Cardinal directions are presented as visual information for guidance and leading. The purpose of this study is to clarify the elements of design for an intuitive better understanding of cardinal directions. First, current cardinal directions were collected from the literature and field studies, and components of design that should be considered when drawing cardinal directions were extracted. Then, using the four types of cardinal directions based on design components as the stimulus, the perspicuity of each diagram was analyzed through paired comparison method. As a result of the integrated evaluation of four types of cardinal directions, the use of the letter N meaning the north direction in any of the types was proved to lead to better understanding. However, depending on the type of cardinal directions, the appropriate state of design element that could help the audience to understand differed. Specifically, if the pointer only indicated north, it was answered that it would be better to understand to display only the letter N, but if there were four pointers indicating four directions, it would be better to display all the four directions. In other words, it will be optimal if the design elements and displayed characters combine appropriately depending on the respective direction number. In addition, since excessive simplification comes to reduce the perspicuity instead, it is required to denote the necessary character information for orientation.

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[in Japanese]

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[in Japanese]

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In this study, the development of a simple isolation method for obtaining yeast Saccharomyces cerevisiae with high fermentative activities from coastal waters was examined. 824 isolates were obtained on YPD2 (glucose 2 %) solid medium from coastal waters of both Tokyo Bay and Sagami Bay in Japan. In the first screening from the isolates, 221 of the 824 yeasts had fermentative activities in YPD2 liquid medium by a Durham pipe test. In the second one, 55 of the 221 yeasts had fermentative activities in YPD30 (glucose 30 %) liquid medium by the same test. In the third one, exact amounts of gas produced by the 55 strains were rapidly measured by a syringe test and the gas productivities of the 29 strains were higher than that of a marine-derived Saccharomyces cerevisiae C19 which was isolated and used for bioethanol production in previous studies (Takagi et al., 2015; Obara et al., 2015; Obara et al., 2012). Above all, the best 4 strains with the highest gas producing activities among the 29 ones were also identified as Saccharomyces cerevisiae. Thus, the yeast species S. cerevisiae was found to be simply isolated from coastal waters by the method as above. In addition, ethanol productivities of 10 strains randomly selected from the 29 ones were measured. There was an almost linear relationship between ethanol and gas productivities in the 10 strains. Therefore, bioethanol productivities of the yeast isolates from coastal waters could be speculated by measuring amounts of gas produced by the syringe test.

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Heterogeneous wireless systems, such as a combination of mobile broadband wireless access (MBWA) and wireless local area network (WLAN), are candidates to achieve large capacity in next generation mobile communication systems. For capacity expansion, small cells of multiple wireless networks are deployed densely in these systems. Many cells overlap. Therefore, users must discover many cells at once for cell selection. Consequently, radio resources are used intensively for cell selection. Cell selection errors occur in dense small cell environments. As described herein, a channel quality map construction scheme using multi-Global Navigation Satellite System (GNSS) signals for heterogeneous wireless networks is proposed. The scheme uses positioning information and the average of signal strength for cell selection. Using positioning information, users can select cells which have a better channel quality quickly and easily. The proposed scheme is considered to be useful to optimize data traffic offloading in the heterogeneous wireless network. The 50 % user throughput and system throughput of the proposed scheme by comparison with the conventional scheme which uses measured instantaneous signal strength was studied. Computer simulation results show that the proposed scheme can improve the 50 % user throughput by 68 % in comparison with the conventional scheme. In addition, the system throughput is enhanced by 10 % compared with the conventional scheme. Furthermore, based on measured data, the positioning accuracy with multi-GNSS signals is a realizable level for the channel quality map construction scheme. This report describes the developed channel quality map construction scheme prototype system.

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In this paper, the mechanism for the antibacterial activity of a mixture of 3,4,5-trihydroxy benzoic acid (GA) and magnesium oxide (MgO) for Escherichia coli (JCM1649, E coli) is investigated. Antibacterial activity was assayed by the liquid dilution method against E coli. E coli in the logarithmic phase and the culture medium with pepton, yeast extract, NaCl, glucose, and MgSO4 7H2O were used in all experiments. The logarithmic phase culture of E coli (1x105 CFU cm-3) was added to the culture medium with GA and/or MgO. A Clark-type oxygen electrode with 1.1 cm-3 volume cell was used for the measurements of the oxygen consumption profile of a mixture of GA and MgO. The concentration of hydrogen peroxide (H2O2) in the mixture was estimated by using porphyrinato-titanium complex. Efficient antibacterial activity was observed on a mixture of 2 mg cm-3 GA and 2 mg cm-3 MgO. The addition of 110 units cm-3 catalase, which is an enzyme of H2O2 decomposition, in a mixture of 2 mg cm-3 GA and 2 mg cm-3 MgO led to the decrease of the antibacterial activity as same as the case of 2 mg cm-3 MgO. Moreover, the production of H2O2 in the mixture was confirmed by the oxygen consumption profile under the addition of 500 units cm-3 catalase. The accumulation of 3-4 mmol dm-3 H2O2 was confirmed in a mixture of 2 mg cm-3 GA and 2 mg cm-3 MgO. The increase in the concentration of H2O2 from 3 mmol dm-3 to 4 mmol dm-3 led to a drastic increase in the antibacterial activity. Based on the results of this study, a possible mechanism for the antibacterial activity of a mixture of GA and MgO is discussed, concerning a synergy effect on the antibacterial action of MgO and that of H2O2.

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