• Title/Summary/Keyword: Bar development

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Development and Durability Characteristics of FRP Reinforcing Bar for Concrete Structures (콘크리트 보강용 FRP 리바의 개발 및 내구 특성)

  • Won, Jong-Pil;Park, Chan-Gi;Yoon, Jong-Han;Hwang, Kum-Sik;Cho, Yong-Jin
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.371-374
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    • 2003
  • The corrosion of steel reinforcing bar(re-bar) has been the major cause of the reinforced concrete deterioration. FRP(Fiber-reinforced polymer) reinforcing bar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. In this study, long-term durability performance of FRP re-bar were evaluated. The mechanical and durability properties of two type of CFRP- and GFRP re-bar were investigated; the FRP re-bars were subjected to alkaline solution, acid solution, salt solution and deionized water. The mechanical and durability properties were investigated by performing tensile and short beam tests. Experimental results confirmed the desirable resistance of FRP re-bar to aggressive chemical environment.

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The Research on Development and Performance of the Rotary bar Cutting tool (Rotary bar 절삭공구 개발 및 성능 평가에 대한 연구)

  • Seo, Jeong-Hwan;Yang, Hae-Jeong;Kim, Kwang
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.6
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    • pp.926-931
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    • 2012
  • Rotary bar was cutting tool being in use for deburring scale after welding metal and for eliminating sharp edges. It was necessary to develop exclusive 6-axis machine being possible to process machining continuously for making an cutting edge of rotary bar and to revise easily machining program. This study aimed at the structural analysis of strength according to the configuration of new made 6-axis machine and at the machining accuracy and durability of rotary bar. As a result of test, the runout of new rotary bar manufactured out of 6-axis machine was decreased from 0.385 mm to 0.027mm extensively than old one. And good cutting ability and durability was obtained equal quality compared with imported products.

Minimization Method of Reading Error in Postal 4 State Bar Code Reader (우편용 4 State 바코드시스템의 판독오차 최소화 방법)

  • 황재각;신미영;박문성
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.1027-1030
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    • 1999
  • Recently many efforts on the development of automatic processing system for delivery sequence sorting have been performed in ETRI, which requires the use of postal 4 state bar code system to encode delivery points. This paper addresses the issue on the reduction of reading error in postal 4 state raster beam based bar code reader by adjusting measured values of bar code width to its average value over each interval. The test results show that the above method reduces the average reading error rate approximately by 90-100%.

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Optimization of Bar-to-Bar Dissimilar Friction Welding of Hydraulic Valve Spool Steel and the Weld Strength Properties and Its AE Evaluation (유공압 밸브 스풀용 강재의 봉대봉 이종재 마찰 용접 최적화와 용접강도 특성 및 AE 평가)

  • 오세규;유인종;박형동;이연탁
    • Journal of Ocean Engineering and Technology
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    • v.10 no.3
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    • pp.24-33
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    • 1996
  • Up to now, most of studies on mechanical properties in friction welded components are about tensile and bending strength. However the fatigue studies on the friction-welded components subjected to repeated stress are not available. The purposes of this study are the development of fundamental design and the development of in-process real-time weld quality evaluation technique by acoustic emission for the bar-to-bar dissimilar friction welding of hydraulic valve spool steels.

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Development of glufosinate-tolerant GMO detection markers for food safety management (식품안전관리를 위한 제초제 glufosinate 특이적 GM 작물 검출마커 개발)

  • Song, Minji;Qin, Yang;Cho, Younsung;Park, TaeSung;Lim, Myung-Ho
    • Korean Journal of Food Science and Technology
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    • v.52 no.1
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    • pp.40-45
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    • 2020
  • Over 500 genetically modified organisms (GMOs) have been developed since 1996, of which nearly 44% have glufosinate herbicide-tolerant traits. Identification of specific markers that can be used to identify herbicide-tolerant traits is challenging as the DNA sequences of the gene(s) of a trait are highly variable depending on the origin of the gene(s), plant species, and developers. To develop specific PCR marker(s) for the detection of the glufosinate-tolerance trait, DNA sequences of several pat or bar genes were compared and a diverse combination of PCR primer sets were examined using certified reference materials or transgenic plants. Based on both the qualitative and quantitative PCR tests, a primer set specific for pat and non-specific for bar was developed. Additionally, a set of markers that can detect both pat and bar was developed, and the quantitative PCR data indicated that the primer pairs were sensitive enough to detect 0.1% of the mixed seed content rate.

