• Title/Summary/Keyword: Segmental analysis

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Design Case Study of Geosynthetic Reinforced Segmental Retaining Walls in Tiered Configuration (다단식 보강토 옹벽의 설계 사례 연구)

  • 유충식;허병주
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.115-125
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    • 2003
  • This paper presents the results of design case study on soil-reinforced segmental retaining walls in tiered configuration. Six different field walls were examined to investigate the appropriateness of their designs within the context of the current design guidelines based on limit equilibrium. Slope stability analysis against the compound failure mode, which is frequently ignored during design, was additionally performed based on the method recommended by FHWA design guidelines. The results indicate that the as-built designs of some of the walls examined do not meet the minimum factors of safety for the external and Internal stabilities, and for the compound failure mode. The implications of the findings from this study are discussed.

Design Aspects of Soil-Reinforced Segmental Retaining Walls in Tiered Arrangement - Case Study (다단식 보강토 옹벽의 설계 - 사례연구)

  • Yoo, Chung-Sik
    • Journal of the Korean Geosynthetics Society
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    • v.1 no.1
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    • pp.31-41
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    • 2002
  • This paper presents the results of stability analyses on soil-reinforced segmental retaining walls in a tiered arrangement. Four different walls were examined to investigate the appropriateness of their designs within the context of the current design guidelines based on limit equilibrium. Slope stability analysis against the compound failure mode, which is frequently ignored during design, was also performed based on the method recommended by FHWA design guidelines. The results indicate that the as-built designs of some of the walls examined do not meet the minimum factors of safety for the external and internal stabilities, and for the compound failure mode. The implications of the findings from this study are discussed.

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Design and Analysis of a Segmental Rotor Type 12/8 Switched Reluctance Motor

  • Zhang, Hongtao;Lee, Dong-Hee;Lee, Chee-Woo;Ahn, Jin-Woo
    • Journal of Power Electronics
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    • v.14 no.5
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    • pp.866-873
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    • 2014
  • In this paper, a novel 12/8 segmental rotor type switched reluctance motor (SRM) is proposed for cooling fan applications. Unlike conventional structures, the rotor of the proposed structure is constructed from a series of discrete segments, and the stator is constructed from two types of stator poles: exciting and auxiliary poles. Moreover, in this structure, short flux paths are taken and no flux reversion exists in the stator. While the auxiliary poles are not wound by the windings, which only provide the flux return path. When compared with the conventional SRM, the proposed structure increases the electrical utilization of the machine and decreases the core losses, which may lead to a higher efficiency. To verify the proposed structure, the finite element method (FEM) and Matlab-Simulink are employed to get the static and dynamic characteristics of the proposed SRM. Finally, a prototype of the proposed motor was tested for characteristic comparisons.

Geosynthetic-Reinforced Segmental Retaining Walls in Tiered Arrangement - Case Study and Field Trial Wall Instrumentation (다단식 보강토 옹벽의 설계 - 사례연구 및 시험시공)

  • Yoo, Chung-Sik;Jung, Hyuk-Sang
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.1
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    • pp.27-36
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    • 2004
  • This paper presents the results of stability analyses on soil-reinforced segmental retaining walls in a tiered arrangement. Four different walls were examined to investigate the appropriateness of their designs within the context of the current design guidelines based on limit equilibrium. Slope stability analysis against the compound failure mode, which is frequently ignored during design, was also performed based on the method recommended by FHWA design guidelines. Also presented are the results of instrumentation on a full-scale field trial wall constructed as part of this study. The implications of the findings from this study are discussed.

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A Study on the selecting behavior of restaurant by segmental group based on foodservice motivation (외식동기에 기초한 세분집단별 외식점 선택행동에 관한 연구)

  • Kim, Young-Hee
    • Journal of Digital Convergence
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    • v.20 no.4
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    • pp.159-168
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    • 2022
  • This study was conducted to classify segmental group based on the factors of foodservice motivation and then conducted a survey for one month from July 15 to August 14, 2021 to analyze the influence of demographic characteristics, usage behavior, and motivation on eating out choice behavior. A total of 310 copies were used for empirical analysis. The result is as follows. First, males showed higher task type than females, and females showed higher number of change type, gastronomic type, and fit type. Second, in demographic characteristics, all groups showed strong motivation for foodservice in married people aged 31-40 and 41-50. Third, in the restaurant selecting behavior difference between the segmental groups according to the motivation for foodservice the most preferred menu was korean food for fit type, gourmet type, duty type and western food was the highest in the change type. Fourth, in the ordering method of difference in restaurant selecting behavior among segmental groups, all four groups showed higher order type than unlimited type or buffets type. The limitations of this study are limited to the food field and analysis should be done, but the results of the study on specific food items have not been obtained. Therefore, it is hoped that the future research will be conducted by designating specific food fields.

