• Title, Summary, Keyword: FSMC

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Performance Analysis of Wireless Communication System with FSMC Model in Nakagami-m Fading Channel (Nakagami-m 페이딩 채널에서 FSMC 모델에 의한 무선 통신시스템의 성능 분석)

  • 조용범;노재성;조성준
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.5
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    • pp.1010-1019
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    • 2004
  • In this paper, we represent Nakagami-m fading channel as finite-State Markov Channel (FSMC) and analyze the performance of wireless communication system with varying the fading channel condition. In FSMC model, the received signal's SNR is divided into finite intervals and these intervals are formed into Markov chain states. Each state is modeled by a BSC and the transition probability is dependent upon the physical characterization of the channel. The steady state probability and average symbol error rate of each state and transition probability are derived by numerical analysis and FSMC model is formed with these values. We found that various fading channels can be represented with FSMC by changing state transition index. In fast fading environment in which state transition index is large, the channel can be viewed as i.i.d. channel and on the contrary, in slow fading channel where state transition index is small, the channel can be represented by simple FSMC model in which transitions occur between just adjacent states. And we applied the proposed FSMC model to analyze the coding gain of random error correcting code on various fading channels via computer simulation.

Effects of Dietary Replacement of Rice Straw with Fermented Spent Mushroom (Flammuliua velutipes) Compost on Availability of Feeds in Sheep, and Growth Performance of Hanwoo Steers (발효 팽이버섯폐배지의 볏짚 대체 급여가 사료의 면양 체내 이용성 및 거세한우의 성장에 미치는 효과)

  • Shinekhuu, Jugdder;Ji, Byung-Ju;Jin, Guang-Lin;Choi, Seong-Ho;Song, Man-Kang
    • Journal of Animal Science and Technology
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    • v.51 no.3
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    • pp.241-248
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    • 2009
  • Metabolic trial with 3 fistulated sheep was conducted in a 3 $\times$ 3 Latin square design and feeding trial with 24 Hanwoo steers in 12 month of age for 20 months was conducted to investigate the replacing effect of rice straw with fermented spent mushroom (Flammuliua velutipes) compost (FSMC) on fermentation characteristics, ruminal effective degradabilty and whole tract digestibility of nutrients in sheep, and to examine the growth performance of Hanwoo steers. Experimental diets for the metabolic trial with sheep were commercial concentrates and rice straw in the ratio of 70 : 30 (CON, DM basis). Same concentrate with 30% FSMC and 70% rice straw (FSMC-30) and 60% FSMC and 40% rice straw(FSMC-60). Diets for Hanwoo steers in three treatments were same as for metabolic trial in replacing ratio of rice straw with FSMC. pH of rumen fluid in sheep was not affected by FSMC. Ammonia-N content in the rumen fluid was highest in the sheep fed FSMC-60 at 3h (P<0.045). The CON diet increased (P<0.001) acetate proportion at 1h and 3h post feeding compared to FSMC-60 diet while propionate proportion was highest in the sheep fed FSMC-60 diet for all the sampling times (P<0.027~P<0.002). Increased proportion of butyrate was observed at 30 min prior to feeding (P<0.031), and 1h (P<0.011) and 6h(P<0.039) post feeding from sheep fed FSMC-30 diet compared to those from sheep fed other diets. Effective degradability in the rumen was not influenced by experimental diets. Whole tract digestibility of crude protein (P<0.031) and neutral detergent fiber (P<0.006) tended to be increased in the sheep fed CON diet while corresponding values were lowest in the sheep fed FSMC-60 diet. Total body weight gain of Hanwoo steers for 8 months was not different among diets, thus daily body gain was not influenced by the experimental diets.

