• Title/Summary/Keyword: Active theory

Search Result 869, Processing Time 0.024 seconds

A Simple Average Power Theory and Modified Compensation Performance Evaluation of Active Power Filters (능동전력필터의 간단한 평균전력이론과 수정된 보상성능 평가법)

  • 정영국;임영철;양승학
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.13 no.3
    • /
    • pp.64-72
    • /
    • 1999
  • The fictitious power theory in time domain is very easy to understand, but power analyzing speed of active power is increased, because power is analyzed using signal tedmiques based on the corre1ation between voltage and current wavefonns. Also, conventional methods in time/frequency domain to evaluate the correlation performance of active power filters are not provided easy solutions. So, the authors have previously proposed 3-D current coordinates which is composed into active component, fundarrental reactive component and distorted component of nonlinear loads current. This trethod has excellent perfonnance, but can not evaluate the characteristics of nonlinear load current whether It is inductive or capacitive. Therefore, To overcorre problems trentioned previously, this paper deals with the simple average power theory and the modified 3-D current coordinates for evaluating the compensation perfonnance of active power filters. To confirm the validity, active power filter simulator is developed using C-language. From the simulation, results are discussed their utility.tility.

  • PDF

Hierarchical Value Structure of Active Seniors for Noodles: Applying Soft Laddering Technique Based on the Means-end Chain Theory (소프트 래더링 기법을 이용한 액티브 시니어의 면류에 대한 가치체계)

  • Oh, Hye-In;Kim, Ga-Hyun;Oh, Ji-Eun;Cho, Mi-Sook
    • Journal of the Korean Society of Food Culture
    • /
    • v.34 no.4
    • /
    • pp.463-473
    • /
    • 2019
  • The aim of this study is to identify the value structure of active seniors for noodles. Noodles are the secondly most preferred and familiar food in Korea, followed by rice. And noodles also have a variety of tastes/flavors and even a variety of ceremonial characteristics. The necessity of offering proper food to seniors has recently increasing because Korea becoming an aged society. This study conducted 1:1 in-depth interviews with 30 active senior participants using the soft laddering technique, which is based on the means-end chain theory. The Implication Matrix and HVM were derived from performing content analysis. The active seniors mainly consider the 'taste', expecting to obtain the 'satisfying taste', and pursuing the 'family affair', 'pleasure', and 'self-satisfaction'. The results of this study indicated that the taste is the most important attribute and the active seniors consider their family as well as the pleasure and satisfaction of their own. Male seniors mainly pursue the 'pleasure' and 'self-satisfaction' by satisfying their taste through considering 'taste' and 'familiarity'. But female seniors mainly pursue the 'family affair' by 'satisfying taste' through considering 'taste'. These results can be used as a basic data for developing noodle products for the elderly. This study will also contribute to the development of special care food and product concepts for the silver generation.

A Reliability Analysis of Rigid Retaining Wall due to the Modes of Wall Movement (벽체변위에 따른 토류벽의 신뢰도해석)

  • Jae, Yeong-Su;Kim, Yong-Pil;Song, Yong-Seon
    • Geotechnical Engineering
    • /
    • v.4 no.1
    • /
    • pp.7-16
    • /
    • 1988
  • The safety factor has been used widely and uniquely at present to check the safety of the structure . However, probability of failure would be logically attempted to check the reliability of the structure in future Coulomb's theory or Rankine's theory has been applied in practice to retaining earth structure in spite of the fact that the lateral earth pressure, which is the primary factor in the determination of wall structure, depends on the modes of wall movement . This study is concentrated on the two modes of , wall movement (active case rotation about bottom(AB) , active case rotation about top(AT)) of the overturning'failure of vertical wall with horizontal sand backfill . The static active earth pressure is determined by applying each of Coulomb's theory, Dubrova's redistribution theory and Chang's method The earthquake active earth pressure is determined by adding Seed and Whitman's earthquake pressure to the static earth pressure , On the condition that design variables are fixed with each of the above earth pressure, reliability is analyzed using the recently developed method of AFOSM (Advanced First Order Second Moment)

