• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1127-1132
• /
• 2003

Suspension system of vehicle have enough endurance during its life time to protect passenger. Spring is one of major part of vehicle. Thus, a fatigue strength evaluation for leaf spring based on road load response was carried out. At first, strain of leaf spring is measured on the city condition and proving ground condition. And next, the damage analysis of road load response data was carried out. And fatigue test of leaf spring were also carried out. Based on -N life relation, fatigue life of leaf spring was evaluated at belgian mode, city mode and drawing test specification. After that, it is compared the design life of leaf spring and evaluated fatigue life by belgian mode, city mode and drawing test specification. From the above, the maximum load-fatigue life relation of leaf spring was defined by test. and new test target of belgian mode and city mode was proposed to accept design specification of leaf spring. It is expect that proposed test target can verify leaf spring fatigue endurance at specific road condition.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.04a
• /
• pp.735-741
• /
• 2011

In the early phase of vehicle development, CAE is conducted as tool for vehicle performance assessment. To maintain acceptable road noise performance, solution for reduced vehicle sensitivity is required. Chassis interface dynamic stiffness characteristics are key component to isolating vibration and noise of road from the vehicle interior. This research provide how to set up the optimized dynamic characteristics under noise effect through DFSS study. CAE-based DOE is performed to build prediction math model, CMS process involves DOE to achieve very fast run times while giving results very comparable. Minimized $95^{th}$ percentile of performance distribution is applied to minimize vehicle sensitivity and road noise levels variation during the optimization process. Finally, the results of optimization were reviewed for performance and robustness.

• Journal of the Korean Society of Systems Engineering
• /
• v.1 no.2
• /
• pp.26-33
• /
• 2005

In this paper, an algorithm is presented to recognize road based on unpaved test courses image. The road images obtained by a video camera undergoes a pre-processing that includes filtering, gray level slicing, masking and identification of unpaved test courses. After this pre-processing, a part of image is grouped into 27 sub-windows and fed into a three-layer feed-forward neural network. The neural network is trained to indicate the road direction. The proposed algorithm has been tested with the images different from the training images, and demonstrated its efficacy for recognizing unpaved road. Based on the test results, it can be said that the algorithm successfully combines the traditional image processing and the neural network principles towards a simpler and more efficient driver warning or assistance system.

• Journal of Institute of Control, Robotics and Systems
• /
• v.22 no.12
• /
• pp.1053-1060
• /
• 2016

As location recognition for autonomous vehicles develops, the need for a precise map for autonomous driving has increased. A precise map must be built based upon accurate position. Recent studies have accelerated research in this area by using various sensors that calculate the accurate position by comparing and recognizing objects around the roads. However, application of such methods is limited because these studies only take objects with significant verticality into consideration. Thus, new research is needed to overcome the limitations: a method that is not constrained by the existence of certain types of surrounding objects shall be proposed. Most roads contain road marking information, such as lanes, direction signs, and pedestrian crossings. Such information on the road surface is a valuable resource for building a precise map. This paper proposes a method of building a precise map by using road marking information.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.13 no.2
• /
• pp.27-33
• /
• 2014

This paper proposes a gradation image processing method for the development of a Road Sign Recognition Platform (RReP), which aims to facilitate the rapid and accurate management and surveying of approximately 160,000 road signs installed along the highways, national roadways, and local roads in the cities, districts (gun), and provinces (do) of Korea. RReP is based on GPS(Global Positioning System), IMU(Inertial Measurement Unit), INS(Inertial Navigation System), DMI(Distance Measurement Instrument), and lasers, and uses an imagery information collection/classification module to allow the automatic recognition of signs, the collection of shapes, pole locations, and sign-type data, and the creation of road sign registers, by extracting basic data related to the shape and sign content, and automated database design. Image division and merging, which were applied in this study, produce superior results compared with local binarization method in terms of speed. At the results, larger texts area were found in images, the accuracy of text recognition was improved when images had been gradated. Multi-threshold values of natural scene images are used to improve the extraction rate of texts and figures based on pattern recognition.

• Coupled systems mechanics
• /
• v.7 no.6
• /
• pp.707-729
• /
• 2018

The semi-active optimal vibration control of nonlinear torsion-bar suspension vehicle systems under random road excitations is an important research subject, and the boundedness of MR dampers and the uncertainty of vehicle systems are necessary to consider. In this paper, the differential equations of motion of the coupling torsion-bar suspension vehicle system with MR damper under random road excitation are derived and then transformed into strongly nonlinear stochastic coupling vibration equations. The dynamical programming equation is derived based on the stochastic dynamical programming principle firstly for the nonlinear stochastic system. The semi-active bounded parametric optimal control law is determined by the programming equation and MR damper dynamics. Then for the uncertain nonlinear stochastic system, the minimax dynamical programming equation is derived based on the minimax stochastic dynamical programming principle. The worst-case disturbances and corresponding semi-active bounded parametric optimal control are obtained from the programming equation under the bounded disturbance constraints and MR damper dynamics. The control strategy for the nonlinear stochastic vibration of the uncertain torsion-bar suspension vehicle system is developed. The good effectiveness of the proposed control is illustrated with numerical results. The control performances for the vehicle system with different bounds of MR damper under different vehicle speeds and random road excitations are discussed.

