• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.6
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• pp.589-601
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• 2016

The hybrid grid was adopted and numerical prediction analysis of propeller unsteady bearing force considering free surface was performed for mode and full-scale KCS hull-propeller-rudder system by employing RANS method and VOF model. In order to obtain the propeller velocity under self-propulsion point, firstly, the numerical simulation for self-propulsion test of full-scale ship is carried out. The results show that the scale effect of velocity at self-propulsion point and wake fraction is obvious. Then, the transient two-phase flow calculations are performed for model and full-scale KCS hull-propeller-rudder systems. According to the monitoring data, it is found that the propeller unsteady bearing force is fluctuating periodically over time and full-scale propeller's time-average value is smaller than model-scale's. The frequency spectrum curves are also provided after fast Fourier transform. By analyzing the frequency spectrum data, it is easy to summarize that each component of the propeller bearing force have the same fluctuation frequency and the peak in BFP is maximum. What's more, each component of full-scale bearing force's fluctuation value is bigger than model-scale's except the bending moment coefficient about the Y-axis.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.37 no.1
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• pp.11-20
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• 2000

This paper presents the method of extracting the contour and shape parameters for moving object tracking in traffic scenes. The contour is extracted by applying difference image method in reduction image and the features are extracted from original image to grow the accuracy of tracking. We used features such as circle distribution, center moment, and maximum and minimum ratio. Data association problem is solved by these features. Kalman filters are used for moving object tracking on real time. The simulation results indicate that the proposed algorithm appears to generate feature vectors good enough for multiple vehicle tracking.

• International Journal of High-Rise Buildings
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• v.5 no.3
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• pp.177-186
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• 2016

Along the subduction-zone of the western Japanese islands, large earthquakes are expected occur around the middle of this century, and long-period ground motions will reach major urban areas, shaking high-rise buildings violently. Since some old high-rise buildings were designed without considering long-period ground motions, reinforcing such buildings is an important issue. An effective method to reinforce existing high-rise buildings is installing additional dampers. However, a problem with ordinary dampers is that they require reinforcement of surrounding columns and girders to support large reaction forces generated during earthquake ground motion. To solve this problem, a deformation-dependent oil damper was developed. The most attractive feature of this damper is to reduce the damping force at the moment when the frame deformation comes close to its maximum value. Due to this feature, the reinforcement of columns, girders, and foundations are no longer required. The authors applied seismic retrofitting with a deformation-dependent oil damper to an existing 54-story office building (Shinjuku Center Building) located in Shinjuku ward, Tokyo, in 2009 to suppress vibration under the long period earthquake ground motions. The seismic responses were observed in the 2011 Tohoku Earthquake, and it is clarified that the damping ratio was higher and the response lower by 20% as compared to the building without dampers.

• Journal of the Korean Geotechnical Society
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• v.31 no.5
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• pp.47-58
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• 2015

Triggering rainfall and geologic conditions with the state of slope hazard were investigated based on the field investigation and collected data on the slope hazard during the period between 2011 and 2014 in Korea. Analysis results showed that most of slope hazards occurred in metamorphic rock and debris flow was the most frequent type of slope hazard. Slope hazard increased when the higher monthly mean rainfall was recorded. However, most of slope hazard occurred when certain time elapsed after the moment of maximum hourly rainfall. Finally, more than one month of long-term rainfall was shown to be related to the frequency of slope hazard in the period.

• Journal of Korean Public Health Nursing
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• v.3 no.1
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• pp.67-73
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• 1989

The purpose of this study was to identify relationship between anxiety and. coping in open heart surgery patients to provide basic information for nursing intervention in stress-coping paradigm. Data were collected from Aug. 1st to Aug. 31st, 1988 through individual interview for about 30 minutes. Tools for this study were 'Spielberger's state anxiety scale and Billings & Moos' coping scale. The subjects were 29 male and 27 female patients who had open heart surgery at S.N.U.H. The data were analyzed by Mean score, Percentage, Pearson product moment correlation coefficient T-test, ANOVA test, and Cronbach's reliability test. The results were as follows. (1) The reliability of coping scale was 0.751 by Cronbach's reliability test. (2) Average coping score of those patients was 2,53 (maximum score:4) and they used equally problem focused coping and emotion focused coping. (3) There was significant difference according to religion in stress·coping(F=2,495, P<0.05) (4) The high anxieties were, the more coping were, and there was significant negative correlation in stress-coping (r=-0.2807, P<0.05)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.376-381
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• 2009

