Recently, wireless telecommunication devices have been used with worldwide spread of the mobile phone, wireless local-area networks (WLAN) and UHF-Radio frequency identification (UHF-RFID). Therefore, EMI problems have been so serious. In the case of indoor use, wireless telecommunication environment is deteriorated by multiplex reflection interference. That interference has to be controlled for improving wireless communication circumstance. Especially, it is thought that the improvement of the multi-path environment is indispensable to secure reliability in UHF-RFID system. In this paper, ultra thin microwave absorber as an improvement technology of the multi-path environment for UHF-RFID system is described. Additionally, a transparent feature is given to this absorber. Because the microwave absorber should not increase the blind area of the observation camera in the region for which UHF-RFID system is used (around the entrance gate of offices or warehouses). In an actual warehouse, the verified result about the effectiveness of tag identification probability improvement with this absorber is also presented.
The specific signal in the actual electromagnetic wave frequently shows some very complex fluctuation forms of non-Gaussian type owing to natural, social and human factors. Furthermore, the observed data are inevitably contaminated by the background noise of arbitrary distribution type. In these situations, it is often desirable to estimate several evaluation quantities such as the peak value, the amplitude probability distribution, the average crossing rate, the pulse spacing and duration distributions, etc. of the specific signal. Without losing their mutual relationships, it is indispensable to estimate the probability distribution or the original wave fluctuation form itself of the specific signal based on the observed noise data. In this study, static and dynamic signal processing methods for estimating a specific signal with the existence of background noise of non-Gaussian distribution forms are proposed. More specifically, by paying attention to the power state variable for a specific signal in the electromagnetic environment, which exhibits complex probability distribution forms, a new type of signal processing method for noise cancellation is proposed. In the case of considering the power state variable, a physical mechanism of contamination by a background noise can be reflected in the noise cancellation method by using an additive property between the specific signal and background noise. The proposed method positively utilizes the additive property of power state variable in the derivation process of the noise cancellation method. Furthermore, the effectiveness of the proposed theoretical method is experimentally confirmed by applying it to an estimation problem in actual electromagnetic environment.
Technologies of the small size reflect-meter constructed in form of RF functional systems in package (SiPs) for RF testers are described. As primary concerns, focusing on the directivity and dynamic range of the reflect-meter performance, we propose the construction and the core circuit topologies to realize a very small reflect-meter SiP that satisfies functions of the vector network analysis for RF testers. The reflect-meter features a very small size of less than 1/50 compared to our conventional hybrid form reflect-meter, and having good performance for RF testers.
This paper describes the first results on transmission performances of newly developed high power amplifier millimeter wave 3-stage GaN_MMICs (monolithic microwave integrated circuit) on a Si substrate and a small size wireless power amplifier module equipped with the GaN_MMIC. The high power type of GaN_MMIC and the voltage gain type are fabricated, and both MMICs show over 28-dBm output power at 38GHz band. The power amplifier module including the MMICs and bias circuits exhibits lower than -34dBc of adjacent channel leakage ratio at 25-dBm output power and QPSK-operation. Moreover, the power module exhibits 16QAM 600-Mbps transmission rate at 25-dBm output power.
A magnetic tunnel junction (MTJ) consisting of a thin insulating layer (a tunnel barrier) sandwiched between two ferromagnetic electrodes exhibits the tunnel magnetoresistance (TMR) effect due to spin-dependent electron tunneling. Since the discovery of room-temperature TMR in the mid-1990s, MTJs with an amorphous aluminum oxide (Al-O) tunnel barrier have been studied extensively. Such MTJs exhibit a magnetoresistance (MR) ratio of several tens of percent at room temperature and have been applied to magnetoresistive random access memory (MRAM) and the read heads of hard disk drives. MTJs with MR ratios substantially higher than 100%, however, are desired for next-generation spintronic devices. In 2001, first-principle theories predicted that the MR ratios of epitaxial Fe/MgO/Fe MTJs with a crystalline MgO(001) barrier would be over 1000% due to the coherent tunneling of specific Bloch states. In 2004, MR ratios of about 200% were obtained for MgO-based MTJs. MTJs with a CoFeB/MgO/CoFeB structure were developed for practical application and found to have MR ratios of above 200% and other practical properties. This article reviews the physics of magnetoresistance in MTJs and the application of MTJs to various spintronic devices such as magnetic sensors, spin-transfer-torque MRAM with perpendicular magnetization, and novel microwave devices.
