• Journal of the Korea Society for Simulation
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• v.27 no.2
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• pp.35-48
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• 2018

The study of air defense against North Korean tactical ballistic missiles (TBM) should consider the rapidly changing battlefield environment. The study for target re-designation for intercept missiles enables effective operation of friendly defensive assets as well as responses to dynamic battlefield. The researches that have been conducted so far do not represent real-time dynamic battlefield situation because the hit probability for the TBM, which plays an important role in the decision making process, is fixed. Therefore, this study proposes a target re-designation algorithm that makes decision based on hit probability which considers real-time field environment. The proposed method contains a trajectory prediction model that predicts the expected trajectory of the TBM from the current position and velocity information by using random forest and moving window. The predicted hit probability can be calculated through the trajectory prediction model and the simulator of the intercept missile, and the calculated hit probability becomes the decision criterion of the target re-designation algorithm for the missile. In the experiment, the validity of the methodology used in the TBM trajectory prediction model was verified and the superiority of using the hit probability through the proposed model in the target re-designation decision making process was validated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.805-817
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• 2016

This study considered the existing approximation theories of solitary wave for stable generation of it with different waveforms in a hydraulic/numerical wave tank for coping with the tsunami. Based on the approximation theory equations, two methods were proposed to estimate various waveforms of solitary wave. They estimate different waveforms and flow rates by applying waveform distribution factor and virtual depth factor with the original approximate expressions of solitary wave. Newly proposed estimation methods of solitary wave were applied in the wave generation of hydraulic/numerical wave tank. In the result, it was able to estimate the positional information signal of wave generator in the hydraulic wave tank and to find that the signal was very similar to an input signal of existing hydraulic model experiment. The waveform and velocity of solitary wave was applied to the numerical wave tank in order to generate wave, which enabled generate waveform of tsunami that was not reproduced with existing solitary wave approximation theory and found that the result had high conformity with existing experiment result. Therefore, it was able to validate and verify the two proposed estimation methods to generate stable tsunami in the hydraulic/numerical wave tank.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.6
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• pp.155-163
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• 2010

The past researches on flood inundation simulation mainly focused on development of numerical models based on unstructured mesh networks to improve model performances. However, despite the accurate simulation results, such models are not suitable for real-time flood inundation forecasting due to a huge computational burden in terms of geographic data processing. In addition, even though various types of vector and raster data are available to be compatible with flood inundation models for post-processes such as flood hazard mapping and flood inundation risk analysis, the unstructured mesh-based models are not effective to fully use such information due to data incommensurability. Therefore, this study aims to develop a raster-based two-dimensional inundation model; it guarantees computational efficiency because of direct application of DEM for flood inundation modeling and also has a good compatibility with various types of raster data, compared to a commercial model such as FLUMEN. We applied the model to simulate the BaekSan levee break in the Nam river during a flood period from August 10 to 13, 2002. The simulation results showed a good agreement with the field-surveyed inundation area and were also very similar with results from the FLUMEN. Moreover, the model provided physically-acceptable velocity vectors with respect to inundating and returning flows due to the difference of water level between channel and lowland.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.245-251
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• 2005

When we design coastal and harbol facilities deepwater design wave and wind speed are the important design parameters. Especially, the analysis of these informations is a vital step for the point of disaster prevention. In this study, we made and an extreme value analysis using a series of deep water significant wave data arranged in the 16 direction and supplied by KORDI real-time wave information system ,and the wind data gained from Wan-Do whether Station 1978-2003. The probability distributions considered in this characteristic analysis were the Weibull, the Gumbel, the Log-Pearson Type III, the Normal, the Lognormal, and the Gamma distribution. The parameter for each distribution was estimated by three methods, i.e. the method of moments, the maximum likelihood, and the method of probability weight moments. Furthermore, probability distributions for the extreme data had been selected by using Chi-square and Kolmogorov-Smirnov test within significant level of 5%, i,e. 95% reliance level. From this study we found that Gumbel distribution is the most proper model for the deep water design wave height off the southwest coast of Korea. However the result shows that the proper distribution made for the selected site is varied in each extreme data set.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.347-354
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• 2006

