• Proceedings of the KOR-KST Conference
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• 2007.05a
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• pp.571-580
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• 2007

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.2
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• pp.163-169
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• 2019

This study is a research to compare efficiency of new cooling system (chiller, pre-cooler) to that of the conventional system at the hydrogen refueling station (HRS). This study includes contents for thermodynamic comparison of cooling system for HRS and comparison of pros and cons of its components. So It is to establish design concept of cooling system of HRS supplying with fuel cell electric vehicle (FCEV). HRS is charging high pressure H2 (700 bar) to FCEV. However cooling system is need to prevent temperature rise in tank. This cooling system consists of pre-cooler and chiller system.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.729-734
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• 2004

The e-Logistics means the virtual business activity and service architecture among the logistics companies based on the Internet technology. The management of vehicles' location in most conventional vehicle tracking system has some critical defects when it deals with data which are continuously changed. It means the conventional vehicle tracking system based on the conventional database is unable eventually to cope with the environment that should manage the frequently changed location of vehicles. The important things in the evaluation of the vehicle tracking system is to determine the threshold of cost of database ,update period and communication period between vehicles and the system. In other words, the difference between the reallocation of vehicle and the data in database can evaluate the overall performance of vehicle tracking systems. Most of the previous works considers only the information that is valid at the current time, and is hard to manage efficiently the past and future information. To overcome this problem, the efforts on moving objects management system(MOMS) and uncertainty processing have been started from a few years ago. In this paper, we propose an uncertainty processing model and system implementation of moving object that tracks the location of the vehicles. We adopted both linear-interpolation method and trigonometric function to chase up the location of vehicles for the past time as well as future time, respectively. We also explain the comprehensive examples of MOMS and uncertainty processing in parcel application that is one of major application of e-Logistics domain.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.253-259
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• 2018

The Korea Convergence Society. Recently, as the 4th industrial revolution is rising, there are many changes in various field of industries. Among these industries, autonomous vehicles based on artificial intelligence, big data and internet of things is one of the most promising industry. Autonomous vehicle stray from classical car domain of manufacturers and suppliers, IT/Electronics suppliers and communication companies are widen their business area to autonomous vehicle technology. In this paper, we analysis the state of art of autonomous vehicle technology and development direction of industries/research institute. Finally, we discuss the social/economic effects of autonomous vehicle.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.115-117
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• 2014

Recently, interesting of U-city with ubiquitous computing technologies has increased and u-city services can improve people's quality of life. Among the u-city services, traffice service is actively developed in our lives. In this paper, we propose the business model and business model process in u-car tracking service. To propose the research purpose, we examined the prior business model and investigated u-car tracking information. And also, we draw scenario and used it to identify business model. To efficiently understand proposed business model, we built business model process of u-car tracking service. The results of study, we proposed business model and business model process with stakeholder, benefiter and value model. This study concludes with implications of the study results as well as limitations and future research directions.

• IE interfaces
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• v.18 no.4
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• pp.390-401
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• 2005

In this paper, we propose an efficient internet-based logistics brokerage concept which can overcome the weakness of the traditional off-line method to intermediate between vehicle owners and shippers for matching empty vehicles and freights. For defining a business model based on the new concept and implementing an information system, it is necessary to analyze the business process for the internet-based logistics brokerage using a modeling methodology. In this paper, we analyze the logistics brokerage process using the UN/CEFACT Modeling Methodology (UMM) being utilized as a standard modeling methodology in the area of electronic commerce. After analyzing the business process, we can expect that the UMM can be used as a useful tool for modeling the business process of electronic commerce in which the description of the collaborative work is very important.