A new approach to the fabrication of multilayer mirrors on an atomic scale at soft x-ray wavelengths is desired to overcome serious problems regarding scattering loss at the rough surface and interface of the multilayer. In this review, resent progress regarding novel approaches utilizing atomic layer epitaxy to the fabrication of multilayer structures for soft x-ray wavelengths is detailed. These novel approaches are expected to solve the above-mentioned problems and then take the place of conventional sputtering methods because of their control performance of the surface on an atomic scale through their self-limiting functions.
We introduce the recent topics concerning the 1D- and 2D- plasmonic crystals, i.e., a wire grid polarizer and a metal mesh device at terahertz frequencies. We show the remarkable increase in polarization characteristics on a freestanding double-layered wire grid polarizer. We also show the performance of metal mesh devices for biosensing application.
A transparent, hard silica glass (SiO2) layer was formed on a conventional protective coat made of silicone ([SiO(CH3)2]n) on a polycarbonate plate by the 157nm F2 laser-induced photochemical modification of silicone into SiO2. An optimum laser irradiation time of the F2 laser was found to form a crack-free SiO2 layer. The high optical transparency of the samples in the visible light region remained unchanged after the F2 laser irradiation. In the Taber abrasion test, the SiO2 layer markedly reduced the number of scratches, resulting in a low haze value. The haze values of the samples also depend on the thickness of the silicone protective coat underneath the SiO2 protective layer. As a result, the difference of haze value was successfully reduced to 1.2%, compared with these of the nonirradiated sample and a bare polycarbonate plate of approximately 3.5 and 46%, respectively, which is comparable to the case of a bare silica glass of approximately 0.9%. In addition, the thickness of the SiO2 protective layer was estimated to be approximately 0.44μm for the 30-s laser irradiation by immersing the samples in 1 wt % hydrogen fluoride aqueous solution and measuring the depth using a surface profilometer.
Nonlinear electronic circuit is widely used in many fields of electronic devices. The importance of nonlinear electronic circuit is increasingly recognized with improvement in the speed and precision of electronic devices, and the development and expansion of use. Here, I give a trend of nonlinear electronic circuit which is introduced for the purpose of contributing to development of a nonlinear electronic circuit from a viewpoint of analog electronic circuit technology including new fields, such as chaos, neuro, and a neural network. From now on, nonlinear electronic circuit will become more important for the electronics, and the circuit technology will be utilized for many fields.
This paper reviews current status and future prospects of radio frequency (RF) filters employing bulk acoustic wave (BAW) resonators. First, their fundamental operation is explained, and it is shown how these devices are fabricated with the skillful use of MEMS and thin film technologies in state of the art. It is also shown how high performances are achieved up to now and what are demanded and investigated for further evolution.
The smart community developed from the micro grid and the smart grid not only solves a problem about the use of the electricity energy but also changes social structure. In addition, the technology of the big data technology has possibility to produce new value from various data in conjunction with the smart community. This article defines the meaning of the big data technology as smart community and introduces the association between them.
By development of sensor and communication technology, M2M (Machine-to-Machine) systems has been gaining much attention recently. A M2M system which connects various sensors and information systems with communication network has a large possibility of application in all fields, such as industry field of manufacturing and agriculture, social field of traffic and energy, and home field of health care and safety control. However, in order to build and deploy M2M systems, there is a major difficulty for engineers in assembling and unifying multiple technologies from various layers. This article describes the trend of M2M technology, such as M2M application integration, M2M framework, M2M technology of network and platform, and M2M technology standardization, based on the activity result of the “M2M Technology Investigation Committees" (2010.10-2012.9) under Technical Committees of Communications in IEEJ.
The magnetic stimulation is the way of stimulating the nervous and muscle tissue with the induced eddy current induced by the stimulation coil and is widely used in the evaluation of the nervous system and the field of the exercise physiology. It is more difficult to focally and deeply stimulate with magnetic stimulation. In this study, we used the 5 shell uniform head model and estimated the eddy current distribution by calculation. As the result, it is shown that the boundary between tissues which have different conductivity affects eddy current distribution.
