Communication control mechanism to adapt the quality change of a communication channel

2002 ◽  
Vol 85 (11) ◽  
pp. 1-12
Author(s):  
Hideo Taniguchi ◽  
Yusuke Noguchi ◽  
Yoshinari Nomura
2021 ◽  
Vol 141 (12) ◽  
pp. 1241-1249
Author(s):  
Takahiro Yoshida ◽  
Minoru Matsuoka ◽  
Hidekazu Suzuki

2012 ◽  
Vol 2 (3) ◽  
pp. 1-10
Author(s):  
Kazuya Odagiri ◽  
Shogo Shimizu ◽  
Naohiro Ishii

As the work for managing a whole LAN effectively withoutlimited purposes, there are works of Policy-based networkmanagement (PBNM). The existing PBNM is defined in someorganizations including the Internet Engineering Task Force(IETF). However, it has structural problems. For example,communications sent from many clients concentrate on acommunication control mechanism called PEP (PolicyEnforcement Point). To improve the problems, we have beenstudying next generation PBNM called Destination AddressingControl System (DACS) Scheme. The DACS Scheme controlsthe whole LAN through communication control by the clientsoftware as PEP which locates on a client computer. We havebeen studied on the aspect of principle until now. In thisresearch, we implement a DACS system to realize a concept ofthe DACS Scheme, and show implement method and results offunctional experiments.


Author(s):  
D. Van Dyck

An (electron) microscope can be considered as a communication channel that transfers structural information between an object and an observer. In electron microscopy this information is carried by electrons. According to the theory of Shannon the maximal information rate (or capacity) of a communication channel is given by C = B log2 (1 + S/N) bits/sec., where B is the band width, and S and N the average signal power, respectively noise power at the output. We will now apply to study the information transfer in an electron microscope. For simplicity we will assume the object and the image to be onedimensional (the results can straightforwardly be generalized). An imaging device can be characterized by its transfer function, which describes the magnitude with which a spatial frequency g is transferred through the device, n is the noise. Usually, the resolution of the instrument ᑭ is defined from the cut-off 1/ᑭ beyond which no spadal information is transferred.


Author(s):  
Edna S. Kaneshiro

It is currently believed that ciliary beating results from microtubule sliding which is restricted in regions to cause bending. Cilia beat can be modified to bring about changes in beat frequency, cessation of beat and reversal in beat direction. In ciliated protozoans these modifications which determine swimming behavior have been shown to be related to intracellular (intraciliary) Ca2+ concentrations. The Ca2+ levels are in turn governed by the surface ciliary membrane which exhibits increased Ca2+ conductance (permeability) in response to depolarization. Mutants with altered behaviors have been isolated. Pawn mutants fail to exhibit reversal of the effective stroke of ciliary beat and therefore cannot swim backward. They lack the increased inward Ca2+ current in response to depolarizing stimuli. Both normal and pawn Paramecium made leaky to Ca2+ by Triton extrac¬tion of the surface membrane exhibit backward swimming only in reactivating solutions containing greater than IO-6 M Ca2+ Thus in pawns the ciliary reversal mechanism itself is left operational and only the control mechanism at the membrane is affected. The topographic location of voltage-dependent Ca2+ channels has been identified as a component of the ciliary mem¬brane since the inward Ca2+ conductance response is eliminated by deciliation and the return of the response occurs during cilia regeneration. Since the ciliary membrane has been impli¬cated in the control of Ca2+ levels in the cilium and therefore is the site of at least one kind of control of microtubule sliding, we have focused our attention on understanding the structure and function of the membrane.


1974 ◽  
Vol 32 (01) ◽  
pp. 057-064 ◽  
Author(s):  
Y Nemerson ◽  
S.A Silverberg ◽  
J Jesty

SummaryTwo reactions of the extrinsic pathway of coagulation, the activations of Factor X and prothrombin, have been studied in purified systems and shown to be self-damping. Factor X was activated by the tissue factor - Factor VII complex, and prothrombin by two systems: the coagulant protein of Taipan venom, and the physiological complex of activated Factor X, Factor V, lipid, and calcium ions. In each case the yield of enzyme, activated Factor X or thrombin, is a function of the concentration of activator. These and other observations are considered as a basis for a control mechanism in coagulation.


2020 ◽  
pp. 65-72
Author(s):  
V. V. Savchenko ◽  
A. V. Savchenko

This paper is devoted to the presence of distortions in a speech signal transmitted over a communication channel to a biometric system during voice-based remote identification. We propose to preliminary correct the frequency spectrum of the received signal based on the pre-distortion principle. Taking into account a priori uncertainty, a new information indicator of speech signal distortions and a method for measuring it in conditions of small samples of observations are proposed. An example of fast practical implementation of the method based on a parametric spectral analysis algorithm is considered. Experimental results of our approach are provided for three different versions of communication channel. It is shown that the usage of the proposed method makes it possible to transform the initially distorted speech signal into compliance on the registered voice template by using acceptable information discrimination criterion. It is demonstrated that our approach may be used in existing biometric systems and technologies of speaker identification.


2019 ◽  
Vol 41 ◽  
pp. 53-62
Author(s):  
I. A. Batyrev ◽  
◽  
S. M. Dobrovolskiy ◽  
A. M. Semenov ◽  
Yu. F. Strugov ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document