• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.151-155
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• 2001

The purpose of this study is to investigate the weldline movement of the laser welded sheets during the warm deep drawing process. For this investigation, Five steps of temperature ranges, from room temperature to $200^{\circ}C$, and two kinds of thickness combination, 0.8 mm${\times}$1.2 mm and 0.8 mm${\times}$1.6 mm SCP1 material sheets, were adopted. Also, the numerical analysis using the PAM-STAMP has been carried out with the same models as the specimens. As a result the higher temperature was adopted, the less weld-line movement was observed.

• Journal of Korean Port Research
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• v.12 no.2
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• pp.337-348
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• 1998

Since 1970s, though many effective construction methods have been established to solve soft ground problems which had occurred in the off shore land reclamation and on shore highway construction, lateral movement of structure on soft ground is still a big problem to engineers. In this study an applicability of criteria for determining the lateral movement of the structure in soft ground is examined and most measured data is obtained from 140 bridge abutments in highway construction sites. Characteristics and effectiveness of existing methods that used for deciding amount of lateral movements of abutment are analyzed using the obtained data. From the analysis, a proper method to prevent lateral movement is proposed. This method is confirmed on several case histories which were constructed on marine clay.

• International Journal of Highway Engineering
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• v.19 no.4
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• pp.69-78
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• 2017

PURPOSES : In this study, we analyzed the road crossing behavior of older pedestrians on a mid-block signalized crosswalk, and compared it to that of younger pedestrians. In addition, we analyzed the correlation between accidents involving older pedestrians while crossing roads and their behavioral characteristics. Finally, we confirmed the reasons for an increase in accidents involving older pedestrians. METHODS : First, 30 areas with the highest incidence of accidents involving older pedestrians while crossing roads were selected as target areas for analysis. Next, we measured the start-up delay (the time elapsed from the moment the signal turns green to the moment the pedestrian starts walking) and head movement (the number of head turns during crossing a road) of 900 (450 older and 450 younger) pedestrians. The next step was to conduct a survey and confirm the differences in judgment between older and younger pedestrians about approaching vehicles. Finally, we analyzed the correlation between the survey results and traffic accidents. RESULTS : The average start-up delay and head movement of the older pedestrians was 1.58 seconds and 3.15 times, respectively. A definite correlation was obtained between head movement and the frequency of pedestrian traffic accidents. The results of our survey indicate that 17.3% of the older pedestrians and 7.8% of the younger pedestrians have a high crash risk. CONCLUSIONS : Behavioral characteristics of older pedestrians were closely correlated with accidents involving older pedestrians while crossing roads in mid-block signalized crosswalks. Our study indicates that in order to reduce the number of accidents involving older pedestrians, it is necessary to develop an improvement plan including measures such as installation of safety facilities taking the behavioral characteristics of older pedestrians into consideration and their safety education.

• Phonetics and Speech Sciences
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• v.15 no.1
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• pp.19-24
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• 2023

This study investigated acoustic (VOT) and articulatory characteristics of Korean velar stops in monosyllabic CV structures to examine how the three-way distinction is realized in the laryngeal and supralaryngeal domains and how the distinction is manifested in male versus female speakers' speech production. EMA data were collected from 22 speakers. In line with previous studies, male speakers preserved the three-way differentiation of velar stops (/k^*/</k/</k^h/) in terms of VOT while female speakers showed only a two-way distinction (/k^*/</k/=/k^h/). As for the kinematic characteristics, a clear three-way distinction was found only in male speakers' peak velocity measure in the C-to-V opening movement (/k^h/</k/</k^*/). For the other kinematic measures (i.e., articulatory closure duration, deceleration duration of the opening movement and the entire opening movement duration), male speakers showed only a two-way distinction between fortis and the other two stops. Female speakers did not show a three-way contrast in any kinematic measure. They showed a two-way distinction between lenis and the other two stops in C-to-V deceleration duration (/k^*/=/k^h/</k/), and a two-way distinction between fortis and lenis stops in the opening movement duration. An overall comparison of VOT and articulatory analyses revealed that the lenis-aspirated kinematic distinction is diminishing, driven by female speakers, in line with the loss of the lenis-aspirated distinction in VOT that could influence supralaryngeal articulation.

• Physical Therapy Rehabilitation Science
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• v.5 no.3
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• pp.113-119
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• 2016

