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SUMMARYThis paper considers chirp pulse microwave CT (CP-MCT), in which the chirp pulse and signal processing technology are used to estimate the internal structure and temperature variation of biological objects. A method is developed in which the CT image to be acquired by actual measurement can be derived by numerical computation. The aftereffect function between the transmitting and receiving antennas is calculated by a Gaussian pulse and the FDTD method. After convolution of the function with the input chirp pulse signal on the time axis, the measured signal at a point is constructed by the same signal processing as in real measurement. This computation is repeated for each point on the translation-scanning axis. The projection data are acquired and the CT image is generated. The validity of this computation procedure, which is called the aftereffect function method, is demonstrated by comparing the resolution and the measured temperature variation in actual measurements with the results of a simulation computation. Using the aftereffect function method, the pointspread function of an imaging system which is difficult to measure, can be derived. An analytical model for the human head is constructed. Simulations are performed for the attenuation distribution and the temperature variation distribution. Based on the results, the feasibility of the biological imaging by CP-MCT is discussed.

In the smart city projects that will "smartize" urban infrastructures, a new access control technology is needed to offer appropriate consumer data to appropriate applications. In this paper, we analyze characteristics and problems of the data access in the service platform for smart public infrastructure and clarify requirements for data access control. Next, we propose a data model and a data access control method that satisfy those requirements. The data model includes access authorization that expresses the contracts between consumer and service provider. In the data access control method, data corresponding to the access authorization is filtered in RDBMS for the performance. Finally, we evaluate the proposed method by implementing a prototype and confirm that the requirements are satisfied.

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