Iwamoto et al. proposed the strong security definition for ramp secret sharing schemes with general access structures, and also proposed an integer optimization approach to construct a secret sharing with the smallest share size and general access structure, based on a threshold secret sharing scheme. This note proves that if the underlying threshold scheme is strongly secure then the constructed multiple assignment scheme gives a strongly secure secret sharing scheme.

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In wireless positioning, estimating the location of a receiver is extremely challenging since the receiver does not transmit signal and it is invisible to sensors. To deal with the issue, we proposes a received signal strength (RSS)-based method to position the receiver based on the signal from the corresponding transmitter. Our results indicate that the proposed method has about 20∼40 meters positioning error in average, which reaches the same level of the positioning error as the conventional RSS-based Tx positioning methods.

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This paper presents an automatic impedance-matching algorithm that can sequentially realize a simultaneous conjugate-matching state for all the elements in an N-element array antenna. The analytical results show that the converged solution obtained from the proposed algorithm agrees well with the solution calculated by the analytical deterministic equation, confirming the validity of the proposed method. The method can be applied to MIMO array antennas.

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An accurate estimation of symbol timing is significant for orthogonal frequency division multiplexing (OFDM) since the symbol timing inaccuracy will lead to phase offset (FO), inter-symbol interference (ISI) and inter-channel interference (ICI). In this letter, a metric function has been designed by taking advantage of the correlation properties of OFDM signals. Computer simulation results show that the scheme is superior because it gets a larger probability that fall into the ISI and ICI free region and has lower computational complexity compared with the conventional methods over frequency-selective channels, which can be used for factory automation (FA) in wireless control network (WCN).

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We propose a secure parent node selection scheme in the IPv6 Routing Protocol for Low-power and Lossy networks (RPL) so that each child node can select a legitimate node as its parent. In the proposed scheme, each node chooses a parent after excluding too good candidate if multiple parent candidates exist. Our scheme utilizes the fact that an attacking node claims falsely a lower rank than that of legitimate nodes. Simulation results show that the proposed scheme reduces the total number of child nodes attached to attacking nodes.

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