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Time interval between stimuli plays a critical role in Pavlov classical conditioning. In this paper, a full-functional memristive Pavlov associative memory circuit with inter-stimulus interval effect is proposed. Compared with previous works, the proposed circuit extends the Pavlov associative memory with time interval to three complex situations of conditioning and realizes bionic associative memory learning curves called inter-stimulus interval effect. On this basis, the phenomena related to time interval in classical conditioning, blocking and facilitation, are implemented. PSPICE is used to simulate the whole circuit, and the simulation results demonstrate above functions. Furthermore, an application on classification is extended on the basis of the proposed circuit. The application circuit is also verified by the simulation results in PSPICE. This paper provides a reference to associative memory based on memristor in complex time situations. [ABSTRACT FROM AUTHOR]

In many densely populated mega-cities around the world, metro systems are becoming overly saturated by the ever-increasing travel demand, which results in overcrowded stations, excessive delay, and unsafe anxieties among riders. The concept of extra-long trains (i.e., trains longer than station platforms) was recently proposed in the literature as a promising way to increase a metro line's capacity without additional infrastructure construction. This paper develops a general modeling framework to optimize train block configuration and operation protocols of a metro line so that extra-long trains can be used under varying demand distribution and infrastructure setting. The design problem is formulated as the integration of two coupled vehicle routing problems which simultaneously optimizes the train block configuration plan, door opening strategy, stop skipping strategy, and train dispatch schedule. This paper proposes two customized solution methods, including an adapted savings heuristic and a destroy-and-repair algorithm. A series of hypothetical examples are tested to demonstrate how the proposed solution approaches outperform an existing commercial solver even for small to moderate problem instances. Moreover, two real-world case studies, with very different demand patterns from two continents, are presented to test the effectiveness of using extra-long trains. Our results show that a metro line with extra-long train operations is capable of serving up to 20%–30% more passenger demand as compared to that with only regular trains, while at the same time producing a similar or lower passenger average travel time. • Design of extra-long trains (i.e., longer than station platforms) in a general setting. • Mixed-integer program to optimize train block configuration and operation protocols. • Customized solution methods (adapted savings and destroy-and-repair). • Extensive experiments with hypothetical and real-world data (from Beijing and Santiago). • Results show significantly increase in metro line capacity without infrastructure construction. [ABSTRACT FROM AUTHOR]

This paper is concerned with propagation phenomena for the solutions of the Cauchy problem associated with a two-patch one-dimensional reaction-diffusion model. It is assumed that each patch has a relatively well-defined structure which is considered as homogeneous. A coupling interface condition between the two patches is involved. We first study the spreading properties of solutions in the case when the per capita growth rate in each patch is maximal at low densities, a configuration which we call the KPP-KPP case, and which turns out to have some analogies with the homogeneous KPP equation in the whole line. Then, in the KPP-bistable case, we provide various conditions under which the solutions show different dynamics in the bistable patch, that is, blocking, virtual blocking (propagation with speed zero), or spreading with positive speed. Moreover, when propagation occurs with positive speed, a global stability result is proved. Finally, the analysis in the KPP-bistable frame is extended to the bistable-bistable case. [ABSTRACT FROM AUTHOR]

This paper describes the methodology underlying the matching between extra-EU counterparts in the Italian Customs and Monopolies Agency data with firms in the Bureau van Dijk Orbis database. Through different validation exercises, we show that the matches stemming from our proposed procedure are largely correct regarding both records and transaction values. The resulting corresponding tables can serve as a useful tool to shed light on the features of the counterparts of Italian firms active in international trade. [ABSTRACT FROM AUTHOR]

The shading and blocking factor plays a significant role in the design of a heliostat field. It is the most computationally expensive task during the optimization process of a heliostat field. Over time, different methods have been developed to calculate the extent of the optical losses associated with shading and blocking. This paper focuses on the famous center point projection method and its implementation using Matlab. This work provides detailed procedures from the perspective of programming and simulation of central receiver systems. The underlying assumptions, the algorithm's strengths, and weaknesses are highlighted. The procedure and simulation parameters will help in developing optimization algorithms for designing high-efficiency heliostat fields. A dense radial staggered heliostat field is used for testing the performance of the algorithm. The field efficiency is calculated at different design points. The results show that the shading loss of the field changes with time, whereas there is negligible variation in the blocking loss. The instantaneous shading loss of a dense radial staggered field on December 21, noontime is 2.12%, whereas the blocking loss is 1.52%. [ABSTRACT FROM AUTHOR]

