• Journal of Power Electronics
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• 제14권2호
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• pp.362-368
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• 2014

This paper proposes a harmonic reduction approach for a pulse width modulation (PWM) AC-AC converters using Bee Colony Optimization (BCO). The optimal switching angles are provided by BCO to minimize harmonic distortions. The sequences of the PWM switching angles are considered as a technical constraint. In this paper, simulation results from various optimization techniques including BCO, Genetic Algorithm (GA), and Particle Swarm Optimization (PSO) are compared. The test results indicate that BCO can provide a better solution than the others in terms of power quality and power factor improvement. Lastly, experiments on a 200W AC-AC converter confirm the performance of the proposed switching pattern in reducing harmonic distortions of the output waveform.

• 제어로봇시스템학회논문지
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• 제17권8호
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• pp.760-767
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• 2011

The flexibility and evolvability are critical characteristics of modern manufacturing to adapt to changes from products and disturbances in the shop floor. The technologies inspired from biology and nature enable to equip the manufacturing systems with these characteristics. This paper proposes an ant colony inspired autonomous manufacturing system in which the resources on the shop floor are considered as the autonomous entities. Each entity overcomes the disturbance by itself or negotiates with the others. The swarm of cognitive agents with the ant-like pheromone based negotiation mechanism is proposed for controlling the shop floor. The functionality of the developed system is proven on the test bed.

• 대한산업공학회지
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• 제35권2호
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• pp.160-170
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• 2009

This paper studies a vehicle routing problem variant which considers customers to require simultaneous delivery and pick-up under time windows(VRPSDP-TW). The objective of this paper is to minimize the total travel distance of routes that satisfy both the delivery and pick-up demand. We propose a heuristic algorithm for solving the VRPSDP-TW, based on the ant colony system(ACS). In route construction, an insertion algorithm based ACS is applied and the interim solution is improved by local search. Through iterative processes, the heuristic algorithm drives the best solution. Experiments are implemented to evaluate a performance of the algorithm on some test instances from literature.

• Toxicological Research
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• 제9권1호
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• pp.61-67
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• 1993

LBD-005, a newly developed recombinant granulocyte-macrophage colony-stimulating factor, was at dose levels of 0, 20, 80 and 320ng/kg/day administered subcutaneously to pregnat New Zealand White rabbits during the organogenetic period. The dams were subjected to caesarean section on day 28 of pregnancy. Effects of test substance on dams and embryonal development of fetuses were examined. No treatment-related changes in clinical signs and necropsy findings of dams were observed in all groups. At 80 and 320 ng/kg, a significant decrease in food consumption followed by a loss in body weight was found.

• 한국경영과학회지
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• 제33권3호
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• pp.17-28
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• 2008

The Steiner arborescence problem is known to be NP-hard. The objective of this problem is to find a minimal Steiner tree which starts from a designated node and spans all given terminal nodes. This paper proposes a method based on a two-step procedure to solve this problem efficiently. In the first step, graph reduction rules eliminate useless nodes and arcs which do not contribute to make an optimal solution. In the second step. ant colony algorithm with use of Prim's algorithm is used to solve the Steiner arborescence problem in the reduced graph. The proposed method based on a two-step procedure is tested in the five test problems. The results show that this method finds the optimal solutions to the tested problems within 50 seconds. The algorithm can be applied to undirected Steiner tree problems with minor changes. 18 problems taken from Beasley are used to compare the performances of the proposed algorithm and Singh et al.'s algorithm. The results show that the proposed algorithm generates better solutions than the algorithm compared.

• Journal of Electrical Engineering and Technology
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• 제6권2호
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• pp.174-181
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• 2011

This paper proposes a novel binary ant colony optimization (NBACO) method. The proposed NBACO is based on the concept and principles of ant colony optimization (ACO), and developed to solve the binary and combinatorial optimization problems. The concept of conventional ACO is similar to Heuristic Dynamic Programming. Thereby ACO has the merit that it can consider all possible solution sets, but also has the demerit that it may need a big memory space and a long execution time to solve a large problem. To reduce this demerit, the NBACO adopts the state probability matrix and the pheromone intensity matrix. And the NBACO presents new updating rule for local and global search. The proposed NBACO is applied to test power systems of up to 100-unit along with 24-hour load demands.

