• Title/Summary/Keyword: Reed field

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Decomposition Characteristics and Seedling Growth of Common Reed (Phragmites australis) by Salt Concentration in Saemangeum Reclaimed Land (새만금 간척지에서 염농도에 따른 갈대(Phragmites australis) 유묘 생장 및 분해 특성)

  • Oh, Yang-Yeol;Kim, Sun;Ryu, Jin-Hee;Lee, Su-Hwan;Lee, Jung-Tae;Bae, Hui-Su;Kim, Young-Joo;Kim, Kil-Young
    • Journal of Environmental Science International
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    • v.28 no.12
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    • pp.1061-1069
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    • 2019
  • Common reed (Phragmites australis) is widespread in reclaimed land and wetland habitats. Every year, the common reed produces extensive colonies by means of underground rhizomes and ground-surface stolons. From an agricultural point of view, the common reed's large biomass is a good material for supplying organic matter. However, it has not yet been studied in terms of seedling production, transplanting conditions, and decomposition characteristics in reclaimed land. Seeds were harvested from the native common reed in Saemangeum, South Korea, the previous year and stored on an open field. The seeds were sowed in the greenhouse at the beginning of April. Common reed decomposition was studied from June to September, with the use of coarse mesh (5 mm) stem litterbags, on three samping dates and with five replicate packs per sample. These packs were dug in five soil condition (low-salinity topsoil, subsoil, high-salinity topsoil, subsoil, paddy topsoil) to 0.2 m and 0.4 m depth. The highest germination rate of common reed seeds was observed in non-salt solution, but the exhibited germination rate was 70% at 9.38 dS m-1. The plant height of young reed decreased steadily with increasing salinity, but leaf number did not decrease by 9.38 dS m-1. The survival rate of the two-year-old reed was 83.3%, which was 35% higher than that of the one-year reed. The transplant success rate was 0% in the no vinyl mulching in the soil, but the first year and second year seedlings survived rates were 63% and 83.3%, respectively, in vinyl mulching. Common reed decomposition rates were faster low salinity than high salinity. All nutrient contents were found to fluctuate significantly with time by soil conditions. We also need to study the growth rate of reed transplanting seedlings by soil moisture contents and the comparison of degradation in common reed tissues.

A Study on Pull-out Capacity and Shear resistance strength change by grasses (초본류에 의한 인발저항력 및 전단저항력 변화에 관한 연구)

  • Kim, Taegyun;Chae, Soo Kwon;Chun, Seung Hoon
    • Journal of Wetlands Research
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    • v.15 no.4
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    • pp.431-440
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    • 2013
  • It was tested in field that a Pull-out Capacity and Shear resistance strength change of reed, common reed and sedge which were planted by mat-type turf and used for revegetation of bank. The testes were done for 9 weeks from end of May and the grasses were planted on sandy soil. Roots grew fastly after planted and increasement of a common reed and sedge root were reduced after 4 weeks but increasement of reed roots were not reduced. The difference of increasement of roots is due to a difference of propagation method. Sedge propagate by seed. Reed and commom reed propagate by seed and subterranean stem and reed has bigger subterranean stem than common reed. So increasement of common reed and sedge roots were slow than reed. By root growth pattern, increasement of pull-out capacity and shear resistance strength showed very similar way of root growth, those of common reed and sedge were fast in early stage of cultivation but were reduced. But increasement of pull-out capacity and shear resistance strength of reed was not reduced. A Maximum shear resistance strength called critical shear resistance strength of common reed and sedge can be Analyzed at 11 weeks after planted.

Research for Carbon Dioxide Fluctuation using Drone above the Mud Flat and Reed Beds in the Suncheon Bay (드론 관측을 통한 순천만 갯벌과 갈대밭 상부 대기의 이산화탄소 농도 분포 연구)

  • Kang, Dong-hwan;Jo, Won Gi;Yun, Yeon Su;Yu, Hun Sun;Jang, Seon Woong;Kim, Dong Lib;Park, Jeong Hwan;Song, Young Chul;Choi, Yong Jae
    • Journal of Environmental Science International
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    • v.29 no.7
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    • pp.703-713
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    • 2020
  • In this study, carbon dioxide concentration and air temperature at different elevations were observed and analyzed in the upper atmosphere of mud flat and reed beds at low tide in Suncheon Bay. The carbon dioxide concentration and air temperature sensors were mounted on the drone, and the carbon dioxide concentration and air temperature by altitude (5 m, 10 m, 20 m, 40 m) at five points in the tidal flat and reed beds were observed in the morning and afternoon. The carbon dioxide concentrations in the upper atmosphere of the tidal flat ranged from 453.0 to 460.2 ppm in the morning and 441.6 to 449.7 ppm in the afternoon. The carbon dioxide concentrations in the upper atmosphere of the reed beds ranged from 448.9 to 452.4 ppm in the morning and 446.0 to 454.4 ppm in the afternoon. The carbon dioxide concentrations in the upper atmosphere of the tidal flat was higher in the morning than in the afternoon, and the carbon dioxide concentration decreased as the altitude increased. The carbon dioxide concentration in the upper atmosphere of the reed beds was similar in the morning and afternoon at all altitudes, and the carbon dioxide concentration decreased as the altitude increased. The correlation coefficient between carbon dioxide concentration and air temperature observed in the tidal flat in the morning was -0.54 ~ -0.77, and the correlation coefficient between carbon dioxide concentration and air temperature observed in the afternoon was 0.56 ~ 0.80. The correlation coefficient between carbon dioxide concentration and temperature observed in the morning in the reed field was low, below 0.3, and the correlation coefficient between carbon dioxide concentration and air temperature observed in the afternoon was 0.35 ~ 0.77. In the upper atmosphere of the tidal flats and reed beds, the linear function was suitable for the change of carbon dioxide concentration as a air temperature, and the coefficient of determination of the estimated linear function was higher in the afternoon than in the morning. Through this study, it was confirmed that the carbon dioxide concentration in the upper atmosphere of the tidal flat and the reed beds was different, and the increase rate of carbon dioxide concentration in the upper atmosphere of the tidal flat and the reed beds was higher in the afternoon than in the morning.

