Arimitsu Shikoda

Magnetic Actuator Group of Globular Type Capable of Free Movement in a Complex Pipe

Finding damage inside pipes is important for the inspection of complex pipes used in nuclear power plants and chemical plants. A number of studies have investigated the mechanisms of an actuator with an electric cable to provide locomotion through various devices in complex pipes. An in-pipe robot capable of movement in narrow complex pipes has not yet been developed. In the present paper, we propose a globular magnetic actuator group that exhibits a very high thrust force and is capable of free reversible motion in complex pipes. Two actuators of the same size and characteristics are coupled by the magnetic connection method, which generates almost no mechanical loss. The globular magnetic actuator group capable of reversible motion through elongation and contraction of eight shape-memory-alloy (SMA) coils was fabricated. Experimental results indicate that the prototype actuator group is able to climb at a rate of 29 mm/s in a straight pipe while pulling a load mass of 48 g.

Development and evaluation of a microstep DFA vulnerability estimation method

Recently, various studies of attack methods of round reduction differential fault analysis (DFA) using fault injection in block cipher-implemented microcontrollers have been reported. However, few studies have focused on the quantitative evaluation method of round reduction DFA vulnerability using detailed fault injection timing dependency of attack success rate. This is required to improve microcontroller security. Hence, we propose a quantitative evaluation method against round reduction DFA using a micro step DFA vulnerability chart and a vulnerability estimator (VE) that consists of pairs of fault injection timing and attack success rate.

KNOPPIX/Math: portable and distributable collection of mathematical software and free documents

We propose a new computer environment for mathematicians that can be set up easily and quickly.

Round addition DFA for microcontroller implemented the triple DES

This article presents a method of round addition attack on triple DES block ciphers using differential fault analysis(DFA). For single DES, the secret key can be easily extracted using one correct ciphertext and two faulty ciphertexts. Even for triple DES, it is shown that the secret key can also extracted, similarly to single DES.

Crashing Modulus Attack on Modular Squaring for Rabin Cryptosystem

The Rabin cryptosystem has been proposed protect the unique ID (UID) in radio-frequency identification tags. The Rabin cryptosystem is a type of lightweight public key system that is theoretically quite secure; however it is vulnerable to several side-channel attacks. In this paper, a crashing modulus attack is presented as a new fault attack on modular squaring during Rabin encryption. This attack requires only one fault in the public key if its perturbed public key can be factored. Our simulation results indicate that the attack is more than 50 percent successful with several faults in practical time. A complicated situation arises when reconstructing the message, including the UID, from ciphertext, i.e., the message and the perturbed public key are not relatively prime. We present a complete and mathematically rigorous message reconstruction algorithm for such a case. Moreover, we propose an exact formula to obtain a number of candidate messages. We show that the number is not generally equal to a power of two.

Effect of visual image features on neural activities: An fMRI study

There are various elements in visual images, such as luminance, edge, color, movement, and shape, that may affect mental activity. In an attempt to explore the neural processes associated with image features, we extracted the edge and spatial frequency characteristics from images of two movies having completely differential features. Using the fMRI technique, we measured the effects of the movies on the physiology of subjects viewing them. It was found that an outdoor movie contains higher-frequency components than an indoor movie. Further, the outdoor movie activates the frontal regions, and this may affect higher-order brain functions such as display of emotions and conscious awareness.