• International Journal of Automotive Technology
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• v.5 no.1
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• pp.33-46
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• 2004

A finite element model development of a 50th percentile male cervical spine is presented in this paper. The model consists of rigid, geometrically accurate vertebrae held together with deformable intervertibral disks, facet joints, and ligaments modeled as a series of nonlinear springs. These deformable structures were rigorously tuned, through failure, to mimic existing experimental data; first as functional unit characterizations at three cervical levels and then as a fully assembled c-spine using the experimental data from Duke University and other data in the NHTSA database. After obtaining satisfactory validation of the performance of the assembled ligamentous cervical spine against available experimental data, 22 cervical muscle pairs, representing the majority of the neck's musculature, were added to the model. Hill's muscle model was utilized to generate muscle forces within the assembled cervical model. The muscle activation level was assumed to be the same for all modeled muscles and the degree of activation was set to correctly predict available human volunteer experimental data from NBDL. The validated model is intended for use as a post processor of dummy measurement within the simulated injury monitor (SIMon) concept being developed by NHTSA where measured kinematics and kinetic data obtained from a dummy during a crash test will serve as the boundary conditions to "drive" the finite element model of the neck. The post-processor will then interrogate the model to determine whether any ligament have exceeded its known failure limit. The model will allow a direct assessment of potential injury, its degree and location thus eliminating the need for global correlates such as Nij.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.2
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• pp.161-168
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• 2015

Recently, due to various environmental problems such as global warming, increases of international oil prices, exhaustion of resource, a paradigm of world automobile market is rapidly changing from conventional vehicles using internal combustion engine to eco-friendly vehicles using electric power such as EV, HEV, PHEV and FCEV. Generally, in order to measure fuel consumption and pollutant emissions of cars, chassis dynamometer tests are performed on various driving cycles before actual driving test. There are many driving cycles for performance evaluation of conventional vehicles. However, there is a lack of researches on driving cycle for EV. In this study, the urban driving cycle for performance evaluation of electric vehicles was developed. This study is composed of two parts. In the part 1, the urban driving cycle 'GUDC-EV(Gwacheon-city Urban Driving Cycle for Electric Vehicles)' was developed by using driving data, which were obtained through actual driving experiment, and statistic analysis with chronological table. In this paper part 2, in order to verify the developed driving cycle GUDC-EV, virtual EV platforms were configured and simulations were performed with actual driving data using In addition, simulation results were compared with existing driving cycles such as FTP-72, NEDC and Japan 10-15.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.1
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• pp.110-115
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• 2006

STSAT-2 is the first satellite which will be launched by the first Korean Space Launch Vehicle(KSLV). Ground station Baseband Control system(GBC) is now developed for STSAT-2. GBC has two functions. One is control data path between satellite control computers and ground station antennas(1.5M, 3.7M, 13M) automatically. The other is sending and receiving data between ground station and satellite. GBC is implemented by FPGA(Field-Programmable Gate Array) which includes almost all logic(for MODEM, PROTOCOL and GBC system control). MODEM in GBC has two uplink FSK modulators(1.2[kbps], 9.6[kbps]) and six downlink FSK demodulators(9.6[kbps], 38.4[kbps]). In hardware, STSAT-2 GBC is smaller than STSAT-1 GBC. In function, STSAT-2 GBC has more features than STSAT-1 GBC. This paper is about GBC structure, functions and test results.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.8
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• pp.56-64
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• 2005

It is prerequisite that we have to fomulate the nonlinear mathematical modeling to design the guidance and control system of rotorcraft-based unmanned aerial vehicle using a small-scaled commercial helicopter. The small-scaled helicopters are very different from the full-scale helicopters in dynamic behavior such as high rotation speed and high frequency dynamic characteristics. In this paper, the formulation of the mathematical model of the small-scaled helicopter to minimize the complexity is presented by component and source build-up approach. It is linearized at the trim condition of hovering and forward flight and analyzed the flight modes. The results of this approach have general trends but a little difference. To verify this approach, it is necessary to compare this theoretical model with experimental results by system identification using flight test as a next research topic.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.10
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• pp.3955-3971
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• 2020

Due to the significant increase in the use of autonomous car technology, it is essential to integrate this technology with high-precision digital map data containing more precise and accurate roadway information, as compared to existing conventional map resources, to ensure the safety of self-driving operations. While existing map technologies may assist vehicles in identifying their locations via Global Positioning System, it is however difficult to update the environmental changes of roadways in these maps. Roadway vision algorithms can be useful for building autonomous vehicles that can avoid accidents and detect real-time location changes. We incorporate a hybrid architectural design that combines unsupervised classification of vision data with supervised joint fusion classification to achieve a better noise-resistant algorithm. We identify, via a deep learning approach, an intelligent hybrid fusion algorithm for fusing multimodal vision feature data for roadway classifications and characterize its improvement in accuracy over unsupervised identifications using image processing and supervised vision classifiers. We analyzed over 93,000 vision frame data collected from a test vehicle in real roadways. The performance indicators of the proposed hybrid fusion algorithm are successfully evaluated for the generation of roadway digital maps for autonomous vehicles, with a recall of 0.94, precision of 0.96, and accuracy of 0.92.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.6
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• pp.11-15
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• 2009

