• Title/Summary/Keyword: continuous joint

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Fatigue Durability Evaluation of Refraction Expansion Joints (굴절형 신축이음장치의 피로내구성 평가)

  • Na, Jun-Su;Lee, Ta;Han, Eui-Seok;Sung, Won-Kyu;Lee, Jong-Suk
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.6
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    • pp.10-15
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    • 2017
  • The refraction expansion joints have been newly developed by complementing the problems of shock, noise, replaceability, displacement in the direction perpendicular to bridge, vertical difference, which are problems of existing expansion joints. The Refraction expansion joints are characterized by continuous surfaces with small impact and low noise. The behavior of the Refraction expansion joints performs the bridge expansion behavior by rotation of the link. In the rotational behavior of the link, the bolt is the central axis of the behavior. Therefore, it can be said that the durability of the bolt is very important. However, the theoretical and experimental verification of the bolt durability of the Refraction expansion joint is lacking. In this paper, to verify the fatigue durability of the bolt, test specimens with a 300 mm Refraction expansion joint were fabricated. A strain gauge dedicated to the bolt was installed inside the manufactured test specimen bolt. The test method was applied in accordance with KS F 4425. The fatigue durability of the bolts assembled inside the diaphragm expansion joint was confirmed by the repeated fatigue test of 2,000,000 cycles.

Evaluation of Shear Capacity on PC Girder-PC Beam Joint (PC 큰 보-PC 작은 보 접합부의 전단성능 평가)

  • Moon, Jeong Ho;Oh, Young Hun;Lim, Jae Hyung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.6
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    • pp.166-174
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    • 2011
  • The object of this study is to evaluate the structural shear capacity of the PC girder-PC beam joint. The dapped end of PC beam and the ledger of PC girder are usually designed to design load. If the end of PC beam can be designed with continuous end, the dapped end of PC beam and the ledger of PC girder do not need to resist to all loads except dead load and construction load. The experimental program was carried out with 7 specimens containing the variable factors as the anchored method of the hanger bar, design load, be or not exist of ledger bars. As a result, the continuity of the dapped end and the ledger were ensured their safety although the design load was only the dead load and the construction load. The shear critical section was expanded toward the effective depth d, the distance from the supported position of the beam. If the ledger is designed according to PCI Design Handbook, the structural system of the ledger is as to the cantilever slab system. But the ledger of this study is as to the 3 side fixed slab system. Therefore the design of the ledger by PCI Design Handbook will lead to highly conservative results.

Is the association of continuous metabolic syndrome risk score with body mass index independent of physical activity? The CASPIAN-III study

  • Heshmat, Ramin;shafiee, Gita;Kelishadi, Roya;Babaki, Amir Eslami Shahr;Motlagh, Mohammad Esmaeil;Arefirad, Tahereh;Ardalan, Gelayol;Ataie-Jafari, Asal;Asayesh, Hamid;Mohammadi, Rasool;Qorbani, Mostafa
    • Nutrition Research and Practice
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    • v.9 no.4
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    • pp.404-410
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    • 2015
  • BACKGROUND/OBJECTIVES: Although the association of body mass index (BMI) with metabolic syndrome (MetS) is well documented, there is little knowledge on the independent and joint associations of BMI and physical activity with MetS risk based on a continuous scoring system. This study was designed to explore the effect of physical activity on interactions between excess body weight and continuous metabolic syndrome (cMetS) in a nationwide survey of Iranian children and adolescents. SUBJECTS/METHODS: Data on 5,625 school students between 10 and 18 years of age were analyzed. BMI percentiles, screen time activity (STA), leisure time physical activity (LTPA) levels, and components of cMetS risk score were extracted. Standardized residuals (z-scores) were calculated for MetS components. Linear regression models were used to study the interactions between different combinations of cMetS, LTPA, and BMI percentiles. RESULTS: Overall, 984 (17.5%) subjects were underweight, whereas 501 (8.9%) and 451 (8%) participants were overweight and obese, respectively. All standardized values for cMetS components, except fasting blood glucose level, were directly correlated with BMI percentiles in all models (P-trend < 0.001); these associations were independent of STA and LTPA levels. Linear associations were also observed among LTPA and standardized residuals for blood pressure, high-density lipoprotein, and waist circumference (P-trend < 0.01). CONCLUSIONS: Our findings suggest that BMI percentiles are associated with cMetS risk score independent of LTPA and STA levels.

