• Title/Summary/Keyword: Parametric Method

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Reliability analysis methods to one-shot device (일회용품의 신뢰성분석 방안)

  • Baik, Jaiwook
    • Industry Promotion Research
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    • v.7 no.4
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    • pp.1-8
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    • 2022
  • There are many one-shot devices that are used once and thrown away. One-shot devices such as firecrackers and ammunition are typical, and they are stored for a while after manufacture and then disposed of after use when necessary. However, unlike general operating systems, these one-shot devices have not been properly evaluated. This study first examines what the government does to secure reliability in the case of ammunition through ammunition stockpile reliability program. Next, in terms of statistical analysis, we show what the reliability analysis methods are for one-shot devices such as ammunition. Specifically, we show that it is possible to know the level of reliability if sampling inspection plan such as KS Q 0001 which is acceptance sampling plan by attributes is used. Next, non-parametric and parametric methods are introduced as ways to determine the storage reliability of ammunition. Among non-parametric methods, Kaplan-Meier method can be used since it can also handle censored data. Among parametric methods, Weibull distribution can be used to determine the storage reliability of ammunition.

Parametric Quantity Take-Off of Earthwork by Comparing the Use of Surface and Solid Models (Surface 및 Solid 방식의 비교를 통한 Parametric 기법의 토공물량산출 방법)

  • Hwang, Hee-Su;Lee, Jae-Hong;Kim, Tae-Young
    • Journal of KIBIM
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    • v.8 no.1
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    • pp.56-62
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    • 2018
  • There exists no precedented case of quantity take-off, using parametric modeling, from BIM-based irregular structures. Civil 3D provides earthwork quantity take-off based on surface modeling. Generally, designers should enter data into the specification additionally after extracting quantity estimation from earthwork modeling design. The objective of this report is to suggest the method from quantity take-off to specification of BIM-based earthwork quantities. We intend to investigate earthwork take-off method by Civil3D and explain why parametric information extraction is required for quantity estimation and specification and how information of earthwork quantity based on solid and surface modeling is connected to open quantity take-off module. It is highly expected that this suggestion would be the practical methodology of earthwork quantity take-off and specification in the field of civil engineering.

Identification of the Movement of Underlying Asset in Real Option Analysis: Studies on Industrial Parametric Table (실물옵션 적용을 위한 산업별 기초자산 확률과정추정)

  • Lee, Jeong-Dong;Gang, A-Ri;Jeong, Jong-Uk
    • Proceedings of the Technology Innovation Conference
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    • 2004.02a
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    • pp.222-245
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    • 2004
  • This paper has an intention of proposing useful parametric tables of each industry group within Korea. These parametric tables can be insightful criteria for those who are dealing with the exact valuation of company, technology or industry through Real Option Analysis (ROA) since the identification of the movement of underlying asset is the very first step to be done. To give the exact estimations of parameters and the most preferred model in each industry group, we cover topics on ROA, stochastic process, and parametric estimation method like Generalized Method of Moments (GMM) and Maximum Likelihood Estimation (MLE). Additionally, specific industry groups, such as, Internet service group and mobile telecommunication service group defined independently in this paper are also examined in terms of its property of movement with the suggesting of the most fitting stochastic model.

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Parametric resonance of composite skew plate under non-uniform in-plane loading

  • Kumar, Rajesh;Kumar, Abhinav;Panda, Sarat Kumar
    • Structural Engineering and Mechanics
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    • v.55 no.2
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    • pp.435-459
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    • 2015
  • Parametric resonance of shear deformable composite skew plates subjected to non-uniform (parabolic) and linearly varying periodic edge loading is studied for different boundary conditions. The skew plate structural model is based on higher order shear deformation theory (HSDT), which accurately predicts the numerical results for thick skew plate. The total energy functional is derived for the skew plates from total potential energy and kinetic energy of the plate. The strain energy which is the part of total potential energy contains membrane energy, bending energy, additional bending energy due to additional change in curvature and shear energy due to shear deformation, respectively. The total energy functional is solved using Rayleigh-Ritz method in conjunction with boundary characteristics orthonormal polynomials (BCOPs) functions. The orthonormal polynomials are generated for unit square domain using Gram-Schmidt orthogonalization process. Bolotin method is followed to obtain the boundaries of parametric resonance region with higher order approximation. These boundaries are traced by the periodic solution of Mathieu-Hill equations with period T and 2T. Effect of various parameters like skew angle, span-to-thickness ratio, aspect ratio, boundary conditions, static load factor on parametric resonance of skew plate have been investigated. The investigation also includes influence of different types of linearly varying loading and parabolically varying bi-axial loading.

