• Title/Summary/Keyword: MRC Model

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Improvement Performance of DS-CDMA/QPSK System with Convolution Coding and MRC Diversity in Millimeter Wave RF Channels (밀리미터파 무선통신로에서 컨볼루션 코딩과 MRC 다이버시티에 의한 DS-CDMA/QPSK 시스템 성능 개선)

  • 김춘구;강희조;최용석
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.4
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    • pp.645-652
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    • 2001
  • In this paper is adopted the One-Ray Rician channel model for AVHS's platoon to short-range IVC (Inter-Vehicle Communication System) and analyzed packet probability characteristics in 60㎓ millimeter wave with very powerful to MP(multipath-wave). Both Convolution coding and MRC diversity is adopted that Multimedia service is satisfied following user's desire increase in the next and analyzed packet probability characteristics of DS-CDMA/QPSK systems.

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Models and Experiments for the Main Topologies of MRC-WPT Systems

  • Yang, Mingbo;Wang, Peng;Guan, Yanzhi;Yang, Zhenfeng
    • Journal of Power Electronics
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    • v.17 no.6
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    • pp.1694-1706
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    • 2017
  • Models and experiments for magnetic resonance coupling wireless power transmission (MRC-WPT) topologies such as the chain topology and branch topology are studied in this paper. Coupling mode theory based energy resonance models are built for the two topologies. Complete energy resonance models including input items, loss coefficients, and coupling coefficients are built for the two topologies. The storage and the oscillation model of the resonant energy are built in the time domain. The effect of the excitation item, loss item, and coupling coefficients on MRC systems are provided in detail. By solving the energy oscillation time domain model, distance enhancing models are established for the chain topology, and energy relocating models are established for the branch topology. Under the assumption that there are no couplings between every other coil or between loads, the maximum transmission capacity conditions are found for the chain topology, and energy distribution models are established for the branch topology. A MRC-WPT experiment was carried out for the verification of the above model. The maximum transmission distance enhancement condition for the chain topology, and the energy allocation model for the branch topology were verified by experiments.

Analysis of Channel Estimation Algorithms in a RAKE Receiver with MRC (MRC 결합의 레이크 수신기에서 채널 추정 알고리즘의 성능분석)

  • 전준수
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.5
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    • pp.970-976
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    • 2004
  • In this paper, we analyze channel estimation algorithms in a RAKE receiver with MRC. There are 3 popular channel estimation algorithms, which are WMSA(Weighted Multi-Slot Averaging) algorithm, EGE(Equal Gain Estimation) algorithm, SSE(Symbol-to-Symbol Estimation) algorithm. We analyze asynchronous IMT-2000(3GPP) which employ 3 different channel estimation algorithms by HP-ADS(Advanced Design System) simulation tool. We used lakes fading channel model for the analysis. from simulation results, we could observe that the performance of WMSA algorithm is better than others in low Doppler effect(3Km/h). However, in the case of high Doppler effect(120km1h), the EGE algorithm is more efficient. In this case the simple estimator with EGE algorithm seems to be more useful.

Design of reference model for model reference sliding model control (모델 기준 슬라이딩 모드 제어기의 기준 모델 설계)

  • Byun, Kyung-Seok
    • Journal of the Institute of Convergence Signal Processing
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    • v.8 no.4
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    • pp.297-306
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    • 2007
  • Model reference control is control method such that overall response of a plant plus controller approaches that of a given reference model. The reference model provides desired trajectory the plant should follow. There are many kinds of control methods in MRC. However, this paper focuses on Model Reference Sliding Mode Control. The plant of these controls is an uncertain and linear system varying in time, of second order, and with SISO. In this paper, a design scheme of reference model is proposed for MRSMC. The scheme determines reference model based on the information on bounded control inputs, reference inputs and system parameters. It is used to choose a Fixed Reference Model in the process of controller design, to update Variable Reference Model when stepwise reference inputs change and to update Instant Reference Model at every sampling time. The simulation results show that the proposed method yields better control performance than the conventional MRC subject to the stepwise reference input when applied to the position control system for motor system.