Many wireless communication systems were developed for medical applications. In early stage, the systems are situated a sort of experimental system. For example, radio capsule is developed as sample picking system in human digestive organs. One of radio telemeter is also implanted in dog. In later stage, the wireless systems are situated as information communication system like GPS, PHS and RFID. Wireless systems in medical scenes are effective to maintain medical quality level.
Recently, 3D is being popular. 3D environment, especially, immersive virtual environment, which provides a large 3D screen or surrounds people by multiple large screens causes virtual (or simulator) sickness. Therefore, many researches have been done in this field, but the method is not standardized. The standardization is strongly required in this research filed. In this paper, novel researches about virtual or simulator sickness are introduced and their evaluation methods are analyzed and explicated. Finally, the standardization of the method for virtual sickness research is attempted. The guideline of the virtual sickness experiment is proposed based on this standardization results.
The Moore's law predicting that the number of transistors on integrated circuits doubles every 18 months since 1970's has been underlying industrial innovation. In the field of neuroscience, a similar trend is observed for the number of simultaneously recorded neuronal cells, which has doubled every 7.4 years since the late 1950's. Neural engineering has emerged from the confluence of these two technological trends and has significantly promoted a number of progresses in our understanding of the brain and the developments of neural prosthesis. In the present paper, we introduce how innovative instrumentation engineering and information technologies have brought benefits in our daily physiological experiments and sometimes led to major discoveries in a discontinuous manner. Furthermore, increasing capacity to acquire and analyze massive data may change not only treatments of neural data, but also scientific approaches in neuroscience.
Huge volumes of data are being created by business and individual activity. Anyone can't help paying attention to “Big data”. Big data is defined as datasets whose size is beyond the ability of typical database software tools to capture, store, manage, and analyze. In this paper, first, we will take a brief look at the infrastructure technologies to handle data that are high-volume, high-velocity, and/or high-variety. It includes Hadoop, NoSQL, CEP, and so on. Then, we will overview data mining techniques such as classification, association, sequence, and clustering that identify repeated and useful patterns in big data. Obstacles to big data application are also described.
With the diversification of the IT service, it becomes important to the user company to select and utilize appropriate IT service continuously. This paper reports IT service management technology becoming more necessary for the user company of the service along the introduction step of the IT service.
This article surveys international standardization status of smart grid cyber security and shows trends in standardization. As a result, this article shows that high-level security requirements are being developed by U.S. and European standardization bodies. Current issues of cyber security standardization are the development of low-level standards, development of guides and tools, and establishment of systems for testing and certification.
This article describes innovations in tourism information systems and their changing after the Internet technologies have appeared. Airline companies in United States started to provide computer reservation system to be made air ticket reservation and to be confirmed their seats in the aircraft. These systems were provided to travel agency to help their business. After around 2000, as the Internet develops, the tourism information systems have been becoming an increasingly development for B2C. Recent research contributions are including innovative user support; user preferences on the web can be analyzed by data mining technology; and the system make a travel plan based on users' preferences.
In this paper, author shows that the importance of energy measurement, and introduce the committee of energy measurement and the use of the data of energy measurement. Actually, in many medium and small buildings, energy measurement system is not installed. One of the reasons of not-installing energy measurement system is the high cost. Therefore, it is important that the merits of energy measurement system are clarified to customers. The research committee of energy measurement system and the use of measured data is started from May, 2011. The items of survey in this committee are the needs, the technical trend and the examples of energy measurement system.
There is expanding market for energy visualization systems because electric power supply and demand has changed after the earthquake and the revised Energy Conservation Law came into force. Accordingly I classified products of HIOKI called energy visualization systems. There is a technology trend that wireless communications and smart phones improve convenience. Furthermore, it is expected that voltage measurement with Non-Metallic contact is introduced for safer measurement.
In Japan, HEMS and cooperation of smart meters has been discussed as a future. In this presentation explains various international standardization trend required for cooperation of HEMS and a smart meter. In addition, to compare the standardization. And HEMS considers the practical use method of the data obtained from a smart meter.
