• 제목/요약/키워드: line-of-sight

검색결과 735건 처리시간 0.025초

VRc Photometry of Dwarf Cepheids

  • Kim, Chulhee-;Michael-D.Joner
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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    • pp.15-15
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    • 1993
  • Revised Yale Isochrone(Green et al, 1987)과 Lee의 HB simulation data(LEE '||'&'||' Demarque 1990)을 이용하여 Park이 만든 CMD simulation program(Park 1983).에 쌍성을 첨가하면 CMD에 어느 정도의 영향을 나타내게 되는가를 조사하였다. MS, SGB와 RGB는 큰 변화가 없었으나, HB에서는 많은 변화를 나타내었다. 193919 S02401193919 ^x We have observed the emission of HC3N J= 4-3, 5-4 10-9 and 12-11 transitions toward the Sgr B2 central region in an area of 150"XISO" with resolutions of16"-48". The intensities and central velocities of line profiles show significant variations with positions. In contrast to the in tensities of the low J-level transitions which gradually increase from the central source toward the outside region the HC3N emission of the high J-level transition become stronger toward the central radio continuum source MO5. Systematic chainge in the radial velocity of each line profile occurs along north-south direction there are a few peaks in most line profiles, and these indicate that there not multiple velocity components along the line of sight. Distributions of excitation temperah at and column density which were estimated from the excitation calculations show the existence of a small(IxEpc),hot(Tex> SOK) core which contains two tempegatlue peaks at -15" east and north of MDS. The column density of HCaN is (1-3):n1014cm-2. Column density at distant position from MD5 is larger than that in the (:entral region. We have deduced that this hot-core has a mass of 10sR1 which i:s about an order of magnitude larger those obtained by previous studies.previous studies.

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테일러드 재킷 봉제방법 비교 연구 - 의복구성 교재를 중심으로 - (A Comparative Study on the Sewing Teaching of Tailored Jacket)

  • 신장희;손희순
    • 한국의상디자인학회지
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    • 제11권2호
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    • pp.75-84
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    • 2009
  • The following research analyzed the sewing teaching of the tailored jacket shown in fashion textbooks, which are currently used in universities and educational organizations in the fashion industry. To analyze the sewing teaching of tailored jackets, we analyzed 35 textbooks in the market. Among them we used 14 textbooks which dealt with the patter formation method of tailored jackets, and cutting and sewing methods. First, the stitching direction and the location of attachment varied. The type of sticking tape and its position also differed, emphasizing the need to make an institutionalized education material which is based on the characteristic of the fabric and its silhouette. Second, controlling the ease length of the right side sewing princess line, or information about the shoulder line and sleeve line of the notch as not specifically shown in the textbooks. Furthermore, not many textbooks showed how to pull the lower part of the texture out of sight, nor did they explain why this needed to be done. Third, the lining is usually slightly larger than the outer texture of the clothing, as the lining is usually tugged in the sewing process, and this method makes the clothes more comfortable. The method of sewing the princessline $0.2{\sim}0.3cm$ outside the outer pattern was the most recommended. The center-back side was usually 2cm in activity measurements, but it turned out that a textbook which required ease treatment on the shoulder line did not do so on the lining material. The textbooks used in this research dealt only with how to manufacture a tailored jacket without full explanation about textures which could influence the manufacturing. The production method and process differed between different textbooks, showing the need to make a institutionalized education material. In a quickly-changing era where there is rapid change in the dressmaking procedure, we need to help students understand the process more easily through a formalized education process.

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Empirical millimeter-wave wideband propagation characteristics of high-speed train environments

  • Park, Jae-Joon;Lee, Juyul;Kim, Kyung-Won;Kwon, Heon-Kook;Kim, Myung-Don
    • ETRI Journal
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    • 제43권3호
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    • pp.377-388
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    • 2021
  • Owing to the difficulties associated with conducting millimeter-wave (mmWave) field measurements, especially in high-speed train (HST) environments, most propagation channels for mmWave HST have been studied using methods based on simulation rather than measurement. In this study, considering a linear cell layout in which base stations are installed along a railway, measurements were performed at 28 GHz with a speed up to 170 km/h in two prevalent HST scenarios: viaduct and tunnel scenarios. By observing the channel impulse responses, we could identify single- and double-bounced multipath components (MPCs) caused by railway static structures such as overhead line equipment. These MPCs affect the delay spread and Doppler characteristics significantly. Moreover, we observed distinct path loss behaviors for the two scenarios, although both are considered line-of-sight (LoS) scenarios. In the tunnel scenario, the path loss exponent (PLE) is 1.3 owing to the waveguide effect, which indicates that the path loss is almost constant with respect to distance. However, the LoS PLE in the viaduct scenario is 2.46, which is slightly higher than the free-space loss.

