• Title/Summary/Keyword: Bar development

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Development of measuring and calibrating technology for moving error and precision of chip mounter using Ball Bar (Ball Bar를 이용한 칩마운터의 운동 오차 정밀도 측정 및 평가 기술 개발)

  • 이창하;김정환;박희재
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.621-628
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    • 2000
  • A kinematic ball bar measuring system can analyze the various errors of a machine tool easil rapidly with only one measurement, But it cannot be used to measure the errors of the equipment the semiconductor manufacturing (e.g. chip mounter, PCB router etc.) not to use a cir interpolation. This paper presents the method to apply a kinematic ball bar measuring system tc machines which use merely a linear interpolation Also, the work of measuring and calibratir various errors of a chip mounter with a kinematic bal1 bar measurement system is accomplished

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Performance Evaluation of Welding Method for Modular of High-Strength Reinforcing Bars to the Nuclear Power Plant Structures (원전구조물 고강도철근 모듈화를 위한 용접방법 성능평가)

  • Lim, Sang-Joon;Lee, Han-Woo;Kim, Hyeong-Seob;Bang, Chang-Joon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.05a
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    • pp.278-280
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    • 2013
  • To minimize construction quantity of nuclear facility, it is required to reduce reinforcing bar amount and solve reinforcing bar concentration and for this, it is necessary to develop application design technology and modular of high strength reinforcing bar. Hence, KHNP reduces excessive reinforcing bar amount which can cause possibility of poor construction of concrete through design standard development and modular of nuclear facility structure using high strength reinforcing bar to raise economics and has its purpose to maintain high-level safety and durability as they are.

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Study of application method for the Rebar Modulation of High-Strength Reinforcing Bars to the Nuclear Power Plant Structures (원전구조물 고강도철근 모듈화를 위한 적용방법 연구)

  • Lim, Sang-Joon;Lee, Byung-Soo;Bang, Chang-Joon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2013.11a
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    • pp.17-18
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    • 2013
  • To minimize construction of nuclear facility, it is required to reduce reinforcing bar amount and solve reinforcing bar concentration and for this, it is necessary to develop appication design technology and modular of high strength reinforcing bar. Hence, KHNP reduces excessive reinforcing bar amount which can cause possibility of poor construction of concrete through design standard development and modular of nuclear facility structure using high strength reinforcing bar to raise economics and has its purpose to maintain high-level safety and durability as they are. This study is to introduce application method for the Rebar Modulation of High-Strength Reinforcing Bars to the Nuclear Power Plant Structures.

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The Emergence and Development of the Lamaist Gateway of $Lokap\bar{a}las$ during the $Jos\breve{o}n$ Dynasty - Some problems on the orientation of the Gateway of Lokapala and on the allocation of the Four Guardian Kings - (조선시대 라마계 천왕문의 수용 및 전개에 대하여 -천왕문의 배치와 사천왕 배열에 관한 문제-)

  • Yi, Dae-Am
    • Journal of architectural history
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    • v.16 no.6
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    • pp.47-66
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    • 2007
  • $Lokap{\bar{a}}las$ are understood as the deities of four directions in Buddhism: $Dhrtar{\bar{a}}stra$ in the East, $Vir{\bar{u}}dhaka$ in the South, $Vir{\bar{u}}p{\bar{a}}ksa$ in the West and $Vai{\acute{s}}ravana$ in the North respectively. Their common name is, therefore, called as the "Four Guardian Kings", whose function is to prevent demonic forces from entering into its sacred world. Although the position of $Lokap{\bar{a}}las$ is to the lowest level in the hierarchy of the minor deities in Buddhism, the cult of $Lokap{\bar{a}}las$ was widely spread and prominent in the countries of Northern Buddhism. It played a significant role in terms of the state-protecting Buddhism, on behalf of it's esoteric and magic power. More than 20 Gateways of the $Lokap{\bar{a}}las$ and $Lokap{\bar{a}}la$ statues were still well preserved in Korea, and they were believed to be constructed after the Japanese attack in 1592. After war, monks had concentrated on restoring ruined temples and building many new Gateways of the Four Guardian Kings over the Korean peninsular. Under such circumstances, even though the $Lokap{\bar{a}}las$ played a significant role as the subject of cult in Korean Buddhism. they might have a small chance to be taught traditional Lama iconography exactly. The purpose of this essay is to examine the relation of orientation of the Gate way of $Lokap{\bar{a}}las$ and allocation of each Kings inside the gate.

