• Title/Summary/Keyword: Design criterion

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Design Criterion for the Size of Micro-scale Pt-catalytic Combustor in Respect of Heat Release Rate (열 방출률에 대한 마이크로 백금 촉매 연소기의 치수 설계 기준)

  • Lee, Gwang Goo;Suzuki, Yuji
    • Journal of the Korean Society of Combustion
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    • v.19 no.4
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    • pp.49-55
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    • 2014
  • Design criterion for the size of micro Pt-catalytic combustor is investigated in terms of heat release rate. One-dimensional plug flow model is applied to determine the surface reaction constants using the experimental data at stoichiometric butane-air mixture. With these reaction constants, the mass fraction of butane and heat release rate predicted by the plug flow model are in good agreement with the experimental data at the combustor exit. The relationship between the size of micro catalytic combustor and mixture flowrate is introduced in the form of product of two terms-the effect of fuel conversion efficiency, and the effect of chemical reaction rate and mass transfer rate.

A Study for Vehicle Dynamic Analysis and Test of Airport Railroad (공항철도 차량 동특성 해석 및 시험에 관한 연구)

  • Yang, Hee-Joo;Seong, Jae-Ho
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.188-193
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    • 2007
  • Airport railroad have required maximum design speed 120km/h and wind speed 50m/s condition as design item of airport railroad vehicles. To design and manufacture the vehicle satisfying these conditions, it must carry out the dynamic behaviors analysis such as hunting stability, ride comfort derailment ratio, unloading ratio and lateral force to meet the criterion described in Urban Railroad Act. Dynamic behaviors of vehicle have carried out using the multi-body dynamics simulation program(VAMPIRE). This paper presents the evaluation methods and criterion used to verify dynamic performance of airport railroad vehicle, and show the analysis results of vehicle dynamic simulation and the test results for vibration and ride comfort measured on running performance tests. As a results, each analysis results and test results meet the criterion described in Urban Railroad Act.

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Form Error Analysis of a Cam Disk Profile Based on ISO Minimum Zone Criterion (ISO 최소영역법에 기준한 캠 디스크의 형상 오차 해석)

  • Kang, Jae-Gwan;Kim, Won-Il
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.5 no.3
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    • pp.80-85
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    • 2006
  • In an effort to reduce the evaluation time of the precision of manufactured disk cams, an effective measuring method with an exclusively built profile-measuring machine and subsequent data analysis procedure is proposed. The design and measuring data are interpolated by cubic spline curves to compute the precision error which is defined by the maximum and minimum distances between two curves. The minimum zone criterion of ISO is employed to evaluate the form error, and genetic algorithm is used to search the orientation and location of design data for the measured data which minimizes the form error. The proposed system was applied to marine engine cams, and it shows that the form error is reduced to 30% down compared with the method which minimizes the form error with the assumption that the centers of measured data design cam curve are identical.

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Assessment of the Strong Motion Duration Criterion of Synthetic Accelerograms (내진설계를 위한 인공지진파 강진지속시간 기준의 평가)

  • Huh, Jung-Won;Jung, Ho-Sub;Kim, Jae-Min;Chung, Yun-Suk
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.133-140
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    • 2006
  • This paper addresses a fundamental research subject to complement and improve current domestic design specifications for the strong motion duration criterion and the envelop function of artificial accelerograms that can be applied to the earthquake-proof design of nuclear structures. The criteria for design response spectra and strong motion duration suggested by WRC RG 1.60 and ASCE Standard 4-98 are commonly being used in the profession, and they are first compared with each other and reviewed. By applying 152 real strong earthquake records that are over magnitude of 5 in the rock sites to the strong motion duration criterion in ASCE 4-98, an empirical regression model that predicts the strong motion duration as a function of earthquake magnitude is then developed. Using synthetically generated earthquake time histories for the five cases whose strong motion durations vary from 6 to 15 seconds, a seismic analysis is conducted to identify effects of the strong motion durations on the seismic responses of nuclear structures.

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Reliability of structures with tuned mass dampers under wind-induced motion: a serviceability consideration

  • Pozos-Estrada, A.;Hong, H.P.;Galsworthy, J.K.
    • Wind and Structures
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    • v.14 no.2
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    • pp.113-131
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    • 2011
  • Excessive wind-induced motion in tall buildings can cause discomfort, affect health, and disrupt the daily activities of the occupants of a building. Dynamic vibration absorbers such as the tuned mass dampers (TMDs) can be used to reduce the wind-induced motion below a specified tolerable serviceability limit state (SLS) criterion. This study investigates whether the same probability of not exceeding specified wind-induced motion levels can be achieved by torsionally sensitive structures without/with linear/nonlinear TMDs subjected to partially correlated wind forces, if they are designed to just meet the same SLS criterion. For the analyses, different structures and the uncertainty in the response, wind load and perception of motion is considered. Numerical results indicate that for structures that are designed or retrofitted without or with optimum linear TMDs and satisfying the same SLS criterion, their probability of exceeding the considered criterion is very consistent, if the inherent correlation between the wind forces is considered in design. However, this consistency deteriorates if nonlinear TMDs are employed. Furthermore, if the correlation is ignored in the design, in many cases a slightly unconservative design, as compared to the designed by considering correlation, is achieved.