  • PDF

The reserch of Kim hong-kyung's view of extra meridians -With the connection yin yang wei qiao mai With four trigram constitution theory- (김홍경의 기경팔맥관(奇經八脈觀)에 관한 연구(硏究) - 음양유교맥(陰陽維蹻脈)과 사상체질(四象體質)의 상관성을 중심으로 -)

  • Jung, Hae-Myeong;Yun, Chang-Yeol
    • Journal of Haehwa Medicine
    • /
    • v.22 no.2
    • /
    • pp.13-21
    • /
    • 2014
  • Subject : Kim hong-kyung(金洪卿)'s view of eight extra meridians Object : Kim hong-kyung has not only deeply studied Saam acupuncture but also the function and characteristics of extra meridian at the same time. Especially, he has tried the study to connect yin yang wei qiao mai(陰陽維蹻脈) with Lee je-ma(李濟馬)'s four trigram constitution theory, therefore the author felt the need to make public the theory and started reserch on the theory. Method : I researched the physiological properties of extra meridians through the past eastern medical literature, I reported on the types of people to show well the properties of extra meridians gathering Kum-oh's verbal explanation when I had classes from him. Result : Kum-oh Kim hong-kyung defined meridians as passways of consciousness and feeling, he interpreted 12 meridians and extra meridians with the view of mind, which has very important meanings in the history of acupuncture in the point of first trial to interpret meridians from this view. He explained Ren mai(任脈) and Du mai(督脈) are meridians which show clearly properties of yin-yang to appear trusts of affirmation and distrusts of denial in the mind, as Ren(任) means entrusting and Du(督) means supervising in English. He explained Chong mai(衝脈) is the meridian representing impulsive man that has a meaning of impulse as being suggested the name of Chong mai, because Chong mai is borrowed from Foot shao yin kidney meridian(足少陰腎經). Dai mai(帶脈) is the meridian representing the characteristics of woman that has a meaning of binding as being suggested from the name of Dai mai which acts when people have something on their flank or they are pregnant, because Dai mai borrowed from Foot shao yang gall bladder meridian. He thought that four trigram divided from yin and yang is innate trigram, so Yang wei mai(陽維脈), Yin wei mai(陰維脈), Yang qiao mai(陽蹻脈), Yin qiao mai(陰蹻脈) among extra meridians have connections with Tai-yang ren(太陽人), Tai-yin ren(太陰人), Shao-yin ren(少陰人), Shao-yang ren(少陽人) of Four trigram constitution theory respectively which was created by Lee je-ma. He explained yang means opponents and wei(維) means binding. Yang wei mai is the meridian to be active when opponents bind or intervene in you, also the meridian is well active to the people who easily criticize others who are rude, to the people who well refuse restraints from organization. Because he explained yin means me and wei(維) means binding. Yin wei mai is the meridian to be active when I bind and intervene in opponents. He also state that the meridian is easily active to the people who have a tendency to gather people and make party apparatus by nature. He explained Yang qiao mai is the meridian to be active in the situation that people are waiting for others to bridge gap because yang means opponents and qiao(蹻) which has a meaning of standing on one's tiptoes means bridging gap between people. He also state the meridian is easily active to Shao yin ren who has a tendency to be passive, to easily settle down and not to move by nature. He explained Yin qiao mai is the meridian to be active in the situation that I bridge gap between me and others to make friends, because yin means me and qiao(蹻) which has a meaning of standing on one's tiptoes means bridging gap between me and others. He also state the meridian is easily active to Shao yang ren who is active in every business and who has remarkable ability to make friends. Conclusion : Kim hong-kyung stated the physiological properties of extra meridians as below. Ren mai is the meridian representing positive confidence which is easily active when people have a mind to trust others, Du mai is the meridian representing negative distrust which is easily active when people have doubts. Chong mai is the meridian representing the characteristics of man that has impulsive characteristics. Dai mai is the meridian representing the characteristics of woman to be easily active when she is pregnant. Yang wei mai has close connections with Tai-yang ren who has a tendency to refuse restraints from others and to criticize on opponent's remarks and behaviors that are wrong. Yin wei mai has close connections with Tai-yin ren, as the meridian is active in the situation that people enjoy restraining and intervening in others. Yang qiao mai has close connections with Shao yin ren, as the meridian is active to the people who are negative and passive by nature. Yin qiao mai has close connections with Shao yang yin who has a strong tendency to make friends easily by nature.