Recently, a new PSC (Prestressed Concrete) bridge system, which is supported by Concrete-filled fiber-reinforced polymer (CFFRP) strut, has been introduced. This bridge is able to reduce self-weight and increase the width of traditional PSC bridges. However, no relevant research has been reported on local behavior of CFFRP strut in the bridge system. The purpose of this study is to investigate local behavior of CFFRP struts using fiber Bragg grating (FBG) sensors. Field tests were performed to examine the hoop strains and longitudinal strains of the FRP strut under various lateral positions and velocities of a test truck. It has been observed that CFFRP strut is under compression regardless of vehicle speed and location. However, the CFFRP strut is sensitive to the lateral position of vehicles in terms of strain magnitude. Results also indicated that the FBG sensors can faithfully record the hoop and longitudinal strains of the FRP strut without electro-magnetic interference.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.1
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• pp.79-85
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• 2006

CFRP(Carbon Fiber Reinforced Plastics) of the advanced composite materials as structural materials for vehicle, has a wide application in light-weigh structural materials of airplanes, ships and automobiles because of high strength and stiffness, However, there is a design variable to be considered in practical application of the laminate composite materials, these materials are vulnerable to transverse impact. This paper is to study the effects of stacking sequence and curvature on the penetration characteristics of composite laminate shell. They are stacked to $[0_3/90_3]S,\;[90_3/0_3]s\;and\;[0_2/90_3/0]s,\;[90_2/0_3/90]s$ and their interlaminar number two and four. They are manufactured to various curvature radius (R=100, 150, 200mm and $\infty$), When the specimen is subjected to transverse impact by a steel ball, the velocity of the steel ball was measured both before and after impact by determing the time for it to pass two ballistics-screen sensors located a known distance apart. The critical penetration energy of specimen A and B with less interfaces were a little higher than those of C and D. As the curvature increases, the critical penetration energy increases linearly because the resistance to the in-plane deformation as well as bending deformation increases, which need higher critical penetration energy. The specimen A and C have higher critical penetration energy than B and D because of different stacking sequences. We examined crack length through a penetration test. For the specimen A with 2interfaces, the longest circumferential direction crack length were observed on the first interface from the impact point. For the specimen B 4-interface, the longest circumferential direction crack length were observed on the second interface from the impact point.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.4
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• pp.480-486
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• 2016

Manufacturers have been applying several technologies that can improve the fuel economy of their cars. The regulated voltage control(RVC) system, is one of those technologies being used in passenger cars. In RVC, the voltage of an alternator is controlled depending on the electrical load demand or battery SOC, although each manufacturer differs from another in terms of detail. RVC can reduce the load of an alternator by consuming the stored energy of a battery and simultaneously generate energy. In this paper, a diesel passenger car equipped with an RVC system was tested under FTP-75 and HWFET modes to evaluate fuel economy as their initial battery SOC(100, 90, 80 and 60 %). The test results showed that the initial SOC affects fuel economy only under the FTP-75 mode. FTP-75 fuel economy of the 60% SOC was 13.2 % lower than the 100 % SOC. Also, the simultaneous consumption of the two energy sources did not appear in 60 % SOC.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.4
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• pp.118-125
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• 2014

As the earth's current global warming has caused elevation of sea water temperature, size of storms is foreseen to increase and consequently large damages on port facilities are to be expected. In addition, due to the improved processing efficiency of port cargo volume and increasing necessity for construction of eco-friendly port, demands for various forms of port facilities are anticipated. In this study, two kinds of nondestructive evaluation (NDE) techniques (rebound hardness and ultrasonic pulse velocity methods) are investigated for the effective maintenance of smart green harbor system. A new methodology to estimate the underwater concrete strengths is proposed and its feasibility is verified throughout a series of experimental works.

• Journal of Korean Medicine Rehabilitation
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• v.25 no.2
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• pp.73-80
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• 2015

Objectives To assess the safety of Shinbaro3 Pharmacopuncture by analyzing the potential single-dose intramuscular toxicity of Shinbaro3 Pharmacopuncture at various dose levels in SD (Spraque-Dawley) rats and Beagle dogs. Methods For evaluation of single-dose intramuscular toxicity of Shinbaro3 Pharmacopuncture, 40 SD rats (20 male and 20 famale) and 4 Beagle dogs (2 male and 2 female) were used. The rats were divided in four groups of 10 each, and treated intramuscularly with Shinbaro3 Pharmacopuncture at doses of 0.3, 0.6 and 1.2 mg/kg in distilled water, and distilled water as a vehicle control group, respectively. The Beagle dogs were divided into two groups of 2 each, and treated intramuscularly with Shinbaro3 Pharmacopuncture at doses of 0.15, and 0.3 mg/kg in distilled water, respectively, and signs of toxicity were observed. After a wash-out period of 3 days, the procedure was repeated with Shinbaro3 Pharmacopuncture at doses of 0.6, and 1.2 mg/kg in distilled water, respectively. Mortality, body weight changes, and necropsy findings were examined during the study period. Results There were no mortalities in either the SD rats or Beagle dogs. There were also no significant differences in adverse effects, body weight, or necropsy findings between the Shinbaro3 Pharmacopuncture and control groups. Conclusions There results suggest that the lethal dose 50 ($LD_{50}$) and approximate lethal dose (ALD) value of the test substance Shinbaro3 Pharmacopuncture are higher than 1.2 mg/kg in SD rats and Beagle dogs.