An LMI Framework for Contraction-based Nonlinear Control Design by Derivatives of Gaussian Process Regression

Contraction theory formulates the analysis of nonlinear systems in terms of Jacobian matrices. Although this provides the potential to develop a linear matrix inequality (LMI) framework for nonlinear control design, conditions are imposed not on controllers but on their partial derivatives, which makes control design challenging. In this paper, we illustrate this so-called integrability problem can be solved by a non-standard use of Gaussian process regression (GPR) for parameterizing controllers and then establish an LMI framework of contraction-based control design for nonlinear discrete-time systems, as an easy-to-implement tool. Later on, we consider the case where the drift vector fields are unknown and employ GPR for functional fitting as its standard use. GPR describes learning errors in terms of probability, and thus we further discuss how to incorporate stochastic learning errors into the proposed LMI framework

Modular control under privacy protection:Fundamental trade-offs

In privacy-preserving controller design, there is usually a trade-off between the privacy level and control performances, and we show in this paper that this trade-off in particular determines a lower bound on the differential privacy level of the closed-loop system. The control task we consider is reference tracking in a plug-and-play setting, and the plant under control is a networked system of modules, each of which has no access to the models of the others. For a module, we first identify the whole set of tracking local controllers based on the Youla parametrization. At the same time, each module, to protect its own privacy, tries to prevent the other interconnected modules to identify its private information; in this context, for example, the tracking reference signal (say, the target production amount if each module is a workshop in a factory) can be viewed as a piece of private information. Each module can tune the parameters of its local controller to increase the privacy level of its reference signal. However, if the distribution of Laplace (resp. uniform) noise is fixed, the differential privacy level of a Laplace (resp. uniform) mechanism cannot be further improved from a ceiling value no matter how one tunes parameters. In other words, for modular systems under local reference tracking control, there is a lower bound on the differential privacy level

Modular control under privacy protection:Fundamental trade-offs

In privacy-preserving controller design, there is usually a trade-off between the privacy level and control performances, and we show in this paper that this trade-off in particular determines a lower bound on the differential privacy level of the closed-loop system. The control task we consider is reference tracking in a plug-and-play setting, and the plant under control is a networked system of modules, each of which has no access to the models of the others. For a module, we first identify the whole set of tracking local controllers based on the Youla parametrization. At the same time, each module, to protect its own privacy, tries to prevent the other interconnected modules to identify its private information; in this context, for example, the tracking reference signal (say, the target production amount if each module is a workshop in a factory) can be viewed as a piece of private information. Each module can tune the parameters of its local controller to increase the privacy level of its reference signal. However, if the distribution of Laplace (resp. uniform) noise is fixed, the differential privacy level of a Laplace (resp. uniform) mechanism cannot be further improved from a ceiling value no matter how one tunes parameters. In other words, for modular systems under local reference tracking control, there is a lower bound on the differential privacy level.</p

A Fundamental Performance Limit of Cloud-based Control in Terms of Differential Privacy Level

In this paper, we address a privacy issue raised by cloud based control. In a cloud based control framework, a plant typically has no access to the models of the cloud system and other plants connected via the cloud system. Under restricted information, the plant is required to design its local controller for achieving control objectives. As a control objective, we consider a tracking problem, and for constant reference signals, a class of tracking controllers is identified based on Youla parametrization. More importantly, as local tracking controllers are implemented, there is a possibility that the cloud system or other plants connected via the cloud system may be able to identify private information of the plant by using the collected signal from the plant; for example, the reference signal (say, the target production amount) of the plant can be viewed as a piece of private information. In order to evaluate the privacy level of the reference signal, we employ the concept of differential privacy. For the Laplace mechanism induced by the entire system, we show that the differential privacy level cannot be further improved from a ceiling value for any parameters of the local controller. In other words, there is a performance limit in terms of differential privacy level, which is determined by the plant and cloud system only.</p

Role of Temporal Processing Stages by Inferior Temporal Neurons in Facial Recognition

