offered. In conclusion, this proposed algorithm showed the possibility of fetal beat separation with a single channel abdominal ECG and it might be adopted to a fetal health monitoring system, by which a single channel abdominal ECG is acquired.

조위승청탕(調胃升淸湯)이 심박수 미세 변화에 미치는 영향 (Effects of Jowisengcheong-tang on Heart Rate Variability)

  • 오승윤;이시우;길은영;주종천
    • 사상체질의학회지
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    • 제20권2호
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    • pp.53-57
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    • 2008
  • 1. Objectives When we give Jowiseungcheong-tang to Taeumin patients, analyzing a change of their autonomic nervous system. It is measured by the heart rate variability(HRV) analyzer. 2. Methods We give Jowiseungcheong-tang to ten Taeumin patients for three days and examine the HRV at first time and three days later. 3. Results and Conclusions We compared two HRV results. The value of RRNN(average of normal RR intervals), SDNN(the standard deviation of all normal RR intervals), RMSSD(the root mean square of successive differences between the normal heart beats) have a downward tendency. Norm HF(normalized high frequency power) have a upward tendency. norm LF (normalized low frequency power) and LHR(LF/HF ratio) have a downward tendency. It means hypofunction of autonomic nervous system. But all results are not significant. We think that restudy is needed with more patients and longer periods afterward.

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평균회귀 심박변이도의 K-평균 군집화 학습을 통한 심실조기수축 부정맥 신호의 특성분석 (Characterization of Premature Ventricular Contraction by K-Means Clustering Learning Algorithm with Mean-Reverting Heart Rate Variability Analysis)

  • 김정환;김동준;이정환;김경섭
    • 전기학회논문지
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    • 제66권7호
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    • pp.1072-1077
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    • 2017
  • Mean-reverting analysis refers to a way of estimating the underlining tendency after new data has evoked the variation in the equilibrium state. In this paper, we propose a new method to interpret the specular portraits of Premature Ventricular Contraction(PVC) arrhythmia by applying K-means unsupervised learning algorithm on electrocardiogram(ECG) data. Aiming at this purpose, we applied a mean-reverting model to analyse Heart Rate Variability(HRV) in terms of the modified poincare plot by considering PVC rhythm as the component of disrupting the homeostasis state. Based on our experimental tests on MIT-BIH ECG database, we can find the fact that the specular patterns portraited by K-means clustering on mean-reverting HRV data can be more clearly visible and the Euclidean metric can be used to identify the discrepancy between the normal sinus rhythm and PVC beats by the relative distance among cluster-centroids.