• 제목/요약/키워드: FIELD EXPERIMENTAL DESIGN

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Lithium Niobate (LiNbO3) Photonic Electric-Field Sensors

  • Jung, Hongsik
    • Journal of Sensor Science and Technology
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    • v.31 no.4
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    • pp.194-213
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    • 2022
  • This study comprehensively reviewed four types of integrated-optic electric-field sensors based on titanium diffused lithium-niobate waveguides: symmetric and asymmetric Mach-Zehnder interferometers, 1×2 directional couplers, and Y-fed balanced-bridge Mach-Zehnder interferometers. First, we briefly explain the crystal properties and electro-optic effect of lithium niobate and the waveguide fabrication process. We theoretically analyzed the key parameters and operating principles of each sensor and antennas. We also describe and compare the design, simulation, implementation, and performance tests: dc and ac characteristics, frequency response, dynamic range, and sensitivity. The experimental results revealed that the sensitivity of the sensor based on the Y-fed balanced bridge Mach-Zehnder interferometer (YBB-MZI) was higher than that of the other types of sensors.

Optimal Design System of Grillage Structure under Constraint of Natural Frequency Based on Genetic Algorithm (고유진동수 제한을 갖는 골조구조의 GA 기반 최적설계 시스템)

  • Kim, Sung Chan;Kim, Byung Joo;Kim, E Dam
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.1
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    • pp.39-45
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    • 2022
  • Normal strategy of structure optimization procedure has been minimum cost or weight design. Minimum weight design satisfying an allowable stress has been used for the ship and offshore structure, but minimum cost design could be used for the case of high human cost. Natural frequency analysis and forced vibration one have been used for the strength estimation of marine structures. For the case of high precision experiment facilities in marine field, the structure has normally enough margin in allowable stress aspect and sometimes needs high natural frequency of structure to obtain very high precise experiment results. It is not easy to obtain a structure design with high natural frequency, since the natural frequency depend on the stiffness to mass ratio of the structure and increase of structural stiffness ordinary accompanies the increase of mass. It is further difficult at the grillage structure design using the profiles, because the properties of profiles are not continuous but discrete, and resource of profiles are limited at the design of grillage structure. In this paper, the grillage structure design system under the constraint of high natural frequency is introduced. The design system adopted genetic algorithm to realize optimization procedure and can be used at the design of the experimental facilities of marine field such as a towing carriage, PMM, test frame, measuring frame and rotating arm.

Numerical Analysis on the Determination of Hydraulic Characteristics of Rubble Mound Breakwater (경사식 방파제의 수리특성 결정을 위한 수치해석)

  • 박현주;전인식;이달수
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.14 no.1
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    • pp.19-33
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    • 2002
  • A numerical method to efficiently secure necessary design informations of the hydraulic characteristics of rubble mound breakwater was attempted here. The method combines the exterior wave field with the interior wave field which is formulated incorporating porous media flow inside the breakwaters. An approximate method based on the long wave assumption was used for the exterior wave field while a boundary element method was used for the interior wave field. A hydraulic experiment was also performed to verify the validity of the numerical analysis. The numerical results were compared with experimental data and results from existing formulae. They generally agreed in both reflection and transmission coefficients. The calculated pore pressures also showed a similar pattern with experimental data, even if they gave some significant differences in their values fur some cases. The main cause of such differences can be attributed to the strongly nonlinear wave field occurring on the frontal slope of the breakwater. The direct input of dynamic pressures(measured from hydraulic experiment) into the numerical method was suggested as a promising method to enhance the predictability of pore pressures.

Development of SW Education Convergence Science Curriculum-linked Experimental Automation Teaching Tool (SW교육 융합 과학교과 연계형 실험 자동화 교구 개발)

  • Son, Min-Woo;Kim, Jin-ha;Ju, Yeong-Tae;Kim, Jong-Sil;Kim, Eung-Kon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.5
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    • pp.967-972
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    • 2020
  • Most of the experimental tools currently used are applied to experiments in the physical field by utilizing sensors and only MBL that are suitable for specific experiments have been developed. However, There is no experimental design stage using SW fusion, and there is a limit to the application of various chemistry experiments in textbooks, and in the case of Arduino, it is difficult for students to learn and understand language when programming. In this paper, we designed and developed a SW education convergence science experiment apparatus including a learner's active experiment design process, overcoming the shortcomings of the existing microcomputer experiment and the limitations of software education.

