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Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers. [ABSTRACT FROM AUTHOR]

The article presents the list of reviewers focused on recognition of 2017 transactions and magazine paper.

The stator ground fault location of large generators can guide rapid maintenance. In this paper, a location criterion without fault transition resistance is constructed by using the fundamental potential and the third harmonic potential of the faulty winding simultaneously. The above potentials of the faulty winding are corresponding to the fault position. To precisely locate the grounding fault, it is necessary to clarify the analytical relationship between the faulty winding potential and the fault position. However, the existing methods often take the coil potential as the unit to analyze the winding potential, which has theoretical errors for the generators with short-pitch winding. Aiming at this problem, a more precise analysis method for winding potential is established by taking the slot conductor potential as the unit. To solve the location criterion, the optimization model for each slot conductor of the faulty phase is constructed. The slot conductor with the smallest optimal objective function value is judged as the faulty slot conductor, and the corresponding decision variable is judged as the fault position. Simulation and experiments verify the effectiveness of the proposed method, which can still meet the needs of engineering applications under multiple adverse conditions. [ABSTRACT FROM AUTHOR]

The article presents deadlines for submission of manuscript in the periodical on December 1, 2016 along with guidelines for manuscript submission. It informs that topics of manuscript includes case studies of incorporation of knowledge of telecommunication standards into professional training; impact of standards education on engineering, technology, society, and economy and best practices for incorporating standards into telecommunication curricula.

Presents the recipient of the APS 2015 R. W. P. King Paper Award. [ABSTRACT FROM PUBLISHER]

Recent advances in computational methods, materials science, and new manufacturing processes are resulting in an unprecedented design flexibility which is driving the geometrical complexity of the components found in modern structures and machines. For safety-critical components, the geometrical complexity poses a significant challenge to the sensitivity of the existing nondestructive evaluation (NDE) methods available for the detection of manufacturing defects or damage that develops while a component is in service. Although X-ray computed tomography is the primary NDE method used to test these parts in current industrial practice, it is widely recognized that it has limited sensitivity to critical defects, such as cracks, especially in the presence of large size parts made of dense materials. The lack of sensitive NDE methods represents a major technology gap that could impede the acceptance of rapidly developing technologies, such as 3-D printing, for the production of safety-critical components. This paper attempts to bridge this gap by exploring the possibility of inspecting a complex-shaped part with ultrasonic waves after it has been encapsulated in ice, under the paradigm of what can be defined as cryo-ultrasonic NDE. The underpinning hypothesis is that through ice encapsulation a complex-shaped part can be transformed into a simple-shaped solid whose volume can be probed with ultrasonic waves, which are known to be highly sensitive to both pores and crack-like defects and over a wide range of material properties. Damage detection is then performed by analyzing cross-sectional images of the ice-encapsulated part obtained by applying migration methods to the ultrasonic signals measured by an array of transducers. This paper lays the foundation for cryo-ultrasonic NDE and presents the first experimental results demonstrating the possibility of imaging defects through multiple ice–metal interfaces. This paves the way to the detection of defects in complex-shaped parts containing internal vanes which have so far limited the use of conventional NDE methods. [ABSTRACT FROM PUBLISHER]

Time-domain near-field scanning is gaining more and more interest within EMC engineering to analyze electromagnetic near-fields of, e.g., quasi-stationar devices. When using a digital oscilloscope to scan the near-fields of an electronic device, the oscilloscope measures time-domain signals that comprise in most cases a large number of frequency components. For many of these components, noncoherent sampling occurs, resulting in spectral leakage when calculating the frequency spectrum of the time-domain signals with the discrete Fourier transform. This paper proposes an improved method to detect the presence of such noncoherently sampled signals as well as an iterative algorithm to obtain accurate approximations of all the frequency components with their accompanying amplitudes and phase angles. The algorithm excels over existing algorithms in obtaining these values especially in situations where several sinusoidal components are close to each other in the spectrum. This is achieved, thanks to an iterative process of removing the influence of the multiple sinusoidal components on each other. This paper contains the mathematical description of the algorithm and a numerical example evaluating the accuracy of the algorithm. The algorithm has a higher accuracy than the existing approaches, e.g., multipoint Interpolated Discrete Fourier Transform (IpDFTs), with only a slight increase of the computational cost. [ABSTRACT FROM AUTHOR]