Structural Behavior of Steel Wire Truss Deck with Continuous Lattices to the Longitudinal Direction (길이방향으로 연속된 래티스를 가지는 철선 트러스데크의 구조 거동)

  • Lee, Sung Ho;Park, Hyung Chul;Oh, Bo Hwan;Cho, Soon Bo
    • Journal of Korean Society of Steel Construction
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    • v.21 no.1
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    • pp.37-44
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    • 2009
  • A truss deck system that has replaced the slab form conventional method has become widely used in the construction of reinforced concrete structures as well as steel structures. The current commercial products, however, have some problems. The discontinuity between the lattice wires on the joint of the bottom wire induces vierendeel behavior, which increases the deflection of the system. In this research, a new truss deck system with continuous lattice wires on the level of the bottom wire was developed to reduce the system's vierendeel behavior and to improve its deformation capacity. To investigate the system's structural behavior, an experimental test and an analysis were performed. The main parameters of the test and analysis were the longitudinal shape and spacing of the lattices. To simulate the loading condition in the construction field, uniform construction loads were directly applied on the deck plates of the analysis model and the test specimens. The results of such analysis and test revealed that the longitudinal shape of the lattice wires is a major factor affecting the structural behavior of a steel wire truss deck. Thus, continuous lattice wires could result in decreased vierendeel behavior in the steel wire truss deck. It was also found that the truss deck system with lattices spaced longer than in the conventional products could be effectively used without increasing the member stresses.

Development of the Robotic Gait Trainer for Persons with Gait Disorder (보행 장애인을 위한 로봇형 보행훈련 시스템의 개발)

  • Hwang, Sung-Jae;Son, Jong-Sang;Kim, Jung-Yoon;Sohn, Ryang-Hee;Kim, Young-Ho
    • Proceedings of the KIEE Conference
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    • 2008.04a
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    • pp.73-74
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    • 2008
  • In this study, we developed a robotic gait trainer which induces the active gait training based on predefined continuous proper lower extremity joint movements. AC servo motors and linear actuators were used to control hip and knee joints of patients and the weight support system was used to support the patient's weight during the gait training. We also implemented a Gill program to set the gait training pattern with several training parameters and to confirm states of patients and the system through the visual feedback. The effectiveness of the gait training system will be determined by the long-term clinical experiments in the future. We expect that the developed robotic gait training system could be applied very practically to recover gait abilities for persons with gait disorder.

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The Comparison of Motor Control During Tracking in the Knee Joint of Subjects With Stroke (무릎 관절 추적 과제에 따른 편마비 환자의 운동조절 비교)

  • Chung, Yi-Jung;Cho, Sang-Hyun;Jeon, Hye-Seon
    • Physical Therapy Korea
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    • v.12 no.3
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    • pp.39-45
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    • 2005
  • Tracking is an experimental paradigm that can be used to study information processing in continuous movements involving accurate, ongoing control of motor performance. The purpose of this study was to identify the effects of knee tracking performance. Six patients with hemiplegia and six age-matched controls participated in the study. The tracking test was administrated. It was composed with regular ranges of $0^{\circ}C$ to $40^{\circ}C$ and randomized range .2 to .4 Hz. Using the Mann-Whitney U test, a comparison was made between subjects who had suffered from stroke and subjects who were well coordinated. The Wilcoxon Matched Pairs Signed Ranks Test was used to compare and analyze the paretic and nonparetic sides of the stroke patients. The results of study were as follows: accuracy index of the tracking test was significantly higher on the control side than paretic and nonparetic sides. Accuracy index scores were significantly higher for nonparetic sides with stroke compared with paretic sides with stroke. This study shows tracking is impaired in paretic and nonparetic knee of subjects with stroke.

