Solving the Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem by Dynamic Programming
DEFF Research Database (Denmark)
Rauff Lind Christensen, Tue; Klose, Andreas; Andersen, Kim Allan
The Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem (SSFCMCTP) is a problem with versatile applications. This problem is a generalization of the Single-Sink, Fixed-Charge Transportation Problem (SSFCTP), which has a fixed-charge, linear cost structure. However, in at least two...... important aspects of supplier selection, an important application of the SSFCTP, this does not reflect the real life situation. First, transportation costs faced by many companies are in fact piecewise linear. Secondly, when suppliers offer discounts, either incremental or all-unit discounts, such savings...
The single-sink fixed-charge transportation problem: Applications and solution methods
DEFF Research Database (Denmark)
Goertz, Simon; Klose, Andreas
2007-01-01
The single-sink fixed-charge transportation problem (SSFCTP) consists in finding a minimum cost flow from a number of supplier nodes to a single demand node. Shipping costs comprise costs proportional to the amount shipped as well as a fixed-charge. Although the SSFCTP is an important special case...... of the well-known fixed-charge transportation problem, just a few methods for solving this problem have been proposed in the literature. After summarising some applications of this problem arising in manufacturing and transportation, we give an overview on approximation algorithms and worst-case results...
The single-sink fixed-charge transportation problem: Applications and solution methods
DEFF Research Database (Denmark)
Goertz, Simon; Klose, Andreas
2007-01-01
The single-sink fixed-charge transportation problem (SSFCTP) consists in finding a minimum cost flow from a number of supplier nodes to a single demand node. Shipping costs comprise costs proportional to the amount shipped as well as a fixed-charge. Although the SSFCTP is an important special case...... of the well-known fixed-charge transportation problem, just a few methods for solving this problem have been proposed in the literature. After summarising some applications of this problem arising in manufacturing and transportation, we give an overview on approximation algorithms and worst-case results...
Algorithms for solving the single-sink fixed-charge transportation problem
DEFF Research Database (Denmark)
Klose, Andreas
2006-01-01
The single-sink fixed-charge transportation problem is an important subproblem of the fixed-charge transportation problem. Just a few methods have been proposed in the literature to solve this problem. In this paper, solution approaches based on dynamic programming and implicit enumeration...... are revisited. It is shown how the problem size as well as the search space of a recently published dynamic programming method can be reduced by exploiting reduced cost information. Additionally, a further implicit enumeration approach relying on solution concepts for the binary knapsack problem is introduced...
Solving the Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem by Dynamic Programming
DEFF Research Database (Denmark)
Rauff Lind Christensen, Tue; Klose, Andreas; Andersen, Kim Allan
are neglected in the SSFCTP. The SSFCMCTP overcome this problem by incorporating a staircase cost structure in the cost function instead of the usual one used in SSFCTP. We present a dynamic programming algorithm for the resulting problem. To enhance the performance of the generic algorithm a number......The Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem (SSFCMCTP) is a problem with versatile applications. This problem is a generalization of the Single-Sink, Fixed-Charge Transportation Problem (SSFCTP), which has a fixed-charge, linear cost structure. However, in at least two...... of enhancements is employed. The problem instance is reduced by variable pegging using a Lagrangean relaxation from which also a flow augmentation scheme is derived. Additionally a reduction in the search space is employed along with a variable transformation which generalizes a transformation known from...
An LP-based heuristic for the fixed charge transportation problem
DEFF Research Database (Denmark)
Klose, Andreas
2007-01-01
The fixed charge transportation problem consists in finding a minimum cost network flow from a set of suppliers to a set of customers. Beside costs proportional to quantities transported, transportation costs also include a fixed charge. The paper describes a linear programming based heuristic ap...... inequalities and flow cover inequalities, the approach also employs Fenchel cuts that are based on embedded 0-1 single node flow sets. Computational results obtained for a set of standard test problem instances are reported.......The fixed charge transportation problem consists in finding a minimum cost network flow from a set of suppliers to a set of customers. Beside costs proportional to quantities transported, transportation costs also include a fixed charge. The paper describes a linear programming based heuristic...... approach for computing lower and upper bounds on the minimal cost. To this end, the LP relaxation is iteratively strengthened by means of adding cuts; in each iteration the current LP solution is then used to guide a local search heuristic. In addition to standard polyhedral cuts as lifted cover...
Iterated local search and record-to-record travel applied to the fixed charge transportation problem
DEFF Research Database (Denmark)
Andersen, Jeanne; Klose, Andreas
, transportation costs do, however, include a fixed charge. Iterated local search and record-to-record travel are both simple local search based meta-heuristics that, to our knowledge, not yet have been applied to the FCTP. In this paper, we apply both types of search strategies and combine them into a single......The fixed charge transportation problem (FCTP) is a well-known and difficult optimization problem with lots of applications in logistics. It consists in finding a minimum cost network flow from a set of suppliers to a set of customers. Beside costs proportional to quantities transported...... heuristic search procedure for the FCTP. The hybrid approach results in a relatively efficient heuristic method, capable to improve the currently best known heuristics for the FCTP on some of the test problem instances usually considered in the literature....
Solving the Single-Sink, Fixed-Charge, Multiple-Choice Transportation Problem by Dynamic Programming
DEFF Research Database (Denmark)
Christensen, Tue; Andersen, Kim Allan; Klose, Andreas
2013-01-01
This paper considers a minimum-cost network flow problem in a bipartite graph with a single sink. The transportation costs exhibit a staircase cost structure because such types of transportation cost functions are often found in practice. We present a dynamic programming algorithm for solving...... this so-called single-sink, fixed-charge, multiple-choice transportation problem exactly. The method exploits heuristics and lower bounds to peg binary variables, improve bounds on flow variables, and reduce the state-space variable. In this way, the dynamic programming method is able to solve large...... instances with up to 10,000 nodes and 10 different transportation modes in a few seconds, much less time than required by a widely used mixed-integer programming solver and other methods proposed in the literature for this problem....
Alternate mutation based artificial immune algorithm for step fixed charge transportation problem
Directory of Open Access Journals (Sweden)
Mahmoud Moustafa El-Sherbiny
2012-07-01
Full Text Available Step fixed charge transportation problem (SFCTP is considered as a special version of the fixed-charge transportation problem (FCTP. In SFCTP, the fixed cost is incurred for every route that is used in the solution and is proportional to the amount shipped. This cost structure causes the value of the objective function to behave like a step function. Both FCTP and SFCTP are considered to be NP-hard problems. While a lot of research has been carried out concerning FCTP, not much has been done concerning SFCTP. This paper introduces an alternate Mutation based Artificial Immune (MAI algorithm for solving SFCTPs. The proposed MAI algorithm solves both balanced and unbalanced SFCTP without introducing a dummy supplier or a dummy customer. In MAI algorithm a coding schema is designed and procedures are developed for decoding such schema and shipping units. MAI algorithm guarantees the feasibility of all the generated solutions. Due to the significant role of mutation function on the MAI algorithm’s quality, 16 mutation functions are presented and their performances are compared to select the best one. For this purpose, forty problems with different sizes have been generated at random and then a robust calibration is applied using the relative percentage deviation (RPD method. Through two illustrative problems of different sizes the performance of the MAI algorithm has been compared with most recent methods.
Iterated local search and record-to-record travel applied to the fixed charge transportation problem
DEFF Research Database (Denmark)
Andersen, Jeanne; Klose, Andreas
, transportation costs do, however, include a fixed charge. Iterated local search and record-to-record travel are both simple local search based meta-heuristics that, to our knowledge, not yet have been applied to the FCTP. In this paper, we apply both types of search strategies and combine them into a single...
Analysis of some greedy algorithms for the single-sink fixed-charge transportation problem
DEFF Research Database (Denmark)
Görtz, Simon; Klose, Andreas
2009-01-01
-charge transportation problem. Nevertheless, just a few methods for solving this problem have been proposed in the literature. In this paper, some greedy heuristic solutions methods for the SSFCTP are investigated. It is shown that two greedy approaches for the SSFCTP known from the literature can be arbitrarily bad...
DEFF Research Database (Denmark)
Kannan, Devika; Govindan, Kannan; Soleimani, Hamed
2014-01-01
approaches are unable to solve real-world instances of such NP-hard problems in a reasonable time. These approaches involve cumbersome computational steps in real-size cases. In order to solve the mixed integer linear programming model, we develop an artificial immune system and a sheep flock algorithm...
The Generalized Fixed-Charge Network Design Problem
DEFF Research Database (Denmark)
Thomadsen, Tommy; Stidsen, Thomas K.
2007-01-01
In this paper we present the generalized fixed-charge network design (GFCND) problem. The GFCND problem is an instance of the so-called generalized network design problems. In such problems, clusters instead of nodes have to be interconnected by a network. The network interconnecting the clusters...... is a fixed-charge network, and thus the GFCND problem generalizes the fixed-charge network design problem. The GFCND problem is related to the more general problem of designing hierarchical telecommunication networks. A mixed integer programming model is described and a branch-cut-and-price algorithm...
求解固定费用运输问题的混沌人工蜂群算法%Chaos Artificial Bee Colony for Fixed-charged Transportation Problem
Institute of Scientific and Technical Information of China (English)
张永前; 蔡延光; 汤雅连
2013-01-01
The artificial bee artificial colony algorithm can fal into local y optima solution easily and emerge stagnation phenomenon,for the sake of overcoming these limitations, enhance the robustness and improve the global search ability,combining the chaos theory,the Chaos Artificial Bee Colony(CABC)algorithm was proposed.The basic thought was produce initial population by introducing chaos sequence into standard Artificial Bee Colony(ABC);the ergodic property can magnify the diversity of population and make it jump out of local y optima solution.Adapting the region of search of partial population dynamical y can accelerate the rate of convergence.After adapting the search space,in order to make the populaton adapt to the new environment,iterating several times before next compress.Experiment result shows the CABC is effective and efficient to solve the fixed-charged transpotation problem.% 针对人工蜂群算法容易陷入局部最优解，从而出现停滞现象，为了克服其局限性，增强算法的鲁棒性以及提高算法的全局搜索能力，结合混沌思想，提出了混沌人工蜂群算法。其基本思想是在标准人工蜂群算法中引入混沌序列产生初始种群，利用混沌的遍历性增大种群的多样性，使其跳出局部最优解；动态调整一部分种群的搜索区域，加快算法的收敛速度；在调整搜索空间后，每进行一次压缩，迭代几次，使群体适应新环境。实验证明利用该算法求解固定费用运输问题是有效可行的。
Tabu search methods for multicommodity capcitated fixed charge network design problem
Energy Technology Data Exchange (ETDEWEB)
Crainic, T.; Farvolden, J.; Gendreau, M.; Soriano, P.
1994-12-31
We address the fixed charge capacitated multicommodity network flow problem with linear costs and no additional side constraints, and present two solution approaches based on the tabu search metaheuristic. In the first case, the search is conducted by exploring the space of the design (integer) variables, while neighbors are evaluated and moves are selected via a capacitated multicommodity minimum cost network flow subproblem. The second approach integrates simplex pivoting rules into a tabu search framework. Here, the search explores the space of flow path variables when all design arcs are open, by using column generation to obtain new variables, and pivoting to determine and evaluate the neighbors of any given solution. Adapting this idea within our tabu search framework represents an interesting challenge, since several of the standard assumptions upon which column generation schemes are based are no longer verified. In particular, the monotonic decrease of the objective function value is no longer ensured, and both variable and fixed costs characterize arcs. On the other hand, the precise definition and generation of the tabu search neighborhoods in a column generation context poses an additional challenge, linked particularly to the description and identification of path variables. We describe the various components, implementation challenges and behaviour of each of the two algorithms, and compare their computational and solution quality performance. Comparisons with known bounding procedures will be presented as well.
Imteyaz, Shahla; Rafiuddin
2016-11-01
Polystyrene (PS) dispersed tin molybdate (TM) composite was prepared by sol-gel method. The membrane was characterized for its thermal stability by TG-DTA. SEM reveals the formation of composite material with uniform surface morphology. Crystallinity and phosphorylation of the membrane was confirmed by X-RD and FT-IR. Membrane potential of different monovalent electrolytes with varying concentration followed the order LiCl > NaCl > NH4Cl > KCl. Membrane potential increases with dilution of electrolytes confirming it to be cation selective in nature. The theoretical value of fixed charge density for the membrane was also evaluated from membrane potential using different approaches proposed by (a) Teorell-Meyer-Sievers (b) Kobatake and (c) Nagasawa, which are comparable with the experimental values. Fixed charge density examined for the electrolytes follows the order LiCl > NaCl > NH4Cl > KCl. Li+ ion shows highest value of fixed charge density in all the methods as the Donnan exclusion is highest for the electrolyte of smaller cation size. Transport number and mobility ratio for ion selectivity also increases with dilution. Membrane shows the lowest permselectivity for K+ while highest for Li+. The strong binding affinity of K+ counter-ion with fixed charge groups on the polymer decreases the membrane charge density and permselectivity. Thus, the membrane shows its applicability in various electro-membrane processes.
A review on fuzzy and stochastic extensions of the multi index transportation problem
Directory of Open Access Journals (Sweden)
Singh Sungeeta
2017-01-01
Full Text Available The classical transportation problem (having source and destination as indices deals with the objective of minimizing a single criterion, i.e. cost of transporting a commodity. Additional indices such as commodities and modes of transport led to the Multi Index transportation problem. An additional fixed cost, independent of the units transported, led to the Multi Index Fixed Charge transportation problem. Criteria other than cost (such as time, profit etc. led to the Multi Index Bi-criteria transportation problem. The application of fuzzy and stochastic concept in the above transportation problems would enable researchers to not only introduce real life uncertainties but also obtain solutions of these transportation problems. The review article presents an organized study of the Multi Index transportation problem and its fuzzy and stochastic extensions till today, and aims to help researchers working with complex transportation problems.
A Survey of Transportation Problems
2014-01-01
This paper aims at being a guide to understand the different types of transportation problems by presenting a survey of mathematical models and algorithms used to solve different types of transportation modes (ship, plane, train, bus, truck, Motorcycle, Cars, and others) by air, water, space, cables, tubes, and road. Some problems are as follows: bus scheduling problem, delivery problem, combining truck trip problem, open vehicle routing problem, helicopter routing problem, truck loading p...
Optimization techniques for Transportation Problems
Directory of Open Access Journals (Sweden)
Gauthaman.P
2017-06-01
Full Text Available This paper infers about optimization technique for various problems in transportation engineering. While for pavement engineering, maintenance is priority issue, for traffic it is signalling which is priority issue. Many optimization methods are discussed though given importance of genetic algorithm approach. While optimization techniques nearly approach practicality, research works are on for modern optimization techniques which not only adds ease of structure but also provide compatibility to modern day problems encountered in transportation engineering. Some of the modern tools are discussed to employ optimization techniques which are quite simple to use and implement once it is calibrated to the desired objective.
Elementary Investigation of Transportation Problems
Directory of Open Access Journals (Sweden)
Edit Schmidt
2009-07-01
Full Text Available For students learning the simplex method of linear programming it is a wellbelovedoccasion to solve the so-called transportation problem by the method ofdistribution. This method is simple to calculate and easy to follow. The simple way ofsolution suggests that its correctness may be proven by basic means. This paper has twomain aims. One of them is to present the problem and to solve it by basic means. The otherone is the analysis of the so-called array-bases defined for this reason. In case of atransportation problem m stores and n destinations are given, and the goods have to betaken from the stores to the destinations such that the cost of transporting has to beminimal. The unit costs of the transportation are given by an array. In the solution someroutes (elements of the array are chosen and the number of units to transport there isgiven. It will be proven that the routes for the optimal transportation compose a basis, andthe solution is also achieved by those through the searches. (The basis of an m n × arrayconsists of m+n−1 elements such that they do not span a loop. In the proof somecharacteristics of the bases are needed, for example that the number of them is finite. Toprove this it is enough to give an easily calculated upper bound, the exact value is given inthe appendix. As an extra result of this calculation some interesting formulas ofcombinatorics are also proven.
JIT-transportation problem and its algorithm
Bai, Guozhong; Gan, Xiao-Xiong
2011-12-01
This article introduces the (just-in-time) JIT-transportation problem, which requires that all demanded goods be shipped to their destinations on schedule, at a zero or minimal destination-storage cost. The JIT-transportation problem is a special goal programming problem with discrete constraints. This article provides a mathematical model for such a transportation problem and introduces the JIT solution, the deviation solution, the JIT deviation, etc. By introducing the B(λ)-problem, this article establishes the equivalence between the optimal solutions of the B(λ)-problem and the optimal solutions of the JIT-transportation problem, and then provides an algorithm for the JIT-transportation problems. This algorithm is proven mathematically and is also illustrated by an example.
Intelligent transportation systems problems and perspectives
Pamuła, Wiesław
2016-01-01
This book presents a discussion of problems encountered in the deployment of Intelligent Transport Systems (ITS). It puts emphasis on the early tasks of designing and proofing the concept of integration of technologies in Intelligent Transport Systems. In its first part the book concentrates on the design problems of urban ITS. The second part of the book features case studies representative for the different modes of transport. These are freight transport, rail transport and aerospace transport encompassing also space stations. The book provides ideas for deployment which may be developed by scientists and engineers engaged in the design of Intelligent Transport Systems. It can also be used in the training of specialists, students and post-graduate students in universities and transport high schools. .
OPTIMIZATION PROBLEMS ON SUBURBAN TRANSPORT SYSTEMS
T. M. Grigorovа
2015-01-01
The paper considers problems that permit to solve such issue as organization of transport service for suburban population with due account of passenger transport fatigue which is considered as one of subconscious criteria for selection of a travel mode. Improvement of transportation process entails an increase in demand for such service. Demands predetermine transport supply and situation on the market depends on supply-and-demand balance. The paper presents an analysis of approaches to the...
The problem of monopoly in rail transport
Directory of Open Access Journals (Sweden)
E.A. Petrenko
2012-04-01
Full Text Available In the article the issues of monopolism in the railway transport are under consideration. It was determined that the railway complex has all the hallmarks of a natural monopoly, a monopoly in the field of freight transportation over long distances. Functioning the railway transport in the form of state monopoly gives rise to a number of problems, which should be solved using the methods of state regulation.
Integrating routing decisions in public transportation problems
Schmidt, Marie E
2014-01-01
This book treats three planning problems arising in public railway transportation planning: line planning, timetabling, and delay management, with the objective to minimize passengers’ travel time. While many optimization approaches simplify these problems by assuming that passengers’ route choice is independent of the solution, this book focuses on models which take into account that passengers will adapt their travel route to the implemented planning solution. That is, a planning solution and passengers’ routes are determined and evaluated simultaneously. This work is technically deep, with insightful findings regarding complexity and algorithmic approaches to public transportation problems with integrated passenger routing. It is intended for researchers in the fields of mathematics, computer science, or operations research, working in the field of public transportation from an optimization standpoint. It is also ideal for students who want to gain intuition and experience in doing complexity proofs ...
Directory of Open Access Journals (Sweden)
Petri Tanska
2013-01-01
Full Text Available The aim of this study was to investigate if the experimentally detected altered chondrocyte volumetric behavior in early osteoarthritis can be explained by changes in the extracellular and pericellular matrix properties of cartilage. Based on our own experimental tests and the literature, the structural and mechanical parameters for normal and osteoarthritic cartilage were implemented into a multiscale fibril-reinforced poroelastic swelling model. Model simulations were compared with experimentally observed cell volume changes in mechanically loaded cartilage, obtained from anterior cruciate ligament transected rabbit knees. We found that the cell volume increased by 7% in the osteoarthritic cartilage model following mechanical loading of the tissue. In contrast, the cell volume decreased by 4% in normal cartilage model. These findings were consistent with the experimental results. Increased local transversal tissue strain due to the reduced collagen fibril stiffness accompanied with the reduced fixed charge density of the pericellular matrix could increase the cell volume up to 12%. These findings suggest that the increase in the cell volume in mechanically loaded osteoarthritic cartilage is primarily explained by the reduction in the pericellular fixed charge density, while the superficial collagen fibril stiffness is suggested to contribute secondarily to the cell volume behavior.
On the Control of the Fixed Charge Densities in Al2O3-Based Silicon Surface Passivation Schemes.
Simon, Daniel K; Jordan, Paul M; Mikolajick, Thomas; Dirnstorfer, Ingo
2015-12-30
A controlled field-effect passivation by a well-defined density of fixed charges is crucial for modern solar cell surface passivation schemes. Al2O3 nanolayers grown by atomic layer deposition contain negative fixed charges. Electrical measurements on slant-etched layers reveal that these charges are located within a 1 nm distance to the interface with the Si substrate. When inserting additional interface layers, the fixed charge density can be continuously adjusted from 3.5 × 10(12) cm(-2) (negative polarity) to 0.0 and up to 4.0 × 10(12) cm(-2) (positive polarity). A HfO2 interface layer of one or more monolayers reduces the negative fixed charges in Al2O3 to zero. The role of HfO2 is described as an inert spacer controlling the distance between Al2O3 and the Si substrate. It is suggested that this spacer alters the nonstoichiometric initial Al2O3 growth regime, which is responsible for the charge formation. On the basis of this charge-free HfO2/Al2O3 stack, negative or positive fixed charges can be formed by introducing additional thin Al2O3 or SiO2 layers between the Si substrate and this HfO2/Al2O3 capping layer. All stacks provide very good passivation of the silicon surface. The measured effective carrier lifetimes are between 1 and 30 ms. This charge control in Al2O3 nanolayers allows the construction of zero-fixed-charge passivation layers as well as layers with tailored fixed charge densities for future solar cell concepts and other field-effect based devices.
A Heuristic Adjacent Extreme Point Algorithm for the Fixed Charge Problem
1973-06-01
r.i*. - •»,-.,„ 4^ e a ’iß"’*M.’U3iuTr csea ■üia Any views expressed in this paper are those of the author. They should not be interpreted as...York, 1961. 4. Clark, R. M., and B. P. Helms, "Decentralized Solid Waste Col- lection Facilities," Journal of the Sanitary Engineering Division
Hub location problems in transportation networks
DEFF Research Database (Denmark)
Gelareh, Shahin; Nickel, Stefan
2011-01-01
In this paper we propose a 4-index formulation for the uncapacitated multiple allocation hub location problem tailored for urban transport and liner shipping network design. This formulation is very tight and most of the tractable instances for MIP solvers are optimally solvable at the root node....... also introduce fixed cost values for Australian Post (AP) dataset....
Resolving beam transport problems in electrostatic accelerators
Energy Technology Data Exchange (ETDEWEB)
Larson, J.D.
1977-01-01
A review is given of problem areas in beam transmission which are frequently encountered during the design, operation and upgrading of electrostatic accelerators. Examples are provided of analytic procedures that clarify accelerator ion optics and lead to more effective beam transport. Suggestions are made for evaluating accelerator design with the goal of improved performance.
OPTIMIZATION PROBLEMS ON SUBURBAN TRANSPORT SYSTEMS
Directory of Open Access Journals (Sweden)
T. M. Grigorovа
2015-01-01
Full Text Available The paper considers problems that permit to solve such issue as organization of transport service for suburban population with due account of passenger transport fatigue which is considered as one of subconscious criteria for selection of a travel mode. Improvement of transportation process entails an increase in demand for such service. Demands predetermine transport supply and situation on the market depends on supply-and-demand balance. The paper presents an analysis of approaches to the estimation of parameters for a suburban transport system with due regard for influence of transport process parameters on the rate of passenger transport fatigue. This rate is estimated through value of an index which demonstrates an activity of passenger’s regulatory systems while performing every element of motion process. Nonlinear regression equation has been used to describe changes in the activity index of the passenger’s regulatory systems when a passenger is taking a standing position in a passenger compartment of a suburban transport facility. In this case value of activity index of regulatory systems before transportation, passenger age, transportation duration, operation factor of transport capacity and ratio of new bus cost to nominal capacity have been taken as variables for calculations.The paper proposes an index change model for assessment of passenger’s transport fatigue when a passenger has a standing position in a transport facility. The model has shown that an impact of the activity index of passenger’s regulatory systems before making any elemental motion is rather pertinent because this index provides information on an initial condition of a person before executing any other elemental motion. The influence of the activity index of passenger’s regulatory systems before making any elemental motion is considered as an important characteristic because it has an impact on passenger’s condition after executing
Transport Test Problems for Hybrid Methods Development
Energy Technology Data Exchange (ETDEWEB)
Shaver, Mark W.; Miller, Erin A.; Wittman, Richard S.; McDonald, Benjamin S.
2011-12-28
This report presents 9 test problems to guide testing and development of hybrid calculations for the ADVANTG code at ORNL. These test cases can be used for comparing different types of radiation transport calculations, as well as for guiding the development of variance reduction methods. Cases are drawn primarily from existing or previous calculations with a preference for cases which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22.
Hybrid Predictive Control for Dynamic Transport Problems
Núñez, Alfredo A; Cortés, Cristián E
2013-01-01
Hybrid Predictive Control for Dynamic Transport Problems develops methods for the design of predictive control strategies for nonlinear-dynamic hybrid discrete-/continuous-variable systems. The methodology is designed for real-time applications, particularly the study of dynamic transport systems. Operational and service policies are considered, as well as cost reduction. The control structure is based on a sound definition of the key variables and their evolution. A flexible objective function able to capture the predictive behaviour of the system variables is described. Coupled with efficient algorithms, mainly drawn from the area of computational intelligence, this is shown to optimize performance indices for real-time applications. The framework of the proposed predictive control methodology is generic and, being able to solve nonlinear mixed-integer optimization problems dynamically, is readily extendable to other industrial processes. The main topics of this book are: ●hybrid predictive control (HPC) ...
Vikse, Krista; Khairallah, George N; McIndoe, J Scott; O'Hair, Richard A J
2013-05-14
A combination of multistage mass spectrometry experiments and density functional theory (DFT) calculations were used to examine the decarboxylation reactions of a series of metal carboxylate complexes bearing a fixed-charge phosphine ligand, [(O3SC6H4)(C6H5)2PM(I)O2CR](-) (M = Cu, Ag, Au; R = Me, Et, benzyl, Ph). Collision-induced dissociation (CID) of these complexes using an LTQ linear ion mass spectrometer results in three main classes of reactions being observed: (1) decarboxylation; (2) loss of the phosphine ligand; (3) loss of carboxylic acid. The gas-phase unimolecular chemistry of the resultant decarboxylated organometallic ions, [(O3SC6H4)(C6H5)2PM(I)R](-), were also explored using CID experiments, and fragment primarily via loss of the phosphine ligand. Energy-resolved CID experiments on [(O3SC6H4)(C6H5)2PM(I)O2CR](-) (M = Cu, Ag, Au; R = Me, Et, benzyl, Ph) using a Q-TOF mass spectrometer were performed to gain a more detailed understanding of the factors influencing coinage metal-catalyzed decarboxylation and DFT calculations on the major fragmentation pathways aided in interpretation of the experimental results. Key findings are that: (1) the energy required for loss of the phosphine ligand follows the order Ag phosphine ligand on decarboxylation is also considered in comparison with previous studies on metal carboxylates that do not contain a phosphine ligand.
THE PROBLEMS OF PASSENGER TRANSPORTATIONS IN AN INTERNATIONAL COMMUNICATION
Directory of Open Access Journals (Sweden)
Yu. S. Barash
2010-05-01
Full Text Available The basic aspects of international passenger transportations in Ukraine are represented. The analysis of present situation in these transportations is carried out. Some variants of solving the problems of passenger transportations in an international communication are considered.
Flow Merging and Hub Route Optimization in Collaborative Transportation
Directory of Open Access Journals (Sweden)
Kerui Weng
2014-01-01
Full Text Available This paper studies the optimal hub routing problem of merged tasks in collaborative transportation. This problem allows all carriers’ transportation tasks to reach the destinations optionally passing through 0, 1, or 2 hubs within limited distance, while a cost discount on arcs in the hub route could be acquired after paying fixed charges. The problem arises in the application of logistics, postal services, airline transportation, and so forth. We formulate the problem as a mixed-integer programming model, and provide two heuristic approaches, respectively, based on Lagrangian relaxation and Benders decomposition. Computational experiments show that the algorithms work well.
CAT SWARM OPTIMIZATION FOR SINGLE STAGE SUPPLY CHAIN DISTRIBUTION SYSTEM WITH FIXED CHARGES
Directory of Open Access Journals (Sweden)
P. Manimaran
2014-01-01
Full Text Available In this paper, Cat Swarm Optimization (CSO Algorithm is proposed for single stage supply chain distribution system with a fixed cost. This paper considers two kinds of cost: a continuous cost, that linearly increases with the amount transported between a supplier and a customer and a fixed cost, which is incurred whenever a non-zero quantity is transported between a supplier and a customer and it is independent of the amount transported. The aim of this paper is to determine the quantities to be distributed to satisfy the customer demand with minimum cost. Since fixed costs results discontinuities in the objective function, solution procedures are become more difficult and are known to be non-deterministic polynomial (NP hard. In this paper Cat Swarm Optimization (CSO Algorithm is proposed for the optimization of single stage supply chain problem to provide optimal or near optimal solution. The results of the proposed model of this paper have been compared with a spanning tree-based Genetic Algorithm and binary coded Genetic Algorithm. Computational results show the superiority of CSO algorithm over other algorithms.
CFTR: covalent and noncovalent modification suggests a role for fixed charges in anion conduction.
Smith, S S; Liu, X; Zhang, Z R; Sun, F; Kriewall, T E; McCarty, N A; Dawson, D C
2001-10-01
The goal of the experiments described here was to explore the possible role of fixed charges in determining the conduction properties of CFTR. We focused on transmembrane segment 6 (TM6) which contains four basic residues (R334, K335, R347, and R352) that would be predicted, on the basis of their positions in the primary structure, to span TM6 from near the extracellular (R334, K335) to near the intracellular (R347, R352) end. Cysteines substituted at positions 334 and 335 were readily accessible to thiol reagents, whereas those at positions 347 and 352 were either not accessible or lacked significant functional consequences when modified. The charge at positions 334 and 335 was an important determinant of CFTR channel function. Charge changes at position 334--brought about by covalent modification of engineered cysteine residues, pH titration of cysteine and histidine residues, and amino acid substitution--produced similar effects on macroscopic conductance and the shape of the I-V plot. The effect of charge changes at position 334 on conduction properties could be described by electrodiffusion or rate-theory models in which the charge on this residue lies in an external vestibule of the pore where it functions to increase the concentration of Cl adjacent to the rate-limiting portion of the conduction path. Covalent modification of R334C CFTR increased single-channel conductance determined in detached patches, but did not alter open probability. The results are consistent with the hypothesis that in wild-type CFTR, R334 occupies a position where its charge can influence the distribution of anions near the mouth of the pore.
Solving Hitchcock's transportation problem by a genetic algorithm
Institute of Scientific and Technical Information of China (English)
CHEN Hai-feng; CHO Joong Rae; LEE Jeong.Tae
2004-01-01
Genetic algorithms (GAs) employ the evolutionary process of Darwin's nature selection theory to find the solutions of optimization problems. In this paper, an implementation of genetic algorithm is put forward to solve a classical transportation problem, namely the Hitchcock's Transportation Problem (HTP), and the GA is improved to search for all optimal solutions and identify them automatically. The algorithm is coded with C++ and validated by numerical examples. The computational results show that the algorithm is efficient for solving the Hitchcock's transportation problem.
A class of ejecta transport test problems
Energy Technology Data Exchange (ETDEWEB)
Hammerberg, James E [Los Alamos National Laboratory; Buttler, William T [Los Alamos National Laboratory; Oro, David M [Los Alamos National Laboratory; Rousculp, Christopher L [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Mariam, Fesseha G [Los Alamos National Laboratory
2011-01-31
Hydro code implementations of ejecta dynamics at shocked interfaces presume a source distribution function ofparticulate masses and velocities, f{sub 0}(m, v;t). Some of the properties of this source distribution function have been determined from extensive Taylor and supported wave experiments on shock loaded Sn interfaces of varying surface and subsurface morphology. Such experiments measure the mass moment of f{sub o} under vacuum conditions assuming weak particle-particle interaction and, usually, fully inelastic capture by piezo-electric diagnostic probes. Recently, planar Sn experiments in He, Ar, and Kr gas atmospheres have been carried out to provide transport data both for machined surfaces and for coated surfaces. A hydro code model of ejecta transport usually specifies a criterion for the instantaneous temporal appearance of ejecta with source distribution f{sub 0}(m, v;t{sub 0}). Under the further assumption of separability, f{sub 0}(m,v;t{sub 0}) = f{sub 1}(m)f{sub 2}(v), the motion of particles under the influence of gas dynamic forces is calculated. For the situation of non-interacting particulates, interacting with a gas via drag forces, with the assumption of separability and simplified approximations to the Reynolds number dependence of the drag coefficient, the dynamical equation for the time evolution of the distribution function, f(r,v,m;t), can be resolved as a one-dimensional integral which can be compared to a direct hydro simulation as a test problem. Such solutions can also be used for preliminary analysis of experimental data. We report solutions for several shape dependent drag coefficients and analyze the results of recent planar dsh experiments in Ar and Xe.
Implict Monte Carlo Radiation Transport Simulations of Four Test Problems
Energy Technology Data Exchange (ETDEWEB)
Gentile, N
2007-08-01
Radiation transport codes, like almost all codes, are difficult to develop and debug. It is helpful to have small, easy to run test problems with known answers to use in development and debugging. It is also prudent to re-run test problems periodically during development to ensure that previous code capabilities have not been lost. We describe four radiation transport test problems with analytic or approximate analytic answers. These test problems are suitable for use in debugging and testing radiation transport codes. We also give results of simulations of these test problems performed with an Implicit Monte Carlo photonics code.
Ship Block Transportation Scheduling Problem Based on Greedy Algorithm
Directory of Open Access Journals (Sweden)
Chong Wang
2016-05-01
Full Text Available Ship block transportation problems are crucial issues to address in reducing the construction cost and improving the productivity of shipyards. Shipyards aim to maximize the workload balance of transporters with time constraint such that all blocks should be transported during the planning horizon. This process leads to three types of penalty time: empty transporter travel time, delay time, and tardy time. This study aims to minimize the sum of the penalty time. First, this study presents the problem of ship block transportation with the generalization of the block transportation restriction on the multi-type transporter. Second, the problem is transformed into the classical traveling salesman problem and assignment problem through a reasonable model simplification and by adding a virtual node to the proposed directed graph. Then, a heuristic algorithm based on greedy algorithm is proposed to assign blocks to available transporters and sequencing blocks for each transporter simultaneously. Finally, the numerical experiment method is used to validate the model, and its result shows that the proposed algorithm is effective in realizing the efficient use of the transporters in shipyards. Numerical simulation results demonstrate the promising application of the proposed method to efficiently improve the utilization of transporters and to reduce the cost of ship block logistics for shipyards.
Uncertain multi-objective multi-product solid transportation problems
Indian Academy of Sciences (India)
DEEPIKA RANI; T R GULATI
2016-05-01
The solid transportation problem is an important generalization of the classical transportation problem as it also considers the conveyance constraints along with the source and destination constraints. The problem can be made more effective by incorporating some other factors, which make it useful in real lifesituations. In this paper, we consider a fully fuzzy multi-objective multi-item solid transportation problem and present a method to find its fuzzy optimal-compromise solution using the fuzzy programming technique. To take into account the imprecision in finding the exact values of parameters, all the parameters are taken as trapezoidal fuzzy numbers. A numerical example is solved to illustrate the methodology
Problems of linear electron (polaron) transport theory in semiconductors
Klinger, M I
1979-01-01
Problems of Linear Electron (Polaron) Transport Theory in Semiconductors summarizes and discusses the development of areas in electron transport theory in semiconductors, with emphasis on the fundamental aspects of the theory and the essential physical nature of the transport processes. The book is organized into three parts. Part I focuses on some general topics in the theory of transport phenomena: the general dynamical theory of linear transport in dissipative systems (Kubo formulae) and the phenomenological theory. Part II deals with the theory of polaron transport in a crystalline semicon
SOLVING TRANSPORTATION PROBLEMS USING THE BEST CANDIDATES METHOD
Sadhak Gautam*, Mridul Jaggi, Santosh Anand
2016-01-01
Problem statement: The optimization processes in mathematics, computer science and economics are solving effectively by choosing the best element from set of available alternatives elements. The most important and successful applications in the optimization refers to transportation problem (TP), that is a special class of the linear programming (LP) in the operation research (OR). Approach: The main objective of transportation problem solution methods is to minimize the cost or the ...
Dynamic Flow Management Problems in Air Transportation
Patterson, Sarah Stock
1997-01-01
In 1995, over six hundred thousand licensed pilots flew nearly thirty-five million flights into over eighteen thousand U.S. airports, logging more than 519 billion passenger miles. Since demand for air travel has increased by more than 50% in the last decade while capacity has stagnated, congestion is a problem of undeniable practical significance. In this thesis, we will develop optimization techniques that reduce the impact of congestion on the national airspace. We start by determining the optimal release times for flights into the airspace and the optimal speed adjustment while airborne taking into account the capacitated airspace. This is called the Air Traffic Flow Management Problem (TFMP). We address the complexity, showing that it is NP-hard. We build an integer programming formulation that is quite strong as some of the proposed inequalities are facet defining for the convex hull of solutions. For practical problems, the solutions of the LP relaxation of the TFMP are very often integral. In essence, we reduce the problem to efficiently solving large scale linear programming problems. Thus, the computation times are reasonably small for large scale, practical problems involving thousands of flights. Next, we address the problem of determining how to reroute aircraft in the airspace system when faced with dynamically changing weather conditions. This is called the Air Traffic Flow Management Rerouting Problem (TFMRP) We present an integrated mathematical programming approach for the TFMRP, which utilizes several methodologies, in order to minimize delay costs. In order to address the high dimensionality, we present an aggregate model, in which we formulate the TFMRP as a multicommodity, integer, dynamic network flow problem with certain side constraints. Using Lagrangian relaxation, we generate aggregate flows that are decomposed into a collection of flight paths using a randomized rounding heuristic. This collection of paths is used in a packing integer
Real-Time Mass Passenger Transport Network Optimization Problems
2005-01-01
The aim of Real-Time Mass Transport Vehicle Routing Problem (MTVRP) is to find a solution to route n vehicles in real time to pick up and deliver m passengers. This problem is described in the context of flexible large-scale mass transportation options that use new technologies for communication among passengers and vehicles. The solution of such a problem is relevant to future transportation options involving large scale real-time routing of shared-ride fleet transit vehicles. However, the g...
Mathematical modeling/problem solving in global oxygen transport.
Farrell, Kevin; Hill, Andrew; Dent, Leon; Nguyen, Minh Ly
2009-08-01
A simplified approach to mathematical modeling/problem solving in global oxygen transport is presented. In addition to standard oxygen transport formulae, it uses the S-Factor and a mathematical relationship relating SvO(2) to the ratio DO(2)/VO(2). This method allows the determination or specification of SvO(2), PvO(2), P(50), and systemic shunting in the context of this simplified approach. Heretofore this has not been possible. With this approach, essentially all clinical problems in global oxygen transport can be dealt with. This is illustrated by the broad scope of the five problems presented.
Energy Technology Data Exchange (ETDEWEB)
Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States); Davidson, Carolyn [National Renewable Energy Lab. (NREL), Golden, CO (United States); McLaren, Joyce [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, John [National Renewable Energy Lab. (NREL), Golden, CO (United States)
2015-09-01
With rapid growth in energy efficiency and distributed generation, electric utilities are anticipating stagnant or decreasing electricity sales, particularly in the residential sector. Utilities are increasingly considering alternative rates structures that are designed to recover fixed costs from residential solar photovoltaic (PV) customers with low net electricity consumption. Proposed structures have included fixed charge increases, minimum bills, and increasingly, demand rates - for net metered customers and all customers. This study examines the electricity bill implications of various residential rate alternatives for multiple locations within the United States. For the locations analyzed, the results suggest that residential PV customers offset, on average, between 60% and 99% of their annual load. However, roughly 65% of a typical customer's electricity demand is non-coincidental with PV generation, so the typical PV customer is generally highly reliant on the grid for pooling services.
Air stable n-doping of WSe2 by silicon nitride thin films with tunable fixed charge density
Chen, Kevin; Kiriya, Daisuke; Hettick, Mark; Tosun, Mahmut; Ha, Tae-Jun; Madhvapathy, Surabhi Rao; Desai, Sujay; Sachid, Angada; Javey, Ali
2014-09-01
Stable n-doping of WSe2 using thin films of SiNx deposited on the surface via plasma-enhanced chemical vapor deposition is presented. Positive fixed charge centers inside SiNx act to dope WSe2 thin flakes n-type via field-induced effect. The electron concentration in WSe2 can be well controlled up to the degenerate limit by simply adjusting the stoichiometry of the SiNx through deposition process parameters. For the high doping limit, the Schottky barrier width at the metal/WSe2 junction is significantly thinned, allowing for efficient electron injection via tunneling. Using this doping scheme, we demonstrate air-stable WSe2 n-MOSFETs with a mobility of ˜70 cm2/V s.
TRANSPORT PROBLEM AND ITS APPLICATION IN “VICTORIA” COMPANY
Directory of Open Access Journals (Sweden)
Ruchinskaya Y. S.
2015-05-01
Full Text Available The article is devoted to optimization of transport streams. The authors investigate the concept of "optimization of transport streams" and the solution of transport tasks by various methods, revealing the minimum cost of costs of transportation of production. The volume of transport tasks of a measure of industrialization of agriculture steadily increases, thus the volume of transportations as agriculture, and the industrial output delivered to agriculture grows. It is necessary to find the optimum structure of vehicles providing the minimum costs for transportation. This classical transport task has about two tens methods of the decision. In our article we study a route of the movement at which there will be minimum costs of transportation of the production on the example of “Viktoriya”. As sales now is one of the most traditional and significant scopes of information technologies, the emerging market of trade even more often faces problems, concerning automation of information and material streams. A widespread problem of this area is optimization of routes of the movement on delivery of goods. Its decision will allow: to guarantee timely delivery of goods to the customer; to cut fuel consumption; to provide rational use of resources vehicle fleet. In the article the technique of creation of the plan of transportation of semi-finished products of "Domashnie Pelmeni" is offered for “Viktoriya” company
Bio-Inspired Meta-Heuristics for Emergency Transportation Problems
Directory of Open Access Journals (Sweden)
Min-Xia Zhang
2014-02-01
Full Text Available Emergency transportation plays a vital role in the success of disaster rescue and relief operations, but its planning and scheduling often involve complex objectives and search spaces. In this paper, we conduct a survey of recent advances in bio-inspired meta-heuristics, including genetic algorithms (GA, particle swarm optimization (PSO, ant colony optimization (ACO, etc., for solving emergency transportation problems. We then propose a new hybrid biogeography-based optimization (BBO algorithm, which outperforms some state-of-the-art heuristics on a typical transportation planning problem.
TRANSPORT CORRIDOR "URAL INDUSTRIAL – URAL POLAR": PROBLEMS, EVOLUTION PATHS
Directory of Open Access Journals (Sweden)
N.V. Tabakov
2007-06-01
Full Text Available The article deals with the theoretic and methodological questions regarding the formation of a transport corridor "Urals industrial – Urals Polar". Analyzed are the main factors that affect the formation of the transport infrastructure. A big effect is centered around the world-view problem, which has to do with the occupation of a human, and the effect of it on nature. Put forth is the possibility to look upon the question of the formation of ma transport corridor "Urals industrial – Urals Polar" in the frame of the forming of the Ural-West-Siberian TPK, taking into account the global transport web.
Energy Technology Data Exchange (ETDEWEB)
RamIrez, Patricio [Departament de Fisica Aplicada, Universitat Politecnica de Valencia, E-46022 Valencia (Spain); Apel, Pavel Yu [Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Joliot-Curie street 6, 141980 Dubna (Russian Federation); Cervera, Javier; Mafe, Salvador [Departament de Fisica de la Terra i Termodinamica, Universitat de Valencia, E-46100 Burjassot (Spain)], E-mail: patraho@fis.upv.es
2008-08-06
We present a complete theoretical study of the relationship between the structure (tip shape and dimensions) and function (selectivity and rectification) of asymmetric nanopores on the basis of previous experimental studies. The theoretical model uses a continuum approach based on the Nernst-Planck equations. According to our results, the nanopore transport properties, such as current-voltage (I-V) characteristics, conductance, rectification ratio, and selectivity, are dictated mainly by the shape of the pore tip (we have distinguished bullet-like, conical, trumpet-like, and hybrid shapes) and the concentration of pore surface charges. As a consequence, the nanopore performance in practical applications will depend not only on the base and tip openings but also on the pore shape. In particular, we show that the pore opening dimensions estimated from the pore conductance can be very different, depending on the pore shape assumed. The results obtained can also be of practical relevance for the design of nanopores, nanopipettes, and nanoelectrodes, where the electrical interactions between the charges attached to the nanostructure and the mobile charges confined in the reduced volume of the inside solution dictate the device performance in practical applications. Because single tracks are the elementary building blocks for nanoporous membranes, the understanding and control of their individual properties should also be crucial in protein separation, water desalination, and bio-molecule detection using arrays of identical nanopores.
An Exact Algorithm for Multi – Product Bulk Transportation Problem
Directory of Open Access Journals (Sweden)
Purusotham, S
2011-09-01
Full Text Available The paper investigates an NP-Hard nature Problem, where several commodities are produced in several plant sites with capacity constraints, and distributed to several destination sites according todemands and transportation constraints. We deal with the special case where the cost of the transportation of the goods from plants to warehouse is a bulk cost. The problem becomes Multi-Product Bulk Transportation Problem (MPBTP where one desires to get the requirement of different products depending on the availabilityfrom any plants. The model intends to minimize the total cost of the bulk transportation for meeting the demands of all products specified over the planning horizon of various warehouses while satisfying the capacity availability of the production plants without according priorities to them at a given time/facility. The practical restriction is that the entire requirement of each warehouse is to meet from one or more plants and a plant can supply to any number of destinations subject to the capacity available of the product at it.For this problem we developed a Pattern Recognition Technique based Lexi Search Algorithm, which comes under the exact methods. The concepts and the algorithm involving in this problem are discussed with a suitable numerical example. We programmed the proposed Lexi Search algorithm using C. This algorithm takes less CPU run time and hence it suggested for solving the higher dimensional problems.
WHY FUZZY ANALYTIC HIERARCHY PROCESS APPROACH FOR TRANSPORT PROBLEMS?
2011-01-01
The evaluation of transport projects has become increasingly complex. Different aspects have to be taken into account and the consequences of the problems are usually far reaching and the different policy alternatives are numerous and difficult to predict. Several pressure or action groups have also emerged causing an even more complex decision making process. The use of multi criteria analysis for the evaluation of transport projects has increased due to this increasing complexity of the pro...
Multiple Choice Knapsack Problem: example of planning choice in transportation.
Zhong, Tao; Young, Rhonda
2010-05-01
Transportation programming, a process of selecting projects for funding given budget and other constraints, is becoming more complex as a result of new federal laws, local planning regulations, and increased public involvement. This article describes the use of an integer programming tool, Multiple Choice Knapsack Problem (MCKP), to provide optimal solutions to transportation programming problems in cases where alternative versions of projects are under consideration. In this paper, optimization methods for use in the transportation programming process are compared and then the process of building and solving the optimization problems is discussed. The concepts about the use of MCKP are presented and a real-world transportation programming example at various budget levels is provided. This article illustrates how the use of MCKP addresses the modern complexities and provides timely solutions in transportation programming practice. While the article uses transportation programming as a case study, MCKP can be useful in other fields where a similar decision among a subset of the alternatives is required. Copyright 2009 Elsevier Ltd. All rights reserved.
Particle swarm optimization - Genetic algorithm (PSOGA) on linear transportation problem
Rahmalia, Dinita
2017-08-01
Linear Transportation Problem (LTP) is the case of constrained optimization where we want to minimize cost subject to the balance of the number of supply and the number of demand. The exact method such as northwest corner, vogel, russel, minimal cost have been applied at approaching optimal solution. In this paper, we use heurisitic like Particle Swarm Optimization (PSO) for solving linear transportation problem at any size of decision variable. In addition, we combine mutation operator of Genetic Algorithm (GA) at PSO to improve optimal solution. This method is called Particle Swarm Optimization - Genetic Algorithm (PSOGA). The simulations show that PSOGA can improve optimal solution resulted by PSO.
A hybrid ACO algorithm for the full truckload transportation problem
Doerner, Karl; Hartl, Richard F.; Reimann, Marc
2001-01-01
In this paper we propose a hybrid ACO approach to solve a full truckload transportation problem. Hybridization is achieved through the use of a problem specific heuristic. This heuristic is utilized both, to initialize the pheromone information and to construct solutions in the ACO pro-cedure. The main idea is to use information about the required fleetsize, by initializing the system with a number of vehicles rather than opening vehicles one at a time as needed. Our results show the advantag...
Nasir, Saima; Ali, Mubarak; Ramirez, Patricio; Gómez, Vicente; Oschmann, Bernd; Muench, Falk; Tahir, Muhammad Nawaz; Zentel, Rudolf; Mafe, Salvador; Ensinger, Wolfgang
2014-08-13
We designed and characterized a cylindrical nanopore that exhibits high electrochemical current rectification ratios at low and intermediate electrolyte concentrations. For this purpose, the track-etched single cylindrical nanopore in polymer membrane was coated with a gold (Au) layer via electroless plating technique. Then, a non-homogeneous fixed charge distribution inside the Au-coated nanopore was obtained by incorporating thiol-terminated uncharged poly(N-isopropylacrylamide) chains in series to poly(4-vinylpyridine) chains, which were positively charged at acidic pH values. The functionalization reaction was checked by measuring the current-voltage curves prior to and after the chemisorption of polymer chains. The experimental nanopore characterization included the effects of temperature, adsorption of chloride ions, electrolyte concentration, and pH of the external solutions. The results obtained are further explained in terms of a theoretical continuous model. The combination of well-established chemical procedures (thiol and self-assembled monolayer formation chemistry, electroless plating, ion track etching) and physical models (two-region pore and Nernst-Planck equations) permits the obtainment of a new nanopore with high current rectification ratios. The single pore could be scaled up to multipore membranes of potential interest for pH sensing and chemical actuators.
