• Journal of the Korean Institute of Intelligent Systems
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• v.13 no.3
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• pp.366-370
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• 2003

In this research, we suggest a hybrid intelligent Web recommendation systems based on Web data mining and case-based reasoning (CBR). One of the important research topics in the field of Internet business is blending artificial intelligence (AI) techniques with knowledge discovering in database (KDD) or data mining (DM). Data mining is used as an efficient mechanism in reasoning for association knowledge between goods and customers＇ preference. In the field of data mining, the features, called attributes, are often selected primary for mining the association knowledge between related products. Therefore, most of researches, in the arena of Web data mining, used association rules extraction mechanism. However, association rules extraction mechanism has a potential limitation in flexibility of reasoning. If there are some goods, which were not retrieved by association rules-based reasoning, we can＇t present more information to customer. To overcome this limitation case, we combined CBR with Web data mining. CBR is one of the AI techniques and used in problems for which it is difficult to solve with logical (association) rules. A Web-log data gathered in real-world Web shopping mall was given to illustrate the quality of the proposed hybrid recommendation mechanism. This Web shopping mall deals with remote-controlled plastic models such as remote-controlled car, yacht, airplane, and helicopter. The experimental results showed that our hybrid recommendation mechanism could reflect both association knowledge and implicit human knowledge extracted from cases in Web databases.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.2
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• pp.32-43
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• 2004

In this paper, a system which can effectively recognize the plate image extracted from camera set on a moving car is proposed. To extract car licence plate from moving vehicles, multiple candidates are maintained based on the strong vertical edges which are found in the region of car licence plate. A candidate region is selected among them based on the ratio of background and characters. We also make a comparative study of recognition performance between support vector machines and modular neural networks. The experimental results lead us to the conclusion that the former is superior to the latter. For a better recognition rate, a simple method combining the support vector machine with modular neural network where the output of the latter is used as the input of the former is suggested and evaluated. As we expected, the hybrid one shows the best result among those three methods we have mentioned.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2106-2112
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• 2013

In a traditional hydraulic elevator, elevator car is descended by down control valve, and the oil hydraulic energy must be lost during the descending stroke. In this paper, hybrid type energy saving unit for a hydraulic elevator is researched to save the hydraulic energy which is lost during the descending stroke. The energy is stored as converted electrical energy, and the saved energy is reused as the auxiliary power for the ascending stroke of elevator car or the main power of other parts. The results show that the output characteristics are stable and good and the research is successful and useful to reuse the saved energy during the descending stroke of elevator car.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.6
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• pp.716-723
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• 2011

The battery capacity of electric/hybrid vehicle is much larger than present automobile. For that reason, the connector of Green Car should be designed to transmit the high-electric voltage. In addition, the electromagnetic wave should be shielded to protect communication and signal circuits. In this study, shielding performance of the connector was analyzed through electromagnetic shield analysis, and a connector of Green Car was designed using thermoelectrical analysis, which is capable of transmitting the high-electric power. In the design of connector structure, the improved stability and workability was considered.

• International Journal of Automotive Technology
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• v.1 no.1
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• pp.48-55
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• 2000

Two major roles of the traction control system (TCS) are to guarantee the acceleration performance and directional stability even in extreme road conditions, under which average drivers may not control the car properly. Commercial TCSs use experiential methods such as lookup table and gain-scheduling to achieve proper performance under various road and vehicle conditions. This paper proposes a new slip controller which uses the brake and the throttle actuator simultaneously. To avoid measurement problems and to get a simple structure, the brake controller and the throttle controller are designed using Lyapunov redesign method and multiple sliding mode control respectively. Through the hybrid use of brake and throttle controllers, the vehicle is insensitive to the variation of the vehicle mass, brake gain and road condition and can achieve the required acceleration performance. The proposed method is validated with simulations based on 15 DOF passenger car model.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.373-375
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• 1997

In this paper, we present IGBT VVVF inverters as a 1C1M propulsion system for electric car. These inverters are composed of high power IGBT's and controlled by compact control units. The control unit performs full digital control by using 32bit DSP and microcontroller. By using CAN-bus, high speed network is constructed within four control units. The stack is simplified and optimized by using plate bus and IGBT driver units of hybrid-type.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.5 s.98
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• pp.104-111
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• 1999

A semi-active suspension system for a vehicle using an Electrorheological Fluid damper has been studied. Apparent viscosity of ERF(Electrorheological Fluid) can be changed rapidly by applying electric field. The damping force of ER damper can be selectively controlled by employing electric field to the ER fluid domain. This paper deals with a two-degree-of-freedom suspension using the ER damper for a quarter car model. An intelligent control method using fuzzy control with genetic algorithm has been employed to control the damping force of the ER damper. The GA designs the optimal structure and performance of Fuzzy Net Controller having hybrid structure. The designed fuzzy net controller has been compared with the skyhook type controller for a quarter car model. The computer simulation results show that the semi-active suspension with ER damper has a good performance in the sense of ride quality with less vibration for ground vehicle.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.616-621
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• 2004

In this paper, the crush characteristics of a tilting train express (TTX) M-car design are evaluated with a head-on collision scenario. Its body shell is divided into three parts - front end, middle section, and rear end. For each part, crush-force relation is evaluated numerically through 3-dimensional shell element analysis with LS-DYNA. TTX's embody structure is a hybrid type structure made of steel and composite materials. Composite sandwich panels are modeled as layered shells whose layers have different material properties. And a damage material model is used to consider the effect of stiffness degradation during deformation. The crush characteristics obtained from these calculations will be used as material modeling data of full-rake collision analyses.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.3
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• pp.105-111
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• 2003

This paper presents an approach to automate process planning of press dies for manufacturing of car bodies. Considering that the press-dies used at the same press operations regardless of the panels they produce or the car models of which they produce panels have similar shapes except for the forming part of the dies, general approaches to recognize manufacturing features from CAD models are not necessary. Therefore, a hybrid approach is proposed combining feature-based design and feature-extraction approaches. The proposed method recognizes features by parsing the parameters extracted from CAD models and finds proper operations by querying the database by the recognized features. An internet-based process planning system is developed to demonstrate the proposed approach and to suggest a new paradigm of process planning system that utilizes an internet access to the CAD system.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.1
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• pp.87-95
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• 2012

In recent years, laser-arc hybrid welding has begun to be adopted for assembly welding of automotive bodies and parts, because the hybrid welding process can weld lapped steel sheets having a larger gap than is possible with laser welding. In this paper, to predict the twist deformation by the hybrid welding when brackets are welded in B pillar of a passenger car, the residual stress using CAE is analyzed and the deformation result of CAE is compared with the measured deformation. First of all, after modeling heat source as intended to be expressed with laser-arc hybrid welding method, heat source fitting is done with welding conditions and a section of welding part obtained through specimen test. In case of heat source functions, laser used conical source and arc used double ellipsoid source. Through the local model analysis, elements which are located in the center of the model are selected. The elements are called WME(Welding Macro Element). This WME is extruded in the welding lines and welding phenomenon of complex parts is accomplished. The deformation amount after hybrid welding is got through a simulation, the validity of simulation is verified by measuring the panel and comparing with the simulation result.