The increasing needs for higher cargo capacity in the container vessels' fleet has led to ship builder's demand for higher power output rating engine to meet the propulsion requirement, thus, leading to the development of super large two stroke low speed diesel engines. This large sized bore engines with more than 12 cylinders are capable of delivering power output up to more than 100,000 bhp at maximum continuous rating. The thrust variation force due to axial vibration occurring in propulsion shafting of these ships are transmitted to ship structure via thrust bearing. This force may vibrate the super structure of ship in the fore-aft direction and the fatigue strength of crank shaft can be decreased by additional bending stress increase in crank shaft pin and journal. In this paper, the axial vibration of propulsion shafting system on the 14RT-flex96C super large diesel engine with 14 cylinders is identified by theoretical analysis and vibration measurement.

• Speech Sciences
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• v.12 no.2
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• pp.89-99
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• 2005

The purpose of the present study were (1) to assess differences in tongue performances and speech intelligibility between normal and dysarthric speakers; and (2) to analyze the possible interrelationships between tongue strength, range of motion, and speech intelligibility in dysarthric patients. In order to measure maximum strength of anterior and lateral tongue strength, a force transducer has been designed. And a ruler was used for guaging range of motion. 'Word intelligibility test' was administered to each group. The results were analyzed by a quantitative statistical method(t test, Pearson product- moment correlation, and one-way ANOVA). The results were as follows; (1) dysarthric speakers showed significantly poorer performance than the normal in the tongue strength, range of motion, and speech intelligibility tasks; (2) the correlation between speech intelligibility and instrumental tongue performance was high in the dysarthric group; and (3) instrumental assessment was coincide with perceptual judgement of dysarthric tongue performance. The present investigation demonstrated that tongue weakness is causally related to articulation deficits in dysarthric. The clinical use of the force transducer would help a speech pathologist to quantify the degree of tongue weakness.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.7
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• pp.627-633
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• 2002

Many isolated featureless domains were explicitly observed even at the air-water interface. We measured the surface pressure shift originating from the photo-isomerization of azobenzene units on the periphery of dendrimers. The maximum surface pressure was gradual1y increased and saturated by cyclic compression and decompression. By irradiation of 365 [nm] light, the surface pressure was increased, which was originated by the photo-isomerization process of the azobenzene group on the periphery from trans to cia form. The increase of the dipole moment ($\mu$), which may increase the interaction among Azo dendrimer molecules, made an important role on surface pressure shift. From the absorbance spectrum by UV irradiation and heat treatment, we can see that the absorbance in the UV region decreases with the increase of the UV irradiation time, but the peak at 350 m, characteristic of dendrimers in the LB monolayers, was not shifted until four irradiation cycles. This suggests that optical behavior and morphological change are affected by the functional group and the symmetric chain.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.1
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• pp.109-121
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• 1999

In this paper, HF band LPDA(Log-periodic Dipole Antenna) and MLPDA(Modified Log-periodic Dipole Antenna) above lossy grounds were analyzed using moment method by considering the practical media parameter of lossy grounds, not assuming free space or perfect ground approximation. The radiation pattern and gain of LPDA and MLPDA as functions of frequency, antenna height from ground, and antenna tilt angle are presented, and the lossy ground effect on antennas characteristics are described. MLPDA was found to exhibit a smaller variation for gain and radiation pattern and a higher maximum beam direction relative to LPDA. It was shown that media parameter of lossy grounds and antenna height have a direct influence on the antenna gain of both LPDA and MLPDA.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.4
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• pp.892-899
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• 1988

A container crane model was tested to investigate wind-load characteristics in uniform flows and ground boundary layers. Drag coefficients and moment coefficients show their minimum values at 0, 90, 180 degrees wind directions and maximum values at 60 and 120 degrees. Strong interactions among structure elements produce such variations of the wind-load with wind directions. The BS-2573 code is shown to over-estimation can be reflected in the design stage of cranes by refining the rule of the designer. Some roundings of coners of the engine room and the machinery room reduce the wind-load by 10 percents. Considerable reductions of the wind-load would be expected if further integrated development of the crane structure are executed.