A complex engineering system typically consists of a group of components/subsystems in a hierarchical structure and the system is monitored at only some, not all, of these hierarchical levels. This paper investigates a Bayesian approach to system reliability prediction using multilevel incomplete data. These data are drawn simultaneously from different component/subsystem levels within the same system, thus need to be analyzed with the consideration of their overlapping nature. In this paper, a Bayesian network model is proposed for modeling the reliability of a multilevel system, where a lower level node can only be connected to one higher level node. Through Bayesian inference, the posterior distributions of lifetime parameters and conditional probabilities in the model are obtained by combining prior beliefs with lifetime data coming from different system levels. This study is also extended to include mixed data types, i.e., both pass/fail data and lifetime data. The effectiveness of the proposed approach is illustrated in a case study. [ABSTRACT FROM PUBLISHER]

A great deal of previous work has studied methods to determine system reliability. That work has defined system reliability as the probability that the production output meets a predetermined demand for a network with many workstations, each of which has random capacity determined by a discrete probability distribution. It is noteworthy that the archival work presents numerous examples, wherein entities are discrete and indivisible, while the analysis is based upon continuous flow, much like a fluid, through the network. The inconsistency, inherent in mixing discrete-entity examples with continuous-flow analysis, can result in erroneous conclusions about the system reliability. The current paper presents a rigorous discrete-analysis analytical approach, which is called the Song rule (Stochastic “Output $\geq$ demand” Networks and their Generation). Based on all examples studied in this paper, the absolute difference ratios between the previous incorrect (as published) and the correct probabilities (from the Song rule) are all greater than 23%. The proposed Song rule analysis is verified to be correct using discrete-event simulation. In addition to providing rigorous analysis for the network problems under consideration, the Song rule is a useful tool for assessing the validity of any future proposed approach for other stochastic reliability problems. [ABSTRACT FROM PUBLISHER]

Uncertain and potentially harsh operating environments are often known to alter the operational performance of a system. In order to maintain system performance while coping with varying operating environments and potential disruptions, the resilience of engineered systems is desirable. Engineering systems are often interconnected in a dimensional way inherently from basic components to subsystems to the system of systems, which poses a grand challenge for system designers to analyze the resilience of such a complex system. Moreover, further complications in the assessment of resilience in the engineering domain are attributed to time-varying system performances, random perturbation occurrences, and probable failures caused by adverse events. This paper presents a dynamic Bayesian network (DBN) approach for the modeling and predictive resilience analysis for dynamic engineered systems. With the inter-time-slice links and the conditional probability tables in a DBN, the system performance could be molded as changing in a discrete time slice, while capturing the temporal probabilistic dependencies between the variables. An industrial-based case study of an electricity distribution system is further studied to demonstrate the effectiveness of the DBN approach for resilience analysis. The approach presented in this paper hopes to aid in realizing resiliency in system designs and to pave the way toward enhancements in developing resilient engineered systems. [ABSTRACT FROM PUBLISHER]

Thanks to the favorable advantage of low cost, integrated three-port dc–dc converters with reduced switches have attracted extensive attention. In order to provide more new topologies, this paper aims to propose a programmable topology derivation method, which effectively simplifies the cumbersome process of the conventional combination method. Instead of the manual connection and examination, the proposed alternative can quickly and rigorously derive multiple viable integrated three-port dc–dc topologies from a great number of possible connections with the aid of computer program. Besides, generalized analysis is also accomplished, with which performance characteristics of all derived converters are simultaneously obtained and then a comprehensive comparison can be easily conducted to select a preferred one for the practical application. Finally, an example-specific application with one input and two outputs is given, with topology selection, design, and experimental results demonstrated in detail. [ABSTRACT FROM AUTHOR]

In robotic mapping and simultaneous localization and mapping, the ability to assess the quality of estimated maps is crucial. While concepts exist for quantifying the error in the estimated trajectory of a robot, or a subset of the estimated feature locations, the difference between all current estimated and ground-truth features is rarely considered jointly. In contrast to many current methods, this paper analyzes metrics, which automatically evaluate maps based on their joint detection and description uncertainty. In the tracking literature, the optimal subpattern assignment (OSPA) metric provided a solution to the problem of assessing target tracking algorithms and has recently been applied to the assessment of robotic maps. Despite its advantages over other metrics, the OSPA metric can saturate to a limiting value irrespective of the cardinality errors and it penalizes missed detections and false alarms in an unequal manner. This paper therefore introduces the cardinalized optimal linear assignment (COLA) metric, as a complement to the OSPA metric, for feature map evaluation. Their combination is shown to provide a robust solution for the evaluation of map estimation errors in an intuitive manner. [ABSTRACT FROM AUTHOR]