• Journal of Energy Engineering
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• v.18 no.1
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• pp.31-36
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• 2009

There are several types of environment friendly vehicle being developed by auto manufactures. HEV (Hybrid Electric Vehicle) is most applicable one among them in actuality. HEV has two power sources, one is an internal combustion engine, the other one is an electric device. The HEV is developed for reducing fuel consumption and emissions. We selected the diesel engine as a main power source of HEV. The tests were carried out under different driving cycles which was CBDBUS (Central Business Driving Bus Schedule) and HWFET (Highway Fuel Economy Test). This research presents a simulation for the fuel economy and the emission of heavy diesel hybrid vehicle according to the SHEV (Serial Hybrid Electric Vehicle), PHEV (Parallel Hybrid Electric Vehicle), Plug-in SHEV and plug-in PHEV.

• Environmental and Resource Economics Review
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• v.29 no.4
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• pp.443-468
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• 2020

Broad effects of fuel-transition in all type of ground transportation have occurred with the help of the advances in electric vehicle (EV) technologies and the increases in EV supply. This research estimates the economic benefit of air environmental improvements, which results from the fuel-transition of high-mileage business cars(taxies) in metropolis. If we consider power production sector for EV operation, some air pollutants will be produced. In this respect, this research takes both the mixture of power sources in power production level and the driving pattern of business cars into account when investigating the economic benefit in air environment resulted from the fuel-transition of business cars(taxies). According to our results, the business cars' fuel transition from LPG to electricity brings about 21.5￦/km (8.6million won/year) of economic benefit in air environment. These results emphasize the necessity and appropriateness of public polices for expanding power production with renewable energies and facilitating EV distribution.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.2048-2055
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• 2001

This paper develops a computational model for estimating the ride quality of a cabover type large-sized truck in a double wheel bumpy ride test. The computational model is developed using ADAMS. To verify the developed model, an actual vehicle double wheel bumpy ride test is performed. In the test, the vehicle maintains a straight course with a constant velocity such that the front two wheels are passed the bump at the same time. The bump has the height of 60mm, and the width of 550mm. In the test, four velocities are used. They are 10kph, 20kph, 30kph and 40kph. Since the large-sized truck's center of gravity location is high, and its weight is heavy, it is a quite severe test condition to perform the test with more than 30kph velocity. In the test, vertical accelerations on the floor of the cab are measured. The measured accelerations are compared to the simulation results. From the comparison, it is shown that the developed model can predict not only the measured acceleration's tendency but also peak accelerations quite well. In this paper, the validated model is utilized to compare the ride quality between a vehicle with a multi-leaf spring and a vehicle with a tapered leaf spring in the front suspension system in a double bumpy ride test.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.3
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• pp.75-96
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• 2016

This paper investigates the usefulness of drones in an urban delivery system. We define the vehicle and drone routing problem with time window (VDRPTW) and present a model that can describe a dual mode delivery system consisting of drones and vehicles in the metropolitan area. Drones are relatively free from traffic congestion but have limited flight range and capacity. Vehicles are not free from traffic congestion, and the complexity of urban road network reduces the efficiency of vehicles. Using drones and vehicles together can reduce inefficiency of the urban delivery system because of their complementary cooperation. In this paper, we assume that drones operate in a point-to-point manner between the depot and customers, and that customers in the need of fast delivery are willing to pay additional charges. For the experiment datasets, we use instances of Solomon (1987), which are well known in the Vehicle Routing Problem society. Moreover, to mirror the urban logistics demand trend, customers who want fast delivery are added to the Solomon's instances. We propose a hybrid evolutionary algorithm for solving VDRPTW. The experiment results provide different useful insights according to the geographical distributions of customers. In the instances where customers are randomly located and in instances where some customers are randomly located while others form some clusters, the dual mode delivery system displays lower total cost and higher customer satisfaction. In instances with clustered customers, the dual mode delivery system exhibits narrow competition for the total cost with the delivery system that uses only vehicles. In this case, using drones and vehicles together can reduce the level of dissatisfaction of customers who take their cargo over the time-window. From the view point of strategic flexibility, the dual mode delivery system appears to be more interesting. In meeting the objective of maximizing customer satisfaction, the use of drones and vehicles incurs less cost and requires fewer resources.