An Experimental Study on the Joints in Ultra High Performance Precast Concrete Segmental Bridges (초고성능 프리캐스트 콘크리트 세그멘탈 교량 접합부에 대한 실험 연구)

  • Lee, Chang-Hong;Chin, Won-Jong;Choi, Eun-Suk;Kim, Young-Jin
    • Journal of the Korea Concrete Institute
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    • v.23 no.2
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    • pp.235-244
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    • 2011
  • Failures of segmental bridges have been attributed to the inadequate joint connection techniques, which led to corrosion of the post-tensioned tendons connecting the segmental joints. The principal objective of this study is to evaluate the performances of the in-situ cast joint and epoxy applied shear key joints as a function of shear and ultimate strengths. Furthermore, shear behavior and strength of shear key joints in ultra high performance precasted concrete segmental bridges are experimentally evaluated to understand its shear failure behavior. The test parameters of shear key shape and type, load-displacement relations, cracking behavior, concrete strength, and fracture modes are considered in the study. Also, several parameters which influence the mechanical behavior of the shear key joint are analyzed. Based on the study results, the optimal shear key shape and joint type are proposed for the joint design and analysis guidelines.

Comparative Analysis of Cervical Arthroplasty Using Mobi-$C^{(R)}$ and Anterior Cervical Discectomy and Husion Using the $Solis^{(R)}$-Cage

  • Park, Jin-Hoon;Roh, Kwang-Ho;Cho, Ji-Young;Ra, Young-Shin;Rhim, Seung-Chul;Noh, Sung-Woo
    • Journal of Korean Neurosurgical Society
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    • v.44 no.4
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    • pp.217-221
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    • 2008
  • Objective : Although anterior cervical discectomy and fusion (ACDF) is the standard treatment for degenerative cervical disc disease, concerns regarding adjacent level degeneration and loss of motion have suggested that arthroplasty may be a better alternative. We have compared clinical and radiological results in patients with cervical disc herniations treated with arthroplasty and ACDF. Methods : We evaluated 53 patients treated for cervical disc herniations with radiculopathy, 21 of whom underwent arthroplasty and 32 of whom underwent ACDF. Clinical results included the Visual Analogue Scale (VAS) score for upper extremity radiculopathy, neck disability index (NDI), duration of hospital stay and convalescence time. All patients were assessed radiologically by measuring cervical lordosis, segmental lordosis and segmental range-of-movement (ROM) of operated and adjacent disc levels. Results : Mean hospital stay (5.62 vs. 6.26 days, p<0.05) and interval between surgery and return to work (1.10 vs 2.92 weeks, p<0.05) were significantly shorter in the arthroplasty than in the fusion group. Mean NDI and extremity VAS score improved after 12 months in both groups. Although it was not significant, segmental ROM of adjacent levels was higher in the fusion group than in the arthroplasty group. And, segmental motion of operated levels in arthroplasty group maintained more than preoperative value at last follow up. Conclusion : Although clinical results were similar in the two groups, postoperative recovery was significantly shorter in the arthroplasty group. Although it was not significant, ROM of adjacent segments was less in the arthroplasty group. Motion of operated levels in arthroplasty group was preserved at last follow up.

Effectiveness of Global Postural Reeducation Compared to Segmental Stretching on Pain, Disability, and QOL of Subjects with Neck and Shoulder Pain

