• Journal of The Korean Astronomical Society
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• v.38 no.2
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• pp.311-314
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• 2005

We report the current status of Japanese lunar exploration SELENE (SELenological and ENgineering Explorer). As of the end of 2004, scientific instruments onboard the Main Orbiter are under final checkout before they are provided to the proto-flight-model (PFM) integration test. Also, we present the future perspectives of the lunar based instruments and facilities. 'In-situ Lunar Orientation Mea-surement (ILOM)' experiment measures the lunar rotation with high accuracy by tracking stars on the Moon with a small photo-zenith-tube type optical telescope. A basic idea of a radio telescope array of very low frequency range on the lunar far-side is also mentioned.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.388-391
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• 2003

We've been following research on the obstacle avoidance that is based on fuzzy control. We previously proposed a new method of automatically generating membership functions, which play an important role in improving accuracy of fuzzy control, by using genetic programming (GP). In this paper, we made two improvements to our proposed method, for the purpose of achieving better intelligence in fuzzy robots. First, the mutation rate is made to change dynamically, according to the coupled chaotic system. Secondly, the population partitioning using deme is introduced by parallel processing. The effectiveness of these improvements is demonstrated through several computer simulations.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.485-488
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• 1998

Elementary school pupils frequently have difficult acquiring creative writing skills, i.e. how to develop the idea to be expressed, how to compose the materials of the outcome or contents. In this paper, we focus on the problems of how to support creative writing work to arrange materials in order to formulate ideas as the stories develop. the stories develop. The basic ideas behind the method are that(1) a basic story is automatically generated by GA-based operations and shown to a user as sequences of pictures, (2) IGA(Interactive Genetic Algorithm) is used to evaluate and select a preferred story, (3) the results are combined with previously stored stories using case-based techniques. Based on these ideas, we have developed a computer supported environment for this purpose and conducted related experiments.

• Journal of Life Science
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• v.12 no.1
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• pp.14-18
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• 2002

Subpopulations of nucleotides that bind specifically to a variety of proteins have been isolated from a population of random sequence RNA/DNA molecules. Roughly one in $10^{13}$ random sequence RNA/DNA molecules folds in such a way as to create a specific binding site for small ligands. Since the development of in vitro selection procedure, more than 50 nucleic acid ligands (aptamers) have been isolated. These molecules are very useful for the study of molecular recognition between nucleic acid and protein/organic compound. In addition to these basic studies this method gives us a dream to produce new drugs against several diseases. We focused on several aptamers which specifically binds to trypsin-like serine proteases (thrombin, human neutrophil elastase, activated protein C and NS3 protease of human hepatitis C virus) and want to introduce their structural characteristics and some functions.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.712-715
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• 2006

This paper presents the nonlinear characteristics of the parametric resonance of a simply supported beam which is inextensible beam. For the beam model, the order-three expanded equation of motion has been determined in a form amenable to a perturbation treatment. The equation of motion is derived by a special Cosserat theory. The method of multiple scales is used to determine the equations that describe to the first-order modulation of the amplitude of simply supported beam. The stability and the bifurcation points of the system are investigated applying the frequency response function.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1051-1051
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• 2001

In 1989, at the 2nd ICNIRS Meeting in Tsukuba, I projected certain directions for NIR technology would take in the future. Among those projections were: (1) An inrush of companies producing FT-NIR instruments. (2) Hybrid NIR Systems (3) Hand-held NIR Technology. All three thrusts have resulted in numerous commercial offerings over the last 12 years Hand-held technology for all fields is growing at an astonishing rate. To date, NIR work at North Carolina State University has produced four (4) hand-held NIR units for: (1) Nicotine and Moisture in tobacco, (2) Vanillin and Moisture in Vanilla Beans, (3) Protein, Moisture and Nitrogen in plant tissue, (4) Chlorophyll and Moisture in Growing Plants: A NIR Spectrometer for Developing Countries. This paper will discuss these developments, including design and performance data.

• Resources Recycling
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• v.11 no.5
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• pp.7-10
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• 2002

Iron nitride magnetic fluid was oxidized by exposing it to the air under normal atmospheric conditions. After exposure of 3.2 hours, the relative saturation magnetization of the iron nitride magnetic fluid is less than 0.4 compared to the value of the unexposed sample, and it is nearly zero after exposure for 1008 hours. The structure of the oxidized iron nitride is considered to be a non-magnetic hematites. The thickness of the oxidation layers of the iron-nitride particles are nearly the same, about 3 nm, regardless of the different particle sizes.

• Journal of applied mathematics & informatics
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• v.9 no.2
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• pp.459-517
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• 2002

The purpose of this paper is to provide a careful and accessible exposition of diffusive logistic equations with indefinite weights which model population dynamics in environments with strong spatial heterogeneity. We prove that the most favorable situations will occur if there is a relatively large favorable region (with good resources and without crowding effects) located some distance away from the boundary of the environment. Moreover we prove that a population will grow exponentially until limited by lack of available resources if the diffusion rate is below some critical value; this idea is generally credited to Thomas Malthus. On the other hand, if the diffusion rate is above this critical value, then the model obeys the logistic equation introduced by P. F. Verhulst .

• Industrial Engineering and Management Systems
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• v.4 no.2
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• pp.136-144
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• 2005

This research deals with an order picking problem in automated storage and retrieval systems (AS/RS). When retrieval requests consist of multiple items and the items are in multiple stock locations, the storage/retrieval (S/R) machine must travel to numerous storage locations to complete each order. The aim of this research is to propose algorithms for the resolution of order picking problems with multiple stock locations to minimize the total time traveled by the S/R machine. We present and compare three alternatives for solving the problem based on enumeration, ordinary heuristic and genetic algorithms. We used a set of 180 different problems that are solved by these three algorithms. The results show that our proposed genetic algorithm is more efficient than the other two.

• Management Science and Financial Engineering
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• v.2 no.1
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• pp.123-145
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• 1996

We consider a priority-based multiclass queue with probabilistic feed-back. There are J service stations. Each customer belongs to one of the several priority classes, and the customers of each class arrive at each station in a Poisson process. A single server serves queued customers on a priority basis with a nonpreemptive scheduling discipline. The customers who complete their services feed back to the system instantaneously and join one of the queues of the stations or depart from the system according to a given probability. In this paper, we propose a new method to simplify the analysis of these queueing systems. By the analysis of busy periods and regenerative processes, we clarify the underlying system structure, and systematically obtain the mean for the sojourn time, i.e., the time from the arrival to the departure from the system, of a customer at every station. The mean for the number of customers queued in each station at an arbitrary time is also obtained simultaneously.