• Korean Journal of Ecology and Environment
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• v.52 no.1
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• pp.9-12
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• 2019

The red-eared slider (Trachemys scripta elegans) is the one of the most popular pets, and the most commonly traded species in the world. It is designated as an ecosystem disturbance species that has been managed in South Korea. To date, no reports of natural or anthropogenic migration and spreading of T. s. elegans in South Korea are available. In the present study, we estimated the expected route and the movable path of one female T. s. elegans found in Namsan-myun, Gyeongsan-si, Gyeongsangbuk-do. Based on the movable path, the potential destination of the female turtle was estimated to be about 282 m and 468 m away. Therefore, the moving distance of the red-eared slider to the nearest water system will be at least 606 m and at most 792 m. Our results provide the first evidence about the natural migration and spreading of exotic turtles. This study can serve as a basis for the management and countermeasures against the introduced of T. s. elegans and other exotic species in South Korea.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2879-2888
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• 2023

In fusion environments, large scales of helium (He) atoms are produced by a radical transformation along with structural damage in structural materials, resulting in material swelling and degradation of physical properties. To understand its irradiation effects, this paper investigates the stability, electronic structure, energetics, charge density distribution, PDOS and TDOS, and diffusion processes of He impurities in 6HSiC materials. The formation energy indicates that a stable, favorable position for interstitial He is the HR site with the lowest energy of 2.40 eV. In terms of vacancy, the He atom initially prefers to substitute at pre-existing Si vacancy than C vacancy due to lower substitution energy. The minimum energy paths (MEPs) with migration energy barriers are also calculated for He impurity by interstitial and vacancy-mediated diffusion. Based on its calculated energy barriers, the most possible diffusion path includes the exchange of interstitial and vacancy sites with effective migration energies ranging from 0.101 eV to 1.0 eV. Our calculation provides a better understanding of the stabilization and diffusion behaviors of He impurities in 6H-SiC materials.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.101-106
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• 2005

A ground penetrating image radar (GPR) using an ultra wideband (UWB)impulse waveform is developed for non destructive detection of metallic pipelines buried under the ground. Dielectric constant of test field is measured and then a GPR system is designed for better detection up to 1 meter deep. By considering total path loss, volume of complete system, and resolution, upper and lower frequencies are chosen. First, a UWB impulse for the frequency bandwidth of the impulse is chosen with rising time less than 1 ns, and then compact planar UWB dipole antenna suitable for frequency bandwidth of a UWB impulse is designed. Also, to receive reflected signals, a digital storage oscilloscope is used. For measurement, a monostatic technique and a migration technique are used. For visualizing underground targets, simple image processing techniques of A-scan removal and B-scan average removal are applied. The prototype of the system is tested on a test field in wet clay soil and it is shown that the developed system has a good ability in detecting underground metal objects, even small targets of several centimeters.

• Journal of the Economic Geographical Society of Korea
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• v.18 no.4
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• pp.467-491
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• 2015

This paper aims at analyzing the characteristics of the immigration path, residential location, and housing ownership structure of Korean immigrants in London metropolitan area. The main results of this study are as follows. Firstly, factors influencing the initial residential location of Korean immigrants are situation of immigrants, immigration region, and help of prior Korean immigrants. Secondly, factors influencing the current residential location of Korean immigrants are income, ability of English, education at United Kingdom, and initial residential location. Thirdly, viewing the characteristics of the of housing ownership structure, migrants tend to reside their own housings while migration period go beyond 10 years and incomes exceed ${\pounds}$50,000. Forth, immigration path types of London Korean Immigrants are divided by ethnic enclave oriented type and mainstream society oriented type.

• The Journal of Bigdata
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• v.5 no.1
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• pp.1-9
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• 2020

The study was conducted with funding from the government (Ministry of Agriculture, Food and Rural Affairs) in 2018 with support from the Agricultural, Food, and Rural Affairs Agency, 318069-03-HD040, and in based on artificial intelligence-based HPAI spread analysis and patterning. The model that is actively used in time series and text mining recently is LSTM (Long Short-Term Memory Models) model utilizing deep learning model structure. The LSTM model is a model that emerged to resolve the Long-Term Dependency Problem that occurs during the Backpropagation Through Time (BPTT) process of RNN. LSTM models have resolved the problem of forecasting very well using variable sequence data, and are still widely used.In this paper study, we used the data of the Call Detailed Record (CDR) provided by KT to identify the migration path of people who are expected to be closely related to the virus. Introduce the results of predicting the path of movement by learning the LSTM model using the path of the person concerned. The results of this study could be used to predict the route of HPAI propagation and to select routes or areas to focus on quarantine and to reduce HPAI spread.

