• Title/Summary/Keyword: Non-Reference

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Characteristic Analysis of Buck Converter by using the Non-Linear Instantaneous Following PWM Controller (강압형 컨버터의 비선형 순시추종 PWM 제어기의 특성 분석)

  • Ra, Byung-Hun;Kim, Sang-Don;Kwon, Soon-Kurl;Lee, Hyun-Woo
    • Proceedings of the KIEE Conference
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    • 2002.11c
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    • pp.378-381
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    • 2002
  • Instantaneous following PWM control technique is pulsed nonlinear dynamic control method. This new control technique using analog integrator is proposed to control the duty ratio D of DC-DC converter. In this control method, the duty ratio of a switch is exactly equal to or proportional to the control reference in the steady state or in a transient. Proposed control method compensates power source perturbation in one switching cycle, and the average value of the dynamic reference in one switching cycle. There is no steady state error nor dynamic error between the control reference and the average value of the switched variable. Experiments with buck converter have demonstrated the robustness of the control method and verified theoretical prediction. The control method is very general and applicable to all type PWM.

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Power Control of a Pitch-controlled Wind Power System (피치제어형 풍력발전시스템의 출력제어)

  • 임종환;허종철
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.4
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    • pp.84-91
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    • 2003
  • The paper presents a power control algorithm for a full pitch-controlled wind power system. The design of a pitch controller, in general, is performed by linearizing the torque in the vicinity of a operating point assuming the tip speed ratio is constant. For power control, however, the tip speed ratio is no longer a constant. In this study, a reference pitch model is derived in terms of a wind speed, angular velocity, and pitch angle. The reference pitch model is used to design a controller without linearizing the non-linear torque model of the blade. The validity of the algorithm is demonstrated with the results produced through sets of simulation.

수직형 마이크로 자이로스코프의 연성 진동과 영점 출력

  • 이승엽;전도영;김택현
    • Journal of KSNVE
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    • v.10 no.5
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    • pp.880-885
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    • 2000
  • In a verical type, vibratory gyroscope, the coupled motion between the reference and sensing vibrations causes the zero-point output which means non-zero sensing vibration without angular velocity. This structural coupling leaks to an inherent discrepancy between the natural frequencies of the reference and sensing oscillations, causing the degradation of the sensing performance and dynamic stability. In this paper, the dynamic characteristics associated the coupling phenomenon are theoretically analyzed. Effects of reference frequency and coupling factor on the rotational direction and amplitude of elliptic oscillation are studied. A technique to predict the existence of curve veering of crossing in frequency trajectories is introduced to apply the design of micro gyroscopes with decoupled structures.

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New Engineering Approach for Estimating Crack Opening Displacement of Complex Cracked Pipes (복합균열이 존재하는 배관의 균열개구변위 계산을 위한 새로운 공학적 계산식)

  • Kim, Yeong-Jin;Heo, Nam-Su;Kim, Yun-Jae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.8
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    • pp.1235-1241
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    • 2001
  • An engineering estimation equation for the crack opening displacement(COD) is proposed for a complex cracked pipe, based on the reference stress approach. To define the reference stress, a simple plastic limit load analysis for the complex cracked pipe subjected to combined bending and tension is performed considering the crack closure effect in the compressive-stressed region. Comparison with ten published test data and the results from existing method shows that the present method not only reduces non-conservatism associated with the existing method, but also provides consistent and overall satisfactory results.

Study on the fast nearest-neighbor searching classifier using distance approximation (거리 근사를 이용하는 고속 최근 이웃 탐색 분류기에 관한 연구)

  • 이일완;채수익
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.2
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    • pp.71-79
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    • 1997
  • In this paper, we propose a new nearest-neighbor classifier with reduced computational complexity in search process. In the proposed classifier, the classes are divided into two sets: reference and non-reference sets. It reduces computational requriement by approximating the distance between the input and a class iwth the information of distances among the calsses. It calculates only the distance between the input and the reference classes. We convert a given classifier into RCC (reduced computational complexity but smal lincrease in misclassification probability of its corresponding RCC classifier. We designed RCC classifiers for the recognition of digits from the NIST database. We obtained an RCC classifier with 60% reduction in the computational complexity with the cost of 0.5% increase in misclassification probability.

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Adaptive Fuzzy Control of Helicopter (헬리콥터의 적응 퍼지제어)

  • 김종화;장용줄;이원창;강근택
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2001.05a
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    • pp.144-147
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    • 2001
  • This paper presents adaptive fuzzy controller which is uncertainty or unknown variation in different parameters with nonlinear system of helicopter. The proposed adaptive fuzzy controller applied TSK(Takagi-Sugeno-Kang) fuzzy system which is not only low number of fuzzy rule, and a linear input-output equation with a constant term, but also can represent a large class of nonlinear system with good accuracy. The adaptive law was designed by using Lyapunov stability theory. The adaptive fuzzy controller is a model reference adaptive controller which can adjust the parameter $\theta$ so that the plant output tracks the reference model output. First of all, system of helicopter was considered as stopping state, and design of controller was simulated from dynamics equation with stopping state. Results show that it is controlled more successfully with a model reference adaptive controller than with a non-adaptive fuzzy controller when there is a modelling error between system and model or a continuous added noise in such unstable system.