This paper focuses on the blocking flow shop scheduling problem with the objective of total flowtime minimisation. This problem assumes that there are no buffers between machines and, due to its application to many manufacturing sectors, it is receiving a growing attention by researchers during the last years. Since the problem is NP-hard, a large number of heuristics have been proposed to provide good solutions with reasonable computational times. In this paper, we conduct a comprehensive evaluation of the available heuristics for the problem and for related problems, resulting in the implementation and testing of a total of 35 heuristics. Furthermore, we propose an efficient constructive heuristic which successfully combines a pool of partial sequences in parallel, using a beam-search-based approach. The computational experiments show the excellent performance of the proposed heuristic as compared to the best-so-far algorithms for the problem, both in terms of quality of the solutions and of computational requirements. In fact, despite being a relative fast constructive heuristic, new best upper bounds have been found for more than 27% of Taillard’s instances. [ABSTRACT FROM AUTHOR]

• The general speed-density diagram of bidirectional pedestrian flow is proposed. • The speed-density diagram of bidirectional pedestrian flow is calibrated by the experimental data. • The pedestrian counter flow is simulated by using the collection of ordinary differential equations. • A pedestrian counter flow control model is proposed to avoid blocking in bidirectional corridors. In this paper, we develop a control model for pedestrian counter flow to avoid blocking in bidirectional corridors. Considering the conflict between two streams, we formulate a general speed-density diagram of bidirectional pedestrian flow based on the previous models in the literature. To accommodate a possible inhomogeneous pedestrian density along the corridor and inflows from various directions, the corridor is divided into several sections. A pedestrian counter flow model is developed to simulate the pedestrian flow between sections by using a collection of ordinary differential equations. The control objective is proposed based on user equilibrium and a capacity-oriented principle, and a linear feedback control model is developed to achieve a controlled inflow that reduces the density of each section to an acceptable level. The level of service of the corridor is improved, and blocking is eliminated by the proposed control model. Finally, sensitivity analysis suggests that the model performance can be improved if the conflict level is reduced. [ABSTRACT FROM AUTHOR]

In the optimal design literature for paired comparison choice experiments it has been proposed that respondent heterogeneity can be modelled by introducing fixed block effects into the linear predictor of the multinomial logit model and D -optimal utility-neutral designs for the modified version of the model have been derived by orthogonally blocking D -optimal utility-neutral designs for the model without block effects. In this paper, we first discuss the proper interpretation of the block effects showing that they only explain a special and non-standard type of respondent heterogeneity which refers to the order in which the alternatives in each pair are presented. Secondly, for the special case of the choice model with block effects in which the main effects of K two-level attributes are to be estimated we show how by using a previously unnoticed relationship with blocked two-level main effects plans for the linear 2 K factorial model new designs for choice experiments can be constructed. These designs are usually non-orthogonally blocked and locally D -optimal in a certain subclass of designs. [ABSTRACT FROM AUTHOR]

• Mathematical notations and constraints of DHHFSP with blocking constraints is formulated. • NEH-Increase heuristic strategy is designed to allocate the jobs to heterogeneous factories. • The neighborhood search strategies cooperatively optimize the scheduling sequence. • A local intensification strategy is presented to reinforce the exploration ability. The hybrid flow shop and distributed flow shop problems have been extensively studied due to their wide industrial applications. However, the distributed heterogeneous hybrid flow shop problems (DHHFSP) with blocking constraints have not yet been well studied up to date. This paper considers how to arrange a variety of jobs to different heterogeneous factories, and each factory has a minimal makespan. The innovations of this paper lie in presenting a mathematical model of the DHHFSP with blocking constraints and designing a collaborative iterative greedy (CIG) algorithm. The CIG contains the problem-specific initialization strategy, the neighborhood search strategy, the destruction-reconstruction strategy, and the local intensification strategy. The cross-factory and inner-factory neighborhood search strategies based on two swap operators are adopted to reduce the blocking time. The local intensification strategy is developed to optimize the scheduling sequence of each factory. The proposed algorithm is empirically compared with five state-of-the-art algorithms on 60 different instance sets. The experimental results show that the proposed algorithm significantly outperforms the compared ones in terms of objective values and relative percentage deviation values. [ABSTRACT FROM AUTHOR]

Abstract: This paper focuses on the study of cyclic job-shop problems with transportation and blocking. Within this domain, there are many real world problems like large scale productions, robotic cells, software pipelining or hoist scheduling. The aim in general is to find, for each machine, a feasible order of all the operations processed on this machine, so that an objective function is optimised. In this paper, we consider the problem of minimising the cycle time (maximising the throughput) in a job-shop environment, where the jobs are transported by a single robot between the machines. Additionally to the problem description, we will give some explanations and interpretation possibilities of the problem height, which is often omitted in the literature. As the main contribution, we will present a new integer programming formulation and show that it outperforms an existing model from the literature. [Copyright &y& Elsevier]