In this paper we have attempted to bring the wavelet transform theory to the dynamic response conversion algorithm. This algorithm is proposed for the problem of estimating the displacement data by defining the transformed responses. In this algerian, the displacement response can be obtained from the measured acceleration records by integration without requiring the knowledge of the initial velocity and displacement information. The advantage of the wavelet transform over either a pure spectral or temporal decomposition of the signal is that the pertinent signals features can be characterized in the time-frequency plane. In the response conversion procedure using the wavelet decomposition signals, not only the static component can be extracted, but also the dynamic displacement component can be separated by the structural mode from the identified displacement response. The applicability of the technique is tested by an example problem using the real bridge's superstructure under several cases of moving load. If the reliability of the identified responses is ensured, it is expected that the proposed method for estimating the impact factor can be useful in the bridge's dynamic test. This method can be useful in those practical cases when the direct measurement of the displacement is difficult as in the dynamic studies of huge structure.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.38 no.2
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• pp.1-8
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• 2001

In this paper, we propose an algorithm which estimates the displacements and velocities of objects in the soccer field from the soccer image sequences. Assuming the time interval of an object movement is given, we transform the object positions into those in the soccer field model and compute the distance and the velocity. When four corresponding pairs of the feature points, such as the crossing points of the lines in the soccer field, exist and three of them are not on a line, we transform the object positions in the soccer image into those in the soccer field by using the perspective displacement field model. In addition, when the soccer image has less than four feature points, we first transform the object positions into those in the image which has more than four feature points, and then transform the positions into those in the soccer field again. To find the coordinate transformation between two images, we estimate the panning and zooming for consecutive images in the sequence. In the experimental results, we quantitatively evaluated the estimation accuracy by applying our algorithm to the synthetic. soccer image sequences generated by graphic tools, and applied it to the real soccer image sequences for broadcasting to show its usefulness.

• Journal of the Korean Geophysical Society
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• v.4 no.2
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• pp.103-111
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• 2001

Geophysical survey was carried out to derive some information on the existence of near-surface anomalous body at Reung-Chi area in Kongju. Resistivity, seismic, magnetic and gravity method were applied. Geophysical survey that was applied was the electrical resistivity survey, seismic survey, magnetic survey, gravity survey. These surveys are analyzed to provide data of high resolution. As a result of analysis of resistivity survey, anomalies showing high resistivity anomaly than around appeared, and the one showing M-shape out of those explains the possibility that underground common or other underground structure or geographical anomalous zone could exist in the underground. As a result of analysis of seismic survey, it is clear that the low velocity layer is spread as far as the bottom of the underground. It is possible to presume that it is a phenomenon appearing while going through the underground space where it is lying in the underground. Area that shows unusual situation in interpretation of data on seismic waves are included into the area that once showed resistivity anomaly, the results of both seismic surveys come in accord. As a result of magnetic survey, a circle-shape of twin magnetic fields in the area where abnormalities are shown between electrical resistivity survey and seismic survey is appeared. Given the area of gravity survey, abnormalities whose density is different from the one around the bottom of the underground. As a result of analogizing the data of underground of the subsurface based on analysis of data from each survey, it was interpreted that anomalous zone exists commonly in the research areas.