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Implementation and Performance Analysis of PLC Scheme based on SISO/MIMO-OFDM using MRC (최대비 합성법을 이용한 SISO/MIMO-OFDM 기반 전력선 통신 방식 구현 및 성능분석)

  • Yoo, Jeong-Hwa;Choe, Sang-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.2B
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    • pp.176-183
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    • 2011
  • In this paper, we propose the implementation and performance analysis of power line communication based on SISO/MIMO-OFDM which focuses on high speed data transmission in smart grid and future power line grid. We employ Zimmermann frequency model and Middleton Class A model as the multipath power line fading channel and impulse noise channel, respectively. In this paper, in order to improve the three-phase or single-phase PLC performance, we introduce a new MRC (called a&f-MRC) which effectively sums up multiple antenna diversity gain and multipath fading diversity gain. Via simulation, we prove the performance advantage over existing SISO/MIMO systems. In addition, we offer the tradeoff on system design through comparing with MRC, EGC and SC.

Evaluation of multiplicative random cascade models for CMIP 6 rainfall data temporal disaggregation (MRC 모형의 CMIP6 강우 자료에 대한 시간 분해 성능 평가)

  • Kwak, Jihye;Lee, Hyunji;Kim, Jihye;Jun, Sang Min;Lee, Jae Nam;Kang, Moon Seong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.367-367
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    • 2021
  • 최근 기후변화로 인해 극한 강우 사상의 빈도가 잦아짐에 따라 수공 구조물의 안전성이 저해되거나 인명 및 재산 피해가 발생할 가능성이 커지고 있다. 기후변화에 따른 기상현상의 변화 추세를 파악하고 대비하기 위해 CMIP (Coupled Model Intercomparison Project Phase)의 GCM(General Circulation Model) 기상자료 산출물이 활발하게 이용되고 있다. 기후변화 시나리오는 홍수기 방재 대책 수립 등의 연구에도 적용되고 있으나, GCM에서 산출된 기상자료의 시간 간격은 24시간 혹은 3시간 정도로 시간적 해상도가 낮아 홍수 모형의 입력자료로 사용되기 어려운 형태를 가지고 있다. 따라서 기후변화 시나리오를 홍수 모의 등의 분야에 접목하기 위해서는 GCM 자료의 시간적 해상도를 1시간 이하로 낮춤으로써 시나리오 산출물이 홍수모형과 적절하게 연결될 수 있도록 해야 한다. MRC (Multiplicative Random Cascade) 모형은 국내외에서 예보강우의 시간 분해 및 일강우 데이터 분해 연구에 활용된 바 있으며 관측 강우에 대하여 분해 성능이 준수함이 확인되었다. 이에 본 연구에서는 MRC 모형을 활용하여 미래 기후변화 시나리오 산출물에 적용함으로써 MRC 모형이 일단위 및 3시간 단위 기후변화 자료의 시간 분해에 대해 적절한 성능을 수행하는지 여부를 분석하고, 기후변화 자료의 최소 시간 간격별 강우 분해 결과를 비교·분석하고자 하였다. 본 연구의 결과는 향후 기후변화 시나리오 기반 기상자료 시간 분해에 대한 MRC 모형의 적용성을 평가하는 기초 자료로 활용될 수 있을 것으로 사료된다.

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Korean Machine Reading Comprehension for Patent Consultation Using BERT (BERT를 이용한 한국어 특허상담 기계독해)

  • Min, Jae-Ok;Park, Jin-Woo;Jo, Yu-Jeong;Lee, Bong-Gun
    • KIPS Transactions on Software and Data Engineering
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    • v.9 no.4
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    • pp.145-152
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    • 2020
  • MRC (Machine reading comprehension) is the AI NLP task that predict the answer for user's query by understanding of the relevant document and which can be used in automated consult services such as chatbots. Recently, the BERT (Pre-training of Deep Bidirectional Transformers for Language Understanding) model, which shows high performance in various fields of natural language processing, have two phases. First phase is Pre-training the big data of each domain. And second phase is fine-tuning the model for solving each NLP tasks as a prediction. In this paper, we have made the Patent MRC dataset and shown that how to build the patent consultation training data for MRC task. And we propose the method to improve the performance of the MRC task using the Pre-trained Patent-BERT model by the patent consultation corpus and the language processing algorithm suitable for the machine learning of the patent counseling data. As a result of experiment, we show that the performance of the method proposed in this paper is improved to answer the patent counseling query.

