• Title/Summary/Keyword: Joint Energy

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Efficacy of Muscle Energy Technique for Temporomandibular Disorders: A Systematic Review and Meta-analysis (턱관절 장애에 대한 근에너지 기법의 효과: 체계적 문헌 고찰 및 메타분석)

  • HongRyoul Yoon;JungWon Byun;SoonJoong Kim
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.18 no.2
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    • pp.31-42
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    • 2023
  • Objectives This study aimed to conduct a systematic review evaluating the effectiveness of muscle energy technique(MET) in temporomandibular joint disorders (TMD). Methods Searches were conducted in 11 electronic databases until October 2023. Randomized controlled trials(RCT) comparing the effect of MET for TMD were included. All studies were evaluated using the Cochrane Risk of Bias tool. Results Nine documents that fulfilled all the criteria were obtained for analysis. All studies showed some concerns in high risk of bias, but showed a significant improvement in pain and maximum mouth opening compared to baseline of MET or control group. MET was not better than extracorporeal shock wave therapy or myofascial release in some outcomes. Conclusions MET seems to be an effective treatment for TMD in some regards, however, can be considered as an adjunct therapy which has weak evidence. Further studies are required due to the inconclusive data and poor homogeneity found in this review.

Influence of Guide Vane Setting in Pump Mode on Performance Characteristics of a Pump-Turbine

  • Li, Deyou;Wang, Hongjie;Nielsen, Torbjorn K.;Gong, Ruzhi;Wei, Xianzhu;Qin, Daqing
    • International Journal of Fluid Machinery and Systems
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    • v.10 no.2
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    • pp.154-163
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    • 2017
  • Performance characteristics in pump mode of pump-turbines are vital for the safe and effective operation of pumped storage power plants. However, the head characteristics are different under different guide vane openings. In this paper, 3-D steady simulations were performed under 13mm, 19mm and 25mm guide vane openings. Three groups of operating points under the three GVOs were chosen based on experimental validation to investigate the influence of guide vane setting on flow patterns upstream and downstream. The results reveal that, the guide vane setting will obviously change the flow pattern downstream, which in turn influences the flow upstream. It shows a strong effect on hydraulic loss (power dissipation) in the guide and stay vanes. It is also found that the hydraulic loss mainly comes from the flow separation and vortices. In addition, in some operating conditions, the change of guide vane opening will change the flow angle at the runner inlet and outlet, which will change the Euler momentum (power input). The joint action of Euler momentum and hydraulic loss results in the change of the head characteristics.

Shoaling Prediction by the Statistical Joint Distribution in the Shallow Water Region (천해역에 있어서의 결합확률분포의 천수변형에 대한 연구)

  • 권정곤
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.3 no.1
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    • pp.14-20
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    • 1991
  • Accurate estimation of irregular wave transformation when the waves propagate from deep water to shallow water region is very important for the design of coastal structures and establishing beach erosion control. In this study. the transformation of directional spectrum is tested numerically using a conservation equation for energy flux and. based upon the joint distribution of wave height. period and wave direction. shoaling effects are predicted in the shallow water region. The applicability of the proposed procedure is verified through comparison with field observation data.

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Improvement of Interfacial Performances on Insulating and Semi-conducting Silicone Polymer Joint by Plasma-treatment