Highlights • An iterated greedy algorithm for the total tardiness parallel blocking flow shop problem. • Constructive heuristics which considers the characteristics of the problem. • Design of experiments to calibrate and select the best variant. Abstract This paper proposes an iterated greedy algorithm for scheduling jobs in F parallel flow shops (lines), each consisting of a series of m machines without storage capacity between machines. This constraint can provoke the blockage of machines if a job has finished its operation and the next machine is not available. The criterion considered is the minimization of the sum of tardiness of all the jobs to schedule, i.e., minimization of the total tardiness of jobs. Notice that the proposed method is also valid for solving the Distributed Permutation Blocking Flow Shop Scheduling Problem (DBFSP), which allows modelling the scheduling process in companies with more than one factory when each factory has an identical flow shop configuration. Firstly, several constructive procedures have been implemented and tested to provide an efficient solution in terms of quality and CPU time. This initial solution is later improved upon with an iterated greedy algorithm that includes a variable neighbourhood search for interchanging or reassigning jobs from the critical line to other lines. Next, two strategies have been tested for selecting the critical line; the one with a higher total tardiness of jobs and the one with a job that has the highest tardiness. The experimental design chooses the best combination of initial solution and critical line selection. Finally, we compare the performance of the proposed algorithm against other benchmark algorithms proposed for the DPFSP, which have been adapted to the problem being considered here since, to the best of our knowledge, this is the first attempt to solve either the Parallel Blocking Flow Shop problem or the Distributed Blocking Flow Shop problem with the goal of minimizing total tardiness. This comparison has allowed us to confirm the good performance of the proposed method. [ABSTRACT FROM AUTHOR]

Abstract: An all-optical approach to achieve finer bandwidth granularity is to time division multiplex low capacity circuits on each wavelength channel and switch time–wavelength slots optically within the network. One such time-slotted network proposed in the literature is the Time Domain Wavelength Interleaved Network (TWIN), which eliminates slot switching within the network by using a non-reconfigurable core and an intelligent edge utilizing a fast tunable laser to emulate fast switching. In contrast to the TWIN, an optical time-slotted network which incorporates slot-switching within the network is the Time Wavelength Switched Network (TWSN), wherein the Time Wavelength Space Routers (TWSRs) are configured to change their routing pattern on a time-slot basis. The TWIN network assigns a unique wavelength to each node in the network and thus requires a total of wavelengths for an -node network. We call such a TWIN network as an unconstrained TWIN network. In this paper, we first provide integer linear programs and heuristic algorithms to solve the scheduling problem for a static traffic matrix (of connections) for both, the unconstrained TWIN and the TWSN networks and also compare their performances under a dynamic traffic scenario. To address the problem of scalability of the unconstrained TWIN network, we propose to design a wavelength-constrained (i.e., ) TWIN network with no switching (TWIN-NS) by using a multicasting strategy. We also propose a variant of the TWIN network which possesses switching capabilities only at the edge nodes (TWIN-ES). Overall, this paper compares both versions of the TWIN networks to the TWSN network and investigates the benefits of having a reconfigurable core as opposed to a non-reconfigurable one. [ABSTRACT FROM AUTHOR]

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Record linkage, referred to also as entity resolution, is the process of identifying pairs of records representing the same real world entity (e.g. a person) within a dataset or across multiple datasets. In order to reduce the number of record comparisons, record linkage frameworks initially perform a process referred to as blocking, which involves splitting records into a set of blocks using a partition (or blocking) scheme. This restricts comparisons among records that belong to the same block during the linkage process. Existing blocking methods are often evaluated using different metrics and independently of the choice of the subsequent linkage method, which makes the choice of an optimal approach very subjective. In this paper we demonstrate that existing evaluation metrics fail to provide strong evidence to support the selection of an optimal blocking method. We conduct an extensive evaluation of different blocking methods using multiple datasets and some commonly applied linkage techniques to show that evaluation of a blocking method must take into consideration the subsequent linkage phase. We propose a novel evaluation technique that takes into consideration multiple factors including the end-to-end running time of the combined blocking and linkage phases as well as the linkage technique used. We empirically demonstrate using multiple datasets that according to this novel evaluation technique some blocking methods can be fairly considered superior to others, while some should be deemed incomparable according to those factors. Finally, we propose a novel blocking method selection procedure that takes into consideration the linkage proficiency and end-to-end time of different blocking methods combined with a given linkage technique. We show that this technique is able to select the best or near best blocking method for unseen data. [ABSTRACT FROM AUTHOR]

