LIVIVO - Das Suchportal für Lebenswissenschaften

switch to English language
Zurück zur letzten Suche Suchhistorie
Erweiterte Suche

Ihre letzten Suchen

  1. AU="Byeongil Kim"
  2. AU="Bosch, Peter J"
  3. AU="Colin R. Jackson" AU="Colin R. Jackson"
  4. AU="Tan, Bruce K"
  5. AU="Alagappan, Annamalai"
  6. AU="Howard, Lauren L."
  7. AU=Nataraj Gita AU=Nataraj Gita
  8. AU="Zi-Lan Wang"
  9. AU="John F. Whitesides"
  10. AU="Kim, Eun-Kyu"
  11. AU="Shapiro, Anne Nicole"
  12. AU="Joseph R. Francica"
  13. AU="Stringer, Kathleen A."
  14. AU="López-Cobo, Sheila"
  15. AU="Sznitman, Raphael"
  16. AU="Philippe Ciais"
  17. AU="Suprasert, Prapaporn"
  18. AU="Chang, Yinshui"
  19. AU="de Oliveira, Alexandre Adalardo"
  20. AU="D'Angelo Exeni, Maria Eugenia"
  21. AU="Godoy, Carla"

Suchergebnis

Treffer 1 - 10 von insgesamt 11

Suchoptionen

  1. Artikel ; Online: Sub-Harmonic Response Analysis of Nonlinear Dynamic Behaviors Induced by Piecewise-Type Nonlinearities in a Torsional Vibratory System

    Jong-Yun Yoon / Byeongil Kim

    Applied Sciences, Vol 12, Iss 1845, p

    2022  Band 1845

    Abstract: Piecewise-type nonlinearities, such as clutch dampers in a torsional system, induce complex nonlinear dynamic behaviors that resemble super- and sub-harmonic responses. This study focuses on investigating the sub-harmonic responses induced by piecewise- ... ...

    Abstract Piecewise-type nonlinearities, such as clutch dampers in a torsional system, induce complex nonlinear dynamic behaviors that resemble super- and sub-harmonic responses. This study focuses on investigating the sub-harmonic responses induced by piecewise-type nonlinearities in the middle of various dynamic behaviors in a torsional vibratory system. To examine the dynamic characteristics in a sub-harmonic regime, the harmonic balance method (HBM) was implemented. Its results were compared with the numerical simulation (NS). To reveal the sub-harmonic responses, the input conditions of the HBM were modified with a small number of input values. In addition, bifurcation diagrams were numerically determined and projected onto stable and unstable solutions of the HBM to examine the effective dynamic behaviors within the unstable regimes. The results of the HBM with the modified input conditions reveal the sub-harmonic effects well, and the comparisons of bifurcation diagrams under unstable conditions lead to an understanding of the complex dynamic behaviors. Overall, this study suggests the first analytical technique to determine the sub-harmonic responses with the HBM, and second investigates the complex dynamic behaviors in a practical vibratory system by considering the bifurcations in the unstable regimes.
    Schlagwörter harmonic balance method ; piecewise-type nonlinearities ; sub-harmonic response ; bifurcation ; multi-staged clutch damper ; torsional system ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Sprache Englisch
    Erscheinungsdatum 2022-02-01T00:00:00Z
    Verlag MDPI AG
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  2. Artikel ; Online: Optimal placement criteria of hybrid mounting system for chassis in future mobility based on beam-type continuous smart structures

    Yang Qiu / Dongwoo Hong / Byeongil Kim

    Scientific Reports, Vol 13, Iss 1, Pp 1-

    2023  Band 17

    Abstract: Abstract Recently, research into the development of hybrid and electric vehicles has been vigorously undertaken, indicating a trend toward the replacement of internal combustion engine vehicles. However, while high efficiency and light weight are crucial ...