  • Lee, Ki-Taek;Huh, Chang-Su
    • Transactions on Electrical and Electronic Materials
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    • v.7 no.1
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    • pp.16-20
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    • 2006
  • In this paper, we investigated the effects of short-term oxygen plasma treatment of semiconducting silicone layer to improve interfacial performances in joints prepared with a insulating silicone materials. Surface characterizations were assessed using contact angle measurement and x-ray photoelectron spectroscopy (XPS), and then adhesion level and electrical performance were evaluated through T-peel tests and electrical breakdown voltage tests of treated semi-conductive and insulating joints. Plasma exposure mainly increased the polar component of surface energy from $0.21\;dyne/cm^2$ to $47\;dyne/cm^2$ with increasing plasma treatment time and then leveled off. Based on XPS analysis, the surface modification can be mainly ascribed to the creation of chemically active functional groups such as C-O, C=O and COH on semi-conductive silicone surface. This oxidized rubber layer is inorganic silica-like structure of Si bound with three to four oxygen atoms ($SiO_x,\;x=3{\sim}4$). The oxygen plasma treatment produces an increase in joint strength that is maximum for 10 min treatment. However, due to brittle property of this oxidized layer, the highly oxidized layer from too much extended treatment could be act as a weak point, decreasing the adhesion strength. In addition, electrical breakdown level of joints with adequate plasma treatment was increased by about $10\;\%$ with model samples of joints prepared with a semi-conducting/ insulating silicone polymer after applied to interface.

Analysis of Joint Multiband Sensing-Time M-QAM Signal Detection in Cognitive Radios

  • Tariq, Sana;Ghafoor, Abdul;Farooq, Salma Zainab
    • ETRI Journal
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    • v.34 no.6
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    • pp.892-899
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    • 2012
  • We analyze a wideband spectrum in a cognitive radio (CR) network by employing the optimal adaptive multiband sensing-time joint detection framework. This framework detects a wideband M-ary quadrature amplitude modulation (M-QAM) primary signal over multiple nonoverlapping narrowband Gaussian channels, using the energy detection technique so as to maximize the throughput in CR networks while limiting interference with the primary network. The signal detection problem is formulated as an optimization problem to maximize the aggregate achievable secondary throughput capacity by jointly optimizing the sensing duration and individual detection thresholds under the overall interference imposed on the primary network. It is shown that the detection problems can be solved as convex optimization problems if certain practical constraints are applied. Simulation results show that the framework under consideration achieves much better performance for M-QAM than for binary phase-shift keying or any real modulation scheme.

A numerical investigation of seismic performance of large span single-layer latticed domes with semi-rigid joints

  • Zhang, Huidong;Han, Qinghua
    • Structural Engineering and Mechanics
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    • v.48 no.1
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    • pp.57-75
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    • 2013
  • It is still inadequate for investigating the highly nonlinear and complex mechanical behaviors of single-layer latticed domes by only performing a force-based demand-capacity analysis. The energy-based balance method has been largely accepted for assessing the seismic performance of a structure in recent years. The various factors, such as span-to-rise ratio, joint rigidity and damping model, have a remarkable effect on the load-carrying capacity of a single-layer latticed dome. Therefore, it is necessary to determine the maximum load-carrying capacity of a dome under extreme loading conditions. In this paper, a mechanical model for members of the semi-rigidly jointed single-layer latticed domes, which combines fiber section model with semi-rigid connections, is proposed. The static load-carrying capacity and seismic performance on the single-layer latticed domes are evaluated by means of the mechanical model. In these analyses, different geometric parameters, joint rigidities and roof loads are discussed. The buckling behaviors of members and damage distribution of the structure are presented in detail. The sensitivity of dynamic demand parameters of the structures subjected to strong earthquakes to the damping is analyzed. The results are helpful to have a better understanding of the seismic performance of the single-layer latticed domes.

A Novel Powered Gait Orthosis using Pneumatic Muscle Actuator

  • Kang, Sung-Jae;Ryu, Jei-Cheong;Moon, In-Hyuk;Ryu, Jae-Wook;Mun, Mu-Seung
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1500-1503
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    • 2003
  • One of the main goals in the rehabilitation of SCI patients is to enable the patient to stand and walk themselves. We are developing high-thrust powered gait orthosis(PGO) that use air muscle actuator(shadow robot Co., UK) to be assisted gait and rehabilitation purposes of them. We made of PD controller and measured hip joint angle by its load and the pressure to control air muscle of PGO. As a results, maximum flexion angle of hip joint is $20^{\circ}$, and angular velocity is 30.4${\pm}2.5^{\circ}/sec$, and then delay time of system was average 0.62${\pm}$0.03s. As the hip flexion angle and the pelvic angle is decreased during the gait with PGO, the patient can walk faster. By using the PGO, the energy consumption can also be decreased. therefore, the proposed PGO can be a very useful assitive device for the paraplegics to walk.

