• Title/Summary/Keyword: Complex field

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Skillful Wind Field Simulation over Complex Terrain using Coupling System of Atmospheric Prognostic and Diagnostic Models (대기예보모형과 진단모형 결합을 통한 복잡지형 바람장 해석능력 평가)

  • Lee, Hwa-Woon;Kim, Dong-Hyeok;Lee, Soon-Hwan;Kim, Min-Jung;Park, Soon-Young;Kim, Hyun-Goo
    • Journal of Environmental Science International
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    • v.19 no.1
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    • pp.27-37
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    • 2010
  • A system coupled the prognostic WRF mesoscale model and CALMET diagnostic model has been employed for predicting high-resolution wind field over complex coastal area. WRF has three nested grids down to from during two days from 24 August 2007 to 26 August 2007. CALMET simulation is performed using both initial meteorological field from WRF coarsest results and surface boundary condition that is Shuttle Radar Topography Mission (SRTM) 90m topography and Environmental Geographic Information System (EGIS) 30m landuse during same periods above. Four Automatic Weather System (AWS) and a Sonic Detection And Ranging (SODAR) are used to verify modeled wind fields. Horizontal wind fields in CM_100m is not only more complex but better simulated than WRF_1km results at Backwoon and Geumho in which there are shown stagnation, blocking effects and orographically driven winds. Being increased in horizontal grid spacing, CM_100m is well matched with vertically wind profile compared SODAR. This also mentions the importance of high-resolution surface boundary conditions when horizontal grid spacing is increased to produce detailed wind fields over complex terrain features.

A Study on Complex Field Network Coding Scheme for Wireless Relay System (무선 릴레이 시스템에서의 Complex Field Network Coding 기법 적용에 관한 연구)

  • Hwang, Won-Jun;Jang, Jun-Hee;Choi, Hyung-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.4C
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    • pp.241-253
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    • 2011
  • In this paper, a CFNC (Complex Field Network Coding) scheme is presented, which focuses on improving transmission efficiency by reducing time slots that are needed to exchange data frames. Conventional CFNC scheme has the advantage of minimizing the number of time slots required for information exchanges. However, there exists serious performance deterioration because the transmit signals are interfered with each other. Moreover, when CFNC scheme is applied, the estimation and compensation performance of fine frequency offset severely deteriorates due to the multiple frequency offsets in received signal of relay node. In order to overcome these critical problems, we propose an improved CFNC scheme with modified maximum likelihood decision method which uses uplink transmit diversity. Also, we propose an enhanced fine frequency offset estimation method and a corresponding compensation method to deal with the multiple frequency offsets. Corresponding simulation results verify that the proposed methods are able to effectively solve the problems of CFNC scheme.

An Importance Analysis of Planning Factors for Constructing Environmental-Friendly Industrial Estate (환경친화적 산업단지 조성을 위한 계획요소의 중요도 분석)

  • Lee, Eun Yeob;Kim, Jung Kon;Lee, Hyun Ju
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.4
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    • pp.1-11
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    • 2012
  • This study prepared the list of planning components required for constructing environment-friendly industrial complex and grasped major environment-friendly planning components by measuring the importance per each planning component via the survey for specialists. As a result of measuring the importance of planning component according to each field for constructing environment-friendly industrial complex, it is indicated that important planning components in natural environment field are establishing complex location plan considering its configuration and slope, excluding projects for steep slope-land, establishing countermeasures for reducing contaminants per its source, and separated location of contamination industry around living space. In living environment field, proposed planning components having relatively high importance are separated location of pollution causing industry, establishing energy saving land use plan, linking with green way, circulation network plan, lowering noise level at roadside, plan for separating between pedestrian and vehicle, securing parking space, extending green park and proper location, installing green buffer zone, conserving and forming landscapes, land use for raising energy efficiency, and expansion of energy source. In case of ecological environment, core planning components such as conserving upper class of ecological naturality degree, conserving main habitat, and biotope forming plan are suggested. This study is limited to find out planning components for constructing environment-friendly physical environment of industrial complex which is a part of non-production process. The approach to solve environmental problem by linking spatially production process and non-production process. There is a need to conduct follow-up study to constructing technique for environment-friendly industrial complex considering production & nonproduction process afterward.

Structure Jacobi Operators of Real Hypersurfaces with Constant Mean Curvature in a Complex Space Form

  • Hwang, Tae Yong;Ki, U-Hang;Kurihara, Hiroyuki
    • Kyungpook Mathematical Journal
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    • v.56 no.4
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    • pp.1207-1235
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    • 2016
  • Let M be a real hypersurface with constant mean curvature in a complex space form $M_n(c),c{\neq}0$. In this paper, we prove that if the structure Jacobi operator $R_{\xi}= R({\cdot},{\xi}){\xi}$ with respect to the structure vector field ${\xi}$ is ${\phi}{\nabla}_{\xi}{\xi}$-parallel and $R_{\xi}$ commute with the structure tensor field ${\phi}$, then M is a homogeneous real hypersurface of Type A.

A Study on the Interior Design Planning for Children Cultural Complex (어린이 복합문화공간 실내계획에 관한 연구)

  • So, Ah-Lum;Mo, Jeong-Hyun
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2009.11a
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    • pp.245-250
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    • 2009
  • A variety of change in modern society has affected a family structure. In addition birth rate is getting lower and nuclear family type is getting common, influence of children has highly increased. According to this phenomenon, needs and concern about education and culture for children increase sharply. Children cultural complex can be learning field, which helps children not only to rediscover the world by themselves but also to have various and abundant experience. The purpose of this study is going to extract a planning factor of the children cultural complex through case studies of korean and oversea project for adaptable children cultural complex. In addition, this study tries to analyze the features of the children cultural complex in korean and oversea. Consequently, The analysis result is to be introduced party room to children cultural complex, used the PVC tile and carpet tile for safety of children and variety, and executed program relevant to nature.