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Perilla transformation using selection markers containing antibiotics and basta (항생제와 제초제 이중 선발 마커를 이용한 들깨 형질전환)

  • Kim, Kyung-Hwan;Lee, Jung-Eun;Ha, Sun-Hwa;Hahn, Bum-Soo;Park, Jong-Sug;Lee, Myung-Hee;Jung, Chan-Sik;Kim, Yong-Hwan
    • Journal of Plant Biotechnology
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    • v.35 no.4
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    • pp.299-306
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    • 2008
  • A modified method of Agrobacterium-mediated perilla transformation was developed using two selection markers of an antibiotics (either hpt or nptll) and an herbicidal (bar) gene. Perilla hypocotyl explants were cocultured with Agrobacterium tumefaciens EHA 105 strain harboring plasmid vector (either pMOG6-Bar or pCK-Bar) for three days, respectively. Primary shoots were selected with antibiotics of hygromycin (15 mg/L) or kanamycin (125 mg/L) and regenerated shoots were further selected with herbicide phosphinothricin (ppt,1.2 mg/L) to obtain authentic transformants. Roots were induced for the regenerated shoots on the MS medium without hormone and 80 putative transgenic plants were obtained. Transgene integration into perilla genome was confirmed by Southern blot and their expression was analyzed by Northern blot. T1 perilla seeds drived from To plants were tested 0.3% basta spray for identification of stable gene delivery to next generation.

Development of Torsion Bar for Antiroll-Bar Assembly for Express Train (고속철도용 안티롤바 어셈블리의 토션바 개발)

  • Tominaga, Yasutoshi;Pyun, Young-Sik;Kim, Dong-Il;Choe, Do-Hyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.9
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    • pp.979-984
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    • 2012
  • An antiroll-bar assembly is a precision component that is designed to control the rolling of railway cars. It is important for ensuring a safe and comfortable ride. A torsion bar is the main part of the antiroll-bar assembly. Now, this part is classified as a consumable, and it is imported into Korea from France. Therefore, there is a strong need to domestically develop a torsion bar suitable for Korean conditions and to reduce cost and improve quality. In this study, an antiroll bar is developed, and it is analyzed and tested by using a road histogram measured on Korean railroads. This bar shows satisfactory results in a comparison with the imported bar. It has a novel design featuring a ring cover made of SUS steels to prevent the corrosion of the torsion bar. Its safety is examined through CAE analysis and wear tests. It is found that its design does not result in a significant difference in static and fatigue safety. Two different SUS steels were investigated in terms of their wear resistance, and the best one was adopted.

Development of a Numerical Model to Analyze the Formation and Development Process of River Mouth Bars (하구사주의 생성 및 발달을 해석하기 위한 수치모델의 개발)

  • Kim, Yeon-Joong;Woo, Joung-Woon;Yoon, Jong-Sung;Kim, Myoung-Kyu
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.6
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    • pp.308-320
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    • 2021
  • An integrated sediment management approach that includes the recovery of the amount of declined sediment supply is effective as a fundamental solution to coastal erosion. During planning, it is essential to analyze the transfer mechanism of the sediments generated from estuaries (the junction between a river and sea) to assess the amount and rate of sediment discharge (from the river to sea) supplied back to the coast. Although numerical models that interpret the tidal sand bar flushing process during flooding have been studied, thus far, there has been no study focusing on the formation and development processes of tidal sand bars. Therefore, this study aims to construct wave deformation, flow regime calculation, and topographic change analysis models to assess the amount of recovered sediment discharge and reproduce the tidal sand bar formation process through numerical analysis for integrated littoral drift management. The tidal sand bar formation process was simulated, and the wave energy and duration of action concepts were implemented to predict the long-term littoral movement. The river flux and wave conditions during winter when tidal sand bars dominantly develop were considered as the external force conditions required for calculation. The initial condition of the topographic data directly after the Maeupcheon tidal sand bar flushing during flooding was set as the initial topography. Consequently, the tidal sand bar formation and development due to nearshore currents dependent on the incident wave direction were reproduced. Approximately 66 h after the initial topography, a sand bar formation was observed at the Maengbang estuary.

