• 제목/요약/키워드: Multiple measurements

검색결과 797건 처리시간 0.026초

인공위성 정렬 측정 정확도 향상을 위한 연구 (A Study on Satellite Alignment Measurements Accuracy Improvement)

  • 최정수;김인걸
    • 한국항공우주학회지
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    • 제48권12호
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    • pp.987-995
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    • 2020
  • 고성능 탑재체들과 자세제어 센서들 간의 정밀정렬은 인공위성의 정확한 자세지향 및 높은 지향 안정성을 위해 필수적이다. 위성 개발사들은 조립 및 시험기간 동안 위성 정렬을 위해 데오드라이트 측정 시스템을 주로 사용한다. 데오드라이트 측정 시 시선 방향 오차, 수평축의 오차, 수직방향 인덱스 오차 그리고 수직축 오차로 인해 측정오차가 발생할 수 있다. 이러한 오차들 뿐 아니라 다수의 데오드라이트를 사용한 측정 시 발생할 수 있는 오차들을 정렬큐브 측정실험을 통해 분석하였다. 정렬큐브 측정실험을 기반으로 정렬측정 정확도를 향상시킬 수 있는 방법이 제안되었고, 측정 결과 위성의 설계 요구조건도 만족시킬 수 있었다.

The Accuracy of Various Value Drivers of Price Multiple Method in Determining Equity Price

  • YOOYANYONG, Pisal;SUWANRAGSA, Issara;TANGJITPROM, Nopphon
    • The Journal of Asian Finance, Economics and Business
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    • 제7권1호
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    • pp.29-36
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    • 2020
  • Stock price multiple is one of the most well-known equity valuation technique used to forecast equity price. It measures by multiplying "the ratio of stock price to a value driver" by a value driver. The value driver can be earning per share (EPS), sales or other financial measurements. The objective of price multiple technique is to evaluate the value of assets and compare how similar assets are priced in the market. Although stock price multiple technique is common in financial filed, studies on the application of the technique in Thailand is still limited. The present study is conducted to serve three major objectives. The first objective is to apply the technique to measure value of firms in banking sector in the Stock Exchange of Thailand. The second objective is to develop composite price multiple index to forecast equity prices. The third objective is to compare valuation accuracy of different value drivers of price multiple (i.e. EPS, Earnings Growth, Earnings Before Interest Taxes Depreciation and Amortization, Sales, Book Value and Composite Index) in forecasting equity prices. Results indicated that EPS is the most accurate value drivers of price multiple used to forecast equity price of firms in baking sector.

이종 다수의 네트워크 기반 휴머노이드를 위한 협조제어 소프트웨어 프레임워크 (Framework of a Cooperative Control Software for Heterogeneous Multiple Network Based Humanoid)

  • 임헌영;강연식;이중재;김종원;유범재
    • 로봇학회논문지
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    • 제3권3호
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    • pp.226-236
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    • 2008
  • In this paper, control software architecture is designed to enable a heterogeneous multiple humanoid robot demonstration executing tasks cooperating with each other. In the heterogeneous humanoid robot team, one large humanoid robot and two small humanoid robots are included. For the efficient and reliable information sharing between many software components for humanoid control, sensing and planning, CORBA based software framework is applied. The humanoid tasks are given in terms of finite state diagram based human-robot interface, which is interpreted into the XML based languages defining the details of the humanoid mission. A state transition is triggered based on the event which is described in terms of conditions on the sensor measurements such as robot locations and the external vision system. In the demonstration of the heterogeneous humanoid team, the task of multiple humanoid cleaning the table is given to the humanoid robots and successfully executed based on the given state diagram.

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다수 상호작용 화염의 공해배출물 특성 (Effect of Flame Interaction on the NO Emission)

  • 김진현;이병준
    • 대한기계학회논문집B
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    • 제29권6호
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    • pp.730-736
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    • 2005
  • It has been reported that the interacting multiple jet flames of propane fuel are not extinguished even at the choking velocity at the nozzle exit if eight small nozzles are arranged along the imaginary circle of $40{\sim}72$ times the diameter of single nozzle. In this research, experiments were conducted to know the NO and CO emission characteristics of the interacting flames. Measurements along the centerline of the flame revealed that decrease in CO concentration was followed by the NO decrease and $O_2$ increase. It was found that interacting flame emitted less NO than that of similar area single jet flame. Also, NO emission of partially premixed interacting flame was decreased up to $17\%$ of that of non-premixed multiple jet flame. Though the mechanism of the NO reduction was not clear from this experiment, it's been shown that partially premixed multiple jet flames could be used to achieve clean and highly stable combustion.

Trust-Tech based Parameter Estimation and its Application to Power System Load Modeling

  • Choi, Byoung-Kon;Chiang, Hsiao-Dong;Yu, David C.
    • Journal of Electrical Engineering and Technology
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    • 제3권4호
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    • pp.451-459
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    • 2008
  • Accurate load modeling is essential for power system static and dynamic analysis. By the nature of the problem of parameter estimation for power system load modeling using actual measurements, multiple local optimal solutions may exist and local methods can be trapped in a local optimal solution giving possibly poor performance. In this paper, Trust-Tech, a novel methodology for global optimization, is applied to tackle the multiple local optimal solutions issue in measurement-based power system load modeling. Multiple sets of parameter values of a composite load model are obtained using Trust-Tech in a deterministic manner. Numerical studies indicate that Trust-Tech along with conventional local methods can be successfully applied to power system load model parameter estimation in measurement-based approaches.

