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An essentialtask of the electronic support measures system is to deinterleave the intercepted radar pulse stream. To improve the radars' antijamming capability and adapt the radars to different application scenarios, the pulse signals emitted by various radars are becoming abundant, causing the pulse stream intercepted by the reconnaissancereceiver to becomemore and more complicated. Apart from fixed pulse repetition interval (PRI) signals, other PRI modulated signals, such as jitter PRI and staggered PRI, also appear in the intercepted radar pulse stream. The aforementioned pulse stream is defined as mixed radar signals in this article. The deinterleaving of mixed radar signals is an inevitable challenge in the field of electronic countermeasures. A novel algorithm for deinterleaving mixed radar signals is proposed in this article. It is flexible for deinterleaving different PRI modulated signals. A sequence retrieval method based on clustering ideas is also proposed in the algorithm, which enables different pulse sequences to be accurately separated. Simulation results show that the new algorithm has great PRI estimation accuracy for mixed radar signals in a large pulse missing rate. [ABSTRACT FROM AUTHOR]

The impedance of lithium-ion (Li-ion) batteries contains information about the dynamics and state parameters of the battery. This information can be utilized to improve the performance and safety of the battery application. The battery impedance is typically modeled by an equivalent-circuit-model (ECM), which provides the dynamic information of the battery. In addition, the variations in the model parameters can be used for the battery state estimation. A fitting algorithm is required to parametrize the ECM due to the nonlinearity of both the battery impedance and ECM. However, conventional fitting algorithms, such as the complex-nonlinear-least-squares (CNLS) algorithm, often have a high computational burden and require selection of initial conditions, which can be difficult to obtain adaptively. This article proposes a novel fitting algorithm for the parametrization of battery ECM based on the geometric shape of the battery impedance in the complex-plane. The algorithm is applied to practical and fast broadband pseudorandom sequence impedance measurements carried out at various state-of-charges (SOC) and temperatures for lithium-iron-phosphate cell. The performance of the method is compared to conventional CNLS algorithm with different initial conditions. The results show that the proposed method provides fast and accurate fit with low computational effort. Moreover, specific ECM parameters are found to be dependent on the battery SOC at various temperatures. [ABSTRACT FROM AUTHOR]

Since its introduction in 1977, the expectation maximization (EM) algorithm has been one of the most important and widely used estimation method in estimating parameters of distributions in the presence of incomplete information. In this paper, a variant of the EM algorithm, the expectation conditional maximization (ECM) algorithm, is introduced for the first time and it provides a promising alternative in estimating the parameters of nonhomogeneous poisson (NHPP) software reliability growth models (SRGM). This algorithm circumvents the difficult M-step of the EM algorithm by replacing it by a series of conditional maximization steps. The utility of the ECM approach is demonstrated in the estimation of parameters of several well-known models for both time domain and time interval software failure data. Numerical examples with real-data indicate that the ECM algorithm performs well in estimating parameters of NHPP SRGM with complex mean value functions and can produce a faster rate of convergence. [ABSTRACT FROM AUTHOR]

This paper aims at presenting a new countermeasure against Side-Channel Analysis (SCA) attacks, whose implementation is based on a hardware-software co-design. The hardware architecture consists of a microprocessor, which executes the algorithm using a false key, and a coprocessor that performs several operations that are necessary to retrieve the original text that was encrypted with the real key. The coprocessor hardly affects the power consumption of the device, so that any classical attack based on such power consumption would reveal a false key. Additionally, as the operations carried out by the coprocessor are performed in parallel with the microprocessor, the execution time devoted for encrypting a specific text is not affected by the proposed countermeasure. In order to verify the correctness of our proposal, the system was implemented on a Virtex 5 FPGA. Different SCA attacks were performed on several functions of AES algorithm. Experimental results show in all cases that the system is effectively protected by revealing a false encryption key. [ABSTRACT FROM AUTHOR]

Forward looking sonars (FLS) are nowadays popular for many different applications. In particular, they can be used for Automatic Target Recognition (ATR) in the context of Mine Countermeasures. Currently, ATR techniques are applied to raw data which generates many false positives and the need for human supervision. Mosaicing FLS data increases target contrast and thus reduces false positive rate. Moreover, it implies a considerable data size reduction which is important if one thinks of exchange of data in real time through an acoustic channel with very limited bandwidth. Results of applying a real-time mosaicing algorithm to FLS data generated during Mine Countermeasures missions are shown and discussed thoroughly in this article. [ABSTRACT FROM AUTHOR]

To decrease potentially harmful effects to the environment and reduce costs of cellular network operators, the exploration of energy saving is significant. In this paper, we shed light on the following energy consumption minimization (ECM) problem: “how to select the smallest set of active base stations (BSs) that can preserve the quality of service (the minimum data rate) required by the users.” Since the ECM problem belongs to the field of integer programming and is NP-hard, we propose two low-complexity approximation algorithms that yield performance guarantees: the iterative minimal set cover algorithm and the iterative maximal coverage (IMC) algorithm. Moreover, by leveraging the submodularity theory, we establish the performance bound of the IMC algorithm. Finally, the computational complexity of our proposed algorithms is analyzed, and a simulation platform is developed to evaluate the number of active BSs of proposed approaches. The numerical results demonstrate that our proposed algorithms outperform the conventional counterpart. [ABSTRACT FROM AUTHOR]

