Displaying publications 61 - 80 of 277 in total

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  1. Ravanfar SA, Razak HA, Ismail Z, Monajemi H
    Sensors (Basel), 2015;15(9):22750-75.
    PMID: 26371005 DOI: 10.3390/s150922750
    This paper reports on a two-step approach for optimally determining the location and severity of damage in beam structures under flexural vibration. The first step focuses on damage location detection. This is done by defining the damage index called relative wavelet packet entropy (RWPE). The damage severities of the model in terms of loss of stiffness are assessed in the second step using the inverse solution of equations of motion of a structural system in the wavelet domain. For this purpose, the connection coefficient of the scaling function to convert the equations of motion in the time domain into the wavelet domain is applied. Subsequently, the dominant components based on the relative energies of the wavelet packet transform (WPT) components of the acceleration responses are defined. To obtain the best estimation of the stiffness parameters of the model, the least squares error minimization is used iteratively over the dominant components. Then, the severity of the damage is evaluated by comparing the stiffness parameters of the identified model before and after the occurrence of damage. The numerical and experimental results demonstrate that the proposed method is robust and effective for the determination of damage location and accurate estimation of the loss in stiffness due to damage.
    Matched MeSH terms: Motion
  2. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2016 Jan 22;116(3):032301.
    PMID: 26849587 DOI: 10.1103/PhysRevLett.116.032301
    The production cross sections of the B^{+}, B^{0}, and B_{s}^{0} mesons, and of their charge conjugates, are measured via exclusive hadronic decays in p+Pb collisions at the center-of-mass energy sqrt[s_{NN}]=5.02  TeV with the CMS detector at the CERN LHC. The data set used for this analysis corresponds to an integrated luminosity of 34.6  nb^{-1}. The production cross sections are measured in the transverse momentum range between 10 and 60  GeV/c. No significant modification is observed compared to proton-proton perturbative QCD calculations scaled by the number of incoherent nucleon-nucleon collisions. These results provide a baseline for the study of in-medium b quark energy loss in Pb+Pb collisions.
    Matched MeSH terms: Motion
  3. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, et al.
    Phys Rev Lett, 2015 Mar 13;114(10):101801.
    PMID: 25815923
    Results are presented from a search for new decaying massive particles whose presence is inferred from an imbalance in transverse momentum and which are produced in association with a single top quark that decays into a bottom quark and two light quarks. The measurement is performed using 19.7  fb^{-1} of data from proton-proton collisions at a center-of-mass energy of 8 TeV, collected with the CMS detector at the CERN LHC. No deviations from the standard model predictions are observed and lower limits are set on the masses of new invisible bosons. In particular, scalar and vector particles, with masses below 330 and 650 GeV, respectively, are excluded at 95% confidence level, thereby substantially extending a previous limit published by the CDF Collaboration.
    Matched MeSH terms: Motion
  4. Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.
    Phys Rev Lett, 2018 Apr 06;120(14):142301.
    PMID: 29694144 DOI: 10.1103/PhysRevLett.120.142301
    The relative yields of ϒ mesons produced in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV and reconstructed via the dimuon decay channel are measured using data collected by the CMS experiment. Double ratios are formed by comparing the yields of the excited states, ϒ(2S) and ϒ(3S), to the ground state, ϒ(1S), in both Pb-Pb and pp collisions at the same center-of-mass energy. The double ratios, [ϒ(nS)/ϒ(1S)]_{Pb-Pb}/[ϒ(nS)/ϒ(1S)]_{pp}, are measured to be 0.308±0.055(stat)±0.019(syst) for the ϒ(2S) and less than 0.26 at 95% confidence level for the ϒ(3S). No significant ϒ(3S) signal is found in the Pb-Pb data. The double ratios are studied as a function of collision centrality, as well as ϒ transverse momentum and rapidity. No significant dependencies are observed.
    Matched MeSH terms: Motion
  5. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2018 May 18;120(20):202301.
