Tokyo Denki University
Recent publications
Mood disorders are a major problem in several developed countries (World Health Organization 2004), and the economic losses due to treatment costs and their impact on work are enormous (Kessler et al. 2006). Therefore, a simple method for assessing depression and stress levels is desirable. Screening methods for patients with major depressive disorder include self-administered psychological tests such as the General Health Questionnaire (GHQ) (Goldberg and Blackwell 1970; Goldberg 1978) and Beck Depression Inventory (BDI) (Beck 1961; Beck et al. 1961).
In recent years, with the progress of neuroscience research, the link between depression and arousal has attracted attention. Many studies have been conducted using physiological indices such as EEG (e.g., late positive potential (LPP) amplitude), magnetoencephalography (e.g., neuromagnetic oscillatory activity), skin conductance, and other physiological indicators (Schmidt et al. 2017; Moratti et al. 2008; Benning and Ait 2017).
With the aging of society, the prevalence of dementia and Parkinson’s disease is increasing. Early detection and preventive treatment of these diseases are important to address this problem. Most Parkinson’s patients have some form of movement disorder, and regular visits to the hospital can be burdensome for the patient and their family. It is also estimated that 90% of patients with Parkinson’s disease have some type of speech disorder. Our research aimed to use voice to estimate health status. Voice analysis has the advantage of being noninvasive and can be remotely controlled using a smartphone or other devices. If Parkinson’s disease patients’ conditions can be monitored remotely, it will reduce the burden of patient visits to the hospital.
Traditionally, jitter, shimmer, and harmonic noise ratio (HNR) have been used as indicators of periodic disturbances in voice. Whereas shimmer measures fluctuations in voice loudness, jitter measures fluctuations in voice pitch, which are affected by vocal fold tension and stiffness. HNR is an indicator of the stability of the harmonic structure and indicates the degree of voice disturbance, especially hoarseness. Figure 7.1 shows a schematic of the jitter and the shimmer. Jitter is a measure of how much each period Ti varies, and shimmer is a measure of how much each amplitude Ai varies. If perfectly periodic, both the jitter and shimmer would be zero.
Background This study aimed to investigate the relationship between participation in football and health-related quality of life (HRQOL) in middle-aged and older men in Japan. Methods This was a survey with cross-sectional design. Middle-aged and older men who were registered members of the Japan Football Association as players were recruited (Football group). We also performed an online survey of middle-aged and older men and categorised them into two groups based on questions for this survey about their current engagement in sports/exercise activities (none group and individual sports group). HRQOL was assessed using the 36-Item Short Form Health Survey (SF-36). The physical component summary (PCS) score and mental component summary (MCS) score were calculated based on eight SF-36 subscales. Results The total number of participants in this survey was 5761 (none: 1988; individual sports: 1,776; football: 1997). After adjustment for covariates, PCS scores revealed no differences among groups (none: 51.2±11.1; individual sports: 51.9±8.9; football: 52.1±5.6), although the corresponding subscale scores differed significantly among groups. The football group exhibited significantly higher MCS scores compared with the other groups (none: 48.9±10.1; individual sports: 52.2±9.5; football: 56.2±7.2). The corresponding subscale scores of the MCS were significantly higher in the Football group compared with the other groups. Conclusions Findings suggest that middle-aged and older men who are registered football players had better HRQOL in the mental aspect compared with those without any exercise habits and to those who engage in individual sports, although the cross-sectional design could not establish causality.
Path cover is one of the well-known NP-hard problems that has received much attention. In this paper, we study a variant of path cover, denoted by MPCv4+\hbox {MPC}^{{4}+}_v, to cover as many vertices in a given graph G=(V,E)G = (V, E) as possible by a collection of vertex-disjoint paths each of order four or above. The problem admits an existing O(V8)O(|V|^8)-time 2-approximation algorithm by applying several time-consuming local improvement operations (Gong et al.: Proceedings of MFCS 2022, LIPIcs 241, pp 53:1–53:14, 2022). In contrast, our new algorithm uses a completely different method and it is an improved O(min{E2V2,V5})O(\min \{|E|^2|V|^2, |V|^5\})-time 1.874-approximation algorithm, which answers the open question in Gong et al. (2022) in the affirmative. An important observation leading to the improvement is that the number of vertices in a maximum matching M of G is relatively large compared to that in an optimal solution of MPCv4+\hbox {MPC}^{{4}+}_v. Our new algorithm forms a feasible solution of MPCv4+\hbox {MPC}^{{4}+}_v from a maximum matching M by computing a maximum-weight path-cycle cover in an auxiliary graph to connect as many edges in M as possible.