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Seismic behavior of reinforced concrete exterior beam-column joints strengthened by ferrocement composites

  • Li, Bo;Lam, Eddie Siu-shu;Wu, Bo;Wang, Ya-yong
    • Earthquakes and Structures
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    • v.9 no.1
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    • pp.233-256
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    • 2015
  • This paper presents an experimental study to assess the effectiveness of using ferrocement to strengthen deficient beam-column joints. Ferrocement is proposed to protect the joint region through replacing concrete cover. Six exterior beam-column joints, including two control specimens and four strengthened specimens, are prepared and tested under constant axial load and quasi-static cyclic loading. Two levels of axial load on column (0.2fc'Ag and 0.4fc'Ag) and two types of skeletal reinforcements in ferrocement (grid reinforcements and diagonal reinforcements) are considered as test variables. Experimental results have indicated that ferrocement as a composite material can enhance the seismic performance of deficient beam-column joints in terms of peak horizontal load, energy dissipation, stiffness and joint shear strength. Shear distortions within the joints are significantly reduced for the strengthened specimens. High axial load (0.4fc'Ag) has a detrimental effect on peak horizontal load for both control and ferrocement-strengthened specimens. Specimens strengthened by ferrocement with two types of skeletal reinforcements perform similarly. Finally, a method is proposed to predict shear strength of beam-column joints strengthened by ferrocement.

Strengthening of non-seismically designed beam-column joints by ferrocement jackets with chamfers

  • Li, Bo;Lam, Eddie Siu-Shu;Cheng, Yuk-Kit;Wu, Bo;Wang, Ya-Yong
    • Earthquakes and Structures
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    • v.8 no.5
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    • pp.1017-1038
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    • 2015
  • This paper presents a strengthening method that involves the use of ferrocement jackets and chamfers to relocate plastic hinge for non-seismically designed reinforced concrete exterior beam-column joints. An experimental study was conducted to assess the effectiveness of the proposed strengthening method. Four half-scale beam-column joints, including one control specimen and three strengthened specimens, were prepared and tested under quasi-static cyclic loading. Strengthening schemes include ferrocement jackets with or without skeleton reinforcements and one or two chamfers. Experimental results have indicated that the proposed strengthening method is effective to move plastic hinge from the joint to the beam and enhance seismic performance of beam-column joints. Shear stress and distortion within the joint region are also reduced significantly in strengthened specimens. Skeleton reinforcements in ferrocement provide limited improvement, except on crack control. Specimen strengthened by ferrocement jackets with one chamfer exhibits slight decrease in peak strength and energy dissipation but with increase in ductility as compared with that of two chamfers. Finally, a method for estimating moment capacity at beam-column interface for strengthened specimen is developed. The proposed method gives reasonable prediction and can ensure formation of plastic hinge at predetermined location in the beam.

Energy efficient joint iterative SIC-MMSE MIMO detection (에너지 효율적 반복 SIC-MMSE MIMO 검출)

  • Ngayahala, F.C. Kamaha;Ahmed, Saleem;Kim, Sooyoung
    • Journal of Satellite, Information and Communications
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    • v.10 no.1
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    • pp.22-28
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    • 2015
  • In this paper, we propose a new computationally efficient joint iterative multi-input multi-output (MIMO) detection scheme using a soft interference cancellation and minimum mean squared-error (SIC-MMSE) method. The critical computational burden of the SIC-MMSE scheme lies in the multiple inverse operations of the complex matrices. We find a new way which requires only a single matrix inversion by utilizing the Taylor series expansion of the matrix, and thus the computational complexity can be reduced. The computational complexity reduction increases as the number of antennas is increased. The simulation results show that our method produces almost the same performances as the conventional SIC-MMSE with reduced computational complexity.