• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.5
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• pp.472-478
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• 2013

This paper presents optimal design procedures of mount based on a magnetorheological(MR) fluid to isolate the vibration in heavy diesel engine system. At first, frequency response and force-displacement transmissibility methods are used to get required damping force that is necessary for effective vibration isolation. From this result, a new type of high damping force engine mount is proposed and the governing equation of Bingham plastic behavior of MR fluid in flow path is mathematically derived under cylindrical coordinates. Finally, parametric design optimization featuring finite element is performed using ANSYS software to get the required damping force in MR mount system which can be used to reduce engine vibration. Damping force of the MR mount is then determined as an objective function in this analysis based on ANSYS. Furthermore, Magnetic analysis is then applied in this process.

• International Journal of Reliability and Applications
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• v.17 no.2
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• pp.137-147
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• 2016

The engine mount of a car subjected to a pre-load related to the weight of the engine, and acts to insulate the vibration coming from the engine by moving on large or small displacement depending on the driving condition of the car. The vibration insulation of the engine mount is an effect obtained by dissipating the mechanical energy into heat by the viscosity characteristic of the rubber and the microscopic behavior of the additive carbon black. Therefore, dynamic stiffness from the intrinsic properties of rubber filled with carbon black at the design stage is an important design consideration. In this paper, we introduced a hyper-elastic, visco-elastic and elasto-plastic model to predict the dynamic characteristics of rubber, and developed a fitting program to determine the material model parameters using MATLAB. The dynamic characteristics analysis of the rubber insulator of the ACTIVE MOUNT was carried out by using MSC.MARC nonlinear structural analysis software, which provides the dynamic characteristics material model. The analysis results were compared with the dynamic characteristics test results of the rubber insulator, which is one of the active mount components, and the analysis results were confirmed to be valid.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.6
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• pp.561-571
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• 2022

An optical mirror assembly is an opto-mechanically coupled system as the optical and mechanical behaviors interact. In the assembly, a flexure mount attached to an optical mirror should be flexible in the radial direction, but rigid for the remaining degrees of freedom for supporting the mirror rigidly and suppressing the wavefront error of the optical mirror. This work presents an optimal design of the flexure mount using topology optimization with thermal stress constraint. By simplifying the optical mirror assembly into finite shell elements, topology optimization model was built for efficient design and good machinability. The stress at the boundary between the optical mirror and the mount together with the first natural frequency were applied as constraints for the optimization problem, while the objective function was set to minimize the strain energy. As a result, we obtained the optimal design of the flexure mount yielding the improved wavefront error, proper rigidity, and machinability.

• Journal of Biosystems Engineering
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• v.29 no.5 s.106
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• pp.385-394
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• 2004

The objectives of this study were to investigate the effectiveness of rubber as an engine mount of walking-type cultivators and to determine its optimal spring constant and damping coefficient using a dynamic simulation of the engine mount system. Four different types of rubber mounts were tested to determine their spring constants and damping coefficients, and the best type was selected for the isolation of the engine vibrations transmitted to the handle. The total vibration levels transmitted to the handle when the rubber mounts weren't installed were 17.52 $m/s^2$. The total vibration levels transmitted to the handle when the rubber mounts were installed were 10.69 $m/s^2$ for Stripe 1, 11.33$m/s^2$ for Stripe 2, 10.92$m/s^2$ for Stripe 3 and 14.19$m/s^2$ for Hive, respectively, resulting in an average of $30\%$ reduction when compared with that without the engine mount. A dynamic model of the cultivator's engine-mount system and its simulation program were developed and verified. A method was proposed to determine the optimal spring constant and damping coefficient of the engine-mount system. It was found from the simulation that a spring constant of 4,100 kN/m and the largest damping coefficient were the most effective for the vibration isolation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.93-99
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• 2012

This paper presents an optimal design of magnetorheological (MR) fluid based mount (MR mount in short) which can be applicable to vibration control of diesel engine of ship. In this work, a mixed - mode including squeeze mode, flow mode and shear mode is proposed and designed. In order to determine actuating damping force of MR mount required for efficient vibration control, excitation force from diesel engine is analyzed. In this analysis, a model of V-type engine is considered and the relationship between velocity and pressure of gas in torque of the piston is derived. Subsequently, by integrating the field-dependent rheological properties of commercially available MR fluid with the excitation force an appropriate size of MR mount is designed. In addition, in order to achieve maximum actuating force with geometric constraints design optimization is undertaken using ANSYS software. Through the magnetic density analysis, optimal design parameters such as bottom gap and radius of coil are determined.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.6
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• pp.80-92
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• 2021

