• Title/Summary/Keyword: Ground Improvement

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Refinement of Ground Truth Data for X-ray Coronary Artery Angiography (CAG) using Active Contour Model

  • Dongjin Han;Youngjoon Park
    • International journal of advanced smart convergence
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    • v.12 no.4
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    • pp.134-141
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    • 2023
  • We present a novel method aimed at refining ground truth data through regularization and modification, particularly applicable when working with the original ground truth set. Enhancing the performance of deep neural networks is achieved by applying regularization techniques to the existing ground truth data. In many machine learning tasks requiring pixel-level segmentation sets, accurately delineating objects is vital. However, it proves challenging for thin and elongated objects such as blood vessels in X-ray coronary angiography, often resulting in inconsistent generation of ground truth data. This method involves an analysis of the quality of training set pairs - comprising images and ground truth data - to automatically regulate and modify the boundaries of ground truth segmentation. Employing the active contour model and a recursive ground truth generation approach results in stable and precisely defined boundary contours. Following the regularization and adjustment of the ground truth set, there is a substantial improvement in the performance of deep neural networks.

A Study on the Improvement Effects of Soft Ground through In-Situ Construction of Quick Lime Pile (생석회파일 현장시험시공 통한 연약지반 개량효과에 관한 연구)

  • 천병식;고갑수;이용한
    • Proceedings of the Korean Geotechical Society Conference
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    • 2000.11a
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    • pp.41-48
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    • 2000
  • Most land development projects and large scale civil works require a great amount of sand. And sand is also the most favorable material for soft ground improvement. The demand for sand is soaring rapidly due to increased number of projects regardless of its limited supply. Therefore, it is not difficult to predict that sand may become depleted and no longer be available as ground improvement material in the near future. Against this backdrop, developing an inexpensive sand-substitution material with an efficient accessibility will be necessary and urgently called for. So quick lime could be recommended as the substitutional material for sand. Quick lime is now preferred by forward developed nations. If Korea is able to take advantage of its abundant supply, economical efficiency could be achieved through massive production as well as being able to take advantage of utilization of natural resources. In this respect the purpose of this paper was to estimate improvement effect of soft ground though in-situ construction of quick lime pile. In-situ construction was peformed in road construction site of soft clay and in this study quick lime from Dan-yang that was estimated prominently in aspect of engineering characteristics was used. Quick lime piles were installed by 1.5m, 2.0m, 3.0m spacing to confirm improvement effect according to spacing and installed piles are 0.4m in diameter, up to 5m in length and the density of quick piles installed is 1.4 t/㎥. Vibrating wire pore water pressure cell was installed to confirm consolidation characteristics in surrounding of quick lime piles and both laboratory test and field test were carried out to confirm strength increase. In conclusion, soft ground improvement by quick lime piles was confirmed.

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A Study on Soil Improvement Effects under Poor Ground Conditions (열악한 지반조건에서 고질공법의 지반보강효과 증대에 관한 연구)

  • 천병식;최기성
    • Geotechnical Engineering
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    • v.12 no.2
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    • pp.115-132
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    • 1996
  • Several soil improvement methods are applied to stabilize soft ground. But, their improvement effects are known to be reduced in view of strength and durability under poor conditions such as marine clay and the ground with the flow of groundwater. The soil improvement method is generally classified as mixing(high pressure) type and injection type, and in this study, for successflll'applications of gelling methods, first in case that mixing method with cement is applied to marine clay, the causes of strength inferiority of treated soil are analyzed, and the effectiveness of improvement is studied, second in case that injection method with water-glass chemical grouts is applied to the ground with the flow of groundwater, soil improvement effects and durability of grouted soil are studied.

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A Case Study on the Effect of Soil Improvement on Anchor Bond Zone (지반개량에 의한 Anchor 정착부 개선효과 사례연구)

  • Kim, Tae-Seob;Song, Sang-Ho;Cho, Kyu-Wan;Lee, Jae-Dong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.1008-1013
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    • 2006
  • Ground anchor method is widely used in the large scale deep excavation of urban area to support a retained wall. Excavation using the ground anchor as a supporting system near a building have many difficulties due to the limitation of construction space. This method can not be applied to the site with the insufficient space from the retained wall to the boundary line. In this case, soil improvement at the anchor bond zone can be used to secure the frictional resistance of ground anchor within the boundary. Through this method, the bond length of anchor can be shortened considerably. This paper deals with the case study on the ground excavation adjacent to a building. The object field is Yongsan Park Tower Construction Site. In this site, the enlarged anchor with soil improvement was applied to solve the problem due to the limitation of construction space. According to the results of field test and monitoring, the anchor with soil improvement is very effective to secure the frictional resistance at the anchor bond zone.

