• Title/Summary/Keyword: Reed expansion

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Development of Phragmites communis Expansion Control Methods at the Wetland Ecological Park (습지생태공원의 갈대확장 조절 기술 개발)

  • Sung, Ki-June;Yee, Yong-Min;Chung, Yong-Hyun;Park, So-Young
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.5
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    • pp.1-11
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    • 2010
  • It is very difficult to control the expansion of reed at a wetland ecological park due to their aggressive reproduction capability. Therefore, proper topography and wetland hydrology should be provided before the construction of a wetland ecological park. Appropriate measures should be taken at the initial stages to prevent reed expansion. Field experiments were conducted at the newly constructed wetland ecological park for 15 months to develop methods to control the reproduction and expansion of Phragmites communis. A complete shading method had the best effect on the prevention of reed reoccurrence among other methods. Complete removal of the rhizomes controlled the reed growth to a greater extent than cutting the aboveground shoots. Water-level manipulation was also better than a half-shading method for the prevention of reed reproduction. These results indicated that soil properties and edge effects can influence the reed growth. Cutting only the aboveground shoots facilitates the growth of reed. These results suggest that reed control should be implemented repeatedly and an alteration in the wetland topography and hydrology may be more effective in the long term. Combination of treatments such as water-level management with shading should be considered to control the growth of reed. Adoptive management for created or restored ecosystem might be considered for accomplishment of its original purpose.

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.

The method to produce GRM coefficient using single transform matrix (단일변수 변환 행렬을 이용한 GRM 상수 생성 방법)

  • 이철우;김영건
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.807-810
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    • 1998
  • This paper propose the method to produce GRM(Generalized Reed-Muller)expansion. The general method to obtain GRM expansion coefficient for p valued n variable is derivation of single variable transform matrix and expand it n times using Kronecker product. In this case the size of matrix increases depending on the augmentation of variables. In this paper we propose the simple algorithm to produce GRM coefficient using a single variable transform matrix.

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Derivation of ternary RM coefficients using single transform matrix (단일변수 변환 행렬을 이용한 3치 RM 상수 생성)

  • 이철우;최재석;신부식;심재환;김홍수
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.745-748
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    • 1999
  • This paper propose the method to derive RM(Reed-Muller) expansion coefficients for Multiple-Valued function. The general method to obtain RM expansion coefficient for p valued n variable is derivation of single variable transform matrix and expand it n times using Kronecker product. The transform matrix used is p$^{n}$ $\times$ p$^{n}$ matrix. In this case the size of matrix increases depending on the augmentation of variables and the operation is complicated. Thus, to solving the problem, we propose derivation of RM expansion coefficients using p$\times$p transform matrix and Karnaugh-map.

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On the Performance of an Orthogonal Frequency Division Multiplexing System in a Mobile Radio Channel (이동 통신 채널에서 직교 주파수 분할 다중 시스템의 성능 연구)

  • 김윤희;송익호;김상우;방영조
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1996.06a
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    • pp.55-59
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    • 1996
  • In this paper, we first analyze the influence of interference due to the time variation and delay spread of the mobile channel on an orthogonal frequency division multiplexing (OFDM) system. With the result, we obtain the bit error rate performance of the 16-QAM OFDM system. Second, we investigate the performance of the Reed-Solomon (RS) coded 16-QAM OFDM system when the number of subcarriers varies. In the investigation, we assume that the information transmission rate and the total bandwidth expansion due to coding, guard interval, and the number of subcarriers are fixed. Under this condition, it is observed that there are optimum numbers of subcarriers that minimize the post decoding symbol error probability of RS code for various channel states.

