• Title/Summary/Keyword: Differential modulation

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Performance of Cooperative Networks with Mixed Relaying Protocols in Railway Environments (철도환경에서 혼합 중계 프로토콜을 이용한 협력 네트워크의 성능)

  • Cho, Woong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.11 no.3
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    • pp.271-276
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    • 2016
  • Cooperative networks enhance the overall communication performance by combining signals from relay nodes and direct signal. In this paper, we analyze the performance of cooperative communication systems which use mixed relaying protocols. By assuming several relay nodes exist between the source node and destination node, we consider the systems use not a single relaying protocol but both decode-and-forward and amplify-and-forward protocols randomly. We analyze the effect of each relying protocol for the overall system performance, and also consider the performance depending on the relay location. Differential modulation scheme which demodulates signal without channel state information is adopted where it can be applicable fast varying channel such as railway environments.

CUDA based Lossless Asynchronous Compression of Ultra High Definition Game Scenes using DPCM-GR (DPCM-GR 방식을 이용한 CUDA 기반 초고해상도 게임 영상 무손실 비동기 압축)

  • Kim, Youngsik
    • Journal of Korea Game Society
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    • v.14 no.6
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    • pp.59-68
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    • 2014
  • Memory bandwidth requirements of UHD (Ultra High Definition $4096{\times}2160$) game scenes have been much more increasing. This paper presents a lossless DPCM-GR based compression algorithm using CUDA for solving the memory bandwidth problem without sacrificing image quality, which is modified from DDPCM-GR [4] to support bit parallel pipelining. The memory bandwidth efficiency increases because of using the shared memory of CUDA. Various asynchronous transfer configurations which can overlap the kernel execution and data transfer between host and CUDA are implemented with the page-locked host memory. Experimental results show that the maximum 31.3 speedup is obtained according to CPU time. The maximum 30.3% decreases in the computation time among various configurations.

Digital CMOS Temperature Sensor Implemented using Switched-Capacitor Circuits

  • Son, Bich;Park, Byeong-Jun;Gu, Gwang-Hoe;Cho, Dae-Eun;Park, Hueon-Beom;Jeong, Hang-Geun
    • Journal of Sensor Science and Technology
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    • v.25 no.5
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    • pp.326-332
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    • 2016
  • A novel CMOS temperature sensor with binary output is implemented by using fully differential switched-capacitor circuits for resistorless implementation of the temperature sensor core. Temperature sensing is based on the temperature characteristics of the pn diodes implemented by substrate pnp transistors fabricated using standard CMOS processes. The binary outputs are generated by using the charge-balance principle that eliminates the division operation of the PTAT voltage by the bandgap reference voltage. The chip was designed in a MagnaChip $0.35-{\mu}m$ CMOS process, and the designed circuit was verified using Spectre circuit simulations. The verified circuit was laid out in an area of $950{\mu}m{\times}557 {\mu}m$ and is currently under fabrication.

Improved Intraframe Coding Method based on H.263 Annex I (H.263 Annex I 기반 화면내 부호화 기법의 성능개선)

  • 유국열
    • Proceedings of the Korea Institute of Convergence Signal Processing
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    • 2001.06a
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    • pp.213-216
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    • 2001
  • The H.263 Annex I method for the intraframe coding is based on the prediction in DCT domain, unlike JPEG, MPEG-1, and MPEG-2 where the intraframe coding uses block DCT, independent of the neighboring blocks. In this paper, we show the ineffectiveness of H.263 Annex I prediction method by mathematically deriving the spatial domain meaning of H.263 Annex I prediction method. Based on the derivation, we propose a prediction method which is based on the spatial correlation property of image signals. From the experiment and derivation, we verified the proposed method.

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Characterization and expression profiles of aquaporins (AQPs) 1a and 3a in mud loach Misgurnus mizolepis after experimental challenges

  • Lee, Sang Yoon;Nam, Yoon Kwon;Kim, Yi Kyung
    • Fisheries and Aquatic Sciences
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    • v.20 no.9
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    • pp.23.1-23.9
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    • 2017
  • Two distinct cDNAs encoding aquaporins (mmAQPs 1a and 3a) were isolated and characterized from mud loach Misgurnus mizolepis. The identified mud loach AQP cDNAs encode for polypeptides of 260 and 302 amino acids. Topology predictions confirmed six putative membrane-spanning domains connected by five loops and the N- and C-terminal domains being cytoplasmic. The mud loach AQPs 1a and 3a showed broad distribution in multiple tissues including immune-responsive tissues as well as osmoregulatory tissues. Hence, the diversity of AQP distribution and expression possibly indicated its differential functions in the regulation of fluid movement in response to environmental stimuli. The transcription of mmAQP genes was differentially modulated by immune challenges. In particular, the mmAQP3a expression level in the liver was more responsive to immune challenges than that of mmAQP1a. Taken together, fish stimulation or infection resulted in significant modulation of mud loach AQP genes, suggesting potential functional roles of these proteins in piscine pathophysiological process.

