• Journal of Institute of Control, Robotics and Systems
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• v.20 no.3
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• pp.313-322
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• 2014

This paper is to survey and put in perspective the working methods of multi-target tracking in clutter. This paper includes theories and practices for data association and related filter structures and is motivated by increasing interest in the area of target tracking, security, surveillance, and multi-sensor data fusion. It is hoped that it will be useful in view of taking into consideration a full understanding of existing techniques before using them in practice.

• Journal of Electrical Engineering and information Science
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• v.3 no.2
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• pp.267-273
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• 1998

This paper introduces an adaptive algorithm determining the measurement-track association problem in multi-target tracking(MTT). We model the target and measurement relationships with mean field theory and then define a MAP estimate for the optimal association. Based on this model, we introduce an energy function defined over the measurement space, that incorporates the natural constraints for target tracking. To find the minimizer of the energy function, we derived a new adaptive algorithm by introducing the Lagrange multipliers and local dual theory. Through the experiments, we show that this algorithm is stable and works well in general environments. Also the advantages of the new algorithm over other algorithms are discussed.

• Journal of Radiation Protection and Research
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• v.14 no.2
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• pp.18-22
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• 1989

In order to calibrate the CR-39 Solid State Nuclear Track Detector (SSNTD), a closed -circulation type SSNTD-Calibration-System containing a radon-cup with the Millipore filter has been set-up, and the tracks produced on the SSNTD were measured for the known amount of radon concentration. Calibration factor for the time integrated radon concentration as a function of the track density on CR-39 was estimated to be $0.24{\pm}0.09(pCi/l)\;day/(Tr/cm^2)$.

• Journal of Radiation Protection and Research
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• v.10 no.2
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• pp.144-147
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• 1985

The spontaneous fission rate of $^{238}U$ has been determined using a solid state track recorder that was a pre-etched mica. Counting the tracks revealed in mica made it possible to calculate the spontaneous fission rate. The mica remained in close contact with a $^{238}UO_2$ foil for about five years. The resulting fission rate was $5.21{\pm}0.33$ fissions/g-sec.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.6
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• pp.186-197
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• 1996

A multiple target tracking (MTT) problem is to track a number of targets in clusttered environment, where measurements may contain uncertainties of measurement origin due to clutter, missed detection, or other targets, as well as measurement noise errors. Hence, an MTT filter should be introduced to resolve this problem. In this paper, a neural network is rpoposed as an MTT filter.

• Journal of The Korean Association For Science Education
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• v.22 no.2
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• pp.345-356
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• 2002

This study investigated the trends in the number of applicants and mean score and applicants' responses on the test items of 'science inquiry' of the College Scholastic Ability Test(CSAT) implemented for 3 years$(1999\;{\sim}2001)$. The results of this study were as follows: The percentage of applicants of science track for 1995 CSAT were 43.13%, but reduced to 29.5% for 2001 CSAT. And unlike other tracks, the percentage of male applicants, ranking above average, of science track was 65.58%, which is about twofold of female applicants(34.42%). The mean score of 'Science inquiry' was 58.6 in 1999, and 69.5 in 2001. And the score of the applicants, ranking above average, of humanity and social science course and science course, were 85.8 and 90.7 respectfully in 2001 CSAT. These high mean scores were caused by the policy of "easy CSAT" so called. Most of test items were developed to have difficulty 60-79% or above 80%. This easy CSAT provoked intense dispute about the discriminating power of CSAT. The mean score of male applicants was higher than that of female. But the difference decreases every year. Applicants were generally very good at solving tests focusing on process skills only but poor at solving tests related to physics or calling for two or more science concepts. Thus special measures to cope with the decrease in applicants, especially female applicants, for science track should be provided. To increase discriminating power of CSAT, it is recommended to develop test items with wider range of difficulty and to reduce test items which are focussing process skills and can be solved without any special science concepts. And special consideration should be given to teaching the content area with poor achievement and high actual difficulty compared to the expected.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.385-396
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• 2014

Lately, more frequent typhoons cause extensive flood and wind damage throughout the summer season. In this respect, this study aims to develop a probabilistic clustering model that uses both typhoon genesis location and trajectories. The proposed model was applied to the 197 typhoon events that made landfall in the Korean peninsula from 1951 to 2012. We evaluate the performance of the proposed clustering model through a simulation study based on synthetic typhoon trajectories. The seven distinguished clusters for typhoons affecting Korean peninsula were identified. It was found that most of typhoon genesis originated from a remote position ($10^{\circ}{\sim}20^{\circ}N$, $120^{\circ}{\sim}150^{\circ}E$) near the Equator. Cluster, type B can be regarded as a major track due to the fact that its frequency is approximately about 25.4% out of 197 events and its direct association with strong positive rainfall anomalies.