Despite intensive investigations in the past, energetic efficiency is still one of the most important unsolved challenges in legged robot locomotion. This paper presents an unconventional approach to the problem of energetically efficient legged locomotion by applying actuation for spring mass running. This approach makes use of mechanical springs incorporated in parallel with relatively low-torque actuation, which is capable of both accommodating large payload and locomotion with low power input by exploiting self-excited vibration. For a systematic analysis, this paper employs both simulation models and physical platforms. The experiments show that the proposed approach is scalable across different payload between 0 and 150 kg, and is able to achieve a total cost of transport of 0.10, which is significantly lower than the previous locomotion robots and most of the biological systems in the similar scale, when actuated with the near-to natural frequency with the maximum payload. [ABSTRACT FROM AUTHOR]

A pulsed discharge plasma (PDP) system with a multineedle-to-plate geometry electrode was applied in this paper to investigate the regeneration of granular activated carbon (GAC) spent with phenol in the PDP system. Regeneration percentage of the GAC under different conditions of initial solution conductivity and pH values was studied to clarify the regeneration of the GAC by the PDP. Formation of hydrogen peroxide (H2O2) with the same solution conditions was also investigated in this paper. The obtained results show that there was the same changing trend of GAC regeneration and H2O2 formation under different solution conditions, which clarify the critical effect of •OH on the GAC regeneration in the PDP system. The methods of scanning electron microscope (SEM), Brunauer–Emmett–Teller, Boehm titration, and Fourier transform infrared spectroscopy (FTIR) were used in this paper to demonstrate the medication of the GAC by the PDP treatment. The obtained results show that the regenerated GAC could recover a partial pore structure compared with the original GAC by the SEM analysis. The surface area, micropore volume, and total pore volume of the regenerated GAC increased, while the mesopore volume and the macropore volume decreased on the regenerated GAC; comparing with the original GAC, there was higher amount of acidic functional groups and lower amount of basic functional groups on the surface of the regenerated GAC; the intensities of O–H, C=C, C=O, and C–O enhanced significantly by the FTIR analysis. [ABSTRACT FROM AUTHOR]

With the development of HVdc transmission technology, the isolation of dc faults is becoming increasingly important. As the most effective solution, hybrid HVdc circuit breaker (CB) is not mature enough, which has restricted its engineering application. Accordingly, this paper proposes an auxiliary dc CB scheme suitable for HVdc grid. In this scheme, the traditional half-bridge modular multilevel converter (MMC) is partially innovated to have the ability of auxiliary breaking operation. With the effect of the MMC auxiliary breaking (MAB) operation at both ends of the fault line, the dc fault current can be easily interrupted and isolated by low-cost CB unit installed in the dc transmission line. The equivalent circuit under MAB process is analyzed, and the fault isolation sequences are designed. Furthermore, the economic comparative analysis among three schemes is performed. Finally, a four-terminal bipolar HVdc grid test model is built in PSCAD/EMTDC; in addition, an MMC prototype with proposed scheme is also developed. The simulation and experimental results validate the effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

Publishing histograms with $\epsilon$ -differential privacy has been studied extensively in the literature. Existing schemes aim at maximizing the utility of the published data, while previous experimental evaluations analyze the privacy/utility trade-off. In this paper, we provide the first experimental evaluation of differentially private methods that goes beyond utility, emphasizing also on another important aspect, namely efficiency. Towards this end, we first observe that all existing schemes are comprised of a small set of common blocks. We then optimize and choose the best implementation for each block, determine the combinations of blocks that capture the entire literature, and propose novel block combinations. We qualitatively assess the quality of the schemes based on the skyline of efficiency and utility, i.e., based on whether a method is dominated on both aspects or not. Using exhaustive experiments on four real datasets with different characteristics, we conclude that there are always trade-offs in terms of utility and efficiency. We demonstrate that the schemes derived from our novel block combinations provide the best trade-offs for time critical applications. Our work can serve as a guide to help practitioners engineer a differentially private histogram scheme depending on their application requirements. [ABSTRACT FROM AUTHOR]

