• 제목/요약/키워드: Analytical Estimation

검색결과 624건 처리시간 0.027초

양측식 영구자석 가동형 슬롯리스 직선 동기전동기의 전자기 특성 및 동특성 해석에 의한 설계정수 도출 (Extraction of Design Parameters through Electromagnetic and Dynamic Analysis of Slotless Double-side PMLSM system)

  • 장원범;이성호;장석명;유대준
    • 전기학회논문지
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    • 제56권12호
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    • pp.2135-2144
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    • 2007
  • This paper presents system design of the slotless double-side Permanent Magnet Linear Synchronous Machine system (PMLSM) through magnetic field analysis and dynamic modeling. In our analysis, 2-D analytical treatments based on the magnetic vector potential were adopted to predict magnetic field with space harmonics by PM mover magnetization and stator winding current. From these, the design parameters such as inductance, Back-emf, and thrust are estimated. And, the electrical dynamic modeling including synchronous speed is completed by calculation of a DC link voltage in effort to obtain the accurate mechanical power from Space Vector Pulse Width Modulation(SVPWM). Therefore, the system design of PMLSM is performed from estimation of design parameters according to PM size and coil turns in magnetic field and from calculation of a DC link voltage to satisfy base speed and base thrust represented as the maximum output power in dynamic modeling. The estimated values from the analysis are verified by the finite element method and experimental results.

거대 구조물의 국부진동계의 등가계 산출과 이를 이용한 최적구조변경법 (A Study on the estimation of an equivalent system of a local vibration system of a huge structure and the Optimum Structural Modification Method)

  • 박석주;황문주;오창근;김성우
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 1998년도 춘계학술발표회 논문집
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    • pp.120-127
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    • 1998
  • It is very difficult to execute the vibration analysis of a huge strucutre, which takes up much time and expense. In this paper we intend to make the equivalent system of a local vibration system of a huge structure with a view to improving the dynamic characteristics and reducing time and expense. First of all, upper deck structure model is maded. And we perform the vibration analysis by the Substructure Synthesis Method and execute the exciting test for the upper deck structure model, and observe the coincidences of two results to confirm the reliability of the analyzing tools used. To make the equivalent system, we give boundary condition to sub-structure that want to be modified and execute the Sensitivity Analysis Method and the Optimum Structural Modification Method. And we execute the structural modification of the equivalent system.. The following can be found from this study. 1. The analytical results are generally coincident with each other. 2. The equivalent system of the superstructure model can be easily obtained using the sensitivity analysis metho and the optimum structural modification method. 3. The structural modification using the equivalent system can be obtained good results above 90% of object value.

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계층화 분석법(Analytic Hierarchy Process)을 활용한 한의사 업무량 산출 (Measurement of Physician's Work for Korean Medicine Services Using Analytic Hierarchy Process)

  • 임병묵;권혁상;한창호;신병철
    • 대한예방한의학회지
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    • 제13권1호
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    • pp.105-115
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    • 2009
  • Background: The resource-based relative value scale has been applied to Korean medicine services as part of the National Health Insurance, yet the proper scoring method for physician's work needs to be developed. Objectives: To measure physician's work for Korean medicine services using Analytical Hierarchy Process(AHP) and to compare results abstracted by AHP with those by Magnitude Estimation method. Methods: We developed the AHP questionnaires for Korean Medicine services and administered it to 12 Korean medicine insurance experts. Weighted scores were calculated and were converted into physician's work scores. Results: In AHP measurement, the physician's work scores for acupuncture activities, especially special acupunctures, far increased, while those for diagnosis and basic consultations decreased. Variations in the scores enlarged. Conclusions: As an alternative, AHP method can be considered for measuring the physician's work for Korean medicine services with careful management of scoring variation.