    PMID: 29864330 DOI: 10.1103/PhysRevLett.120.202301
    The prompt D^{0} meson azimuthal anisotropy coefficients, v_{2} and v_{3}, are measured at midrapidity (|y|<1.0) in Pb-Pb collisions at a center-of-mass energy sqrt[s_{NN}]=5.02  TeV per nucleon pair with data collected by the CMS experiment. The measurement is performed in the transverse momentum (p_{T}) range of 1 to 40  GeV/c, for central and midcentral collisions. The v_{2} coefficient is found to be positive throughout the p_{T} range studied. The first measurement of the prompt D^{0} meson v_{3} coefficient is performed, and values up to 0.07 are observed for p_{T} around 4  GeV/c. Compared to measurements of charged particles, a similar p_{T} dependence, but smaller magnitude for p_{T}<6  GeV/c, is found for prompt D^{0} meson v_{2} and v_{3} coefficients. The results are consistent with the presence of collective motion of charm quarks at low p_{T} and a path length dependence of charm quark energy loss at high p_{T}, thereby providing new constraints on the theoretical description of the interactions between charm quarks and the quark-gluon plasma.
    Matched MeSH terms: Motion
  6. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2018 Dec 14;121(24):242301.
    PMID: 30608764 DOI: 10.1103/PhysRevLett.121.242301
    Measurements of fragmentation functions for jets associated with an isolated photon are presented for the first time in pp and Pb-Pb collisions. The analysis uses data collected with the CMS detector at the CERN LHC at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Fragmentation functions are obtained for jets with p_{T}^{jet}>30  GeV/c in events containing an isolated photon with p_{T}^{γ}>60  GeV/c, using charged tracks with transverse momentum p_{T}^{trk}>1  GeV/c in a cone around the jet axis. The association with an isolated photon constrains the initial p_{T} and azimuthal angle of the parton whose shower produced the jet. For central Pb-Pb collisions, modifications of the jet fragmentation functions are observed when compared to those measured in pp collisions, while no significant differences are found in the 50% most peripheral collisions. Jets in central Pb-Pb events show an excess (depletion) of low (high) p_{T} particles, with a transition around 3  GeV/c. This measurement shows for the first time the in-medium shower modifications of partons (quark dominated) with well-defined initial kinematics. It constitutes a new well-controlled reference for testing theoretical models of the parton passage through the quark-gluon plasma.
    Matched MeSH terms: Motion
  7. Mohamad N, Abdul Khanan MF, Ahmad A, Md Din AH, Shahabi H
    Sensors (Basel), 2019 Aug 31;19(17).
    PMID: 31480412 DOI: 10.3390/s19173778
    Evaluating water level changes at intertidal zones is complicated because of dynamic tidal inundation. However, water level changes during different tidal phases could be evaluated using a digital surface model (DSM) captured by unmanned aerial vehicle (UAV) with higher vertical accuracy provided by a Global Navigation Satellite System (GNSS). Image acquisition using a multirotor UAV and vertical data collection from GNSS survey were conducted at Kilim River, Langkawi Island, Kedah, Malaysia during two different tidal phases, at high and low tides. Using the Structure from Motion (SFM) algorithm, a DSM and orthomosaics were produced as the main sources of data analysis. GNSS provided horizontal and vertical geo-referencing for both the DSM and orthomosaics during post-processing after field observation at the study area. The DSM vertical accuracy against the tidal data from a tide gauge was about 12.6 cm (0.126 m) for high tide and 34.5 cm (0.345 m) for low tide. Hence, the vertical accuracy of the DSM height is still within a tolerance of ±0.5 m (with GNSS positioning data). These results open new opportunities to explore more validation methods for water level changes using various aerial platforms besides Light Detection and Ranging (LiDAR) and tidal data in the future.
