• Title/Summary/Keyword: form-accuracy

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Flapwise and non-local bending vibration of the rotating beams

  • Mohammadnejad, Mehrdad;Saffari, Hamed
    • Structural Engineering and Mechanics
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    • v.72 no.2
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    • pp.229-244
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    • 2019
  • Weak form integral equations are developed to investigate the flapwise bending vibration of the rotating beams. Rayleigh and Eringen nonlocal elasticity theories are used to investigate the rotatory inertia and Size-dependency effects on the flapwise bending vibration of the rotating cantilever beams, respectively. Through repetitive integrations, the governing partial differential equations are converted into weak form integral equations. The novelty of the presented approach is the approximation of the mode shape function by a power series which converts the equations into solvable one. Substitution of the power series into weak form integral equations results in a system of linear algebraic equations. The natural frequencies are determined by calculation of the non-trivial solution for resulting system of equations. Accuracy of the proposed method is verified through several numerical examples, in which the influence of the geometry properties, rotatory inertia, rotational speed, taper ratio and size-dependency are investigated on the natural frequencies of the rotating beam. Application of the weak form integral equations has made the solution simpler and shorter in the mathematical process. Presented relations can be used to obtain a close-form solution for quick calculation of the first five natural frequencies of the beams with flapwise vibration and non-local effects. The analysis results are compared with those obtained from other available published references.

Understanding of 3D Human Body Motion based on Mono-Vision (단일 비전 기반 인체의 3차원 운동 해석)

  • Han, Young-Mo
    • The KIPS Transactions:PartB
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    • v.18B no.4
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    • pp.193-200
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    • 2011
  • This paper proposes a low-cost visual analyzer algorithm of human body motion for real-time applications such as human-computer interfacing, virtual reality applications in medicine and telemonitoring of patients. To reduce cost of its use, we design the algorithm to use a single camera. To make the proposed system to be used more conveniently, we avoid from using optical markers. To make the proposed algorithm be convenient for real-time applications, we design it to have a closed-form with high accuracy. To design a closed-form algorithm, we propose an idea that formulates motion of a human body joint as a 2D universal joint model instead of a common 3D spherical joint model, without any kins of approximation. To make the closed-form algorithm has high accuracy, we formulates the estimation process to be an optimization problem. Thus-desined algorithm is applied to each joint of the human body one after another. Through experiments we show that human body motion capturing can be performed in an efficient and robust manner by using our algorithm.

Recognition of Bill Form using Feature Pyramid Network (FPN(Feature Pyramid Network)을 이용한 고지서 양식 인식)

  • Kim, Dae-Jin;Hwang, Chi-Gon;Yoon, Chang-Pyo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.4
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    • pp.523-529
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    • 2021
  • In the era of the Fourth Industrial Revolution, technological changes are being applied in various fields. Automation digitization and data management are also in the field of bills. There are more than tens of thousands of forms of bills circulating in society and bill recognition is essential for automation, digitization and data management. Currently in order to manage various bills, OCR technology is used for character recognition. In this time, we can increase the accuracy, when firstly recognize the form of the bill and secondly recognize bills. In this paper, a logo that can be used as an index to classify the form of the bill was recognized as an object. At this time, since the size of the logo is smaller than that of the entire bill, FPN was used for Small Object Detection among deep learning technologies. As a result, it was possible to reduce resource waste and increase the accuracy of OCR recognition through the proposed algorithm.

Domain Question Answering System (도메인 질의응답 시스템)

  • Yoon, Seunghyun;Rhim, Eunhee;Kim, Deokho
    • KIISE Transactions on Computing Practices
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    • v.21 no.2
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    • pp.144-147
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    • 2015
  • Question Answering (QA) services can provide exact answers to user questions written in natural language form. This research focuses on how to build a QA system for a specific domain area. Online and offline QA system architecture of targeted domain such as domain detection, question analysis, reasoning, information retrieval, filtering, answer extraction, re-ranking, and answer generation, as well as data preparation are presented herein. Test results with an official Frequently Asked Question (FAQ) set showed 68% accuracy of the top 1 and 77% accuracy of the top 5. The contribution of each part such as question analysis system, document search engine, knowledge graph engine and re-ranking module for achieving the final answer are also presented.

Research on Standardization of Sasang Typology Formulae English Translation (사상(四象) 방제명(方劑名)의 영역(英譯) 표준화(標準化)에 대한 연구(硏究))

  • Kim, Hyun-Koo;Ahn, Sang-Young;Kwon, Oh-Min;Ahn, Sang-Woo
    • The Journal of Korean Medicine
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    • v.34 no.1
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    • pp.103-115
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    • 2013
  • Objectives: This study proposes a new form of English translation in comparison with that shown in English books related to Sasang Constitutional medicine formulae which have been published up to now. Methods: This study formulated a new form of English translation guidelines by making a comparative analysis of the English translation cases listed in "Korean-English Dictionary of Oriental Medicine", "Longevity and Life Preservation in Eastern Medicine", and "Introduction to Sasang Constitutional Medicine". Results: This study as a common rules suggested that names of preparation form should be placed at the very end of the formula name and the first letters of the major words of the formula name should be capitalized. In addition, for the sake of accuracy in English translation of the formula name, this study divided the formula names into 8 types. The 8 sorts of types include: (a) Materia Medica + Preparation Form, (b) Materia Medica + Indication + Preparation Form, (c) Materia Medica Numbers + Preparation Form, (d) Indication + Preparation Form, (e) Concept + Preparation Form, (f) Concept + Materia Medica + Preparation Form, (g) Concept + Indication + Preparation Form, (h) Etcetera. In these types, medicinal herbs should be written in scientific name, and translation of indication can follow Noun+~ing participle form. In case of the terms having a Korean-medicine-based meaning, this study aimed for source-oriented translation. Conclusions: This study provides a general English translation method and examples of the formula names for Sasang constitutional medicine.

