• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2814-2820
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• 2011

Railway bridge, contact of vehicle needs to design considering the running safety about the running train load of the railway bridge, ride comfort and dynamic safety. Also, upper structure of the railway bridge has to satisfy design standard about moving load(train). So, the railway bridge has to satisfy the requirement for vertical acceleration of the bridge deck, vertical displacement of the bridge and face distortion, which is suggested railway design standard in Korea(2011.5.). In this study, it was investigated and evaluated to the running safety about the running train load of the railway bridge, ride comfort and dynamic safety with railway design standard for steel composite(Steel Box Girder) railway bridge considering KTX, freight train and standard train load.

• Journal of the Korean Society of Clothing and Textiles
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• v.24 no.7
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• pp.1073-1080
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• 2000

Moisture transfer property of fabrics has known as one of the most important factors deciding wearer's subjective comfort not only thermally but also of sensorial. As a decisive property of fabric materials in determining human sensorial comfort, moisture vapor management property of heat resistant workwear material was examined in terms of increasing and decreasing rate and maximum value of relative humidity in the microclimate under the sweat pulse situation. An unique moisture regulation index, B$_{d}$, was calculated from the measurements using a novel dynamic sweating hot plate apparatus and was used to assess the buffering capacity of fabrics against a moisture vapor sweat pulse.e.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.4
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• pp.139-147
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• 2001

2 DOF half-car model with 6 semi-active suspension units is utilized to evaluate the tracked vehicle dynamic performance simulated by several suspension control algorithms. The target of this research is to improve the ride comfort to maintain operator's handling capability when the tracked vehicle travels fast on the rough road. The control algorithms for suspension systems, such as full state feedback active, full state feedback semi-active, sky-hook active, sky-hook semi-active, and on-off systems, are evaluated and analyzed in view point of ride comfort. The dynamic performances of vehicle are expressed and evaluated by vibratory characteristic evaluation curves, performance indices and frequency characteristic curves. The simulation results show that the performances of sky-hook algorithms for ride comfort nearly follow those of full state feedback algorithms and on-off algorithm is recommendatory when the vehicle runs relatively fast.

• International Journal of Safety
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• v.6 no.1
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• pp.7-10
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• 2007

In this paper, we found that modification of the local flexibility (or local stiffness) of the 4 parts on which shock absorbers are mounted in the vehicle body has some influence the level of ride safety and comfort. Multi-body dynamic analysis considering the flexibility of the vehicle body is performed using MSC/ADAMS and MSC/NASTRAN. More concretely speaking, natural frequencies and mode shapes computed by MSC/NASTRAN are used as input data for multi-body dynamic analysis in MSC/ADAMS. It is confirmed that the ride comfort can be improved by appropriately changing the local stiffness of the vehicle body through several simulations using MSC/ADAMS.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.546-549
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• 2004

The T-50/A-50 Golden Eagle was developed for a supersonic trainer and light combat aircraft. At the design stage, vibration control plans were established and applied. For cockpit vibration, crew comfort vibration level was defined by the requirement of MIL-A-8892. It is found that the T-50/A-50 meets the requirement of cockpit vibration from the flight test data analysis. This paper contains the results of cockpit vibration analysis using the flight test data and the results of human vibration analysis lot the pilot inside aircraft. The human vibration level of pilot is increased as dynamic pressure is increased and at the specific high dynamic pressure, the ride comfort indicates 'a little uncomfortable'. Overall analysis results show that the vibration level of T-50/A-50 cockpit is tolerable and not critical for pilot's comfort.

• Coupled systems mechanics
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• v.8 no.2
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• pp.169-184
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• 2019

This research work presents a study that aims to assess the dynamic structural behaviour and also investigate the human comfort levels of a reinforced concrete building, when subjected to nondeterministic wind dynamic loadings, considering the effect of masonry infills on the global stiffness of the structural model. In general, the masonry fills most of the empty areas within the structural frames of the buildings. Although these masonry infills present structural stiffness, the common practice of engineers is to adopt them as static loads, disregarding the effect of the masonry infills on the global stiffness of the structural system. This way, in this study a numerical model based on sixteen-storey reinforced concrete building with 48 m high and dimensions of $14.20m{\times}15m$ was analysed. This way, static, modal and dynamic analyses were carried out in order to simulate the structural model based on two different strategies: no masonry infills and masonry infills simulated by shell finite elements. In this investigation, the wind action is considered as a nondeterministic process with unstable properties and also random characteristics. The fluctuating parcel of the wind is decomposed into a finite number of harmonic functions proportional to the structure resonant frequency with phase angles randomly determined. The nondeterministic dynamic analysis clearly demonstrates the relevance of a more realistic numerical modelling of the masonry infills, due to the modifications on the global structural stiffness of the building. The maximum displacements and peak accelerations values were reduced when the effect of the masonry infills (structural stiffness) were considered in the dynamic analysis. Finally, it can be concluded that the human comfort evaluation of the sixteen-storey reinforced concrete building can be altered in a favourable way to design.

• Journal of the korean Society of Automotive Engineers
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• v.8 no.3
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• pp.55-67
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• 1986

The safety and comfort of car seats wee studied by utilization of engineering analysis/ experiment and human engineering data. As important factors of the static seating comfort, static spring constant, body pressure distribution, driving posture were discussed. In connection with the dynamic seating comfort, vibrational characteristics of domestic car seats(natural frequencies, damping, frequency spectrum, transmission ratio)were measured and discussed. Finally, the safety of the seat was analyzed and evaluated through calculation and experiments.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.4
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• pp.70-75
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• 2018

This paper describes an Integrate Dynamic Control system with Brake System (IDCB) for SUV vehicles. The system was developed to stabilize the lateral dynamics, maintain the steerability and improve the ride comfort on various roads. A fuzzy logic control method is used to design the IDCB. The performance of the IDCB is validated under different road and driving conditions. The results show that the IDCB tracks the reference yaw rate under all tested conditions; in addition, it reduces the body slip angle and roll angle. When a vehicle runs on a split-${\mu}$ road and a brake input is applied, the IDCB virtually eliminates the lateral dynamics. Thus, the IDCB improves the lateral stability, preserves the steerability and enhances the ride comfort of vehicles.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1929-1934
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• 2011

Recently the maximum speed becomes the most important performance in high speed train. But the speed up of train will not give the passenger good riding comfort. The semi-active suspension system by using variable damper with hydraulic solenoid valve is used to solve this problem. But the variable damper with hydraulic solenoid valve requires tank for supplying fluid. In this study, the MR(Magneto Rheological) damper was considered instead of hydraulic variable damper in order to improve riding comfort. Dynamic simulation was conducted for semi-active suspension system with MR damper was made by using Matlab-Simulink S/W. According to control strategy of MR damper for improving ride comfort in railway vehicle, The riding comfort of the railway vehicle with semi-active suspension system was analyzed and compared with conventional suspension system by using the program.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.12 no.3
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• pp.204-212
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• 2002

The ride comfort is one of the important dynamic performances of railway vehicle and is affected by the various factors, such as vibration, sound, temperature, humidity, etc. In general, vibration is known to be a major effect of rode comfort. There are many studies on the evaluation methods of ride comfort in the railway vehicle vibration. Each of the evaluation methods suggested by Spelling and in the standards recommends a different evaluation method and guidance. So users must review whether they can apply it to their railway system or not. In this study, we have suggested the relationship between several evaluation methods using the statistical vibration model based on the experimental data.