    Matched MeSH terms: Motion
  8. Ahad Javanmardi, Zainab Ibrahim, Khaled Gheadi, Mohammed Jameel, Usman Hanif, Gordan, Meisam
    Scientific Research Journal, 2018;15(1):1-14.
    MyJurnal
    Nowadays, development of cable-stayed bridges is increasing around the world. The mitigation of seismic forces to these bridges are obligatory to prevent damages or failure of its structural members. Herein, this paper aimed to determine the near-fault ground motion effect on an existing cablestayed bridge equipped with lead-rubber bearing. In this context, Shipshaw cable-stayed bridge is selected as the case study. The selected bridge has a span of 183.2 m composite deck and 43 m height of steel tower. 2D finite element models of the non-isolated and base isolated bridges are modelled by using SAP2000. Three different near-fault ground motions which are Tabas 1978, Cape Mendocino 1992 and Kobe 1995 were subjected to the 2D FEM models in order to determine the seismic behaviour of the bridge. The near-fault ground motions were applied to the bridge in the longitudinal direction. Nonlinear dynamic analysis was performed to determine the dynamic responses of the bridge. Comparison of dynamic response of nonisolated and base isolated bridge under three different near-fault ground motions were conducted. The results obtained from numerical analyses of the bridge showed that the isolation system lengthened the period of bridge and minimised deck displacement, base shear and base moment of the bridge. It is concluded that the isolation system significantly reduced the destructive effects of near-fault ground motions on the bridge.
    Matched MeSH terms: Motion
  9. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2018 Nov 30;121(22):221802.
    PMID: 30547617 DOI: 10.1103/PhysRevLett.121.221802
    The first evidence of events consistent with the production of a single top quark in association with a photon is reported. The analysis is based on proton-proton collisions at sqrt[s]=13  TeV and recorded by the CMS experiment in 2016, corresponding to an integrated luminosity of 35.9  fb^{-1}. Events are selected by requiring the presence of a muon (μ), a photon (γ), an imbalance in transverse momentum from an undetected neutrino (ν), and at least two jets (j) of which exactly one is identified as associated with the hadronization of a b quark. A multivariate discriminant based on topological and kinematic event properties is employed to separate signal from background processes. An excess above the background-only hypothesis is observed, with a significance of 4.4 standard deviations. A fiducial cross section is measured for isolated photons with transverse momentum greater than 25 GeV in the central region of the detector. The measured product of the cross section and branching fraction is σ(pp→tγj)B(t→μνb)=115±17(stat)±30(syst)  fb, which is consistent with the standard model prediction.
    Matched MeSH terms: Motion
  10. Lund LA, Omar Z, Khan I
    Heliyon, 2019 Mar;5(3):e01345.
    PMID: 30949601 DOI: 10.1016/j.heliyon.2019.e01345
    This study investigates the numerical solutions of MHD boundary layer and heat transfer of the Williamson fluid flow on the exponentially vertical shrinking sheet, having variable thickness and thermal conductivity under effects of the velocity and thermal slip parameters. It is also assumed that shrinking/stretching velocity, as well as the wall temperature, has the exponential function form. In this study, the continuity, momentum and energy equations with buoyancy parameter and Hartmann number are incorporated especially in the Williamson fluid flow case. Similarity transformation variables have been employed to formulate the ordinary differential equations (ODEs) from partial differential equations (PDEs). The resultant ODEs are solved by shooting method with Runge Kutta of fourth order method in Maple software. The effects of the different applied non-dimensional physical parameters on the boundary layer and heat transfer flow problems are presented in graphs. The effects of Williamson parameter, Prandtl number, and slip parameters on velocity and temperature profiles have been thoroughly demonstrated and discussed. The numerical results show that the buoyancy force and the slip parameters contribute to the occurrence of the dual solutions on the boundary layer and heat transfer flow problems. Furthermore, the stability analysis suggests that the first solution is stable and physically possible.