• Journal of Korea Water Resources Association
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• v.48 no.6
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• pp.463-477
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• 2015

The recent unusual climate and extreme weather events have frequently given unexpected disaster and damages, facing difficulties in the management of water resources. In particular, climate change could result in intensified typhoons, and this would be the worst case scenario that can happen. The primary objective of this study is to identify the patterns of typhoon-induced precipitation and the associated synoptic pattern. This study focused on analyzing precipitation patterns over the South Korea using historic records as opposed to a specified season or duration, and further investigates the potential connection with heavy rainfall to synoptic patterns. In this study, we used the best track data provided by the Regional Specialized Meteorological Center of Japan for 40 years from 1973 to 2012. The patterns of the typhoon-induced precipitation were categorized into four groups according to a given typhoon track information, and then the associated synoptic climatology patterns were further investigated. The results demonstrate that the typhoon-induced precipitation patterns could be grouped and potentially simulated according to the identified synoptic patterns. Our future work will focus on developing a short-term forecasting model of typhoon-induced precipitation considering the identified climate patterns as inputs.

• Journal of The Korean Association For Science Education
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• v.14 no.2
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• pp.214-224
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• 1994

The Ministry of Education established the plan to adopt a new college enterance examination system, so called Scholastic Ability Test for college, from 1994. The National Board of Educational Evaluation had carried out 7 experimental trials for the new examination system. Eventhough, the governmental officials advertised the purpose and characteristics of the new examination system, many students and parents did not understand the essential point very well. In this study the researcher tried to analyze the 7 trial examination items and the first Scholastic Ability Test for college carried out 1993. In this study, the researcher tried to find out all the items appeared in the 7 trials. In the analysis, all the individual items from the 1st trial to the 7th trial were used. The research results showed that the items were evenly distributed in all the four areas(Physics, Chemistry, Biology and Earth Science) of science content; however, they were heavily concentrated on data or information analysis categoris in the inquiry domain. In the domain of context, laboratory context was the major item context. The scores were also analyzed. The results showed that no significant difference between male and female students. However, science track students showed higher achievement scores than the non-science track student. The examination result showed high correlation with the tests routinely have carried out in schools. The over all analysis showed the new examination system showed very different characteristics to the conventional tests. Therefore, for the student to get successful result in the Scholastic Ability Test, they should change the way of study. They should try to understand scientific concepts rather than to memorize them. They should invest their time to carry out real experiments rather than to focus on the princples and laws of science. One of the most important thing would be for the student to apply what they learned to real life situations.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.152-152
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• 2022

Only employing historical data limits the estimation of the full distribution of probable Tropical Cyclone (TC) risk due to the insufficiency of samples. Addressing this limitation, this study introduces a semi-physical TC rainfall model that produces spatially and temporally resolved TC rainfall data to improve TC risk assessments. The model combines a statistical-based track model based on the Markov renewal process to produce synthetic TC tracks, with a physics-based model that considers the interaction between TC and the atmospheric environment to estimate TC rainfall. The simulated data from the combined model are then fitted to a probability distribution function to compute the spatially heterogeneous risk brought by landfalling TCs. The methodology is employed in South Korea as a case study to be able to implement a country-scale-based vulnerability inspection from damaging TC impacts. Results show that the proposed model can produce TC tracks that do not only follow the spatial distribution of past TCs but also reveal new paths that could be utilized to consider events outside of what has been historically observed. The model is also found to be suitable for properly estimating the total rainfall induced by landfalling TCs across various points of interest within the study area. The simulated TC rainfall data enable us to reliably estimate extreme rainfall from higher return periods that are often overlooked when only the historical data is employed. In addition, the model can properly describe the distribution of rainfall extremes that show a heterogeneous pattern throughout the study area and that vary per return period. Overall, results show that the proposed approach can be a valuable tool in providing sufficient TC rainfall samples that could be an aid in improving TC risk assessment.