• International Journal of Automotive Technology
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• v.8 no.6
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• pp.791-798
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• 2007

The hydraulic hybrid vehicle(HHV) is an application of hydrostatic transmission technology to improve vehicle fuel economy and emissions. A relatively lower energy density of hydraulic accumulator and complicated coordinating operations between two power sources require a special energy management strategy to maximize the fuel saving potential. This paper presents a new type of configuration for parallel HHV to minimize the disadvantages of the hydraulic accumulator, as well as a methodology for developing an energy management strategy tailored specially for PHHV. Based on an analysis of the optimal energy distribution between two power sources over a representative urban driving cycle with a Dynamic Programming(DP) algorithm, a fuzzy-based optimal torque management strategy is designed and developed to control the torque distribution. Simulation results demonstrates that the optimal torque management strategy maximizes the advantages of this hybrid type of configuration, and the high power density characteristics of hydraulic technology effectively improve the robustness of the energy management strategy and fuel economy of the PHHV.

• Journal of the Korea Society of Computer and Information
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• v.21 no.9
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• pp.91-100
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• 2016

In this research, emergency vehicle dispatching problems faced with in the wake of massive natural disasters are considered. Here, the emergency vehicle dispatching problems can be regarded as a single machine stochastic scheduling problems, where the processing times are independently and identically distributed random variables, are considered. The objective of minimizing the expected number of tardy jobs, with distinct job due dates that are independently and arbitrarily distributed random variables, is dealt with. For these problems, optimal static-list policies can be found by solving corresponding assignment problems. However, for the special cases where due dates are exponentially distributed random variables, using a proposed dynamic programming approach is found to be relatively faster than solving the corresponding assignment problems. This so-called Pivot Dynamic Programming approach exploits necessary optimality conditions derived for ordering the jobs partially.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.6
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• pp.389-394
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• 2018

Remotely operated vehicle(ROV) and autonomous underwater vehicle(AUV) have been used for underwater surveys, underwater exploration, resource harvesting, offshore plant maintenance and repair, and underwater construction. It is hard for people to work in the deep sea. Therefore, we need a vision control system of underwater submersible that can replace human eyes. However, many people have difficulty in developing a deep-sea image control system due to the deep sea special environment such as high pressure, brine, waterproofing and communication. In this paper, we will develop an Ethernet based remote image control system that can control the image mounted on ROV.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.12
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• pp.1099-1103
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• 2013

A combat vehicle needs to have an air-conditioning unit. Accordingly, new combat systems have tended to apply an integrated heating, cooling, and ventilating system. The air conditioning unit used depends on the combat vehicle's purpose of use. In this study, we studied an air-conditioning unit for an armored combat vehicle as a special use and military specification and tried to improve the air-conditioning unit's performance.

• Journal of Biosystems Engineering
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• v.37 no.3
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• pp.148-154
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• 2012

Purpose: In order to improve road-friendliness of heavy vehicles, a fuzzy hybrid control strategy consisting of a hybrid control strategy and a fuzzy logic control module is proposed. The performance of the proposed strategy should be effectively evaluated using a hardware-in-the-loop (HIL) simulation model of a semi-active suspension system based on the fuzzy hybrid control strategy prior to real vehicle implementations. Methods: A hardware-in-the-loop (HIL) simulation system was synthesized by utilizing a self-developed electronic control unit (ECU), a PCI-1711 multi-functional data acquisition board as well as the previously developed quarter-car simulation model. Road-friendliness of a semi-active suspension system controlled by the proposed control strategy was simulated via the HIL system using Dynamic Load Coefficient (DLC) and Dynamic Load Stress Factor (DLSF) criteria. Results: Compared to a passive suspension, a semi-active suspension system based on the fuzzy hybrid control strategy reduced the DLC and DLSF values. Conclusions: The proposed control strategy of semi-active suspension systems can be employed to improve road-friendliness of road vehicles.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.103-108
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• 2004

The motivation of this study comes from the problem recognition that the headway of passing vehicle in signalized intersections can not be merely determined by departing sequence. Traffic speed and headway data of passing vehicles in signalized intersection have been obtained by using magnetic detectors(NC 97) and detecting program, and the data was analyzed. Without special treatment, the model established on passing behavior of vehicles was meaningless from statistical view point. Hence, special treatments such as filtering (upper 85% offensive driver driven vehicle's) and log scaling of data were carried on. With this new data, meaningful model (where coefficient of determination is 0.91) was established. This model explained the fact that vehicle headway in signalized intersection is affected by speed and headway of previous vehicle and speed of itself.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.7 no.4
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• pp.135-141
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• 2008

Independent suspension axle and final reduction gear for special-purpose vehicles such as a armored vehicles are almost imported in Germany etc. so, developing them is necessary to save cost. In severe condition (open fields, water surface driving, obstacle pass), special-purpose vehicles must work well. Drop box, axle and final reduction gear performed static analysis. We know that is possible weight reduction. The purpose of this paper is to find out the optimal shape of final reduction gear's case by means of response surface methodology. The response surface method is the statistical method which can be applied to the non-sensitivity based optimization. The response surface which is constructed by the least square method contains only the polynomial terms so that the global maximum and minimum points are easily obtained.

• The Korean Journal of Emergency Medical Services
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• v.26 no.1
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• pp.87-99
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• 2022

Purpose: This study aimed to provide basic data for the improvement of the standards related to the performance improvement of the firefighting equipment standards for special ambulances. Methods: Among the domestic firefighting equipment standards, the special ambulance standard was compared with the NFPA 1917 standard for the United States automobile ambulance 2019 and European Union European standard EN 1789 medical vehicle and its equipment, a road ambulance. Results: Anti-skid performance based on indoor noise standards, performance standards for interior lights, seat belt warning device, child car seat fixing device, safety handle, auxiliary footrest, and flooring materials should be supplemented. Conclusion: It is necessary to strengthen the production and performance standards for improvement to a level corresponding to the national standards, such as the United States and European Union.

• ETRI Journal
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• v.38 no.4
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• pp.787-797
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• 2016

Mining, construction, and other special vehicles for heavy use are designed to work under high-performance and off-road working conditions. The driving and executive mechanisms of the support structures and superstructures of these vehicles frequently operate under high loads. Such high loads place the equipment under constant risk of an accident and can jeopardize the dynamic stability of the machinery. An experimental investigation was conducted on a refuse collection vehicle. The aim of this research was to determine the working conditions of a real vehicle: the kinematics of the waste container, that is, a hydraulic rotate drum for waste collection; the dynamics of the load manipulator (superstructure); the vibrations of the vehicle mass; and the strain (stress) of the elements responsible for the supporting structure. For an examination of the force (weight) on the rear axle of a heavy vehicle, caused by its own weight and additional load, a universal measurement system is proposed. As a result of this investigation, we propose an alternative system for continuous vehicle weighing during waste collection while in motion, that is, an on-board weighing system, and provide suggestions for measuring equipment designs.

• Aerospace Engineering and Technology
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• v.7 no.2
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• pp.144-150
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• 2008

Bogie(The Launch vehicle transporter) is the special land transportation vehicle for the LV (Launch vehicle) which is used for not only the transportation-means of LV from LVAB(Launch Vehicle Assembly Building) to LP(Launch Pad) but also one of principal tools for launch operation sequence. Due to the multi-role of Bogie, The technical requirements of bogie are very complicated. Especially launch operation has performed with not only bogie but also many ground support equipments. So, it is impossible to establish technical requirements of bogie without whole understanding of launch operation. This paper was made for arranging whole launch operation sequence and technical requirements of bogie based on the this sequence.