• 제목/요약/키워드: feedback controls

검색결과 171건 처리시간 0.026초

적출된 쥐심장을 이용한 Fructose-1, 6 diphosphate의 심근보호 효과에 관한 실험 (Myocardial Preserving Effect of Fructose-1, 6-diphosphate in Isolated Rat Heart)

  • 이철주;조수신;류재온;김문환;김세환;이익호;박소라;서창국
    • Journal of Chest Surgery
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    • 제26권2호
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    • pp.75-79
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    • 1993
  • Myocardial protection against ischemic and reperfusion injuries is still in troublesome eventhough couples of the way of myocardial protection have been applied since 1970's. One of the possibility in myocardial protection is adding Fructose-l,6-diphosphate(FDP) in cardioplegic solution. It is assumed that FDP can promote ATP production under anaerobic condition as well as inhibiting the supressing effect of lactate on phosphofructokinase. We compared the myocardial protecting effects of FDP in crystalloid cardioplegic solution (St. Thomas formula, 10$^{\circ}C$, pH = 7.4) and reperfusate using isolated rat hearts in modified Langendorf apparatus by the parameters of preischemic and post reperfusing heart rate, time to first beat, occurance of arrhythmia, time to stabilization, and the rate of left ventricular pressure developing. Group A (n = 10), containing no FDP in cardioplegic and reperfusing solutions was control. Group B (n = 5), containing FDP in cardioplegic solution, showed statistically significant superiority of postischemic left ventricular pressure development than the control group. Group C (n = 5), containing FDP in reperfusate, showed statistically significant myocardial depressing effect than the controls. Other parameters were unremarkable. The cause is uncertain, but it is assumed that the negative feedback inhibition of FDP in energy metabolism or unknown blocking effect of FDP on certain transmembrane ionic currents is present. In conclusion, 1) FDP in cardioplegic solution has beneficial effect on postischemic left ventricular preservation. 2) FDP is strong acid when is hydrolyzed, so precise acid titration is neccessary. 3) FDP in reperfusate has negative left ventricular preservation, otherwise the mechanism is still uncertain.

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가슴 성형 경험자의 성형 동기와 성형 후 평가 -이상적 신체이미지 내면화를 통한 의복 소비행동의 변화- (Motives for Selecting Breast Augmentation and Post-Operative Evaluations of Korean Women who have Undergone Cosmetic Breast Surgery -Internalization of Ideal Body-Image Reflected on Clothing Consumption Behavior-)

  • 김수연;이혜영;고애란
    • 한국의류학회지
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    • 제34권5호
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    • pp.740-753
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    • 2010
  • This study analyzes the motives of Korean women for choosing breast augmentation in a cultural and relational context; in addition, it investigates their evaluations after surgery. Data was collected through in-depth interviews with 10 Korean women in their 20s and 30s who have received cosmetic breast augmentation. Enlarged and made-up breasts are a form of clothing that symbolizes the socio-economic status of women. In the vertical and individualized Korean society, the desire of women for a fashionable body invigorated the appearance management market. Fashion consumers have passively internalized the ideal body trends as the concept of the ideal body-image, which has been constructed by the social structure, markets, and the media. The analysis was rooted in post-modern feminist perspectives on the female body. The ideal body-image internalization process through the social interactions of participants was the main cultural factor to choose breast surgery. The self-image and conformity/individuality of participant were categorized as relational factors for the motivation to undergo breast surgery. The result showed that after surgery the participants achieved positive feedback from their social relationships. They expressed or hid their socio-economic statuses through their purchased fashion bodies. They also showed higher self-esteem and feelings of satisfaction by pursuing individuality and conformity as a member of society. Moreover, they achieved wider fashion options and greater controls over their public/private/secret clothing choices for certain occasions. Cosmetic breast surgery positively empowered individual women while reinforcing the socially manipulated body ideals that oppress women at the same time. Participants internalized socially constructed values and justified their surgery choices.

가상 환경에서의 해마 모델에 대한 대화식 형상 분석☆ (Interactive Shape Analysis of the Hippocampus in a Virtual Environment)

  • 김정식;최수미
    • 인터넷정보학회논문지
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    • 제10권5호
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    • pp.165-181
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    • 2009
  • 본 논문은 해마의 형상 분석을 위한 효과적인 모델 표현 방법과 분석 과정에서의 실제감을 향상시키는 스테레오-햅틱 장치 기반의 대화형 가상 환경을 제공한다. 매개변수형 표면 모델과 골격 표현은 해마의 형상을 효과적으로 표현하고 이러한 정보를 옥트리 자료 구조에 저장하여 대화형의 형상 분석 작업을 가능하게 한다. 그리고 골격 기반 정규화 방법은 다양한 모달리티를 갖는 의료 영상으로부터 생성된 3차원 해마 모델들의 위치와 방위를 정확하게 맞추어주는 기능을 수행한다. 또한 본 논문에서는 정상인 해마 형상 집단과 간질 환자 해마 형상 집단의 정확한 분류 작업을 수행하기 위하여 SVM 알고리즘 기반의 분류기 모델을 구축하였다. 실험 결과를 통하여 본 논문에서 제안한 표현 구조는 다양한 단계의 형상 표현을 제공하며 SVM 기반 분류기는 두 집단간 형상 차이를 분석하기 위한 효과적이었음을 확인하였다. 또한 스테레오 디스플레이 장치와 햅틱 장치를 결합한 가상환경은 사용자에게 향상된 공간 인지와 조작력을 제공하기 때문에 의료 분야에서의 해마 모델과 같은 다양한 해부학적 구조에 대한 분석 작업에 효과적으로 활용될 수 있다.