Objective: The effect of abdominal expansion maneuver (AEM) and abdominal draw-in maneuver (ADIM) on postural control in an unsupported position in stroke patients. Design: Randomized controlled trial. Methods: A total of 36 persons with hemiplegic stroke participated in this study. The subjects were randomly divided into an AEM experimental group (n=12), an experimental ADIM group (n=12), and a control group (n=12). We collected the general characteristics of all subjects and the pre-test results before the intervention and after 4 weeks of the intervention. The trunk stabilization training of the ADIM and AEM group were performed 15 minutes a day, 3 times a week for 4 weeks, and general physical therapy was performed 2 times a day, 30 minutes per session, 5 times a week for all three groups. The control group received joint mobilizations, muscle strengthening, endurance strengthening, and gait exercises along with treatment of the central nervous system, such as neuro-developmental treatment, mat, and gait training. The AEM is an inspiratory phase of tidal breathing expanding the lateral lower ribcage in a lateral direction with minimal superior movements of the chest. Then the lower abdomen expands and the navel moves in an anterior-caudal direction. The ADIM is a repeated contraction and relaxation of the anal sphincter during inspiration. The navel pulls the lower abdomen to the direction of the spine without the movement of the trunk and pelvis. Results: Before and after the interventions, medial-lateral axis movement distance, anterior-posterior axis movement distance, sway mean velocity, and sway area 95% was a statistically significant change in all three groups (p<0.05). The post-hoc test showed a significant improvement in medial-lateral axis movement distance, anterior-posterior axis movement distance, sway mean velocity, and sway area in the AEM group compared with the control group, and in the ADIM group compared with the control group (p<0.05). Conclusions: In conclusion, both AEM training and ADIM training are necessary interventions to maintain the independent sitting position according to the characteristics of the patient.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.315-316
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• 2007

This paper presents a new methodology to improve movement database for a humanoid robot. The database is initially full of human motions so that the kinetics characteristics of human movement are immanent in it. then, the database is updated to the pseudo-optimal motions for the humanoid robot to perform more natural motions, which contain the kinetics characteristics of robot. for this, we use the evolutionary algorithm. the methodology consists of two processes : (1) the offline imitation learning of human movement and (2) the online generation of natural motion. The offline process improve the initial human motion database using the evolutionary algorithm and inverse dynamics-based optimization. The optimization procedure generate new motions using the movement primitive database, minimizing the joint torque. This learning process produces a new database that can endow the humanoid robot with natural motions, which requires minimal torques. In online process, using the linear combination of the motion primitive in this updated database, the humanoid robot can generate the natural motions in real time. The proposed framework gives a systematic methodology for a humanoid robot to learn natural motions from human motions considering dynamics of the robot. The experiment of catching a ball thrown by a man is performed to show the feasibility of the proposed framework.

• Journal of Sensor Science and Technology
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• v.21 no.2
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• pp.144-150
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• 2012

A microphone for fully implantable hearing device was generally implanted under the skin of the temporal bone. So, the implanted microphone's characteristics can be affected by the accompanying noise due to masticatory movement. In this paper, the implantable microphone with 2-channels structure was designed for reduction of the generated noise signal by masticatory movement. And an experimental model for generation of the noise by masticatory movement was developed with considering the characteristics of human temporal bone and skin. Using the model, the speech signal by a speaker and the artificial noise by a vibrator were supplied simultaneously into the experimental model, the electrical signals were measured at the proposed microphone. The collected signals were processed using a general adaptive filter with least mean square(LMS) algorithm. To confirm performance of the proposed methods, the correlation coefficient and the signal to noise ratio(SNR) before and after the signal processing were calculated. Finally, the results were compared each other.

• Journal of the Korean Society for Library and Information Science
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• v.56 no.4
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• pp.223-238
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• 2022

The discovery of new historical resources is important in that it ensures the sustainability of future researches and enables new interpretations and expansion of them. The purpose of this study is to describe the characteristics of Chinese reports related to the newly discovered Gwangju Student Movement in terms of contents. In particular, since Chinese reports contain the same expressions and contents, we tried to figure out which materials from Korea and Japan were cited the same and what kind of relationships there were. The analysis results are as follows: First, the relationship between the reports on December 6, 1929, which were newly claimed as the first reports, and the Gwangju Student Movement was explained in detail. Although there is no specific indication that the distributing of manifesto and arresting case on December 6th in Seoul was related to the Gwangju Student Movement, it should be viewed as the first reports made to support it. Second, in previous studies, it was revealed that the contents known as the newspaper's own reports were actually quoted from previous reports in Korea or Japan. Third, it was confirmed that the contents of reports could be affected by the citation reports according to the political characteristics of the newspapers.

• Journal of Biomedical Engineering Research
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• v.2 no.2
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• pp.145-150
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• 1981

In this paper, we measured the tracking response time of horizontal eye movement to the target moving according to the square waveform to investigate the predictive characteristics of the human oculomotor system. And in the experiment we used the square waves with an amplitude of 5 degree and frequencies o.1, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 Hz. Random occurrences of the human eye movement reponse time were analyzed using a finite Markov chain process and we found the results as follows. From both the experimental and theoretical results, we found the trend showing that Predictive characteristics moved from the transient state to the steady state.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.271-273
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• 2000

This paper presents the dynamic characteristics Linear DC Motor(LDM) using 3 Dimensional Equivalent Magnetic Circuit Network Method(3-D EMCN) by voltage driven. The movement of mover substitutes for the movement of magnetization in permanent magnet expressed by Fourier series. The Dynamic characteristics are carried out from coupling the electrical circuit equation and mechanical kinetic equation.