Classification Rule for Optimal Blocking for Nonregular Factorial Designs

  • Park, Dong-Kwon;Kim, Hyoung-Soon;Kang, Hee-Kyoung
    • Communications for Statistical Applications and Methods
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    • v.14 no.3
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    • pp.483-495
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    • 2007
  • In a general fractional factorial design, the n-levels of a factor are coded by the $n^{th}$ roots of the unity. Pistone and Rogantin (2007) gave a full generalization to mixed-level designs of the theory of the polynomial indicator function using this device. This article discusses the optimal blocking scheme for nonregular designs. According to hierarchical principle, the minimum aberration (MA) has been used as an important criterion for selecting blocked regular fractional factorial designs. MA criterion is mainly based on the defining contrast groups, which only exist for regular designs but not for nonregular designs. Recently, Cheng et al. (2004) adapted the generalized (G)-MA criterion discussed by Tang and Deng (1999) in studying $2^p$ optimal blocking scheme for nonregular factorial designs. The approach is based on the method of replacement by assigning $2^p$ blocks the distinct level combinations in the column with different blocks. However, when blocking level is not a power of two, we have no clue yet in any sense. As an example, suppose we experiment during 3 days for 12-run Plackett-Burman design. How can we arrange the 12-runs into the three blocks? To solve the problem, we apply G-MA criterion to nonregular mixed-level blocked scheme via the mixed-level indicator function and give an answer for the question.

Design and Simulation of Very Low Head Axial Hydraulic Turbine with Variation of Swirl Velocity Criterion

  • Muis, Abdul;Sutikno, Priyono
    • International Journal of Fluid Machinery and Systems
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    • v.7 no.2
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    • pp.68-79
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    • 2014
  • The type of turbine developed is based on the very low head of water potential source for the electric power production. The area of research is focused for the axial water turbine that can be applied at the simple site open channel with has a very low cost and environmental impact compared to the conventional hydro installation. High efficiency of axial turbine which applied to the very low potential head will made this type of turbine can be used at wider potential site. Existing irrigation weir and river area will be the perfect site for this turbine. This paper will compare the effects of the variation of swirl velocity criterion during the design of the blade of guide vane and rotor of the turbine. Effects of the swirl velocity criterion is wider known as a vortex conditions (free vortex, force vortex and swirl velocity constant), and the free vortex is the very popular condition that applied by most of turbine designer, therefore will be interesting to do a comparison against other criterion. ANSYS Fluent will be used for simulation and to determine the predictive performance obtained by each of design criteria.

A Study on the Contamination Criterion Map of Seashore Areas in Korea (전국 해안지역의 오손분포도 산정에 관한 연구)

  • Kim, Joon-Eel;Kim, Dong-Myung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.10
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    • pp.89-96
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    • 2008
  • The objective of this study is to establish the algorithm for contamination criterion map based on the recent weather condition. Present criterion was established by the study on the countermeasure of salt contamination for electrical equipment. It did not represent recent weather condition. Therefore it is necessary to develop a contamination criterion map for assessment of contamination in design areas in Korea. To develop contamination criterion map of seashore areas, we used relational numerical formula based on past measurement data with the amount of rainfall, geomorphic variables(elevation slope, land use). These results are expected to be used as a reference material for design distribution facilities in seashore areas.

Efficient Design of SVD-Based 2-D Digital Filters Using Specification Symmetry and Order-Selecting Criterion

  • Deng, Tian-Bo;Eriko Saito;Eiji Okamoto
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1784-1787
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    • 2002
  • Two-dimensional (2-D) digital filters are widely useful inn image processing and other 2-D digital signal processing fields, but designing 2-D filters is much more difficult than designing one-dimensional (1-D) ones. This paper provides a new insight into the existing singular value decomposition (SVD)-based design approach in the sense that the SVD-based design can be performed more efficiently by exploiting the symmetries of the given 2-D magnitude specifications. By using the specification symmetries. only half of the 1-D filters (sub-filters) need to be designed. which significantly simplifies the design process and reduces the computer storage required for 1-D sub-filter coefficients. Another novel point of this paper si that an objective criterion is proposed for selecting appropriate sub-filter orders in order to reduce the hardware implementation cost. A design example is given to illustrate the effectiveness of the SVD-based design approach by exploiting specification symmetry and new order-selecting criterion.

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Fracture Mechanics Approach to X-Ray Diffraction Method for Spot Welded Lap Joint Structure of Rolled Steel Considered Residual Stress (잔류응력을 고려한 압연강 용접구조물의 X-ray 회절법에 의한 파괴 역학적 고찰)

  • Baek, Seung-Yeb;Bae, Dong-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.10
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    • pp.1179-1185
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    • 2011
  • Cold and hot-rolled carbon steel sheets are commonly used in railroad cars or commercial vehicles such as the automobile. The sheets used in these applications are mainly fabricated by spot welding, which is a type of electric resistance welding. However, the fatigue strength of a spot-welded joint is lower than that of the base metal because of high stress concentration at the nugget edge of the spot-welded part. In particular, the fatigue strength of the joint is influenced by not only geometrical and mechanical factors but also the welding conditions for the spot-welded joint. Therefore, there is a need for establishing a reasonable criterion for a long-life design for spot-welded structures. In this thesis, ${\Delta}P-N_f$ relation curves have been used to determine a long-life fatigue-design criterion for thin-sheet structures. However, as these curves vary under the influence of welding conditions, mechanical conditions, geometrical factors, etc. It is very difficult to systematically determine a fatigue-design criterion on the basis of these curves. Therefore, in order to eliminate such problems, the welding residual stresses generated during welding and the stress distributions around the weld generated by external forces were numerically and experimentally analyzed on the basis of the results, reassessed fatigue strength of gas welded joints.