The largest minimum weights among quaternary Hermitian linear complementary dual codes are known for dimension 2. In this paper, we give some conditions on the nonexistence of quaternary Hermitian linear complementary dual codes with large minimum weights. As a consequence, we completely determine the largest minimum weights for dimension 3, by using a classification of some quaternary codes. In addition, for a positive integer s, an entanglement-assisted quantum error-correcting [[21s + 5, 3, 16s + 3; 21s + 2]] code with maximal entanglement is constructed for the first time from a quaternary Hermitian linear complementary dual [26, 3, 19] code.

This paper deals with the colorization-based image coding algorithm. In this algorithm, a color image is compressed by encoding its luminance image by standard coding method such as JPEG coding and by storing several color pixels called as representative pixels (RPs). In decoding phase, a color image is restored from luminance image and color information of RPs using the image colorization technique. While previous studies have achieved a high coding performance, the compression method of RPs has not been considered because the positions of RPs are inhomogeneous. In order to improve the image coding performance, this paper proposes the RPs compression algorithm using the graph Fourier transform. Numerical results show that proposed algorithm achieves better performance than JPEG2000 coding.

The hexapod legs of insects achieve stable walking motions on various surfaces. This paper proposes a walking hexapod microrobot that mimics an insect's walking behavior. Miniaturization of the robot is an important issue. The miniaturized robotic component is fabricated by the micro electro mechanical systems (MEMS) process, which is based on the IC production process using silicon wafer as the starting material. The miniature rotary actuator is constructed from miniature silicon components and an artificial muscle wire based on shape memory alloy (SMA). The material property of SMA enables the miniaturization of the actuator. Four artificial muscle wires, which shrink by a heating process, are attached to the rotor in a four-through pattern. The joining material is a conductive paste. A rotary motion is generated by successively passing an electric current to the artificial muscle wire. Continuous heating shrinks the artificial muscle wire, decreasing its displacement during the rotational motion. Therefore, the actuator requires a cooling process, which reduces its operating speed. To achieve high-speed operational walking of the MEMS microrobot locomotion by the artificial muscle wire actuator, a two-hole-type rotor with low heat capacity was developed, and its thermal distribution and heat transition were observed. Also, the lead wires of the artificial muscle wire are located inside the microrobot's body. After externally connecting with a pulse-type artificial neural network IC controller developed by us, the microrobot traveled at 21.2 mm/min.

This paper proposes monolithic magnetic circuits for a micro-electro-mechanical system (MEMS) magnetic device. The problem with existing miniature magnetic devices is the fabrication of the miniature magnetic circuit, such as a winding wire. The proposed magnetic circuit has a miniature three-dimensional coil structure and a magnetic core within the monolithic structure. Multilayer ceramic technology that is used for miniature electronic elements is applied during the fabrication process. In this paper, various differently shaped single-coil or multi-coil-type magnetic circuits are described. Moreover, the magnetic flux of the circuits is analyzed and the circuit is applied to miniature magnetic devices. To produce the miniature mechanical components, the MEMS process is used. The fabricated single-coil-type circuit is applied to a MEMS magnetic motor. The developed MEMS magnetic motor has three multilayered circuits and is built within the MEMS structural component. The diameter and height of the motor are 4.22 and 6.04 mm, respectively. The multi-coil-type circuits are applied to a MEMS turbine generator. Both single-phase and three-phase generators are fabricated. The single-phase generator is combined with a multilayered step-wise shape circuit, in which the magnetic material is arranged around the magnet. The three-phase generator is combined with a separated type and has an air gap between each coil pattern. These two devices demonstrate rotational motion and power generation, respectively. The rotational speed of the MEMS motor is 1080 rpm. The output power of the single-phase and three-phase generators is 1.74 and 1.41 µVA, respectively.

This paper presents the integrated circuit (IC) which could output a driving waveform to generate the walking motion of the piezoelectric element impact-type micro electro mechanical systems (MEMS) microrobot. The microrobot was made from silicon wafer fabricated by micro fabrication technology. The size of the fabricated robot was 4.0 × 4.6 × 3.6 mm. IC design of the pulse-type hardware neuron model (P-HNM) had been done by using CMOS process. P-HNM has the same basic features of biological neurons to generate the pulse waveform. Therefore, P-HNM outputs the driving waveform using electrical oscillation such as biological neuron. In this paper, we showed that the P-HNM which outputs the driving waveform for the piezoelectric element impact-type MEMS actuator could design as bare chip IC. As a result, we showed that P-HNM with driving circuit could generate the driving waveform of the rotary-type actuator of piezoelectric element impact-type MEMS microrobot. The generation of the driving waveform could realize without any software programs or analog digital converters.

