Koichi Hori

Bio: Koichi Hori is an academic researcher from University of Tokyo. The author has contributed to research in topics: Concept learning & Knowledge-based systems. The author has an hindex of 24, co-authored 159 publications receiving 2219 citations. Previous affiliations of Koichi Hori include Tokyo Institute of Technology & Fujitsu.

Klebsormidium flaccidum genome reveals primary factors for plant terrestrial adaptation

Abstract: The colonization of land by plants was a key event in the evolution of life. Here we report the draft genome sequence of the filamentous terrestrial alga Klebsormidium flaccidum (Division Charophyta, Order Klebsormidiales) to elucidate the early transition step from aquatic algae to land plants. Comparison of the genome sequence with that of other algae and land plants demonstrate that K. flaccidum acquired many genes specific to land plants. We demonstrate that K. flaccidum indeed produces several plant hormones and homologues of some of the signalling intermediates required for hormone actions in higher plants. The K. flaccidum genome also encodes a primitive system to protect against the harmful effects of high-intensity light. The presence of these plant-related systems in K. flaccidum suggests that, during evolution, this alga acquired the fundamental machinery required for adaptation to terrestrial environments.

UPF3 suppresses aberrant spliced mRNA in Arabidopsis

Abstract: It has been reported that eukaryotic organisms have a nonsense-mediated mRNA decay (NMD) system to exclude aberrant mRNAs that produce truncated proteins. NMD is an RNA surveillance pathway that degrades mRNAs possessing premature translation termination codons (PTCs), thus avoiding production of possibly toxic truncated proteins. Three interacting proteins, UPF1, UPF2 and UPF3, are required for NMD in mammals and yeasts, and their amino acid sequences are well conserved among most eukaryotes, including plants. In this study, 'The Arabidopsis Information Resource' database was searched for mRNAs with premature termination codons. We selected five of these mRNAs and checked for the presence of PTCs in these mRNAs when translated in vivo. As a result we identified aberrant mRNAs produced by alternative splicing for each gene. These genes produced at least one alternative splicing variant including a PTC (PTC+) and another variant without a PTC (PTC-). We analyzed their PTC+/PTC- ratios in wild-type Arabidopsis and upf3 mutant plants and showed that the PTC+/PTC- ratios were higher in atupf3 mutant plants than wild-type plants and that the atupf3 mutant was less able to degrade mRNAs with premature termination codons than wild-type plants. This indicated that the AtUPF3 gene is required by the plant NMD system to obviate aberrantly spliced mRNA.

Fault Detection by Mining Association Rules from House-keeping Data

Abstract: This paper proposes a novel anomaly detection method for spacecraft systems based on data-mining techniques. This method automatically constructs a system behavior model in the form of a set of rules by applying pattern clustering and association rule mining to the time-series data obtained in the learning phase, then detects anomalies by checking the subsequent on-line data with the acquired rules. A major advantage of this approach is that it requires little a priori knowledge on the system.

A system for aiding creative concept formation

Abstract: This paper describes a system named AA1 (Articulation Aid 1) which aids human users in the formation of new concepts in the domain of engineering and science. From the viewpoint of concept formation, one main process of creation is divergent thinking in which broad alternatives are searched, and another process is convergent thinking in which a unique solution is sought. From the viewpoint of human activities, creation also includes the aspect of collaboration among people and the aspect of individual reflection, although they are interrelated. AA1, the system presented in this paper, supports divergent thinking during individual reflection. Engineers and scientists usually scrawl many notes on paper while exploring new possible concepts in the divergent thinking process. A system is needed to reflect the fragments of concepts that are not articulated yet and thereby stimulate the formation of new concepts. AA1 builds a two-dimensional space from the words the user provides. Looking at this space and other precedent spaces, the user can form new concepts little by little. The main feature of AA1 different, from existing hypermedia systems and CSCW systems is the strategy for building the space presented to the user. The system is as nonprescriptive as possible, but it gives stimulation for the user to form concepts that he could not by using only pencil and paper. Experimentation has shown that the space which AA1 displays can effectively help the user to build new concepts. The most prominent effect is that empty regions in the space automatically configured by the system often lead to new concepts. >

Anomaly detection: A survey

Abstract: Anomaly detection is an important problem that has been researched within diverse research areas and application domains. Many anomaly detection techniques have been specifically developed for certain application domains, while others are more generic. This survey tries to provide a structured and comprehensive overview of the research on anomaly detection. We have grouped existing techniques into different categories based on the underlying approach adopted by each technique. For each category we have identified key assumptions, which are used by the techniques to differentiate between normal and anomalous behavior. When applying a given technique to a particular domain, these assumptions can be used as guidelines to assess the effectiveness of the technique in that domain. For each category, we provide a basic anomaly detection technique, and then show how the different existing techniques in that category are variants of the basic technique. This template provides an easier and more succinct understanding of the techniques belonging to each category. Further, for each category, we identify the advantages and disadvantages of the techniques in that category. We also provide a discussion on the computational complexity of the techniques since it is an important issue in real application domains. We hope that this survey will provide a better understanding of the different directions in which research has been done on this topic, and how techniques developed in one area can be applied in domains for which they were not intended to begin with.

The knowledge-creating company : how Japanese companies create the dynamics of innovation

Abstract: How has Japan become a major economic power, a world leader in the automotive and electronics industries? What is the secret of their success? The consensus has been that, though the Japanese are not particularly innovative, they are exceptionally skilful at imitation, at improving products that already exist. But now two leading Japanese business experts, Ikujiro Nonaka and Hiro Takeuchi, turn this conventional wisdom on its head: Japanese firms are successful, they contend, precisely because they are innovative, because they create new knowledge and use it to produce successful products and technologies. Examining case studies drawn from such firms as Honda, Canon, Matsushita, NEC, 3M, GE, and the U.S. Marines, this book reveals how Japanese companies translate tacit to explicit knowledge and use it to produce new processes, products, and services.

The Act of Creation

Abstract: While the study of psychology has offered little in the way of explaining the creative process, Koestler examines the idea that we are at our most creative when rational thought is suspended--for example, in dreams and trancelike states. All who read The Act of Creation will find it a compelling and illuminating book.

Time and Narrative

Abstract: In the first two volumes of this work, Paul Ricoeur examined the relations between time and narrative in historical writing, fiction, and theories of literature. This final volume, a comprehensive reexamination and synthesis of the ideas developed in volumes 1 and 2, stands as Ricoeur's most complete and satisfying presentation of his own philosophy.