Parametric numerical study of wind barrier shelter

  • Telenta, Marijo;Batista, Milan;Biancolini, M.E.;Prebil, Ivan;Duhovnik, Jozef
    • Wind and Structures
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    • v.20 no.1
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    • pp.75-93
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    • 2015
  • This work is focused on a parametric numerical study of the barrier's bar inclination shelter effect in crosswind scenario. The parametric study combines mesh morphing and design of experiments in automated manner. Radial Basis Functions (RBF) method is used for mesh morphing and Ansys Workbench is used as an automation platform. Wind barrier consists of five bars where each bar angle is parameterized. Design points are defined using the design of experiments (DOE) technique to accurately represent the entire design space. Three-dimensional RANS numerical simulation was utilized with commercial software Ansys Fluent 14.5. In addition to the numerical study, experimental measurement of the aerodynamic forces acting on a vehicle is performed in order to define the critical wind disturbance scenario. The wind barrier optimization method combines morphing, an advanced CFD solver, high performance computing, and process automaters. The goal is to present a parametric aerodynamic simulation methodology for the wind barrier shelter that integrates accuracy and an extended design space in an automated manner. In addition, goal driven optimization is conducted for the most influential parameters for the wind barrier shelter.

An improved parametric formulation for the variationally correct distortion immune three-noded bar element

  • Mukherjee, Somenath;Manju, S.
    • Structural Engineering and Mechanics
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    • v.38 no.3
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    • pp.261-281
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    • 2011
  • A new method of formulation of a class of elements that are immune to mesh distortion effects is proposed here. The simple three-noded bar element with an offset of the internal node from the element center is employed here to demonstrate the method and the principles on which it is founded upon. Using the function space approach, the modified formulation is shown here to be superior to the conventional isoparametric version of the element since it satisfies the completeness requirement as the metric formulation, and yet it is in agreement with the best-fit paradigm in both the metric and the parametric domains. Furthermore, the element error is limited to only those that are permissible by the classical projection theorem of strains and stresses. Unlike its conventional counterpart, the modified element is thus not prone to any errors from mesh distortion. The element formulation is symmetric and thus satisfies the requirement of the conservative nature of problems associated with all self-adjoint differential operators. The present paper indicates that a proper mapping set for distortion immune elements constitutes geometric and displacement interpolations through parametric and metric shape functions respectively, with the metric components in the displacement/strain replaced by the equivalent geometric interpolation in parametric co-ordinates.

Parametric Array Sonar System Based on Maximum Likelihood Detection (최대우도 검파에 기반한 파라메트릭 어레이 소나 시스템)

  • Han, Jeong-Hee;Lee, Chong-Hyun;Paeng, Dong-Guk;Bae, Jin-Ho;Kim, Won-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.48 no.1
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    • pp.25-31
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    • 2011
  • In the underwater communications, transmitted acoustic signal is corrupted by interference from multipath. A parametric array transducer is capable of radiating a narrow beam with very low sidelobe levels. In certain cases, the parametric array transducer can help the multipath problem. To improve the performance of the underwater communications, the statistical signal processing methods will be required. In the paper, the communication system using a parametric array transducer was demonstrated. To detect the received signal of the communication system based on the on-off keying, the maximum likelihood method using averaged signal for a particular window size is used. The communication system has GUI using LebVIEW which allows the user to change the parameter. The GUI can also be easily modified based on the characteristics of a parametric array transducer. The implemented system can effectively evaluate the performance of the parametric array transducer.