Contribution: This paper shows that participating in a year-round program for African–American male middle school students (ages 10–14) can positively impact their attitudes toward STEM, their confidence in problem solving and team work, and their interest in STEM careers, but may not impact the interest in taking STEM classes to the same extent. Background: Increasing the number of under-represented minorities pursuing degrees in science and engineering through formal and informal learning activities has been a focus in the United States for many years. Efforts to diversify the engineering workforce have often targeted students in high school and college (ages 15–22), with varying success. Intended Outcomes: This program was designed to increase participants’ content knowledge, interest in STEM courses, interest in STEM careers, interest in attending college, and improve their attitudes about STEM. Application Design: Approaches used included: 1) introducing software tools that encouraged critical thinking, creativity and independent learning; 2) integrating engineering and software design processes; 3) providing projects that were age- and culturally-appropriate; and 4) using ethnically matched mentors. Findings: After almost two years in the program participants show improved attitudes toward STEM, more interest and career choices in computing and engineering, and increased interest in attending college. These findings suggested that summer and academic year programs can be effective for cultivating interest in computing and engineering careers, but their impact on interest in studying related subjects may need further study. [ABSTRACT FROM AUTHOR]

Spin-transfer torque random access memory (STT-RAM) is a promising technology for future nonvolatile caches and memories. To increase the storage density, multilevel cell (MLC) technique was recently introduced to STT-RAM designs at the cost of degraded access speed, reliability, and energy efficiency. Existing MLC STT-RAM cache architectures primarily focus on the performance and energy optimizations but ignore the crucial demand for reliability. In this paper, we propose “TriZone”—a holistic design scheme for MLC STT-RAM cache to simultaneously meet the requirements of performance, energy, and reliability. Three cache block configurations, namely hard, soft, and mixed, are constructed with the hard-bit, soft-bit, and both hard-bit and soft-bit of MLC STT-RAM, respectively. By observing the difference of these cache blocks, a nonuniform strength ECC (NUS-ECC) is developed to guarantee the operational reliability of a cache block with a variable decoding delay adapting to the needs of error correction (e.g., the number of the erroneous bits). The whole MLC STT-RAM cache is then partitioned into three regions, each of which is composed of different cache blocks. In order to achieve the best tradeoff among performance, energy, and reliability, we then introduce the dynamic cache partitioning to determine the partition of this tri-way MLC STT-RAM cache according to the runtime characteristic of various applications. Experiment results show that compared with conventional performance-driven MLC STT-RAM cache design with pessimistic ECC, TriZone can improve the system performance and energy by averagely 11.7% (10.0%) and 13.3% (15.7%), respectively, for single-threaded (multiprogram) applications. The additional area overhead associated with NUS-ECC is limited by ~ 3%. [ABSTRACT FROM AUTHOR]

The design structure matrix (DSM), also called the dependency structure matrix, has become a widely used modeling framework across many areas of research and practice. The DSM brings advantages of simplicity and conciseness in representation, and, supported by appropriate analysis, can also highlight important patterns in system architectures (design structures), such as modules and cycles. A literature review in 2001 cited about 100 DSM papers; there have been over 1000 since. Thus, it is useful to survey the latest DSM extensions and innovations to help consolidate progress and identify promising opportunities for further research. This paper surveys the DSM literature, primarily from archival journals, and organizes the developments pertaining to building, displaying, analyzing, and applying product, process, and organization DSMs. It then addresses DSM applications in other domains, as well as recent developments with domain mapping matrices (DMMs) and multidomain matrices (MDMs). Overall, DSM methods are becoming more mainstream, especially in the areas of engineering design, engineering management, management/organization science, and systems engineering. Despite significant research contributions, however, DSM awareness seems to be spreading more slowly in the realm of project management. [ABSTRACT FROM AUTHOR]

This paper proposes a robust PD control scheme for flexible-joint robots based on a disturbance observer (DOB). In this paper, the DOB is applied only to the motor-side dynamics of the robot, and the uncertainties on the motor-side are successfully eliminated. It is shown that the proposed DOB-based approach guarantees global asymptotic stability. To this end, two special treatments are required. First, unlike the typical configuration of the DOB, nominal states of the motor-side are fed back to the PD controller. Second, a control input that makes the nominal states stable is additionally introduced. The proposed approach was verified using multi-degree-of-freedom experiments. [ABSTRACT FROM PUBLISHER]

This paper describes an exploding wire experiment to measure the electrical specific action to melt of structural alloys of copper and aluminum, including C10100, C11000, C18000, C18200, Al6061, and Al7075. These alloys, which are commonly used in railguns and other pulsed power devices, are not produced in fine wire form. Instead of wires, we developed a technique to test macroscopic samples ( 0.25~mm\times 0.5~mm cross section) manufactured with wire electrical discharge machining. This paper includes a description of the design considerations for such macroscopic exploding wire experiments. [ABSTRACT FROM PUBLISHER]

