• Title/Summary/Keyword: Positive Feedback

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Design of the Voltage-Controlled Sinusoidal Oscillator Using an OTA-C Simulated Inductor

  • Park, Ji-Mann;Chung, Won-Sup;Park, Young-Soo;Jun, Sung-Ik;Chung, Kyo-Il
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.770-773
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    • 2002
  • Two sinusoidal voltage-controlled oscillators using linear operational transconductance amplifiers are presented in this paper: One is based on the positive-feedback bandpass oscillator model and the other on the negative-feedback Colpitts model. The bandpass VCO consists of a noninverting amplifier and a current-controlled LC-tuned circuit which is realized by two linear OTA's and two grounded capacitors, while the Colpitts VCO consists of an inverting amplifier and a current-controlled LC-tuned circuit realized by three linear OTA's and three grounded capacitors. Prototype circuits have been built with discrete components. The experimental results have shown that the Colpitts VCO has a linearity error of less than 5 percent, a temperature coefficient of less than rm 100 ppm/$^{circ}C$, and a $pm1.5 Hz $frequency drift over an oscillation frequency range from 712Hz to 6.3kHz. A total harmonic distortion of 0.3 percent has been measured for a 3.3kHz oscillation and the corresponding peak-to-peak amplitude was 1V. The experimental results for bandpass VCO are also presented.

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An Analytical Synthesis Method of Dynamic Systems in Terms of Bond Graphs (본드선도를 이용한 동적시스템의 해석적 종합방법)

  • Park, Jeon-Su;Kim, Jong-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.11
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    • pp.3507-3515
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    • 1996
  • This paper presents an attempt to find the physical structure of dynamic systems which achieves the behavior of a given system function. The scheme pursued by the paper would be regarded as synthesizing dynamic systems, and a method to synthesize them analytically is proposed by means of bond graph prototypes. The method adopts several conceptsused to synthesize networks in the electrical field, but yet deconstrates its own strengths such as the freedom from assigning causality and determining junction types. Also, itis shown that this method has further advantages in reticulating a given specification into feedforward and feedback components relative to network synthesis and the method is examined though an example to trace the outline of the analytical synthesis of dynamic systems using bond graph prototypes.

Improvement of Relevance Feedback for Image Retrieval (영상 검색을 위한 적합성 피드백의 개선)

  • Yoon, Su-Jung;Park, Dong-Kwon;Won, Chee-Sun
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.39 no.4
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    • pp.28-37
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    • 2002
  • In this paper, we present an image retrieval method for improving retrieval performance by fusion of probabilistic method and query point movement. In the proposed algorithm, the similarity for probabilistic method and the similarity for query point movement are fused in the computation of the similarity between a query image and database image. The probabilistic method used in this paper is suitable for handling negative examples. On the other hand, query point movement deals with the statistical property of positive examples. Combining these two methods, our goal is to overcome their shortcoming. Experimental results show that the proposed method yields better performances over the probabilistic method and query point movement, respectively.

Satisfaction with Evaluation Method for Fundamental Nursing Practical Skill Education Through Cell Phone Animation Self-Monitoring and Feedback - Focus on Foley Catheterization - (휴대폰 동영상 자기관찰 및 피드백을 통한 기본간호학 실기 교육평가방법에 관한 만족도 - 정체도뇨관 삽입을 중심으로 -)

  • Kim, Yeong-Hie
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.15 no.2
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    • pp.134-142
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    • 2008
  • Purpose: This study was done to identify satisfaction with the method of evaluating practical skills in fundamental nursing through cellular phone animation self-monitoring and feedback. Method: The participants were 163 first-year student nurses. Data were collected from October 1 to 5 2007 using a structured questionnaire. Results: The average score for satisfaction was 3.65(${\pm}.69$) and the highest score was for the item, "I was pleased to have the opportunity of relearning by looking back at my behaviors through self monitoring" with 4.05(${\pm}.89$). The average score for dissatisfaction was 3.23(${\pm}.90$) and the highest score was "I memorized only orders according to the checklist" with 3.65(${\pm}.97$). The practical tests method showed a significant difference according to motivation for application to college of nursing (F=3.11, p=.047). There was a significant positive correlation between practical education satisfaction and test method (r=.363, p=.000). Conclusion: These findings show that there is a need to develop strategies to improve practical test methods for student nurses.

