• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.168.4-168
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• 2001

A great many species of fish congregate in schools, reducing the risk of being eaten by predators and giving one of the considerable survival advantages for fishes. Such a fish school is self-organized only due to individual behaviors for matching the speed and direction with the neighboring fishes. It is interesting to simulate these fish school by small robots, because we can understand how the group structure emerges from the interaction among neighboring individuals. We use a nice simulator for Khepera robot presented by Oliver Michel. It is shown that the Khepera simulator is easily applied to fish school due to the algorithm introduced by I Aoki. The simulator includes sensor noise so appropriately that the simulator can be transferred easily to the real environment. The results of simulation are given as follows: (1) The stability as a group is shown by plotting mean deviations from the center of group ...

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.164.1-164
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• 2001

Q-learning is a recent reinforcement learning algorithm that does not need a modeling of environment and it is a suitable approach to learn behaviors for autonomous agents. But when it is applied to multi-agent learning with many I/O states, it is usually too complex and slow. To overcome this problem in the multi-agent learning system, we propose the successive Q-learning algorithm. Successive Q-learning algorithm divides state-action pairs, which agents can have, into several Q-functions, so it can reduce complexity and calculation amounts. This algorithm is suitable for multi-agent learning in a dynamically changing environment. The proposed successive Q-learning algorithm is applied to the prey-predator problem with the one-prey and two-predators, and its effectiveness is verified from the efficient avoidance ability of the prey agent.

• Ocean Systems Engineering
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• v.7 no.1
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• pp.39-51
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• 2017

Fishes detect various sensory stimuli, which may be used to direct their behavior. Especially, the visual and water flow detection information are critical for locating prey, predators, and school formation. In this study, we examined the specific role of these two different type of stimulation (vision and vibration) during the obstacle avoidance behavior of carp, Cyprinus carpio. When a visual obstacle was presented, the carp efficiently turned and swam away in the opposite direction. In contrast, vibration stimulation of the left or right side with a vibrator did not induce strong turning behavior. The vibrator only regulated the direction of turning when presented in combination with the visual obstacle. Our results provide first evidence on the innate capacity that dynamically coordinates visual and vibration signals in fish and give insights on the novel modulation method of fish behavior without training.

• Fisheries and Aquatic Sciences
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• v.10 no.3
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• pp.159-169
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• 2007

The complex 2-dimensional movements of fish during an annual migration circuit were generated and simulated by a chaotic model of fish movement, which was expanded from a small-scale movement model. Fish migration was modeled as a neural network including stimuli, central decision-making, and output responses as variables. The input stimuli included physical stimuli (temperature, salinity, turbidity, flow), biotic factors (prey, predators, life cycle) and landmarks or navigational aids (sun, moon, weather), values of which were all normalized as ratios. By varying the amplitude and period coefficients of the klinokinesis index using chaotic equations, model results (i.e., spatial orientation patterns of migration through time) were represented as fish feeding, spawning, overwintering, and sheltering. Simulations using this model generated 2-dimesional annual movements of sea bream migration in the southern and western seas of the Korean Peninsula. This model of object-oriented and large-scale fish migration produced complicated and sensitive migratory movements by varying both the klinokinesis coefficients (e.g., the amplitude and period of the physiological month) and the angular variables within chaotic equations.

• Korean journal of applied entomology
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• v.32 no.4
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• pp.373-381
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• 1993

Resistance evolution to organophosphate-based pesticides in apple and pear inhabiting arthropods of western North America extends to many classes of pest and some beneficial species. Resistance management programs to minimize resistance in pests while exploiting it in natural enemies have met with mixed success. Among beneficials, resistances have been exploited mostly among predators of pest mites. Evolution of resistant mites, leafminers, leafhopper, aphids, leafrollers and some internal fruit feeders have led to development of new monitoring methods and means to delay or avoid resistance. But it is resistance to azinphosmethyl in codling moth (Cydia pomonella) that is changing the pest control system and moving it from chemical to biologically-based means. Newly merging IPM system will depend more on use of biological, cultural, behavior and genetic controls. But more selective pesticides also will be needed to augment pheromones, resistant host plants and genetically altered organisms. These more biologically-based tactics will be prone to resistance evolution in pests as well, if used too unilaterally and/or too extensively.

• Journal of Species Research
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• v.3 no.1
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• pp.35-38
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• 2014

The article considers the influence of hunting (legitimate and uncontrolled) on the population of the Siberian roe deer, musk deer, elk, red and northern deer in Pribaikalje. The data on the forms and methods of hunting, the dynamics of the number of animals and the results of their production are given. For comparison, the acts of such a limiting factor as predators are specified. Reasons for the low number of wild ungulates are determined and main problems are formulated.

• 한국환경농학회:학술대회논문집
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• 2011.07a
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• pp.292-292
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• 2011

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.16 no.3
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• pp.151-167
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• 2012

In this paper, we investigate the dynamic behaviors of a one-prey and two-predator system with Holling-type II functional response and defensive ability by introducing a proportion that is periodic impulsive harvesting for all species and a constant periodic releasing, or immigrating, for predators at different fixed time. We establish conditions for the local stability and global asymptotic stability of prey-free periodic solutions by using Floquet theory for the impulsive equation, small amplitude perturbation skills. Also, we prove that the system is uniformly bounded and is permanent under some conditions via comparison techniques. By displaying bifurcation diagrams, we show that the system has complex dynamical aspects.

• Animal Systematics, Evolution and Diversity
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• v.35 no.2
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• pp.73-75
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• 2019

Members of this family Sciomyzidae are known as marsh flies and snail-killing flies because most of the known larvae are obligate predators of Mollusca, especially freshwater and terrestrial Gastropoda. Most species are found in the shallow ephemeral aquatic habitats with rich organic substrates, such as the hard-water streams, small ponds and lakes in mountain valleys. To date, a total of 8 marsh fly species in 4 genera have been known in Korea. During a taxonomic survey of the family Sciomyzidae in Korea, the authors have found the genus Ditaeniella Sack, 1939; thus, it was discovered for the first time in Korea. This genus can be distinguished by the other related taxa with hairs over much of the mesopleuri, hairs on the prosternum and one orbital seta. In addition, the nominate species, Ditaeniella grisescens Meigen, 1830 was also firstly recoded in the Korean fauna.

• Animal Systematics, Evolution and Diversity
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• v.37 no.1
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• pp.15-18
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• 2021

Flies of the genus Lispe are large, dark gray, and have well-developed palpi. Most Lispe species are found in damp sandy and muddy environments, such as borders of marshes, seashore areas, swamps, lakes, ponds, streams, and rice paddy fields. Both adults and larvae are predators of various small aquatic insects. Previously, five species of Lispe had been identified in Korea: L. assimilis Wiedemann, 1824, L. litorea Fallén, 1825, L. orientalis Wiedemann, 1824, L. patellitarsis Becker, 1914, and L. tentaculata (DeGeer, 1776). In this paper, we record a sixth Lispe species, L. consanguinea Loew, 1858, for the first time in Korea. The diagnosis and illustrations of this species are provided in addition to a key to the Korean Lispe species.