• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.4
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• pp.188-196
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• 2001

This paper presents and efficient algorithm for the loss minimization by automatic sectionalizing switch operation in distribution systems. Ant colony algorithm is multi-agent system in which the behaviour of each single agent, called artificial ant, is inspired by the behaviour of real ants. Ant colony algorithm is suitable for combinatiorial optimization problem as network reconfiguration because it use the long term memory, called pheromone, and heuristic information with the property of the problem. The proposed methodology with some adoptions have been applied to improve the computation time and convergence property. Numerical examples demonstrate the validity and effectiveness of the proposed methodology using a KEPCO's distribution system.

• Entomological Research
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• v.48 no.6
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• pp.505-513
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• 2018

The red imported fire ant is considered one of the most notorious invasive species because of its adverse impact on both humans and ecosystems. Public concern regarding red imported fire ants has been increasing, as they have been found seven times in South Korea. Even if red imported fire ants are not yet colonized in South Korea, a proper quarantine plan is necessary to prevent their widespread distribution. As a basis for quarantine planning, we modeled the potential distribution of the red imported fire ant under current climate conditions using six different species distribution models (SDMs) and then selected the random forest (RF) model for modeling the potential distribution under climate change. We acquired occurrence data from the Global Biodiversity Information Facility (GBIF) and bioclimatic data from WorldClim. We modeled at the global scale to project the potential distribution under the current climate and then applied models at the local scale to project the potential distribution of the red imported fire ant under climate change. Modeled results successfully represent the current distribution of red imported fire ants. The potential distribution area for red imported fire ants increased to include major harbors and airports in South Korea under the climate change scenario (RCP 8.5). Thus, we are able to provide a potential distribution of red imported fire ant that is necessary to establish a proper quarantine plan for their management to minimize adverse impacts of climate change.

• The Korean Journal of Soil Zoology
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• v.3 no.2
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• pp.58-62
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• 1998

To find out ant fauna in the Mt. Chiak, collection tours were taken in three courses for two years. As a result, The ant fauna of Mt. Chiak were confirmed to be 45 species belonging to 23 genera under 4 subfamilies. Among them, ten species were new to Gangweon-province and Myrmica sp. 6 was new to Korea. Ants fauna of Gangweon-province at together became 74 species under 28 genera. In Ponerinae, ants fauna have become 5 species under 4 genera, in Myrmicinae, 20 species under 13 genera, in Dolichoderinae 1 species under 1 genera and in Formicinae 19 species under 5 genera.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.107-110
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• 2008

Tropical fire ant, Solenopsis geminata (Fabricius) is distributed over the tropical and temperate areas. It is a polyphagous pest attacking to various plant and causes the pain to the people doing outdoor work. So it is known for a hygienic pest to human being, especially the people doing outdoor activities. It can cause severe pain to human, even with just a bite. Of particular concern is the possibility of its settlement in this country, if it invade to the farmlands and/or forests of Jeju Island and southern part in Korea. It is listed as a regulated pest in Plant Quarantine Act of Korea. This ant is usually imported through a ship and early settled in the port area where it is already distributed. Recently its distribution is rapidly spreading into Southeast Asia and southern part of China. In Korea, it was detected the one time in 1990s, but was detected the ten times from 2000 to 2006 by an imported plant quarantine process. Therefore, we would like to provide some information on the species, including morphology, distribution, host plant, damaged symptom and its general bionomics, which will be useful data for plant quarantine process and control.

• The Korean Journal of Soil Zoology
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• v.1 no.1
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• pp.5-23
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• 1996

To clarify the ants fauna in Chollabukdo, field survey was carried out for about 10 years from 1986 to 1995. As a result, 1,699 clonies were collected and identified. These clonies were composed of 76 species belonging to the 31 genera of 5 subfamilies. The list of ants in Chollabukdo was prepared with them involving a subfamily, 6 genera and 18 species newly recorded from Chollabukdo. In NSC analysis between areas, zones and clonies respectively, all 16 areas were continuous expect Bangchukdo. In block analysis of ant distribution. 28 species were found only in mountain-zone and 4 species in island-zone. Among 5 subfamilies distributied in Chollabukdo, Myrmicinae is the most abundant, but Cerapacinae is the oppisite. The Lasius of Formicinae is the most abundant genus among 31 genera investigated.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.80-85
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• 1991

For the study of ant fauna in Mt. Kyeryongsan, we selected three areas and collected 317 colonies nine times from 1986 to 1990. The communities of ants were composed of 3 subfamilies, 23 genera and 45 species. Among them, Solenopsis sp. was an unrecorded species in Korea. The number of ant species distributed in each area was almost the same, and the species distributed uniformly in the nine subareas were Paratrechina flavipes and Aphaenogaster japonica. The number of species collected in the only one subarea were ten, and six among them were collected in the area of Sinwonsa temple, the westward slope. It is remarkable that Camponotus tokioensis, which is known to be distributed only in the island and coast so far, is found to be distributed in the area of Sinwonsa temple as well.

