• Title/Summary/Keyword: Lee Joon Gu

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Performance Test of Noise Reducers Installed on Noise Barrier (방음벽 상단의 소음감소기 성능 시험)

  • Kang, Dae-Joon;Lee, Jae-Won;Gu, Jin-Hoi
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.388-391
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    • 2006
  • The use of noise barrier is being increased to reduce the environmental noise in these days. Also, many noise reducers installed at the top of noise barrier are developed for improving the performance of noise reduction. So we evaluate the performance of the noise reducers and compare the results. Results of the field tests show that the insertion loss due to the noise reducers is up to 10.6 dB.

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The Derivation of Estimation Function of Long-age Strength Concrete with Ternary Blended Cement (삼성분계 혼합형 시멘트의 장기재령강도 추정 함수 유도)

  • Lee, Joon-Gu;Park, Kwang-Su;Kim, Meyong-Won;Kim, Kwan-Ho;Kang, Suk-Hwa
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.236-239
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    • 2004
  • The ternary blended cement(TBC) which the ability of resistance for seawater, the effect of decreation of hydration heat of concrete and long-age strength are known to be superior to other types was used to derive the estimation function of 91-age strength, 28-age strength with 28-age strength, 7-age strength respectively by analyzing the characteristics of statistics of compressive strength. The sample specimens was made after testing the variations of slump, air-contents during 30 minutes for consideration of transportation period. The functions might be expected to be useful for construction smoothness and reasonable quality control of concrete with TBC.

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The Study on the design of durability of Concrete in Agricultural Hydraulic Structures (농업용 수리구조물의 내구성 설계방안 연구)

  • Park Kwang Su;Kim Meyong Won;Kim Kwan Ho;Lee Joon Gu
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.830-833
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    • 2004
  • Hydraulic structures have been constructed with low cost concrete so as to increase the investment efficiency. But, it has caused to produce structures having excess internal voids inside concrete. As the construction of agricultural irrigation and drainage project is concentrated on off-farming season and scattered in wider area, variation of quality of structures is big and it caused increase of internal voids. Due to that reason, hazardous substance is passing rather freely through the voids causing occur of crack and accordingly life time of structures is getting shortened. It is necessary to make a thesis of design criteria for design strength to increase life time, range of variation of quality, strength of ready-mixed concrete proper to design strength, and water-cement ratio and air content.

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Analysis of Major Factors and Guideline for Road Traffic Noise Prediction (도로교통소음의 주요 예측인자 분석 및 예측지침)

  • Kang, Dae-Joon;Lee, Jae-Won;Gu, Jin-Hoi
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.6
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    • pp.515-520
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    • 2010
  • The noise map has been applied to predicting the effect of noise and establishing the noise abatement measure for several years overseas. However the introduction of the noise map in Korea is at the initial stage. Thus, we surveyed the several prediction models for road traffic noise used in EU, and the method of applying the noise map in noise impact assessment. In order to improve the noise impact assessment we have to apply the noise map, and propose the guideline of predicting the road traffic noise. We intend to obtain coherency and accuracy of prediction results. As a result of this study, we know that the prediction guideline is an essential prerequisite in order to predict the unified and accurate road traffic noise.

Characteristics of vehicle mufflers and improvement measures of vehicle exhaust noise (자동차 소음기 특성 및 배기소음 개선 방안)

  • Lee, Jae-Won;Kang, Dae-Joon;Gu, J.H.;Park, H.K.;Kim, T.S.;Kweon, H.J.;Kim, J.C.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.05a
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    • pp.897-900
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    • 2007
  • Vehicles are exhausting various environmental pollutions such as exhaust gas, noise, and so on. This study investigates only noise problems by vehicles, especially the vehicle exhaust noise. It is known that the exhaust noise among those is over 20% of vehicle noise when the vehicle is suddenly accelerated or normally accelerated. In this study, we mainly investigate the exhaust noise of vehicle so that we intend to show the measures to decrease the illegal tuning mufflers and reduce the exhaust noise problems. In the conclusion, we suggest the new appropriate standard to control the tuning mufflers and reduce the exhaust noise induced by vehicles.

