• Title/Summary/Keyword: DOA

Search Result 245, Processing Time 0.035 seconds

The Planning Concepts and Design Principles of Dok-Rak-Dang Block (독락당(獨樂堂) 일곽(一郭)의 계획개념과 설계원리)

  • Jang, Sun-Joo
    • Journal of the Korean housing association
    • /
    • v.24 no.6
    • /
    • pp.93-101
    • /
    • 2013
  • This research purposes to understand architectural aim which the owners of buildings in the Doa-Rak-Dang block pursue through the history of family and construction. Moreover its other purpose is to find the design concepts which were selected to achieve the aim and the design elements which were applied to realize the design concepts. To accomplish the objects, it got rid of a stationary viewpoint but it approached with a dynamic viewpoint which can read the changes in the steps during various periods. Through the 100-year history of construction, the architectural aim of the Doa-Rak-Dang block is to establish the tradition of the Ok-San-Pa family to get over the social limitations of the family of a child by a concubine which began from Lee, Eun-Juk's mistress. The design concepts which were used by the owners of the Dok-Rak-Dang block to achieve the purpose are the extension of public territory and the enrichment of territoriality which have social-political, economical and symbolic means. The geometric applications such as axises and regulating lines were the design elements which were chosen to fulfill the concepts. If the establishment of the architectural aim and design concepts, the process of selecting and constructing proper design elements, and the geometric application in the process are the design principles of the Doa-Rak-Dang block, the principles can be summarized as the geometric applications of axises and regulating lines interacting as the standard of the extension of public area.

MUSIC-Based Direction Finding through Simple Signal Subspace Estimation (간단한 신호 부공간 추정을 통한 MUSIC 기반의 효과적인 도래방향 탐지)

  • Choi, Yang-Ho
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.48 no.4
    • /
    • pp.153-159
    • /
    • 2011
  • The MUSIC (MUltiple SIgnal Classification) method estimates the directions of arrival (DOAs) of the signals impinging on a sensor array based on the fact that the noise subspace is orthogonal to the signal subspace. In the conventional MUSIC, an estimate of the basis for the noise subspace is obtained by eigendecomposing the sample matrix, which is computationally expensive. In this paper, we present a simple DOA estimation method which finds an estimate of the signal subspace basis directly from the columns of the sample matrix from which the noise power components are removed. DOA estimates are obtained by searching for minimum points of a cost function which is defined using the estimated signal subspace basis. The minimum points are efficiently found through the Brent method which employs parabolic interpolation. Simulation shows that the simple estimation method virtually has the same performance as the complex conventional method based on the eigendecomposition.

Direction of Arrival Estimation in Colored Noise Using Wavelet Decomposition (웨이브렛 분해를 이용한 유색잡음 환경하의 도래각 추정)

  • Kim, Myoung-Jin
    • Journal of the Institute of Electronics Engineers of Korea SP
    • /
    • v.37 no.6
    • /
    • pp.48-59
    • /
    • 2000
  • Eigendecomposition based direction-of-arrival(DOA) estimation algorithm such as MUSIC(multiple signal classification) is known to perform well and provide high resolution in white noise environment. However, its performance degrades severely when the noise process is not white. In this paper we consider the DOA estimation problem in a colored noise environment as a problem of extracting periodic signals from noise, and we take the problem to the wavelet domain. Covariance matrix of multiscale components which are obtained by taking wavelet decomposition on the noise has a special structure which can be approximated with a banded sparse matrix. Compared with noise the correlation between multiscale components of narrowband signal decays slowly, hence the covariance matrix does not have a banded structure. Based on this fact we propose a DOA estimation algorithm that transforms the covariance matrix into wavelet domain and removes noise components located in specific bands. Simulations have been carried out to analyze the proposed algorithm in colored noise processes with various correlation properties.

