Comments on “A Multi-factor User Authentication and Key Agreement Protocol Based on Bilinear Pairing for the Internet of Things”

Wireless Personal Communications - The Internet of Things (IoT) presents a new paradigm of the future internet that intends to provide interactive communication between various processing object...     

Notes on “A Temporal-Credential-Based Mutual Authentication and Key Agreement Scheme for Wireless Sensor Networks”

Xue et al. recently proposed an innovative mutual authentication and key agreement scheme for wireless sensor networks based on temporal credential using smart cards. However, in this paper we demonstrate that their scheme is vulnerable to password guessing attacks, node capture attacks and denial-of-service attacks. Furthermore we show that their scheme has some inconsistencies which make it less secure and more computationally costly than originally presented.     

Secure and Efficient Mutual Adaptive User Authentication Scheme for Heterogeneous Wireless Sensor Networks Using Multimedia Client–Server Systems

In hierarchical wireless sensor networks (H-WSNs), adaptive user authentication scheme has attracted significantly for the purposes of mutual authentication, session key establishment and resiliency to the attacks, like impersonation, parallel-session and password guessing. Several user authentication schemes have been proposed recently; though the schemes have had many potential vulnerabilities, such as key-impersonation, user anonymity, eavesdropping and masquerade. Thus, this paper proposes secure-cum-efficient mutual adaptive user authentication (S-Cum-EMAUA) scheme for practical use in H-WSNs. The scheme of S-Cum-EMAUA) is not only resilient to the most of the potential attacks, but also provides mutual authentication, user anonymity and session-key establishment. In addition, the proposed scheme is well secured, since it has the usage of the hash-function and X-OR operation.

     

On the Form Invariance and Lie Symmetry of Birkhoffian Systems

The conservation laws (of first integrals) of mechanical systems are always of mathematical importance, and they are regarded as a manifestation of some profound physical principle. The modern means of finding conservation laws are mainly Noether symmetry and Lie symmetry. The Noether symmetry is an invariance of Hamiltonian action under the infinitesimal transformations of time and the coordinates. The Lie symmetry is an invariance of the differential equations of motion under the infinites…     

On the Capacity Degradation Due to Coexistence of WCDMA and CDMA2000 Systems

In this paper,we investigate the capacity degradation due to the coexistence of WCDMA and CDMA2000 net-works by system-level Monte Carlo simulation.Both systems are simulated according to the deployment of macro cells,andspeech service is considered.The capacity losses under different carrier spacing and different geographical offset are evalu-ated.Simulation results show that considerable capacity loss is seen when WCDMA is the victim system,while the influ-ence of WCDMA to CDMA2000 is slight.Increasing carrier-to-carrier spacing and decreasing geographical offset lead toless capacity loss and co-locating the base stations of both systems is a preferred solution.     

Implementation of the Broad-band User Access Network and the Study of the Key Algorithm for Improving the Performance of Asymmetrical Networks

Implementation of the Broad-band User Access Network and the Study of the Key Algorithm for Improving the Performance of Asymmetrical Networks     

Performance Modeling of the Fast and Reliable Two-Layer Retransmission for CDMA Systems

1　Introduction　With the proliferation of the World Wide Web (WWW)in our daily life, a number of wireless data services[1] suchas voice, audio, video streaming, file and web downloadingalso need to be supported in the wireless access networks.To bring the WWW traffic to the wireless mobile devices, itis important that a suitable protocol or standard is chosen tocater to the growing demands of data services over wirelesschannels which could handle a wide variety of multimediatraffic with …     

On measuring the permittivity of “living” wood for microwave remote sensing

A procedure for measuring the permittivity of “living” wood is proposed. The permittivity of the trunk of a growing tree ε ₁ ^* has been measured by this procedure. Simultaneously, samples of wood of the same tree have been taken and their permittivities ε ₀ ^* determined under laboratory conditions. The obtained values has been compared, and considerable disagreement between measured ε ₁ ^* and ε ₀ ^* has been revealed. The study has been performed to model the reflection of microwaves from the forest.     

Implementation of the Broad band User AccessNetwork and the Study of the Key Algorithm for Improving the Performance of Asymmetrical Networks

This thesis is based on the design and development of ADSL access networks. We h ave completed the hardware and software functions in two main ADSL equipments: A TU C and ATU R. With the system design, we carry out researches to find out ef fective methods to improved performance in the following aspects: (a) how to all ocate limited bandwith among services with different QoS requirements and (b) what is the effect of asymmetric links on TCP end to end flow control mech anism. We make detailed analyses and propose useful solutions to those problems we find. The main contents of this thesis are as follows: (1) the design and rea l ization of ADSL access system. This part includes the principles of ADSL access technology, ADSL broadband access network architecture, and ATM over ADSL protoc ol models that we use in our system. We give detailed hardware and software desi gn steps in this part, and list system testing results to show the system perfor mance. In our hardware, the CPU is a RISC microprocessor. Combined with a high speed digital signal processor, the whole system can hold high reliability. Our software design platform is a Psos multi task real time operation system. We h ave developed a series of hardware drivers besides other tasks for high level co ntrol and interruption processing. Currently, our system has reached the expecte d performance under test environment. Our next step is the development of DSLAM and in this part we give a feasible design scheme. (2) Packet scheduling policy I n ADSL system. In order to optimize ATU R performance, we need a scheduling pol icy to regulate the order and number of packet output to the uplink. For this pu rpose, we study the scheduling algorithm design methods in a single network node and their performance. After studying the existing algorithms carefully, we fir st conclude certain important design principles and criterions for scheduling po licy evaluation. And then by using service curve function, we make detailed perf ormance analysis of a typical scheduling policy — the earliest deadline first. The advantage of characterizing service by using a function is that the service curve can provide a wide spectrum of service characterization. With this method, we first develop a generalized algorithm for calculating the deadlines used in the service curve based on the earliest deadline first policy, and then design a simplified computing program for an important curve. After that, holding fair b andwidth allocation and packet deadline guarantee as policy evaluation standards , we analyze this scheduling policy performance and propose solutions to those p roblems that we find. Finally, we, in theory, prove these improving algorithms. All these solutions and algorithms we design in this part are now under developm ent in real systems and will enhance system performance. (3) Effects of asymmetr I c links on TCP performance and solutions. TCP is a widely used transmission cont rol protocol. It regulates its forward data sending through reverse ACKs. What a re the new problems to its flow control mechanism on asymmetric links and how to solve them are the two main points of this part. We first study the relationshi p between normalized bandwidth ratio, link buffer capacity and TCP link throughp ut under asymmetric link models. We find that TCP ack transportation on slow bac kward link is a key reason that causes the problems in TCP asymmetric links. Ser ving this as a start point, we present several improving solutions to TCP flow c ontrol algorithm and test them through simulation. Besides, TCP has been widely implemented in many networks. To give compatibility with current TCP end users, we use scheduling solutions to regulate data packet and ack packet transmission ratio onto uplinks. In the theoretical analysis of several typical scheduling po licies, we find a feasible algorithm to control TCP data efficiency on asymmetri c links. Finally, we prove those analyses and propose algorithm through simulati on.     