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천연가스 개조 승용차에 대한 실험적 연구(1) - 연비, 배기 및 주행 성능 (Experimental Study on Natural Gas Conversion Vehicle(1) - Fuel Economy, Emission and Roadability)

  • 김형구;김인옥;엄인용
    • 한국자동차공학회논문집
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    • 제23권4호
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    • pp.410-419
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    • 2015
  • In this study, the roadability, fuel economy and emission characteristics were evaluated for a natural gas converted vehicle. The results are as follows; Not only the shortage of power was observed in stall test, but also large deterioration of acceleration performance was exposed in roadability. Compared to the original LPG system, the acceleration is 76% in start acceleration and 45 ~ 65% in overtaking acceleration, especially the decline became larger when air conditioner is at work. Furthermore, because the mapping data, which controls the injection depending on driving condition, do not match up with injection system, the failure of air-fuel ratio feedback control occurs resulting from the large gap between the required and the really supplied amount of fuel. This failure cause the exhaust gas to emit without catalytic conversion and the fuel economy based on the fuel heat value to get worse 22% in the mode test and 16% in road test respectively. In addition, the existing injection system does not secure enough fuel at the starting so that it may lead to the fail of clod start, the deterioration of hot start and inharmonic of engine at the idle after start.

자기유사성 네트워크에서 트래픽 제어에 의한 성능 개선 (Adaptive Data Hiding Techniques for Secure Communication of Images)

  • 석경휴;나상동
    • 한국통신학회논문지
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    • 제29권6B호
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    • pp.575-583
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    • 2004
  • 본 논문에서는 MTS 정체 프레임워크를 윈도우 기반 정체 제어, 특히 TCP로 확장하고 TCP의 대역폭 소비 반응의 적극성을 LTS 자기유사성 네트워크 상태의 함수 형태에서 연구한다. RTT가 결정한 피드백 루프의 시간 한계를 초과하는 정보의 형태로 조정하는 LTS 제어모듈과 TCP를 연계시키는 방법으로 연구하며, 또 정보는 개연적인 특성을 갖고 여러 시간대에 걸쳐 분산되는 기존 윈도우를 기반으로 실현되기 때문에, 이를 효과적으로 활용할 수 있는 방법으로 개선하고, MTS TCP의 성능을 자기 유사성 트래픽의 물리적 모델링에 기반 한 시뮬레이션을 벤치마크 환경을 통해 수행된다. 본 논문은 자기유사성 트래픽 조건에서 프로토콜 스택의 전송 프로토콜 변화의 영향을 파악 및 평가하는 방법론을 활용하고, 과중한 워크로드 조건에서 시뮬레이션을 통해 성능 개선을 평가 비교한다.

DRC Finals 2015 에서 휴머노이드 로봇의 자동차 운전과 하차에 관한 전략 (Strategies for Driving and Egress for the Vehicle of a Humanoid Robot in the DRC Finals 2015)

  • 안동현;신주성;전용범;손기원;장기호;폴오;조백규
    • 제어로봇시스템학회논문지
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    • 제22권11호
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    • pp.912-918
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    • 2016
  • This paper presents various strategies for humanoid vehicle driving and egress tasks. For driving, a tele-operating system that controls a robot based on a human operator's commands is built. In addition, an autonomous assistant module is developed for the operator. Normal position control can result in severe damage to robots when they egress from vehicles. To prevent this problem, another approach that mixes various joint control techniques is adopted in this study. Additionally, a footplate is newly designed and attached to the vehicle floor for the ground landing phase of the egress task. The attached plate enables the robot to step down onto the ground in a safe manner. For stable locomotion, a balance controller is designed for the humanoid. For the design of the controller, the robot is modeled using an inverted pendulum that consists of a spring and a damper. Then, a state feedback controller (with pole placement and a state observer) is built based on the simplified model. Many approaches that are presented in this paper were successfully applied to a full-sized humanoid, DRC-HUBO+, in the DARPA Robotics Challenge Finals, which were held in the United States in 2015.