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Fast Synthesis based on Ternary Universal Logic Module $U_h$ (3치 범용 논리 모듈 $U_h$에 의한 빠른 논리 합성)

  • 김영건;김종오;김흥수
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.31B no.1
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    • pp.57-63
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    • 1994
  • The logic function synthesis using ULM U$_h$ is constructed based on canonic Reed-Muller expansion coefficient for a given function. This paper proposes the fast synthesis algorithm using ULM U$_h$ for ternary function. By using circuit cost and synthesis method of proposed in this paper, order of control input variable minimum number of ULM U$_h$ can be decided in the synthesis of n-variable ternary function. Accordingly, this method enables to optimum circuit realization for ternary function synthesis using ULM ULM U$_h$ and can be applied to ternary function synthesis using ULM U$_h$. The complexity of search for select the order of all control input variables is (n+2)(n-1)/2.

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The VLSI implementation of RS Decoder using the Modified Euclidean Algorithm (변형 유클리디안 알고리즘을 이용한 리드 - 솔로몬 디코더의 VLSI 구현)

  • 최광석;김수원
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.679-682
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    • 1998
  • This paper presents the VLSI implementation of RS(reed-solomon) decoder using the Modified Euclidean Algorithm(hereafter MEA) for DVD(Digital Versatile Disc) and CD(Compact Disc). The decoder has a capability of correcting 8-error or 16-erasure for DVD and 2-error or 4-erasure for CD. The technique of polynomial evaluation is introduced to realize syndrome calculation and a polynomial expansion circuit is developed to calculate the Forney syndrome polynomial and the erasure locator polynomial. Due to the property of our system with buffer memory, the MEA architecture can have a recursive structure which the number of basic operating cells can be reduced to one. We also proposed five criteria to determine an uncorrectable codeword in using the MEA. The overall architecture is a simple and regular and has a 4-stage pipelined structure.

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The New Generation Circulation Method to Generalized Reed-Muller(GRM) Coefficients over GF(3) (극수의 순환성을 이용한 새로운 GF(3)상의 GRM 상수 생성 방법)

  • Lee, Chol-U;Che, Wenzhe;Kim, Heung-Soo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.10 s.340
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    • pp.17-24
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    • 2005
  • This paper propose a new generation method of GRM coefficients using the circulation property of polarity over GF(3). The general method to derive GRM coefficients are obtain the filled polarity of GRM coefficients using RM expansion and expand it for the polarities. Since the general method has many operations when the number of the variables are incremented. Proposed method in this paper simplifies the generation procedure and reduces a number of operators compare to parallel type because of the cyclic property of polarity. Comparing to the proposed papers, the proposed method use only adders without multiplier. So it improves the complexity of the system with efficient composition of the circuits.

A Production Method to GRM Coefficients of Multiple Valued Logic Function (다치논리함수의 GRM상수 생성 방법)

  • 신부식;심재환;김흥수
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.5
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    • pp.67-75
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    • 1999
  • This paper presents a production method to GRM coefficients which are consist of $P^n$ polarities to n variables over GF(p). In general production method to GRM coefficients is derived from RM coefficients to polarity 0 using RM expansion and extended to GRM coefficients. The procedure of proposed production method to GRM coefficients is consists of 2 steps. First, obtain the optimal polarity which is contains a minimal operation to single variable and then apply the same process to all generation process of GRM coefficients using cyclic property of the polarity. Proposed method simplify the generation procedure and reduces a number of operators because of the cyclic property of polarity.

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A Study on the Constructing the Function using Extension Edge Valued Graph (모서리값 확장 그래프를 사용한 함수구성에 관한연구)

  • Park, Chun-Myoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.4
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    • pp.863-868
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    • 2013
  • In recently years, many digital logic systems based on graph theory are analyzed and synthesized. This paper presented a method of constructing the function using edge valued extension graph which is based on graph theory. The graph is applied to a new data structure. from binary graph which is recently used in constructing the digital logic systems based on the graph theory. We discuss the mathematical background of literal and reed-muller expansion, and we discuss the edge valued extension graph which is the key of this paper. Also, we propose the algorithms which is the function derivation based on the proposed edge valued extension graph. That is the function minimization method of the n-variables m-valued functions and showed that the algorithm had the regularity with module by which the same blocks were made concerning about the schematic property of the proposed algorithm.