α,α-Difluoro-β-amino amides are one of the attractive building blocks of biologically active compounds such as fluorinated pharmaceutical mimics and oligopeptides. Herein, we describe zinc-promoted Reformatosky reaction of aldimines using bromodifluoroacetamides...
Mode matching (MM) is a sound field reproduction method based on spherical harmonic expansion. In this study, we propose a higher-order MM method using a limited number of microphones based on the sparse equivalent method. Simulation experiments show that the proposed method achieves a significant improvement in reproduction accuracy.
We present numerical analysis of the lateral movement of a spherical capsule in the steady and pulsatile channel flow of a Newtonian fluid for a wide range of oscillatory frequencies. Each capsule membrane satisfying strain-hardening characteristics is simulated for different Reynolds numbers Re and capillary numbers Ca . Our numerical results showed that capsules with high Ca exhibit axial focusing at finite Re similarly to the inertialess case. We observe that the speed of the axial focusing can be substantially accelerated by making the driving pressure gradient oscillate in time. We also confirm the existence of an optimal frequency that maximises the speed of axial focusing, which remains the same found in the absence of inertia. For relatively low Ca , however, the capsule exhibits off-centre focusing, resulting in various equilibrium radial positions depending on Re . Our numerical results further clarify the existence of a specific Re for which the effect of the flow pulsation to the equilibrium radial position is maximum. The roles of channel size on the lateral movements of the capsule are also addressed. Throughout our analyses, we have quantified the radial position of the capsule in a tube based on an empirical expression. Given that the speed of inertial focusing can be controlled by the oscillatory frequency, the results obtained here can be used for label-free cell alignment/sorting/separation techniques, e.g. for circulating tumour cells in cancer patients or precious haematopoietic cells such as colony-forming cells.
In this paper, we consider the Cauchy problem for the nonlinear Schrödinger equations. In particular, we show the existence of asymptotically free solutions for the dissipative nonlinear Schrödinger equations under mass supercritical setting p1+4/np\ge 1+4/n in n1n\ge 1 space dimensions with data which belong to the weighted Sobolev space H2sFH2γH^s_2\cap {\mathcal {F}} H^\gamma _2 for some s,γ(0,1](0,n/2).s, \gamma \in (0,1]\cap (0,n/2). In previous paper Hoshino (J Differ Equ 266:4997–5011, 2019), the existence of asymptotically free solutions for the dissipative nonlinear Schrödinger equations for some 1+4/(n+2γ)<p<1+4/n1+4/(n+2\gamma )<p<1+4/n in n1n\ge 1 space dimensions with data which belong to the weighted Lebesgue space FH2γ{\mathcal {F}}H^\gamma _2 for some 0<γmin(n/2,1)0<\gamma \le \min (n/2,1) has been studied. The problem for supercritical case remains unresolved. Moreover we show the existence of final state ϕ+H2sFH2γ\phi _+ \in H^s_2\cap {\mathcal {F}}H^\gamma _2 and which is not equal to zero; ϕ+0\phi _+\not =0. This fact gives us new knowledge.
How humans estimate causality is one of the central questions of cognitive science, and many studies have attempted to model this estimation mechanism. Previous studies indicate that the pARIs model is the most descriptive of human causality estimation among 42 normative and descriptive models defined using two binary variables. In this study, we build on previous research and attempt to develop a new descriptive model of human causal induction with multi-valued variables. We extend the applicability of pARIs to non-binary variables and verify the descriptive performance of our model, pARIsmean, by conducting a causal induction experiment involving human participants. We also conduct computer simulations to analyse the properties of our model (and, indirectly, some tendencies in human causal induction). The experimental results showed that the correlation coefficient between the human response values and the values of our model was r = .976, indicating that our model is a valid descriptive model of human causal induction with multi-valued variables. The simulation results also indicated that our model is a good estimator of population mutual information when only a small amount of observational data is available and when the probabilities of cause and effect are nearly equal and both probabilities are small.
The purpose of this paper is to design a path following control system based on the kinematics of the Lizard-Inspired Single-Actuated robot (LISA). LISA is a new type of robot that mimics the quadrupedal walking morphology of lizards with a four-bar linkage mechanism and can realize both propulsion and turning with 1 degree-of-freedom. To achieve this purpose, this paper takes 3 approaches: kinematics formulation, control system design, and numerical simulation. In the kinematics formulation, we formulate LISA’s turning angle, stride length, posture, propulsive direction, curvature, and position coordinate. In control system design, we design a control system that converges not only distance error but also the posture error and control input. Conditional equations that can achieve these 3 control targets are formulated using forward kinematics and reference path functions, and control inputs are obtained by solving the inverse problem. Numerical simulations verify the effectiveness of the designed control system using 3 types of trajectories: linear, circular, and a combination of circular and linear trajectories. As a result, it is confirmed that the designed control system is effective for all 3 types of trajectories and that not only the distance error but also the attitude and control input can be converged.
