• Title/Summary/Keyword: Consolidation method

Search Result 691, Processing Time 0.025 seconds

A Study on the Automation Equipment Development of RC Technology(II) -Improvement of Position Controller- (RC 기술의 자동화 장치 개발에 관한 연구(II) -위치 제어기의 개선-)

  • Kim, Ki-Joon;Kim, Sang-Jin;Song, Ja-Youn
    • Proceedings of the KIEE Conference
    • /
    • 1994.11a
    • /
    • pp.314-316
    • /
    • 1994
  • The operation of RC(Rod Consolidation) technology carry out highly radiation environment. It requires remote operation and automation for efficient handling and for minimizing radiation exposure to the operator. So we investigated up and down position control of shock absorber device in RC system. To verify the research experimentally, a RC system was set up and PI control method was applied. Fuzzy control method was also tested to further improve control behavior.

  • PDF

Measurement Method of Residual Stresses in Thick Composite Cylinders (두꺼운 복합재 원통의 잔류응력 측정방법)

  • Kim, Jong-Woon;Park, Dong-Chang;Lee, Dai-Gil
    • Proceedings of the Korean Society For Composite Materials Conference
    • /
    • 2005.04a
    • /
    • pp.245-248
    • /
    • 2005
  • During manufacturing thick composite cylinders, large thermal residual stresses are developed and induce catastrophic interlaminar failures. Since the residual stresses are dependent on many process parameters, such as temperature distribution during cure, cure shrinkage, winding tension, and migration of fibers, calculation of the residual stresses is very difficult. Therefore a radial-cut method have been used to measure the residual stresses in the composite cylinders. But the conventional radial-cut method needs to know numerous material properties which are not only troublesome to obtain but also vary with change of fiber arrangement during consolidation. In this paper, a new radial-cut method with cut-cylinder-bending test was proposed and the measured residual stresses were compared with calculated thermal residual stresses. It was found that the new radial-cut method which does not need to know any of material properties gave better estimation of residual stresses regardless of radial variation of material properties. Additionally, interlaminar tensile strength could be obtained by the cut-cylinder-bending test.

  • PDF

A Study on the tension of Geogid on Pile-supported Construction Method (성토지지말뚝공법 중 섬유보강재의 인장력 검토에 관한 연구)

  • Moon, In-Ho;Park, Jong-Gwan;Lee, Il-Wha
    • Proceedings of the KSR Conference
    • /
    • 2008.11b
    • /
    • pp.905-917
    • /
    • 2008
  • Road or Railway construction over soft ground is needed to be considered on secondary consolidation which will be caused differential settlement, lack of transport serviceability, higher maintenance cost. Especially for the railway construction in the second phase of Gyung-Bu or Ho-Nam high speed railway, concrete slab track has been adapted as a safe and cost effective geotechnical solution. In this case controlling the total settlement under the tolerance is essential. And pile supported geogrid reinforced construction method is suggested as a solution for the problem of the traditional method on soft soil treatments. Pile supported geogrid reinforced construction method consists of piles that are designed to transfer the load of the embankment through the compressible soil layer to a firm foundation. The load from the embankment must be effectively transferred to the piles to prevent punching of the piles through the embankment fill creating differential settlement at the surface of the embankment. The arrangement of the piles can create soil arching to carry the load of embankment to the piles. In order to minimize the number of piles geogrid reinforced pile supported construction method is being used on a regular basis. This method consists of one or more layers of geogrid reinforcement placed between the top of the piles and the bottom of the embankment. This paper presents several methods of pile supported geogrid reinforced construction and calculation results from the several methods and comparison of them.

  • PDF

A novel laboratory method for measuring the hydraulic conductivity of dredged slurry with high water contents

  • Cong Mou;Jian-wen Ding;Jian-hua Wang;Xing Wan
    • Geomechanics and Engineering
    • /
    • v.33 no.3
    • /
    • pp.317-326
    • /
    • 2023
  • Accurately measuring the hydraulic conductivity of dredged slurry (HCODS) is a difficult task and usually requires highly developed experimental techniques. To resolve such problem, this paper presents a novel laboratory method, where a double drainage sedimentation test (DDST) is proposed to generate a downward seepage after the end of primary consolidation (EOP). Based on the established stress equilibrium equations, it is figured out that the determination of local hydraulic gradients requires the effective stress distribution to be measured. Accordingly, an additional single drainage sedimentation test (SDST) with the same initial water content is performed in the novel laboratory method, which can be utilized to establish the relationship between effective stress and water content for investigated slurry. Thus, HCODS can be determined via a pair of SDST and DDST, with the water contents after the EOP measured. The corresponding calculation procedure is given in details. With a simply-designed settling column, the hydraulic conductivity tests were performed on three types of dredged slurry. The results demonstrated the effectiveness of the novel laboratory method in measuring HCODS.

