• Title/Summary/Keyword: feed back theory

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A Construction Theory of Multiple-Valued Logic Sequential Machines on $GF(2^M)$

  • 박춘명;김흥수
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.24 no.5
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    • pp.823-832
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    • 1987
  • This pper presents a method for constructing multiple-valued logic sequential machines based on Galois field. First, we assign all elements in GF(2**m) to bit codes using mathematical properties of GF(2**m). Then, we realized the sequencial machine circuits with and withoutm feed-back. 1) Sequential machines with feed-back are constructed by using only MUX from state-transition diagram expressing the information of sequential machines. 2) Sequential machines without feed-back are constructed by following steps. First, we assigned states in state-transition disgram to state bit codes, then obtained state function and predecessor table explaining the relationship between present states and previous states. Next, we obtained next-state function from state function and predecessor table. Finally we realized the circuit using MUX and decoder.

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Finite Element Modeling for Free Vibration Control of Beam Structures using Piezoelectric Sensors and Actuators (압전감지기와 압전작동기를 이용한 보구조물의 자유진동제어에 대한 유한요소 모형화)

  • 송명관;한인선;김선훈;최창근
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.16 no.2
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    • pp.183-195
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    • 2003
  • In this study, the method of the finite element modeling for free vibration control of beam-type smart structures with bonded plate-type piezoelectric sensors and actuators is proposed. Constitutive equations for the direct piezoelectric effect and converse piezoelectric effect of piezoelectric materials are considered. By using the variational principle, the equations of motion for the smart beam finite element are derived. The proposed 2-node beam finite element is an isoparametric element based on Timoshenko beam theory. Therefore, by analyzing beam-type smart structures with smart beam finite elements, it is possible to simulate the control of the structural behavior by applying voltages to piezoelectric actuators and monitoring of the structural behavior by sensing voltages of piezoelectric sensors. By using the smart beam finite element and constant-gain feed back control scheme, the formulation of the free nitration control for the beam structures with bonded plate-tyPe Piezoelectric sensors and actuators is proposed.

Dynamic Spectrum Load Balancing for Cognitive Radio in Frequency Domain and Time Domain

  • Chen, Ju-An;Sohn, Sung-Hwan;Gu, Jun-Rong;Kim, Jae-Moung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.8 no.3
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    • pp.71-82
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    • 2009
  • As a solution to spectrum under-utilization problem, Cognitive radio (CR) introduces a dynamic spectrum access technology. In the area, one of the most important problems is how secondary users (SUs) should choose between the available channels, which means how to achieve load balancing between channels. We consider spectrum load balancing problem for CR system in frequency domain and especially in time domain. Our objective is to balance the load among the channels and balance the occupied time length of slots for a fixed channel dynamically in order to obtain a user-optimal solution. In frequency domain, we refer to Dynamic Noncooperative Scheme with Communication (DNCOOPC) used in distributed system and a distributed Dynamic Spectrum Load Balancing algorithm (DSLB) is formed based on DNCOOPC. In time domain, Spectrum Load Balancing method with QoS support is proposed based on Dynamic Feed Back theory and Hash Table (SLBDH). The performance of DSLB and SLBDH are evaluated. In frequency domain, DSLB is more efficient compared with existing Compare_And_Balance (CAB) algorithm and gets more throughput compared with Spectrum Load Balancing (SLB) algorithm. Also, DSLB is a fair scheme for all devices. In time domain, SLBDH is an efficient and precise solution compared with Spectrum Load Smoothing (SLS) method.

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Structure Optimization of Neural Networks using Rough Set Theory (러프셋 이론을 이용한 신경망의 구조 최적화)

  • 정영준;이동욱;심귀보
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1998.03a
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    • pp.49-52
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    • 1998
  • Neural Network has good performance in pattern classification, control and many other fields by learning ability. However, there is effective rule or systematic approach to determine optimal structure. In this paper, we propose a new method to find optimal structure of feed-forward multi-layer neural network as a kind of pruning method. That eliminating redundant elements of neural network. To find redundant elements we analysis error and weight changing with Rough Set Theory, in condition of executing back-propagation leaning algorithm.

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Global Function Approximations Using Wavelet Neural Networks (웨이블렛 신경망을 이용한 전역근사 메타모델의 성능비교)

  • Shin, Kwang-Ho;Lee, Jong-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.8
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    • pp.753-759
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    • 2009
  • Feed-forward neural networks have been widely used as function approximation tools in the context of global approximate optimization. In the present study, a wavelet neural network (WNN) which is based on wavelet transform theory is suggested as an alternative to a traditional back-propagation neural network (BPN). The basic theory of wavelet neural network is briefly described, and approximation performance is tested using a nonlinear multimodal function and a composite rotor blade analysis problem. Laplacian of Gaussian function, Mexican function, and Morlet function are considered during the construction of WNN architectures. In addition, approximation results from WNN are compared with those from BPN.

