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A study on stability analysis of biochemical reaction system with negative feedback regulation
Takashi Nakakuki 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10
In this paper, stability of a biochemical reaction system with negative feedback regulation is considered. It is well known that such a system induces a Hopf bifurcation depending on an input level or kinetic parameters. Although the eigenvalue analysis is a powerful method for evaluating the bifurcation and the stability, applying the method to a highdimensional system with many nonlinear rate equations would be a troublesome task in model-based analysis since many hand-calculations of partial differentiation are needed to obtain a Jacobian matrix. Then, a simple and straightforward method based on Nyquist criterion is proposed. The method is a kind of describing function method, and the vector locus for the Nyquist criterion is drawn computationally by performing frequency response test for equivalent transfer function of the open loop system.
KATAYAMA, Masaki,NAKAKUKI, Jun,PEE, Jae-Hwan,KOBAYASHI, Yuichi Ceramic Society of Japan 2013 JOURNAL OF THE CERAMIC SOCIETY OF JAPAN - Vol.121 No.1419
<P>Cordierite ceramics were prepared from several types of kaolin powders and talc powders having various median particle size with nanometer-sized alumina sol. Powder mixtures were uniaxially pressed, followed by cold isostatic pressing to make thin compacts. Crystal orientation of talc particle and resultant cordierite were evaluated using the X-ray diffraction profile measured on the uniaxially pressed surface of calcined compacts and sintered compacts, respectively. Coarser talc powders above 3 mu m aligned their c-axis in vertical to the uniaxially pressed surface of the calcined compact during uniaxially pressing, owing to highly anisotropic tabular shape. The crystal orientation of resultant cordierite increased with an increase in the crystal orientation of talc powders on the pressed surface. This result indicated that the c-axis of cordierite crystal preferably oriented vertically to the c-axis of talc particle oriented. Using the combination of kaolin powders below 5 mu m and talc powders having median particle size between 3 and 5 mu m, densely sintered cordierite, having a relative density of 95% and high crystal orientation of approximately 85% [I-110/(I-110+I-002)], could be obtained. (C)2013 The Ceramic Society of Japan. All rights reserved.</P>
Stability Analysis of Wnt-ERK cellular signalling by using Nyquist Criterion
Taisei Hidaka,Takashi Nakakuki 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10
We have previously reported an analysis method for intracellular signal transduction systems by using Nyquist criterion in which we provided a proof-of-principle study with the Goodwin oscillator as a simple model that is a threedimensional small system with a negative feedback regulation. In this study, we try to apply our method based on Nyquist criterion to a practical cancer cell signalling model on the Wnt-ERK pathway that is a 31-dimensional ordinary differential equation system with the six multiple feedback regulations. In this study, two different feedback loops that are mediated by a same signalling molecule are investigated. By applying our method to the analysis of each feedback loop independently, the effect of them on the stability of the whole system is compared.
Linear time-varying modeling of inter-organ regulatory system
Daisuke Eto,Takashi Nakakuki,Jun-ichi Imura 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11
In this study, we propose a linear time-varying model of the inter-organ regulatory system. It is well-known that the regulation of energy metabolism is highly controlled by complex metabolic pathways coupled among various organs. On the other hand, a malfunction of this regulatory system can induce various pathological conditions related to the metabolic syndrome, implying that homeostasis of energy expenditure in the inter-organ regulatory system can be treated as a control problem, given an appropriate mathematical model. Moderately abstracting the complex mechanisms and maintaining the comprehensiveness of the inter-organ networks, we construct a simple model comprised of 16 states and 31 rate equations. Since our model is described as a linear time-varying system, it is expected that various control theories can be applied for the model-based analysis of the inter-organ regulatory system.