누설전류가 작은 $1.3\mum$ GaInAsP/InP 평면매립형 레이저 다이오드

  • Lee, Jung-Gi;Cho, Ho-Sung;Park, Kyung-Hyun;Park, Chan-Yong;Lee, Yong-Tak
    • ETRI Journal
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    • v.13 no.4
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    • pp.2-9
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    • 1991
  • Buried-heterostructure lasers are more difficult to fabricate than weakly index guided or gain guided lasers. However, these strongly index guided structures are most suitable for a source of lightwave transmission systems. But, for conventional etched mesa buried heterostructure lasers, the regrowth of InP blocking layer is difficult and irreproducible. So, there are inevitable leakage currents flowing outside the active region resulting poor performance. To eliminate these problems, we used a planar buried heterostructure. As a results, the average threshold current was 28mA and the differential quantum efficiency was about 20% per facet for $1.3\mum$ GaInAsP/InP PBH-LD. The initial forward leakage current was not exceeding $1\muA$ and the reverse voltage for $-10\muA$ was -3V~-5V, these are improved figure of 1mA~10mA and -1V~-3V for EMBH laser diode. The chip modulation bandwidth was more than 2.4GHz for $1.5I_th$.

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Analyzed the performances for system withlimiter discriminator detection and integrate and dump post detection filtering (부분대역 재밍하에서 리미터-변별기 검파와 Integrate-and-Dump 펄터링을 고려한시스템의 성능 분석)

  • 이봉수;이사원
    • Journal of the Korea Society of Computer and Information
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    • v.3 no.4
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    • pp.78-85
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    • 1998
  • In this paper, we analyzed the performances for FH/CPFSK system with limiter - discriminator detection and integrate-and-dump post-detection filtering under thermal noise and partial-band jamming noise. And, we considered intersymbol interference - related SNR and differential phase parameters for all eight of the possible adjacent bit data patterns, FM noise clicks for evaluating FH/CPFSK and CPFSK systems. In result, the optimum modulation index h was 0.7 and the optimum value of bandwidth-time product D was 1.0. Next, when we considered the thermal noise under the partial-band jamming, the thermal noise significantly influenced the error probability of system below 20dB approximately but could ignore above 20dB.

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An Adaptive Fuzzy Current Controller with Neural Network For Field-Oriented Controller Induction Machine

  • Lee, Kyu-Chan;Lee, Hahk-Sung;Cho, Kyu-Bock;Kim, Sung-Woo
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.227-230
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    • 1993
  • Recently, the development of novel control methodology enables us to improve the performance of AC-machine drives by using pulse width modulation (PWM) technique. Usually, the dynamic characteristic of induction motor (IM) has been represented by the 5-th order nonlinear differential equation. This dynamics, however, can be reduced to 3-rd order dynamics by applying direct control of IM input current. This methodology concludes that it is much easier to control IM by means of the field-oriented methods employing the current controller. Therefore a precise current control is crucial to achieve a high control performance both in dynamic and steady state operations. This paper presents an adaptive fuzzy current controller with artificial neural network (ANN) for field-oriented controlled IM. This new control structure is able to adaptively minimize a current ripple while maintaining constant switching frequency. Especially the proposed controller employs neuro-computing philosophy as well as adaptive learning pattern recognizing principles with respect to variations of the system parameters. The proposed approach is applied to the IM drive system, and its performance is tested through various simulations. Simulation results show that the proposed system, compared among several known classical methods, has a superb performance.

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Differential expression of the 27 kDa cathepsin L-like cysteine protease in developmental stages of Spirometra erinacei

  • Kong, Yoon;Yun, Doo-Hee;Cho, Seung-Yull;Sohn, Woon-Mok;Chung, Young-Bae;Kang, Shin-Yong
    • Parasites, Hosts and Diseases
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    • v.38 no.3
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    • pp.195-199
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    • 2000
  • The 27 kDa cathepsin L-like cysteine protease of Spirometra erinocei plerocercoid is known to play an important function in tissue penetration, nutrient uptake and immune modulation in human sparganosis. In the present study, the expression of this enzyme was examined at different developmental stages of S. erinacei including immature egg, coracidium, plerocercoid in tadpole and rat, and adult Proteolytic activity against carboxybenzoyl-phenylalanyl-arginyl-7-amino-4-rnethylcournarin was do tooted in the extracts of coracidia and plerocercoid while no activity was observed in those of immature egg and adult. The specific activity in coraridial extracts was lower than that in the plerocercoid. Reverse transcription-polymerase chain reaction and Northern biol analysis demonstrated that the gene was expressed in the coracidium and plerocercoid but not in immature egg and adult. These results suggest that the 27 kDa cysteine protease is only expressed in the stages involving active migration of the parasite in the host tissue.

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Differential Modulation of Volatile Constituents in Artemisia princeps and Artemisia argyi Plants after Gamma Ray or Electron Beam Irradiation

  • Kim, Ji Hong;Cho, Eun Ju;Lee, Min Hee;Kim, Ji Eun;Chung, Byung Yeoup;Kim, Tae Hoon;Kim, Jin-Hong
    • Journal of Radiation Industry
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    • v.6 no.1
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    • pp.17-21
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    • 2012
  • The effects of gamma ray or electron beam irradiation on herbaceous medicinal plants were investigated in terms of the composition of volatile constituents using the aerial parts or leaves of Artemisia princeps Pamp. cv. Ganghwayakssuk and Artemisia argyi cvs. Namhaeyakssuk and Hwanghaessuk. The composition of volatile constituents in leaves was clearly distinguishable among the three Artemisia cultivars. However, the relative proportions of the major volatile constituents such as 1,8-cineole, ${\alpha}$-pinene, camphene, santolina triene, and artemesia triene, were similarly changed in two or three cultivars by gamma ray or electron beam irradiation. In particular, the proportion of 1,8-cineole was increased up to 1.29- to 1.71-fold in the three cultivars after irradiation with gamma ray. These results suggest that gamma ray or electron beam irradiation can be applied to modulate the composition of volatile constituents in the leaves of Artemisia plants.