In this paper, we investigate a system composed of mixtures of one-shot units with nonhomogeneous and time-dependent characteristics. We propose analytical expressions to predict system reliability metrics and consider a physics-statistics-based lifetime model to demonstrate the units’ failure mechanism as well as its failure process uncertainty. We design a sequence of optimum accelerated non-destructive testing (NDT) plans to predict the reliability metrics of the system and show that a well-designed sequential accelerated NDTs is an effective approach to shorten the test duration with negligible consequence on system reliability metrics. [ABSTRACT FROM PUBLISHER]

Accelerated life testing has been widely applied to obtain the reliability information of an asset (component) at use conditions when the component is highly reliable. In accelerated life testing, tested components are exposed to stress levels more severe than usual so that more component failures can be observed in a short period of time. Most existing statistical models assume a known parametric relationship between the lifetime (or lifetime characteristic) and accelerating stresses. In this paper, we propose semiparametric modeling for the relationship between the lifetime characteristic and accelerating stresses. The proposed model is suitable for both single and multiple accelerating stress cases. A maximum penalized likelihood estimation method is developed to estimate the model parameters. A simulation study is implemented to illustrate the performance of the proposed model, and a real-world case study is conducted to demonstrate the proposed model. [ABSTRACT FROM PUBLISHER]

By combining the nonprobabilistic reliability theory with optimization design approach, this paper proposes a mixed reliability-based optimization method for the heat transfer system design with both fuzzy and interval parameters in material property, external load, and boundary condition. Fuzzy variables are used to represent subjective uncertainties associated with expert opinions; whereas, interval variables are adopted to quantify objective uncertainties with limited information. Based on the level-cut strategy, the mixed uncertain problem is transformed into a pure interval problem first. Then, a modified reliability analysis method using an interval ranking strategy and integral operation is presented to precisely assess the system safety possibility. Subsequently, a mixed reliability-based optimization model with fuzzy and interval parameters is established, which is a nested optimization problem with huge computational cost. A subinterval perturbation method is eventually presented for temperature field prediction, which can replace the inner loop optimization and improve the computational efficiency. A transient heat conduction example about a three-layer thermal structure verifies the superiority of the proposed model and method for mixed reliability analysis and optimization in practical engineering. [ABSTRACT FROM PUBLISHER]

In the process of long-term use, the uncertainty of an engineering structure often presents time-variant or dynamic characteristics due to the influence of stochastic loads and material performance degradations. In such a situation, the structural design optimization will involve an important problem of time-variant reliability-based design optimization (TRBDO). Performing TRBDO involves a nested optimization, which will lead to extremely low computational efficiency. In this paper, a single-loop approach (SLA) is proposed to convert the nested optimization in TRBDO into a sequence iterative process composed of the time-variant reliability analysis (TRA), constraint discretization, and design optimization. In each iteration step, the TRA method based on stochastic process discretization is first used to calculate the time-variant reliability of constraints; second, through introducing the concept of the target reliability index of discretized time period and proposing the corresponding algorithm, each time-variant constraint is discretized into a series of time-invariant constraints to formulate a conventional reliability-based design optimization problem. The approach exhibits a good comprehensive performance in terms of efficiency and convergence. The validity and practicality of the SLA are validated by two numerical examples and a design problem for the chassis of a self-balancing vehicle. [ABSTRACT FROM PUBLISHER]

Recent progress in high-level synthesis (HLS) has helped raise the abstraction level of hardware design. HLS flows reduce designer effort by allowing development in a high-level language, which improves debugging, code reuse and ability to explore different implementation options. However, although the HLS process is fast, implementation and performance analysis still require lengthy logic synthesis and physical design. For design optimization, HLS tools require design space exploration to obtain parallelism at multiple levels of granularity including parallelism within a single HLS-generated core and parallelism between multiple instances of cores. Core interconnect and external bandwidth limitations can significantly impact feasible options in the design space. With many dimensions in a design space exploration, it quickly becomes infeasible to perform full logic synthesis and physical design for each possible design point. However, generation and evaluation of communications infrastructure as part of the exploration is critical to determine the system performance. Thus, in this paper, we extend the prior multilevel granularity parallelism exploration in the FCUDA HLS flow, which takes CUDA code as design input and generates a corresponding field programmable gate array implementation. Our framework performs an initial characterization of the application design space, then analytically explores the design space considering parallelism, core interconnect, and external memory bandwidth, and selects a pareto-optimal set of designs. Our flow is completely automated to perform the exploration to characterize the analytical model, perform the exploration, select a solution, and integrate multiple instantiations of FCUDA cores via an advanced extensible interface bus interconnect. Our results demonstrate that this new FCUDA flow efficiently identifies and generates implementations with up to $5\times $ improved system performance compared to single-level granularity parallelism (core-level optimization). [ABSTRACT FROM PUBLISHER]