A Study on the Relationship between Degree of Rust Condition and Bond Strength in Reinforced Concrete Members (철근의 부식정도와 부착강도에 대한 연구)

  • 유환구;이병덕;김국한;안태송
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.04b
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    • pp.621-626
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    • 1998
  • An experimental investigation on the reinforcing bar corrosion and relationshid of reinforcing bar and concrete bond strength has been conducted to establish the allowable limit of rust in the construction field. The reinforcing bars used in this study were rusted before embedding in concrete. The first component of this experiment is to make rust of reinforcing bar rust artificially based on Faraday's theory at certain rates such as 2, 4, 6, 8 and 10% of reinforcing bar weight. For estimation of the amount of rust by weight, Clarke's solution and Shot blasting were adopted and compared. Parameters include 240 and 450kg/㎠ of compressive strengths and diameter of reinforcing bar (16, 19 and 25mm) corresponding development length for pull-ort test. And, pull-out tests were carried. out according to KSF 2441 and ASTMC 234 to investigate the effect of the corrosion rate on reinforcing bar-concrete bond behavior. It is found from the test results that the test techniques for corrosion of bar used in this study is relatively effective and correct test method. Results shows that up to 2% of rust increases the bond strength regardless of concrete strength and diameter of reinforcing bar like the existing data. It might be because of the roughness from rust. As expected, the bond strength increases as compressive strength of concrete increases and the diameter of bar decreases.

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Economic Design of Variable Sample Size ${\bar{X}}$ Control Chart Using a Surrogate Variable (대용변수를 이용한 가변형 부분군 크기 ${\bar{X}}$ 관리도의 경제적 설계)

  • Lee, Tae Hoon;Lee, Min Koo;Kwon, Hyuck Moo;Hong, Sung Hoon;Lee, Jooho
    • Journal of Korean Society for Quality Management
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    • v.45 no.4
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    • pp.943-956
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    • 2017
  • Purpose: This paper proposes a VSS(Variable Sample Size) ${\bar{X}}$ control chart using surrogate variable and shows its effectiveness compared with FSS(Fixed Sample Size) ${\bar{X}}$ control chart using either performance variable or surrogate variable. Methods: The expected cost function of VSS ${\bar{X}}$ control chart is derived. The optimal designs are then found for numerical examples using a GA(genetic algorithm) and compared to those of the FSS ${\bar{X}}$ control charts. Results: Computational results show that VSS ${\bar{X}}$ control chart using surrogate variables is superior to FSS ${\bar{X}}$ control chart using either performance variable or surrogate variable from the economic view points. Conclusion: The proposed VSS ${\bar{X}}$ control chart will be useful in industry fields where a performance variable is not avaliable or too costly.

Development of the UPC-A Barcode Recognition Algorithm for Smartphone Applications (스마트 폰 어플리케이션 적용을 위한 UPC-A Bar code 인식 알고리즘 개발)

  • Lee, Sang-Joon;Lee, Sang-Yong;Lee, Young-Bum;Lee, Myoung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.1
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    • pp.174-183
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    • 2011
  • This paper is about a bar code decoding algorithm developed for smart phone applications. The algorithm consists of bar code data extraction procedure, bar code signal estimation procedure, and bar code decoding procedure. To detect the peak bar code module, a DSTW had been applied because of its outstanding performance in ECG peak detection. In order to minimize errors due to non-uniform light effect, the proposed algorithm was acted as a baseline wandering filter based on module peaks detection. The algorithm had been tested to evaluate the performance under the conditions of blurring, non-uniformed light and white noises. The algorithm had shown excellent performance in reconstruction of bar code decoding, compared to other conventional methods. In order to show the possibility of applying the algorithm to a smart phone, a real UPC-A type 150 bar code pictures obtained from a smart phone camera was applied to the algorithm, achieving the correct recognition rate of 97.33%.

Improved Power Output by a Piezoelectric Cantilever after Addition of a Cylindrical Bar (원통 봉을 적용한 압전 캔틸레버의 성능 향상)

  • Lee, Youngjin;Kim, Seiki;Kim, Young-Deuk
    • Journal of the Korean Ceramic Society
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    • v.51 no.5
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    • pp.516-521
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    • 2014
  • This paper describes the development of a new piezoelectric unimorph cantilever structure intended to improve electrical output power, compared to a conventional cantilever. The proposed structure employs a cylindrical bar attached to one side of a steel plate, which is a significant factor in forced vibration mode. The feasibility of the proposed methodology was assessed experimentally and theoretically. The influence of three different types of bar material (i.e., stainless steel, silicon rubber, and urethane), and bar position, on the output voltage were examined and compared with those without the bar. The optimal position and material for the bar were identified through experimental and theoretical analyses. It appears that the electrical output power of the proposed cantilever is about 40% higher than that of a conventional unimorph cantilever.

Structural Performance of Steel Pipe Splice for SD500 High-strength Reinforcing Bar under Cyclic Loading

  • Kim, Hyong-Kee
    • Architectural research
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    • v.10 no.1
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    • pp.13-23
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    • 2008
  • It is the purpose of this study to evaluate the structural performance of steel pipe splice for SD500 high-strength reinforcing bar, through a cyclic loading test. The experimental variables adopted in this study include the development length of rebar, the type of sleeve, and size of reinforcing bar, among others. The results of this study showed that the developed steel pipe splice system for SD500 high-strength reinforcing bar, retained the structural performance required in domestic, ACI and AIJ code. It is considered that the study result presented in this paper can be helpful in developing a reasonable design method for a steel pipe splice system for SD500 high-strength reinforcing bar.