• Title/Summary/Keyword: research tendon

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Study on the Ultimate Flexural Behavior Analysis of Prestressed Concrete Beam with External Unbonded Tendons (외적 비부착강선을 가진 프리스트레스트 콘크리트 보의 극한휨거동 해석)

  • 오병환;유성원;신정성
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10b
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    • pp.662-667
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    • 1998
  • Recently, the using PSC with external unbonded tendons is increased. However, the behavior of external unbonded tendons is different with that of bonded internal tendon at ultimate state by compatibility condition, the slip with friction at deviator and the change of tendon eccentricity e.t.c., So, the analytical research considered the effect of these inherent characters was performed and the tendency of external unbonded tendons was estimated by numerical examples. By the analytical results, load-deflection relationship and stress increment of external unbonded tendons were similar to those of internal bonded tendon at initial elastic behavior state. Those characters were, however, smaller than those character of internal bonded tendons. For external unbonded tendons, if the 1 deviator which is positioned at maximum moment point and more 2 deviators which are position between maximum moment point and support are existed, the flexural behavior is similar to internal bonded tendons.

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Development of a Model for the Estimation of Knee Joint Moment at MVC (MVC 상태에서의 무릎관절 모멘트 추정을 위한 모델 개발)

  • Nam, Yoon-Su;Lee, Woo-Eun
    • Journal of Biomedical Engineering Research
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    • v.29 no.3
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    • pp.222-230
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    • 2008
  • This paper introduces a method of estimating the knee joint moment developed during MVC. By combining the Hill-type muscle model and analytic results on moment arm and musculotendon length change as a function of hip and knee joint angle, the knee joint moment at a specific knee joint angle during MVC is determined. Many differences between the estimated results and the experimental data are noted. It is believed that these differences originate from inaccurate information on the muscle-tendon parameters. The establishment of exact values for the subject's muscle parameters is almost impossible task. However, sensitivity analysis shows that the tendon slack length is the most critical parameter when applying the Hill-type muscle model. The effect of a change of this parameter on the muscle length force relationship is analyzed in detail.

Study of External Prestressing in P.C. Box girder Bridges for Maintenance and Repairment (P.C BOX 교의 유지보수용 EXTERNAL PRESTRESSING에 관한 연구)

  • 김기봉;임춘대;이안호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.361-365
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    • 1995
  • P.C box bridges is divided into internal prestressing and extermal prestressing based on arrangement of tendon. In this research the method of establishment of dviation block in advance and analysis of block and the control relationship of tension of external tendon and displacement should be examined by practical example of high speed rail way in aspects of maintenance and repairment.

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The Comparison of Sonographic Features of Ankle Ligament and Tendon in Affected Side With Non-Affected Side Ambulatory of Hemiplegic Patients (보행 가능한 편마비 환자에서 편측 및 건측 하지 발목 관절의 인대와 힘줄의 초음파 비교)

  • Park, Ji-Woong;An, Jae-Ki;Park, Yong-Bum;Bae, Won-Sik
    • Physical Therapy Korea
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    • v.17 no.2
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    • pp.60-66
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    • 2010
  • In chronic ambulatory hemiplegic patients, structural changes might be developed at both ankles possibly due to unequal and repetitive weight bearing on tendons and ligaments. We examined ankles by sonography to find out structural changes of tendons and ligaments of both ankles in ambulatory hemiplegic patients. Nineteen ambulatory hemiplegic patients over 1 year were included as study subjects. All subjects had no previous trauma or disease history in their ankle joints and they were able to walk independently or with supervision but had spastic ankles with equinovarus tendency. We examined both ankle joints by sonography to see joint effusion and measure width, thickness, and area of tendons of the tibialis anterior, tibialis posterior, and Achilles, and also ligaments of the anterior talofibular and calcaneofibular. We compared sonographic features of the hemi-side ankle with the sound-side ankle. There were no significant differences between hemi-side and sound-side ankles in almost all measured parameters of tendons and ligaments. However, the width of the hemi-side tibialis posterior tendon ($7.24{\pm}1.52$ mm) was narrower than the sound-side tendon ($8.61{\pm}1.37$ mm). With the amount of active joint motion and weight bearing possibly preventing ligament and tendon atrophy even though marked weakness, spasticity occurred during the chronic hemiplegic phase.

