Cyclic Route Research Articles

Sorting Out Interval Valued Neutrosophic Fuzzy Shortest Cycle Route Problem by Reduced Matrix Method

The assertiveness theory next addresses the difficulties of the travelling salesman after discussing the problem with transportation and assignment. The Shortest Cycling Route Problem (SCRP) finds the shortest route that stops in each city exactly once using a preset set of cities and their bilateral distances. The arc lengths in TSO are typically seen as representing travel time or travel expenses rather than actual distance. The precise arc length cannot be predicted because cargo, climate, road conditions, and other factors also can affect the journey time or cost. For handling the unpredictability in SCRP, fuzzy set theory provides a new tool. The shortest cyclic route problem with interval-valued neutrosophic fuzzy numbers as cost coefficients is solved using the simplified matrix techniques in this study. Reduced Matrix Method is used to solve a numerical problem and its efficacy is demonstrated.

Precedence constrained generalized traveling salesman problem: Polyhedral study, formulations, and branch-and-cut algorithm

The Precedence Constrained Generalized Traveling Salesman Problem (PCGTSP) is an extension of two well-known combinatorial optimization problems — the Generalized Traveling Salesman Problem (GTSP) and the Precedence Constrained Asymmetric Traveling Salesman Problem (PCATSP), whose path version is known as the Sequential Ordering Problem (SOP). Similarly to the classic GTSP, the goal of the PCGTSP, for a given input digraph and partition of its node set into clusters, is to find a minimum cost cyclic route (tour) visiting each cluster in a single node. In addition, as in the PCATSP, feasible tours are restricted to visit the clusters with respect to the given partial order. Unlike the GTSP and SOP, to the best of our knowledge, the PCGTSP still remain to be weakly studied both in terms of polyhedral theory and algorithms. In this paper, for the first time for the PCGTSP, we propose several families of valid inequalities, establish dimension of the PCGTS polytope and prove sufficient conditions ensuring that the extended Balas’ π- and σ-inequalities become facet-inducing. Relying on these theoretical results and evolving the state-of-the-art algorithmic approaches for the PCATSP and SOP, we introduce a family of MILP-models (formulations) and several variants of the branch-and-cut algorithm for the PCGTSP. We prove their high performance in a competitive numerical evaluation against the public benchmark library PCGTSPLIB, a known adaptation of the classic SOPLIB to the problem in question.

In-vivo quantification of electron flow through photosystem I – Cyclic electron transport makes up about 35% in a cyanobacterium

Photosynthetic electron flow, driven by photosystem I and II, provides chemical energy for carbon fixation. In addition to a linear mode a second cyclic route exists, which only involves photosystem I. The exact contributions of linear and cyclic transport are still a matter of debate. Here, we describe the development of a method that allows quantification of electron flow in absolute terms through photosystem I in a photosynthetic organism for the first time. Specific in-vivo protocols allowed to discern the redox states of plastocyanin, P700 and the FeS-clusters including ferredoxin at the acceptor site of PSI in the cyanobacterium Synechocystis sp. PCC 6803 with the near-infrared spectrometer Dual-KLAS/NIR. P700 absorbance changes determined with the Dual-KLAS/NIR correlated linearly with direct determinations of PSI concentrations using EPR. Dark-interval relaxation kinetics measurements (DIRKPSI) were applied to determine electron flow through PSI. Counting electrons from hydrogen oxidation as electron donor to photosystem I in parallel to DIRKPSI measurements confirmed the validity of the method. Electron flow determination by classical PSI yield measurements overestimates electron flow at low light intensities and saturates earlier compared to DIRKPSI. Combination of DIRKPSI with oxygen evolution measurements yielded a proportion of 35% of surplus electrons passing PSI compared to PSII. We attribute these electrons to cyclic electron transport, which is twice as high as assumed for plants. Counting electrons flowing through the photosystems allowed determination of the number of quanta required for photosynthesis to 11 per oxygen produced, which is close to published values.