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Depositional Characteristics of Busan Clay, Effects of Artesian Pressure, and Experiences from Ground Improvement (부산 점토의 퇴적 특성, 피압의 영향 및 지반 개량에서 얻은 경험)

  • Kim, Sang-Kyu
    • Proceedings of the Korean Geotechical Society Conference
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    • 2007.09a
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    • pp.3-38
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    • 2007
  • The depositional characteristics of Busan clay are initially described in this paper. The deposits of the Nakdong River estuary are composed of some different layers, which have been affected by marine transgression and regression. The upper clay layer is thick and soft. The lower clay layer and some depth of the upper clay layer have been leached by artesian pressure existing in an aquifer below. The clay shows unique physical and engineering characteristics due to leaching. Several large-scale reclamation projects have been performed in this delta area. The preloading method using long vertical drains has been applied for soft ground improvement. Experiences obtained from ground improvement are mentioned in connection with the depositional characteristics of the clay layers.

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Power/Ground Plane Modeling and Experimental Characterization for EMI Improvement in TFT-LCD Driving Circuit (TFT-LCD 구동회로에서의 EMI 개선을 위한 Power/Ground Plane 모델링 및 실험적 검증)

  • Cho, Kang-Yeon;Nah, Wan-Soo;Lee, Hae-Hoon;Lee, Sung-Kyu
    • Proceedings of the KIEE Conference
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    • 2005.11a
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    • pp.44-47
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    • 2005
  • This paper presents the efficient plan for the EMI improvement from of TFT-LCD Module. It investigates the frequency characteristics of Power/Ground Plane of TFT-LCD drive circuit PCB concretely. After the frequency characteristics is reviewed, EMI improvement is tried to insert to RC termination between Power/Ground Plane and to shift resonance frequency. It is confirmed by a simulation result and RC Termination which is inserted the point where the resonance characteristics change is necessary. It applied in 19 "SXGA TFT-LCD drive circuits and the EMI improvement verification is described.

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The Improvement Effects of Soft Ground by Quick Lime Pile (생석회파일에 의한 연약지반개량효과)

  • 천병식;고갑수;장은석;임지섭;이용한
    • Proceedings of the KSR Conference
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    • 1999.05a
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    • pp.383-389
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    • 1999
  • This paper is a study on the improvement effects by quick lime pile through theoretical analysis and in-situ construction test. Effects of strength increase is studied to verify the improvement effects of soft ground arounding quick lime pile. First, engineering characteristics of quick lime and ground was studied, in the second place, laboratory test(consolidation test, triaxial compression test) and in-situ test(portable cone penetration test, vane test) were peformed for verification of strength increase of adjacent ground. Finally, the results of in-situ test were compared with those of theorecal study. From in-situ test results, strength at 28th curing days(6.11-6.55t/㎡) was twice as great as strength before improvement(3.06t/㎡) and was slightly greater than theoretical value(4.95t/㎡).

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The Effect of TAS Method by an Auxiliary Method to Tunnel (터널보조공법으로서 TAS공법의 적용효과)

  • 천병식;여유현;백정식;최춘식;윤계한;황송연
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.213-220
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    • 2002
  • Generally it is informed that urethane materials are superior to the others in physical characteristics, durability, ground improvement and the influence to environment . But, the existing urethane methods are too expensive to apply. So this study has analyzed the applicability of TAS method which has developed the existing urethane injection mechanism. From the results, Extending the max-infection distance over l0m from 6m which the existing methods could inject to, TAS method has proved to be economical. Also, the TAS method is obtained quickly to ground improvement effect in various tunnel constructions because rise-time was relatively shorter than that of cement-grouting. Therefore, it is expected that TAS method would be applied a lot for water proof and ground improvement etc. owing to its many advantages mentioned the above.

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The Study of Improvement Effect of Ground Settlements and Bearing Capacity by Stone Columns (스톤컬럼 공법의 지내력 증진 효과에 대한 연구)

  • Park, Sang-Kook;Lee, Song
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.4
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    • pp.123-132
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    • 2008
  • Aseries of in-situ tests and ground water level measurements with stone and slug materials had been conducted to find out effect of ground settlement reduction and bearing capacity improvement by the Stone Column method. As the result of the tests, it was proved that the Stone Column method is effective for reduction of ground settlement and improvement of bearing capacity. In addition the ground water level went down without overburden load. These results show that the Stone Column method is effective for an increase in density and resistance to liquefaction. The results of estimation of ground settlement and bearing capacity by general theoretical equation, it show that the Stone Column method increases bearing capacity by 2.7~5.7 times and decreases ground settlement by 2~3.5 times.

A Study on the Application of SCS for the Surface Stabilization of Ultra-soft Ground (초연약지반 표층처리를 위한 SCS의 적용성 조사 연구)

  • Chun, Byung-Sik;Yang, Hyung-Chil;Yoo, Young-Nam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.10a
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    • pp.425-428
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    • 2005
  • To resolve land demand by the development of various industries and the cityward tendency of population, the construction of ultra-soft ground that is unused in the past has been progressing with activity. The ultra-soft ground has very small shear strength and large deformation, so leads to many problems in ground improvement in construction. In order to dispose of these problems, it is necessary to develope the chemical materials that can be applied to the surface stabilization of ultra-soft ground. In this study, the new ground treatment that is using cement and SCS is compared, analyzed with existing ground treatment. In addition, through the laboratory tests that check the characteristic of congealment and strength, the application of SCS in field is affirmed.

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