• The Journal of Economics, Marketing and Management
• /
• v.12 no.5
• /
• pp.53-62
• /
• 2024

Purpose: As globalization continues to advance, China's trade cooperation with foreign countries has become increasingly close, and its outward-oriented economy has entered a rapid development stage. With the launch of the Belt and Road Initiative in 2013, favorable conditions for China's overseas direct investment have been created. This paper is based on the financial development in Belt and Road countries. Research design, data and methodology: Using panel data from 2006 to 2020 covering 64 countries along the Belt and Road, the paper classifies regions and compares regions with higher levels of financial development. It provides descriptive statistics and employs the Fixed Effects Model (FEM) for regression analysis to thoroughly study the factors affecting China's Foreign Direct Investment (FDI). Results: The research results indicate that the size, efficiency, and structure of financial development all have a significant positive impact on China's FDI. Conclusions: However, factors such as trade openness (OPEN) and per capita disposable income (LnAGDP) did not pass the significance test, possibly because the level of openness of a country for outward foreign direct investment is not a significant factor to consider. Finally, based on the empirical findings, a series of policy recommendations are proposed to enhance China's FDI levels.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.4
• /
• pp.131-140
• /
• 2012

The shortest path search algorithm of navigation is generally based on Dijkstra algorithm and considers only the distance using the weight. Dijkstra algorithm based on the distance mainly ought to perform the 'number of nodes 1' and requires a lot of memory, for it is to start from the starting node and to decide the shortest path for all the nodes. Also, it searches only the same identical path in case of any bottleneck due to an accident nearby, since it is based only on the distance, and hence does not have a system that searches the detour road. In order to solve this problem, this paper considers only the travelling time per road (travelling speed * distance), without applying speed criteria (smoothness, slow speed, stagnation and accident control) or road class (express road, national road and provincial road). This provides an advantage of searching the detour, considering the reality that there are differences in time take for the car to travel on different roads with same distance, due to any accident, stagnation, or repair construction. The suggested algorithm proves that it can help us to reach the destination within the shortest time, making a detour from any congested road (outbreak) on providing an information on traveling time continuously(real-time) even though there is an accident in a particular road.

• The Journal of Society for e-Business Studies
• /
• v.6 no.1
• /
• pp.101-121
• /
• 2001

MOCT(Ministry of Construction St Transportation) suggested "A Plan for Implementation of Knowledge-based Economy for the Construction Industry" to add high value to a construction industry. by means of knowledge-based management. However, there is no knowledge management system which considers characteristics of a domestic construction industry. So a useful knowledge vanished the moment a company terminated a construction Uoject. Therefore, it is necessary to develop "An application method of a knowledge management system for the construction industry" which takes a real environment into consideration. This study aims to present the road map of a knowledge management system which helps the bodies of the construction industry(government, research center/university, enterprise, etc) to do a knowledge activity efficiently. To accomplish this objective, we analyzed overall knowledge management activities. In addition we suggested an implementation direction and strategy of a knowledge management system for the construction industry. As results of this study, we presented the road map of a knowledge management system for the construction industry, which is composed of policy forum, study forum, professional forum, research forum and knowledge 8t information DB. We expect that results of this study will be used as a basis for implementing the knowledge portal that brings a construction industry to a high value added industry.

• International Journal of Highway Engineering
• /
• v.14 no.4
• /
• pp.163-173
• /
• 2012

PURPOSES : The purpose of this study is to check the possibilities of traffic pattern analysis using MatSIM for urban road network operation in incident case. METHODS : One of the stochastic dynamic models is MatSIM. MatSIM is a transportation simulation tool based on stochastic dynamic model and activity based model. It is an open source software developed by IVT, ETH zurich, Switzerland. In MatSIM, various scenario comparison analyses are possible and analyses results are expressed using the visualizer which shows individual vehicle movements and traffic patterns. In this study, trip distribution in 24-hour, traffic volume, and travel speed using MatSIM are similar to those of measured values. Therefore, results of MatSIM are reasonable comparing with measured values. Traffic patterns are changed according to incident from change of individual behavior. RESULTS : The simulation results and the actual measured values are similar. The simulation results show reasonable ranges which can be used for traffic pattern analysis. CONCLUSIONS : The change of traffic pattern including trip distribution, traffic volumes and speeds according to various incident scenarios can be used for traffic control policy decision to provide effective operation of urban road network.