A Study on the Determination of the Optimal Parameter for the Evaluation of the Effective Prestress Force on the Bonded Tendon (부착식 텐던의 유효 긴장력 평가를 위한 최적의 매개변수 결정에 관한 연구)

  • Jang, Jung Bum;Lee, Hong Pyo;Hwang, Kyeong Min;Song, Young Chul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.2A
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    • pp.161-168
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    • 2010
  • The bonded tendon was adopted to the reactor building of some operating nuclear power plants in Korea and the assessment of the effective prestress force on the bonded tendon is being issued as an important pending problem for continuous operation beyond their design life. The sensitivity analysis of various parameters was carried out to evaluate the effective prestress force using the system identification technique and the optimal parameters were determined for SI technique in this study. The 1/5 scaled post-tensioned concrete beams with the bonded tendon type were manufactured and in order to investigate the relationship of the natural frequency and the displacement to the effective prestress force, impact test, SIMO sine sweep test and bending test using the optical fiber sensor and the compact displacement transducer were carried out. As a result of tests, both the natural frequency and the displacement show the good relationship with the effective prestress force and both parameters are available for the SI technique to estimate the effective prestress force.

Effects of Lumbar Central Posteroanterior Mobilization on Isometric Knee Extension and Patellar Tendon Reflex Amplitude: A Pilot Study

  • Kim, Bo Kyung;An, Ho Jung;Heo, Seo Yoon;Kim, Byeong Jo;Choi, Wan Suk
    • Journal of International Academy of Physical Therapy Research
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    • v.9 no.1
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    • pp.1435-1441
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    • 2018
  • The main focus of this study was to investigate effects of lumbar central posteroanterior (PA) mobilization on isometric knee extension (IKE) ability and patellar tendon reflex amplitude (PTRA) in healthy university students. University students aged 19-26 (male; 10, female; 10) without any neurological disorders participated voluntarily and excluded the subjects with abnormal reflexes. The participation had an average body mass of $64.25{\pm}13.52kg$, an average height of $1.66{\pm}0.08m$, and an average Body Mass Index (BMI) of $23.07{\pm}3.21$. Every student was randomly assigned to be received squatting exercise and PA mobilization sequentially with 5 days of wash out period. IKE and PTRA were not significantly different between the two groups after the intervention. All the outcome measures were arranged into two data groups; PA mobilization and squatting exercise data group. In the PA mobilization data group, IKE and PTRA significantly increased after the intervention, however, these aspects were decreased in the squatting exercise group. These findings suggest that IKE and PTRA increase immediately after PA mobilization, therefore PA mobilization could be a valuable topic for controlled clinical trials.

Effects of Stressed and Unstressed Reinforcements on Prestressed Concrete Members with Unbonded Tendons

  • Moon, Jeong-Ho;Shin, Kyung-Jae;Lim, Jae-Hyung;Lee, Sun-Hwa
    • KCI Concrete Journal
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    • v.12 no.1
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    • pp.131-138
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    • 2000
  • The research purpose of this paper is to investigate the influential Parameters on the unbonded tendon stress. The parameters were the reinforcing ratio, the prestressing ratio, and the loading type. To this end. first, the influence of parameters were examined with twenty eight test results obtained from references. Then, an experimental study was carried out with nine specimens. Test variables were the reinforcing ratio and the prestressing ratio. Specimens were divided equally into three groups and each group had a different level of the reinforcing ratio. Each specimen within a group has a different level of the prestressing ratio. The investigation with previous and current tests revealed the followings; (1) the length of crack distribution zone does not have a close relation with the length of plastic hinge. (2) the prestressing ratio does not affect both the length of crack distribution and the length of plastic hinge, (3) the tendon stress variation is in reverse relation with the ratios of mild steels and tendons, (4) the loading type nay not affect significantly the length of crack distribution zone, (5) AASHTO LRFD Code equation and Moon/Lim's design equation predicted the test results well with some safety margins.