A Study on Technology Transfer of Bokto Seeding Method for Crop Production - Based on Theory of Asian and Pacific Center for Transfer of Technology(APCTT) - (복토직파재배기술의 수용과 기술 확산에 관한 연구 - 아시아태평양기술이전센터(APCTT) 이론을 중심으로 -)

  • Ahn, D.H.;Park, K.H.;Kang, Y.K.
    • Journal of Practical Agriculture & Fisheries Research
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    • v.10 no.1
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    • pp.29-41
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    • 2008
  • This research was conducted to develop a technology transfer and farmer's extension of newly released technology of Bokto seeding method for crop and vegetable production based on the theory of Asian and Pacific Center for Transfer of Technology(APCTT). This technology has recently transferred to not only Korea but also other countries like North Korea, China, Japan, Taiwan, Russia and Africa(Cameroon, Sudan and South Africa) since 2005. It has known as a highly reduction of production cost in terms of labors, chemical fertilizer and pesticides as well as environmental friendly due to a deep and side banded placement of chemical fertilizer at basal application. In addition this technology was proven to a precision farming on sowing depth and mechanism of chemical application method and also highly resistant against disasters like typhoon, flooding, low temperature, drought and lodging due to silicate application. It has improved a constraints such as a poor seedling establishment, weed occurrence, lodging, low yield and poor grain and eating quality in the previous direct seeding methods but still have a problem in occurrence of weedy rice and ununiformed operation of wet or flooded soil condition. Also this technology has a limit in marketing and A/S system. Based on a theory of APCTT evaluation and analysis this technology may be more concentrated on establishment of a special cooperation team among researcher and scientists, extension workers, industry sections and governmental sectors in order to rapidly transfer this technology to farmer's field. Also there will be needed to operate a web site for this newly released technology to inform and exchange an idea, experiences and newly improved information. A feed back system might be operated in this technology as well to improve a technology under way on users' operation. Also user's manual will be internationally released and provided for farmer's instruction and training at field site.

Design Automation of the Compressive Coil Spring (압축코일스프링의 설계자동화)

  • 권혁홍;최선준
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.6
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    • pp.140-151
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    • 2000
  • Springs for vehicle suspension control the vibration of a car and influence on the ridability, safety, and life of a car. in the paper, the computer aided design program has been developed, which design the leaf spring shape from the given specifications using basic theory and the expert\`s knowledge, and the design results are checked by the analysis theory in order to increase the accuracy, and feed back to the design input. For the purpose of easy use, this program consists of pull-down menu and interactive input mode. To prove the effectiveness of this program, two springs, of which one is symmetric, other asymmetric, are designed and analyzed, and the outputs are compared to the experiments. Considering the tolerance of the given specifications, the results are good.

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Design Program Development of the Leaf Spring for Suspension (현가장치용 겹판스프링의 설계프로그램 개발)

  • Choi, S.J.;Choi, Y.C.;Choi, J.C.;Kwon, H.H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.1
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    • pp.20-32
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    • 1995
  • Springs for vehicle suspension control the vibration of a car and influence on the ridability, safety, and life of a car. In the paper, the computer aided design program has been developed, which design the leaf spring shape from the given specifications using basic theory and the expert's knowledge, and the design results are checked by the analysis theory in order to increase the accuracy, and feed back to the design input. For the purpose of easy use, this program consists of pull-down menu and interactive input mode. To prove the effectiveness of this program. two springs, of which one is symmetric, other asymmetric, are designed and analyzed, and the outputs are compared to the experiments. Considering the tolerance of the given specifications, the results are good.

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A Qualitative Study of the Adaptation Process of Dietary Education Program for Marriage Immigrant Women using the Normalization Process Theory (일상화 과정 이론에 근거한 결혼이주여성 대상 식생활 교육 프로그램 일상화 과정에 대한 질적 연구)

  • Kim, In Seon;Hwang, Ji-Yun
    • Journal of the Korean Society of Food Culture
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    • v.34 no.3
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    • pp.325-333
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    • 2019
  • This study was a qualitative investigation of the process of adaptation of nutrition education programs by marriage immigrant women who completed education programs for training of food citizen leaders. Focus group interviews of seven marriage immigrant women from Vietnam, China, Mongolia and Russia were conducted and analyzed based on the Normalization Process Theory (NPT). Participants were aware of the purpose of the education program (coherence) and their confidence in organizing and reconstructing the knowledge of nutrition was increased after education (reflexive monitoring). However, they had difficulties attending long-term education programs (cognitive participation) and overcoming language barriers (collective action). Although the program was beneficial for the participants in that they could apply acquired nutrition knowledge to their everyday life as food citizen leaders, the continuous monitoring and feed-back system (management), customized application, and consideration of personal and social factors need to be developed and facilitated. In addition, various programs targeting marriage immigrant women may increase economic independence of these women. The NPT proved beneficial in conceptualizing the barriers and facilitators to implementing nutrition education. The successful implementation of nutrition intervention needs special support to overcome barriers to cognitive participation and collective action.

Analysis and Design Theory of Aperture-Coupled Cavity-Fed Back-to-Back Microstrip Directional Coupler (개구면 결합 공진기 급전 마이크로스트립 방향성결합기 해석 및 설계)

  • Nam, Sang-Ho;Jang, Guk-Hyun;Nam, Kyung-Min;Lee, Jang-Hwan;Kim, Chul-Un;Kim, Jeong-Phill
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.44 no.3 s.357
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    • pp.7-17
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    • 2007
  • An analysis and design theory of an aperture-coupled cavity-fed back-to-back microstrip directional coupler is presented for the efficient and optimized design. For this purpose, an equivalent network is developed, and simple but accurate calculations of circuit element values are described. Design equations of the coupler are derived based on the equivalent circuit. In order to determine various structural design parameters, the evolutionary hybrid optimization method based on the genetic algorithm and Nelder-Mead method is invoked. As a validation check of the proposed theory and optimized design method, a 10 dB directional coupler was designed and fabricated. The measured coupling was 10.3 dB at 3 GHz, and the return loss and isolation were 31.8 dB and 30.5 dB, respectively. The directional coupler also showed very good quadrature phase characteristics. Good agreements between the measured and the design specifications fully validate the proposed network analysis and design procedure.