    Abstract Abstract Recently, research into the development of hybrid and electric vehicles has been vigorously undertaken, indicating a trend toward the replacement of internal combustion engine vehicles. However, while high efficiency and light weight are crucial in the development of vehicles, they increase the excitation force of the engine. In addition, sensor placement in future mobility is very important since it causes malfunctioning of autonomous driving systems when the location and orientation of sensors are changed due to excessive vehicle vibration. To reduce the structure-borne noise and vibration caused by engine excitation, an active engine mounting system must be installed in an optimal location. Thus, in this study, to determine the optimal location for an active engine mounting system applied to a beam structure, a series of simulations with two different methodologies are performed. The overall beam structure with two active mounting systems is modeled based on the lumped parameter model. To determine the optimal position of the active mounting system, it is moved to equal intervals, and the force and phase of the active mounts at each location combination are calculated based on static and dynamic methods. The optimal position is suggested such that the vibration reduction is maximized, while the applied force is minimized. Additionally, a feasibility experiment is conducted to validate the proposed criteria and confirm the simulation results. The results demonstrate that the optimal location of the active engine mounting system with a minimized force requirement and maximized vibration reduction can be identified.
    Schlagwörter Medicine ; R ; Science ; Q
    Thema/Rubrik (Code) 621
    Sprache Englisch
    Erscheinungsdatum 2023-02-01T00:00:00Z
    Verlag Nature Portfolio
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  3. Artikel ; Online: Quantification of active bearing input force for vibration reduction performance of unbalanced rotor systems

    Dongwoo Hong / Hyeongill Lee / Youkyung Han / Byeongil Kim

    Scientific Reports, Vol 13, Iss 1, Pp 1-

    2023  Band 13

    Abstract: Abstract Recently, rotating machinery has been widely applied in various mechanical systems such as hydroelectric and nuclear power plants. When mechanical systems are operated, the main rotor is rotated to manufacture the product. If a fault occurs in ... ...

    Abstract Abstract Recently, rotating machinery has been widely applied in various mechanical systems such as hydroelectric and nuclear power plants. When mechanical systems are operated, the main rotor is rotated to manufacture the product. If a fault occurs in the rotor, then the system is damaged. Thus, to avoid malfunction of the system and rotor damage, vibration issues because of bending, misalignment, and imbalance should be considered. In this regard, a smart structure-based active bearing system is extensively researched and developed to control rotor vibration. This system can continuously improve the noise, vibration, and harshness performance under various operating conditions by controlling the dynamic characteristics of the active bearing. This study focused on the effect of rotor motion control by quantifying the active bearing force and phase when an active bearing was applied in a simple rotor model. A simple rotor with two active bearing systems was modeled based on lumped-parameter modeling. In the rotor model, the active bearing, which had two piezoelectric actuators and rubber grommets placed in both the x- and y-directions, was located on both sides to control the vibration. The interaction between the rotor and the active bearing system was considered to quantify the force and phase of this system. Furthermore, through simulation, the motion control effect was validated when an active bearing was applied in the rotor model.
    Schlagwörter Medicine ; R ; Science ; Q
    Thema/Rubrik (Code) 670
    Sprache Englisch
    Erscheinungsdatum 2023-06-01T00:00:00Z
    Verlag Nature Portfolio
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  4. Artikel ; Online: Vibration characteristics of an active mounting system for motion control of a plate-like structure in future mobilities

    Dongwoo Hong / Yang Qiu / Byeongil Kim

    Scientific Reports, Vol 13, Iss 1, Pp 1-

    2023  Band 17

    Abstract: Abstract The vibration and noise caused by electric motors in hybrid and electric vehicles (EVs) generate complex signals with a mid-frequency band, which causes uncomfortable vibration and noise. In order to isolate the vibration and noise, active ... ...

    Abstract Abstract The vibration and noise caused by electric motors in hybrid and electric vehicles (EVs) generate complex signals with a mid-frequency band, which causes uncomfortable vibration and noise. In order to isolate the vibration and noise, active engine mounting systems based on smart structures have attracted attention. Thus, in this study, the vibration attenuation performance was validated through simulation and feasibility experiments by applying an active mounting system using a piezoelectric stack actuator. A plate structure with three paths, consisting of two passive paths and one active path, was modeled using the lumped parameter method. The source part was excited by a sinusoidal and modulated signal with a mid-frequency band to validate the vibration attenuation performance. Furthermore, (1) mathematical modeling with a source-path-receiver structure was proposed based on lumped parameter modeling, (2) normalized least mean square (NLMS) and multi-NLMS algorithms were applied to implement motion control, and (3) a principal experimental setup was designed to validate the simulation results. Through this process, the vibration attenuation performance of the proposed active mount structure was validated.
    Schlagwörter Medicine ; R ; Science ; Q
    Thema/Rubrik (Code) 621 ; 690
    Sprache Englisch
    Erscheinungsdatum 2023-09-01T00:00:00Z
    Verlag Nature Portfolio
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  5. Artikel ; Online: Stability and bifurcation analysis of super- and sub-harmonic responses in a torsional system with piecewise-type nonlinearities