  • Jeon, Hochung;Kim, Giwon
    • The Journal of Korean Physical Therapy
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    • v.29 no.1
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    • pp.7-15
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    • 2017
  • Purpose: This randomized controlled trial was conducted to compare the effectiveness of global postural reeducation to segmental stretching in subjects with neck and shoulder pain. Methods: Sixteen subjects with neck and shoulder pain were randomized into two intervention groups, a global posture reeducation group (n=8) that performed muscle chain stretching, and a segmental stretching group (n=8) that performed conventional static muscle stretching. The intervention program consisted of two 40 minutes individual sessions per week for four weeks. Subjects were evaluated pre-intervention, two-week after intervention and at a four-week follow-up appointment for pain intensity, disability and health-related quality of life. Two-way repeated analysis of variance was used for between-time and between-group comparisons. The significance level was 0.05. Results: Significant pain relief and decreasing discomfort of the neck and shoulder were observed after intervention in both groups, and there was an interaction between time lapse and groups (pain, F=10.31, neck disability, F=25.45, shoulder disability, F=12.82, p<0.05). Quality of life also improved after intervention in both groups. Moreover, the physical components score improved, and a significant interaction was observed between time and groups (F=4.85, p<0.05). However, no significant improvement in mental component score of quality of life and no significant interaction between time and groups were observed (p>0.05). Conclusion: These findings suggest that a GPR intervention in subjects with neck and shoulder pain induces greater improvement of pain and disability and quality of life than segmental stretching.

Analysis of Radiological and Clinical Results in Treatment of Open Segmented Tibia Fractures: A Comparison between Intramedullary Nailing and Minimal Invasive Plate Osteosynthesis

  • Kim, Ji Wan;Song, Hyung Keun
    • Journal of Trauma and Injury
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    • v.29 no.3
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    • pp.76-81
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    • 2016
  • Purpose: The purpose of this study was to compare the data comprehensively including not only the clinical and radiographic outcomes but some parameters related to operation between the minimally invasive plate osteosynthesis (MIPO) technique and intramedullary nailing (IMN) for treatment of segmental tibia shaft fractures. Methods: We conducted a retrospective study of 31 patients (mean age, 49.3 years, range, 27-74 years), with a mean follow-up of 14.1 months (range, 12-19 months) with acute segmental tibial fractures (AO 42-C2) who underwent either surgical treatment of MIPO or IMN. In accordance with the Gustilo-Anderson classification, 11 were type I, 5 were type II, and 15 were type III. Initial compartment syndrome was confirmed in 2 cases. Results: There were no statistically significant differences in terms of the patient demographic data between the two groups. The time to definitive fixation was longer in the MIPO group (mean $13.7{\pm}10.9days$; range, 2-27) than in the intramedullary group (mean $5.4{\pm}9.6days$; range, 0-35) with statistically significant difference (p=0.002). Bony union was observed in most of cases but except 5 cases of nonunion were diagnosed (3 in the MIPO vs 2 in IMN, p=0.188). The average bone healing time was 27.1 weeks (10 to 56 weeks) in MIPO group and 23.2 weeks (13 to 66 weeks) in IMN group, respectively (p=0.056). Overall complications were 5 cases in MIPO group and 2 cases in the IMN group. Difference in LEFS was not statistically significant between both groups (p=0.824). Conclusion: This study showed that segmental tibia shaft fractures treated with both MIPO and intramadullary nailing was challenging with relatively high complication rate. A well planned sequential strategy with keeping the soft tissue and personality of fracture in mind is utmost significant as much as the choice of surgical modalities.

A STUDY OF UPPER LIP PROFILE CHANGE AFTER ANTERIOR SEGMENTAL SETBACK OSTEOTOMY (상악 분절골 후퇴술 후의 상순위치 변화 연구)

  • Noh, Kwang-Seob;Hong, Jong-Rak;Kim, Chang-Soo
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.31 no.3
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    • pp.274-278
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    • 2005
  • Purpose : Prediction for soft tissue change after orthognathic surgery is very important for the final esthetics. In this study, we have tried to get the amount of upper lip movement relative to bony segment movement after anterior segmental osteotomy by cephalmetric analysis to predict final upper lip position after surgery. Material and Methods : 20 patients was studied on whom anterior segmental osteotmy as performed by Cupar method during the years 2002 to 2003. Cephalometric radiograph were taken at 1month before surgery and 6 month after surgery. Change of upper lip was measured on landmark Ls and Sto relative to hard tissue (landmark Ia) setback on these X-rays and analyzed. Results : 1. Upper lip setback movement. Setback of upper lip showed proportional relation to the hard tissue setback and the ratio was about 84%(p=0.001). 2. Upper lip downward movement. Downward movement of upper lip showed no proportional relation to hard tissue setback And the amount was mean 1.38 mm and SD 1.21mm (p=0.922). Conclusion : The posterior movement of upper lip is affected by hard tissue movement and shows good proportional change whereas downward movement is not so much influenced by hard tissue movement. And we think slight downward movement shown in this study could be explained by the V-Y closure performed during surgery.