Oichi Atoda

Latrine use in a low density Japanese badger (Meles anakuma) population determined by a continuous tracking system

Abstract. To reveal latrine use patterns in low density Japanese badgers, a novel “Trace Recorder” system was developed to track three individuals (two males and a female) between two groups in Hinode-town, a suburb of Tokyo in 1997. A young adult male was observed to intrude into the ranges of neighbouring adult females during the mating season and to make frequent visits to hinter and border latrines within their natal ranges. Findings suggest that extra-group mating may be facilitated by the border latrine communication where scent marking can be effective information sources of badger presence and oestrous status.

A Synthesis Method for Similar Texture Images based on Minute Shape Features.

A synthetic method for generating arbitrary number of not the same but similar texture images has been developed. The method includes processes to extract basic shape elements from texture images originating in actual objects, to select them to reappear the image features and to arrange them in an image plane. The authors have already proposed the shape-pass type filter bank assuming that the sensual impression mainly depends on minute shapes existing in the texture images. By use of nine basic shape elements, namely black/white-roof, black/white-line, black/white-snake, black/white-pepper, and cliff, natural texture images originating in actual objects have been characterized by feature vectors in a nine dimensional space. To generate arbitrary number of similar texture images, minute shape pieces are collected from original texture images and arranged so that the feature vectors may become locally similar to the original images. By the method, a number of similar texture images have successfully been generated, and the results of questionnaires on the synthesized texture images to universities students have shown the effectiveness of the method.

“Programmic filters”: A framework for the design of high‐performance nonlinear filters for low‐level picture processing

Into the chaotic space of nonlinear spatial filters for low-level picture processing such as smoothing or textural feature extraction, we introduce a design framework in which a designer converts heuristics into filter functions, similarly to the activity of a computer programmer formulating program concepts in the framework of a programming language. First, to assure uniform gain and bias change, filters are constrained to respond in the same manner as their linear counterparts. Then it is shown that a quasi-linear filter is generated from successive application of several rules similar to a sentence from a parse tree. Filters so generated are called programmic filters. Some of the rules allow Boolean functions, which are suitable to heuristic thought. Thus, the set of those rules constitutes the filter design framework. Examples of high-performance programmic filters including an edge-preserving texture-reject filter are presented.

The “pattern associative memory” and its use in logic programming language processors

The traditional speed improvement of the logic language processing system has been based on the parallelism of clauses, and aimed at speeding up of the unification. However, there can be another approach. By introducing a specific function to the memory hardware, the database can be managed independently of the host CPU. Then the speed is improved by minimizing the data traffic through the von Neumann bottleneck in the retrieval of candidate clauses. This paper proposes a pattern associative memory (PAM) which maintains the clauses by the structural representation in it and retrieves them by pattern matching with a high speed. To make use of argument parallelism of clauses, parallel hashing is adopted in PAM. The individual hash table employs some local search algorithms in combination with the open addressing scheme of hashing to improve the efficiency of managing records within clusters. It was verified by simulation that the compound hash algorithm is sufficiently useful for the load factor of 60 percent or less. A PAM hardware is implemented and applied in Prolog processing to demonstrate the feasibility and usefulness of the proposed method.