In this review, we focus on the role of temporal stages of encoded facial information in the visual system, which might enable the efficient determination of species, identity, and expression. Facial recognition is an important function of our brain and is known to be processed in the ventral visual pathway, where visual signals are processed through areas V1, V2, V4, and the inferior temporal (IT) cortex. In the IT cortex, neurons show selective responses to complex visual images such as faces, and at each stage along the pathway the stimulus selectivity of the neural responses becomes sharper, particularly in the later portion of the responses. In the IT cortex of the monkey, facial information is represented by different temporal stages of neural responses, as shown in our previous study: the initial transient response of face-responsive neurons represents information about global categories, i.e., human vs. monkey vs. simple shapes, whilst the later portion of these responses represents information about detailed facial categories, i.e., expression and/or identity. This suggests that the temporal stages of the neuronal firing pattern play an important role in the coding of visual stimuli, including faces. This type of coding may be a plausible mechanism underlying the temporal dynamics of recognition, including the process of detection/categorization followed by the identification of objects. Recent single-unit studies in monkeys have also provided evidence consistent with the important role of the temporal stages of encoded facial information. For example, view-invariant facial identity information is represented in the response at a later period within a region of face-selective neurons. Consistent with these findings, temporally modulated neural activity has also been observed in human studies. These results suggest a close correlation between the temporal processing stages of facial information by IT neurons and the temporal dynamics of face recognition

Diplomacia cultural como forma de exercício de poder: soft power coreano.

O Sistema Internacional atual necessita de um olhar arrojado com novas abordagens perante os argumentos tradicionais. O presente artigo caminha na temática da Diplomacia Cultural, destaca a importância da Cultura para as Relações Internacionais e mostra como ela foi capaz de mudar a percepção de poder no Sistema Internacional. O estudo apresenta o Soft Power (conceito criado por Joseph Nye) e como esse poder contribui para o desenvolvimento socioeconômico sul coreano. O movimento cultural Hallyu Wave é uma peça essencial para o entendimento da renovação sul coreana. Os produtos culturais dessa onda são a materialização do presente Soft Power desenvolvido. O governo por meio de uma política Estatal conseguiu projetar uma melhor imagem de seu país para o mundo, por meio de investimentos em sua cultura pop. A Coreia, foi capaz de reforçar seu posicionamento e assim atrair um maior número de possíveis colaboradores Internacionais. O presente estudo demonstra como crescimento econômico da Coreia foi simultâneo ao investimento em cultura pop. Em seguida será apresentado de forma preliminar o arcabouço teórico da Cultura, Poder Brando e Diplomacia Cultural. Sucessivamente é fornecido um panorama do fenômeno da Onda Coreana e esmiuçado seus produtos pop culturais com seu alcance. O texto defenderá que a promoção e investimento cultural são capazes de oferecer novas formas de relações entre agentes globais e uma nova perspectiva a respeito da política internacional. A Coreia do Sul foi um exemplo de como a Política Cultural é capaz de reestruturar e desenvolver as potencialidades de uma nação

Lipid Rafts: Keys to Sperm Maturation, Fertilization, and Early Embryogenesis

Cell membranes are composed of many different lipids and protein receptors, which are important for regulating intracellular functions and cell signaling. To orchestrate these activities, the cell membrane is compartmentalized into microdomains that are stably or transiently formed. These compartments are called “lipid rafts”. In gamete cells that lack gene transcription, distribution of lipids and proteins on these lipid rafts is focused during changes in their structure and functions such as starting flagella movement and membrane fusion. In this paper, we describe the role of lipid rafts in gamete maturation, fertilization, and early embryogenesis

Sensory-to-motor processing of the ocular-following response.

Abstract The ocular-following response is a slow tracking eye movement that is elicited by sudden drifting movements of a large-field visual stimulus in primates. It helps to stabilize the eyes on the visual scene. Previous single unit recordings and chemical lesion studies have reported that the ocular-following response is mediated by a pathway that includes the medial superior temporal (MST) area of the cortex and the ventral paraflocculus (VPFL) of the cerebellum. Using a linear regression model, we systematically analyzed the quantitative relationships between the complex temporal patterns of neural activity at each level with sensory input and motor output signals (acceleration, velocity, and position) during ocular-following. The results revealed the following: (1) the temporal firing pattern of the MST neurons locally encodes the dynamic properties of the visual stimulus within a limited range. On the other hand, (2) the temporal firing pattern of the Purkinje cells in the cerebellum globally encodes almost the entire motor command for the ocular-following response. We conclude that the cerebellum is the major site of the sensory-to-motor transformation necessary for ocular-following, where population coding is integrated into rate coding.

シカヨウ レーザー ノ リンショウ オウヨウ ニツイテ

Several types of lasers have been developed and tried to be clinically applied to the oral area. Lasers have been used for various clinical practices, diagnosis and prevention of dental caries, treatment for periodontal disease, hypersensitive dentin, relieving pain, and root canal infections. The Er:YAG laser is the only dental laser that has the potential to ablate both dental hard tissue and soft tissue. In this report, I introduce the practical procedure of some cases using the Er:YAG laser, and discuss the utility of Er:YAG laser application on oral soft tissue or hard tissue