Formation of a Positive Fixed Charge at c -Si (111 )/a -Si3N3.5:H Interfaces
Hintzsche, L. E.; Fang, C. M.; Marsman, M.; Lamers, M. W. P. E.; Weeber, A. W.; Kresse, G.
2015-06-01
Modern electronic devices are unthinkable without the well-controlled formation of interfaces at heterostructures. These structures often involve at least one amorphous material. Modeling such interfaces poses a significant challenge, since a meaningful result can be expected only by using huge models or by drawing from many statistically independent samples. Here we report on the results of high-throughput calculations for interfaces between crystalline silicon (c -Si ) and amorphous silicon nitride (a -Si3N3.5:H ), which are omnipresent in commercially available solar cells. The findings reconcile only partly understood key features. At the interface, threefold-coordinated Si atoms are present. These are caused by the structural mismatch between the amorphous and crystalline parts. The local Fermi level of undoped c -Si lies well below that of a -Si N :H . To align the Fermi levels in the device, charge is transferred from the a -Si N :H part to the c -Si part resulting in an abundance of positively charged, threefold-coordinated Si atoms at the interface. This explains the existence of a positive, fixed charge at the interface that repels holes.
Directory of Open Access Journals (Sweden)
Thiago M Pinto
Full Text Available We present a model for the electric potential profile across the membranes of neuronal cells. We considered the resting and action potential states, and analyzed the influence of fixed charges of the membrane on its electric potential, based on experimental values of membrane properties of the spinal ganglion neuron and the neuroblastoma cell. The spinal ganglion neuron represents a healthy neuron, and the neuroblastoma cell, which is tumorous, represents a pathological neuron. We numerically solved the non-linear Poisson-Boltzmann equation for the regions of the membrane model we have adopted, by considering the densities of charges dissolved in an electrolytic solution and fixed on both glycocalyx and cytoplasmic proteins. Our model predicts that there is a difference in the behavior of the electric potential profiles of the two types of cells, in response to changes in charge concentrations in the membrane. Our results also describe an insensitivity of the neuroblastoma cell membrane, as observed in some biological experiments. This electrical property may be responsible for the low pharmacological response of the neuroblastoma to certain chemotherapeutic treatments.
Pinto, Thiago M; Wedemann, Roseli S; Cortez, Célia M
2014-01-01
We present a model for the electric potential profile across the membranes of neuronal cells. We considered the resting and action potential states, and analyzed the influence of fixed charges of the membrane on its electric potential, based on experimental values of membrane properties of the spinal ganglion neuron and the neuroblastoma cell. The spinal ganglion neuron represents a healthy neuron, and the neuroblastoma cell, which is tumorous, represents a pathological neuron. We numerically solved the non-linear Poisson-Boltzmann equation for the regions of the membrane model we have adopted, by considering the densities of charges dissolved in an electrolytic solution and fixed on both glycocalyx and cytoplasmic proteins. Our model predicts that there is a difference in the behavior of the electric potential profiles of the two types of cells, in response to changes in charge concentrations in the membrane. Our results also describe an insensitivity of the neuroblastoma cell membrane, as observed in some biological experiments. This electrical property may be responsible for the low pharmacological response of the neuroblastoma to certain chemotherapeutic treatments.
A method for unbalanced transportation problems in fuzzy environment
Indian Academy of Sciences (India)
Deepika Rani; T R Gulati; Amit Kumar
2014-06-01
In this paper, we consider the fully fuzzy unbalanced transportation problem in which the total availability/production is more than the total demand and propose a method to solve it. Such problems are usually solved by adding a dummy destination. Since the dummy destination has no existence in reality, the excess availability is not transported at all and is held back at one or more origins. The method proposed in this paper gives the additional information that to which of the destination(s) the excess availability be transported for future demand at minimum cost. The advantage of the proposed method over the existing method is that the fuzzy optimal solution obtained does not involve the dummy destination. The method has been illustrated with the help of an example.
A Heuristic Approach for International Crude Oil Transportation Scheduling Problems
Yin, Sisi; Nishi, Tatsushi; Izuno, Tsukasa
In this paper, we propose a heuristic algorithm to solve a practical ship scheduling problem for international crude oil transportation. The problem is considered as a vehicle routing problem with split deliveries. The objective of this paper is to find an optimal assignment of tankers, a sequence of visiting and loading volume simultaneously in order to minimize the total distance satisfying the capacity of tankers. A savings-based meta-heuristic algorithm with lot sizing parameters and volume assignment heuristic is developed. The proposed method is applied to solve a case study with real data. Computational results demonstrate the effectiveness of the heuristic algorithm compared with that of human operators.
Evaluation of Organizational Problems in Urban Transportation: Antakya Example
Directory of Open Access Journals (Sweden)
Turan ARSLAN
2011-01-01
Full Text Available Due to overlapping jurisdictional boundaries between the city municipality and township municipalities, Antakya resembles metropolises, however its administrative and regulatory framework are not similar; this particular situation creates a serious difficulty in solving especially transportation related problems. It results in conflicts within jurisdictions between the city and township municipalities particularly on taking actions against those problems. This, moreover, creates problems and hurdles in achieving sustainable development for the city. Especially the increasing use of private cars has, recently, put burdens on non-adequate transport infrastructure and aggravated the existing problems. The increasing congestion, accidents, and environmental and social problems call for necessary decisive actions and policies. However, in order to achieve success in the actions and policies, re-organization of the administrative structure of the transport policymaking is evident. In this paper, the attention is drawn to possible changes in the organization structure considering the objectives set out clearly in 5-year development programs of Turkey as well as experiences observed in developing and developed countries.
Speedup of Particle Transport Problems with a Beowulf Cluster
Directory of Open Access Journals (Sweden)
Zhongxiang Zhao
2006-01-01
Full Text Available The MCNP code is a general Monte Carlo N-Particle Transport program that is widely used in health physics, medical physics and nuclear engineering for problems involving neutron, photon and electron transport[1]. However, due to the stochastic nature of the algorithms employed to solve the Boltzmann transport equation, MCNP generally exhibits a slow rate of convergence. In fact, engineers and scientists can quickly identify intractable versions of their most challenging and CPU-intensive problems. For example, despite the latest advancements in personal computers (PCs and quantum leaps in their computational capabilities, an ordinary electron transport problem could require up to several CPU-days or even CPU-weeks on a typical desktop PC of today. One common contemporary approach to help address these performance limitations is by taking advantage of parallel processing. In fact, the very nature of the Monte Carlo approach embedded within MCNP is inherently parallel because, at least in principle, every particle history can potentially be tracked individually in an independent processor. In practice, however, there are many issues that must be confronted to achieve a reasonable level of parallelization. First, of course, a suitable parallel computing platform is required. Next, the computer program itself should exploit parallelism from within by combining such tools as Fortran-90 and PVM, for example. This article describes the installation and performance testing of the latest release of MCNP, Version 5 (MCNP5, compiled with PGI Fortran-90 and with PVM on a recently assembled 22-node Beowulf cluster that is now a dedicated platform for the faculty and students of the University of Cincinnatis Nuclear and Radiological Engineering (UCNRE Program. The performance of a neutron transport problem and that of a more challenging gamma-electron (coupled problem are both highlighted. The results show that the PVM-compiled MCNP5 version with 20 tasks
Activation energy of negative fixed charges in thermal ALD Al{sub 2}O{sub 3}
Energy Technology Data Exchange (ETDEWEB)
Kühnhold-Pospischil, S. [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, Albertstr. 21, 79104 Freiburg (Germany); Freiburg Materials Research Center FMF, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Str. 21, 79104 Freiburg (Germany); Saint-Cast, P.; Richter, A.; Hofmann, M. [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany)
2016-08-08
A study of the thermally activated negative fixed charges Q{sub tot} and the interface trap densities D{sub it} at the interface between Si and thermal atomic-layer-deposited amorphous Al{sub 2}O{sub 3} layers is presented. The thermal activation of Q{sub tot} and D{sub it} was conducted at annealing temperatures between 220 °C and 500 °C for durations between 3 s and 38 h. The temperature-induced differences in Q{sub tot} and D{sub it} were measured using the characterization method called corona oxide characterization of semiconductors. Their time dependency were fitted using stretched exponential functions, yielding activation energies of E{sub A} = (2.2 ± 0.2) eV and E{sub A} = (2.3 ± 0.7) eV for Q{sub tot} and D{sub it}, respectively. For annealing temperatures from 350 °C to 500 °C, the changes in Q{sub tot} and D{sub it} were similar for both p- and n-type doped Si samples. In contrast, at 220 °C the charging process was enhanced for p-type samples. Based on the observations described in this contribution, a charging model leading to Q{sub tot} based on an electron hopping process between the silicon and Al{sub 2}O{sub 3} through defects is proposed.
A contribution to problems of clean transport of bulk materials
Directory of Open Access Journals (Sweden)
Fedora Jaroslav
1996-03-01
Full Text Available The lecture analyses the problem of development of the pipe conveyor with a rubber belt, the facitities of its application in the practice and environmental aspects resulting from its application. The pipe conveyor is a new perspective transport system. It enables ransporting bulk materials (coal, crushed, rock, coke, plant ash, fertilisers, limestones, time in a specific operations (power plants, heating plants.cellulose, salt, sugar, wheat and other materials with a minimum effect on the environment. The transported material is enclosed in the pipeline so that there is no escape of dust, smell or of the transported material itself. The lecture is aimed at: - the short description of the operating principle and design of the pipe conveyor which was developed in the firm Matador Púchov in cooperation with the firm TEDO, - the analysis of experiencie in working some pipe conveyors which were under operation for a certain
Transport processes in space physics and astrophysics problems and solutions
Dosch, Alexander
2016-01-01
This is the problems and solution manual for the graduate text with the same title and published as Lecture Notes in Physics Vol 877 which provides the necessary mathematical and physics background to understand the transport of gases, charged particle gases, energetic charged particles, turbulence, and radiation in an astrophysical and space physics context. The very detailed and self-contained problems and solutions will be an essential part of the training of any graduate student wishing to enter and pursuing research in this field. .
Error estimation and adaptivity for transport problems with uncertain parameters
Sahni, Onkar; Li, Jason; Oberai, Assad
2016-11-01
Stochastic partial differential equations (PDEs) with uncertain parameters and source terms arise in many transport problems. In this study, we develop and apply an adaptive approach based on the variational multiscale (VMS) formulation for discretizing stochastic PDEs. In this approach we employ finite elements in the physical domain and generalize polynomial chaos based spectral basis in the stochastic domain. We demonstrate our approach on non-trivial transport problems where the uncertain parameters are such that the advective and diffusive regimes are spanned in the stochastic domain. We show that the proposed method is effective as a local error estimator in quantifying the element-wise error and in driving adaptivity in the physical and stochastic domains. We will also indicate how this approach may be extended to the Navier-Stokes equations. NSF Award 1350454 (CAREER).
An Algorithm for the Mixed Transportation Network Design Problem.
Liu, Xinyu; Chen, Qun
2016-01-01
This paper proposes an optimization algorithm, the dimension-down iterative algorithm (DDIA), for solving a mixed transportation network design problem (MNDP), which is generally expressed as a mathematical programming with equilibrium constraint (MPEC). The upper level of the MNDP aims to optimize the network performance via both the expansion of the existing links and the addition of new candidate links, whereas the lower level is a traditional Wardrop user equilibrium (UE) problem. The idea of the proposed solution algorithm (DDIA) is to reduce the dimensions of the problem. A group of variables (discrete/continuous) is fixed to optimize another group of variables (continuous/discrete) alternately; then, the problem is transformed into solving a series of CNDPs (continuous network design problems) and DNDPs (discrete network design problems) repeatedly until the problem converges to the optimal solution. The advantage of the proposed algorithm is that its solution process is very simple and easy to apply. Numerical examples show that for the MNDP without budget constraint, the optimal solution can be found within a few iterations with DDIA. For the MNDP with budget constraint, however, the result depends on the selection of initial values, which leads to different optimal solutions (i.e., different local optimal solutions). Some thoughts are given on how to derive meaningful initial values, such as by considering the budgets of new and reconstruction projects separately.
PROBLEMS AND PROSPECTS OF TRANSPORT TECHNOLOGY FOR VILLAGES
Directory of Open Access Journals (Sweden)
Byshоv N. V.
2015-03-01
Full Text Available Modern condition agricultural transport (a significant part of it about 70% is characterized by a strong deterioration of the rolling stock, the unsatisfactory state of the production base. More than 30% of vehicles operated outside the normative service life, the rest approaching to that state. In general, the provision of agrarian and industrial complex with agricultural vehicles is way below agrotechnical requirements. In the long term, farm machine engineering should focus on indicators of the technical level achieved by best samples of foreign agricultural machinery. Priority development is likely to receive the development of innovative technologies that provide a significant increase in productivity, efficiency and resource conservation in agriculture. To address the shortcomings of transport services agrarian and industrial complex we should improve transport technology with the use of transport logistics, expand and update the existing vehicle fleet, but due to the low solvency of agricultural companies and high prices for of automotive engineering, the problem of providing agricultural vehicles becomes most acute. Thus, the creation of new science-based solutions in technology and engineering for transportation farm produce in terms of Russia's AIC is the actual scientific and technical task that contributes significantly to the development of the country, as well as enhances the enjoyment of breakeven, competitive manufacturing
Mass Transport Vehicle Routing Problem (MTVRP) and the Associated Network Design Problem (MTNDP)
2005-01-01
This research studies a new class of dynamic problem MTVRP where n vehicles are routed in real time in a fast varying environment to pickup and deliver m passengers when both n and m are big. The problem is very relevant to future transportation options involving large scale real-time routing of shared-ride fleet transit vehicles. Traditionally, dynamic routing solutions were found as static approximations for smaller-scale problems or using local heuristics for the larger-scale ones. General...
The conservative characteristic FD methods for atmospheric aerosol transport problems
Fu, Kai; Liang, Dong
2016-01-01
In the paper, we develop the new conservative characteristic finite difference methods (C-CFD) for the atmospheric aerosol transport problems. We propose the time second-order and spatial high-order conservative characteristic finite difference methods for the aerosol vertical advection-diffusion process and the two-dimensional conservative characteristic finite difference methods for aerosol horizontal transport process in the second-order splitting algorithm. Based on the characteristic form of advection-diffusion equations tracking back along the characteristic curve, we treat the integrals over the tracking cells at the previous time level by the conservative interpolations and propose to treat the diffusion terms by the average along the characteristics, where the high-order discrete fluxes are obtained by approximating the cumulative mass function and are continuous at the tracking points. The important feature is that the proposed C-CFD schemes preserve mass and have second-order accuracy in time and high-order accuracy in space. Numerical tests are taken to show the accuracy in time and space and mass conservation of our C-CFD schemes, compared with the standard CFD method. A real case of air quality modelling during the 2008 Beijing Olympics and a severe haze in North China are further simulated and analyzed by using our C-CFD algorithm. Simulated results are in good agreement with observations. The developed C-CFD algorithm can be used for efficiently solving large scale atmospheric aerosol transport problems.
Directory of Open Access Journals (Sweden)
A.M. Shendrik
2014-03-01
Full Text Available The container gas transportation for low and medium level consumers as an alternative to pipelines is considered. The options for gas supply schemes, based on road and rail transport are given. The advantages and disadvantages of both types of gas transporting are described, the areas of their effective using are separated in the article. Promising implementations of technology in environment of economic crisis and also considering world trends of energy development are presented. The most advanced organization of compressed gas condensate transportation of unprepared gas fields in large diameter universal cylindrical balloons (up to 1000 mm are reasoned. The problem of compressed gas sea transportation are well disclosed, but the alternative ways of gas transportation by land are not investigated enough. Compressed Natural Gas (CNG Technology - is new promising technology for natural gas transportation by specially designed vessels – CNG-vessels. The feature of this technology is that natural gas can be downloaded directly near gas deposits and unloaded - directly into the customer's network. This eliminates significant capital investments in underwater pipelining or gas liquefaction plants. The main objects of investment are CNG-vessels themselves. The most attractive places for implementation of CNG-technology are sea (offshore natural gas deposits. Numerous international experts estimate the natural gas transportation by CNG-vessels in 1.5-2.0 times more cost-beneficial in comparison with offshore pipelines transportation, or in comparison with LNG (Liquefied Natural Gas shipping with natural gas transportation volume between 0.5 and 4.0 billion cubic meters per year on the route from 250 to 2,500 sea miles. This technology makes possible to provide gas supplement to the mountain and abounding in water areas, remote and weakly gasified regions. Described technology deserves special attention in the case of depleted and low-power oil and
A Solution Proposal To Indefinite Quadratic Interval Transportation Problem
Directory of Open Access Journals (Sweden)
Hasan Dalman
2013-12-01
Full Text Available The data of real world applications generally cannot be expressed strictly. An efficient way of handling this situation is expressing the data as intervals. Thus, this paper focus on the Indefinite Quadratic Interval Transportation Problem (IQITP in which all the parameters i.e. cost and risk coefficients of the objective function, supply and demand quantities are expressed as intervals. A Taylor series approach is presented for the solution of IQITP by means of the expression of intervals with its left and right limits. Also a numerical example is executed to illustrate the procedure.
Transportation problem: A special case for linear programing problems in mining engineering
Institute of Scientific and Technical Information of China (English)
Ali Mahrous A.M.; Sik Yang Hyung
2012-01-01
In real world applications the supply,the demand and the transportation cost per unit of the quantities in a transportation problem are hardly specified precisely because of the changing economic and environmental conditions.It is also important that the time required for transportation should be minimum.In this paper a method has been proposed for the minimization of transportation costs.Supply and transportation costs per unit of the quantities are also determined.The present study was carried out to evaluate the quality of gravel to know its suitability for aggregate (raw material for concrete and road).The samples of gravel were analyzed for petrographic,physical,mechanical and chemical properties.Samples were categorized as quartzite group and carbonate group according to ASTM standard 295.Among these,samples of quartzite group were found dominant.The petrography examination of gravels which was carried out constituted of opal,tridymite,chalcedony,crystobalite and alkali carbonates rocks.Those minerals react with alkalis in cement leading to expansion and cracking of concrete.Other components such as sulfides,sulfates,halites,iron oxides,clay minerals and anhydrites are examined,which might be present as coating and impurities.The present study indicated that all samples are suitable for concrete making and obtain the optimum solution for transporting these materials from quarries to cities with minimum cost according to Egyptian Code.
Dou, Y. N.; He, Y.; Huang, C. Y.; Zhou, C. L.; Ma, X. G.; Chen, R.; Chu, J. H.
2012-11-01
In this work, surface passivation of thermal atomic layer deposited (ALD) Al2O3 films on Si has been investigated. A quantitative analysis shows that field-effect passivation based on surface fixed charge combined with chemical passivation is assumed to contribute to the passivation performance and that a low defect density is critical to passivation quality. The surface fixed negative charge, which is exponentially modulated from ˜0 cm-2 to -2×1012 cm-2 by annealing, is proposed to have arisen from the reconstruction of the interfacial SiO x layer.
Dynamic Scheduling for Cloud Reliability using Transportation Problem
Directory of Open Access Journals (Sweden)
P. Balasubramanie
2012-01-01
Full Text Available Problem statement: Cloud is purely a dynamic environment and the existing task scheduling algorithms are mostly static and considered various parameters like time, cost, make span, speed, scalability, throughput, resource utilization, scheduling success rate and so on. Available scheduling algorithms are mostly heuristic in nature and more complex, time consuming and does not consider reliability and availability of the cloud computing environment. Therefore there is a need to implement a scheduling algorithm that can improve the availability and reliability in cloud environment. Approach: We propose a new algorithm using modified linear programming problem transportation based task scheduling and resource allocation for decentralized dynamic cloud computing. The Main objective is to improve the reliability of cloud computing environment by considering the resources available and itâs working status of each Cluster periodically and maximizes the profit for the cloud providers by minimizing the total cost for scheduling, allocation and execution cost and minimizing total turn-around, total waiting time and total execution time. Our proposed algorithm also utilizes task historical values such as past success rate, failure rate of task in each Cluster and previous execution time and total cost for various Clusters for each task from Task Info Container (TFC for tasks scheduling resource allocation for near future. Results: Our approach TP Scheduling (Transpotation Problem based responded for various tasks assigned by clients in poisson arrival pattern and achieved the improved reliability in dynamic decentralized cloud environment. Conclusion: With our proposed TP Scheduling algorithn we improve the Reliability of the decentralized dynamic cloud computing.
A note on the solution of fuzzy transportation problem using fuzzy linear system
Directory of Open Access Journals (Sweden)
P. Senthilkumar
2013-08-01
Full Text Available In this paper, we discuss the solution of a fuzzy transportation problem, with fuzzy quantities. The problem is solved in two stages. In the first stage, the fuzzy transportation problem is reduced to crisp system by using the lower and upper bounds of fuzzy quantities. In the second stage, the crisp transportation problems are solved by usual simplex method. The procedure is illustrated with numerical examples.
Modified Approach for Optimization of Real Life Transportation Problem in Neutrosophic Environment
Directory of Open Access Journals (Sweden)
Akanksha Singh
2017-01-01
Full Text Available To the best of our knowledge, there is only one approach for solving neutrosophic cost minimization transportation problems. Since neutrosophic transportation problems are a new area of research, other researchers may be attracted to extend this approach for solving other types of neutrosophic transportation problems like neutrosophic solid transportation problems, neutrosophic time minimization transportation problems, neutrosophic transshipment problems, and so on. However, after a deep study of the existing approach, it is noticed that a mathematical incorrect assumption has been used in these existing approaches; therefore there is a need to modify these existing approaches. Keeping the same in mind, in this paper, the existing approach is modified. Furthermore, the exact results of some existing transportation problems are obtained by the modified approach.
Optimum and equilibrium in a transport problem with queue effects
Crippa, Gianluca; Pratelli, Aldo
2008-01-01
Consider a distribution of citizens in an urban area in which some services (supermarkets, post offices...) are present. Each citizen, in order to use a service, spends an amount of time which is due both to the travel time to the service and to the queue time waiting in the service. The choice of the service to be used is made by every citizen in order to be served more quickly. Two types of problems can be considered: a global optimization of the total time spent by the citizens of the whole city (we define a global optimum and we study it with techniques from optimal mass transportation) and an individual optimization, in which each citizen chooses the service trying to minimize just his own time expense (we define the concept of equilibrium and we study it with techniques from game theory). In this framework we are also able to exhibit two time-dependent strategies (based on the notions of prudence and memory respectively) which converge to the equilibrium.
Health Problems and Risk Factors Associated with Long Haul Transport of Horses in Australia
Padalino, Barbara; Hall, Evelyn; Raidal, Sharanne; Celi, Pietro; Knight, Peter; Jeffcott, Leo; Muscatello, Gary
2015-01-01
Simple Summary Records from road transport of horses from Perth to Sydney over a two year period were analysed to explore the incidence of transport related issues and identify risk factors. Transportation resulted in health problems in 2.8% of the transported horses, and in fatalities in 0.24%. Journey duration and season were risk factors for the development of transport related health problems, while breed, sex and age did not predict disease or injury risk. Overall, this study provides statistics to inform policy development for the equine transport industry and enhance management of the transported horse. Abstract Equine transportation is associated with a variety of serious health disorders causing economic losses. However; statistics on horse transport are limited and epidemiological data on transport related diseases are available only for horses transported to abattoirs for slaughter. This study analysed reports of transport related health problems identified by drivers and horse owners for 180 journeys of an Australian horse transport company transporting horses between Perth and Sydney (~4000 km) in 2013–2015. Records showed that 97.2% (1604/1650) of the horses arrived at their destination with no clinical signs of disease or injury. Based on the veterinary reports of the affected horses; the most common issues were respiratory problems (27%); gastrointestinal problems (27%); pyrexia (19%); traumatic injuries (15%); and death (12%). Journey duration and season had a significant effect on the distribution of transport related issues (p < 0.05); with a marked increase of the proportion of the most severe problems (i.e., gastrointestinal; respiratory problems and death) in spring and after 20 h in transit. Although not statistically significant; elevated disease rate predictions were seen for stallions/colts; horses aged over 10 years; and Thoroughbreds. Overall; the data demonstrate that long haul transportation is a risk for horse health and welfare and
Energy Technology Data Exchange (ETDEWEB)
Verdu, G. [Departamento de Ingenieria Quimica Y Nuclear, Universitat Politecnica de Valencia, Cami de Vera, 14, 46022. Valencia (Spain); Capilla, M.; Talavera, C. F.; Ginestar, D. [Dept. of Nuclear Engineering, Departamento de Matematica Aplicada, Universitat Politecnica de Valencia, Cami de Vera, 14, 46022. Valencia (Spain)
2012-07-01
PL equations are classical high order approximations to the transport equations which are based on the expansion of the angular dependence of the angular neutron flux and the nuclear cross sections in terms of spherical harmonics. A nodal collocation method is used to discretize the PL equations associated with a neutron source transport problem. The performance of the method is tested solving two 1D problems with analytical solution for the transport equation and a classical 2D problem. (authors)
On bi-criteria two-stage transportation problem: a case study
Directory of Open Access Journals (Sweden)
Ahmad MURAD
2010-01-01
Full Text Available The study of the optimum distribution of goods between sources and destinations is one of the important topics in projects economics. This importance comes as a result of minimizing the transportation cost, deterioration, time, etc. The classical transportation problem constitutes one of the major areas of application for linear programming. The aim of this problem is to obtain the optimum distribution of goods from different sources to different destinations which minimizes the total transportation cost. From the practical point of view, the transportation problems may differ from the classical form. It may contain one or more objective function, one or more stage to transport, one or more type of commodity with one or more means of transport. The aim of this paper is to construct an optimization model for transportation problem for one of mill-stones companies. The model is formulated as a bi-criteria two-stage transportation problem with a special structure depending on the capacities of suppliers, warehouses and requirements of the destinations. A solution algorithm is introduced to solve this class of bi-criteria two-stage transportation problem to obtain the set of non-dominated extreme points and the efficient solutions accompanied with each one that enables the decision maker to choose the best one. The solution algorithm mainly based on the fruitful application of the methods for treating transportation problems, theory of duality of linear programming and the methods of solving bi-criteria linear programming problems.
Directory of Open Access Journals (Sweden)
Dr.M.S.Annie Christi,
2016-02-01
Full Text Available This paper presents a solution methodology for transportation problem in an intuitionistic fuzzy environment in which cost are represented by pentagonal intuitionistic fuzzy numbers. Transportation problem is a particular class of linear programming, which is associated with day to day activities in our real life. It helps in solving problems on distribution and transportation of resources from one place to another. The objective is to satisfy the demand at destination from the supply constraints at the minimum transportation cost possible. The problem is solved using a ranking technique called Accuracy function for pentagonal intuitionistic fuzzy numbers and Russell’s Method. An illustrative example is given to verify this approach.
Solving wood chip transport problems with computer simulation.
Dennis P. Bradley; Sharon A. Winsauer
1976-01-01
Efficient chip transport operations are difficult to achieve due to frequent and often unpredictable changes in distance to market, chipping rate, time spent at the mill, and equipment costs. This paper describes a computer simulation model that allows a logger to design an efficient transport system in response to these changing factors.
An Efficient Algorithm For Variant Bulk Transportation Problem
Directory of Open Access Journals (Sweden)
Sobhan Babu.K
2010-07-01
Full Text Available A large number of real-world planning problems called Combinatorial Optimization Problems share the following properties: They are Optimization Problems, are easy to state, and have a finite but usually very large number of feasible solutions. Lexi-Search is by far the mostly used tool for solving large scale NP-hard Combinatorial Optimization problems. Lexi-Search is, however, an algorithm paradigm, which has to be filled out for each specific problem type, and numerous choices for each of the components exist. Even then, principles for the design of efficient Lexi-Search algorithms have emerged over the years. Although Lexi-Search methods are among the most widely used techniques for solving hard problems, it is still a challenge to make these methods smarter. The motivation of the calculation of the lower bounds is based on ideas frequently used in solving problems. Computationally, the algorithm extended the size of problem and find better solution.
Fixing or Transferring Environmental Problems in the Transport Sector?
DEFF Research Database (Denmark)
Walnum, Hans Jakob
Transport accounts for 25 percent of global energy related greenhouse gas emissions and over half of the world’s oil consumption. The energy consumption is growing at a rate higher than any other sector. The thesis addresses some of the shortcomings with current policy strategies for reducing...... energy use and greenhouse gas emissions in the transport sector. The thesis fosters an in depth discussion of how geographical transfer effects, trade off effects and rebound effects are present in energy and climatic mitigation strategies in the transport sector. A better understanding of this could...
Tabu search algorithms for job-shop problems with a single transport robot
Hurink, Johann; Knust, Sigrid
2005-01-01
We consider a generalized job-shop problem where the jobs additionally have to be transported between the machines by a single transport robot. Besides transportation times for the jobs, empty moving times for the robot are taken into account. The objective is to determine a schedule with minimal ma
Tabu search algorithms for job-shop problems with a single transport robot
Hurink, J.L.; Knust, S.
2001-01-01
We consider a generalized job-shop problem where the jobs additionally have to be transported between the machines by a single transport robot. Besides transportation times for the jobs, empty moving times for the robot are taken into account. The objective is to determine a schedule with minimal ma
Health Problems and Risk Factors Associated with Long Haul Transport of Horses in Australia
Directory of Open Access Journals (Sweden)
Barbara Padalino
2015-12-01
Full Text Available Equine transportation is associated with a variety of serious health disorders causing economic losses. However; statistics on horse transport are limited and epidemiological data on transport related diseases are available only for horses transported to abattoirs for slaughter. This study analysed reports of transport related health problems identified by drivers and horse owners for 180 journeys of an Australian horse transport company transporting horses between Perth and Sydney (~4000 km in 2013–2015. Records showed that 97.2% (1604/1650 of the horses arrived at their destination with no clinical signs of disease or injury. Based on the veterinary reports of the affected horses; the most common issues were respiratory problems (27%; gastrointestinal problems (27%; pyrexia (19%; traumatic injuries (15%; and death (12%. Journey duration and season had a significant effect on the distribution of transport related issues ( p < 0.05; with a marked increase of the proportion of the most severe problems ( i.e. , gastrointestinal; respiratory problems and death in spring and after 20 h in transit. Although not statistically significant; elevated disease rate predictions were seen for stallions/colts; horses aged over 10 years; and Thoroughbreds. Overall; the data demonstrate that long haul transportation is a risk for horse health and welfare and requires appropriate management to minimize transport stress.
Health Problems and Risk Factors Associated with Long Haul Transport of Horses in Australia.
Padalino, Barbara; Hall, Evelyn; Raidal, Sharanne; Celi, Pietro; Knight, Peter; Jeffcott, Leo; Muscatello, Gary
2015-12-10
Equine transportation is associated with a variety of serious health disorders causing economic losses. However; statistics on horse transport are limited and epidemiological data on transport related diseases are available only for horses transported to abattoirs for slaughter. This study analysed reports of transport related health problems identified by drivers and horse owners for 180 journeys of an Australian horse transport company transporting horses between Perth and Sydney (~4000 km) in 2013-2015. Records showed that 97.2% (1604/1650) of the horses arrived at their destination with no clinical signs of disease or injury. Based on the veterinary reports of the affected horses; the most common issues were respiratory problems (27%); gastrointestinal problems (27%); pyrexia (19%); traumatic injuries (15%); and death (12%). Journey duration and season had a significant effect on the distribution of transport related issues ( p problems ( i.e. , gastrointestinal; respiratory problems and death) in spring and after 20 h in transit. Although not statistically significant; elevated disease rate predictions were seen for stallions/colts; horses aged over 10 years; and Thoroughbreds. Overall; the data demonstrate that long haul transportation is a risk for horse health and welfare and requires appropriate management to minimize transport stress.
Transportation problem with plant closure and relocation of machines
Directory of Open Access Journals (Sweden)
Lmariouh Jamal
2012-09-01
Full Text Available This paper is interested in a food industrial group which produces large quantities of sugar and distributes it to warehouses and customers. The group should review its distribution policy, in particular, to optimize transportation costs and reduce losses caused by the current organization. In this paper, we propose an integer linear model to optimize the travel of full loaded trucks taking into account respect of the groups peculiarities. We study a second integer linear model taking into account transportation and production costs and allowing the possibility of closing some plants. Finally, the last model aims to review the production capacity of each plant through a redeployment of its production lines.
Local matching indicators for transport problems with concave costs
Delon, Julie; Sobolevskii, Andrei
2011-01-01
In this paper, we introduce a class of indicators that enable to compute efficiently optimal transport plans associated to arbitrary distributions of N demands and M supplies in R in the case where the cost function is concave. The computational cost of these indicators is small and independent of N. A hierarchical use of them enables to obtain an efficient algorithm.
Dangerous Goods Transport Problems in the European Union and Poland
Directory of Open Access Journals (Sweden)
Gabriel Nowacki
2016-04-01
Full Text Available The paper refers to threat assessment of dangerous goods (DG in transportation of the European Union and the Republic of Poland. Dangerous goods in the European Union are carried by inland waterways, rail and road. In Poland 87.5% of DG have been carried by road and 12.5% by rail in 2014. DG can cause an accident and lead to fires, explosions and chemical poisoning or burning with considerable harm to people and the environment. There is not monitoring system in Poland to control in real time road transportation of dangerous goods. Proposition of National System of Monitoring Dangerous Goods in Poland was presented. Realization of mentioned kind of system may significantly contribute to improving safety of people and environment.
Preliminary identification of buffet problems in high speed civil transport
Ravindra, Krishnaswamy
1994-01-01
In the present study, some effort is made to identify whether empennage buffet is a relevant factor in the design and operation of the High Speed Civil Transport (HSCT). Based on some results of the only operational supersonic transport, Concorde and the innumerable studies that exist on the tail buffet of high performance airplanes, CFD analyses on the HSCT as well as low speed wind tunnel tests on models, it appears as though buffet will be a factor that needs attention in the proper design of empennage structure. Utilizing the existing empirical relation between the reduced frequency of the leading edge vortices and the geometric parameters, it is estimated that the characteristic frequencies of the vortices from the wing cranks are in the range of certain fundamental frequencies of the wing-fuselage-empennage structure. Buffet is believed to be critical during take-off, climb, descent and landing. Computational and experimental data available in open literature indicate coherent vortex flow structure in the empennage region at supersonic cruise speeds. This raises further concern on the fatigue life of the empennage structure. Three second generation supersonic transport designs taken from open literature are briefly compared with the 'empennage buffet' in mind. Future research efforts relating to buffet studies on the HSCT are summarized. A bibliography pertaining to the present research, including relevant studies on the first generation supersonic transport is presented. The effect of rounded wing leading edges on the present frequency estimates needs further study. The effect of engine exhaust on the flow field in the empennage region also needs further study.
A.M. Shendrik; M.I. Fyk
2014-01-01
The container gas transportation for low and medium level consumers as an alternative to pipelines is considered. The options for gas supply schemes, based on road and rail transport are given. The advantages and disadvantages of both types of gas transporting are described, the areas of their effective using are separated in the article. Promising implementations of technology in environment of economic crisis and also considering world trends of energy development are presented. The most ad...
Energy Technology Data Exchange (ETDEWEB)
Colliander, J.
1985-12-01
The following problems have been indentified: - A rational structure of transporting requires an established and relatively open market. - The necessary rolling stock for fuel conveyance by rail is not available. - Roads have to be improved and new roads have to be built. Railways with low load now might get a motivation for reinforcement. - Because of the irregular spread of consumption storing and terminals problems will arise and increase the cost of transport. - Terminals and stores are situated at a convenient place for one single enterprice. On a far-away aim this will not be rational.
A novel algorithm for solving two-objective fuzzy transportation problems
Directory of Open Access Journals (Sweden)
A. Sheikhi
2014-05-01
Full Text Available Normal 0 false false false EN-US X-NONE AR-SA A new method is proposed for finding efficient solution sets for fuzzy two objective transportation problems using ranking function and percent of function one solution is introduced for transportation problem and explained with the proposed model. Decision maker can obtain efficient solutions with the proposed method and selects the most preferred one among them.
The model of multi-agent interaction in a transportation problem with a corruption component
Malafeyev, Oleg; Saifullina, Darya; Ivaniukovich, Georgiy; Marakhov, Vladimir; Zaytseva, Irina
2017-07-01
The transportation problem of multi-agent interaction between different goods' transporters with a corruption component is formalized and studied in the paper. An illustrative example is given. The results of the paper allow to find a compromise solution and calculate the profit functions for all agents.
Opportunity Structure for Gambling and Problem Gambling among Employees in the Transport Industry
Revheim, Tevje; Buvik, Kristin
2009-01-01
Working conditions for employees in the transport sector might present an opportunity structure for gambling by providing access to gambling during the workday. This study investigates connections between opportunity structure, gambling during the workday, and gambling problems among employees in the transport sector. Data has been collected from…
Iterative methods for stationary convection-dominated transport problems
Energy Technology Data Exchange (ETDEWEB)
Bova, S.W.; Carey, G.F. [Univ. of Texas, Austin, TX (United States)
1994-12-31
It is well known that many iterative methods fail when applied to nonlinear systems of convection-dominated transport equations. Most successful methods for obtaining steady-state solutions to such systems rely on time-stepping through an artificial transient, combined with careful construction of artificial dissipation operators. These operators provide control over spurious oscillations which pollute the steady state solutions, and, in the nonlinear case, may become amplified and lead to instability. In the present study, we investigate Taylor Galerkin and SUPG-type methods and compare results for steady-state solutions to the Euler equations of gas dynamics. In particular, we consider the efficiency of different iterative strategies and present results for representative two-dimensional calculations.
Indian Academy of Sciences (India)
ALI EBRAHIMNEJAD
2016-03-01
Transportation problem (TP) is an important network structured linear programming problem that arises in several contexts and has deservedly received a great deal of attention in the literature. The central concept in this problem is to find the least total transportation cost of a commodity in order to satisfy demands at destinations using available supplies at origins in a crisp environment. In real life situations, the decision maker may not be sure about the precise values of the coefficients belonging to the transportation problem. The aim of this paper is to introduce a formulation of TP involving interval-valued trapezoidal fuzzy numbers for the transportation costs and values of supplies and demands. We propose a fuzzy linear programming approach for solvinginterval-valued trapezoidal fuzzy numbers transportation problem based on comparison of interval-valued fuzzy numbers by the help of signed distance ranking. To illustrate the proposed approach an application example issolved. It is demonstrated that study of interval-valued trapezoidal fuzzy numbers transportation problem gives rise to the same expected results as those obtained for TP with trapezoidal fuzzy numbers.
Energy Technology Data Exchange (ETDEWEB)
DeSteese, J.G.
1979-03-01
This report contains a summary characterization of the petroleum transportation system and an assessment of some potential problems that may impact petroleum transportation in the United States during the balance of the century. A primary purpose of this task is to provide information and perspective that contribute to the evaluation of research and development needs and priorities in future programs. The system characterization in Section 3 includes a review of petroleum product movements, modal operations and comparisons, and transportation regulations and safety. This system overview summarizes domestic production and consumption scenarios to the year 2000. A median scenario based on published projections shows that the US will probably rely on foreign oil to supply between 40 and 50 percent of domestic petroleum needs throughout the balance of the century. Potential problems in petroleum transportation were identified by the analysis and prioritization of current issues. The relative priorities of problem concerns were judged on the basis of their overall impact on the system and the immediacy of this potential impact. Two classes of concern are distinguished: 1. Potential problems that appear to require new programmatic action, in addition to effort already committed, to minimize the possible future impact of these concerns. 2. Latent concerns that may increase or decrease in priority or entirely change in nature as they develop. While the trend of these concerns should be monitored, new program action does not appear necessary at this time.
Projected discrete ordinates methods for numerical transport problems
Energy Technology Data Exchange (ETDEWEB)
Larsen, E.W.
1985-01-01
A class of Projected Discrete-Ordinates (PDO) methods is described for obtaining iterative solutions of discrete-ordinates problems with convergence rates comparable to those observed using Diffusion Synthetic Acceleration (DSA). The spatially discretized PDO solutions are generally not equal to the DSA solutions, but unlike DSA, which requires great care in the use of spatial discretizations to preserve stability, the PDO solutions remain stable and rapidly convergent with essentially arbitrary spatial discretizations. Numerical results are presented which illustrate the rapid convergence and the accuracy of solutions obtained using PDO methods with commonplace differencing methods.
Computer-aided analysis of nonlinear problems in transport phenomena
Brown, R. A.; Scriven, L. E.; Silliman, W. J.
1980-01-01
The paper describes algorithms for equilibrium and steady-state problems with coefficients in the expansions derived by the Galerkin weighted residual method and calculated from the resulting sets of nonlinear algebraic equations by the Newton-Raphson method. Initial approximations are obtained from nearby solutions by continuation techniques as parameters are varied. The Newton-Raphson technique is preferred because the Jacobian of the solution is useful for continuation, for analyzing the stability of solutions, for detecting bifurcation of solution families, and for computing asymptotic estimates of the effects on any solution of small changes in parameters, boundary conditions, and boundary shape.
Distributed Approach for Solving Time-Dependent Problems in Multimodal Transport Networks
Directory of Open Access Journals (Sweden)
Carlos Galvez-Fernandez
2009-01-01
Full Text Available This paper presents an alternative approach for time-dependent multimodal transport problem. We describe a new graph structure to abstract multimodal networks, called transfer graph, which adapts to the distributed nature of real information sources of transportation networks. A decomposition of the Shortest Path Problem in transfer graph is proposed to optimize the computation time. This approach was computationally tested in several experimental multimodal networks having different size and complexity. The approach was integrated in the multimodal transport service of the European Carlink platform, where it has been validated in real scenarios. Comparision with other related works is provided.
Dynamic estimation of transport demand: solutions - requirements - problems
Energy Technology Data Exchange (ETDEWEB)
Beckmann, K.J.; Rindsfueser, G. [Technische Hochschule Aachen (Germany). Lehrstuhl und Inst. fuer Stadtbauwesen
1999-07-01
The following contribution presents requirements, difficulties and first attempts at modelling a temporal short interval estimation of transport demand. For the simulation of motorway traffic (for an area within the state of North-Rhine-Westfalia, NRW) methods of temporal disaggregation of existing tripmatrices have been worked out within the framework of the Northrhine-Westfalian research cooperation for traffic simulation and environmental impacts 'NRW-FVU' (Nordrhein-Westfaelischer Forschungsverbund Verkehrssimulation und Umweltwirkungen). To simulate urban traffic (example: Wuppertal) methods of estimating temporal short interval trip-matrices were conceived and tested. The matrices were supplied for microsimulation with Cellular Automat (CA) and for the dynamic route choice and traffic assignment (DRUM, Dynamische Routensuche und Umlegung). The comparison of both methods, based on the estimated link loads (ADT and hourly loads), supplies deviations ranging within the mean variation of counted values. It therefore can be inferred that these methods, which are different with regard to computing intensity and data requirements, should be used depending on the tasks and the intended precision of the results. The specific pros and cons are important operational criteria. It also becomes obvious that in future methodical advancements should be examined on the basis of activity(-chain)-based approaches. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Herrmann, Kristin A.; Wysocki, Vicki H.; Vorpagel, Erich R.
2005-05-25
Aspartic acid (Asp)-containing peptides with the fixed charge derivative tris(2,4,6-trimethoxyphenyl) phosphonium (tTMP-P+) were explored computationally and experimentally by H/D exchange and fragmentation studies in order to probe the phenomenon of selective cleavage C-terminal to Asp in the absence of a ''mobile'' proton. Ab initio modeling of the tTMP-P+ electrostatic potential demonstrates the positive charge is distributed on the phosphonium group and therefore is not initiating or directing fragmentation as would a ''mobile'' proton. Geometry optimizations and vibrational analyses of different aspartic acid conformations show the aspartic acid structure with a hydrogen bond between the side chain hydroxy and backbone carbonyl lies 2.8 kcal/mol above the lowest energy conformer. In reactions with D2O, the phosphonium-derived doubly charged peptide (H+)P+LDIFSDF rapidly exchanges all 12 of its exchangeable hydrogens for deuterium and also displays a non-exchanging population. With no added proton, P+LDIFSDF exchanges a maximum of four of eleven exchangeable hydrogens for deuterium. No exchange is observed when all acidic groups are converted to the corresponding methyl esters. Together, these H/D exchange results indicate that the acidic hydrogens are ''mobile locally'' because they are able to participate in exchange even in the absence of an added proton. Fragmentation of two distinct (H+)P+LDIFSDF ion populations shows the non-exchanging population displays selective cleavage, while the exchanging population fragments more evenly across the peptide backbone. This result demonstrates that H/D exchange can sometimes distinguish between and provide a means of separation of different protonation motifs, and that these protonation motifs can have an effect on the fragmentation.
Hussain, Mozammil; Natarajan, Raghu N; Chaudhary, Gulafsha; An, Howard S; Andersson, Gunnar B J
2011-05-01
Disc swelling pressure (P(swell)) facilitated by fixed charged density (FCD) of proteoglycans (P(fcd)) and strain-dependent permeability (P(strain)) are of critical significance in the physiological functioning of discs. FCD of proteoglycans prevents any excessive matrix deformation by tissue stiffening, whereas strain-dependent permeability limits the rate of stress transfer from fluid to solid skeleton. To date, studies involving the modeling of FCD of proteoglycans and strain-dependent permeability have not been reported for the cervical discs. The current study objective is to compare the relative contributions of strain-dependent permeability and FCD of proteoglycans in predicting cervical disc biomechanics. Three-dimensional finite element models of a C5-C6 segment with three different disc compositions were analyzed: an SPFP model (strain-dependent permeability and FCD of proteoglycans), an SP model (strain-dependent permeability alone), and an FP model (FCD of proteoglycans alone). The outcomes of the current study suggest that the relative contributions of strain-dependent permeability and FCD of proteoglycans were almost comparable in predicting the physiological behavior of the cervical discs under moment loads. However, under compression, strain-dependent permeability better predicted the in vivo disc response than that of the FCD of proteoglycans. Unlike the FP model (least stiff) in compression, motion behavior of the three models did not vary much from each other and agreed well within the standard deviations of the corresponding in vivo published data. Flexion was recorded with maximum P(fcd) and P(strain), whereas minimum values were found in extension. The study data enhance the understanding of the roles played by the FCD of proteoglycans and strain-dependent permeability and porosity in determining disc tissue swelling behavior. Degenerative changes involving strain-dependent permeability and/or loss of FCD of proteoglycans can further be
Problems of economic security in Russian transportation and intermediate carrier infrastructure
Directory of Open Access Journals (Sweden)
Valeriy Anatol'evich Tsvetkov
2012-03-01
Full Text Available This paper reviews the basic problems of economic security in infrastructural ensuring of the implementation of transportation and intermediate carrier potential of Russia: development and reconstruction of communication lines, usage of innovative transportation methods, building a network of transportation and logistics centers, development of regional airport hubs and others. Particular attention is paid to the problems of transportation and transit potential implementation of Siberia and the Far East. It is shown that the increase of transit facilities in the territory of Russia takes place in a competitive market of infrastructure projects. At the same time it is emphasized that along with exhausting the possibilities of commodity economy development, a natural competitive advantage of Russia as a transport bridge between Europe, Asia and America will be implemented in full force.
Problems of economic security in Russian transportation and intermediate carrier infrastructure
Directory of Open Access Journals (Sweden)
Valeriy Anatol'evich Tsvetkov
2012-06-01
Full Text Available This paper reviews the basic problems of economic security in infrastructural ensuring of the implementation of transportation and intermediate carrier potential of Russia: development and reconstruction of communication lines, usage of innovative transportation methods, building a network of transportation and logistics centers, development of regional airport hubs and others. Particular attention is paid to the problems of transportation and transit potential implementation of Siberia and the Far East. It is shown that the increase of transit facilities in the territory of Russia takes place in a competitive market of infrastructure projects. At the same time it is emphasized that along with exhausting the possibilities of commodity economy development, a natural competitive advantage of Russia as a transport bridge between Europe, Asia and America will be implemented in full force.
The FN method for anisotropic scattering in neutron transport theory: the critical slab problem.
Gülecyüz, M. C.; Tezcan, C.
1996-08-01
The FN method which has been applied to many physical problems for isotropic and anisotropic scattering in neutron transport theory is extended for problems for extremely anisotropic scattering. This method depends on the Placzek lemma and the use of the infinite medium Green's function. Here the Green's function for extremely anisotropic scattering which was expressed as a combination of the Green's functions for isotropic scattering is used to solve the critical slab problem. It is shown that the criticality condition is in agreement with the one obtained previously by reducing the transport equation for anisotropic scattering to isotropic scattering and solving using the FN method.
Energy Technology Data Exchange (ETDEWEB)
Dmitriy Y. Anistratov; Adrian Constantinescu; Loren Roberts; William Wieselquist
2007-04-30
This is a project in the field of fundamental research on numerical methods for solving the particle transport equation. Numerous practical problems require to use unstructured meshes, for example, detailed nuclear reactor assembly-level calculations, large-scale reactor core calculations, radiative hydrodynamics problems, where the mesh is determined by hydrodynamic processes, and well-logging problems in which the media structure has very complicated geometry. Currently this is an area of very active research in numerical transport theory. main issues in developing numerical methods for solving the transport equation are the accuracy of the numerical solution and effectiveness of iteration procedure. The problem in case of unstructured grids is that it is very difficult to derive an iteration algorithm that will be unconditionally stable.
Fractional Goal Programming for Fuzzy Solid Transportation Problem with Interval Cost
Directory of Open Access Journals (Sweden)
B. Radhakrishnan
2014-09-01
Full Text Available In this paper, we study a solid transportation problem with interval cost using fractional goal programming approach (FGP. In real life applications of the FGP problem with multiple objectives, it is difficult for the decision-maker(s to determine the goal value of each objective precisely as the goal values are imprecise, vague, or uncertain. Therefore, a fuzzy goal programming model is developed for this purpose. The proposed model presents an application of fuzzy goal programming to the solid transportation problem. Also, we use a special type of non-linear (hyperbolic membership functions to solve multi-objective transportation problem. It gives an optimal compromise solution. The proposed model is illustrated by using an example.
Intermodal safety research needs report of the sixth workshop on national transportation problems
Energy Technology Data Exchange (ETDEWEB)
Warshawer, A.J. (ed.)