    Jong-Yun Yoon / Byeongil Kim

    Scientific Reports, Vol 11, Iss 1, Pp 1-

    2021  Band 18

    Abstract: Abstract The nonlinear dynamic behaviors induced by piecewise-type nonlinearities generally reflect super- and sub-harmonic responses. Various inferences can be drawn from the stability conditions observed in nonlinear dynamic behaviors, especially when ... ...

    Abstract Abstract The nonlinear dynamic behaviors induced by piecewise-type nonlinearities generally reflect super- and sub-harmonic responses. Various inferences can be drawn from the stability conditions observed in nonlinear dynamic behaviors, especially when they are projected in physical motions. This study aimed to investigate nonlinear dynamic characteristics with respect to variational stability conditions. To this end, the harmonic balance method was first implemented by employing Hill’s method, and the time histories under stable and unstable conditions were examined using a numerical simulation. Second, the super- and sub-harmonic responses were investigated according to frequency upsweeping based on the arc-length continuation method. While the stability conditions vary along the arc length, the bifurcation phenomena also show various characteristics depending on their stable or unstable status. Thus, the study findings indicate that, to determine the various stability conditions along the direction of the arc length, it is fairly reasonable to determine nonlinear dynamic behaviors such as period-doubling, period-doubling cascade, and quasi-periodic (or chaotic) responses. Overall, this study suggests analytical and numerical methods to understand the super- and sub-harmonic responses by comparing the arc length of solutions with the variational stability conditions.
    Schlagwörter Medicine ; R ; Science ; Q
    Thema/Rubrik (Code) 621
    Sprache Englisch
    Erscheinungsdatum 2021-12-01T00:00:00Z
    Verlag Nature Portfolio
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  6. Artikel ; Online: Quantification of Active Structural Path for Vibration Reduction Control of Plate Structure under Sinusoidal Excitation

    Dongwoo Hong / Byeongil Kim

    Applied Sciences, Vol 9, Iss 4, p

    2019  Band 711

    Abstract: The engines of electric and hybrid vehicles cause vibration and noise with complex frequency spectra. This tendency is observed especially for mid-frequency components. Therefore, there are limitations in achieving vibration attenuation using only ... ...

    Abstract The engines of electric and hybrid vehicles cause vibration and noise with complex frequency spectra. This tendency is observed especially for mid-frequency components. Therefore, there are limitations in achieving vibration attenuation using only structural changes, which is the conventional isolation method. A smart structure-based active engine mounting system is a core technology that can continuously improve the noise, vibration, and harshness performance under various operating conditions by continuously controlling the dynamic characteristics of the mount. It can replace the existing mount technology which supports the engine by realizing both static and dynamic stiffness. This study focuses on vibration reduction for a typical mid-frequency excitation. Based on a source⁻path⁻receiver structure, a mathematical model for a 3D plate structure with three active paths is proposed. The amplitude and phase of the actuator were calculated for the reduction of given vibrations on the basis of the model. When controlling with the proposed method, it was necessary to perform a large amount of computation and to newly define the modeling according to the structural change. To solve this inconvenience, the NLMS (normalized least mean squares) algorithm was applied, and the results were compared. It is shown that the application of the NLMS algorithm to perform the overall vibration reduction is more effective than the previous method.
    Schlagwörter plate structure ; NVH ; active path ; engine mounting system ; piezoelectric actuator ; rubber mount ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Thema/Rubrik (Code) 621
    Sprache Englisch
    Erscheinungsdatum 2019-02-01T00:00:00Z
    Verlag MDPI AG
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  7. Artikel ; Online: Development of Multi-DOF Model of Automotive LED Headlamp Assembly for Force Transmission Prediction Using MATLAB GUI

    Muhammad Moghees Ud Din / Byeongil Kim

    Applied Sciences, Vol 10, Iss 5906, p

    2020  Band 5906

    Abstract: The use of Light-emitting diodes (LEDs) in automobile headlamps began two decades ago. Since then, several design and efficiency improvements have been made. However, the reliability and durability of these LED systems remain uncertain. There are several ...