    Matched MeSH terms: Motion
  11. Fernandez IG, Ahmad SA, Wada C
    Sensors (Basel), 2020 Aug 19;20(17).
    PMID: 32825029 DOI: 10.3390/s20174675
    Falls are among the main causes of injuries in elderly individuals. Balance and mobility impairment are major indicators of fall risk in this group. The objective of this research was to develop a fall risk feedback system that operates in real time using an inertial sensor-based instrumented cane. Based on inertial sensor data, the proposed system estimates the kinematics (contact phase and orientation) of the cane. First, the contact phase of the cane was estimated by a convolutional neural network. Next, various algorithms for the cane orientation estimation were compared and validated using an optical motion capture system. The proposed cane contact phase prediction model achieved higher accuracy than the previous models. In the cane orientation estimation, the Madgwick filter yielded the best results overall. Finally, the proposed system was able to estimate both the contact phase and orientation in real time in a single-board computer.
    Matched MeSH terms: Motion
  12. ALIATULNAJIHA AYUB, MOHD ASAMUDIN A RAHMAN
    MyJurnal
    A numerical study is conducted to determine the Vortex Induced Motion (VIM) effects on Deep-Draft Semi-Submersibles (DDSS). The VIM phenomena is a crucial problem that can cause severe impact on the fatigue life of mooring risers in DDSS. Therefore, a comprehensive numerical simulation is conducted using the Acusolve computational fluid dynamics (CFD) software. Five models of immersed columns with different aspect ratios (ie. 0.6, 0.8, 1.0, 1.2 and 1.4) are numerically investigated under two different incidence angles, which are 0° and 45°. The transverse and in-line vibration amplitude, amplitude of lift force coefficient and vortex shedding are analyzed. The numerical measurements are obtained to see the response of horizontal plane motions, which are transverse, in line and yaw motions. This study with detailed numerical results from parametric data will contribute future studies and the comparisons are made to demonstrate the capability of the present CFD approach.
    Matched MeSH terms: Motion
  13. Keller M, Kastenberger T, Anoar AF, Kaiser P, Schmidle G, Gabl M, et al.
    Arch Orthop Trauma Surg, 2020 Jun;140(6):835-842.
    PMID: 32124031 DOI: 10.1007/s00402-020-03386-7
    INTRODUCTION: This study evaluated the use of a free vascularized bone graft with and without cartilage from the medial femoral condyle (MFC) in patients with recalcitrant scaphoid non-union, with a special focus on union rates and the osteochondral graft for proximal pole destruction.

    MATERIALS AND METHODS: Thirty-eight avascular scaphoid non-unions in 37 patients who were treated with a free osteoperiosteal or osteochondral MFC graft were retrospectively evaluated (mean follow-up 16 months). Bone union, the scapholunate and the radiolunate angles were evaluated on X-ray images. The range of motion, grip strength, VAS, DASH and PRWE scores were evaluated clinically.

    RESULTS: The overall union rate was 95%. Bone union was achieved in 27 out of 29 (93%) scaphoids treated with a free osteoperiosteal MFC grafts and in 9 out of 9 (100%) scaphoids treated with a free osteochondral MFC graft. The range of motion remained almost unchanged, while grip strength increased significantly (34 kg vs. 44 kg) and the VAS (22-5), DASH (59-19) and PRWE (62-30) score decreased significantly. The scapholunate (71°-65°) and radiolunate (28°-18°) angle decreased. No major donor site morbidity was observed. Postoperative complications were observed in eight cases (21%).

    CONCLUSIONS: The vascularized medial femoral bone graft leads to a good functional outcome in the treatment of scaphoid non-unions. The graft provides adequate blood supply and structural stability to the scaphoid. A proximal pole destruction can be replaced using an osteochondral graft with promising short-term results preventing carpal osteoarthritis and collapse.

    Matched MeSH terms: Range of Motion, Articular
  14. Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.
    Phys Rev Lett, 2017 Apr 21;118(16):162301.