Studies on control mechanism and performance of a novel pneumatic-driven active dynamic vibration absorber

  • Kunjie Rong;Xinghua Li;Zheng Lu;Siyuan Wu
    • Structural Engineering and Mechanics
    • /
    • v.87 no.2
    • /
    • pp.117-127
    • /
    • 2023
  • To efficiently attenuate seismic responses of a structure, a novel pneumatic-driven active dynamic vibration absorber (PD-ADVA) is proposed in this study. PD-ADVA aims to realize closed-loop control using a simple and intuitive control algorithm, which takes the structure velocity response as the input signal and then outputs an inverse control force to primary structure. The corresponding active control theory and phase control mechanism of the system are studied by numerical and theoretical methods, the system's control performance and amplitude-frequency characteristics under seismic excitations are explored. The capability of the proposed active control system to cope with frequency-varying random excitation is evaluated by comparing with the optimum tuning TMD. The analysis results show that the control algorithm of PD-ADVA ensures the control force always output to the structure in the opposite direction of the velocity response, indicating that the presented system does not produce a negative effect. The phase difference between the response of uncontrolled and controlled structures is zero, while the phase difference between the control force and the harmonic excitation is π, the theoretical and numerical results demonstrate that PD-ADVA always generates beneficial control effects. The PD-ADVA can effectively mitigate the structural seismic responses, and its control performance is insensitive to amplitude. Compared with the optimum tuning TMD, PD-ADVA has better control performance and higher system stability, and will not have negative effects under seismic wave excitations.

A Study on Intelligent Decentralized Active Suspension Control System with Descriptor LMI Design Method

  • Park, Jung-Hyen
    • Journal of information and communication convergence engineering
    • /
    • v.6 no.2
    • /
    • pp.198-203
    • /
    • 2008
  • An Intelligent optimal control system design algorithm in active suspension equipment adopting linear matrix inequalities control system design theory with representing by descriptor system form is presented. The validity of the linear matrix inequalities intelligent decentralized control system design with representing by descriptor system form in active suspension system through the numerical examples is also investigated.

Applications of Experiential Learning Theory to Graduate Medical Education (졸업 후 의학교육에 경험학습이론의 활용)

  • Lee, Young Hee;Kim, Byung Soo
    • Korean Medical Education Review
    • /
    • v.11 no.1
    • /
    • pp.11-20
    • /
    • 2009
  • The purpose of this study was to introduce the concepts of experiential learning and the Kolb's model, and to review some applications of experiential learning theory in graduate medical education. The published literature on GME and education for general practitioners applying the experiential theory and the Kolb's model was reviewed. Experience learning defined the cyclical learning process which emphasizes the learners' reflective thinking of the learners' concrete experiences and their active participation in continuous learning actives. Kolb includes this 'cycle of learning' as a central principle in his experiential learning theory. This is typically expressed as a four-stage cycle of learning. Kolb's cycle moves through concrete experience(CE), reflective observation(RO), abstract conceptualization(AC) and active experimentation(AE). Components of continuing education of the adult learner were based on autonomy, context of learning, and competence and performance as educational objectives. Some strategies for graduate medical education were reflective thinking, self-directed learning, morning reporting and feedback with peer review, etc. Opportunities for learning from experience in practical life can be made to enhance reflective thinking and performance of practitioners. Strategies to develop reflective practice among physicians should be explored by further research.