This paper studies the symbolic reachability relations of a class of parameterized systems in the framework of regular model checking. The modules of each system are instantiated from a globally synchronized template, and each globally synchronized template is represented by a finite state automaton whose event set consists of global events and local events. It is shown that the symbolic reachability relations of these systems are effectively iteration-closed star languages. And for any iteration-closed star language, there exists a template with only global events that realizes it. Application of the symbolic reachability analysis to computing the entrance control functions that enforce deadlock freeness and blocking freeness is then illustrated for systems with idle modules. In particular, we show that the maximally permissive entrance control functions can be encoded using finite state automata. [ABSTRACT FROM AUTHOR]

This paper presents an efficient, exact and sustainable schedulability analysis for hierarchical scheduling when a hybrid scheduling strategy is applied to a uniprocessor real-time system. We concentrate on the situation in which each application is to run on a server with an earliest deadline first (EDF) scheduler, and the tasks of each application are required to meet their given hard real-time constraints. We show how blocking can be considered in a hierarchical system to let the applications and the tasks share non-preemptable resources at global and local levels. This hierarchical system model is easy to implement, and the proposed analysis does not require making any online scheduling decisions, hence no extra scheduling overhead is required. Through extensive experiments, we show that our schedulability analysis has a very high acceptance ratio for the application tasks and that the proposed analysis is also highly efficient; in nearly all cases, less than 12 times the calculations of the response time on average is required to complete an analysis for a set of tasks within an application. Therefore, the proposed schedulability analysis significantly reduces the required computations and increases the acceptance ratio. Furthermore, the proposed approach is quite general and there are no restrictions on the task parameters, each task could be periodic or sporadic, and they can have arbitrary relative deadlines. [ABSTRACT FROM AUTHOR]

With the increase in production levels, a pattern of industrial production has shifted from a single factory to multiple factories, resulting in a distributed production model. The distributed flowshop scheduling problem (DPFSP) is of great research significance as a frequent pattern in real production activities. In this paper, according to real-world scenarios, we have added blocking constraints and sequence-dependent setup times (SDST) to the DFSP and proposed a distributed blocking flowshop scheduling problem with sequence-dependent setup times (DBFSP_SDST). In a distributed environment, the allocation of resources and utilization have become an urgent problem to be solved. In addition, scheduling problems related to resource conservation have also attracted increasing attention. Therefore, we study DBFSP_SDST and consider minimizing the energy consumption cost of the critical factory (critical factory is the factory with maximum energy consumption cost) under resource balance. To tackle this problem, an effective iterated greedy algorithm based on a learning-based variable neighborhood search algorithm (VNIG) is proposed. In VNIG, an efficient construction heuristic is well designed. Two different local searches based on the characteristics of the proposed problem are developed to enhance the local exploitation by neighborhood searching. A learning-based selection variable neighborhood search strategy is designed to avoid the solution trapping in local optima. By conducting extensive simulation experiments, the proposed VNIG shows superior performance compared with artificial chemical reaction optimization (CRO, 2017), the discrete artificial bee colony algorithm (DABC, 2018), the iterative greedy algorithm with a variable neighborhood search scheme (IGR, 2021), and the evolution strategy approach (ES, 2022). • A mathematical model of an energy-balance DBFSP_SDST is formulated. • An efficient heuristic is presented to generate a high-quality initial solution. • Two different local searches based on the characteristics of the proposed problem are developed. • A learning-based selection variable neighborhood search is designed. • The VNIG shows superior performance compared with four algorithms on 90 instances. [ABSTRACT FROM AUTHOR]

The paper describes how to modify the two-sided Hari–Zimmermann algorithm for computation of the generalized eigenvalues of a matrix pair ( A, B ), where B is positive definite, to an implicit algorithm that computes the generalized singular values of a pair ( F, G ). In addition, we present blocking and parallelization techniques for speedup of the computation. For triangular matrix pairs of a moderate size, numerical tests show that the double precision sequential pointwise algorithm is several times faster than the Lapack DTGSJA algorithm, while the accuracy is slightly better, especially for small generalized singular values. Cache-aware algorithms, implemented either as the block-oriented, or as the full block algorithm, are several times faster than the pointwise algorithm. The algorithm is almost perfectly parallelizable, so parallel shared memory versions of the algorithm are perfectly scalable, and their speedup almost solely depends on the number of cores used. A hybrid shared/distributed memory algorithm is intended for huge matrices that do not fit into the shared memory. [ABSTRACT FROM AUTHOR]