1976-04-01
This conference brought together DOT policymakers, university principal investigators and other professionals to consider the intermodal safety research requirements of the Department of Transportation. The objectives of the conference were: (1) to highlight safety problems and needed transportation safety research identified by DOT modal safety managers and to stimulate university or university/industry teams to respond with research proposals which emphasize multi-modal applicability and a system view; and (2) to provide a forum for university research groups to inform DOT safety managers of promising new directions in transportation safety research and new tools with which to address safety related problems. The conference addressed the research requirements for safety as identified by the Statement of National Transportation Policy and by the modal safety managers in three principal contexts, each a workshop panel: I, Inter-Institutional Problems of Transportation Safety. Problems were described as: Federal-State, local; Federal-Industry; Federal-Public, Consumer groups. II, Goal Setting and Planning for Transportation Safety Programs. Issues were: modifying risk behavior, safety as a social value, and involving citizens in development of standards as a way of increasing probability of achieving program objectives. III, DOT Information, Management, and Evaluation Systems Requirements. Needs were: data requirements and analytic tools for management of safety programs.
Metaheuristics for the dynamic stochastic dial-a-ride problem with expected return transports.
Schilde, M; Doerner, K F; Hartl, R F
2011-12-01
The problem of transporting patients or elderly people has been widely studied in literature and is usually modeled as a dial-a-ride problem (DARP). In this paper we analyze the corresponding problem arising in the daily operation of the Austrian Red Cross. This nongovernmental organization is the largest organization performing patient transportation in Austria. The aim is to design vehicle routes to serve partially dynamic transportation requests using a fixed vehicle fleet. Each request requires transportation from a patient's home location to a hospital (outbound request) or back home from the hospital (inbound request). Some of these requests are known in advance. Some requests are dynamic in the sense that they appear during the day without any prior information. Finally, some inbound requests are stochastic. More precisely, with a certain probability each outbound request causes a corresponding inbound request on the same day. Some stochastic information about these return transports is available from historical data. The purpose of this study is to investigate, whether using this information in designing the routes has a significant positive effect on the solution quality. The problem is modeled as a dynamic stochastic dial-a-ride problem with expected return transports. We propose four different modifications of metaheuristic solution approaches for this problem. In detail, we test dynamic versions of variable neighborhood search (VNS) and stochastic VNS (S-VNS) as well as modified versions of the multiple plan approach (MPA) and the multiple scenario approach (MSA). Tests are performed using 12 sets of test instances based on a real road network. Various demand scenarios are generated based on the available real data. Results show that using the stochastic information on return transports leads to average improvements of around 15%. Moreover, improvements of up to 41% can be achieved for some test instances.
Directory of Open Access Journals (Sweden)
Yan Sun
2015-09-01
Full Text Available Purpose: The purpose of study is to solve the multi-modal transportation routing planning problem that aims to select an optimal route to move a consignment of goods from its origin to its destination through the multi-modal transportation network. And the optimization is from two viewpoints including cost and time. Design/methodology/approach: In this study, a bi-objective mixed integer linear programming model is proposed to optimize the multi-modal transportation routing planning problem. Minimizing the total transportation cost and the total transportation time are set as the optimization objectives of the model. In order to balance the benefit between the two objectives, Pareto optimality is utilized to solve the model by gaining its Pareto frontier. The Pareto frontier of the model can provide the multi-modal transportation operator (MTO and customers with better decision support and it is gained by the normalized normal constraint method. Then, an experimental case study is designed to verify the feasibility of the model and Pareto optimality by using the mathematical programming software Lingo. Finally, the sensitivity analysis of the demand and supply in the multi-modal transportation organization is performed based on the designed case. Findings: The calculation results indicate that the proposed model and Pareto optimality have good performance in dealing with the bi-objective optimization. The sensitivity analysis also shows the influence of the variation of the demand and supply on the multi-modal transportation organization clearly. Therefore, this method can be further promoted to the practice. Originality/value: A bi-objective mixed integer linear programming model is proposed to optimize the multi-modal transportation routing planning problem. The Pareto frontier based sensitivity analysis of the demand and supply in the multi-modal transportation organization is performed based on the designed case.
One of the methods for optimizing a part of supply chain by using transportation problem model
Directory of Open Access Journals (Sweden)
Ostojić-Dabić Svetlana A.
2016-01-01
Full Text Available Supply chain is coordinated system of people, resources, information, etc., involved in the movement of materials from a state of raw materials to final customer, and to ensure the integration of all participants and the exchange of information along the entire supply chain.. One of potential problem of SC that is the subject of optimization and with whose improvement is achieved a series of effects - economic, environmental, etc. is transportation problem. The choice of method for optimization of this problem has a significant impact on the quality of the solutions, which are shown in this paper on the example of the supply chain of fruit producing company. The paper applied two algorithms to optimize part of the supply chain: exact and heuristic. The result of their use is the reduction of the transport operation, as well as insight into the overall way that the transport part of the supply chain function, and the possibilities for its improvement.
Transport dissipative particle dynamics model for mesoscopic advection-diffusion-reaction problems
Li, Zhen; Yazdani, Alireza; Tartakovsky, Alexandre; Karniadakis, George Em
2015-01-01
We present a transport dissipative particle dynamics (tDPD) model for simulating mesoscopic problems involving advection-diffusion-reaction (ADR) processes, along with a methodology for implementation of the correct Dirichlet and Neumann boundary conditions in tDPD simulations. tDPD is an extension of the classic dissipative particle dynamics (DPD) framework with extra variables for describing the evolution of concentration fields. The transport of concentration is modeled by a Fickian flux a...
BILEVEL PROGRAMMING MODEL AND SOLUTION METHOD FOR MIXED TRANSPORTATION NETWORK DESIGN PROBLEM
Institute of Scientific and Technical Information of China (English)
Haozhi ZHANG; Ziyou GAO
2009-01-01
By handling the travel cost function artfully, the authors formulate the transportation mixed network design problem (MNDP) as a mixed-integer, nonlinear bilevel programming problem, in which the lower-level problem, comparing with that of conventional bilevel DNDP models, is not a side constrained user equilibrium assignment problem, but a standard user equilibrium assignment problem. Then, the bilevel programming model for MNDP is reformulated as a continuous version of bilevel programming problem by the continuation method. By virtue of the optimal-value function, the lower-level assignment problem can be expressed as a nonlinear equality constraint. Therefore, the bilevel programming model for MNDP can be transformed into an equivalent single-level optimization problem. By exploring the inherent nature of the MNDP, the optimal-value function for the lower-level equilibrium assignment problem is proved to be continuously differentiable and its functional value and gradient can be obtained efficiently. Thus, a continuously differentiable but still nonconvex optimization formulation of the MNDP is created, and then a locally convergent algorithm is proposed by applying penalty function method. The inner loop of solving the subproblem is mainly to implement an all-or-nothing assignment. Finally, a small-scale transportation network and a large-scale network are presented to verify the proposed model and algorithm.
A Compensatory Approach to Multiobjective Linear Transportation Problem with Fuzzy Cost Coefficients
Directory of Open Access Journals (Sweden)
Hale Gonce Kocken
2011-01-01
Full Text Available This paper deals with the Multiobjective Linear Transportation Problem that has fuzzy cost coefficients. In the solution procedure, many objectives may conflict with each other; therefore decision-making process becomes complicated. And also due to the fuzziness in the costs, this problem has a nonlinear structure. In this paper, fuzziness in the objective functions is handled with a fuzzy programming technique in the sense of multiobjective approach. And then we present a compensatory approach to solve Multiobjective Linear Transportation Problem with fuzzy cost coefficients by using Werner's and operator. Our approach generates compromise solutions which are both compensatory and Pareto optimal. A numerical example has been provided to illustrate the problem.
Directory of Open Access Journals (Sweden)
Nurdan Cetin
2014-01-01
Full Text Available We consider a multiobjective linear fractional transportation problem (MLFTP with several fractional criteria, such as, the maximization of the transport profitability like profit/cost or profit/time, and its two properties are source and destination. Our aim is to introduce MLFTP which has not been studied in literature before and to provide a fuzzy approach which obtain a compromise Pareto-optimal solution for this problem. To do this, first, we present a theorem which shows that MLFTP is always solvable. And then, reducing MLFTP to the Zimmermann’s “min” operator model which is the max-min problem, we construct Generalized Dinkelbach’s Algorithm for solving the obtained problem. Furthermore, we provide an illustrative numerical example to explain this fuzzy approach.
Multigrid Approach to Solving the Long Transportation Problem on a Regular Grid in Cost Space
1993-06-01
feasible solution has an optimal solution ( Bazaraa , 1990). Some traditional solution methods are presf-nted next. D. THE SIMPLEX METHOD Whenever feasible...root to every node in D. If the solution to a minimal cost flow problem is examined graphically it corresponds to a spanning tree in the network ( Bazaraa ...REFERENCES Balas, Egon, "Solution of Large-Scale Transportation Problems Through Aggregation," Operations Research, 13, 1965, pp. 82-84. Bazaraa , M.S
Energy Technology Data Exchange (ETDEWEB)
T. Downar
2009-03-31
The overall objective of the work here has been to eliminate the approximations used in current resonance treatments by developing continuous energy multi-dimensional transport calculations for problem dependent self-shielding calculations. The work here builds on the existing resonance treatment capabilities in the ORNL SCALE code system.
Solutions of Multi Objective Fuzzy Transportation Problems with Non-Linear Membership Functions
Directory of Open Access Journals (Sweden)
Dr. M. S. Annie Christi
2016-11-01
Full Text Available Multi-objective transportation problem with fuzzy interval numbers are considered. The solution of linear MOTP is obtained by using non-linear membership functions. The optimal compromise solution obtained is compared with the solution got by using a linear membership function. Some numerical examples are presented to illustrate this.
Energy Technology Data Exchange (ETDEWEB)
Todd Arbogast; Steve Bryant; Clint N. Dawson; Mary F. Wheeler
1998-08-31
This report describes briefly the work of the Center for Subsurface Modeling (CSM) of the University of Texas at Austin (and Rice University prior to September 1995) on the Partnership in Computational Sciences Consortium (PICS) project entitled Grand Challenge Problems in Environmental Modeling and Remediation: Groundwater Contaminant Transport.
Scenarios for solving a non-linear transportation problem in multi-agent systems
DEFF Research Database (Denmark)
Brehm, Robert; Top, Søren; Mátéfi-Tempfli, Stefan
2017-01-01
We introduce and provide an evaluation on two scenarios and related algorithms for implementation of a multi-agent system to solve a type of non-linear transportation problem using distributed optimization algorithms based on dual decomposition and consensus. The underlying fundamental optimization...
Directory of Open Access Journals (Sweden)
Dalbinder Kour
2015-12-01
Full Text Available This paper focuses on solving the transportation problems with neutrosophic data for the first time. The indeterminacy factor has been considered in Transportation Problems (TP. The two methods of linear programming – Fuzzy Linear Programming (FLP and Crisp Linear Programming (CLP are discussed with reference to neutrosophic transportation problems. The first method uses the membership, non-membership and indeterminacy degrees separately to find the crisp solution using the Fuzzy Programming Technique and then the optimal solution is calculated in terms of neutrosophic data with the help of defined cost membership functions. The satisfaction degree is then calculated to check the better solution. The second method directly solves the TP to find crisp solution considering a single objective function. The cost objective function is taken as neutrosophic data and the methods have been used as such for the first time. Both the methods have been illustrated with the help of a numerical example and these are then applied to solve a real life multi - objective and multi-index transportation problem. Finally the results are compared.
A Case Study: Problem-Based Learning for Civil Engineering Students in Transportation Courses
Ahern, A. A.
2010-01-01
This paper describes two case studies where problem-based learning (PBL) has been introduced to undergraduate civil engineering students in University College Dublin. PBL has recently been put in place in the penultimate and final year transport engineering classes in the civil engineering degree in University College Dublin. In this case study,…
Directory of Open Access Journals (Sweden)
Md. Ashraful Babu,
2014-01-01
Full Text Available Basic feasible solution is the initial solution of transportation problem. There are several transportation algorithms to determine feasible solution. These algorithms are only way to get optimal solution because optimal solution obtains from the initial basic feasible solution using some optimality test methods such as MODIModified Distribution Method and Stepping Stone Method where MODI is the most efficient method to determine optimal solution. Before applying MODI on feasible solution we have to resolve degeneracy if it occurs and also make sure that allocations (non-negative basic variable are should not form a closed loop when we draw horizontal and vertical paths from allocated cells to allocated cells. Degeneracy occurs when supply and demand are satisfied simultaneously it can be resolved if one row or column of them is crossed out and another remains with zero supply or demand. Difficulty arise when if all uncrossed out rows or column have (remaining zero supply or demand. In that case, Vogel‟s Approximation Method (VAM and some other methods solve that by allocating these zero supply or demand using Least Cost Method (LCM. But in some problem when we make allocation by LCM in that particular case then closed loop is formed and not possible to apply any optimality test method. So that optimal solution is not possible to determine in that case. In this paper we resolve this particular problem and find a new approach to allocate zero supply or demand so that closed loop will not be formed.
Hybrid Approach for the Public Transportation Time Dependent Orienteering Problem with Time Windows
Garcia, Ander; Arbelaitz, Olatz; Vansteenwegen, Pieter; Souffriau, Wouter; Linaza, Maria Teresa
The Time Dependent Orienteering Problem with Time Windows (TDOPTW) consists of a set of locations with associated time windows and scores. Visiting a location allows to collect its score as a reward. Traveling time between locations varies depending on the leave time. The objective is to obtain a route that maximizes the obtained score within a limited amount of time. In this paper we target the use of public transportation in a city, where users may move on foot or by public transportation. The approach can also be applied to the logistic sector, for example to the multimodal freight transportation. We apply an hybrid approach to tackle the problem. Experimental results for the city of San Sebastian show we are able to obtain valid routes in real-time.
Problems of optimal transportation on the circle and their mechanical applications
Plakhov, Alexander; Tchemisova, Tatiana
2017-02-01
We consider a mechanical problem concerning a 2D axisymmetric body moving forward on the plane and making slow turns of fixed magnitude about its axis of symmetry. The body moves through a medium of non-interacting particles at rest, and collisions of particles with the body's boundary are perfectly elastic (billiard-like). The body has a blunt nose: a line segment orthogonal to the symmetry axis. It is required to make small cavities with special shape on the nose so as to minimize its aerodynamic resistance. This problem of optimizing the shape of the cavities amounts to a special case of the optimal mass transportation problem on the circle with the transportation cost being the squared Euclidean distance. We find the explicit solution for this problem when the amplitude of rotation is smaller than a fixed critical value, and give a numerical solution otherwise. As a by-product, we get explicit description of the solution for a class of optimal transportation problems on the circle.
Directory of Open Access Journals (Sweden)
Özgür Başkan
2014-09-01
Full Text Available Differential Evolution algorithm has effectively been used to solve engineering optimization problems recently. The Differential Evolution algorithm, which uses similar principles with Genetic Algorithms, is more robust on obtaining optimal solution than many other heuristic algorithms with its simpler structure. In this study, Differential Evolution algorithm is applied to the transportation network design problems and its effectiveness on the solution is investigated. In this context, Differential Evolution based models are developed using bi-level programming approach for the solution of the transportation network design problem and determination of the on-street parking places in urban road networks. In these models, optimal investment and parking strategies are investigated on the upper level. On the lower level, deterministic traffic assignment problem, which represents drivers' responses, is solved using Frank-Wolfe algorithm and VISUM traffic modeling software. In order to determine the effectiveness of the proposed models, numerical applications are carried out on Sioux-Falls test network. Results showed that the Differential Evolution algorithm may effectively been used for the solution of transportation network design problems.
Directory of Open Access Journals (Sweden)
J. Fabian Lopez
2010-01-01
Full Text Available We consider a Pickup and Delivery Vehicle Routing Problem (PDP commonly encountered in real-world logistics operations. The problem involves a set of practical complications that have received little attention in the vehicle routing literature. In this problem, there are multiple vehicle types available to cover a set of pickup and delivery requests, each of which has pickup time windows and delivery time windows. Transportation orders and vehicle types must satisfy a set of compatibility constraints that specify which orders cannot be covered by which vehicle types. In addition we include some dock service capacity constraints as is required on common real world operations. This problem requires to be attended on large scale instances (orders ≥ 500, (vehicles ≥ 150. As a generalization of the traveling salesman problem, clearly this problem is NP-hard. The exact algorithms are too slow for large scale instances. The PDP-TWDS is both a packing problem (assign order to vehicles, and a routing problem (find the best route for each vehicle. We propose to solve the problem in three stages. The first stage constructs initials solutions at aggregate level relaxing some constraints on the original problem. The other two stages imposes time windows and dock service constraints. Our results are favorable finding good quality solutions in relatively short computational times.
General theory of spherically symmetric boundary-value problems of the linear transport theory.
Kanal, M.
1972-01-01
A general theory of spherically symmetric boundary-value problems of the one-speed neutron transport theory is presented. The formulation is also applicable to the 'gray' problems of radiative transfer. The Green's function for the purely absorbing medium is utilized in obtaining the normal mode expansion of the angular densities for both interior and exterior problems. As the integral equations for unknown coefficients are regular, a general class of reduction operators is introduced to reduce such regular integral equations to singular ones with a Cauchy-type kernel. Such operators then permit one to solve the singular integral equations by the standard techniques due to Muskhelishvili. We discuss several spherically symmetric problems. However, the treatment is kept sufficiently general to deal with problems lacking azimuthal symmetry. In particular the procedure seems to work for regions whose boundary coincides with one of the coordinate surfaces for which the Helmholtz equation is separable.
Calculation of transport coefficient profiles in modulation experiments as an inverse problem
Escande, D F
2011-01-01
The calculation of transport profiles from experimental measurements belongs in the category of inverse problems which are known to come with issues of ill-conditioning or singularity. A reformulation of the calculation, the matricial approach, is proposed for periodically modulated experiments, within the context of the standard advection-diffusion model where these issues are related to the vanishing of the determinant of a 2x2 matrix. This sheds light on the accuracy of calculations with transport codes, and provides a path for a more precise assessment of the profiles and of the related uncertainty.
Energy Technology Data Exchange (ETDEWEB)
NONE
1998-04-01
The over-reaching goal of the Groundwater Grand Challenge component of the Partnership in Computational Science (PICS) was to develop and establish the massively parallel approach for the description of groundwater flow and transport and to address the problem of uncertainties in the data and its interpretation. This necessitated the development of innovative algorithms and the implementation of massively parallel computational tools to provide a suite of simulators for groundwater flow and transport in heterogeneous media. This report summarizes the activities and deliverables of the Groundwater Grand Challenge project funded through the High Performance Computing grand challenge program of the Department of Energy from 1995 through 1997.
Mixed-integer programming methods for transportation and power generation problems
Damci Kurt, Pelin
This dissertation conducts theoretical and computational research to solve challenging problems in application areas such as supply chain and power systems. The first part of the dissertation studies a transportation problem with market choice (TPMC) which is a variant of the classical transportation problem in which suppliers with limited capacities have a choice of which demands (markets) to satisfy. We show that TPMC is strongly NP-complete. We consider a version of the problem with a service level constraint on the maximum number of markets that can be rejected and show that if the original problem is polynomial, its cardinality-constrained version is also polynomial. We propose valid inequalities for mixed-integer cover and knapsack sets with variable upper bound constraints, which appear as substructures of TPMC and use them in a branch-and-cut algorithm to solve this problem. The second part of this dissertation studies a unit commitment (UC) problem in which the goal is to minimize the operational cost of power generators over a time period subject to physical constraints while satisfying demand. We provide several exponential classes of multi-period ramping and multi-period variable upper bound inequalities. We prove the strength of these inequalities and describe polynomial-time separation algorithms. Computational results show the effectiveness of the proposed inequalities when used as cuts in a branch-and-cut algorithm to solve the UC problem. The last part of this dissertation investigates the effects of uncertain wind power on the UC problem. A two-stage robust model and a three-stage stochastic program are compared.
Sugden, Karen; Arseneault, Louise; Harrington, HonaLee; Moffitt, Terrie E.; Williams, Benjamin; Caspi, Avshalom
2010-01-01
Objective Bullying is the act of intentionally and repeatedly causing harm to someone who has difficulty defending him or herself, and is a relatively wide-spread school-age phenomenon. Being the victim of bullying is associated with a broad spectrum of emotional problems; however, not all children who are bullied go on to develop such problems. Method We tested the hypothesis that the relationship between bullying victimization and emotional problems was moderated by variation in the serotonin transporter (5-HTT) gene in 2,232 British children comprising the Environmental Risk (E-Risk) study cohort. Results Our data supported the hypothesis that children's bullying victimization leads to their developing emotional problems, and that genetic variation in the 5-HTTLPR moderates this relationship. Specifically, frequently bullied children with the SS genotype were at greater risk of developing emotional problems at age 12 than children with the SL or LL genotype. Furthermore, we demonstrated that this genetic moderation persisted (a) after controlling for children's pre-victimization emotional problems by assessing intra-individual change in problems between ages 5 and 12 years, and (b) after controlling for other risk factors shared by children growing up in the same family by comparing emotional problems in twins discordant for bullying victimization. Conclusions These findings are further evidence that the 5-HTTLPR moderates the risk of emotional disturbance after exposure to stressful events. PMID:20643316
Harmony search optimization algorithm for a novel transportation problem in a consolidation network
Davod Hosseini, Seyed; Akbarpour Shirazi, Mohsen; Taghi Fatemi Ghomi, Seyed Mohammad
2014-11-01
This article presents a new harmony search optimization algorithm to solve a novel integer programming model developed for a consolidation network. In this network, a set of vehicles is used to transport goods from suppliers to their corresponding customers via two transportation systems: direct shipment and milk run logistics. The objective of this problem is to minimize the total shipping cost in the network, so it tries to reduce the number of required vehicles using an efficient vehicle routing strategy in the solution approach. Solving several numerical examples confirms that the proposed solution approach based on the harmony search algorithm performs much better than CPLEX in reducing both the shipping cost in the network and computational time requirement, especially for realistic size problem instances.
Discrete and continuum links to a nonlinear coupled transport problem of interacting populations
Duong, M. H.; Muntean, A.; Richardson, O. M.
2017-02-01
We are interested in exploring interacting particle systems that can be seen as microscopic models for a particular structure of coupled transport flux arising when different populations are jointly evolving. The scenarios we have in mind are inspired by the dynamics of pedestrian flows in open spaces and are intimately connected to cross-diffusion and thermo-diffusion problems holding a variational structure. The tools we use include a suitable structure of the relative entropy controlling TV-norms, the construction of Lyapunov functionals and particular closed-form solutions to nonlinear transport equations, a hydrodynamics limiting procedure due to Philipowski, as well as the construction of numerical approximates to both the continuum limit problem in 2D and to the original interacting particle systems.
Dzikuć, Maciej; Adamczyk, Janusz; Piwowar, Arkadiusz
2017-07-01
According to the report of the World Health Organization (WHO) on the list of 50 cities with the most polluted air in Europe as many as 33 are located in Poland. All the cities that are on the list exceed the maximum concentration of dust recommended by WHO at least three times. In the Lubuskie Province there is a very serious problem of maintaining good air quality. The air in Poland is among the most polluted in the European Union and this also applies to less-industrialized areas, such as Lubuskie, where the concentration levels of substances hazardous to human health and the environment are recorded as exceeded. One of the main factors affecting the poor air quality in the region is road transport. It is not just a problem near roads with heavy traffic, but also applies to the cities, where there is a large movement of cars, which are often old and do not meet current environmental standards. This article aims to identify the main sources of low emission from road transport and identify potential solutions to help reduce emission from this sector. The actions aimed at limiting low emission from road transport can bring a significant positive ecological effect. The aim of this article is to review one of the main sources of low emission in the province of Lubuskie, which is transportation. Moreover, the authors of the paper indicate the main problems associated with the emission coming from road transport and describe the possibilities for opportunities to reduce pollution from this sector. In addition, the article presents the three-scenario simulation of annual emissions from passenger cars that could take place in 2020.
IMPROVING INITIAL GENERATIONS IN PSO ALGORITHM FOR TRANSPORTATION NETWORK DESIGN PROBLEM
2015-01-01
Transportation Network Design Problem (TNDP) aims to select the best project sets among a number of new projects. Recently, metaheuristic methods are applied to solve TNDP in the sense of finding better solutions sooner. PSO as a metaheuristic method is based on stochastic optimization and is a parallel revolutionary computation technique. The PSO system initializes with a number of random solutions and seeks for optimal solution by improving generations. This paper studies the be...
FUNDAMENTAL MATRIX OF LINEAR CONTINUOUS SYSTEM IN THE PROBLEM OF ESTIMATING ITS TRANSPORT DELAY
Directory of Open Access Journals (Sweden)
N. A. Dudarenko
2014-09-01
Full Text Available The paper deals with the problem of quantitative estimation for transport delay of linear continuous systems. The main result is received by means of fundamental matrix of linear differential equations solutions specified in the normal Cauchy form for the cases of SISO and MIMO systems. Fundamental matrix has the dual property. It means that the weight function of the system can be formed as a free motion of systems. Last one is generated by the vector of initial system conditions, which coincides with the matrix input of the system being researched. Thus, using the properties of the system- solving for fundamental matrix has given the possibility to solve the problem of estimating transport linear continuous system delay without the use of derivation procedure in hardware environment and without formation of exogenous Dirac delta function. The paper is illustrated by examples. The obtained results make it possible to solve the problem of modeling the pure delay links using consecutive chain of aperiodic links of the first order with the equal time constants. Modeling results have proved the correctness of obtained computations. Knowledge of transport delay can be used when configuring multi- component technological complexes and in the diagnosis of their possible functional degeneration.
Esparcia-Alcázar, Anna I; Martínez-García, Anaís; García-Sánchez, Pablo; Alfaro-Cid, Eva; Sharman, Ken
2009-01-01
EVITA, standing for Evolutionary Inventory and Transportation Algorithm, is a two-level methodology designed to address the Inventory and Transportation Problem (ITP) in retail chains. The top level uses an evolutionary algorithm to obtain delivery patterns for each shop on a weekly basis so as to minimise the inventory costs, while the bottom level solves the Vehicle Routing Problem (VRP) for every day in order to obtain the minimum transport costs associated to a particular set of patterns. The aim of this paper is to investigate whether a multiobjective approach to this problem can yield any advantage over the previously used single objective approach. The analysis performed allows us to conclude that this is not the case and that the single objective approach is in gene- ral preferable for the ITP in the case studied. A further conclusion is that it is useful to employ a classical algorithm such as Clarke & Wright's as the seed for other metaheuristics like local search or tabu search in order to prov...
A Deterministic-Monte Carlo Hybrid Method for Time-Dependent Neutron Transport Problems
Energy Technology Data Exchange (ETDEWEB)
Justin Pounders; Farzad Rahnema
2001-10-01
A new deterministic-Monte Carlo hybrid solution technique is derived for the time-dependent transport equation. This new approach is based on dividing the time domain into a number of coarse intervals and expanding the transport solution in a series of polynomials within each interval. The solutions within each interval can be represented in terms of arbitrary source terms by using precomputed response functions. In the current work, the time-dependent response function computations are performed using the Monte Carlo method, while the global time-step march is performed deterministically. This work extends previous work by coupling the time-dependent expansions to space- and angle-dependent expansions to fully characterize the 1D transport response/solution. More generally, this approach represents and incremental extension of the steady-state coarse-mesh transport method that is based on global-local decompositions of large neutron transport problems. An example of a homogeneous slab is discussed as an example of the new developments.
Zheng, Weixiong
2016-01-01
In this paper, we present an accurate and robust scaling operator based on material optical thickness (OT) for the least-squares spherical harmonics (LSP$_N$) method for solving neutron transport problems. LSP$_N$ without proper scaling is known to be erroneous in highly scattering medium, if the optical thickness of the material is large. A previously presented scaling developed by Manteuffel, et al.\\ does improve the accuracy of LSP$_N$, in problems where the material is optically thick. With the method, however, essentially no scaling is applied in optically thin materials, which can lead to an erroneous solution with presence of highly scattering medium. Another scaling approach, called the reciprocal-removal (RR) scaled LSP$_N$, which is equivalent to the self-adjoint angular flux (SAAF) equation, has numerical issues in highly-scattering materials due to a singular weighting. We propose a scaling based on optical thickness that improves the solution in optically thick media while avoiding the singularit...
Improving the primal-dual algorithm for the transportation problem in the plane
Kaijser, Thomas
2009-01-01
The transportation problem in the plane - how to move a set of objects from one set of points to another set of points in the cheapest way - is a very old problem going back several hundreds of years. In recent years the solution of the problem has found applications in the analysis of digital images when searching for similarities and discrepancies between images. The main drawback, however, is the long computation time for finding the solution. In this paper we present some new results by which the time for solving the transportation problem in the plane can be reduced substantially. As cost-function we choose a distance-function between points in the plane. We consider both the case when the distance-function is equal to the ordinary Euclidean distance, as well as the case when the distance-function is equal to the square of the Euclidean distance. This latter distance-function has the advantage that it is integer-valued if the coordinates of the points in the plane are integers.
C5 Benchmark Problem with Discrete Ordinate Radiation Transport Code DENOVO
Energy Technology Data Exchange (ETDEWEB)
Yesilyurt, Gokhan [ORNL; Clarno, Kevin T [ORNL; Evans, Thomas M [ORNL; Davidson, Gregory G [ORNL; Fox, Patricia B [ORNL
2011-01-01
The C5 benchmark problem proposed by the Organisation for Economic Co-operation and Development/Nuclear Energy Agency was modeled to examine the capabilities of Denovo, a three-dimensional (3-D) parallel discrete ordinates (S{sub N}) radiation transport code, for problems with no spatial homogenization. Denovo uses state-of-the-art numerical methods to obtain accurate solutions to the Boltzmann transport equation. Problems were run in parallel on Jaguar, a high-performance supercomputer located at Oak Ridge National Laboratory. Both the two-dimensional (2-D) and 3-D configurations were analyzed, and the results were compared with the reference MCNP Monte Carlo calculations. For an additional comparison, SCALE/KENO-V.a Monte Carlo solutions were also included. In addition, a sensitivity analysis was performed for the optimal angular quadrature and mesh resolution for both the 2-D and 3-D infinite lattices of UO{sub 2} fuel pin cells. Denovo was verified with the C5 problem. The effective multiplication factors, pin powers, and assembly powers were found to be in good agreement with the reference MCNP and SCALE/KENO-V.a Monte Carlo calculations.
MULTICRITERIА PROBLEM OF FINDING THE OPTIMAL PATHS FOR LARGE-SCALE TRANSPORT SYSTEM
Directory of Open Access Journals (Sweden)
Pavlov D. A.
2015-11-01
Full Text Available This article explores the multicriteria problems arise in the organization of routes in large-scale transport management system. As a mathematical tool for constructing a model, we were using the prefractal graphs. Prefractal graphs naturally reflect structure of the device of communications of transport system, reflecting its important features – locality and differentiation. Locality is provided with creation of internal routes (city, raionwide, etc.. Differentiation is understood as division of routes on intra regional, interregional and international. The objective is reduced to a covering of prefractal graphs by the simple paths which are crossed on edges and nodes. On the set of feasible solutions, vector criterion function with certain criteria is based. In concepts of transport system, the given criteria have concrete substantial interpretation, the transport routes allowing to design considering features of system. In this article, we construct polynomial algorithms for finding optimal according to certain criteria decision. By the criteria which aren't optimizing the allocated routes their estimates of the lower and upper bounds are given. On all given algorithms the estimates of computing complexity confirming advantage of use of methods of prefractal and fractal graphs before classical methods of the theory of graphs are constructed and proved
Computing the time-continuous Optimal Mass Transport Problem without Lagrangian techniques
Besson, Olivier; Pousin, Jérôme
2010-01-01
This work originates from a heart's images tracking which is to generate an apparent continuous motion, observable through intensity variation from one starting image to an ending one both supposed segmented. Given two images p0 and p1, we calculate an evolution process p(t, \\cdot) which transports p0 to p1 by using the optimal extended optical flow. In this paper we propose an algorithm based on a fixed point formulation and a time-space least squares formulation of the mass conservation equation for computing the optimal mass transport problem. The strategy is implemented in a 2D case and numerical results are presented with a first order Lagrange finite element, showing the efficiency of the proposed strategy.
Directory of Open Access Journals (Sweden)
Gogina Elena Sergeevna
2012-12-01
big cities of Russia. At the same time, the quality of the waste water treated by local water treatment stations fails to meet the present-day standard requirements. Moreover, potable water shall not be used for the purpose of washing transport vehicles. Within the recent 10 years, MGSU has developed a number of research projects aimed at the resolution of this problem. The concept developed by the MGSU specialists is to attain the highest quality of treated waste water generated by car washes and transport enterprises using the most advanced technologies of water treatment rather than to design new water treatment plants. Various methods may be applied for this purpose: restructuring of water treatment facilities, advanced feed, updated regulations governing the operation of water treatment plants.
Scheduling of flow shop problems on 3 machines in fuzzy environment with double transport facility
Sathish, Shakeela; Ganesan, K.
2016-06-01
Flow shop scheduling is a decision making problem in production and manufacturing field which has a significant impact on the performance of an organization. When the machines on which jobs are to be processed are placed at different places, the transportation time plays a significant role in production. Further two different transport agents where 1st takes the job from 1st machine to 2nd machine and then returns back to the first machine and the 2nd takes the job from 2nd machine to 3rd machine and then returns back to the 2nd machine are also considered. We propose a method to minimize the total make span; without converting the fuzzy processing time to classical numbers by using a new type of fuzzy arithmetic and a fuzzy ranking method. A numerical example is provided to explain the proposed method.
AN EXPANDED CHARACTERISTIC-MIXED FINITE ELEMENT METHOD FOR A CONVECTION-DOMINATED TRANSPORT PROBLEM
Institute of Scientific and Technical Information of China (English)
Ling Guo; Huan-zhen Chen
2005-01-01
In this paper, we propose an Expanded Characteristic-mixed Finite Element Method for approximating the solution to a convection dominated transport problem. The method is a combination of characteristic approximation to handle the convection part in time and an expanded mixed finite element spatial approximation to deal with the diffusion part.The scheme is stable since fluid is transported along the approximate characteristics on the discrete level. At the same time it expands the standard mixed finite element method in the sense that three variables are explicitly treated: the scalar unknown, its gradient, and its flux. Our analysis shows the method approximates the scalar unknown, its gradient,and its flux optimally and simultaneously. We also show this scheme has much smaller time-truncation errors than those of standard methods. A numerical example is presented to show that the scheme is of high performance.
IMPROVING INITIAL GENERATIONS IN PSO ALGORITHM FOR TRANSPORTATION NETWORK DESIGN PROBLEM
Directory of Open Access Journals (Sweden)
Navid Afkar
2015-02-01
Full Text Available Transportation Network Design Problem (TNDP aims to select the best project sets among a number of new projects. Recently, metaheuristic methods are applied to solve TNDP in the sense of finding better solutions sooner. PSO as a metaheuristic method is based on stochastic optimization and is a parallel revolutionary computation technique. The PSO system initializes with a number of random solutions and seeks for optimal solution by improving generations. This paper studies the behavior of PSO on account of improving initial generation and fitness value domain to find better solutions in comparison with previous attempts.
Aungkulanon, Pasura; Luangpaiboon, Pongchanun
2016-01-01
Response surface methods via the first or second order models are important in manufacturing processes. This study, however, proposes different structured mechanisms of the vertical transportation systems or VTS embedded on a shuffled frog leaping-based approach. There are three VTS scenarios, a motion reaching a normal operating velocity, and both reaching and not reaching transitional motion. These variants were performed to simultaneously inspect multiple responses affected by machining parameters in multi-pass turning processes. The numerical results of two machining optimisation problems demonstrated the high performance measures of the proposed methods, when compared to other optimisation algorithms for an actual deep cut design.
Basic problems and new potentials in monitoring sediment transport using Japanese pipe type geophone
Sakajo, Saiichi
2016-04-01
The authors have conducted a lot of series of monitoring of sediment transport by pipe type geophone in a model hydrological channel with various gradients and water discharge, using the various size of particles from 2 to 21 mm in the diameter. In the case of casting soils particle by particle into the water channel, 1,000 test cases were conducted. In the case of casting all soils at a breath into the water channel, 100 test cases were conducted. The all test results were totally analyzed by the conventional method, with visible judgement by video pictures. Then several important basic problems were found in estimating the volume and particle distributions by the conventional method, which was not found in the past similar studies. It was because the past studies did not consider the types of collisions between sediment particle and pipe. Based on these experiments, the authors have firstly implemented this idea into the old formula to estimate the amount of sediment transport. In the formula, two factors of 1) the rate of sensing in a single collision and 2) the rate of collided particles to a cast all soil particles were concretely considered. The parameters of these factors could be determined from the experimental results and it was found that the obtained formula could estimate grain size distribution. In this paper, they explain the prototype formula to estimate a set of volume and distribution of sediment transport. Another finding in this study is to propose a single collision as a river index to recognize its characteristics of sediment transport. This result could characterize the risk ranking of sediment transport in the rivers and mudflow in the mountainous rivers. Furthermore, in this paper the authors explain how the preciseness of the pipe geophone to sense the smaller sediment particles shall be improved, which has never been able to be sensed.
Crudden, Adele; Antonelli, Karla; O'Mally, Jamie
2016-01-01
Social problem-solving skills and transportation self-efficacy were assessed for 48 vocational rehabilitation consumers with visual disabilities who required assistance securing work transportation. Social problem solving was at the upper end of the normed average; transportation self-efficacy averaged 101.5 out of 140. Level of vision loss was not associated with score differences; urban residence related to slightly higher self-efficacy than suburban or rural residency. Participants appeared to have the skills necessary to secure employment transportation, but were less confident about transportation-seeking activities that required more initiative of social interaction. Training and information might help consumers gain confidence in these tasks and increase viable transportation options.
Discrete ordinates transport methods for problems with highly forward-peaked scattering
Energy Technology Data Exchange (ETDEWEB)
Pautz, S.D.
1998-04-01
The author examines the solutions of the discrete ordinates (S{sub N}) method for problems with highly forward-peaked scattering kernels. He derives conditions necessary to obtain reasonable solutions in a certain forward-peaked limit, the Fokker-Planck (FP) limit. He also analyzes the acceleration of the iterative solution of such problems and offer improvements to it. He extends the analytic Fokker-Planck limit analysis to the S{sub N} equations. This analysis shows that in this asymptotic limit the S{sub N} solution satisfies a pseudospectral discretization of the FP equation, provided that the scattering term is handled in a certain way (which he describes) and that the analytic transport solution satisfies an analytic FP equation. Similar analyses of various spatially discretized S{sub N} equations reveal that they too produce solutions that satisfy discrete FP equations, given the same provisions. Numerical results agree with these theoretical predictions. He defines a multidimensional angular multigrid (ANMG) method to accelerate the iterative solution of highly forward-peaked problems. The analyses show that a straightforward application of this scheme is subject to high-frequency instabilities. However, by applying a diffusive filter to the ANMG corrections he is able to stabilize this method. Fourier analyses of model problems show that the resulting method is effective at accelerating the convergence rate when the scattering is forward-peaked. The numerical results demonstrate that these analyses are good predictors of the actual performance of the ANMG method.
Kent, James; Holdaway, Daniel
2015-01-01
A number of geophysical applications require the use of the linearized version of the full model. One such example is in numerical weather prediction, where the tangent linear and adjoint versions of the atmospheric model are required for the 4DVAR inverse problem. The part of the model that represents the resolved scale processes of the atmosphere is known as the dynamical core. Advection, or transport, is performed by the dynamical core. It is a central process in many geophysical applications and is a process that often has a quasi-linear underlying behavior. However, over the decades since the advent of numerical modelling, significant effort has gone into developing many flavors of high-order, shape preserving, nonoscillatory, positive definite advection schemes. These schemes are excellent in terms of transporting the quantities of interest in the dynamical core, but they introduce nonlinearity through the use of nonlinear limiters. The linearity of the transport schemes used in Goddard Earth Observing System version 5 (GEOS-5), as well as a number of other schemes, is analyzed using a simple 1D setup. The linearized version of GEOS-5 is then tested using a linear third order scheme in the tangent linear version.
Bula, Gustavo Alfredo; Prodhon, Caroline; Gonzalez, Fabio Augusto; Afsar, H Murat; Velasco, Nubia
2017-02-15
This work focuses on the Heterogeneous Fleet Vehicle Routing problem (HFVRP) in the context of hazardous materials (HazMat) transportation. The objective is to determine a set of routes that minimizes the total expected routing risk. This is a nonlinear function, and it depends on the vehicle load and the population exposed when an incident occurs. Thus, a piecewise linear approximation is used to estimate it. For solving the problem, a variant of the Variable Neighborhood Search (VNS) algorithm is employed. To improve its performance, a post-optimization procedure is implemented via a Set Partitioning (SP) problem. The SP is solved on a pool of routes obtained from executions of the local search procedure embedded on the VNS. The algorithm is tested on two sets of HFVRP instances based on literature with up to 100 nodes, these instances are modified to include vehicle and arc risk parameters. The results are competitive in terms of computational efficiency and quality attested by a comparison with Mixed Integer Linear Programming (MILP) previously proposed.
Liang, Dong; Fu, Kai; Wang, Wenqia
2016-11-01
can be applied to model spatial multi-component aerosol transport problems in large domains in atmosphere.
Arenas, Jorge P
2008-11-01
The public, increasingly well-informed about the problem of excessive noise, is taking actions for the development of new transport infrastructure projects and improvement of existing infrastructure. In addition, many countries have implemented mandatory Environmental Impact Assessment procedures. As a result, the construction of sound barriers has become a common measure, which can be used by an agency to mitigate potentially significant noise impacts. A sound barrier, eventually, will become part of the surrounding landscape and could be a cause of impact for ecosystems, the road users and those who live alongside the road. Basically, this article discusses these potential effects in the context of environmental assessment procedures. In addition, results of a pilot survey conducted at a residential area affected by the construction of a barrier are presented. Although most residents felt that sleeping conditions improved after the barrier was built, most important negative reactions are the loss of sunlight and visual impact.
Directory of Open Access Journals (Sweden)
hasan hosseini nasab
2016-02-01
Full Text Available Operations research is a commonly used method in many subjects nowadays. One applicable domain of operation research is the problem of facility layout and location. In this paper, a new mathematical programing model is developed for an optimal facility location and assignment. The model includes two objective functions. The first one minimizes the total material handling and fixed costs of facility location. Because of the importance of energy and the main role of fossil fuel in transportation, the second objective function, minimizes the total cost of fuel consumption. To consider the real condition in the proposed model, the cost of fuel, is considered to increase stepwise gradually. In the proposed model the coefficients of objective function are considered to be probabilistic and some of constraints to be fuzzy variables. Using a new approach, this model can be changed to a robust model. To prove the applicability of the model, it is examined for a real condition of facility location.
Fuzzy Programming With Quadratic Membership Functions For Multi-objective Transportation Problem
Directory of Open Access Journals (Sweden)
Satyanarayana Murthy Akkapeddi
2015-08-01
Full Text Available In the present paper, a fuzzy programming model with quadratic membership functions has been developed for the solution of a Multi-Objective Transportation problem. In literature, several fuzzy programming approaches exist with various types of membership functions such as linear, exponential, hyperbolic etc. These membership functions are defined, by taking the lower and upper values of the objective functions into account. In some cases, these methods fail to obtain an integer compromise optimal solution. In the present method, two coefficients of the quadratic membership functions are determined by the lower and upper values of the objective functions. The other coefficient is taken as a variable in the fuzzy programming approach. This means that the membership curve is fixed at the two end points and set free in between. Application of the method on numerical examples proved that the approach could generate integer compromise optimal solutions.
The EGS4 Code System: Solution of Gamma-ray and Electron Transport Problems
Nelson, W. R.; Namito, Yoshihito
1990-03-01
In this paper we present an overview of the EGS4 Code System -- a general purpose package for the Monte Carlo simulation of the transport of electrons and photons. During the last 10-15 years EGS has been widely used to design accelerators and detectors for high-energy physics. More recently the code has been found to be of tremendous use in medical radiation physics and dosimetry. The problem-solving capabilities of EGS4 will be demonstrated by means of a variety of practical examples. To facilitate this review, we will take advantage of a new add-on package, called SHOWGRAF, to display particle trajectories in complicated geometries. These are shown as 2-D laser pictures in the written paper and as photographic slides of a 3-D high-resolution color monitor during the oral presentation. 11 refs., 15 figs.
Energy Technology Data Exchange (ETDEWEB)
Marignac, Y.; Coeytaux, X. [Wise-Paris, 75 (France); Large, J.H. [Nuclear Engineer, Large and Associates, Londres (United Kingdom)
2004-09-15
This report concerns the safety and the protection of plutonium dioxide transported from Cogema La Hague to the mixed oxide fuel plant of Marcoule and Cadarache. The French approach of the transport safety is based on the combining of two essential principles: the first one affirms that the performances of the FS47 container in regard of containment (norms TS-R-1 from IAEA for the accidental conditions) is conceived to resist in any situation even terrorism or sabotage. In fact, the IAEA norm follows a probabilistic study without a voluntary attack such a terrorist one. The second principle rests on the ability to prevent the treat of terrorism acts, because of a secrecy policy on the plutonium transport. It appeared that the Green peace association has succeeded several times to know exactly the hours, the trips of the plutonium transport and this simple thing raises more questions than it solves. (N.C.)
Transport dissipative particle dynamics model for mesoscopic advection- diffusion-reaction problems
Energy Technology Data Exchange (ETDEWEB)
Zhen, Li; Yazdani, Alireza; Tartakovsky, Alexandre M.; Karniadakis, George E.
2015-07-07
We present a transport dissipative particle dynamics (tDPD) model for simulating mesoscopic problems involving advection-diffusion-reaction (ADR) processes, along with a methodology for implementation of the correct Dirichlet and Neumann boundary conditions in tDPD simulations. tDPD is an extension of the classic DPD framework with extra variables for describing the evolution of concentration fields. The transport of concentration is modeled by a Fickian flux and a random flux between particles, and an analytical formula is proposed to relate the mesoscopic concentration friction to the effective diffusion coefficient. To validate the present tDPD model and the boundary conditions, we perform three tDPD simulations of one-dimensional diffusion with different boundary conditions, and the results show excellent agreement with the theoretical solutions. We also performed two-dimensional simulations of ADR systems and the tDPD simulations agree well with the results obtained by the spectral element method. Finally, we present an application of the tDPD model to the dynamic process of blood coagulation involving 25 reacting species in order to demonstrate the potential of tDPD in simulating biological dynamics at the mesoscale. We find that the tDPD solution of this comprehensive 25-species coagulation model is only twice as computationally expensive as the DPD simulation of the hydrodynamics only, which is a significant advantage over available continuum solvers.
Transport coefficients for the shear dynamo problem at small Reynolds numbers.
Singh, Nishant K; Sridhar, S
2011-05-01
We build on the formulation developed in S. Sridhar and N. K. Singh [J. Fluid Mech. 664, 265 (2010)] and present a theory of the shear dynamo problem for small magnetic and fluid Reynolds numbers, but for arbitrary values of the shear parameter. Specializing to the case of a mean magnetic field that is slowly varying in time, explicit expressions for the transport coefficients α(il) and η(il) are derived. We prove that when the velocity field is nonhelical, the transport coefficient α(il) vanishes. We then consider forced, stochastic dynamics for the incompressible velocity field at low Reynolds number. An exact, explicit solution for the velocity field is derived, and the velocity spectrum tensor is calculated in terms of the Galilean-invariant forcing statistics. We consider forcing statistics that are nonhelical, isotropic, and delta correlated in time, and specialize to the case when the mean field is a function only of the spatial coordinate X(3) and time τ; this reduction is necessary for comparison with the numerical experiments of A. Brandenburg, K. H. Rädler, M. Rheinhardt, and P. J. Käpylä [Astrophys. J. 676, 740 (2008)]. Explicit expressions are derived for all four components of the magnetic diffusivity tensor η(il)(τ). These are used to prove that the shear-current effect cannot be responsible for dynamo action at small Re and Rm, but for all values of the shear parameter.
Bürger, Raimund; Kumar, Sarvesh; Ruiz-Baier, Ricardo
2015-10-01
The sedimentation-consolidation and flow processes of a mixture of small particles dispersed in a viscous fluid at low Reynolds numbers can be described by a nonlinear transport equation for the solids concentration coupled with the Stokes problem written in terms of the mixture flow velocity and the pressure field. Here both the viscosity and the forcing term depend on the local solids concentration. A semi-discrete discontinuous finite volume element (DFVE) scheme is proposed for this model. The numerical method is constructed on a baseline finite element family of linear discontinuous elements for the approximation of velocity components and concentration field, whereas the pressure is approximated by piecewise constant elements. The unique solvability of both the nonlinear continuous problem and the semi-discrete DFVE scheme is discussed, and optimal convergence estimates in several spatial norms are derived. Properties of the model and the predicted space accuracy of the proposed formulation are illustrated by detailed numerical examples, including flows under gravity with changing direction, a secondary settling tank in an axisymmetric setting, and batch sedimentation in a tilted cylindrical vessel.
Analytical calculations of neutron slowing down and transport in the constant-cross-section problem
Energy Technology Data Exchange (ETDEWEB)
Cacuci, D.G.
1978-04-01
Aspects of the problem of neutron slowing down and transport in an infinite medium consisting of a single nuclide that scatters elastically and isotropically and has energy-independent cross sections were investigated. The method of singular eigenfunctions was applied to the Boltzmann Equation governing the Laplace transform (with respect to the lethargy variable) of the neutron flux. A new sufficient condition for the convergence of the coefficients of the expansion of the scattering kernel in Legendre polynomials was rigorously derived for this energy-dependent problem. Formulas were obtained for the lethargy-dependent spatial moments of the scalar flux that are valid for medium to large lethargies. Use was made of the well-known connection between the spatial moments of the Laplace-transformed scalar flux and the moments of the flux in the ''eigenvalue space.'' The calculations were aided by the construction of a closed general expression for these ''eigenvalue space'' moments. Extensive use was also made of the methods of combinatorial analysis and of computer evaluation of complicated sequences of manipulations. For the case of no absorption it was possible to obtain for materials of any atomic weight explicit corrections to the age-theory formulas for the spatial moments M/sub 2n/(u) of the scalar flux that are valid through terms of the order of u/sup -5/. The evaluation of the coefficients of the powers of n, as explicit functions of the nuclear mass, represent one of the end products of this investigation. In addition, an exact expression for the second spatial moment, M/sub 2/(u), valid for arbitrary (constant) absorption, was derived. It is now possible to calculate analytically and rigorously the ''age'' for the constant-cross-section problem for arbitrary (constant) absorption and nuclear mass. 5 figures, 1 table.