A Study on a VLSI Architecture for Reed-Solomon Decoder Based on the Berlekamp Algorithm (Berlekamp 알고리즘을 이용한 Reed-Solomon 복호기의 VLSI 구조에 관한 연구)

  • 김용환;정영모;이상욱
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.11
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    • pp.17-26
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    • 1993
  • In this paper, a VlSI architecture for Reed-Solomon (RS) decoder based on the Berlekamp algorithm is proposed. The proposed decoder provided both erasure and error correcting capability. In order to reduc the chip area, we reformulate the Berlekamp algorithm. The proposed algorithm possesses a recursive structure so that the number of cells for computing the errata locator polynomial can be reduced. Moreover, in our approach, only one finite field multiplication per clock cycle is required for implementation, provided an improvement in the decoding speed, and the overall architecture features parallel and pipelined structure, making a real time decoding possible. From the performance evaluation, it is concluded that the proposed VLSI architecture is more efficient in terms of VLSI implementation than the rcursive architecture based on the Euclid algorithm.

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Reed-Solomon Decoder using Berlekamp-Massey Algorithm for Digital TV (디지털 TV용 Reed-Solomon 복호기의 구현)

  • Park, Chang-Il;Kim, Jong-Tae
    • Proceedings of the KIEE Conference
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    • 1999.07g
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    • pp.3212-3214
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    • 1999
  • RS(Reed-Solomon)부호는 오류 정정을 위한 채널 코딩기법중의 하나로 특히 연집 오류에 대해 강한 특성을 갖고 있으며, CD-P(Compact Disc Player), DAT(Digital Audio Tape). VTR, DVD(Digital Video Disc), 디지탈 TV 디코더등에서 사용되고 있다. 본 논문은 Galois Field, GF[$2^8$]상에서 (204. 188. 8)의 규격을 갖는 디지탈 TV용 RS 복호기의 구현에 관한 연구로 8개의 심볼 오류까지 정정 가능하다. 오증 계산은 16개의 오증 계산셀로 구성되어 지며, 오류 위치 다항식을 계산하는데 있어서는 Berlekamp-Massey 알고리즘을 사용한다. VHDL로 설계되어 Synopsys를 이용하여 검증 및 합성하였다.

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Establishment of Herbicide Screening Methods for Reed (Phragmites communis Trin.) Control - I. Propagation of Reed (갈대(Reed, Phragmites communis Trin.)의 방제를 위한 제초제 스크리닝방법의 확립 - I. 갈대의 육묘)

  • Hwang, I.T.;Choi, J.S.;Lee, H.J.;Hong, K.S.;Cho, K.Y.
    • Korean Journal of Weed Science
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    • v.16 no.1
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    • pp.21-27
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    • 1996
  • This experiment was conducted to find out an effective propagation method for reed(Phragmites communis Trin.), ensuring a continuous herbicide screening for reed control. Reed propagation methods were compared under a greenhouse condition using tour different materials; seeds, rhizomes, depressed stolons of P. japonica Steud., and stem cuttings. Although reed seeds were easy to harvest and store, their germination rate(${\leq}$5%) was very low and seedling growth from the seeds was slow. Rhizomes were difficult to harvest and their harvest time was limited from November to March. Furthermore, reed propagation using rhizomes had problems of a relatively low germination rate(46%), no uniformity in size and shape, individual differences at the early stage of growth, and difficulties in material storage. Rate of reed growth from rhizomes was higher in commercial soil mix(Boo Nong soil) than in sand or in sand+upland soil(1:1). Depressed stolons of P. japonica had a moderate germination rate(65%) and were relatively easy to harvest. However, their harvest time was limited only from August to September. Propagation method using stem cuttings had several advantages over the above methods using other materials. Reed plants could uniformly be propagated from the stem cuttings with a relatively high germination rate(75%). Stem cuttings of central nodes showed a higher germination rate compared to those of upper or lower nodes. Stem cuttings from the field should be used immediately after harvest, since their germination rate decreased rapidly when they were stored under a wet- or a dry-refrigerated condition. Furthermore, the germination of stem cuttings tended to decrease when they were collected from the field after August. This indicates that there is a limitation of harvest time for stem cuttings. However, a year-round propagation of reed using stem cuttings is possible if parent plants are grown in a greenhouse, and thus herbicide screening for reed control could continuously be performed.