The inclusion of various new test types in production test suites with the hope of keeping defect escape level in check continuously increases the test cost while the economics of the intensely competitive consumer marketplace dictates test strategies that are low cost yet still effective in defect detection. An adaptive test methodology is proposed in this paper to address the simultaneous demand for efficiency and effectiveness in testing through an adaptive prioritization of test vectors according to defect detection effectiveness, subsequently, leading to the identification of a compact yet effective test set. Experimental results confirm the effectiveness of the vector prioritization process and show substantial cost reduction levels. [ABSTRACT FROM PUBLISHER]

This paper introduces a speed-sensorless method for detecting rotor asymmetries in wound rotor induction machines working under nonstationary conditions. The method is based on the time–frequency analysis of rotor currents and on a subsequent transformation, which leads to the following goals: unlike conventional spectrograms, it enables to show the diagnostic results as a simple graph, similar to a Fourier spectrum, but where the fault components are placed always at the same positions, regardless the working conditions of the machine; moreover, it enables to assess the machine condition through a very small set of parameters. These characteristics facilitate the understanding and processing of the diagnostic results, and thus, help to design improved monitoring and predictive maintenance systems. Also these features make the proposed method very suitable for condition monitoring of wind power generators, because it fits well with the usual nonstationary working conditions of wind turbines, and makes feasible the transmission of significant diagnostic information to the remote monitoring center using standard data transmission systems. Simulation results and experimental tests, carried out on a 5-kW laboratory rig, show the validity of the proposed method and illustrate its advantages regarding previously developed diagnostic methods under nonstationary conditions. [ABSTRACT FROM AUTHOR]

Dynamic frequency regulation and effect of penetration of static and inertial sources on system stability are important issues for islanded microgrid power quality and reliability. This paper presents a novel strategy of utilizing an inverter-based source as a voltage source inverter or virtual synchronous generator (VSG). Electromechanical and power modes are critical for small signal stability of an isolated microgrid having static and inertial sources. Interaction of these modes is analyzed through eigenvalue analysis of microgrid model and differential equations describing respective modes. Inertia is important for providing fault current, determining steady state and transient stability, and better system frequency profile. A novel technique is proposed to include inertia virtually to the inverter-based sources by adding swing equation. Furthermore, inverter-based sources with traditional and modified droop controls and VSGs are compared with respect to inertia, energy, and stability. The proposed control and stability comparison are verified through experimental microgrid setup having three inverter-based sources, which can be alternately operated as VSGs. [ABSTRACT FROM AUTHOR]

An electrical and mechanical design process for a traction motor in a hybrid bus application is studied. Usually, the design process of an electric machine calls for close cooperation between various engineering disciplines. Compromises may be required to satisfy the boundary conditions of electrical, thermal, and mechanical performances. From the mechanical point of view, the stress values and the safety factors should be at a reasonable level and the construction lifetime predicted by a fatigue analysis. In a vehicle application, the motor has to be capable of generating high torque when accelerating, and in normal operation, the losses of the machine should be low to be able to cool the machine. Minimization of the no-load iron losses becomes a very important electrical design requirement if the traction motor and the generator are mechanically connected with an internal combustion engine when it is operating as the only source of torque. The manufacturing costs of the motor are also taken into account in this paper. [ABSTRACT FROM PUBLISHER]

Collocated adaptive control of underactuated mechanical systems is still a concern for the control community. The main difficulty comes from the nonlinearity of the collocated inverse dynamics with respect to the base parameters, which forbids the direct application of classical adaptive control schemes. This paper extends and encompasses the Slotine's adaptive control, which was developed for fully actuated mechanical systems, to stabilize the collocated state space of an underactuated mechanical system. The key point is to define the sliding variable as the difference between the system's velocity and an exogenous state whose dynamics is considered as control input. We first revisit the Slotine's result in view of this definition and then show how to extend it to the underactuated case. Stability and convergence of time-varying reference trajectories for the collocated dynamics are shown to be in the sense of Lyapunov. Global well-posedness of the control laws is achieved by means of a new algebraic property of the mass matrix. Simulations, comparisons to existing control strategies, and experimental results on a two-link manipulator verify the soundness of the proposed approach. [ABSTRACT FROM PUBLISHER]