A Fine-scale Half Ring-like Structure around a Pore

  • 송동욱;채종철
    • 천문학회보
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    • 제38권2호
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    • pp.87.2-87.2
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    • 2013
  • We studied a fine-scale half ring-like structure around a pore seen from the high spectral and the high spatial resolution data. Our observations were carried out using the Fast Imaging Solar Spectrograph (FISS) and the InfraRed Imaging Magnetograph (IRIM) installed at the 1.6 meter New Solar Telescope of Big Bear Solar Observatory (BBSO) on 2012 July 19. During the observations, we found a fine-scale half ring-like structure located very close to a pore (~0.4 arcsec apart from the pore). It was seen in the far wing images of the $H{\alpha}$ and Ca II $8542{\AA}$ lines, but it was not seen in the line center images of two lines. The length of the structure is about 4200 km and the width is about 350 km. We determined its line-of-sight velocity using the Doppler shift of the centroid of the Ti II line ($6559.6{\AA}$, close to the $H{\alpha}$ line) and determined horizontal velocity using the NAVE method. we also investigated the magnetic configurations using the Stokes I, Q, U, and V maps of the IRIM. As a results, we found that it has a high blue-shift velocity (~2km) faster than the photospheric features and has a strong horizontal component of the magnetic field. Based on our findings, we suggest that it is associated with small flux emergence, which occurs very close to the pore. Even though it is very small structure, this kind of magnetic configuration can be in chare of the upper chromosphere heating, especially above the pore.

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Ray-Tracing 알고리즘을 이용한 CCTV배치 평가시뮬레이션 (Simulation to Evaluate CCTV Positioning in Use of Ray-Tracing Algorithm)

  • 김석태;안상욱
    • 한국실내디자인학회논문집
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    • 제22권6호
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    • pp.40-48
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    • 2013
  • Utilization of CCTV in crime prevention for public safety is accepted as the most effective measure in terms of crime prevention and control. Also, it is frequently used as a device that shows evidence of an unexpected situation or record on public social relationship. However, it is rare to find a study that qualitatively accessed the monitoring performance of a certain space depending on the choice and positioning of CCTVs. Thus, this study suggested a technology that can quantitatively compare and assess the monitoring performance of CCTVs depending on view angle and effective sight range of cameras as well as the monitoring performance depending on positioning measures. For the analysis, the concept of 3-dimensional surveillance field in the form of a frustum was suggested while deriving 3-dimensional range of sight and quantitative monitoring performance by applying Isovist theory. For the analysis technology, space of analysis subject, point of view (camera), and target point (measurement node) were installed at a 3-dimensional space and in use of ray-tracing algorithm, the line segment that was visually connected between the point of view and target point was extracted and accumulated. For such verification, analysis application was constructed and then applied to four alternative models on view angle and distance as well as four alternatives on positioning in order to verify its efficacy. Through the experiment, it was possible to compare and assess visibility depending on alternatives while quantifying the results by understanding the shadow areas beyond the monitoring range.

Demonstration of the Effectiveness of Monte Carlo-Based Data Sets with the Simplified Approach for Shielding Design of a Laboratory with the Therapeutic Level Proton Beam

  • Lai, Bo-Lun;Chang, Szu-Li;Sheu, Rong-Jiun
    • Journal of Radiation Protection and Research
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    • 제47권1호
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    • pp.50-57
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    • 2022
  • Background: There are several proton therapy facilities in operation or planned in Taiwan, and these facilities are anticipated to not only treat cancer but also provide beam services to the industry or academia. The simplified approach based on the Monte Carlo-based data sets (source terms and attenuation lengths) with the point-source line-of-sight approximation is friendly in the design stage of the proton therapy facilities because it is intuitive and easy to use. The purpose of this study is to expand the Monte Carlo-based data sets to allow the simplified approach to cover the application of proton beams more widely. Materials and Methods: In this work, the MCNP6 Monte Carlo code was used in three simulations to achieve the purpose, including the neutron yield calculation, Monte Carlo-based data sets generation, and dose assessment in simple cases to demonstrate the effectiveness of the generated data sets. Results and Discussion: The consistent comparison of the simplified approach and Monte Carlo simulation results show the effectiveness and advantage of applying the data set to a quick shielding design and conservative dose assessment for proton therapy facilities. Conclusion: This study has expanded the existing Monte Carlo-based data set to allow the simplified approach method to be used for dose assessment or shielding design for beam services in proton therapy facilities. It should be noted that the default model of the MCNP6 is no longer the Bertini model but the CEM (cascade-exciton model), therefore, the results of the simplified approach will be more conservative when it was used to do the double confirmation of the final shielding design.