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Effects of a Thera-Band Exercise Program on Pain, Knee Flexion ROM, and Psychological Parameters Following Total Knee Arthroplasty (슬관절 전치환술 후 세라밴드 운동프로그램이 수술 후 통증, 슬관절 굴곡각도 및 심리적 지수에 미치는 효과)

  • Yun, Ji Yeong;Lee, Jong Kyung
    • Journal of Korean Academy of Nursing
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    • v.45 no.6
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    • pp.823-833
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    • 2015
  • Purpose: The purpose of the study was to investigate the effects of the Thera-Band exercise program following total knee arthroplasty. Methods: The research design for this study was a nonequivalent control group non-synchronized design. Participants were 30 patients for the experimental group and 30 patients for the control group. The experimental group participated in the Thera-Band exercise program in addition to conventional CPM (continuous passive motion) exercise. The control group received conventional CPM exercise only. Outcome measures were pain, knee flexion range of motion, CRP, and psychological parameters (self-efficacy and fear of falling). Data were analyzed using ${\chi}^2$-test, Fisher's exact test, t-test, and repeated measure ANOVA with SPSS/PC version 21.0. Results: There were significant improvement in self-efficacy, and decreases in pain, and fear of falling in the experimental group compared to the control group. However, no significant differences were found between the two groups for CRP and knee flexion ROM. Conclusion: The Thera-Band exercise program gave an additional benefit over the conventional CPM exercise for patients following total knee arthroplasty, and is recommended for use as an effective nursing intervention for patients after total knee arthroplasty.

Biomechanical Evaluation of a Manual Wheelchair with Forward. Reverse Propulsion (정.역 구동 방식 수도 휠체어의 인체공학적 성능 분석)

  • Shin, Eung-Soo;Lee, Hee-Tae;Ahn, Seong-Chul
    • Proceedings of the KSME Conference
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    • 2001.06c
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    • pp.464-469
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    • 2001
  • This work provides the biomechanical evaluations of a manual wheelchair with a bi-directional driving system. The new propulsion strategy can be accomplished by employing a special gear system that converts the oscillatory motion of a handrim into the unidirectional output motion of a wheel. A main feature of the forward. backward propulsion is to supply continuous driving torque without break. Motion. analysis has been performed through 2-dimensional image processing for measuring the kinematic properties of the upper arm and fore arm. Then, the inverse dynamics analysis has been done for obtaining the joint torques, the handrim forces and input/output powers. Results show that the output power by the forward. reverse propulsion is almost twice as much as that by conventional propulsion. Also, the new propulsion is expected to reduce the fatigues and injuries at arm joints by employing more muscle groups for movement. In conclusion, the forward. reverse propulsion can greatly improve the performances of manual wheelchairs by providing better mobility as well as by guaranteeing several advantages from a biomechanical viewpoint. Future development of a manual wheelchair optimized for the bi-directional propulsion will further improve the propulsion performances.

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Postoperative Electroacupuncture in 2 Dogs showed Continuous Lameness after the Reduction of Medial Patellar Luxation (슬개골 내측탈구 교정술 후 지속적 파행을 보이는 개에서의 전침치료 2례)

  • 이주명;권오경;남치주
    • Journal of Veterinary Clinics
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    • v.16 no.1
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    • pp.230-234
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    • 1999
  • Canine medial patellar luxation can cause hindlimb lameness in toy breeds and surgical operation needs when the lameness does not improve or worsen. In this study, the 2 dogs that showed postoperative non-weight bearing lameness were treated with electroacupuncture (EA) and the effects of postoperative EA were examined. Xue Hai (Sea of Blood), Du Bi (calf's nose, 2 acupoint), Zu San Li (leg 3 miles) acupoints were used in acupuncture. Xue Hai acupoint was connected to positive pole and Zu San Li was negative for 20 min with 2~5 volt, 5~30 Hz in EA. In case 1, EA were performed eight times for 26 days after 29th postoperative day and walking was improved from 6th EA. In case 2, EA were conducted five times for 17 day after 26th postoperative day and walking was improved from 4th EA. It may be possible to improve walking by EA treatment in the dogs that show post-operative non-weight bearing lameness, but the relationship between the effects of EA and the injury of stifle joint should be inspected.

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Sample-spacing Approach for the Estimation of Mutual Information (SAMPLE-SPACING 방법에 의한 상호정보의 추정)

  • Huh, Moon-Yul;Cha, Woon-Ock
    • The Korean Journal of Applied Statistics
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    • v.21 no.2
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    • pp.301-312
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    • 2008
  • Mutual information is a measure of association of explanatory variable for predicting target variable. It is used for variable ranking and variable subset selection. This study is about the Sample-spacing approach which can be used for the estimation of mutual information from data consisting of continuous explanation variables and categorical target variable without estimating a joint probability density function. The results of Monte-Carlo simulation and experiments with real-world data show that m = 1 is preferable in using Sample-spacing.