Transport dissipative particle dynamics model for mesoscopic advection-diffusion-reaction problems
Li, Zhen; Yazdani, Alireza; Tartakovsky, Alexandre; Karniadakis, George Em
2015-07-01
We present a transport dissipative particle dynamics (tDPD) model for simulating mesoscopic problems involving advection-diffusion-reaction (ADR) processes, along with a methodology for implementation of the correct Dirichlet and Neumann boundary conditions in tDPD simulations. tDPD is an extension of the classic dissipative particle dynamics (DPD) framework with extra variables for describing the evolution of concentration fields. The transport of concentration is modeled by a Fickian flux and a random flux between tDPD particles, and the advection is implicitly considered by the movements of these Lagrangian particles. An analytical formula is proposed to relate the tDPD parameters to the effective diffusion coefficient. To validate the present tDPD model and the boundary conditions, we perform three tDPD simulations of one-dimensional diffusion with different boundary conditions, and the results show excellent agreement with the theoretical solutions. We also performed two-dimensional simulations of ADR systems and the tDPD simulations agree well with the results obtained by the spectral element method. Finally, we present an application of the tDPD model to the dynamic process of blood coagulation involving 25 reacting species in order to demonstrate the potential of tDPD in simulating biological dynamics at the mesoscale. We find that the tDPD solution of this comprehensive 25-species coagulation model is only twice as computationally expensive as the conventional DPD simulation of the hydrodynamics only, which is a significant advantage over available continuum solvers.
Energy Technology Data Exchange (ETDEWEB)
Kesten, M. [Messer Griesheim Industriegase GmbH, Koeln (Germany); Meyer, G. [Messer Griesheim Industriegase GmbH, Koeln (Germany)
1997-09-01
The development of pressure cylinders for (gaseous or liquid) hydrogen is reported. The introduction of composite materials in pressure cylinder technology permitted to get a better grip on the problem of hydrogen embrittlement. (MM) [Deutsch] Berichtet wird ueber die Entwicklung von Wasserstoffdruckbehaeltern (fuer gasfoermigen oder fluessigen Wasserstoff). Durch die Einfuehrung von Verbundmaterialien in der Druckbehaeltertechnologie konnte man das Problem der Wasserstoffversproedung besser in den Griff bekommen. (MM)
Energy Technology Data Exchange (ETDEWEB)
Vergnaud, T.; Nimal, J.C. (CEA Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France))
1990-01-01
The three-dimensional polycinetic Monte Carlo particle transport code TRIPOLI has been under development in the French Shielding Laboratory at Saclay since 1965. TRIPOLI-1 began to run in 1970 and became TRIPOLI-2 in 1978: since then its capabilities have been improved and many studies have been performed. TRIPOLI can treat stationary or time dependent problems in shielding and in neutronics. Some examples of solved problems are presented to demonstrate the many possibilities of the system. (author).
A Branch-and-Cut Algorithm for Elementary Shortest Path Problem with Resource Constraints
DEFF Research Database (Denmark)
Jepsen, Mads Kehlet; Petersen, Bjørn; Spoorendonk, Simon
The elementary shortest path with resource constraints are commonly solved with dynamic programming algorithms. We present a branch-and-cut algorithm for the undirected version. Two types of resources are discussed: A capacity and a fixed charge resource. The former is the subproblem of the capac...... of the capacitated vehicle routing problem and the latter is for the split delivery version....
Saumier, Louis-Philippe; Khouider, Boualem
2010-01-01
We present a numerical method to solve the optimal transport problem with a quadratic cost when the source and target measures are periodic probability densities. This method relies on a numerical resolution of the corresponding Monge-Amp\\`ere equation. We use an existing Newton-like algorithm that we generalize to the case of a non uniform final density. The main idea consists of designing an iterative scheme where the fully nonlinear equation is approximated by a non-constant coefficient linear elliptic PDE that we discretize and solve at each iteration, in two different ways: a second order finite difference scheme and a fast Fourier transform (FFT) method. The FFT method, made possible thanks to a preconditioning step based on the coefficient-averaged equation, results in an overall O(P log P)-operations algorithm, where P is the number of discretization points. In particular, we use fourth order finite differences to approximate the action of the densities on the solution iterates, which result in more a...
Benchmarking the invariant embedding method against analytical solutions in model transport problems
Directory of Open Access Journals (Sweden)
Wahlberg Malin
2006-01-01
Full Text Available The purpose of this paper is to demonstrate the use of the invariant embedding method in a few model transport problems for which it is also possible to obtain an analytical solution. The use of the method is demonstrated in three different areas. The first is the calculation of the energy spectrum of sputtered particles from a scattering medium without absorption, where the multiplication (particle cascade is generated by recoil production. Both constant and energy dependent cross-sections with a power law dependence were treated. The second application concerns the calculation of the path length distribution of reflected particles from a medium without multiplication. This is a relatively novel application, since the embedding equations do not resolve the depth variable. The third application concerns the demonstration that solutions in an infinite medium and in a half-space are interrelated through embedding-like integral equations, by the solution of which the flux reflected from a half-space can be reconstructed from solutions in an infinite medium or vice versa. In all cases, the invariant embedding method proved to be robust, fast, and monotonically converging to the exact solutions.
Application of the invariant embedding method to analytically solvable transport problems
Energy Technology Data Exchange (ETDEWEB)
Wahlberg, Malin
2005-05-01
The applicability and performance of the invariant embedding method for calculating various transport quantities is investigated in this thesis. The invariant embedding method is a technique to calculate the reflected or transmitted fluxes in homogeneous half-spaces and slabs, without the need for solving for the flux inside the medium. In return, the embedding equations become non-linear, and in practical cases they need to be solved by numerical methods. There are, however, fast and effective iterative methods available for this purpose. The objective of this thesis is to investigate the performance of these iterative methods in model problems, in which also an exact analytical solution can be obtained. Some of these analytical solutions are also new, hence their derivation constitutes a part of the thesis work. The cases investigated in the thesis all concern the calculation of reflected fluxes from half-spaces. The first problem treated was the calculation of the energy spectrum of reflected (sputtered) particles from a multiplying medium, where the multiplication arises from recoil production (i.e. like binary fission), when bombarded by o flux of monoenergetic particles of the same type. Both constant cross sections and energy dependent cross sections with a power law dependence were used in the calculations. The second class of problems concerned the calculation of the path length distribution of reflected particles from a medium without multiplication. It is an interesting new observation that the distribution of the path length travelled in the medium before reflection can be calculated with invariant embedding methods, which actually do not solve the flux distribution in the medium. We have tested the accuracy and the convergence properties of the embedding method also for this case. Finally, very recently a theory of connecting the infinite and half-space medium solutions by embedding-like integral equations was developed and reported in the literature
A novel transport based model for wire media and its application to scattering problems
Forati, Ebrahim
Artificially engineered materials, known as metamaterials, have attracted the interest of researchers because of the potential for novel applications. Effective modeling of metamaterials is a crucial step for analyzing and synthesizing devices. In this thesis, we focus on wire medium (both isotropic and uniaxial) and validate a novel transport based model for them. Scattering problems involving wire media are computationally intensive due to the spatially dispersive nature of homogenized wire media. However, it will be shown that using the new model to solve scattering problems can simplify the calculations a great deal. For scattering problems, an integro-differential equation based on a transport formulation is proposed instead of the convolution-form integral equation that directly comes from spatial dispersion. The integro-differential equation is much faster to solve than the convolution equation form, and its effectiveness is confirmed by solving several examples in one-, two-, and three-dimensions. Both the integro-differential equation formulation and the homogenized wire medium parameters are experimentaly confirmed. To do so, several isotropic connected wire medium spheres have been fabricated using a rapid-prototyping machine, and their measured extinction cross sections are compared with simulation results. Wire parameters (period and diameter) are varied to the point where homogenization theory breaks down, which is observed in the measurements. The same process is done for three-dimensional cubical objects made of a uniaxail wire medium, and their measured results are compared with the numerical results based on the new model. The new method is extremely fast compared to brute-force numerical methods such as FDTD, and provides more physical insight (within the limits of homogenization), including the idea of a Debye length for wire media. The limits of homogenization are examined by comparing homogenization results and measurement. Then, a novel
Wheelchair Users’ Accessibility Problems in Public Transportation-Case of Metro Bus
Directory of Open Access Journals (Sweden)
Ayse Nilay Evcil
2014-06-01
Full Text Available Every day, in urban areas, the mobility of people and goods forms inner urban transportation. When urban transportation is carried in the form of public transportation, it becomes a public service. The urban public transport is one of the important services for all citizens since it is a public service provision. This service is provided by local government and it has been offered as a service without any distinctions between young, old, children, men, women, disabled, employee or retired or briefly to the society. Additionally, traffic congestion and the expence of owing and maintaining vehicles increase public transport usage in cities.
Meysman, F.J.R.; Middelburg, J.J.; Herman, P.M.J.; Heip, C.H.R.
2003-01-01
The MEDIA (Modelling Early DIAgenesis) software package comprises a flexible and extensible software system that provides problem-solving assistance for simulating 1D reactive transport in surface sediments. MEDIA allows multiple diagenetic models to be built by extending a model template with new m
Directory of Open Access Journals (Sweden)
A. Khodadadi
2014-04-01
Full Text Available In most manufacturing and distribution systems, semi-finished jobs are transferred from one processing facility to another by transporters such as automated guided vehicles and conveyors and finished jobs are delivered to customers or warehouses by vehicles such as trucks. Most machine scheduling models assume either that there are a finite number of transporters for delivering jobs or that jobs are delivered instantaneously from one location to another without transportation time involved. In this study we study a new simple heuristic algorithm for a ‘3-machine, n-job’ flow shop scheduling problem in which transportation time and break down times of machines are considered. A heuristic approach method to find optimal and near optimal sequence minimizing the total elapsed time.
Certain specific problems of a construction of a monorail transporter for mines of Tataban'ya
Energy Technology Data Exchange (ETDEWEB)
Styrna, R.; Fellegi, V.; Vago, I.
1980-01-01
A shaft type suspension transporter was introduced into operation in the first quarter of 1978 at one coal mine of Tataban'shikh strip mines (Hungary). The basic assignment was to transport auxiliary materials and equipment spare parts into the mine. It was necessary to solve a set of engineering problems, which take into account specific aspects of the operation of the suspension-type transporters in underground conditions, in particular, assuring the movement of cargo along a complex projectory, automatic control trajectory, and solution of a problem related to going through ventilation doors. The structure of the change in the transport control is described in detail. The system for control has low-voltage (42V) and high voltage (22OV) AC circuits. Automatic control of the exhaust doors during movement of the transporter in a mine shaft is accomplished by using standard pneumatic elements made by the Austrian firm, Festo. Actuation of the elements is accomplished by compressed air with a pressure of 3.5-5atm which is safe for mines. Certain design dimensions of the pneumatic components and their catalog description are presented. It is shown that results of the first tests are satisfactory.
Energy Technology Data Exchange (ETDEWEB)
Cartier, J
2006-04-15
This thesis focuses on mathematical analysis, numerical resolution and modelling of the transport equations. First of all, we deal with numerical approximation of the solution of the transport equations by using a mixed-hybrid scheme. We derive and study a mixed formulation of the transport equation, then we analyse the related variational problem and present the discretization and the main properties of the scheme. We particularly pay attention to the behavior of the scheme and we show its efficiency in the diffusion limit (when the mean free path is small in comparison with the characteristic length of the physical domain). We present academical benchmarks in order to compare our scheme with other methods in many physical configurations and validate our method on analytical test cases. Unstructured and very distorted meshes are used to validate our scheme. The second part of this thesis deals with two transport problems. The first one is devoted to the study of diffusion due to boundary conditions in a transport problem between two plane plates. The second one consists in modelling and simulating radiative transfer phenomenon in case of the industrial context of inertial confinement fusion. (author)
Energy Technology Data Exchange (ETDEWEB)
Filho, J. F. P. [Institute de Matematica, Estatistica e Fisica, Universidade Federal do Rio Grande, Av. Italia, s/n, 96203-900 Rio Grande, RS (Brazil); Barichello, L. B. [Institute de Matematica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 9500, 91509-900 Porto Alegre, RS (Brazil)
2013-07-01
In this work, an analytical discrete ordinates method is used to solve a nodal formulation of a neutron transport problem in x, y-geometry. The proposed approach leads to an important reduction in the order of the associated eigenvalue systems, when combined with the classical level symmetric quadrature scheme. Auxiliary equations are proposed, as usually required for nodal methods, to express the unknown fluxes at the boundary introduced as additional unknowns in the integrated equations. Numerical results, for the problem defined by a two-dimensional region with a spatially constant and isotropically emitting source, are presented and compared with those available in the literature. (authors)
Energy Technology Data Exchange (ETDEWEB)
Thomas, Edward V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stork, Christopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mattingly, John K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2015-07-01
Inverse radiation transport focuses on identifying the configuration of an unknown radiation source given its observed radiation signatures. The inverse problem is traditionally solved by finding the set of transport model parameter values that minimizes a weighted sum of the squared differences by channel between the observed signature and the signature pre dicted by the hypothesized model parameters. The weights are inversely proportional to the sum of the variances of the measurement and model errors at a given channel. The traditional implicit (often inaccurate) assumption is that the errors (differences between the modeled and observed radiation signatures) are independent across channels. Here, an alternative method that accounts for correlated errors between channels is described and illustrated using an inverse problem based on the combination of gam ma and neutron multiplicity counting measurements.
A preliminary study of the OECD/NEA 3D transport problem using the lattice code DRAGON
Energy Technology Data Exchange (ETDEWEB)
Martin, N.; Marleau, G.; Hebert, A. [Inst. de genie nucleaire, Ecole Polytechnique de Montreal, Montreal, Quebec (Canada)
2008-07-01
In this paper we present a preliminary analysis of the NEA3D-TAB-2007 transport problem proposed by the OECD/NEA expert group on radiative transfer. This computational benchmark was originally proposed by Y. Azmy in 2007 to test the performance of 3D transport methods and codes over a suite of problems defined by large variations in space parameters. Two deterministic methods were applied to generate the numerical solutions: the discrete ordinates method (S{sub N}), and the method of open characteristics of I.R. Suslov (MCCG). We provide comparisons between MCNP reference solutions and MCCG and DRAGON-S{sub N} results in order to reveal the advantages and limitations of both methods. (author)
Modeling the impact of air transport on the economy - practices, problems and prospects
Directory of Open Access Journals (Sweden)
Sonia Huderek-Glapska
2016-03-01
Full Text Available Background: The issue of measuring the contribution of air transport to the regional economy is very important nowadays since many airport infrastructure projects are being implemented, using available European Union funds. As a result of growing transport needs and increasing incomes among the population, the air transport market is strongly developing. This development results to many direct and indirect socio-economic benefits to locations in close proximity of an airport but also in the whole economy. The measurement of these benefits is important because the decisions made with respect to air transport influence local and regional economic performance. The most commonly used tool for measuring the positive effects associated with the operation of an airport is the input-output analysis. The aim of the article is to present the characteristics of the input-output method, to indicate its applications in Poland - the country with the most dynamic growth of air transport, to present the possible limitations of this method and propose improvements. Methods: The method used in this research is one that measures the effects of changes in the economy as a result of air transport activity. Particular input-output analysis is used. Results: On the background of the results of modeling the impact of polish airport on regional economy in 2009 the updated analysis in 2012 is provided. The economic impacts of Krakow, Katowice, Wroclaw and Szczecin airports are estimated. Then the limitations of input-output method are presented and suggestions of possible improvements are made. Comments: Proper measurement of the impact of airport's operation and investment on the economy, leads to more effective air transport policy development. For future research, the advanced input-output method to assess the positive impact of airports on regional development is recommended. However, a comprehensive assessment of the operation and expansion of airport
Sugden, Karen; Arseneault, Louise; Harrington, HonaLee; Moffitt, Terrie E.; Williams, Benjamin; Caspi, Avshalom
2010-01-01
Objective: Bullying is the act of intentionally and repeatedly causing harm to someone who has difficulty defending him- or herself, and is a relatively widespread school-age phenomenon. Being the victim of bullying is associated with a broad spectrum of emotional problems; however, not all children who are bullied go on to develop such problems.…
Prospects of and Problems in Using Natural Gas for Motor Transport in RUSSIA
Chikishev, E.; Ivanov, A.; Anisimov, I.; Chainikov, D.
2016-08-01
This article is devoted to increasing the use of natural gas in Russia as a measure to decrease the negative influence of motor transport on the environment. A brief analysis of the global fleet of natural gas vehicles is provided above. The documents accepted in Russia to promote public awareness of compressed natural gas in transport are submitted. The basic reasons keeping the growth of natural gas vehicle fleets in Russia consist of weak branching of refuelling stations; difficulty in determining the actual amount of compressed natural gas required; and control methods of the consumption of gas fuel. The offers promoting the growth of the fleet of natural gas vehicles are given.
Institute of Scientific and Technical Information of China (English)
姚磊华
1997-01-01
A generalized upwind scheme with fractional steps for 3-D mathematical models of convection dominating groundwater quality is suggested. The mass transport equation is split into a convection equation and a dispersive equation. The generalized upwind scheme is used to solve the convection equation and the finite element method is used to compute the dispersive equation. These procedures which not only overcome the phenomenon of the negative concentration and numerical dispersion appear frequently with normal FEM or FDM to solve models of convection dominating groundwater transport but also avoid the step for computing each node velocity give a more suitable method to calculate the concentrations of the well points.
Directory of Open Access Journals (Sweden)
Yekini Shehu
2010-01-01
real Banach space which is also uniformly smooth using the properties of generalized f-projection operator. Using this result, we discuss strong convergence theorem concerning general H-monotone mappings and system of generalized mixed equilibrium problems in Banach spaces. Our results extend many known recent results in the literature.
Directory of Open Access Journals (Sweden)
Guina Sotomayor Alzamora
2013-12-01
Full Text Available The hub-and-spoke network design problem, also known as the hub location problem, aims to find the concentration points in a given network flow so that the sum of the distances of the linkages is minimized. In this work, we compare discrete solutions of this problem, given by the branch-and-cut method applied to the p-hub median model, with continuous solutions, given by the hyperbolic smoothing technique applied to a min-sum-min model. Computational experiments for particular instances of the Brazilian air transportation system, with the number of hubs varying from 2 to 8, are conducted with the support of a discretization heuristic and the Voronoi diagram.
Tuning microtubule-based transport via filamentous MAPs: the problem of dynein
Vershinin, Michael; Xu, Jing; Razafsky, David S.; King, Stephen J.; Gross, Steven P.
2010-01-01
We recently proposed that regulating the single-to-multiple motor transition was a likely strategy for regulating kinesin-based transport in vivo. Here, we use an in vitro bead assay coupled with an optical trap to investigate how this proposed regulatory mechanism affects dynein-based transport. We show that tau’s regulation of kinesin function can proceed without interfering with dynein-based transport. Surprisingly, at extremely high tau levels—where kinesin cannot bind microtubules—dynein can still contact microtubules. The difference between tau’s effects on kinesin- and dynein-based motility suggests that tau can be used to tune relative amounts of plus-end and minus-end directed transport. As in the case of kinesin, we find that the 3RS isoform of tau is a more potent inhibitor of dynein binding to microtubules. We show that this isoform-specific effect is not due to steric interference of tau’s projection domains, but rather due to tau’s interactions with the motor at the microtubule surface. Nonetheless, we do observe a modest steric interference effect of tau away from the microtubule and discuss the potential implications of this for molecular motor structure. PMID:18373727
DELIVERY AND PICK-UP PROBLEM TRANSPORTATION - MILK RUN AND CONVENTIONAL SYSTEMS
Directory of Open Access Journals (Sweden)
Delmo Alves de Moura
2016-09-01
Full Text Available This paper examines the role of inventory and transportation in the supply system of parts adopted by most of the Brazilian automotive companies to feed their assembly lines. It is a system for programmed collection of pieces called Milk Run that aims, within a window of time, to collect parts from suppliers, fulfilling established routes in order to minimize the cost of transport operations and reducing inventory in the supply chain. Milk Run, a scheduled collection system of parts can be carried out by automotive industry itself: the automaker manage the best route for its collector vehicle, determining the quantity of parts required to collect at each supplier within a given route, aiming to best utilize the capacity of the vehicle. Another way to work within the Milk Run system is the automaker to find the best routing and determines the amount of parts needed to be collected from each supplier on each trip. The collection, however, is held by a third carrier. As a third way of working, the assembler can determine the quantity of parts to collect and when it will require them. A logistics carrier determines the best routing for the collection of pieces in order to meet the production plan so that there is not a lack of parts or components on the assembly line, which would lead to a stop. In this case, the logistics carrier transports parts on its own fleet of vehicles or transfer the transport operation to a carrier.
Philip, Bobby; Berrill, Mark A.; Allu, Srikanth; Hamilton, Steven P.; Sampath, Rahul S.; Clarno, Kevin T.; Dilts, Gary A.
2015-04-01
This paper describes an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors is described. Details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstrating the achieved efficiency of the algorithm are presented. Furthermore, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods. Finally, we demonstrate the power of the coupling methodology by considering problems with couplings between surface and volume physics and coupling of nonlinear thermal transport in fuel rods to an external radiation transport code.
Energy Technology Data Exchange (ETDEWEB)
Talukdar, P.; Steven, M.; Issendorff, F.V.; Trimis, D. [Institute of Fluid Mechanics (LSTM), University of Erlangen-Nuremberg, Cauerstrasse 4, D 91058 Erlangen (Germany)
2005-10-01
The finite volume method of radiation is implemented for complex 3-D problems in order to use it for combined heat transfer problems in connection with CFD codes. The method is applied for a 3-D block structured grid in a radiatively participating medium. The method is implemented in non-orthogonal curvilinear coordinates so that it can handle irregular structure with a body-fitted structured grid. The multiblocking is performed with overlapping blocks to exchange the information between the blocks. Five test problems are considered in this work. In the first problem, present work is validated with the results of the literature. To check the accuracy of multiblocking, a single block is divided into four blocks and results are validated against the results of the single block simulated alone in the second problem. Complicated geometries are considered to show the applicability of the present procedure in the last three problems. Both radiative and non-radiative equilibrium situations are considered along with an absorbing, emitting and scattering medium. (author)
Reuter, Matthew G; Harrison, Robert J
2013-09-21
We revisit the derivation of electron transport theories with a focus on the projection operators chosen to partition the system. The prevailing choice of assigning each computational basis function to a region causes two problems. First, this choice generally results in oblique projection operators, which are non-Hermitian and violate implicit assumptions in the derivation. Second, these operators are defined with the physically insignificant basis set and, as such, preclude a well-defined basis set limit. We thus advocate for the selection of physically motivated, orthogonal projection operators (which are Hermitian) and present an operator-based derivation of electron transport theories. Unlike the conventional, matrix-based approaches, this derivation requires no knowledge of the computational basis set. In this process, we also find that common transport formalisms for nonorthogonal basis sets improperly decouple the exterior regions, leading to a short circuit through the system. We finally discuss the implications of these results for first-principles calculations of electron transport.
Stochastic Aspect of the Tomographic Reconstruction Problems in a Transport Model
Kharin, Igor
2010-01-01
The stochastic differential and integral equations describing the system of particles weakly interacting among themselves which are absorbed and scattered by particles of a medium are considered. The time-dependent transport equation with scattering is studied taking into account stochastic nature of parameters in nuclear imaging. Using dynamic attenuated Radon transform the solution of transport equation may be derived taking into account of the scattering as perturbation. We analyze the influence of the random variables upon the image reconstruction both generally and in more details for the case of point source. It is shown by the example of the method of the filtered back projection (FBP) that unaccounted small fluctuations of attenuation coefficient can cause essential distortions of image texture and degradation of the resolution at image reconstruction in single-photon emission computerized tomography (SPECT) and less in X-ray computerized tomography (CT). The mechanism of these distortions is analyzed...
Cobos, Agustín C.; Poma, Ana L.; Alvarez, Guillermo D.; Sanz, Darío E.
2016-10-01
We introduce an alternative method to calculate the steady state solution of the angular photon flux after a numerical evolution of the time-dependent Boltzmann transport equation (BTE). After a proper discretization the transport equation was converted into an ordinary system of differential equations that can be iterated as a weighted Richardson algorithm. As a different approach, in this work the time variable regulates the iteration process and convergence criteria is based on physical parameters. Positivity and convergence was assessed from first principles and a modified Courant-Friedrichs-Lewy condition was devised to guarantee convergence. The Penelope Monte Carlo method was used to test the convergence and accuracy of our approach for different phase space discretizations. Benchmarking was performed by calculation of total fluence and photon spectra in different one-dimensional geometries irradiated with 60Co and 6 MV photon beams and radiological applications were devised.
Directory of Open Access Journals (Sweden)
Carsten Gottschlich
Full Text Available Finding solutions to the classical transportation problem is of great importance, since this optimization problem arises in many engineering and computer science applications. Especially the Earth Mover's Distance is used in a plethora of applications ranging from content-based image retrieval, shape matching, fingerprint recognition, object tracking and phishing web page detection to computing color differences in linguistics and biology. Our starting point is the well-known revised simplex algorithm, which iteratively improves a feasible solution to optimality. The Shortlist Method that we propose substantially reduces the number of candidates inspected for improving the solution, while at the same time balancing the number of pivots required. Tests on simulated benchmarks demonstrate a considerable reduction in computation time for the new method as compared to the usual revised simplex algorithm implemented with state-of-the-art initialization and pivot strategies. As a consequence, the Shortlist Method facilitates the computation of large scale transportation problems in viable time. In addition we describe a novel method for finding an initial feasible solution which we coin Modified Russell's Method.
Gottschlich, Carsten; Schuhmacher, Dominic
2014-01-01
Finding solutions to the classical transportation problem is of great importance, since this optimization problem arises in many engineering and computer science applications. Especially the Earth Mover's Distance is used in a plethora of applications ranging from content-based image retrieval, shape matching, fingerprint recognition, object tracking and phishing web page detection to computing color differences in linguistics and biology. Our starting point is the well-known revised simplex algorithm, which iteratively improves a feasible solution to optimality. The Shortlist Method that we propose substantially reduces the number of candidates inspected for improving the solution, while at the same time balancing the number of pivots required. Tests on simulated benchmarks demonstrate a considerable reduction in computation time for the new method as compared to the usual revised simplex algorithm implemented with state-of-the-art initialization and pivot strategies. As a consequence, the Shortlist Method facilitates the computation of large scale transportation problems in viable time. In addition we describe a novel method for finding an initial feasible solution which we coin Modified Russell's Method.
Calibration of the Transport Parameters of a Local Problem of Water Quality in Igap\\'o I Lake
Romeiro, Neyva M L; Cirilo, Eliandro R; Natti, Paulo L
2011-01-01
The calibration of a model refers to the process by which one can estimate some parameters by comparisons with observed data. Due to the dynamical nature of the environment, variations between predicted and observed values occur. Thus, the environmental parameters may vary due to random temperature changes, time of discharge flow, time of the day, and other conditions. Such variations can be minimized by identifying and optimizing some parameters of the transport model, like the values of diffusion coefficients in x and y directions and the kinetic parameter that describes the process of removing pollutants. This paper presents results concerning the calibration of transport parameters for two-dimensional problems of water quality (fecal coliform control) at Igap\\'o I Lake, located in Londrina, Paran\\'a, Brazil. Thus, the convection-diffusion-reaction equation, which describes mathematically the process studied in this work, is resolved by a semidiscrete finite element method (SUPG) which combines finite diff...
Problems with the implementation of bus transport contracting in South Africa
Directory of Open Access Journals (Sweden)
Jackie Walters
2012-11-01
Full Text Available South Africa has had a policy of competitive tendering for the provision of public transport services (subsidised commuter bus services since the mid-1980s. Although this policy approach was conceptualised by the previous government, prior to the transfer of political power in 1994, it was reaffirmed in a 1996 White Paper on National Transport Policy. Despite the nearly 25 years that have passed since the intention to tender services, only about 32% of the subsidy budget is currently spent on some form of contracting. The majority of services are still operated on authorisations (interim contracts which formalised services that operators were operating pre-1994. The purpose of this paper is to analyse the reasons why public transport contracting policy progress has been so slow in South Africa. The paper relies on an extensive study that was conducted regarding policy implementation obstacles in general, as well as a questionnaire survey among the subsidised commuter bus operators to solicit their views on the reasons for the delay in the implementation of the contracting system in the country. The findings of the survey indicate that the major issues hindering the implementation of the contracting system are to be found in a lack of funding, lack of capacity to implement policy and major operational issues in the permit offices.
Directory of Open Access Journals (Sweden)
Hamid Tikani
2016-11-01
Full Text Available In this paper, we study the problem of integrated capacitated hub location problem and seat inventory control considering concept and techniques of revenue management. We consider an airline company maximizes its revenue by utilizing the best network topology and providing proper booking limits for all itineraries and fare classes. The transportation system arises in the form of a star/star network and includes both hub-stop and non-stop flights. This problem is formulated as a two-stage stochastic integer program with mixed-integer recourse. We solve various instances carried out from the Turkish network data set. Due to the NP-hardness of the problem, we propose a hybrid optimization method, consisting of an evolutionary algorithm based on genetic algorithm and exact solution. The quality of the solutions found by the proposed meta-heuristic is compared with the original version of GA and the mathematical programming model. The results obtained by the proposed model imply that integrating hub location and seat inventory control problem would help to increase the total revenue of airline companies. Also, in the case of serving non-stop flights, the model can provide more profit by employing less number of hubs.
Epting, Shane
2016-12-01
Transportation infrastructure tremendously affects the quality of life for urban residents, influences public and mental health, and shapes social relations. Historically, the topic is rich with social and political controversy and the resultant transit systems in the United States cause problems for minority residents and issues for the public. Environmental justice frameworks provide a means to identify and address harms that affect marginalized groups, but environmental justice has limits that cannot account for the mainstream population. To account for this condition, I employ a complex moral assessment measure that provides a way to talk about harms that affect the public.
Energy Technology Data Exchange (ETDEWEB)
Thuc, P. D.; Bich, H. V.; Son, T. C.; Hoe, L. D.; Vygovskoy, V. P. [J. V. Vietsovpetro (Viet Nam)
2003-06-01
Problems encountered in transporting crude oil with high wax content in a submarine pipeline, built without thermal insulation, are reviewed. The focus is on crystallization and deposition of the wax on the walls, the resulting reduction in pipeline diameter leading to higher pressure drop, and the formation of gelled interlocking structures of wax crystals in the pipeline which can lead to shutdown. Methods to reduce wax deposition and gelling, and modelling to predict restart pressures and flow characteristics to improve the pumpability of Vietsovpetro's high paraffin crude oil are described. 6 refs., 5 tabs., 1 fig.
Brands, Ties; van Berkum, Eric C.
2014-01-01
The optimization of infrastructure planning in a multimodal network is defined as a multi-objective network design problem, with accessibility, use of urban space by parking, operating deficit and climate impact as objectives. Decision variables are the location of park and ride facilities, train
Brands, T.; Berkum, van E.C.
2014-01-01
The optimization of infrastructure planning in a multimodal network is defined as a multi-objective network design problem, with accessibility, use of urban space by parking, operating deficit and climate impact as objectives. Decision variables are the location of park and ride facilities, train st
Energy Technology Data Exchange (ETDEWEB)
Serrano, S.E.
1990-08-01
A new methodology to model the time and space evolution of groundwater variables in a system of acquifers when certain components of the model, such as the geohydrologic information, the boundary conditions, the magnitude and variability of the sources or physical parameters are uncertain and defined in stochastic terms. This facilitates a more realistic statistical representation of groundwater flow and groundwater pollution forecasting for either the saturated or the unsaturated zone. The method is based on applications of modern mathematics to the solution of the resulting stochastic transport equations. The procedure exhibits considerable advantages over the existing stochastic modeling techniques.
A correction technique for the dispersive effects of mass lumping for transport problems
Guermond, Jean-Luc
2013-01-01
This paper addresses the well-known dispersion effect that mass lumping induces when solving transport-like equations. A simple anti-dispersion technique based on the lumped mass matrix is proposed. The method does not require any non-trivial matrix inversion and has the same anti-dispersive effects as the consistent mass matrix. A novel quasi-lumping technique for P2 finite elements is introduced. Higher-order extensions of the method are also discussed. © 2012 Elsevier B.V.
The Slab Albedo Problem Using Singular Eigenfunctions and the Third Form of the Transport Equation
Kaskas, Ayþe; Tezcan, Cevdet
1997-01-01
The albedo and the transmission factor for slabs are obtained using the infinite medium Green's function in terms of the singular eigenfunctions in the third form of the transport equation. Our analytical results are simple as in FN-method and the convergence of the numerical results is as faster as in the CN-method. Calculations are also carried out by various incoming angular fluxes and uncollided neutrons are taken into account. Our numerical results are in very good agreement with the results of the CN method.
A branch-and-cut algorithm for the elementary shortest path problem with resource constraints
DEFF Research Database (Denmark)
Jepsen, Mads Kehlet; Petersen, Bjørn; Spoorendonk, Simon
The elementary shortest path with resource constraints have commonly been solved with dynamic programming algorithms. Assuming an undirected graph, we present a compact formulation of this problem and a branch-and-cut algorithm to solve it. Two types of resources are discussed: a capacity...... and a fixed charge resource. The former is the subproblem of the capacitated vehicle routing problem and the latter is from the split delivery version. Computational results are presented and compared to dynamic programming algorithms....
[The immuno-endocrine system. A new endocrine theory: the problem of the packed transport].
Csaba, György
2011-05-15
Since the eighties of the last century hormone content was justified in immune cells (lymphocytes, granulocytes, monocytes, macrophages and mast cells), which produce, store and secrete these hormones. Although the amount of these materials in immune cells is relatively small, the mass of the producers (immune cells) is so large, that the phenomenon must be considered from endocrinological point of view, underlying the important differences between the "classical" and immuno-endocrine systems. Cells of the classic (built-in) endocrine system are mono-producers, while immune cells can synthesize many types of hormones (polyproducers). In addition, these cells can transport the whole hormone-producing machinery to the site of need, producing a local effect. This can be observed, for example, in the case of endorphin producing immune cells during inflammation and during early pregnancy around the chorionic villi. Hormone producing immune cells also have receptors for many hormones, so that they are poly-receivers. Via hormone producing and receiving capacity there is a bidirectional connection between the neuro-endocrine and immuno-endocrine systems. In addition, there is a network inside the immuno-endocrine system. The packed transport theory attempts to explain the mechanism and importance of the immuno-endocrine system.
Geostatistical Sampling Methods for Efficient Uncertainty Analysis in Flow and Transport Problems
Liodakis, Stylianos; Kyriakidis, Phaedon; Gaganis, Petros
2015-04-01
In hydrogeological applications involving flow and transport of in heterogeneous porous media the spatial distribution of hydraulic conductivity is often parameterized in terms of a lognormal random field based on a histogram and variogram model inferred from data and/or synthesized from relevant knowledge. Realizations of simulated conductivity fields are then generated using geostatistical simulation involving simple random (SR) sampling and are subsequently used as inputs to physically-based simulators of flow and transport in a Monte Carlo framework for evaluating the uncertainty in the spatial distribution of solute concentration due to the uncertainty in the spatial distribution of hydraulic con- ductivity [1]. Realistic uncertainty analysis, however, calls for a large number of simulated concentration fields; hence, can become expensive in terms of both time and computer re- sources. A more efficient alternative to SR sampling is Latin hypercube (LH) sampling, a special case of stratified random sampling, which yields a more representative distribution of simulated attribute values with fewer realizations [2]. Here, term representative implies realizations spanning efficiently the range of possible conductivity values corresponding to the lognormal random field. In this work we investigate the efficiency of alternative methods to classical LH sampling within the context of simulation of flow and transport in a heterogeneous porous medium. More precisely, we consider the stratified likelihood (SL) sampling method of [3], in which attribute realizations are generated using the polar simulation method by exploring the geometrical properties of the multivariate Gaussian distribution function. In addition, we propose a more efficient version of the above method, here termed minimum energy (ME) sampling, whereby a set of N representative conductivity realizations at M locations is constructed by: (i) generating a representative set of N points distributed on the
Optimal design for problems involving flow and transport phenomena in saturated subsurface systems
Mayer, Alex S.; Kelley, C. T.; Miller, Cass T.
Estimation problems arise routinely in subsurface hydrology for applications that range from water resources management to water quality protection to subsurface restoration. Interest in optimal design of such systems has increased over the last two decades and this area is considered an important and active area of research. In this work, we review the state of the art, assess important challenges that must be resolved to reach a mature level of understanding, and summarize some promising approaches that might help meet some of the challenges. While much has been accomplished to date, we conclude that more work remains before comprehensive, efficient, and robust solution methods exist to solve the most challenging applications in subsurface science. We suggest that future directions of research include the application of direct search solution methods, and developments in stochastic and multi-objective optimization. We present a set of comprehensive test problems for use in the research community as a means for benchmarking and comparing optimization approaches.
Energy Technology Data Exchange (ETDEWEB)
Tres, Anderson [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Matematica Aplicada; Becker Picoloto, Camila [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Prolo Filho, Joao Francisco [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Inst de Matematica, Estatistica e Fisica; Dias da Cunha, Rudnei; Basso Barichello, Liliane [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Inst de Matematica
2014-04-15
In this work a study of two-dimensional fixed-source neutron transport problems, in Cartesian geometry, is reported. The approach reduces the complexity of the multidimensional problem using a combination of nodal schemes and the Analytical Discrete Ordinates Method (ADO). The unknown leakage terms on the boundaries that appear from the use of the derivation of the nodal scheme are incorporated to the problem source term, such as to couple the one-dimensional integrated solutions, made explicit in terms of the x and y spatial variables. The formulation leads to a considerable reduction of the order of the associated eigenvalue problems when combined with the usual symmetric quadratures, thereby providing solutions that have a higher degree of computational efficiency. Reflective-type boundary conditions are introduced to represent the domain on a simpler form than that previously considered in connection with the ADO method. Numerical results obtained with the technique are provided and compared to those present in the literature. (orig.)
Algorithms for Pallet Building and Truck Loading in an Interdepot Transportation Problem
Directory of Open Access Journals (Sweden)
Maria Teresa Alonso
2016-01-01
Full Text Available This paper deals with the problem of a logistics company that has to serve its customers by first putting the products on pallets and then loading the pallets into trucks. Besides the standard geometric constraints of products not overlapping each other and not exceeding the dimensions of pallets and trucks, in this real problem, there are many other constraints, related to the total weight of the load, the maximum weight supported by each axle, and the distribution of the load inside the truck. Although the problem can be decomposed into two phases, pallet loading and truck loading, we have taken a combined approach, building and placing pallets at the same time. For each position in the truck, a pallet is built and tailored for that position according to the constraints of height and weight. We have developed a GRASP algorithm, in which the constructive algorithm is randomized and an improvement phase is added to obtain high-quality solutions. The algorithm has been tested on two sets of real instances with different characteristics, involving up to 44 trucks. The results show that solutions with an optimal or near optimal number of trucks are obtained in very short computing times.
DATA MINING WORKSPACE AS AN OPTIMIZATION PREDICTION TECHNIQUE FOR SOLVING TRANSPORT PROBLEMS
Directory of Open Access Journals (Sweden)
Anastasiia KUPTCOVA
2016-09-01
Full Text Available This article addresses the study related to forecasting with an actual high-speed decision making under careful modelling of time series data. The study uses data-mining modelling for algorithmic optimization of transport goals. Our finding brings to the future adequate techniques for the fitting of a prediction model. This model is going to be used for analyses of the future transaction costs in the frontiers of the Czech Republic. Time series prediction methods for the performance of prediction models in the package of Statistics are Exponential, ARIMA and Neural Network approaches. The primary target for a predictive scenario in the data mining workspace is to provide modelling data faster and with more versatility than the other management techniques.
PART I – USUAL PROBLEMS OF OPTIMIZING THE ACTION SYSTEMS OFTHE BAND TRANSPORTERS
Directory of Open Access Journals (Sweden)
Nicoleta-Maria MIHUT
2012-05-01
Full Text Available Most of the systems of electric action are non-linear systems, including the continuous transportsystems with band, that could be brought by linearization and negligence at the linear system. The latest news inthe field of static convertors, of the new transfer schemes of electric energy, make possible the analysis of theaction systems of the continuous transport installations with band as linearisable systems. For the linearisableaction systems described by state equations, there are two consecrated calculation methods of the optimaltrajectory of the system, the variational calculation and the Euler-Lagrange algorithm, as the latter one isconsidered by the specialty literature as an optimum generator, and the first one as an extremum generator. Butthe two methods need conditions reviewed enough in the Euler-Lagrange conditions
Nick, H M; Raoof, A; Centler, F; Thullner, M; Regnier, P
2013-02-01
The reactive mixing between seawater and terrestrial water in coastal aquifers influences the water quality of submarine groundwater discharge. While these waters come into contact at the seawater groundwater interface by density driven flow, their chemical components dilute and react through dispersion. A larger interface and wider mixing zone may provide favorable conditions for the natural attenuation of contaminant plumes. It has been claimed that the extent of this mixing is controlled by both, porous media properties and flow conditions. In this study, the interplay between dispersion and reactive processes in coastal aquifers is investigated by means of numerical experiments. Particularly, the impact of dispersion coefficients, the velocity field induced by density driven flow and chemical component reactivities on reactive transport in such aquifers is studied. To do this, a hybrid finite-element finite-volume method and a reactive simulator are coupled, and model accuracy and applicability are assessed. A simple redox reaction is considered to describe the degradation of a contaminant which requires mixing of the contaminated groundwater and the seawater containing the terminal electron acceptor. The resulting degradation is observed for different scenarios considering different magnitudes of dispersion and chemical reactivity. Three reactive transport regimes are found: reaction controlled, reaction-dispersion controlled and dispersion controlled. Computational results suggest that the chemical components' reactivity as well as dispersion coefficients play a significant role on controlling reactive mixing zones and extent of contaminant removal in coastal aquifers. Further, our results confirm that the dilution index is a better alternative to the second central spatial moment of a plume to describe the mixing of reactive solutes in coastal aquifers.
Nick, H.M.
2013-02-01
The reactive mixing between seawater and terrestrial water in coastal aquifers influences the water quality of submarine groundwater discharge. While these waters come into contact at the seawater groundwater interface by density driven flow, their chemical components dilute and react through dispersion. A larger interface and wider mixing zone may provide favorable conditions for the natural attenuation of contaminant plumes. It has been claimed that the extent of this mixing is controlled by both, porous media properties and flow conditions. In this study, the interplay between dispersion and reactive processes in coastal aquifers is investigated by means of numerical experiments. Particularly, the impact of dispersion coefficients, the velocity field induced by density driven flow and chemical component reactivities on reactive transport in such aquifers is studied. To do this, a hybrid finite-element finite-volume method and a reactive simulator are coupled, and model accuracy and applicability are assessed. A simple redox reaction is considered to describe the degradation of a contaminant which requires mixing of the contaminated groundwater and the seawater containing the terminal electron acceptor. The resulting degradation is observed for different scenarios considering different magnitudes of dispersion and chemical reactivity. Three reactive transport regimes are found: reaction controlled, reaction-dispersion controlled and dispersion controlled. Computational results suggest that the chemical components\\' reactivity as well as dispersion coefficients play a significant role on controlling reactive mixing zones and extent of contaminant removal in coastal aquifers. Further, our results confirm that the dilution index is a better alternative to the second central spatial moment of a plume to describe the mixing of reactive solutes in coastal aquifers. © 2012 Elsevier B.V.
Problemática sanitaria y social de la accidentalidad del transporte terrestre
Directory of Open Access Journals (Sweden)
Daniel Alfaro-Basso
2008-01-01
Full Text Available Los accidentes de tránsito son un problema de salud pública mundial. En el Perú entre los años 2000 y 2006 han muerto 18 879 personas, tres de cada cuatro fueron varones, y 16,7% menores de edad. En este artículo se revisan los factores asociados a la letalidad y las medidas para reducirla, las estadísticas nacionales y lo que se viene realizando para afrontar esta problemática.
Comparison of some popular Monte Carlo solution for proton transportation within pCT problem
Energy Technology Data Exchange (ETDEWEB)
Evseev, Ivan; Assis, Joaquim T. de; Yevseyeva, Olga [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Inst. Politecnico], E-mail: evseev@iprj.uerj.br, E-mail: joaquim@iprj.uerj.br, E-mail: yevseyeva@iprj.uerj.br; Lopes, Ricardo T.; Cardoso, Jose J.B.; Silva, Ademir X. da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Lab. de Instrumentacao Nuclear], E-mail: ricardo@lin.ufrj.br, E-mail: jjbrum@oi.com.br, E-mail: ademir@con.ufrj.br; Vinagre Filho, Ubirajara M. [Instituto de Engenharia Nuclear IEN/CNEN-RJ, Rio de Janeiro, RJ (Brazil)], E-mail: bira@ien.gov.br; Hormaza, Joel M. [UNESP, Botucatu, SP (Brazil). Inst. de Biociencias], E-mail: jmesa@ibb.unesp.br; Schelin, Hugo R.; Paschuk, Sergei A.; Setti, Joao A.P.; Milhoretto, Edney [Universidade Tecnologica Federal do Parana, Curitiba, PR (Brazil)], E-mail: schelin@cpgei.cefetpr.br, E-mail: sergei@utfpr.edu.br, E-mail: jsetti@gmail.com, E-mail: edneymilhoretto@yahoo.com
2007-07-01
The proton transport in matter is described by the Boltzmann kinetic equation for the proton flux density. This equation, however, does not have a general analytical solution. Some approximate analytical solutions have been developed within a number of significant simplifications. Alternatively, the Monte Carlo simulations are widely used. Current work is devoted to the discussion of the proton energy spectra obtained by simulation with SRIM2006, GEANT4 and MCNPX packages. The simulations have been performed considering some further applications of the obtained results in computed tomography with proton beam (pCT). Thus the initial and outgoing proton energies (3 / 300 MeV) as well as the thickness of irradiated target (water and aluminum phantoms within 90% of the full range for a given proton beam energy) were considered in the interval of values typical for pCT applications. One from the most interesting results of this comparison is that while the MCNPX spectra are in a good agreement with analytical description within Fokker-Plank approximation and the GEANT4 simulated spectra are slightly shifted from them the SRIM2006 simulations predict a notably higher mean energy loss for protons. (author)
Institute of Scientific and Technical Information of China (English)
WU Hongchun; LIU Pingping; ZHOU Yongqiang; CAO Liangzhi
2007-01-01
The fuel assembly or core with unstructured geometry is frequently used in the advanced reactor. To calculate the fuel assembly, the transmission probability method (TPM) is widely used. However, the rectangular or hexagonal meshes are mainly used in the TPM codes for the normal core structure. The triangle meshes are most useful for expressing the complicated unstructured geometry. Even though the finite element method and Monte-Carlo methodare well suited for solving the unstructured geometry problem, they are very time-consuming. Therefore, a TPM code based on the triangle meshes is developed here. This code was applied to the hybrid fuel geometry, and compared with the results of the MCNP code and other codes. The results of the comparison were consistent with each other. The TPM with triangle meshes can thus be applied to the two-dimensional arbitrary fuel assembly.
Directory of Open Access Journals (Sweden)
Carlos Alberto González Calderón
2011-01-01
Full Text Available Este artículo está basado en datos obtenidos en los más recientes estudios de transporte que se han realizado en el Área Metropolitana del Valle de Aburrá. (Medellín y otros 9 municipios. Estos estudios fueron la Encuesta Origen Destino (2005, análisis de las rutas de buses (2005 y el Plan Maestro de Movilidad (2006. En el artículo se explica el proceso utilizado para el desarrollo de una aplicación informática para resolver el problema determinístico de equilibrio de usuario en la red vial de Medellín. El código fue construido usando Visual Basic.NET ® y Microsoft Excel ® para la ejecución de algunas operaciones en un segmento de la red vial de Medellín. La distribución del flujo del equilibrio de usuario fue encontrada usando el algoritmo de Frank-Wolfe y fueron analizados algunos aspectos tales como número de iteraciones, patrones de convergencia, tiempo de respuesta y cambios en la demanda de viajes en la red. Los modelos de asignación del tránsito fueron analizados para las horas pico de la tarde. Se compararon los resultados de la asignación del tránsito del algoritmo desarrollado en este trabajo con los resultados de TransCAD ® para los datos del 2005 y fue encontrado que el software es un poco más rápido que el algoritmo, pero sin embargo éste último puede ser una buena herramienta para profesionales y estudiantes para la modelación de redes pequeñas.
Philip, Bobby; Allu, Srikanth; Hamilton, Steven P; Sampath, Rahul S; Clarno, Kevin T; Dilts, Gary A
2014-01-01
This paper describes an efficient and nonlinearly consistent parallel solution methodology for solving coupled nonlinear thermal transport problems that occur in nuclear reactor applications over hundreds of individual 3D physical subdomains. Efficiency is obtained by leveraging knowledge of the physical domains, the physics on individual domains, and the couplings between them for preconditioning within a Jacobian Free Newton Krylov method. Details of the computational infrastructure that enabled this work, namely the open source Advanced Multi-Physics (AMP) package developed by the authors is described. Details of verification and validation experiments, and parallel performance analysis in weak and strong scaling studies demonstrating the achieved efficiency of the algorithm are presented. Furthermore, numerical experiments demonstrate that the preconditioner developed is independent of the number of fuel subdomains in a fuel rod, which is particularly important when simulating different types of fuel rods...
Transport and its energy-related air pollution problems in Bangkok
Energy Technology Data Exchange (ETDEWEB)
Boontherawara, N.; Panich, S.; Phiu-Nual, K.
