• Title/Summary/Keyword: far field

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Study on mapping of dark matter clustering from real space to redshift space

  • Zheng, Yi;Song, Yong-Seon
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.38.2-38.2
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    • 2016
  • The mapping of dark matter clustering from real to redshift spaces introduces the anisotropic property to the measured density power spectrum in redshift space, known as the Redshift Space Distortion (hereafter RSD) effect. The mapping formula is intrinsically non-linear, which is complicated by the higher order polynomials due to the indefinite cross correlations between the density and velocity fields, and the Finger-of-God (hereafter FoG) effect due to the randomness of the peculiar velocity field. Furthermore, the rigorous test of this mapping formula is contaminated by the unknown non-linearity of the density and velocity fields, including their auto- and cross-correlations, for calculating which our theoretical calculation breaks down beyond some scales. Whilst the full higher order polynomials remains unknown, the other systematics can be controlled consistently within the same order truncation in the expansion of the mapping formula, as shown in this paper. The systematic due to the unknown non-linear density and velocity fields is removed by separately measuring all terms in the expansion using simulations. The uncertainty caused by the velocity randomness is controlled by splitting the FoG term into two pieces, 1) the non-local FoG term being independent of the separation vector between two different points, and 2) the local FoG term appearing as an indefinite polynomials which is expanded in the same order as all other perturbative polynomials. Using 100 realizations of simulations, we find that the best fitted non-local FoG function is Gaussian, with only one scale-independent free parameter, and that our new mapping formulation accurately reproduces the observed power spectrum in redshift space at the smallest scales by far, up to k ~ 0.3 h/Mpc, considering the resolution of future experiments.

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Linear Tapered Slot Rectifying Antenna for Portable UHF-Band RFID System (휴대용 UHF대역 RFID 시스템을 위한 선형 테이퍼드 슬롯 정류 안테나)

  • Pyo, Seongmin
    • Journal of IKEEE
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    • v.24 no.1
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    • pp.368-371
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    • 2020
  • In this paper, we propose a linear tapered slot rectifying antenna for a portable UHF-band RFID system. Since the proposed rectifying antenna does not use a dielectric substrate, the planar antenna is implemented with a thin metal thickness. The rectifier circuit converts input RF power into output DC voltage using a voltage doubler circuit based on two anti-parallel schottky diodes. The rectifying antenna is integrated by the voltage doubler circuit into a linear tapered slot antenna. For conjugate impedance matching of the rectifying circuit and the linear tapered slot antenna, the source-pull method was utilized by adjusting the angle of the tapered slot and the length of the antenna feed line. The proposed antenna prototype has been verified with the electrical and radiation characteristics through RF-DC conversion and far-field radiation test in open space measurement environment. Finally, the proposed antenna is realized to 0.23-wavelength (75 mm) and 0.18-wavelength (60 mm) at 915 MHz center frequency.

A Reinvestigation on Key Issues Associated with the Yimjin Boundary Making and Demarcation(1712~1713): Reconstructing the Distribution of Boundary Markers Based on Actual Survey Documents (역대 실지조사기록 검토를 통한 임진정계 경계표지물 분포 복원)

  • Lee, Kang-Won
    • Journal of the Korean Geographical Society
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    • v.51 no.5
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    • pp.577-612
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    • 2016
  • The distribution of boundary markers, set up during the Yimjin(1712) Boundary Making and Demarcation(YBMD), has less been addressed so far, although it is key material evidence on which we can reconstruct the whole processes of YBMD, together with the correction of widespread myths around YBMD. This paper aims to clarify the questions on the distribution of boundary markers associated with YBMD, built during August 1712 to September 1713, by reinterpreting the key documents of Actual Survey on them: Huh Ryang and Park Dosang(1913), Kim Woosik(1883), Lee Joongha(1885), Wu Luzhen(1907), Osone Seiji(1907), and Liu Jianfeng(1908), together with topographic maps by Japanese Imperial Army(1933), the report of expedition to Mt. Baekdu by Chungjin Teachers' College(1948), and the report of field survey by Jilin province's expedition(1957). As a result, the distribution of boundary markers built in 1712~1713 is successfully reconstructed, and summarized in the format of table and maps.

