• Title/Summary/Keyword: Segmental Method

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Flexural Stiffness Effects on Constant Depth PC Segmental Bridge Constructed by Free Cantilever Method (균일한 단면 높이를 갖고 FCM 공법으로 시공되는 PC 세그멘탈교량의 거동에 대한 휨강성의 영향)

  • Lee, Jae Hoon;Lee, Myeong Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.5
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    • pp.1-11
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    • 1993
  • Precast/Prestressed concrete segmental bridges with moderate range of span length normally have a constant section height for economic segment manufacturing. Inside sectional dimension is often controlled for design of non-prismatic section between supports when variable stiffness is required. It is usual, in the preliminary design stage, to adopt trial bridge sections by past experience or by approximately estimated member forces. Three bridge models of different member stiffness have been selected to investigate flexural stiffness effects on member forces for preliminary design stage. The selected bridge stiffness has been determined by the flexibility index from review of the practically usable sections.

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The Effect of Heel Height on Lumbar Sagittal Curvature at Standing Posture (기립자세에서 신발 굽의 높이가 요추부 시상만곡각에 미치는 영향)

  • Yoon, Bum-Chul;Lee, Myung-Hwa
    • Journal of Korean Physical Therapy Science
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    • v.5 no.4
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    • pp.763-775
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    • 1998
  • Some segment or segments of the body must compensate for the heel, and the higher the heel the greater the compensation. Such compensation was once generally thought to take place in the lumbar region and therefore to increase the lumbar lordosis. The purpose of this study is to analyze changes of lumbar sagittal curvature in barefoot and 6cm 12cm high-heel stance. We selected 19 subjects(11 males, 8 females} without history of lower back pain, significant spinal abnormality. And lateral view X-ray of lumbar region from T12 to S1 was taken of each individual. On each X-ray film, lumbar lordotic angle lumbosacral angle and lumbar segmental angles were measured by Cobb method. We drew the following interpretations from the analysis of measured variables of the lumbar region. 1. In comparison of barefoot 6cm heel 12cm heel stance, lumbar lordotic angle had a tendency to decrease according as the heel height was higher. The change in lumbar lordosis measured in high-heel stance was inconsistent with clinical forkelord of hyperlordosis in wearers of high-heeled. 2. Lumbar lordotic angle from T12 to L5 showed sex difference, and was more lordotic in female(p<0.05). 3. There was no sex difference in lumbosacral angle and lumbar segmental angles(p>0.05). 4. There was a significant correlation between lumbar lordotic angle and lumbosacral angle(r>0.60).

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Case Study on the Countermeasure Methods and Collapsed Sources of Segmental Retaining Wall Considering Site Conditions (시공환경을 고려한 블록식 보강토옹벽의 붕괴요인 분석 및 대책방안 사례연구)

  • Han, Jung-Geun;Cho, Sam-Deok;Jeong, Sang-Seom;Lee, Kwang-Wo;Kim, Ji-Sun
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.3
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    • pp.35-43
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    • 2005
  • The geosynthetic reinforced segmental retaining walls(SRW) are improved that the disadvantage of existed retaining wall and the workability in field. Recently, the segmental retaining wall is replacing the exited wall because it is quickly advanced to using by the block in-situ. The use, therefore, is increasing. But, the trends of the large scaled construction was developed that the problems likely to crack and collapse, those are caused of careless in design and construction of SRW not considering about various surrounding conditions. In this study, the cause analysis on destructed SRW was carried out that based on the datum of measured displacement of walls, rainfall features and ground sounding conditions. Also, the analysis of the global slope stability was carried out on collapsed section and non-collapsed section using critical equilibrium method. For the rational stability and analysis of slope including SRW structure, the site conditions including situations of topography, ground and histories of construction and collapse etc should be considered. The rational countermeasure methods for non-collapsed and collapsed areas may be sustained as much as possible current state.

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Segmental Resection and Replantation for Primary Malignant or Aggressive Tumors of the Upper Limb (상지에 발생한 악성 및 침윤성 종양의 분절절제 및 재접합술)

