• Title/Summary/Keyword: Bi-directional test

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Financial Development and Output Growth: A Panel Study for Asian Countries

  • Jun, Sangjoon
    • East Asian Economic Review
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    • v.16 no.1
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    • pp.97-115
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    • 2012
  • This paper investigates the relationship between financial markets and output growth for a panel of 27 Asian countries over 1960-2009. It utilizes the recently-developed panel cointegration techniques to test and estimate the long-run equilibrium relationship between real GDP and financial development proxies. Real GDP and financial development variables are found to have unit roots and to be cointegrated, based on various panel unit root tests and panel cointegration tests. We find that there is a statistically significant positive bi-directional cointegrating relationship between financial development and output growth by three distinct methods of panel cointegration estimation. Empirical findings suggest that financial market development promotes output growth and in turn output growth stimulates further financial development.

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D-UPFC Application as the Series Power Device in the Massive Roof-top PVs and Domestic Loads

  • Lee, Kyungsoo
    • Current Photovoltaic Research
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    • v.4 no.4
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    • pp.131-139
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    • 2016
  • This paper shows the series power device in the massive roof-top PVs and domestic loads. D-UPFC as the series power device controls the distribution voltage during voltage rise (or fall) condition. D-UPFC consists of the bi-directional ac-ac converter and the transformer. In order to verify the D-UPFC voltage control, the distribution model is used in the case study. D-UPFC enables the voltage control in the distribution voltage range. Dynamic voltage control from voltage rise and voltage fall conditions is performed. Scaled-down experimental test of the D-UPFC is verified the voltage control and it is well performed without high voltage spikes in the inductive load.

Dynamic Characteristic of A Bi-dirctional Damper Using A Tuned Mass Damper and A Tuned Liquid Column Damper (TMD와 TLCD를 이용한 2방향 감쇠기의 동적특성)

  • Lee, Sung-Kyung;Min, Kyung-Won;Park, Eun-Churn
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.6
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    • pp.589-596
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    • 2008
  • This study introduces the design of a bi-directional damper using a tuned mass damper(TMD) and a tuned liquid column damper(TLCD) and presents experimental verifications to confirm its control performance. The damper used in this study behaves as a TMD in a specific translational direction and acts as a TLCD in the other orthogonal direction. First, shaking table test is performed to investigate the coupled effect of control forces produced by TMD and TLCD. Then, the parameters that affect to dynamic characteristics of the proposed damper are quantitatively evaluated based on the experimental results. Testing results shows that the damper used in this study produces control forces coupled by TLCD and TMD, as it is excited by waves with an incident angle. Also, it is observed that the damper can be used to reduce bi-directional responses of building structures.

Analysis of a Bi-directional Load Test Result on tong PHC Piles in Consideration of Residual Load (잔류하중을 고려한 장대 PHC 말뚝의 양방향 재하시험 결과해석)

  • Kim, Sung-Ryul;Chung, Sung-Gyo;Lee, Bong-Yeol
    • Journal of the Korean Geotechnical Society
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    • v.24 no.6
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    • pp.85-93
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    • 2008
  • For long piles driven in deep clay deposits, it is difficult to estimate the ultimate bearing capacity due to large resistance induced by long embedded depth, and also the load transfer curve due to large residual load induced by negative skin friction, even with the performance of pile load tests. In this research, a hi-directional load test on a PHC pile driven in deep soft deposit was performed in order to evaluate the tip and shaft resistances separately, which are feasible to estimate the ultimate bearing capacity of the pile. Residual load of the pile was determined by continuous monitoring of pile strains after the pile installation. The true resistance and true load-movement curve of the pile were properly estimated by taking account of the residual load. A model far behavior of the shaft resistance vs. movement was also proposed, which includes the effects of residual load based on the experiment. Consequently, it was proved that the residual load should be taken into consideration for correctly analyzing load test results of piles in deep clay deposits.

Electromagnetic Immunity Test Environments of Advanced Vehicles with Communication Systems (첨단자동차의 전자파 내성 실험 환경에 관한 연구: 외부통신 장치를 중심으로)

  • Woo, Hyungu
    • Journal of Auto-vehicle Safety Association
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    • v.14 no.1
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    • pp.14-19
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    • 2022
  • Recently, automobile industries have developed ADAS, smart cars, connected cars, automated driving systems, which communicate with outsides of a vehicle not only in uni-directional way but also in bi-directional way. It is necessary to examine the electromagnetic immunity of vehicles equipped with those communication systems. The electromagnetic immunity tests are carried out in an electromagnetic semi anechoic chamber, which is cut off from the outside electromagnetically. In this study, additional test environments were designed and tested and as a result they are shown to be effective to create test environments in an experimental chamber for electromagnetic immunity tests of vehicles equipped with communication systems.

A Case Study on Application of Bi-directional Pile Load Test for verifing the Bearing Capacity of a Large-diameter Drilled Shaft Pile (자갈층에 근입된 대구경 현장타설말뚝의 지지능력 확인을 위한 양방향 재하시험 적용사례)

  • Lee, Min-Hee;Jung, Sung-Min;Kim, Sang-Il;Choi, Yong-Kyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.506-513
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    • 2006
  • In this study, multi-level hi-direction pile load tests for drilled shaft pile socketed into the gravel were performed. The lower and upper hi-direction load test assemblies were located on tip of pile and 15m above the tip of pile. Based on the results of pile load test, it was analyzed bearing capacity of gravel, skin firction of upper soils and skin friction of lower soils. It was confirmed that drilled shaft socketed into the gravel had enough bearing capacity.