1995-12-31
Suspended Particulate Matter (SPM) is a major pollutant, followed by carbon monoxide and lead, as the ambient levels of these pollutants all exceed international standards such as those laid down by the World Health Organization (WHO). In order to meet these standards, it is necessary to reduce the emissions of these pollutants by 84.9%, 47.3%, and 13.0% respectively. Ambient air quality in Bangkok will continue to deteriorate to an unacceptable level by the year 2000, if no action is taken over and above implementation of already approved projects (including mass transit projects). Carbon monoxide and hydrocarbon emissions could be reduced by 28 and 22% respectively, with the implementation of Reasonable Technology Measures used to control vehicle emissions alone. These measures include inspection and maintenance programs. Their success is dependent on effective quality control and on the application of stringent standards. However, these measures would have little impact in reducing the emissions of SPM. It can therefore be concluded that Reasonable Technology Measures will be insufficient to address Bangkok`s air pollution problems, without complementary measures to reduce traffic congestion. Implementation of the traffic measures outlined under the Demand-Management Policy Scenario alone will reduce CO and HC emissions by up to 45%. These measures serve to reduce traffic congestion and increase the average travel speed. However, in order to improve air quality to internationally acceptable levels, traffic measures must be implemented in conjunction with the Reasonable Technology Scenario. This will provide an additional reduction of CO and HC emissions by 45%.
Directory of Open Access Journals (Sweden)
Guido Noto
2015-06-01
Full Text Available Italian New Public Management (NPM has been mainly characterized by a political orientation toward power decentralization to local governments and privatization of public companies. Nowadays, local utilities in Italy are often run by joint stock companies controlled by public agencies such as Regional and Municipal Administrations. Due to this transformation, these companies must comply with a set of diverse expectations coming from a wide range of stakeholders, related to their financial, competitive and social performance. Such fragmented governance increases the presence of “wicked” problems in the decision-making sphere of these entities. Given this multi-level governance structure, how do these agents influence public services performance? In recent years, coordination and inter-institutional joint action have been identified as possible approaches for dealing with governance fragmentation and wicked problems deriving from it. How can we adapt a performance management perspective in order to help us reform the system and so have a better collaboration between the stakeholders involved? In order to address and discuss these research questions, a case study will be developed. The case concerns AMAT, the local utility providing the public transportation service in the Municipality of Palermo (Italy. The result of this study is a dynamic model including a set of performance indicators that help us in understanding the impact of the governing structure on the system’s performance.
Energy Technology Data Exchange (ETDEWEB)
Cacuci, Dan Gabriel, E-mail: cacuci@cec.sc.edu
2016-04-15
Highlights: • Predictive Modeling of Coupled Multi-Physics Systems (PM-CMPS) methodology is used. • Impact of measurements for reducing predicted uncertainties is highlighted. • Presented thermal-hydraulics benchmark illustrates generally applicable concepts. - Abstract: This work presents the application of the “Predictive Modeling of Coupled Multi-Physics Systems” (PM-CMPS) methodology conceived by Cacuci (2014) to a “test-section benchmark” problem in order to quantify the impact of measurements for reducing the uncertainties in the conceptual design of a proposed experimental facility aimed at investigating the thermal-hydraulics characteristics expected in the conceptual design of the G4M reactor (GEN4ENERGY, 2012). This “test-section benchmark” simulates the conditions experienced by the hottest rod within the conceptual design of the facility's test section, modeling the steady-state conduction in a rod heated internally by a cosinus-like heat source, as typically encountered in nuclear reactors, and cooled by forced convection to a surrounding coolant flowing along the rod. The PM-CMPS methodology constructs a prior distribution using all of the available computational and experimental information, by relying on the maximum entropy principle to maximize the impact of all available information and minimize the impact of ignorance. The PM-CMPS methodology then constructs the posterior distribution using Bayes’ theorem, and subsequently evaluates it via saddle-point methods to obtain explicit formulas for the predicted optimal temperature distributions and predicted optimal values for the thermal-hydraulics model parameters that characterized the test-section benchmark. In addition, the PM-CMPS methodology also yields reduced uncertainties for both the model parameters and responses. As a general rule, it is important to measure a quantity consistently with, and more accurately than, the information extant prior to the measurement. For
Structural element solution for fuzzy multi-objective transportation problem%模糊多目标运输问题的结构元解法
Institute of Scientific and Technical Information of China (English)
郭嗣琮; 张景姝
2011-01-01
In order to solve a class of fuzzy multi-objective transportation problem, the problem is transformed into a single objective transportation problem using fuzzy structural element method. In terms of the fuzzy multi-objective transportation problems, their goals are formulated as the fuzzy cost of transportation problems. With the application of fuzzy structural element theory, various expert opinions are combined into fuzzy composite indicator values using fuzzy algorithm which is based on the fuzzy structuring elements. Therefore, a multi-objective transportation problem is transformed into a fuzzy single objective transportation problem. The single-objective transportation problem can be solved using the weighted sorting criteria of fuzzy number's structured element. The case study demonstrates that the proposed method for solving the fuzzy multi-objective transportation problems has a significant application prospective.%为了解决一类具有模糊多目标的运输问题,采用模糊结构元方法,将问题转化为单目标的运输问题再求解.对于具有模糊多目标的运输问题,这些目标被归结为运输问题的模糊成本,利用模糊结构元理论,将多名专家意见通过基于模糊结构元的模糊算法集结为模糊综合指标值,进而将模糊多目标运输问题转化为模糊单目标的运输问题,并利用模糊数的结构元加权排序准则对单目标运输问题进行求解,最后给出了数值例子.该方法对于解决具有模糊多目标的运输问题具有一定的应用前景.
Bronštein, Mihhail, 1923-
2003-01-01
Ettekanne 3.-4. detsembrini 2003 Tallinnas toimunud rahvusvahelisel konverents-näitusel "Logistics and transport in international trade" analüüsib Euroopa Liidu ja Venemaa transpordipoliitika mõju Baltimaade transiitkaubandusele ja transpordisüsteemidele
Bronštein, Mihhail, 1923-
2003-01-01
Ettekanne 3.-4. detsembrini 2003 Tallinnas toimunud rahvusvahelisel konverents-näitusel "Logistics and transport in international trade" analüüsib Euroopa Liidu ja Venemaa transpordipoliitika mõju Baltimaade transiitkaubandusele ja transpordisüsteemidele
Romero, Virginia; Vega, Víctor; García, Javier; Zierold, Robert; Nielsch, Kornelius; Prida, Víctor M; Hernando, Blanca; Benavente, Juana
2013-05-01
Nanoporous anodic alumina membranes (NPAMs) were produced by the two-step anodization method in sulphuric, oxalic and phosphoric acidic electrolytes displaying a hexagonally ordered spatial arrangement of pores with well controlled nanopore size distribution and low porosity. Some selected NPAMs were further modified by conformal coating their surface and inner pore walls with a thin layer of SiO2 by means of atomic layer deposition (ALD), which reduces both the pore radii and porosity but it also seems to affect to the electric fixed charge on the membranes surface. A comparative study about the influence of silica modification of NPAMs surfaces on the ionic transport through the nanoporous membranes has been performed by measuring membrane potentials and electrochemical impedance spectroscopy with NaCl solutions. According to these results, a direct correlation between the membrane effective fixed charge and the NaCl diffusion coefficient can be established. The coating with a SiO2 thin layer causes a reduction of 75% in the positive effective fixed charge of the NPAMs independently of their pore radii and the increase in counterion transport (cation transport number and diffusion coefficient) even through constrained nanopores, which can be of interest in several applications (microfluidics, drug delivery, nanofilter devices, etc.). Moreover, slight changes in the membrane/solution interface due to the SiO2 cover layer are also indicated.
Fazayeli, Saeed; Eydi, Alireza; Kamalabadi, Isa Nakhai
2017-07-01
Nowadays, organizations have to compete with different competitors in regional, national and international levels, so they have to improve their competition capabilities to survive against competitors. Undertaking activities on a global scale requires a proper distribution system which could take advantages of different transportation modes. Accordingly, the present paper addresses a location-routing problem on multimodal transportation network. The introduced problem follows four objectives simultaneously which form main contribution of the paper; determining multimodal routes between supplier and distribution centers, locating mode changing facilities, locating distribution centers, and determining product delivery tours from the distribution centers to retailers. An integer linear programming is presented for the problem, and a genetic algorithm with a new chromosome structure proposed to solve the problem. Proposed chromosome structure consists of two different parts for multimodal transportation and location-routing parts of the model. Based on published data in the literature, two numerical cases with different sizes generated and solved. Also, different cost scenarios designed to better analyze model and algorithm performance. Results show that algorithm can effectively solve large-size problems within a reasonable time which GAMS software failed to reach an optimal solution even within much longer times.
Reuter, Matthew G; Harrison, Robert J
2014-05-01
The thesis of Brandbyge's comment [J. Chem. Phys. 140, 177103 (2014)] is that our operator decoupling condition is immaterial to transport theories, and it appeals to discussions of nonorthogonal basis sets in transport calculations in its arguments. We maintain that the operator condition is to be preferred over the usual matrix conditions and subsequently detail problems in the existing approaches. From this operator perspective, we conclude that nonorthogonal projectors cannot be used and that the projectors must be selected to satisfy the operator decoupling condition. Because these conclusions pertain to operators, the choice of basis set is not germane.
White, Joey
The applicability of the dataflow architecture to a telemetry simulation is examined with particular reference to the problem of interfacing the simulation with an engineering model flight computer. The discussion covers the transport loop lag problem, simulation moding and control, the dataflow architecture solution, telemetry formatting and serialization, uplink command synchronization and reception, command validation and routing, and on-board computer interface and telemetry data request/response processing. The concepts discussed here have been developed for application on a training simulation for the NASA Orbital Maneuvering Vehicle.
2013-01-01
It is of crucial importance to be able to identify the location of atmospheric pollution sources in our planet. Global models of atmospheric transport in combination with diverse Earth observing systems are a natural choice to achieve this goal. It is shown that the ability to successfully reconstruct the location and magnitude of an instantaneous source in global chemical transport models (CTMs) decreases rapidly as a function of the time interval between the pollution release and the observ...
Directory of Open Access Journals (Sweden)
Юрий Алексеевич Кругляк
2015-09-01
Full Text Available Non-equilibrium Green’s functions (NEGF method in matrix form is presented and applied to model transport problems for 1D and 2D conductors using Huckel approximation in the «bottom – up» approach of modern nanoelectronics. General method to account for electric contacts in Schrödinger equation is given. Elastic and spin dephasing modeling and account for non-coherent processes are also discussed
Kochunas, Brendan; Fitzgerald, Andrew; Larsen, Edward
2017-09-01
A central problem in nuclear reactor analysis is calculating solutions of steady-state k-eigenvalue problems with thermal hydraulic feedback. In this paper we propose and utilize a model problem that permits the theoretical analysis of iterative schemes for solving such problems. To begin, we discuss a model problem (with nonlinear cross section feedback) and its justification. We proceed with a Fourier analysis for source iteration schemes applied to the model problem. Then we analyze commonly-used iteration schemes involving non-linear diffusion acceleration and feedback. For each scheme we show (1) that they are conditionally stable, (2) the conditions that lead to instability, and (3) that traditional relaxation approaches can improve stability. Lastly, we propose a new iteration scheme that theory predicts is an improvement upon the existing methods.
Directory of Open Access Journals (Sweden)
Shou-feng Ji
2017-06-01
Full Text Available The increasing concern on global warming is prompting transportation sector to take into account more sustainable operation strategies. Among them, intermodal transportation (IT has already been regarded as one of the most effective measures on carbon reductions. This paper focuses on the model and algorithm for a certain kind of IT, namely multi-objective multi-sourcing intermodal transportation network design problem (MO_MITNDP, in which carbon emission factors are specially considered. The MO_MITNDP is concerned with determining optimal transportation routes and modes for a series of freight provided by multiple sourcing places to find good balance between the total costs and time efficiencies. First, we establish a multi-objective integer programming model to formulate the MO_MITNDP with total cost (TTC and maximum flow time (MFT criteria. Specifically, carbon emission costs distinguished by the different transportation mode and route are included in the cost function. Second, to solve the MO_MITNDP, a hybrid estimation of distribution algorithm (HEDA combined with a heterogeneous marginal distribution and a multi-objective local search is proposed, in which the from the Pareto dominance scenario. Finally, based on randomly generated data and a real-life case study of Jilin Petrochemical Company (JPC, China, simulation experiments and comparisons are carried out to demonstrate the effectiveness and application value of the proposed HEDA.
Energy Technology Data Exchange (ETDEWEB)
Benfer, Rolf-Dieter; Kohake, Holger [RWE Vertrieb AG, Dortmund (Germany); Gabler, Andreas; Wesche, Florian A. [White and Case LLP, Duesseldorf (Germany)
2011-01-15
The feeding of biogas into the public grid is still beset with many difficulties which relate to its transport and withdrawal and the balancing of accounts. These difficulties are attributable to differing regulations in the Renewable Energy Law (EEG) and the Gas Network Access Ordinance. In practice this has led to inaccuracies in the use of terms and promotion mechanisms and in the interpretation of the interactions between these regulations. This article uses the provisions of the EEG on the conversion of biogas into electricity as an example to show how a systematic approach and concise definition of the relevant domains of regulation can help create more clarity. Using this as a point of departure it develops practical paths of resolution for biogas suppliers and EEG plant operators which can serve to create a viable biogas market in the future.
Practical use of SPRINT and a moving grid interface for a class of 1D non-linear transport problems
van Eijkeren JCH; Zegeling PA; Hassanizadeh SM
1991-01-01
Environmental problems tend to become of still greater complexity. The mathematical formulation of these problems often results in a set of differential equations, which urges the need for robust differential equation solvers. Moreover, these solvers should be implemented within a user-friendly an
Suthikarnnarunai, N.; Olinick, E.
2009-01-01
We present a case study on the application of techniques for solving the Vehicle Routing Problem (VRP) to improve the transportation service provided by the University of The Thai Chamber of Commerce to its staff. The problem is modeled as VRP with time windows, split deliveries, and a mixed fleet. An exact algorithm and a heuristic solution procedure are developed to solve the problem and implemented in the AMPL modeling language and CPLEX Integer Programming solver. Empirical results indicate that the heuristic can find relatively good solutions in a small fraction of the time required by the exact method. We also perform sensitivity analysis and find that a savings in outsourcing cost can be achieved with a small increase in vehicle capacity.
Energy Technology Data Exchange (ETDEWEB)
Nunes, Rogerio Chaffin
2002-03-15
In this work, the system of differential equations obtained by the angular approach of the two-dimensional transport equation by the discrete ordinates method is solved through the formulation of finite elements with the objective of investigating the sensitivity of the outgoing flux of radiation with the incoming flux and the properties of absorption and scattering of the medium. The variational formulation for the system of differential equations of second order with the generalized boundary conditions of Neumann (third type) allows an easy implementation of the method of the finite elements with triangular mesh and approximation space of first order. The geometry chosen for the simulations is a circle with a non homogeneous circular form in its interior. The mapping of Dirichlet-Neumann is studied through various simulations involving the incoming flux, the outgoing flux and the properties of the medium. (author)
Santillana, Mauricio
2013-01-01
It is of crucial importance to be able to identify the location of atmospheric pollution sources in our planet. Global models of atmospheric transport in combination with diverse Earth observing systems are a natural choice to achieve this goal. It is shown that the ability to successfully reconstruct the location and magnitude of an instantaneous source in global chemical transport models (CTMs) decreases rapidly as a function of the time interval between the pollution release and the observation time. A simple way to quantitatively characterize this phenomenon is proposed based on the effective -undesired- numerical diffusion present in current Eulerian CTMs and verified using idealized numerical experiments. The approach presented consists of using the adjoint-based optimization method in a state-of-the-art CTM, GEOS-Chem, to reconstruct the location and magnitude of a realistic pollution plume for multiple time scales. The findings obtained from these numerical experiments suggest a time scale of 2 days a...
Heitmuller, Franklin T.; Asquith, William H.
2008-01-01
The Texas Department of Transportation commonly builds and maintains low-water crossings (LWCs) over streams in the Edwards Plateau in Central Texas. LWCs are low-height structures, typically constructed of concrete and asphalt, that provide acceptable passage over seasonal rivers or streams with relatively low normal-depth flow. They are designed to accommodate flow by roadway overtopping during high-flow events. The streams of the Edwards Plateau are characterized by cobble- and gravel-sized bed material and highly variable flow regimes. Low base flows that occur most of the time occasionally are interrupted by severe floods. The floods entrain and transport substantial loads of bed material in the stream channels. As a result, LWCs over streams in the Edwards Plateau are bombarded and abraded by bed material during floods and periodically must be maintained or even replaced.
Doisneau, François; Arienti, Marco; Oefelein, Joseph C.
2017-01-01
For sprays, as described by a kinetic disperse phase model strongly coupled to the Navier-Stokes equations, the resolution strategy is constrained by accuracy objectives, robustness needs, and the computing architecture. In order to leverage the good properties of the Eulerian formalism, we introduce a deterministic particle-based numerical method to solve transport in physical space, which is simple to adapt to the many types of closures and moment systems. The method is inspired by the semi-Lagrangian schemes, developed for Gas Dynamics. We show how semi-Lagrangian formulations are relevant for a disperse phase far from equilibrium and where the particle-particle coupling barely influences the transport; i.e., when particle pressure is negligible. The particle behavior is indeed close to free streaming. The new method uses the assumption of parcel transport and avoids to compute fluxes and their limiters, which makes it robust. It is a deterministic resolution method so that it does not require efforts on statistical convergence, noise control, or post-processing. All couplings are done among data under the form of Eulerian fields, which allows one to use efficient algorithms and to anticipate the computational load. This makes the method both accurate and efficient in the context of parallel computing. After a complete verification of the new transport method on various academic test cases, we demonstrate the overall strategy's ability to solve a strongly-coupled liquid jet with fine spatial resolution and we apply it to the case of high-fidelity Large Eddy Simulation of a dense spray flow. A fuel spray is simulated after atomization at Diesel engine combustion chamber conditions. The large, parallel, strongly coupled computation proves the efficiency of the method for dense, polydisperse, reacting spray flows.
Energy Technology Data Exchange (ETDEWEB)
Doisneau, François, E-mail: fdoisne@sandia.gov; Arienti, Marco, E-mail: marient@sandia.gov; Oefelein, Joseph C., E-mail: oefelei@sandia.gov
2017-01-15
For sprays, as described by a kinetic disperse phase model strongly coupled to the Navier–Stokes equations, the resolution strategy is constrained by accuracy objectives, robustness needs, and the computing architecture. In order to leverage the good properties of the Eulerian formalism, we introduce a deterministic particle-based numerical method to solve transport in physical space, which is simple to adapt to the many types of closures and moment systems. The method is inspired by the semi-Lagrangian schemes, developed for Gas Dynamics. We show how semi-Lagrangian formulations are relevant for a disperse phase far from equilibrium and where the particle–particle coupling barely influences the transport; i.e., when particle pressure is negligible. The particle behavior is indeed close to free streaming. The new method uses the assumption of parcel transport and avoids to compute fluxes and their limiters, which makes it robust. It is a deterministic resolution method so that it does not require efforts on statistical convergence, noise control, or post-processing. All couplings are done among data under the form of Eulerian fields, which allows one to use efficient algorithms and to anticipate the computational load. This makes the method both accurate and efficient in the context of parallel computing. After a complete verification of the new transport method on various academic test cases, we demonstrate the overall strategy's ability to solve a strongly-coupled liquid jet with fine spatial resolution and we apply it to the case of high-fidelity Large Eddy Simulation of a dense spray flow. A fuel spray is simulated after atomization at Diesel engine combustion chamber conditions. The large, parallel, strongly coupled computation proves the efficiency of the method for dense, polydisperse, reacting spray flows.
Energy Technology Data Exchange (ETDEWEB)
Basso Barichello, Liliane; Dias da Cunha, Rudnei [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Inst. de Matematica; Becker Picoloto, Camila [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Engenharia Mecanica; Tres, Anderson [Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil). Programa de Pos-Graduacao em Matematica Aplicada
2015-05-15
A nodal formulation of a fixed-source two-dimensional neutron transport problem, in Cartesian geometry, defined in a heterogeneous medium, is solved by an analytical approach. Explicit expressions, in terms of the spatial variables, are derived for averaged fluxes in each region in which the domain is subdivided. The procedure is an extension of an analytical discrete ordinates method, the ADO method, for the solution of the two-dimensional homogeneous medium case. The scheme is developed from the discrete ordinates version of the two-dimensional transport equation along with the level symmetric quadrature scheme. As usual for nodal schemes, relations between the averaged fluxes and the unknown angular fluxes at the contours are introduced as auxiliary equations. Numerical results are in agreement with results available in the literature.
The GVK EMRI maternal and neonatal transport system in India: a mega plan for a mammoth problem.
Kumutha, J; Rao, G V Ramana; Sridhar, B N; Vidyasagar, D
2015-10-01
Maternal and infant mortality has been a major concern in India with the Government taking serious efforts to achieve the Millennium Development Goals by 2015. Ganapathy Venkata Krishna Reddy Emergency Management and Research Institute (GVK EMRI) is one such effort and is the country's first emergency service provider working under the public-private partnership model to provide emergency response services and quality pre-hospital care to any sick person, pregnant mothers, and sick neonates. Since the introduction of the emergency medical services, institutional deliveries have increased in all states and union territories where the ambulances have been deployed and the majority of mothers have been provided the required emergency care at the appropriate time. This in turn has helped in considerably reducing the maternal mortality. GVK EMRI has partnered with the government of Tamil Nadu and deployed specialized neonatal ambulances to ensure safe transport of newborns. The safe transport of sick, vulnerable neonates and the improvement in survival of transported neonates over the years advocate scaling up of this program to other states, which would greatly contribute towards reducing infant and neonatal mortality.
Niemi, Antti H.
2013-12-01
We investigate the application of the discontinuous Petrov-Galerkin (DPG) finite element framework to stationary convection-diffusion problems. In particular, we demonstrate how the quasi-optimal test space norm improves the robustness of the DPG method with respect to vanishing diffusion. We numerically compare coarse-mesh accuracy of the approximation when using the quasi-optimal norm, the standard norm, and the weighted norm. Our results show that the quasi-optimal norm leads to more accurate results on three benchmark problems in two spatial dimensions. We address the problems associated to the resolution of the optimal test functions with respect to the quasi-optimal norm by studying their convergence numerically. In order to facilitate understanding of the method, we also include a detailed explanation of the methodology from the algorithmic point of view. © 2013 Elsevier Ltd. All rights reserved.
Niemi, Antti
2013-05-01
We revisit the finite element analysis of convection-dominated flow problems within the recently developed Discontinuous Petrov-Galerkin (DPG) variational framework. We demonstrate how test function spaces that guarantee numerical stability can be computed automatically with respect to the optimal test space norm. This makes the DPG method not only stable but also robust, that is, uniformly stable with respect to the Péclet number in the current application. We employ discontinuous piecewise Bernstein polynomials as trial functions and construct a subgrid discretization that accounts for the singular perturbation character of the problem to resolve the corresponding optimal test functions. We also show that a smooth B-spline basis has certain computational advantages in the subgrid discretization. The overall effectiveness of the algorithm is demonstrated on two problems for the linear advection-diffusion equation. © 2011 Elsevier B.V.
Niemi, Antti H.
2011-05-14
We revisit the finite element analysis of convection dominated flow problems within the recently developed Discontinuous Petrov-Galerkin (DPG) variational framework. We demonstrate how test function spaces that guarantee numerical stability can be computed automatically with respect to the so called optimal test space norm by using an element subgrid discretization. This should make the DPG method not only stable but also robust, that is, uniformly stable with respect to the Ṕeclet number in the current application. The e_ectiveness of the algorithm is demonstrated on two problems for the linear advection-di_usion equation.
集装箱卡车运输问题的基于图的建模方法%Graph-based modeling method for container truck transportation problems
Institute of Scientific and Technical Information of China (English)
张瑞友; 汪定伟; 尹原永
2011-01-01
对港口和发货人/收货人之间的集装箱卡车运输问题给出了基于图的建模方法.该图不仅可以描述进出口空箱或满箱的运输,而且可以描述空集装箱作为运输资源的属性,这种图将确定的活动描述为顶点,将不确定的活动描述为弧,称为确定活动在顶点上的图(DAOV图).基于这种方法,建立了集装箱卡车运输问题的基本情形、多堆场多港口情形以及堆场上的空箱数目给定情形的数学模型；相应问题被描述为带时间窗的多旅行商问题(m-TSPTW)、多堆场的m-TSPTW以及带资源约束的m-TSPTW.而且这种方法可以扩展到集装箱卡车运输问题的更一般情形,这体现出该建模方法的有效性.%A graph-based modeling method of container truck transportation problems between terminals and final shippers/receivers was proposed in this paper. The graph can formulate not only the transportation of import/export full/empty containers, but also the transportation resource attribute of empty containers. The graph denotes determinate activities with vertexes and denotes indeterminate activities with arcs. Therefore, it is named as determinate-activities-on-vertexes (DAOV) graph. Based on the proposed graph, the basic case, multi-depot multi-terminal case, and the case with given number of empty containers on depots, of the container truck transportation problems were mathematically modeled. They fall into the multiple traveling salesman problem with time windows (m-TSPTW), multi-depot m-TSPTW, and m-TSPTW with resource constraints, respectively. Furthermore, the modeling method can be extended to more general cases of the problems, which indicates the validity of the presented graph-based modeling method.
Physical properties of fixed-charge layer double hydroxides
Hines, D. R.; Solin, S. A.; Costantino, Umberto; Nocchetti, Morena
2000-05-01
The physical properties of a series of layer double hydroxides (LDH) of the form [(CO3)0.195(1-x)Cl0.39x(H2O)y]:[Zn0.61Al0.39(OH)2], 0layer water molecules form a hydration ring which defines the height of the solvated, nested Cl anion. The water molecules can tilt around their C2v axis such that the height of the solvated Cl ion is a function of the number of molecules forming the hydration ring. The composition dependence of the basal spacing, determined from x-ray-diffraction powder patterns measured as a function of humidity and temperature for these materials, is a function of both the Cl concentration (x) and the number of guest layer water molecules (y). Distinct basal spacing curves are observed for fully hydrated, partially hydrated, and dehydrated materials. At x=1 the Cl end-member material exhibits a change in stacking sequence from a 3R polytype to a 2H polytype upon dehydration. The dehydrated form of this material also exhibits a (3×3)R30° superlattice ordering of the Cl ions. Due to the nesting of the Cl ion and the active nature of the water molecules, the basal spacing vs x curve for the dehydrated materials is the only curve that can be fit by the discrete finite layer rigidity model. The interlayer rigidity parameter for LDH materials has been determined to be p=4.84+/-0.06 indicating that these materials are stiffer than class-II layered solids but not as stiff as class-III layered solids.
Enhanced electron transfer dissociation through fixed charge derivatization of cysteines.
Vasicek, Lisa; Brodbelt, Jennifer S
2009-10-01
Electron transfer dissociation (ETD) has proven to be a promising new ion activation method for proteomics applications due to its ability to generate c- and z-type fragment ions in comparison to the y- and b-type ions produced upon the more conventional collisional activation of peptides. However, low precursor charge states hinder the success of electron-based activation methods due to competition from nondissociative charge reduction and incomplete sequence coverage. In the present report, the reduction and alkylation of disulfide bonds prior to ETD analysis is evaluated by comparison of three derivatization reagents: iodoacetamide (IAM), N,N-dimethyl-2-chloro-ethylamine (DML), and (3-acrylamidopropyl)-trimethyl ammonium chloride (APTA). While both the DML and APTA modifications lead to an increase in the charge states of peptides, the APTA-peptides provided the most significant improvement in percent fragmentation and sequence coverage for all peptides upon ETD, including formation of diagnostic ions that allow characterization of both the C- and N-termini. In addition, the formation of product ions in multiple charge states upon ETD is minimized for the APTA-modified peptides.
Energy Technology Data Exchange (ETDEWEB)
Kirichenko, N A; Shcherbina, M E; Serkov, A A [Moscow Institute of Physics and Technology (State University), Dolgoprudnyi, Moscow Region (Russian Federation); Rakov, I I [Wave Research Center, A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)
2015-12-31
The behaviour of a colloidal solution of gold nanoparticles irradiated by a repetitively pulsed laser with a pulse duration of a few nanoseconds is investigated theoretically and experimentally. A mathematical model is constructed, which allows the behaviour of the nanoparticle distribution function to be described. The model is based on the transport equation in the 'space' of particle sizes. The proposed model allows for a relatively simple study and makes it possible to establish some common patterns in the behaviour of an ensemble of nanoparticles under various conditions. The results obtained are in satisfactory agreement with the available experimental data. (nanophotonics)
Hague, D. S.; Woodbury, N. W.
1975-01-01
The Mars system is a tool for rapid prediction of aircraft or engine characteristics based on correlation-regression analysis of past designs stored in the data bases. An example of output obtained from the MARS system, which involves derivation of an expression for gross weight of subsonic transport aircraft in terms of nine independent variables is given. The need is illustrated for careful selection of correlation variables and for continual review of the resulting estimation equations. For Vol. 1, see N76-10089.
Energy Technology Data Exchange (ETDEWEB)
Kosaka, Shinya; Saji, Etsuro [In-Core Fuel Management System Department, Toden Software, Inc., Tokyo (Japan)
2000-12-01
A characteristics transport theory code, CHAPLET, has been developed for the purpose of making it practical to perform a whole LWR core calculation with the same level of calculational model and accuracy as that of an ordinary single assembly calculation. The characteristics routine employs the CACTUS algorithm for drawing ray tracing lines, which assists the two key features of the flux solution in the CHAPLET code. One is the direct neutron path linking (DNPL) technique which strictly connects angular fluxes at each assembly interface in the flux solution separated between assemblies. Another is to reduce the required memory storage by sharing the data related to ray tracing among assemblies with the same configuration. For faster computation, the coarse mesh rebalance (CMR) method and the Aitken method were incorporated in the code and the combined use of both methods showed the most promising acceleration performance among the trials. In addition, the parallelization of the flux solution was attempted, resulting in a significant reduction in the wall-clock time of the calculation. By all these efforts, coupled with the results of many verification studies, a whole LWR core heterogeneous transport theory calculation finally became practical. CHAPLET is thought to be a useful tool which can produce the reference solutions for analyses of an LWR (author)
Directory of Open Access Journals (Sweden)
Noor Ageng Setiyanto
2012-02-01
Full Text Available Jaringan adalah salah satu mata kuliah wajib bagi mahasiswa Ilmu Komputer. Tidak adanya media pembelajaran berbasis komputer pada mata kuliah tersebut, menimbulkan kesulitan bagi dosen dalam menyampaikan materi. Materi yang terkandung dalam jaringan komputer adalah 7 layer OSI dan TCP/IP dengan 4 layer. Salah satu layer tersebut adalah layer Transport yang terdiri dari susunan koneksi, proses koneksi, koneksi diantara host yang masih sulit dipahami mahasiswa karena bersifat abstrak dan tidak dapat dilihat dengan mata. Oleh karena itu, penelitian ini berisi tentang pembelajaran multimedia menggunakan pendekatan berbasis masalah. Data yang didapatkan pada awal penelitian untuk menemukan masalah yang dihadapi oleh mahasiswa, kemudian menganalisa kebutuhan mahasiswa, dan merancang visualisasi dari pembelajaran multimedia. Mahasiswa mendapatkan gambaran dari lalu lintas data dengan jelas, dan dapat menjelaskan apa yang terjadi pada koneksi antar host. Hasil yang ditunjukkan adalah peningkatan signifikan pada 2 kelompok mahasiswa yang masing-masing beranggotakan 32 mahasiswa. Pada tes kompetensi konvensional, kelompok satu mendapatkan rata-rata 62.7 dan kelompok dua dengan rata-rata 72. Kemudian hasil yang didapatkan ketika menggunakan pembelajaran multimedia, kelompok satu mendapatkan rata-rata 73 atau 10.3 dan kelompok dua meningkat menjadi 82 atau 10. Ini berarti bahwa rata-rata nilai dari mahasiswa meningkat dibandingkan dengan menggunakan pembelajaran konvensional. Kata kunci : jaringan komputer, layer Transport, pembelajaran berbasis masalah.
Loeb, Norman G.; Wang, Hailan; Cheng, Anning; Kato, Seiji; Fasullo, John T.; Xu, Kuan-Man; Allan, Richard P.
2016-05-01
Satellite based top-of-atmosphere (TOA) and surface radiation budget observations are combined with mass corrected vertically integrated atmospheric energy divergence and tendency from reanalysis to infer the regional distribution of the TOA, atmospheric and surface energy budget terms over the globe. Hemispheric contrasts in the energy budget terms are used to determine the radiative and combined sensible and latent heat contributions to the cross-equatorial heat transports in the atmosphere (AHTEQ) and ocean (OHTEQ). The contrast in net atmospheric radiation implies an AHTEQ from the northern hemisphere (NH) to the southern hemisphere (SH) (0.75 PW), while the hemispheric difference in sensible and latent heat implies an AHTEQ in the opposite direction (0.51 PW), resulting in a net NH to SH AHTEQ (0.24 PW). At the surface, the hemispheric contrast in the radiative component (0.95 PW) dominates, implying a 0.44 PW SH to NH OHTEQ. Coupled model intercomparison project phase 5 (CMIP5) models with excessive net downward surface radiation and surface-to-atmosphere sensible and latent heat transport in the SH relative to the NH exhibit anomalous northward AHTEQ and overestimate SH tropical precipitation. The hemispheric bias in net surface radiative flux is due to too much longwave surface radiative cooling in the NH tropics in both clear and all-sky conditions and excessive shortwave surface radiation in the SH subtropics and extratropics due to an underestimation in reflection by clouds.
Directory of Open Access Journals (Sweden)
Rayane Florentina Scárdua
2016-12-01
Full Text Available Several transportation problems like traffic jam, crowded public transportation, parking shortage and pollution is caused by the actual scenario of urban mobility. The transport of passengers by charter is an alternative to improve the quality of urban mobility avoiding traffic jam and reducing pollution. Several companies offer as a benefit to their employees this type of transport to carry them to the company from their home and vice versa. Thus, it is proposed in this paper an adaptation of a mathematical model based on Open Vehicle Routing Problem (OVRP for planning the transport of employees by a chartered bus fleet in order to reduce the total cost spent by the company. The model was applied to a company located in Vitória-ES and the results obtained by the model indicated a reduction in the cost of transportation when compared to the currently paid by the company.
Energy Technology Data Exchange (ETDEWEB)
Carnahan, C. L.
1981-07-01
The function, J(x,y), which has appeared frequently in analytical solutions of a variety of technical problems, is described and its applications briefly reviewed. Two detailed examples of applications are given. Tabulations of functions related to J(x,y) are listed, and relationships of J(x,y) to these functions are stated. Methods of computation of J(x,y), suitable for use with digital computers, are described.
Directory of Open Access Journals (Sweden)
Yu Zhang
2014-01-01
Full Text Available We consider an ad hoc Floyd-A∗ algorithm to determine the a priori least-time itinerary from an origin to a destination given an initial time in an urban scheduled public transport (USPT network. The network is bimodal (i.e., USPT lines and walking and time dependent. The modified USPT network model results in more reasonable itinerary results. An itinerary is connected through a sequence of time-label arcs. The proposed Floyd-A∗ algorithm is composed of two procedures designated as Itinerary Finder and Cost Estimator. The A∗-based Itinerary Finder determines the time-dependent, least-time itinerary in real time, aided by the heuristic information precomputed by the Floyd-based Cost Estimator, where a strategy is formed to preestimate the time-dependent arc travel time as an associated static lower bound. The Floyd-A∗ algorithm is proven to guarantee optimality in theory and, demonstrated through a real-world example in Shenyang City USPT network to be more efficient than previous procedures. The computational experiments also reveal the time-dependent nature of the least-time itinerary. In the premise that lines run punctually, “just boarding” and “just missing” cases are identified.
Energy Technology Data Exchange (ETDEWEB)
Mariotti, F., E-mail: francesca.mariotti@bologna.enea.i [ENEA-BAS-ION IRP Radiation Protection Institute, Via dei Colli 16, 40136, Bologna (Italy); Gualdrini, G. [ENEA-BAS-ION IRP Radiation Protection Institute, Via dei Colli 16, 40136, Bologna (Italy)
2011-04-15
The ORAMED (Optimization of RAdiation protection for MEDical staff) Working Tasks (WP4) is addressed at evaluating extremity doses (and dose distributions across the hands) of medical staff working in nuclear medicine departments, to study the influence of protective devices such as syringe and vial shields, to improve such devices when possible and to propose 'levels of reference doses' for each standard nuclear medicine procedure. In particular task 4 is concerned with the study of the extremity dosimetry for the hand of operators devoted to the preparation and administration stages of the usage, for example, of {sup 99m}Tc, {sup 18}F and {sup 90}Y (Zevalin) radionuclides. The aim of this report consists in the study of photon-electron equilibrium conditions at 0.07 mm in the skin to justify a simplified 'kerma approximation' approach in the planned complex Monte Carlo voxel hand modeling. Furthermore a detailed investigation on primary electron and secondary bremsstrahlung photon transport from {sup 90}Y to speed up the calculations was performed. The results obtained in the simplified investigated conditions could be of help for the production calculations, introducing, if necessary, suited correction factors applicable to the complex condition results.
McCready, Mark J.; Leighton, David T.
1987-01-01
Discusses the problems created in graduate chemical engineering programs when students enter with a wide diversity of understandings of transport phenomena. Describes a two-semester graduate transport course sequence at the University of Notre Dame which focuses on fluid mechanics and heat and mass transfer. (TW)
Institute of Scientific and Technical Information of China (English)
许碧欢
2004-01-01
For solving linear variational inequalities (LVI), the projection and contraction method of Levenberg-Marquardt type needs less iterations than an elementary projection and contraction method. However, the method of Levenberg-Marquardt type has to calculate the inverse of a matrix and hence it is unsuitable for large problems. In this paper, using the special structure of the constraint matrix, we present a PC method of Levenberg-Marquardt type for LVI arising from transportation problem without calculating any inverse matrices.Several computational experiments are presentded to indicate that the methods is good for solving the transportation problem.
Bagchi, Prosenjit
2016-11-01
In this talk, two problems in multiphase biological flows will be discussed. The first is the direct numerical simulation of whole blood and drug particulates in microvascular networks. Blood in microcirculation behaves as a dense suspension of heterogeneous cells. The erythrocytes are extremely deformable, while inactivated platelets and leukocytes are nearly rigid. A significant progress has been made in recent years in modeling blood as a dense cellular suspension. However, many of these studies considered the blood flow in simple geometry, e.g., straight tubes of uniform cross-section. In contrast, the architecture of a microvascular network is very complex with bifurcating, merging and winding vessels, posing a further challenge to numerical modeling. We have developed an immersed-boundary-based method that can consider blood cell flow in physiologically realistic and complex microvascular network. In addition to addressing many physiological issues related to network hemodynamics, this tool can be used to optimize the transport properties of drug particulates for effective organ-specific delivery. Our second problem is pseudopod-driven motility as often observed in metastatic cancer cells and other amoeboid cells. We have developed a multiscale hydrodynamic model to simulate such motility. We study the effect of cell stiffness on motility as the former has been considered as a biomarker for metastatic potential. Funded by the National Science Foundation.
库存与配送管理联合决策分析%Research on the Ineventory-Transportation Integrated Opitimization Problem
Institute of Scientific and Technical Information of China (English)
李纬; 邹洁君
2012-01-01
文章基于系统、集成化的思想．以江苏省电力公司电力科学研究院计量中心为例．针对一个配送中心和多个需求商组成的两级供应链系统下库存运输问题（ITIO）开展研究。运用了多级线性规划理论建立了库存／配送一体化模型，从而将库存、配送两方面成本统一起来．在两者之间寻求一个平衡点进行一体化决策。对于降低电力企业的物流总成本具有重要意义。%Therefore, according to system and integrated idea, if the enterprise could find a balance point to make the decision by considering the cost of inventory and distribution together, this thesis will solve the Inventory/Transportation Integrated Optimization problem in two-stage supply chain of one-to-multiple inventory system and will be more significant for decreasing the total logistics cost.
Directory of Open Access Journals (Sweden)
C. Cholet
2017-07-01
Full Text Available The aim of this study is to present a framework that provides new ways to characterize the spatio-temporal variability of lateral exchanges for water flow and solute transport in a karst conduit network during flood events, treating both the diffusive wave equation and the advection–diffusion equation with the same mathematical approach, assuming uniform lateral flow and solute transport. A solution to the inverse problem for the advection–diffusion equations is then applied to data from two successive gauging stations to simulate flows and solute exchange dynamics after recharge. The study site is the karst conduit network of the Fourbanne aquifer in the French Jura Mountains, which includes two reaches characterizing the network from sinkhole to cave stream to the spring. The model is applied, after separation of the base from the flood components, on discharge and total dissolved solids (TDSs in order to assess lateral flows and solute concentrations and compare them to help identify water origin. The results showed various lateral contributions in space – between the two reaches located in the unsaturated zone (R1, and in the zone that is both unsaturated and saturated (R2 – as well as in time, according to hydrological conditions. Globally, the two reaches show a distinct response to flood routing, with important lateral inflows on R1 and large outflows on R2. By combining these results with solute exchanges and the analysis of flood routing parameters distribution, we showed that lateral inflows on R1 are the addition of diffuse infiltration (observed whatever the hydrological conditions and localized infiltration in the secondary conduit network (tributaries in the unsaturated zone, except in extreme dry periods. On R2, despite inflows on the base component, lateral outflows are observed during floods. This pattern was attributed to the concept of reversal flows of conduit–matrix exchanges, inducing a complex water mixing effect
Cholet, Cybèle; Charlier, Jean-Baptiste; Moussa, Roger; Steinmann, Marc; Denimal, Sophie
2017-07-01
The aim of this study is to present a framework that provides new ways to characterize the spatio-temporal variability of lateral exchanges for water flow and solute transport in a karst conduit network during flood events, treating both the diffusive wave equation and the advection-diffusion equation with the same mathematical approach, assuming uniform lateral flow and solute transport. A solution to the inverse problem for the advection-diffusion equations is then applied to data from two successive gauging stations to simulate flows and solute exchange dynamics after recharge. The study site is the karst conduit network of the Fourbanne aquifer in the French Jura Mountains, which includes two reaches characterizing the network from sinkhole to cave stream to the spring. The model is applied, after separation of the base from the flood components, on discharge and total dissolved solids (TDSs) in order to assess lateral flows and solute concentrations and compare them to help identify water origin. The results showed various lateral contributions in space - between the two reaches located in the unsaturated zone (R1), and in the zone that is both unsaturated and saturated (R2) - as well as in time, according to hydrological conditions. Globally, the two reaches show a distinct response to flood routing, with important lateral inflows on R1 and large outflows on R2. By combining these results with solute exchanges and the analysis of flood routing parameters distribution, we showed that lateral inflows on R1 are the addition of diffuse infiltration (observed whatever the hydrological conditions) and localized infiltration in the secondary conduit network (tributaries) in the unsaturated zone, except in extreme dry periods. On R2, despite inflows on the base component, lateral outflows are observed during floods. This pattern was attributed to the concept of reversal flows of conduit-matrix exchanges, inducing a complex water mixing effect in the saturated zone
MALFLIET, R
1993-01-01
We discuss the present status of relativistic transport theory. Special emphasis is put on problems of topical interest: hadronic features, thermodynamical consistent approximations and spectral properties.
Actuation and ion transportation of polyelectrolyte gels
Hong, Wei; Wang, Xiao
2010-04-01
Consisting of charged network swollen with ionic solution, polyelectrolyte gels are known for their salient characters including ion exchange and stimuli responsiveness. The active properties of polyelectrolyte gels are mostly due to the migration of solvent molecules and solute ions, and their interactions with the fixed charges on the network. In this paper, we extend the recently developed nonlinear field theory of polyelectrolyte gels by assuming that the kinetic process is limited by the rate of the transportation of mobile species. To study the coupled mechanical deformation, ion migration, and electric field, we further specialize the model to the case of a laterally constrained gel sheet. By solving the field equations in two limiting cases: the equilibrium state and the steady state, we calculate the mechanical responses of the gel to the applied electric field, and study the dependency on various parameters. The results recover the behavior observed in experiments in which polyelectrolyte gels are used as actuators, such as the ionic polymer metal composite. In addition, the model reveals the mechanism of the selectivity in ion transportation. Although by assuming specific material laws, the reduced system resembles those in most existing models in the literature, the theory can be easily generalized by using more realistic free-energy functions and kinetic laws. The adaptability of the theory makes it suitable for studying many similar material systems and phenomena.
Institute of Scientific and Technical Information of China (English)
欧阳斌; 李忠奎; 凤振华
2014-01-01
从低碳交通规划概念和内涵着手，本文分析了当前世界典型国家和我国低碳交通运输规划的发展现状和存在的主要问题，并对我国低碳交通运输规划研究的前景进行了展望。研究结果表明，我国低碳交通运输发展缺乏支撑规划的理论与方法和适应低碳技术与管理创新的配套政策体系；未来应注重加强低碳交通运输战略规划的理论基础与顶层设计，注重政府公共政策创新与市场机制运用的有机结合，构建绿色低碳现代综合运输体系。%From the concept and connotation of low-carbon transport,the article analyzes development status,research status and the main problems existing in low-carbon transport planning in typical countries and China and looks to the prospect of low-carbon transport planning research in China. The research results show that there is lack of theory and methodology of planning and supporting policy system adapting to the low-carbon technology and management innovation in the development of low-carbon transport in China;it is required to strengthen the theoretical basis and top-level design of low-carton transport and transport strategic planning,attach importance to the organic combination of public policy innovation with the application of market mechanism and construct a green and low-carbon transport system.
Intelligent Freigth Transport Systems
DEFF Research Database (Denmark)
Overø, Helene Martine; Larsen, Allan; Røpke, Stefan
2009-01-01
The Danish innovation project entitled “Intelligent Freight Transport Systems” aims at developing prototype systems integrating public intelligent transport systems (ITS) with the technology in vehicles and equipment as well as the IT-systems at various transport companies. The objective is to en......The Danish innovation project entitled “Intelligent Freight Transport Systems” aims at developing prototype systems integrating public intelligent transport systems (ITS) with the technology in vehicles and equipment as well as the IT-systems at various transport companies. The objective...... is to enhance the efficiency and lower the environmental impact in freight transport. In this paper, a pilot project involving real-time waste collection at a Danish waste collection company is described, and a solution approach is proposed. The problem corresponds to the dynamic version of the waste collection...... problem which can be formulated as a dynamic version of the vehicle routing problem with time windows (VRPTW)....
Sonuga-Barke, E.; Oades, R.D.; Psychogiou, L.; Chen, W.; Franke, B.; Buitelaar, J.K.; Banaschewski, T.; Ebstein, R.P.; Gil, M.; Anney, R.; Miranda, A.; Roeyers, H.; Rothenberger, A.; Sergeant, J.A.; Steinhausen, H.C.; Thompson, M.; Asherson, P.; Faraone, S.V.
2009-01-01
BACKGROUND: Mothers' positive emotions expressed about their children with attention deficit/hyperactivity disorder (ADHD) are associated with a reduced likelihood of comorbid conduct problems (CP). We examined whether this association with CP, and one with emotional problems (EMO), is moderated by
Sonuga-Barke, Edmund J. S.; Oades, Robert D.; Psychogiou, Lamprini; Chen, Wai; Franke, Barbara; Buitelaar, Jan; Banaschewski, Tobias; Ebstein, Richard P.; Gil, Michael; Anney, Richard; Miranda, Ana; Roeyers, Herbert; Rothenberger, Aribert; Sergeant, Joseph; Steinhausen, Hans Christoph; Thompson, Margaret; Asherson, Philip; Faraone, Stephen V.
2009-01-01
Background: Mothers' positive emotions expressed about their children with attention deficit/hyperactivity disorder (ADHD) are associated with a reduced likelihood of comorbid conduct problems (CP). We examined whether this association with CP, and one with emotional problems (EMO), is moderated by variants within three genes, previously reported…
Picca, Paolo; Furfaro, Roberto; Kargel, Jeffrey; Ganapol, Barry D.
2008-04-01
Remote sensing studies are often based on simplified approaches describing the photon transport in absorbing and scattering media. The main purpose of the present paper is to show the potentiality of modeling directly the transport phenomena by mean of linear Boltzmann equation. Some details about the solution method of the integro-differential equation are reported with a collection of results of relevance in planetary study domain. An inverse approach based on artificial neural network is also proposed to retrieve the optical properties of planetary surfaces and its performances are tested in various cases.
Energy Technology Data Exchange (ETDEWEB)
Schunk, P.R.; Sackinger, P.A.; Rao, R.R. [and others
1996-01-01
GOMA is a two- and three-dimensional finite element program which excels in analyses of manufacturing processes, particularly those involving free or moving interfaces. Specifically, the full-Newton-coupled heat, mass, momentum, and pseudo-solid mesh motion algorithm makes GOMA ideally suited for simulating processes in which the bulk fluid transport is closely coupled to the interfacial physics. Examples include, but are not limited to, coating and polymer processing flows, soldering, crystal growth, and solid-network or solution film drying. The code is based on the premise that any boundary can be (1) moving or free, with an apriori unknown position dictated by the distinguishing physics, (2) fixed, according to a global analytical representation, or (3) moving in time and space under user-prescribed kinematics. The goal is to enable the user to predict boundary position or motion simultaneously with the physics of the problem being analyzed and to pursue geometrical design studies and fluid-structure interaction problems. The moving mesh algorithm treats the entire domain as a computational Lagrangian solid that deforms subject to the physical principles which dictate boundary position. As an added benefit, the same Lagrangian solid mechanics can be exploited to solve multi-field problems for which the solid motion and stresses interact with other transport phenomena, either within the same material phase (e.g. shrinking coating) or in neighboring material phases (e.g. flexible blade coating). Thus, analyses of many fluid-structure interaction problems and deformable porous media problems are accessible. This document serves as a user`s guide and reference for GOMA and provides a brief overview of GOMA`s capabilities, theoretical background, and classes of problems for which it is targeted.