The capacitated directed cycle hub location and routing problem under congestion

This paper deals with hub-and-spoke network design in the liner shipping sector. It introduces a capacitated directed cycle hub location and cargo routing problem under congestion. The problem involves four decisions: location of hub ports; allocation of non-hub ports to hub ports; construction of a directed cyclic route at the hub port network level; and the routing of cargo between all origin-destination demand pairs in the network. The objective is to minimize the cost which includes fixed hub opening, feeder collection and distribution, inter-hub transportation, cargo handling, and non-linear hub port congestion costs. We present a mixed integer linear programming model in which the non-linear congestion costs at the hub ports are approximated through a (semi-continuous) piecewise linear function and use this model to calculate lower bounds on the objective function. We also develop a Tabu Search algorithm, which employs a hierarchical approach for the different decisions in the hub-and-spoke network design problem, with customized procedures for the generation of the initial solution and the selection of the search moves. The neighborhood search is diversified by randomly changing the locations of hubs based on their location frequency history in previous solutions. Computational experiments, using instances from the literature and problems based on real-world data, demonstrate that the algorithm finds high quality solutions in a reasonable time. The experiments show that the network design can be highly influenced by scale economies in mainline vs. feeder transportation costs, the port locations and hinterland flows, and congestion at the hub ports.

A Compromise Decision Support Multi Objective Travelling Salesman Problem

The multi objective travelling salesman problem simultaneously optimizes several objectives. It is also called as shortest cyclic route model with multiple objectives provides the shortest route. In this article, the compromised decision support solutions are processed for a multi objective travelling salesman problem. The dynamic programming approach for optimal path with state space tree is used to get the shortest route for the objectives. Based on decision maker's preference, the compromised solution for the multi objective travelling salesman problem is obtained. The proposed methodology is very simple and easy way to get the shortest route which is illustrated with an example.

Promoting cooperation by setting a ceiling payoff for defectors under three-strategy public good games

ABSTRACTThe puzzle of altruistic behaviours among multi-agent systems poses a dilemma, which has been an overlapping topic that covers many subjects. The public goods game can be regarded as a paradigm for modelling and exploring it. In the traditional definition of public goods game, the equally divided benefit among all participants leads to the dominance of defection. Much effort has been made to explain the evolution of cooperation, including the model in which the payoff ceilings for defectors are introduced. Further, we study a three-strategy evolutionary public goods game by providing the role of being loners. The payoff ceilings will take effect when the number of cooperators exceeds some threshold. Analysis results by following the replicator dynamics indicate that lower values of the payoff ceilings can better promote levels of public cooperation. Importantly, a remarkable cyclic route has been found: when receiving relative lower benefits, loners act as catalysts, helping the population to escape from mutual defection to cooperation. And, the stable equilibrium points from cooperation to isolation can be realised by improving the fixed payoffs of loners. Finally, broader ceilings also for cooperators provide us more hints about how to suppress the spreading of defectors under certain conditions.

Fabrication of Ti-Al intermetallics by a two-stage aluminothermic reduction process using Na2TiF6

A novel two-stage method, based on aluminothermic reduction of Na2TiF6, has been proposed to prepare Ti-Al intermetallic alloys in this paper. The entire process of the two-stage aluminothermic reduction was introduced in detail. The result of thermal analysis demonstrated that the aluminothermic reduction reaction was an exothermic process and occurred at approximately 660 °C. Besides Ti-containing cryolite, pure Ti3Al, TiAl and TiAl3 intermetallics could be prepared after the first stage reduction. Further, in secondary reduction, Ti-containing cryolite contained Ti4+, TiOS and Ti-Al intermetallics could be purified completely. As a result, pure cryolite and Al-Ti alloy were obtained. A concept of continuous and cyclic route was proposed. The two-stage aluminothermic reduction process provided a high productivity and pollution-free metallurgical way for preparing Ti-Al intermetallic alloys.

A scheme for determining vehicle routes based on Arc-based service network design

ABSTRACTIn freight transportation, less-than-truckload carriers often need to assign each vehicle a cyclic route so that drivers can come back home after a certain period of time. However, the Node-Arc model for service network design addresses decisions on each arc and does not determine routes directly, although the vehicle balancing constraint ensures that the number of outgoing vehicles equals the number of incoming vehicles at each node. How to transform the optimized service network into a set of vehicle routes remains an important problem that has not yet been studied. In this paper, we propose a three-phase scheme to address this problem. In the first stage, we present an algorithm based on the depth-first search to find all of the different cyclic routes in a service network design solution. In the second stage, we propose to prune poor cyclic routes using real-life constraints so that a collection of acceptable vehicle routes can be obtained before route assignment. Some of the pruning can also be done in the first stage to speed up the proposed algorithm. In the third stage, we formulate the problem of selecting a set of cyclic routes to cover the entire network as a weighted set covering problem. The resulting model is formulated as an integer program and solved with IBM ILOG CPLEX solver. Experimental results on benchmark instances for service network design indicate the effectiveness of the proposed scheme which gives high-quality solutions in an efficient way.