Mount Tai, with an elevation of 1,532 meters, has a reputation as 'The Most Revered of the Five Sacred Mountains(五嶽獨尊)', despite not being the highest mountain in China. The literati of the past dynasties created a multitude of works based on the landscape of Mount Tai. Traditional literature is a part of national culture that directly reflects the national characteristics and styles, and is an important part of humanities, which can be linked to landscapes. The purpose of this study is to investigate the landscape elements and characteristics of Mount Tai by analyzing the landscape types and elements and the Kernel Density, Mean Center and Standard Deviational Ellipse of the landscape elements appearing in the representative poems of traditional literature. The research results of this study are summarized as follows. First, Mount Tai is a scenic spot dominated by human activities, different from the natural landscape of prior research related to scenic spots. Second, among the landscape elements of Mount Tai, the importance of "sunrise", "cyan", "towering" and "majestic", "Divine Dragon" is confirmed, symbolizing the hope, brightness, vitality, national stability and prosperity represented by Mount Tai, which can explain the leadership position of Mount Tai. Third, it can be found from the poems about Mount Tai that various landscape elements were embodied in belief (the behavior of gods or emperors) in the Pre-Qin, Sui and Tang dynasties, while in modern times, landscape elements are shown by action (climbing and looking far into distance), so it can be said that the landscape elements have changed from belief landscapes to experience landscapes. Fourth, the spatial distribution of landscape elements in the past dynasties was widely distributed in the Daiding(岱頂). Approaching the modern times, the mean center moved from south outside of Mount Tai to the summit of Mount Tai, and the spatial distribution changed from a widely scattered distribution to narrow linear distribution centered on Mount Tai. The present study is of great significance to provide key factors or spaces for future landscape protection and restoration of Mount Tai.

• 대한핵의학회:학술대회논문집
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• 1997.05a
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• pp.124-126
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• 1997

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.8
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• pp.767-773
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• 2010

In the present work, vibration control performance of piezoactuator-based active mount system for unmanned aero vehicle(UAV) equipment is evaluated via hardware in the loop simulation(HILS). At first, the vibration level of UAV is measured and from this vibration data, the proper piezostack actuator is selected. Then, the dynamic model of active mount system including four active mounts and UAV camera equipment is derived. In order to evaluate vibration control performance, the HILS system is constructed. The proposed mount is prepared as hardware part and the other mounts are considered in software part. A sliding mode controller is designed and implemented to the HILS system. Effective vibration control results are presented in both time and frequency domains.

• 대한예방의학회:학술대회논문집
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• 1994.02a
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• pp.549-559
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• 1994

A subgroup or workers from a secondary lead smelter was defined to include those with blood lead levels not exceeding $80{\mu}g/100\;ml$ and with no pest history of elevated blood lead. Central nervous system symptoms (tiredness, sleeplessness, irritability, headache) were reported by 55% of the group and muscle and joint pain by 39%. Zinc proteporphyrin (ZPP) levels were elevated in 71% or cases. Low hemoglobin levels (less than 14 gm/l00 ml) were round in more than a third of the workers. While BUN and creatinine were mostly in the normal range, there - nevertheless n correlation between ZPP and both BUN and creatinine. Reduced nerve-conduction velocities were present in 25% or the group; this was not significantly different from findings in Ii control group. The data indicate that n blood level of $80{\mu}g/100\;ml$ is an inappropriate biological guide in the prevention or lead disease.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.4
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• pp.386-392
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• 2008

This paper presents active vibration control performance of a hybrid mount. The proposed hybrid mount is devised by adopting both piezostack as an active actuator and rubber as a passive element. After experimentally identifying actuating force characteristics of the piezostack and dynamic characteristics of the rubber, the hybrid mount was designed and manufactured. Subsequently, a vibration control system with a specific mass loading is constructed, and its governing equations of motion are derived. In order to actively attenuate vibration transmitted from the base, a feedforward controller is formulated and experimentally realized. Vibration control responses are then evaluated in time and frequency domains.