DEFF Research Database (Denmark)
Brandbyge, Mads
2014-01-01
In a recent paper Reuter and Harrison [J. Chem. Phys.139, 114104 (2013)] question the widely used mean-field electron transport theories, which employ nonorthogonal localized basis sets. They claim these can violate an “implicit decoupling assumption,” leading to wrong results for the current...
Energy Technology Data Exchange (ETDEWEB)
Hauck, Cory D [ORNL; Alldredge, Graham [University of Maryland; Tits, Andre [University of Maryland
2012-01-01
We present a numerical algorithm to implement entropy-based (M{sub N}) moment models in the context of a simple, linear kinetic equation for particles moving through a material slab. The closure for these models - as is the case for all entropy-based models - is derived through the solution of constrained, convex optimization problem. The algorithm has two components. The first component is a discretization of the moment equations which preserves the set of realizable moments, thereby ensuring that the optimization problem has a solution (in exact arithmetic). The discretization is a second-order kinetic scheme which uses MUSCL-type limiting in space and a strong-stability-preserving, Runge-Kutta time integrator. The second component of the algorithm is a Newton-based solver for the dual optimization problem, which uses an adaptive quadrature to evaluate integrals in the dual objective and its derivatives. The accuracy of the numerical solution to the dual problem plays a key role in the time step restriction for the kinetic scheme. We study in detail the difficulties in the dual problem that arise near the boundary of realizable moments, where quadrature formulas are less reliable and the Hessian of the dual objection function is highly ill-conditioned. Extensive numerical experiments are performed to illustrate these difficulties. In cases where the dual problem becomes 'too difficult' to solve numerically, we propose a regularization technique to artificially move moments away from the realizable boundary in a way that still preserves local particle concentrations. We present results of numerical simulations for two challenging test problems in order to quantify the characteristics of the optimization solver and to investigate when and how frequently the regularization is needed.
加强放射性物品运输安全管理的几点建议%The Problems and Suggestions on Supervision of the Radioactive Material Transport
Institute of Scientific and Technical Information of China (English)
曹芳芳; 阙骥; 张敏; 潘玉婷
2012-01-01
介绍了我国放射性物品运输安全监管法规建立的背景和意义,总结分析了《放射性物品运输安全管理条例》实施后我国放射性物品运输中存在的问题,并针对性地提出了几点建议。%The developing background and importance of the rules on supervision of the radioactive mate-rial transport are discussed in the paper. Based on the existing problems found in the process of implementing the rule "Regulations for the safe transport of Radioactive Material", some countermeasures are proposed.
Problems, Prospects And Challenges.
African Journals Online (AJOL)
Urban Road Transportation in Nigeria From 1960 To 2006: Problems, Prospects And Challenges. ... Ethiopian Journal of Environmental Studies and Management ... The paper suggested the construction of more motor-able roads within cities ...
Energy Technology Data Exchange (ETDEWEB)
Curbelo, Jesus P.; Alves Filho, Hermes; Barros, Ricardo C., E-mail: jperez@iprj.uerj.br, E-mail: halves@iprj.uerj.br, E-mail: rcbarros@pq.cnpq.br [Universidade do Estado do Rio de Janeiro (UERJ), Nova Friburgo, RJ (Brazil). Instituto Politecnico. Programa de Pos-Graduacao em Modelagem Computacional; Hernandez, Carlos R.G., E-mail: cgh@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (InSTEC), La Habana (Cuba)
2015-07-01
The spectral Green's function (SGF) method is a numerical method that is free of spatial truncation errors for slab-geometry fixed-source discrete ordinates (S{sub N}) adjoint problems. The method is based on the standard spatially discretized adjoint S{sub N} balance equations and a nonstandard adjoint auxiliary equation expressing the node-average adjoint angular flux, in each discretization node, as a weighted combination of the node-edge outgoing adjoint fluxes. The auxiliary equation contains parameters which act as Green's functions for the cell-average adjoint angular flux. These parameters are determined by means of a spectral analysis which yields the local general solution of the S{sub N} equations within each node of the discretization grid. In this work a number of advances in the SGF adjoint method are presented: the method is extended to adjoint S{sub N} problems considering linearly anisotropic scattering and non-zero prescribed boundary conditions for the forward source-detector problem. Numerical results to typical model problems are considered to illustrate the efficiency and accuracy of the o offered method. (author)
Directory of Open Access Journals (Sweden)
Carolyn Webster-Stratton
2012-07-01
Full Text Available Disruptive behavior disorders in children are on the increase. However, there is evidence that the younger a child is at the time of intervention, the more positive the behavioral effects on his/her adjustment at home and at school. Parental education might be an effective way of addressing early problems. The Incredible Years (IY programs were designed to prevent and treat behavior problems when they first appear (in infancy-toddlerhood through middle childhood and to intervene in multiple areas through parent, teacher, and child training. This paper summarizes the literature demonstrating the impact of the IY parent, teacher and child intervention programs, and describes in more detail the work done in Portugal so far to disseminate IY programs with fidelity, with particular emphasis on the IY Basic Preschool Parenting and Teacher Classroom Management programs.
Directory of Open Access Journals (Sweden)
A. REGGIANI
2000-01-01
Full Text Available This paper presents an overview of European policy on the interconnected cross-border transport networks as well as severe problems in estimating empirically the avalanche of goods movements in the European Union (EU. In particular, it deals with the Transalpine freight transport case, which represents one of the most challenging operational and policy issues of the present and future – both international (EU and national (the Alpine countries – freight transport development. The paper is organised to briefly describe the main objectives of EU transport policy, to generally introduce the concept of intermodal transport with particular emphasis on intermodal freight transport and to describe past, present and future development of Trans-Alpine intermodal transport. The scenarios of future development of Trans-Alpine intermodal transport have been particularly analysed.
带外包的服饰运输调度问题的优化%Optimization for Apparel Transportation Scheduling Problem with Outsourcing
Institute of Scientific and Technical Information of China (English)
杨军; 蔡延光; 汤雅连; 江泽东
2014-01-01
由于服饰产品是一种时效性很强的商品，而且服饰产品在配送过程中可以外包给快递公司进行配送，对带外包和硬时间窗的服饰运输调度问题（ Apparel products Vehicle Routing Problem with Hard Time Win－dows and Outsourcing， AVRPHTWO）进行分析，并构建了AVRPHTWO、一般性VRP （ Vehicle Routing Prob－lem）和VRPSTW （ Vehicle Routing Problem with Soft Time Windows）的数学模型，通过对基本的人工鱼群算法（ artificial fish swarm algorithm， AFSA）进行改进，混沌搜索被引入人工鱼群算法来提高算法的全局收敛性，反馈策略用来指导人工鱼的移动，以此来提高收敛精度。应用混沌人工鱼群算法（ chaotic artificial fish swarm al－gorithm， CAFSA）及遗传算法（ genetic algorithm， GA）对所建立的三种模型求解，通过对实验数据进行处理，证明了AVRPHTWO模型和混沌人工鱼群算法求解此类模型的有效性，进一步证明了问题模型的复杂程度影响算法寻优能力，问题模型简单时，遗传算法更优；问题模型复杂时，混沌人工鱼群算法更优。%Apparel product, as a strong timeliness goods, can be outsourced by the Express Company in the process of de-livery.This paper analyzes the Apparel products Vehicle Routing Problem with Hard Time Windows and Outsourcing ( AVRPHT-WO) , and then builds the AVRPHTWO model, Vehicle Routing Problem with Soft Time Windows ( VRPSTW) model and general mathematical model of Vehicle Routing Problem( VRP) , improving the basic artificial fish swarm algorithm ( AFSA) , introducing the chaotic search in order to improve the global convergence of the artificial fish swarm algorithm, using feedback strategy to guide the movement of the artificial fish, in order to improve the convergence precision.By way of chaotic artificial fish swarm algorithm ( CAFSA) and genetic algorithm ( GA) to solve the three kinds of model, based on the
Complexity of Public Transport Networks
Institute of Scientific and Technical Information of China (English)
LU Huapu; SHI Ye
2007-01-01
The theory of complex networks was used to classify public transport networks into public transportation route networks, public transportation transfer networks, and bus station networks. The practical significance of the network parameters was then analyzed. The public transport networks in Langfang, Jining, and Dalian were then chosen as specific research cases. The results show that the public transportation networks have the characteristics of complex networks. In addition, the urban transportation network parameters all significantly affect the accessibility, convenience, and terrorist security capability of the urban public transportation network. The results link the findings with the actual situations to explore means to solve transportation system problems.
Geissler, P. Wenzel
2011-01-01
Based upon Kenyan ethnography, this article examines the gap between the bioethics aversion to value transfers in clinical trials, and research participants’ and researchers’ expectations of these. This article focuses upon so-called ‘transport reimbursement’ (TR): monetary payments to participants that are framed as mere refund of transport expenses, but which are of considerable value to recipients. The interest in this case lies not so much in the unsurprising gap between regulatory norms and poor study subjects’ lives, but in the way in which this discrepancy between bioethical discourse and materialities of survival is silenced. In spite of the general awareness that TR indeed is about the material value of research, about value calculation, and expectations of return, it is not publicly discussed as such – unless ironically, in jest, or in private. This double-blindness around ‘reimbursement’ has provoked discussions among ethicists and anthropologists, some of which propose that the work that generates scientific value should be recognised as labour and participants, accordingly, paid. Here, this paper argues that such a re-vision of trial participation as work rather than as a gift for the public good, risks abrogating the possibility of ‘the public’ that is not only a precondition of public medical science, but also its potential product. The supposedly radical solution of tearing away the veils of misrecognition that ‘free’ gifting ideology lays upon the realities of free labour, though analytically plausible, fails to recognise the utopian openings within clinical trial transactions that point beyond the present – towards larger forms of social association, and towards future alignments of scientific possibilities and human lives. PMID:23914253
Institute of Scientific and Technical Information of China (English)
谭永朝; 过文魁
2016-01-01
Many cities in China currently experience similar transportation problems even though those cit-ies have a very different characteristic, which critically reveals the common deficiencies of urban land use development. To address the problem, this paper reviews the evolution of land use development in urban ar-ea since 1990s through a case study of Hangzhou. The paper points out that while the widely adopted land-use driven development in Chinese cities has laid an economic foundation for urban development, it is also responsible for unregulated expansion of urban space and related problems. To effectively alleviate these urban transportation problems, the paper urges to change the land-use driven development mode, empha-size TOD and particularly public transit-oriented development, and optimize the investment in transporta-tion infrastructure.%现阶段，基本情况差异较大的许多城市集中显现交通共性问题，反映出当前中国城市用地发展模式可能存在非常关键的共性不足。针对上述问题，以杭州市为研究案例，探讨自20世纪90年代以来市区用地空间发展的演变。指出中国城市正广泛采用的用地驱动发展模式，既是城市发展的经济基础，同时也是导致城市空间形态无规则扩张，进而产生相关问题的根源。最后指出，只有转变以土地开发为导向的发展模式，坚持以交通尤其是以公共交通为导向的空间发展，并优化交通基础设施的投资结构，才能有效缓解城市交通共性问题。
Energy Technology Data Exchange (ETDEWEB)
Logan, Jean [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States)], E-mail: logan@bnl.gov; Wang, Gene-jack; Telang, Frank; Fowler, Joanna S.; Alexoff, David; Zabroski, John; Jayne, Millard; Hubbard, Barbara; King, Payton; Carter, Pauline; Shea, Colleen; Xu, Youwen; Muench, Lisa; Schlyer, David [Medical Department, Brookhaven National Laboratory, Upton, NY 11973 (United States); Learned-Coughlin, Susan; Cosson, Valerie [GlaxoSmithKline, Research Triangle Park, NC 27709 (United States); Volkow, Nora D. [National Institute on Drug Abuse, Bethesda, MD 20892 (United States); Ding, Yu-shin [Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, CT 06520-8048 (United States)
2007-08-15
Results from human studies with the PET radiotracer (S,S)-[{sup 11}C]O-methyl reboxetine ([{sup 11}C](S,S)-MRB), a ligand targeting the norepinephrine transporter (NET), are reported. Quantification methods were determined from test/retest studies, and sensitivity to pharmacological blockade was tested with different doses of atomoxetine (ATX), a drug that binds to the NET with high affinity (K{sub i}=2-5 nM). Methods: Twenty-four male subjects were divided into different groups for serial 90-min PET studies with [{sup 11}C](S,S)-MRB to assess reproducibility and the effect of blocking with different doses of ATX (25, 50 and 100 mg, po). Region-of-interest uptake data and arterial plasma input were analyzed for the distribution volume (DV). Images were normalized to a template, and average parametric images for each group were formed. Results: [{sup 11}C](S,S)-MRB uptake was highest in the thalamus (THL) and the midbrain (MBR) [containing the locus coeruleus (LC)] and lowest for the caudate nucleus (CDT). The CDT, a region with low NET, showed the smallest change on ATX treatment and was used as a reference region for the DV ratio (DVR). The baseline average DVR was 1.48 for both the THL and MBR with lower values for other regions [cerebellum (CB), 1.09; cingulate gyrus (CNG) 1.07]. However, more accurate information about relative densities came from the blocking studies. MBR exhibited greater blocking than THL, indicating a transporter density {approx}40% greater than THL. No relationship was found between DVR change and plasma ATX level. Although the higher dose tended to induce a greater decrease than the lower dose for MBR (average decrease for 25 mg=24{+-}7%; 100 mg=31{+-}11%), these differences were not significant. The different blocking between MBR (average decrease=28{+-}10%) and THL (average decrease=17{+-}10%) given the same baseline DVR indicates that the CDT is not a good measure for non-NET binding in both regions. Threshold analysis of the
Scheduling Problem of JIT Purchasing Based 3PL Transportation%基于JIT采购的3PL运输调度问题研究
Institute of Scientific and Technical Information of China (English)
王菲; 宋志刚
2011-01-01
研究Just in Time(JIT)背景下制造商主导的第三方物流(Third Party Logistics,3PL)运输调度问题.制造商根据其生产计划的要求进行采购.使用C-W路线优化算法,在线路规划中考虑了车辆载重量、容积以及车辆到达时间的影响,实现以最小的成本达到JIT采购的目的,并用一个实例验证了修正的C-W算法对解决采购物流中运输调度问题的适用性.%The paper studies the vehicle scheduling problem for manufacturer-led 3PL systems under JIT condition using C-W algorithm. Vehicle carriage load, capacity and arriving time as constraint conditions, ehe paper works on the route schedule to minimize the cost of JIT purchase. Then an example is given to confirm the applicability of the modified C-W algorithm in solving vehicle scheduling problems.
Institute of Scientific and Technical Information of China (English)
王俊鸿; 修桂华
2008-01-01
蚁群算法在解决车辆路径问题VRP(Vehicle Routing Problem)上表现了很大优势,但也存在全局搜索能力较低、易出现停滞等缺陷.提出的二次蚁群算法是指先用改进的自适应蚁群算法对VRP求得一个可行解,再用求解旅行商问题TSP(Traveling Salesman Problem)的蚁群算法对所得到的解进一步优化,从而得到最优解.从两个实验仿真结果的数据上看,该算法具有很强的搜索能力,克服了基本蚁群算法的某些弊端,能够有效地求解车辆路径问题.
Study on Problems in Passenger Vehicle Logistics and Transportation Solutions%乘用车物流运输计划问题
Institute of Scientific and Technical Information of China (English)
周建军; 张顺; 臧碧莲; 林道荣
2015-01-01
对于整车物流问题，先研究每辆轿运车有效的乘用车各种方案，从装载方案、行车路线、目的地、区分上、下层等角度引入基于运输需求的轿运车数量的决策变量，建立了整数线性规划模型，并利用启发式算法求解了该模型，主要是考虑顺带问题，使总成本较低。%In this paper, we first analyzed some effective passenger vehicle transportation solutions, then from the angles of loading, route, destination and stacking, etc., introduced in the decision-making variables concerning the quantity of the car carriers, built the corresponding integer linear programming model and at the end, used a heuristic algorithm to solve it.
Institute of Scientific and Technical Information of China (English)
龙继林
2011-01-01
Service quality is an important aspect of the competitiveness of civil aviation transport industry and a significant source for the competitive edge of the industry.This paper firstly analyzes the crucial impact factors and main problems in the sustainable improvement of China′s civil aviation transport service quality.Then,it puts forward countermeasures in light of these problems.The countermeasures include mainly following aspects.Firstly,service quality criteria should be set and combined with the execution and supervision.Secondly,the long—term mechanism should be founded by combining temporary checkup and regular checkup of service quality.Thirdly,the mechanism of both rewards and punishment should be built.Fourthly,the sustainable improvement of service quality can be achieved by solving surface problems and fundamental problems simultaneously while paying more attention to fundamental problems.Fifthly,the effective sustainable feedback mechanism should be built of passengers′ quality perception.Finally,service quality criteria should be revised whenever necessary in order to offer impetus for the sustainable improvement of service quality.%服务质量是民航运输业竞争力的重要内容,也是行业竞争优势的重要来源。针对推动民航运输服务质量改进的关键影响因素,以及我国民航运输服务质量持续改进中存在的问题,应通过深化对服务质量标准建设的认识,将标准制定与执行监督有机结合;建立临时质量检查与常态质量考核有机结合的长效机制;实行奖惩并举,推拉结合的服务质量促进机制;形成标本兼治,重在治本的服务质量持续改进原则;建立乘客质量感知的持续反馈机制;加强标准适时修订,为服务质量持续改进提供动力等策略实现民航运输服务质量持续改进。
The Instruments of Transport Policy
Directory of Open Access Journals (Sweden)
Gordana Štefančić
2006-09-01
Full Text Available The work proposes the transport policy instruments, suchas the infrastructure measures, management measures and informationprovision measures as the means that could reduceor eliminate transport problems. All these measures have beenfollowed through the provisions for passenger cars, provisionsfor public transport, provisions for cyclists and pedestrians andprovisions regarding transport. A range of solutions is given toreduce congestion, improve accessibility and improve the trafficconditions for those who depend on public transport along withthe improvement of environmental conditions.
Kinsella, John J.
1970-01-01
Discussed are the nature of a mathematical problem, problem solving in the traditional and modern mathematics programs, problem solving and psychology, research related to problem solving, and teaching problem solving in algebra and geometry. (CT)
ANALYISIS OF TRANSPORTATION SYSTEMS AND TRANSPORTATION POLICIES IN TURKEY
Directory of Open Access Journals (Sweden)
Ali Payıdar AKGÜNGÖR
2004-03-01
Full Text Available Transportation systems have to be considered and analysed as a whole while transportation demand, becoming as a natural outcome of socioeconomic and socio-cultural structure, is being evaluated. It is desired that transportation system, which will be selected for both passenger and freight transport, should be rapid, economic, safe, causing least harm to environment and appropriate for the conditions of a country. However, it is difficult for a transportation system to have all these properties. Every transportation system has advantages and disadvantages over each other. Therefore, comprehensive plans for future periods have to be prepared and how the sources of the country should be reasonably distributed among transportation systems must be investigated. Also, transportation plans have to be prepared to get coordinated operations among transportation systems while great investments are instituted in the entire country. There is no doubt that it is possible with combined transportation instead of concentration on one transportation system. Transportation policies in Turkey should be questioned since the level of highway transportation usage reaches to 95 % and level of sea transportation usage drops to less than 1 % in spite of being surrounded with sea in three sides of our land. In this paper, transportation systems and transportation policies in Turkey are evaluated in general and problems are analysed. Proposals are presented for the solutions of these problems.
Cola, Adriano; Farella, Isabella
2013-07-22
Schottky CdTe X-ray detectors exhibit excellent spectroscopic performance but suffer from instabilities. Hence it is of extreme relevance to investigate their electrical properties. A systematic study of the electric field distribution and the current flowing in such detectors under optical perturbations is presented here. The detector response is explored by varying experimental parameters, such as voltage, temperature, and radiation wavelength. The strongest perturbation is observed under 850 nm irradiation, bulk carrier recombination becoming effective there. Cathode and anode irradiations evidence the crucial role of the contacts, the cathode being Ohmic and the anode blocking. In particular, under irradiation of the cathode, charge injection occurs and peculiar kinks, typical of trap filling, are observed both in the current-voltage characteristic and during transients. The simultaneous access to the electric field and the current highlights the correlation between free and fixed charges, and unveils carrier transport/collection mechanisms otherwise hidden.
Directory of Open Access Journals (Sweden)
Isabella Farella
2013-07-01
Full Text Available Schottky CdTe X-ray detectors exhibit excellent spectroscopic performance but suffer from instabilities. Hence it is of extreme relevance to investigate their electrical properties. A systematic study of the electric field distribution and the current flowing in such detectors under optical perturbations is presented here. The detector response is explored by varying experimental parameters, such as voltage, temperature, and radiation wavelength. The strongest perturbation is observed under 850 nm irradiation, bulk carrier recombination becoming effective there. Cathode and anode irradiations evidence the crucial role of the contacts, the cathode being Ohmic and the anode blocking. In particular, under irradiation of the cathode, charge injection occurs and peculiar kinks, typical of trap filling, are observed both in the current-voltage characteristic and during transients. The simultaneous access to the electric field and the current highlights the correlation between free and fixed charges, and unveils carrier transport/collection mechanisms otherwise hidden.
Institute of Scientific and Technical Information of China (English)
齐琳
2013-01-01
Taking related theories and the situations of employee training in China as the background, combines the actual mode of rail-way transport enterprise operation management This paper analyzes the problems and the reasons exist in training work in-depth, and puts forward four countermeasures to improve staff educational training.%以我国员工培训的相关理论和现状为背景，结合铁路运输企业运营管理的实际模式，对培训工作存在的问题及原因进行深度剖析，从而提出完善员工教育培训的对策建议。
Institute of Scientific and Technical Information of China (English)
胡延华
2014-01-01
In this paper, we pointed out the merits of the ro-ro practice in the transportation of sedan cars, then analyzed the problems to be solved in the development of this practice in Shenzhen, and at the end, proposed the specific solutions.%指出轿车滚装运输因运送数量大、安全、经济、便捷、环保，目前已经成为世界趋势。深圳轿车滚装运输需求巨大、拥有全国最早经营国内滚装业务且业务量最大的企业，但目前深圳轿车滚装运输仍存在诸多问题亟待解决，最后提出了相应的解决方案。
Institute of Scientific and Technical Information of China (English)
祁会军
2015-01-01
The phenomenon of throwing away dead animals in highway occurs frequently at present,and this could bring hidden danger to animal epidemic prevention. In this article,the countermeasures for highway animal transporta-tion supervision were proposed for reference through analyzing the problems in the work of supervision authorities .%动物贩运人员在高速公路随意丢弃病死动物现象屡有发生，这给动物防疫工作留下隐患。本文通过分析监管部门工作中存在的问题，提出了针对在高速公路随意丢弃病死动物监管的对策，供同行参考。
Institute of Scientific and Technical Information of China (English)
郑平; 杨喜瑞; 郑婷丹
2012-01-01
The thesis presents realistic significance of regional integration of communications and transportation in Zhuhai, Zhongshan and Jiangmen, points out the problems in it such as city planning is not uniform, regional communications and transportation information can not be shared, information network is not perfect, lack of effective coordination organization and mechanism, and puts forward the measures like unifying though, integrating management function and regulations.%本文论述了珠中江区域交通一体化的现实意义,同时也指出了珠中江在城市规划不统一、区域内交通运输信息不能共享、交通网络不完善、缺少有效的三市协调机构与机制等问题,最后提出了要实现珠中江交通运输一体化必须在思想观念上、管理职能上、法规政策等方面首先实现一体化等对策.
Interaction of railway and marine transport (Murmansk Transport Hub
Directory of Open Access Journals (Sweden)
Sokolov A.A.
2015-03-01
Full Text Available The classification of problems of interaction between water (marine and railway transport on the example of the Murmansk Transport Hub has been presented; some prospects for the development of technology for interaction with the logistics of transportation of general cargo in the Murmansk Commercial Seaport, Murmansk Marine Fishing Port, and oil terminals of the Kola Bay have been shown
The cost of transportation`s oil dependence
Energy Technology Data Exchange (ETDEWEB)
Greene, D.L.
1995-05-01
Transportation is critical to the world`s oil dependence problem because of the large share of world oil it consumes and because of its intense dependence on oil. This paper will focus on the economic costs of transportation`s oil dependence.
Institute of Scientific and Technical Information of China (English)
胡觉亮; 李红芳; 董建明; 蒋义伟
2013-01-01
在考虑加工与运输协同调度的单机排序问题中,每个工件尺寸不同,工件在一台机器加工后,由m辆有容量限制的运输工具运送到同一个顾客处,目标是极小化最后一个送到其顾客的工件的到达时间,本文给出了该问题的一个最优算法,并且证明了该算法的最坏情况界为3/2.%Supply chain management has been one of the most important and widely discussed topics in the production and operation field over the last decade. Generally speaking, a supply chain includes all the interactions among suppliers, manufactures, distributors, and customers. Due to market globalization, coordination among different stages in the supply chain to optimize overall system performance has become more practical and received attention from both industry professionals and academic researchers. In particular, the linkage between job scheduling and delivery of finished jobs is extremely important. Job scheduling and delivery of finished jobs are two critical steps in supply chain management, and they play important roles in the supply chain. The coordination between job scheduling and delivery of finished goods can improve customer service level, reduces operational cost, and optimize the whole system. In this paper, we consider a two-stage supply chain scheduling problem in which the first stage is job scheduling and the second stage is job delivery. Jobs are delivered in batches by a vehicle. The key problem is to coordinate scheduling and transportation of jobs with the objective of minimizing the time taken to have the last finished job arrive at its customer. In the study of the supply chain scheduling problem, many researches have considered scheduling problems with only one vehicle or unlimited vehicles. In this paper, we consider the more general case of the problem in which limited vehicles are employed and each job may occupy a different amount of physical space in a vehicle. The problem is described formally
Pudasaini, Shiva P.; Fischer, Jan-Thomas; Mergili, Martin
2017-04-01
Debris flows are gravity driven mixture flows of soil, sand, rock and water. The solid particles and viscous fluid governs the rheological properties, and their coupling significantly influences the dynamics. For example, debris flows can dramatically increase their volume and destructive potential, and become exceptionally mobile by entraining bed material. The mixture composition can evolve to strikingly change the spatial distribution of particles and fluid, and thus frictional and viscous resistance. So, erosion-deposition and phase-separation between solid and fluid, which strongly depend on material composition, play a critical role in debris flow dynamics. Proper understanding of these complex physical processes is very important in accurate description of impact forces, inundation areas, landscape evolution and developing reliable mitigation plans. Predicting the underlying processes of erosion, phase-separation and deposition in debris flow are long-standing challenges. However, due to lack of data and suitable models, there exists no runout prediction method that includes observed processes of erosion of dry and saturated beds, entrainment and diffusion of eroded material, grain sorting, phase-separation, levee/lobe formation and evolution of deposition patterns. Based on innovative mechanical models for erosion-deposition (Pudasaini and Fischer, 2016a) and phase-separation (Pudasaini and Fischer, 2016b) that explicitly consider changes in local flow compositions, and their basic/potential validations, we present a novel, unified, efficient and fully coupled solution method to these true multi-phase, three-dimensional mass flow problems. As debris flows are better described by a three-phase mixture that include viscous fluid, and fine and coarse grains as compared to often used single-phase models, we propose model extensions that consists of three-phases including yield strength. Thus, we present an advanced mass flow simulation model aiming to
Multi-Agent Systems for Transportation Planning and Coordination
J.M. Moonen (Hans)
2009-01-01
textabstractMany transportation problems are in fact coordination problems: problems that require communication, coordination and negotiation to be optimally solved. However, most software systems targeted at transportation have never approached it this way, and have instead concentrated on centrali
Intelligent Transport Systems in the Management of Road Transportation
Kalupová, Blanka; Hlavoň, Ivan
2016-11-01
Extension of European Union causes increase of free transfer of people and goods. At the same time they raised the problems associated with the transport, e.g. congestion and related accidents on roads, air traffic delays and more. To increase the efficiency and safety of transport, the European Commission supports the introduction of intelligent transport systems and services in all transport sectors. Implementation of intelligent transport systems and services in the road transport reduces accident frequency, increases the capacity of existing infrastructure and reduces congestions. Use of toll systems provides resources needed for the construction and operation of a new road network, improves public transport, cycling transport and walking transport, and also their multimodal integration with individual car transport.
Directory of Open Access Journals (Sweden)
Sílvia Maria Santana Mapa
2012-01-01
Full Text Available O objetivo do trabalho é avaliar a qualidade das soluções para o problema de localização-alocação de instalações geradas por um SIG-T (Sistema de Informação Geográfica para Transportes, obtidas após a utilização combinada das rotinas Localização de Facilidades e Problema do Transporte, quando comparadas com as soluções ótimas obtidas a partir de modelo matemático exato baseado em Programação Linear Inteira Mista (PLIM, desenvolvido externamente ao SIG. Os modelos foram aplicados a três simulações: a primeira propõe a abertura de fábricas e alocação de clientes no Estado de São Paulo; a segunda envolve um atacadista e um estudo de localização de centros de distribuição e alocação dos clientes varejistas; a terceira localiza creches em um contexto urbano, alocando a demanda. Os resultados mostraram que, quando se considera a capacidade das instalações, o modelo otimizante PLIM chegou a apresentar, em um dos cenários simulados, resultados até 37% melhores do que o SIG, além de propor locais diferentes para abertura de novas instalações. Quando não se considera a capacidade, o modelo SIG se mostrou tão eficiente quanto o modelo exato PLIM, chegando exatamente às mesmas soluções.This study aims to evaluate the quality of the solutions for facility location-allocation problems generated by a GIS-T (Geographic Information System for Transportation software. These solutions were obtained from combining the Facility Location and Transportation Problem routines, when compared with the optimal solutions, which were obtained using the exact mathematical model based on the Mixed Integer Linear Programming (MILP developed externally to the GIS. The models were applied to three simulations: the first one proposes set up businesses and customers' allocation in the state of São Paulo; the second involves a wholesaler and an investigation of distribution center location and retailers' allocation; and the third one
Container Logistic Transport Planning Model
Directory of Open Access Journals (Sweden)
Xin Zhang
2013-05-01
Full Text Available The study proposed a stochastic method of container logistic transport in order to solve the unreasonable transportation’s problem and overcome the traditional models’ two shortcomings. Container transport has rapidly developed into a modern means of transportation because of their significant advantages. With the development, it also exacerbated the flaws of transport in the original. One of the most important problems was that the invalid transport had not still reduced due to the congenital imbalances of transportation. Container transport exacerbated the invalid transport for the empty containers. To solve the problem, people made many efforts, but they did not make much progress. There had two theoretical flaws by analyzing the previous management methods in container transport. The first one was the default empty containers inevitability. The second one was that they did not overall consider how to solve the problem of empty containers allocation. In order to solve the unreasonable transportation’s problem and overcome the traditional models’ two shortcomings, the study re-built the container transport planning model-gravity model. It gave the general algorithm and has analyzed the final result of model.
Energy Technology Data Exchange (ETDEWEB)
Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-06-15
We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.
Transport, energy and environment
Energy Technology Data Exchange (ETDEWEB)
NONE
1996-12-01
Transportation demands a large and increasing share of total energy consumption in Europe. At the same time many European countries are facing difficult decisions in achieving their long term environmental goals. Therefore energy policy, environmental policy and transport policy should be seen and discussed in a common perspective. In particular the relative contribution from the transport sector and the energy sector involves a number of important and difficult issues. The aim of the conference was to bring together economists, scientists, manufactures, energy planners, transport planners, and decision makers in order to discuss the importance of the transport sector in relation to energy demand and long term environmental goals. General conference sessions covered. Trends in Transport Energy Demand and Environmental constraints, Technological Development and New Transport Systems, Lifestyle Changes and the Transport Sector, Megacities: Solutions to the Transport and Air Pollution Problems, Effectiveness of Public Policies, Transport and Energy sector, and Methods, Models and Data. The conference took place at Hotel Marienlyst, Elsinore, Denmark and attracted wide interest. The participants represented 14 different countries covering international organisations, ministries, universities, research centres, consulting firms, industry etc. (EG)
Heuristics for Multidimensional Packing Problems
DEFF Research Database (Denmark)
Egeblad, Jens
In this thesis we consider solution methods for packing problems. Packing problems occur in many different situations both directly in the industry and as sub-problems of other problems. High-quality solutions for problems in the industrial sector may be able to reduce transportation and production...... costs significantly. For packing problems in general are given a set of items and one of more containers. The items must be placed within the container such that some objective is optimized and the items do not overlap. Items and container may be rectangular or irregular (e.g. polygons and polyhedra...... methods. Two important problem variants are the knapsack packing problem and the strip-packing problem. In the knapsack packing problem, each item is given a profit value, and the problem asks for the subset with maximal profit that can be placed within one container. The strip-packing problem asks...
Energy Technology Data Exchange (ETDEWEB)
OLSON,CRAIG L.
2000-05-17
Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.
Panel 4 - applications to transportation
Energy Technology Data Exchange (ETDEWEB)
Nichols, F. [Argonne National Lab., IL (United States); Au, J. [Sundstrand Aerospace, Rockford, IL (United States); Bhattacharya, R. [Universal Energy Systems, Inc., Dayton, OH (United States); Bhushan, B. [Ohio State Univ., Columbus (United States); Blunier, D. [Caterpillar, Inc., Peoria, IL (United States); Boardman, B. [Deere & Co., Moline, IL (United States); Brombolich, L. [Compu-Tec Engineering, Chesterfield, MO (United States); Davidson, J. [Vanderbilt Univ., Nashville, TN (United States); Graham, M. [Northwestern Univ., Evanston, IL (United States); Hakim, N. [Detroit Diesel Corp., MI (United States); Harris, K. [Dubbeldee Harris Diamond Corp., Mt. Arlington, NJ (United States); Hay, R. [Norton Diamond Film, Northboro, MA (United States); Herk, L. [Southwest Research Inst., Southfield, MI (United States); Hojnacki, H.; Rourk, D. [Intelligent Structures Incorporated, Canton, MI (United States); Kamo, R. [Adiabatics, Inc., Columbus, IN (United States); Nieman, B. [Allied-Signal Inc., Des Plaines, IL (United States); O`Neill, D. [3M, St. Paul, MN (United States); Peterson, M.B. [Wear Sciences, Arnold, MD (United States); Pfaffenberger, G. [Allison Gas Turbine, Indianapolis, IN (United States); Pryor, R.W. [Wayne State Univ., Detroit, MI (United States); Russell, J. [Superconductivity Publications, Inc., Somerset, NJ (United States); Syniuta, W. [Advanced Mechanical Technology, Inc., Newton, MA (United States); Tamor, M. [Ford Motor Co., Dearborn, MI (United States); Vojnovich, T. [Dept. of Energy, Washington, DC (United States); Yarbrough, W. [Pennsylvania State Univ., University Park (United States); Yust, C.S. [Oak Ridge National Lab., TN (United States)
1993-01-01
The aim of this group was to compile a listing of current and anticipated future problem areas in the transportation industry where the properties of diamond and DLC films make them especially attractive and where the panel could strongly endorse the establishment of DOE/Transportation Industry cooperative research efforts. This section identifies the problem areas for possible applications of diamond/DLC technology and presents indications of current approaches to these problems.
Institute of Scientific and Technical Information of China (English)
吴子啸; 付凌峰
2012-01-01
Because travel demands are affected by a host of factors such as social economic development, geographic layout, infrastructure development and information technology, development of transportation planning models is often restricted by data availability, modeling theory, time, budget, and etc. Taking Zhengzhou as an example, this paper discusses the problems of theoretical complexity and technique innovation in transportation model development and application. The paper first compares the functionalities and limitations of traditional trip-based models with the activity-based models. Focusing on trip-based and four-stage modeling approaches, the paper elaborates the challenges and theoretical drawbacks in model development and discusses how to introduce new methodologies such as OD estimation and traffic generation model in traditional travel demand analysis. Finally, the paper presents the application framework of transportation planning model on forecasting short-term and medium-term travel demand.%由于出行涉及社会、地理、工程、信息等多个领域并且诸多因素相互作用,交通模型的开发和应用往往受制于数据获取、建模理论、时间与费用预算等现实约束.以郑州市为例,探讨交通模型开发和应用中的理论困惑与技术创新.首先对比传统的基于出行的模型和基于活动的模型的优缺点及局限性.然后,针对交通模型开发所采用的基于出行的建模理论和四阶段建模方法,重点阐述建模的困难所在及内在的理论瑕疵,并探讨OD反推、生成量模型等新方法在传统需求分析框架中的应用.在此基础上,提出交通模型在短期预测和近期预测方面的应用框架.
... you are having balance problems, see your doctor. Balance disorders can be signs of other health problems, such ... cases, treating the illness that is causing the disorder will help with the balance problem. Exercises, a change in diet, and some ...
Directory of Open Access Journals (Sweden)
Muhammad Aslam Noor
2004-01-01
Full Text Available We consider a new class of equilibrium problems, known as hemiequilibrium problems. Using the auxiliary principle technique, we suggest and analyze a class of iterative algorithms for solving hemiequilibrium problems, the convergence of which requires either pseudomonotonicity or partially relaxed strong monotonicity. As a special case, we obtain a new method for hemivariational inequalities. Since hemiequilibrium problems include hemivariational inequalities and equilibrium problems as special cases, the results proved in this paper still hold for these problems.
On the Ramified Optimal Allocation Problem
Xia, Qinglan
2011-01-01
This paper proposes an optimal allocation problem with ramified transport technology in a spatial economy. Ramified transportation is used to model the transport economy of scale in group transportation observed widely in both nature and efficiently designed transport systems of branching structures. The ramified allocation problem aims at finding an optimal allocation plan as well as an associated optimal allocation path to minimize overall cost of transporting commodity from factories to households. This problem differentiates itself from existing ramified transportation literature in that the distribution of production among factories is not fixed but endogenously determined as observed in many allocation practices. It's shown that due to the transport economy of scale in ramified transportation, each optimal allocation plan corresponds equivalently to an optimal assignment map from households to factories. This optimal assignment map provides a natural partition of both households and allocation paths. We...
Groupage Cargo Transportation Model
Directory of Open Access Journals (Sweden)
Aleksejevs Ruslans
2016-03-01
Full Text Available In this work we consider a specific problem of optimal planning of maritime transportation of multiproduct cargo by ships of one (corporate strategy or several (partially corporate strategy companies: the core of the problem consists of the existence of the network of intermediate seaports (i.e. transitional seaports, where for every ship arrived the cargo handling is done, and which are situated between the starting and the finishing seaports. In this work, there are mathematical models built from scratch in the form of multicriteria optimization problem; then the goal attainment method of Gembicki is used for reducing the built models to a one-criterion problem of linear programming.
TRANSPORT OF COUNTERFEIT GOODS
Directory of Open Access Journals (Sweden)
Dagmar Babčanová
2014-09-01
Full Text Available The paper is focused on a current problem of transport of counterfeit goods in the European Union. Counterfeiting has a strong influence on the distribution organizations worldwide because most of counterfeit goods threaten the health and safety of consumers. Counterfeiting is a serious problem in the world economy today. The purpose of this paper is to point out the danger of counterfeiting in connection with the transport of Intellectual Property (IP rights - infringing goods. Background of the paper’s content is based on secondary data research of publicly available sources - international statistics and world reports.
A Fixed-Charge Multicommodity Network Flow Algorithm and a Warehouse Location Application.
1985-08-01
design. That is, incremental changes to their systems evolved in response to particular changes in demography, technology , acquisitions, divestitures, etc...ice cream and confectionaries . (b) Take-home ice cream. (c) House brand products. (d) Loose pack stick/novelty items. (e) Take-home stick/novelty items...for Naval Analyses 1 2000 Beauregard Street Alexandria, VA 22311 Operations Research Center Room E40-164 Massachusetts Institute of Technology Attn: R
Antila, Hanne S; Salonen, Emppu
2015-04-15
The Thole induced point dipole model is combined with three different point charge fitting methods, Merz-Kollman (MK), charges from electrostatic potentials using a grid (CHELPG), and restrained electrostatic potential (RESP), and two multipole algorithms, distributed multipole analysis (DMA) and Gaussian multipole model (GMM), which can be used to describe the electrostatic potential (ESP) around molecules in molecular mechanics force fields. This is done to study how the different methods perform when intramolecular polarizability contributions are self-consistently removed from the fitting done in the force field parametrization. It is demonstrated that the polarizable versions of the partial charge models provide a good compromise between accuracy and computational efficiency in describing the ESP of small organic molecules undergoing conformational changes. For the point charge models, the inclusion of polarizability reduced the the average root mean square error of ESP over the test set by 4-10%.
Sustainability - and sustainable transport
Energy Technology Data Exchange (ETDEWEB)
Thisgaard, P.
1996-12-31
To gain the fulfillment of basic sustainable objectives in a medium- and long-term perspective for transport. The necessary activities must be genuinely complementary i.e. it must solve problems within at least two sectors and at the same time this activity must be sustainable in a Brundtland report perspective. The transport sector must take steps to develop an `ECO-NOMY`. The principle here is a `fusion` of economy and ecology, and the first place this can take place is in the transport sector. This can only take place in a close cooperation between the transport sector and the other sectors of society. Methods to carry out cross-sectional priorities and allocation of resources must be developed in order to avoid societal sub-optimization of single issue solutions. Besides, a development of public administration must take place through a very heavy limitation of the principles of `sector thinking` as well as the carrying through of totally new principles in the selection of personnel as well as the principles of promotion and control. `Management by objectives` combined with an emphasis of certain moral codes - may contribute substantially to such a development. The principles are to economize with resources and as far as possible adjust the supply to a given demand with reasonable regard to comfort and transport considerations. Besides, the transport sector must try to solve other sector`s sociological problems and actively try to point out where other sectors create problems for the transport sector which prevent this in becoming `sustainable`. The transport sector must also continually try to forward its ability to change by avoiding capital investment or other forms of bindings which might hinder a different development if or when important technological changes occur. In a number of ways you can point to different concrete possibilities with the following headlines: diversification, integration, development of vehicles, information and concrete project areas
Urban transportation: Perspectives on mobility and choice
Sincoff, M. Z. (Editor); Dajani, J. S. (Editor); Arnold, G. R.; Bird, J. W.; Brooks, C. M. (Editor); Cobb, W. E.; Cross, J. E.; Darby, L. F.; Erb, N. H.; Ficht, J. C.
1974-01-01
A study of urban transportation systems are presented characterized by intensive scrutiny of many ideas, philosophies, and academic perspectives. This report is intended to communicate some dimensions of the urban transportation problem to the general public.
Safeguarding Schiphol Airports accessibility for freight transport
van der Heijden, Matthijs C.; van Harten, Aart; Ebben, Mark; Saanen, Y.A.; Valentin, E.C.; Verbraeck, A.
2001-01-01
Automated, underground freight transport should enable sustainable economic growth in the Amsterdam area in the Netherlands. An innovative transport system, which guarantees reliable logistics and which avoids congestion problems, is currently being developed. This logistics system will be highly
DEFF Research Database (Denmark)
Gether, Ulrik; Andersen, Peter H; Larsson, Orla M
2006-01-01
The concentration of neurotransmitters in the extracellular space is tightly controlled by distinct classes of membrane transport proteins. This review focuses on the molecular function of two major classes of neurotransmitter transporter that are present in the cell membrane of neurons and....../or glial cells: the solute carrier (SLC)1 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of glutamate, and the SLC6 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of dopamine, 5-HT, norepinephrine, glycine and GABA....... Recent research has provided substantial insight into the structure and function of these transporters. In particular, the recent crystallizations of bacterial homologs are of the utmost importance, enabling the first reliable structural models of the mammalian neurotransmitter transporters...
Executive Educator, 1990
1990-01-01
This special section on student transportation offers a case study of a school system that recycles buses for safety drills; articles on fuel-saving strategies, the pros and cons of contracting for transportation services or operating a publicly owned bus fleet, and advice on full cost accounting for transportation costs; and a transportation…
Energy Technology Data Exchange (ETDEWEB)
Kuroishi, Takeshi; Hoang, Anh Tuan; Nomura, Yasushi; Okuno, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
2003-03-01
The reactivity effect of the asymmetry of axial burnup profile in burnup credit criticality safety is studied for a realistic PWR spent fuel transport cask proposed in the current OECD/NEA Phase II-C benchmark problem. The axial burnup profiles are simulated in 21 material zones based on in-core flux measurements varying from strong asymmetry to more or less no asymmetry. Criticality calculations in a 3-D model have been performed using the continuous energy Monte Carlo code MCNP-4B2 and the nuclear data library JENDL-3.2. Calculation conditions are determined with consideration of the axial fission source convergence. Calculations are carried out not only for cases proposed in the benchmark but also for additional cases assuming symmetric burnup profile. The actinide-only approach supposed for first domestic introduction of burnup credit into criticality evaluation is also considered in addition to the actinide plus fission product approach adopted in the benchmark. The calculated results show that k{sub eff} and the end effect increase almost linearly with increasing burnup axial offset that is defined as one of typical parameters showing the intensity of axial burnup asymmetry. The end effect is more sensitive to the asymmetry of burnup profile for the higher burnup. For an axially distributed burnup, the axial fission source distribution becomes strongly asymmetric as its peak shifts toward the top end of the fuel's active zone where the local burnup is less than that of the bottom end. The peak of fission source distribution becomes higher with the increase of either the asymmetry of burnup profile or the assembly-averaged burnup. The conservatism of the assumption of uniform axial burnup based on the actinide-only approach is estimated quantitatively in comparison with the k{sub eff} result calculated with experiment-based strongest asymmetric axial burnup profile with the actinide plus fission product approach. (author)
Energy Technology Data Exchange (ETDEWEB)
Kuroishi, Takeshi; Hoang, Anh Tuan; Nomura, Yasushi; Okuno, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
2003-03-01
The reactivity effect of the asymmetry of axial burnup profile in burnup credit criticality safety is studied for a realistic PWR spent fuel transport cask proposed in the current OECD/NEA Phase II-C benchmark problem. The axial burnup profiles are simulated in 21 material zones based on in-core flux measurements varying from strong asymmetry to more or less no asymmetry. Criticality calculations in a 3-D model have been performed using the continuous energy Monte Carlo code MCNP-4B2 and the nuclear data library JENDL-3.2. Calculation conditions are determined with consideration of the axial fission source convergence. Calculations are carried out not only for cases proposed in the benchmark but also for additional cases assuming symmetric burnup profile. The actinide-only approach supposed for first domestic introduction of burnup credit into criticality evaluation is also considered in addition to the actinide plus fission product approach adopted in the benchmark. The calculated results show that k{sub eff} and the end effect increase almost linearly with increasing burnup axial offset that is defined as one of typical parameters showing the intensity of axial burnup asymmetry. The end effect is more sensitive to the asymmetry of burnup profile for the higher burnup. For an axially distributed burnup, the axial fission source distribution becomes strongly asymmetric as its peak shifts toward the top end of the fuel's active zone where the local burnup is less than that of the bottom end. The peak of fission source distribution becomes higher with the increase of either the asymmetry of burnup profile or the assembly-averaged burnup. The conservatism of the assumption of uniform axial burnup based on the actinide-only approach is estimated quantitatively in comparison with the k{sub eff} result calculated with experiment-based strongest asymmetric axial burnup profile with the actinide plus fission product approach. (author)
Institute of Scientific and Technical Information of China (English)
魏江宁; 陆志强; 奚立峰
2009-01-01
The vehicle routing problem with time windows as well as multiple pickups and deliveries was studied in collaborative transportation mode. A mathematical model was developed considering the factors such as the number of trucks rented, the distances covered, and the penalty due to service delay. A hybrid genetic algorithm was proposed accordingly, integrating the restarting scheme which is able to improve the initial population and avoid premature convergence respectively. In addition, the local research strategy was fully used to get the optimal value quickly. The results of the computational experiment indicate that the proposed algorithm is effective.%研究了协同物流模式下,单车库、多集散点的带时间窗以及单点多批次配送与集货请求的联合运输问题.考虑车辆的租用费用、行驶费用、未按时完成服务产生的惩罚费用等因素,建立了数学模型并提出了混合遗传算法.算法中加入了重启动机制,以提高种群质量和避免早熟收敛,并采用局部搜索策略以快速寻找最优值.数值实验证明,混合遗传算法求解该类运输调度问题具有良好的效果,且算法效率较高.
... de los dientes Video: Getting an X-ray Learning Problems KidsHealth > For Kids > Learning Problems Print A ... for how to make it better. What Are Learning Disabilities? Learning disabilities aren't contagious, but they ...
... your legs or feet Movement disorders such as Parkinson's disease Diseases such as arthritis or multiple sclerosis Vision or balance problems Treatment of walking problems depends on the cause. Physical therapy, surgery, or mobility aids may help.
Urban Road Transportation in Nigeria From 1960 To 2006 ...
African Journals Online (AJOL)
Choice-Academy
Ethiopian Journal of Environmental Studies and Management Vol.1 No.1 March. ... The nature of urban road transportation problems in Nigeria as at today can ... the provision of transport services within cities and inter-cities transport system.
Physiological responses of food animals to road transportation stress
African Journals Online (AJOL)
Physiological responses of food animals to road transportation stress. ... African Journal of Biotechnology ... streaked compliance by transporters, several studies still report severe welfare problems during road transportation of food animals.
Transportation optimization with fuzzy trapezoidal numbers based on possibility theory.
He, Dayi; Li, Ran; Huang, Qi; Lei, Ping
2014-01-01
In this paper, a parametric method is introduced to solve fuzzy transportation problem. Considering that parameters of transportation problem have uncertainties, this paper develops a generalized fuzzy transportation problem with fuzzy supply, demand and cost. For simplicity, these parameters are assumed to be fuzzy trapezoidal numbers. Based on possibility theory and consistent with decision-makers' subjectiveness and practical requirements, the fuzzy transportation problem is transformed to a crisp linear transportation problem by defuzzifying fuzzy constraints and objectives with application of fractile and modality approach. Finally, a numerical example is provided to exemplify the application of fuzzy transportation programming and to verify the validity of the proposed methods.