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사각헝 탱크 구조의 접수 진동 특성에 관한 연구 (Analytical and Experimental Study on Vibration Characteristics for Rectangular Tank Structure Filled with Fluid)

  • 최수현;김극수;손성완
    • 한국소음진동공학회논문집
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    • 제12권3호
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    • pp.195-203
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    • 2002
  • In the engine room and the aft part areas of the ship, there exist so many tank structures contacting with fresh water or sea water or oil. If these structures exhibit excessive vibrations during the sea trials, it takes a lot of cost, time and effort to improve vibration situation because the reinforcement work requires emptying the fluid out of the tanks, additional welding and special painting. It is therefore very important to predict a precise vibration characteristics of the tank structures at the design stage, however it is not easy to estimate vibration characteristics of the structures because of difficulties for accurate evaluation of the added (or virtual) mass effect due to the fluid inside the tank. In this paper, numerical and experimental approaches have been performed to present same fundamental data necessary for anti-vibration design of tank structures contacting with fluid, by investigating vibration behaviors of rectangular tank structure for various water depths.

선박의 홀수 측정을 위한 초음파 펄스 신호의 해석기법 (An Analysis Technique of Ultrasonic Pulse Signal for Measuring Ship's Draught)

  • 이은방;이상집
    • 한국항해학회지
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    • 제19권4호
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    • pp.1-8
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    • 1995
  • Although ship's draught information onboard is substantial for both the safety of navigation and the estimation of loaded cargoes, its accuracy depends, in conventional surveying method, on the skillfulness of observers and the condition of the sea surface round the vessel. To obtain more accurate information accessibly, measuring instruments with sophisticated sensors such as mechanical, electronic and ultrasonic transducers have been developed. However, they have still limitation in accuracy and in making up a system due to the complexity of processing signal. In this paper, we propose a new technique for analyzing ultrasonic pulse signal, in order to improve the measurement accuracy and simplify a remote sensing system of draught by ultrasonic waves. In this technique, pulse signal is translated into phase curve which is composed of the phase value defined in time domain. Then, the time interval between two signals different in waveform, is waveform, is analytically determined by calculating average time difference on phase curves. Also, analytical procedure can be carried out in real time with the successive five data sampled at T/4, for high speed digital processing with computer and A/D converter. This technique is useful for measuring draught under the influence of sea condition and for interfacing its data briefly to the integrated bridge system.

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공동주택관리사의 전문직화를 위한 탐색적 연구 (A Study for Professionalizlng of Multi-family Housing Manager)

  • 은난순;유병선;홍형옥
    • 가정과삶의질연구
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    • 제21권3호
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    • pp.109-121
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    • 2003
  • The purpose of this study was to investigate the difficulty of doing job among housing manager. It might be Provide the basic opinion which could be used for professionalizing of housing manager. The survey had been made 156 housing manager in managerial situation of multi-family housing for sale(so called condominium). The analytical methods adopted in this study were frequency, percentage, 1-test, one-way ANOVA, post-hoc estimation(Scheffe test), correlation by the SPSS 10.1 for Windows program. The major findings of this study were as follows. First, it was revealed that many housing manager thought about Residents' Committee In the negative. Because housing manager considered that Residents' Committee interfered in housing manager's business, on the other hand they set a low value on Residents' Committee disposition and its knowledge about housing management. Second, it was founded that a lot of housing manager felt uneasy about his employment for the reason mentioned. Actually Residents' Committee exercised its influence over hiring as well as dismissing housing manager in any management alternatives. Third, it was necessary that synthetic plan might be prepared for housing manager to educate, to re-educate, to furnish information etc. about related in housing management for the specialization of housing management.

NEW SPECTROSCOPIC METHODS FOR THE SIMULTANEOUS ESTIMATION OF FUNDAMENTAL ATMOSPHERIC PARAMETERS USING THE LINE DEPTH RATIOUS

  • Kim, Chul-Hee;Moon, B.K.;Lee, I.H.
    • 천문학회지
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    • 제45권2호
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    • pp.25-29
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    • 2012
  • New methods are developed to estimate the effective temperature (Te), surface gravity (log g), and metallicity ([A/H]) simultaneously with the spectral line depth ratios. Using the model atmosphere grids, depth values are calculated for the wavelength range of $4000{\AA}-5600{\AA}$ for various temperatures, gravities, and metallicities. All possible different combinations of line depth ratios for different pairs of ratios are investigated. A graphical 3D figure is produced with X, Y, and Z axes corresponding to Te, log g, and [A/H], respectively. By reading a cross point of two curves plotted by a connection of three parameters obtained from spectral line depth ratio pairs on each of the three projected planes, Te, log g, and [A/H] are determined simultaneously. In addition, an analytical method is devised based on the similar algorithm developed for the graphical method. Our methods were applied to estimate the fundamental atmospheric parameters of the Sun and Arcturus.