    Abstract The use of Light-emitting diodes (LEDs) in automobile headlamps began two decades ago. Since then, several design and efficiency improvements have been made. However, the reliability and durability of these LED systems remain uncertain. There are several approaches for reliability analysis, e.g., thermal, electrical, optical, or structural. The first three issues have been studied in the past, but there has been minimal focus on structural and dynamic durability. Uneven road conditions and impact forces acting on the headlamp module can damage components and misalign the aiming mechanism. Moreover, the functionality could be disturbed, thereby decreasing the efficiency of the system. To determine the forces acting inside the module on each component, this study proposes a simulation technique for predicting the magnitude of forces transmitted from the automobile chassis to the headlamp module under even and uneven road conditions. A vibration system with 23 degrees-of-freedom is developed and equations of motion are derived using Newton’s second law of motion. Solving this system of equations with Simulink and MATLAB provided the linear and angular displacements of each element, which were then utilized to calculate the forces transmitted through these elements. Two forcing conditions were compared and the locations with maximum forces are highlighted.
    Schlagwörter force transmission ; multi-degrees-of-freedom ; graphical user interface (GUI) ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Thema/Rubrik (Code) 620
    Sprache Englisch
    Erscheinungsdatum 2020-08-01T00:00:00Z
    Verlag MDPI AG
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  8. Artikel ; Online: Enhanced Adaptive Filtering Algorithm Based on Sliding Mode Control for Active Vibration Rejection of Smart Beam Structures

    Byeongil Kim / Jong-yun Yoon

    Applied Sciences, Vol 7, Iss 7, p

    2017  Band 750

    Abstract: This article investigates vibration rejection for a continuous smart structure using piezoelectric bimorph patches. Such a structure has inherent nonlinearities, such as hysteresis and creep, and the whole system may experience unexpected disturbances, ... ...

    Abstract This article investigates vibration rejection for a continuous smart structure using piezoelectric bimorph patches. Such a structure has inherent nonlinearities, such as hysteresis and creep, and the whole system may experience unexpected disturbances, uncertainties, and noise from external sources. Thus, it is very important to design the active control scheme carefully with adaptive filtering systems to deal with these conditions. An advanced adaptive filtering algorithm was developed based on the conventional least mean squares (LMS) method and sliding mode control for the active vibration rejection system. The sliding mode controller is applied to the standard LMS algorithm to overcome problems with misadjustment and excess error in an optimal manner. A numerical analysis and laboratory experiment show that the technique can significantly attenuate the vibration of the smart structure at different levels and broadband frequency spectra. In addition, unidentified impedance is chosen to change the distribution of the mass, and the robustness and the adaptivity of the proposed approach are verified. The experimental results show that the method can isolate impulse-type vibrations of at least 2.8 dB, even with the adjusted mass arrangement.
    Schlagwörter active vibration rejection ; adaptive filtering system ; filtered-X LMS ; sliding mode control ; least mean squares algorithm ; smart structures ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Thema/Rubrik (Code) 621
    Sprache Englisch
    Erscheinungsdatum 2017-07-01T00:00:00Z
    Verlag MDPI AG
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  9. Artikel ; Online: Development of Multi-Staged Adaptive Filtering Algorithm for Periodic Structure-Based Active Vibration Control System

    Qiu Yang / Kyeongnak Lee / Byeongil Kim

    Applied Sciences, Vol 9, Iss 3, p

    2019  Band 611

    Abstract: A digital adaptive filtering system is applied to various fields such as current disturbance, noise cancellation, and active vibration and noise control. The least mean squares (LMS) algorithm is widely adopted, owing to its simplicity and low ... ...