Experimental Investigations on the Flexural Behavior of One-Way Concrete Slabs Reinforced with GFRP Re-Bar Bundle (유리섬유 보강 플래스틱 Re-Bar 다발로 보강된 1방향 콘크리트 슬래브의 휨거동에 관한 실험적 연구)

  • 윤순종;김병석;유성근;정재호;정상균
    • Composites Research
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    • v.16 no.3
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    • pp.32-40
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    • 2003
  • In recent years, the investigation on the development of fiber reinforced plastic(FRP) Re-Bar has been greatly increased due to the attractive physical and mechanical properties of FRP. The primary reason of such a tendency is in the fact that it does not ordinarily cause durability problems such as those associated with steel reinforcement corrosion. This study is an experimental investigation on the flexural behavior of one-way concrete slabs, which can be used to construct bridge deck, reinforced with GFRP Re-Bar bundle. The tensile tests of GFRP Re-Bar produced by domestic industry and third point bending tests of one-way slab specimens reinforced with GFRP Re-Bar bundle are peformed. For all slab specimens, load-deflection relations are predicted by using the ACI committee 440 and the results are compared with experimental ones. In order to establish the design criteria or guidelines of concrete flexural member reinforced with FRP Re-Bar, it is needed to evaluate the serviceability limit state as well as the strength limit state.

Evaluation of Structural Performance of RC Beam with Different Depths to Lap Splice Detail of SD700 Headed Bar (SD700 확대머리 철근의 겹침이음 상세를 적용한 단차가 있는 RC 보의 구조성능 평가)

  • Lee, Ji-Hyeong;Kim, Seung-Hun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.6
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    • pp.262-269
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    • 2021
  • This paper conducts an evaluation of the structural performance of the lap splice detail of SD700 headed bar experiment for developing an RC beam with different depths joint details. The experiment variable is lap splice length, yield strength, and end anchorage of main reinforcements. For all specimens, a headed bar was applied to the main reinforcement of the beam with low depth (B2), and the beam with high depth (B1) was applied to the main reinforcement with two splice methods: straight headed bar and 90° hooked-headed bar. The experimental results were that specimens of applying SD500 and SD600 had the results of flexural fracture at the lap splice location, which maximum load was similar. For specimens of appling SD500, the 90° hooked-headed bar of B1, suppressed horizontal cracks in the lap splice section compared to the straight headed bar. Specimens of applying an SD 700 headed bar had the results of brittle anchorage failure. In addition, maximum load was increased with the lap splice length increasing. For specimens of applying SD700 headed bar, test for test maximum load/theoretical load for test development length/design development length were estimated to be 1.30~1.48 for the ACI 318-19 equation, and 1.14~1.30 for the KDS-2021 equation. Thus, ACI 318-19 equation had conservatively greater safety factors as estimated development lengththened.

Experimental analysis of geomorphic changes in weir downstream by behavior of alternate bar upstream (보 상류 교호사주의 거동에 따른 하류 지형변화에 대한 실험적 분석)

  • Lee, KyungSu;Jang, Chang-Lae;Kim, GiJung
    • Journal of Korea Water Resources Association
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    • v.52 no.spc2
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    • pp.801-810
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    • 2019
  • This study analyzes the impact on geomorphic changes downstream due to alternate bars developed weir upstream through laboratory experiments. The disturbance, such as a spur in the side wall, of the flow at the inlet of the channel triggers the development of alternate bar upstream at the beginning of the experiment, and gradually moved downstream with keeping their shapes over time. The bed in the downstream of weir in the mid of channel scoured due to the scarcity of sediment inflow because weir upstream traps it. Moreover, bar migration speed decreases as the bars approaches to the weir with time. However, as time increases, the alternate bars upstream migrate over the weir, and sediment in the eroded bed of the weir downstream are deposited. The phase of the bar upstream changes oppositely after passing through the weir. The phase of the bar downstream changes rapidly as the shape of alternate bar is clear upstream, which is affected by the strong disturbance. The phase of bar changes, and the bar migration speed decreases gradually with time, and finally stopped due to forcing effects on the bar by the disturbance. The faster the reaction of alternate bar with a long spur, the larger the bar height formed downstream and the shorter the bar length. This means that the larger the forcing effect of bar, the more it affects the bar migration. In addition, although the size of the alternate bar increases over time, the bar doesn't migrate downstream and a forced bar is generated.