• Fire Science and Engineering
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• v.16 no.3
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• pp.26-31
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• 2002

Bromotrifluoromethane(halon-1301) and bromochlorodifluoromethane(halon-1211) have been widely used as a clean fire extinguishing agents due to their outstanding properties. However, production and use of halon are currently being phased out under an international agreements Montreal Protocol because of global environmental concerns and HFCs have been considered as promising alter-natives for the replacement of halon since their ozone depletion potentials are low. The vapor-liquid equilibrium data are required as important basic information in evaluating the solubility of clean fire extinguishing agents and determining their optimal compositions. In this work, we chose HFCs such as HFC-22 HFC-125, and HFC-l34a for gaseous fire extinguishing agents and nitrogen as a pressurization gas for a proper jet velocity of these agents. Phase equilibria for binary mixtures of nitrogen/HFC-22, nitrogen/HFC-125, and nitrogen/HFC-l34a were measured in the temperature range from 283.15K to 303.15K. For equilibrium measurement, we used a circulation type apparatus in which both vapor and liquid phases were continuously recirculated. The experimental data were relatively well correlated with the Peng-Robinson equation of state with Wong-Sandier mixing rules.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1527-1533
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• 2001

Garole is a prolific, rare, less known and small size Indian sheep breed found in low and humid Sunderban region of West Bengal. Although information on stored Garole ram liquid semen upto 24 h is available, but there is a need to further investigate the short-term and long-term preservability of Garole ram semen for extensive utilization of this valuable germplasm by artificial insemination. The aim of the present study was to apply computer-assisted sperm analysis technique for assessing the motion characteristics of Garole ram semen stored (i) in liquid state at refrigeration temperature for short-term preservation upto 48 h and (ii) in frozen state at $-196^{\circ}C$ for long-term preservation after packaging in mini straws. Short-term preservation had a significant effect on motility (p<0.01) as the motility progressively decreased from 90.1% at 0 h to 85.5% and 73.2% after 24 and 48 h of storage, respectively. Although the decline in rapid moving sperms was also significant (p<0.01) on storage but the decrease was more pronounced at 48 h as compared to 24 h of storage period. Storage of chilled semen had also a significant effect on % linearity (p<0.05), % straightness (p<0.01), sperm velocities (p<0.01), amplitude of lateral head displacement (p<0.01) and beat frequency (pO.Ol) of spermatozoa. The replication had a significant effect for all the variables except average path and straight line velocity. However, the interactions of short-term storage and replication were non-significant for most of the variables except % of medium moving sperms, sperm velocities and beat frequency. On long-term preservation of Garole ram spermatozoa under controlled conditions the mean post-thaw recovery of 70.4 and 71.4% motile spermatozoa was achieved having 48.8 and 48.9% of rapidly motile spermatozoa, respectively in both the replicates. The effect of replication on cryopreservation was significant (p<0.05) on amplitude of lateral head displacement and beat frequency, but there was no significant effect on motility, rapidly motile spermatozoa, linearity, straightness and sperm velocities of frozen-thawed spermatozoa. It can be concluded from these results that an average 70% motility can be achieved on storage of Garole ram semen in chilled liquid state upto 48 h or in liquid nitrogen after freezing under controlled conditions in straws. However, further studies are required to evaluate the fertility of short-term and long-term preserved Garole ram semen for extensive use of this prolific sheep breed.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.5
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• pp.404-411
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• 2009

We introduce in this paper a new method for smooth foldover-free warping of images, based on the vector field deformation technique proposed by Von Funck et al. It allows users to specify the constraints in two different ways: positional constraints to constrain the position of a point in the image and gradient constraints to constrain the orientation and scaling of some parts of the image. From the user-specified constraints, it computes in the image domain a C1-continuous velocity vector field, along which each pixel progressively moves from its original position to the target. The target positions of the pixels are obtained by solving a set of partial derivative equations with the 4th order Runge-Kutta method. We show how our method can be useful for texture mapping with hard constraints. We start with an unconstrained planar embedding of a target mesh using a previously known method (Least Squares Conformal Map). Then, in order to obtain a texture map that satisfies the given constraints, we use the proposed warping method to align the features of the texture image with those on the unconstrained embedding. Compared to previous work, our method generates a smoother texture mapping, offers higher level of control for defining the constraints, and is simpler to implement.