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A Study on the Reinterpretation of ChonJu Palkyong for Improvement of Landscape Identity (경관정체성 향상을 위한 전주팔경의 해석에 관한 연구)

  • 신상섭;노재현
    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.4
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    • pp.25-35
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    • 1999
  • This thesis is to newly understand the value and the meaning of Chonju Palkyong(全州八景) by the specific gravity in making a counter-proposal in other to improve the landscape identity of modern city and at the same time. I intended to group the grafting device for the preservation and regeneration of modern history cultural environment through the interpretation of landscape construction. The meaning system of Chonju Palkyong showed the symbolic system which a landscape construction, four directions and two places has and exhibited the landscape shape possessing a luxuriant local feature peculiar to Chonju, preserving visual bound language of a classical Palkyong. Especially, it implies the use of the substantial landscape experienced factor, the expressions about natural phenomena and the matter which has melted human living circumstances. The landscape construction and it's form show the system which forms the different time field, a far landscape and a mid distance landscape and a near landscape, etc., under the visual, psychological, scenic influenced area, preserving the feature of the similar and typical type of Sosang Palkyoung(瀟湘八景) which intended to seek the local reappearance of the famous site experienced type and natural matter which famous place and local conduct were combined. The object space of Chonju Palkyong area representing the nature of historical landscape cultural assets, pushed by the greater part of the development based theory, shows injured aspects, but needs to play a part to seek such a up-to-date successive plan as the reconstruction of the destroyed historical landscape area which motivated Palkyong, the establishment of useful area, the embodiment of the cultural identity of Palkyong area and the becoming of the educational cultural life space. The analysis of the landscape construction of Chonju Palkyong and the grouping of the modern successive plan which I considered in this thesis, will be able to become a fundamental data to carry out the preservation of historical landscape and the landscape plan in the city.

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Fast GF(2m) Multiplier Architecture Based on Common Factor Post-Processing Method (공통인수 후처리 방식에 기반한 고속 유한체 곱셈기)

  • 문상국
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.6
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    • pp.1188-1193
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    • 2004
  • So far, there have been grossly 3 types of studies on GF(2m) multiplier architecture, such as serial multiplication, array multiplication, and hybrid multiplication. Serial multiplication method was first suggested by Mastrovito (1), to be known as the basic CF(2m) multiplication architecture, and this method was adopted in the array multiplier (2), consuming m times as much resource in parallel to extract m times of speed. In 1999, Paar studied further to get the benefit of both architecture, presenting the hybrid multiplication architecture (3). However, the hybrid architecture has defect that only complex ordo. of finite field should be used. In this paper, we propose a novel approach on developing serial multiplier architecture based on Mastrovito's, by modifying the numerical formula of the polynomial-basis serial multiplication. The proposed multiplier architecture was described and implemented in HDL so that the novel architecture was simulated and verified in the level of hardware as well as software. The implemented GF(2m) multiplier shows t times as fast as the traditional one, if we modularized the numerical expression by t number of parts.

Front-side Texturing of Crystalline Silicon Solar Cell by Micro-contact Printing (마이크로 컨텍 프린팅 기법을 이용한 결정질 실리콘 태양전지의 전면 텍스쳐링)

  • Hong, Jihwa;Han, Yoon-Soo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.11
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    • pp.841-845
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    • 2013
  • We give a textured front on silicon wafer for high-efficiency solar cells by using micro contact printing method which uses PDMS (polydimethylsiloxane) silicon rubber as a stamp and SAM (self assembled monolayer)s as an ink. A random pyramidal texturing have been widely used for a front-surface texturing in low cost manufacturing line although the cell with random pyramids on front surface shows relatively low efficiency than the cell with inverted pyramids patterned by normal optical lithography. In the past two decades, the micro contact printing has been intensively studied in nano technology field for high resolution patterns on silicon wafer. However, this promising printing technique has surprisingly never applied so far to silicon based solar cell industry despite their simplicity of process and attractive aspects in terms of cost competitiveness. We employ a MHA (16-mercaptohexadecanoic acid) as an ink for Au deposited $SiO_2/Si$ substrate. The $SiO_2$ pattern which is same as the pattern printed by SAM ink on Au surface and later acts as a hard resist for anisotropic silicon etching was made by HF solution, and then inverted pyramidal pattern is formed after anisotropic wet etching. We compare three textured surface with different morphology (random texture, random pyramids and inverted pyramids) and then different geometry of inverted pyramid arrays in terms of reflectivity.