낮은 도로조명 방식의 기구디자인 개발연구 (A Study of the Development of Lighting Equipment on Low Height Road Lighting)

  • 이미애;황인태;김훈
    • 조명전기설비학회논문지
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    • 제23권8호
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    • pp.1-7
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    • 2009
  • 본 연구는 도로의 조명 방식을 기존의 높은 폴 조명 방식에서 낮은 위치의 조명방식으로 새롭게 접근하여 도로의 내 외부 경관의 시 환경을 쾌적하게 하고, 장해 광(눈부심 후사 광)의 요소를 제거하는 환경 친화적인 조명 방식을 제시하고자 하였다. 도로경관이 중요하게 되고 있는 현 추세를 고려하여 경관적인 요소로서의 역할을 위한 미려한 디자인을 중심으로의 연구내용을 제시하였다. 이를 위하여 국내외 낮은 조명의 이용실태를 조사하고, 개선사항을 찾고자 하였으며, 보다 효율을 높일 수 있는 방안을 모색하였다. 또한 낮은 조명의 설치가 이루어지게 되는 도로의 주요 시설물에 대한 자료 및 현장조사를 통하여, 조명기구의 설치 표준을 제시하였고, 국내 실정에 적합한 낮은 조명의 개발방향과 조명기구 디자인의 방향을 제시하였다.

다양한 투과 각도에서 측정된 투과형 펄스 시추공 레이더 신호 분석 (Analysis of cross-borehole pulse radar signatures measured at various tunnel angles)

  • 김상욱;김세윤
    • 지구물리와물리탐사
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    • 제13권1호
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    • pp.96-101
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    • 2010
  • 수 백 미터 깊이에 위치하고 있는 폐쇄된 지하터널을 탐지하기 위하여 펄스 레이더 시스템이 최근 개발되었다 개발원 펄스 레이더 시스템의 탐지능력을 확인하기 위하여, 터널시험장에서 터널 주변의 여러 시추공 중에서 터널측과 15도 간격으로 수평각이 비틀어진 5가지 탐사경로를 선정하였다. 공기로 채워진 터널을 중심으로 20 미터 구간에 대해 레이더 신호의 측정이 이루어 졌다. 도착시간, 감쇠, 분산시간으로 구성된 세가지 기본 변수들이 수신된 신호의 첫번째 첨두치와 두번째 첨두치의 위치로부터 계산되었다. 터널측과 탐사 경로가 45도 이상 비틀어졌을 때 이러한 변수들을 사용하여 레이더 시스템이 터널을 탐지할 수 있었다.

지향성 안테나를 사용하는 IEEE802.16j 멀티 홉 릴레이 시스템의 용량 분석 (Capacity Analysis of IEEE802.16j MMR System Using Directional Antenna)

  • 김승연;유창진;김세진;류승완;조충호;이형우
    • 한국통신학회논문지
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    • 제34권2B호
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    • pp.170-177
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    • 2009
  • 본 논문에서는 본 논문에서는 BS(Base Station, 기지국)와 RS(Relay Station, 중계기)가 지향성 안테나를 갖는 multi-tier 기반의 NBTC (Narrow-Beam Trisector Cell)와 WBTC (Wide-Beam Trisector Cell) 구조를 제안하고, 두 시스템에서 동일 채널 간섭 (Co-channel interference)에 의한 용량을 두 개의 채널 모델을 적용하여 분석하였다. 분석을 통해 $2^{nd}$ tier로 구성한 한 클러스터에서 발생하는 총 용량은 LOS(Line of Sight)의 존재 여부에 따라 NBTC 구조 셀과 WBTC 구조 셀의 총 용량이 달라짐을 알 수 있었다. 본 논문의 결과는 향후 차세대 이동통신 및 와이브로 시스템에서 간섭을 고려한 멀티 홉 RS 도입 시에 참고할 만한 가이드라인을 제시할 수 있을 것이다.

A Model Calculation of Solar Microwave Burst Structure

  • Choi, Yong-Seok
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 1995년도 한국우주과학회보 제4권1호
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    • pp.21-21
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    • 1995
  • The structures of 17GHz microwave burst for bipolar sunspots have investigated. which included the effects of the projected shapes of radio sources as they traverse across the solar disk using a magnetic loop employing a model of solenoid coils. An ensemble of high-energy electrons confined in the loop be assumed. The projected brightnesls distributions of gyrosynchrotron emission in x- and o-modes are computed and converted into total intensity and circular polarization difference at 17GHz for various heliocentric distances using numerical integration of the transfer equation along the line of sight. The results of computations at 17GHz for optical thin case will be presented. and the effects of the orientation of the loop will be discussed in detail, as well as the effect of size, position, Structure, and polarization of the emission. Also the results of the various physical P8lrameters such as the strength of magnetic field. high and low energy cut-off of accelerated electrons. spectral index and density of electrons will be preslmted. After comparing the results of model calculation with observations. we found that the observations can be well explained in terms of a loop model and its projection effect.effect.

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