Recently, GPGPU (General Purpose computation on Graphics Processing Units) has become popular with great success, especially in scientific fields such as fluid dynamics, image processing, and visualization using particle methods. In this paper, we discuss how the GPGPU is used in implementations of parallel ant colony optimization (ACO) for fast solution of quadratic assignment problems (QAPs). As for the ACO, we use the cunning ant system (cAS) which is one of the most promising ACO algorithms.
The aerospace engineering is required to employ sophisticated techniques in each technology field such as aerodynamics, structure, prolusion, and control. Recently, Multi-Disciplinary Optimization (MDO) design techniques have been put to practical use for the design of aircraft/spacecraft design with simulation technology, instead of the design by trial and error. In this report, the overview of the MDO technology with simulation is discussed and several examples of authors' study about MDO problems are reviewed.
We review several Just-In-Time methods for data-driven control, in particular which have been developed by the author, and discuss the potential for expantion of this research field. In the Just-In-Time methods, an estimated function is approximated locally with respect to a query to use the training data generated by the estimated function. The training data are stored in a database and the only most related data to the query are searched and extracted for the approximation. In this article, we introduce PID controller tuning, predivtive control, and fault detection based on the Just-In-Time concept.
It is of prime importance to maintain voltage profile in distribution systems with a large amount of distributed generators. Moreover, in the systems with renewable energies, the voltage control becomes more difficult issue due to their uncertain fluctuation. Hence, in this paper, the recent situation of the voltage control researches is introduced. Especially, the concept of hierarchic voltage control to be applied to Japanese distribution systems is shown in detail.
PID control has been developing for improving control performance. To enhance the PID control, this paper describes a design method using the maximum sensitivity of a control system because robust stability can be designed by the maximum sensitivity. In this paper, load-disturbance performance and set-point one are optimized, respectively, and then, PID parameters are optimized for combined performance such that desired robust stability is achieved. Finally, to demonstrate its effectiveness, simulation results are shown.
As well known, human sensing is useful for our life. But, the development of the human sensing system is not easy, because the shape and the movement of human are complicated; the environment of obtaining image is not always constant and so on. We have developed some methods of identifying individuals using facial image, counting passing people, observing of human behave and so on. In this paper, human smart sensing and its applications are introduced. In addition, examples of application are shown.
Recently, haptic display attracts attentions in some fields such as virtual reality, human interface and so on. Typically, kinesthesia and tactile sensation are indicated separately, they need their own suitable actuator specifications. Many types of haptic display devices have been proposed and developed so far under this situation. This manuscript presents recent haptic displays as history of device development and categorization of principles. Haptic sensors have been also considered to acquire haptic information or to realize haptic interaction between human and objects. These devices can perform as realistic haptic sensation for certain application. In the next period, these proposals and trials will contribute evolution in new fields like touch screen operation. For such evolution, interaction and cooperation among researchers surrounding human haptic sensation will be important.
This paper introduces fusional sensing technologies via multiple sensory perceptions. As actual examples, human detection and tracking system for human behavior recognition is introduced. EEG measurement and analysis methods are also described as an example real system which is titled “Visualization of the Mind Status using the EEG”. Through the review of these example, current and future direction of this field is discussed.
Brain-Computer Interface (BCI) is a system to obtain information from the brain signal to control computers. P300 and motor imagery task of Electroencephalogram (EEG) are mainly used features for BCI. However, BCI with P300 classifies only two states and features of motor imagery task are too obscure to be classified easily. Therefore, we propose a method to increase the number of classified states with high accuracy by mixed signal processing for P300 and motor imaginary task. BCI using P300 and motor imaginary task is going to have more bit rate than conventional BCI. We design a experiment which gives 4 classes data as control, P300, and P300 during motor imagery of right or left hand. First, we confirm that P300 appear during motor imagery task. In addition, we examine the best method for feature extraction. Finally, we classify 4 classes by multi-class Support Vector Machines, and show the efficacy of mixed signal which contain P300 and motor imagery.