Novel Approach for Modeling Wireless Fading Channels Using a Finite State Markov Chain

  • Salam, Ahmed Abdul;Sheriff, Ray;Al-Araji, Saleh;Mezher, Kahtan;Nasir, Qassim
    • ETRI Journal
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    • v.39 no.5
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    • pp.718-728
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    • 2017
  • Empirical modeling of wireless fading channels using common schemes such as autoregression and the finite state Markov chain (FSMC) is investigated. The conceptual background of both channel structures and the establishment of their mutual dependence in a confined manner are presented. The novel contribution lies in the proposal of a new approach for deriving the state transition probabilities borrowed from economic disciplines, which has not been studied so far with respect to the modeling of FSMC wireless fading channels. The proposed approach is based on equal portioning of the received signal-to-noise ratio, realized by using an alternative probability construction that was initially highlighted by Tauchen. The associated statistical procedure shows that a first-order FSMC with a limited number of channel states can satisfactorily approximate fading. The computational overheads of the proposed technique are analyzed and proven to be less demanding compared to the conventional FSMC approach based on the level crossing rate. Simulations confirm the analytical results and promising performance of the new channel model based on the Tauchen approach without extra complexity costs.

Throughput of Coded DS CDMA/Unslotted ALOHA Networks with Variable Length Data Traffic and Two User Classes in Rayleigh Fading FSMC Model

  • Tseng, Shu-Ming;Chiang, Li-Hsin;Wang, Yung-Chung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.12
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    • pp.4324-4342
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    • 2014
  • Previous papers analyzed the throughput performance of the CDMA ALOHA system in Rayleigh fading channel, but they assume that the channel coefficient of Rayleigh fading was the same in the whole packet, which is not realistic. We recently proposed the finite-state Markov channel (FSMC) model to the throughput analysis of DS uncoded CDMA/unslotted ALOHA networks for fixed length data traffic in the mobile environment. We now propose the FSMC model to the throughput analysis of coded DS CDMA/unslotted ALOHA networks with variable length data traffic and one or two user classes in the mobile environment. The proposed DS CDMA/unslotted ALOHA wireless networks for two user classes with access control can maintain maximum throughput for the high priority user class under high message arrival per packet duration.

Using GA-FSMC for Precise Water Level Control of Double Tank (GA-FSMC를 이용한 이중탱크의 정밀한 수위 제어)

  • Park, Hyun-Chul;Park, Doo-Hwan;Song, Hong-Jun;Jo, Hyun-Woo;Lee, Joon-Tark
    • Proceedings of the KIEE Conference
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    • pp.2192-2195
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    • 2002
  • Even though, tanks are used at the many industry plants, it is very difficult to control the tank level without any overflow and shortage; moreover, cause of its complication of dynamics and nonlinearity, it's impossible to realize the accurate control using the mathematical model which can be applied to the various operation modes. However, the sliding mode controller(SMC) is known as having the robust variable structures for the nonlinear control systems with the parametric perturbations and with the sudden disturbances. It's difficult to find SMC's parameters, and SMC is bring chattering which injures actuator and increases error. In this paper, Genetic Aloglism based Fuzzy Sliding Mode Controller(GA-FSMC) for the precise control of the coupled tank level was proposed. Genetic Algolism and Fuzzy logic are adapted to find SMC's parameters and reduce the chattering. The simulation result is shown that the tank level could be satisfactorily controlled with less overshoot and steady-state error by the proposed GA-FSMC.

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A fuzzy Sliding Mode Control of Wheeled Mobile Robot with a Differential Drive

  • Kang, Young-Hoon;Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
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    • pp.265-270
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    • 1998
  • In this paper we introduce a modeling of wheeled mobile robot with a differential drive derived by R.M. DeSantis and using the dynamics model-ing with some disturbance term we control the wheeled mobile robot using fuzzy sliding mode control(FSMC) method. In a fuzzy control approach it is very difficult to prove the stability of the fuzzy controller. Therefore, to overcome that difficult proof of the stability in a fuzzy control method, we first propose a sliding mode controller and prove the stability of the proposed controller. Next, transforming the proposed sliding mode controller into a fuzzy sliding mode controller without changing the basic structure of the sliding mode con-troller, we easily obtain a fuzzy sliding mode con-troller(FSMC) whose stability is guaranteed with-out difficult stability proof procedure of the proposed FSMC.