A practical way to increase the effective capacity of a microprocessor’s cache, without physically increasing the cache size, is to employ data compression. Last-Level Caches (LLC) are particularly amenable to such compression schemes, since the primary purpose of the LLC is to minimize the miss rate, i.e., it directly benefits from a larger logical capacity. In compressed LLCs, the cacheline size varies depending on the achieved compression ratio. Our observations indicate that this size information gives useful hints when managing the cache (e.g., when selecting a victim), which can lead to increased cache performance. However, there are currently no replacement policies tailored to compressed LLCs; existing techniques focus primarily on locality information. This article introduces the concept of size-aware cache management as a way to maximize the performance of compressed caches. Upon analyzing the benefits of considering size information in the management of compressed caches, we propose a novel mechanism—called Effective Capacity Maximizer (ECM)—to further enhance the performance and energy consumption of compressed LLCs. The proposed technique revolves around four fundamental principles: ECM Insertion (ECM-I), ECM Promotion (ECM-P), ECM Eviction Scheduling (ECM-ES), and ECM Replacement (ECM-R). Extensive simulations with memory traces from real applications running on a full-system simulator demonstrate significant improvements compared to compressed cache schemes employing conventional locality-aware cache replacement policies. Specifically, our ECM shows an average effective capacity increase of 18.4 percent over the Least-Recently Used (LRU) policy, and 23.9 percent over the Dynamic Re-Reference Interval Prediction (DRRIP) [1] scheme. This translates into average system performance improvements of 7.2 percent over LRU and 4.2 percent over DRRIP. Moreover, the average energy consumption is also reduced by 5.9 percent over LRU and 3.8 percent over DRRIP. [ABSTRACT FROM AUTHOR]

This paper presents a new real-time \H2-consumption-minimization energy management strategy for a fuel cell hybrid emergency power system of a more electric aircraft (MEA). Compared to existing \H2-consumption-minimization strategies based on the equivalent fuel consumption [such as the well-known equivalent consumption minimization strategy (ECMS)], the proposed strategy is less sensitive to the load profile, as the cost function to be optimized does not involve the evaluation of the equivalent fuel consumption, which strongly depends on the whole mission profile. This improves the robustness of the energy management system toward load profile variations, while minimizing the \H2 consumption. Using two typical emergency mission profiles of an MEA, the performance of the proposed strategy is compared with the ECMS through simulations and experiments. Moreover, an off-line optimization-based algorithm is developed to ascertain the validity of the proposed strategy in terms of fuel consumption. [ABSTRACT FROM PUBLISHER]

Abstract: Side-channel attacks by cryptanalysis are becoming a serious threat for cryptographers, who are designing systems that are more robust in terms of hardware and algorithm threats, aiming to thwart violations of the secrecy of securely processed information. As our contribution on a related issue, we propose a new secure logic, called charge-sharing symmetric adiabatic logic (CSSAL), for resistance against differential power analysis (DPA) attacks. We verify the security of the proposed CSSAL by carefully analyzing the individual logic functions corresponding to 16 possible dual-input transitions. Then, we compare the results with those of previous secure logic styles using the same parameters and under the same conditions. The figure of merit to measure the resistance of the logic against DPA attacks has been calculated from the variation in power consumption per input transition. The SPICE simulation results show that our proposed logic balances the peak current traces for all input logic transitions, consuming power uniformly over every cycle, and thus making the input–output data resilient to a DPA attack. Moreover, the ability of the proposed CSSAL in a bit-parallel cellular multiplier over shows its significant power reduction compared to conventional secure logic styles and its efficient resistance to DPA attacks. [Copyright &y& Elsevier]

A joint channel impulse response (CIR) and noise-variance estimation scheme is proposed for multiuser multiple-input–multiple-output (MIMO) orthogonal frequency-division multiplexing/space-division multiple access (OFDM/SDMA) systems, which is based on the expectation-conditional maximization (ECM) algorithm. Multiple users communicating over fading channels exhibiting a range of different characteristics are considered in this paper. Channel estimation becomes quite challenging in this scenario since an increased number of independent transmitter–receiver links having different statistical characteristics have to be simultaneously estimated for each subcarrier. To cope with this scenario, we design an ECM-based joint CIR and noise-variance estimator for multiuser MIMO OFDM/SDMA systems, which is capable of simultaneously estimating diverse CIRs and noise variance. Furthermore, we propose a forward error code (FEC)-aided decision-directed channel estimation scheme based on the ECM algorithm, which further improves the ECM algorithm by exploiting the error correction capability of an FEC decoder for iteratively exchanging information between the decoder and the ECM algorithm. [ABSTRACT FROM PUBLISHER]