• Title/Summary/Keyword: 4-derivation

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Derivation of the Foschini and Shepp's Joint-Characteristic Function for the First-and Second-Order Polarization-Mode-Dispersion Vectors Using the Fokker-Planck Method

  • Lee, Jae-Seung
    • Journal of the Optical Society of Korea
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    • v.12 no.4
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    • pp.240-243
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    • 2008
  • Using the well-known Fokker-Planck method, this paper presents a standard way to find the joint-characteristic function for the first- and second-order polarization-mode-dispersion vectors originally derived by Foschini and Shepp. Compared with the Foschini and Shepp's approach, the Fokker-Planck approach gives a more accurate and straightforward way to find the joint-characteristic function.

A Derivation of Comprehensive Protection Ratio and Its Applications for Microwave Relay System Networks

  • Suh Kyoung-Whoan
    • Journal of electromagnetic engineering and science
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    • v.6 no.2
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    • pp.103-109
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    • 2006
  • This paper suggests an efficient and comprehensive algorithm of the protection ratio derivation and illustrates some calculated results applicable to the initial planning of frequency coordination in the fixed wireless access networks. The net filter discrimination associated with Tx spectrum mask and overall Rx filter characteristic has been also examined to show the effect of the adjacent channel interference. The calculations for co-channel and adjacent channel protection ratios are performed for the current microwave frequency band of 6.7 GHz including Tx spectrum mask and Rx filter response. According to results, fade margin and co-channel protection ratio reveal 41.4 and 75.2 dB, respectively, for 64-QAM and 60 km at BER $10^{-6}$. It is shown that the net filter discrimination with 40 MHz channel bandwidth provides 28.9 dB at the first adjacent channel, which yields 46.3 dB of adjacent channel protection ratio. In addition, the protection ratio of 38 GHz radio relay system is also reviewed for millimeter wave band applications. The proposed method gives some advantages of an easy and systematic extension for protection ratio calculation and is also applied to frequency coordination in fixed millimeter wave networks.

Investigation of Importance of Evanescent Modes in Predicting the Transformation of Water Waves by the Linear Wave Theory: 1. Derivation of Equations of Wave Energy (선형파 이론에 의한 파랑변형 예측 시 소멸파 성분의 중요성 검토: 1. 에너지 식 유도)

  • 이창훈;조용식
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.4
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    • pp.282-285
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    • 2002
  • The magnitude of evanescent modes in terms of dynamics is investigated in case that the transformation of water waves is predicted using the linear wave theory. In other words, derivation is made of both the kinetic and potential wave energies of evanescent modes as welt as propagating modes. The evanescent modes consist of compound components of propagating and evanescent modes, those of identically equal evanescent modes, and those of identically different evanescent modes. The wave energy per a horizontal distance decreases exponentially with the distance.

Derivation of the Basin Instantaneous Unit Hydrograph Considering the Network Geometry and Hillslope of Small Basin (소유역의 수로기하학적특성과 사면을 고려한 유역순간단위도의 유도)

  • Kim, Jae Han;Yoon, Seok Young
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.2
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    • pp.161-171
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    • 1993
  • The basin instantaneous unit hydrograph was derived by considering the network geometry and hillslope. The network geometry is quantified in a function, termed the width function, that reflects the distribution of runoff with flow distance from the outlet. The model using the derivation of the basin IUH consists of two components: the routing component of the initial distribution through the network by means of a simplified diffusion approximation and the hillslope component by means of a exponential distribution that is the probability density function of the travel time in the hillslope. The application of this method was tested on four observed flood data of Bocheong stream and Wi stream. The results show that the proposed method can be used for the analysis of the basin IUH.

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Priority Derivation of Modular House Cost Reduction Factors through Case Analysis (시공사례 분석을 통한 모듈러 주택 원가절감 우선순위 항목 도출)

  • Ryu, Kuk-Mu;Moon, Ye-Ji;Cho, Byoung-Hoo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.66-67
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    • 2016
  • Modular construction is attracting attention as the solution of recent problems in construction site. Such as lack of construction workforce, increasing labor costs, work delay due to extreme weather events and strengthening government regulations. However, despite the many advantages, Modular construction has not been activated dueto high construction costs compared to other construction methods. Accordingly, the object of this study is priority derivation of prefabricated house cost reduction factors and use as basic research data. For research performance, we have analyzed the blueprint and bill of quantities of a modular construction based public dormitory which was built in 2013. In result, the proportion of modular construction and on-site construction is 66% and 34%, and the construction cost proportion by activity was devided in to construction(79%), machinery(7%), electricity(5%) and civil(9%). Among these results in order to reduce costs, interior finishing(19.4) steel-frame(16.9%), metal works(13.5%), RC(11.8%), joinery(7.3%) is the order requires focused management.

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An Optimum Choice of Approximation Path for Derivation of New Class of Closed-Form Green's Functions (새로운 형태의 Closed-Form 그린함수의 유도를 위한 근사 경로의 최적선택)

  • Lee Young-Soon;Kim Eui-Jung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.4 s.95
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    • pp.418-426
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    • 2005
  • Based upon three level approximation and the steepest descent path(SDP) method, we consider an optimum choice of approximation path for derivation of new class of closed-flrm Green's functions which can lead to the analytic evaluation of MoM(Method of Moment) matrix elements. It is observed that the present method can give more accurate evaluation of the spatial Green's functions than the previous method, even without the advance investigation of the spectral functions, over a wide frequency range. In order to check the validity of the present method, some numerical results are presented.