An Evaluation of Smeared Zone Due to Mandrel Penetration (맨드렐 관입에 기인하는 스미어 존의 평가)

  • 박영목
    • Journal of the Korean Geotechnical Society
    • /
    • v.19 no.6
    • /
    • pp.217-225
    • /
    • 2003
  • An experimental study was conducted to evaluate the smeared effect due to mandrel penetration into soft ground for a vertical drain installation. Laboratory tests were performed to investigate the formation of a smear zone, the variations of strength, and the consolidation characteristics in the disturbed zone using two types(CL at Yangsan site and OH at Pohang site) of soft clayey soils. The smear zone effect was evaluated focusing on mandrel shape, mandrel size, penetration speed, and ground condition. Based on laboratory test results, the diameter of the smear zone$(d_s)$ ranged from 3.08 and 3.92 times that of mandrel$(d_m)$. It was also found that the $(d_s/d_m)$ value of the circular shape of the mandrel is smaller than those of square and rectangular shapes. The value of $(d_s/d_m)$ decreased with larger mandrel size, lower penetration speed in the CL soil, and higher penetration speed in the OH soil. However, natural water content was minimally affected by $(d_s/d_m)$. Respectively, the coefficients of horizontal consolidation$(C_{hs})$ and horizontal Permeability$(K_s)$ of smear zone ranged from 0.81 to 0.87 times, and 0.73 to 0.83 times those of the undisturbed zone. Based on this study, the values of $C_{hs}, K_s$ and unconfined compressive strength$(q_{us})$ in the smear zone were the lowest at close vicinity of the mandrel and increased linearly with distance from the mandrel. Further, the $(q_{us})$ varied from 0.5 to 0.9 times that of the undisturbed zone strength.

Study on Fairness Consolidation of Real Estate Auctions Secured for Bank NPLs (은행 부실채권(NPL) 담보부동산 경매의 공정성 강화방안 연구)

  • No, Han-Jang
    • The Journal of the Korea Contents Association
    • /
    • v.15 no.11
    • /
    • pp.397-409
    • /
    • 2015
  • The Global Financial Crisis and introduction of International Financial Reporting Standards (IFRS) urged the banks to strengthen their asset qualities. The banks dispose their non performing loans(NPLs) consistently to maintain a sufficient BIS capital adequacy ratio. Accordingly, the interests in auctions, as a disposal method, of real estates that secured for NPLs are on the increasing. This study suggest an alternative for fairness consolidation of real estate auctions which secured for NPLs. First, the impartial entry barriers for NPL sales markets need to be eliminated for fair bidding competition in auctions for real estate that secured for NPLs. In addition, the portion of NPL disposal by real estate auctions need to be expanded. Second, the asymmetry of trade information in the retail markets of NPLs and the abuse of offset by NPL owners' also should be restricted. The Fairness improvement of NPL trading process and real estate auction process that secured for them would of great use in the protection of bidders. Futhermore, it would also contribute to the revitalization of real estate auction markets and the resolution of NPLs of banks through fair disposal of distressed assets.

Media Role in the Transition and Consolidation Period of Democracy: A Comparative Study of Korea and Spain (민주주의의 이행 및 공고화 과정에서 미디어의 역할: 한국과 스페인의 비교)

  • Cho, Hang-Je
    • Korean journal of communication and information
    • /
    • v.18
    • /
    • pp.269-303
    • /
    • 2002
  • This article presents a historical account of media role in the transition and consolidation period of democracy. Despite the assumption that media plays a important role in the construction of democracy, it is less clear how the media can affect the process of political change itself. This article seeks to answer some of these question, based on the Mill's macro-social comparative 'method of difference' of Korea and Spain. It is widely agreed that both states achieve democracy through transaction from above(pacts). Media role, however, differs significantly in accordance with authoritarian legacies and civic representativeness of the pacts. Whereas Korean dailies is deepening given market oligopoly and prior practices after democratization, Spain dailies market entirely changed in both structural and spiritual respects. As a result, Korean dailies substantially lacks in civic representativeness as before, contrary to Spain. Spain television settled a sort of the external pluralism. Korean television is pursuing the BBC type of internal pluralism. In Korea, television is more commercial than Spain. Consequently, Spain media serve the consolidation of democracy more than Korea on the whole.

  • PDF

Implant Removal after Percutaneous Short Segment Fixation for Thoracolumbar Burst Fracture : Does It Preserve Motion?

