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Infill wall effects on the dynamic characteristics of RC frame systems via operational modal analysis

  • Komur, Mehmet A.;Kara, Mehmet E.;Deneme, Ibrahim O.
    • Structural Engineering and Mechanics
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    • v.74 no.1
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    • pp.121-128
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    • 2020
  • This paper presents an experimental study on the dynamic characteristics of infilled reinforced concrete (RC) frames. A 1/3-scaled, one-bay, three-storey RC frame was produced and tested by using operational modal analysis (OMA). The experiments were performed on five specimens: one reference frame with no infill walls and four frames with infill walls. The RC frame systems included infill walls made of hollow clay brick, which were constructed in four different patterns. The dynamic characteristics of the patterns, including the frequency, mode shapes and damping ratios in the in-plane direction, were obtained by 6 accelerometers. Twenty-minute records under ambient vibration were collected for each model, and the dynamic characteristics were determined using the ambient vibration testing and modal identification software (ARTeMIS). The experimental studies showed that the infill walls significantly affected the frequency value, rigidity and damping ratio of the RC frame system.

Development of Creep Deflection Analysis Method and Program for CANDU Pressure Tube (중수로 압력관의 크리프 처짐 해석 기법 및 프로그램 개발)

  • Shim, Do-Jun;Huh, Nam-Su;Park, Bo-Kyu;Chang, Yoon-Suk;Kim, Yun-Jae;Kim, Young-Jin;Jung, Hyun-Kyu
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.66-71
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    • 2004
  • Estimation of the CANDU pressure tube deflection is important since the deflection may cause significant structural failure due to hydrogen diffusion and blister. However, there is no appropriate engineering model to estimate it exactly. The purpose of this paper is to propose a new analysis method and program to resolve this issue. For development of proper analysis method, a series of finite element analyses has been carried under elastic-creep condition. In addition, for effective estimation of the creep deflection, an analysis program named PC-DAS was developed based on the proposed method. Comparison of simple case study results with corresponding reference ones showed good agreement. Therefore, the proposed method and program can be utilized as one of valuable toolkit for integrity assessment of CANDU pressure tube.

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Development of a Real-Time Steady State Detector of a Heat Pump System to Develop Fault Detection and Diagnosis System (열펌프의 고장진단시스템 구축을 위한 정상상태 진단기 개발)

  • Kim, Min-Sung;Yoon, Seok-Ho;Kim, Min-Soo
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2070-2075
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    • 2008
  • Identification of steady-state is the first step in developing a fault detection and diagnosis (FDD) system. In a complete FDD system, the steady-state detector will be included as a module in a self-learning algorithm which enables the working system's reference model to "tune" itself to its particular installation. In this study, a steady-state detector of a residential air conditioner based on moving windows was designed. Seven representing measurements were selected as key features for steady-state detection. The optimized moving window size and the feature thresholds was suggested through startup transient test and no-fault steady-state test. Performance of the steady-state detector was verified during indoor load change test. From the research, the general methodology to design a moving window steady-state detector was provided for vapor compression applications.

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Development of Evaluation Method and Experimental Verification of a 300kW Small Engine Cogeneration System (300kW급 소형 엔진 열병합발전시스템의 평가기술 개발 및 실증시험)

  • Choi, Jae-Joon;Park, Hwa-Choon
    • Proceedings of the SAREK Conference
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    • 2007.11a
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    • pp.453-458
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    • 2007
  • The importance of the evaluation and verification of small-size cogeneration system has been emphasized because there is no KS-code related to the small-size cogeneration system. The evaluation method of small-size engine cogeneration system was investigated by the reference of Japan evaluation code, JIS B-8122 and international standard organization, ISO-8528. Evaluation method was introduced such as start-test, rapid-load-up and rapid-load-down, etc. The evaluation method was applied to the 300kW small-size gas engine cogeneration system newly developed. The precise and strict evaluation and verification of the system will help the developing cogeneration system to optimum condition. It will also be a base document of KS-Code.

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Modern State of Models for Fundamental Adhesion - A Review Extended Abstract

  • Possart, Wulff
    • Journal of Adhesion and Interface
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    • v.3 no.1
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    • pp.43-51
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    • 2002
  • Advanced adhesive technologies and demanding applications of adhesive joints can no longer be developed successfully by the traditional "trial and error" approach. Appropriate technical solutions require reference to a reliable basis of well-established scientific knowledge about the elementary mechanisms of adhesion (i.e. the 'fundamental adhesion') as they are responsible for the capability of the compound w transmit mechanical force between the adhesive and the substrate surface (i.e. the 'practical adhesion'). Adhesion mechanisms also influence the formation of polymer structure in the adhesive and the resulting macromolecular dynamics in the interphase that is formed in the adhesive near to the substrate. These manifold molecular factors rule the macroscopic behaviour of an adhesive bond line in terms of mechanical and other physical properties as well as in terms of durability. This paper reviews the level of refinement that understanding of fundamental adhesion has achieved up to now.

