Construction Of Chains Research Articles

Rail transport in supply chains

The paper discusses the problem of competitiveness between the rail and road transport with reference to the EU policy for sustainable development of the transport branch. The paper presents the idea of complexity of services which facilitates the development of logistic networks. The authors formulate preliminary assumptions recommended for designing and construction of multimodal hubs. Further, they describe examples of European and Polish businesses which, thanks to the consolidation of services, widened their offer of logistic capabilities. The authors highlight the need for action aiming at the reversal of the unfavorable trend and increasing the cargo flow by rail, and not road. Finally, they discuss the necessity to reform the current freight transport by rail through the construction of comprehensive supply chains.

Vertical Connections on the Construction Market

Abstract The specificity of construction as an economic activity and of the construction product (goods and services) determine the existence of a complex vertical chain of links, involving different actors, which they perform simultaneously the function of the buyer of the product from a previous participant and vendor product to the next participant. In practice, this means that in every unit of the vertical chain construction firm as a buyer of resources and services can be monopsony or oligopsony, on the other hand as the seller of the created product may be in the role of a monopoly or oligopoly on the market. The aim of the study is the analysis the model of a bilateral monopoly on the resource and product market, the conditions of equilibrium and the behavior of the construction firm at the entrance and the exit, taking into account the specificities of different segments of the construction market.

Semantic-Enhanced Multi-Dimensional Markov Chains on Semantic Trajectories for Predicting Future Locations.

In this work, we investigate the performance of Markov Chains with respect to modelling semantic trajectories and predicting future locations. In the first part, we examine whether and to what degree the semantic level of semantic trajectories affects the predictive performance of a spatial Markov model. It can be shown that the choice of the semantic level when describing trajectories has a significant impact on the accuracy of the models. High-level descriptions lead to better results than low-level ones. The second part introduces a multi-dimensional Markov Chain construct that considers, besides locations, additional context information, such as time, day and the users’ activity. While the respective approach is able to outperform our baseline, we could also identify some limitations. These are mainly attributed to its sensitivity towards small-sized training datasets. We attempt to overcome this issue, among others, by adding a semantic similarity analysis component to our model that takes the varying role of locations due each time to the respective purpose of visiting the particular location explicitly into consideration. To capture the aforementioned dynamics, we define an entity, which we refer to as Purpose-of-Visit-Dependent Frame (PoVDF). In the third part of this work, we describe in detail the PoVDF-based approach and we evaluate it against the multi-dimensional Markov Chain model as well as with a semantic trajectory mining and prefix tree based model. Our evaluation shows that the PoVDF-based approach outperforms its competition and lays a solid foundation for further investigation.

Fault Tolerance and QoS based Pervasive Computing using Markov State Transition Model

Fault-tolerance is significant in pervasive computing environments. Recently, few research works has been developed for reducing the fault, occurring in pervasive computing. However, there is a need for a fault tolerance mechanism to reduce the link failures and unwanted mobile node access (in pervasive computing environment). In order to overcome these limitations, Markov State Transition Based Fault Tolerance (MST-FT) Model is proposed. The main objective of MST-FT Model is to achieve resource efficient QoS in pervasive computing environment by avoiding the link failures and unwanted mobile node usages. Initially, the optimization of link failures is achieved by maintaining Markov chain of high energy mobile nodes on the wireless network communication path. The mobile nodes with higher energy and minimal drain rate are combined to form a chain in its corresponding path of communication in order to minimize the link failures in pervasive computing. Next, the inappropriate mobile node usage is avoided by selecting only the authorized mobile nodes for Markov chain construction to effective network communication, which resulting in improved fault tolerant rate. Therefore, MST-FT Model provides higher resource efficient QoS as compared to existing works. The performance of MST-FT Model is measured in terms of fault tolerant rate, execution time, energy consumption rate and quality of service level. The simulation results show that the MST-FT Model is able to improve the fault tolerant rate by 13% and also reduces the energy consumption rate of resource efficient QoS by 25%, when compared to previous works.

