• Title/Summary/Keyword: step-by-step method

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A Study on the Subject Selection of VE Using Decision Weights Techniques (VE 대상선정을 위한 평가항목의 가중치 결정방법에 관한 연구)

  • Ryu Hyung-Han;Bae Soo-Yong;Hwang Jae-Woo;Yun Dong-Jin;Lee Sang-Beom
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2005.05a
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    • pp.149-155
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    • 2005
  • Was used at step space-time mainly after VE technique sponsors in domestic in the 1960s but have been expanded to design step recently. Possibility of value elevation or cost reduction must choose member that is effectively for active and effective application of VE technique. In this study, when enforce design VE examining for weight decision corrosion protection been using in weight grant composition estimation technique, target choice process wishes to suggest formality and method that can be achieved effectively. Main conclusion of this study sorts valuation items step by step for weight appropriation of valuation basis and give point on article of high position point after expert which employer is included estimates article by low rank step and this presented high position method that do union itembyitemandestablishesbyitemweight. Did these techniques for giving weights so that importance for weight appropriation developed estimation program, and data save of target estimation standard and target estimation standard is possible using straight sit.

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New Double-Connected Multi-Step Inverter for SVC (SVC를 위한 새로운 이중접속방식의 멀티스텝 인버터)

  • 최세완;양승욱;김기용
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.460-463
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    • 1999
  • A new multi-step voltage source inverter is proposed in this paper. The proposed scheme is composed of the double-connected 12-step inverter with an auxiliary circuit. The auxiliary circuit includes two voltage dividing capacitors, two switching devices and a low KVA autotransformer. The resultant system is shown to be a 24-step inverter suitable for large scale SVC applications in which the PWM method can not be employed. The design parameters are derived from the analysis of voltages and currents by means of switching functions. The simulation results verify the proposed concept.

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A study on the tracking algorithm of satellite antenna system (위성 안테나 시스템의 추적 알고리즘에 관한 연구)

  • 강우신;조창호;이상철;조도현;이상효
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.128-128
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    • 2000
  • An antenna tracking technique, referred to as "step track", is commonly used in communication applications. In this paper, an algorithm to improve the step-tracking technique for satellite tracking is proposed. We suggest a method by which the antenna scans the azimuth, detects the satellite signal without the position information, and points quickly to the direction receiving the signal of peak level. After reaching the peak level, the step-track system maintains enough signal levels to receive satellite broadcasting normally. Performance of the Tracking Algorithm proposed in this paper are verified with simulation.

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Development of higher performance algorithm for dynamic PIV

  • NISHIO Shigeru
    • 한국가시화정보학회:학술대회논문집
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    • 2004.12a
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    • pp.25-32
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    • 2004
  • The new algorithm for higher performance of dynamic PIV has been proposed. Present study considered mathematical basis of PIV analysis for multiple-time-step images and it enables us to analyze the high time-resolution PIV, which is obtained by dynamic PIV system. Conventional single pair image PIV analysis gives us the velocity field data in each time step but it sometimes contains unnecessary information of target flow. Present technique utilize multi-time step correlation information, and it is analyzed.

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Effects of Crystallization Behavior on Microwave Dielectric Properties of CaMgSi2O6 Glass-Ceramics

  • Choi, Bo Kyeong;Kim, Eung Soo
    • Journal of the Korean Ceramic Society
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    • v.50 no.1
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    • pp.70-74
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    • 2013
  • Dependence of microwave dielectric properties on the crystallization behaviors of $CaMgSi_2O_6$ (diopside) glass-ceramics was investigated with different heat treatment methods (one and/or two-step). The crystallization behaviors of the specimens, crystallite size and degree of crystallization, were evaluated by differential thermal analysis (DTA), scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis by combined Rietveld and reference intensity ratio (RIR) methods. With an increase in heattreatment temperature, the dielectric constant (K) and the quality factor (Qf) increased due to the increase of the crystallite size and degree of crystallization. The specimens heat-treated by the two-step method had a higher degree of crystallization than the specimens heat-treated by the one-step method, which induced improvement in the quality factor (Qf) of the specimens.

Accurate Determination of Hydrogen Adsorption on Metal Materials Considering the Equations of State and its Influential Errors

  • Cho, Won-Chul;Park, Chu-Sik;Han, Sang-Sup
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • 2006.09b
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    • pp.1229-1230
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    • 2006
  • Adsorption isotherms of hydrogen by step-by-step method are widely used. However, the relations between the equations of state and the accumulated errors produced by step-by-step method and the mechanical errors of pressure or temperature controller were not analyzed. Considering the influence of various errors on the equations of state, we could find out the factors and compare the performance of the equations of state.