This paper presents a high performing Discrete Artificial Bee Colony algorithm for the blocking flow shop problem with flow time criterion. To develop the proposed algorithm, we considered four strategies for the food source phase and two strategies for each of the three remaining phases (employed bees, onlookers and scouts). One of the strategies tested in the food source phase and one implemented in the employed bees phase are new. Both have been proved to be very effective for the problem at hand. The initialization scheme named HPF2( λ , μ ) in particular, which is used to construct the initial food sources, is shown in the computational evaluation to be one of the main procedures that allow the DABC_RCT to obtain good solutions for this problem. To find the best configuration of the algorithm, we used design of experiments (DOE). This technique has been used extensively in the literature to calibrate the parameters of the algorithms but not to select its configuration. Comparing it with other algorithms proposed for this problem in the literature demonstrates the effectiveness and superiority of the DABC_RCT. [ABSTRACT FROM AUTHOR]

In this paper, we develop an approximation method for throughput in tandem queues with multiple independent reliable servers at each stage and finite buffers between service stations. We consider the blocking after service (BAS) blocking protocol of each service stage. The service time distribution of each server is exponential. The approximation is based on the decomposition of the system into a set of coupled subsystems which are modeled by two-stage tandem queue with two buffers and are analyzed by using the level dependent quasi-birth-and-death (LDQBD) process. [ABSTRACT FROM AUTHOR]

The blocking job shop (BJS) problem is an extension of a job shop problem with no buffer constraints. It means that after a job is completed on the current machine, it remains on that machine until the next machine becomes available. This paper addresses an extension of the BJS problem, which takes into account transferring jobs between different machines using a limited number of automated guided vehicles (AGV), called a BJS–AGV problem. Two integer non-linear programming (INLP) models are proposed. A two-stage heuristic algorithm that combines an improving timetabling method and a local search is proposed to solve the BJS–AGV problem. A neighborhood structure in the local search is proposed based on a disjunctive graph model. According to the characteristics of the BJS–AGV problem, four principles are proposed to guarantee the feasibility of the search neighborhood. Computation results are presented for a set of benchmarking tests, some of which are enlarged by transportation times between different machines. The numerical results show the effectiveness of the proposed two-stage algorithm. [ABSTRACT FROM AUTHOR]

Abstract: Linear aggregation in the input is an effective method to reduce the online computational burden of model predictive control (MPC) but at the cost of degradations in the closed-loop performance. In this paper, an improved aggregation-based MPC algorithm is developed to reduce these degradations. In this algorithm, a time-varying base vector is utilized in conjunction with the quasi-equivalent aggregation strategy. Furthermore, by relaxing the constraints with a sequence of reachable sets, a switching strategy is adopted to enlarge the attractive region of the resulting aggregation-based MPC. [Copyright &y& Elsevier]

• A mathematical model of a blocking hybrid flow shop scheduling problem with energy consumption criteria is proposed. • A simple global perturbation based on a half-swap operator is proposed to further search for the potentially best solution. • A local perturbation strategy based on a swap operator is designed to ensure the convergence of the algorithm. • The proposed algorithm is applied to 140 test instances with different scales and compared with state-of-the-art algorithms and can obtain the best solution to the BHFSP. With the continuous development of national economies, problems of various energy consumption levels and pollution emissions in manufacturing have attracted attention from researchers. Most existing research has focused on reducing economic costs and energy consumption. However, the Hybrid Flow Shop Scheduling Problem with energy-efficient criteria has not yet been well studied, especially with blocking constraints. This paper is the first to present a mathematical model of the blocking hybrid flow shop problem with an energy-efficient criterion and a modified Iterative Greedy algorithm based on a swap strategy designed to optimize the constructed model. In the proposed algorithm, first, a heuristic is adopted to generate the initial solution. Second, a local perturbation strategy based on a swap operator is designed to ensure the convergence of the algorithm. Third, a simple global perturbation strategy based on a half-swap operator is proposed as a means to further search for the potentially best solution with the traditional simulated annealing criterion. The proposed algorithm is applied to 150 test instances at different scales and compared to state-of-the-art algorithms. The experimental results demonstrate that the proposed algorithm outperforms the compared algorithms and can obtain a better solution. [ABSTRACT FROM AUTHOR]