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Development of 500kW Tidal Current Energy Converter and Uldolmok Field Test (500kW 조류력 발전장치 개발 및 울돌목 실증시험)

  • Sim, Wooseung;Choe, Ickhung;Lee, Kyuchan;Kim, Haiwook;Bae, Jonggug;Min, Kehsik
    • 한국신재생에너지학회:학술대회논문집
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    • 2011.11a
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    • pp.159.2-159.2
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    • 2011
  • Hyundai Heavy Industries has developed a tidal current energy converter utilizing the accumulated technology as the world largest constructor for ship and offshore structures. The model has two sets of turbines in both ends in order to utilize the bi-directional current flows in flood and ebb tide. The torque produced by turbine in tidal current is directly delivered to generator along the horizontal axis, in which the turbine, gear, generator, gear and turbine are connected successively. The manufactured model for field test has the turbine diameter of 5 meters to produce the maximum power of 500kW at maximum current speed of 5m/s. The technical verification of tidal power converter was performed by means of small scale model test in towing tank as well as field test at the Strait of Uldolmok located in Jindo of Jeollanamdo province. Field test was performed by mounting the tidal current converter on the SEP(Self Elevating Platform) which could lower the 4 vertical legs on the seabed and could elevate platform over the water surface using the hydraulic power for itself. The field test performed for a month shows that power output is similar or larger compared with the expected one in design stage. This paper presents the development of tidal current energy converter and real sea field test by Hyundai Heavy Industries. This project has finished successfully and provided the technical advance toward commercial services for tidal current power generation in the south-west region in Korea.

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A Numerical Study on the Estimation Method of the Results of Static Pile Load Test Using the Results of Bi-directional Pile Load Test of Barrette Piles (바렛말뚝의 양방향재하시험을 이용한 정적압축재하시험 결과 추정방법에 관한 수치해석적 연구)

  • Hong, Young-Suk;Yoo, Jae-Won;Kang, Sang-Kyun;Choi, Moon-Bong;Lee, Kyung-Im
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.1
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    • pp.39-53
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    • 2019
  • Bi-directional pile load test (briefly called 'BDH PLT') cannot be performed at loading levels where ultimate bearing capacity could be assessed in field, it is not possible to precisely determine both ultimate load and yield load and under loading. Since the load is transmitted separately to the skin and the end unlike the static pile load test (briefly called 'SPLT') and the direction of loading on the skin is opposite, such methods could have a result different from actual movements of shafts. In this study, three-dimensional finite element method (briefly called '3D FEM') analysis was conducted from results of the BDH PLT, made with barret piles, which were large-diameter cast-in-place concrete piles, and the calculated design constants were applied to the 3D FEM analysis of the SPLT to interpret them numerically and then, actual behaviors of cast-in-place concrete piles were estimated. First, using the results of the BDH PLT with cast-in-place concrete piles, behaviors of the piles made by loading upwards and downwards were analyzed to calculate load-displacement. Second, the design constants, calculated by the 3D FEM analysis and the back analysis, were applied on the 3D FEM analysis for the SPLT, and from these results, behaviors of the SPLT through the BDH PLT was analyzed. Last, the results of the 3D FEM analysis of the SPLT through the BDH PLT was expressed in relationships as {A ratio of bearing capacity of the SPLT and of the BDH PLT (y)} ~ {A ratio of reference displacement and pile circumference (x)}, and they were all classified by reference displacement at 10.0 mm, 15.0 mm, and 25.4 mm.

Model Test of O-Cell Pile Load Test with Variable End Plate (가변선단재하판을 이용한 양방향말뚝재하시험의 모형실험)

  • Joo, Yong-Sun;Kim, Nak-Kyung;Kim, Sung-Kyu;Kim, Ung-Jin;Park, Jong-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.476-481
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    • 2009
  • Bi-directional load test is one of O-cell tests. The O-cell test is a system which may be used for performing static load tests on cast in situ reinforced concrete bored piles. The technique was devised and developed by Osterberg of Northwestern University(USA) and has been in use around the world. The principle of the method is that an O-cell is installed in a cast in situ bored pile base. Once the pile concrete reaches its design strength the cell is connected to an hydraulic pump and pressured. Pressurization causes the cell to expand, developing an upward force on the section of pile above the cell loads, pile movements and strains within the pile then enable the capacity of the pile and its load settlement curves to be ascertained. The O-cell pile load test with variable end plate is operated on second steps - the first step is to confirming end bearing capacity with variable end plate and the second step is similar to the conventional O-cell test. In the study, To calculate ultimate capacity of bi-directional load test using model with the pile with variable end plate O-cell.

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The Study on the Bi-directional Ejection Air Curtain System for Blocking Smoke Diffusion in case of Tunnel Fire (터널 화재시 연기확산 차단을 위한 양방향 토출 에어커튼 시스템에 대한 연구)

  • Yang, Sang-Ho;Choi, Young-Seok;Kim, Jung-Yup;Kim, Nam-Goo;Kim, Kyung-Yup
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.5
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    • pp.43-53
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    • 2014
  • This paper presents a the study on air curtain system of top and bottom bi-directional jet air discharge for blocking the spread of smoke in case of tunnel fire. The five kinds different air curtains of A, B, C, D, and E of models for various performance tested after manufactured. A results of the various performance test obtained the best efficiency from E model air curtain. And optimize the injection angle of the air curtain nozzle through the three-dimensional computational fluid dynamics (CFD) analysis and analyzed the effects of external pressure of tunnel. and also single factor design have been applied. At present, our attention is focused on the velocity distribution(flow width and flow position) of 1.5m on the ground in tunnel. Also, analyzed the influence of draft in the tunnel. Detailed effects of discharge angle of air curtain and velocity at nozzle exit are discussed.