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Smart Far-Field Wireless Power Transfer via Time Reversal (시간 역전을 기반으로 한 지능적 원거리 무선전력전송)

  • Park, Hong Soo;Hong, Ha Young;Hong, Sun K.
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.4
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    • pp.285-289
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    • 2018
  • In this paper, we demonstrate electromagnetic wave focusing and rectification based on time reversal as a smart method for far-field wireless power transfer. Time reversal in a complex propagation environment allows for transmission of high peak power pulses by focusing the electromagnetic waves selectively regardless of the receiver position. We demonstrate wave focusing and radio frequency (RF) to direct current (DC) rectification via numerical simulation of a complex propagation environment. The results reveal that time reversal can ensure peak power up to 12 dB greater compared to a narrowband continuous wave signal, thereby enhancing the rectified DC voltage with better efficiency.

High-frequency Magnetic Properties of Ni-Zn-Co Ferrites Used for Mangetic Shielding in NFC (NFC의 자기 차폐용 Ni-Zn-Co 페라이트 자성체의 고주파 자기특성)

  • Ryu, Yo-Han;Kim, Sung-Soo
    • Journal of Powder Materials
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    • v.21 no.6
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    • pp.429-433
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    • 2014
  • This study investigated the magnetic properties and frequency dispersion of complex permeability of Ni-Zn-Co ferrites used for magnetic shielding in near field communication (NFC) system. The sintered specimens of $(Ni_{0.7}Zn_{0.3})_{1-x}Co_xFe_2O_4$ composition were prepared by the conventional ceramic processing. The coercive force and saturation magnetization were measured by vibrating sample magnetometer. The complex permeability was measured by RF impedance analyzer in the range of 1 MHz~1.8 GHz. The coercive force increased and saturation magnetization decreased with increasing the Co substitution. The real and imaginary parts of complex permeability decreased and the resonance frequency increased with Co substitution, which was attributed to the increase in crystal anisotropy field and reduction in saturation magnetization. The effect of Co substitution could be found in reducing the magnetic loss to nearly zero at the operating frequency of NFC (13.56 MHz).

Detection of Defect Patterns on Wafer Bin Map Using Fully Convolutional Data Description (FCDD) (FCDD 기반 웨이퍼 빈 맵 상의 결함패턴 탐지)

  • Seung-Jun Jang;Suk Joo Bae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.46 no.2
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    • pp.1-12
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    • 2023
  • To make semiconductor chips, a number of complex semiconductor manufacturing processes are required. Semiconductor chips that have undergone complex processes are subjected to EDS(Electrical Die Sorting) tests to check product quality, and a wafer bin map reflecting the information about the normal and defective chips is created. Defective chips found in the wafer bin map form various patterns, which are called defective patterns, and the defective patterns are a very important clue in determining the cause of defects in the process and design of semiconductors. Therefore, it is desired to automatically and quickly detect defective patterns in the field, and various methods have been proposed to detect defective patterns. Existing methods have considered simple, complex, and new defect patterns, but they had the disadvantage of being unable to provide field engineers the evidence of classification results through deep learning. It is necessary to supplement this and provide detailed information on the size, location, and patterns of the defects. In this paper, we propose an anomaly detection framework that can be explained through FCDD(Fully Convolutional Data Description) trained only with normal data to provide field engineers with details such as detection results of abnormal defect patterns, defect size, and location of defect patterns on wafer bin map. The results are analyzed using open dataset, providing prominent results of the proposed anomaly detection framework.

Complex Field Network Coding with MPSK Modulation for High Throughput in UAV Networks

  • Mingfei Zhao;Rui Xue
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.8
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    • pp.2281-2297
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    • 2024
  • Employing multiple drones as a swarm to complete missions can sharply improve the working efficiency and expand the scope of investigation. Remote UAV swarms utilize satellites as relays to forward investigation information. The increasing amount of data demands higher transmission rate and complex field network coding (CFNC) is deemed as an effective solution for data return. CFNC applied to UAV swarms enhances transmission efficiency by occupying only two time slots, which is less than other network coding schemes. However, conventional CFNC applied to UAVs is combined with constant coding and modulation scheme and results in a waste of spectrum resource when the channel conditions are better. In order to avoid the waste of power resources of the relay satellite and further improve spectral efficiency, a CFNC transmission scheme with MPSK modulation is proposed in this paper. For the proposed scheme, the satellite relay no longer directly forwards information, but transmits information after processing according to the current channel state. The proposed transmission scheme not only maintains throughput advantage of CFNC, but also enhances spectral efficiency, which obtains higher throughput performance. The symbol error probability (SEP) and throughput results corroborated by Monte Carlo simulation show that the proposed transmission scheme improves spectral efficiency in multiples compared to the conventional CFNC schemes. In addition, the proposed transmission scheme enhances the throughput performance for different topology structures while keeping SEP below a certain value.

Flow Field Analysis around Multi-Cylinders Using Particle Image Velocimetry (PIV를 이용한 다수원주 주위 유동장 해석)

  • 전완수;박준수;권순홍;하동대;최장운;이만형
    • Journal of Ocean Engineering and Technology
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    • v.10 no.3
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    • pp.89-95
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    • 1996
  • The flow field around four cylinders for various angles was investigated utilizing particle image velocimetry(PIV) technique. Flow field was recorded by video camera first. Then application of PIV technique was done to the flow field. The results turned out to be useful to analyze complex flow field around multiple cylinders.

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