DEFF Research Database (Denmark)
Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg
2014-01-01
The transportation system is the backbone of economic and social progress and the means by which humans access goods and services and connect with one another. Yet, as the scale of transportation activities has grown worldwide, so too have the negative environmental, social, and economic impacts...... that relate to the construction and maintenance of transportation infrastructure and the operation or use of the different transportation modes. The concept of sustainable transportation emerged in response to these concerns as part of the broader notion of sustainable development. Given the transportation...... sector’s significant contribution to global challenges such as climate change, it is often said that sustainable development cannot be achieved without sustainable transportation....
Transportation energy use in Mexico
Energy Technology Data Exchange (ETDEWEB)
Sheinbaum, C.; Meyers, S.; Sathaye, J.
1994-07-01
This report presents data on passenger travel and freight transport and analysis of the consequent energy use in Mexico during the 1970--1971 period. We describe changes in modal shares for passenger travel and freight transport, and analyze trends in the energy intensity of different modes. We look in more detail at transportation patterns, energy use, and the related environmental problems in the Mexico City Metropolitan Area, and also discuss policies that have been implemented there to reduce emissions from vehicles.
Urban transportation projects conceptualised:
DEFF Research Database (Denmark)
Pineda, Andres Felipe Valderrama
During the last ten years two innovations in urban transportation have been accomplished in two different parts of the planet: in the city of Bogotá, in Colombia, the first mass bus rapid transit system was designed, built and put into operation becoming the most visible icon of a great urban...... is straightforward: transportation projects transform cities. The paradoxical reality thus is that a problem that has been traditionally conceptualized in technical terms (transportation engineering, transportation economics, planning theory, traffic engineering, urban planning, etc.), has tremendous consequences...... idea underlying all this approaches is that cities, policies and their support systems co-evolve in permanent interaction shaping one another. Thus, if change is to be produced in desired ways actions must be taken in all fronts to render a desired result. In a wider perspective this approach to urban...
Appraisal of Transport Projects
DEFF Research Database (Denmark)
Jensen, Anders Vestergaard
The evaluation of transport projects has traditionally been based on quantitative descriptions of selected impacts by the use of cost-benefit analysis (CBA). However, environmental impacts are now taking into consideration when decisions have to be made, regarding which large transport projects...... complexity. Optimisation has been replaced with satisficing, where satisficing is defined as finding an acceptable or satisfactory solution to a problem instead of a socio-economical optimal solution. This calls for new approaches of appraising transport projects that goes beyond what the classical CBA......, seems suitable for. As a result of the above mentioned issues regarding conflict of interests, multiple impacts, participation of stakeholders, and sustainability, additional approaches for appraisal have been suggested. Multi-criteria decision analysis (MCDA) has been introduced in the transport...
A Novel Metaheuristic for Travelling Salesman Problem
Directory of Open Access Journals (Sweden)
Vahid Zharfi
2013-01-01
Full Text Available One of the well-known combinatorial optimization problems is travelling salesman problem (TSP. This problem is in the fields of logistics, transportation, and distribution. TSP is among the NP-hard problems, and many different metaheuristics are used to solve this problem in an acceptable time especially when the number of cities is high. In this paper, a new meta-heuristic is proposed to solve TSP which is based on new insight into network routing problems.
2011-01-01
La problemática encontrada en el análisis realizado por la tesis se puede resumir brevemente en un marco de competencias disperso y que no considera el transporte por tubería como un todo, sino sectorialmente (energía, por un lado, y modo de transporte, por otro), unido a un vacío normativo, necesitado de las correspondientes leyes, reglamentos y normas técnicas. Ambas cosas son grandemente perjudiciales para el adecuado fomento y desarrollo de este tipo de infraestructura. La tesis, tras el ...
DEFF Research Database (Denmark)
Christensen, Anders Bøggild; Rasmussen, Tove; Bundesen, Peter Verner
Sociale problemer kan betragtes som selve udgangspunktet for socialt arbejde, hvor ambitionen er at råde bod på problemerne og sikre, at udsatte borgere får en bedre tilværelse. Det betyder også, at diskussionen af sociale problemer er afgørende for den sociale grundfaglighed. I denne bog sætter en...... række fagfolk på tværs af det danske socialfaglige felt fokus på sociale problemer. Det diskuteres, hvad vi overhovedet forstår ved sociale problemer, hvordan de opstår, hvilke konsekvenser de har, og ikke mindst hvordan man som fagprofessionel håndterer sociale problemer i det daglige arbejde. Bogen er...... skrevet som lærebog til professionsuddannelser, hvor sociale problemer udgør en dimension, bl.a. socialrådgiver-, pædagog- og sygeplejerskeuddannelserne....
Directory of Open Access Journals (Sweden)
Terent'eva Elena Olegovna
2013-09-01
Full Text Available Inner and outer Lamb problems are of extreme importance for various applications in geophysics, as these problems are often used for simulation of wave fields accompanying earthquakes. Solutions of the outer Lamb problem of concentrated force impact applied to the free surface of an elastic half-plane are analyzed in this article. Two solutions are compared: the analytical solution obtained in 1984 and the solution obtained in a modern FEM complex Abaqus.
Terent'eva Elena Olegovna
2013-01-01
Inner and outer Lamb problems are of extreme importance for various applications in geophysics, as these problems are often used for simulation of wave fields accompanying earthquakes. Solutions of the outer Lamb problem of concentrated force impact applied to the free surface of an elastic half-plane are analyzed in this article. Two solutions are compared: the analytical solution obtained in 1984 and the solution obtained in a modern FEM complex Abaqus.
DEFF Research Database (Denmark)
Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg
2014-01-01
The transportation system is the backbone of economic and social progress and the means by which humans access goods and services and connect with one another. Yet, as the scale of transportation activities has grown worldwide, so too have the negative environmental, social, and economic impacts ...... sector’s significant contribution to global challenges such as climate change, it is often said that sustainable development cannot be achieved without sustainable transportation....
... BMI Calculator myhealthfinder Immunization Schedules Nutrient Shortfall Questionnaire Knee ProblemsPain, swelling, stiffness and "water" on the knee are common symptoms. Follow this chart for more ...
Skovhus, Randi Boelskifte; Thomsen, Rie
2017-01-01
This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the "What's the problem represented to be" (WPR) approach. Forty-nine…
Skovhus, Randi Boelskifte; Thomsen, Rie
2017-01-01
This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the "What's the problem represented to be" (WPR) approach. Forty-nine…
Stochastic models of intracellular transport
Bressloff, Paul C.
2013-01-09
The interior of a living cell is a crowded, heterogenuous, fluctuating environment. Hence, a major challenge in modeling intracellular transport is to analyze stochastic processes within complex environments. Broadly speaking, there are two basic mechanisms for intracellular transport: passive diffusion and motor-driven active transport. Diffusive transport can be formulated in terms of the motion of an overdamped Brownian particle. On the other hand, active transport requires chemical energy, usually in the form of adenosine triphosphate hydrolysis, and can be direction specific, allowing biomolecules to be transported long distances; this is particularly important in neurons due to their complex geometry. In this review a wide range of analytical methods and models of intracellular transport is presented. In the case of diffusive transport, narrow escape problems, diffusion to a small target, confined and single-file diffusion, homogenization theory, and fractional diffusion are considered. In the case of active transport, Brownian ratchets, random walk models, exclusion processes, random intermittent search processes, quasi-steady-state reduction methods, and mean-field approximations are considered. Applications include receptor trafficking, axonal transport, membrane diffusion, nuclear transport, protein-DNA interactions, virus trafficking, and the self-organization of subcellular structures. © 2013 American Physical Society.
[Recommendations for neonatal transport].
Moreno Hernando, J; Thió Lluch, M; Salguero García, E; Rite Gracia, S; Fernández Lorenzo, J R; Echaniz Urcelay, I; Botet Mussons, F; Herranz Carrillo, G; Sánchez Luna, M
2013-08-01
During pregnancy, it is not always possible to identify maternal or foetal risk factors. Infants requiring specialised medical care are not always born in centres providing intensive care and will need to be transferred to a referral centre where intensive care can be provided. Therefore Neonatal Transport needs to be considered as part of the organisation of perinatal health care. The aim of Neonatal Transport is to transfer a newborn infant requiring intensive care to a centre where specialised resources and experience can be provided for the appropriate assessment and continuing treatment of a sick newborn infant. Intrauterine transfer is the ideal mode of transport when the birth of an infant with risk factors is diagnosed. Unfortunately, not all problems can be detected in advance with enough time to safely transfer a pregnant woman. Around 30- 50% of risk factors will be diagnosed during labour or soon after birth. Therefore, it is important to have the knowledge and resources to resuscitate and stabilise a newborn infant, as well as a specialised neonatal transport system. With this specialised transport it is possible to transfer newly born infants with the same level of care that they would receive if they had been born in a referral hospital, without increasing their risks or affecting the wellbeing of the newborn. The Standards Committee of the Spanish Society of Neonatology reviewed and updated recommendations for intrauterine transport and indications for neonatal transfer. They also reviewed organisational and logistic factors involved with performing neonatal transport. The Committee review included the type of personnel who should be involved; communication between referral and receiving hospitals; documentation; mode of transport; equipment to stabilise newly born infants; management during transfer, and admission at the referral hospital.
... do to help diagnose your prostate problem. Physical Exam A physical exam may help diagnose the cause ... sleep avoid or drink fewer liquids that have caffeine or alcohol in them avoid medicines that may ...
DEFF Research Database (Denmark)
Skovhus, Randi Boelskifte; Thomsen, Rie
2016-01-01
This article introduces a method to critical reviews and explores the ways in which problems have been formulated in knowledge production on career guidance in Denmark over a 10-year period from 2004 to 2014. The method draws upon the work of Bacchi focussing on the ‘What's the problem represented...... to be’ (WPR) approach. Forty-nine empirical studies on Danish youth career guidance were included in the study. An analysis of the issues in focus resulted in nine problem categories. One of these, ‘targeting’, is analysed using the WPR approach. Finally, the article concludes that the WPR approach...... provides a constructive basis for a critical analysis and discussion of the collective empirical knowledge production on career guidance, stimulating awareness of problems and potential solutions among the career guidance community....
... our e-newsletter! Aging & Health A to Z Kidney Problems Basic Facts & Information The kidneys are two ... the production of red blood cells. What are Kidney Diseases? For about one-third of older people, ...
... Tongue pain may also occur with: Diabetic neuropathy Leukoplakia Mouth ulcers Oral cancer After menopause, some women ... problem. Medicine may be prescribed for mouth ulcers, leukoplakia, oral cancer, and other mouth sores. Anti-inflammatory ...
... monitoring to test how strong your erection is Psychological tests to check for depression and other emotional problems ... the principles of the Health on the Net Foundation (www.hon.ch). The information provided herein should ...
... getting enough air. Sometimes you can have mild breathing problems because of a stuffy nose or intense ... panic attacks Allergies If you often have trouble breathing, it is important to find out the cause.
... For Consumers Consumer Information by Audience For Women Sleep Problems Share Tweet Linkedin Pin it More sharing ... PDF 474KB) En Español Medicines to Help You Sleep Tips for Better Sleep Basic Facts about Sleep ...
... Ear Nose & Throat Emotional Problems Eyes Fever From Insects or Animals Genitals and Urinary Tract Glands & Growth ... an irregular shape (astigmatism), it will threaten normal vision development and must be corrected as early as ...
Directory of Open Access Journals (Sweden)
Diana Ludrovcová
2016-08-01
Full Text Available Purpose and Originality: The research is aimed to the animal transports issue, from two points of view – first is the animal cruelty and second is the policy and economic consideration. The goal is to acquaint the readers with the transports risks and its cruelty and evaluation of the economic, political aspects for he involved countries. The study is oriented on more points of view, what is rare in works with a similar theme. Method: This paper examines many issues and examinations from different authors and subsequently summarized the findings with authors own knowledge to one expanded unit. Results: Results proves, that livestock transports have negative impact on animal´s health, environment. Number of transported animals is rising every year. Society: Research familiarize the society with the animal transports, cruelty against animals during them, and influence of transports on some countries, their economy, policy. People get better informed and can form their own opinion on this topic. They may start acting, undertaking some steps to improve the present situation, what could help a lot to animals and environment. Limitations / further research: Future research could show progress and improvement of transports, quality of food supply and economics.
Directory of Open Access Journals (Sweden)
Linda STEG
2007-01-01
Full Text Available This paper discusses possible contributions of psychologists to sustainable transportation. It is argued that in order to reach sustainable transportation, among others, behaviour changes of individual car users are needed. As transport policies will be more effective if they target important antecedents of travel behaviour, first, factors influencing such behaviour are discussed. It is argued that car use is very attractive and sometimes even necessary for many different reasons. This implies that a combination of policies is called for, each targeting different factors that support car use and hinder the use of more sustainable modes of transport. Next, the paper elaborates on policy strategies that may be employed to achieve sustainable transportation by changing car use. Increasing the attractiveness of sustainable transport modes by means of pull measures seems not sufficient to reduce the level of car use. Besides, car use should be made less attractive by means of push measures to force drivers to reconsider their travel behaviour. The acceptability of such policies may be increased by clearly communicating the aim of these policies, and the expected positive consequences (e.g., less congestion, improved environmental quality. Moreover, possible negative effects for individual freedom may be compensated by implementing additional policies aimed at facilitating the use of sustainable transport modes.
Heuristics for Multidimensional Packing Problems
DEFF Research Database (Denmark)
Egeblad, Jens
In this thesis we consider solution methods for packing problems. Packing problems occur in many different situations both directly in the industry and as sub-problems of other problems. High-quality solutions for problems in the industrial sector may be able to reduce transportation and production...... costs significantly. For packing problems in general are given a set of items and one of more containers. The items must be placed within the container such that some objective is optimized and the items do not overlap. Items and container may be rectangular or irregular (e.g. polygons and polyhedra......) and may be defined in any number of dimensions. Solution methods are based on theory from both computational geometry and operations research. The scientific contributions of this thesis are presented in the form of six papers and a section which introduces the many problem types and recent solution...
Kellerer, Hans; Pisinger, David
2004-01-01
Thirteen years have passed since the seminal book on knapsack problems by Martello and Toth appeared. On this occasion a former colleague exclaimed back in 1990: "How can you write 250 pages on the knapsack problem?" Indeed, the definition of the knapsack problem is easily understood even by a non-expert who will not suspect the presence of challenging research topics in this area at the first glance. However, in the last decade a large number of research publications contributed new results for the knapsack problem in all areas of interest such as exact algorithms, heuristics and approximation schemes. Moreover, the extension of the knapsack problem to higher dimensions both in the number of constraints and in the num ber of knapsacks, as well as the modification of the problem structure concerning the available item set and the objective function, leads to a number of interesting variations of practical relevance which were the subject of intensive research during the last few years. Hence, two years ago ...
Urban transportation projects conceptualised:
DEFF Research Database (Denmark)
Pineda, Andres Felipe Valderrama
During the last ten years two innovations in urban transportation have been accomplished in two different parts of the planet: in the city of Bogotá, in Colombia, the first mass bus rapid transit system was designed, built and put into operation becoming the most visible icon of a great urban...... in the life of cities and citizens. Thus a problem that is often outlined in technical terms is also a problem of political choice at different levels. Therefore, the challenge to confront is how to bring together a comprehensive approach that takes into account policy making, community building and technical...
Rail transport systems approach
2017-01-01
This book shows how the systems approach is employed by scientists in various countries to solve specific problems concerning railway transport. In particular, the book describes the experiences of scientists from Romania, Germany, the Czech Republic, the UK, Russia, Ukraine, Lithuania and Poland. For many of these countries there is a problem with the historical differences between the railways. In particular, there are railways with different rail gauges, with different signaling and communication systems, with different energy supplies and, finally, with different political systems, which are reflected in the different approaches to the management of railway economies. The book’s content is divided into two main parts, the first of which provides a systematic analysis of individual means of providing and maintaining rail transport. In turn, the second part addresses infrastructure and management development, with particular attention to security issues. Though primarily written for professionals involved...
Assessment of synfuel transportation to year 2000
Energy Technology Data Exchange (ETDEWEB)
Wakamiya, W.; Sebelien, K.B.; Parkhurst, M.A.
1979-03-01
This report identifies and discusses potential problems in the transportation of synthetic fuels (synfuels) which if allowed to persist unresolved will hamper the development of these energy materials between now and the year 2000. The emergence of transportation-related problems in shale oil and coal synfuel development will be highly dependent upon their chemical similitude with analagous fossil fuels. Hence, definitive resolution of the question of whether new transportation problems exist is dependent upon clear characterization of the synfuels chemical composition. Hydrogen and methanol represent unique cases since these materials are already in commercial production. The major transportation problem identified with fuel economics based on these materials is related to bulk use. To date, shipment volumes have been relatively small and, in the case of hydrogen, can be accommodated with costly, more specialized packaging. Scale-up for major energy use may introduce a new set of transportation problems.
Research on the application of VRP theory in logistics transportation
Directory of Open Access Journals (Sweden)
Zhu Ruiqi
2017-01-01
Full Text Available Logistics transportation problem is a hot issue in today’s research, with the diversification of transport vehicles, the complexity of the transportation network, the choice of logistics transportation route is a NP problem in combinatorial optimization. The paper discusses the relevant knowledge of VRP and physical distribution routing, such as the relationship between them, how to describe the distribution problem with VRP, how to build up mathematical model and so on and meanwhile, points out the direction of research.
DEFF Research Database (Denmark)
Liu, Zhou
Flow and sediment transport are important in relation to several engineering topics, e.g. erosion around structures, backfilling of dredged channels and nearshore morphological change. The purpose of the present book is to describe both the basic hydrodynamics and the basic sediment transport...... mechanics. Chapter 1 deals with fundamentals in fluid mechanics with emphasis on bed shear stress by currents, while chapter 3 discusses wave boundary layer theory. They are both written with a view to sediment transport. Sediment transport in rivers, cross-shore and longshore are dealt with in chapters 2......, 4 and 5, respectively. It is not the intention of the book to give a broad review of the literature on this very wide topic. The book tries to pick up information which is of engineering importance. An obstacle to the study of sedimentation is the scale effect in model tests. Whenever small...
Shah, D. B.
1984-01-01
Describes a course designed to achieve a balance between exposing students to (1) advanced topics in transport phenomena, pointing out similarities and differences between three transfer processes and (2) common methods of solving differential equations. (JN)
Millennium Challenge Corporation — The evaluation examines impacts of the Transportation Project in three ways. First, we calculate economic rates of return associated with reduced user costs for each...
Transportation Network Topologies
Holmes, Bruce J.; Scott, John
2004-01-01
A discomforting reality has materialized on the transportation scene: our existing air and ground infrastructures will not scale to meet our nation's 21st century demands and expectations for mobility, commerce, safety, and security. The consequence of inaction is diminished quality of life and economic opportunity in the 21st century. Clearly, new thinking is required for transportation that can scale to meet to the realities of a networked, knowledge-based economy in which the value of time is a new coin of the realm. This paper proposes a framework, or topology, for thinking about the problem of scalability of the system of networks that comprise the aviation system. This framework highlights the role of integrated communication-navigation-surveillance systems in enabling scalability of future air transportation networks. Scalability, in this vein, is a goal of the recently formed Joint Planning and Development Office for the Next Generation Air Transportation System. New foundations for 21st thinking about air transportation are underpinned by several technological developments in the traditional aircraft disciplines as well as in communication, navigation, surveillance and information systems. Complexity science and modern network theory give rise to one of the technological developments of importance. Scale-free (i.e., scalable) networks represent a promising concept space for modeling airspace system architectures, and for assessing network performance in terms of scalability, efficiency, robustness, resilience, and other metrics. The paper offers an air transportation system topology as framework for transportation system innovation. Successful outcomes of innovation in air transportation could lay the foundations for new paradigms for aircraft and their operating capabilities, air transportation system architectures, and airspace architectures and procedural concepts. The topology proposed considers air transportation as a system of networks, within which
C. Cerruti / FI
2006-01-01
A large number of pallet-crates (panières grillagées), which are used for transporting equipment and for removals, have been dispatched to various locations around the CERN site. We kindly request all users who may have such crates in their possession and no longer need them to make the necessary arrangements (EDH request to the Transport Group) to return them to Building 133, as we currently have no more in stock. Claude CERRUTI / FI-PI
Routing and scheduling problems
DEFF Research Database (Denmark)
Reinhardt, Line Blander
be that the objects routed have an availability time window and a delivery time window or that locations on the path have a service time window. When routing moving transportation objects such as vehicles and vessels schedules are made in connection with the routing. Such schedules represent the time for the presence...... to a destination on a predefined network, the routing and scheduling of vessels in a liner shipping network given a demand forecast to be covered, the routing of manpower and vehicles transporting disabled passengers in an airport and the vehicle routing with time windows where one version studied includes edge...... of a connection between two locations. This could be an urban bus schedule where busses are routed and this routing creates a bus schedule which the passengers between locations use. In this thesis various routing and scheduling problems will be presented. The topics covered will be routing from an origin...
Baronti, Marco; van der Putten, Robertus; Venturi, Irene
2016-01-01
This book, intended as a practical working guide for students in Engineering, Mathematics, Physics, or any other field where rigorous calculus is needed, includes 450 exercises. Each chapter starts with a summary of the main definitions and results, which is followed by a selection of solved exercises accompanied by brief, illustrative comments. A selection of problems with indicated solutions rounds out each chapter. A final chapter explores problems that are not designed with a single issue in mind but instead call for the combination of a variety of techniques, rounding out the book’s coverage. Though the book’s primary focus is on functions of one real variable, basic ordinary differential equations (separation of variables, linear first order and constant coefficients ODEs) are also discussed. The material is taken from actual written tests that have been delivered at the Engineering School of the University of Genoa. Literally thousands of students have worked on these problems, ensuring their real-...
... have cold or flu symptoms?YesNoDo you have tooth pain on the same side as the ear pain ... or 2 days, see your doctor.Start OverDiagnosisA tooth problem can radiate pain to the ear on the same side.Self ...
Safety in the Transport Sector
DEFF Research Database (Denmark)
Jørgensen, Kirsten
2012-01-01
In EU the transport sector has an incident rate of accidents at work at 40 pr 1000 employees. The Danish insurance company CODAN has insured a big part of this sector concerning transport of gods on shore. The purpose of the project is to document the safety problems in the sector and to develop......, unloading or work with transport equipment carried out at many different work places. The main safety problems are falls, heavy lifting, poor ergonomic working conditions, hits or collisions with gods, equipments or falling objects, the traffic risk situations, work with animals and finally the risk...... of violence and robbery. The transport branch is characterized by many small enterprises of which 97% of the enterprises in Denmark have less than 50 employees and 89% have less than 10 employees. The intervention in 5 small enterprises show a relevant focus on both the risk for occupational accidents...
DEFF Research Database (Denmark)
Janstrup, Kira; Rose, Trine Høyer; Andersen, Kent Høj
The main purpose of this project is to use integer programming to create a model that minimizes the costs for container transportation by ship. To make the model as realistic as possible it will be based on information from a large shipping company about the vessel layout and container types....... In addition to our project two other projects are made where an optimal solution to the container stowage problem also is tried to be found, but by using constraint programming and local search instead respectively. We will therefore in the end compare these three methods and the achieved results on fastness...
DEFF Research Database (Denmark)
Janstrup, Kira
2010-01-01
The main purpose of this project is to use integer programming to create a model that minimizes the costs for container transportation by ship. To make the model as realistic as possible it will be based on information from a large shipping company about the vessel layout and container types....... In addition to our project two other projects are made where an optimal solution to the container stowage problem also is tried to be found, but by using constraint programming and local search instead respectively. We will therefore in the end compare these three methods and the achieved results on fastness...
Institute of Scientific and Technical Information of China (English)
Gueorgui A.Yurgenson
2004-01-01
Geotechgjgensis is mineralogical geochemical transformation of minerals, rocks, and ores as consequence of impact on them in the process of performing geological-exploration and irrigation works, extracting and processing mineral resources, constructing transport, civil and military objects. These effects lead to discontinuity and moving different scale fragments of upper part of lithospere and conjugate hydro-and biosphere zones. Discontinuity predttermines the disturbance of matural systems dynamic equilibriu and acceleration ofmftter transformation and migration processes. The final aim of studying geotechnogenesis minseralogy and geochemistry is the establishment of scientific foundations for developing ecological safety measures including also utilization fo geotechnogene deposits.
Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah@Rozita
2016-11-01
Two new methods adopted from methods commonly used in the field of transportation and logistics are proposed to solve a specific issue of investment allocation problem. Vehicle routing problem and capacitated vehicle routing methods are applied to optimize the fund allocation of a portfolio of investment assets. This is done by determining the sequence of the assets. As a result, total investment risk is minimized by this sequence.
Forms of Approximate Radiation Transport
Brunner, G
2002-01-01
Photon radiation transport is described by the Boltzmann equation. Because this equation is difficult to solve, many different approximate forms have been implemented in computer codes. Several of the most common approximations are reviewed, and test problems illustrate the characteristics of each of the approximations. This document is designed as a tutorial so that code users can make an educated choice about which form of approximate radiation transport to use for their particular simulation.
Institute of Scientific and Technical Information of China (English)
贾勤波
2012-01-01
Upon the basis of our rich experience of many years in the transportation of large-type equipments, many difficulties arising in the course of transporting TBM, which may restrain the transportation of TBM on highways, are systematically summed up in the paper,with greater stress placed on the handling of extra-large parts of TBM, such as the cutting head, the main beam, cutting head supports and so on. The retraining factors include the width of the road,height limits, requirements in traffic loads, continuous slope uphill or downhill, taking a turn, etc. All those above-mentioned difficulties are technically solved, with some useful methods or suggestions put forward. The results of our practice may provide good references for peers so as to facilitate the transportation of extra-large equipments.%根据多年大件运输的经验，针对TBM运输过程中刀盘、主轴承、主梁及刀盘支撑等超大超限件，系统地总结了可能制约TBM公路运输的诸多难题，例如路面宽度、高度限制，通行荷载要求，连续大坡度上下坡及转弯困扰等，从技术角度提出相应解决办法和措施，可供同行参考，以期顺利实施大件运输。
World Bank
2013-01-01
In many Russian cities, these growing demands for mobility are not adequately met by the existing urban transport infrastructure and services. Most municipalities have had difficulties in planning and managing the development of their urban transport systems in a coherent manner, which is a precondition for successful resolution of the existing transport problems. In addition, there is a n...
1987-06-01
and f. Let us consider the problem of finding the minimal constant C. We are thus interested in 2~ IVA u dx (1.24) C = sup . u2u (0 (F =0 (u dx"<u(O...fournir des bornes superieures ou inferieures, C.R. Acad. Sci., Paris 235, 995-997. .V Prodi, G. (1962]: Theoremi di tipo locale per il sistema de Navier
Directory of Open Access Journals (Sweden)
Yaping Hu
2015-01-01
the nonsmooth convex optimization problem. First, by using Moreau-Yosida regularization, we convert the original objective function to a continuously differentiable function; then we use approximate function and gradient values of the Moreau-Yosida regularization to substitute the corresponding exact values in the algorithm. The global convergence is proved under suitable assumptions. Numerical experiments are presented to show the effectiveness of this algorithm.
Ho, Clifford K
2006-01-01
This book presents a compilation of state-of-the art studies on gas and vapor transport processes in porous and fractured media. A broad set of models and processes are presented, including advection/diffusion, the Dusty Gas Model, enhanced vapor diffusion, phase change, coupled processes, solid/vapor sorption, and vapor-pressure lowering. Numerous applications are also presented that illustrate these processes and models in current problems facing the scientific community. This book fills a gap in the general area of transport in porous and fractured media; an area that has historically been dominated by studies of liquid-phase flow and transport. This book identifies gas and vapor transport processes that may be important or dominant in various applications, and it exploits recent advances in computational modeling and experimental methods to present studies that distinguish the relative importance of various mechanisms of transport in complex media.
AUTOMATION OF CONVEYOR BELT TRANSPORT
Directory of Open Access Journals (Sweden)
Nenad Marinović
1990-12-01
Full Text Available Belt conveyor transport, although one of the most economical mining transport system, introduce many problems to mantain the continuity of the operation. Every stop causes economical loses. Optimal operation require correct tension of the belt, correct belt position and velocity and faultless rolls, which are together input conditions for automation. Detection and position selection of the faults are essential for safety to eliminate fire hazard and for efficient maintenance. Detection and location of idler roll faults are still open problem and up to now not solved successfully (the paper is published in Croatian.
DEFF Research Database (Denmark)
Bill, Jan; Roesdahl, Else
2007-01-01
On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport; on the related technologies and their developments......On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport; on the related technologies and their developments...
Inverse methods for radiation transport
Bledsoe, Keith C.
Implicit optimization methods for solving the inverse transport problems of interface location identification, source isotope weight fraction identification, shield material identification, and material mass density identification are explored. Among these optimization methods are the Schwinger inverse method, Levenberg-Marquardt method, and evolutionary algorithms. Inverse problems are studied in one-dimensional spherical and two-dimensional cylindrical geometries. The scalar fluxes of unscattered gamma-ray lines, leakages of neutron-induced gamma-ray lines, and/or neutron multiplication in the system are assumed to be measured. Each optimization method is studied on numerical test problems in which the measured data is simulated using the same deterministic transport code used in the optimization process (assuming perfectly consistent measurements) and using a Monte Carlo code (assuming less-consistent, more realistic measurements). The Schwinger inverse method and Levenberg-Marquardt methods are found to be successful for problems with relatively few (i.e. 4 or fewer) unknown parameters, with the former being the best for unknown isotope problems and the latter being more adept at interface location, unknown material mass density, and mixed parameter problems. A study of a variety of evolutionary algorithms indicates that the differential evolution method is the best for inverse transport problems, and outperforms the Levenberg-Marquardt method on problems with large numbers of unknowns. An algorithm created by combining different variants of the differential evolution method is shown to be highly successful on spherical problems with unscattered gamma-ray lines, while a basic differential evolution approach is more useful for problems with scattering and in cylindrical geometries. A hybrid differential evolution/Levenberg-Marquardt algorithm also was found to show promise for fast and robust solution of inverse problems.
Eckmann, B
2008-01-01
At the close of the 1980s, the independent contributions of Yann Brenier, Mike Cullen and John Mather launched a revolution in the venerable field of optimal transport founded by G Monge in the 18th century, which has made breathtaking forays into various other domains of mathematics ever since. The author presents a broad overview of this area.
Institute of Scientific and Technical Information of China (English)
R.E. Waltz
2007-01-01
@@ There has been remarkable progress during the past decade in understanding and modeling turbulent transport in tokamaks. With some exceptions the progress is derived from the huge increases in computational power and the ability to simulate tokamak turbulence with ever more fundamental and physically realistic dynamical equations, e.g.
DEFF Research Database (Denmark)
Ronsse, Frederik; Jørgensen, Henning; Schüßler, Ingmar
2014-01-01
Worldwide, the use of transport fuel derived from biomass increased four-fold between 2003 and 2012. Mainly based on food resources, these conventional biofuels did not achieve the expected emission savings and contributed to higher prices for food commod - ities, especially maize and oilseeds...
Cheverry, Christophe
2017-02-01
This article is concerned with the relativistic Vlasov equation, for collisionless axisymmetric plasmas immersed in a strong magnetic field, like in tokamaks. It provides a consistent kinetic treatment of the microscopic particle phase-space dynamics. It shows that the turbulent transport can be completely described through WKB expansions.
Drenth, K.F.
1999-01-01
The transport system comprises at least one road surface (2) and at least one vehicle (4) on wheels (6). The road surface (2) has a substantially bowl-shaped cross section and the vehicle (4) is designed so that the wheels (6) run directly on the road surface (2) while the road surface (2) acts as a
Surety applications in transportation
Energy Technology Data Exchange (ETDEWEB)
Matalucci, R.V.; Miyoshi, D.S.
1998-01-01
Infrastructure surety can make a valuable contribution to the transportation engineering industry. The lessons learned at Sandia National Laboratories in developing surety principles and technologies for the nuclear weapons complex and the nuclear power industry hold direct applications to the safety, security, and reliability of the critical infrastructure. This presentation introduces the concepts of infrastructure surety, including identification of the normal, abnormal, and malevolent threats to the transportation infrastructure. National problems are identified and examples of failures and successes in response to environmental loads and other structural and systemic vulnerabilities are presented. The infrastructure surety principles developed at Sandia National Laboratories are described. Currently available technologies including (a) three-dimensional computer-assisted drawing packages interactively combined with virtual reality systems, (b) the complex calculational and computational modeling and code-coupling capabilities associated with the new generation of supercomputers, and (c) risk-management methodologies with application to solving the national problems associated with threats to the critical transportation infrastructure are discussed.
Institute of Scientific and Technical Information of China (English)
李英俊; 陈志祥
2012-01-01
针对生产与运输两个过程的联合决策,通过分析一类生产-运输批量优化问题,建立的混合0-1整数规划模型整合了多产品多阶段能力约束批量生产和产品运输.其中运输成本由运输工具使用数量决定,当企业内部运输能力不能满足运输需求时可将运输外包,但需支付更高的运输成本.根据此问题的特点,构造改进蚁群算法求解,令其信息素和启发信息都存在0和1两种状态下的不同取值,通过转移概率确定0-1生产准备矩阵,进一步得到生产矩阵和运输计划.仿真实验结果表明在生产批量决策的同时考虑运输,可以减少运输成本,令总费用最小,通过将实验结果与其他优化算法比较,所构造的蚁群算法寻优概率是100％,平均进化10代,平均耗时小于l s,稳定性和求解效率均高于其他算法,是求解这类问题一种有效与适用的算法.%Aiming at the implementation of joint decision of production and transportation, production-transportation lot-sizing problem is discussed, which is a multi-item-and-multi-period capacitated lot-sizing and transportation problem. This problem is then formulated as a 0-1 mixed integer programming problem. In this model, the transportation cost is decided by the numbers of containers. However, if demands ex-ceed the transportation capacity, it can be outsourced, but with higher freight rate. After analyzing the properties of the model, an improved ant colony algorithm (ANT) is proposed. By this algorithm, different value of pheromone and heuristic information is set as 0-state or 1 -state. Then, the 0-1 setup matrix, production matrix, and transportation plan can be obtained accordingly. A numerical example shows that integrated production and transportation can effectively reduce the procurement cost and further reduce the total cost. Comparison with other methods shows that the searching optimization probability of the proposed ANT is 100% , the average
Transportation and the marketplace
Energy Technology Data Exchange (ETDEWEB)
Soeoet, S. [Univ. of Illinois, Chicago, IL (United States)
1996-12-31
In the Chicago six-county metropolitan area, the number of registered vehicles grew by over 800,000 vehicles in the 1980s; by contrast the population increased by just over 150,000 during the same time. This ratio of growth in automobiles versus population (five to one) has contributed to overall increases in travel, congestion and energy use. The objective of this report is to examine how and why this has occurred and what we might expect in the near future to address the growing traffic problems and energy use. Specifically, the focus is on energy use by household vehicles and other forms of passenger travel. Data on population trends, gasoline prices, commuting and transit use, and transportation energy use are presented and interpreted. Intelligent transportation systems and decreased single vehicle emissions are briefly described as methods to decrease congestion and pollution. 9 figs., 2 tabs.
Institute of Scientific and Technical Information of China (English)
张永宾; 陈培友
2012-01-01
建立多个煤炭运输配送中心,将煤炭运输的第三方物流以物流联盟的形式组织在一起,根据客户的需求量和煤配中心的存储量和车辆等信息,建立物流联盟的煤炭车辆调度模型,并采用免疫克隆选择算法进行求解,实验分析表明模型和算法是有效的.%This paper proposes a vehicle dispatching model for coal distribution and transportation in logistics alliances formed through third party logistics. According to it, multiple coal distribution and transportation centers are built and information such as customer demand volume, the storage and fleet capacity of the centers is considered in the formulation of the model. Finally immune clonal selection algorithm is used to solve the model and an experimental analysis proves the validity of the model and the algorithm.
Stability and Transport in Magnetic Confinement Systems
Weiland, Jan
2012-01-01
Stability and Transport in Magnetic Confinement Systems provides an advanced introduction to the fields of stability and transport in tokamaks. It serves as a reference for researchers with its highly-detailed theoretical background, and contains new results in the areas of analytical nonlinear theory of transport using kinetic theory and fluid closure. The use of fluid descriptions for advanced stability and transport problems provide the reader with a better understanding of this topic. In addition, the areas of nonlinear kinetic theory and fluid closure gives the researcher the basic knowledge of a highly relevant area to the present development of transport physics.
Integrated transport and renewable energy systems
DEFF Research Database (Denmark)
Mathiesen, Brian Vad; Lund, Henrik; Nørgaard, P.
2008-01-01
No single technology can solve the problem of ever increasing CO2 emissions from transport. Here, a coherent effort to integrate transport into energyplanning is proposed, using multiple means promoting sustainable transport. It is concluded that a 100 per cent renewable energy transport system...... is possible but is connected to significant challenges in the path towards it. Biomass is a limited resource and it is important to avoid effecting the production of food. The integration of the transport with the energy system is crucial as is a multi-pronged strategy. Short term solutions have to consider...
Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N
1998-05-01
In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.
Decision Support for Planning of Multimodal Transportation with Multiple Objectives
DEFF Research Database (Denmark)
Petersen, Hanne Løhmann
This thesis treats two different planning problems from the transportation industry; one from freight transport and one from passenger transport. Each problem emerges as a combination of problems that are already known from the operational research literature, and introduces a new view of well...... phase, and considers passenger inconvenience at transfers at the same time. The paper presents a mathematical model of the problem, and the implementation of a large neighbourhood search solution procedure. The problem is solved for a real-life based problem instance, containing eight bus lines...
Fundamental aspects of plasma chemical physics transport
Capitelli, Mario; Laricchiuta, Annarita
2013-01-01
Fundamental Aspects of Plasma Chemical Physics: Tranpsort develops basic and advanced concepts of plasma transport to the modern treatment of the Chapman-Enskog method for the solution of the Boltzmann transport equation. The book invites the reader to consider actual problems of the transport of thermal plasmas with particular attention to the derivation of diffusion- and viscosity-type transport cross sections, stressing the role of resonant charge-exchange processes in affecting the diffusion-type collision calculation of viscosity-type collision integrals. A wide range of topics is then discussed including (1) the effect of non-equilibrium vibrational distributions on the transport of vibrational energy, (2) the role of electronically excited states in the transport properties of thermal plasmas, (3) the dependence of transport properties on the multitude of Saha equations for multi-temperature plasmas, and (4) the effect of the magnetic field on transport properties. Throughout the book, worked examples ...
Directory of Open Access Journals (Sweden)
Xin-He Miao
2012-01-01
Full Text Available This paper investigates the Lipschitz continuity of the solution mapping of symmetric cone (linear or nonlinear complementarity problems (SCLCP or SCCP, resp. over Euclidean Jordan algebras. We show that if the transformation has uniform Cartesian P-property, then the solution mapping of the SCCP is Lipschitz continuous. Moreover, we establish that the monotonicity of mapping and the Lipschitz continuity of solutions of the SCLCP imply ultra P-property, which is a concept recently developed for linear transformations on Euclidean Jordan algebra. For a Lyapunov transformation, we prove that the strong monotonicity property, the ultra P-property, the Cartesian P-property, and the Lipschitz continuity of the solutions are all equivalent to each other.
A Course on the Physics of Urban and Environmental Problems
Marston, Edwin H.
1970-01-01
Presents a physics course for social scientists. Physics problems are presented within the context of several urban and environmental case studies. The problems considered include transportation, air pollution, thermal pollution of water, and scarcity of resources. (LS)
Optimal transportation networks models and theory
Bernot, Marc; Morel, Jean-Michel
2009-01-01
The transportation problem can be formalized as the problem of finding the optimal way to transport a given measure into another with the same mass. In contrast to the Monge-Kantorovitch problem, recent approaches model the branched structure of such supply networks as minima of an energy functional whose essential feature is to favour wide roads. Such a branched structure is observable in ground transportation networks, in draining and irrigation systems, in electrical power supply systems and in natural counterparts such as blood vessels or the branches of trees. These lectures provide mathematical proof of several existence, structure and regularity properties empirically observed in transportation networks. The link with previous discrete physical models of irrigation and erosion models in geomorphology and with discrete telecommunication and transportation models is discussed. It will be mathematically proven that the majority fit in the simple model sketched in this volume.
Multi-Agent Transport Planning
Zutt, J.; Witteveen, C.
2005-01-01
We discuss a distributed transport planning problem with competitive autonomous actors that carry out time-constrained pick-up delivery orders from customers. The agents have to find conflict-free routes to execute a series of orders they have accepted. Hatzack and Nebel [2] were the first to sugges
Transporter Classification Database (TCDB)
U.S. Department of Health & Human Services — The Transporter Classification Database details a comprehensive classification system for membrane transport proteins known as the Transporter Classification (TC)...
TRENDS FOR PERSPECTIVE DEVELOPMENT OF AGRICULTURAL TRANSPORT
Directory of Open Access Journals (Sweden)
Uspensky I. A.
2014-09-01
Full Text Available In this article we present a study of current problems connected with the formation of a park of automobiles, tractors and aggregates for transportation of agricultural products and ways of their solution
AMRH and High Energy Reinicke Problem
Energy Technology Data Exchange (ETDEWEB)
Shestakov, A I; Greenough, J A
2001-05-14
The authors describe AMRH results on a version of the Reinicke problem specified by the V and V group of LLNL's A-Div. The simulation models a point explosion with heat conduction. The problem specification requires that the heat conduction be replaced with diffusive radiation transport. The matter and radiation energy densities are tightly coupled.
Directory of Open Access Journals (Sweden)
GERMÁN CORREA DÍAZ
2010-04-01
Full Text Available Los servicios de transporte público operan de manera sistémica, así como lo hace todo aquello que se mueve en la ciudad. Toda intervención que se haga respecto a uno de los modos que la gente usa para movilizarse afecta inevitablemente al resto. Desde que en Santiago entró en operaciones un Sistema Integrado de Transporte Público, como es el Transantiago, pasó la hora de seguir haciendo inversiones en proyectos aislados relativos a la movilidad urbana. Es hora más bien de racionalizar sistémicamen-te dichas inversiones y evaluarlas en consecuencia. Los grandes proyectos de transporte urbano deben dejar de ser la idea emblemática de algún gobernante. En cambio, deben pasar a ser evaluados y decididos desde una visión sistémica y organizada sobre el territorio, el desarrollo urbano y la movilidad, estableciendo mejor el óptimo social de las inversiones públicas y privadas. De esta manera se servirá mejor al interés común de los habitantes de la ciudad.Public transport services operate in a systemic manner and so does everything that moves in the city. Interventions in one of the modes people use to move around affect inevitably the rest. Today, when a new Public Transport Integrated System as Transantiago is operating, whatever its problems, it makes no longer sense to keep making investments in isolated transport projects. It is time to rationalize such investments from a systemic point of view, evaluating them likewise. Large urban transport projects should no longer be the emblematic idea of some individual Government authority. Instead, they should be evaluated and decided upon from the standpoint of a systemic and organized vision of the territory, urban development and mobility, thus better establishing a social optimum of public and private investments. In this way the real common interest of the city dwellers would be better served.
Where does slow axonal transport go?
Terada, Sumio
2003-12-01
Axonal transport is the specialized and well-developed intracellular transport system for regulated and/or long-distance transport based on generalized cellular machineries. Among them, slow axonal transport conveys cytoplasmic proteins. The motor molecule, the nature of transporting complex and the transport regulation mechanism for slow transport are still unclarified. There has been a dispute regarding the nature of transporting complex of cytoskeletal proteins, polymer-sliding hypothesis versus subunit-transport theory. Recent data supporting the hypothesis of polymer sliding in cultured neurons only reconfirm the previously reported structure and this inference suffers from the lack of ultrastructural evidence and the direct relevance to the physiological slow transport phenomenon in vivo. Observation of the moving cytoskeletal proteins in vivo using transgenic mice or squid giant axons revealed that subunits do move in a microtubule-dependent manner, strongly indicating the involvement of microtubule-based motor kinesin. If the slow transport rate reflects the intermittent fast transport dependent on kinesin motor, we have to investigate the molecular constituents of the transporting complex in more detail and evaluate why the motor and cargo interaction is so unstable. This kind of weak and fluctuating interaction between various molecular pairs could not be detected by conventional techniques, thus necessitating the establishment of a new experimental system before approaching the molecular regulation problem.
The individual car transportation and its aspects
Jiří Alina
2009-01-01
Automobile transport is integral part of everyday modern live. On the other hand all the time bigger quantity of cars on roads and motorways slows down the transport speed, road are overloaded, congested, thereby human mobility holds down. Last but not least heavy traffic bears much bad influence above all for environment and landscape. On that ground it's needed to analyze individual car transport, its aspects, usage and problems. Consequences, which have been found from research, are in man...
Institute of Scientific and Technical Information of China (English)
2013-01-01
The drug delivery under surveillance and investigation by temptation are the special and effective investigative measures which are most frequently used in judicial practice. The former which has been validated by the new Criminal Procedure Law is used to solve the cases of drug trafcking and transportation. According to whether the drugs are substituted or not, the drug delivery can be categorized into real drug delivery under surveillance and drug substitute delivery under surveillance. The former is the commission of drug trafcking while he latter is attempted drug trafcking, which should be handled differently. The collection of evidences through the investigation by temptation belongs to the category of illegal evidences, which should be eliminated. But the investigation by providing an opportunity to tempt the crime is an effective and correct measure in investigating such cases. Trafcking drug for making profits is not the necessary key element of drug trafcking. The symbol of the commission of the drug trafcking is the delivery of drug. According to the purposes of drug transportation, it can be categorized into three:drug transportation for smuggling or sale, for transfer and for taking, which are three different crimes.% 控制下交付和诱惑侦查作为司法实践中侦破贩卖、运输毒品案件最常用且有效的特殊侦查措施，前者已经得到我国新刑事诉讼法认可，对于利用其侦破的毒品买卖案件，按照毒品是否被侦查机关替换，可以区分为原物的控制下交付和替代物的控制下交付，原物的控制下交付可以构成贩卖毒品罪的既遂，以无毒物替代毒品则只能构成贩卖毒品罪的未遂，而对于利用后者侦破的毒品案件则需要区别对待，利用犯意型诱惑侦查收集的证据属于非法证据排除的范畴，而机会提供型诱惑侦查则可以作为侦破毒品案件的有效、正当措施。“以牟利为目的”
Institute of Scientific and Technical Information of China (English)
李玲悦; 叶春明
2011-01-01
"11·15" big fire in Shanghai caused huge human and economic losses. If the fire engines can arrive more quickly without the poor transportation system, the results maybe different. How to transform the changed routing transportation into the vehicle routing problem (VRP), and solving the applicable driving routing, it has great practical significance and economic value to the urban emergency or the logistics enterprise. Particle Swarm Optimization (PSO) is used in this paper to solve the VRP. This paper proposes a novel particle presentation for the VRP, establishes an algorithm of PSO for this kind of problem, and analysis an instance when using the algorithm.%"11·15"的上海特大火灾造成了巨大的人员与经济的损失.如果消防车辆能克服交通系统的不畅而更及时赶到的话,或许结果会不一样.因此如何将路径变化运输转化为车辆路径问题(Vehicle Routing Problem,VRP),并求解恰当的行车路径,对于城市应急以及日常的物流配送企业都有着重大的现实意义及经济价值.文中将微粒群算法(Particle Swarm Optimization,PSO)应用于车辆路径问题,建立车辆路径问题的微粒群算法的教学描述,编译出此问题的程序,并对一个实例进行仿真分析.
The Driving Factors of Passenger Transport
De Jong, G.C.; Van de Riet, O.A.W.T.
2008-01-01
Over the past few decades passenger transport has grown rapidly resulting in a multitude of problems including severe traffic congestion and pollution. It is expected that passenger transport will continue to grow rapidly in the future, which will worsen the situation even further. The traditional
RFID Application in Global Container Transportation
Institute of Scientific and Technical Information of China (English)
2008-01-01
This article introduces the problems of container transportation, then analyzes the RFID application in container transportation management. It gives some suggestions to improve the trade actuality, ensure the trade security and promote the efficiency of logistics. Although there are some limitations to generalize this technology, the cheap standardized RFID system will serve global ports with the development of the information technology.
2001-01-01
The Space Shuttle Atlantis, STS-110 mission, deployed this railcar, called the Mobile Transporter, and an initial 43-foot section of track, the S0 (S-zero) truss, preparing the International Space Station (ISS) for future spacewalks. The first railroad in space, the Mobile Transporter will allow the Station's robotic arm to travel up and down the finished truss for future assembly and maintenance. The 27,000-pound S0 truss is the first of 9 segments that will make up the Station's external framework that will eventually stretch 356 feet (109 meters), or approximately the length of a football field. The completed truss structure will hold solar arrays and radiators to provide power and cooling for additional international research laboratories from Japan and Europe that will be attached to the Station. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002. STS-110's Extravehicular Activity (EVA) marked the first use of the Station's robotic arm to maneuver spacewalkers around the Station.
Institute of Scientific and Technical Information of China (English)
G. Shanmugam
2015-01-01
The synonymous use of the general term“landslide”, with a built-in reference to a sliding motion, for all varieties of mass-transport deposits (MTD), which include slides, slumps, debrites, topples, creeps, debris avalanches etc. in subaerial, sublacustrine, sub-marine, and extraterrestrial environments has created a multitude of conceptual and nomen-clatural problems. In addition, concepts of triggers and long-runout mechanisms of mass movements are loosely applied without rigor. These problems have enormous implications for studies in process sedimentology, sequence stratigraphy, palaeogeography, petroleum geol-ogy, and engineering geology. Therefore, the objective of this critical review is to identify key problems and to provide conceptual clarity and possible solutions. Speciifc issues are the fol-lowing:(1) According to“limit equilibrium analyses”in soil mechanics, sediment failure with a sliding motion is initiated over a shear surface when the factor of safety for slope stability (F) is less than 1. However, the term landslide is not meaningful for debris lfows with a lfowing mo-tion. (2) Sliding motion can be measured in oriented core and outcrop, but such measurement is not practical on seismic proifles or radar images. (3) Although 79 MTD types exist in the geological and engineering literature, only slides, slumps, and debrites are viable depositional facies for interpreting ancient stratigraphic records. (4) The use of the term landslide for high-velocity debris avalanches is inappropriate because velocities of mass-transport processes cannot be determined in the rock record. (5) Of the 21 potential triggering mechanisms of sediment failures, frequent short-term events that last for only a few minutes to several hours or days (e.g., earthquakes, meteorite impacts, tsunamis, tropical cyclones, etc.) are more relevant in controlling deposition of deep-water sands than sporadic long-term events that last for thousands to millions of years (e
Many men have sexual problems. They become more common as men age. Problems can include Erectile dysfunction Reduced or lost interest in sex ... problems may also be factors. Occasional problems with sexual function are common. If problems last more than ...