• Journal of Korean Society of Water and Wastewater
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• v.27 no.4
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• pp.413-428
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• 2013

In this study, Ant Colony Algorithm(ACO) was used for optimal model. ACO which are metaheuristic algorithm for combinatorial optimization problem are inspired by the fact that ants are able to find the shortest route between their nest and food source. For applying the model to water distribution systems, pipes, tanks(reservoirs), pump construction and pump operation cost were considered as object function and pressure at each node and reservoir level were considered as constraints. Modified model from Ostfeld and Tubaltzev(2008) was verified by applying 2-Looped, Hanoi and Ostfeld's networks. And sensitivity analysis about ant number, number of ants in a best group and pheromone decrease rate was accomplished. After the verification, it was applied to real water network from S water treatment plant. As a result of the analysis, in the Two-looped network, the best design cost was found to $419,000 and in the Hanoi network, the best design cost was calculated to $6,164,384, and in the Ostfeld's network, the best design cost was found to $3,525,096. These are almost equal or better result compared with previous researches. Last, the cost of optimal design for real network, was found for 66 billion dollar that is 8.8 % lower than before. In addition, optimal diameter for aged pipes was found in this study and the 5 of 8 aged pipes were changed the diameter. Through this result, pipe construction cost reduction was found to 11 percent lower than before. And to conclusion, The least cost design model on water distribution system was developed and verified successfully in this study and it will be very useful not only optimal pipe change plan but optimization plan for whole water distribution system.

• Korean journal of applied entomology
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• v.31 no.2
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• pp.101-112
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• 1992

For the studies of ant founa in Mt. Togyusan, we collected 476 colonies in 1986, 1989, and 1 1991. The communities of ants were composed of 4 subfamilies, 22 genera and 44 species. The a ants of Mt. Togyusan consisted of 21 species and 12 genera in Myrmicinae, 20 species of 6 g genera in Formicinae, 4 species of 3 genera in Ponerinae, and 1 species of 1 genera in D Dolichoderinae. The vertical distribution of the ants in Mt. Togyusan was distributed 41 species in 93% of total species at the altitude of 500 m. The upper limit line of vertical distribution was distributed of 5 species included Pacycondyla astutus and Messor aciculatus at the a altitude of 700 m, and 10 species included Ponera japonica, Leptothorax congrus, ,Lasius b brunneus, and Parairechina flaevipes at the altitude of 1000 m.

• IE interfaces
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• v.19 no.1
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• pp.1-8
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• 2006

The mobile communication network has to offer good quality of services (QoS), high capacity, and more coverage at a lower cost. However, with the increase of cellular user, the shortage of capacity due to unbalanced call distribution and lack of QoS are common. This paper deals with dynamic sectorization for efficient resource management to solve load unbalancing among microcells in CDMA (Code Division Multiple Access) microcellular system. Dynamic load balancing can be effected by grouping micro-cells properly and grouping can be developed through a routing mechanism. Therefore, we use ants and their routes to choose the optimum grouping of micro-cells into sectors using Multiple Ant Colony System (MACS)in this paper.

• The KIPS Transactions:PartB
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• v.16B no.3
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• pp.195-202
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• 2009

In this paper, we propose the regions segmentation method of the white matter and the gray matter for brain MR image by using the ant colony optimization algorithm. Ant Colony Optimization (ACO) is a new meta heuristics algorithm to solve hard combinatorial optimization problem. This algorithm finds the expected pixel for image as the real ant finds the food from nest to food source. Then ants deposit pheromone on the pixels, and the pheromone will affect the motion of next ants. At each iteration step, ants will change their positions in the image according to the transition rule. Finally, we can obtain the segmentation results through analyzing the pheromone distribution in the image. We compared the proposed method with other threshold methods, viz. the Otsu' method, the genetic algorithm, the fuzzy method, and the original ant colony optimization algorithm. From comparison results, the proposed method is more exact than other threshold methods for the segmentation of specific region structures in MR brain image.