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A study on Constitutional Characteristics of Taeyangin (태양인(太陽人) 체질특성에 관한 연구)

  • Kim, Dal-Rae
    • Journal of Sasang Constitutional Medicine
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    • v.17 no.1
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    • pp.56-66
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    • 2005
  • 1. Objectives I, the author, interviewed Taeyangin patients who were proved by clinical effect and also focused in bibliography to compare with Taeyangin patients case then I found out a several differences. 2. Methods I discoursed with comparing bibliography witch stated Taeyangin characteristics, such as ${\ulcorner}$Dongyi Suse Bowon${\lrcorner}$, ${\ulcorner}$Hwangje Nekyung${\lrcorner}$, ${\ulcorner}$Joongyi Chejilhak${\lrcorner}$, with interviewed 8 Taeyangin patients. 3. Results All of these 8 Taeyangin's men and women had very strong sharp-sighted. In characteristics and mental state, they usually were rather conservative than decisiveness, quick-tempered. In women case, they had average 1.78 children, no sterility, and didn't show a anger or sadness. The most of case ,showing a very sensitive reaction to food, were Nechoksojangbyung(內觸小腸病證). 4. Conclusions These results could be a important reference documents to classify Taeyangin in clinic.

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BGA Height Measurement Using Pattern Beam (패턴 빔을 이용한 BGA 단차 측정)

  • Shin, Sang-Hoon;Yu, Young-Hun
    • Korean Journal of Optics and Photonics
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    • v.20 no.6
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    • pp.361-365
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    • 2009
  • We describe a simple method to obtain an optical sectioning in a conventional wide-field microscope by projecting a single spatial frequency grid pattern onto the object. Using a patterned beam, we have measured the height of BGA with a rough surface that provide the coherence noise. The configuration of the height measurement system using pattern beam is simple. The image acquired by this system is not depend on the coherence noises. This system is also applicable to the sample reference plan that has no pattern on ground. The reappearance and accuracy are outstanding and applicable to many industrial optical metrology.

Image Fidelity Assessment Using the Edge Histogram Descriptor of MPEG-7

  • Won, Chee-Sun
    • ETRI Journal
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    • v.29 no.5
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    • pp.703-705
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    • 2007
  • An image fidelity assessment using the edge histogram descriptor (EHD) of MPEG-7 is presented. Neither additional data nor fragile watermarking is needed, and there is no need to access the original image as a reference. Only the EHDs of the original image and the received image are required. The peak signal-to-noise ratio (PSNR) obtained by comparing the EHD extracted from the received image and that of the original image is used to assess the noise level of the received image. Experimental results show that the PSNRs calculated from the conventional pixel-to-pixel gray level and from the proposed bin-to-bin EHD maintain a proportional relationship. This implies that the EHD can be used instead of image data for the image fidelity assessments.

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RADIOLOGIC STUDY ON THE POSTERIOR ASPECT OF THE MAXILLA FOLLOWING THE RADICAL OPERATION OF PARANASAL SINUSES. (상악동 근치수술후의 상악골 후연의 변화에 대한 방사선학적 연구)

  • Park No Won;You Dong Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.15 no.1
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    • pp.59-66
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    • 1985
  • The Purpose of this study is to detect morphological changes of the maxilla following the operation of paranasal sinuses in the orthopantomogram. 1) The measurement of the angle set up by two reference lines which represent posterior aspect of the maxilla and skull base was made. 2) The mean angle in the post-operative patients showed significantly smaller than that in the normal subjects. 3) The forms of posterior aspect of maxilla were classified into 5 types. (flat, convex, concave, uneven and obliterated.) 4) In contrast with the convex type in the majority of normal subjects, approximately half of the post-operative patients showed the concave type. 5) These results may suggest that the superior part of the posterior aspect of the maxilla tend to depress following the operation of these paranasal sinuses.

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Research on In-band Spurious Evasion Techniques of Hybrid Frequency Synthesizer

  • Kim, Seung-Woo;Yoo, Woo-Sung
    • Journal of IKEEE
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    • v.19 no.2
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    • pp.176-185
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    • 2015
  • The study aims to a design hybrid frequency synthesizer in spectrum analyzer and to propose new techniques designed for evasion of in-band spurious. The study focuses on calculating the exact location of multiple phase locked loop of hybrid frequency synthesizer and spurious of direct digital synthesizer to evade in-band spurious outside of frequency range that the user wants to see and thereby simulating technique to improve input related spurious of spectrum analyzer for algorithm. The proposed technique is designed to calculate spurious evasion algorithm in central processing system when in-band spurious arises, and to move output frequency of DDS(direct digital synthesizer) into the place where no in-band spurious exists thereby improving performance of frequency synthesizer. The study used simulation and result representation to prove the effectiveness of the proposed technique.