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Clinical anatomic consideration of the superficial layer of the masseter muscle for botulinum toxin injection (보툴리눔 톡신 주사를 위한 깨물근 얕은층의 임상해부학적 고찰)

  • Lee, Hyung-Jin;Kim, Hee-Jin
    • The Journal of the Korean dental association
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    • v.55 no.5
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    • pp.365-369
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    • 2017
  • In clinical dentistry, botulinum toxin is generally used to treat the square jaw, bruxism, and temporomandibular joint diseases. Recently, this procedure has been expanded and applied for cosmetic purposes, and it is becoming a key task to be aware of the precise anatomical structure of the target muscles to be cautious during treatment and how to prevent side effects. Therefore, the purpose of this study is to observe the anatomical structure of the superficial layer of masseter muscle and to provide a most effective botulinum toxin injection method through clinical anatomical consideration. It was observed that the muscle belly of superficial part of the superficial layer was originated from the deep to the aponeurosis of masseter muscle and descend, then changed gradually into the tendon structure attaching to the inferior border of the mandible. In this study, we named this structure deep inferior tendon. This structure was observed in all specimens. We conclude that the use of superficial layer and deep layer injection should be considered to prevent paradoxical masseteric bulging in consideration of the deep inferior tendon of superficial part of superficial layer of masseter muscle.

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Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autograft : Advantage, Disadvantage, Hamstring Regeneration (자가 슬건을 이용한 재건술: 장점, 단점, 슬건의 재생)

  • Kim, Jin-Goo;Choi, Jeong-Yoon
    • Journal of the Korean Arthroscopy Society
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    • v.14 no.2
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    • pp.92-101
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    • 2010
  • The Hamstring autograft and the bone patellar bone tendon autograft have been widely used for anterior cruciate ligament reconstruction. In recent years, use of hamstring autograft for ACL reconstrution has been increased. The reason seems to be the advantages of the hamstring tendon such as high ultimate tensile load, low donor site morbidity and development of graft fixation method. These theoretical advantages have been increased as studies have shown that hamstring tendons actually regenerate after harvesting for ACL reconstruction. However, the concerns have arisen regarding the disadvantages of hamstring harvest, which were weakness of tibial internal rotation, the loss of flexion strength. The flexion strength loss has been controversial, therefore it needs to study whether restoration of flexion strength after hamstring regeneration is or not. In this study, we reviewed the current research of concerns on the advantage and disadvantage of hamstring tendon autograft and the hamstring regeneration. Furthermore, we compared the earlier studies and experiences regarding Hamstring regeneration with our research.

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Experimental Evaluation for Ultimate Flexural Behaviors of PSC beams with A Corroded Tendon (PS강연선이 부식된 PSC보의 극한휨거동 평가실험)

  • Youn, Seok-Goo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.33 no.3
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    • pp.843-854
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    • 2013
  • This paper presents experimental research work for the evaluation of ultimate flexural behaviors of prestressed concrete beams with a corroded tendon. In order to evaluate the effects of loss of prestress or loss of tendon area on the ultimate flexural strength of prestressed concrete beams, static load tests are conducted using five prestressed concrete beams. After exposing prestressing tendons in two test beams using 25mm drill bit, the exposed tendons were corroded using an accelerating corrosion equipment to simulate loss of tendon area. During the tests, steel strains, concrete strains and displacements at the center of test beams were measured, and acoustic emission measurements were conducted to detect wire fractures. Based on the test results, evaluation method for predicting flexural strength of prestressed concrete beams with corroded tendons is investigated. In addition, evaluation methods for predicting the existence of corroded tendons in post-tensioned prestressed concrete beams at service loads are discussed.