[in Japanese]

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An understanding of the way a natural system handles information can lead to more effective artificial optimization techniques. There are successful optimization algorithms found in biosystems that have proven useful in engineering applications (artificial neural networks, genetic algorithms, immune system algorithms, etc). Okayama et al. developed a new biosystem-derived optimization algorithm called a DNA algorithm (DNAA). They found that the insertion of introns is effective for protecting important exons from mutation and DNAAs performed robustly even under a fairly high rate of mutation in string search problems and knapsack problems. In this study, we have focused on exon shuffling as a new optimization technique for the DNAA. The intron-exon organization of eukaryotic genes suggests that new combinations of exons can be created by recombining them within the intervening intron sequences, yielding rearranged genes with altered functions. This evolutionary mechanism of recombining exons from unrelated genes is known as exon shuffling. We consider modules as ‘building blocks’ which can be a part of high fitness solutions. To evaluate the performance of the DNAA we used a traveling salesman problem (TSP), one of the most widely used challenges for combinational optimization. In the experiment, we used a 100-city TSP. The intron insertion ratio and intron deletion ratio were varied from 2 to 128. The DNAA could approximate optimal tour routes in the 100-city TSP.

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This paper describes the development of a Windows-based design program for tractor rotary blade arrangements. The program assists with the design or enhancement of holder-type arrangements or the flange-type arrangements and incorporates performance evaluation data. The performance of rotary blade arrangements is evaluated through seven measures covering soil condition after tillage, the degree of vibration of the arrangement, and the power required for tillage. The design program confirmed part of a hypothesis and experimental result of earlier research, because the torque average of flange-type arrangements was about 80% of the torque average of holder-type arrangement in the simulation. The design program was also able to contribute to improvement in the performance of a commercial rotary blade arrangement by using the database.

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We developed a system for automatically monitoring 24-hour behavior of sheep using computer vision. We designed an algorithm for identifying sheep within images. This algorithm applied thresholding to a density histogram generated from mobile objects identified by a frame difference method. Template matching was applied to binary images generated with the thresholding.
To assess the performance of the prototype software, an experiment was conducted using Suffolk sheep. In the experiment, an outdoor fenced area of about 5m x 5m was constructed. Images of the behavior of the sheep were captured with a monochrome video camera and infrared illuminators from a height of approximately 5m for 24 hours. From the captured images, sheep position coordinates were automatically measured and recorded with the prototype software at one-second intervals.
Position error was calculated for each image sampled at five-minute intervals. Position errors of more than the width of a sheep occurred at a rate of 24.3%. It was considered that the position error decreased by improving the measurement environment. A mean of the position error except the images with the clear cause of an error was 15.1 pixels, which was approximately 1/2 the width of a sheep.

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The purpose of this paper is to clarify the economic efficiency of a Japanese “Fruit Farming Income Stabilization Program” within the framework of a non-cooperative game under oligopolistic market conditions. The income stabilization program seeks to mitigate the impact of falling prices on farmers in a good harvest year. This paper investigates two topics. It firstly estimates the marginal revenue and marginal cost of mandarin orange farmers' cooperative shipping. It then compares the estimated marginal revenue and marginal cost of each mandarin orange farmers' cooperative in view of their strategic information use.
The main conclusions of this paper are summarized as follows:
1) In a good harvest year, the best response strategy is for all mandarin orange farmers' cooperatives to follow a fruit farming income stabilization program.
2) In a bad harvest year, the best response strategy is for some mandarin orange farmers' cooperatives to withdraw from a fruit farming income stabilization program.
3) Considering these results it is reasonable for mandarin orange farmers' cooperatives to follow this program.
On the other hand, there are various kinds of agricultural policy on mandarin orange production. They are, for instance, a deficiency payment system for the shipment of fruit for juice processing, an acreage reduction program, and so on. It is important that the Fruit Farming Income Stabilization Program be coupled with these programs. Therefore, opportunity cost must be a crucial component of any discussion about the economic efficiency of the program.

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We propose the following as a procedure for appropriate pesticide use; (1) creating a pesticide use plan and exercising judgment prior to pesticide use, (2) recording intended pesticide use and its rationale immediately prior to pesticide application. The design and implementation of a system that supports appropriate pesticide use are presented based on this procedure. This paper describes a navigation system for appropriate pesticide use (Nouyaku-Navi), which is composed of a pest control guidance facility, a pesticide use planning facility, a pesticide use plan assessment function, a pesticide use field alert function, and pesticide use recording. With a personal computer, a user of Nouyaku-Navi can readily obtain the latest data necessary for the pest control guideline making, including details of pesticides registered to control a particular pest. They can create a pesticide use plan and have its suitability assessed by the judgment server.
Mobile phone access lets this suitability assessment be carried out from the farmer's agrichemical store or out in the field. The pesticide use plan can readily be converted into a historical record of pesticide use once the assessment of pesticide application has been completed. In the pesticide use field alert function, two judgment results, “judgment up to the present date” or “judgment from tomorrow” are displayed based on the both historical pesticide use records and future pesticide use plans. Problems clarified in a 2004 trial of the prototype system with about 450 people have almost been solved in the latest version of the system. The following are the focus of current efforts; (1) the introduction of sequential judgment and planning in the pesticide use planning support facility, (2) the development of the stand alone type system of the site alert and pesticide use recording for mobile phone, (3) the further accumulation of a pesticide a Japanese Article Number (JAN) code in the data base.

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