• Tribology and Lubricants
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• v.2 no.1
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• pp.69-77
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• 1986

The motion of journal in a bearing is considered separately as rotation and translation, and then the equations of motion are derived. The bearing load capacities for these motions are calculated from the lubrication theory. The numeric integration of the equations of motion gives various journal orbit depending on force cycles and bearing parameters.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.111-123
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• 2006

In the design of bridges, exact evaluation of traffic loading is very important for the safety and maintenance of bridges. In general, traffic loading is represented by live load (including impact load) and fatigue load. For exact evaluation of traffic loading, it is important to get reliable and comprehensive truck data including the traffic and weight information. It requires the development of Bridge Weigh-In-Motion (BWIM), which measures the truck weights without stopping the traffic. Objectives of the study is (1) to develop the BWIM system, (2) to verified the system in bridges in Highways.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.4D
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• pp.511-518
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• 2011

Truck weight data are essential for road infrastructure design, maintenance and management. WIM (Weigh-In-Motion) system provides highway planners, researchers and officials with statistical data. Recently high speed WIM data also uses to support a vehicle weight regulation and enforcement activities. This paper aims at developing axle load estimating models with high speed WIM data collected from national highway. We also suggest a method to estimate axle load using simple regression model for WIM system. The model proposed by this paper, resulted in better axle load estimation in all class of vehicle than conventional model. The developed axle load estimating model will used for on-going or re-calibration procedures to ensure an adequate level of WIM system performance. This model can also be used for missing axle load data imputation in the future.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1709-1712
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• 2008

The trunk is inclined to the loaded side when carrying an object as one of activities of daily living. As the reaction to this behavior the human body may be inclined to his/her trunk to unloaded side. The present study investigated the biomechanical effects of weight variation for sided load carriage during walking upon joint moments and muscle torques, through the tracker agent and joint driving dynamic analysis. To perform the experiment one male was selected as subject for the study. Gait analysis was performed by using a 3D motion analysis system. Thirty nine 14mm reflective markers, according to the plug-in marker set, were attached to the subject. We used BRG.LifeMOD(Biomechanics Research Group, Inc., USA), for skeletal modeling and inverse and joint driving dynamic simulation during one gait cycle. In walking with a sided load carriage, the subject modeled held the carriage with the right hand, which weighed 0, 5, 10, 15kg, 20kg respectively. The result of this simulation showed that knee and hip in the coronal plane were inclined to the loaded side and loaded side had larger moments as the sided load carriage was increased. On the other hand thoracic and lumbar in the coronal plane had larger negative values as the sided loaded carriage was increased. The thoracic and lumbar in the transverse plane also had larger values as the sided load was increased. And the several muscles of loaded side were increased as increasing sided load. It could be concluded that human body is adopted to side loaded circumstances by showing more biologic force. These results could be very useful in analysis for delivery motion of daily life.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1169-1172
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• 2005

For elderly people, an advanced training machine that uses actuator and can adjust load according to muscle activity is proposed. The proposed machine allows users to have a safe and effective training through exercise close to ordinal motion appears in daily life such as stretching or stooping motion. A muscle activity sensor real-timely monitors the activation level of user's muscle during the exercise and the training load is adjusted based on the measured data. The training load is exerted and continuously controlled by electric/pneumatic actuator.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.2
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• pp.125-134
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• 2003

In order to rate current bridge load carrying capacity, typically two methods are used. These are Allowable Stress Rating (ASR) and Load Factor Rating (LFR). Using the rating factors, there are many attempts to make a connection between rating factors and probability concept. The main purpose of the paper is computing the probability of overload using rating factors and probability concept. In this paper, the load rating methods are briefly explained, and the probability concept is connected to rating factors by using live load from Weigh-in-Motion (WIM). Based on the live load model and rati ng factor, the computation procedure of the probability of overload is explained.

• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.15-21
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• 2005

In this paper, the procedure of generation and application of nonlinear wave loads for structural design of large container carrier was described. Ship motion and wave load was calculated by modified strip method. Pressure acting on wetted hull surface was calculated taking into account of relative hull motion to the wave. Design wave height was determined based on the most sensitive wave length considering rule vertical wave bending moment at head sea or fellowing sea condition. And the enforced heeling angie concept which was introduced by Germanischer Lloyd (GL) classification had been used to simulate high torsional moment in way of fore hold parts similar to actual sea going condition. Using wave load generated from this dynamic load calculation, FE analyses were performed. With this result, yielding, buckling, hatch diagonal deflection and fatigue strength of hatch corners were reviewed based on the requirement of GL classification. The results of FE analysis show good compatibility with GL classification.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.641-644
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• 2000

Recently As the performance of the personal computer has been improving rapidly lots of research for the pc-based numerical computer actively progress in an easy repair maintenance and improving the performance with less cost. This paper presents the design using complex programmable logic device(CPLD). The CPU of Motion Controller that function as the real time control of the independent multi-axis motion the error-detect module and external I/O control made use of 80C196KC, In this paper The PC-NC effectively distributed to the load of NCK(numerical computer kernel) and have the advantage of high speed and precision.

• Journal of the Korea Society for Simulation
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• v.19 no.1
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• pp.13-22
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• 2010

This paper describes tagline PD control for reduction of motion for the heavy cargo(load) suspended by a floating crane. The equations of motion are set up considering the 6-degree-of-freedom floating crane and the 6-degree-of-freedom load based on multi-body system dynamics. The tagline mechanism is applied to floating crane to control motion of the heavy cargo(load). The winch, mounted on the deck of floating crane, is used to control the tension of tagline. To generate control force, PD control algorithm is applied. Numerical simulation and experiment is executed to verify the tagline control mechanism. The numerical simulation and experiment shows that the tagline control mechanism reduces the motion of the load suspended by a floating crane.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.95-107
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• 2016

The axle weight of a vehicle in motion can be measured with a low-speed or high-speed weigh-in-motion (WIM). However, the axial load dynamically change depending on the vehicle's characteristics-such as the chassis or axle structure-or the characteristics of the driving environment such as road flatness. The changes in dynamic load lead to differences between the vehicle's weight measured at rest and the vehicle's weight measured in motion. For this Study, an experiment was conducted with an instrumented vehicle to analyze the range of errors caused by uncontrollable environmental factors by identifying the characteristics of the dynamic load changes of a vehicle in motion, and determine the appropriate scale for the accuracy evaluation of a high-speed WIM, as a preparatory research for the introduction of unmanned overweight enforcement systems in the future. The key findings from the experiment are summarized as follows. First, The gross weight of the tested vehicle changed by approximately 1% at low velocities and approximately by 4% at high velocities, and the vehicle's axle weight changed by approximately 1-3%, at low velocities and by 2-9% at high velocities. A single axle showed larger weight changes than individual axles in a group. Secondly, The vehicle's gross weight and the axle weight on the impact section were up to eight times and three-to-twelve times higher, respectively, than its gross weight and the axle weight on the flat section. The vibration frequency of the vehicle's dynamic load was measured at between 2.4 and 5.8Hz, and found to return to the normal amplitude after moving approximately 30 meters.