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Examining Customers' Continuance Intentions towards E-wallet Usage: The Emergence of Mobile Payment Acceptance in Vietnam

  • PHUONG, Nguyen Ngoc Duy;LUAN, Ly Thien;DONG, Vu Van;KHANH, Nguyen Le Nhat
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.505-516
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    • 2020
  • The purpose of the research is to identify antecedents of mobile wallet continuance intention in Vietnam. A self-administered questionnaire was distributed to collect data from a total of 276 respondents. Partial least squares structural equation modeling was employed for analyzing the data. Five mobile wallet features - mobile application quality, mobile wallet familiarity, situational normality, payment security, and feedback mechanism - are introduced as fundamental elements, which influence customer' continuance intention to use mobile wallet in Vietnam. The results indicate that mobile quality application and familiarity can significantly influence perceived ease-of-use (PEOU) and perceived usefulness (PU), but situational normality has an impact only on PEOU. PEOU and PU are positively related to satisfaction. On the other hand, payment security and feedback mechanism affect positively customer' trust. As a result, the positive effects that satisfaction and trust have on electronic wallet continuance intention are confirmed. The findings can be used to advise mobile wallet providers to improve their platform design and services to retain users. As a theoretical contribution, this study combines the Technology Acceptance Model, Unified Theory of Acceptance and Use of Technology to investigate the key determinants on continuance intention in the context of electronic wallet in Vietnam.

A New Design Method for T-S Fuzzy Controller with Pole Placement Constraints

  • Joh, Joongseon;Jeung, Eun-Tae;Chung, Won-Jee;Kwon, Sung-Ha
    • Journal of the Korean Institute of Intelligent Systems
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    • v.7 no.3
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    • pp.72-80
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    • 1997
  • A new design method for Takagi-Sugeno (T-S in short) fuzzy controller which guarantees global asymptotic stability and satisfies a desired performance is proposed in this paper. The method uses LMI(Linear Matrix Inequality) approach to find the common symmetric positive definite matrix P and feedback fains K/sub i/, i= 1, 2,..., r, numerically. The LMIs for stability criterion which treats P and K'/sub i/s as matrix variables is derived from Wang et al.'s stability criterion. Wang et al.'s stability criterion is nonlinear MIs since P and K'/sub i/s are coupled together. The desired performance is represented as $ LMIs which place the closed-loop poles of $ local subsystems within the desired region in s-plane. By solving the stability LMIs and pole placement constraint LMIs simultaneously, the feedback gains K'/sub i/s which gurarntee global asymptotic stability and satisfy the desired performance are determined. The design method is verified by designing a T-S fuzzy controller for an inverted pendulum with a cart using the proposed method.

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Effect of Personality and Social Motive on Franchise Customers' Citizenship Behavior

  • Sthapit, Anesh;Oh, Min-Jung;Hwang, Yoon-Yong
    • Journal of Distribution Science
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    • v.13 no.10
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    • pp.35-44
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    • 2015
  • Purpose - This study focuses on the voluntary performance of franchise customers as a result of inherent social motives. It examines the interplay between traits and motives, and their influence on customer citizenship behavior (CCB). Research design, data, and methodology - Empirical evidence from the responses of 288 university students, validates that individual traits are related to social motives, which provides a basis for CCB. The results suggest that social motives do influence an individual's intention to provide feedback, advocate, help, or tolerate. Structural Equation Modeling using AMOS 22 was employed to test the concept. Results - This research illustrates that extraversion has a dominant influence on affiliation motive, and agreeableness is a strong predictor of the altruism motive among franchise customers. Conclusion - All three traits have positive influence on the power motive. Power and altruism motives were found to be the main determinants of CCB in a social setting. The power motive was a better predictor of advocacy and tolerance. The altruism motive significantly predicted helping and tolerance. Feedback was only positively predicted by the affiliation motive.