РОССИЯ В ГЛОБАЛЬНЫХ ЦЕПОЧКАХ СОЗДАНИЯ СТОИМОСТИ

A new dimension of the globalization process of the 21st century is the spread of global value chains (GVCs), or fragmentation of production. The construction of value chains in the transnational context is shown. The concepts, peculiarities of GVCs, estimation of participation in them of particular countries, including Russia, are considered. Russia’s role in GVCs as one of the world’s leading energy suppliers is analyzed on the basis of current statistics of leading international databases (WIOD, TiVA). For successful integration of Russia into the GVC, it is necessary to reconsider the priorities of state industrial and economic policy. Taking that into account, one of the main goals should become creating healthy institutional environment and developing the strategy of supporting national companies in the strategic economic spheres (especially in manufacturing). While adjusting the state economic policy it’s important not only to create new competitive advantages, but also to maintain the existing ones. Russian Federation plays a significant role in the GVCs as one of the world’s main natural resources suppliers, with high revenues of the energy companies involved. It’s important to broaden Russian companies’ activity in the GVCs not only in the lower parts (resources), but also to move upward the GVC by taking part in the upper levels (R&D, marketing, etc.). Russian energy policy in the last few years noticeably changed. The existing GVCs with the EU companies have been created decades ago, main Russian energy companies are important part of European GVC’s. But now, due to political situation, such cooperation is considered to be mostly vulnerability, and not as solemnly benefit. Moreover, such situation coincides with the existing great demand for the energy resources from the countries of the Asian-Pacific region, especially China. Therefore, Russian “Turn to the East”, which was initially a geopolitical move, has gained a strong economic dimension now.&nbsp

The ILLIAD project: sustainable, local or localized, innovative food chains – application to apricot production

ILLIAD (2012-2015), a French national project, aims to propose a set of indicators of system sustainability (sustainable food system, local agri-food systems, food chain analysis), and to test them on three case studies, which are three typical trajectories of construction of sustainable food chains, namely chain innovation (stone fruits), chain differentiation (rice) and territorial embedding (wheat). Although French apricot production resists outside competition, it is weakened by the high variability of harvests and the resulting high variability of apricot price and supply, particularly for processing. A solution to this variability could be the setting up of dedicated orchards with long-term commitments from both producer and processor. The project explores the conditions and consequences of this dedicated orchard, from technical to economic points of view. An ideotype for a dedicated orchard will be built, including aspects of cultivar selection, and conditions in terms of chain organization will be designed. Concerning fresh apricot, the ILLIAD project will work on development of alternative marketing channels, such as direct sales from producers to consumers.

Cluster strategy and supply chain management

PurposeThe purpose of this paper is to highlight the characteristic role of specialized markets and traders in the internationalization of emerging economies by examining the linkages between supply chain management (SCM) and industrial clustering in China.Design/methodology/approachMulti-method approach was employed as primary data were collected from a case study of Shaoxing textile cluster, and was supplemented with secondary data to triangulate the findings. The proposition that competitive advantages of industrial clusters facilitate effective SCM was explored.FindingsThe authors reveal that China’s cost advantage is manifested in the entire value chain. The provision of business friendly amenities as a result of synergetic benefits of vertical and horizontal integration of supply clusters promotes competitiveness of SMEs and region as a whole. Moreover, specialized markets and international traders found to play significant role in sustainable cluster development.Research limitations/implicationsAs with fieldwork and case studies, generalization should be drawn with care. Systematic synthesis of relevant case studies is recommended.Practical implicationsThe study endorses the construction of local supply chains and suggests implementation of cluster strategy by focusing on environment-specific execution of triple helix model.Originality/valueThe article elaborates the linkages between cluster theory and SCM both within cluster and between interspersed clusters. It also explains how specialized markets and global players are enabling concentrated supply networks. The paper recommends extension of “Triple helix + 1 model” by making local community part of the underlying framework.

A multi-agent system for management information support of regional innovations

This paper presents development experience of architecture, principles of functioning, software engineering and modeling of multi-agent system for information support of regional business processes. The main purpose of the system is integration of distributed heterogeneous information resources and web-services devoted to innovations in the Internet. The system provides an automated search of potential business partners, an interactive innovation chains construction and selection thae most efficient of them. The necessity of system dynamics modeling methodology using in development of business processes support systems is discussed. Agent-based technologies are examined. Special attention is given to development of virtual business environment conceptual model. Our conceptual model is used as a basis for the system structure, algorithms, functionality and relationships between its main architectural components representation. Specifically, we show how to use the conceptual modeling methodology, system dynamics and multi-agent system technology in developing a multi-agent system for integration of distributed heterogeneous information resources and services devoted to innovations.