    PMID: 28474955 DOI: 10.1103/PhysRevLett.118.162301
    The relative modification of the prompt ψ(2S) and J/ψ yields from pp to PbPb collisions, at the center-of-mass energy of 5.02 TeV per nucleon pair, is presented. The analysis is based on pp and PbPb data samples collected by the CMS experiment at the LHC in 2015, corresponding to integrated luminosities of 28.0  pb^{-1} and 464  μb^{-1}, respectively. The double ratio of measured yields of prompt charmonia reconstructed through their decays into muon pairs, (N_{ψ(2S)}/N_{J/ψ})_{PbPb}/(N_{ψ(2S)}/N_{J/ψ})_{pp}, is determined as a function of PbPb collision centrality and charmonium transverse momentum p_{T}, in two kinematic intervals: |y|<1.6 covering 6.5
    Matched MeSH terms: Motion
  15. Ahmad, D., Jamarei, O., Sulaiman, S., Fashina, A.B., Akande, F.B.
    MyJurnal
    The motion resistances of 660 mm pneumatic and rigid bicycle wheels of the same rim diameter were measured experimentally using the developed tractor-towed single non-lug narrow wheel motion resistance test rig for traction studies. The motion resistances measured were taken to be the towing forces determined in real time using Mecmesin Basic Force Gauge (BFG 2500). The test variables included two test surfaces [tilled and wet (mud) surfaces], the dynamic load and the towing velocity. The tyre inflation pressure of 414 kPa was chosen to make the surface synonymous with that of the rigid wheel. Motion resistance ratios of the two wheels were determined empirically and through semi-empirical approach. The motion resistances of the rigid wheel were found to be greater than those of the pneumatic wheel for both surfaces. Consequently, the motion resistance ratios of the rigid wheel were greater than those obtained
    from the pneumatic wheel. Analysis of variance showed that there were significant differences between the means of the motion resistance measured on the test surfaces, as well as between the two wheels and their interactions with the test surfaces. The motion resistance ratio exhibited a linear relationship with the towing velocity, while the relationship with the dynamic load was quadratic. However, such a relationship is either direct or inverse with the respective variables. The motion resistance ratio models for the pneumatic and rigid wheels showed that on different test conditions of the dynamic loads and the towing velocities, the relationships between the motion resistance ratio and the dynamic load, and motion resistance with dynamic load were also different.
    Matched MeSH terms: Motion
  16. Tai, C.C., Abbas, A.A., Varaprasad, M., Choon, S.K.
    Malays Orthop J, 2007;1(1):22-25.
    MyJurnal
    We report on the medium term outcome of five patients (ten hips) who underwent one stage bilateral total hip arthroplasty. Both Harris Hip Scores and Oxford Hip Scores improved postoperatively as did range of motion. There was no radiographic evidence of loosening in any hip arthroplasty involved in this study, however one revision surgery was needed due to periprosthetic fracture. There were no increased medical complications. Based on our limited experience, we believe that one stage bilateral total hip arthroplasty is safe in selected patients.
    Matched MeSH terms: Range of Motion, Articular
  17. Zainap Lamat, Yuhani Jamian, Mohd Agus Adib Eskandar
    MyJurnal
    Sarawak has experienced several earthquakes of local origin and was also affected by long-distance earthquake that originated from Southern Philippine and the Straits of Macassar, Sulu Sea and Celebes Sea. The objectives for this study were to conduct site specific ground response analysis and develop design response spectra for Bakun area by using 1-D equivalent linear ground response analysis. The site characterisation was carried out utilising the soil profile and soil property data of the selected site. Local surface fault ruptures were investigated for possible hazards due to intraplate earthquakes. Earthquake ground motion records were selected based on characteristics of the controlling earthquakes for an area and the maximum magnitude faults were considered for risk assessment. The site-specific response spectra represent the predicted surface ground motions that reflect the levels of strong motion amplitude and frequency content at a particular site. The site-specific ground response analysis for Bakun site found that the peak ground acceleration at bedrock was amplified from 0.16 g to 0.33 g at the ground surface.