Development of Far Field RF Power Harvesting Testbed (원거리 무선 전력 하베스팅 테스트 시스템 개발)

  • Kim, Min Jae;Lim, Wonseob;Bae, Jongseok;Park, Ju Hyun;Park, Young Jun;Lee, Jong Min;Trinh-Van, Son;Kim, Dong In;Lee, Kang Yoon;Hwang, Keum Cheol;Yang, Youngoo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.10
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    • pp.1922-1930
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    • 2015
  • This paper presents the system design, implement, and measurement results of the testbed for the wireless RF energy harvesting system. The developed testbed can be used for RF power transfer and data communication using the 2.4 GHz and 900 MHz frequency bands. It allows to evaluate the system performances for the RF power and data transmission. The testbed can also be used to develop algorithms for efficient energy harvesting.

Suggestions on the Campus FM Services by Establishing Framework in the form of Performance Indicator(Pi) Based on FM_KS (KS 시설관리 표준규격을 바탕으로 한 대학시설 FM 서비스 발전방향)

  • Shin, Eun-Young;Kim, Yu-Jin;Kim, Jun-Ha
    • Journal of the Korean Institute of Educational Facilities
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    • v.22 no.1
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    • pp.37-45
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    • 2015
  • Over the years, great attention has been shown to the function of the campus facilities that should be well-equipped, operated and maintained to better support university's two main goals: providing education and supporting research. Properly managing campus facilities is the initial step to be prepared to meet the rapidly changing global educational standard. However, so far, no definitive answer has been given to the question of what service level/scope is appropriate for the effective campus facility management (FM) in Korea. Therefore, at the outset, it is imperative to establish the framework for the standardized campus FM services. The main focus of this research is to provide comprehensive understanding on the campus FM by establishing the framework in the form of FM performance indicator (PI). As the first step, FM standards set by Korean Agency for Technology and Standards (KATS) has been thoroughly reviewed and analyzed to establish the framework for FM standards applicable to campus facility management. Secondly, extensive literature review on the development of performance indicator (PI) for the educational facilities has been conducted to classify PI types and complement FM_KS. Finally, specific guideline and PIs developed by APPA which is globally well-known association in the field of FM for higher education facilities has been added to the combined PI which is the mixed form of FM_KS and PIs from the previous literature. This research provides campus facility managers and FM outsourcing service providers with framework in the form of PI to support future directions of effective campus FM services.

Spatial Filtering Techniques for Geospatial AR Applications in R-tree (R-tree에서 GeoSpatial AR 응용을 위한 공간필터링 기법)

  • Park, Jang-Yoo;Lee, Seong-Ho;Nam, Kwang-Woo
    • Spatial Information Research
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    • v.19 no.1
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    • pp.117-126
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    • 2011
  • Recently, AR applications provide location-based spatial information by GPS. Also, the spatial information is displayed by the angle of the camera. So far, traditional spatial indexes in spatial database field retrieve and filter spatial information by the minimum bounding rectangle (MBR) algorithm.(ex. R-tree) MBR strategy is a useful technique in the geographic information systems and location based services. But MBR technique doesn't reflect the characteristics of spatial queries in AR. Spatial queries of AR applications have high possibility of the dead space area between MBRs of non-leaf node and query area. We propose triangle node filtering algorithm that improved efficiency of spatial retrieval used the triangle node filtering techniques by exclusion the dead space. In this paper, the proposed algorithm has been implemented on PostgreSQL/PostGIS. Experimental results show the spatial retrieval that using the proposed algorithm better performance than the spatial retrieval that of the minimum bounding rectangle algorithm.

MT surveys near Century Zinc Mine, NW Queensland, Australia (호주 Century 아연 광산에서의 MT 탐사)

  • Lee, Tae-Jong;Lee, Seong-Kon;Song, Yoon-Ho;Cull, James
    • Geophysics and Geophysical Exploration
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    • v.10 no.4
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    • pp.345-352
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    • 2007
  • Two-dimensional (2D) MT surveys near the Century mine in Australia have been performed with very far remote reference in Esashi, Japan (RR_ESS) as well as Gregory Downs (RR_GREG), which are roughly 6,400 km and 80 km apart from the survey area, respectively. Good quality of MT data could be obtained by remote reference processing with RR_GREG, while the coherency of magnetic fields between field sites and RR_ESS was not sufficient to be used as remote data. Both 2D and 3D inversion of 2D profile data represented the general geological structure beneath the survey area. The main target of the survey, Termite Range Fault, appeared as a boundary between a conductive block to the north and a resistive block to the south in the reconstructed resistivity section, and is inclined slightly to the north-east direction.