A Study on the Effected Factor for Vibration Criteria of Sensitive Equipment (정밀장비의 진동허용규제치에 미치는 인자에 관한 연구)

  • 이홍기;장강석;김두훈;김사수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.302-307
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    • 1998
  • In the production of semiconductor wafer, optical and electron microscopes, ion-beam, laser device must maintain their alignments within a sub-micrometer. This equipment requires a vibration free environment to provide its proper function. Especially, lithography and inspection devices, which have sub-nanometer class high accuracy and resolution, have come to necessity for producing more improved giga and tera class semiconductor wafers. This high technology equipments require very strict environmental vibration standard, vibration criteria, in proportion to the accuracy of the manufacturing, inspecting devices. The vibration criteria of high sensitive equipment should be represented in the form of exactness and accuracy, because this is used as basic data for the design of building structure and structural dynamics of equipment. The study on the evaluation of the factors affecting the permissible vibration criteria is required to design the efficient isolation system of the semiconductor manufacturing of equipment. This paper deals with the properties of the effected factor for vibration criteria of high sensitive equipment.

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Optimization of the FDM Parameters Using the Taguchi Method (다구찌방법을 이용한 FDM 파라미터의 최적화)

  • 엄태승;최우천;홍대희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.483-486
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    • 2001
  • Rapid Prototyping(RP) has been widely applied in designing and developing processes a new product. The functional requirements of a rapid prototyping system are high speed and high accuracy, and they depend on the operating parameters, some of which can be set by users. The accuracy is evaluated by dimensional errors and form errors of manufactured pars. A specially designed specimen with various features has been used for the accuracy evaluation. According to the Taguchi experimental design techniques, and orthogonal array of experiments has been set which has the least number of experimental runs to find the parametric effects. A laser scanner is used to obtain the point data of the parts and Surfacer is used to determine the lengths and angles. The conditions for the FDM manufacturing parametrs have been found.

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A study of an OMM system for machined spherical form measurement using the volumetric error compensation of Machining Center (머시닝센터의 오차보상을 통한 구면 가공형상 측정 OMM 시스템 연구)

  • 이찬호;오창진;이응석;김성청
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.838-841
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    • 2000
  • To improve the accuracy of products and improve the product quality, we need to enhance the machining accuracy of the machine tools. To this point of view, measurement and inspection of finished part as well as error analysis of machine tools has been studied for last several decades. OMM(On the Machine Measurement) has been issued to alternate with CMM, pointing out disadvantages of high expenses and lots of setting time in CMM. In this paper, we study 1) the spherical surface manufacturing by volumetric error compensation of machine tool, 2) the system development of OMM without detaching work piece from a bed of machine tool after working. 3) the generation of the finished part profile by On the machine measurement. Furthermore, the output of OMM is compared with that of CMM, and verified the feasibility of the measurement system.

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Application to Real Time Repetitive Control in Belt Drive Systems (벨트 구동 시스템에서의 실시간 반복제어 응용)

  • 유영순
    • Journal of Institute of Control, Robotics and Systems
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    • v.4 no.4
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    • pp.420-426
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    • 1998
  • It is the purpose of this paper to make a preliminary study on the use of repetitive control to improve velocity accuracy by eliminating repetitive disturbances caused by machining inaccuracies of the axis of rotation location. If the control system can be intelligent enough to compensate for such machining errors, then one may be able to improve the accuracy of the velocity control, or alternatively, one may maintain the same accuracy and relax the machining tolerances required. This could decrease cost significantly. Experiments are performed testing repetitive control methods on a constant speed rolling operation testbed. The experimental results show very substantial decreases in the tracking error of the system. Spectral data of the output motion are given to demonstrate the attenuation of the disturbance frequencies and harmonics, related to the bandwidth being used. It is seen that the simplest form of repetitive control which is very easily implemented, can produce striking improvement in control system performance in such belt drive rolling operations, and the learning can be accomplished in a short time.

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Mismatching Refinement with Domain Decomposition and Its Application to the Finite Element Analysis of the Extrusion Process (영역분할에 의한 격자세분화 기법 및 압출공정의 유한요소해석에의 적용)

  • Park, Keun;Yang, Dong-Yol
    • Transactions of Materials Processing
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    • v.8 no.3
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    • pp.284-293
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    • 1999
  • The rigid-plastic finite element analysis requires a large amount of computation time due to its non-linearity. For economic computation, mismatching refinement, and efficient domain decomposition method with different mesh density for each sub domain, is developed. A modified velocity alternating scheme for the interface treatment is proposed in order to obtain good convergence and accuracy. As a numerical example, the axisymmetric extrusion process is analyzed. The results are discussed for the various velocity update schemes form the viewpoint of convergence and accuracy. The three-dimen-sional extrusion process with rectangular section is analyzed in order to verify the effectiveness of the proposed method. Comparing the results with those of the conventional method of full region analysis, the accuracy and the computational efficiency of the proposed method are then discussed.

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