汽车自动变速系统的能源效益及可靠性

本文通过探讨汽车自动变速系统的工作流程,分析了如何提升汽车变速系统的可靠性及能源效率等问题.     

Scheduling Correlated IoT Application Requests Within IoT Eco-System: An Incremental Cloud Oriented Approach

Wireless Personal Communications - In the era of adopting Internet everywhere, the recent modernization through incredible Internet of Things (IoT) makes the world more shrewd and automated....     

Energy Efficiency Trade-Off Between Duty-Cycling and Wake-Up Radio Techniques in IoT Networks

Wireless Personal Communications - For robust monitoring, control and proper energy management of renewable energy sources (RES), wireless sensing networks (WSNs) are proved to be a vital solution....     

Energy Efficiency Optimization of NOMA IoT Communication for 5G

Mobile Networks and Applications - With the rapid increase in the number of mobile users and the continuous emergence of new wireless multimedia services, 5G mobile communication technology that...     

Circular Layout Cutsets: An Approach for Improving Consecutive Cutset Bounds for Network Reliability

In this paper, we introduce a new type of parameterized class of cutsets for the 2-terminal network reliability problem, called the circular layout (CL) cutsets with parameter k, and devise a polynomial time algorithm for computing upper bounds from such structures. The CL cutsets, and the devised bounding method are characterized by the following aspects. 1) CL cutsets include the well known class of consecutive minimal cutsets, introduced by Shanthikumar, as a proper subset. Thus, bounds obtained by our main algorithm yield strict improvements on the basic consecutive cutsets algorithm. We note that extensive empirical studies done to date have shown that the consecutive cutsets method, when empowered by heuristics for choosing suitable cutsets, yields competitive bounds. 2) CL cutsets satisfy the semilattice structure required by Shier's algorithm for computing upper bounds in time polynomial in the number of cuts in a given cutset. Thus, CL cutsets define a new class of efficiently constructible cutsets of polynomial size that benefit from such generalized algorithm. 3) For any fixed value of the parameter k, the devised bounding method can be adapted to satisfy stringent constant-time update constraints, required by the most probable state algorithm of Colbourn & Harms , for obtaining iteratively improvable bounds, without adding significant time overhead to the method. Moreover, the devised bounding algorithm is easy to implement, and the obtained numerical results show more than a 32% improvement over bounds obtained by the basic consecutive cutsets algorithm     

面向大规模物联网的无人机通信感知一体化能效优化算法

针对大规模物联网场景下无人机通信感知一体化系统存在的重复感知和能量受限等问题,提出了一种基于聚类算法的能效优化方案。该方案在满足无人机的移动性和感知能力约束下,通过联合设计无人机的三维轨迹和发射功率来最大化系统能效。由于该问题是非凸的,首先将其解耦为两个子问题,然后利用模拟退火算法和标准凸优化技术来求解无人机的悬停位置和飞行速度以获取最优轨迹,最后根据最优轨迹推导发射功率的闭合表达式,求得每个悬停位置的最优发射功率。与传统的二维和三维方案相比,所提基于聚类的能效优化方案在收敛速度提高4倍的基础上能提升20%~30%系统能效。     

增强建筑节能意识搞好电信建筑节能设计

从可持续发展战略的要求出发，论述了电信建筑节能的意义，指出了电信建筑节能的关键在设计环节，并提出了当前电信建筑节能设计工作的重点内容。     

冗余余数系统低复杂度快速纠错算法设计

余数系统由于具有增强传输信息在并行系统中鲁棒性的优势,已被广泛应用在无线局域网(WLAN)以及码分多址通信技术(CDMA)等领域。而余数系统中的纠错检错是保证传输数据可靠性和高效性的关键问题。该文根据有限环上剩余类的性质提出溢出判定定理,不重复判断定理和唯一性区间搜索定理,并在此基础上进一步提出采用模运算代替传统中国剩余定理进行快速恢复的单错误纠错算法,将复杂度降低为O(k,r);提出不重复判定纠错算法;并对于一般错误情形,设计通过比较算子实现的搜索纠错算法。其中搜索纠错算法能直接实现系统最大纠错能力,且避免依靠复杂模运算算子实现,系统吞吐率得以提高;与传统算法相比,计算复杂度由多项式级降低至对数级。     

提高二极管激光器的能量转换效率

二极管激光器的核心是埋置在半导体结中间波导内的增益介质．即量子阱。量子阱具有的特定能级使通过二极管激光器的电流在所要求的波长处产生粒子数反转。光波导使光子沿正确的方向运行，一对反射镜构成谐振腔。     

提高计算机测控系统可靠性的方法

许多计算机测控系统用于军事领域和重要的工业控制场合，提高计算机测控系统的可靠性具有重要的应用价值。本文从设计和测试的角度提出了有关提高计算机测控系统可靠性的方法和措施。     

An Enhanced Decision-Making Fault Detection Model in Medical IoT Embedded Systems

Wireless Personal Communications - In the Internet of Things (IoT) embedded systems, error-detecting code methods are used to predict fault detection in a data block. Applying an error-detecting...     