A Study on the Healing Interface around Void space of Contemporary Houses (현대주택의 허공간 주변의 치유적 인터페이스에 관한 연구)

  • Kim, Jinhee;Kim, Kwangho
    • Journal of The Korea Institute of Healthcare Architecture
    • /
    • v.22 no.2
    • /
    • pp.15-23
    • /
    • 2016
  • Purpose: Planning space of the house is important as a universal place to relieve stress of contemporary people. Void space is easy to perform mental and cultural programs in aspect of affording the healing behavior. The "Interface" accommodates healing behaviors through mutual interchange between void space and solid space as the edge of the solid space around void space. This study presents a efficient theory of healing space through combining space theory with the Kitwood's theory of psychiatry used for the art therapy. Methods: Spatial elements based on Kitwood's theory converges towards 2 behavioral elements; Meditation(-), Sense of Community(+). Balancing with reciprocal complement between behaviors of passive and stable "Meditation(-)" and active and released "Sense of Community(+)" was analysed. Results: "Faciliation" can be used in combination with "Flow(+)" as active factor. "Validation" is combined with "Prospect(+,-)", and divides into 2 factor ; "Recognition-Refreshment(-)", "Reaction-Social Exchange(+)". "Holding" is combined with "Refuge(-)" as passive factor. Implications: This study established concept of spatial healing elements in connection with theory of Psychiatry about Alzheimer that is extreme situation of stress. This study is expected to enhance the validity and efficiency in analysis of healing space.

Vibration control of a time-varying modal-parameter footbridge: study of semi-active implementable strategies

  • Soria, Jose M.;Diaz, Ivan M.;Garcia-Palacios, Jaime H.
    • Smart Structures and Systems
    • /
    • v.20 no.5
    • /
    • pp.525-537
    • /
    • 2017
  • This paper explores different vibration control strategies for the cancellation of human-induced vibration on a structure with time-varying modal parameters. The main motivation of this study is a lively urban stress-ribbon footbridge (Pedro $G\acute{o}mez$ Bosque, Valladolid, Spain) that, after a whole-year monitoring, several natural frequencies within the band of interest (normal paring frequency range) have been tracked. The most perceptible vibration mode of the structure at approximately 1.8 Hz changes up to 20%. In order to find a solution for this real case, this paper takes the annual modal parameter estimates (approx. 14000 estimations) of this mode and designs three control strategies: a) a tuned mass damper (TMD) tuned to the most-repeated modal properties of the aforementioned mode, b) two semi-active TMD strategies, one with an on-off control law for the TMD damping, and other with frequency and damping tuned by updating the damper force. All strategies have been carefully compared considering two structure models: a) only the aforementioned mode and b) all the other tracked modes. The results have been compared considering human-induced vibrations and have helped the authors on making a decision of the most advisable strategy to be practically implemented.

Collision-Free Arbitration Protocol for Active RFID Systems

  • Wang, Honggang;Pei, Changxing;Su, Bo
    • Journal of Communications and Networks
    • /
    • v.14 no.1
    • /
    • pp.34-39
    • /
    • 2012
  • Collisions between tags greatly reduce the identification speed in radio frequency identification (RFID) systems and increase communication overhead. In particular for an active RFID system, tags are powered by small batteries, and a large number of re-transmissions caused by collisions can deteriorate and exhaust the tag energy which may result in missing tags. An efficient collision-free arbitration protocol for active RFID systems is proposed in this paper. In this protocol, a new mechanism involving collision detection, collision avoidance, and fast tag access is introduced. Specifically, the pulse burst duration and busy-tone-detection delay are introduced between the preamble and data portion of a tag-to-reader (T-R) frame. The reader identifies tag collision by detecting pulses and transmits a busy tone to avoid unnecessary transmission when collision occurs. A polling process is then designed to quickly access the collided tags. It is shown that the use of the proposed protocol results in a system throughput of 0.612, which is an obvious improvement when compared to the framed-slotted ALOHA (FSA) arbitration protocol for ISO/IEC 18000-7 standard. Furthermore, the proposed protocol greatly reduces communication overhead, which leads to energy conservation.