Evidence-based logic chains demonstrate multiple impacts of trace metals on ecosystem services

Trace metals can have far-reaching ecosystem impacts. In this study, we develop consistent and evidence-based logic chains to demonstrate the wider effects of trace metal contamination on a suite of ecosystem services. They demonstrate knock-on effects from an initial receptor that is sensitive to metal toxicity, along a cascade of impact, to final ecosystem services via alterations to multiple ecosystem processes. We developed logic chains to highlight two aspects of metal toxicity: for impacts of copper pollution in soil ecosystems, and for impacts of mercury in freshwaters. Each link of the chains is supported by published evidence, with an indication of the strength of the supporting science. Copper pollution to soils (134 unique chains) showed a complex network of pathways originating from direct effects on a range of invertebrate and microbial taxa and plants. In contrast, mercury pollution on freshwaters (63 unique chains) shows pathways that broadly follow the food web of this habitat, reflecting the potential for mercury bioaccumulation. Despite different pathways, there is considerable overlap in the final ecosystem services impacted by both of these metals and in both ecosystems. These included reduced human-use impacts (food, fishing), reduced human non-use impacts (amenity value) and positive or negative alterations to climate regulation (impacts on carbon sequestration). Other final ecosystem goods impacted include reduced crop production, animal production, flood regulation, drinking water quality and soil purification. Taking an ecosystem services approach demonstrates that consideration of only the direct effects of metal contamination of soils and water will considerably underestimate the total impacts of these pollutants. Construction of logic chains, evidenced by published literature, allows a robust assessment of potential impacts indicating primary, secondary and tertiary effects.

Design of agile supply chains including the trade-off between number of partners and reliability

The reliability of supply partners is particularly vital in agile supply chains as it is vulnerable to the inability of a supply partner to meet its high responsiveness and flexibility requirements resulting in the disruption of the whole network. Disruption can have expensive and extensive results for the entire agile supply chain. To mitigate the risk of disruption and improve the reliability of the whole agile supply chain, decision-makers need to pay more attention to supply chain design and construction while simultaneously taking into account the sourcing strategy decisions. This paper proposes a series of models for the design of agile supply chains using dynamic programming modeling. These provide decision-makers with a systematic way of analyzing one of the key decisions of sourcing strategy, namely the trade-off between the number of supply partners and reliability. The efficacy of the models is demonstrated through their application to a Chinese bus and coach manufacturer by way of an empirical illustration. The results show that this approach is effective for this application, and it can be applied in other related decision-making scenarios. The methods offered in this paper provide managers with a practical tool to design their agile supply chains while considering the trade-offs between the number of partners and the reliability of the entire agile supply chain.

Chernoff approximation of subordinate semigroups

This note is devoted to the approximation of evolution semigroups generated by some Markov processes and hence to the approximation of transition probabilities of these processes. The considered semigroups correspond to processes obtained by subordination (i.e. by a time-change) of some original (parent) Markov processes with respect to some subordinators, i.e. Lévy processes with a.s. increasing paths (they play the role of the new time). If the semigroup, corresponding to a parent Markov process, is not known explicitly then neither the subordinate semigroup, nor even the generator of the subordinate semigroup are known explicitly too. In this note, some (Chernoff) approximations are constructed for subordinate semigroups (in the case when subordinators have either known transitional probabilities, or known and bounded Lévy measure) under the condition that the parent semigroups are not known but are already Chernoff-approximated. As it has been shown in the recent literature, this condition is fulfilled for several important classes of Markov processes. This fact allows, in particular, to use the constructed Chernoff approximations of subordinate semigroups, in order to approximate semigroups corresponding to subordination of Feller processes and (Feller type) diffusions in Euclidean spaces, star graphs and Riemannian manifolds. Such approximations can be used for direct calculations and simulation of stochastic processes. The method of Chernoff approximation is based on the Chernoff theorem and can be interpreted also as a construction of Markov chains approximating a given Markov process and as the numerical path integration method of solving the corresponding PDE/SDE.

Toward tailoring Majorana bound states in artificially constructed magnetic atom chains on elemental superconductors.

Realizing Majorana bound states (MBS) in condensed matter systems is a key challenge on the way toward topological quantum computing. As a promising platform, one-dimensional magnetic chains on conventional superconductors were theoretically predicted to host MBS at the chain ends. We demonstrate a novel approach to design of model-type atomic-scale systems for studying MBS using single-atom manipulation techniques. Our artificially constructed atomic Fe chains on a Re surface exhibit spin spiral states and a remarkable enhancement of the local density of states at zero energy being strongly localized at the chain ends. Moreover, the zero-energy modes at the chain ends are shown to emerge and become stabilized with increasing chain length. Tight-binding model calculations based on parameters obtained from ab initio calculations corroborate that the system resides in the topological phase. Our work opens new pathways to design MBS in atomic-scale hybrid structures as a basis for fault-tolerant topological quantum computing.