Robust design scheme of VS-MRC to time-varying plant

  • Tanaka, Kanya;Shibata, Satoru;Shimizu, Akira;Sakamoto, Masaru;Uchikado, Shigeru
    • 제어로봇시스템학회:학술대회논문집
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    • 1995.10a
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    • pp.56-59
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    • 1995
  • In this paper, we propose a new rubust design scheme of a variable structure type model reference control (VS-MRC) which can be applied to linear time-varing plants. Our idea is started from the hypothesis that the plant consists of two parts, i.e., one has time-invariant parameters and the other has time-varying parameters. We consider the former the nominal part of the plant and the latter a kind of disturbance to the nominal one. In this design scheme, the ordinary VS-MRC is adopted to the nominal part and the signum function is introduced to eliminate the influence of the disturbance.

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Performance Analysis of MC-DS/CDMA System with Phase Error and Hybrid SC/MRC-(2/3) Diversity (위상 에러와 하이브리드 SC/MRC-(2/3)기법을 고려한 MC-DS/CDMA 시스템의 성능 분석)

  • Kim Won-Sub;Park Jin-Soo
    • The KIPS Transactions:PartC
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    • v.11C no.6 s.95
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    • pp.835-842
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    • 2004
  • In this paper, we have analyzed the MC-DS/CDMA system with input signal synchronized completely through adjustment of the gain in the PLL loop, by using the hybrid SC/MRC-(2/3) technique, which is said to one of the optimal diversity techniques under the multi-path fading environment, assuming that phase error is defined to the phase difference between the received signal from the multi-path and the reference signal in the PLL of the receiver. Also, assuming that the regarded radio channel model for the mobile communication is subject to the Nakagami-m fading channel, we have developed the expressions and performed the simulation under the consideration of various factor, in the MC/DS-CDMA system with the hybrid SC.MRC-(2/3) diversity method, such as the Nakagami fading index(m), $the\;number\;of\;paths\;(L_p),$ the number of hybrid SC.MRC-(2/3) $diversity\;branches\;(L,\;L_c),$ the number of users (K), the number of subcarriers (U), and the gain in the PLL loop. As a result of the simulation, it has been confirmed that the performance improvement of the system can be achieved by adjusting properly the PLL loop in order for the MC/DS-CDMA system with the hybrid SC/MRC-(2/3) diversity method to receive a fully synchronized signal. And the value of the gain in the PLL loop should exceed 7dB in order for the system to receive the signal with prefect synchronization, even though there might be a slight difference according to the values of the fading index and the spread processing gain of the subcarrier.

A study of the Mori Radicis Cortex pre-treatment on transient ischemic brain injury in mice (상백피(桑白皮) 메탄올 추출물 전처치가 일과성 허혈에 의한 생쥐의 뇌 손상에 미치는 영향)

  • Chung, Byung-Woo;Lim, Jae-Yu;Lee, Se-Eun;Lee, Byoungho;Lim, Sehyun;Lim, Chiyeon;Cho, Suin
    • The Korea Journal of Herbology
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    • v.32 no.1
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    • pp.25-31
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    • 2017
  • Objectives : Mori Radicis Cortex (MRC), the root epidermis of Morus alba L., has been traditionally used to treat lung-related diseases in Korean Medicine. The common of MRC is Mulberry bark Morus bark, and it's pharmaceutical properties and taste are known as sweet and cold, and it promotes urination and reduce edema by reducing heat from the lungs and soothe asthma. In the present study, anti-apoptotic mechanism of MRC in middle cerebral artery occlusion (MCAO) model in mice. Methods : Two-hundred grams of MRC was extracted with methanol at room temperature for 5 days, and this was repeated one time. After filtration, the methanol was removed using vacuum evaporator, then stored at $-20^{\circ}C$ until use. C57BL/6 male mice were housed in an environment with controlled humidity, temperature, and light cycle. In order to determine beneficial effects of MRC on ischemia induced brain damage, infarct volume, neurological deficit scores, activities of several apoptosis-related proteins such as caspase-8, -9, Bcl-xL in MCAO-induced brains of mice were analyzed. Mice in MRC-treated groups were orally administered 30, 100, or 300 mg/kg of body weight for three consecutive days before commencing the MCAO procedure. Results : Pre-treatment of MRC significantly reduced infarct volume in MCAO subjected mice applied with 300 mg/kg of MRC methanol extract, and MRC effectively inhibited Bcl-xL reduction and caspase-9 activation caused by MCAO-induced brain damage. Conclusions : MRC showed neuro-protective effects by regulating apoptosis-related protein signals, and it can be a potential candidate for the therapy of ischemia-induced brain damage.