CODOG 함정 추진체계 시뮬레이터 개발 (Development of CODOG Propulsion System Simulator)

  • 장재희;신승우;김민곤;오진석
    • 한국정보통신학회논문지
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    • 제21권9호
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    • pp.1808-1817
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    • 2017
  • 대잠, 대함, 보급 등, 함정에 요구되는 임무가 다양해지면서 함정의 추진체계 또한 임무를 효과적으로 수행하기 위해 ECS(Engineering Control System)를 필요로 한다. ECS는 추진체계를 모니터링하고 제어함으로써 함정이 임무를 수행할 수 있도록 한다. 최근 ECS 국산화 개발이 진행되면서 ECS에 대한 시험 검증을 위한 시스템이 요구되었고, CODOG 기반의 함정 추진체계 시뮬레이터를 개발하였다. CODOG 기반의 함정 추진체계 시뮬레이터는 가스터빈 모델, 디젤엔진 모델, 감속기어 모델, 가변추진기 모델로 나누어 제어 명령에 대한 피드백을 모의한다. 실험 결과, ECS 추진 모드에 따른 가스터빈, 디젤엔진 및 축의 속도, 토크, 출력 등을 확인할 수 있었다.

Using Multimedia to Improve Listening Comprehension in the EFL Classroom

  • Park, Seung-Won
    • 영어어문교육
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    • 제8권2호
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    • pp.105-115
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    • 2003
  • The four skills of a language are basically required for a communication. They are very important for a learner to develop the balanced language acquisition. Today both listening and speaking skills are emphasized in the global era rather than reading and writing proficiencies. The reason is really why the learners' communicative competence is more needed than the accurate knowledge of a structure in the language. For this reason, the listening comprehension should be taught effectively using the following strategies. First, the sound difference of a language must be taught. Language is a complicated process to convey the comprehensive meaning combined with the internal and external factors of a language. In other words, the meaning for the sound of language should be transmitted by the unit of vocabulary and syntax. Second, a good listening comprehension requires the familiarity and much experience with a lot of English words to understand English sentences unconsciously. Third, as understanding the structure of language is effective for the listening comprehension, the better listening comprehension can be possible through the meaningful exercise. Fourth, the compound process of listening comprehension requires the comprehensive understanding of language, but not the separate understanding of language. Fifth, the appropriate application of the multimedia courseware helps improve the listening comprehension better than that of the existing audio, video, tape recorder and so on. Using multimedia courseware is useful as follows: A learner is able to take as much lesson as he/she wants. It does take little time to repeat about what he/she takes a lesson. It gives the lively picture with the native speakers' voices. It gives him/her(a learner) a feedback effect continuously through the interaction of computer. It controls his/her lesson in accordance with the level of a learner.

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저항-커패시턴스 시정수 회로를 이용하여 지터 특성을 개선한 위상고정루프 (A Jitter Characteristic Improved PLL with RC Time Constant Circuit)

  • 안성진;최영식
    • 전자공학회논문지
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    • 제54권2호
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    • pp.133-138
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    • 2017
  • 본 논문은 RC 시정수 회로를 이용하여 지터 특성을 개선한 위상고정루프의 구조를 제안하였다. RC 시정수 회로에서는 루프 필터 전압이 작은 시정수와 큰 시정수 값을 가지는 회로를 통과하여 비교기로 전달된다. 작은 시정수 값을 가지는 회로를 지나는 신호는 거의 루프 필터 출력 전압과 같은 값을 가진다. 큰 시정수 값을 가지는 회로를 지나는 신호는 루프 필터 출력전압의 평균값을 가지며, 비교기회로에서 기준 신호 역할을 한다. 비교기의 출력 신호는 루프 필터에 전류를 공급하는 보조 전하펌프를 제어한다. 루프 필터 출력 전압이 상승하면 보조 전하펌프는 루프 필터에서 전류를 방전시켜 루프 필터 출력 전압이 하강하게 하고, 또는 루프 필터 출력 전압이 하강하면 보조 전하펌프는 루프 필터에서 전류를 충전시켜 루프 필터 출력 전압이 상승하게 한다. 이런 부궤환 루프는 필터 출력 전압 변동 폭을 줄여서 지터 크기를 감소시켜준다.

A Deep Belief Network for Electricity Utilisation Feature Analysis of Air Conditioners Using a Smart IoT Platform

  • Song, Wei;Feng, Ning;Tian, Yifei;Fong, Simon;Cho, Kyungeun
    • Journal of Information Processing Systems
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    • 제14권1호
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    • pp.162-175
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    • 2018
  • Currently, electricity consumption and feedback mechanisms are being widely researched in Internet of Things (IoT) areas to realise power consumption monitoring and management through the remote control of appliances. This paper aims to develop a smart electricity utilisation IoT platform with a deep belief network for electricity utilisation feature modelling. In the end node of electricity utilisation, a smart monitoring and control module is developed for automatically operating air conditioners with a gateway, which connects and controls the appliances through an embedded ZigBee solution. To collect electricity consumption data, a programmable smart IoT gateway is developed to connect an IoT cloud server of smart electricity utilisation via the Internet and report the operational parameters and working states. The cloud platform manages the behaviour planning functions of the energy-saving strategies based on the power consumption features analysed by a deep belief network algorithm, which enables the automatic classification of the electricity utilisation situation. Besides increasing the user's comfort and improving the user's experience, the established feature models provide reliable information and effective control suggestions for power reduction by refining the air conditioner operation habits of each house. In addition, several data visualisation technologies are utilised to present the power consumption datasets intuitively.