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Fuzzy sliding mode controllers for high performance control of AC servo motors (AC 서보 모터의 고성능 제어를 위한 퍼지 슬라이딩 모드 제어기)

  • 김광수;조동일
    • 제어로봇시스템학회:학술대회논문집
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    • pp.732-735
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    • 1997
  • Variable Structure Controller(VSC) is usually known to have robustness to bounded exogenous disturbances. The robustness is attributed to the discontinuous term in the control input. However, this discontinuous term also causes an undesirable effect called chattering. To alleviate chattering, a hybrid controller consisting of VSC and Fuzzy Logic Controller(FLC) is proposed, which belongs to the category of Fuzzy Sliding Mode Controller(FSMC). The role of FLC in FSMC is to replace a fixed gain of a discontinuous term with a time-varying one based on a specified rule base. The characteristics of proposed controller are shown to be similar to those of VSC with a saturation function instead of sign function. The only remarkable difference is the nonlinearity whose form can be adjusted by free parameters, normalize gain, denormalize gain, and membership functions. Applied to AC servo motor, the proposed controller is compared with VSC in a regulation problem as well as a speed tracking problem. The simulation results show a substantial chatter reduction.

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Design of the fuzzy sliding mode controller with double pole inverted pendulum (두개의 pole을 갖는 도립 진자의 퍼지 슬라이딩 모드 제어기 설계)

  • 강항균;한종길;함운철
    • 제어로봇시스템학회:학술대회논문집
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    • pp.188-191
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    • 1996
  • In this paper, we derive dynamic equation of double pole inverted pendulum using Lagrangian equation, and design the fuzzy sliding mode controller. We demonstrate that the designed controller regulates double pole simultaneously regardless of cart position by computer simulation.

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A New Approach to the Design of An Adaptive Fuzzy Sliding Mode Controller

  • Lakhekar, Girish Vithalrao
    • International Journal of Ocean System Engineering
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    • v.3 no.2
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    • pp.50-60
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    • 2013
  • This paper presents a novel approach to the design of an adaptive fuzzy sliding mode controller for depth control of an autonomous underwater vehicle (AUV). So far, AUV's dynamics are highly nonlinear and the hydrodynamic coefficients of the vehicles are difficult to estimate, because of the variations of these coefficients with different operating conditions. These kinds of difficulties cause modeling inaccuracies of AUV's dynamics. Hence, we propose an adaptive fuzzy sliding mode control with novel fuzzy adaptation technique for regulating vertical positioning in presence of parametric uncertainty and disturbances. In this approach, two fuzzy approximator are employed in such a way that slope of the linear sliding surface is updated by first fuzzy approximator, to shape tracking error dynamics in the sliding regime, while second fuzzy approximator change the supports of the output fuzzy membership function in the defuzzification inference module of fuzzy sliding mode control (FSMC) algorithm. Simulation results shows that, the reaching time and tracking error in the approaching phase can be significantly reduced with chattering problem can also be eliminated. The effectiveness of proposed control strategy and its advantages are indicated in comparison with conventional sliding mode control FSMC technique.

Application of robust fuzzy sliding-mode controller with fuzzy moving sliding surfaces for earthquake-excited structures

  • Alli, Hasan;Yakut, Oguz
    • Structural Engineering and Mechanics
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    • v.26 no.5
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    • pp.517-544
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    • 2007
  • This study shows a fuzzy tuning scheme to fuzzy sliding mode controller (FSMC) for seismic isolation of earthquake-excited structures. The sliding surface can rotate in the phase plane in such a direction that the seismic isolation can be improved. Since ideal sliding mode control requires very fast switch on the input, which can not be provided by real actuators, some modifications to the conventional sliding-mode controller have been proposed based on fuzzy logic. A superior control performance has been obtained with FSMC to deal with problems of uncertainty, imprecision and time delay. Furthermore, using the fuzzy moving sliding surface, the excellent system response is obtained if comparing with the conventional sliding mode controller (SMC), as well as reducing chattering effect. For simulation validation of the proposed seismic response control, 16-floor tall building has been considered. Simulations for six different seismic events, Elcentro (1940), Hyogoken (1995), Northridge (1994), Takochi-oki (1968), the east-west acceleration component of D$\ddot{u}$zce and Bolu records of 1999 D$\ddot{u}$zce-Bolu earthquake in Turkey, have been performed for assessing the effectiveness of the proposed control approach. Then, the simulations have been presented with figures and tables. As a result, the performance of the proposed controller has been quite remarkable, compared with that of conventional SMC.