Abstract: This paper proposes a discrete particle swarm optimization (DPSO) algorithm for the m-machine permutation flowshop scheduling problem with blocking to minimize the makespan, which has a strong industrial background, e.g., many production processes of chemicals and pharmaceuticals in chemical industry can be reduced to this problem. To prevent the DPSO from premature convergence, a self-adaptive diversity control strategy is adopted to diversify the population when necessary by adding a random perturbation to the velocity of each particle according to a probability controlled by the diversity of the current population. In addition, a stochastic variable neighborhood search is used as the local search to improve the search intensification. Computational results using benchmark problems show that the proposed DPSO algorithm outperforms previous algorithms proposed in the literature and that it can obtain 111 new best known upper bounds for the 120 benchmark problems. [Copyright &y& Elsevier]

Abstract: This paper demonstrates that antibody-modified field effect transistors (FETs), which were treated with bovine serum albumin (BSA) blocking, had quantitative capability for tumor marker detection in blood serum. Antibody-modified surface covered with 0.1% BSA effectively minimized nonspecific adsorption of blood proteins. Tumor markers with their isoelectric points of around 5 generated strong signals in body environmental pH (pH 7.4) in proteins with isoelectric points ranging from 3 to 10. Detection of a tumor marker alpha-fetoprotein in blood serum at required level for clinical diagnosis (10ng/mL) was achieved. The obtained results suggest that the fabricated FETs be expected to practical application in medical fields for direct detection of multi-tumor markers from blood. [Copyright &y& Elsevier]

Abstract: The paper describes several efficient parallel implementations of the one-sided hyperbolic Jacobi-type algorithm for computing eigenvalues and eigenvectors of Hermitian matrices. By appropriate blocking of the algorithms an almost ideal load balancing between all available processors/cores is obtained. A similar blocking technique can be used to exploit local cache memory of each processor to further speed up the process. Due to diversity of modern computer architectures, each of the algorithms described here may be the method of choice for a particular hardware and a given matrix size. All proposed block algorithms compute the eigenvalues with relative accuracy similar to the original non-blocked Jacobi algorithm. [Copyright &y& Elsevier]

Abstract: The analysis of the solar power collected at the receiver in solar tower systems requires the use of efficient and accurate numerical codes. This paper presents a new Fortran computer program, CRS4-2 (an acronym for Crs4 Research Software for Central Receiver Solar System SimulationS), for the simulation of the optical performance of a central receiver solar plant. The implemented mathematical algorithm allows for the calculation of cosine, shading and blocking effects for heliostats arbitrarily arranged in the solar field. Special attention has been given to ensure the maximum flexibility concerning the number, dimension, shape, and position of the heliostats. In the present implementation, the solar field can be composed of both square and circular heliostats possibly mixed together, each one of them characterized by the size and height from the ground. The modular design of CRS4-2 allows the extension to heliostats of arbitrary shape with only minor modifications of the code. Shading and blocking effects are computed by a tessellation of the heliostats: therefore, the numerical accuracy depends only on the refinement of the tessellation. The application to actual systems has shown that the approach is stable and general. [Copyright &y& Elsevier]

Abstract: An all-optical approach to reduce the speed mismatch between electronic sources and high-speed wavelength channels is to time-division multiplex low-capacity circuits onto each wavelength. In such a Time-Wavelength-Switched Network (TWSN), the optical crossconnects (OXCs) are configured to switch time-wavelength-slots within the network. The OXCs can be deployed with a bank of fiber delay lines (FDLs) to improve the connection slot scheduling and decrease the connection blocking probability. In this paper, we consider the two broad scenarios of sharing a bank of FDLs: shared per output link (SPL) and shared per crossconnect (SPC). We present several OXC architectures and develop graph formulations that can be used to optimally solve the scheduling problem. We also incorporate wavelength conversion and feedback in these architectures and study the impact of various FDL configurations on a crossconnect’s performance. Results using numerical simulations show that the FDL configuration does in fact affect the performance of the OXC. We also evaluate the performance of an OXC equipped with an FDL bank for both the SPL and SPC scenarios by considering sparse wavelength converters (limited number of full range wavelength converters). Results show that using sparse converters along with FDLs could provide significant benefits. [Copyright &y& Elsevier]

Abstract: In the present paper, it is first reminded that the probability of granular blocking of a suspension crossing a flow contraction increases with the number of particles crossing the obstacles, their volume fraction and the ratio between the diameter of the particles and the contraction gap. It is moreover reminded that this phenomenon can be described using a simple dimensionless geometric parameter as this phenomenon only slightly depends on the rheology of the suspending fluid. An adaptation of this dimensionless parameter to the specific case of concrete is proposed and compared to experimental results. Finally, an application to the prediction of the passing ability of Ordinary Rheology Concrete (ORC) and Self Compacting Concrete (SCC) is proposed and compared to the European technical recommendations. [Copyright &y& Elsevier]