Flow Analysis of Profile Extrusion by a Modified Cross-sectional Numerical Method

  • Seo, Dongjin;Youn, Jae-Ryoun
    • Fibers and Polymers
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    • v.1 no.2
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    • pp.103-110
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    • 2000
  • Flow analysis of profile extrusion is essential for design and production of a profile extrusion die. Velocity, pressure, and temperature distribution in an extrusion die are predicted and compared with the experimental results. A two dimensional numerical method is proposed for three dimensional analysis of the flow field within the profile extrusion die by applying a modified cross-sectional numerical method. Since the cross-sectional shape of the die is varied gradually, it is assumed that the pressure is constant within a cross-sectional plane that is perpendicular to the flow direction. With this assumption, the velocity component in the cross-sectional direction is neglected. The exact cross-sectional shape at any position is calculated based on the geometry of standard cross-sections. The momentum and energy equations are solved with proper boundary conditions at a cross-section and then the same calculation is carried out for the next cross-section using the current calculated values. An L-shaped profile extrusion die is produced and employed for experimental investigation using a commercially available polypropylene. Numerical prediction for the varying cross-sectional shape provides better results than the previous studies and is in good agreement with the experimental results.

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Numerical and Experimental Studies of Dual Subsea Pipelines in Trench

  • Jo, Chul H.;Shin, Young S.;Min, Kyoung H.
    • Journal of Ship and Ocean Technology
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    • v.6 no.2
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    • pp.12-22
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    • 2002
  • Offshore pipelines play an important role in the transportation of gas, oil, water and oil products. It is common to have a group of pipelines in the oil and gas field. To reduce the installation cost and time, dual pipelines are designed. There are great advantages in the installation of dual pipelines over two separate single lines. It can greatly reduce the cost for trench, back-filling and installation. However the installation of dual pipelines often requires technical challenges. Pipelines should be placed to be stable against external loadings during installation and design life period. Dual pipelines in trench can reduce the influence of external forces. To investigate the flow patterns and forces as trench depth and slope changes, number of experiments are conducted with PIV(Particle Image Velocimetry) equipment in a Circulating Water Channel. Numerical approaches to simulate experimental conditions are also made to compare with experimental results. The velocity fields around dual pipelines in trench are investigated and analysed. Comparison of both results show similar patterns of flow around pipelines. It is proved that the trench depth contributes significantly on hydrodynamic stability. The trench slope also affects the pipeline stability. The results can be applied in the stability design of dual pipelines in trench section. The complex flow patterns can be effectively linked in the understanding of fluid motions around multi-circular bodies in trench.

Strategic Culture Marketing Enhancing Brand Image and Customers' Loyalty - Focusing on Multi-dimensional approach for Companies, Consumers, and Other Subjects - (브랜드의 이미지와 충성도를 높이는 문화마케팅 전략에 관한 연구 -기업, 소비자, 지원대상의 다차원적 접근을 중심으로-)

  • Lee, Yun-Kyung;Shin, Kyu-Hee;Hwang, Sun-Jin
    • Journal of the Korean Society of Costume
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    • v.59 no.5
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    • pp.167-179
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    • 2009
  • The purposes of this study were to explore the influence on fashion brand image and brand loyalty according to fit of the fashion brand with cultural art field, motivation in culture marketing of the apparel company, and involvement of the consumers in art activities. The subjects ware 274 male and female in 20s and 30s living in Seoul and Gyeonggi area. The study was obtained through the use of an experimental design which was $2{\times}[2{\times}2]$ mixed factorial design. The summary main results were as follows. First, as far as the effect of the three variables on the social contribution image of the fashion brand, the results of the 3-way interaction are positive. Second, as far as the effect of the three variables on the product image of the fashion brand, the data suggests that only the main-effect of motivation in culture marketing of the apparel company is meaningfully positive. Third, as far as the effect of the three variables on fashion brand loyalty, both fit of the fashion brand with cultural art field and involvement of the consumers in art activities variables show positive results.