How to Achieve the Capacity of Asymmetric Channels

We survey coding techniques that enable reliable transmission at rates that approach the capacity of an arbitrary discrete memoryless channel. In particular, we take the point of view of modern coding theory and discuss how recent advances in coding for symmetric channels help provide more efficient solutions for the asymmetric case. We consider, in more detail, three basic coding paradigms. The first one is Gallager's scheme that consists of concatenating a linear code with a non-linear mapping so that the input distribution can be appropriately shaped. We explicitly show that both polar codes and spatially coupled codes can be employed in this scenario. Furthermore, we derive a scaling law between the gap to capacity, the cardinality of the input and output alphabets, and the required size of the mapper. The second one is an integrated scheme in which the code is used both for source coding, in order to create codewords distributed according to the capacity-achieving input distribution, and for channel coding, in order to provide error protection. Such a technique has been recently introduced by Honda and Yamamoto in the context of polar codes, and we show how to apply it also to the design of sparse graph codes. The third paradigm is based on an idea of B\"ocherer and Mathar, and separates the two tasks of source coding and channel coding by a chaining construction that binds together several codewords. We present conditions for the source code and the channel code, and we describe how to combine any source code with any channel code that fulfill those conditions, in order to provide capacity-achieving schemes for asymmetric channels. In particular, we show that polar codes, spatially coupled codes, and homophonic codes are suitable as basic building blocks of the proposed coding strategy.

Conservation and Divergence in the Candida Species Biofilm Matrix Mannan-Glucan Complex Structure, Function, and Genetic Control.

ABSTRACTCandida biofilms resist the effects of available antifungal therapies. Prior studies with Candida albicans biofilms show that an extracellular matrix mannan-glucan complex (MGCx) contributes to antifungal sequestration, leading to drug resistance. Here we implement biochemical, pharmacological, and genetic approaches to explore a similar mechanism of resistance for the three most common clinically encountered non-albicans Candida species (NAC). Our findings reveal that each Candida species biofilm synthesizes a mannan-glucan complex and that the antifungal-protective function of this complex is conserved. Structural similarities extended primarily to the polysaccharide backbone (α-1,6-mannan and β-1,6-glucan). Surprisingly, biochemical analysis uncovered stark differences in the branching side chains of the MGCx among the species. Consistent with the structural analysis, similarities in the genetic control of MGCx production for each Candida species also appeared limited to the synthesis of the polysaccharide backbone. Each species appears to employ a unique subset of modification enzymes for MGCx synthesis, likely accounting for the observed side chain diversity. Our results argue for the conservation of matrix function among Candida spp. While biogenesis is preserved at the level of the mannan-glucan complex backbone, divergence emerges for construction of branching side chains. Thus, the MGCx backbone represents an ideal drug target for effective pan-Candida species biofilm therapy.

Performance Measurement of Military Supply Chains

Defence is the largest item of physical expenditure in the Union budget presented by the Government of India every year. A substantial portion of the budget is allocated for equipping the army, a task which is performed by a very complex and extended supply chain. Therefore, it is essential that the performance of the military’s supply chain is measured and monitored, so that the nation derives value from the expenditure made on the supply chain. Moreover, the effectiveness of the supply chain provides the defence forces competitive advantage, and thus its performance has a direct bearing on the country’s security. The wars in future are more likely to be a competition between the rival supply chains. Development of a suitable framework for measuring the performance of any extended supply chain is a challenging task. The challenge arises from the very design and nature of the supply chain construct. The entities which constitute the supply chain invariably have varied goals and objectives, and therefore more than often, they indulge in adversarial practices and operate in an environment of mutual distrust. The paper dwells upon the conceptual development of an ideal performance measurement framework for the military supply chain. It compares the military and commercial supply chains, and discusses some of the principal performance measurement frameworks, like the Balanced scorecard, Supply Chain Operations Reference model amongst others used by the commercial supply chains. It also discusses the endeavours made towards supply chain performance evaluation by some of the modern militaries to include that of the United States, United Kingdom, and Australia. It also briefly covers the Indian approach to evaluation of supply chain performance. The paper brings out the relevance of the subject, challenges there in, and its importance to the country’s armed forces.