• 한국정밀공학회지
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• 제29권4호
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• pp.373-379
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• 2012

Disruptions in manufacturing systems caused by system changes and disturbances such as the tool wear, machine breakdown, malfunction of transporter, and so on, reduce the productivity and the increase of downtime and manufacturing cost. In order to cope with these challenges, a new method to build an intelligent manufacturing system with biological principles, namely an ant colony inspired manufacturing system, is presented. In the developed system, the manufacturing system is considered as a swarm of cognitive agents where work-pieces, machines and transporters are controlled by the corresponding cognitive agent. The system reacts to disturbances autonomously based on the algorithm of each autonomous entity or the cooperation with them. To develop the ant colony inspired manufacturing system, the disturbances happened in the machining shop of a transmission case were analyzed to classify them and to find out the corresponding management methods. The system architecture with the autonomous characteristics was generated with the cognitive agent and the ant colony technology. A test bed was implemented to prove the functionality of the developed system.

• Smart Structures and Systems
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• 제18권3호
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• pp.425-448
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• 2016

In this paper, a new Pigeon Colony Algorithm (PCA) based on the features of a pigeon colony flying is proposed for solving global numerical optimization problems. The algorithm mainly consists of the take-off process, flying process and homing process, in which the take-off process is employed to homogenize the initial values and look for the direction of the optimal solution; the flying process is designed to search for the local and global optimum and improve the global worst solution; and the homing process aims to avoid having the algorithm fall into a local optimum. The impact of parameters on the PCA solution quality is investigated in detail. There are low-dimensional functions, high-dimensional functions and systems of nonlinear equations that are used to test the global optimization ability of the PCA. Finally, comparative experiments between the PCA, standard genetic algorithm and particle swarm optimization were performed. The results showed that PCA has the best global convergence, smallest cycle indexes, and strongest stability when solving high-dimensional, multi-peak and complicated problems.

• 도서관문화
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• 제17권2호
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• pp.3-8
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• 1976

We sampled the fungi on the grounds of the floor and books in the library for the purpose of attack the fungi in the traditional library. We cultured it on the Sabouraud Dextrose Agar(Baltimore Biological Laboratory) and was obtained the fungi of six species, Here irradiated the ultra violet lamp(100V, 15W, 253Å), which was occurred to the colony after 24 hours. And irradiation by 2hrs/day for 2days here. The other method, we were sterilized test by the methanal fumigation The following results were obtained 1. All rearing is suspensed the result of the ultra violet rays irradiation, but the colony that is gained from the grounds of the floor in the library is not sterilized. 2. The result of air tight box to methanal 14ℊ/㎥ for the 24hours fumigation, each test group(the fungi of six species) is all sterilized.

• Toxicological Research
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• 제13권3호
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• pp.303-306
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• 1997

Antigenic potential of genetically engineered human granulocyte colony-stimulating factor (CJ-50001) was assessed in guinea pigs and mice. In active systemic anaphylaxis (ASA) test, although CJ-50001 at 50 $\mu\textrm{g}$ /head induced anaphylactic responses, CJ-50001 5 $\mu\textrm{g}$ /head alone or 50 $\mu\textrm{g}$ / head with adjuvant did not induce anaphylactic responses. In passive systemic anaphylaxis test (PCA) or passive hemagglutination test (PHA), CJ-50001 did not induce positive responses. It is concluded that, in light of the fact that CJ-50001 was antigenic only in ASA but not in PCA or PHA and also that CJ-50001 is a foreign human recombinant protein to guinea pigs, CJ-50001 may not induce systemic allergic react-ion in its clinical use in human.