    Matched MeSH terms: Motion
  18. Mohsen Salarpour, Milad Jajarmizadeh, Zulkifli Yusop, Fadhilah Yusof
    Sains Malaysiana, 2014;43:1865-1871.
    The modeling of rainfall-runoff relationship in a watershed is very important in designing hydraulic structures, controlling flood and managing storm water. Artificial Neural Networks (ANNs) are known as having the ability to model nonlinear mechanisms. This study aimed at developing a Generalized Feed Forward (GFF) network model for predicting annual flood (depth) of Johor River in Peninsular Malaysia. In order to avoid over training, cross-validation technique was performed for optimizing the model. In addition, predictive uncertainty index was used to protect of over parameterization. The governing training algorithm was back propagation with momentum term and tangent hyperbolic types was used as transfer function for hidden and output layers. The results showed that the optimum architecture was derived by linear tangent hyperbolic transfer function for both hidden and output layers. The values of Nash and Sutcliffe (NS) and root mean square error (RMSE) obtained 0.98 and 5.92 for the test period. Cross validation evaluation showed 9 process elements is adequate in hidden layer for optimum generalization by considering the predictive uncertainty index obtained (0.14) for test period which is acceptable.
    Matched MeSH terms: Motion
  19. Md. Jashim Uddin, Md. Ismail A, Hamad M
    Sains Malaysiana, 2012;41:1139-1148.
    The steady laminar combined convective flow with heat and mass transfer of a Newtonian viscous incompressible fluid over a permeable flat plate with linear hydrodynamic and thermal slips has been investigated numerically. The velocity of the external flow, the suction/injection velocity and the temperature of the plate surface are assumed to vary nonlinearly following the power law with the distance along the plate from the origin. Lie group analysis is used to develop the similarity transformations and the governing momentum, the energy conservation and the mass conservation equations are converted to a system of coupled nonlinear ordinary differential equations with the associated boundary conditions. The resulting equations are solved numerically using the Runge-Kutta-Fehlberg fourth-fifth order numerical method. The effects of hydrodynamic slip parameter (a), thermal slip parameter (b), suction/injection parameter (fw), power law parameter (m), buoyancy ratio parameter (N), Prandtl number (Pr) and Schmidt number (Sc) on the fluid flow, heat transfer and mass transfer characteristics are investigated and presented graphically. We have also shown the effects of the Reynolds number (Re) and the power law parameter (m) on the velocity slip and the thermal slip factors. Good agreement is found between the numerical results of the present paper and published results.
    Matched MeSH terms: Motion
  20. Nur Husna Md. Yusoff, Md. Jashim Uddin, Ahmad Izani Md. Ismail
    Sains Malaysiana, 2014;43:151-159.
    A combined similarity-numerical solution of the magnetohydrodynamic boundary layer slip flow of an electrically conducting non-Newtonian power-law nanofluid along a heated radiating moving vertical plate is explored. Our nanofluid model incorporates the influences of the thermophoresis and the Brownian motion. The basic transport equations are made dimensionless first and then suitable similarity transformations are applied to reduce them into a set of nonlinear ordinary differential equations with the associated boundary conditions. The reduced equations are then solved numerically. Graphical results for the non-dimensional flow velocity, the temperature and the nanoparticles volume fraction profiles as well as for the friction factor, the local Nusselt and the Sherwood numbers are exhibited and examined for various values of the controlling parameters to display the interesting aspects of the solutions. It was found that the friction factor increases with the increase of the magnetic field (M), whilst it is decreased with the linear momentum slip parameter (a). The linear momentum slip parameter (a) reduces the heat transfer rates and the nanoparticles volume fraction rates. Our results are compatible with the existing results for a special case.
    Matched MeSH terms: Motion
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