Upconversion Properties of Y2(MoO4)3:Er3+/Yb3+ Particles Synthesized via Cyclic Microwave-Assisted Sol-Gel Route

Upconversion Properties of Y2(MoO4)3:Er3+/Yb3+ Particles Synthesized via Cyclic Microwave-Assisted Sol-Gel Route

Photoheterotrophic fluxome in Synechocystis sp. strain PCC 6803 and its implications for cyanobacterial bioenergetics.

This study investigated metabolic responses in Synechocystis sp. strain PCC 6803 to photosynthetic impairment. We used 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU; a photosystem II inhibitor) to block O2 evolution and ATP/NADPH generation by linear electron flow. Based on (13)C-metabolic flux analysis ((13)C-MFA) and RNA sequencing, we have found that Synechocystis sp. PCC 6803 employs a unique photoheterotrophic metabolism. First, glucose catabolism forms a cyclic route that includes the oxidative pentose phosphate (OPP) pathway and the glucose-6-phosphate isomerase (PGI) reaction. Glucose-6-phosphate is extensively degraded by the OPP pathway for NADPH production and is replenished by the reversed PGI reaction. Second, the Calvin cycle is not fully functional, but RubisCO continues to fix CO2 and synthesize 3-phosphoglycerate. Third, the relative flux through the complete tricarboxylic acid (TCA) cycle and succinate dehydrogenase is small under heterotrophic conditions, indicating that the newly discovered cyanobacterial TCA cycle (via the γ-aminobutyric acid pathway or α-ketoglutarate decarboxylase/succinic semialdehyde dehydrogenase) plays a minimal role in energy metabolism. Fourth, NAD(P)H oxidation and the cyclic electron flow (CEF) around photosystem I are the two main ATP sources, and the CEF accounts for at least 40% of total ATP generation from photoheterotrophic metabolism (without considering maintenance loss). This study not only demonstrates a new topology for carbohydrate oxidation but also provides quantitative insights into metabolic bioenergetics in cyanobacteria.

Land-use regression modelling of highway ultrafine particle number concentrations

Ultrafine particles (UFP; diameter < 100 nm) are suspended atmospheric solids of concern to human health due to their small diameters. Vehicles emit significant numbers of UFP, leading to steep spatial gradients on, and near, high traffic roadways. Particle number concentrations were measured while driving a cyclic route on four Toronto highways during non-rush hour weekday periods during the summer. These data were averaged over roadway length segments to create a concentration map of the route. Road segment-averaged concentrations were bimodal, and ranged from 26,000 to 106,500 particles cm-3, which is significantly greater than the average background downtown Toronto concentration (15,500 cm-3). A land-use regression model incorporating diesel truck traffic, six land use types, and distance to Lake Ontario, accounted for 34% of the variability of on-road concentrations. Understanding the complex spatial distribution of urban UFP is integral to designing epidemiological studies and understanding commute...

A New Method for Intelligent Message Network Management in Ubiquitous Sensor Networks

Ubiquitous Sensor Network (USN) computing is a useful technology forautonomic integrating in different environments which can be available anywhere.Managing USN plays an important role on the availability of nodes and paths. Inorder to manage nodes there is a cyclic route starts from manager, passing nodes,and come back to manager as feedback. In this paper, a new, self-optimizing methodpresented for finding this cyclic path by combining epsilon greedy and geneticalgorithm and then it is compared with other well-known methods in terms of cost ofthe route they find and the power consumption. The results show that the route thatis found by our new method costs at least 53% less than other methods. However insome cases, it uses 32% more energy for finding the route which can be compensatein traversing the shorter route. The overall simulation results in prototype data showthe effectiveness of the proposed method.

Exact solutions of some optimization problems of transport logistics

A problem for constructing the shortest cyclic route that ensures homogeneous cargo is delivered from producers to consumers by a transport vehicle of limited capacity is considered. Formalizations in the form of Boolean quadratic programming and linear integer programming problems are given. Comparative analysis of the efficiency of three exact algorithms is performed. The problem of finding the minimal admissible capacity of the transport vehicle is considered as an auxiliary problem. Dependence of the length of the optimal route on the capacity of the transport vehicle is studied experimentally.

Structural and magnetic investigation of styrene–divinylbenzene encapsulated iron oxide nanoparticles

The magnetite nanoparticles were prepared in the mesoporous styrene–divinylbenzene template by an in situ chemical cyclic route. Precipitation of magnetite occurred after adding NaOH into the Fe aqueous solution. Each nanoparticle was prepared in a layer-by-layer manner; N chemical synthesis cycles were applied. The crystalline quality and crystal phase were examined by X-ray diffraction (XRD) measurements. The size distribution was obtained from transmission electron microscopy (TEM). The particle size increased with the number of chemical cycles. Dynamic properties assessed by AC susceptibility revealed a slowing of the magnetic relaxation of the smaller particles due to dipolar interaction between nanoparticles. The AC data was well described by the Vogel–Fulcher relationship. The magnetic parameters obtained from magnetization hysteresis loops showed a dependence with N.