Comparison of cone-beam computed tomography cephalometric measurements using a midsagittal projection and conventional two-dimensional cephalometric measurements

  • Jung, Pil-Kyo;Lee, Gung-Chol;Moon, Cheol-Hyun
    • 대한치과교정학회지
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    • 제45권6호
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    • pp.282-288
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    • 2015
  • Objective: This study investigated whether it is possible to use a two-dimensional (2D) standard in three-dimensional (3D) analysis, by comparing the angles and lengths measured from a midsagittal projection in 3D cone-beam computed tomography (CBCT) with those measured by 2D lateral cephalometric radiography (LCR). Methods: Fifty patients who underwent both LCR and CBCT were selected as subjects. CBCT was reoriented in 3 different methods and the measuring-points were projected onto the midsagittal plane. Twelve angle values and 8 length values were measured on both LCR and CBCT and compared. Results: Repeated measures analysis of the variance revealed statistically significant differences in 7 angular and 5 linear measurements among LCR and 3 types of CBCT (p < 0.05). Of these 12 measurements, multiple comparisons showed that 6 measurements (ANB, AB to FH, IMPA, FMA, Co-Gn, Go-Me) were not significantly different in pairwise comparisons. LCR was significantly different from 3 types of CBCT in 3 angular (SN to FH, interincisal angle, FMIA) and 2 linear (S-Go, Co-ANS) measurements. The CBCT method was similar for all measurements, except for 1 linear measurement, i.e., S-N. However, the disparity between the mean values for all parameters was within the range of clinical measurement error. Conclusions: 3D-CBCT analysis, using midsagittal projection, is a useful method in which the 2D-LCR normative values can be used. Although the measurements changed with reorientation, these changes were not clinically significant.

세라믹스 재료의 열분석 (Thermal Analysis of Ceramic Materials)

  • 차재민;류리위;류봉기
    • 세라미스트
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    • 제22권4호
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    • pp.393-401
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    • 2019
  • Thermal analysis means the analysis of a change in a property of a sample, which is related to an imposed temperature alteration. Measurements are usually made with increasing temperature, but isothermal measurements or measurements made with decreasing temperatures are also possible. In fact, any measuring technique can be made into a thermal analysis technique by adding thermal control. Simultaneous use of multiple techniques increases the power of thermal analysis, and modern instrumentation has permitted extensive growth of application. The basic theories of thermal analysis are well developed and some of them are explained in this paper.

돼지 생체에서 부분육 형질의 추정 (Estimation of Carcass Cut Traits in Live Pigs)

  • 도창희
    • Journal of Animal Science and Technology
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    • 제49권2호
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    • pp.203-212
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    • 2007
  • 돼지의 부분육의 중량과 수율의 개량을 위하여 생체에서 이를 측정할 수 있는 수단이 필요하다. 4개의 교잡 계통돈 돼지 432두에 대하여 시기별 생체 측정치와 도축자료를 조사하였다. 생체중 및 도체중 그리고 부분육의 중량은 도축일령에 의해 영향을 거의 모두 받고 있지만 수율에 있어서는 삼겹살과 목심에만 유의성있게 영향하는 것으로 나타났다. 부분육의 형질과 시기별 생체 측정치간의 상관 조사에서 대부분의 체측정치에서 검정 종료시의 측정치가 다른 시기의 측정치보다 상관이 높게 나타났고, 부분육 형질의 예측을 위한 회귀식에서도 검정 개시와 출하시의 체측정치 보다 검정 종료시 체측정치를 이용하였을 때 결정계수가 모든 부분육의 형질에서 높아 가장 정확하게 추정하였다. 부분육 형질을 평균 출하일령으로 보정한 뒤, 검정 종료시 체측정치의 3차 다항회귀 식에 의한 부분육 형질의 예측에서 중량과 수율의 결정계수가 각각 0.59~0.68과 0.33~0.43의 범위를 보여주어 이를 돼지의 부분육 형질의 개량을 위해 활용하면 국내 선호부위가 우수한 한국형 종돈의 생산이 기대된다.

역산란 문제에서의 비유연성 (Nonuniqueness in Inverse Scattering Problems)

  • 김세윤;라정웅
    • 대한전자공학회논문지
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    • 제26권9호
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    • pp.1317-1321
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    • 1989
  • The nonuniqueness of solutions to inverse scattering problems for the reconstruction of cross sectional permitivity distributions on dielectric cylinder is illustrated in view of numerical analysis based on the spectral inverse scattering scheme with the moment-method procedures. It is also shown that some additional treatmenents such as multiple measurements, various incidences, etc. are not effective to assure the uniqueness.

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