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The issue of security in fog has several challenges and one of which is to create a secure channel that connects fog layer to the end devices. Therefore, efficient and secure key distribution is very important to create this channel. One solution is key pre-distribute that the keys generation and distribution between nodes are before the network establishment. This article presents an algorithm for key pre-distribution in fog networks that focuses on the relationship between end devices and the fog layer. The proposed scheme is a hybrid scheme that uses the K-MEANS algorithm for nodes hierarchical clustering. Then the residual design is used to generate the key chain and BIBD design is used for key pre-distribution in headers. The proposed method is completely independent of the mobility model of and its communication and computation overheads are of the order of O(q). Also, the network connectivity is above 0.8 and close to the BIBD design, which is a fully connected KPS, and the probability of capturing the entire network in case of capturing the nodes is almost equal to 0. In the proposed method for a network with size N, the size of the key chain is N 4. [ABSTRACT FROM AUTHOR]

The high-performance CPU is taken as processors and Vxworks is taken as the design kernels for most flight control systems, which has the problems of high cost, large size and non-disclosure of kernel source code. A low-cost and reliable flight control system for a small UAV is designed. A flight control hardware system consisting of micro-controller, various sensors and actuators is developed based on STM32F4 to realize the control of attitude and rudder position. FreeRTOS embedded real-time operating system with open source code is introduced as software platform to develop flight control software, so as to realize the functions of flight control, autonomous navigation and flight management. The flight control system is validated by flight test of fixed-wing aviation model. The results show that the designed system has high stability, high control accuracy and fast response.

The usual procedure for indentifying the block design to be connected is rank of C matrix (information matrix) should be (v - 1), if this violates then design becomes disconnected. Several authors obtained robustness criteria against the loss of one block or more than one blocks based on connected property. Because connectedness is one of the important criteria to find the robustness of the residual design. Tsai and Liao (2013) discussed the minimum break down criteria and connectedness criteria of block design to obtain the robust design against the lost of whole block. In this investigation, we have developed other criteria, which is alternate method of Tsai and Liao (2013) to find connectedness of the block design based on block information matrix, Fd of the block design of size two. Further, we have also observed as numbers of blocks are being deleted, the overall A-efficiency of the residual design decreases. [ABSTRACT FROM AUTHOR]

The dual codes of the ternary linear codes of the residual designs of biplanes on 56 points are used to prove the nonexistence of quasisymmetric 2‐(56,12,9) and 2‐(57,12,11) designs with intersection numbers 0 and 3, and the nonexistence of a 2‐(267,57,12) quasi‐3 design. The nonexistence of a 2‐(149,37,9) quasi‐3 design is also proved. [ABSTRACT FROM AUTHOR]

Geographic routing protocols in wireless sensor networks require providing location information of sinks to source nodes. Most studies have only focused on two-dimensional (2D) sensing field, but the real-world applications of sensor networks are in a three-dimensional (3D) environment. This paper presents a new scheme based on residual design principles for 3D networks. In this scheme, sink location announcement (SLA) and sink location query (SLQ) packets are forwarded along two blocks. The node located at the intersection of the two blocks sends the sink position to the source. In the proposed method, SLA and SLQ messages constructed using residual design blocks. For this purpose, the mapping from residual design to sink location service have been proposed. In order to analyze proposed algorithm's performance, a series of simulations have been conducted using the NS-2 network simulator. Simulation results indicate that proposed algorithm can significantly reduce the communication overhead and energy consumption. [ABSTRACT FROM AUTHOR]

The anti-lock braking system (ABS) is an essential part in ensuring safe driving in vehicles. The Security of onboard safety systems is very important. In order to monitor the functions of ABS and avoid any malfunction, a model-based methodology with respect to structural analysis is employed in this paper to achieve an efficient fault detection and identification (FDI) system design. The analysis involves five essential steps of SA applied to ABS, which includes critical faults analysis, fault modelling, fault detectability analysis and fault isolability analysis, Minimal Structural Over-determined (MSO) sets selection, and MSO-based residual design. In terms of the four faults in the ABS, they are evaluated to be detectable through performing a structural representation and making the Dulmage-Mendelsohn decomposition with respect to the fault modelling, and then they are proved to be isolable based on the fault isolability matrix via SA. After that, four corresponding residuals are generated directly by a series of suggested equation combinations resulting from four MSO sets. The results generated by numerical simulations show that the proposed FDI system can detect and isolate all the injected faults, which is consistent with the theoretical analysis by SA, and also eventually validated by experimental testing on the vehicle (EcoCAR2) ABS.

