Detecting innovative topics based on user-interest ontology

In this paper, we detect “innovative topics”, those that are new and hopefully interesting to the user. We try to expand user interests significantly by letting the user browse those topics.We first generate user-interest ontologies that allow user profiles to be constructed as a hierarchy of classes where a user interest weight is assigned to each class and instance. Next, we measure the similarity between user interests by using interest weights on their user-interest ontologies and generate user group G_U that has high similarity to user u. The innovative topics for u are then detected by determining a suitable size of G_U and analyzing the ontologies in G_U.     

An application of polyalcohols prepared from diols. I. Elastic polymers with functional groups prepared by chemical modifications

An elastic polymer with hydroxymethyl side chains, which contains some crosslinked structure, has been prepared by treating its prepolymer with maleic anhydride and styrene in the presence of an initiator. Its mechanical properties were varied largely by the molar ratio of the hydroxyl group:maleic anhydride:styrene. A typical example of the polymer showed elongation 69%, tensile strength 0.85 kgf/mm², and Young's modulus 9.4 kgf/mm². Some other modifications are also examined.     

Development of insulation technology in compact SF6 gas‐filled bushings: Development of compact 800‐kV SF6 gas‐filled bushings

Efforts of designers of gas‐insulated switchgear (GIS) are currently focused on such features as smaller installation area and economical efficiency. Circuit breakers (CB), disconnecting switches (DS), and earthing switches (ES) have been redesigned in more compact configurations. Compactness and light‐weight requirements are applied also to bushings used in GIS. GIS bushings can be divided in three general types: capacitor, gas‐filled, and molded bushings. Requirements of the light weight and the economical efficiency of gas‐filled bushings can be satisfied by improvements in insulation technology. Size reduction can be effectively achieved by moderation of the electric field strength on the outside surface of the hollow insulator in the area of the inner grounded electrode tip. We devised a new inner grounded electrode structure consisting of a cylindrical electrode and a ring electrode supported by column electrodes. This paper describes the effect of reduction of the maximum value of electric field strength on the outside surface of the hollow insulator by a new type of grounded electrode. Then, improvement of insulation performance for electrodes with insulation coating in SF₆ gas is described as the composite insulation technology. Finally, the efficiency of these insulation technologies is described by the basic insulation test results of a prototype compact 800‐kV SF₆ gas‐filled bushing. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 171(1): 19–27, 2010; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20898     

Crystal habit modification of ammonium perchlorate by ethylene glycol

Ammonium perchlorate (AP)-based composite propellant has been widely used as a solid propellant, but higher burning rates are in demand. We report that crystal-habit-modified AP is an effective oxidizer that increases the burning rates of propellants. The modified APs have a dendritic shape. However, dendritic AP is not convenient to mix and cast in an AP/binder slurry because of its high viscosity. We attempted to prepare a crystal-habit-modified AP with polygon or sphere form. The crystal habit of AP was modified by ethylene glycol such that the intensity of the lattice plane (2 1 0) of the modified AP was remarkably high. The shape was almost hexahedral, and the mean particle diameter was approximately 150 μm.     

Difference in precipitation rates of air-borne salts collected by the dry gauze method and the Doken tank method

This study compares the precipitation rates of air-borne salts analyzed by the dry gauze method (JIS Z2382) and the Doken (Public Works Research Institute) tank method. Because of the difference of calculation method, direction of prevailing wind causes the difference of salt precipitation rates by these methods. In addition, the Doken tank method has lower capture ability for air-born salt than the dry gauze method under the condition of low supply of air-born salt. While, air-born salt with wet deposition potentially increases salt precipitation of the Doken tank method. As a result, these methods yield different salt precipitation rates.     

Photoemission study on natural oxidation of Cu3Au with synchrotron radiation

We report the results of a study of the natural oxidation of Cu₃Au(110) with high‐resolution X‐ray photoemission spectroscopy in conjunction with synchrotron radiation. The clean surface of Cu₃Au(110) is terminated with 50% Au and 50% Cu atoms. After natural oxidation in the air, Cu atoms segregate on the surface and produce Cu‐oxide. As a result, Au atoms move into the bulk. Au atoms below the oxide reduce the diffusion of O atoms farther into bulk and limit the oxide thickness. The face dependence of natural oxidation indicates that the diffusion of Cu atoms also contributes to oxide formation. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 175(4): 43–47, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21149     

An analysis of interactive influences in Mazda’s Yokokai Keiretsu

In a keiretsu, i.e., a set of companies with interlocking business relationships, it is important for corporate management to identify those companies over which they reciprocally exercise greater influence and power. In this article we employ a DEcision MAking Trial and Evaluation Laboratory (DEMATEL) to illustrate the reciprocal influence of each company in Mazda’s Yokokai keiretsu, as measured by the number of transactions and cross-shareholdings. Furthermore, we calculate the centrality index of each company, and then analyze the relationship between centrality index and influence in order to identify the determinants of the influence. Based on the findings, we identify some characteristics of effective relationships which have important managerial implications.