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Preparation of a axis oriented $YBa_2Cu_3O_{7-\delta}$ thin films by RF magnetron sputtering (RF 마그네트론 스퍼터링법에 의한 a-축 배향 $YBa_2Cu_3O_{7-\delta}$박막의 제조)

  • Lee, J.J.;Kim, Y.H.;Shin, J.;Lee, K.H.;Choi, S.S.;Hahn, T.S.
    • Korean Journal of Materials Research
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    • v.4 no.4
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    • pp.459-465
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    • 1994
  • A-axis oriened YBCO thin flims were grown on $LaAIO_{3}$ single crystal substrate by off-axis rf magnetron sputtering method. We used two kinds of process to get a-axis oriented fi1ms;one-step process and two-step process. In one-step process, films are grown in single step in which substrate temperature( $T_s$) is in the range of $590^{\circ}C$ to $680^{\circ}C$. On the other hand, in two step process a-axis oriented thin film templates i f about 30nm thickness is deposited at low temperature first, and subsequently films are grown at elevated temperature to the final thickness of about 100nm. In the case of one step process($T_s$ ~)$600^{\circ}C$), prefered a-axis orientation is dominant and Cu-rich phases segregate at the surface. Segregations decrease and ($00 \ell$) peaks increase upon increasing $T_s$. The films prepared by two step method appeared to have strong(h00) peaks as the deposition rate increased. Microstructure shows pin holes resulted from mixed phases of a-axis and c-axis oriented films. In both cases of one step and two step process, as TS decreases, prepared films show stronger a-axis orientation. However electrical properties of the films are depressed with lower $T_c$ and wider $\Delta T$ as $T_s$ decreases.

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Tuning Test of a Double-Swirl Gas Turbine Combustor using Six Sigma Tools (Six Sigma 기법을 이용한 이중 스월 가스터빈 연소기의 튜닝시험)

  • Lee, Min Chul;Ahn, Kwang Ick;Yoon, Youngbin
    • 한국연소학회:학술대회논문집
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    • 2012.04a
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    • pp.195-196
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    • 2012
  • This paper describes combustion tuning methodology of double-swirl gas turbine combustor using six sigma tools. This methodology is consist of five steps-Define, Identify, Design, Optimize and Verify (DIDOV). First, the NOx reduction target was defined in the step design; second, the current status of the plant was diagnosed in the step of identify; third, the vital few control parameters to achieve the defined target were determined by analyzing the correlation between the control parameters and NOx emissions in the step of design; fourth, the optimum condition was derived from one of the six sigma tools in the step of optimize; finally, the optimum condition was verified by applying the condition to the gas turbine combustor in the step of verify. As a result of the suggested method, averaged NOx emissions were reduced by more than 70% and the standard deviation was improved by more than 60%. Thus, this methodology can be attributed to the efficient reduction of NOx emission with saving combustion tuning time.

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Modified Asymmetrical Variable Step Size Incremental Conductance Maximum Power Point Tracking Method for Photovoltaic Systems

  • Tian, Yong;Xia, Bizhong;Xu, Zhihui;Sun, Wei
    • Journal of Power Electronics
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    • v.14 no.1
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    • pp.156-164
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    • 2014
  • The power-voltage (P-V) characteristic of a photovoltaic (PV) array is nonlinear and time varying with the change in atmospheric conditions. As a result, the maximum power point tracking (MPPT) technique must be applied in PV systems to maximize the generated energy. The incremental conductance (INC) algorithm, one of the MPPT strategies, is widely used for its high tracking accuracy, good adaptability to rapidly changing atmospheric conditions, and easy implementation. This paper presents a modified asymmetrical variable step size INC MPPT method that is based on the asymmetrical feature of the P-V curve. Compared with conventional fixed or variable step size method, the proposed method can effectively improve tracking accuracy and speed. The theoretical foundation and design principle of the proposed approach are validated by the simulation and experimental results.

Studies on the One Bath Two Step Dyeing of Wool/Cationized Cotton Blends with Acid Dye/Reactive Dye (양모/카티온화 면 혼방품의 산성염료/반응성염료에 의한 1욕2단 염색에 관한 연구)

  • 성우경;이춘길;권오경
    • Textile Coloration and Finishing
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    • v.11 no.2
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    • pp.46-54
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    • 1999
  • The conventional dyeing of wool/cotton blends involves a two bath two step method, i.e., after dyeing of the wool component with acid dyes in an acidic dyebath at $100^\circ{C}$, the dyeing of the cotton component with reactive dyes in an alkaline dyebath is performed. In order to overcome the disadvantage of the conventional two bath two step dyeing method of wool/cotton blends, it had prompted significant effort to the development of the one bath dyeing method which can accomplish savings in time, energy and water usage. To improve dyeing property of wool/cotton blends, cotton component was pretreated with cationizing agent containing chlorohydrine group in aqueous solution of sodium hydroxide. This study was carried out to investigate dyeing possibilities of wool/cationized cotton blends with acid dye/reactive dye by one bath two step method.

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