This study is to propose a timber-steel hybrid beam string structure with local lumbers of general distribution. The proposed system is that local constructors can handle locally grown lumber without special materials or techniques. We obtained the structural performance of this unique construction method through bending experimental tests of individual assembled upper-string members and structural tests and structural analysis of the timber-steel hybrid beam string structure. Findings through this study include the following: ・The bending performance of the joints of the upper chords of laminated timber under wind loads at blowdown and unbalanced snow loads was determined through structural tests. ・An elastic analysis with replacement of beam and spring elements was performed to obtain specifications of sections and joints for various loading conditions. ・Through bending experimental tests on the timber-steel hybrid beam string structure, we considered that the analytical results are compared and the validity of the experimental results.
We present a system for identifying individual penguins in flock images by combining appearance-based penguin detection with RGB images and spectral-based penguin identification with hyperspectral (HS) information. For the spectral-based identification, we propose a classification and ensemble approach inspired by the observation that many animals have similar color patterns. For example, penguins typically have black and white coloration, with consistent color distributions across individuals. The proposed system's effectiveness was experimentally validated with a mean Average Precision (mAP) metric. The proposed Appearance-and-Spectral-Based identification system significantly outperformed conventional appearance-based and spectral-based systems.
In this paper, we propose a method for constructing a gaze direction estimation model using Vision Transformer (ViT) as a fundamental technology for developing input interfaces using eye movement. Eye movement measurement methods using machine learning enable highly accurate estimation but require many computational resources. Therefore, in this paper, we consider a calibration-free and lightweight gaze direction identification model with implementation in gaze input interfaces in mind. The proposed method constructs a gaze direction classification model by fine-tuning a large-scale pre-trained model of ViT using the constructed dataset. The training dataset was constructed by extracting the face region as a still image for each frame from a video image captured by a webcam and then focusing on the area near the eyeball. In addition, we experimented to evaluate the performance of the gaze direction estimation model constructed using the proposed method. As a result of the experiment, the accuracy rate and macro average F-value of the proposed method were approximately 19.0 points higher than the conventional method, and we confirmed the overall improvement of the classification performance under calibration-free.
The organic flexible electronics is an attractive research that wearable human sensing device on human fingernails. Generally, the strain gauge for human sensing is formed on plastic films. Therefore, when fix the film sensor on curved surface such as human nails, it is difficult good contact. In this study, we proposed a process which form patterned film of PEDOT:PSS (Poly(3,4-ethylenedioxythiophene):Poly(4-styrenesulfonate)) on 3D curved plastic curved substrate by micro contact printing method. Moreover, we fabricated strain gauge on flexible polyimide substrate and measured static electrical characteristics. It enables to form patterned film on such as human nails and fabricate strain gauge directly. The results show that direct printed PEDOT:PSS films on curved surface can be used to strain sensor, which leads to monitoring human body by sensing of human nail anytime.
This study analyzes the standardization efforts of specification classification systems in Japan’s construction industry, focusing on historical cases such as the “Universal Building Construction Index” and the “Building Code Index.” It further examines the future directions for information-sharing systems within the industry. Inspired by ISO and Western classification systems, these initiatives aimed to organize and share information. However, limited technology and industry consensus hindered their adoption, with the focus on facet-based formats possibly contributing to this. Technological advances allow data exchange without standard codes, enabling more flexible sharing. The study suggests limited standardization and machine-readable data as practical strategies.
In electric railroads, inverter-controlled vehicles have been used for a long time. In recent years, efficiency of each subsystem of energy-saving traction drive systems has been increased. However, the energy efficiency during operation has not been studied, especially during cruising control. This study developed a method to analyze and reduce powering energy consumption in cruising control based on operation data obtained by an IoT remote monitoring system. The study also showed the achievement of energy saving by performing simulation.
Institution pages aggregate content on ResearchGate related to an institution. The members listed on this page have self-identified as being affiliated with this institution. Publications listed on this page were identified by our algorithms as relating to this institution. This page was not created or approved by the institution. If you represent an institution and have questions about these pages or wish to report inaccurate content, you can contact us here.
609 members
Manabu Ichino
  • School of Science and Engineering
Akira Hirano
  • Department of Communication Engineering
Hiroshi Inaba
  • Division of Informatics (AST)
Koichi Yamazaki
  • School of Science and Engineering
Shigenobu Toné
  • Graduate School of Science and Engineering
Information
Address
Tokyo, Japan