Russian federal program on transportation development
Inozemtsev, Vladimir G.
2002-04-01
The transportation infrastructure of the Russia is a vast network of automotive ways, railroads, waterways, pipelines and supporting transportation infrastructures. All kinds of modern transportation use high-level technology. It is necessary to apply last scientific achievements for transportation safety and service feature improvements. Scientific and engineering developments of the Russian transportation have been decreased during the last ten years due to economical problems in our country. Russian government, Federal Ministries, and scientific organizations understand inadmissibility of the transportation lag. Therefore, the Federal Program named 'Updating of the Russian transportation system' has been accepted. To provide a modern stage of the transportation system development based on last science achievement it will spend many scientific and industrial resources. Therefore, it is difficult to overestimate development and using of photonic systems for all kinds of the transportation. The First Conference on Photonics for Transportation (1999) was devoted to the state of the art of photonic system application for on ground and aerospace vehicles, navigation, inspection, observation and monitoring equipments for transportation, and novel photonic elements. After that novel approaches on photonics and its applications for transportation have been in Russia.
METHODOLOGY OF PUBLIC TRANSPORT SERVICE QUALITY
Directory of Open Access Journals (Sweden)
Olga Saginova
2016-01-01
Full Text Available The paper analysis approaches to establishing a system of indicators for public transport service quality in Moscow using customers’ expectations and current characteristics of transportation service. The topic is relevant due to using a new model of transportation service in Moscow involving private transportation companies, which requires establishing uniform service quality standards. Object of research. Public transport service quality Objectives. Using modern marketing concepts and customer oriented approach to service quality assessment develop a comprehensive methodology of managing public transport service quality. Methods. The paper uses Russian and foreign research publications in service quality assessment as well as results of research project by a team of scientists from Plekhanov Russian University of Economics. Methods of comparative research, netnography and marketing research (focus groups and survey methods were used. Results. After analyzing the public transportation problems in the megapolis, current transportation policy and survey of foreign experience, transportation service standards of EC, USA and CIS, a structure and method of establishing a self-regulated system of improving transportation service quality was developed basing on a marketing approach. Conclusions/relevance. The developed methodology of establishing a self-regulating system of improving the transportation service quality is based on a marketing approach, and the structure of a system of indicators to assess the service quality, basic indicators of expected and perceived quality of transportation service.
Surveillance systems for intermodal transportation
Jakovlev, Sergej; Voznak, Miroslav; Andziulis, Arunas
2015-05-01
Intermodal container monitoring is considered a major security issue in many major logistic companies and countries worldwide. Current representation of the problem, we face today, originated in 2002, right after the 9/11 attacks. Then, a new worldwide Container Security Initiative (CSI, 2002) was considered that shaped the perception of the transportation operations. Now more than 80 larger ports all over the world contribute to its further development and integration into everyday transportation operations and improve the regulations for the developing regions. Although, these new improvements allow us to feel safer and secure, constant management of transportation operations has become a very difficult problem for conventional data analysis methods and information systems. The paper deals with a proposal of a whole new concept for the improvement of the Containers Security Initiative (CSI) by virtually connecting safety, security processes and systems. A conceptual middleware approach with deployable intelligent agent modules is proposed to be used with possible scenarios and a testbed is used to test the solution. Middleware examples are visually programmed using National Instruments LabView software packages and Wireless sensor network hardware modules. An experimental software is used to evaluate he solution. This research is a contribution to the intermodal transportation and is intended to be used as a means or the development of intelligent transport systems.
Synchronizing production and air transportation scheduling using mathematical programming models
Zandieh, M.; Molla-Alizadeh-Zavardehi, S.
2009-08-01
Traditional scheduling problems assume that there are always infinitely many resources for delivering finished jobs to their destinations, and no time is needed for their transportation, so that finished products can be transported to customers without delay. So, for coordination of these two different activities in the implementation of a supply chain solution, we studied the problem of synchronizing production and air transportation scheduling using mathematical programming models. The overall problem is decomposed into two sub-problems, which consists of air transportation allocation problem and a single machine scheduling problem which they are considered together. We have taken into consideration different constraints and assumptions in our modeling such as special flights, delivery tardiness and no delivery tardiness. For these purposes, a variety of models have been proposed to minimize supply chain total cost which encompass transportation, makespan, delivery earliness tardiness and departure time earliness tardiness costs.
2010-04-01
... immediately follow the cover page of the prospectus or the pricing information section that immediately follows the cover page. Pricing information means price and price-related information that you may omit..., commonly referred to as the pro forma ratio. Instructions to paragraph 503(d): 1. Definitions....
Transport Processes in Dendritic Crystallization
Glicksman, M. E.
1984-01-01
Free dentritic growth refers to the unconstrained development of crystals within a supercooled melt, which is the classical dendrite problem. The development of theoretical understanding of dendritic growth and its experimental status is sketched showing that transport theory and interfacial thermodynamics (capillarity theory) are insufficient ingredients to develop a truly predictive model of dendrite formation. The convenient, but incorrect, notion of maximum velocity was used for many years to estimate the behavior of dendritic transformations until supplanted by modern dynamic stability theory. The proper combinations of transport theory and morphological stability seem to be able to predict the salient aspects of dendritic growth, especially in the neighborhood of the tip.
Transport of ions across peritoneal membrane.
Islam, Nurul; Bulla, Nisar A; Islam, Shahina
2004-12-15
The electrical conductance of ions across the peritoneal membrane of young buffalo (approximately 18-24 months old) has been recorded. Aqueous solutions of NaF, NaNO3, NaCl, Na2SO4, KF, KNO3, KCl, K2SO4, MgCl2, CaCl2, CrCl3, MnCl2, FeCl3, CoCl2, and CuCl2 were used. The conductance values have been found to increase with increase in concentration as well as with temperature (15 to 35 degrees C) in these cases. The slope of plots of specific conductance, kappa, versus concentration exhibits a decrease in its values at relatively higher concentrations compared to those in extremely dilute solutions. Also, such slopes keep on increasing with increase in temperature. In addition, the conductance also attains a maximum limiting value at higher concentrations in the said cases. This may be attributed to a progressive accumulation of ionic species within the membrane. The kappa values of electrolytes follow the sequence for the anions: SO4(2-)>Cl->NO3->F- while that for the cations: K+>Na+>Ca2+>Mn2+>Co2+>Cu2+>Mg2+>Cr3+>Fe3+. In addition, the diffusion of ions depends upon the charge on the membrane and its porosity. The membrane porosity in relation to the size of the hydrated species diffusing through the membrane appears to determine the above sequence. As the diffusional paths in the membrane become more difficult in aqueous solutions, the mobility of large hydrated ions gets impeded by the membrane framework and the interaction with the fixed charge groups on the membrane matrix. Consequently, the membrane pores reduce the conductance of small ions, which are much hydrated. An increase in conductance with increase in temperature may be due to the state of hydration, which implies that the energy of activation for the ionic transport across the membrane follows the sequence of crystallographic radii of ions accordingly. The Eyring's equation, kappa=(RT/Nh)exp[-DeltaH*/RT]exp[DeltaS*/R], has been found suitable for explaining the temperature dependence of conductance in
Vgi Based Urban Public Transport
Teymurian, F.; Alesheikh, A. A.; Alimohammadi, A.; Sadeghi-Niaraki, A.
2013-09-01
Recent advances in information technology have made geographic information system (GIS) a powerful and affordable tool for planning and decision making in various fields such as the public transportation. These technologies such as the social network (e.g. face-book, twitter), new technologies such as ubiquitous, mobile, Web 2.0, geo tagging and RFID can help to create better shapes and forms of the communication and geo-collaboration for public. By using these, user-generated content and spatial information can be easily and quickly produced and shared in a dynamic, interactive, multimedia and distributed environment. The concept of volunteered geographic information (VGI) has been introduced by the transaction from consultation to content interaction. VGI describes any type of content that has a geographic element and has been voluntarily collected. In other words, ordinary users; without a professional training, can participate in generating and using the spatial information. As a result, the gaps between the producers and users of GIS and spatial information, has been considerably reduced. Public transportation is one of the most important elements of the transportation system. Rapid growth of the cities has resulted in high increase of demand for the public transportation which created new challenges. Improvement of the desirability of public transportation can increase its efficiency, reduction of the environmental pollution (such as air and noise pollution), traffic problems, and fuel consumption. Hence, development of an urban public transportation system which is responsive to citizen's need and motivates them to use public transportation system is one of the most important objectives and issues that urban planners and designers are concerned about. One solution to achieve this, goal is to develop public transportation system by assistance from the system users. According to approach, users are considered as the valuable resources, because people who are
Hypersonic transports - Economics and environmental effects.
Petersen, R. H.; Waters, M. H.
1973-01-01
An economic analysis of hypersonic transports is presented to show projected operating costs (direct and indirect) and return on investment. Important assumptions are varied to determine the probable range of values for operating costs and return on investment. The environmental effects of hypersonic transports are discussed and compared to current supersonic transports. Estimates of sideline and flyover noise are made for a typical hypersonic transport, and the sonic boom problem is analyzed and discussed. Since the exhaust products from liquid hydrogen-fueled engines differ from those of kerosene-fueled aircraft, a qualitative assessment of air pollution effects is made.
Hypersonic transports: Economics and environmental effects
Petersen, R. H.; Waters, M. H.
1972-01-01
An economic analysis of hypersonic transports is presented to show projected operating costs (direct and indirect) and return on investment. Important assumptions are varied to determine the probable range of values for operating costs and return on investment. The environmental effects of hypersonic transports are discussed and compared to current supersonic transports. Estimates of sideline and fly-over noise are made for a typical hypersonic transport, and the sonic boom problem is analyzed and discussed. Since the exhaust products from liquid hydrogen-fueled engines differ from those of kerosene-fueled aircraft, a qualitative assessment of air pollution effects is made.
ASPECTS OF ARMY ROAD TRANSPORT MANAGEMENT
Directory of Open Access Journals (Sweden)
M. Japhet
2012-02-01
Full Text Available A basic tenet of transport management must be the efficient operation of all constituent parts of the transport function. In recognition of the growing urgency of the energy problem as a primary goal and of the need to maintain a high level of combat readiness at the same time, this article will look, albeit briefly, at the various aspects of road transport that need to be dealt with in the search for cost-effectiveness. Five major elements of road transport management are: Purchasing policy; maintenance; driver training and control; movements planning and procedures; and Research and Development.
Lob, W S
1990-09-01
Mobile robots perform fetch-and-carry tasks autonomously. An intelligent, sensor-equipped mobile robot does not require dedicated pathways or extensive facility modification. In the hospital, mobile robots can be used to carry specimens, pharmaceuticals, meals, etc. between supply centers, patient areas, and laboratories. The HelpMate (Transitions Research Corp.) mobile robot was developed specifically for hospital environments. To reach a desired destination, Help-Mate navigates with an on-board computer that continuously polls a suite of sensors, matches the sensor data against a pre-programmed map of the environment, and issues drive commands and path corrections. A sender operates the robot with a user-friendly menu that prompts for payload insertion and desired destination(s). Upon arrival at its selected destination, the robot prompts the recipient for a security code or physical key and awaits acknowledgement of payload removal. In the future, the integration of HelpMate with robot manipulators, test equipment, and central institutional information systems will open new applications in more localized areas and should help overcome difficulties in filling transport staff positions.
Schäfer, Harald
2013-01-01
Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and
Design of multimodal transport networks: A hierarchical approach
Van Nes, R.
2002-01-01
Multimodal transport, that is using two or more transport modes for a trip between which a transfer is necessary, seems an interesting approach to solving today's transportation problems with respect to the deteriorating accessibility of city centres, recurrent congestion, and environmental impact.
Design of multimodal transport networks: A hierarchical approach
Van Nes, R.
2002-01-01
Multimodal transport, that is using two or more transport modes for a trip between which a transfer is necessary, seems an interesting approach to solving today's transportation problems with respect to the deteriorating accessibility of city centres, recurrent congestion, and environmental impact.
Impact of inflow transport approximation on light water reactor analysis
Choi, Sooyoung; Smith, Kord; Lee, Hyun Chul; Lee, Deokjung
2015-10-01
The impact of the inflow transport approximation on light water reactor analysis is investigated, and it is verified that the inflow transport approximation significantly improves the accuracy of the transport and transport/diffusion solutions. A methodology for an inflow transport approximation is implemented in order to generate an accurate transport cross section. The inflow transport approximation is compared to the conventional methods, which are the consistent-PN and the outflow transport approximations. The three transport approximations are implemented in the lattice physics code STREAM, and verification is performed for various verification problems in order to investigate their effects and accuracy. From the verification, it is noted that the consistent-PN and the outflow transport approximations cause significant error in calculating the eigenvalue and the power distribution. The inflow transport approximation shows very accurate and precise results for the verification problems. The inflow transport approximation shows significant improvements not only for the high leakage problem but also for practical large core problem analyses.
An adaptive approach to implementing innovative urban transport solutions
Marchau, V.; Walker, W.; Van Duin, R.
2009-01-01
Urban transport is facing an increasing number of problems. Innovative technological solutions have been proposed for many of these problems. The implementation of these solutions, however, is surrounded by many uncertainties—for example, future relevant developments for urban transport demand and s
New basic safety regulations of radioactive material transport in Russia
Energy Technology Data Exchange (ETDEWEB)
Ananiev, V.V. [Div. of the Decommission of Nuclear and Radiation-Hazardous Object of the Federal Agency for Atomic Energy, Moscow (Russian Federation); Ershov, V.N. [FGUP ' ' Emergency Response Centre' ' , St-Petersburg (Russian Federation); Shvedov, M.O. [Div. of Nuclear and Radiation Safety of the Federal Agency for Atomic Energy, Moscow (Russian Federation)
2004-07-01
In the paper the system of normative regulation of radioactive material transport in Russia, basic principles and provisions of the new Russian regulations, available deviations from rules IAEA regulations are briefly considered. The problems, connected with putting in force of the new regulations in practice of transport, including problems of usage earlier designed and manufactured packages are considered as well.
Transporting particulate material
Aldred, Derek Leslie [North Hollywood, CA; Rader, Jeffrey A [North Hollywood, CA; Saunders, Timothy W [North Hollywood, CA
2011-08-30
A material transporting system comprises a material transporting apparatus (100) including a material transporting apparatus hopper structure (200, 202), which comprises at least one rotary transporting apparatus; a stationary hub structure (900) constraining and assisting the at least one rotary transporting apparatus; an outlet duct configuration (700) configured to permit material to exit therefrom and comprising at least one diverging portion (702, 702'); an outlet abutment configuration (800) configured to direct material to the outlet duct configuration; an outlet valve assembly from the material transporting system venting the material transporting system; and a moving wall configuration in the material transporting apparatus capable of assisting the material transporting apparatus in transporting material in the material transporting system. Material can be moved from the material transporting apparatus hopper structure to the outlet duct configuration through the at least one rotary transporting apparatus, the outlet abutment configuration, and the outlet valve assembly.
Mathematical problems in meteorological modelling
Csomós, Petra; Faragó, István; Horányi, András; Szépszó, Gabriella
2016-01-01
This book deals with mathematical problems arising in the context of meteorological modelling. It gathers and presents some of the most interesting and important issues from the interaction of mathematics and meteorology. It is unique in that it features contributions on topics like data assimilation, ensemble prediction, numerical methods, and transport modelling, from both mathematical and meteorological perspectives. The derivation and solution of all kinds of numerical prediction models require the application of results from various mathematical fields. The present volume is divided into three parts, moving from mathematical and numerical problems through air quality modelling, to advanced applications in data assimilation and probabilistic forecasting. The book arose from the workshop “Mathematical Problems in Meteorological Modelling” held in Budapest in May 2014 and organized by the ECMI Special Interest Group on Numerical Weather Prediction. Its main objective is to highlight the beauty of the de...
Plant Transporter Identification
DEFF Research Database (Denmark)
Larsen, Bo
Membrane transport proteins (transporters) play a critical role for numerous biological processes, by controlling the movements of ions and molecules in and out of cells. In plants, transporters thus function as gatekeepers between the plant and its surrounding environment and between organs......, tissues, cells and intracellular compartments. Since plants are highly compartmentalized organisms with complex transportation infrastructures, they consequently have many transporters. However, the vast majority of predicted transporters have not yet been experimentally verified to have transport...... activity. This project contains a review of the implemented methods, which have led to plant transporter identification, and present our progress on creating a high-throughput functional genomics transporter identification platform....
Plant Transporter Identification
DEFF Research Database (Denmark)
Larsen, Bo
Membrane transport proteins (transporters) play a critical role for numerous biological processes, by controlling the movements of ions and molecules in and out of cells. In plants, transporters thus function as gatekeepers between the plant and its surrounding environment and between organs......, tissues, cells and intracellular compartments. Since plants are highly compartmentalized organisms with complex transportation infrastructures, they consequently have many transporters. However, the vast majority of predicted transporters have not yet been experimentally verified to have transport...... activity. This project contains a review of the implemented methods, which have led to plant transporter identification, and present our progress on creating a high-throughput functional genomics transporter identification platform....
Transportation and the environment.
Banister, D.; Anderton, K.; Bonilla, D.; Givoni, M.; Schwanen, T.
2011-01-01
The growth of CO2-intensive transport, mobility and the impact of transport on the environment are reviewed. The recent global exponential growth in transport is unsustainable and must end unless the transport sector can decarbonize. The paper examines solutions for low-carbon transport systems; the
Photon transport through layered media
Masood, W
1999-01-01
The objective of this project is to study photon transport in layered media. In this regard the properties of the photon have been studied. The interactions that it makes with matter have been studied as well. ANISN code has been run for the sample problems regarding neutron and photon transport. As the project pertains to the transport of photons the layered media, therefore, photon energy spectrum was calculated using isotopes inventory calculation code ORIKAN which is run using 12 energy groups. The photon cross-section library used has a 21 group structure. The 12 group structure was expanded into 21 groups by using the method of histogram splitting. Calculations were made to find values of the energy transmitted at the outermost surface of the shield and then plotted for varying thicknesses of the shield. Finally, the results obtained have been discussed.
Road Transport Entrepreneurs and Road Transportation Revolution ...
African Journals Online (AJOL)
Toshiba
An International Multidisciplinary Journal, Ethiopia. Vol. 7 (4), Serial No. ... Nnewi Igbo emerged as pioneer road transport entrepreneurs and charted this novel ..... the cardinal motives for venturing into the transport industry. (Maduewesi ...
Global Optimization for Transport Network Expansion and Signal Setting
Directory of Open Access Journals (Sweden)
Haoxiang Liu
2015-01-01
Full Text Available This paper proposes a model to address an urban transport planning problem involving combined network design and signal setting in a saturated network. Conventional transport planning models usually deal with the network design problem and signal setting problem separately. However, the fact that network capacity design and capacity allocation determined by network signal setting combine to govern the transport network performance requires the optimal transport planning to consider the two problems simultaneously. In this study, a combined network capacity expansion and signal setting model with consideration of vehicle queuing on approaching legs of intersection is developed to consider their mutual interactions so that best transport network performance can be guaranteed. We formulate the model as a bilevel program and design an approximated global optimization solution method based on mixed-integer linearization approach to solve the problem, which is inherently nnonlinear and nonconvex. Numerical experiments are conducted to demonstrate the model application and the efficiency of solution algorithm.
... Other Dental Problems Diabetes & Sexual & Urologic Problems Preventing Diabetes Problems View or Print All Sections Heart Disease & ... prevent or delay sexual and urologic problems. Depression & Diabetes Depression is common among people with a chronic, ...
Transport Phenomena and Materials Processing
Kou, Sindo
1996-10-01
An extremely useful guide to the theory and applications of transport phenomena in materials processing This book defines the unique role that transport phenomena play in materials processing and offers a graphic, comprehensive treatment unlike any other book on the subject. The two parts of the text are, in fact, two useful books. Part I is a very readable introduction to fluid flow, heat transfer, and mass transfer for materials engineers and anyone not yet thoroughly familiar with the subject. It includes governing equations and boundary conditions particularly useful for studying materials processing. For mechanical and chemical engineers, and anyone already familiar with transport phenomena, Part II covers the many specific applications to materials processing, including a brief description of various materials processing technologies. Readable and unencumbered by mathematical manipulations (most of which are allocated to the appendixes), this book is also a useful text for upper-level undergraduate and graduate-level courses in materials, mechanical, and chemical engineering. It includes hundreds of photographs of materials processing in action, single and composite figures of computer simulation, handy charts for problem solving, and more. Transport Phenomena and Materials Processing: * Describes eight key materials processing technologies, including crystal growth, casting, welding, powder and fiber processing, bulk and surface heat treating, and semiconductor device fabrication * Covers the latest advances in the field, including recent results of computer simulation and flow visualization * Presents special boundary conditions for transport phenomena in materials processing * Includes charts that summarize commonly encountered boundary conditions and step-by-step procedures for problem solving * Offers a unique derivation of governing equations that leads to both overall and differential balance equations * Provides a list of publicly available computer
Noise-induced quantum transport
Ghosh, Pulak Kumar; Barik, Debashis; Ray, Deb Shankar
2004-01-01
We analyze the problem of directed quantum transport induced by external exponentially correlated telegraphic noise. In addition to quantum nature of the heat bath, nonlinearity of the periodic system potential brings in quantum contribution. We observe that quantization, in general, enhances classical current at low temperature, while the differences become insignificant at higher temperature. Interplay of quantum diffusion and quantum correction to system potential is analyzed for various r...
Directory of Open Access Journals (Sweden)
Behar E.
2006-11-01
Full Text Available L'exploitation en mer des gisements de combustibles fossiles fluides a amplifié le besoin d'accroître nos connaissances sur les hydrates qui sont susceptibles de boucher les installations de production, de traitement et de transport. Dans cette publication, la structure moléculaire des hydrates I, II et H est rappelée, ensuite l'analyse physico-chimique de leur formation est succinctement décrite tant sur les plans thermodynamique que cinétique. Enfin, les remèdes possibles aux problèmes rencontrés par les compagnies opératrices sont indiqués, essentiellement les inhibiteurs thermodynamiques classiques tels que les alcools ou les sels qui diminuent la température de formation des hydrates, et les additifs dispersants qui évitent la croissance et/ou l'agglomération des cristaux. Pour terminer, une boucle pilote de circulation originale est présentée, ses caractéristiques qui permettent la validation des additifs dispersants dans des conditions hydrodynamiques et physico-chimiques représentatives étant soulignées. Offshore exploitation of fossil fluid fuels has emphasized the need of improving our knowledge on hydrates which can plug production, treatment and transport facilities. In this paper, the molecular structure of I, II and H hydrates is recalled, then the physical-chemistry of their formation is briefly reviewed from both the thermodynamic and the kinetic points of view. Finally, the possible remedies to the problems met by operating companies are described, mainly classical thermodynamic inhibitors such as alcohols or salts which decrease the hydrates formation temperature, and dispersant additives which avoid crystals growth and/or agglomeration. At last an original circulation loop at pilot scale is presented, its characteristics which allow the testing of dispersant additives under representative hydrodynamic and physico-chemical conditions being outlined.
Saxton Transportation Operations Laboratory
Federal Laboratory Consortium — The Saxton Transportation Operations Laboratory (Saxton Laboratory) is a state-of-the-art facility for conducting transportation operations research. The laboratory...
Smart Growth and Transportation
Describes the relationship between smart growth and transportation, focusing smart and sustainable street design, transit-oriented development, parking management, sustainable transportation planning, and related resources.
Energy Technology Data Exchange (ETDEWEB)
Fevotte, F
2008-10-15
In the past years, the Method of Characteristics (MOC) has become a popular tool for the numerical solution of the neutron transport equation. Among its most interesting advantages are its good precision over computing time ratio, as well as its ability to accurately describe complicated geometries using non structured meshes. In order to reduce the need for computing resources in the method of characteristics, we propose in this dissertation two lines of improvement. The first axis of development is based on an analysis of the transverse integration technique in the method of characteristics. Various limitations have been discerned in this regard, which we intend to correct by proposing a new variant of the method of characteristics. Through a better treatment of material discontinuities in the geometry, our aim is to increase the accuracy of the transverse integration formula in order to decrease the computing resources without sacrificing the quality of the results. This method has been numerically tested in order to show its interest. Analysing the numerical results obtained with this new method also allows better understanding of the transverse integration approximations. Another improvement comes from the observation that industrial reactor cores exhibit very complex structures, but are often partly composed of a lattice of geometrically identical cells or assemblies. We propose a systematic method taking advantage of repetitions in the geometry to reduce the storage requirements for geometric data. Based on the group theory, this method can be employed for all lattice geometries. We present some numerical results showing the interest of the method in industrial contexts. (author)
Argonne Code Center: benchmark problem book
Energy Technology Data Exchange (ETDEWEB)
1977-06-01
This report is a supplement to the original report, published in 1968, as revised. The Benchmark Problem Book is intended to serve as a source book of solutions to mathematically well-defined problems for which either analytical or very accurate approximate solutions are known. This supplement contains problems in eight new areas: two-dimensional (R-z) reactor model; multidimensional (Hex-z) HTGR model; PWR thermal hydraulics--flow between two channels with different heat fluxes; multidimensional (x-y-z) LWR model; neutron transport in a cylindrical ''black'' rod; neutron transport in a BWR rod bundle; multidimensional (x-y-z) BWR model; and neutronic depletion benchmark problems. This supplement contains only the additional pages and those requiring modification. (RWR)
Class and Home Problems: Optimization Problems
Anderson, Brian J.; Hissam, Robin S.; Shaeiwitz, Joseph A.; Turton, Richard
2011-01-01
Optimization problems suitable for all levels of chemical engineering students are available. These problems do not require advanced mathematical techniques, since they can be solved using typical software used by students and practitioners. The method used to solve these problems forces students to understand the trends for the different terms…
Class and Home Problems: Optimization Problems
Anderson, Brian J.; Hissam, Robin S.; Shaeiwitz, Joseph A.; Turton, Richard
2011-01-01
Optimization problems suitable for all levels of chemical engineering students are available. These problems do not require advanced mathematical techniques, since they can be solved using typical software used by students and practitioners. The method used to solve these problems forces students to understand the trends for the different terms…
Problems of feeding the armed forces
Directory of Open Access Journals (Sweden)
B. C. Ray Sarkar
1952-01-01
Full Text Available The main problems encountered in the proper supply of foodstuffs for the maintenance of defence forces relate to procurement, preservation and storage of food stuffs and their supply and transport on one hand, evaluation of nutritional requirement to the forces engaged in different kinds of work and designing of rations to serve specific purposes on the other. Apart from-these problems which are quite broad in nature, there are others of specific character
Fast transport optimization on the circle
Delon, Julie; Sobolevskii, Andrei
2009-01-01
Consider the problem of optimally matching two measures on the circle, or equivalently two periodic measures on the real line, and suppose the cost of matching two points satisfies the Monge condition. We introduce a notion of locally optimal transport plan, motivated by the weak KAM (Aubry-Mather) theory, and show that all locally optimal transport plans are conjugate to shifts. This theory is applied to a transportation problem arising in image processing: for two sets of point masses, both of which have the same total mass, find an optimal transport plan with respect to a given cost function that satisfies the Monge condition. For the case of N real-valued point masses we present an O(N log epsilon) algorithm that approximates the optimal cost within epsilon; when all masses are integer multiples of 1/M, the algorithm gives an exact solution in O(N log M) operations.
Heijden, van der M.C.; Harten, van A.; Ebben, M.J.R.; Saanen, Y.A.; Valentin, E.C.; Verbraeck, A.
2001-01-01
Automated, underground freight transport should enable sustainable economic growth in the Amsterdam area in the Netherlands. An innovative transport system, which guarantees reliable logistics and which avoids congestion problems, is currently being developed. This logistics system will be highly au
CSIR Research Space (South Africa)
Nordengen, Paul A
2008-04-01
Full Text Available vehicle transport industry through a Road Transport Management System (RTMS) with the aim of contributing to the road authorities’ efforts to address the above problems. During 2003 a heavy vehicle accreditation scheme was developed and implemented...
Energy Technology Data Exchange (ETDEWEB)
NONE
2002-07-01
Maritime transportation of spent fuels from Australia to France fits into the contract between COGEMA and ANSTO, signed in 1999. This document proposes nine information cards in this domain: HIFAR a key tool of the nuclear, scientific and technological australian program; a presentation of the ANSTO Australian Nuclear Science and Technology Organization; the HIFAR spent fuel management problem; the COGEMA expertise in favor of the research reactor spent fuel; the spent fuel reprocessing at La Hague; the transports management; the transport safety (2 cards); the regulatory framework of the transports. (A.L.B.)
Scattered Neutron Tomography Based on A Neutron Transport Inverse Problem
Energy Technology Data Exchange (ETDEWEB)
William Charlton
2007-07-01
Neutron radiography and computed tomography are commonly used techniques to non-destructively examine materials. Tomography refers to the cross-sectional imaging of an object from either transmission or reflection data collected by illuminating the object from many different directions.
The Vessel Schedule Recovery Problem
DEFF Research Database (Denmark)
Brouer, Berit Dangaard; Plum, Christian Edinger Munk; Vaaben, Bo;
Maritime transportation is the backbone of world trade and is accountable for around 3% of the worlds CO2 emissions. We present the Vessel Schedule Recovery Problem (VSRP) to evaluate a given disruption scenario and to select a recovery action balancing the trade off between increased bunker cons...... consumption and the impact on the remaining network and the customer service level. The model is applied to 4 real cases from Maersk Line. Solutions are comparable or superior to those chosen by operations managers. Cost savings of up to 58% may be achieved....
Angular quadratures for improved transport computations
Energy Technology Data Exchange (ETDEWEB)
Abu-Shumays, I.K.
1999-07-22
This paper introduces new octant-range, composite-type Gauss and mid-point rule angular quadrature formulas for neutron and photon transport computations. A generalization to octant-range quadratures is also introduced in order to allow for discontinuities at material interfaces for two- and three-dimensional transport problems which can be modeled with 60-degree triangular or hexagonal mesh subdivisions in the x-y plane.
The German Saenger space transportation system concept
Koelle, D. E.; Kuczera, H.; Hoegenauer, E.
The vehicle configuration, performance criteria, and technological problems of the Saenger space transportation system are reviewed. The vehicle consists of a two-stage system, including a hypersonic first stage employing turboramjet propulsion. The cruise speed is Mach 4.4, with the capability to accelerate to Mach 6.8 prior to separation of the upper stage. Two different upper stages are proposed to fulfull the different requirements of manned space flight and unmanned payload transportation.
Vehicle routing problem in investment fund allocation
Mamat, Nur Jumaadzan Zaleha; Jaaman, Saiful Hafizah; Ahmad, Rokiah Rozita; Mohd, Ismail
2013-04-01
Since its introduction by Dantzig and Ramser in 1959, vehicle routing problem keeps evolving in theories, applications and variability. The evolution in computing and technology are also important contributors to research in solving vehicle routing problem. The main sectors of interests among researchers and practitioners for vehicle routing problem are transportation, distribution and logistics. However, literature found that concept and benefits of vehicle routing problem are not taken advantages of by researchers in the field of investment. Other methods found used in investment include multi-objective programming, linear programming, goal programming and integer programming. Yet the application of vehicle routing problem is not fully explored. A proposal on a framework of the fund allocation optimization using vehicle routing problem is presented here. Preliminary results using FTSE Bursa Malaysia data testing the framework are also given.
DEFF Research Database (Denmark)
Zeuthen, Thomas
2010-01-01
Transport through lipids and aquaporins is osmotic and entirely driven by the difference in osmotic pressure. Water transport in cotransporters and uniporters is different: Water can be cotransported, energized by coupling to the substrate flux by a mechanism closely associated with protein...... transport. Epithelial water transport is energized by the movements of ions, but how the coupling takes place is uncertain. All epithelia can transport water uphill against an osmotic gradient, which is hard to explain by simple osmosis. Furthermore, genetic removal of aquaporins has not given support...... to osmosis as the exclusive mode of transport. Water cotransport can explain the coupling between ion and water transport, a major fraction of transepithelial water transport and uphill water transport. Aquaporins enhance water transport by utilizing osmotic gradients and cause the osmolarity...
Numerical models for differential problems
Quarteroni, Alfio
2014-01-01
In this text, we introduce the basic concepts for the numerical modelling of partial differential equations. We consider the classical elliptic, parabolic and hyperbolic linear equations, but also the diffusion, transport, and Navier-Stokes equations, as well as equations representing conservation laws, saddle-point problems and optimal control problems. Furthermore, we provide numerous physical examples which underline such equations. We then analyze numerical solution methods based on finite elements, finite differences, finite volumes, spectral methods and domain decomposition methods, and reduced basis methods. In particular, we discuss the algorithmic and computer implementation aspects and provide a number of easy-to-use programs. The text does not require any previous advanced mathematical knowledge of partial differential equations: the absolutely essential concepts are reported in a preliminary chapter. It is therefore suitable for students of bachelor and master courses in scientific disciplines, an...
Reeves, Charles A.
2000-01-01
Uses the chicken problem for sixth grade students to scratch the surface of systems of equations using intuitive approaches. Provides students responses to the problem and suggests similar problems for extensions. (ASK)
Problems in differential equations
Brenner, J L
2013-01-01
More than 900 problems and answers explore applications of differential equations to vibrations, electrical engineering, mechanics, and physics. Problem types include both routine and nonroutine, and stars indicate advanced problems. 1963 edition.
Monte Carlo methods for particle transport
Haghighat, Alireza
2015-01-01
The Monte Carlo method has become the de facto standard in radiation transport. Although powerful, if not understood and used appropriately, the method can give misleading results. Monte Carlo Methods for Particle Transport teaches appropriate use of the Monte Carlo method, explaining the method's fundamental concepts as well as its limitations. Concise yet comprehensive, this well-organized text: * Introduces the particle importance equation and its use for variance reduction * Describes general and particle-transport-specific variance reduction techniques * Presents particle transport eigenvalue issues and methodologies to address these issues * Explores advanced formulations based on the author's research activities * Discusses parallel processing concepts and factors affecting parallel performance Featuring illustrative examples, mathematical derivations, computer algorithms, and homework problems, Monte Carlo Methods for Particle Transport provides nuclear engineers and scientists with a practical guide ...
Exactly solvable quantum Sturm-Liouville problems
Buyukasik, Sirin A.; Pashaev, Oktay K.; Tigrak-Ulas, Esra
2009-01-01
The harmonic oscillator with time-dependent parameters covers a broad spectrum of physical problems from quantum transport, quantum optics, and quantum information to cosmology. Several methods have been developed to quantize this fundamental system, such as the path integral method, the Lewis-Riese
Exactly solvable quantum Sturm-Liouville problems
Buyukasik, Sirin A.; Pashaev, Oktay K.; Tigrak-Ulas, Esra
2009-01-01
The harmonic oscillator with time-dependent parameters covers a broad spectrum of physical problems from quantum transport, quantum optics, and quantum information to cosmology. Several methods have been developed to quantize this fundamental system, such as the path integral method, the Lewis-Riese
Success and failures in urban transport planning in Europe — understanding the transport system
Indian Academy of Sciences (India)
Hermann Knoflacher
2007-08-01
Technological determinism has become a kind of religion for many people since it appears to offer solutions for societal problems as never before in history. Transport is one of the fascinating technology branches developed during the last 200 years. Effortless movement over long distances has become possible for car users as long as cheap fossil energy is available. However, the effect of fast transport on urban structures and society was not taken into account when developing these technical means. Technologists and economists have used indicators for expected beneﬁts of these fast transport modes without taking into account the real system effects on society and urban structures. Plausible assumptions and hopes instead of scientiﬁc understanding of the complex system are used in practice. In contradiction to widely held beliefs of transportation planners, there is actually no growth of mobility if counted in number of trips per person per day, no time saving by increasing speed in the system, and no real freedom of modal choice. Modal choice is dependent on physical and other structures, the artiﬁcial environment built by urban planners, transport experts and political decisions. The core hypothesis of traditional urban and transport planning ‘growth of mobility’, ‘travel time saving by increasing speed’ and ‘freedom of modal choice’ are myths and do not exist in the real urban and transport system. This is the reason why urban planning and transport planning based on traditional non-scientiﬁc assumptions is creating continuously not only more transport problems, but also environmental and social as well as economic problems all over the world, where these principals are applied. Urban transport planning in Europe, understanding the transport system and the solutions are presented in this paper.
Grandin, Temple
2016-01-01
Simple Summary Breeding sows and boars that are shipped to slaughter, auctions, or buying stations have a greater risk for welfare problems because they are older animals. Sows are sold when they fail to rebreed, are too thin or have difficulty walking. The transport guidelines of four organizations were compared. Most guidelines typically do not allow transport of non-ambulatory, severely injured animals or sows likely to give birth. The guidelines were less likely to agree on transport of extremely thin sows. Abstract Sows and boars that have reached the end of their productive lives have a greater risk for welfare problems. This paper reviews literature on culling reasons that may affect the animals’ fitness for transport. The top two reasons identified for culling boars were: obesity and reproductive problems. Sows are most often culled due to lameness, low body condition, or failure to rebreed. The OIE (World Organization for Animal Health) fitness for transport guidelines that would apply to sows and boars were compared with documents from the Canadian Code of Practice, Northern American Meat Institute (NAMI), EU-UK-DEFRA (European Union-United Kingdom, Dept. Environment, Food and Rural Affairs), U.S. National Pork Board, European Practical Guidelines to Assess Fitness for Transport of Pigs, and U.S. Pork Trucker Quality Assurance. The guidelines had the greatest agreement on the following fitness for transport issues: non-ambulatory, severely injured animals, sows in the last ten percent of pregnancy and sows with uterine prolapses were not fit for transport. There was less agreement on low body condition. One of the reasons for the lack of agreement is that there were stakeholders who specialized in transporting and processing extremely thin animals. A standard that would severely restrict the transport and slaughter of these animals could hinder the business practices of these stakeholders. Many welfare specialists would agree that some of these animals
Multilevel transport solution of LWR reactor cores
Energy Technology Data Exchange (ETDEWEB)
Jose Ignacio Marquez Damian; Cassiano R.E. de Oliveira; HyeonKae Park
2008-09-01
This work presents a multilevel approach for the solution of the transport equation in typical LWR assemblies and core configurations. It is based on the second-order, even-parity formulation of the transport equation, which is solved within the framework provided by the finite element-spherical harmonics code EVENT. The performance of the new solver has been compared with that of the standard conjugate gradient solver for diffusion and transport problems on structured and unstruc-tured grids. Numerical results demonstrate the potential of the multilevel scheme for realistic reactor calculations.
Improved Collaborative Transport Planning at Dutch Logistics Service Provider Fritom
Buijs, Paul; Lopez Alvarez, Jose Alejandro; Veenstra, Marjolein; Roodbergen, Kees Jan
2016-01-01
We study the collaborative transport planning for two autonomous business units of Fritom, a Dutch logistics service provider. This difficult planning problem does not fit any existing type of vehicle routing problem proposed in the academic literature; therefore, we define a new problem class, the
Constipation and Defecation Problems
... Home / Digestive Health Topic / Constipation and Defecation Problems Constipation and Defecation Problems Basics Resources Overview Constipation is one of the most frequent gastrointestinal complaints ...
Energy Technology Data Exchange (ETDEWEB)
2009-07-01
The TERM (Transport and Environment Reporting Mechanism) 2008 report examines performance of the transport sector vis-a-vis environmental performance and concludes that there are plenty of options for synenergies between different policy initiatives but also risk of measures counteracting each other. -Although there is growing awareness of to the transport sector's disproportionate impact on the environment, the report shows that there is little evidence of improved performance or a shift to sustainable transport across Europe. In particular: 1) freight transport has continued to grow; 2) passenger travel by road and air has continued to increase; 3) greenhouse gas emissions increased between 1990 and 2006; 4) air quality is still a problem across Europe despite continued reductions in air pollutant emissions from vehicles; and 5) transport noise levels are affecting the quality of life and health if EU citizens. (ln)
Linear inverse problem of the reactor dynamics
Volkov, N. P.
2017-01-01
The aim of this work is the study transient processes in nuclear reactors. The mathematical model of the reactor dynamics excluding reverse thermal coupling is investigated. This model is described by a system of integral-differential equations, consisting of a non-stationary anisotropic multispeed kinetic transport equation and a delayed neutron balance equation. An inverse problem was formulated to determine the stationary part of the function source along with the solution of the direct problem. The author obtained sufficient conditions for the existence and uniqueness of a generalized solution of this inverse problem.
ADVANCED CUTTINGS TRANSPORT STUDY
Energy Technology Data Exchange (ETDEWEB)
Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington
2003-04-30
Experiments on the flow loop are continuing. Improvements to the software for data acquisition are being made as additional experience with three-phase flow is gained. Modifications are being made to the Cuttings Injection System in order to improve control and the precision of cuttings injection. The design details for a drill-pipe Rotation System have been completed. A US Patent was filed on October 28, 2002 for a new design for an instrument that can generate a variety of foams under elevated pressures and temperatures and then transfer the test foam to a viscometer for measurements of viscosity. Theoretical analyses of cuttings transport phenomena based on a layered model is under development. Calibrations of two nuclear densitometers have been completed. Baseline tests have been run to determine wall roughness in the 4 different tests sections (i.e. 2-in, 3-in, 4-in pipes and 5.76-in by 3.5-in annulus) of the flow loop. Tests have also been conducted with aerated fluids at EPET conditions. Preliminary experiments on the two candidate aqueous foam formulations were conducted which included rheological tests of the base fluid and foam stability reports. These were conducted after acceptance of the proposal on the Study of Cuttings Transport with Foam Under Elevated Pressure and Elevated Temperature Conditions. Preparation of a test matrix for cuttings-transport experiments with foam in the ACTF is also under way. A controller for instrumentation to measure cuttings concentration and distribution has been designed that can control four transceivers at a time. A prototype of the control circuit board was built and tested. Tests showed that there was a problem with radiated noise. AN improved circuit board was designed and sent to an external expert to verify the new design. The new board is being fabricated and will first be tested with static water and gravel in an annulus at elevated temperatures. A series of viscometer tests to measure foam properties have
Zeuthen, Thomas
2010-04-01
Transport through lipids and aquaporins is osmotic and entirely driven by the difference in osmotic pressure. Water transport in cotransporters and uniporters is different: Water can be cotransported, energized by coupling to the substrate flux by a mechanism closely associated with protein. In the K(+)/Cl(-) and the Na(+)/K(+)/2Cl(-) cotransporters, water is entirely cotransported, while water transport in glucose uniporters and Na(+)-coupled transporters of nutrients and neurotransmitters takes place by both osmosis and cotransport. The molecular mechanism behind cotransport of water is not clear. It is associated with the substrate movements in aqueous pathways within the protein; a conventional unstirred layer mechanism can be ruled out, due to high rates of diffusion in the cytoplasm. The physiological roles of the various modes of water transport are reviewed in relation to epithelial transport. Epithelial water transport is energized by the movements of ions, but how the coupling takes place is uncertain. All epithelia can transport water uphill against an osmotic gradient, which is hard to explain by simple osmosis. Furthermore, genetic removal of aquaporins has not given support to osmosis as the exclusive mode of transport. Water cotransport can explain the coupling between ion and water transport, a major fraction of transepithelial water transport and uphill water transport. Aquaporins enhance water transport by utilizing osmotic gradients and cause the osmolarity of the transportate to approach isotonicity.
Parabolic Perturbation of a Nonlinear Hyperbolic Problem Arising in Physiology
Colli, P.; Grasselli, M.
We study a transport-diffusion initial value problem where the diffusion codlicient is "small" and the transport coefficient is a time function depending on the solution in a nonlinear and nonlocal way. We show the existence and the uniqueness of a weak solution of this problem. Moreover we discuss its asymptotic behaviour as the diffusion coefficient goes to zero, obtaining a well-posed first-order nonlinear hyperbolic problem. These problems arise from mathematical models of muscle contraction in the framework of the sliding filament theory.
Some problems with the food packaging practices in Ghana ...
African Journals Online (AJOL)
... inadequate and ineffective packaging, especially during transportation, cost of ... lack of standards and specifications and environmental issues have all been ... How these problems impact on the country's drive towards food security as well ...
Minimum-Time Quantum Transport with Bounded Trap Velocity
Stefanatos, Dionisis
2011-01-01
We formulate the problem of efficient transport of a quantum particle trapped in a harmonic potential which can move with a bounded velocity, as a minimum-time problem on a linear system with bounded input. We completely solve the corresponding optimal control problem and obtain an interesting bang-bang solution. These results are expected to find applications in quantum information processing, where quantum transport between the storage and processing units of a quantum computer is an essential step. They can also be extended to the efficient transport of Bose-Einstein condensates, where the ability to control them is crucial for their potential use as interferometric sensors.
Radioactive materials transport accident analysis
Energy Technology Data Exchange (ETDEWEB)
McSweeney, T.I.; Maheras, S.J.; Ross, S.B. [Battelle Memorial Inst. (United States)
2004-07-01
Over the last 25 years, one of the major issues raised regarding radioactive material transportation has been the risk of severe accidents. While numerous studies have shown that traffic fatalities dominate the risk, modeling the risk of severe accidents has remained one of the most difficult analysis problems. This paper will show how models that were developed for nuclear spent fuel transport accident analysis can be adopted to obtain estimates of release fractions for other types of radioactive material such as vitrified highlevel radioactive waste. The paper will also show how some experimental results from fire experiments involving low level waste packaging can be used in modeling transport accident analysis with this waste form. The results of the analysis enable an analyst to clearly show the differences in the release fractions as a function of accident severity. The paper will also show that by placing the data in a database such as ACCESS trademark, it is possible to obtain risk measures for transporting the waste forms along proposed routes from the generator site to potential final disposal sites.
Transportation Technology: Rail Transport and Logistics
Lang, Aaron B.
2011-01-01
Transportation can simply be defined as the movement of goods, services, and people from one location to another. Without an efficient means to transport goods from place to place, the economy would be nothing like it is today. Throughout the history of the United States, American railroads have paved the way toward creating a nation of great…
Strategic vehicle fleet management - the make or buy problem
Adam Redmer
2014-01-01
Background: Fleets constitute the most important production means in transportation. Their appropriate management is crucial for all companies having transportation duties. The paper is the first one of a series of three papers that the author dedicates to the strategic vehicle fleet management topic. Methods: The paper discusses ways of fulfilling company's transportation needs (MAKE-or-BUY problem). It means the choice between using company's own and outside fleet (buying t...
Climate and transportation; Klima und Verkehr
Energy Technology Data Exchange (ETDEWEB)
Fabian, P. [Muenchen Univ. (Germany). Lehrstuhl fuer Bioklimatologie und Immissionsforschung
1996-06-01
This short contribution discusses emissions of the transportation sector, i.e. the global problem of carbon dioxide emissions and the regional ecological problem of nitric oxide, VOC and CO photosmog emissions. Reduction strategies are discussed. (RHM) [Deutsch] Im vorliegenden, kurzen Beitrag wird auf die Emissionen des Verkehrs, die Emissionen von CO{sub 2} - ein globales Klimaproblem - sowie die Emission von NO{sub x}, VOCs und CO-Photosmog als regionals Umwelt- und Klimaproblem eingegangen. Abschliessend werden Reduktionsstrategien dieskutiert. (RHM)
WALLS, FOREST
PRESENT MIGRANT LABOR PROBLEMS AND SOLUTIONS WHICH HAVE BEEN PROPOSED ARE PRESENTED. THE FIRST PROBLEM AREA IS PROVIDING EDUCATION FOR MIGRANT CHILDREN. THIS IS HINDERED BY THE PROBLEM OF SECURING COMPLIANCE WITH MINIMUM EDUCATION LAWS AND BY LAWS PROHIBITING EMPLOYMENT OF CHILDREN DURING SCHOOL HOURS. A SECOND PROBLEM AREA IS THAT OF CHILD LABOR.…
Cheryl A. Smith
2008-01-01
Diagnosing Christmas tree problems can be a challenge, requiring a basic knowledge of plant culture and physiology, the effect of environmental influences on plant health, and the ability to identify the possible causes of plant problems. Developing a solution or remedy to the problem depends on a proper diagnosis, a process that requires recognition of a problem and...
Quadratic eigenvalue problems.
Energy Technology Data Exchange (ETDEWEB)
Walsh, Timothy Francis; Day, David Minot
2007-04-01
In this report we will describe some nonlinear eigenvalue problems that arise in the areas of solid mechanics, acoustics, and coupled structural acoustics. We will focus mostly on quadratic eigenvalue problems, which are a special case of nonlinear eigenvalue problems. Algorithms for solving the quadratic eigenvalue problem will be presented, along with some example calculations.
Solving the Dial-a-Ride Problem using Genetic Algorithms
DEFF Research Database (Denmark)
Jørgensen, Rene Munk; Larsen, Jesper; Bergvinsdottir, Kristin Berg
2007-01-01
In the Dial-a-Ride problem (DARP), customers request transportation from an operator. A request consists of a specified pickup location and destination location along with a desired departure or arrival time and capacity demand. The aim of DARP is to minimize transportation cost while satisfying...
Transport processes at fluidic interfaces
Reusken, Arnold
2017-01-01
There are several physico-chemical processes that determine the behavior of multiphase fluid systems – e.g., the fluid dynamics in the different phases and the dynamics of the interface(s), mass transport between the fluids, adsorption effects at the interface, and transport of surfactants on the interface – and result in heterogeneous interface properties. In general, these processes are strongly coupled and local properties of the interface play a crucial role. A thorough understanding of the behavior of such complex flow problems must be based on physically sound mathematical models, which especially account for the local processes at the interface. This book presents recent findings on the rigorous derivation and mathematical analysis of such models and on the development of numerical methods for direct numerical simulations. Validation results are based on specifically designed experiments using high-resolution experimental techniques. A special feature of this book is its focus on an interdisciplina...