Enhanced Secure Error Correction Code Schemes in Time Reversal UWB Systems

In this paper, secure channel coding schemes based on turbo codes are suggested for time reversal ultra wideband (TR-UWB) systems. Turbo code has the capability of error correction near Shannon’s limit. Adding security to turbo code is an attractive idea since it could reduce the overall processing cost of providing secure coded data and enjoys the advantages of high-speed encryption and decryption with high security, smaller encoder and decoder size and greater efficiency. The proposed turbo code schemes are labeled as follows: secure puncturing rate, secure frame length, and secure interleaving. Using these scenarios, secure turbo code is defined in a way that the redundant information used for error correction is not pre-determined by the nature of the error correction part of the algorithm but it can be chosen arbitrarily out of the whole set of possible strings. The lower bound of bit error probability for secure turbo code schemes in AWGN and TR-UWB systems are evaluated. Analytical and simulation results show secure turbo code performance is very satisfying. Various crypto-analytical attacks are investigated against these schemes. Based on this analysis, secure turbo code structures changed during the encryption procedure to increase the complexity of linear and differential cryptanalysis. It is seen that the performance of conventional turbo code and random frame length with Poisson distribution are the same. Comparing these schemes shows, secure interleaving approach has the best performance and secure puncturing rate the worst, but the latter provides the most security. The enhanced security of UWB, due to rich multipath nature of UWB channel, could be exploited. Due to space-time focusing property of time reversal UWB, there is an environmental confidentiality (or spatial security), which is additional security for secure turbo code in this system. Using secure turbo code, it is possible to increase the transmission range of UWB systems.     

New Approach for Error Compensation in Coded V-BLAST OFDM Systems

In this paper, we investigate coded layered space-time architectures for frequency-selective fading multiple-input multiple-output orthogonal frequency-division multiplexing (OFDM) channels. By computing outage capacity formulas, we will show that the capacity of the vertical Bell Labs layered space-time (V-BLAST) architecture can closely approach the Shannon capacity in the frequency-selective OFDM environment. Motivated by the capacity analysis, we propose pragmatic approaches which preserve the optimality of the layered space-time concept. We present methods to prevent the error propagation from catastrophically affecting the signal detection in subsequent layers. First, we start with a comprehensive signal modeling which includes error propagation. We derive an improved signal detector and describe the optimal soft-bit log-likelihood ratio value-computation method by taking decision errors into account for soft-input channel decoding. Then, to further enhance the V-BLAST performance, we show that cancellation using decoded decisions from previous layers makes the decision errors almost completely disappear, so that the layered space-time architecture can approach the attainable channel capacity. Finally, simulations confirm that the proposed schemes show a significant performance improvement over the conventional methods     

An Empirical Bayes Approach to Reliability

A Bayesian reliability estimation technique known as the ``empirical Bayes approach' is developed which uses previous experience nce to get a Bayesian point estimator. The techniques require no knowledge of the form of the unknown prior distribution and are robust to assumptions about its form. Empirical Bayes techniques are applicable to situations in which prior, independent observations of the random variable X from the random couple (?, X) are available where ? is the observed parameter of interest distributed in accordance with the unknown prior distribution. Performance comparisons of the empirical Bayes and other well established techniques are developed by examples for the binomial, exponential, Normal, and Poisson situations which often occur in reliability problems. In all cases the empirical Bayes estimator performed better than the classical estimator in minimizing the average squared error.     

An Approach to Reliability in Measurements in India

Importance of the 3-echelon system and its implementation scheme in India based upon one echelon-I Laboratory (Primary Standards), 4 Regional and other local echelon-II laboratories and 18 state and other echelon-III laboratories broadly under the STQC program, Department of Electronics, Government of India, is discussed with emphasis on compatibility and traceability to National/International Standards. Coordination of various activities through Government agency, uniformity of reporting procedures, etc., current programs with different international agencies and steps taken to ensure compatibility in measurements are briefly discussed.     

Correction to: An IoT Service Aggregation Method Based on Dynamic Planning for QoE Restraints

Mobile Networks and Applications - The original version of this article unfortunately contained mistakes in the author group and affiliation sections. Author Khan Muhammad’s given name and...     

An Energy Efficient Message Scheduling Algorithm Considering Node Failure in IoT Environment

Advancements in the area of computing and the networking gave birth to a new concept Internet of Things (IoT). This can be thought as “network of future” connecting diverse objects/things together. The focus is on scheduling the messages in an IoT environment where things/sensors are clustered into IoT subgroups, each subgroup has a message broker that delivers the messages originated from the group to the ultimate receiver of the sensed data. The message scheduler works at the broker level to decide which message to be transmitted first. This scheduling improves the overall IoT system efficiency. Furthermore to keep the flow of services provided by these things/sensors continuous and non-disruptive, the optimal tackling of the faulty or failed nodes has become the salient feature of the proposed scheduling algorithm. The faults or failures identified on time help to initiate recovery or replacement procedures. To find the right level of replacement nodes deployed for the sensor network, we consider the energy a scarce resource and the cost of deployment of the backup nodes as per failure of the node occurring in the underlying environment. In this work we propose an energy efficient recovery and backup node selection for IoT systems followed with energy efficient message scheduling. Simulation results show the effectiveness and efficiency of the proposed message scheduling considering the node failure with recovery and replacement technique.     

Virtual Machine Scheduling for Improving Energy Efficiency in laaS Cloud

In IaaS Cloud, different mapping relationships between virtual machines （VMs） and physical machines （PMs） cause different resource utilization, so how to place VMs on PMs to reduce energy consumption is becoming one of the major concerns for cloud providers. The existing VM scheduling schemes propose optimize PMs or network resources utilization, but few of them attempt to improve the energy efficiency of these two kinds of resources simultaneously. This paper proposes a VM scheduling scheme meeting multiple resource constraints, such as the physical server size （CPU, memory, storage, bandwidth, etc.） and network link capacity to reduce both the numbers of active PMs and network elements so as to finally reduce energy consumption. Since VM scheduling problem is abstracted as a combination of bin packing problem and quadratic assignment problem, which is also known as a classic combinatorial optimization and NP-hard problem. Accordingly, we design a two- stage heuristic algorithm to solve the issue, and the simulations show that our solution outperforms the existing PM- or network-only optimization solutions.