  • PDF

Closed-Form Expression of Approximate ML DOA Estimates in Bistatic MIMO Radar System (바이스태틱 MIMO 레이다 시스템에 적용되는 ML 도래각 추정 알고리즘의 근사 추정치에 대한 Closed-Form 표현)

  • Paik, Ji Woong;Kim, Jong-Mann;Lee, Joon-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.28 no.11
    • /
    • pp.886-893
    • /
    • 2017
  • Recently, for detection of low-RCS targets, bistatic radar and multistatic radar have been widely employed. In this paper, we present the process of deriving the received signal modeling of the bistatic MIMO radar system and deals with the performance analysis of applying the bistatic signal to the ML arrival angle estimation algorithm. In case of the ML algorithm, as the number of the targets increases, azimuth search dimension for DOA estimation also increases, which implies that the ML algorithm for multiple targets is computationally very intensive. To solve this problem a closed-form expression of estimation error is presented for performance analysis of the algorithm.

Performance Analysis of DCMP and ZF based on Spatial Channel Response Estimation by ESPRIT (ESPRIT에 의한 공간 채널응답 추정치에 기초를 둔 방향구속 전력 최소화법과 제로포싱 알고리즘의 성능평가)

  • Jeong, Jung-Sik;Yim, Jeong-Bin;Ahn, Young-Sup
    • Journal of Navigation and Port Research
    • /
    • v.26 no.5
    • /
    • pp.543-548
    • /
    • 2002
  • It has been known that the DCMP(Directionally Constrained Minimization of Power) and the ZF(Zero Forcing) can improve the SINR performance of an array antenna system by using spatial signature of wireless channel. This paper analyzes the performance of DCMP and ZF in multiple scattering environments. To obtain the spatial signature of wireless channel. both DOA(Directional of Arrival) and AS(Angular spread) of the received signals were estimated by using ESPRIT. The performance of the DCMP and the ZF was analyzed theoretically. By computer simulation of SINR performance was evaluated.

RFID Based Mobile Robot Docking Using Estimated DOA (방향 측정 RFID를 이용한 로봇 이동 시스템)

  • Kim, Myungsik;Kim, Kwangsoo
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.37C no.9
    • /
    • pp.802-810
    • /
    • 2012
  • This paper describes RFID(Radio Frequency Identification) based target acquisition and docking system. RFID is non-contact identification system, which can send relatively large amount of information using RF signal. Robot employing RFID reader can identify neighboring tag attached objects without any other sensing or supporting systems such as vision sensor. However, the current RFID does not provide spatial information of the identified object, the target docking problem remains in order to execute a task in a real environment. For the problem, the direction sensing RFID reader is developed using a dual-directional antenna. The dual-directional antenna is an antenna set, which is composed of perpendicularly positioned two identical directional antennas. By comparing the received signal strength in each antenna, the robot can know the DOA (Direction of Arrival) of transmitted RF signal. In practice, the DOA estimation poses a significant technical challenge, since the RF signal is easily distorted by the surrounded environmental conditions. Therefore, the robot loses its way to the target in an electromagnetically disturbed environment. For the problem, the g-filter based error correction algorithm is developed in this paper. The algorithm reduces the error using the difference of variances between current estimated and the previously filtered directions. The simulation and experiment results clearly demonstrate that the robot equipped with the developed system can successfully dock to a target tag in obstacles-cluttered environment.

Study on the Method of Analyzing the Plasticizer of Petrochemical Products using MD-GC/MS (MD-GC/MS를 활용한 석유화학제품의 가소제(DOA, DOP) 분석방법 연구)

  • Doe, Jin-woo;Youn, Ju-min;Kang, Hyung-kyu;Hwang, In-ha;Ha, Jong-han;Na, Byung-ki
    • Journal of the Korean Applied Science and Technology
    • /
    • v.34 no.4
    • /
    • pp.1085-1093
    • /
    • 2017
  • Plasticizers are materials added to give softness and elasticity to plastics having rigid properties to give soft properties as products, and they are mainly added to high molecular materials to give flexibility to improve workability and to improve cold resistance, resistance to volatility and electrical properties. It is used for the purpose. Most plasticizers are inert liquids, similar in function to solvents but with high molecular weight and no volatility. In addition, when dissolved in petrochemical products, only the plasticizer is separated by the matrix effect with other compounds, and qualitative and quantitative analysis. In this study, qualitative and quantitative analysis of DOA and DOP, which are representative components of petrochemical products, were conducted using MD-GC/MS and developed an optimal plasticizer analysis method.