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Drone Infrared Thermography Method for Leakage Inspection of Reservoir Embankment (드론 열화상활용 저수지 제체 누수탐사)

  • Lee, Joon Gu;Ryu, Yong Chul;Kim, Young Hwa;Choi, Won;Kim, Han Joong
    • Journal of The Korean Society of Agricultural Engineers
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    • v.60 no.6
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    • pp.21-31
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    • 2018
  • The result of examination of diagnostic method, which is composed of a combination of a thermal camera and a drone that visually shows the temperature of the object by detecting the infrared rays, for detecting the leakage of earth dam was driven in this research. The drone infrared thermography method was suggested to precise safety diagnosis through direct comparing the two method results of electrical resistivity survey and thermal image survey. The important advantage of the thermal leakage detection method was the simplicity of the application, the quickness of the results, and the effectiveness of the work in combination with the existing diagnosis method.

A Study on Quality Characteristic of PC Concrete According to the Accelerated Curing Conditions (촉진양생조건에 따른 PC 콘크리트의 품질 특성에 관한 연구)

  • Kim, Kwan-Ho;Park, Kwang-Soo;Shin, Su-Gyun;Lee, Joon-Gu
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2001.10a
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    • pp.119-122
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    • 2001
  • Annual demand of a precast concrete bench flume used in the irrigation canal of arable land readjustment has continuously increased units recently. The average life time of the precast concrete bench flume was estimated $8{\sim}10$ years, which is too shorter than the life time of in-site placed concrete structures. In order to increase the compressive strength of the precast concrete bench flumes, the highest temperature of being lower than $95^{\circ}C$ was suggested in this study, Through analyzing the relation between the compressive strength and the amount of chloride penetration into concrete specimens, a new formula early estimating durability of the concrete structure was suggested.

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Assessment of Appropriate Period and Cost(P&C) of Repair and Improvement for Irrigational Structures (논문 - 수리시설물의 적정개보수 주기 및 비용 산정)

  • Lee, Joon-Gu;Kim, Myong-Won;Shin, Tae-Ho
    • KCID journal
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    • v.18 no.2
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    • pp.142-160
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    • 2011
  • This study was performed to apply the preventive management technique that is known for more economic and preventive for disaster than corrective technique to Repair & Improvement(R&I) Project policy of irrigational facilities. The appropriate periods of R&I Project had been driven to 40yrs, 24yrs, 27yrs, and 29yrs for reservoir, Pumping and drainage pumping station, Diversion weir and Irrigation & drainage canal respectively. The cost of R&I Project for 10 years had been estimated as 616.9 billion won per year including the 85 billion won for the project of 'Disaster prevention and Function continuity'. After the period of 'Improvement all at once', about 30yrs, 421.8 billion won was requested for 'Function continuity'.

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Preliminary Studies on the Measurement of the Free Thyroxine in the Serum by the Radioimmunoassay (방사면역측정법(放射免疫測定法)에 의한 혈중(血中) 유리(遊離) Thyroxine 농도측정(濃度測定)에 대(對)한 기초적(基礎的) 검토(檢討))

  • Lee, Joon-Il
    • Journal of radiological science and technology
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    • v.10 no.1
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    • pp.85-90
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    • 1987
  • Preliminary studies on the measurement of the free thyroxine in the serum with Amerlex $FT_{4}$ RIA kit were investigated using a tracer as $^{125}I-T_{4}$ derivative which is not almostly bound to thyroxine binding globulin, etc. The results are followed: 1. Linearity was tested on standards at various concentrations, and reproducibility and accuracy was excellent. 2. The antibody specificity is also excellent, and standard calibration curve of total $T_{4}$ was similar that of adding the TBG inhibitor. 3. Each value of $T_{4}$ in serum (the normal group, the hypothyroidism patients the pregnant women and the TBG dificiency patients) was not significant. As mentioned above, this method is more simple and rapid, compared to the other method.

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The quality condition of concrete in the hydraulic structures and a plan improving Quality (콘크리트 수리구조물의 품질상태와 개선방향)

  • Park, Kwang-Su;Shin, Su-Kyun;Kim, Kwan-Ho;Lee, Joon-Gu;Kim, Meyong-Won;Jang, Dan-Gum
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2003.10a
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    • pp.407-410
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    • 2003
  • The actual quality of the concrete in the structure for Irrigation may differ from that represented by the cylinders because the age, consolidation, or curing of the in-place material may not be well represented by the standard test specimens. The objective of this paper is to offer a base data of specification is the best fit the ready-mixed concrete strength to the specified, and to address this deficiency, so that the strength information of the concrete in the structure for Irrigation can be rationally accounted for in the assessment of the quality condition of this. The strength of concrete in the hydraulic structures is checked using strength of core obtained from that, and 28-day-old cylinder strength is analyzed using cylinder data of the ready-mixed concrete.

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