  • Hahn, Soo-Bong;Lee, Woo-Suk;Shin, Kyoo-Ho
    • The Journal of the Korean bone and joint tumor society
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    • v.6 no.1
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    • pp.10-16
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    • 2000
  • Object : The aim of the current study is to assess the results of segmental resection and replantation for primary malignant or aggressive tumors of the upper limb. Materials and Methods : From 1986 to 1994, ten patients who had primary malignant or aggressive tumors of the upper limb were managed with segmental resection and replantation method. The average duration of follow-up was 7 years and 7 months. Primary indication of this method is stage II B tumors which, because of their extend, could otherwise be adequately treated only by amputation. Three patients had chondrosarcoma, two had osteosarcoma, two had giant cell tumors with pathologic fracture, one had extensive chondroblastoma, one had Ewings sarcoma, and one had leiomyosarcoma. The location of the tumor was humerus in 6 patients, scapula in 3 patients, and soft tissue of forearm in 1 patient. Wide resection margins were achieved in 7 patients and marginal margin in three. Results : One patient died on 40 months after surgery due to systemic metastasis. Nine patients have remained disease free without local recurrence or metastasis. The average overall functional rating was 65% (43~90%) for ten patients on the last follow-up by the functional rating system of Enneking. The mean grasping power and pinching power of operative hand was 75%(28~95%) and 65%(43~90%) of the opposite hand, respectively. Complications associated with this surgical method included three wound dehiscences and one nerve injury that resolved with proper wound care and time. Conclusion : It was concluded that segmental resection and replantation might be used for partial limb salvage in selected cases for the treatment of primary malignant or aggressive tumors of the upper limb.

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Results and implications of the damage index method applied to a multi-span continuous segmental prestressed concrete bridge

  • Wang, Ming L.;Xu, Fan L.;Lloyd, George M.
    • Structural Engineering and Mechanics
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    • v.10 no.1
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    • pp.37-51
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    • 2000
  • Identification of damage location based on modal measurement is an important problem in structural health monitoring. The damage index method that attempts to evaluate the changes in modal strain energy distribution has been found to be effective under certain circumstances. In this paper two damage index methods using bending strain energy and shear strain energy have been evaluated for numerous cases at different locations and degrees of damage. The objective is to evaluate the feasibility of the damage index method to localize the damage on large span concrete bridge. Finite element models were used as the test structures. Finally this method was used to predict the damage location in an actual structure, using the results of a modal survey from a large concrete bridge.

A Study of Inter-observer Agreements of Spiral Chest Computed Tomography in Diagnosing Pulmonary Embolism (폐색전증에서 나선형 컴퓨터 전산화 단층촬영의 관찰자간의 일치도에 관한 연구)

  • Kim, Yang-Ki;Lee, Young Mok;Kim, Ki-up;Uh, Soo-taek;Kim, Yong Hoon;Park, Choon Sik;Hwang, Jung-Hwa;Kim, Dong Hun;Goo, Dong-Erk;Choi, Deuk-Lin
    • Tuberculosis and Respiratory Diseases
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    • v.59 no.5
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    • pp.473-479
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    • 2005
  • Background : A pulmonary embolism often presents with nonspecific symptoms and signs. However, a delayed diagnosis can result in catastrophic outcome. The majority of preventable deaths associated with a pulmonary embolism can be ascribed to a missed diagnosis rather than to the failure of existing treatments. Therefore, accurate and rapid diagnostic methods are essential for the management of a pulmonary embolism. The recent generation of multidetector-row spiral CT scanners appears to outperform other imaging modalities in detecting a central and peripheral pulmonary embolism. However, there are some variations in the interpretations of the findings between observers. This study examined the inter-observer differences of the diagnoses in patients with a pulmonary embolism. Method : 64 patients who were diagnosed with a pulmonary embolism either clinically or with spiral chest CT from 2002 to 2004, were included. Two thoracic radiologists interpreted the multidetector-row spiral CT in terms of the diagnosis of a pulmonary embolism and the location of the thrombus independently. Among 64 patients, 14 patients were excluded because there was no evidence of a pulmonary embolism or there was different interpretation of the pulmonary embolism between radiologists. A clinical diagnosis was based on "Rules for predicting the probability of embolism". Results : The mean score of the patients according to the Wells method was $3.91{\pm}0.30$ (0-9). The accordance of the radiologists was 95% in the main, 85% in the lobar, 91.2% in the segmental, and 96% in the sub-segmental pulmonary arteries. After excluding the negative interpretation from both radiologists, their agreement was 76.2%(${\kappa}.$ 0.83) in the main, 57.6%(${\kappa}.$ 0.63) in the lobar, 51.5%(${\kappa}.$ 0.63) in the segmental, and 34.6%(${\kappa}.$ 0.49) in the sub-segmental pulmonary arteries. Conclusion : Chest CT has been recently applied to patients suspected of having a pulmonary embolism. It was found that spiral CT is a rapid test for diagnosing a thrombus, and there was reliable accordance between the observers from the area of the large pulmonary arteries. However, there was a lack of agreement between the observers in diagnosing thrombi located distal to the sub-segmental arteries.

