• 한국자동차공학회논문집
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• 제21권3호
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• pp.148-156
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• 2013

Since the demand for new military vehicle to fulfill the necessary conditions such as multi-purpose, high-mobility, and survivability has raised continuously from the army, the prototype of a Korean light tactical vehicle was developed to meet these requirements using our own technology. In particular, the new tactical vehicle was equipped with a double wishbone independent suspension to improve ride and handling and maximize off-road driving performance. In this paper, a comprehensive virtual durability process to evaluate the service life of the prototype is presented. A reliability of the trimmed body model based on CATIA data was verified by comparison result between mode analysis and modal test. The dynamic model was constructed using ADAMS/Car, and then the weight distribution and lateral slope driving performance of it were compared with the results of static weight and lateral slope tests. The validity of the VTL(Virtual Test Lab) was checked with test results from the 3-inch spaced impact road. The durability performances of trimmed body and suspension components were evaluated through MSM(Modal Superposition Method) fatigue analysis. It is shown that the virtual durability process could be a helpful tool to find out the weak areas and improve their structures in developing new military vehicle.

• Structural Monitoring and Maintenance
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• 제6권4호
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• pp.317-346
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• 2019

Performance assessment of pavements proves useful, in terms of handling the ride quality, controlling the travel time of vehicles and adequate maintenance of pavements. Roughness profiles provide a good measure of the deteriorating condition of the pavement. For the accurate estimates of pavement roughness from dynamic vehicle responses, vehicle parameters should be known accurately. Information on vehicle parameters is uncertain, due to the wear and tear over time. Hence, condition monitoring of pavement requires the identification of pavement roughness along with vehicle parameters. The present study proposes a scheme which estimates the roughness profile of the pavement with the use of accurate estimates of vehicle parameters computed in parallel. Pavement model used in this study is a two-layer Euler-Bernoulli beam resting on a nonlinear Pasternak foundation. The asphalt topping of the pavement in the top layer is modeled as viscoelastic, and the base course bottom layer is modeled as elastic. The viscoelastic response of the top layer is modeled with the help of the Burgers model. The vehicle model considered in this study is a half car model, fitted with accelerometers at specified points. The identification of the coupled system of vehicle-pavement interaction employs a coupled scheme of an unbiased minimum variance estimator and an optimization scheme. The partitioning of observed noisy quantities to be used in the two schemes is investigated in detail before the analysis. The unbiased minimum variance estimator (MVE) make use of a linear state-space formulation including roughness, to overcome the linearization difficulties as in conventional nonlinear filters. MVE gives estimates for the unknown input and fed into the optimization scheme to yield estimates of vehicle parameters. The issue of ill-posedness of the problem is dealt with by introducing a regularization equivalent term in the objective function, specifically where a large number of parameters are to be estimated. Effect of different objective functions is also studied. The outcome of this research is an overall measure of pavement condition.

• 한국중재학회지:중재연구
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• 제20권3호
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• pp.93-120
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• 2010

In 1978, Chinese reform and opening caused a big changes in Chinese labor relationship. Through reforming and opening, China gave up part of state ownership system and group ownership system, permitted private ownership system, and also opened the way for capitalists to ride again. Since China was established, the labor relationship ceased for 30 years has been appeared. However because the top priority aim of China's reform was economic growth, the protection of the rights and interests of labor was pushed back on the policy priority list. China takes foreign capitals based on cheap labor force quickly and China come up the worldwide plants. Since reformed, China keeps an economic growth rate of 9.7% annually for 30years. This economic growth is based on labor's sacrifice. However, Chinese fast economic growth causes side effects such as increasement of the gap between the wealthy and the poor, increasement of unbalanced development between regions, and the increasement of conflict between labor and management. Especially, according to changes in labors' level of consciousness, the labors recognized that their rights and interests are exploited by employers. Therefore, the labor dispute is continuously increasing. Chinese government changes their policy from the policy focusing on enterprise development to the policy protecting labor's rights and interests. In order to protect labor's rights and interests, China conducts labor contract law and labor dispute conciliation arbitration law in 2008. This kind of changes in Chinese labor environment affect a lot to Korean companies which already entered into China or are willing to enter. According to studying on present situation and resolution system in Chinese labor dispute, this paper suggests the proper countermeasure related to labor dispute of Korean companies which entered in China. First, the success rate of labor dispute conciliation by enterprise labor dispute conciliation committee is around 20% during recent several years and the success rate by year is in decline. Therefore, when labor dispute is occurred, our companies which entered into China better use other labor dispute methods such as negotiation and arbitration than conciliation in order to settle a conflict. Second, from the Korean enterprises entered in China point of view, there exists a problem not to sue except special cases which provided in the law even though they are dissatisfied with arbitrate judgment. Thus, when labor dispute occurred, Korean enterprises try to do best to settle the dispute through negotiation. However, in case of that the dispute cannot be settled by negotiation, they have to attend in the arbitration as if it is a last chance. Third, Korean enterprises keep in mind that dispute handling procedures between labor union and users or between labor group and users are different, and then deal with separately. Thus, dispute between labor and users have to follow arbitrate procedures as a necessary procedure, but in case of dispute related to group contract, namely dispute against labor union, labor dispute can be settled by arbitrate or suit, so after figuring out the situation exactly, it is necessary to select more advantageous way in order to settle the dispute. Moreover, in case of the dispute between labor union, they have to keep in mind that conciliation procedures cannot be used.