The China fusion engineering test reactor (CFETR) is an ITER-like tokamak system for fusion energy development. It could output 50-200 MW fusion power in phase I for demonstrating power generation with complete structure of fusion power plant, and 1 GW output power can be expected in phase II. Its ITER-like HV substation receives power from the 500 kV transmission grid for powering its pulsed power electric network (PPEN) and steady-state electric power network (SSEN). This paper describes the concept design of the electric power system, with emphasis on its turbine generator implemented with flexible doubly fed induction generator (DFIG). DFIG has ride through ability during the plasma-off period. Its capability diagram is configured to analyze its operation range. Similar to ITER, the CFETR also requires about 1 GVar reactive power to be compensated. Based on this requirement, the generator is expected to generate part of reactive power to compensate and stabilize the local power network. [ABSTRACT FROM PUBLISHER]

This paper analyzes the influences of the factors in a capacitor-driven multi-stage synchronous induction coilgun (SICG) and optimal combination of the design parameters based on orthogonal experiment design (OED). Finite element transient solver is used to calculate the motion characteristics of a multi-stage SICG. The muzzle speed is set to be the target of the optimization. System parameters (factors), levels and orthogonal array (OA) are determined by the order. Three optimization schemes are compared, including stage-by-stage optimization, section optimization and full optimization. Optimal combination of the three-stage SICG is obtained, as well as important order of factors. It shows that a set of comparatively better parameters and relatively higher efficiency could be achieved through orthogonal optimum. Wire diameter and coil diameter are the most important factors that influence the system efficiency of the launcher. Besides them, length of coil, trigger position and number of turns have less influence for the system in the important order. Section optimization could reduce the amount of computations compared to full optimization and a set of comparatively better parameters and relatively higher efficiency could be achieved. It is suggested to optimize a multi-stage SICG. How to choose the factors from lots of parameters is according to the engineering practice. Improper choices of the value in levels may cause unable to reach an optimum. The conclusion will be useful for coilgun design. [ABSTRACT FROM PUBLISHER]

Conservation voltage reduction (CVR) and distributed-generation (DG) integration are popular strategies implemented by utilities to improve energy efficiency. This paper investigates the interactions between CVR and DG placement to minimize load consumption in distribution networks, while keeping the lowest voltage level within the predefined range. The optimal placement of DG units is formulated as a stochastic optimization problem considering the uncertainty of DG outputs and load consumptions. A sample average approximation algorithm-based technique is developed to solve the formulated problem effectively. A multiple replications procedure is developed to test the stability of the solution and calculate the confidence interval of the gap between the candidate solution and optimal solution. The proposed method has been applied to the IEEE 37-bus distribution test system with different scenarios. The numerical results indicate that the implementations of CVR and DG, if combined, can achieve significant energy savings. [ABSTRACT FROM AUTHOR]

This paper presents a novel time-domain fault location algorithm on HVDC transmission lines. The Bergeron line model is adopted to construct a time-domain fault location equation, considering unsynchronized two-end measurement and uncertain line parameters. The zero time reference point is set to the sample point of arrival at each end for the traveling wave-head. Time-tags of all sample points change with the zero time reference. So the time difference of two-end measurements has changed also, and equals the time difference between arrivals at two ends for the traveling wave-head. That makes it possible to mix the traveling wave theory with the Bergeron time-domain fault location method. Besides, the ratio coefficient of wave velocities between different frequencies and digital band-pass filter are presented for better performance of the proposed method. Simulations and tests demonstrate that the proposed method can locate faults accurately on the HVDC lines even in the case of loss of signals from GPS. [ABSTRACT FROM AUTHOR]

Attracting K–12 students to pursue careers in science, technology, engineering, and mathematics (STEM) is viewed as a critical element for benefiting both the economy and society. This paper describes an outreach program, conducted in a Brooklyn, NY, USA, public middle school, aimed at educating students in mechatronics, biology, and bioinspiration. The program is designed to foster student interest in STEM subjects, especially engineering-related concepts, by actively demonstrating their application in solving tangible real-world problems. It consists of a series of lectures and practical activities that culminate with a hands-on bioinspiration-based event at the New York Aquarium. Survey results show that students who participated in the program have a better understanding of the relationship between engineering and nature, demonstrate improved knowledge of select STEM topics, and are more interested in pursuing STEM careers. [ABSTRACT FROM PUBLISHER]