A Study on the Curved Form Generation Methodology of the Brick Architecture by Stretcher Bond - Focused on the Parametric Design Process - (길이쌓기에 따른 벽돌건축의 곡면형태 생성방법에 관한 연구 - 파라메트릭 디자인 프로세스를 중심으로 -)

  • Cho, Heayon;Lee, Hyunsoo
    • Korean Institute of Interior Design Journal
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    • v.26 no.6
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    • pp.163-171
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    • 2017
  • Brick is not only aesthetically beautiful and emotional material, but also eco-friendly and good building commodity for human health. Nonetheless, the use of brick has declined, due to the difficulty of building high-rise buildings and the limitation of the free form implementation. However, modern society is increasingly interested in environmentally friendly finishing materials for solving environmental problems. From this point of view, the brick architecture is being reexamined as a material to improve the living environment and to provide comfort without destroying nature. In addition, the development of digital technology enables the implementation of various types of masonry method and curved forms. Parametric design is one of the ways to realize the curved forms and various architectural expressions for brick architecture. In this background, the purpose of this study is to develop algorithms that can easily generate curved brick walls through parametric design, enable various pattern designs, and respond to real-time feedback. The details of the study are as follows. First of all, we examine organic architecture, the trend of brick architecture, and the concept of parametric design. Secondly, In order to generate curved surface with complex curvature, major planning factors affecting form generation are examined. Finally, we develop a parametric design method that consists of generating a curved surface for brick arrangement, implementing a parametric algorithm, and generating a curved form using bricks. Consequentially, we propose an algorithm that can maximize the use of ready-made bricks without using cut bricks to design curved walls and present efficient and economical design alternatives.

An Approximate Method for the Buckling Analysis of a Composite Lattice Rectangular Plate

  • Kim, Yongha;Kim, Pyunghwa;Kim, Hiyeop;Park, Jungsun
    • International Journal of Aeronautical and Space Sciences
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    • v.18 no.3
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    • pp.450-466
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    • 2017
  • This paper defines the modified effective membrane stiffness, bending stiffness considering the directionally dependent mechanical properties and mode shape function of a composite lattice rectangular plate, which is assumed to be a Kirchhoff-Love plate. It subsequently presents an approximate method of conducting a buckling analysis of the composite lattice rectangular plate with various boundary conditions under uniform compression using the Ritz method. This method considers the coupled buckling mode as well as the global and local buckling modes. The validity of the present method is verified by comparing the results of the finite element analysis. In addition, this paper performs a parametric analysis to investigate the effects of the design parameters on the critical load and buckling mode shape of the composite lattice rectangular plate based on the present method. The results allow a database to be obtained on the buckling characteristics of composite lattice rectangular plates. Consequently, it is concluded that the present method which facilitates the calculation of the critical load and buckling mode shape according to the design parameters as well as the parametric analysis are very useful not only because of their structural design but also because of the buckling analysis of composite lattice structures.

Non-parametric Modeling of Cutter Swept Surfaces for Cutting Simulation (모의가공을 위한 공구 이동 궤적면의 비매개변수형 모델링)

  • 정연찬;최병규
    • Korean Journal of Computational Design and Engineering
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    • v.1 no.1
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    • pp.45-55
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    • 1996
  • This paper presents a new approach to non-parametric modeling of cutter swept surface (CSS) for cutting simulation. Instead of explicitly modeling cutter swept volumes, silhouette curves of the cutter surface are utilized in computing the z-value of the CSS at a grid point on the x,y-plane. The non-parametric evaluation of the CSS constitutes the integral part of 3-axis cutting simulation. The proposed method is more efficient than the existing ones in the case of conventional cutters (i.e., ball-end mills and flat-end mills), and more importantly, it enables the non-parametric modeling of the CSS for the round-end mills which was not possible with the existing methods.

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