• Journal of Biomedical Engineering Research
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• v.25 no.4
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• pp.283-288
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• 2004

The finite element modeling of small female occupant for crash simulation is presented in this paper subsequently to the part I of articulated rigid body model. The limbs and internal components are additionally modeled by joining them to the articulated rigid body model for predicting the crash injuries such as bone fractures and joint dislocations. The behavioral characteristics of each limbs and internal components were validated against available cadaveric test results. Accordingly, the human model proposed in this paper could be utilized for the investigation of impact injury mechanism and further complement the lacking biofidelity of current crash dummy.

• Journal of Biomedical Engineering Research
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• v.20 no.1
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• pp.21-27
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• 1999

In order to increase our understanding of the injury mechanism in the child occupant, three year old child model was developed using commercial dynamic package DADS. Total 14 segments and 12 joints were used to compose a model in three points belted condition with booster seat. HYGE sled test case was simulated to validate the developed model. Based on the comparison of the model and published test results, the developed model appears to be a resonable representation of the three year old dummy.

• Tunnel and Underground Space
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• v.14 no.6 s.53
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• pp.411-422
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• 2004

Sinkhole subsidence occurs over abandoned mine workings and can be detrimental to human lives, damage to properties and other surface structures. In this study, simulation of sinkhole development process is performed using special finite element procedure. Especially, creation of mine voids due to roof falls and generation of goaf from broken rocks are simulated using active-passive-active finite elements. An active or solid element can be made passive or void once the tensile failure criterion is satisfied in the specified sinkhole formation zone. Upon completion of sinkhole development process, these passive elements in again be made active to simulate goal region. Several finite element models are analyzed to evaluate the relationships between sinkhole formation with width of gallery. depth of mine, roof condition and bulking factor of roof rocks. This study demonstrates that the concept of passive elements in numerical analysis can be used effectively for analyzing sinkhole formation or roof fall phenomenon in general.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1187-1191
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• 2011

In this paper, the development of an adjustable load limiter is presented, which is a component of the seat belt. The adjustable load limiter is loaded at different levels for varied weights and heights of occupant. The recent regulation FMVSS 208 demands strict safety standards for different percentiles of dummy size. In this work, high- and low-level load conditions are proposed according to dummy scale and thoracic injury criteria. The suggested load conditions were verified by performing a sled test using the benchmark model. A dual-level load limiter has been developed on the basis of these tests. Experiments were conducted on the product performance, and finite element analysis was carried out; the results confirmed the points for improvement.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.18-30
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• 2010

As the automobile industry is developing, the number of deaths and injuries has increased. To reduce the damages from automobile accidents, the government of each country proposes experimental conditions for reproducing the accident and establishes the vehicle safety regulations. Automotive manufacturers are trying to make safer vehicles by satisfying the requirements. The Hybrid III crash test dummy is a standard Anthropomorphic Test Device (ATD) used for measuring the occupant's injuries in a frontal impact test. Since a real crash test using a vehicle is fairly expensive, a computer simulation using the Finite Element Method (F.E.M.) is widely used. Therefore, a detailed and robust F.E. dummy model is needed to acquire more accurate occupant injury data and behavior during the crash test. To achieve this goal, a detailed F.E. model of the Hybrid III 5th percentile female dummy is constructed by using the reverse engineering technique in this research. A modeling process is proposed to construct the F.E. model. The proposed modeling process starts from disassembling the physical dummy. Computer Aided Design (CAD) geometry data is constructed by three-dimensional (3-D) scanning of the disassembled physical dummy model. Based on the geometry data, finite elements of each part are generated. After mesh generation, each part is assembled with other parts using the joints and rigid connection elements. The developed F.E. model of dummy is simulated based on the FMVSS 572 validation regulations. The results of simulation are compared with the results of physical tests.

• Journal of Auto-vehicle Safety Association
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• v.9 no.4
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• pp.14-19
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• 2017

The mortality rate of car-pedestrian accidents is quite high compared to the frequency of accident. Recently, governments and insurance companies tend to establish and implement new safety standards for pedestrian protection such as EURO-NCAP and K-NCAP. The performance for the pedestrian protection has been gradually improved, but it is still insufficient. Therefore, various studies for the pedestrian protection are being carried out. The car-pedestrian accident is simulated in order to study to the upper legform test of the EURO-NCAP protocol. A pedestrian dummy model is employed and the results are discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.523-524
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• 2006

It is necessary to have a model that describes the anthropometry of the crash victim with a sufficient accuracy Koreans, however, do not have their own pedestrian dummies to be used in pedestrian collision tests. They have to use European and American dummies for their safety analysis. In this study scaled pedestrian dummies were constructed by using MADYMO. The dummies represent Korean average males and females aged from 25 to 29. The scaled Korean dummies and MADYMO human models were used to obtain and compare the pedestrian dynamic behaviors and injury criteria during the impact events.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.8
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• pp.450-456
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• 2003

This paper proposes a multiple time-series model with dummy variables for one-hour ahead load forecasting. We used 11 dummy variables that were classified by day characteristics such as day of the week, holiday, and special holiday. Also, model specification and selection of input variables including dummy variables were made by test statistics such as AIC(Akaike Information Criterion) and t-test statistics of each coefficient. OLS (Ordinary Least Squares) method was used for estimation and forecasting. We found out that model specifications for each hour are not identical usually at 30％ of optimal significance level, and dummy variables reduce the forecasting error if they are classified properly. The proposed model has much more accurate estimates in forecasting with less MAPE (Mean Absolute Percentage Error).

• Journal of the Korean Society of Mechanical Technology
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• v.13 no.3
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• pp.57-64
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• 2011

Vibrations on the floor in a car are transmitted to the foot, hip, and back from the seat. Human body recognizes these vibrations, but the sensitivity for each vibration is different. To evaluate these vibrations, RMS(root mean square) of accelerations, VDV(vibration does value) are commonly used. The ride comfort evaluation is usually carried out by experiments of real cars which are expensive. The purpose of this paper is to briefly review the status of several ride vibration standards and criteria having relevance to construction machinery vehicles and to suggest recommendations for the effective use of such criteria in vehicle / component development.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.341-345
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• 2005

In this paper, we propose an algorithm for the approximation of FIR filters by IIR filters. The algorithm is based on a concept of the balanced model reduction. Head-related transfer functions(HRTFs) of dummy-head are approximated by 32-order IIR filters. The binaural sounds using the approximated HRTFs are reproduced by headphone, and serves as a cue of sound image localization. Experiment of sound image are carried out for 10 participants with computer simulation and DSP board respectively. The results of the experiments show that the localization using the approximated HRTFs by IIR filters is the same accuracy as the case of FIR filters that simulate the HRTFs.