Active Vibration Control Experiment of Cantilever Using Active Linear Actuator for Active Engine Mount (능동 엔진 마운트 제어용 Active Linear Actuator를 이용한 외팔보 능동진동제어 실험)

  • Yang, Dong-Ho;Kwak, Moon-K.;Kim, Jung-Hoon;Park, Woon-Hwan;Sim, Ho-Seok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.12
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    • pp.1176-1182
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    • 2010
  • Vibrations caused by automobile engine are absorbed mostly by a passive-type engine mount. However, user specifications for automobile vibrations require more stringent conditions and higher standard. Hence, active-type engine mount have been developed to cope with such specifications. The active-type engine mount consists of sensor, actuator and controller where a control algorithm is implemented. The performance of the active engine mount depends on the control algorithm if the sensor and actuator satisfies the specification. The control algorithm should be able to suppress persistent vibrations caused by the engine which are related to engine revolution. In this study, three control algorithms are considered for suppressing persistent vibrations, which are the positive position feedback control algorithm, the strain-rate feedback control algorithm, and the modified higher harmonic control algorithm. Experimental results show that all the control algorithms considered in this study are effective in suppressing resonant vibrations but the modified higher harmonic controller is the most effective controller for non-resonant vibrations.

Effects of Intra-abdominal Pressure with Visual Feedback on Muscle Activation of Upper Trapezius and Sternomastoid during Forced Inspiration in Individuals with Costal Respiration

  • Kim, Kwang-Su;Shin, Hwa-Kyung
    • The Journal of Korean Physical Therapy
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    • v.32 no.2
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    • pp.75-79
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    • 2020
  • Purpose: This study analyzed the immediate effects of intra-abdominal pressure with visual feedback on the muscle activation of the upper trapezius and sternomastoid during natural inspiration and forced inspiration in individuals with costal respiration. Methods: The eighteen individuals with upper costal breathing pattern participated in this study. Surface electromyography was used to analyze the muscle activity of the upper trapezius and sternomastoid during natural inspiration and forced inspiration before and after intra-abdominal pressure. Results: A significant difference in muscle activation was observed with the muscle type, inspiration type, and test session (p<0.05). The muscle activities of the sternomastoid and upper trapezius decreased significantly during forced inspiration after intra-abdominal pressure training (p<0.05). On the other hand, there was no significant difference during natural inspiration in both muscles (p>0.05). A comparison of the difference between the pre-test and post-test during forced inspiration revealed the upper trapezius to be significantly larger than the sternomastoid (p<0.05). No significant difference was noted during natural inspiration (p>0.05). Conclusion: The intra-abdominal pressure has positive effects on correcting the breathing patterns in individuals with costal respiration.

A Semantics Analysis in the Net Arts fran a Cybernetics Perspective (사이버네틱스 관점에서 본 넷 아트에 나타난 의미론적 분석)

  • Eun, Chang Ik
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.7 no.3
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    • pp.123-136
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    • 2011
  • Arts gains a new relation as the new academic area that deals with living organisms and through this technology, it affects everything, such as the body, entity, consciousness and unconsciousness to bring an overall change. Based on this premise, arts require a different interpretation from the previous product-focused interpretation or the analysis focusing on the aesthetics. As the result of arts using the scientific methods, I examined the changes of the arts semantics and how it evolved with what kind of contents and characteristics. The net art with the internet base also form a close relationship with the social and cultural codes. In categorizing the social issues and the topical discussions with semantic factors that evolve from the digital biological perspective, it can be divided into four types of complex interaction, positive feedback negative feedback, and amplification of unsettledness. Based on the characteristics of the multimedia and the interactive reaction, the technique and the imagery amplify the message through a spatial and timely meeting in a mutual repletion. In other words, the emotional communication is used to attempt the messages from the products and the expression in various methods.