Konoritsu musen rokaru eria nettowaku ni okeru tagen akusesu hoshiki ni kansuru kenkyu

制度:新 ; 報告番号:甲3738号 ; 学位の種類:博士(国際情報通信学) ; 授与年月日:2012/7/25 ; 早大学位記番号:新6109Waseda Universit

Proposal of MIMO Ultra-Wide Band Antenna with Low Mutual Coupling

In this paper, a new ultra-wide band (UWB) MIMO antenna is proposed. A MIMO antenna set consists of two single ultra-wide band antennas. This simple and compact MIMO antenna, which is designed to work from 3.1 GHz to 10.6 GHz, has a broad bandwidth with the VSWR ≤ 2. In addition, MIMO antenna characteristics such as radiation pattern, maximal gain are thoroughly investigated

Kinematic and dynamic modelling for a class of hybrid robots composed of m local closed-loop linkages appended to an n-link serial manipulator

Recently, more and more hybrid robots have been designed to meet the increasing demand for a wide spectrum of applications. However, development of a general and systematic method for kinematic design and dynamic analysis for hybrid robots is rare. Most publications deal with the kinematic and dynamic issues for individual hybrid robots rather than any generalization. Hence, in this paper, we present a novel method for kinematic and dynamic modelling for a class of hybrid robots. First, a generic scheme for the kinematic design of a general hybrid robot mechanism is proposed. In this manner, the kinematic equation and the constraint equations for the robot class are derived in a generalized case. Second, in order to simplify the dynamic modelling and analysis of the complex hybrid robots, a Lemma about the analytical relationship among the generalized velocities of a hybrid robot system is proven in a generalized case as well. Last, examples of the kinematic and dynamic modelling of a newly designed hybrid robot are presented to demonstrate and validate the proposed method

Structure and Electrochemical Impedance of LiNix_{x}Mn2−x_{2 - x}O4_{4}

Ni-substitution spinel LiNixMn2−xO4 (x = 0, 0.1, 0.2) materials were synthesized by the sol--gel method. The structure and  morphology of the samples were characterized by the X-ray diffraction (XRD)  and the scanning electron microscopy. The ac conduction of the materials was  investigated by electrochemical impedance spectroscopy (EIS) measurements.  The refinement results showed that the substitution of Ni decreased the  lattice constant and Mn--O distance, while increased Li--O bond length and  16c octahedral volume. The EIS results confirmed the decrease of  conductivity with increasing Ni substitution content. Based on XRD and EIS  results, the relationship between the crystal structure and electrochemical  behavior of the materials was discussed and explained

PCA-Aided Linear Precoding in Massive MIMO Systems with Imperfect CSI

In this paper, a low-complexity linear precoding algorithm based on the principal component analysis technique in combination with the conventional linear precoders, called Principal Component Analysis Linear Precoder (PCA-LP), is proposed for massive MIMO systems. The proposed precoder consists of two components: the first one minimizes the interferences among neighboring users and the second one improves the system performance by utilizing the Principal Component Analysis (PCA) technique. Numerical and simulation results show that the proposed precoder has remarkably lower computational complexity than its low-complexity lattice reduction-aided regularized block diagonalization using zero forcing precoding (LC-RBD-LR-ZF) and lower computational complexity than the PCA-aided Minimum Mean Square Error combination with Block Diagonalization (PCA-MMSE-BD) counterparts while its bit error rate (BER) performance is comparable to those of the LC-RBD-LR-ZF and PCA-MMSE-BD ones

Digital twins of robotic systems: increasing capability for industrial applications

Digital twin is one of the emerging areas of research and technology development and the enabling technologies of Smart Manufacturing and Industry 4.0. This study aims to develop and demonstrate a proof-of-concept prototype with a case study of the digital twin of a robotic system. The system has two main elements: the virtual element and the physical or the real element. The virtual element of system has been built based on the Unity platform, which is a cross-platform game engine developed by Unity Software Inc., and the physical element was built with the use of two servomotors and the NVIDIA® Jetson Nano™ Developer Kit. The virtual and the physical elements are connected and communicated via using the TCP socket protocol suite. A digital twin model of the ABB IRB 120 robot was successfully developed and demonstrated. The collected data include the joint angle position values of the physical and virtual models, and they are stored both locally and in the cloud for the future system development, which can be used as for minimizing the errors between the physical and virtual models of digital twins of robotic systems. The successfully developed digital twin model can be considered as the cost-effective solutions for demonstrating and evaluating potential applications of digital twins in industrial practices as well as in higher educations and research

Description of 3 Cases in Vietnam of Aspirin Desensitization in Patients With Coronary Artery Disease and Coexisting Aspirin Hypersensitivity

Aspirin (ASA) hypersensitivity comprises types I to III (Cox-1 mediated) and types IV and V (IgE antibody mediated). Rapid, low-dose (81-325 mg/day) ASA desensitization regimens are known to be useful in establishing ASA tolerance in patients with coronary artery disease and coexisting ASA/nonsteroidal anti-inflammatory drug hypersensitivity. We document 3 cases in Vietnam of desensitization to ASA in patients with coronary artery disease and coexisting ASA hypersensitivity. One of these 3 patients had probable immune-mediated hypersensitivity, whereas the remaining 2 had probable Cox-1-mediated reactions. The regimen of desensitization we employed for each patient was designed to account for the probable mechanism of hypersensitivity in the individual and further modified according to the degree of tolerance observed, with all 3 patients eventually achieving a daily cardioprotective dosage of ASA. Keywords: Vietnam, aspirin (ASA) hypersensitivity, ASA desensitization, coronary artery diseas