In a typical office building, the energy-saving of lighting is an important problem because the lighting accounts for 40% of the total electric power consumption in the entire building. However, the lighting affects the amenity of an office space, and inappropriate energy-saving of the lighting decreases the productivity of office workers. Therefore, a lighting control system for the office building must achieve the appropriate energy-saving based on careful and accurate control of light dimming. This paper proposes a lighting control method, which saves the power consumption of lighting with keeping the accuracy in light dimming. In the proposed method, to control the lighting optimally, the lighting influence matrix, which associates the dimming rate pattern of light sources with the illuminance distribution on desks in an office space, is introduced, and a dimming inverse problem is solved by using this matrix. The dimming rate pattern obtained by the proposed method can minimize the power consumption of lighting while maintaining the target illuminance in the area where the office workers seat themselves at their desks. We implemented an energy saving lighting control system based on the proposed method and carried out evaluation experiments by applying this system to an actual office space. Experimental results show that the proposed method increases the evaluation index, which combines energy-saving ratio and dimming accuracy, by 9% compared to conventional energy-saving operations.
This paper presents the design of nonlinear servo system using fuzzy method. The idea behind this control method is to divide the operating region of nonlinear system into collection of local linear servo control system and apply fuzzy method for calculation the control input. The control input of each local linear servo system is calculated using Davison-Smith method and Hikita pole assignment method. We can prove that the all of states of the fuzzy servo system are bounded and output errors converge to zero using Lyapunov method. The simulations are done to nonlinear mass-spring-damper system to illustrate the effectiveness of the proposed method.
Recently, the research of humanoid robotics is very popular. However, few humanoid robots usually have the tiptoe due to complicated mechanism and control, etc. though the degrees of freedom of the joint increase by appending a tiptoe to the robot foot and a leg construction with the high movement ability can be expected. In this paper, an autonomous attitude stabilization control based on a repetitive bending and stretching movement with standing on the tiptoe is proposed. Namely, the control performance is verified under a narrow situation of the stable range by using a tiptoe of one-legged robot. When a one-legged robot moves each joint by using the tiptoe without an attitude stabilization planning, the ZMP (Zero-Moment Point) of robot goes over the boundary of a contact surface often. As the result, the robot falls down due to the occurrence of an unstable situation. The compensation of ZMP by using a force sensor set up the ankle is a general method in conventional humanoid robots. However, the center of gravity and ZMP are calculated from motion data because providing a force sensor for the verification of movements using a tiptoe is so difficult. The autonomous stabilization is achieved by controlling an imaginary inverted pendulum (IIP) that passes through the center of gravity from the robot tiptoe. In other words, the VSS adaptive control suppresses as much as possible the disturbance concerning a change of the center of gravity caused by the robot movement. The I-PD control system is designed to both joints of an ankle and a knee, and two reference angles of sinusoid wave are given to their joints without inverse kinematics in an experiment. Simultaneously, VSS adaptive control input for the attitude stabilization is given to a tiptoe joint. Finally, the validity of the proposed system is demonstrated through some simulations and experiments.
In this paper we propose a feature-based alignment method for visualizing geographical content on a movable paper map using non-calibrated projector-camera pair. In order to project correctly aligned geographical content on a movable paper map, we detect two kinds of features: printed features and projected features on a paper map. First, we print landmark points as map features on the paper map for registration purpose. We then project landmark points onto the paper map. We then detect these printed and projected features simultaneously. The transformation from the projector coordinate system to the image coordinate system is estimated using the feature correspondences. This transformation is used to warp the geographical content before the corrected projection. In succeeding frames, the features are tracked in order to update the transformation. We evaluated our method against the motion of the paper map, the camera and the projector with average projection error of 9.5 pixels.
The purpose of this study is to propose a new creation method of high-resolution images using DCT. Images enlarged with image interpolation method blur due to the lack of high-frequency components. Super-resolution method is important in improving the sense of resolution of such images. In the proposed method, high-frequency components of images enlarged with bi-linear interpolation are restored to refine the enlarged images. Restoring high-frequency components is implemented by each focused block on the enlarged image. Since the high-frequency components of the focused blocks are lacked, they are searched from a database by means of DCT sign index. Here, the database is learned from multiple nature description images in advance. In addition, the DCT sign index used for search is generated from signs of DCT coefficient of the low-frequency components of the focused blocks. The proposed method made fast search of the database possible with the use of the DCT sign index. From many simulation results, the proposed method is proved effective.