    Abstract A digital adaptive filtering system is applied to various fields such as current disturbance, noise cancellation, and active vibration and noise control. The least mean squares (LMS) algorithm is widely adopted, owing to its simplicity and low computational burden. A limitation of the LMS algorithm with fixed step size is the trade-off between convergence speed and stability. Several studies have tried to overcome this limitation by varying the step size according to filter input and error; however, the related algorithms with variable step size have not been suitable for signals with complex frequency spectra. As the error decreases, the quality of the output signal deteriorates due to the increase in the higher-order components, depending on the characteristics of the algorithm. Therefore, a novel adaptive filtering algorithm was proposed to overcome these drawbacks. It increased the stability of the system by decreasing the step size using an exponential function. In addition, the error was reduced through normalization using the power of the input signal in the initial state, and the misadjustments in the system were adjusted properly by introducing an energy autocorrelation function of instantaneous error. Furthermore, a novel multi-staged adaptive LMS (MSA-LMS) algorithm was introduced and applied to active periodic structures. The proposed algorithm was validated by simulation and observed to be superior to the conventional LMS algorithms. The results of this study can be applied to active control systems for the reduction of vibration and noise signals with complex spectra in next-generation powertrains, such as hybrid and electric vehicles.
    Schlagwörter least mean squares ; multi-staged adaptive LMS ; active vibration control ; Technology ; T ; Engineering (General). Civil engineering (General) ; TA1-2040 ; Biology (General) ; QH301-705.5 ; Physics ; QC1-999 ; Chemistry ; QD1-999
    Sprache Englisch
    Erscheinungsdatum 2019-02-01T00:00:00Z
    Verlag MDPI AG
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

  10. Artikel ; Online: Effects of Home-Based Computerized Cognitive Training in Community-Dwelling Adults With Mild Cognitive Impairment

    Ji Soo Baik / Ji Hong Min / Sung-Hwa Ko / Mi Sook Yun / Byunghoon Lee / Nae Yoon Kang / Byeongil Kim / Hyunsuk Lee / Yong-Il Shin

    IEEE Journal of Translational Engineering in Health and Medicine, Vol 12, Pp 97-

    2024  Band 105

    Abstract: Objective: There is a growing importance for the home-based (HB) support services, and computerized cognitive training (CCT) has been reported as an effective intervention for cognitive impairment. However, there is still a need for further verification ... ...

    Abstract Objective: There is a growing importance for the home-based (HB) support services, and computerized cognitive training (CCT) has been reported as an effective intervention for cognitive impairment. However, there is still a need for further verification of the effect of HB-CCT. This study aimed to determine the effectiveness of HB-CCT on the cognitive function of community-dwelling adults with mild cognitive impairment (MCI) as well as safety in its use. Methods: Fifty community-dwelling adults with MCI were included, of which 25 each were randomized to either HB-CCT or control groups. Evaluations of comprehensive cognition, memory, attention, language, executive function, and depression were performed before and after the intervention, including three times a week for eight weeks in the intervention group and eight weeks apart with no intervention in the control group. Results: In baseline and post-evaluation comparisons, the HB-CCT group showed significant improvements, while the control group did not show significant changes. Statistically significant variations were noted between the HB-CCT and control groups in all post-intervention evaluations relative to baseline. Additionally, no side effects were observed. Conclusion: Beneficial effects on cognition and depression were noted in the intervention group compared with the control group, suggesting that HB-CCT may be a positive tool for cognitive improvement in adults with MCI.
    Schlagwörter Cognitive function ; memory ; community dwelling ; aged ; computer-assisted instruction ; Computer applications to medicine. Medical informatics ; R858-859.7 ; Medical technology ; R855-855.5
    Thema/Rubrik (Code) 796
    Sprache Englisch
    Erscheinungsdatum 2024-01-01T00:00:00Z
    Verlag IEEE
    Dokumenttyp Artikel ; Online
    Datenquelle BASE - Bielefeld Academic Search Engine (Lebenswissenschaftliche Auswahl)

    Volltext online

    Zusatzmaterialien

    Kategorien

    Fernleihe an ZB MED

    Sie können sich den gewünschten Titel als lokale Nutzerin oder lokaler Nutzer von ZB MED direkt an den Standort Köln schicken lassen.

Zum Seitenanfang