In this paper, we presented the 4.0, 2.7, 2.5 (mm), width, length, height size biomimetics micro robot system which was inspired by ant. The micro robot system was made from silicon wafer fabricated by micro electro mechanical systems (MEMS) technology. The mechanical system of the robot was equipped with small size rotary type actuators, link mechanisms and six legs to realize the insect-like switching behavior. In addition, we constructed the complementary metal oxide semiconductor integrated circuit neural networks (CMOS IC NN) as a locomotion controlling system. The CMOS IC NN utilized the pulse-type hardware neuron model (P-HNM) as a basic component. The CMOS IC NN outputs the driving pulses using synchronization phenomena such as biological neural networks. The driving pulses can operate the actuators of the biomimetics micro robot directly. Therefore, the CMOS IC NN realized the robot control without using any software programs or A/D converters. The micro robot emulated the locomotion method and the neural networks of an insect with rotary type actuators, link mechanisms and CMOS IC NN. The micro robot performed forward and backward locomotion, and also changed direction by inputting an external trigger pulse. The locomotion speed was 26.4 (mm/min) when the step width was 0.88 (mm).

This paper present the integrated circuit (IC) chip of pulse-type hardware neural networks (P-HNN) which can generate the driving waveform of hexapod walking micro electro mechanical systems (MEMS) micro robot. The driving waveform of micro robot is oscillatory waveform of electrical activity such as living organisms. Basic components of the P-HNN are the cell body model and inhibitory synaptic model. The cell body model and inhibitory synaptic model has the same basic features of biological neurons such as threshold, refractory period, spatio-temporal summation characteristics and enables the generation of continuous action potentials. P-HNN was constructed by metal-oxide semiconductor field-effect transistor (MOSFET), can be integrated by IC production lines. P-HNN output the driving waveform using synchronization phenomena such as biological neural networks. Four output signal ports were extracted from P-HNN and they were connected to the actuators. The driving pulses can operate the actuators of MEMS micro robot directly. Therefore, P-HNN realized the robot control without using any software programs or A/D converters. The size of the micro robot fabricate by the MEMS technology is 4.0 (mm) × 2.7 (mm) × 2.5 (mm), width, length, height size. The frame of the robot is made of silicon wafer, equipped with the rotary type actuators, the link mechanisms and 6 legs. The MEMS micro robot emulates the hexapod walking method and the neural networks of the insect by the rotary type actuators, link mechanisms and IC chip of P-HNN. As a result, we show that IC chip of P-HNN can control the hexapod walking of fabricated MEMS micro robot, and also switched the direction by inputting the external trigger pulse. The locomotion speed was 26.4 (mm/minutes) when the step width was 0.88 (mm).

This paper presents the locomotion generator of MEMS (Micro Electro Mechanical Systems) micro robot. The locomotion generator demonstrates the locomotion of the micro robot, controlled by the P-HINN (Pulse-Type Hardware Inhibitory Neural Networks). P-HINN generates oscillatory patterns of electrical activity such as living organisms. Basic components are the cell body models and inhibitory synaptic models. P-HINN has the same basic features of biological neurons such as threshold, refractory period, spatio-temporal summation characteristics and enables the generation of continuous action potentials. P-HINN was constructed by MOSFETs, can be integrated by CMOS technology. Same as the living organisms P-HINN realized the robot control without using any software programs, or A/D converters. The size of the micro robot fabricated by the MEMS technology was 4×4×3.5 mm. The frame of the robot was made of silicon wafer, equipped with the rotary type actuators, the link mechanisms and 6 legs. The MEMS micro robot emulated the locomotion method and the neural networks of the insect by the rotary type actuators, link mechanisms and P-HINN. As a result, we show that P-HINN can control the forward and backward locomotion of fabricated MEMS micro robot, and also switched the direction by inputting the external trigger pulse. The locomotion speed was 19.5 mm/min and the step width was 1.3 mm.

It is well known that locomotion rhythms of living organisms are generated by CPG (central pattern generator). In this paper, we discuss the synchronization phenomena and oscillation patterns of the coupled oscillators system using pulse-type hardware neuron models (P-HNMs) for the purpose of constructing the CPG model. It is shown that the plural coupled P-HNMs connected by excitatory-inhibitory mutual coupling can generate various oscillation patterns. Therefore, we construct the CPG model by using the coupled P-HNMs to generate several locomotion rhythms. As a result, we show clearly that the IC chip of CPG model, which can generate the quadruped locomotion patterns, can be constructed by CMOS process.