• Journal of Korean Society of Transportation
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• v.10 no.1
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• pp.5-20
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• 1992

Even though the types of ramp facilities in Korea are not various like other countries operations in these sections are very important because ramp merging and /or diverging flow affects freeway overall sections. In this study existing methodologies especially the gap acceptance model and the regression model in USHCM are evaluated with our field data. By gap acceptance model the merging capacity is founded 2.360 pcph which is increased by 7% than the capacity of freeway basic section. And in comparison of actual lane 1 volume to the estimation volume by HCM model the model slightly overestimates the actual volue.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.197-200
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• 2005

This paper presents an analytical model for evaluation of Tension Stiffening Effect by actual Bond-Slip relationships between the reinforcement and the surrounding concrete. The presence of longitudinal splitting cracks was found to significantly after the tension stiffening. The model is applied to the longitudinal splittings cracks and derived to Tension stiffening model. The predicted values are shown to be in good agreement with the experimentally measured data.

• Transactions of the Korean Society of Mechanical Engineers
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• v.5 no.4
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• pp.303-311
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• 1981

Machine tool dynamics is investigated under actual working conditions. Experimental evaluation of cutting dynamics in a lathe is made with cutting conditions and cutting positions varied. The thrust force and the toolpost and tailstock accelerations during turning process are modelled and analyzed by employing Dynamic Data System methodology. It is found that two acceleration signals are good enough to replace the thrust force, when used for machine tool identification under cutting process and for chatter detection.

• Journal of the military operations research society of Korea
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• v.3 no.1
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• pp.137-150
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• 1977

The effectiveness of an actual combat tank system is analyzed. A measure of effectiveness which includes performance and reliability called pseudo-reliability is introduced. A model is introduced to optimize the design of the system in which the system pseudo-reliability is maximized subject to cost constraint. This model is a nonlinear programming problem and is solved by the sequential unconstrained minimization technique (SUMT). A numerical exampl with actual data from the test evaluation of five combat tanks is used to illustrate the model.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.2012-2015
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• 2010

In this paper, the mathematical models of the superheater and the desuperheater are derived based on the fundamental laws of physics, mass and energy balance. The parameters of the models are developed for the 500[MW] thermal power plant using the actual data. The simulated model outputs are well matched with the actual ones. It is expected that the proposed models are useful for the temperature controller design of the thermal power plant.

• Journal of the Korean Society of Safety
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• v.8 no.2
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• pp.23-29
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• 1993

In this study, the method of deciding simulation test conditions is developed by computer program compared to actual vehicle test as accurately as possible. These results of analytical test conditions are conformed by simulation test using the brake dynamometer by comparison with test results of actual vehicle. Results of simulation test by these analytical results show good agreement with the vehicle test results. The analytical simulation test conditions provide the input data to brake dynamometer which follows : - each test inertia corresponding to braking deceleration - test condition of input control : brake line pressure - test condition of output control : braking torque

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.105-112
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• 2006

Freak waves in the ocean are recently drawing much attention as a natural disaster to ocean structures and navigating ships as well. Several observation data, among them the Draupner New Year Wave, show the very impressive feature of Freak waves whose wave height is up to three times as high as the significant wave height of surrounding waves, In addition, Freak wave appears as an isolated very high crest in somewhat stationary random waves of same order in their wavelengths. Bearing such characteristics in mind, one notices its extraordinary steepness. This strongly suggests that Freak wave is not long lived but transient nature on the whole. A great number of studies to explain these natures were published from both theoretical and numerical point of view. However it is not sure if they are applicable to actual ocean environment. In this paper, we deal with the results concerning abnormal and/or Freak waves from in-situ ocean wave data and point out several remarks to the problems lain behind the contributions in this context. A physical experiment is described to reinforce the subject discussed from the observation data.

• Transactions of the Society of Information Storage Systems
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• v.3 no.2
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• pp.94-112
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• 2007

Nano-sized inverted domain dots in ferroelectric materials have potential application in ultrahigh-density rewritable data storage systems. Herein, a data storage system is presented based on scanning non-linear dielectric microscopy and a thin film of ferroelectric single-crystal lithium tantalite. Through domain engineering, we succeeded to form an smallest artificial nano-domain single dot of 5.1 nm in diameter and artificial nano-domain dot-array with a memory density of 10.1 Tbit/$inch^2$ and a bit spacing of 8.0 nm, representing the highest memory density for rewritable data storage reported to date. Sub-nanosecond (500psec) domain switching speed also has been achieved. Next, long term retention characteristic of data with inverted domain dots is investigated by conducting heat treatment test. Obtained life time of inverted dot with the radius of 50nm was 16.9 years at $80^{\circ}C$. Finally, actual information storage with low bit error and high memory density was performed. A bit error ratio of less than $1\times10^{-4}$ was achieved at an areal density of 258 Gbit/inch2. Moreover, actual information storage is demonstrated at a density of 1 Tbit/$inch^2$.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.2
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• pp.103-111
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• 2000

The objectives of the study are to know the strain distribution and modal dynamic behaviour of steel bridge girders by actual traffic load. The live load effect depends on many parameters including the span length, gross vehicle weight, axle weight, axle configuration so on. For the estimation of static and dynamic characteristic, strain data caused by moving loads and traffic characteristics of passing vehicle under actual traffic load have measured using Bridge Weigh in Motion. To confirm the reliability of BWIM system, strain data measured using the $120{\Omega}$ strain gauge under the same condition. It is considered that the data acquired from BWIM system have reliability through the analysis and comparison between stress measured by strain data from BWIM and computed by FEM. Additionally according to the measured strain data of up-line and down-line on the highway, the up-line bridge grows more faster than the down-line bridge and girder 4 and 5 carry more load when vehicles pass the inner line and girder 2 and 3 does when vehicles pass the outer line as this case(the bridge composed with 5 girders).

• Journal of Korean language education
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• v.29 no.3
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• pp.255-292
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• 2018

Most grading scales of Korean language proficiency tests are based on existing grading scales that are not empirically verified. The purpose of this study is to develop an empirically verified scale descriptor. The 'Performance data-driven approach' that is suggested by Fulcher (1987) was used to develop the detailed description of characteristics for each level of performance. This study is focused on the functional phase of speech samples analysis (coding data) to create explanatory categories of discourse skills into which individual observations of speech phenomena can be scored. The speech samples that were collected through this study demonstrated stages of speech that can be a foundation of a grading scale. The data used in the study was collected from 23 native speakers of Korean. Speech samples were recorded from simulated speaking tests using the 'REFUSAL' task, and transcribed for analysis. The transcript was analyzed using discourse analysis. The result showed that the 'REFUSAL' task needs to go through four functional phases in actual communication. Furthermore, this study found specific and detailed explanatory categories of discourse competence based on the actual native speaker's speech data. Such findings are expected to contribute to the development of more valid and reliable speaking assessment.