Characterization of a LSCF/GDC Cathode Composite in Solid Oxide Fuel Cells Using Impedance Spectroscopy

  • Hwang, Jin-Ha;Lee, Byung-Kook
    • 한국세라믹학회지
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    • 제42권12호
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    • pp.793-799
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    • 2005
  • A composite cathode of LSCF$(La_{0.6}Sr_{0.4}Co_{0.2}Fe_{0.8}O_3)\;and\;GDC\; (Gd_2O_3-doped\;CeO_2:Ce_{0.9}Gd_{0.1}O_{1.95_})$ was characterized in terms of an electrode response, using a point contact in an Yttria-Stabilized Zirconia (YSZ) electrolyte incorporated into AC two-point impedance spectroscopy. The point-contacted configuration amplifies the responses occurring near the YSZ/cathode interface through the aligned point contact on the planar LSCF/GDC electrode. The point contact interface increases the bulk resistance allowing the estimation of the point contact geometry and resolving the electrode-related responses. The resultant impedance spectra are analyzed through an equivalent circuit model constructed by resistors and constant phase elements. The bulk responses can be resolved from the electrode-related portions in terms of spreading resistance. The electrode-related polarizations are measured in terms of temperature and oxygen partial pressure. The modified impedance spectroscopy is discussed in terms of methodology and analytical aspects, toward resolving the electrode-polarization issues in solid oxide fuel cells.

철도편익 증대를 위한 소요차량수 산정 방안 (Estimation of the Optimum Number of Rail Cars to Increase the Benefit)

  • 김경태;이진선;박범환
    • 한국철도학회논문집
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    • 제13권3호
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    • pp.333-338
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    • 2010
  • 철도투자사업의 경제성 증대를 위해서는 새로운 편익의 발굴도 중요하지만 비용 부문에서 과다하게 책정되는 부분을 개선하는 것도 매우 중요하다. 본 논문은 철도부문의 편익을 제고하기 위해 철도차량의 정차 패턴까지 고려한 최적화 모형을 이용하여 분석할 것을 제안한다. 기존의 방법은 주요 역에 모두 정차한다는 시나리오를 토대로 운행시간을 작성하였으나 이는 실제 운행 여건과는 맞지 않는다. 열차별 정차 패턴을 고려하여 소요 차량수를 산정할 경우 계획 단계에서 적용되는 차량구입비를 합리적으로 산정할 수 있고 경제성 분석에도 긍정적인 영향을 주는 것으로 분석되었다.

다경간 연속 교량의 내진성능 평가를 위한 개선된 모드별 비탄성 정적해석방법의 응용성 연구 (Applicability of Improved Modal Pushover Analysis of Multi-Span Bridges Under Earthquake Load)

  • 곽효경;신동규
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.795-800
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    • 2007
  • In the previous study, a simple but effective analysis procedure, named as an Improved Modal Pushover Analysis (IMPA) was proposed to estimates the seismic capacities of multi-span continuous bridge structures, on the basis of the modal pushover analysis which considers all the dynamic modes of a structure. Differently from other previous studies, IMPA maintains the simplicity of the capacity-demand curve method and also gives a better estimation of the maximum dynamic response of a structure. Nevertheless, its applicability has never been approved for multi-span continuous bridges with large differences in the length of their adjacent piers. This paper, accordingly, concentrates on a parametric study to verify the efficiency and limitation in application of IMPA through a correlation study between various analytical models including the Equivalent Single Degree Of Freedom (ESDOF) and Modal Pushover Analysis (MPA) usually used in the seismic design of structures. Based on the obtained numerical results, this paper introduces a practical guidance and/or limitation for using IMPA to predict the seismic response of a bridge effectively.

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