In this paper, we describe research results arising from a technology transfer exercise on agent-oriented requirements engineering with an industry partner. We introduce two improvements to the state-of-the-art in agent-oriented requirements engineering, designed to mitigate two problems experienced by ourselves and our industry partner: (1) the lack of systematic methods for agent-oriented requirements elicitation and modelling; and (2) the lack of prescribed deliverables in agent-oriented requirements engineering. We discuss the application of our new approach to an aircraft turnaround simulator built in conjunction with our industry partner, and show how agent-oriented models can be derived and used to construct a complete requirements package. We evaluate this by having three independent people design and implement prototypes of the aircraft turnaround simulator, and comparing the three prototypes. Our evaluation indicates that our approach is effective at delivering correct, complete, and consistent requirements that satisfy the stakeholders, and can be used in a repeatable manner to produce designs and implementations. We discuss lessons learnt from applying this approach. [ABSTRACT FROM PUBLISHER]

This paper presents a computational method that employs Natural Language Processing (NLP) and text mining techniques to support requirements engineers in extracting and modeling goals from textual documents. We developed a NLP-based goal elicitation approach within the context of KAOS goal-oriented requirements engineering method. The hierarchical relationships among goals are inferred by automatically building taxonomies from extracted goals. We use smart metering system as a case study to investigate the proposed approach. Smart metering system is an important subsystem of the next generation of power systems (smart grids). Goals are extracted by semantically parsing the grammar of goal-related phrases in abstracts of research publications. The results of this case study show that the developed approach is an effective way to model goals for complex systems, and in particular, for the research-intensive complex systems. [ABSTRACT FROM PUBLISHER]

In this paper we develop a general framework to reason about testing. The difficulty of testing is assessed in terms of the amount of tests that must be applied to determine whether the system is correct or not. Based on this criterion, five testability classes are presented and related. We also explore conditions that enable and disable finite testability, and their relation to testing hypotheses is studied. We measure how far incomplete test suites are from being complete, which allows us to compare and select better incomplete test suites. The complexity of finding that measure, as well as the complexity of finding minimum complete test suites, is identified. Furthermore, we address the reduction of testing problems to each other, that is, we study how the problem of finding test suites to test systems of some kind can be reduced to the problem of finding test suites for another kind of systems. This enables to export testing methods. In order to illustrate how general notions are applied to specific cases, many typical examples from the formal testing techniques domain are presented. [ABSTRACT FROM PUBLISHER]

We propose in this paper to consider code-smells detection as a distributed optimization problem. The idea is that different methods are combined in parallel during the optimization process to find a consensus regarding the detection of code-smells. To this end, we used Parallel Evolutionary algorithms (P-EA) where many evolutionary algorithms with different adaptations (fitness functions, solution representations, and change operators) are executed, in a parallel cooperative manner, to solve a common goal which is the detection of code-smells. An empirical evaluation to compare the implementation of our cooperative P-EA approach with random search, two single population-based approaches and two code-smells detection techniques that are not based on meta-heuristics search. The statistical analysis of the obtained results provides evidence to support the claim that cooperative P-EA is more efficient and effective than state of the art detection approaches based on a benchmark of nine large open source systems where more than 85 percent of precision and recall scores are obtained on a variety of eight different types of code-smells. [ABSTRACT FROM PUBLISHER]

The framework of dynamic movement primitives (DMPs) contains many favorable properties for the execution of robotic trajectories, such as indirect dependence on time, response to perturbations, and the ability to easily modulate the given trajectories, but the framework in its original form remains constrained to the kinematic aspect of the movement. In this paper, we bridge the gap to dynamic behavior by extending the framework with force/torque feedback. We propose and evaluate a modulation approach that allows interaction with objects and the environment. Through the proposed coupling of originally independent robotic trajectories, the approach also enables the execution of bimanual and tightly coupled cooperative tasks. We apply an iterative learning control algorithm to learn a coupling term, which is applied to the original trajectory in a feed-forward fashion and, thus, modifies the trajectory in accordance to the desired positions or external forces. A stability analysis and results of simulated and real-world experiments using two KUKA LWR arms for bimanual tasks and interaction with the environment are presented. By expanding on the framework of DMPs, we keep all the favorable properties, which is demonstrated with temporal modulation and in a two-agent obstacle avoidance task. [ABSTRACT FROM PUBLISHER]

Prospective authors are requested to submit new, unpublished manuscripts for inclusion in the upcoming event described in this call for papers. [ABSTRACT FROM AUTHOR]

These instructions give guidelines for preparing papers for this publication. Presents information for authors publishing in this journal. [ABSTRACT FROM PUBLISHER]