• Journal of the Economic Geographical Society of Korea
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• v.18 no.1
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• pp.17-44
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• 2015

This paper aims at elucidating the characteristics of immigration path and residential location, and analyzing the factors influencing housing ownership structure and preference of residential location factors of Korean immigrants in Los Angeles. The main results of this study are as follows. Firstly, immigration paths of Korean Immigrants are divided by spatial assimilation type and network of mainstream society oriented type. Secondly, according to the results of binomial logistic regression analysis, Korean town as a current residential location is selected by low-income class, aged migrants group, housing non-owner group and longer migration period group. Thirdly, migrants tend to retain detached housings in residential area of mainstream society while migration period go beyond 10 years and incomes exceed $60,000. Finally, according to ANOVA tests on the preferences of residential location factors. high-income and home owers groups more prefer location factors such as economics, natural environment, housing interior facilities, network of mainstream society.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.1
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• pp.1-18
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• 2023

Similar software is often developed with the Clone-And-Own (CAO) approach that copies and modifies existing artifacts. The CAO approach is considered as a bad practice because it makes maintenance difficult as the number of cloned products increases. Software product line engineering is a methodology that can solve the issue of the CAO approach by developing a product family through systematic reuse. Migrating product families that have been developed with the CAO approach to the product line engineering begins with finding, integrating, and building them as reusable assets. However, cloning occurs at various levels from directories to code lines, and their structures can be changed. This makes it difficult to build product line code base simply by finding clones. Successful migration thus requires unifying the source code's file path, class name, and method signature. This paper proposes a clustering method that identifies a set of similar codes scattered across product variants and some of their method full paths are different, so path unification is necessary. In order to show the effectiveness of the proposed method, we conducted an experiment using the Apo Games product line, which has evolved with the CAO approach. As a result, the average precision of clustering performed without preprocessing was 0.91 and the number of identified common clusters was 0, whereas our method showed 0.98 and 15 respectively.

• Journal of Korea Multimedia Society
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• v.7 no.10
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• pp.1421-1435
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• 2004

When various work was given from user, the existing mobile agent model migrated from node to node and process the work at the point that much traffics according to passive routing schedule are happened, until it makes service the work result, time cost of round work process for the distributed nodes are increased. Therefore, the existing agent systems need migration method to solve the problems of agent size increment or a lack of interoperability among agent systems. To solve these problems in this thesis, we design and implement an CORBA-based Mobile Agent Model(CMAM) for the efficient work process into the distributed nodes, when the mobile agents are migrated among the nodes, using an optimal path search by sensing of network traffic.

• Journal of Internet Computing and Services
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• v.12 no.2
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• pp.47-53
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• 2011

When some sensors under Wireless Sensor Networks fail or become energy-exhausted, redundant mobile sensors might be moved to recover the sensing holes. Within rugged terrain where wheeled sensors are unsuitable, other type of mobile sensors, such as hopping sensors, are needed. In this paper, we address the problem of relocating hopping sensors to the detected sensing holes. Recent study for this work considered the relocation using the shortest path between clusters; however, the shortest path might be used repeatedly and create other sensing holes. In order to overcome the mentioned problem, we propose relocation schemes using the most disjointed paths or multi-paths. Simulation results show that the proposed schemes guarantee more balanced migration distributions of efficient sensors and higher movement success ratios of required sensors than those of the shortest path-based scheme.

• Journal of Marine Life Science
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• v.4 no.1
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• pp.14-21
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• 2019

This review paper discussed the decadal fluctuations in the catch of the common squid, Todarodes pacificus (T. pacificus) by focusing on migration and distribution patterns. Since 1980s, changes in T. pacificus catches were due to climate regime shift in Korean waters. Fluctuation patterns of catches were different between the East Sea and the Yellow Sea. Generally PDO (Pacific Decadal Oscillation) phase shows a negative correlation with strength of warm current to the East Sea. In 1980s when PDO was positive phase (+), T. pacificus catch was higher in the Yellow, but it was lower in the East Sea. In 1990s when PDO was negative phase (-), T. pacificus catch showed opposite trend compared with 1980s. Such spatial and decadal fluctuations of T. pacificus catch were due to its northward migration along with the warm current or southward movement against the current. In the East Sea, strong (weak) warm current period, the current path has been shifted toward the East Sea coast of Korea (central East Sea or the coast of Japan). It has a correlation with PDO. In the positive PDO phase (1980s), the fishing ground was located on the eastern side of Ulleungdo, whereas during negative PDO phase (1990s), they were situated near the southeastern coast of the Korean peninsula. In the 1980s, volume transport passing into the Yellow Sea increased, whereas volume transport in the East Sea decreased. This is one of major reason increasing T. pacificus larvae in the Yellow Sea.