Upconversion Properties of Gd2(MoO4)3:Er3+/Yb3+ Green Phosphors Synthesized via Cyclic Microwave-Modified Sol-Gel Route

Upconversion Properties of Gd2(MoO4)3:Er3+/Yb3+ Green Phosphors Synthesized via Cyclic Microwave-Modified Sol-Gel Route

Preparation, Micromorphology and Optical Properties of SPION/BaWO4:Er3+, Yb3+ Composites via Cyclic Microwave-Assisted Metathetic Route

Preparation, Micromorphology and Optical Properties of SPION/BaWO4:Er3+, Yb3+ Composites via Cyclic Microwave-Assisted Metathetic Route

Integrated operation of the photorespiratory cycle and cytosolic metabolism in the modulation of primary nitrogen assimilation and export of organic N-transport compounds from leaves: A hypothesis

Photorespiration is generally considered to be an essentially dissipative process, although it performs some protective and essential functions. A theoretical appraisal indicates that the loss of freshly assimilated CO2 due to photorespiration in well-watered plants may not be as high as generally believed. Even under moderately adverse conditions, these losses may not exceed 10%. The photorespiratory metabolism of the source leaves of well-watered and well-nourished crop plants ought to be different from that of other leaves because the fluxes of the export of both carbohydrates and organic N-transport compounds in source leaves is quite high. With a heuristic approach that involved the dovetailing of certain metabolic steps with the photorespiratory cycle (PR-cycle), a novel network is proposed to operate in the source-leaves of well-watered and well-nourished plants. This network allows for the diversion of metabolites from their cyclic-routes in sizeable quantities. With the removal of considerable quantities of glycine and serine from the cyclic route, the number of RuBP oxygenation events would be several times those of the formation of hydroxypyruvate. Thus, to an extreme extent, photorespiratory metabolism would become open-ended and involve much less futile recycling of glycine and serine. Conversion of glyoxylate to glycine has been proposed to be a crucial step in the determination of the relative rates of the futile (cyclic) and anabolic (open-ended) routes. Thus, in the source leaves of well-watered and well-nourished plants, the importance of the cyclic route is limited to the salvaging of photorespiratory intermediates for the regeneration of RuBP. The proposed network is resilient enough to coordinate the rates of the assimilation of carbon and nitrogen in accordance with the moisture and N-fertility statuses of the soil.

Developing the Branch and Bound Method in the Problem of Searching for the Optimal Cyclic Route (Cyclic Rural Postman Problem)

A mathematical model is constructed for the applied problem of the optimization of closed routes, i.e., the rural postman problem. A two-stage method of the branch-and-bound type is proposed, which finds the solution or establishes the unsolvability of the problem. The first stage of the method includes testing the sufficient unsolvability conditions and the vertex-edge transformation procedure. This reduces the solution time at the second stage by the proposed modification of the Little algorithm. This procedure uses (for the first time) the partition of the solution set into disjoint subsets with the help of three branching rules and computation of the corresponding lower-bound estimates of the optimal solution. The proposed method correctly searches for the optimal solution of the Hamiltonian rural postman problem and of the general and Hamiltonian traveling salesman problems.

Preparation and Optical Properties of SPION/SrMoO4:Er3+, Yb3+ Composites via Cyclic Microwave-Assisted Metathetic Route

Preparation and Optical Properties of SPION/SrMoO4:Er3+, Yb3+ Composites via Cyclic Microwave-Assisted Metathetic Route

Quantifying the impact of inland transport times on container fleet sizing in liner shipping services with uncertainties

Container fleet sizing is a key issue in liner shipping industry. Although container shipping is an intermodal transport system, inland container movements are often beyond the control of shipping lines. It is vital to understand how the inland transport times and their variability affect the container fleet sizing. This paper first formulates the container fleet sizing problem in liner services with uncertain customer demands and stochastic inland transport times. Simulation-based optimisation approaches are then employed to solve the problem. Two typical shipping services, one cyclic route in trans-Pacific lane and the other more complicated route in Europe---Asia lane, are used as case studies. A quantitative relationship between the optimal container fleet size and the inland transport time is established. The impact of uncertainties in inland times on the fleet sizing is also investigated. The results provide shipping companies useful insights into making strategic decisions.