NEC

About: NEC is a company organization based out in Tokyo, Japan. It is known for research contribution in the topics: Signal & Layer (electronics). The organization has 33269 authors who have published 57670 publications receiving 835952 citations. The organization is also known as: NEC Corporation & NEC Electronics Corporation.

An Orthogonally Multiplexed QAM System Using the Discrete Fourier Transform

Abstract: An orthogonally multiplexed QAM (O-QAM) system is a multichannel system with a baud rate spacing between adjacent carrier frequencies; this property is desirable to digitally implement the system using the discrete Fourier transformation (DFT). This paper provides a novel digital signal processing method based on an N /2-point DFT processing in the O-QAM system. A complexity comparison between a digital O-QAM system and a digital singlechannel QAM system shows that the digital O-QAM system using the new method is more economical than the digitally implemented conventional single-channel data transmission system.

Receipt-free mix-type voting scheme: a practical solution to the implementation of a voting booth

Abstract: We present a receipt-free voting scheme based on a mixtype anonymous channel[Cha81, PIK93]. The receipt-freeness property [BT94] enables voters to hide how they have voted even from a powerful adversary who is trying to coerce him. The work of [BT94] gave the first solution using a voting booth, which is a hardware assumption not unlike that in current physical elections. In our proposed scheme, we reduce the physical assumptions required to obtain receipt-freeness. Our sole physical assumption is the existence of a private channel through which the center can send the voter a message without fear of eavesdropping.

Generalized Learning Vector Quantization

Abstract: We propose a new learning method, "Generalized Learning Vector Quantization (GLVQ)," in which reference vectors are updated based on the steepest descent method in order to minimize the cost function. The cost function is determined so that the obtained learning rule satisfies the convergence condition. We prove that Kohonen's rule as used in LVQ does not satisfy the convergence condition and thus degrades recognition ability. Experimental results for printed Chinese character recognition reveal that GLVQ is superior to LVQ in recognition ability.

Nanometer-scale switches using copper sulfide

Abstract: We describe a nanometer-scale switch that uses a copper sulfide film and demonstrate its performance. The switch consists of a copper sulfide film, which is a chalcogenide semiconductor, sandwiched between copper and metal electrodes. Applying a positive or negative voltage to the metal electrode can repeatedly switch its conductance in under 100 μs. Each state can persist without a power supply for months, demonstrating the feasibility of nonvolatile memory with its nanometer scale. While biasing voltages, copper ions can migrate in copper sulfide film and can play an important role in switching.