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Design of DSP Instructions and their Hardware Architecture for Reed-Solomon Codecs (Reed-Solomon 부호화/복호화를 위한 DSP 명령어 및 하드웨어 설계)

  • 이재성;선우명훈
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.6A
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    • pp.405-413
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    • 2003
  • This paper presents new DSP (Digital Signal Processor) instructions and their hardware architecture to efficiently implement RS (Reed-Solomon) codecs, which is one of the most widely used FEC (Forward Error Control) algorithms. The proposed DSP architecture can implement various primitive polynomials by program, and thus, hardwired codecs can be replaced. The new instructions and their hardware architecture perform GF (Galois Field) operations using the proposed GF multiplier and adder. Therefore, the proposed DSP architecture can significantly reduce the number of clock cycles compared with existing DSP chips. It can perform RS decoding rate of up to 228.1 Mbps on 130MHz DSP chips.

Construction of Digital Logic Systems based on the GFDD (GFDD에 기초한 디지털논리시스템 구성)

  • Park Chun-Myoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.9 no.8
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    • pp.1774-1779
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    • 2005
  • This paper propose the design method of the constructing the digital logic systems over galois fields using by the galois field decision diagram(GFDD) that is based on the graph theory. The proposed design method is as following. First of all, we discuss the mathematical properties of the galois fields and the basic properties of the graph theory. After we discuss the operational domain and the functional domain, we obtain the transformation matrixes, $\psi$GF(P)(1) and $\xi$GF(P)(1), in the case of one variable, that easily manipulate the relationship between two domains. And we extend above transformation matrixes to n-variable case, we obtain $\psi$GF(P)(1) and $\xi$GF(P)(1). We discuss the Reed-Muller expansion in order to obtain the digital switching functions of the P-valued single variable. And for the purpose of the extend above Reed-Muller expansion to more two variables, we describe the Kronecker product arithmetic operation.

A Study of Pull-out strength increasement by root of grasses (식물뿌리에 의한 인발력 증가에 관한 연구)

  • Kim, Taegyun;Chae, Soo Kwon;Chun, Seung Hoon;Jeong, Jae Cheol
    • Journal of Wetlands Research
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    • v.14 no.2
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    • pp.199-210
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    • 2012
  • In this study, a pull-out strength increasement of grasses was tested in field and the relationship between a weight of root and pull-out strength was established. The tested grasses were commmon reed, reed and sedge which were cultivated by mat-type like turf and used for revegetation of bank. The shear stress of soil at a section can be discribed as a function of root area and pull-out strength, therefore the result of this study will be used as a foundational data for reinforcing the shear stress of the revegetated bank. The heavier weight of root increased, the stronger shear stress was for all grasses. But the relationship between the weight and the shear stress were different by a kind of grass. The difference between common reed, sedge and reed is due to difference of growth and propagation. A reed propagates by subterranean stem and a root weight and pull-out strength are linearly increased by root and growth of subterranean stem.

Effects of Cutting Frequency and Level of Nitrogen Fertilization on Growth Characteristics, Dry Matter Yield and Nutritive Value of Reed Canarygrass (예취횟수 및 질소시비수준이 Reed Canarygrass의 생육특성, 건물수량 및 사료가치에 미치는 영향)

  • Kim, Weon-Ho;Kim, Dong-Am;Seo, Sung;Shin, Dong-Eun;Choi, Ki-Jun;Kim, Ki-Yong
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.20 no.1
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    • pp.55-60
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    • 2000
  • This experiment was carried out to determine the effect of cutting frequency(3rd and 5th cut) and level of nitrogen fertilization(l50 + liquid manure, 300 and 450kgha) on growth characteristics, dry matter yield and nutritive vaule of reed canarygrass(Pha1aris arundinacea L.), at the forage experimental field, College of Agriculture and Life Sciences, SNU, Suweon. Plant height of 3rd cutting(79.2cm) was significantly higher than that of 5th cutting(58.0cm). And dry mattter yield of cutting frequency was observed in 3rd cutting(16,902kgPna) and 5th cutting(l7,833kg/ha) As the nitrogen fertilization was increased, DM yield was significantly increased(p<0.05). When the nitrogen fertilization was applied at the level 150 + liquid manure, 300 and 450kg, dry matter yields were 16,5 12, 17,123 and 18,368kg/ha, respectively. The contents of neutral detergent fiber(NDF), acid detergent fiber(ADF) and in vitro dry matter digestibility(1VDMD) were similar among cutting frequency. However, slightly higher NDF, ADF and IVDMD contents were found in 5th cutting, but there was not affected by nitrigen fertilization. Based on the results of this experiment, it were indicated that to 5th cutting and 450kg nitrogen fertilization could be obtained from the increase of dry matter yield and nutritive value (Key words : Cutting frequency, Nitrogen fertilization, Dry matter yield, Nutritive Value, Reed canarygrass)

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