Design and Construction of the Green Wall System considering Distribution Effect of Earth Pressure by Soil Nail (쏘일네일의 토압분담효과를 고려한 그린월 시스템의 설계 및 시공)

  • Park, Si-Sam;Cho, Sung-Han
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.3
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    • pp.1-7
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    • 2006
  • The Green Wall system, developed in Austria early 1960, is one of segmental concrete crib type earth retaining wall. Green wall is constructed as procedures that lay the front stretchers, rear stretchers and headers then making a rigid body through harden filled soil of interior cell. Green wall has pro-environmental advantages that able to grow grass in front space of stretchers and decrease cutting ground. In Europe, Green wall used without other reinforcement method. However, green wall used with other reinforcement method like a soil nailing because of environmental problem. This study was performed to introduce the design case by 'Two-Body Translation mechanism' to be able to consider distribution of earth pressure in the soil nailing when designing the green wall using soil nailing system. Also, this study attempts to evaluate the earth pressure change when advanced soil nailing system is constructed using $FLAC^{2D}$ ver. 3.30 program and 'Two-Body Translation mechanism'.

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Performance Improvement in Speech Recognition by Weighting HMM Likelihood (은닉 마코프 모델 확률 보정을 이용한 음성 인식 성능 향상)

  • 권태희;고한석
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.2
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    • pp.145-152
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    • 2003
  • In this paper, assuming that the score of speech utterance is the product of HMM log likelihood and HMM weight, we propose a new method that HMM weights are adapted iteratively like the general MCE training. The proposed method adjusts HMM weights for better performance using delta coefficient defined in terms of misclassification measure. Therefore, the parameter estimation and the Viterbi algorithms of conventional 1:.um can be easily applied to the proposed model by constraining the sum of HMM weights to the number of HMMs in an HMM set. Comparing with the general segmental MCE training approach, computing time decreases by reducing the number of parameters to estimate and avoiding gradient calculation through the optimal state sequence. To evaluate the performance of HMM-based speech recognizer by weighting HMM likelihood, we perform Korean isolated digit recognition experiments. The experimental results show better performance than the MCE algorithm with state weighting.

The Earth Pressure Distribution of Crib Wall (Crib Wall의 토압분포)

  • Oh, Sewook;Kwon, Youngcheul;Bae, Wooseok
    • Journal of the Korean GEO-environmental Society
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    • v.7 no.5
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    • pp.41-48
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    • 2006
  • Crib wall is one of the segmental grid retaining walls using headers and stretchers to establish the framework of the wall. In this method, grids formed by the intersection of headers and stretchers are generally filled with the gravel to maintain the weight of the wall. Therefore, the construction can be carried out with higher speed and much economically when compared with the concrete retaining wall. Furthermore, it has high drain capacity, and environmentally friendly aspects also have been pointed out because the possibility of the planting at the front of the wall. However, in the crib wall method, the relative movement between the individual headers and stretchers was generally recognized, and stress redistribution in the gravel filling was also observed when subjected to the external loading and self-weight of filling. Therefore, it has been thought that the distribution of the earth pressure in the crib wall system differ from that of the concrete retaining wall. In this study, the surcharge tests using the scaled model crib wall was carried out to observe the distribution of the earth pressure in the segmental grid retaining wall. The earth pressure was measured in the six specified height of wall, and the distribution of the pressure was analyzed. Furthermore, the earth pressure by computation or by the test using the concrete retaining wall was also considered to make comparison.

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Reduced Model of the PC Segmental Multispan Bridge Constructed by Free Cantilever Method for Investigation of Deflection and Member Force (캔틸레버공법 PC 세그멘탈 다경간 교량의 처짐 및 단면력 검토를 위한 축소모델에 관한 연구)

  • Lee, Jae Hoon;Lee, Myeong-Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.13 no.4
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    • pp.1-13
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    • 1993
  • In design of prestressed concrete structures, structural analysis is performed normally several times for selection of adequate sectional dimension and tendon amount. Especially for precast segmental multi-span bridges. time consuming structural analysis process due to time dependent material properties and structural system change could be effectively reduced by use of a reduced-span bridge model. 5-span and 3-span bridges are selected as reduced-span models for the 10-span full bridge to investigate the acceptability in practical design. The analytical results of deflection, total moment, statical moment, and ultimate moment of the reduced span-models are compared with those of the 10-span full bridge. Application of the load factors to structural analysis for ultimate moment calculation in prestressed concrete is reviewed and a rational method is proposed.

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