• A magnetic field-based active stiffening control methodology for concrete is introduced. • To demonstrate the concept, pressure-driven flow of pastes through a narrow slit was investigated. • The confined flow of pastes containing magnetisable particles can be actively controlled by a magnetic field. Formwork leakage has become one of the important challenges of modern construction parallel to the increase in use of self-compacting cementitious materials. Excessive formwork pressure coupled with the highly flowable nature of these materials could lead to increased formwork leakage. This paper introduces a magnetic field-based active stiffening control methodology that could be beneficial for reducing formwork leakage during casting. As a demonstration of formwork leakage, pressure-driven flow through a narrow slit was investigated on magnetisable pastes containing 40% fly ash. The active stiffening control was incorporated by applying an external magnetic field at the outflow. The mass of the outflowing material was continuously recorded, and the flow rate and final net mass loss evaluated. Experimental results showed reduction in flow rate after applying the external magnetic field due to the agglomeration of magnetisable particles contained in the fly ash at the outflow region. It is concluded that the confined flow of pastes containing magnetisable particles can be actively controlled by the application of a magnetic field. The effectiveness of the introduced methodology is mainly dependent on the introduced magnetic field strength, paste viscosity, flow width to magnetisable particle size ratio and pressure level. [ABSTRACT FROM AUTHOR]

Can we rely on the analysis of flux decline to evaluate the risks of a filter media to be clogged during filtration of a given particle suspension? This important issue can be dealt with a macroscopic approach described in this paper. We seek to identify and quantify the successive prevailing mechanisms which occur during a filtration run, directly and solely from experimental flux data. This is achieved from the collection of experimental data (filtrate volume V vs. time t) and the use of the differential equation (d²t/dV²) = k(dt/dV)n. A methodology is then proposed to define and validate experimental procedures with the purpose of quantifying occurring fouling mechanism. For the purpose of illustrating its valuable impact for a bench marking procedure, the methodology has been applied on a model system composed of a bentonite suspension and a series of microfiltration membranes of different structures. [ABSTRACT FROM AUTHOR]

This paper focuses on the scheduling problem of flexible assembly systems (FASs) without intermediate buffers. The main characteristic of the problem is that as no intermediate buffer exists between consecutive machines, blocking and deadlock constraints must be considered. Petri nets are used to model the considered FASs, and a novel hybrid particle swarm optimization (HPSO) algorithm is proposed to minimize the makespan. The proposed algorithm is the combination of the discrete PSO, particle repairing algorithm, particle improvement strategy, and local search method. First, each candidate solution for the problem is encoded as a permutation with repetition of part numbers, and can be uniquely decoded into a sequence of transitions. To ensure the feasibility of solutions, a repairing algorithm is developed, in which a deadlock avoidance policy is used. Then, a particle improvement policy is proposed to improve the performance of particles. Meanwhile, a local search method is designed and incorporated into HPSO to improve its search ability. Experiments are conducted to verify the effectiveness of the particle improvement policy and local search method. Comparisons between HPSO and ten other algorithms are performed. The comparison results and analysis show that our proposed algorithm can find feasible solutions for all tested instances, and is superior to other scheduling algorithms in terms of finding better solutions and performance stability. [ABSTRACT FROM AUTHOR]

Abstract: It is known that for blocked designs a judicious sequencing of blocks may allow one to obtain early and insightful results regarding influential parameters in the experiment. Such findings may justify the early termination of the experiment thereby producing cost and time savings. This paper introduces an approach for selecting the optimal sequence of blocks for regular two-level blocked fractional factorial split-plot screening experiments. An optimality criterion is developed so as to give priority to the early estimation of low-order factorial effects. This criterion is then applied to the minimum aberration blocked fractional factorial split-plot designs tabled in McLeod and Brewster [2004. The design of blocked fractional factorial split-plot experiments. Technometrics 46, 135–146]. We provide a catalog of optimal block sequences for 16 and 32-run minimum aberration blocked fractional factorial split-plot designs run in either 4 or 8 blocks. [Copyright &y& Elsevier]

Abstract: The combination of techniques based on reordering data with classic code restructuring techniques for increasing the locality in the execution of sparse algebra codes is studied in this paper. The reordering techniques are based on, first modeling the locality in run-time, and then applying a heuristic for increasing it. After this, a code restructuring technique specially tuned for sparse algebra codes called register blocking is applied. The product of a sparse matrix by a dense vector (SpM × V) is the code studied on different monoprocessors and distributed memory multiprocessors. The combination of both techniques was tested for a broad set of matrices from real problems and known repositories. The results expressed in terms of execution time show that an adequate reordering of the data improves the efficiency of applying register blocking, therefore, reducing the execution time for the sparse algebra code considered. [Copyright &y& Elsevier]