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Family Variables affecting Compulsive Buying Behavior on Fashion Products (강박구매행동에 영향을 미치는 가족변인에 관한 연구: 패션제품을 중심으로)

  • Lee, Seung-Hee
    • Journal of Fashion Business
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    • v.13 no.4
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    • pp.77-84
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    • 2009
  • The purpose of this study was to examine family factors affecting compulsive buying behavior. Three hundred fifty-five female college students who had purchased fashion products through Internet shopping or TV home shopping participated in this study. For data analysis, descriptive statistics, correlation analysis, t-test, multiple regression, and reliability test. As the results, approximately 18% of respondents were revealed as compulsive buyers. Compulsive consumption scores were correlated to higher previous childhood consumption experience, family matters, parents' compulsive consumption tendency, and reference group. Also, results of multiple regression revealed that previous childhood consumption experience, parents' compulsive consumption tendency, and reference group were significantly related to compulsive buying, Finally, there were significantly differences between compulsive buyers and non-compulsive buyers on previous childhood consumption experiences, parents' compulsive consumption tendency, and reference group. Based on these results, this study would provide significant implications to academic scholars, consumer policy decision makers, and marketers.

A Fast Mode Decision of Non-anchor Pictures in Multi-view Video Coding for 3D Applications (3D 응용을 위한 다시점 영상 부호화에서 비기준 화면의 빠른 모드결정 기법)

  • Jung, Choong-Hyun;Shin, Kwang-Mu;Park, Seong-Ho;Chung, Ki-Dong
    • Journal of Korea Multimedia Society
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    • v.15 no.7
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    • pp.859-869
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    • 2012
  • The Multi-view Video Coding (MVC) which is exploiting disparities between views has been developed to improve the coding efficiency of multi-view video. But MVC has a problem of having high computing complexities because of disparity estimation. This paper propose a fast mode decision for non-anchor picture to reduce the computational time of MVC. The proposed method uses two phases. Anchor pictures in hierarchical B picture structure have a higher correlation with prediction mode selection of non-anchor pictures, so in the first phase, prediction mode of non-anchor pictures is selected by exploiting the macro-block regions in anchor picture. In the second phase, we select a reference direction of inter prediction mode exploiting a higher correlation among reference directions of inter prediction modes of 7 block sizes. Experimental results show that the proposed method could save average about 44% in the encoding time with negligible coding efficiency losses.

Multicarbohydrase Enzymes for Non-ruminants

  • Masey O'Neill, H.V.;Smith, J.A.;Bedford, M.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.2
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    • pp.290-301
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    • 2014
  • The first purpose of this review is to outline some of the background information necessary to understand the mechanisms of action of fibre-degrading enzymes in non-ruminants. Secondly, the well-known and understood mechanisms are described, i) eliminating the nutrient encapsulating effect of the cell wall and ii) ameliorating viscosity problems associated with certain Non Starch Polysaccharides, particularly arabinoxylans and ${\beta}$-glucans. A third, indirect mechanism is then discussed: the activity of such enzymes in producing prebiotic oligosaccharides and promoting beneficial cecal fermentation. The literature contains a wealth of information on various non starch polysaccharide degrading enzyme (NSPase) preparations and this review aims to conclude by discussing this body of work, with reference to the above mechanisms. It is suggested that the way in which multi- versus single-component products are compared is often flawed and that some continuity should be employed in methods and terminology.

A Study on Non-Verbal Expressions for the Realization of Narrative Visualization -Focusing on a 3D Cat Character, "Puss" (내러티브 시각화 구현을 위한 비언어적 표현 연구-3D 고양이 캐릭터 "Puss"를 중심으로)

  • Lee, Young-Suk;Kim, Sang-Nam
    • Journal of Korea Multimedia Society
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    • v.19 no.3
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    • pp.659-672
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    • 2016
  • In animated films, characters materialize narratives through acting. The narrative is an element to materialize accurate delivery of lines and emotions. The non-verbal actions should express lots of emotions and lines in scenes, and also they can be used as a way of empathy. This study analyzed the visualization factors of narrative focusing on a cat character frequently shown in animated films. For this, the visualization factors of non-verbal actions expressed in characters' personal space and dynamic space were extracted. Based on this, it aims to suggest the emotion expressing method of characters to realize effective narrative visualization. In the future, it aims to be used as reference data in case when producing non-verbal communication for 3D characters.