In situ analysis of capturing dynamics of magnetic nanoparticles in a microfluidic system

  • Munir, Ahsan;Zhu, Zanzan;Wang, Jianlong;Zhou, H. Susan
    • Smart Structures and Systems
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    • v.12 no.1
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    • pp.1-22
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    • 2013
  • Magnetic nanoparticle based bioseparation in microfluidics is a multiphysics phenomenon that involves interplay of various parameters. The ability to understand the dynamics of these parameters is a prerequisite for designing and developing more efficient magnetic cell/bio-particle separation systems. Therefore, in this work proof-of-concept experiments are combined with advanced numerical simulation to design and optimize the capturing process of magnetic nanoparticles responsible for efficient microfluidic bioseparation. A low cost generic microfluidic platform was developed using a novel micromolding method that can be done without a clean room techniques and at much lower cost and time. Parametric analysis using both experiments and theoretical predictions were performed. It was found that flow rate and magnetic field strength greatly influence the transport of magnetic nanoparticles in the microchannel and control the capturing efficiency. The results from mathematical model agree very well with experiments. The model further demonstrated that a 12% increase in capturing efficiency can be achieved by introducing of iron-grooved bar in the microfluidic setup that resulted in increase in magnetic field gradient. The numerical simulations were helpful in testing and optimizing key design parameters. Overall, this work demonstrated that a simple low cost experimental proof-of-concept setup can be synchronized with advanced numerical simulation not only to enhance the functional performance of magneto-fluidic capturing systems but also to efficiently design and develop microfluidic bioseparation systems for biomedical applications.

A Study on Progressive Die Design by the using of Finite Element Method (유한요소법을 이용한 프로그레시브 금형 설계에 관한 연구)

  • Park, Chul-Woo;Kim, Young-Min;Kim, Chul;Kim, Young-Ho;Choi, Jae-Chan
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.1012-1016
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    • 2002
  • This paper describes a research work of developing computer-aided design of a product with bending and piercing for progressive working. An approach to the system for progressive working is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in Auto-LISP on the Auto-CAD with a personal computer and is composed of four main modules, which are input and shape treatment, flat pattern layout, strip layout, and die layout modules. The system is designed by considering several factors, such as bending sequences by fuzzy set theory, complexities of blank geometry, punch profiles, and the availability of a press equipment. Strip layout drawing generated in the strip layout module is presented in 3-D graphic forms, including bending sequences and piercing processes with punch profiles divided into for external area. The die layout module carries out die design for each process obtained from the results of the strip layout. Results obtained using the modules enable the manufacturer for progressive working of electric products to be more efficient in this field.

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A Study on the Development of a Computer Aided Conceptual Die Dosing System for Fine Blanking (파인블랭킹 금형의 개념설계 자동화에 관한 연구)

  • Kwak T. S.;Choi C. H.;Seo M. G.;Bae W. B.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.05a
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    • pp.71-76
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    • 2001
  • This paper describes a research work of developing system for conceptual die design system for Fine blanking. The method of approaching to the system is based on the knowledge-based rules. Knowledge for the system is formulated from experimental results and the empirical knowledge of field experts. This system has been written in VisualLISP on the AutoCAD using a personal computer and in Microsoft Visual Basic ver.6.0. Transference of data is accomplished by DXF (Drawing Exchange Format) method. This system consists of six modules, which are cognition of a drawing, cognition of shear length, calculation of shear force, materials properties database, determination of degree of difficulty of the product, determination of approximate life of punch and die modules. Results carried out in each module will provide efficiency to the designer and the manufacturer of die for Fine blanking. But the main focus of this system is the design of die for Fine blanking in the level of general concept. In order to use powerful tool in this field, developed system will be studied continuously.

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