Chen and Cheng (Ann. Statist. 27 (1999) 1948) got the relationships between a blocked symmetrical factorial design and its residual design. In this paper, we extend the study to the case of blocked mixed-level factorial designs. By introducing a concept of blocked consulting design and using MacWilliams identities and Krawtchouk polynomials in coding theory, we obtain combinatorial identities that govern the relationships between the partitioned wordlength patterns of a blocked regular mixed factorial design and that of its blocked consulting design. Based on these identities, we furthermore establish some general rules for identifying minimum aberration blocked mixed factorial designs in terms of their blocked consulting designs. As applications, some blocked 412n and 422n designs with 16 and 32 runs are tabulated. [Copyright &y& Elsevier]

This paper argues that true optionality does exist. It is even inherently tied up with the procedure of parameter setting in child language [Kampen, J. van, Proceedings of the Workshop on Optionality (1995), OTS, Utrecht University]. The marked value of a parameter is set by adding a grammatical feature to a lexical category. The enriched category requires a mere specific licensing and will in general block its initial less specified default variant. The default variant survives sometimes, leading to optionality. Two clear cases of optionality are presented here. The first case is pied-piping in Polish adult and in Dutch child language, the second case is long reflexives in Dutch. The two cases show how the optionality may be due to an independently existing licensing possibility within the same grammar. The alternative explanation by Kroch [J. Lang. Variat. Change 1.3 (1989) 244], Roeper [Bilingualism: Language and Cognition 2(3) (1999)] and Yang [Oxford University Press (2002)] of two co-existing grammars is rejected by the present proposal. [ABSTRACT FROM AUTHOR]

We consider the distributed blocking flowshop scheduling problem (DBFSP) which is a meaningful generalization of the blocking flowshop scheduling problem in the distributed production environment. The objective of minimizing the total flowtime is relevant and important in the current dynamic manufacturing environment, but, as far as we know, it has not been investigated in the DBFSP previously. In this paper, a population-based iterated greedy (PBIG) algorithm is proposed to solve the DBFSP with the total flowtime criterion, which takes the advantage of both the population-based search approach and the iterated greedy algorithm. First, an effective constructive heuristic is proposed by integrating two existing constructive approaches to initialize the population with a high level of quality and diversity. Second, three different procedures to generate the offspring solutions are tested for the effective exploration capability, each of which rationally combines the destruction, reconstruction and selection operator. Third, the insertion neighborhood and swap neighborhood are investigated to enhance the local exploitation ability and a hybrid local search procedure that utilizes simultaneously both the two neighborhoods are proposed. The comprehensive experimental evaluation based on a total of 720 well-known instances shows that the proposed algorithms outperform the existing effective algorithms at a significant margin. • We study the distributed blocking flowshop scheduling problem for total flowtime. • We propose a novel population-based iterated greedy algorithm. • We propose a constructive heuristic to obtain good initial solutions. • We propose three local search methods and three selection operators. • We compare the proposed algorithms with effective algorithms in the literature. [ABSTRACT FROM AUTHOR]

The hybrid flow shop scheduling problem is one of the most relevant optimization problem in manufacturing industry. In this paper, we investigate the blocking hybrid flow shop scheduling problem under the constraint of sequence dependent setup time. The objective is to minimize the total tardiness and earliness with uniform parallel machines under the constraint of sequence dependent setup time. To solve this kind of problems, significant developments of new meta-heuristic algorithms make it possible to implement new metaheuristics inspired by the behavior of living beings or natural phenomena. In this context, we suggest six algorithms based on the migratory bird optimization and the water wave optimization algorithms. We give three new versions for each meta-heuristic in order to solve this optimization problem. The main improvement of the suggested algorithms concerns the exploration phase of the neighborhood system. The enhancement approaches are based on the iterated greedy algorithm, the greedy randomized adaptive search procedure, the path relinking technique and the local search procedures. These modifications in the two nature inspired meta-heuristics make it possible to develop a new neighborhood generation structure constituting hybrid optimization algorithms. A comparative study between the different proposed methods is carried out on a variety of problems ranging from small to relatively large size instances. The simulations show good performances recorded by the water wave optimization algorithm in term of quality and convergence speed towards the best solution. • Blocking hybrid flow shop scheduling problem is studied. • Uniform parallel machines with setup time is considered. • Enhanced migratory bird algorithm is used to solve the problem. • Water wave optimization algorithm is considered. • Several benchmarks are used to evaluate the performance of algorithms. [ABSTRACT FROM AUTHOR]