A residual design $$\mathcal{{D}}_B$$ with respect to a block B of a given design $${\mathcal{{D}}}$$ is defined to be linearly embeddable over GF( p) if the p-ranks of the incidence matrices of $${\mathcal{{D}}}_B$$ and $${\mathcal{{D}}}$$ differ by one. A sufficient condition for a residual design to be linearly embeddable is proved in terms of the minimum distance of the linear code spanned by the incidence matrix, and this condition is used to show that the residual designs of several known infinite classes of designs are linearly embeddable. A necessary condition for linear embeddability is proved for affine resolvable designs and their residual designs. As an application, it is shown that a residual design of the classical affine design of the planes in AG $$(3,2^2)$$ admits two nonisomorphic embeddings over GF(2) that give rise to the only known counterexamples to Hamada's conjecture over a field of non-prime order. [ABSTRACT FROM AUTHOR]

Key distribution is one of the most challenging security issues in wireless sensor networks. To achieve a high level of security, each pair of nodes must share a secret key in order to communicate with each other. Recently, many researchers have used combinatorial designs as key pre-distribution scheme in wireless sensor networks. In this paper, we describe a new construction of a design in combinatorial algebraic called residual design and use it for key establishment. This is the first time for application of residual design. Our approach is a highly scalable key management scheme for wireless sensor networks which provides a good secure connectivity. We show that the basic mapping from residual design to key pre-distribution has an extremely high network scalability while this mapping does not have high resilience. Therefore, we present a new approach for key pre-distribution based on residual design that improves the resilience of the network while maintaining connectivity and high scalability. We also explain that the computational cost and storage overhead is low. Performance and security properties of the proposed scheme are studied both analytically and computationally to compare our scheme to main existing schemes. The obtained results show that at equal key-ring size, our scheme provides better scalability with high connectivity and resilience. [ABSTRACT FROM AUTHOR]

This paper studies sensor and actuator fault diagnosis for a class of linear time-invariant (LTI) industrial control systems. Based on the dynamic model obtained using system identification, a method is proposed that can diagnose all sensor and actuator faults in the control system when they do not happen simultaneously. First, a structured residual design method is developed for coupled systems. Then model errors that occur in system identification are considered and the robust isolability is analyzed. Finally, online decision rules are given which are easy to implement. The method does not require fault data and can deal with small faults that cannot be detected by inspecting input–output signals. Verification in the high temperature gas-cooled reactor pebble-bed module (HTR-PM) simulation platform shows good potential of the method for complex industrial control systems. [ABSTRACT FROM AUTHOR]

Health monitoring of automated manual transmission (AMT) in modern vehicles can play a critical role to avoid its malfunctions and ensure vehicle functional safety. In order to meet this demand, this paper presents a model-based fault detection and identification (FDI) scheme for AMT. After developing the fault model of AMT, structural analysis (SA)-based fault detectability and isolability is realized with the available set of sensors, prior to design and development of residuals. The residuals are generated by employing the theory of SA, where the concepts of analytical redundant relationship (ARR) are utilized to make residuals stable and robust. Finally, the proposed FDI scheme is successfully evaluated to detect and isolate the sensor faults in EcoCAR2 AMT. [ABSTRACT FROM AUTHOR]

Abstract: Let be a Hadamard -design. Suppose that the prime divides , but that does not divide . A result of Klemm implies that every residual design of has -rank at least . Also, every derived design of has -rank at least if . We show that when is a skew Hadamard design, the -ranks of the residual and derived designs are at least even if divides or . We construct infinitely many examples where the -rank is exactly . [Copyright &y& Elsevier]

An orderly algorithm combined with clique searching is used to show that there are—up to isomorphism, in all cases—325,062 resolvable 2-(16,4,2) designs with 339,592 resolutions, 19,072,802 2-(13,6,5) designs, and 15,111,019 2-(14,7,6) designs. Properties of the classified designs are further discussed. [Copyright &y& Elsevier]

The anti-lock braking system (ABS) is an essential part in ensuring safe driving in vehicles. The Security of onboard safety systems is very important. In order to monitor the functions of ABS and avoid any malfunction, a model-based methodology with respect to structural analysis is employed in this paper to achieve an efficient fault detection and identification (FDI) system design. The analysis involves five essential steps of SA applied to ABS, which includes critical faults analysis, fault modelling, fault detectability analysis and fault isolability analysis, Minimal Structural Over-determined (MSO) sets selection, and MSO-based residual design. In terms of the four faults in the ABS, they are evaluated to be detectable through performing a structural representation and making the Dulmage-Mendelsohn decomposition with respect to the fault modelling, and then they are proved to be isolable based on the fault isolability matrix via SA. After that, four corresponding residuals are generated directly by a series of suggested equation combinations resulting from four MSO sets. The results generated by numerical simulations show that the proposed FDI system can detect and isolate all the injected faults, which is consistent with the theoretical analysis by SA, and also eventually validated by experimental testing on the vehicle (EcoCAR2) ABS. [ABSTRACT FROM AUTHOR]