Machine-to-machine (M2M) communication networks consist of resource-constrained autonomous devices, also known as autonomous Internet of things (IoTs) or machine-type communication devices (MTCDs) which act as a backb...Machine-to-machine (M2M) communication networks consist of resource-constrained autonomous devices, also known as autonomous Internet of things (IoTs) or machine-type communication devices (MTCDs) which act as a backbone for Industrial IoT, smart cities, and other autonomous systems. Due to the limited computing and memory capacity, these devices cannot maintain strong security if conventional security methods are applied such as heavy encryption. This article proposed a novel lightweight mutual authentication scheme including elliptic curve cryptography (ECC) driven end-to-end encryption through curve25519 such as (i): efficient end-to-end encrypted communication with pre-calculation strategy using curve25519;and (ii): elliptic curve Diffie-Hellman (ECDH) based mutual authentication technique through a novel lightweight hash function. The proposed scheme attempts to efficiently counter all known perception layer security threats. Moreover, the pre-calculated key generation strategy resulted in cost-effective encryption with 192-bit curve security. It showed comparative efficiency in key strength, and curve strength compared with similar authentication schemes in terms of computational and memory cost, communication performance and encryption robustness.展开更多
This article deals with a linear classical approach for the robust output reference trajectory tracking control of nonlinear SISO Lagrangian systems with a controllable(fAat)tangent linearization around an operating e...This article deals with a linear classical approach for the robust output reference trajectory tracking control of nonlinear SISO Lagrangian systems with a controllable(fAat)tangent linearization around an operating equilibrium point.An endogenous injections and exogenous feedback(EIEF)approach is proposed,which is naturally equivalent to the generalized propor-tional integral control method and to a robust classical compensation network.It is shown that the EIEF controller is also equivalent,within a frequency domain setting demanding respect for the separation principle,to the reduced order observer based active disturbance rejection control approach.The proposed linear control approach is robust with respect to total dis-turbances and,thus,it is ffective for the linear control of the nonlinear Lagrangian system.An ilustrative nonlinear rotary crane Lagrangian system example,which is non-feedback linearizable,is presented along with digital computer simulations.展开更多
Vaginal infections are suffered by millions of women of reproductive age. Recent research has shown that timely diagnosis of these infections avoids complications in the patient’s health. Since the symptoms of infect...Vaginal infections are suffered by millions of women of reproductive age. Recent research has shown that timely diagnosis of these infections avoids complications in the patient’s health. Since the symptoms of infections caused by yeast and bacteria are similar, the patient is not always treated properly. Membranes with three different thicknesses (66 μm, 83 μm, 128 μm) were produced by electrospinning of polylactic polymer (PLA) and were used as a biological sieve to detect microorganisms present in vaginal infections, bacteria or yeasts. Electrospinning technique is a technique that allows the generation of membranes from nanofibers of material polymeric and therefore, obtaining porous structures. The size of the fibers was observed as well as the morphology and the size of the pores, using the scanning electron microscopy (SEM). The effectiveness of these membranes was proven by the cultivation of the bacteria that passed through the polymeric membrane and the yeasts retained by it. The membranes allowed the retention of yeasts of Candida albicans type with dimensions of 7 μm, which allowed the separation of Brevibacterium ravens purgense bacteria with dimensions of 1.4 μm, thus demonstrating their effectiveness as biological sieve.展开更多
文摘Machine-to-machine (M2M) communication networks consist of resource-constrained autonomous devices, also known as autonomous Internet of things (IoTs) or machine-type communication devices (MTCDs) which act as a backbone for Industrial IoT, smart cities, and other autonomous systems. Due to the limited computing and memory capacity, these devices cannot maintain strong security if conventional security methods are applied such as heavy encryption. This article proposed a novel lightweight mutual authentication scheme including elliptic curve cryptography (ECC) driven end-to-end encryption through curve25519 such as (i): efficient end-to-end encrypted communication with pre-calculation strategy using curve25519;and (ii): elliptic curve Diffie-Hellman (ECDH) based mutual authentication technique through a novel lightweight hash function. The proposed scheme attempts to efficiently counter all known perception layer security threats. Moreover, the pre-calculated key generation strategy resulted in cost-effective encryption with 192-bit curve security. It showed comparative efficiency in key strength, and curve strength compared with similar authentication schemes in terms of computational and memory cost, communication performance and encryption robustness.
基金The work of M.A.Aguilar-Orduia and B.C.Gomez-Leon was supported by Consejo Nacional de Ciencia y Tec-nologia(CONACYT)Mexico under Scholarship Grants no.702805 and no.1039577,respectively.
文摘This article deals with a linear classical approach for the robust output reference trajectory tracking control of nonlinear SISO Lagrangian systems with a controllable(fAat)tangent linearization around an operating equilibrium point.An endogenous injections and exogenous feedback(EIEF)approach is proposed,which is naturally equivalent to the generalized propor-tional integral control method and to a robust classical compensation network.It is shown that the EIEF controller is also equivalent,within a frequency domain setting demanding respect for the separation principle,to the reduced order observer based active disturbance rejection control approach.The proposed linear control approach is robust with respect to total dis-turbances and,thus,it is ffective for the linear control of the nonlinear Lagrangian system.An ilustrative nonlinear rotary crane Lagrangian system example,which is non-feedback linearizable,is presented along with digital computer simulations.
文摘Vaginal infections are suffered by millions of women of reproductive age. Recent research has shown that timely diagnosis of these infections avoids complications in the patient’s health. Since the symptoms of infections caused by yeast and bacteria are similar, the patient is not always treated properly. Membranes with three different thicknesses (66 μm, 83 μm, 128 μm) were produced by electrospinning of polylactic polymer (PLA) and were used as a biological sieve to detect microorganisms present in vaginal infections, bacteria or yeasts. Electrospinning technique is a technique that allows the generation of membranes from nanofibers of material polymeric and therefore, obtaining porous structures. The size of the fibers was observed as well as the morphology and the size of the pores, using the scanning electron microscopy (SEM). The effectiveness of these membranes was proven by the cultivation of the bacteria that passed through the polymeric membrane and the yeasts retained by it. The membranes allowed the retention of yeasts of Candida albicans type with dimensions of 7 μm, which allowed the separation of Brevibacterium ravens purgense bacteria with dimensions of 1.4 μm, thus demonstrating their effectiveness as biological sieve.