  • Kim, Hyeun Sung;Kim, Seok Won;Ju, Chang Il;Wang, Hui Sun;Lee, Sung Myung;Kim, Dong Min
    • Journal of Korean Neurosurgical Society
    • /
    • v.55 no.2
    • /
    • pp.73-77
    • /
    • 2014
  • Objective : The purpose of this study was to evaluate the efficacy of implant removal of percutaneous short segment fixation after vertebral fracture consolidation in terms of motion preservation. Methods : Between May 2007 and January 2011, 44 patients underwent percutaneous short segment screw fixation due to a thoracolumbar burst fracture. Sixteen of these patients, who underwent implant removal 12 months after screw fixation, were enrolled in this study. Motor power was intact in all patients, despite significant vertebral height loss and canal compromise. The patients were divided into two groups by degree of osteoporosis : Group A (n=8), the non-osteoporotic group, and Group B (n=8), the osteoporotic group. Imaging and clinical findings including vertebral height loss, kyphotic angle, range of motion (ROM), and complications were analyzed. Results : Significant pain relief was achieved in both groups at final follow-up versus preoperative values. In terms of vertebral height loss, both groups showed significant improvement at 12 months after screw fixation and restored vertebral height was maintained to final follow-up in spite of some correction loss. ROM (measured using Cobb's method) in flexion and extension in Group A was $10.5^{\circ}$ ($19.5/9.0^{\circ}$) at last follow-up, and in Group B was $10.2^{\circ}$ ($18.8/8.6^{\circ}$) at last follow-up. Both groups showed marked improvement in ROM as compared with the screw fixation state, which was considered motionless. Conclusion : Removal of percutaneous implants after vertebral fracture consolidation can be an effective treatment to preserve motion regardless of osteoporosis for thoracolumbar burst fractures.

Correlation of Constrained Modulus for Busan Clay using DMT (DMT를 이용한 부산점토의 변형계수 추정)

  • Hong, Sung-Jin;Cho, Yong-Soon;Jung, Sang-Jin;Lee, Woo-Jin
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2008.03a
    • /
    • pp.613-618
    • /
    • 2008
  • Because the flat dilatometer (DMT) is operated in appropriate strain level, it has been known as an adoptable in-situ tool to evaluate the compressibility of soils compare with other in-situ test tools, such as SPT and CPT. This study is concerned about prediction method of constrained modulus by DMT, and a series of DMT and consolidation tests are performed at Busan new-port, Yangsan and Noksan test sites. By comparing DMT results with lab tests, the suitability of constrained modulus correlation, which is suggested by Marchetti, is investigated in Busan clay and new correlation is suggested. In lab test result, the compression indices ($C_c$) of Busan clay are turned out to be 0.4~0.12, and the constrained moduli are found out 0.5MPa~3MPa and these are increase with depth. The predicted constrained moduli using Marchetti's correlation are turned out 0.5MPa~4MPa, and these are bigger than measured constrained moduli by lab tests. By analyzing lab test and DMT results, it is shown that the correlation coefficient ($R_M=M/E_D$) has a linear relationship with (1/$I_D$) in Busan.

  • PDF

Applying TRIZ Theory to Fashion Design - Focused on Rei Kawakubo's Fashion Design - (트리즈(TRIZ)이론에 의한 패션디자인의 적용 - 레이 가와쿠보의 패션디자인을 중심으로 -)

  • Kim, Sung Hyon;Kim, Min-Ja
    • Journal of the Korean Society of Costume
    • /
    • v.62 no.7
    • /
    • pp.79-96
    • /
    • 2012
  • Creativity is a rising topic in the current society. The emphasis on creativity is valued as a key factor for success in all areas including but not limited to politics, economy, culture, arts and design. The field of Fashion design is probably one of the few areas that talk about creativity as a necessary quality to survive. The purpose of this study is to introduce TRIZ(Teoriya Reshniya Izobretatelsskikh Sadatch) as a theoretical tool to generate creativity in fashion design. TRIZ is a creative method of problem solving based on data analysis of outcomes invented by engineering. The fundamental concept of TRIZ has been researched through documentary studies, and practical case studies of product designs are used. Fashion design cases from Comme des Garcons by Rei Kawakubo are used to apply TRIZ in fashion design. Rei Kawakubo's design philosophy has been studied through fashion writings and visual sources in books, exhibition catalog, www. style. com and online shopping mall sites. This study has selected four principles among forty inventive theories of TRIZ: segmentation; asymmetry; consolidation; and preliminary action to apply to Rei Kawakubo's fashion design. As a result, TRIZ can be applicable to fashion design as a creative thinking methodology. By using the four principles of TRIZ, this study shows how Rei Kawakubo's design enhanced its efficiency and aesthetics of the products and was distinguished from existing items. It is meaningful to demonstrate a possibility of adopting engineering based creative methodology in fashion design to widen the perspective and to raise a question for the need of interdisciplinary creative methodology with traditional aesthetic approach in fashion design.