A Combinatorial Approach to the Symmetry of $q,t$-Catalan Numbers

The $q,t$-Catalan numbers $C_n(q,t)$ are polynomials in $q$ and $t$ that reduce to the ordinary Catalan numbers when $q=t=1$. These polynomials have important connections to representation theory, algebraic geometry, and symmetric functions. Haglund and Haiman discovered combinatorial formulas for $C_n(q,t)$ as weighted sums of Dyck paths (or equivalently, integer partitions contained in a staircase shape). This paper undertakes a combinatorial investigation of the joint symmetry property $C_n(q,t)=C_n(t,q)$. We conjecture some structural decompositions of Dyck objects into “mutually opposite” subcollections that lead to a bijective explanation of joint symmetry in certain cases. A key new idea is the construction of infinite chains of partitions that are independent of $n$ but induce the joint symmetry for all $n$ simultaneously. Using these methods, we prove combinatorially that for $0\leq k\leq 9$ and all $n$, the terms in $C_n(q,t)$ of total degree $\binom{n}{2}-k$ have the required symmetry property.

Introduction

Introduction

Catalytic Enantioselective Synthesis of Planar Chiral Cyclophanes

Abstract The catalytic enantioselective synthesis of planar chiral cyclophanes has been achieved by two types of transition-metal catalysis: (1) enantioselective construction of aromatic rings by transition-metal-catalyzed [2+2+2] cycloaddition reactions; (2) enantioselective construction of ansa chains by transition-metal-catalyzed coupling reactions. The former approach has been achieved by the cationic rhodium(I)/H8-BINAP complex-catalyzed enantioselective intramolecular [2+2+2] cycloaddition of triynes, which afforded planar chiral dioxa[6]–[12]metacyclophanes with high ee values, although the yields were low. Planar chiral carba[10]–[12]paracyclophanes could also be synthesized with high yields and ee values by the cationic rhodium(I)/BDPP complex-catalyzed enantioselective intermolecular [2+2+2] cycloaddition of cyclic diynes with monoynes. On the other hand, the latter approach was achieved by the cationic rhodium(I)/BINAPHANE or palladium(II)/BINAP complex-catalyzed double C–S bond formation between dithiols and 1,4-bis(bromomethyl)benzenes, which afforded planar chiral dithia[9]–[12]paracyclophanes and dithia[3.3]paracyclophanes with varying yields and ee values.

Product carbon footprint assessment supporting the green supply chain construction in household appliance manufacturers

Supply chain carbon emission is one of the factors considered in the green supply chain management. A method was designed to support the green supply chain measures based on the carbon footprint assessment for products. A research for 3 typical household appliances carbon footprint assessment was conducted to explore using product carbon footprint assessment method to guide the green supply chain management of the manufacturers. The result could reflect the differences directions on green supply chain management of manufacturers of washing machine, air conditioner and microwave, respectively That is, the washing machine manufacturer should pay attention to the low carbon activities in upstream suppliers in highest priority, and also the promotion of product energy efficiency. The air conditioner manufacturer should pay attention to the product energy efficiency increasing in highest priority, and the improvement of refrigerant to decrease its GWP. And the microwave manufacture could only focus on the energy efficiency increasing because it contributes most of the carbon emission to its carbon footprint. Besides, the representativeness of product and the applicability of the method were also discussed. As the manufacturer could master the technical information on raw material and components of its products to conduct the product carbon footprint assessment, this method could help the manufacturer to identify the effective green supply chain measures in the preliminary stage.

Efficient construction and enhanced capacitive properties of interfacial polymerized polyaniline nanofibers with the assistance of isopropanol in aqueous phase

The construction of polyaniline (PANI) chains in the interfacial polymerization was controlled by introducing isopropanol (IPA) as a co–solvent into aqueous phase. The influences of the IPA content on the morphology, microstructure and electrochemical behaviors of PANI products were investigated by field emission scanning electron microscopy, ultraviolet–visible spectroscopy, Fourier transform infrared spectroscopy, X–ray diffraction analysis as well as electrical and electrochemical measurements. It is found that the growth and migration of PANI molecules strongly depended on the IPA content through tuning the hydrogen–bonding strength between PANI chains and IPA molecules. With the increasing of the IPA content, the role of IPA played on the construction of PANI chains changed gradually from promoting the formation of PANI nanofibers to inhibiting the migration of PANI molecules into aqueous phase, which would result in more irregular shaped particles. Moreover, PANI electrode at the current density of 1Ag−1 reached its greatest specific capacitance of 539Fg−1 at 5% IPA content, with a secondary maximum of 475Fg−1 for 50% IPA content in aqueous phase, which were both higher than 444Fg−1 for the nanofibers prepared in the absence of IPA. It is demonstrated that a great enhancement on the capacitive properties can be achieved by introducing a small amount of IPA which would be of benefit to promote the formation of PANI nanofibers with larger ratio of height to diameter.