Address for the Beginning Issue of “RFID Technologies and Applicationsn”

Recently RFID technology got a widely attentions. As a result of this, RFID Technology and Application is published as the first professional RFID publication mainly issuing in the China and Hong Kong, Macao and Taiwan. This article summarizes the RFID characteristic, suitable applied field and its development situation and its developing reason in Asia-Pacific area. The article also presents the Magazine's target and goal, column and the future perspective.     

Joint Frequency Offset and Channel Estimation for MIMO Systems in the Presence of Timing Error

This paper deals with the problem of joint frequency offset (FO) and channel estimation for multi-input multi-output (MIMO) systems in the presence of a timing error. Two equivalent signal models with FO and a timing error are given, and then a joint estimation method is derived. The proposed estimation method consists of two steps. Firstly, a maximum likelihood (ML) FO estimator is proposed based on the second signal model. Secondly, based on the FO estimate, we formulate the timing error and channel estimation as a problem of composite hypothesis testing according to the first signal model, and then solve the problem using a composite hypothesis testing approach. Simulation results are performed to show the effectiveness of the proposed method.     

On the Electret Effect in Polymer–Ferroelectric Piezoceramic Composites with Various Values of the Electronegativity of the Polymer Matrix and Piezophase Cations

The influence of the electronegativity of phases, which is controlled by composite crystallization under the conditions of the effect of the electric discharge and covalence of piezophase cations, on the formation mechanism of the stable electret effect is determined. The specific features of the formation of the electret effect in composites based on polyolefins (HDPE, PP), fluorine-containing polymers (F42), and ferroelectric piezoelectric ceramics of the family of lead zirconate–titanate (Pb(Zr,Ti)O₃) crystallized under conditions of the effect of electric discharge plasma, are revealed. A physical model of electret composites taking into account the role of homocharges and heterocharges formed in a composite by its dispersion with piezoceramic particles of various structures—rhombohedral, tetragonal, and heterogeneous—is proposed.     

Robust Fault Estimation and Accommodation for a Class of T–S Fuzzy Systems with Local Nonlinear Models

This paper focuses on the problems of fault estimation and accommodation for a class of T–S fuzzy systems with local nonlinear models and having an external disturbance and sensor and actuator faults, simultaneously. A fuzzy robust fault estimation observer is designed to estimate the system state and sensor and actuator faults. Compared with existing results, the observer not only is robust to the disturbance but also has a wider application range and more freedom for design. To compensate for the effect of faults and to stabilize the closed-loop system, an observer-based fault-tolerant controller is proposed. The separate design of the observer and controller avoids coupling between them. Finally, a simulation is conducted to demonstrate the effectiveness of the proposed method.     

On the Fabrication of Graphene p–n Junctions and Their Application for Detecting Terahertz Radiation

Semiconductors - A new method for the formation of lateral p–n junctions in epitaxial graphene with the use of UV (ultraviolet) radiation is considered. The UV illumination method makes it...     

On a “central inequality” in the theory of input-output systems

In the stability and sensitivity theory of general, nonlinear input-output systems we encounter a certain inequality concerning solely the nominal system that plays a central role in the whole theory. In particular, this central inequality, combined with other assumptions, implies (a) stability of the nominal system, (b) robustness, and (c) insensitivity of the input-output system. This paper presents conditions equivalent to this central inequality, and a further result on the stability-robustness problem.     

Transformable “Tubulin Traps” Interfere with Mitochondrial Autophagy and Promote the Elimination of Glioblastoma

Protective autophagy of mitochondria is an important cause of high mortality in glioblastoma (GBM). Because of its serious impact on the treatment effect, it is in urgent need of combined treatment. Based on the regulatory function of the tubulin system on autophagy and inspired by the natural characteristics of neurofilament regulating tubulin polymerization, an in situ self-assembled “tubulin trap” is designed. Specifically, the system is a transformable block polymer, which can self-assemble into spherical nanoparticles in water. After targeting GBM cells, they can transform into nanofibers under the intracellular GSH conditions, interfering with autophagy. The research shows that, in mouse GBM xenograft models, the transformable nanofibers with the function of destroying tubulin homeostasis can be combined with ceramide in the treatment of GBM.