Development of drinking support device for spinal cord injuries to enhance quality of life
Ayano Tanishima,Takashi Nakakuki,Hiroto Noguchi,Takashi Kanamaru 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10
Spinal cord injury causes a paralysis of any part of the body depending on which part of spinal cord is destroyed. It is well known that a severity of the paralysis is determined by both a location and a degree of injury in the vertebral bones. For example, in a case of injury at the C4 vertebral bone a patient is paralyzed from the neck down, and needs a caregiver to help almost all activities of daily life. Recently, a quality of life is considered to be important, and various welfare devices have been proposed to realize a better life of a patient. Regarding a C4 patient, drinking water by oneself whenever he/she wants to do is strongly desired in the daily life. In this paper, we develop a drinking support device for a C4 patient. The device is evaluated in a rehabilitation hospital, and it is shown that all requirements on structure, degree of freedom, safety, conform, daily maintenance, etc. are satisfied with an acceptable level.
A study on a waist power assist suit for a caregiver to prevent lower back pain
Yoshitoshi Ikeya,Takashi Nakakuki 제어로봇시스템학회 2013 제어로봇시스템학회 국제학술대회 논문집 Vol.2013 No.10
We currently develop a waist power assist suit for a caregiver that physically supports his/her lifting and twist motions to prevent lower back pain. In our earlier studies, a DC motor-driven mechanism has been proposed where two motors that are attached at both sides of lower back generate the assistive torque for a lifting motion by driving them in the same direction, and for a twist motion by driving them in different directions. In this paper, we address to reduce the suit weight, refine the design, and to improve how to put on the suit. Regarding a signal processing for motion recognition, we also have studied a surface EMG-based signal processing with support vector machine. Although the recognition rate with the sensing system is promising off-line, the algorithm is quite complicated for implementation to a microcomputer. In this paper, we propose a simple signal processing for motion recognition based on surface EMG.
Frequency Response Analysis of Large-Scale Biological Systems
Takaaki Moriyama,Takashi Nakakuki 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10
In this paper, we propose an analysis method for a complicated and huge biological system. As a target system, we employ a newly published signal transduction system with transcriptional control. Our method is based on a extension of frequency response analysis. Since an output response depends on both frequency and amplitude of input signal, we straightforward construct a Bode-like diagram using three-dimensional space regarding frequency, amplitude and evaluation value. We also propose that a ratio of L2 norms between input and output signals is good to use for an evaluation value.
Analysis of Gene Network in MCF-7 Human Breast Cancer Cells
Ryohei Shiraishi,Takashi Nakakuki 제어로봇시스템학회 2012 제어로봇시스템학회 국제학술대회 논문집 Vol.2012 No.10
Recent technological progress on high-throughput measurements for gene expression such as microarray analysis enables us to collect time-series gene expression data for each of tens of thousands of genes. Although a genomic analysis with those data has identified key genes relating to various diseases, few results on estimation of gene regulatory networks with real microarray data are available so far. Recently, the immediately early response (IER) genes upon epidermal growth factor stimulation in a human breast cancer cell line, MCF-7, have been identified in which time-course microarray data were measured during 90 minutes and 63 IER genes were chosen from tens of thousands of genes by using statistical analysis. In this paper, we estimate the gene regulatory networks among the 63 IER genes. To this end, we apply an estimation method based on a mixed logic dynamical modeling developed in an earlier study to the microarray data. However, the original method is executable for continuous gene expression time-series data whereas the real microarray time-course data have very few time points. In addition, some presetting parameters in the model are critical for a successful result on a network estimation. Then, we add a preprocessing and Monte Carlo-based calculation for the original method.
Design method for biomolecular circuit with plasticity
Kenta Hidaka,Takashi Nakakuki 제어로봇시스템학회 2021 제어로봇시스템학회 국제학술대회 논문집 Vol.2021 No.10
In this paper, we propose a design method for a biomolecular circuit that can dynamically change its function according to repetitive input stimuli. In DNA computing, which involves the construction of a DNA reaction system that executes desired information processing, the circuit function strongly depends on the network structure and reaction rate parameters of the chemical reaction system. In other words, it is necessary to design a DNA circuit specialized for a specific circuit function. We aimed to achieve “plasticity” of the DNA circuit by addressing the motivating example; for a two-input one-output DNA circuit, its function is initially YES logic but turns to OR logic as the repetitive input stimuli are given. Our proposed method was verified by numerical simulations based on reaction kinetics while utilizing dependable computer-aided software.